/* * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include <linux/kernel.h> #include <linux/bio.h> #include <linux/buffer_head.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/pagemap.h> #include <linux/highmem.h> #include <linux/time.h> #include <linux/init.h> #include <linux/string.h> #include <linux/backing-dev.h> #include <linux/mpage.h> #include <linux/swap.h> #include <linux/writeback.h> #include <linux/statfs.h> #include <linux/compat.h> #include <linux/bit_spinlock.h> #include <linux/xattr.h> #include <linux/posix_acl.h> #include <linux/falloc.h> #include <linux/slab.h> #include <linux/ratelimit.h> #include <linux/mount.h> #include <linux/btrfs.h> #include <linux/blkdev.h> #include <linux/posix_acl_xattr.h> #include <linux/uio.h> #include "ctree.h" #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" #include "print-tree.h" #include "ordered-data.h" #include "xattr.h" #include "tree-log.h" #include "volumes.h" #include "compression.h" #include "locking.h" #include "free-space-cache.h" #include "inode-map.h" #include "backref.h" #include "hash.h" #include "props.h" #include "qgroup.h" struct btrfs_iget_args { struct btrfs_key *location; struct btrfs_root *root; }; struct btrfs_dio_data { u64 outstanding_extents; u64 reserve; u64 unsubmitted_oe_range_start; u64 unsubmitted_oe_range_end; }; static const struct inode_operations btrfs_dir_inode_operations; static const struct inode_operations btrfs_symlink_inode_operations; static const struct inode_operations btrfs_dir_ro_inode_operations; static const struct inode_operations btrfs_special_inode_operations; static const struct inode_operations btrfs_file_inode_operations; static const struct address_space_operations btrfs_aops; static const struct address_space_operations btrfs_symlink_aops; static const struct file_operations btrfs_dir_file_operations; static const struct extent_io_ops btrfs_extent_io_ops; static struct kmem_cache *btrfs_inode_cachep; struct kmem_cache *btrfs_trans_handle_cachep; struct kmem_cache *btrfs_transaction_cachep; struct kmem_cache *btrfs_path_cachep; struct kmem_cache *btrfs_free_space_cachep; #define S_SHIFT 12 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, }; static int btrfs_setsize(struct inode *inode, struct iattr *attr); static int btrfs_truncate(struct inode *inode); static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); static noinline int cow_file_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written, int unlock); static struct extent_map *create_pinned_em(struct inode *inode, u64 start, u64 len, u64 orig_start, u64 block_start, u64 block_len, u64 orig_block_len, u64 ram_bytes, int type); static int btrfs_dirty_inode(struct inode *inode); #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS void btrfs_test_inode_set_ops(struct inode *inode) { BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; } #endif static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, struct inode *inode, struct inode *dir, const struct qstr *qstr) { int err; err = btrfs_init_acl(trans, inode, dir); if (!err) err = btrfs_xattr_security_init(trans, inode, dir, qstr); return err; } /* * this does all the hard work for inserting an inline extent into * the btree. The caller should have done a btrfs_drop_extents so that * no overlapping inline items exist in the btree */ static int insert_inline_extent(struct btrfs_trans_handle *trans, struct btrfs_path *path, int extent_inserted, struct btrfs_root *root, struct inode *inode, u64 start, size_t size, size_t compressed_size, int compress_type, struct page **compressed_pages) { struct extent_buffer *leaf; struct page *page = NULL; char *kaddr; unsigned long ptr; struct btrfs_file_extent_item *ei; int err = 0; int ret; size_t cur_size = size; unsigned long offset; if (compressed_size && compressed_pages) cur_size = compressed_size; inode_add_bytes(inode, size); if (!extent_inserted) { struct btrfs_key key; size_t datasize; key.objectid = btrfs_ino(inode); key.offset = start; key.type = BTRFS_EXTENT_DATA_KEY; datasize = btrfs_file_extent_calc_inline_size(cur_size); path->leave_spinning = 1; ret = btrfs_insert_empty_item(trans, root, path, &key, datasize); if (ret) { err = ret; goto fail; } } leaf = path->nodes[0]; ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, ei, trans->transid); btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); btrfs_set_file_extent_encryption(leaf, ei, 0); btrfs_set_file_extent_other_encoding(leaf, ei, 0); btrfs_set_file_extent_ram_bytes(leaf, ei, size); ptr = btrfs_file_extent_inline_start(ei); if (compress_type != BTRFS_COMPRESS_NONE) { struct page *cpage; int i = 0; while (compressed_size > 0) { cpage = compressed_pages[i]; cur_size = min_t(unsigned long, compressed_size, PAGE_SIZE); kaddr = kmap_atomic(cpage); write_extent_buffer(leaf, kaddr, ptr, cur_size); kunmap_atomic(kaddr); i++; ptr += cur_size; compressed_size -= cur_size; } btrfs_set_file_extent_compression(leaf, ei, compress_type); } else { page = find_get_page(inode->i_mapping, start >> PAGE_SHIFT); btrfs_set_file_extent_compression(leaf, ei, 0); kaddr = kmap_atomic(page); offset = start & (PAGE_SIZE - 1); write_extent_buffer(leaf, kaddr + offset, ptr, size); kunmap_atomic(kaddr); put_page(page); } btrfs_mark_buffer_dirty(leaf); btrfs_release_path(path); /* * we're an inline extent, so nobody can * extend the file past i_size without locking * a page we already have locked. * * We must do any isize and inode updates * before we unlock the pages. Otherwise we * could end up racing with unlink. */ BTRFS_I(inode)->disk_i_size = inode->i_size; ret = btrfs_update_inode(trans, root, inode); return ret; fail: return err; } /* * conditionally insert an inline extent into the file. This * does the checks required to make sure the data is small enough * to fit as an inline extent. */ static noinline int cow_file_range_inline(struct btrfs_root *root, struct inode *inode, u64 start, u64 end, size_t compressed_size, int compress_type, struct page **compressed_pages) { struct btrfs_trans_handle *trans; u64 isize = i_size_read(inode); u64 actual_end = min(end + 1, isize); u64 inline_len = actual_end - start; u64 aligned_end = ALIGN(end, root->sectorsize); u64 data_len = inline_len; int ret; struct btrfs_path *path; int extent_inserted = 0; u32 extent_item_size; if (compressed_size) data_len = compressed_size; if (start > 0 || actual_end > root->sectorsize || data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) || (!compressed_size && (actual_end & (root->sectorsize - 1)) == 0) || end + 1 < isize || data_len > root->fs_info->max_inline) { return 1; } path = btrfs_alloc_path(); if (!path) return -ENOMEM; trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { btrfs_free_path(path); return PTR_ERR(trans); } trans->block_rsv = &root->fs_info->delalloc_block_rsv; if (compressed_size && compressed_pages) extent_item_size = btrfs_file_extent_calc_inline_size( compressed_size); else extent_item_size = btrfs_file_extent_calc_inline_size( inline_len); ret = __btrfs_drop_extents(trans, root, inode, path, start, aligned_end, NULL, 1, 1, extent_item_size, &extent_inserted); if (ret) { btrfs_abort_transaction(trans, root, ret); goto out; } if (isize > actual_end) inline_len = min_t(u64, isize, actual_end); ret = insert_inline_extent(trans, path, extent_inserted, root, inode, start, inline_len, compressed_size, compress_type, compressed_pages); if (ret && ret != -ENOSPC) { btrfs_abort_transaction(trans, root, ret); goto out; } else if (ret == -ENOSPC) { ret = 1; goto out; } set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); btrfs_delalloc_release_metadata(inode, end + 1 - start); btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); out: /* * Don't forget to free the reserved space, as for inlined extent * it won't count as data extent, free them directly here. * And at reserve time, it's always aligned to page size, so * just free one page here. */ btrfs_qgroup_free_data(inode, 0, PAGE_SIZE); btrfs_free_path(path); btrfs_end_transaction(trans, root); return ret; } struct async_extent { u64 start; u64 ram_size; u64 compressed_size; struct page **pages; unsigned long nr_pages; int compress_type; struct list_head list; }; struct async_cow { struct inode *inode; struct btrfs_root *root; struct page *locked_page; u64 start; u64 end; struct list_head extents; struct btrfs_work work; }; static noinline int add_async_extent(struct async_cow *cow, u64 start, u64 ram_size, u64 compressed_size, struct page **pages, unsigned long nr_pages, int compress_type) { struct async_extent *async_extent; async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); BUG_ON(!async_extent); /* -ENOMEM */ async_extent->start = start; async_extent->ram_size = ram_size; async_extent->compressed_size = compressed_size; async_extent->pages = pages; async_extent->nr_pages = nr_pages; async_extent->compress_type = compress_type; list_add_tail(&async_extent->list, &cow->extents); return 0; } static inline int inode_need_compress(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; /* force compress */ if (btrfs_test_opt(root, FORCE_COMPRESS)) return 1; /* bad compression ratios */ if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) return 0; if (btrfs_test_opt(root, COMPRESS) || BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS || BTRFS_I(inode)->force_compress) return 1; return 0; } /* * we create compressed extents in two phases. The first * phase compresses a range of pages that have already been * locked (both pages and state bits are locked). * * This is done inside an ordered work queue, and the compression * is spread across many cpus. The actual IO submission is step * two, and the ordered work queue takes care of making sure that * happens in the same order things were put onto the queue by * writepages and friends. * * If this code finds it can't get good compression, it puts an * entry onto the work queue to write the uncompressed bytes. This * makes sure that both compressed inodes and uncompressed inodes * are written in the same order that the flusher thread sent them * down. */ static noinline void compress_file_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, struct async_cow *async_cow, int *num_added) { struct btrfs_root *root = BTRFS_I(inode)->root; u64 num_bytes; u64 blocksize = root->sectorsize; u64 actual_end; u64 isize = i_size_read(inode); int ret = 0; struct page **pages = NULL; unsigned long nr_pages; unsigned long nr_pages_ret = 0; unsigned long total_compressed = 0; unsigned long total_in = 0; unsigned long max_compressed = SZ_128K; unsigned long max_uncompressed = SZ_128K; int i; int will_compress; int compress_type = root->fs_info->compress_type; int redirty = 0; /* if this is a small write inside eof, kick off a defrag */ if ((end - start + 1) < SZ_16K && (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) btrfs_add_inode_defrag(NULL, inode); actual_end = min_t(u64, isize, end + 1); again: will_compress = 0; nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1; nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE); /* * we don't want to send crud past the end of i_size through * compression, that's just a waste of CPU time. So, if the * end of the file is before the start of our current * requested range of bytes, we bail out to the uncompressed * cleanup code that can deal with all of this. * * It isn't really the fastest way to fix things, but this is a * very uncommon corner. */ if (actual_end <= start) goto cleanup_and_bail_uncompressed; total_compressed = actual_end - start; /* * skip compression for a small file range(<=blocksize) that * isn't an inline extent, since it doesn't save disk space at all. */ if (total_compressed <= blocksize && (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) goto cleanup_and_bail_uncompressed; /* we want to make sure that amount of ram required to uncompress * an extent is reasonable, so we limit the total size in ram * of a compressed extent to 128k. This is a crucial number * because it also controls how easily we can spread reads across * cpus for decompression. * * We also want to make sure the amount of IO required to do * a random read is reasonably small, so we limit the size of * a compressed extent to 128k. */ total_compressed = min(total_compressed, max_uncompressed); num_bytes = ALIGN(end - start + 1, blocksize); num_bytes = max(blocksize, num_bytes); total_in = 0; ret = 0; /* * we do compression for mount -o compress and when the * inode has not been flagged as nocompress. This flag can * change at any time if we discover bad compression ratios. */ if (inode_need_compress(inode)) { WARN_ON(pages); pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); if (!pages) { /* just bail out to the uncompressed code */ goto cont; } if (BTRFS_I(inode)->force_compress) compress_type = BTRFS_I(inode)->force_compress; /* * we need to call clear_page_dirty_for_io on each * page in the range. Otherwise applications with the file * mmap'd can wander in and change the page contents while * we are compressing them. * * If the compression fails for any reason, we set the pages * dirty again later on. */ extent_range_clear_dirty_for_io(inode, start, end); redirty = 1; ret = btrfs_compress_pages(compress_type, inode->i_mapping, start, total_compressed, pages, nr_pages, &nr_pages_ret, &total_in, &total_compressed, max_compressed); if (!ret) { unsigned long offset = total_compressed & (PAGE_SIZE - 1); struct page *page = pages[nr_pages_ret - 1]; char *kaddr; /* zero the tail end of the last page, we might be * sending it down to disk */ if (offset) { kaddr = kmap_atomic(page); memset(kaddr + offset, 0, PAGE_SIZE - offset); kunmap_atomic(kaddr); } will_compress = 1; } } cont: if (start == 0) { /* lets try to make an inline extent */ if (ret || total_in < (actual_end - start)) { /* we didn't compress the entire range, try * to make an uncompressed inline extent. */ ret = cow_file_range_inline(root, inode, start, end, 0, 0, NULL); } else { /* try making a compressed inline extent */ ret = cow_file_range_inline(root, inode, start, end, total_compressed, compress_type, pages); } if (ret <= 0) { unsigned long clear_flags = EXTENT_DELALLOC | EXTENT_DEFRAG; unsigned long page_error_op; clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0; page_error_op = ret < 0 ? PAGE_SET_ERROR : 0; /* * inline extent creation worked or returned error, * we don't need to create any more async work items. * Unlock and free up our temp pages. */ extent_clear_unlock_delalloc(inode, start, end, NULL, clear_flags, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | page_error_op | PAGE_END_WRITEBACK); goto free_pages_out; } } if (will_compress) { /* * we aren't doing an inline extent round the compressed size * up to a block size boundary so the allocator does sane * things */ total_compressed = ALIGN(total_compressed, blocksize); /* * one last check to make sure the compression is really a * win, compare the page count read with the blocks on disk */ total_in = ALIGN(total_in, PAGE_SIZE); if (total_compressed >= total_in) { will_compress = 0; } else { num_bytes = total_in; } } if (!will_compress && pages) { /* * the compression code ran but failed to make things smaller, * free any pages it allocated and our page pointer array */ for (i = 0; i < nr_pages_ret; i++) { WARN_ON(pages[i]->mapping); put_page(pages[i]); } kfree(pages); pages = NULL; total_compressed = 0; nr_pages_ret = 0; /* flag the file so we don't compress in the future */ if (!btrfs_test_opt(root, FORCE_COMPRESS) && !(BTRFS_I(inode)->force_compress)) { BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; } } if (will_compress) { *num_added += 1; /* the async work queues will take care of doing actual * allocation on disk for these compressed pages, * and will submit them to the elevator. */ add_async_extent(async_cow, start, num_bytes, total_compressed, pages, nr_pages_ret, compress_type); if (start + num_bytes < end) { start += num_bytes; pages = NULL; cond_resched(); goto again; } } else { cleanup_and_bail_uncompressed: /* * No compression, but we still need to write the pages in * the file we've been given so far. redirty the locked * page if it corresponds to our extent and set things up * for the async work queue to run cow_file_range to do * the normal delalloc dance */ if (page_offset(locked_page) >= start && page_offset(locked_page) <= end) { __set_page_dirty_nobuffers(locked_page); /* unlocked later on in the async handlers */ } if (redirty) extent_range_redirty_for_io(inode, start, end); add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0, BTRFS_COMPRESS_NONE); *num_added += 1; } return; free_pages_out: for (i = 0; i < nr_pages_ret; i++) { WARN_ON(pages[i]->mapping); put_page(pages[i]); } kfree(pages); } static void free_async_extent_pages(struct async_extent *async_extent) { int i; if (!async_extent->pages) return; for (i = 0; i < async_extent->nr_pages; i++) { WARN_ON(async_extent->pages[i]->mapping); put_page(async_extent->pages[i]); } kfree(async_extent->pages); async_extent->nr_pages = 0; async_extent->pages = NULL; } /* * phase two of compressed writeback. This is the ordered portion * of the code, which only gets called in the order the work was * queued. We walk all the async extents created by compress_file_range * and send them down to the disk. */ static noinline void submit_compressed_extents(struct inode *inode, struct async_cow *async_cow) { struct async_extent *async_extent; u64 alloc_hint = 0; struct btrfs_key ins; struct extent_map *em; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_io_tree *io_tree; int ret = 0; again: while (!list_empty(&async_cow->extents)) { async_extent = list_entry(async_cow->extents.next, struct async_extent, list); list_del(&async_extent->list); io_tree = &BTRFS_I(inode)->io_tree; retry: /* did the compression code fall back to uncompressed IO? */ if (!async_extent->pages) { int page_started = 0; unsigned long nr_written = 0; lock_extent(io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1); /* allocate blocks */ ret = cow_file_range(inode, async_cow->locked_page, async_extent->start, async_extent->start + async_extent->ram_size - 1, &page_started, &nr_written, 0); /* JDM XXX */ /* * if page_started, cow_file_range inserted an * inline extent and took care of all the unlocking * and IO for us. Otherwise, we need to submit * all those pages down to the drive. */ if (!page_started && !ret) extent_write_locked_range(io_tree, inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, btrfs_get_extent, WB_SYNC_ALL); else if (ret) unlock_page(async_cow->locked_page); kfree(async_extent); cond_resched(); continue; } lock_extent(io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1); ret = btrfs_reserve_extent(root, async_extent->compressed_size, async_extent->compressed_size, 0, alloc_hint, &ins, 1, 1); if (ret) { free_async_extent_pages(async_extent); if (ret == -ENOSPC) { unlock_extent(io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1); /* * we need to redirty the pages if we decide to * fallback to uncompressed IO, otherwise we * will not submit these pages down to lower * layers. */ extent_range_redirty_for_io(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1); goto retry; } goto out_free; } /* * here we're doing allocation and writeback of the * compressed pages */ btrfs_drop_extent_cache(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, 0); em = alloc_extent_map(); if (!em) { ret = -ENOMEM; goto out_free_reserve; } em->start = async_extent->start; em->len = async_extent->ram_size; em->orig_start = em->start; em->mod_start = em->start; em->mod_len = em->len; em->block_start = ins.objectid; em->block_len = ins.offset; em->orig_block_len = ins.offset; em->ram_bytes = async_extent->ram_size; em->bdev = root->fs_info->fs_devices->latest_bdev; em->compress_type = async_extent->compress_type; set_bit(EXTENT_FLAG_PINNED, &em->flags); set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); em->generation = -1; while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em, 1); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, 0); } if (ret) goto out_free_reserve; ret = btrfs_add_ordered_extent_compress(inode, async_extent->start, ins.objectid, async_extent->ram_size, ins.offset, BTRFS_ORDERED_COMPRESSED, async_extent->compress_type); if (ret) { btrfs_drop_extent_cache(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, 0); goto out_free_reserve; } /* * clear dirty, set writeback and unlock the pages. */ extent_clear_unlock_delalloc(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, NULL, EXTENT_LOCKED | EXTENT_DELALLOC, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK); ret = btrfs_submit_compressed_write(inode, async_extent->start, async_extent->ram_size, ins.objectid, ins.offset, async_extent->pages, async_extent->nr_pages); if (ret) { struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; struct page *p = async_extent->pages[0]; const u64 start = async_extent->start; const u64 end = start + async_extent->ram_size - 1; p->mapping = inode->i_mapping; tree->ops->writepage_end_io_hook(p, start, end, NULL, 0); p->mapping = NULL; extent_clear_unlock_delalloc(inode, start, end, NULL, 0, PAGE_END_WRITEBACK | PAGE_SET_ERROR); free_async_extent_pages(async_extent); } alloc_hint = ins.objectid + ins.offset; kfree(async_extent); cond_resched(); } return; out_free_reserve: btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); out_free: extent_clear_unlock_delalloc(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, NULL, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK | PAGE_SET_ERROR); free_async_extent_pages(async_extent); kfree(async_extent); goto again; } static u64 get_extent_allocation_hint(struct inode *inode, u64 start, u64 num_bytes) { struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_map *em; u64 alloc_hint = 0; read_lock(&em_tree->lock); em = search_extent_mapping(em_tree, start, num_bytes); if (em) { /* * if block start isn't an actual block number then find the * first block in this inode and use that as a hint. If that * block is also bogus then just don't worry about it. */ if (em->block_start >= EXTENT_MAP_LAST_BYTE) { free_extent_map(em); em = search_extent_mapping(em_tree, 0, 0); if (em && em->block_start < EXTENT_MAP_LAST_BYTE) alloc_hint = em->block_start; if (em) free_extent_map(em); } else { alloc_hint = em->block_start; free_extent_map(em); } } read_unlock(&em_tree->lock); return alloc_hint; } /* * when extent_io.c finds a delayed allocation range in the file, * the call backs end up in this code. The basic idea is to * allocate extents on disk for the range, and create ordered data structs * in ram to track those extents. * * locked_page is the page that writepage had locked already. We use * it to make sure we don't do extra locks or unlocks. * * *page_started is set to one if we unlock locked_page and do everything * required to start IO on it. It may be clean and already done with * IO when we return. */ static noinline int cow_file_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written, int unlock) { struct btrfs_root *root = BTRFS_I(inode)->root; u64 alloc_hint = 0; u64 num_bytes; unsigned long ram_size; u64 disk_num_bytes; u64 cur_alloc_size; u64 blocksize = root->sectorsize; struct btrfs_key ins; struct extent_map *em; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; int ret = 0; if (btrfs_is_free_space_inode(inode)) { WARN_ON_ONCE(1); ret = -EINVAL; goto out_unlock; } num_bytes = ALIGN(end - start + 1, blocksize); num_bytes = max(blocksize, num_bytes); disk_num_bytes = num_bytes; /* if this is a small write inside eof, kick off defrag */ if (num_bytes < SZ_64K && (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) btrfs_add_inode_defrag(NULL, inode); if (start == 0) { /* lets try to make an inline extent */ ret = cow_file_range_inline(root, inode, start, end, 0, 0, NULL); if (ret == 0) { extent_clear_unlock_delalloc(inode, start, end, NULL, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DEFRAG, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); *nr_written = *nr_written + (end - start + PAGE_SIZE) / PAGE_SIZE; *page_started = 1; goto out; } else if (ret < 0) { goto out_unlock; } } BUG_ON(disk_num_bytes > btrfs_super_total_bytes(root->fs_info->super_copy)); alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); while (disk_num_bytes > 0) { unsigned long op; cur_alloc_size = disk_num_bytes; ret = btrfs_reserve_extent(root, cur_alloc_size, root->sectorsize, 0, alloc_hint, &ins, 1, 1); if (ret < 0) goto out_unlock; em = alloc_extent_map(); if (!em) { ret = -ENOMEM; goto out_reserve; } em->start = start; em->orig_start = em->start; ram_size = ins.offset; em->len = ins.offset; em->mod_start = em->start; em->mod_len = em->len; em->block_start = ins.objectid; em->block_len = ins.offset; em->orig_block_len = ins.offset; em->ram_bytes = ram_size; em->bdev = root->fs_info->fs_devices->latest_bdev; set_bit(EXTENT_FLAG_PINNED, &em->flags); em->generation = -1; while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em, 1); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0); } if (ret) goto out_reserve; cur_alloc_size = ins.offset; ret = btrfs_add_ordered_extent(inode, start, ins.objectid, ram_size, cur_alloc_size, 0); if (ret) goto out_drop_extent_cache; if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) { ret = btrfs_reloc_clone_csums(inode, start, cur_alloc_size); if (ret) goto out_drop_extent_cache; } if (disk_num_bytes < cur_alloc_size) break; /* we're not doing compressed IO, don't unlock the first * page (which the caller expects to stay locked), don't * clear any dirty bits and don't set any writeback bits * * Do set the Private2 bit so we know this page was properly * setup for writepage */ op = unlock ? PAGE_UNLOCK : 0; op |= PAGE_SET_PRIVATE2; extent_clear_unlock_delalloc(inode, start, start + ram_size - 1, locked_page, EXTENT_LOCKED | EXTENT_DELALLOC, op); disk_num_bytes -= cur_alloc_size; num_bytes -= cur_alloc_size; alloc_hint = ins.objectid + ins.offset; start += cur_alloc_size; } out: return ret; out_drop_extent_cache: btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0); out_reserve: btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); out_unlock: extent_clear_unlock_delalloc(inode, start, end, locked_page, EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | EXTENT_DELALLOC | EXTENT_DEFRAG, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); goto out; } /* * work queue call back to started compression on a file and pages */ static noinline void async_cow_start(struct btrfs_work *work) { struct async_cow *async_cow; int num_added = 0; async_cow = container_of(work, struct async_cow, work); compress_file_range(async_cow->inode, async_cow->locked_page, async_cow->start, async_cow->end, async_cow, &num_added); if (num_added == 0) { btrfs_add_delayed_iput(async_cow->inode); async_cow->inode = NULL; } } /* * work queue call back to submit previously compressed pages */ static noinline void async_cow_submit(struct btrfs_work *work) { struct async_cow *async_cow; struct btrfs_root *root; unsigned long nr_pages; async_cow = container_of(work, struct async_cow, work); root = async_cow->root; nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >> PAGE_SHIFT; /* * atomic_sub_return implies a barrier for waitqueue_active */ if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 5 * SZ_1M && waitqueue_active(&root->fs_info->async_submit_wait)) wake_up(&root->fs_info->async_submit_wait); if (async_cow->inode) submit_compressed_extents(async_cow->inode, async_cow); } static noinline void async_cow_free(struct btrfs_work *work) { struct async_cow *async_cow; async_cow = container_of(work, struct async_cow, work); if (async_cow->inode) btrfs_add_delayed_iput(async_cow->inode); kfree(async_cow); } static int cow_file_range_async(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written) { struct async_cow *async_cow; struct btrfs_root *root = BTRFS_I(inode)->root; unsigned long nr_pages; u64 cur_end; int limit = 10 * SZ_1M; clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS); while (start < end) { async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); BUG_ON(!async_cow); /* -ENOMEM */ async_cow->inode = igrab(inode); async_cow->root = root; async_cow->locked_page = locked_page; async_cow->start = start; if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS && !btrfs_test_opt(root, FORCE_COMPRESS)) cur_end = end; else cur_end = min(end, start + SZ_512K - 1); async_cow->end = cur_end; INIT_LIST_HEAD(&async_cow->extents); btrfs_init_work(&async_cow->work, btrfs_delalloc_helper, async_cow_start, async_cow_submit, async_cow_free); nr_pages = (cur_end - start + PAGE_SIZE) >> PAGE_SHIFT; atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); btrfs_queue_work(root->fs_info->delalloc_workers, &async_cow->work); if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { wait_event(root->fs_info->async_submit_wait, (atomic_read(&root->fs_info->async_delalloc_pages) < limit)); } while (atomic_read(&root->fs_info->async_submit_draining) && atomic_read(&root->fs_info->async_delalloc_pages)) { wait_event(root->fs_info->async_submit_wait, (atomic_read(&root->fs_info->async_delalloc_pages) == 0)); } *nr_written += nr_pages; start = cur_end + 1; } *page_started = 1; return 0; } static noinline int csum_exist_in_range(struct btrfs_root *root, u64 bytenr, u64 num_bytes) { int ret; struct btrfs_ordered_sum *sums; LIST_HEAD(list); ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, bytenr + num_bytes - 1, &list, 0); if (ret == 0 && list_empty(&list)) return 0; while (!list_empty(&list)) { sums = list_entry(list.next, struct btrfs_ordered_sum, list); list_del(&sums->list); kfree(sums); } return 1; } /* * when nowcow writeback call back. This checks for snapshots or COW copies * of the extents that exist in the file, and COWs the file as required. * * If no cow copies or snapshots exist, we write directly to the existing * blocks on disk */ static noinline int run_delalloc_nocow(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, int force, unsigned long *nr_written) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; struct extent_buffer *leaf; struct btrfs_path *path; struct btrfs_file_extent_item *fi; struct btrfs_key found_key; u64 cow_start; u64 cur_offset; u64 extent_end; u64 extent_offset; u64 disk_bytenr; u64 num_bytes; u64 disk_num_bytes; u64 ram_bytes; int extent_type; int ret, err; int type; int nocow; int check_prev = 1; bool nolock; u64 ino = btrfs_ino(inode); path = btrfs_alloc_path(); if (!path) { extent_clear_unlock_delalloc(inode, start, end, locked_page, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); return -ENOMEM; } nolock = btrfs_is_free_space_inode(inode); if (nolock) trans = btrfs_join_transaction_nolock(root); else trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { extent_clear_unlock_delalloc(inode, start, end, locked_page, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); btrfs_free_path(path); return PTR_ERR(trans); } trans->block_rsv = &root->fs_info->delalloc_block_rsv; cow_start = (u64)-1; cur_offset = start; while (1) { ret = btrfs_lookup_file_extent(trans, root, path, ino, cur_offset, 0); if (ret < 0) goto error; if (ret > 0 && path->slots[0] > 0 && check_prev) { leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); if (found_key.objectid == ino && found_key.type == BTRFS_EXTENT_DATA_KEY) path->slots[0]--; } check_prev = 0; next_slot: leaf = path->nodes[0]; if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto error; if (ret > 0) break; leaf = path->nodes[0]; } nocow = 0; disk_bytenr = 0; num_bytes = 0; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid > ino) break; if (WARN_ON_ONCE(found_key.objectid < ino) || found_key.type < BTRFS_EXTENT_DATA_KEY) { path->slots[0]++; goto next_slot; } if (found_key.type > BTRFS_EXTENT_DATA_KEY || found_key.offset > end) break; if (found_key.offset > cur_offset) { extent_end = found_key.offset; extent_type = 0; goto out_check; } fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_type = btrfs_file_extent_type(leaf, fi); ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); if (extent_type == BTRFS_FILE_EXTENT_REG || extent_type == BTRFS_FILE_EXTENT_PREALLOC) { disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); extent_offset = btrfs_file_extent_offset(leaf, fi); extent_end = found_key.offset + btrfs_file_extent_num_bytes(leaf, fi); disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); if (extent_end <= start) { path->slots[0]++; goto next_slot; } if (disk_bytenr == 0) goto out_check; if (btrfs_file_extent_compression(leaf, fi) || btrfs_file_extent_encryption(leaf, fi) || btrfs_file_extent_other_encoding(leaf, fi)) goto out_check; if (extent_type == BTRFS_FILE_EXTENT_REG && !force) goto out_check; if (btrfs_extent_readonly(root, disk_bytenr)) goto out_check; if (btrfs_cross_ref_exist(trans, root, ino, found_key.offset - extent_offset, disk_bytenr)) goto out_check; disk_bytenr += extent_offset; disk_bytenr += cur_offset - found_key.offset; num_bytes = min(end + 1, extent_end) - cur_offset; /* * if there are pending snapshots for this root, * we fall into common COW way. */ if (!nolock) { err = btrfs_start_write_no_snapshoting(root); if (!err) goto out_check; } /* * force cow if csum exists in the range. * this ensure that csum for a given extent are * either valid or do not exist. */ if (csum_exist_in_range(root, disk_bytenr, num_bytes)) goto out_check; nocow = 1; } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { extent_end = found_key.offset + btrfs_file_extent_inline_len(leaf, path->slots[0], fi); extent_end = ALIGN(extent_end, root->sectorsize); } else { BUG_ON(1); } out_check: if (extent_end <= start) { path->slots[0]++; if (!nolock && nocow) btrfs_end_write_no_snapshoting(root); goto next_slot; } if (!nocow) { if (cow_start == (u64)-1) cow_start = cur_offset; cur_offset = extent_end; if (cur_offset > end) break; path->slots[0]++; goto next_slot; } btrfs_release_path(path); if (cow_start != (u64)-1) { ret = cow_file_range(inode, locked_page, cow_start, found_key.offset - 1, page_started, nr_written, 1); if (ret) { if (!nolock && nocow) btrfs_end_write_no_snapshoting(root); goto error; } cow_start = (u64)-1; } if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { struct extent_map *em; struct extent_map_tree *em_tree; em_tree = &BTRFS_I(inode)->extent_tree; em = alloc_extent_map(); BUG_ON(!em); /* -ENOMEM */ em->start = cur_offset; em->orig_start = found_key.offset - extent_offset; em->len = num_bytes; em->block_len = num_bytes; em->block_start = disk_bytenr; em->orig_block_len = disk_num_bytes; em->ram_bytes = ram_bytes; em->bdev = root->fs_info->fs_devices->latest_bdev; em->mod_start = em->start; em->mod_len = em->len; set_bit(EXTENT_FLAG_PINNED, &em->flags); set_bit(EXTENT_FLAG_FILLING, &em->flags); em->generation = -1; while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em, 1); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(inode, em->start, em->start + em->len - 1, 0); } type = BTRFS_ORDERED_PREALLOC; } else { type = BTRFS_ORDERED_NOCOW; } ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, num_bytes, num_bytes, type); BUG_ON(ret); /* -ENOMEM */ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) { ret = btrfs_reloc_clone_csums(inode, cur_offset, num_bytes); if (ret) { if (!nolock && nocow) btrfs_end_write_no_snapshoting(root); goto error; } } extent_clear_unlock_delalloc(inode, cur_offset, cur_offset + num_bytes - 1, locked_page, EXTENT_LOCKED | EXTENT_DELALLOC, PAGE_UNLOCK | PAGE_SET_PRIVATE2); if (!nolock && nocow) btrfs_end_write_no_snapshoting(root); cur_offset = extent_end; if (cur_offset > end) break; } btrfs_release_path(path); if (cur_offset <= end && cow_start == (u64)-1) { cow_start = cur_offset; cur_offset = end; } if (cow_start != (u64)-1) { ret = cow_file_range(inode, locked_page, cow_start, end, page_started, nr_written, 1); if (ret) goto error; } error: err = btrfs_end_transaction(trans, root); if (!ret) ret = err; if (ret && cur_offset < end) extent_clear_unlock_delalloc(inode, cur_offset, end, locked_page, EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK); btrfs_free_path(path); return ret; } static inline int need_force_cow(struct inode *inode, u64 start, u64 end) { if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) return 0; /* * @defrag_bytes is a hint value, no spinlock held here, * if is not zero, it means the file is defragging. * Force cow if given extent needs to be defragged. */ if (BTRFS_I(inode)->defrag_bytes && test_range_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_DEFRAG, 0, NULL)) return 1; return 0; } /* * extent_io.c call back to do delayed allocation processing */ static int run_delalloc_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written) { int ret; int force_cow = need_force_cow(inode, start, end); if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) { ret = run_delalloc_nocow(inode, locked_page, start, end, page_started, 1, nr_written); } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) { ret = run_delalloc_nocow(inode, locked_page, start, end, page_started, 0, nr_written); } else if (!inode_need_compress(inode)) { ret = cow_file_range(inode, locked_page, start, end, page_started, nr_written, 1); } else { set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &BTRFS_I(inode)->runtime_flags); ret = cow_file_range_async(inode, locked_page, start, end, page_started, nr_written); } return ret; } static void btrfs_split_extent_hook(struct inode *inode, struct extent_state *orig, u64 split) { u64 size; /* not delalloc, ignore it */ if (!(orig->state & EXTENT_DELALLOC)) return; size = orig->end - orig->start + 1; if (size > BTRFS_MAX_EXTENT_SIZE) { u64 num_extents; u64 new_size; /* * See the explanation in btrfs_merge_extent_hook, the same * applies here, just in reverse. */ new_size = orig->end - split + 1; num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE); new_size = split - orig->start; num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE); if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE) >= num_extents) return; } spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents++; spin_unlock(&BTRFS_I(inode)->lock); } /* * extent_io.c merge_extent_hook, used to track merged delayed allocation * extents so we can keep track of new extents that are just merged onto old * extents, such as when we are doing sequential writes, so we can properly * account for the metadata space we'll need. */ static void btrfs_merge_extent_hook(struct inode *inode, struct extent_state *new, struct extent_state *other) { u64 new_size, old_size; u64 num_extents; /* not delalloc, ignore it */ if (!(other->state & EXTENT_DELALLOC)) return; if (new->start > other->start) new_size = new->end - other->start + 1; else new_size = other->end - new->start + 1; /* we're not bigger than the max, unreserve the space and go */ if (new_size <= BTRFS_MAX_EXTENT_SIZE) { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents--; spin_unlock(&BTRFS_I(inode)->lock); return; } /* * We have to add up either side to figure out how many extents were * accounted for before we merged into one big extent. If the number of * extents we accounted for is <= the amount we need for the new range * then we can return, otherwise drop. Think of it like this * * [ 4k][MAX_SIZE] * * So we've grown the extent by a MAX_SIZE extent, this would mean we * need 2 outstanding extents, on one side we have 1 and the other side * we have 1 so they are == and we can return. But in this case * * [MAX_SIZE+4k][MAX_SIZE+4k] * * Each range on their own accounts for 2 extents, but merged together * they are only 3 extents worth of accounting, so we need to drop in * this case. */ old_size = other->end - other->start + 1; num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE); old_size = new->end - new->start + 1; num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE); if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE) >= num_extents) return; spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents--; spin_unlock(&BTRFS_I(inode)->lock); } static void btrfs_add_delalloc_inodes(struct btrfs_root *root, struct inode *inode) { spin_lock(&root->delalloc_lock); if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { list_add_tail(&BTRFS_I(inode)->delalloc_inodes, &root->delalloc_inodes); set_bit(BTRFS_INODE_IN_DELALLOC_LIST, &BTRFS_I(inode)->runtime_flags); root->nr_delalloc_inodes++; if (root->nr_delalloc_inodes == 1) { spin_lock(&root->fs_info->delalloc_root_lock); BUG_ON(!list_empty(&root->delalloc_root)); list_add_tail(&root->delalloc_root, &root->fs_info->delalloc_roots); spin_unlock(&root->fs_info->delalloc_root_lock); } } spin_unlock(&root->delalloc_lock); } static void btrfs_del_delalloc_inode(struct btrfs_root *root, struct inode *inode) { spin_lock(&root->delalloc_lock); if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) { list_del_init(&BTRFS_I(inode)->delalloc_inodes); clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, &BTRFS_I(inode)->runtime_flags); root->nr_delalloc_inodes--; if (!root->nr_delalloc_inodes) { spin_lock(&root->fs_info->delalloc_root_lock); BUG_ON(list_empty(&root->delalloc_root)); list_del_init(&root->delalloc_root); spin_unlock(&root->fs_info->delalloc_root_lock); } } spin_unlock(&root->delalloc_lock); } /* * extent_io.c set_bit_hook, used to track delayed allocation * bytes in this file, and to maintain the list of inodes that * have pending delalloc work to be done. */ static void btrfs_set_bit_hook(struct inode *inode, struct extent_state *state, unsigned *bits) { if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC)) WARN_ON(1); /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testing for the DELALLOC * bit, which is only set or cleared with irqs on */ if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; u64 len = state->end + 1 - state->start; bool do_list = !btrfs_is_free_space_inode(inode); if (*bits & EXTENT_FIRST_DELALLOC) { *bits &= ~EXTENT_FIRST_DELALLOC; } else { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents++; spin_unlock(&BTRFS_I(inode)->lock); } /* For sanity tests */ if (btrfs_test_is_dummy_root(root)) return; __percpu_counter_add(&root->fs_info->delalloc_bytes, len, root->fs_info->delalloc_batch); spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->delalloc_bytes += len; if (*bits & EXTENT_DEFRAG) BTRFS_I(inode)->defrag_bytes += len; if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, &BTRFS_I(inode)->runtime_flags)) btrfs_add_delalloc_inodes(root, inode); spin_unlock(&BTRFS_I(inode)->lock); } } /* * extent_io.c clear_bit_hook, see set_bit_hook for why */ static void btrfs_clear_bit_hook(struct inode *inode, struct extent_state *state, unsigned *bits) { u64 len = state->end + 1 - state->start; u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1, BTRFS_MAX_EXTENT_SIZE); spin_lock(&BTRFS_I(inode)->lock); if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) BTRFS_I(inode)->defrag_bytes -= len; spin_unlock(&BTRFS_I(inode)->lock); /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testing for the DELALLOC * bit, which is only set or cleared with irqs on */ if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; bool do_list = !btrfs_is_free_space_inode(inode); if (*bits & EXTENT_FIRST_DELALLOC) { *bits &= ~EXTENT_FIRST_DELALLOC; } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents -= num_extents; spin_unlock(&BTRFS_I(inode)->lock); } /* * We don't reserve metadata space for space cache inodes so we * don't need to call dellalloc_release_metadata if there is an * error. */ if (*bits & EXTENT_DO_ACCOUNTING && root != root->fs_info->tree_root) btrfs_delalloc_release_metadata(inode, len); /* For sanity tests. */ if (btrfs_test_is_dummy_root(root)) return; if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID && do_list && !(state->state & EXTENT_NORESERVE)) btrfs_free_reserved_data_space_noquota(inode, state->start, len); __percpu_counter_add(&root->fs_info->delalloc_bytes, -len, root->fs_info->delalloc_batch); spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->delalloc_bytes -= len; if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && test_bit(BTRFS_INODE_IN_DELALLOC_LIST, &BTRFS_I(inode)->runtime_flags)) btrfs_del_delalloc_inode(root, inode); spin_unlock(&BTRFS_I(inode)->lock); } } /* * extent_io.c merge_bio_hook, this must check the chunk tree to make sure * we don't create bios that span stripes or chunks */ int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset, size_t size, struct bio *bio, unsigned long bio_flags) { struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; u64 logical = (u64)bio->bi_iter.bi_sector << 9; u64 length = 0; u64 map_length; int ret; if (bio_flags & EXTENT_BIO_COMPRESSED) return 0; length = bio->bi_iter.bi_size; map_length = length; ret = btrfs_map_block(root->fs_info, rw, logical, &map_length, NULL, 0); /* Will always return 0 with map_multi == NULL */ BUG_ON(ret < 0); if (map_length < length + size) return 1; return 0; } /* * in order to insert checksums into the metadata in large chunks, * we wait until bio submission time. All the pages in the bio are * checksummed and sums are attached onto the ordered extent record. * * At IO completion time the cums attached on the ordered extent record * are inserted into the btree */ static int __btrfs_submit_bio_start(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 bio_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret = 0; ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); BUG_ON(ret); /* -ENOMEM */ return 0; } /* * in order to insert checksums into the metadata in large chunks, * we wait until bio submission time. All the pages in the bio are * checksummed and sums are attached onto the ordered extent record. * * At IO completion time the cums attached on the ordered extent record * are inserted into the btree */ static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 bio_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret; ret = btrfs_map_bio(root, rw, bio, mirror_num, 1); if (ret) { bio->bi_error = ret; bio_endio(bio); } return ret; } /* * extent_io.c submission hook. This does the right thing for csum calculation * on write, or reading the csums from the tree before a read */ static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 bio_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA; int ret = 0; int skip_sum; int async = !atomic_read(&BTRFS_I(inode)->sync_writers); skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; if (btrfs_is_free_space_inode(inode)) metadata = BTRFS_WQ_ENDIO_FREE_SPACE; if (!(rw & REQ_WRITE)) { ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata); if (ret) goto out; if (bio_flags & EXTENT_BIO_COMPRESSED) { ret = btrfs_submit_compressed_read(inode, bio, mirror_num, bio_flags); goto out; } else if (!skip_sum) { ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); if (ret) goto out; } goto mapit; } else if (async && !skip_sum) { /* csum items have already been cloned */ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) goto mapit; /* we're doing a write, do the async checksumming */ ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, inode, rw, bio, mirror_num, bio_flags, bio_offset, __btrfs_submit_bio_start, __btrfs_submit_bio_done); goto out; } else if (!skip_sum) { ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); if (ret) goto out; } mapit: ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); out: if (ret < 0) { bio->bi_error = ret; bio_endio(bio); } return ret; } /* * given a list of ordered sums record them in the inode. This happens * at IO completion time based on sums calculated at bio submission time. */ static noinline int add_pending_csums(struct btrfs_trans_handle *trans, struct inode *inode, u64 file_offset, struct list_head *list) { struct btrfs_ordered_sum *sum; list_for_each_entry(sum, list, list) { trans->adding_csums = 1; btrfs_csum_file_blocks(trans, BTRFS_I(inode)->root->fs_info->csum_root, sum); trans->adding_csums = 0; } return 0; } int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, struct extent_state **cached_state) { WARN_ON((end & (PAGE_SIZE - 1)) == 0); return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, cached_state); } /* see btrfs_writepage_start_hook for details on why this is required */ struct btrfs_writepage_fixup { struct page *page; struct btrfs_work work; }; static void btrfs_writepage_fixup_worker(struct btrfs_work *work) { struct btrfs_writepage_fixup *fixup; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; struct page *page; struct inode *inode; u64 page_start; u64 page_end; int ret; fixup = container_of(work, struct btrfs_writepage_fixup, work); page = fixup->page; again: lock_page(page); if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { ClearPageChecked(page); goto out_page; } inode = page->mapping->host; page_start = page_offset(page); page_end = page_offset(page) + PAGE_SIZE - 1; lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, &cached_state); /* already ordered? We're done */ if (PagePrivate2(page)) goto out; ordered = btrfs_lookup_ordered_range(inode, page_start, PAGE_SIZE); if (ordered) { unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, &cached_state, GFP_NOFS); unlock_page(page); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); goto again; } ret = btrfs_delalloc_reserve_space(inode, page_start, PAGE_SIZE); if (ret) { mapping_set_error(page->mapping, ret); end_extent_writepage(page, ret, page_start, page_end); ClearPageChecked(page); goto out; } btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); ClearPageChecked(page); set_page_dirty(page); out: unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, &cached_state, GFP_NOFS); out_page: unlock_page(page); put_page(page); kfree(fixup); } /* * There are a few paths in the higher layers of the kernel that directly * set the page dirty bit without asking the filesystem if it is a * good idea. This causes problems because we want to make sure COW * properly happens and the data=ordered rules are followed. * * In our case any range that doesn't have the ORDERED bit set * hasn't been properly setup for IO. We kick off an async process * to fix it up. The async helper will wait for ordered extents, set * the delalloc bit and make it safe to write the page. */ static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) { struct inode *inode = page->mapping->host; struct btrfs_writepage_fixup *fixup; struct btrfs_root *root = BTRFS_I(inode)->root; /* this page is properly in the ordered list */ if (TestClearPagePrivate2(page)) return 0; if (PageChecked(page)) return -EAGAIN; fixup = kzalloc(sizeof(*fixup), GFP_NOFS); if (!fixup) return -EAGAIN; SetPageChecked(page); get_page(page); btrfs_init_work(&fixup->work, btrfs_fixup_helper, btrfs_writepage_fixup_worker, NULL, NULL); fixup->page = page; btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work); return -EBUSY; } static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, struct inode *inode, u64 file_pos, u64 disk_bytenr, u64 disk_num_bytes, u64 num_bytes, u64 ram_bytes, u8 compression, u8 encryption, u16 other_encoding, int extent_type) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_file_extent_item *fi; struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_key ins; int extent_inserted = 0; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; /* * we may be replacing one extent in the tree with another. * The new extent is pinned in the extent map, and we don't want * to drop it from the cache until it is completely in the btree. * * So, tell btrfs_drop_extents to leave this extent in the cache. * the caller is expected to unpin it and allow it to be merged * with the others. */ ret = __btrfs_drop_extents(trans, root, inode, path, file_pos, file_pos + num_bytes, NULL, 0, 1, sizeof(*fi), &extent_inserted); if (ret) goto out; if (!extent_inserted) { ins.objectid = btrfs_ino(inode); ins.offset = file_pos; ins.type = BTRFS_EXTENT_DATA_KEY; path->leave_spinning = 1; ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi)); if (ret) goto out; } leaf = path->nodes[0]; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_type(leaf, fi, extent_type); btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); btrfs_set_file_extent_offset(leaf, fi, 0); btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); btrfs_set_file_extent_compression(leaf, fi, compression); btrfs_set_file_extent_encryption(leaf, fi, encryption); btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(path); inode_add_bytes(inode, num_bytes); ins.objectid = disk_bytenr; ins.offset = disk_num_bytes; ins.type = BTRFS_EXTENT_ITEM_KEY; ret = btrfs_alloc_reserved_file_extent(trans, root, root->root_key.objectid, btrfs_ino(inode), file_pos, ram_bytes, &ins); /* * Release the reserved range from inode dirty range map, as it is * already moved into delayed_ref_head */ btrfs_qgroup_release_data(inode, file_pos, ram_bytes); out: btrfs_free_path(path); return ret; } /* snapshot-aware defrag */ struct sa_defrag_extent_backref { struct rb_node node; struct old_sa_defrag_extent *old; u64 root_id; u64 inum; u64 file_pos; u64 extent_offset; u64 num_bytes; u64 generation; }; struct old_sa_defrag_extent { struct list_head list; struct new_sa_defrag_extent *new; u64 extent_offset; u64 bytenr; u64 offset; u64 len; int count; }; struct new_sa_defrag_extent { struct rb_root root; struct list_head head; struct btrfs_path *path; struct inode *inode; u64 file_pos; u64 len; u64 bytenr; u64 disk_len; u8 compress_type; }; static int backref_comp(struct sa_defrag_extent_backref *b1, struct sa_defrag_extent_backref *b2) { if (b1->root_id < b2->root_id) return -1; else if (b1->root_id > b2->root_id) return 1; if (b1->inum < b2->inum) return -1; else if (b1->inum > b2->inum) return 1; if (b1->file_pos < b2->file_pos) return -1; else if (b1->file_pos > b2->file_pos) return 1; /* * [------------------------------] ===> (a range of space) * |<--->| |<---->| =============> (fs/file tree A) * |<---------------------------->| ===> (fs/file tree B) * * A range of space can refer to two file extents in one tree while * refer to only one file extent in another tree. * * So we may process a disk offset more than one time(two extents in A) * and locate at the same extent(one extent in B), then insert two same * backrefs(both refer to the extent in B). */ return 0; } static void backref_insert(struct rb_root *root, struct sa_defrag_extent_backref *backref) { struct rb_node **p = &root->rb_node; struct rb_node *parent = NULL; struct sa_defrag_extent_backref *entry; int ret; while (*p) { parent = *p; entry = rb_entry(parent, struct sa_defrag_extent_backref, node); ret = backref_comp(backref, entry); if (ret < 0) p = &(*p)->rb_left; else p = &(*p)->rb_right; } rb_link_node(&backref->node, parent, p); rb_insert_color(&backref->node, root); } /* * Note the backref might has changed, and in this case we just return 0. */ static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, void *ctx) { struct btrfs_file_extent_item *extent; struct btrfs_fs_info *fs_info; struct old_sa_defrag_extent *old = ctx; struct new_sa_defrag_extent *new = old->new; struct btrfs_path *path = new->path; struct btrfs_key key; struct btrfs_root *root; struct sa_defrag_extent_backref *backref; struct extent_buffer *leaf; struct inode *inode = new->inode; int slot; int ret; u64 extent_offset; u64 num_bytes; if (BTRFS_I(inode)->root->root_key.objectid == root_id && inum == btrfs_ino(inode)) return 0; key.objectid = root_id; key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; fs_info = BTRFS_I(inode)->root->fs_info; root = btrfs_read_fs_root_no_name(fs_info, &key); if (IS_ERR(root)) { if (PTR_ERR(root) == -ENOENT) return 0; WARN_ON(1); pr_debug("inum=%llu, offset=%llu, root_id=%llu\n", inum, offset, root_id); return PTR_ERR(root); } key.objectid = inum; key.type = BTRFS_EXTENT_DATA_KEY; if (offset > (u64)-1 << 32) key.offset = 0; else key.offset = offset; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (WARN_ON(ret < 0)) return ret; ret = 0; while (1) { cond_resched(); leaf = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) { goto out; } else if (ret > 0) { ret = 0; goto out; } continue; } path->slots[0]++; btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid > inum) goto out; if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) continue; extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) continue; /* * 'offset' refers to the exact key.offset, * NOT the 'offset' field in btrfs_extent_data_ref, ie. * (key.offset - extent_offset). */ if (key.offset != offset) continue; extent_offset = btrfs_file_extent_offset(leaf, extent); num_bytes = btrfs_file_extent_num_bytes(leaf, extent); if (extent_offset >= old->extent_offset + old->offset + old->len || extent_offset + num_bytes <= old->extent_offset + old->offset) continue; break; } backref = kmalloc(sizeof(*backref), GFP_NOFS); if (!backref) { ret = -ENOENT; goto out; } backref->root_id = root_id; backref->inum = inum; backref->file_pos = offset; backref->num_bytes = num_bytes; backref->extent_offset = extent_offset; backref->generation = btrfs_file_extent_generation(leaf, extent); backref->old = old; backref_insert(&new->root, backref); old->count++; out: btrfs_release_path(path); WARN_ON(ret); return ret; } static noinline bool record_extent_backrefs(struct btrfs_path *path, struct new_sa_defrag_extent *new) { struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info; struct old_sa_defrag_extent *old, *tmp; int ret; new->path = path; list_for_each_entry_safe(old, tmp, &new->head, list) { ret = iterate_inodes_from_logical(old->bytenr + old->extent_offset, fs_info, path, record_one_backref, old); if (ret < 0 && ret != -ENOENT) return false; /* no backref to be processed for this extent */ if (!old->count) { list_del(&old->list); kfree(old); } } if (list_empty(&new->head)) return false; return true; } static int relink_is_mergable(struct extent_buffer *leaf, struct btrfs_file_extent_item *fi, struct new_sa_defrag_extent *new) { if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr) return 0; if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) return 0; if (btrfs_file_extent_compression(leaf, fi) != new->compress_type) return 0; if (btrfs_file_extent_encryption(leaf, fi) || btrfs_file_extent_other_encoding(leaf, fi)) return 0; return 1; } /* * Note the backref might has changed, and in this case we just return 0. */ static noinline int relink_extent_backref(struct btrfs_path *path, struct sa_defrag_extent_backref *prev, struct sa_defrag_extent_backref *backref) { struct btrfs_file_extent_item *extent; struct btrfs_file_extent_item *item; struct btrfs_ordered_extent *ordered; struct btrfs_trans_handle *trans; struct btrfs_fs_info *fs_info; struct btrfs_root *root; struct btrfs_key key; struct extent_buffer *leaf; struct old_sa_defrag_extent *old = backref->old; struct new_sa_defrag_extent *new = old->new; struct inode *src_inode = new->inode; struct inode *inode; struct extent_state *cached = NULL; int ret = 0; u64 start; u64 len; u64 lock_start; u64 lock_end; bool merge = false; int index; if (prev && prev->root_id == backref->root_id && prev->inum == backref->inum && prev->file_pos + prev->num_bytes == backref->file_pos) merge = true; /* step 1: get root */ key.objectid = backref->root_id; key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; fs_info = BTRFS_I(src_inode)->root->fs_info; index = srcu_read_lock(&fs_info->subvol_srcu); root = btrfs_read_fs_root_no_name(fs_info, &key); if (IS_ERR(root)) { srcu_read_unlock(&fs_info->subvol_srcu, index); if (PTR_ERR(root) == -ENOENT) return 0; return PTR_ERR(root); } if (btrfs_root_readonly(root)) { srcu_read_unlock(&fs_info->subvol_srcu, index); return 0; } /* step 2: get inode */ key.objectid = backref->inum; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; inode = btrfs_iget(fs_info->sb, &key, root, NULL); if (IS_ERR(inode)) { srcu_read_unlock(&fs_info->subvol_srcu, index); return 0; } srcu_read_unlock(&fs_info->subvol_srcu, index); /* step 3: relink backref */ lock_start = backref->file_pos; lock_end = backref->file_pos + backref->num_bytes - 1; lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, &cached); ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); if (ordered) { btrfs_put_ordered_extent(ordered); goto out_unlock; } trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out_unlock; } key.objectid = backref->inum; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = backref->file_pos; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) { goto out_free_path; } else if (ret > 0) { ret = 0; goto out_free_path; } extent = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_file_extent_item); if (btrfs_file_extent_generation(path->nodes[0], extent) != backref->generation) goto out_free_path; btrfs_release_path(path); start = backref->file_pos; if (backref->extent_offset < old->extent_offset + old->offset) start += old->extent_offset + old->offset - backref->extent_offset; len = min(backref->extent_offset + backref->num_bytes, old->extent_offset + old->offset + old->len); len -= max(backref->extent_offset, old->extent_offset + old->offset); ret = btrfs_drop_extents(trans, root, inode, start, start + len, 1); if (ret) goto out_free_path; again: key.objectid = btrfs_ino(inode); key.type = BTRFS_EXTENT_DATA_KEY; key.offset = start; path->leave_spinning = 1; if (merge) { struct btrfs_file_extent_item *fi; u64 extent_len; struct btrfs_key found_key; ret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (ret < 0) goto out_free_path; path->slots[0]--; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_len = btrfs_file_extent_num_bytes(leaf, fi); if (extent_len + found_key.offset == start && relink_is_mergable(leaf, fi, new)) { btrfs_set_file_extent_num_bytes(leaf, fi, extent_len + len); btrfs_mark_buffer_dirty(leaf); inode_add_bytes(inode, len); ret = 1; goto out_free_path; } else { merge = false; btrfs_release_path(path); goto again; } } ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*extent)); if (ret) { btrfs_abort_transaction(trans, root, ret); goto out_free_path; } leaf = path->nodes[0]; item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len); btrfs_set_file_extent_offset(leaf, item, start - new->file_pos); btrfs_set_file_extent_num_bytes(leaf, item, len); btrfs_set_file_extent_ram_bytes(leaf, item, new->len); btrfs_set_file_extent_generation(leaf, item, trans->transid); btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); btrfs_set_file_extent_compression(leaf, item, new->compress_type); btrfs_set_file_extent_encryption(leaf, item, 0); btrfs_set_file_extent_other_encoding(leaf, item, 0); btrfs_mark_buffer_dirty(leaf); inode_add_bytes(inode, len); btrfs_release_path(path); ret = btrfs_inc_extent_ref(trans, root, new->bytenr, new->disk_len, 0, backref->root_id, backref->inum, new->file_pos); /* start - extent_offset */ if (ret) { btrfs_abort_transaction(trans, root, ret); goto out_free_path; } ret = 1; out_free_path: btrfs_release_path(path); path->leave_spinning = 0; btrfs_end_transaction(trans, root); out_unlock: unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end, &cached, GFP_NOFS); iput(inode); return ret; } static void free_sa_defrag_extent(struct new_sa_defrag_extent *new) { struct old_sa_defrag_extent *old, *tmp; if (!new) return; list_for_each_entry_safe(old, tmp, &new->head, list) { kfree(old); } kfree(new); } static void relink_file_extents(struct new_sa_defrag_extent *new) { struct btrfs_path *path; struct sa_defrag_extent_backref *backref; struct sa_defrag_extent_backref *prev = NULL; struct inode *inode; struct btrfs_root *root; struct rb_node *node; int ret; inode = new->inode; root = BTRFS_I(inode)->root; path = btrfs_alloc_path(); if (!path) return; if (!record_extent_backrefs(path, new)) { btrfs_free_path(path); goto out; } btrfs_release_path(path); while (1) { node = rb_first(&new->root); if (!node) break; rb_erase(node, &new->root); backref = rb_entry(node, struct sa_defrag_extent_backref, node); ret = relink_extent_backref(path, prev, backref); WARN_ON(ret < 0); kfree(prev); if (ret == 1) prev = backref; else prev = NULL; cond_resched(); } kfree(prev); btrfs_free_path(path); out: free_sa_defrag_extent(new); atomic_dec(&root->fs_info->defrag_running); wake_up(&root->fs_info->transaction_wait); } static struct new_sa_defrag_extent * record_old_file_extents(struct inode *inode, struct btrfs_ordered_extent *ordered) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_path *path; struct btrfs_key key; struct old_sa_defrag_extent *old; struct new_sa_defrag_extent *new; int ret; new = kmalloc(sizeof(*new), GFP_NOFS); if (!new) return NULL; new->inode = inode; new->file_pos = ordered->file_offset; new->len = ordered->len; new->bytenr = ordered->start; new->disk_len = ordered->disk_len; new->compress_type = ordered->compress_type; new->root = RB_ROOT; INIT_LIST_HEAD(&new->head); path = btrfs_alloc_path(); if (!path) goto out_kfree; key.objectid = btrfs_ino(inode); key.type = BTRFS_EXTENT_DATA_KEY; key.offset = new->file_pos; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out_free_path; if (ret > 0 && path->slots[0] > 0) path->slots[0]--; /* find out all the old extents for the file range */ while (1) { struct btrfs_file_extent_item *extent; struct extent_buffer *l; int slot; u64 num_bytes; u64 offset; u64 end; u64 disk_bytenr; u64 extent_offset; l = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(l)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto out_free_path; else if (ret > 0) break; continue; } btrfs_item_key_to_cpu(l, &key, slot); if (key.objectid != btrfs_ino(inode)) break; if (key.type != BTRFS_EXTENT_DATA_KEY) break; if (key.offset >= new->file_pos + new->len) break; extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item); num_bytes = btrfs_file_extent_num_bytes(l, extent); if (key.offset + num_bytes < new->file_pos) goto next; disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent); if (!disk_bytenr) goto next; extent_offset = btrfs_file_extent_offset(l, extent); old = kmalloc(sizeof(*old), GFP_NOFS); if (!old) goto out_free_path; offset = max(new->file_pos, key.offset); end = min(new->file_pos + new->len, key.offset + num_bytes); old->bytenr = disk_bytenr; old->extent_offset = extent_offset; old->offset = offset - key.offset; old->len = end - offset; old->new = new; old->count = 0; list_add_tail(&old->list, &new->head); next: path->slots[0]++; cond_resched(); } btrfs_free_path(path); atomic_inc(&root->fs_info->defrag_running); return new; out_free_path: btrfs_free_path(path); out_kfree: free_sa_defrag_extent(new); return NULL; } static void btrfs_release_delalloc_bytes(struct btrfs_root *root, u64 start, u64 len) { struct btrfs_block_group_cache *cache; cache = btrfs_lookup_block_group(root->fs_info, start); ASSERT(cache); spin_lock(&cache->lock); cache->delalloc_bytes -= len; spin_unlock(&cache->lock); btrfs_put_block_group(cache); } /* as ordered data IO finishes, this gets called so we can finish * an ordered extent if the range of bytes in the file it covers are * fully written. */ static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) { struct inode *inode = ordered_extent->inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans = NULL; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct extent_state *cached_state = NULL; struct new_sa_defrag_extent *new = NULL; int compress_type = 0; int ret = 0; u64 logical_len = ordered_extent->len; bool nolock; bool truncated = false; nolock = btrfs_is_free_space_inode(inode); if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { ret = -EIO; goto out; } btrfs_free_io_failure_record(inode, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len - 1); if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) { truncated = true; logical_len = ordered_extent->truncated_len; /* Truncated the entire extent, don't bother adding */ if (!logical_len) goto out; } if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ /* * For mwrite(mmap + memset to write) case, we still reserve * space for NOCOW range. * As NOCOW won't cause a new delayed ref, just free the space */ btrfs_qgroup_free_data(inode, ordered_extent->file_offset, ordered_extent->len); btrfs_ordered_update_i_size(inode, 0, ordered_extent); if (nolock) trans = btrfs_join_transaction_nolock(root); else trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL; goto out; } trans->block_rsv = &root->fs_info->delalloc_block_rsv; ret = btrfs_update_inode_fallback(trans, root, inode); if (ret) /* -ENOMEM or corruption */ btrfs_abort_transaction(trans, root, ret); goto out; } lock_extent_bits(io_tree, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len - 1, &cached_state); ret = test_range_bit(io_tree, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len - 1, EXTENT_DEFRAG, 1, cached_state); if (ret) { u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item); if (0 && last_snapshot >= BTRFS_I(inode)->generation) /* the inode is shared */ new = record_old_file_extents(inode, ordered_extent); clear_extent_bit(io_tree, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len - 1, EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); } if (nolock) trans = btrfs_join_transaction_nolock(root); else trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL; goto out_unlock; } trans->block_rsv = &root->fs_info->delalloc_block_rsv; if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) compress_type = ordered_extent->compress_type; if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { BUG_ON(compress_type); ret = btrfs_mark_extent_written(trans, inode, ordered_extent->file_offset, ordered_extent->file_offset + logical_len); } else { BUG_ON(root == root->fs_info->tree_root); ret = insert_reserved_file_extent(trans, inode, ordered_extent->file_offset, ordered_extent->start, ordered_extent->disk_len, logical_len, logical_len, compress_type, 0, 0, BTRFS_FILE_EXTENT_REG); if (!ret) btrfs_release_delalloc_bytes(root, ordered_extent->start, ordered_extent->disk_len); } unpin_extent_cache(&BTRFS_I(inode)->extent_tree, ordered_extent->file_offset, ordered_extent->len, trans->transid); if (ret < 0) { btrfs_abort_transaction(trans, root, ret); goto out_unlock; } add_pending_csums(trans, inode, ordered_extent->file_offset, &ordered_extent->list); btrfs_ordered_update_i_size(inode, 0, ordered_extent); ret = btrfs_update_inode_fallback(trans, root, inode); if (ret) { /* -ENOMEM or corruption */ btrfs_abort_transaction(trans, root, ret); goto out_unlock; } ret = 0; out_unlock: unlock_extent_cached(io_tree, ordered_extent->file_offset, ordered_extent->file_offset + ordered_extent->len - 1, &cached_state, GFP_NOFS); out: if (root != root->fs_info->tree_root) btrfs_delalloc_release_metadata(inode, ordered_extent->len); if (trans) btrfs_end_transaction(trans, root); if (ret || truncated) { u64 start, end; if (truncated) start = ordered_extent->file_offset + logical_len; else start = ordered_extent->file_offset; end = ordered_extent->file_offset + ordered_extent->len - 1; clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS); /* Drop the cache for the part of the extent we didn't write. */ btrfs_drop_extent_cache(inode, start, end, 0); /* * If the ordered extent had an IOERR or something else went * wrong we need to return the space for this ordered extent * back to the allocator. We only free the extent in the * truncated case if we didn't write out the extent at all. */ if ((ret || !logical_len) && !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) btrfs_free_reserved_extent(root, ordered_extent->start, ordered_extent->disk_len, 1); } /* * This needs to be done to make sure anybody waiting knows we are done * updating everything for this ordered extent. */ btrfs_remove_ordered_extent(inode, ordered_extent); /* for snapshot-aware defrag */ if (new) { if (ret) { free_sa_defrag_extent(new); atomic_dec(&root->fs_info->defrag_running); } else { relink_file_extents(new); } } /* once for us */ btrfs_put_ordered_extent(ordered_extent); /* once for the tree */ btrfs_put_ordered_extent(ordered_extent); return ret; } static void finish_ordered_fn(struct btrfs_work *work) { struct btrfs_ordered_extent *ordered_extent; ordered_extent = container_of(work, struct btrfs_ordered_extent, work); btrfs_finish_ordered_io(ordered_extent); } static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end, struct extent_state *state, int uptodate) { struct inode *inode = page->mapping->host; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_ordered_extent *ordered_extent = NULL; struct btrfs_workqueue *wq; btrfs_work_func_t func; trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); ClearPagePrivate2(page); if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, end - start + 1, uptodate)) return 0; if (btrfs_is_free_space_inode(inode)) { wq = root->fs_info->endio_freespace_worker; func = btrfs_freespace_write_helper; } else { wq = root->fs_info->endio_write_workers; func = btrfs_endio_write_helper; } btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL, NULL); btrfs_queue_work(wq, &ordered_extent->work); return 0; } static int __readpage_endio_check(struct inode *inode, struct btrfs_io_bio *io_bio, int icsum, struct page *page, int pgoff, u64 start, size_t len) { char *kaddr; u32 csum_expected; u32 csum = ~(u32)0; csum_expected = *(((u32 *)io_bio->csum) + icsum); kaddr = kmap_atomic(page); csum = btrfs_csum_data(kaddr + pgoff, csum, len); btrfs_csum_final(csum, (char *)&csum); if (csum != csum_expected) goto zeroit; kunmap_atomic(kaddr); return 0; zeroit: btrfs_warn_rl(BTRFS_I(inode)->root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u", btrfs_ino(inode), start, csum, csum_expected); memset(kaddr + pgoff, 1, len); flush_dcache_page(page); kunmap_atomic(kaddr); if (csum_expected == 0) return 0; return -EIO; } /* * when reads are done, we need to check csums to verify the data is correct * if there's a match, we allow the bio to finish. If not, the code in * extent_io.c will try to find good copies for us. */ static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio, u64 phy_offset, struct page *page, u64 start, u64 end, int mirror) { size_t offset = start - page_offset(page); struct inode *inode = page->mapping->host; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_root *root = BTRFS_I(inode)->root; if (PageChecked(page)) { ClearPageChecked(page); return 0; } if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) return 0; if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM); return 0; } phy_offset >>= inode->i_sb->s_blocksize_bits; return __readpage_endio_check(inode, io_bio, phy_offset, page, offset, start, (size_t)(end - start + 1)); } void btrfs_add_delayed_iput(struct inode *inode) { struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; struct btrfs_inode *binode = BTRFS_I(inode); if (atomic_add_unless(&inode->i_count, -1, 1)) return; spin_lock(&fs_info->delayed_iput_lock); if (binode->delayed_iput_count == 0) { ASSERT(list_empty(&binode->delayed_iput)); list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs); } else { binode->delayed_iput_count++; } spin_unlock(&fs_info->delayed_iput_lock); } void btrfs_run_delayed_iputs(struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; spin_lock(&fs_info->delayed_iput_lock); while (!list_empty(&fs_info->delayed_iputs)) { struct btrfs_inode *inode; inode = list_first_entry(&fs_info->delayed_iputs, struct btrfs_inode, delayed_iput); if (inode->delayed_iput_count) { inode->delayed_iput_count--; list_move_tail(&inode->delayed_iput, &fs_info->delayed_iputs); } else { list_del_init(&inode->delayed_iput); } spin_unlock(&fs_info->delayed_iput_lock); iput(&inode->vfs_inode); spin_lock(&fs_info->delayed_iput_lock); } spin_unlock(&fs_info->delayed_iput_lock); } /* * This is called in transaction commit time. If there are no orphan * files in the subvolume, it removes orphan item and frees block_rsv * structure. */ void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_block_rsv *block_rsv; int ret; if (atomic_read(&root->orphan_inodes) || root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) return; spin_lock(&root->orphan_lock); if (atomic_read(&root->orphan_inodes)) { spin_unlock(&root->orphan_lock); return; } if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) { spin_unlock(&root->orphan_lock); return; } block_rsv = root->orphan_block_rsv; root->orphan_block_rsv = NULL; spin_unlock(&root->orphan_lock); if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) && btrfs_root_refs(&root->root_item) > 0) { ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root, root->root_key.objectid); if (ret) btrfs_abort_transaction(trans, root, ret); else clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state); } if (block_rsv) { WARN_ON(block_rsv->size > 0); btrfs_free_block_rsv(root, block_rsv); } } /* * This creates an orphan entry for the given inode in case something goes * wrong in the middle of an unlink/truncate. * * NOTE: caller of this function should reserve 5 units of metadata for * this function. */ int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_block_rsv *block_rsv = NULL; int reserve = 0; int insert = 0; int ret; if (!root->orphan_block_rsv) { block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); if (!block_rsv) return -ENOMEM; } spin_lock(&root->orphan_lock); if (!root->orphan_block_rsv) { root->orphan_block_rsv = block_rsv; } else if (block_rsv) { btrfs_free_block_rsv(root, block_rsv); block_rsv = NULL; } if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, &BTRFS_I(inode)->runtime_flags)) { #if 0 /* * For proper ENOSPC handling, we should do orphan * cleanup when mounting. But this introduces backward * compatibility issue. */ if (!xchg(&root->orphan_item_inserted, 1)) insert = 2; else insert = 1; #endif insert = 1; atomic_inc(&root->orphan_inodes); } if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED, &BTRFS_I(inode)->runtime_flags)) reserve = 1; spin_unlock(&root->orphan_lock); /* grab metadata reservation from transaction handle */ if (reserve) { ret = btrfs_orphan_reserve_metadata(trans, inode); BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */ } /* insert an orphan item to track this unlinked/truncated file */ if (insert >= 1) { ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode)); if (ret) { atomic_dec(&root->orphan_inodes); if (reserve) { clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, &BTRFS_I(inode)->runtime_flags); btrfs_orphan_release_metadata(inode); } if (ret != -EEXIST) { clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, &BTRFS_I(inode)->runtime_flags); btrfs_abort_transaction(trans, root, ret); return ret; } } ret = 0; } /* insert an orphan item to track subvolume contains orphan files */ if (insert >= 2) { ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root, root->root_key.objectid); if (ret && ret != -EEXIST) { btrfs_abort_transaction(trans, root, ret); return ret; } } return 0; } /* * We have done the truncate/delete so we can go ahead and remove the orphan * item for this particular inode. */ static int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; int delete_item = 0; int release_rsv = 0; int ret = 0; spin_lock(&root->orphan_lock); if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, &BTRFS_I(inode)->runtime_flags)) delete_item = 1; if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED, &BTRFS_I(inode)->runtime_flags)) release_rsv = 1; spin_unlock(&root->orphan_lock); if (delete_item) { atomic_dec(&root->orphan_inodes); if (trans) ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode)); } if (release_rsv) btrfs_orphan_release_metadata(inode); return ret; } /* * this cleans up any orphans that may be left on the list from the last use * of this root. */ int btrfs_orphan_cleanup(struct btrfs_root *root) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_key key, found_key; struct btrfs_trans_handle *trans; struct inode *inode; u64 last_objectid = 0; int ret = 0, nr_unlink = 0, nr_truncate = 0; if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) return 0; path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } path->reada = READA_BACK; key.objectid = BTRFS_ORPHAN_OBJECTID; key.type = BTRFS_ORPHAN_ITEM_KEY; key.offset = (u64)-1; while (1) { ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; /* * if ret == 0 means we found what we were searching for, which * is weird, but possible, so only screw with path if we didn't * find the key and see if we have stuff that matches */ if (ret > 0) { ret = 0; if (path->slots[0] == 0) break; path->slots[0]--; } /* pull out the item */ leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); /* make sure the item matches what we want */ if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) break; if (found_key.type != BTRFS_ORPHAN_ITEM_KEY) break; /* release the path since we're done with it */ btrfs_release_path(path); /* * this is where we are basically btrfs_lookup, without the * crossing root thing. we store the inode number in the * offset of the orphan item. */ if (found_key.offset == last_objectid) { btrfs_err(root->fs_info, "Error removing orphan entry, stopping orphan cleanup"); ret = -EINVAL; goto out; } last_objectid = found_key.offset; found_key.objectid = found_key.offset; found_key.type = BTRFS_INODE_ITEM_KEY; found_key.offset = 0; inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL); ret = PTR_ERR_OR_ZERO(inode); if (ret && ret != -ESTALE) goto out; if (ret == -ESTALE && root == root->fs_info->tree_root) { struct btrfs_root *dead_root; struct btrfs_fs_info *fs_info = root->fs_info; int is_dead_root = 0; /* * this is an orphan in the tree root. Currently these * could come from 2 sources: * a) a snapshot deletion in progress * b) a free space cache inode * We need to distinguish those two, as the snapshot * orphan must not get deleted. * find_dead_roots already ran before us, so if this * is a snapshot deletion, we should find the root * in the dead_roots list */ spin_lock(&fs_info->trans_lock); list_for_each_entry(dead_root, &fs_info->dead_roots, root_list) { if (dead_root->root_key.objectid == found_key.objectid) { is_dead_root = 1; break; } } spin_unlock(&fs_info->trans_lock); if (is_dead_root) { /* prevent this orphan from being found again */ key.offset = found_key.objectid - 1; continue; } } /* * Inode is already gone but the orphan item is still there, * kill the orphan item. */ if (ret == -ESTALE) { trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out; } btrfs_debug(root->fs_info, "auto deleting %Lu", found_key.objectid); ret = btrfs_del_orphan_item(trans, root, found_key.objectid); btrfs_end_transaction(trans, root); if (ret) goto out; continue; } /* * add this inode to the orphan list so btrfs_orphan_del does * the proper thing when we hit it */ set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, &BTRFS_I(inode)->runtime_flags); atomic_inc(&root->orphan_inodes); /* if we have links, this was a truncate, lets do that */ if (inode->i_nlink) { if (WARN_ON(!S_ISREG(inode->i_mode))) { iput(inode); continue; } nr_truncate++; /* 1 for the orphan item deletion. */ trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { iput(inode); ret = PTR_ERR(trans); goto out; } ret = btrfs_orphan_add(trans, inode); btrfs_end_transaction(trans, root); if (ret) { iput(inode); goto out; } ret = btrfs_truncate(inode); if (ret) btrfs_orphan_del(NULL, inode); } else { nr_unlink++; } /* this will do delete_inode and everything for us */ iput(inode); if (ret) goto out; } /* release the path since we're done with it */ btrfs_release_path(path); root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; if (root->orphan_block_rsv) btrfs_block_rsv_release(root, root->orphan_block_rsv, (u64)-1); if (root->orphan_block_rsv || test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) { trans = btrfs_join_transaction(root); if (!IS_ERR(trans)) btrfs_end_transaction(trans, root); } if (nr_unlink) btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink); if (nr_truncate) btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate); out: if (ret) btrfs_err(root->fs_info, "could not do orphan cleanup %d", ret); btrfs_free_path(path); return ret; } /* * very simple check to peek ahead in the leaf looking for xattrs. If we * don't find any xattrs, we know there can't be any acls. * * slot is the slot the inode is in, objectid is the objectid of the inode */ static noinline int acls_after_inode_item(struct extent_buffer *leaf, int slot, u64 objectid, int *first_xattr_slot) { u32 nritems = btrfs_header_nritems(leaf); struct btrfs_key found_key; static u64 xattr_access = 0; static u64 xattr_default = 0; int scanned = 0; if (!xattr_access) { xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS, strlen(XATTR_NAME_POSIX_ACL_ACCESS)); xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT, strlen(XATTR_NAME_POSIX_ACL_DEFAULT)); } slot++; *first_xattr_slot = -1; while (slot < nritems) { btrfs_item_key_to_cpu(leaf, &found_key, slot); /* we found a different objectid, there must not be acls */ if (found_key.objectid != objectid) return 0; /* we found an xattr, assume we've got an acl */ if (found_key.type == BTRFS_XATTR_ITEM_KEY) { if (*first_xattr_slot == -1) *first_xattr_slot = slot; if (found_key.offset == xattr_access || found_key.offset == xattr_default) return 1; } /* * we found a key greater than an xattr key, there can't * be any acls later on */ if (found_key.type > BTRFS_XATTR_ITEM_KEY) return 0; slot++; scanned++; /* * it goes inode, inode backrefs, xattrs, extents, * so if there are a ton of hard links to an inode there can * be a lot of backrefs. Don't waste time searching too hard, * this is just an optimization */ if (scanned >= 8) break; } /* we hit the end of the leaf before we found an xattr or * something larger than an xattr. We have to assume the inode * has acls */ if (*first_xattr_slot == -1) *first_xattr_slot = slot; return 1; } /* * read an inode from the btree into the in-memory inode */ static void btrfs_read_locked_inode(struct inode *inode) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_inode_item *inode_item; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_key location; unsigned long ptr; int maybe_acls; u32 rdev; int ret; bool filled = false; int first_xattr_slot; ret = btrfs_fill_inode(inode, &rdev); if (!ret) filled = true; path = btrfs_alloc_path(); if (!path) goto make_bad; memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); ret = btrfs_lookup_inode(NULL, root, path, &location, 0); if (ret) goto make_bad; leaf = path->nodes[0]; if (filled) goto cache_index; inode_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); inode->i_mode = btrfs_inode_mode(leaf, inode_item); set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item)); inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime); inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime); inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime); inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime); inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime); inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime); BTRFS_I(inode)->i_otime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->otime); BTRFS_I(inode)->i_otime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->otime); inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); inode->i_version = btrfs_inode_sequence(leaf, inode_item); inode->i_generation = BTRFS_I(inode)->generation; inode->i_rdev = 0; rdev = btrfs_inode_rdev(leaf, inode_item); BTRFS_I(inode)->index_cnt = (u64)-1; BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); cache_index: /* * If we were modified in the current generation and evicted from memory * and then re-read we need to do a full sync since we don't have any * idea about which extents were modified before we were evicted from * cache. * * This is required for both inode re-read from disk and delayed inode * in delayed_nodes_tree. */ if (BTRFS_I(inode)->last_trans == root->fs_info->generation) set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); /* * We don't persist the id of the transaction where an unlink operation * against the inode was last made. So here we assume the inode might * have been evicted, and therefore the exact value of last_unlink_trans * lost, and set it to last_trans to avoid metadata inconsistencies * between the inode and its parent if the inode is fsync'ed and the log * replayed. For example, in the scenario: * * touch mydir/foo * ln mydir/foo mydir/bar * sync * unlink mydir/bar * echo 2 > /proc/sys/vm/drop_caches # evicts inode * xfs_io -c fsync mydir/foo * <power failure> * mount fs, triggers fsync log replay * * We must make sure that when we fsync our inode foo we also log its * parent inode, otherwise after log replay the parent still has the * dentry with the "bar" name but our inode foo has a link count of 1 * and doesn't have an inode ref with the name "bar" anymore. * * Setting last_unlink_trans to last_trans is a pessimistic approach, * but it guarantees correctness at the expense of occasional full * transaction commits on fsync if our inode is a directory, or if our * inode is not a directory, logging its parent unnecessarily. */ BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans; path->slots[0]++; if (inode->i_nlink != 1 || path->slots[0] >= btrfs_header_nritems(leaf)) goto cache_acl; btrfs_item_key_to_cpu(leaf, &location, path->slots[0]); if (location.objectid != btrfs_ino(inode)) goto cache_acl; ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); if (location.type == BTRFS_INODE_REF_KEY) { struct btrfs_inode_ref *ref; ref = (struct btrfs_inode_ref *)ptr; BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref); } else if (location.type == BTRFS_INODE_EXTREF_KEY) { struct btrfs_inode_extref *extref; extref = (struct btrfs_inode_extref *)ptr; BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf, extref); } cache_acl: /* * try to precache a NULL acl entry for files that don't have * any xattrs or acls */ maybe_acls = acls_after_inode_item(leaf, path->slots[0], btrfs_ino(inode), &first_xattr_slot); if (first_xattr_slot != -1) { path->slots[0] = first_xattr_slot; ret = btrfs_load_inode_props(inode, path); if (ret) btrfs_err(root->fs_info, "error loading props for ino %llu (root %llu): %d", btrfs_ino(inode), root->root_key.objectid, ret); } btrfs_free_path(path); if (!maybe_acls) cache_no_acl(inode); switch (inode->i_mode & S_IFMT) { case S_IFREG: inode->i_mapping->a_ops = &btrfs_aops; BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; inode->i_fop = &btrfs_file_operations; inode->i_op = &btrfs_file_inode_operations; break; case S_IFDIR: inode->i_fop = &btrfs_dir_file_operations; if (root == root->fs_info->tree_root) inode->i_op = &btrfs_dir_ro_inode_operations; else inode->i_op = &btrfs_dir_inode_operations; break; case S_IFLNK: inode->i_op = &btrfs_symlink_inode_operations; inode_nohighmem(inode); inode->i_mapping->a_ops = &btrfs_symlink_aops; break; default: inode->i_op = &btrfs_special_inode_operations; init_special_inode(inode, inode->i_mode, rdev); break; } btrfs_update_iflags(inode); return; make_bad: btrfs_free_path(path); make_bad_inode(inode); } /* * given a leaf and an inode, copy the inode fields into the leaf */ static void fill_inode_item(struct btrfs_trans_handle *trans, struct extent_buffer *leaf, struct btrfs_inode_item *item, struct inode *inode) { struct btrfs_map_token token; btrfs_init_map_token(&token); btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token); btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token); btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size, &token); btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token); btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token); btrfs_set_token_timespec_sec(leaf, &item->atime, inode->i_atime.tv_sec, &token); btrfs_set_token_timespec_nsec(leaf, &item->atime, inode->i_atime.tv_nsec, &token); btrfs_set_token_timespec_sec(leaf, &item->mtime, inode->i_mtime.tv_sec, &token); btrfs_set_token_timespec_nsec(leaf, &item->mtime, inode->i_mtime.tv_nsec, &token); btrfs_set_token_timespec_sec(leaf, &item->ctime, inode->i_ctime.tv_sec, &token); btrfs_set_token_timespec_nsec(leaf, &item->ctime, inode->i_ctime.tv_nsec, &token); btrfs_set_token_timespec_sec(leaf, &item->otime, BTRFS_I(inode)->i_otime.tv_sec, &token); btrfs_set_token_timespec_nsec(leaf, &item->otime, BTRFS_I(inode)->i_otime.tv_nsec, &token); btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode), &token); btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation, &token); btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token); btrfs_set_token_inode_transid(leaf, item, trans->transid, &token); btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token); btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token); btrfs_set_token_inode_block_group(leaf, item, 0, &token); } /* * copy everything in the in-memory inode into the btree. */ static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode) { struct btrfs_inode_item *inode_item; struct btrfs_path *path; struct extent_buffer *leaf; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->leave_spinning = 1; ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, 1); if (ret) { if (ret > 0) ret = -ENOENT; goto failed; } leaf = path->nodes[0]; inode_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); fill_inode_item(trans, leaf, inode_item, inode); btrfs_mark_buffer_dirty(leaf); btrfs_set_inode_last_trans(trans, inode); ret = 0; failed: btrfs_free_path(path); return ret; } /* * copy everything in the in-memory inode into the btree. */ noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode) { int ret; /* * If the inode is a free space inode, we can deadlock during commit * if we put it into the delayed code. * * The data relocation inode should also be directly updated * without delay */ if (!btrfs_is_free_space_inode(inode) && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID && !root->fs_info->log_root_recovering) { btrfs_update_root_times(trans, root); ret = btrfs_delayed_update_inode(trans, root, inode); if (!ret) btrfs_set_inode_last_trans(trans, inode); return ret; } return btrfs_update_inode_item(trans, root, inode); } noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode) { int ret; ret = btrfs_update_inode(trans, root, inode); if (ret == -ENOSPC) return btrfs_update_inode_item(trans, root, inode); return ret; } /* * unlink helper that gets used here in inode.c and in the tree logging * recovery code. It remove a link in a directory with a given name, and * also drops the back refs in the inode to the directory */ static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *dir, struct inode *inode, const char *name, int name_len) { struct btrfs_path *path; int ret = 0; struct extent_buffer *leaf; struct btrfs_dir_item *di; struct btrfs_key key; u64 index; u64 ino = btrfs_ino(inode); u64 dir_ino = btrfs_ino(dir); path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } path->leave_spinning = 1; di = btrfs_lookup_dir_item(trans, root, path, dir_ino, name, name_len, -1); if (IS_ERR(di)) { ret = PTR_ERR(di); goto err; } if (!di) { ret = -ENOENT; goto err; } leaf = path->nodes[0]; btrfs_dir_item_key_to_cpu(leaf, di, &key); ret = btrfs_delete_one_dir_name(trans, root, path, di); if (ret) goto err; btrfs_release_path(path); /* * If we don't have dir index, we have to get it by looking up * the inode ref, since we get the inode ref, remove it directly, * it is unnecessary to do delayed deletion. * * But if we have dir index, needn't search inode ref to get it. * Since the inode ref is close to the inode item, it is better * that we delay to delete it, and just do this deletion when * we update the inode item. */ if (BTRFS_I(inode)->dir_index) { ret = btrfs_delayed_delete_inode_ref(inode); if (!ret) { index = BTRFS_I(inode)->dir_index; goto skip_backref; } } ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, dir_ino, &index); if (ret) { btrfs_info(root->fs_info, "failed to delete reference to %.*s, inode %llu parent %llu", name_len, name, ino, dir_ino); btrfs_abort_transaction(trans, root, ret); goto err; } skip_backref: ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); if (ret) { btrfs_abort_transaction(trans, root, ret); goto err; } ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode, dir_ino); if (ret != 0 && ret != -ENOENT) { btrfs_abort_transaction(trans, root, ret); goto err; } ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir, index); if (ret == -ENOENT) ret = 0; else if (ret) btrfs_abort_transaction(trans, root, ret); err: btrfs_free_path(path); if (ret) goto out; btrfs_i_size_write(dir, dir->i_size - name_len * 2); inode_inc_iversion(inode); inode_inc_iversion(dir); inode->i_ctime = dir->i_mtime = dir->i_ctime = current_fs_time(inode->i_sb); ret = btrfs_update_inode(trans, root, dir); out: return ret; } int btrfs_unlink_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *dir, struct inode *inode, const char *name, int name_len) { int ret; ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); if (!ret) { drop_nlink(inode); ret = btrfs_update_inode(trans, root, inode); } return ret; } /* * helper to start transaction for unlink and rmdir. * * unlink and rmdir are special in btrfs, they do not always free space, so * if we cannot make our reservations the normal way try and see if there is * plenty of slack room in the global reserve to migrate, otherwise we cannot * allow the unlink to occur. */ static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir) { struct btrfs_root *root = BTRFS_I(dir)->root; /* * 1 for the possible orphan item * 1 for the dir item * 1 for the dir index * 1 for the inode ref * 1 for the inode */ return btrfs_start_transaction_fallback_global_rsv(root, 5, 5); } static int btrfs_unlink(struct inode *dir, struct dentry *dentry) { struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_trans_handle *trans; struct inode *inode = d_inode(dentry); int ret; trans = __unlink_start_trans(dir); if (IS_ERR(trans)) return PTR_ERR(trans); btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0); ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry), dentry->d_name.name, dentry->d_name.len); if (ret) goto out; if (inode->i_nlink == 0) { ret = btrfs_orphan_add(trans, inode); if (ret) goto out; } out: btrfs_end_transaction(trans, root); btrfs_btree_balance_dirty(root); return ret; } int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *dir, u64 objectid, const char *name, int name_len) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_dir_item *di; struct btrfs_key key; u64 index; int ret; u64 dir_ino = btrfs_ino(dir); path = btrfs_alloc_path(); if (!path) return -ENOMEM; di = btrfs_lookup_dir_item(trans, root, path, dir_ino, name, name_len, -1); if (IS_ERR_OR_NULL(di)) { if (!di) ret = -ENOENT; else ret = PTR_ERR(di); goto out; } leaf = path->nodes[0]; btrfs_dir_item_key_to_cpu(leaf, di, &key); WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); ret = btrfs_delete_one_dir_name(trans, root, path, di); if (ret) { btrfs_abort_transaction(trans, root, ret); goto out; } btrfs_release_path(path); ret = btrfs_del_root_ref(trans, root->fs_info->tree_root, objectid, root->root_key.objectid, dir_ino, &index, name, name_len); if (ret < 0) { if (ret != -ENOENT) { btrfs_abort_transaction(trans, root, ret); goto out; } di = btrfs_search_dir_index_item(root, path, dir_ino, name, name_len); if (IS_ERR_OR_NULL(di)) { if (!di) ret = -ENOENT; else ret = PTR_ERR(di); btrfs_abort_transaction(trans, root, ret); goto out; } leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); btrfs_release_path(path); index = key.offset; } btrfs_release_path(path); ret = btrfs_delete_delayed_dir_index(trans, root, dir, index); if (ret) { btrfs_abort_transaction(trans, root, ret); goto out; } btrfs_i_size_write(dir, dir->i_size - name_len * 2); inode_inc_iversion(dir); dir->i_mtime = dir->i_ctime = current_fs_time(dir->i_sb); ret = btrfs_update_inode_fallback(trans, root, dir); if (ret) btrfs_abort_transaction(trans, root, ret); out: btrfs_free_path(path); return ret; } static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) { struct inode *inode = d_inode(dentry); int err = 0; struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_trans_handle *trans; if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) return -ENOTEMPTY; if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) return -EPERM; trans = __unlink_start_trans(dir); if (IS_ERR(trans)) return PTR_ERR(trans); if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { err = btrfs_unlink_subvol(trans, root, dir, BTRFS_I(inode)->location.objectid, dentry->d_name.name, dentry->d_name.len); goto out; } err = btrfs_orphan_add(trans, inode); if (err) goto out; /* now the directory is empty */ err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry), dentry->d_name.name, dentry->d_name.len); if (!err) btrfs_i_size_write(inode, 0); out: btrfs_end_transaction(trans, root); btrfs_btree_balance_dirty(root); return err; } static int truncate_space_check(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytes_deleted) { int ret; /* * This is only used to apply pressure to the enospc system, we don't * intend to use this reservation at all. */ bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted); bytes_deleted *= root->nodesize; ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv, bytes_deleted, BTRFS_RESERVE_NO_FLUSH); if (!ret) { trace_btrfs_space_reservation(root->fs_info, "transaction", trans->transid, bytes_deleted, 1); trans->bytes_reserved += bytes_deleted; } return ret; } static int truncate_inline_extent(struct inode *inode, struct btrfs_path *path, struct btrfs_key *found_key, const u64 item_end, const u64 new_size) { struct extent_buffer *leaf = path->nodes[0]; int slot = path->slots[0]; struct btrfs_file_extent_item *fi; u32 size = (u32)(new_size - found_key->offset); struct btrfs_root *root = BTRFS_I(inode)->root; fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) { loff_t offset = new_size; loff_t page_end = ALIGN(offset, PAGE_SIZE); /* * Zero out the remaining of the last page of our inline extent, * instead of directly truncating our inline extent here - that * would be much more complex (decompressing all the data, then * compressing the truncated data, which might be bigger than * the size of the inline extent, resize the extent, etc). * We release the path because to get the page we might need to * read the extent item from disk (data not in the page cache). */ btrfs_release_path(path); return btrfs_truncate_block(inode, offset, page_end - offset, 0); } btrfs_set_file_extent_ram_bytes(leaf, fi, size); size = btrfs_file_extent_calc_inline_size(size); btrfs_truncate_item(root, path, size, 1); if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) inode_sub_bytes(inode, item_end + 1 - new_size); return 0; } /* * this can truncate away extent items, csum items and directory items. * It starts at a high offset and removes keys until it can't find * any higher than new_size * * csum items that cross the new i_size are truncated to the new size * as well. * * min_type is the minimum key type to truncate down to. If set to 0, this * will kill all the items on this inode, including the INODE_ITEM_KEY. */ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode, u64 new_size, u32 min_type) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_file_extent_item *fi; struct btrfs_key key; struct btrfs_key found_key; u64 extent_start = 0; u64 extent_num_bytes = 0; u64 extent_offset = 0; u64 item_end = 0; u64 last_size = new_size; u32 found_type = (u8)-1; int found_extent; int del_item; int pending_del_nr = 0; int pending_del_slot = 0; int extent_type = -1; int ret; int err = 0; u64 ino = btrfs_ino(inode); u64 bytes_deleted = 0; bool be_nice = 0; bool should_throttle = 0; bool should_end = 0; BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); /* * for non-free space inodes and ref cows, we want to back off from * time to time */ if (!btrfs_is_free_space_inode(inode) && test_bit(BTRFS_ROOT_REF_COWS, &root->state)) be_nice = 1; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = READA_BACK; /* * We want to drop from the next block forward in case this new size is * not block aligned since we will be keeping the last block of the * extent just the way it is. */ if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || root == root->fs_info->tree_root) btrfs_drop_extent_cache(inode, ALIGN(new_size, root->sectorsize), (u64)-1, 0); /* * This function is also used to drop the items in the log tree before * we relog the inode, so if root != BTRFS_I(inode)->root, it means * it is used to drop the loged items. So we shouldn't kill the delayed * items. */ if (min_type == 0 && root == BTRFS_I(inode)->root) btrfs_kill_delayed_inode_items(inode); key.objectid = ino; key.offset = (u64)-1; key.type = (u8)-1; search_again: /* * with a 16K leaf size and 128MB extents, you can actually queue * up a huge file in a single leaf. Most of the time that * bytes_deleted is > 0, it will be huge by the time we get here */ if (be_nice && bytes_deleted > SZ_32M) { if (btrfs_should_end_transaction(trans, root)) { err = -EAGAIN; goto error; } } path->leave_spinning = 1; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) { err = ret; goto out; } if (ret > 0) { /* there are no items in the tree for us to truncate, we're * done */ if (path->slots[0] == 0) goto out; path->slots[0]--; } while (1) { fi = NULL; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); found_type = found_key.type; if (found_key.objectid != ino) break; if (found_type < min_type) break; item_end = found_key.offset; if (found_type == BTRFS_EXTENT_DATA_KEY) { fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_type = btrfs_file_extent_type(leaf, fi); if (extent_type != BTRFS_FILE_EXTENT_INLINE) { item_end += btrfs_file_extent_num_bytes(leaf, fi); } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { item_end += btrfs_file_extent_inline_len(leaf, path->slots[0], fi); } item_end--; } if (found_type > min_type) { del_item = 1; } else { if (item_end < new_size) break; if (found_key.offset >= new_size) del_item = 1; else del_item = 0; } found_extent = 0; /* FIXME, shrink the extent if the ref count is only 1 */ if (found_type != BTRFS_EXTENT_DATA_KEY) goto delete; if (del_item) last_size = found_key.offset; else last_size = new_size; if (extent_type != BTRFS_FILE_EXTENT_INLINE) { u64 num_dec; extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); if (!del_item) { u64 orig_num_bytes = btrfs_file_extent_num_bytes(leaf, fi); extent_num_bytes = ALIGN(new_size - found_key.offset, root->sectorsize); btrfs_set_file_extent_num_bytes(leaf, fi, extent_num_bytes); num_dec = (orig_num_bytes - extent_num_bytes); if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && extent_start != 0) inode_sub_bytes(inode, num_dec); btrfs_mark_buffer_dirty(leaf); } else { extent_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); extent_offset = found_key.offset - btrfs_file_extent_offset(leaf, fi); /* FIXME blocksize != 4096 */ num_dec = btrfs_file_extent_num_bytes(leaf, fi); if (extent_start != 0) { found_extent = 1; if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) inode_sub_bytes(inode, num_dec); } } } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { /* * we can't truncate inline items that have had * special encodings */ if (!del_item && btrfs_file_extent_encryption(leaf, fi) == 0 && btrfs_file_extent_other_encoding(leaf, fi) == 0) { /* * Need to release path in order to truncate a * compressed extent. So delete any accumulated * extent items so far. */ if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE && pending_del_nr) { err = btrfs_del_items(trans, root, path, pending_del_slot, pending_del_nr); if (err) { btrfs_abort_transaction(trans, root, err); goto error; } pending_del_nr = 0; } err = truncate_inline_extent(inode, path, &found_key, item_end, new_size); if (err) { btrfs_abort_transaction(trans, root, err); goto error; } } else if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) { inode_sub_bytes(inode, item_end + 1 - new_size); } } delete: if (del_item) { if (!pending_del_nr) { /* no pending yet, add ourselves */ pending_del_slot = path->slots[0]; pending_del_nr = 1; } else if (pending_del_nr && path->slots[0] + 1 == pending_del_slot) { /* hop on the pending chunk */ pending_del_nr++; pending_del_slot = path->slots[0]; } else { BUG(); } } else { break; } should_throttle = 0; if (found_extent && (test_bit(BTRFS_ROOT_REF_COWS, &root->state) || root == root->fs_info->tree_root)) { btrfs_set_path_blocking(path); bytes_deleted += extent_num_bytes; ret = btrfs_free_extent(trans, root, extent_start, extent_num_bytes, 0, btrfs_header_owner(leaf), ino, extent_offset); BUG_ON(ret); if (btrfs_should_throttle_delayed_refs(trans, root)) btrfs_async_run_delayed_refs(root, trans->delayed_ref_updates * 2, 0); if (be_nice) { if (truncate_space_check(trans, root, extent_num_bytes)) { should_end = 1; } if (btrfs_should_throttle_delayed_refs(trans, root)) { should_throttle = 1; } } } if (found_type == BTRFS_INODE_ITEM_KEY) break; if (path->slots[0] == 0 || path->slots[0] != pending_del_slot || should_throttle || should_end) { if (pending_del_nr) { ret = btrfs_del_items(trans, root, path, pending_del_slot, pending_del_nr); if (ret) { btrfs_abort_transaction(trans, root, ret); goto error; } pending_del_nr = 0; } btrfs_release_path(path); if (should_throttle) { unsigned long updates = trans->delayed_ref_updates; if (updates) { trans->delayed_ref_updates = 0; ret = btrfs_run_delayed_refs(trans, root, updates * 2); if (ret && !err) err = ret; } } /* * if we failed to refill our space rsv, bail out * and let the transaction restart */ if (should_end) { err = -EAGAIN; goto error; } goto search_again; } else { path->slots[0]--; } } out: if (pending_del_nr) { ret = btrfs_del_items(trans, root, path, pending_del_slot, pending_del_nr); if (ret) btrfs_abort_transaction(trans, root, ret); } error: if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) btrfs_ordered_update_i_size(inode, last_size, NULL); btrfs_free_path(path); if (be_nice && bytes_deleted > SZ_32M) { unsigned long updates = trans->delayed_ref_updates; if (updates) { trans->delayed_ref_updates = 0; ret = btrfs_run_delayed_refs(trans, root, updates * 2); if (ret && !err) err = ret; } } return err; } /* * btrfs_truncate_block - read, zero a chunk and write a block * @inode - inode that we're zeroing * @from - the offset to start zeroing * @len - the length to zero, 0 to zero the entire range respective to the * offset * @front - zero up to the offset instead of from the offset on * * This will find the block for the "from" offset and cow the block and zero the * part we want to zero. This is used with truncate and hole punching. */ int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len, int front) { struct address_space *mapping = inode->i_mapping; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; char *kaddr; u32 blocksize = root->sectorsize; pgoff_t index = from >> PAGE_SHIFT; unsigned offset = from & (blocksize - 1); struct page *page; gfp_t mask = btrfs_alloc_write_mask(mapping); int ret = 0; u64 block_start; u64 block_end; if ((offset & (blocksize - 1)) == 0 && (!len || ((len & (blocksize - 1)) == 0))) goto out; ret = btrfs_delalloc_reserve_space(inode, round_down(from, blocksize), blocksize); if (ret) goto out; again: page = find_or_create_page(mapping, index, mask); if (!page) { btrfs_delalloc_release_space(inode, round_down(from, blocksize), blocksize); ret = -ENOMEM; goto out; } block_start = round_down(from, blocksize); block_end = block_start + blocksize - 1; if (!PageUptodate(page)) { ret = btrfs_readpage(NULL, page); lock_page(page); if (page->mapping != mapping) { unlock_page(page); put_page(page); goto again; } if (!PageUptodate(page)) { ret = -EIO; goto out_unlock; } } wait_on_page_writeback(page); lock_extent_bits(io_tree, block_start, block_end, &cached_state); set_page_extent_mapped(page); ordered = btrfs_lookup_ordered_extent(inode, block_start); if (ordered) { unlock_extent_cached(io_tree, block_start, block_end, &cached_state, GFP_NOFS); unlock_page(page); put_page(page); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); goto again; } clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end, EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); ret = btrfs_set_extent_delalloc(inode, block_start, block_end, &cached_state); if (ret) { unlock_extent_cached(io_tree, block_start, block_end, &cached_state, GFP_NOFS); goto out_unlock; } if (offset != blocksize) { if (!len) len = blocksize - offset; kaddr = kmap(page); if (front) memset(kaddr + (block_start - page_offset(page)), 0, offset); else memset(kaddr + (block_start - page_offset(page)) + offset, 0, len); flush_dcache_page(page); kunmap(page); } ClearPageChecked(page); set_page_dirty(page); unlock_extent_cached(io_tree, block_start, block_end, &cached_state, GFP_NOFS); out_unlock: if (ret) btrfs_delalloc_release_space(inode, block_start, blocksize); unlock_page(page); put_page(page); out: return ret; } static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode, u64 offset, u64 len) { struct btrfs_trans_handle *trans; int ret; /* * Still need to make sure the inode looks like it's been updated so * that any holes get logged if we fsync. */ if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) { BTRFS_I(inode)->last_trans = root->fs_info->generation; BTRFS_I(inode)->last_sub_trans = root->log_transid; BTRFS_I(inode)->last_log_commit = root->last_log_commit; return 0; } /* * 1 - for the one we're dropping * 1 - for the one we're adding * 1 - for updating the inode. */ trans = btrfs_start_transaction(root, 3); if (IS_ERR(trans)) return PTR_ERR(trans); ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1); if (ret) { btrfs_abort_transaction(trans, root, ret); btrfs_end_transaction(trans, root); return ret; } ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset, 0, 0, len, 0, len, 0, 0, 0); if (ret) btrfs_abort_transaction(trans, root, ret); else btrfs_update_inode(trans, root, inode); btrfs_end_transaction(trans, root); return ret; } /* * This function puts in dummy file extents for the area we're creating a hole * for. So if we are truncating this file to a larger size we need to insert * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for * the range between oldsize and size */ int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) { struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct extent_map *em = NULL; struct extent_state *cached_state = NULL; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; u64 hole_start = ALIGN(oldsize, root->sectorsize); u64 block_end = ALIGN(size, root->sectorsize); u64 last_byte; u64 cur_offset; u64 hole_size; int err = 0; /* * If our size started in the middle of a block we need to zero out the * rest of the block before we expand the i_size, otherwise we could * expose stale data. */ err = btrfs_truncate_block(inode, oldsize, 0, 0); if (err) return err; if (size <= hole_start) return 0; while (1) { struct btrfs_ordered_extent *ordered; lock_extent_bits(io_tree, hole_start, block_end - 1, &cached_state); ordered = btrfs_lookup_ordered_range(inode, hole_start, block_end - hole_start); if (!ordered) break; unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, GFP_NOFS); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); } cur_offset = hole_start; while (1) { em = btrfs_get_extent(inode, NULL, 0, cur_offset, block_end - cur_offset, 0); if (IS_ERR(em)) { err = PTR_ERR(em); em = NULL; break; } last_byte = min(extent_map_end(em), block_end); last_byte = ALIGN(last_byte , root->sectorsize); if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { struct extent_map *hole_em; hole_size = last_byte - cur_offset; err = maybe_insert_hole(root, inode, cur_offset, hole_size); if (err) break; btrfs_drop_extent_cache(inode, cur_offset, cur_offset + hole_size - 1, 0); hole_em = alloc_extent_map(); if (!hole_em) { set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); goto next; } hole_em->start = cur_offset; hole_em->len = hole_size; hole_em->orig_start = cur_offset; hole_em->block_start = EXTENT_MAP_HOLE; hole_em->block_len = 0; hole_em->orig_block_len = 0; hole_em->ram_bytes = hole_size; hole_em->bdev = root->fs_info->fs_devices->latest_bdev; hole_em->compress_type = BTRFS_COMPRESS_NONE; hole_em->generation = root->fs_info->generation; while (1) { write_lock(&em_tree->lock); err = add_extent_mapping(em_tree, hole_em, 1); write_unlock(&em_tree->lock); if (err != -EEXIST) break; btrfs_drop_extent_cache(inode, cur_offset, cur_offset + hole_size - 1, 0); } free_extent_map(hole_em); } next: free_extent_map(em); em = NULL; cur_offset = last_byte; if (cur_offset >= block_end) break; } free_extent_map(em); unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state, GFP_NOFS); return err; } static int btrfs_setsize(struct inode *inode, struct iattr *attr) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; loff_t oldsize = i_size_read(inode); loff_t newsize = attr->ia_size; int mask = attr->ia_valid; int ret; /* * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a * special case where we need to update the times despite not having * these flags set. For all other operations the VFS set these flags * explicitly if it wants a timestamp update. */ if (newsize != oldsize) { inode_inc_iversion(inode); if (!(mask & (ATTR_CTIME | ATTR_MTIME))) inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb); } if (newsize > oldsize) { /* * Don't do an expanding truncate while snapshoting is ongoing. * This is to ensure the snapshot captures a fully consistent * state of this file - if the snapshot captures this expanding * truncation, it must capture all writes that happened before * this truncation. */ btrfs_wait_for_snapshot_creation(root); ret = btrfs_cont_expand(inode, oldsize, newsize); if (ret) { btrfs_end_write_no_snapshoting(root); return ret; } trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { btrfs_end_write_no_snapshoting(root); return PTR_ERR(trans); } i_size_write(inode, newsize); btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL); pagecache_isize_extended(inode, oldsize, newsize); ret = btrfs_update_inode(trans, root, inode); btrfs_end_write_no_snapshoting(root); btrfs_end_transaction(trans, root); } else { /* * We're truncating a file that used to have good data down to * zero. Make sure it gets into the ordered flush list so that * any new writes get down to disk quickly. */ if (newsize == 0) set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, &BTRFS_I(inode)->runtime_flags); /* * 1 for the orphan item we're going to add * 1 for the orphan item deletion. */ trans = btrfs_start_transaction(root, 2); if (IS_ERR(trans)) return PTR_ERR(trans); /* * We need to do this in case we fail at _any_ point during the * actual truncate. Once we do the truncate_setsize we could * invalidate pages which forces any outstanding ordered io to * be instantly completed which will give us extents that need * to be truncated. If we fail to get an orphan inode down we * could have left over extents that were never meant to live, * so we need to guarantee from this point on that everything * will be consistent. */ ret = btrfs_orphan_add(trans, inode); btrfs_end_transaction(trans, root); if (ret) return ret; /* we don't support swapfiles, so vmtruncate shouldn't fail */ truncate_setsize(inode, newsize); /* Disable nonlocked read DIO to avoid the end less truncate */ btrfs_inode_block_unlocked_dio(inode); inode_dio_wait(inode); btrfs_inode_resume_unlocked_dio(inode); ret = btrfs_truncate(inode); if (ret && inode->i_nlink) { int err; /* * failed to truncate, disk_i_size is only adjusted down * as we remove extents, so it should represent the true * size of the inode, so reset the in memory size and * delete our orphan entry. */ trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { btrfs_orphan_del(NULL, inode); return ret; } i_size_write(inode, BTRFS_I(inode)->disk_i_size); err = btrfs_orphan_del(trans, inode); if (err) btrfs_abort_transaction(trans, root, err); btrfs_end_transaction(trans, root); } } return ret; } static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) { struct inode *inode = d_inode(dentry); struct btrfs_root *root = BTRFS_I(inode)->root; int err; if (btrfs_root_readonly(root)) return -EROFS; err = inode_change_ok(inode, attr); if (err) return err; if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { err = btrfs_setsize(inode, attr); if (err) return err; } if (attr->ia_valid) { setattr_copy(inode, attr); inode_inc_iversion(inode); err = btrfs_dirty_inode(inode); if (!err && attr->ia_valid & ATTR_MODE) err = posix_acl_chmod(inode, inode->i_mode); } return err; } /* * While truncating the inode pages during eviction, we get the VFS calling * btrfs_invalidatepage() against each page of the inode. This is slow because * the calls to btrfs_invalidatepage() result in a huge amount of calls to * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting * extent_state structures over and over, wasting lots of time. * * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all * those expensive operations on a per page basis and do only the ordered io * finishing, while we release here the extent_map and extent_state structures, * without the excessive merging and splitting. */ static void evict_inode_truncate_pages(struct inode *inode) { struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree; struct rb_node *node; ASSERT(inode->i_state & I_FREEING); truncate_inode_pages_final(&inode->i_data); write_lock(&map_tree->lock); while (!RB_EMPTY_ROOT(&map_tree->map)) { struct extent_map *em; node = rb_first(&map_tree->map); em = rb_entry(node, struct extent_map, rb_node); clear_bit(EXTENT_FLAG_PINNED, &em->flags); clear_bit(EXTENT_FLAG_LOGGING, &em->flags); remove_extent_mapping(map_tree, em); free_extent_map(em); if (need_resched()) { write_unlock(&map_tree->lock); cond_resched(); write_lock(&map_tree->lock); } } write_unlock(&map_tree->lock); /* * Keep looping until we have no more ranges in the io tree. * We can have ongoing bios started by readpages (called from readahead) * that have their endio callback (extent_io.c:end_bio_extent_readpage) * still in progress (unlocked the pages in the bio but did not yet * unlocked the ranges in the io tree). Therefore this means some * ranges can still be locked and eviction started because before * submitting those bios, which are executed by a separate task (work * queue kthread), inode references (inode->i_count) were not taken * (which would be dropped in the end io callback of each bio). * Therefore here we effectively end up waiting for those bios and * anyone else holding locked ranges without having bumped the inode's * reference count - if we don't do it, when they access the inode's * io_tree to unlock a range it may be too late, leading to an * use-after-free issue. */ spin_lock(&io_tree->lock); while (!RB_EMPTY_ROOT(&io_tree->state)) { struct extent_state *state; struct extent_state *cached_state = NULL; u64 start; u64 end; node = rb_first(&io_tree->state); state = rb_entry(node, struct extent_state, rb_node); start = state->start; end = state->end; spin_unlock(&io_tree->lock); lock_extent_bits(io_tree, start, end, &cached_state); /* * If still has DELALLOC flag, the extent didn't reach disk, * and its reserved space won't be freed by delayed_ref. * So we need to free its reserved space here. * (Refer to comment in btrfs_invalidatepage, case 2) * * Note, end is the bytenr of last byte, so we need + 1 here. */ if (state->state & EXTENT_DELALLOC) btrfs_qgroup_free_data(inode, start, end - start + 1); clear_extent_bit(io_tree, start, end, EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1, &cached_state, GFP_NOFS); cond_resched(); spin_lock(&io_tree->lock); } spin_unlock(&io_tree->lock); } void btrfs_evict_inode(struct inode *inode) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_block_rsv *rsv, *global_rsv; int steal_from_global = 0; u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); int ret; trace_btrfs_inode_evict(inode); evict_inode_truncate_pages(inode); if (inode->i_nlink && ((btrfs_root_refs(&root->root_item) != 0 && root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) || btrfs_is_free_space_inode(inode))) goto no_delete; if (is_bad_inode(inode)) { btrfs_orphan_del(NULL, inode); goto no_delete; } /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */ if (!special_file(inode->i_mode)) btrfs_wait_ordered_range(inode, 0, (u64)-1); btrfs_free_io_failure_record(inode, 0, (u64)-1); if (root->fs_info->log_root_recovering) { BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, &BTRFS_I(inode)->runtime_flags)); goto no_delete; } if (inode->i_nlink > 0) { BUG_ON(btrfs_root_refs(&root->root_item) != 0 && root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID); goto no_delete; } ret = btrfs_commit_inode_delayed_inode(inode); if (ret) { btrfs_orphan_del(NULL, inode); goto no_delete; } rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); if (!rsv) { btrfs_orphan_del(NULL, inode); goto no_delete; } rsv->size = min_size; rsv->failfast = 1; global_rsv = &root->fs_info->global_block_rsv; btrfs_i_size_write(inode, 0); /* * This is a bit simpler than btrfs_truncate since we've already * reserved our space for our orphan item in the unlink, so we just * need to reserve some slack space in case we add bytes and update * inode item when doing the truncate. */ while (1) { ret = btrfs_block_rsv_refill(root, rsv, min_size, BTRFS_RESERVE_FLUSH_LIMIT); /* * Try and steal from the global reserve since we will * likely not use this space anyway, we want to try as * hard as possible to get this to work. */ if (ret) steal_from_global++; else steal_from_global = 0; ret = 0; /* * steal_from_global == 0: we reserved stuff, hooray! * steal_from_global == 1: we didn't reserve stuff, boo! * steal_from_global == 2: we've committed, still not a lot of * room but maybe we'll have room in the global reserve this * time. * steal_from_global == 3: abandon all hope! */ if (steal_from_global > 2) { btrfs_warn(root->fs_info, "Could not get space for a delete, will truncate on mount %d", ret); btrfs_orphan_del(NULL, inode); btrfs_free_block_rsv(root, rsv); goto no_delete; } trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { btrfs_orphan_del(NULL, inode); btrfs_free_block_rsv(root, rsv); goto no_delete; } /* * We can't just steal from the global reserve, we need to make * sure there is room to do it, if not we need to commit and try * again. */ if (steal_from_global) { if (!btrfs_check_space_for_delayed_refs(trans, root)) ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size); else ret = -ENOSPC; } /* * Couldn't steal from the global reserve, we have too much * pending stuff built up, commit the transaction and try it * again. */ if (ret) { ret = btrfs_commit_transaction(trans, root); if (ret) { btrfs_orphan_del(NULL, inode); btrfs_free_block_rsv(root, rsv); goto no_delete; } continue; } else { steal_from_global = 0; } trans->block_rsv = rsv; ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); if (ret != -ENOSPC && ret != -EAGAIN) break; trans->block_rsv = &root->fs_info->trans_block_rsv; btrfs_end_transaction(trans, root); trans = NULL; btrfs_btree_balance_dirty(root); } btrfs_free_block_rsv(root, rsv); /* * Errors here aren't a big deal, it just means we leave orphan items * in the tree. They will be cleaned up on the next mount. */ if (ret == 0) { trans->block_rsv = root->orphan_block_rsv; btrfs_orphan_del(trans, inode); } else { btrfs_orphan_del(NULL, inode); } trans->block_rsv = &root->fs_info->trans_block_rsv; if (!(root == root->fs_info->tree_root || root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) btrfs_return_ino(root, btrfs_ino(inode)); btrfs_end_transaction(trans, root); btrfs_btree_balance_dirty(root); no_delete: btrfs_remove_delayed_node(inode); clear_inode(inode); } /* * this returns the key found in the dir entry in the location pointer. * If no dir entries were found, location->objectid is 0. */ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, struct btrfs_key *location) { const char *name = dentry->d_name.name; int namelen = dentry->d_name.len; struct btrfs_dir_item *di; struct btrfs_path *path; struct btrfs_root *root = BTRFS_I(dir)->root; int ret = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name, namelen, 0); if (IS_ERR(di)) ret = PTR_ERR(di); if (IS_ERR_OR_NULL(di)) goto out_err; btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); out: btrfs_free_path(path); return ret; out_err: location->objectid = 0; goto out; } /* * when we hit a tree root in a directory, the btrfs part of the inode * needs to be changed to reflect the root directory of the tree root. This * is kind of like crossing a mount point. */ static int fixup_tree_root_location(struct btrfs_root *root, struct inode *dir, struct dentry *dentry, struct btrfs_key *location, struct btrfs_root **sub_root) { struct btrfs_path *path; struct btrfs_root *new_root; struct btrfs_root_ref *ref; struct extent_buffer *leaf; struct btrfs_key key; int ret; int err = 0; path = btrfs_alloc_path(); if (!path) { err = -ENOMEM; goto out; } err = -ENOENT; key.objectid = BTRFS_I(dir)->root->root_key.objectid; key.type = BTRFS_ROOT_REF_KEY; key.offset = location->objectid; ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path, 0, 0); if (ret) { if (ret < 0) err = ret; goto out; } leaf = path->nodes[0]; ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) || btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) goto out; ret = memcmp_extent_buffer(leaf, dentry->d_name.name, (unsigned long)(ref + 1), dentry->d_name.len); if (ret) goto out; btrfs_release_path(path); new_root = btrfs_read_fs_root_no_name(root->fs_info, location); if (IS_ERR(new_root)) { err = PTR_ERR(new_root); goto out; } *sub_root = new_root; location->objectid = btrfs_root_dirid(&new_root->root_item); location->type = BTRFS_INODE_ITEM_KEY; location->offset = 0; err = 0; out: btrfs_free_path(path); return err; } static void inode_tree_add(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_inode *entry; struct rb_node **p; struct rb_node *parent; struct rb_node *new = &BTRFS_I(inode)->rb_node; u64 ino = btrfs_ino(inode); if (inode_unhashed(inode)) return; parent = NULL; spin_lock(&root->inode_lock); p = &root->inode_tree.rb_node; while (*p) { parent = *p; entry = rb_entry(parent, struct btrfs_inode, rb_node); if (ino < btrfs_ino(&entry->vfs_inode)) p = &parent->rb_left; else if (ino > btrfs_ino(&entry->vfs_inode)) p = &parent->rb_right; else { WARN_ON(!(entry->vfs_inode.i_state & (I_WILL_FREE | I_FREEING))); rb_replace_node(parent, new, &root->inode_tree); RB_CLEAR_NODE(parent); spin_unlock(&root->inode_lock); return; } } rb_link_node(new, parent, p); rb_insert_color(new, &root->inode_tree); spin_unlock(&root->inode_lock); } static void inode_tree_del(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; int empty = 0; spin_lock(&root->inode_lock); if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) { rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree); RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node); empty = RB_EMPTY_ROOT(&root->inode_tree); } spin_unlock(&root->inode_lock); if (empty && btrfs_root_refs(&root->root_item) == 0) { synchronize_srcu(&root->fs_info->subvol_srcu); spin_lock(&root->inode_lock); empty = RB_EMPTY_ROOT(&root->inode_tree); spin_unlock(&root->inode_lock); if (empty) btrfs_add_dead_root(root); } } void btrfs_invalidate_inodes(struct btrfs_root *root) { struct rb_node *node; struct rb_node *prev; struct btrfs_inode *entry; struct inode *inode; u64 objectid = 0; if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) WARN_ON(btrfs_root_refs(&root->root_item) != 0); spin_lock(&root->inode_lock); again: node = root->inode_tree.rb_node; prev = NULL; while (node) { prev = node; entry = rb_entry(node, struct btrfs_inode, rb_node); if (objectid < btrfs_ino(&entry->vfs_inode)) node = node->rb_left; else if (objectid > btrfs_ino(&entry->vfs_inode)) node = node->rb_right; else break; } if (!node) { while (prev) { entry = rb_entry(prev, struct btrfs_inode, rb_node); if (objectid <= btrfs_ino(&entry->vfs_inode)) { node = prev; break; } prev = rb_next(prev); } } while (node) { entry = rb_entry(node, struct btrfs_inode, rb_node); objectid = btrfs_ino(&entry->vfs_inode) + 1; inode = igrab(&entry->vfs_inode); if (inode) { spin_unlock(&root->inode_lock); if (atomic_read(&inode->i_count) > 1) d_prune_aliases(inode); /* * btrfs_drop_inode will have it removed from * the inode cache when its usage count * hits zero. */ iput(inode); cond_resched(); spin_lock(&root->inode_lock); goto again; } if (cond_resched_lock(&root->inode_lock)) goto again; node = rb_next(node); } spin_unlock(&root->inode_lock); } static int btrfs_init_locked_inode(struct inode *inode, void *p) { struct btrfs_iget_args *args = p; inode->i_ino = args->location->objectid; memcpy(&BTRFS_I(inode)->location, args->location, sizeof(*args->location)); BTRFS_I(inode)->root = args->root; return 0; } static int btrfs_find_actor(struct inode *inode, void *opaque) { struct btrfs_iget_args *args = opaque; return args->location->objectid == BTRFS_I(inode)->location.objectid && args->root == BTRFS_I(inode)->root; } static struct inode *btrfs_iget_locked(struct super_block *s, struct btrfs_key *location, struct btrfs_root *root) { struct inode *inode; struct btrfs_iget_args args; unsigned long hashval = btrfs_inode_hash(location->objectid, root); args.location = location; args.root = root; inode = iget5_locked(s, hashval, btrfs_find_actor, btrfs_init_locked_inode, (void *)&args); return inode; } /* Get an inode object given its location and corresponding root. * Returns in *is_new if the inode was read from disk */ struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location, struct btrfs_root *root, int *new) { struct inode *inode; inode = btrfs_iget_locked(s, location, root); if (!inode) return ERR_PTR(-ENOMEM); if (inode->i_state & I_NEW) { btrfs_read_locked_inode(inode); if (!is_bad_inode(inode)) { inode_tree_add(inode); unlock_new_inode(inode); if (new) *new = 1; } else { unlock_new_inode(inode); iput(inode); inode = ERR_PTR(-ESTALE); } } return inode; } static struct inode *new_simple_dir(struct super_block *s, struct btrfs_key *key, struct btrfs_root *root) { struct inode *inode = new_inode(s); if (!inode) return ERR_PTR(-ENOMEM); BTRFS_I(inode)->root = root; memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; inode->i_op = &btrfs_dir_ro_inode_operations; inode->i_fop = &simple_dir_operations; inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; inode->i_mtime = current_fs_time(inode->i_sb); inode->i_atime = inode->i_mtime; inode->i_ctime = inode->i_mtime; BTRFS_I(inode)->i_otime = inode->i_mtime; return inode; } struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) { struct inode *inode; struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_root *sub_root = root; struct btrfs_key location; int index; int ret = 0; if (dentry->d_name.len > BTRFS_NAME_LEN) return ERR_PTR(-ENAMETOOLONG); ret = btrfs_inode_by_name(dir, dentry, &location); if (ret < 0) return ERR_PTR(ret); if (location.objectid == 0) return ERR_PTR(-ENOENT); if (location.type == BTRFS_INODE_ITEM_KEY) { inode = btrfs_iget(dir->i_sb, &location, root, NULL); return inode; } BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY); index = srcu_read_lock(&root->fs_info->subvol_srcu); ret = fixup_tree_root_location(root, dir, dentry, &location, &sub_root); if (ret < 0) { if (ret != -ENOENT) inode = ERR_PTR(ret); else inode = new_simple_dir(dir->i_sb, &location, sub_root); } else { inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL); } srcu_read_unlock(&root->fs_info->subvol_srcu, index); if (!IS_ERR(inode) && root != sub_root) { down_read(&root->fs_info->cleanup_work_sem); if (!(inode->i_sb->s_flags & MS_RDONLY)) ret = btrfs_orphan_cleanup(sub_root); up_read(&root->fs_info->cleanup_work_sem); if (ret) { iput(inode); inode = ERR_PTR(ret); } } return inode; } static int btrfs_dentry_delete(const struct dentry *dentry) { struct btrfs_root *root; struct inode *inode = d_inode(dentry); if (!inode && !IS_ROOT(dentry)) inode = d_inode(dentry->d_parent); if (inode) { root = BTRFS_I(inode)->root; if (btrfs_root_refs(&root->root_item) == 0) return 1; if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) return 1; } return 0; } static void btrfs_dentry_release(struct dentry *dentry) { kfree(dentry->d_fsdata); } static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct inode *inode; inode = btrfs_lookup_dentry(dir, dentry); if (IS_ERR(inode)) { if (PTR_ERR(inode) == -ENOENT) inode = NULL; else return ERR_CAST(inode); } return d_splice_alias(inode, dentry); } unsigned char btrfs_filetype_table[] = { DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK }; static int btrfs_real_readdir(struct file *file, struct dir_context *ctx) { struct inode *inode = file_inode(file); struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_item *item; struct btrfs_dir_item *di; struct btrfs_key key; struct btrfs_key found_key; struct btrfs_path *path; struct list_head ins_list; struct list_head del_list; int ret; struct extent_buffer *leaf; int slot; unsigned char d_type; int over = 0; u32 di_cur; u32 di_total; u32 di_len; int key_type = BTRFS_DIR_INDEX_KEY; char tmp_name[32]; char *name_ptr; int name_len; int is_curr = 0; /* ctx->pos points to the current index? */ bool emitted; /* FIXME, use a real flag for deciding about the key type */ if (root->fs_info->tree_root == root) key_type = BTRFS_DIR_ITEM_KEY; if (!dir_emit_dots(file, ctx)) return 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = READA_FORWARD; if (key_type == BTRFS_DIR_INDEX_KEY) { INIT_LIST_HEAD(&ins_list); INIT_LIST_HEAD(&del_list); btrfs_get_delayed_items(inode, &ins_list, &del_list); } key.type = key_type; key.offset = ctx->pos; key.objectid = btrfs_ino(inode); ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto err; emitted = false; while (1) { leaf = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto err; else if (ret > 0) break; continue; } item = btrfs_item_nr(slot); btrfs_item_key_to_cpu(leaf, &found_key, slot); if (found_key.objectid != key.objectid) break; if (found_key.type != key_type) break; if (found_key.offset < ctx->pos) goto next; if (key_type == BTRFS_DIR_INDEX_KEY && btrfs_should_delete_dir_index(&del_list, found_key.offset)) goto next; ctx->pos = found_key.offset; is_curr = 1; di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); di_cur = 0; di_total = btrfs_item_size(leaf, item); while (di_cur < di_total) { struct btrfs_key location; if (verify_dir_item(root, leaf, di)) break; name_len = btrfs_dir_name_len(leaf, di); if (name_len <= sizeof(tmp_name)) { name_ptr = tmp_name; } else { name_ptr = kmalloc(name_len, GFP_KERNEL); if (!name_ptr) { ret = -ENOMEM; goto err; } } read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1), name_len); d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)]; btrfs_dir_item_key_to_cpu(leaf, di, &location); /* is this a reference to our own snapshot? If so * skip it. * * In contrast to old kernels, we insert the snapshot's * dir item and dir index after it has been created, so * we won't find a reference to our own snapshot. We * still keep the following code for backward * compatibility. */ if (location.type == BTRFS_ROOT_ITEM_KEY && location.objectid == root->root_key.objectid) { over = 0; goto skip; } over = !dir_emit(ctx, name_ptr, name_len, location.objectid, d_type); skip: if (name_ptr != tmp_name) kfree(name_ptr); if (over) goto nopos; emitted = true; di_len = btrfs_dir_name_len(leaf, di) + btrfs_dir_data_len(leaf, di) + sizeof(*di); di_cur += di_len; di = (struct btrfs_dir_item *)((char *)di + di_len); } next: path->slots[0]++; } if (key_type == BTRFS_DIR_INDEX_KEY) { if (is_curr) ctx->pos++; ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted); if (ret) goto nopos; } /* * If we haven't emitted any dir entry, we must not touch ctx->pos as * it was was set to the termination value in previous call. We assume * that "." and ".." were emitted if we reach this point and set the * termination value as well for an empty directory. */ if (ctx->pos > 2 && !emitted) goto nopos; /* Reached end of directory/root. Bump pos past the last item. */ ctx->pos++; /* * Stop new entries from being returned after we return the last * entry. * * New directory entries are assigned a strictly increasing * offset. This means that new entries created during readdir * are *guaranteed* to be seen in the future by that readdir. * This has broken buggy programs which operate on names as * they're returned by readdir. Until we re-use freed offsets * we have this hack to stop new entries from being returned * under the assumption that they'll never reach this huge * offset. * * This is being careful not to overflow 32bit loff_t unless the * last entry requires it because doing so has broken 32bit apps * in the past. */ if (key_type == BTRFS_DIR_INDEX_KEY) { if (ctx->pos >= INT_MAX) ctx->pos = LLONG_MAX; else ctx->pos = INT_MAX; } nopos: ret = 0; err: if (key_type == BTRFS_DIR_INDEX_KEY) btrfs_put_delayed_items(&ins_list, &del_list); btrfs_free_path(path); return ret; } int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; int ret = 0; bool nolock = false; if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) return 0; if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode)) nolock = true; if (wbc->sync_mode == WB_SYNC_ALL) { if (nolock) trans = btrfs_join_transaction_nolock(root); else trans = btrfs_join_transaction(root); if (IS_ERR(trans)) return PTR_ERR(trans); ret = btrfs_commit_transaction(trans, root); } return ret; } /* * This is somewhat expensive, updating the tree every time the * inode changes. But, it is most likely to find the inode in cache. * FIXME, needs more benchmarking...there are no reasons other than performance * to keep or drop this code. */ static int btrfs_dirty_inode(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; int ret; if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) return 0; trans = btrfs_join_transaction(root); if (IS_ERR(trans)) return PTR_ERR(trans); ret = btrfs_update_inode(trans, root, inode); if (ret && ret == -ENOSPC) { /* whoops, lets try again with the full transaction */ btrfs_end_transaction(trans, root); trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) return PTR_ERR(trans); ret = btrfs_update_inode(trans, root, inode); } btrfs_end_transaction(trans, root); if (BTRFS_I(inode)->delayed_node) btrfs_balance_delayed_items(root); return ret; } /* * This is a copy of file_update_time. We need this so we can return error on * ENOSPC for updating the inode in the case of file write and mmap writes. */ static int btrfs_update_time(struct inode *inode, struct timespec *now, int flags) { struct btrfs_root *root = BTRFS_I(inode)->root; if (btrfs_root_readonly(root)) return -EROFS; if (flags & S_VERSION) inode_inc_iversion(inode); if (flags & S_CTIME) inode->i_ctime = *now; if (flags & S_MTIME) inode->i_mtime = *now; if (flags & S_ATIME) inode->i_atime = *now; return btrfs_dirty_inode(inode); } /* * find the highest existing sequence number in a directory * and then set the in-memory index_cnt variable to reflect * free sequence numbers */ static int btrfs_set_inode_index_count(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_key key, found_key; struct btrfs_path *path; struct extent_buffer *leaf; int ret; key.objectid = btrfs_ino(inode); key.type = BTRFS_DIR_INDEX_KEY; key.offset = (u64)-1; path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; /* FIXME: we should be able to handle this */ if (ret == 0) goto out; ret = 0; /* * MAGIC NUMBER EXPLANATION: * since we search a directory based on f_pos we have to start at 2 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody * else has to start at 2 */ if (path->slots[0] == 0) { BTRFS_I(inode)->index_cnt = 2; goto out; } path->slots[0]--; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != btrfs_ino(inode) || found_key.type != BTRFS_DIR_INDEX_KEY) { BTRFS_I(inode)->index_cnt = 2; goto out; } BTRFS_I(inode)->index_cnt = found_key.offset + 1; out: btrfs_free_path(path); return ret; } /* * helper to find a free sequence number in a given directory. This current * code is very simple, later versions will do smarter things in the btree */ int btrfs_set_inode_index(struct inode *dir, u64 *index) { int ret = 0; if (BTRFS_I(dir)->index_cnt == (u64)-1) { ret = btrfs_inode_delayed_dir_index_count(dir); if (ret) { ret = btrfs_set_inode_index_count(dir); if (ret) return ret; } } *index = BTRFS_I(dir)->index_cnt; BTRFS_I(dir)->index_cnt++; return ret; } static int btrfs_insert_inode_locked(struct inode *inode) { struct btrfs_iget_args args; args.location = &BTRFS_I(inode)->location; args.root = BTRFS_I(inode)->root; return insert_inode_locked4(inode, btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root), btrfs_find_actor, &args); } static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *dir, const char *name, int name_len, u64 ref_objectid, u64 objectid, umode_t mode, u64 *index) { struct inode *inode; struct btrfs_inode_item *inode_item; struct btrfs_key *location; struct btrfs_path *path; struct btrfs_inode_ref *ref; struct btrfs_key key[2]; u32 sizes[2]; int nitems = name ? 2 : 1; unsigned long ptr; int ret; path = btrfs_alloc_path(); if (!path) return ERR_PTR(-ENOMEM); inode = new_inode(root->fs_info->sb); if (!inode) { btrfs_free_path(path); return ERR_PTR(-ENOMEM); } /* * O_TMPFILE, set link count to 0, so that after this point, * we fill in an inode item with the correct link count. */ if (!name) set_nlink(inode, 0); /* * we have to initialize this early, so we can reclaim the inode * number if we fail afterwards in this function. */ inode->i_ino = objectid; if (dir && name) { trace_btrfs_inode_request(dir); ret = btrfs_set_inode_index(dir, index); if (ret) { btrfs_free_path(path); iput(inode); return ERR_PTR(ret); } } else if (dir) { *index = 0; } /* * index_cnt is ignored for everything but a dir, * btrfs_get_inode_index_count has an explanation for the magic * number */ BTRFS_I(inode)->index_cnt = 2; BTRFS_I(inode)->dir_index = *index; BTRFS_I(inode)->root = root; BTRFS_I(inode)->generation = trans->transid; inode->i_generation = BTRFS_I(inode)->generation; /* * We could have gotten an inode number from somebody who was fsynced * and then removed in this same transaction, so let's just set full * sync since it will be a full sync anyway and this will blow away the * old info in the log. */ set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); key[0].objectid = objectid; key[0].type = BTRFS_INODE_ITEM_KEY; key[0].offset = 0; sizes[0] = sizeof(struct btrfs_inode_item); if (name) { /* * Start new inodes with an inode_ref. This is slightly more * efficient for small numbers of hard links since they will * be packed into one item. Extended refs will kick in if we * add more hard links than can fit in the ref item. */ key[1].objectid = objectid; key[1].type = BTRFS_INODE_REF_KEY; key[1].offset = ref_objectid; sizes[1] = name_len + sizeof(*ref); } location = &BTRFS_I(inode)->location; location->objectid = objectid; location->offset = 0; location->type = BTRFS_INODE_ITEM_KEY; ret = btrfs_insert_inode_locked(inode); if (ret < 0) goto fail; path->leave_spinning = 1; ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems); if (ret != 0) goto fail_unlock; inode_init_owner(inode, dir, mode); inode_set_bytes(inode, 0); inode->i_mtime = current_fs_time(inode->i_sb); inode->i_atime = inode->i_mtime; inode->i_ctime = inode->i_mtime; BTRFS_I(inode)->i_otime = inode->i_mtime; inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_inode_item); memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item, sizeof(*inode_item)); fill_inode_item(trans, path->nodes[0], inode_item, inode); if (name) { ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, struct btrfs_inode_ref); btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); btrfs_set_inode_ref_index(path->nodes[0], ref, *index); ptr = (unsigned long)(ref + 1); write_extent_buffer(path->nodes[0], name, ptr, name_len); } btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_free_path(path); btrfs_inherit_iflags(inode, dir); if (S_ISREG(mode)) { if (btrfs_test_opt(root, NODATASUM)) BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; if (btrfs_test_opt(root, NODATACOW)) BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | BTRFS_INODE_NODATASUM; } inode_tree_add(inode); trace_btrfs_inode_new(inode); btrfs_set_inode_last_trans(trans, inode); btrfs_update_root_times(trans, root); ret = btrfs_inode_inherit_props(trans, inode, dir); if (ret) btrfs_err(root->fs_info, "error inheriting props for ino %llu (root %llu): %d", btrfs_ino(inode), root->root_key.objectid, ret); return inode; fail_unlock: unlock_new_inode(inode); fail: if (dir && name) BTRFS_I(dir)->index_cnt--; btrfs_free_path(path); iput(inode); return ERR_PTR(ret); } static inline u8 btrfs_inode_type(struct inode *inode) { return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; } /* * utility function to add 'inode' into 'parent_inode' with * a give name and a given sequence number. * if 'add_backref' is true, also insert a backref from the * inode to the parent directory. */ int btrfs_add_link(struct btrfs_trans_handle *trans, struct inode *parent_inode, struct inode *inode, const char *name, int name_len, int add_backref, u64 index) { int ret = 0; struct btrfs_key key; struct btrfs_root *root = BTRFS_I(parent_inode)->root; u64 ino = btrfs_ino(inode); u64 parent_ino = btrfs_ino(parent_inode); if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key)); } else { key.objectid = ino; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; } if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, key.objectid, root->root_key.objectid, parent_ino, index, name, name_len); } else if (add_backref) { ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, parent_ino, index); } /* Nothing to clean up yet */ if (ret) return ret; ret = btrfs_insert_dir_item(trans, root, name, name_len, parent_inode, &key, btrfs_inode_type(inode), index); if (ret == -EEXIST || ret == -EOVERFLOW) goto fail_dir_item; else if (ret) { btrfs_abort_transaction(trans, root, ret); return ret; } btrfs_i_size_write(parent_inode, parent_inode->i_size + name_len * 2); inode_inc_iversion(parent_inode); parent_inode->i_mtime = parent_inode->i_ctime = current_fs_time(parent_inode->i_sb); ret = btrfs_update_inode(trans, root, parent_inode); if (ret) btrfs_abort_transaction(trans, root, ret); return ret; fail_dir_item: if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { u64 local_index; int err; err = btrfs_del_root_ref(trans, root->fs_info->tree_root, key.objectid, root->root_key.objectid, parent_ino, &local_index, name, name_len); } else if (add_backref) { u64 local_index; int err; err = btrfs_del_inode_ref(trans, root, name, name_len, ino, parent_ino, &local_index); } return ret; } static int btrfs_add_nondir(struct btrfs_trans_handle *trans, struct inode *dir, struct dentry *dentry, struct inode *inode, int backref, u64 index) { int err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, dentry->d_name.len, backref, index); if (err > 0) err = -EEXIST; return err; } static int btrfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; struct inode *inode = NULL; int err; int drop_inode = 0; u64 objectid; u64 index = 0; /* * 2 for inode item and ref * 2 for dir items * 1 for xattr if selinux is on */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) return PTR_ERR(trans); err = btrfs_find_free_ino(root, &objectid); if (err) goto out_unlock; inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, btrfs_ino(dir), objectid, mode, &index); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_unlock; } /* * If the active LSM wants to access the inode during * d_instantiate it needs these. Smack checks to see * if the filesystem supports xattrs by looking at the * ops vector. */ inode->i_op = &btrfs_special_inode_operations; init_special_inode(inode, inode->i_mode, rdev); err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); if (err) goto out_unlock_inode; err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); if (err) { goto out_unlock_inode; } else { btrfs_update_inode(trans, root, inode); unlock_new_inode(inode); d_instantiate(dentry, inode); } out_unlock: btrfs_end_transaction(trans, root); btrfs_balance_delayed_items(root); btrfs_btree_balance_dirty(root); if (drop_inode) { inode_dec_link_count(inode); iput(inode); } return err; out_unlock_inode: drop_inode = 1; unlock_new_inode(inode); goto out_unlock; } static int btrfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; struct inode *inode = NULL; int drop_inode_on_err = 0; int err; u64 objectid; u64 index = 0; /* * 2 for inode item and ref * 2 for dir items * 1 for xattr if selinux is on */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) return PTR_ERR(trans); err = btrfs_find_free_ino(root, &objectid); if (err) goto out_unlock; inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, btrfs_ino(dir), objectid, mode, &index); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_unlock; } drop_inode_on_err = 1; /* * If the active LSM wants to access the inode during * d_instantiate it needs these. Smack checks to see * if the filesystem supports xattrs by looking at the * ops vector. */ inode->i_fop = &btrfs_file_operations; inode->i_op = &btrfs_file_inode_operations; inode->i_mapping->a_ops = &btrfs_aops; err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); if (err) goto out_unlock_inode; err = btrfs_update_inode(trans, root, inode); if (err) goto out_unlock_inode; err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); if (err) goto out_unlock_inode; BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; unlock_new_inode(inode); d_instantiate(dentry, inode); out_unlock: btrfs_end_transaction(trans, root); if (err && drop_inode_on_err) { inode_dec_link_count(inode); iput(inode); } btrfs_balance_delayed_items(root); btrfs_btree_balance_dirty(root); return err; out_unlock_inode: unlock_new_inode(inode); goto out_unlock; } static int btrfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { struct btrfs_trans_handle *trans = NULL; struct btrfs_root *root = BTRFS_I(dir)->root; struct inode *inode = d_inode(old_dentry); u64 index; int err; int drop_inode = 0; /* do not allow sys_link's with other subvols of the same device */ if (root->objectid != BTRFS_I(inode)->root->objectid) return -EXDEV; if (inode->i_nlink >= BTRFS_LINK_MAX) return -EMLINK; err = btrfs_set_inode_index(dir, &index); if (err) goto fail; /* * 2 items for inode and inode ref * 2 items for dir items * 1 item for parent inode */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) { err = PTR_ERR(trans); trans = NULL; goto fail; } /* There are several dir indexes for this inode, clear the cache. */ BTRFS_I(inode)->dir_index = 0ULL; inc_nlink(inode); inode_inc_iversion(inode); inode->i_ctime = current_fs_time(inode->i_sb); ihold(inode); set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index); if (err) { drop_inode = 1; } else { struct dentry *parent = dentry->d_parent; err = btrfs_update_inode(trans, root, inode); if (err) goto fail; if (inode->i_nlink == 1) { /* * If new hard link count is 1, it's a file created * with open(2) O_TMPFILE flag. */ err = btrfs_orphan_del(trans, inode); if (err) goto fail; } d_instantiate(dentry, inode); btrfs_log_new_name(trans, inode, NULL, parent); } btrfs_balance_delayed_items(root); fail: if (trans) btrfs_end_transaction(trans, root); if (drop_inode) { inode_dec_link_count(inode); iput(inode); } btrfs_btree_balance_dirty(root); return err; } static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { struct inode *inode = NULL; struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; int err = 0; int drop_on_err = 0; u64 objectid = 0; u64 index = 0; /* * 2 items for inode and ref * 2 items for dir items * 1 for xattr if selinux is on */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) return PTR_ERR(trans); err = btrfs_find_free_ino(root, &objectid); if (err) goto out_fail; inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, btrfs_ino(dir), objectid, S_IFDIR | mode, &index); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_fail; } drop_on_err = 1; /* these must be set before we unlock the inode */ inode->i_op = &btrfs_dir_inode_operations; inode->i_fop = &btrfs_dir_file_operations; err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); if (err) goto out_fail_inode; btrfs_i_size_write(inode, 0); err = btrfs_update_inode(trans, root, inode); if (err) goto out_fail_inode; err = btrfs_add_link(trans, dir, inode, dentry->d_name.name, dentry->d_name.len, 0, index); if (err) goto out_fail_inode; d_instantiate(dentry, inode); /* * mkdir is special. We're unlocking after we call d_instantiate * to avoid a race with nfsd calling d_instantiate. */ unlock_new_inode(inode); drop_on_err = 0; out_fail: btrfs_end_transaction(trans, root); if (drop_on_err) { inode_dec_link_count(inode); iput(inode); } btrfs_balance_delayed_items(root); btrfs_btree_balance_dirty(root); return err; out_fail_inode: unlock_new_inode(inode); goto out_fail; } /* Find next extent map of a given extent map, caller needs to ensure locks */ static struct extent_map *next_extent_map(struct extent_map *em) { struct rb_node *next; next = rb_next(&em->rb_node); if (!next) return NULL; return container_of(next, struct extent_map, rb_node); } static struct extent_map *prev_extent_map(struct extent_map *em) { struct rb_node *prev; prev = rb_prev(&em->rb_node); if (!prev) return NULL; return container_of(prev, struct extent_map, rb_node); } /* helper for btfs_get_extent. Given an existing extent in the tree, * the existing extent is the nearest extent to map_start, * and an extent that you want to insert, deal with overlap and insert * the best fitted new extent into the tree. */ static int merge_extent_mapping(struct extent_map_tree *em_tree, struct extent_map *existing, struct extent_map *em, u64 map_start) { struct extent_map *prev; struct extent_map *next; u64 start; u64 end; u64 start_diff; BUG_ON(map_start < em->start || map_start >= extent_map_end(em)); if (existing->start > map_start) { next = existing; prev = prev_extent_map(next); } else { prev = existing; next = next_extent_map(prev); } start = prev ? extent_map_end(prev) : em->start; start = max_t(u64, start, em->start); end = next ? next->start : extent_map_end(em); end = min_t(u64, end, extent_map_end(em)); start_diff = start - em->start; em->start = start; em->len = end - start; if (em->block_start < EXTENT_MAP_LAST_BYTE && !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { em->block_start += start_diff; em->block_len -= start_diff; } return add_extent_mapping(em_tree, em, 0); } static noinline int uncompress_inline(struct btrfs_path *path, struct page *page, size_t pg_offset, u64 extent_offset, struct btrfs_file_extent_item *item) { int ret; struct extent_buffer *leaf = path->nodes[0]; char *tmp; size_t max_size; unsigned long inline_size; unsigned long ptr; int compress_type; WARN_ON(pg_offset != 0); compress_type = btrfs_file_extent_compression(leaf, item); max_size = btrfs_file_extent_ram_bytes(leaf, item); inline_size = btrfs_file_extent_inline_item_len(leaf, btrfs_item_nr(path->slots[0])); tmp = kmalloc(inline_size, GFP_NOFS); if (!tmp) return -ENOMEM; ptr = btrfs_file_extent_inline_start(item); read_extent_buffer(leaf, tmp, ptr, inline_size); max_size = min_t(unsigned long, PAGE_SIZE, max_size); ret = btrfs_decompress(compress_type, tmp, page, extent_offset, inline_size, max_size); kfree(tmp); return ret; } /* * a bit scary, this does extent mapping from logical file offset to the disk. * the ugly parts come from merging extents from the disk with the in-ram * representation. This gets more complex because of the data=ordered code, * where the in-ram extents might be locked pending data=ordered completion. * * This also copies inline extents directly into the page. */ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, size_t pg_offset, u64 start, u64 len, int create) { int ret; int err = 0; u64 extent_start = 0; u64 extent_end = 0; u64 objectid = btrfs_ino(inode); u32 found_type; struct btrfs_path *path = NULL; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_file_extent_item *item; struct extent_buffer *leaf; struct btrfs_key found_key; struct extent_map *em = NULL; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_trans_handle *trans = NULL; const bool new_inline = !page || create; again: read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, start, len); if (em) em->bdev = root->fs_info->fs_devices->latest_bdev; read_unlock(&em_tree->lock); if (em) { if (em->start > start || em->start + em->len <= start) free_extent_map(em); else if (em->block_start == EXTENT_MAP_INLINE && page) free_extent_map(em); else goto out; } em = alloc_extent_map(); if (!em) { err = -ENOMEM; goto out; } em->bdev = root->fs_info->fs_devices->latest_bdev; em->start = EXTENT_MAP_HOLE; em->orig_start = EXTENT_MAP_HOLE; em->len = (u64)-1; em->block_len = (u64)-1; if (!path) { path = btrfs_alloc_path(); if (!path) { err = -ENOMEM; goto out; } /* * Chances are we'll be called again, so go ahead and do * readahead */ path->reada = READA_FORWARD; } ret = btrfs_lookup_file_extent(trans, root, path, objectid, start, trans != NULL); if (ret < 0) { err = ret; goto out; } if (ret != 0) { if (path->slots[0] == 0) goto not_found; path->slots[0]--; } leaf = path->nodes[0]; item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); /* are we inside the extent that was found? */ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); found_type = found_key.type; if (found_key.objectid != objectid || found_type != BTRFS_EXTENT_DATA_KEY) { /* * If we backup past the first extent we want to move forward * and see if there is an extent in front of us, otherwise we'll * say there is a hole for our whole search range which can * cause problems. */ extent_end = start; goto next; } found_type = btrfs_file_extent_type(leaf, item); extent_start = found_key.offset; if (found_type == BTRFS_FILE_EXTENT_REG || found_type == BTRFS_FILE_EXTENT_PREALLOC) { extent_end = extent_start + btrfs_file_extent_num_bytes(leaf, item); } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { size_t size; size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); extent_end = ALIGN(extent_start + size, root->sectorsize); } next: if (start >= extent_end) { path->slots[0]++; if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) { err = ret; goto out; } if (ret > 0) goto not_found; leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != objectid || found_key.type != BTRFS_EXTENT_DATA_KEY) goto not_found; if (start + len <= found_key.offset) goto not_found; if (start > found_key.offset) goto next; em->start = start; em->orig_start = start; em->len = found_key.offset - start; goto not_found_em; } btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em); if (found_type == BTRFS_FILE_EXTENT_REG || found_type == BTRFS_FILE_EXTENT_PREALLOC) { goto insert; } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { unsigned long ptr; char *map; size_t size; size_t extent_offset; size_t copy_size; if (new_inline) goto out; size = btrfs_file_extent_inline_len(leaf, path->slots[0], item); extent_offset = page_offset(page) + pg_offset - extent_start; copy_size = min_t(u64, PAGE_SIZE - pg_offset, size - extent_offset); em->start = extent_start + extent_offset; em->len = ALIGN(copy_size, root->sectorsize); em->orig_block_len = em->len; em->orig_start = em->start; ptr = btrfs_file_extent_inline_start(item) + extent_offset; if (create == 0 && !PageUptodate(page)) { if (btrfs_file_extent_compression(leaf, item) != BTRFS_COMPRESS_NONE) { ret = uncompress_inline(path, page, pg_offset, extent_offset, item); if (ret) { err = ret; goto out; } } else { map = kmap(page); read_extent_buffer(leaf, map + pg_offset, ptr, copy_size); if (pg_offset + copy_size < PAGE_SIZE) { memset(map + pg_offset + copy_size, 0, PAGE_SIZE - pg_offset - copy_size); } kunmap(page); } flush_dcache_page(page); } else if (create && PageUptodate(page)) { BUG(); if (!trans) { kunmap(page); free_extent_map(em); em = NULL; btrfs_release_path(path); trans = btrfs_join_transaction(root); if (IS_ERR(trans)) return ERR_CAST(trans); goto again; } map = kmap(page); write_extent_buffer(leaf, map + pg_offset, ptr, copy_size); kunmap(page); btrfs_mark_buffer_dirty(leaf); } set_extent_uptodate(io_tree, em->start, extent_map_end(em) - 1, NULL, GFP_NOFS); goto insert; } not_found: em->start = start; em->orig_start = start; em->len = len; not_found_em: em->block_start = EXTENT_MAP_HOLE; set_bit(EXTENT_FLAG_VACANCY, &em->flags); insert: btrfs_release_path(path); if (em->start > start || extent_map_end(em) <= start) { btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]", em->start, em->len, start, len); err = -EIO; goto out; } err = 0; write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em, 0); /* it is possible that someone inserted the extent into the tree * while we had the lock dropped. It is also possible that * an overlapping map exists in the tree */ if (ret == -EEXIST) { struct extent_map *existing; ret = 0; existing = search_extent_mapping(em_tree, start, len); /* * existing will always be non-NULL, since there must be * extent causing the -EEXIST. */ if (start >= extent_map_end(existing) || start <= existing->start) { /* * The existing extent map is the one nearest to * the [start, start + len) range which overlaps */ err = merge_extent_mapping(em_tree, existing, em, start); free_extent_map(existing); if (err) { free_extent_map(em); em = NULL; } } else { free_extent_map(em); em = existing; err = 0; } } write_unlock(&em_tree->lock); out: trace_btrfs_get_extent(root, em); btrfs_free_path(path); if (trans) { ret = btrfs_end_transaction(trans, root); if (!err) err = ret; } if (err) { free_extent_map(em); return ERR_PTR(err); } BUG_ON(!em); /* Error is always set */ return em; } struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page, size_t pg_offset, u64 start, u64 len, int create) { struct extent_map *em; struct extent_map *hole_em = NULL; u64 range_start = start; u64 end; u64 found; u64 found_end; int err = 0; em = btrfs_get_extent(inode, page, pg_offset, start, len, create); if (IS_ERR(em)) return em; if (em) { /* * if our em maps to * - a hole or * - a pre-alloc extent, * there might actually be delalloc bytes behind it. */ if (em->block_start != EXTENT_MAP_HOLE && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) return em; else hole_em = em; } /* check to see if we've wrapped (len == -1 or similar) */ end = start + len; if (end < start) end = (u64)-1; else end -= 1; em = NULL; /* ok, we didn't find anything, lets look for delalloc */ found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start, end, len, EXTENT_DELALLOC, 1); found_end = range_start + found; if (found_end < range_start) found_end = (u64)-1; /* * we didn't find anything useful, return * the original results from get_extent() */ if (range_start > end || found_end <= start) { em = hole_em; hole_em = NULL; goto out; } /* adjust the range_start to make sure it doesn't * go backwards from the start they passed in */ range_start = max(start, range_start); found = found_end - range_start; if (found > 0) { u64 hole_start = start; u64 hole_len = len; em = alloc_extent_map(); if (!em) { err = -ENOMEM; goto out; } /* * when btrfs_get_extent can't find anything it * returns one huge hole * * make sure what it found really fits our range, and * adjust to make sure it is based on the start from * the caller */ if (hole_em) { u64 calc_end = extent_map_end(hole_em); if (calc_end <= start || (hole_em->start > end)) { free_extent_map(hole_em); hole_em = NULL; } else { hole_start = max(hole_em->start, start); hole_len = calc_end - hole_start; } } em->bdev = NULL; if (hole_em && range_start > hole_start) { /* our hole starts before our delalloc, so we * have to return just the parts of the hole * that go until the delalloc starts */ em->len = min(hole_len, range_start - hole_start); em->start = hole_start; em->orig_start = hole_start; /* * don't adjust block start at all, * it is fixed at EXTENT_MAP_HOLE */ em->block_start = hole_em->block_start; em->block_len = hole_len; if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) set_bit(EXTENT_FLAG_PREALLOC, &em->flags); } else { em->start = range_start; em->len = found; em->orig_start = range_start; em->block_start = EXTENT_MAP_DELALLOC; em->block_len = found; } } else if (hole_em) { return hole_em; } out: free_extent_map(hole_em); if (err) { free_extent_map(em); return ERR_PTR(err); } return em; } static struct extent_map *btrfs_new_extent_direct(struct inode *inode, u64 start, u64 len) { struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_map *em; struct btrfs_key ins; u64 alloc_hint; int ret; alloc_hint = get_extent_allocation_hint(inode, start, len); ret = btrfs_reserve_extent(root, len, root->sectorsize, 0, alloc_hint, &ins, 1, 1); if (ret) return ERR_PTR(ret); /* * Create the ordered extent before the extent map. This is to avoid * races with the fast fsync path that would lead to it logging file * extent items that point to disk extents that were not yet written to. * The fast fsync path collects ordered extents into a local list and * then collects all the new extent maps, so we must create the ordered * extent first and make sure the fast fsync path collects any new * ordered extents after collecting new extent maps as well. * The fsync path simply can not rely on inode_dio_wait() because it * causes deadlock with AIO. */ ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid, ins.offset, ins.offset, 0); if (ret) { btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); return ERR_PTR(ret); } em = create_pinned_em(inode, start, ins.offset, start, ins.objectid, ins.offset, ins.offset, ins.offset, 0); if (IS_ERR(em)) { struct btrfs_ordered_extent *oe; btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1); oe = btrfs_lookup_ordered_extent(inode, start); ASSERT(oe); if (WARN_ON(!oe)) return em; set_bit(BTRFS_ORDERED_IOERR, &oe->flags); set_bit(BTRFS_ORDERED_IO_DONE, &oe->flags); btrfs_remove_ordered_extent(inode, oe); /* Once for our lookup and once for the ordered extents tree. */ btrfs_put_ordered_extent(oe); btrfs_put_ordered_extent(oe); } return em; } /* * returns 1 when the nocow is safe, < 1 on error, 0 if the * block must be cow'd */ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, u64 *orig_start, u64 *orig_block_len, u64 *ram_bytes) { struct btrfs_trans_handle *trans; struct btrfs_path *path; int ret; struct extent_buffer *leaf; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_file_extent_item *fi; struct btrfs_key key; u64 disk_bytenr; u64 backref_offset; u64 extent_end; u64 num_bytes; int slot; int found_type; bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW); path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode), offset, 0); if (ret < 0) goto out; slot = path->slots[0]; if (ret == 1) { if (slot == 0) { /* can't find the item, must cow */ ret = 0; goto out; } slot--; } ret = 0; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid != btrfs_ino(inode) || key.type != BTRFS_EXTENT_DATA_KEY) { /* not our file or wrong item type, must cow */ goto out; } if (key.offset > offset) { /* Wrong offset, must cow */ goto out; } fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); found_type = btrfs_file_extent_type(leaf, fi); if (found_type != BTRFS_FILE_EXTENT_REG && found_type != BTRFS_FILE_EXTENT_PREALLOC) { /* not a regular extent, must cow */ goto out; } if (!nocow && found_type == BTRFS_FILE_EXTENT_REG) goto out; extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); if (extent_end <= offset) goto out; disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); if (disk_bytenr == 0) goto out; if (btrfs_file_extent_compression(leaf, fi) || btrfs_file_extent_encryption(leaf, fi) || btrfs_file_extent_other_encoding(leaf, fi)) goto out; backref_offset = btrfs_file_extent_offset(leaf, fi); if (orig_start) { *orig_start = key.offset - backref_offset; *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); } if (btrfs_extent_readonly(root, disk_bytenr)) goto out; num_bytes = min(offset + *len, extent_end) - offset; if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) { u64 range_end; range_end = round_up(offset + num_bytes, root->sectorsize) - 1; ret = test_range_bit(io_tree, offset, range_end, EXTENT_DELALLOC, 0, NULL); if (ret) { ret = -EAGAIN; goto out; } } btrfs_release_path(path); /* * look for other files referencing this extent, if we * find any we must cow */ trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = 0; goto out; } ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode), key.offset - backref_offset, disk_bytenr); btrfs_end_transaction(trans, root); if (ret) { ret = 0; goto out; } /* * adjust disk_bytenr and num_bytes to cover just the bytes * in this extent we are about to write. If there * are any csums in that range we have to cow in order * to keep the csums correct */ disk_bytenr += backref_offset; disk_bytenr += offset - key.offset; if (csum_exist_in_range(root, disk_bytenr, num_bytes)) goto out; /* * all of the above have passed, it is safe to overwrite this extent * without cow */ *len = num_bytes; ret = 1; out: btrfs_free_path(path); return ret; } bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end) { struct radix_tree_root *root = &inode->i_mapping->page_tree; int found = false; void **pagep = NULL; struct page *page = NULL; int start_idx; int end_idx; start_idx = start >> PAGE_SHIFT; /* * end is the last byte in the last page. end == start is legal */ end_idx = end >> PAGE_SHIFT; rcu_read_lock(); /* Most of the code in this while loop is lifted from * find_get_page. It's been modified to begin searching from a * page and return just the first page found in that range. If the * found idx is less than or equal to the end idx then we know that * a page exists. If no pages are found or if those pages are * outside of the range then we're fine (yay!) */ while (page == NULL && radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) { page = radix_tree_deref_slot(pagep); if (unlikely(!page)) break; if (radix_tree_exception(page)) { if (radix_tree_deref_retry(page)) { page = NULL; continue; } /* * Otherwise, shmem/tmpfs must be storing a swap entry * here as an exceptional entry: so return it without * attempting to raise page count. */ page = NULL; break; /* TODO: Is this relevant for this use case? */ } if (!page_cache_get_speculative(page)) { page = NULL; continue; } /* * Has the page moved? * This is part of the lockless pagecache protocol. See * include/linux/pagemap.h for details. */ if (unlikely(page != *pagep)) { put_page(page); page = NULL; } } if (page) { if (page->index <= end_idx) found = true; put_page(page); } rcu_read_unlock(); return found; } static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, struct extent_state **cached_state, int writing) { struct btrfs_ordered_extent *ordered; int ret = 0; while (1) { lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, cached_state); /* * We're concerned with the entire range that we're going to be * doing DIO to, so we need to make sure there's no ordered * extents in this range. */ ordered = btrfs_lookup_ordered_range(inode, lockstart, lockend - lockstart + 1); /* * We need to make sure there are no buffered pages in this * range either, we could have raced between the invalidate in * generic_file_direct_write and locking the extent. The * invalidate needs to happen so that reads after a write do not * get stale data. */ if (!ordered && (!writing || !btrfs_page_exists_in_range(inode, lockstart, lockend))) break; unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, cached_state, GFP_NOFS); if (ordered) { /* * If we are doing a DIO read and the ordered extent we * found is for a buffered write, we can not wait for it * to complete and retry, because if we do so we can * deadlock with concurrent buffered writes on page * locks. This happens only if our DIO read covers more * than one extent map, if at this point has already * created an ordered extent for a previous extent map * and locked its range in the inode's io tree, and a * concurrent write against that previous extent map's * range and this range started (we unlock the ranges * in the io tree only when the bios complete and * buffered writes always lock pages before attempting * to lock range in the io tree). */ if (writing || test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) btrfs_start_ordered_extent(inode, ordered, 1); else ret = -ENOTBLK; btrfs_put_ordered_extent(ordered); } else { /* * We could trigger writeback for this range (and wait * for it to complete) and then invalidate the pages for * this range (through invalidate_inode_pages2_range()), * but that can lead us to a deadlock with a concurrent * call to readpages() (a buffered read or a defrag call * triggered a readahead) on a page lock due to an * ordered dio extent we created before but did not have * yet a corresponding bio submitted (whence it can not * complete), which makes readpages() wait for that * ordered extent to complete while holding a lock on * that page. */ ret = -ENOTBLK; } if (ret) break; cond_resched(); } return ret; } static struct extent_map *create_pinned_em(struct inode *inode, u64 start, u64 len, u64 orig_start, u64 block_start, u64 block_len, u64 orig_block_len, u64 ram_bytes, int type) { struct extent_map_tree *em_tree; struct extent_map *em; struct btrfs_root *root = BTRFS_I(inode)->root; int ret; em_tree = &BTRFS_I(inode)->extent_tree; em = alloc_extent_map(); if (!em) return ERR_PTR(-ENOMEM); em->start = start; em->orig_start = orig_start; em->mod_start = start; em->mod_len = len; em->len = len; em->block_len = block_len; em->block_start = block_start; em->bdev = root->fs_info->fs_devices->latest_bdev; em->orig_block_len = orig_block_len; em->ram_bytes = ram_bytes; em->generation = -1; set_bit(EXTENT_FLAG_PINNED, &em->flags); if (type == BTRFS_ORDERED_PREALLOC) set_bit(EXTENT_FLAG_FILLING, &em->flags); do { btrfs_drop_extent_cache(inode, em->start, em->start + em->len - 1, 0); write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em, 1); write_unlock(&em_tree->lock); } while (ret == -EEXIST); if (ret) { free_extent_map(em); return ERR_PTR(ret); } return em; } static void adjust_dio_outstanding_extents(struct inode *inode, struct btrfs_dio_data *dio_data, const u64 len) { unsigned num_extents; num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE); /* * If we have an outstanding_extents count still set then we're * within our reservation, otherwise we need to adjust our inode * counter appropriately. */ if (dio_data->outstanding_extents) { dio_data->outstanding_extents -= num_extents; } else { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents += num_extents; spin_unlock(&BTRFS_I(inode)->lock); } } static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { struct extent_map *em; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_state *cached_state = NULL; struct btrfs_dio_data *dio_data = NULL; u64 start = iblock << inode->i_blkbits; u64 lockstart, lockend; u64 len = bh_result->b_size; int unlock_bits = EXTENT_LOCKED; int ret = 0; if (create) unlock_bits |= EXTENT_DIRTY; else len = min_t(u64, len, root->sectorsize); lockstart = start; lockend = start + len - 1; if (current->journal_info) { /* * Need to pull our outstanding extents and set journal_info to NULL so * that anything that needs to check if there's a transaction doesn't get * confused. */ dio_data = current->journal_info; current->journal_info = NULL; } /* * If this errors out it's because we couldn't invalidate pagecache for * this range and we need to fallback to buffered. */ if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create)) { ret = -ENOTBLK; goto err; } em = btrfs_get_extent(inode, NULL, 0, start, len, 0); if (IS_ERR(em)) { ret = PTR_ERR(em); goto unlock_err; } /* * Ok for INLINE and COMPRESSED extents we need to fallback on buffered * io. INLINE is special, and we could probably kludge it in here, but * it's still buffered so for safety lets just fall back to the generic * buffered path. * * For COMPRESSED we _have_ to read the entire extent in so we can * decompress it, so there will be buffering required no matter what we * do, so go ahead and fallback to buffered. * * We return -ENOTBLK because that's what makes DIO go ahead and go back * to buffered IO. Don't blame me, this is the price we pay for using * the generic code. */ if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || em->block_start == EXTENT_MAP_INLINE) { free_extent_map(em); ret = -ENOTBLK; goto unlock_err; } /* Just a good old fashioned hole, return */ if (!create && (em->block_start == EXTENT_MAP_HOLE || test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { free_extent_map(em); goto unlock_err; } /* * We don't allocate a new extent in the following cases * * 1) The inode is marked as NODATACOW. In this case we'll just use the * existing extent. * 2) The extent is marked as PREALLOC. We're good to go here and can * just use the extent. * */ if (!create) { len = min(len, em->len - (start - em->start)); lockstart = start + len; goto unlock; } if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && em->block_start != EXTENT_MAP_HOLE)) { int type; u64 block_start, orig_start, orig_block_len, ram_bytes; if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) type = BTRFS_ORDERED_PREALLOC; else type = BTRFS_ORDERED_NOCOW; len = min(len, em->len - (start - em->start)); block_start = em->block_start + (start - em->start); if (can_nocow_extent(inode, start, &len, &orig_start, &orig_block_len, &ram_bytes) == 1) { if (type == BTRFS_ORDERED_PREALLOC) { free_extent_map(em); em = create_pinned_em(inode, start, len, orig_start, block_start, len, orig_block_len, ram_bytes, type); if (IS_ERR(em)) { ret = PTR_ERR(em); goto unlock_err; } } ret = btrfs_add_ordered_extent_dio(inode, start, block_start, len, len, type); if (ret) { free_extent_map(em); goto unlock_err; } goto unlock; } } /* * this will cow the extent, reset the len in case we changed * it above */ len = bh_result->b_size; free_extent_map(em); em = btrfs_new_extent_direct(inode, start, len); if (IS_ERR(em)) { ret = PTR_ERR(em); goto unlock_err; } len = min(len, em->len - (start - em->start)); unlock: bh_result->b_blocknr = (em->block_start + (start - em->start)) >> inode->i_blkbits; bh_result->b_size = len; bh_result->b_bdev = em->bdev; set_buffer_mapped(bh_result); if (create) { if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) set_buffer_new(bh_result); /* * Need to update the i_size under the extent lock so buffered * readers will get the updated i_size when we unlock. */ if (start + len > i_size_read(inode)) i_size_write(inode, start + len); adjust_dio_outstanding_extents(inode, dio_data, len); btrfs_free_reserved_data_space(inode, start, len); WARN_ON(dio_data->reserve < len); dio_data->reserve -= len; dio_data->unsubmitted_oe_range_end = start + len; current->journal_info = dio_data; } /* * In the case of write we need to clear and unlock the entire range, * in the case of read we need to unlock only the end area that we * aren't using if there is any left over space. */ if (lockstart < lockend) { clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, unlock_bits, 1, 0, &cached_state, GFP_NOFS); } else { free_extent_state(cached_state); } free_extent_map(em); return 0; unlock_err: clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend, unlock_bits, 1, 0, &cached_state, GFP_NOFS); err: if (dio_data) current->journal_info = dio_data; /* * Compensate the delalloc release we do in btrfs_direct_IO() when we * write less data then expected, so that we don't underflow our inode's * outstanding extents counter. */ if (create && dio_data) adjust_dio_outstanding_extents(inode, dio_data, len); return ret; } static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio, int rw, int mirror_num) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret; BUG_ON(rw & REQ_WRITE); bio_get(bio); ret = btrfs_bio_wq_end_io(root->fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR); if (ret) goto err; ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); err: bio_put(bio); return ret; } static int btrfs_check_dio_repairable(struct inode *inode, struct bio *failed_bio, struct io_failure_record *failrec, int failed_mirror) { int num_copies; num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info, failrec->logical, failrec->len); if (num_copies == 1) { /* * we only have a single copy of the data, so don't bother with * all the retry and error correction code that follows. no * matter what the error is, it is very likely to persist. */ pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n", num_copies, failrec->this_mirror, failed_mirror); return 0; } failrec->failed_mirror = failed_mirror; failrec->this_mirror++; if (failrec->this_mirror == failed_mirror) failrec->this_mirror++; if (failrec->this_mirror > num_copies) { pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n", num_copies, failrec->this_mirror, failed_mirror); return 0; } return 1; } static int dio_read_error(struct inode *inode, struct bio *failed_bio, struct page *page, unsigned int pgoff, u64 start, u64 end, int failed_mirror, bio_end_io_t *repair_endio, void *repair_arg) { struct io_failure_record *failrec; struct bio *bio; int isector; int read_mode; int ret; BUG_ON(failed_bio->bi_rw & REQ_WRITE); ret = btrfs_get_io_failure_record(inode, start, end, &failrec); if (ret) return ret; ret = btrfs_check_dio_repairable(inode, failed_bio, failrec, failed_mirror); if (!ret) { free_io_failure(inode, failrec); return -EIO; } if ((failed_bio->bi_vcnt > 1) || (failed_bio->bi_io_vec->bv_len > BTRFS_I(inode)->root->sectorsize)) read_mode = READ_SYNC | REQ_FAILFAST_DEV; else read_mode = READ_SYNC; isector = start - btrfs_io_bio(failed_bio)->logical; isector >>= inode->i_sb->s_blocksize_bits; bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page, pgoff, isector, repair_endio, repair_arg); if (!bio) { free_io_failure(inode, failrec); return -EIO; } btrfs_debug(BTRFS_I(inode)->root->fs_info, "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n", read_mode, failrec->this_mirror, failrec->in_validation); ret = submit_dio_repair_bio(inode, bio, read_mode, failrec->this_mirror); if (ret) { free_io_failure(inode, failrec); bio_put(bio); } return ret; } struct btrfs_retry_complete { struct completion done; struct inode *inode; u64 start; int uptodate; }; static void btrfs_retry_endio_nocsum(struct bio *bio) { struct btrfs_retry_complete *done = bio->bi_private; struct inode *inode; struct bio_vec *bvec; int i; if (bio->bi_error) goto end; ASSERT(bio->bi_vcnt == 1); inode = bio->bi_io_vec->bv_page->mapping->host; ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize); done->uptodate = 1; bio_for_each_segment_all(bvec, bio, i) clean_io_failure(done->inode, done->start, bvec->bv_page, 0); end: complete(&done->done); bio_put(bio); } static int __btrfs_correct_data_nocsum(struct inode *inode, struct btrfs_io_bio *io_bio) { struct btrfs_fs_info *fs_info; struct bio_vec *bvec; struct btrfs_retry_complete done; u64 start; unsigned int pgoff; u32 sectorsize; int nr_sectors; int i; int ret; fs_info = BTRFS_I(inode)->root->fs_info; sectorsize = BTRFS_I(inode)->root->sectorsize; start = io_bio->logical; done.inode = inode; bio_for_each_segment_all(bvec, &io_bio->bio, i) { nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len); pgoff = bvec->bv_offset; next_block_or_try_again: done.uptodate = 0; done.start = start; init_completion(&done.done); ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, pgoff, start, start + sectorsize - 1, io_bio->mirror_num, btrfs_retry_endio_nocsum, &done); if (ret) return ret; wait_for_completion(&done.done); if (!done.uptodate) { /* We might have another mirror, so try again */ goto next_block_or_try_again; } start += sectorsize; if (nr_sectors--) { pgoff += sectorsize; goto next_block_or_try_again; } } return 0; } static void btrfs_retry_endio(struct bio *bio) { struct btrfs_retry_complete *done = bio->bi_private; struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); struct inode *inode; struct bio_vec *bvec; u64 start; int uptodate; int ret; int i; if (bio->bi_error) goto end; uptodate = 1; start = done->start; ASSERT(bio->bi_vcnt == 1); inode = bio->bi_io_vec->bv_page->mapping->host; ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize); bio_for_each_segment_all(bvec, bio, i) { ret = __readpage_endio_check(done->inode, io_bio, i, bvec->bv_page, bvec->bv_offset, done->start, bvec->bv_len); if (!ret) clean_io_failure(done->inode, done->start, bvec->bv_page, bvec->bv_offset); else uptodate = 0; } done->uptodate = uptodate; end: complete(&done->done); bio_put(bio); } static int __btrfs_subio_endio_read(struct inode *inode, struct btrfs_io_bio *io_bio, int err) { struct btrfs_fs_info *fs_info; struct bio_vec *bvec; struct btrfs_retry_complete done; u64 start; u64 offset = 0; u32 sectorsize; int nr_sectors; unsigned int pgoff; int csum_pos; int i; int ret; fs_info = BTRFS_I(inode)->root->fs_info; sectorsize = BTRFS_I(inode)->root->sectorsize; err = 0; start = io_bio->logical; done.inode = inode; bio_for_each_segment_all(bvec, &io_bio->bio, i) { nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len); pgoff = bvec->bv_offset; next_block: csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset); ret = __readpage_endio_check(inode, io_bio, csum_pos, bvec->bv_page, pgoff, start, sectorsize); if (likely(!ret)) goto next; try_again: done.uptodate = 0; done.start = start; init_completion(&done.done); ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, pgoff, start, start + sectorsize - 1, io_bio->mirror_num, btrfs_retry_endio, &done); if (ret) { err = ret; goto next; } wait_for_completion(&done.done); if (!done.uptodate) { /* We might have another mirror, so try again */ goto try_again; } next: offset += sectorsize; start += sectorsize; ASSERT(nr_sectors); if (--nr_sectors) { pgoff += sectorsize; goto next_block; } } return err; } static int btrfs_subio_endio_read(struct inode *inode, struct btrfs_io_bio *io_bio, int err) { bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; if (skip_csum) { if (unlikely(err)) return __btrfs_correct_data_nocsum(inode, io_bio); else return 0; } else { return __btrfs_subio_endio_read(inode, io_bio, err); } } static void btrfs_endio_direct_read(struct bio *bio) { struct btrfs_dio_private *dip = bio->bi_private; struct inode *inode = dip->inode; struct bio *dio_bio; struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); int err = bio->bi_error; if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) err = btrfs_subio_endio_read(inode, io_bio, err); unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset, dip->logical_offset + dip->bytes - 1); dio_bio = dip->dio_bio; kfree(dip); dio_bio->bi_error = bio->bi_error; dio_end_io(dio_bio, bio->bi_error); if (io_bio->end_io) io_bio->end_io(io_bio, err); bio_put(bio); } static void btrfs_endio_direct_write_update_ordered(struct inode *inode, const u64 offset, const u64 bytes, const int uptodate) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_ordered_extent *ordered = NULL; u64 ordered_offset = offset; u64 ordered_bytes = bytes; int ret; again: ret = btrfs_dec_test_first_ordered_pending(inode, &ordered, &ordered_offset, ordered_bytes, uptodate); if (!ret) goto out_test; btrfs_init_work(&ordered->work, btrfs_endio_write_helper, finish_ordered_fn, NULL, NULL); btrfs_queue_work(root->fs_info->endio_write_workers, &ordered->work); out_test: /* * our bio might span multiple ordered extents. If we haven't * completed the accounting for the whole dio, go back and try again */ if (ordered_offset < offset + bytes) { ordered_bytes = offset + bytes - ordered_offset; ordered = NULL; goto again; } } static void btrfs_endio_direct_write(struct bio *bio) { struct btrfs_dio_private *dip = bio->bi_private; struct bio *dio_bio = dip->dio_bio; btrfs_endio_direct_write_update_ordered(dip->inode, dip->logical_offset, dip->bytes, !bio->bi_error); kfree(dip); dio_bio->bi_error = bio->bi_error; dio_end_io(dio_bio, bio->bi_error); bio_put(bio); } static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 offset) { int ret; struct btrfs_root *root = BTRFS_I(inode)->root; ret = btrfs_csum_one_bio(root, inode, bio, offset, 1); BUG_ON(ret); /* -ENOMEM */ return 0; } static void btrfs_end_dio_bio(struct bio *bio) { struct btrfs_dio_private *dip = bio->bi_private; int err = bio->bi_error; if (err) btrfs_warn(BTRFS_I(dip->inode)->root->fs_info, "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d", btrfs_ino(dip->inode), bio->bi_rw, (unsigned long long)bio->bi_iter.bi_sector, bio->bi_iter.bi_size, err); if (dip->subio_endio) err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err); if (err) { dip->errors = 1; /* * before atomic variable goto zero, we must make sure * dip->errors is perceived to be set. */ smp_mb__before_atomic(); } /* if there are more bios still pending for this dio, just exit */ if (!atomic_dec_and_test(&dip->pending_bios)) goto out; if (dip->errors) { bio_io_error(dip->orig_bio); } else { dip->dio_bio->bi_error = 0; bio_endio(dip->orig_bio); } out: bio_put(bio); } static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev, u64 first_sector, gfp_t gfp_flags) { struct bio *bio; bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags); if (bio) bio_associate_current(bio); return bio; } static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root, struct inode *inode, struct btrfs_dio_private *dip, struct bio *bio, u64 file_offset) { struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio); int ret; /* * We load all the csum data we need when we submit * the first bio to reduce the csum tree search and * contention. */ if (dip->logical_offset == file_offset) { ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio, file_offset); if (ret) return ret; } if (bio == dip->orig_bio) return 0; file_offset -= dip->logical_offset; file_offset >>= inode->i_sb->s_blocksize_bits; io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset); return 0; } static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, int rw, u64 file_offset, int skip_sum, int async_submit) { struct btrfs_dio_private *dip = bio->bi_private; int write = rw & REQ_WRITE; struct btrfs_root *root = BTRFS_I(inode)->root; int ret; if (async_submit) async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); bio_get(bio); if (!write) { ret = btrfs_bio_wq_end_io(root->fs_info, bio, BTRFS_WQ_ENDIO_DATA); if (ret) goto err; } if (skip_sum) goto map; if (write && async_submit) { ret = btrfs_wq_submit_bio(root->fs_info, inode, rw, bio, 0, 0, file_offset, __btrfs_submit_bio_start_direct_io, __btrfs_submit_bio_done); goto err; } else if (write) { /* * If we aren't doing async submit, calculate the csum of the * bio now. */ ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1); if (ret) goto err; } else { ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio, file_offset); if (ret) goto err; } map: ret = btrfs_map_bio(root, rw, bio, 0, async_submit); err: bio_put(bio); return ret; } static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip, int skip_sum) { struct inode *inode = dip->inode; struct btrfs_root *root = BTRFS_I(inode)->root; struct bio *bio; struct bio *orig_bio = dip->orig_bio; struct bio_vec *bvec = orig_bio->bi_io_vec; u64 start_sector = orig_bio->bi_iter.bi_sector; u64 file_offset = dip->logical_offset; u64 submit_len = 0; u64 map_length; u32 blocksize = root->sectorsize; int async_submit = 0; int nr_sectors; int ret; int i; map_length = orig_bio->bi_iter.bi_size; ret = btrfs_map_block(root->fs_info, rw, start_sector << 9, &map_length, NULL, 0); if (ret) return -EIO; if (map_length >= orig_bio->bi_iter.bi_size) { bio = orig_bio; dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED; goto submit; } /* async crcs make it difficult to collect full stripe writes. */ if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK) async_submit = 0; else async_submit = 1; bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); if (!bio) return -ENOMEM; bio->bi_private = dip; bio->bi_end_io = btrfs_end_dio_bio; btrfs_io_bio(bio)->logical = file_offset; atomic_inc(&dip->pending_bios); while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) { nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len); i = 0; next_block: if (unlikely(map_length < submit_len + blocksize || bio_add_page(bio, bvec->bv_page, blocksize, bvec->bv_offset + (i * blocksize)) < blocksize)) { /* * inc the count before we submit the bio so * we know the end IO handler won't happen before * we inc the count. Otherwise, the dip might get freed * before we're done setting it up */ atomic_inc(&dip->pending_bios); ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, async_submit); if (ret) { bio_put(bio); atomic_dec(&dip->pending_bios); goto out_err; } start_sector += submit_len >> 9; file_offset += submit_len; submit_len = 0; bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS); if (!bio) goto out_err; bio->bi_private = dip; bio->bi_end_io = btrfs_end_dio_bio; btrfs_io_bio(bio)->logical = file_offset; map_length = orig_bio->bi_iter.bi_size; ret = btrfs_map_block(root->fs_info, rw, start_sector << 9, &map_length, NULL, 0); if (ret) { bio_put(bio); goto out_err; } goto next_block; } else { submit_len += blocksize; if (--nr_sectors) { i++; goto next_block; } bvec++; } } submit: ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum, async_submit); if (!ret) return 0; bio_put(bio); out_err: dip->errors = 1; /* * before atomic variable goto zero, we must * make sure dip->errors is perceived to be set. */ smp_mb__before_atomic(); if (atomic_dec_and_test(&dip->pending_bios)) bio_io_error(dip->orig_bio); /* bio_end_io() will handle error, so we needn't return it */ return 0; } static void btrfs_submit_direct(int rw, struct bio *dio_bio, struct inode *inode, loff_t file_offset) { struct btrfs_dio_private *dip = NULL; struct bio *io_bio = NULL; struct btrfs_io_bio *btrfs_bio; int skip_sum; int write = rw & REQ_WRITE; int ret = 0; skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS); if (!io_bio) { ret = -ENOMEM; goto free_ordered; } dip = kzalloc(sizeof(*dip), GFP_NOFS); if (!dip) { ret = -ENOMEM; goto free_ordered; } dip->private = dio_bio->bi_private; dip->inode = inode; dip->logical_offset = file_offset; dip->bytes = dio_bio->bi_iter.bi_size; dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9; io_bio->bi_private = dip; dip->orig_bio = io_bio; dip->dio_bio = dio_bio; atomic_set(&dip->pending_bios, 0); btrfs_bio = btrfs_io_bio(io_bio); btrfs_bio->logical = file_offset; if (write) { io_bio->bi_end_io = btrfs_endio_direct_write; } else { io_bio->bi_end_io = btrfs_endio_direct_read; dip->subio_endio = btrfs_subio_endio_read; } /* * Reset the range for unsubmitted ordered extents (to a 0 length range) * even if we fail to submit a bio, because in such case we do the * corresponding error handling below and it must not be done a second * time by btrfs_direct_IO(). */ if (write) { struct btrfs_dio_data *dio_data = current->journal_info; dio_data->unsubmitted_oe_range_end = dip->logical_offset + dip->bytes; dio_data->unsubmitted_oe_range_start = dio_data->unsubmitted_oe_range_end; } ret = btrfs_submit_direct_hook(rw, dip, skip_sum); if (!ret) return; if (btrfs_bio->end_io) btrfs_bio->end_io(btrfs_bio, ret); free_ordered: /* * If we arrived here it means either we failed to submit the dip * or we either failed to clone the dio_bio or failed to allocate the * dip. If we cloned the dio_bio and allocated the dip, we can just * call bio_endio against our io_bio so that we get proper resource * cleanup if we fail to submit the dip, otherwise, we must do the * same as btrfs_endio_direct_[write|read] because we can't call these * callbacks - they require an allocated dip and a clone of dio_bio. */ if (io_bio && dip) { io_bio->bi_error = -EIO; bio_endio(io_bio); /* * The end io callbacks free our dip, do the final put on io_bio * and all the cleanup and final put for dio_bio (through * dio_end_io()). */ dip = NULL; io_bio = NULL; } else { if (write) btrfs_endio_direct_write_update_ordered(inode, file_offset, dio_bio->bi_iter.bi_size, 0); else unlock_extent(&BTRFS_I(inode)->io_tree, file_offset, file_offset + dio_bio->bi_iter.bi_size - 1); dio_bio->bi_error = -EIO; /* * Releases and cleans up our dio_bio, no need to bio_put() * nor bio_endio()/bio_io_error() against dio_bio. */ dio_end_io(dio_bio, ret); } if (io_bio) bio_put(io_bio); kfree(dip); } static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb, const struct iov_iter *iter, loff_t offset) { int seg; int i; unsigned blocksize_mask = root->sectorsize - 1; ssize_t retval = -EINVAL; if (offset & blocksize_mask) goto out; if (iov_iter_alignment(iter) & blocksize_mask) goto out; /* If this is a write we don't need to check anymore */ if (iov_iter_rw(iter) == WRITE) return 0; /* * Check to make sure we don't have duplicate iov_base's in this * iovec, if so return EINVAL, otherwise we'll get csum errors * when reading back. */ for (seg = 0; seg < iter->nr_segs; seg++) { for (i = seg + 1; i < iter->nr_segs; i++) { if (iter->iov[seg].iov_base == iter->iov[i].iov_base) goto out; } } retval = 0; out: return retval; } static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_dio_data dio_data = { 0 }; size_t count = 0; int flags = 0; bool wakeup = true; bool relock = false; ssize_t ret; if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset)) return 0; inode_dio_begin(inode); smp_mb__after_atomic(); /* * The generic stuff only does filemap_write_and_wait_range, which * isn't enough if we've written compressed pages to this area, so * we need to flush the dirty pages again to make absolutely sure * that any outstanding dirty pages are on disk. */ count = iov_iter_count(iter); if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &BTRFS_I(inode)->runtime_flags)) filemap_fdatawrite_range(inode->i_mapping, offset, offset + count - 1); if (iov_iter_rw(iter) == WRITE) { /* * If the write DIO is beyond the EOF, we need update * the isize, but it is protected by i_mutex. So we can * not unlock the i_mutex at this case. */ if (offset + count <= inode->i_size) { inode_unlock(inode); relock = true; } ret = btrfs_delalloc_reserve_space(inode, offset, count); if (ret) goto out; dio_data.outstanding_extents = div64_u64(count + BTRFS_MAX_EXTENT_SIZE - 1, BTRFS_MAX_EXTENT_SIZE); /* * We need to know how many extents we reserved so that we can * do the accounting properly if we go over the number we * originally calculated. Abuse current->journal_info for this. */ dio_data.reserve = round_up(count, root->sectorsize); dio_data.unsubmitted_oe_range_start = (u64)offset; dio_data.unsubmitted_oe_range_end = (u64)offset; current->journal_info = &dio_data; } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK, &BTRFS_I(inode)->runtime_flags)) { inode_dio_end(inode); flags = DIO_LOCKING | DIO_SKIP_HOLES; wakeup = false; } ret = __blockdev_direct_IO(iocb, inode, BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev, iter, offset, btrfs_get_blocks_direct, NULL, btrfs_submit_direct, flags); if (iov_iter_rw(iter) == WRITE) { current->journal_info = NULL; if (ret < 0 && ret != -EIOCBQUEUED) { if (dio_data.reserve) btrfs_delalloc_release_space(inode, offset, dio_data.reserve); /* * On error we might have left some ordered extents * without submitting corresponding bios for them, so * cleanup them up to avoid other tasks getting them * and waiting for them to complete forever. */ if (dio_data.unsubmitted_oe_range_start < dio_data.unsubmitted_oe_range_end) btrfs_endio_direct_write_update_ordered(inode, dio_data.unsubmitted_oe_range_start, dio_data.unsubmitted_oe_range_end - dio_data.unsubmitted_oe_range_start, 0); } else if (ret >= 0 && (size_t)ret < count) btrfs_delalloc_release_space(inode, offset, count - (size_t)ret); } out: if (wakeup) inode_dio_end(inode); if (relock) inode_lock(inode); return ret; } #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len) { int ret; ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS); if (ret) return ret; return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap); } int btrfs_readpage(struct file *file, struct page *page) { struct extent_io_tree *tree; tree = &BTRFS_I(page->mapping->host)->io_tree; return extent_read_full_page(tree, page, btrfs_get_extent, 0); } static int btrfs_writepage(struct page *page, struct writeback_control *wbc) { struct extent_io_tree *tree; struct inode *inode = page->mapping->host; int ret; if (current->flags & PF_MEMALLOC) { redirty_page_for_writepage(wbc, page); unlock_page(page); return 0; } /* * If we are under memory pressure we will call this directly from the * VM, we need to make sure we have the inode referenced for the ordered * extent. If not just return like we didn't do anything. */ if (!igrab(inode)) { redirty_page_for_writepage(wbc, page); return AOP_WRITEPAGE_ACTIVATE; } tree = &BTRFS_I(page->mapping->host)->io_tree; ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc); btrfs_add_delayed_iput(inode); return ret; } static int btrfs_writepages(struct address_space *mapping, struct writeback_control *wbc) { struct extent_io_tree *tree; tree = &BTRFS_I(mapping->host)->io_tree; return extent_writepages(tree, mapping, btrfs_get_extent, wbc); } static int btrfs_readpages(struct file *file, struct address_space *mapping, struct list_head *pages, unsigned nr_pages) { struct extent_io_tree *tree; tree = &BTRFS_I(mapping->host)->io_tree; return extent_readpages(tree, mapping, pages, nr_pages, btrfs_get_extent); } static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) { struct extent_io_tree *tree; struct extent_map_tree *map; int ret; tree = &BTRFS_I(page->mapping->host)->io_tree; map = &BTRFS_I(page->mapping->host)->extent_tree; ret = try_release_extent_mapping(map, tree, page, gfp_flags); if (ret == 1) { ClearPagePrivate(page); set_page_private(page, 0); put_page(page); } return ret; } static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) { if (PageWriteback(page) || PageDirty(page)) return 0; return __btrfs_releasepage(page, gfp_flags & GFP_NOFS); } static void btrfs_invalidatepage(struct page *page, unsigned int offset, unsigned int length) { struct inode *inode = page->mapping->host; struct extent_io_tree *tree; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; u64 page_start = page_offset(page); u64 page_end = page_start + PAGE_SIZE - 1; u64 start; u64 end; int inode_evicting = inode->i_state & I_FREEING; /* * we have the page locked, so new writeback can't start, * and the dirty bit won't be cleared while we are here. * * Wait for IO on this page so that we can safely clear * the PagePrivate2 bit and do ordered accounting */ wait_on_page_writeback(page); tree = &BTRFS_I(inode)->io_tree; if (offset) { btrfs_releasepage(page, GFP_NOFS); return; } if (!inode_evicting) lock_extent_bits(tree, page_start, page_end, &cached_state); again: start = page_start; ordered = btrfs_lookup_ordered_range(inode, start, page_end - start + 1); if (ordered) { end = min(page_end, ordered->file_offset + ordered->len - 1); /* * IO on this page will never be started, so we need * to account for any ordered extents now */ if (!inode_evicting) clear_extent_bit(tree, start, end, EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS); /* * whoever cleared the private bit is responsible * for the finish_ordered_io */ if (TestClearPagePrivate2(page)) { struct btrfs_ordered_inode_tree *tree; u64 new_len; tree = &BTRFS_I(inode)->ordered_tree; spin_lock_irq(&tree->lock); set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags); new_len = start - ordered->file_offset; if (new_len < ordered->truncated_len) ordered->truncated_len = new_len; spin_unlock_irq(&tree->lock); if (btrfs_dec_test_ordered_pending(inode, &ordered, start, end - start + 1, 1)) btrfs_finish_ordered_io(ordered); } btrfs_put_ordered_extent(ordered); if (!inode_evicting) { cached_state = NULL; lock_extent_bits(tree, start, end, &cached_state); } start = end + 1; if (start < page_end) goto again; } /* * Qgroup reserved space handler * Page here will be either * 1) Already written to disk * In this case, its reserved space is released from data rsv map * and will be freed by delayed_ref handler finally. * So even we call qgroup_free_data(), it won't decrease reserved * space. * 2) Not written to disk * This means the reserved space should be freed here. */ btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE); if (!inode_evicting) { clear_extent_bit(tree, page_start, page_end, EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1, &cached_state, GFP_NOFS); __btrfs_releasepage(page, GFP_NOFS); } ClearPageChecked(page); if (PagePrivate(page)) { ClearPagePrivate(page); set_page_private(page, 0); put_page(page); } } /* * btrfs_page_mkwrite() is not allowed to change the file size as it gets * called from a page fault handler when a page is first dirtied. Hence we must * be careful to check for EOF conditions here. We set the page up correctly * for a written page which means we get ENOSPC checking when writing into * holes and correct delalloc and unwritten extent mapping on filesystems that * support these features. * * We are not allowed to take the i_mutex here so we have to play games to * protect against truncate races as the page could now be beyond EOF. Because * vmtruncate() writes the inode size before removing pages, once we have the * page lock we can determine safely if the page is beyond EOF. If it is not * beyond EOF, then the page is guaranteed safe against truncation until we * unlock the page. */ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct page *page = vmf->page; struct inode *inode = file_inode(vma->vm_file); struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; char *kaddr; unsigned long zero_start; loff_t size; int ret; int reserved = 0; u64 reserved_space; u64 page_start; u64 page_end; u64 end; reserved_space = PAGE_SIZE; sb_start_pagefault(inode->i_sb); page_start = page_offset(page); page_end = page_start + PAGE_SIZE - 1; end = page_end; /* * Reserving delalloc space after obtaining the page lock can lead to * deadlock. For example, if a dirty page is locked by this function * and the call to btrfs_delalloc_reserve_space() ends up triggering * dirty page write out, then the btrfs_writepage() function could * end up waiting indefinitely to get a lock on the page currently * being processed by btrfs_page_mkwrite() function. */ ret = btrfs_delalloc_reserve_space(inode, page_start, reserved_space); if (!ret) { ret = file_update_time(vma->vm_file); reserved = 1; } if (ret) { if (ret == -ENOMEM) ret = VM_FAULT_OOM; else /* -ENOSPC, -EIO, etc */ ret = VM_FAULT_SIGBUS; if (reserved) goto out; goto out_noreserve; } ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ again: lock_page(page); size = i_size_read(inode); if ((page->mapping != inode->i_mapping) || (page_start >= size)) { /* page got truncated out from underneath us */ goto out_unlock; } wait_on_page_writeback(page); lock_extent_bits(io_tree, page_start, page_end, &cached_state); set_page_extent_mapped(page); /* * we can't set the delalloc bits if there are pending ordered * extents. Drop our locks and wait for them to finish */ ordered = btrfs_lookup_ordered_range(inode, page_start, page_end); if (ordered) { unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); unlock_page(page); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); goto again; } if (page->index == ((size - 1) >> PAGE_SHIFT)) { reserved_space = round_up(size - page_start, root->sectorsize); if (reserved_space < PAGE_SIZE) { end = page_start + reserved_space - 1; spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents++; spin_unlock(&BTRFS_I(inode)->lock); btrfs_delalloc_release_space(inode, page_start, PAGE_SIZE - reserved_space); } } /* * XXX - page_mkwrite gets called every time the page is dirtied, even * if it was already dirty, so for space accounting reasons we need to * clear any delalloc bits for the range we are fixing to save. There * is probably a better way to do this, but for now keep consistent with * prepare_pages in the normal write path. */ clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end, EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS); ret = btrfs_set_extent_delalloc(inode, page_start, end, &cached_state); if (ret) { unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); ret = VM_FAULT_SIGBUS; goto out_unlock; } ret = 0; /* page is wholly or partially inside EOF */ if (page_start + PAGE_SIZE > size) zero_start = size & ~PAGE_MASK; else zero_start = PAGE_SIZE; if (zero_start != PAGE_SIZE) { kaddr = kmap(page); memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start); flush_dcache_page(page); kunmap(page); } ClearPageChecked(page); set_page_dirty(page); SetPageUptodate(page); BTRFS_I(inode)->last_trans = root->fs_info->generation; BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid; BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit; unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); out_unlock: if (!ret) { sb_end_pagefault(inode->i_sb); return VM_FAULT_LOCKED; } unlock_page(page); out: btrfs_delalloc_release_space(inode, page_start, reserved_space); out_noreserve: sb_end_pagefault(inode->i_sb); return ret; } static int btrfs_truncate(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_block_rsv *rsv; int ret = 0; int err = 0; struct btrfs_trans_handle *trans; u64 mask = root->sectorsize - 1; u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1); if (ret) return ret; /* * Yes ladies and gentlemen, this is indeed ugly. The fact is we have * 3 things going on here * * 1) We need to reserve space for our orphan item and the space to * delete our orphan item. Lord knows we don't want to have a dangling * orphan item because we didn't reserve space to remove it. * * 2) We need to reserve space to update our inode. * * 3) We need to have something to cache all the space that is going to * be free'd up by the truncate operation, but also have some slack * space reserved in case it uses space during the truncate (thank you * very much snapshotting). * * And we need these to all be separate. The fact is we can use a lot of * space doing the truncate, and we have no earthly idea how much space * we will use, so we need the truncate reservation to be separate so it * doesn't end up using space reserved for updating the inode or * removing the orphan item. We also need to be able to stop the * transaction and start a new one, which means we need to be able to * update the inode several times, and we have no idea of knowing how * many times that will be, so we can't just reserve 1 item for the * entirety of the operation, so that has to be done separately as well. * Then there is the orphan item, which does indeed need to be held on * to for the whole operation, and we need nobody to touch this reserved * space except the orphan code. * * So that leaves us with * * 1) root->orphan_block_rsv - for the orphan deletion. * 2) rsv - for the truncate reservation, which we will steal from the * transaction reservation. * 3) fs_info->trans_block_rsv - this will have 1 items worth left for * updating the inode. */ rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); if (!rsv) return -ENOMEM; rsv->size = min_size; rsv->failfast = 1; /* * 1 for the truncate slack space * 1 for updating the inode. */ trans = btrfs_start_transaction(root, 2); if (IS_ERR(trans)) { err = PTR_ERR(trans); goto out; } /* Migrate the slack space for the truncate to our reserve */ ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, min_size); BUG_ON(ret); /* * So if we truncate and then write and fsync we normally would just * write the extents that changed, which is a problem if we need to * first truncate that entire inode. So set this flag so we write out * all of the extents in the inode to the sync log so we're completely * safe. */ set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); trans->block_rsv = rsv; while (1) { ret = btrfs_truncate_inode_items(trans, root, inode, inode->i_size, BTRFS_EXTENT_DATA_KEY); if (ret != -ENOSPC && ret != -EAGAIN) { err = ret; break; } trans->block_rsv = &root->fs_info->trans_block_rsv; ret = btrfs_update_inode(trans, root, inode); if (ret) { err = ret; break; } btrfs_end_transaction(trans, root); btrfs_btree_balance_dirty(root); trans = btrfs_start_transaction(root, 2); if (IS_ERR(trans)) { ret = err = PTR_ERR(trans); trans = NULL; break; } ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, min_size); BUG_ON(ret); /* shouldn't happen */ trans->block_rsv = rsv; } if (ret == 0 && inode->i_nlink > 0) { trans->block_rsv = root->orphan_block_rsv; ret = btrfs_orphan_del(trans, inode); if (ret) err = ret; } if (trans) { trans->block_rsv = &root->fs_info->trans_block_rsv; ret = btrfs_update_inode(trans, root, inode); if (ret && !err) err = ret; ret = btrfs_end_transaction(trans, root); btrfs_btree_balance_dirty(root); } out: btrfs_free_block_rsv(root, rsv); if (ret && !err) err = ret; return err; } /* * create a new subvolume directory/inode (helper for the ioctl). */ int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, struct btrfs_root *new_root, struct btrfs_root *parent_root, u64 new_dirid) { struct inode *inode; int err; u64 index = 0; inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid, new_dirid, S_IFDIR | (~current_umask() & S_IRWXUGO), &index); if (IS_ERR(inode)) return PTR_ERR(inode); inode->i_op = &btrfs_dir_inode_operations; inode->i_fop = &btrfs_dir_file_operations; set_nlink(inode, 1); btrfs_i_size_write(inode, 0); unlock_new_inode(inode); err = btrfs_subvol_inherit_props(trans, new_root, parent_root); if (err) btrfs_err(new_root->fs_info, "error inheriting subvolume %llu properties: %d", new_root->root_key.objectid, err); err = btrfs_update_inode(trans, new_root, inode); iput(inode); return err; } struct inode *btrfs_alloc_inode(struct super_block *sb) { struct btrfs_inode *ei; struct inode *inode; ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS); if (!ei) return NULL; ei->root = NULL; ei->generation = 0; ei->last_trans = 0; ei->last_sub_trans = 0; ei->logged_trans = 0; ei->delalloc_bytes = 0; ei->defrag_bytes = 0; ei->disk_i_size = 0; ei->flags = 0; ei->csum_bytes = 0; ei->index_cnt = (u64)-1; ei->dir_index = 0; ei->last_unlink_trans = 0; ei->last_log_commit = 0; ei->delayed_iput_count = 0; spin_lock_init(&ei->lock); ei->outstanding_extents = 0; ei->reserved_extents = 0; ei->runtime_flags = 0; ei->force_compress = BTRFS_COMPRESS_NONE; ei->delayed_node = NULL; ei->i_otime.tv_sec = 0; ei->i_otime.tv_nsec = 0; inode = &ei->vfs_inode; extent_map_tree_init(&ei->extent_tree); extent_io_tree_init(&ei->io_tree, &inode->i_data); extent_io_tree_init(&ei->io_failure_tree, &inode->i_data); ei->io_tree.track_uptodate = 1; ei->io_failure_tree.track_uptodate = 1; atomic_set(&ei->sync_writers, 0); mutex_init(&ei->log_mutex); mutex_init(&ei->delalloc_mutex); btrfs_ordered_inode_tree_init(&ei->ordered_tree); INIT_LIST_HEAD(&ei->delalloc_inodes); INIT_LIST_HEAD(&ei->delayed_iput); RB_CLEAR_NODE(&ei->rb_node); return inode; } #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS void btrfs_test_destroy_inode(struct inode *inode) { btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); } #endif static void btrfs_i_callback(struct rcu_head *head) { struct inode *inode = container_of(head, struct inode, i_rcu); kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); } void btrfs_destroy_inode(struct inode *inode) { struct btrfs_ordered_extent *ordered; struct btrfs_root *root = BTRFS_I(inode)->root; WARN_ON(!hlist_empty(&inode->i_dentry)); WARN_ON(inode->i_data.nrpages); WARN_ON(BTRFS_I(inode)->outstanding_extents); WARN_ON(BTRFS_I(inode)->reserved_extents); WARN_ON(BTRFS_I(inode)->delalloc_bytes); WARN_ON(BTRFS_I(inode)->csum_bytes); WARN_ON(BTRFS_I(inode)->defrag_bytes); /* * This can happen where we create an inode, but somebody else also * created the same inode and we need to destroy the one we already * created. */ if (!root) goto free; if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM, &BTRFS_I(inode)->runtime_flags)) { btrfs_info(root->fs_info, "inode %llu still on the orphan list", btrfs_ino(inode)); atomic_dec(&root->orphan_inodes); } while (1) { ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); if (!ordered) break; else { btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup", ordered->file_offset, ordered->len); btrfs_remove_ordered_extent(inode, ordered); btrfs_put_ordered_extent(ordered); btrfs_put_ordered_extent(ordered); } } btrfs_qgroup_check_reserved_leak(inode); inode_tree_del(inode); btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); free: call_rcu(&inode->i_rcu, btrfs_i_callback); } int btrfs_drop_inode(struct inode *inode) { struct btrfs_root *root = BTRFS_I(inode)->root; if (root == NULL) return 1; /* the snap/subvol tree is on deleting */ if (btrfs_root_refs(&root->root_item) == 0) return 1; else return generic_drop_inode(inode); } static void init_once(void *foo) { struct btrfs_inode *ei = (struct btrfs_inode *) foo; inode_init_once(&ei->vfs_inode); } void btrfs_destroy_cachep(void) { /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); kmem_cache_destroy(btrfs_inode_cachep); kmem_cache_destroy(btrfs_trans_handle_cachep); kmem_cache_destroy(btrfs_transaction_cachep); kmem_cache_destroy(btrfs_path_cachep); kmem_cache_destroy(btrfs_free_space_cachep); } int btrfs_init_cachep(void) { btrfs_inode_cachep = kmem_cache_create("btrfs_inode", sizeof(struct btrfs_inode), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT, init_once); if (!btrfs_inode_cachep) goto fail; btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", sizeof(struct btrfs_trans_handle), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); if (!btrfs_trans_handle_cachep) goto fail; btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction", sizeof(struct btrfs_transaction), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); if (!btrfs_transaction_cachep) goto fail; btrfs_path_cachep = kmem_cache_create("btrfs_path", sizeof(struct btrfs_path), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); if (!btrfs_path_cachep) goto fail; btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", sizeof(struct btrfs_free_space), 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL); if (!btrfs_free_space_cachep) goto fail; return 0; fail: btrfs_destroy_cachep(); return -ENOMEM; } static int btrfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { u64 delalloc_bytes; struct inode *inode = d_inode(dentry); u32 blocksize = inode->i_sb->s_blocksize; generic_fillattr(inode, stat); stat->dev = BTRFS_I(inode)->root->anon_dev; spin_lock(&BTRFS_I(inode)->lock); delalloc_bytes = BTRFS_I(inode)->delalloc_bytes; spin_unlock(&BTRFS_I(inode)->lock); stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + ALIGN(delalloc_bytes, blocksize)) >> 9; return 0; } static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(old_dir)->root; struct btrfs_root *dest = BTRFS_I(new_dir)->root; struct inode *new_inode = d_inode(new_dentry); struct inode *old_inode = d_inode(old_dentry); u64 index = 0; u64 root_objectid; int ret; u64 old_ino = btrfs_ino(old_inode); if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) return -EPERM; /* we only allow rename subvolume link between subvolumes */ if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) return -EXDEV; if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID)) return -ENOTEMPTY; if (S_ISDIR(old_inode->i_mode) && new_inode && new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) return -ENOTEMPTY; /* check for collisions, even if the name isn't there */ ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, new_dentry->d_name.name, new_dentry->d_name.len); if (ret) { if (ret == -EEXIST) { /* we shouldn't get * eexist without a new_inode */ if (WARN_ON(!new_inode)) { return ret; } } else { /* maybe -EOVERFLOW */ return ret; } } ret = 0; /* * we're using rename to replace one file with another. Start IO on it * now so we don't add too much work to the end of the transaction */ if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size) filemap_flush(old_inode->i_mapping); /* close the racy window with snapshot create/destroy ioctl */ if (old_ino == BTRFS_FIRST_FREE_OBJECTID) down_read(&root->fs_info->subvol_sem); /* * We want to reserve the absolute worst case amount of items. So if * both inodes are subvols and we need to unlink them then that would * require 4 item modifications, but if they are both normal inodes it * would require 5 item modifications, so we'll assume their normal * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items * should cover the worst case number of items we'll modify. */ trans = btrfs_start_transaction(root, 11); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out_notrans; } if (dest != root) btrfs_record_root_in_trans(trans, dest); ret = btrfs_set_inode_index(new_dir, &index); if (ret) goto out_fail; BTRFS_I(old_inode)->dir_index = 0ULL; if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { /* force full log commit if subvolume involved. */ btrfs_set_log_full_commit(root->fs_info, trans); } else { ret = btrfs_insert_inode_ref(trans, dest, new_dentry->d_name.name, new_dentry->d_name.len, old_ino, btrfs_ino(new_dir), index); if (ret) goto out_fail; /* * this is an ugly little race, but the rename is required * to make sure that if we crash, the inode is either at the * old name or the new one. pinning the log transaction lets * us make sure we don't allow a log commit to come in after * we unlink the name but before we add the new name back in. */ btrfs_pin_log_trans(root); } inode_inc_iversion(old_dir); inode_inc_iversion(new_dir); inode_inc_iversion(old_inode); old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime = new_dir->i_mtime = old_inode->i_ctime = current_fs_time(old_dir->i_sb); if (old_dentry->d_parent != new_dentry->d_parent) btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid, old_dentry->d_name.name, old_dentry->d_name.len); } else { ret = __btrfs_unlink_inode(trans, root, old_dir, d_inode(old_dentry), old_dentry->d_name.name, old_dentry->d_name.len); if (!ret) ret = btrfs_update_inode(trans, root, old_inode); } if (ret) { btrfs_abort_transaction(trans, root, ret); goto out_fail; } if (new_inode) { inode_inc_iversion(new_inode); new_inode->i_ctime = current_fs_time(new_inode->i_sb); if (unlikely(btrfs_ino(new_inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { root_objectid = BTRFS_I(new_inode)->location.objectid; ret = btrfs_unlink_subvol(trans, dest, new_dir, root_objectid, new_dentry->d_name.name, new_dentry->d_name.len); BUG_ON(new_inode->i_nlink == 0); } else { ret = btrfs_unlink_inode(trans, dest, new_dir, d_inode(new_dentry), new_dentry->d_name.name, new_dentry->d_name.len); } if (!ret && new_inode->i_nlink == 0) ret = btrfs_orphan_add(trans, d_inode(new_dentry)); if (ret) { btrfs_abort_transaction(trans, root, ret); goto out_fail; } } ret = btrfs_add_link(trans, new_dir, old_inode, new_dentry->d_name.name, new_dentry->d_name.len, 0, index); if (ret) { btrfs_abort_transaction(trans, root, ret); goto out_fail; } if (old_inode->i_nlink == 1) BTRFS_I(old_inode)->dir_index = index; if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { struct dentry *parent = new_dentry->d_parent; btrfs_log_new_name(trans, old_inode, old_dir, parent); btrfs_end_log_trans(root); } out_fail: btrfs_end_transaction(trans, root); out_notrans: if (old_ino == BTRFS_FIRST_FREE_OBJECTID) up_read(&root->fs_info->subvol_sem); return ret; } static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { if (flags & ~RENAME_NOREPLACE) return -EINVAL; return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry); } static void btrfs_run_delalloc_work(struct btrfs_work *work) { struct btrfs_delalloc_work *delalloc_work; struct inode *inode; delalloc_work = container_of(work, struct btrfs_delalloc_work, work); inode = delalloc_work->inode; filemap_flush(inode->i_mapping); if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &BTRFS_I(inode)->runtime_flags)) filemap_flush(inode->i_mapping); if (delalloc_work->delay_iput) btrfs_add_delayed_iput(inode); else iput(inode); complete(&delalloc_work->completion); } struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode, int delay_iput) { struct btrfs_delalloc_work *work; work = kmalloc(sizeof(*work), GFP_NOFS); if (!work) return NULL; init_completion(&work->completion); INIT_LIST_HEAD(&work->list); work->inode = inode; work->delay_iput = delay_iput; WARN_ON_ONCE(!inode); btrfs_init_work(&work->work, btrfs_flush_delalloc_helper, btrfs_run_delalloc_work, NULL, NULL); return work; } void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work) { wait_for_completion(&work->completion); kfree(work); } /* * some fairly slow code that needs optimization. This walks the list * of all the inodes with pending delalloc and forces them to disk. */ static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput, int nr) { struct btrfs_inode *binode; struct inode *inode; struct btrfs_delalloc_work *work, *next; struct list_head works; struct list_head splice; int ret = 0; INIT_LIST_HEAD(&works); INIT_LIST_HEAD(&splice); mutex_lock(&root->delalloc_mutex); spin_lock(&root->delalloc_lock); list_splice_init(&root->delalloc_inodes, &splice); while (!list_empty(&splice)) { binode = list_entry(splice.next, struct btrfs_inode, delalloc_inodes); list_move_tail(&binode->delalloc_inodes, &root->delalloc_inodes); inode = igrab(&binode->vfs_inode); if (!inode) { cond_resched_lock(&root->delalloc_lock); continue; } spin_unlock(&root->delalloc_lock); work = btrfs_alloc_delalloc_work(inode, delay_iput); if (!work) { if (delay_iput) btrfs_add_delayed_iput(inode); else iput(inode); ret = -ENOMEM; goto out; } list_add_tail(&work->list, &works); btrfs_queue_work(root->fs_info->flush_workers, &work->work); ret++; if (nr != -1 && ret >= nr) goto out; cond_resched(); spin_lock(&root->delalloc_lock); } spin_unlock(&root->delalloc_lock); out: list_for_each_entry_safe(work, next, &works, list) { list_del_init(&work->list); btrfs_wait_and_free_delalloc_work(work); } if (!list_empty_careful(&splice)) { spin_lock(&root->delalloc_lock); list_splice_tail(&splice, &root->delalloc_inodes); spin_unlock(&root->delalloc_lock); } mutex_unlock(&root->delalloc_mutex); return ret; } int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput) { int ret; if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) return -EROFS; ret = __start_delalloc_inodes(root, delay_iput, -1); if (ret > 0) ret = 0; /* * the filemap_flush will queue IO into the worker threads, but * we have to make sure the IO is actually started and that * ordered extents get created before we return */ atomic_inc(&root->fs_info->async_submit_draining); while (atomic_read(&root->fs_info->nr_async_submits) || atomic_read(&root->fs_info->async_delalloc_pages)) { wait_event(root->fs_info->async_submit_wait, (atomic_read(&root->fs_info->nr_async_submits) == 0 && atomic_read(&root->fs_info->async_delalloc_pages) == 0)); } atomic_dec(&root->fs_info->async_submit_draining); return ret; } int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput, int nr) { struct btrfs_root *root; struct list_head splice; int ret; if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) return -EROFS; INIT_LIST_HEAD(&splice); mutex_lock(&fs_info->delalloc_root_mutex); spin_lock(&fs_info->delalloc_root_lock); list_splice_init(&fs_info->delalloc_roots, &splice); while (!list_empty(&splice) && nr) { root = list_first_entry(&splice, struct btrfs_root, delalloc_root); root = btrfs_grab_fs_root(root); BUG_ON(!root); list_move_tail(&root->delalloc_root, &fs_info->delalloc_roots); spin_unlock(&fs_info->delalloc_root_lock); ret = __start_delalloc_inodes(root, delay_iput, nr); btrfs_put_fs_root(root); if (ret < 0) goto out; if (nr != -1) { nr -= ret; WARN_ON(nr < 0); } spin_lock(&fs_info->delalloc_root_lock); } spin_unlock(&fs_info->delalloc_root_lock); ret = 0; atomic_inc(&fs_info->async_submit_draining); while (atomic_read(&fs_info->nr_async_submits) || atomic_read(&fs_info->async_delalloc_pages)) { wait_event(fs_info->async_submit_wait, (atomic_read(&fs_info->nr_async_submits) == 0 && atomic_read(&fs_info->async_delalloc_pages) == 0)); } atomic_dec(&fs_info->async_submit_draining); out: if (!list_empty_careful(&splice)) { spin_lock(&fs_info->delalloc_root_lock); list_splice_tail(&splice, &fs_info->delalloc_roots); spin_unlock(&fs_info->delalloc_root_lock); } mutex_unlock(&fs_info->delalloc_root_mutex); return ret; } static int btrfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; struct btrfs_path *path; struct btrfs_key key; struct inode *inode = NULL; int err; int drop_inode = 0; u64 objectid; u64 index = 0; int name_len; int datasize; unsigned long ptr; struct btrfs_file_extent_item *ei; struct extent_buffer *leaf; name_len = strlen(symname); if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root)) return -ENAMETOOLONG; /* * 2 items for inode item and ref * 2 items for dir items * 1 item for updating parent inode item * 1 item for the inline extent item * 1 item for xattr if selinux is on */ trans = btrfs_start_transaction(root, 7); if (IS_ERR(trans)) return PTR_ERR(trans); err = btrfs_find_free_ino(root, &objectid); if (err) goto out_unlock; inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, dentry->d_name.len, btrfs_ino(dir), objectid, S_IFLNK|S_IRWXUGO, &index); if (IS_ERR(inode)) { err = PTR_ERR(inode); goto out_unlock; } /* * If the active LSM wants to access the inode during * d_instantiate it needs these. Smack checks to see * if the filesystem supports xattrs by looking at the * ops vector. */ inode->i_fop = &btrfs_file_operations; inode->i_op = &btrfs_file_inode_operations; inode->i_mapping->a_ops = &btrfs_aops; BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); if (err) goto out_unlock_inode; path = btrfs_alloc_path(); if (!path) { err = -ENOMEM; goto out_unlock_inode; } key.objectid = btrfs_ino(inode); key.offset = 0; key.type = BTRFS_EXTENT_DATA_KEY; datasize = btrfs_file_extent_calc_inline_size(name_len); err = btrfs_insert_empty_item(trans, root, path, &key, datasize); if (err) { btrfs_free_path(path); goto out_unlock_inode; } leaf = path->nodes[0]; ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, ei, trans->transid); btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); btrfs_set_file_extent_encryption(leaf, ei, 0); btrfs_set_file_extent_compression(leaf, ei, 0); btrfs_set_file_extent_other_encoding(leaf, ei, 0); btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); ptr = btrfs_file_extent_inline_start(ei); write_extent_buffer(leaf, symname, ptr, name_len); btrfs_mark_buffer_dirty(leaf); btrfs_free_path(path); inode->i_op = &btrfs_symlink_inode_operations; inode_nohighmem(inode); inode->i_mapping->a_ops = &btrfs_symlink_aops; inode_set_bytes(inode, name_len); btrfs_i_size_write(inode, name_len); err = btrfs_update_inode(trans, root, inode); /* * Last step, add directory indexes for our symlink inode. This is the * last step to avoid extra cleanup of these indexes if an error happens * elsewhere above. */ if (!err) err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index); if (err) { drop_inode = 1; goto out_unlock_inode; } unlock_new_inode(inode); d_instantiate(dentry, inode); out_unlock: btrfs_end_transaction(trans, root); if (drop_inode) { inode_dec_link_count(inode); iput(inode); } btrfs_btree_balance_dirty(root); return err; out_unlock_inode: drop_inode = 1; unlock_new_inode(inode); goto out_unlock; } static int __btrfs_prealloc_file_range(struct inode *inode, int mode, u64 start, u64 num_bytes, u64 min_size, loff_t actual_len, u64 *alloc_hint, struct btrfs_trans_handle *trans) { struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_map *em; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_key ins; u64 cur_offset = start; u64 i_size; u64 cur_bytes; u64 last_alloc = (u64)-1; int ret = 0; bool own_trans = true; if (trans) own_trans = false; while (num_bytes > 0) { if (own_trans) { trans = btrfs_start_transaction(root, 3); if (IS_ERR(trans)) { ret = PTR_ERR(trans); break; } } cur_bytes = min_t(u64, num_bytes, SZ_256M); cur_bytes = max(cur_bytes, min_size); /* * If we are severely fragmented we could end up with really * small allocations, so if the allocator is returning small * chunks lets make its job easier by only searching for those * sized chunks. */ cur_bytes = min(cur_bytes, last_alloc); ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0, *alloc_hint, &ins, 1, 0); if (ret) { if (own_trans) btrfs_end_transaction(trans, root); break; } last_alloc = ins.offset; ret = insert_reserved_file_extent(trans, inode, cur_offset, ins.objectid, ins.offset, ins.offset, ins.offset, 0, 0, 0, BTRFS_FILE_EXTENT_PREALLOC); if (ret) { btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 0); btrfs_abort_transaction(trans, root, ret); if (own_trans) btrfs_end_transaction(trans, root); break; } btrfs_drop_extent_cache(inode, cur_offset, cur_offset + ins.offset -1, 0); em = alloc_extent_map(); if (!em) { set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); goto next; } em->start = cur_offset; em->orig_start = cur_offset; em->len = ins.offset; em->block_start = ins.objectid; em->block_len = ins.offset; em->orig_block_len = ins.offset; em->ram_bytes = ins.offset; em->bdev = root->fs_info->fs_devices->latest_bdev; set_bit(EXTENT_FLAG_PREALLOC, &em->flags); em->generation = trans->transid; while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em, 1); write_unlock(&em_tree->lock); if (ret != -EEXIST) break; btrfs_drop_extent_cache(inode, cur_offset, cur_offset + ins.offset - 1, 0); } free_extent_map(em); next: num_bytes -= ins.offset; cur_offset += ins.offset; *alloc_hint = ins.objectid + ins.offset; inode_inc_iversion(inode); inode->i_ctime = current_fs_time(inode->i_sb); BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; if (!(mode & FALLOC_FL_KEEP_SIZE) && (actual_len > inode->i_size) && (cur_offset > inode->i_size)) { if (cur_offset > actual_len) i_size = actual_len; else i_size = cur_offset; i_size_write(inode, i_size); btrfs_ordered_update_i_size(inode, i_size, NULL); } ret = btrfs_update_inode(trans, root, inode); if (ret) { btrfs_abort_transaction(trans, root, ret); if (own_trans) btrfs_end_transaction(trans, root); break; } if (own_trans) btrfs_end_transaction(trans, root); } return ret; } int btrfs_prealloc_file_range(struct inode *inode, int mode, u64 start, u64 num_bytes, u64 min_size, loff_t actual_len, u64 *alloc_hint) { return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, min_size, actual_len, alloc_hint, NULL); } int btrfs_prealloc_file_range_trans(struct inode *inode, struct btrfs_trans_handle *trans, int mode, u64 start, u64 num_bytes, u64 min_size, loff_t actual_len, u64 *alloc_hint) { return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, min_size, actual_len, alloc_hint, trans); } static int btrfs_set_page_dirty(struct page *page) { return __set_page_dirty_nobuffers(page); } static int btrfs_permission(struct inode *inode, int mask) { struct btrfs_root *root = BTRFS_I(inode)->root; umode_t mode = inode->i_mode; if (mask & MAY_WRITE && (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { if (btrfs_root_readonly(root)) return -EROFS; if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) return -EACCES; } return generic_permission(inode, mask); } static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(dir)->root; struct inode *inode = NULL; u64 objectid; u64 index; int ret = 0; /* * 5 units required for adding orphan entry */ trans = btrfs_start_transaction(root, 5); if (IS_ERR(trans)) return PTR_ERR(trans); ret = btrfs_find_free_ino(root, &objectid); if (ret) goto out; inode = btrfs_new_inode(trans, root, dir, NULL, 0, btrfs_ino(dir), objectid, mode, &index); if (IS_ERR(inode)) { ret = PTR_ERR(inode); inode = NULL; goto out; } inode->i_fop = &btrfs_file_operations; inode->i_op = &btrfs_file_inode_operations; inode->i_mapping->a_ops = &btrfs_aops; BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; ret = btrfs_init_inode_security(trans, inode, dir, NULL); if (ret) goto out_inode; ret = btrfs_update_inode(trans, root, inode); if (ret) goto out_inode; ret = btrfs_orphan_add(trans, inode); if (ret) goto out_inode; /* * We set number of links to 0 in btrfs_new_inode(), and here we set * it to 1 because d_tmpfile() will issue a warning if the count is 0, * through: * * d_tmpfile() -> inode_dec_link_count() -> drop_nlink() */ set_nlink(inode, 1); unlock_new_inode(inode); d_tmpfile(dentry, inode); mark_inode_dirty(inode); out: btrfs_end_transaction(trans, root); if (ret) iput(inode); btrfs_balance_delayed_items(root); btrfs_btree_balance_dirty(root); return ret; out_inode: unlock_new_inode(inode); goto out; } /* Inspired by filemap_check_errors() */ int btrfs_inode_check_errors(struct inode *inode) { int ret = 0; if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) && test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags)) ret = -ENOSPC; if (test_bit(AS_EIO, &inode->i_mapping->flags) && test_and_clear_bit(AS_EIO, &inode->i_mapping->flags)) ret = -EIO; return ret; } static const struct inode_operations btrfs_dir_inode_operations = { .getattr = btrfs_getattr, .lookup = btrfs_lookup, .create = btrfs_create, .unlink = btrfs_unlink, .link = btrfs_link, .mkdir = btrfs_mkdir, .rmdir = btrfs_rmdir, .rename2 = btrfs_rename2, .symlink = btrfs_symlink, .setattr = btrfs_setattr, .mknod = btrfs_mknod, .setxattr = btrfs_setxattr, .getxattr = generic_getxattr, .listxattr = btrfs_listxattr, .removexattr = btrfs_removexattr, .permission = btrfs_permission, .get_acl = btrfs_get_acl, .set_acl = btrfs_set_acl, .update_time = btrfs_update_time, .tmpfile = btrfs_tmpfile, }; static const struct inode_operations btrfs_dir_ro_inode_operations = { .lookup = btrfs_lookup, .permission = btrfs_permission, .get_acl = btrfs_get_acl, .set_acl = btrfs_set_acl, .update_time = btrfs_update_time, }; static const struct file_operations btrfs_dir_file_operations = { .llseek = generic_file_llseek, .read = generic_read_dir, .iterate = btrfs_real_readdir, .unlocked_ioctl = btrfs_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = btrfs_ioctl, #endif .release = btrfs_release_file, .fsync = btrfs_sync_file, }; static const struct extent_io_ops btrfs_extent_io_ops = { .fill_delalloc = run_delalloc_range, .submit_bio_hook = btrfs_submit_bio_hook, .merge_bio_hook = btrfs_merge_bio_hook, .readpage_end_io_hook = btrfs_readpage_end_io_hook, .writepage_end_io_hook = btrfs_writepage_end_io_hook, .writepage_start_hook = btrfs_writepage_start_hook, .set_bit_hook = btrfs_set_bit_hook, .clear_bit_hook = btrfs_clear_bit_hook, .merge_extent_hook = btrfs_merge_extent_hook, .split_extent_hook = btrfs_split_extent_hook, }; /* * btrfs doesn't support the bmap operation because swapfiles * use bmap to make a mapping of extents in the file. They assume * these extents won't change over the life of the file and they * use the bmap result to do IO directly to the drive. * * the btrfs bmap call would return logical addresses that aren't * suitable for IO and they also will change frequently as COW * operations happen. So, swapfile + btrfs == corruption. * * For now we're avoiding this by dropping bmap. */ static const struct address_space_operations btrfs_aops = { .readpage = btrfs_readpage, .writepage = btrfs_writepage, .writepages = btrfs_writepages, .readpages = btrfs_readpages, .direct_IO = btrfs_direct_IO, .invalidatepage = btrfs_invalidatepage, .releasepage = btrfs_releasepage, .set_page_dirty = btrfs_set_page_dirty, .error_remove_page = generic_error_remove_page, }; static const struct address_space_operations btrfs_symlink_aops = { .readpage = btrfs_readpage, .writepage = btrfs_writepage, .invalidatepage = btrfs_invalidatepage, .releasepage = btrfs_releasepage, }; static const struct inode_operations btrfs_file_inode_operations = { .getattr = btrfs_getattr, .setattr = btrfs_setattr, .setxattr = btrfs_setxattr, .getxattr = generic_getxattr, .listxattr = btrfs_listxattr, .removexattr = btrfs_removexattr, .permission = btrfs_permission, .fiemap = btrfs_fiemap, .get_acl = btrfs_get_acl, .set_acl = btrfs_set_acl, .update_time = btrfs_update_time, }; static const struct inode_operations btrfs_special_inode_operations = { .getattr = btrfs_getattr, .setattr = btrfs_setattr, .permission = btrfs_permission, .setxattr = btrfs_setxattr, .getxattr = generic_getxattr, .listxattr = btrfs_listxattr, .removexattr = btrfs_removexattr, .get_acl = btrfs_get_acl, .set_acl = btrfs_set_acl, .update_time = btrfs_update_time, }; static const struct inode_operations btrfs_symlink_inode_operations = { .readlink = generic_readlink, .get_link = page_get_link, .getattr = btrfs_getattr, .setattr = btrfs_setattr, .permission = btrfs_permission, .setxattr = btrfs_setxattr, .getxattr = generic_getxattr, .listxattr = btrfs_listxattr, .removexattr = btrfs_removexattr, .update_time = btrfs_update_time, }; const struct dentry_operations btrfs_dentry_operations = { .d_delete = btrfs_dentry_delete, .d_release = btrfs_dentry_release, };