// SPDX-License-Identifier: GPL-2.0 /* * fs/ext4/fast_commit.c * * Written by Harshad Shirwadkar * * Ext4 fast commits routines. */ #include "ext4.h" #include "ext4_jbd2.h" #include "ext4_extents.h" #include "mballoc.h" /* * Ext4 Fast Commits * ----------------- * * Ext4 fast commits implement fine grained journalling for Ext4. * * Fast commits are organized as a log of tag-length-value (TLV) structs. (See * struct ext4_fc_tl). Each TLV contains some delta that is replayed TLV by * TLV during the recovery phase. For the scenarios for which we currently * don't have replay code, fast commit falls back to full commits. * Fast commits record delta in one of the following three categories. * * (A) Directory entry updates: * * - EXT4_FC_TAG_UNLINK - records directory entry unlink * - EXT4_FC_TAG_LINK - records directory entry link * - EXT4_FC_TAG_CREAT - records inode and directory entry creation * * (B) File specific data range updates: * * - EXT4_FC_TAG_ADD_RANGE - records addition of new blocks to an inode * - EXT4_FC_TAG_DEL_RANGE - records deletion of blocks from an inode * * (C) Inode metadata (mtime / ctime etc): * * - EXT4_FC_TAG_INODE - record the inode that should be replayed * during recovery. Note that iblocks field is * not replayed and instead derived during * replay. * Commit Operation * ---------------- * With fast commits, we maintain all the directory entry operations in the * order in which they are issued in an in-memory queue. This queue is flushed * to disk during the commit operation. We also maintain a list of inodes * that need to be committed during a fast commit in another in memory queue of * inodes. During the commit operation, we commit in the following order: * * [1] Lock inodes for any further data updates by setting COMMITTING state * [2] Submit data buffers of all the inodes * [3] Wait for [2] to complete * [4] Commit all the directory entry updates in the fast commit space * [5] Commit all the changed inode structures * [6] Write tail tag (this tag ensures the atomicity, please read the following * section for more details). * [7] Wait for [4], [5] and [6] to complete. * * All the inode updates must call ext4_fc_start_update() before starting an * update. If such an ongoing update is present, fast commit waits for it to * complete. The completion of such an update is marked by * ext4_fc_stop_update(). * * Fast Commit Ineligibility * ------------------------- * * Not all operations are supported by fast commits today (e.g extended * attributes). Fast commit ineligibility is marked by calling * ext4_fc_mark_ineligible(): This makes next fast commit operation to fall back * to full commit. * * Atomicity of commits * -------------------- * In order to guarantee atomicity during the commit operation, fast commit * uses "EXT4_FC_TAG_TAIL" tag that marks a fast commit as complete. Tail * tag contains CRC of the contents and TID of the transaction after which * this fast commit should be applied. Recovery code replays fast commit * logs only if there's at least 1 valid tail present. For every fast commit * operation, there is 1 tail. This means, we may end up with multiple tails * in the fast commit space. Here's an example: * * - Create a new file A and remove existing file B * - fsync() * - Append contents to file A * - Truncate file A * - fsync() * * The fast commit space at the end of above operations would look like this: * [HEAD] [CREAT A] [UNLINK B] [TAIL] [ADD_RANGE A] [DEL_RANGE A] [TAIL] * |<--- Fast Commit 1 --->|<--- Fast Commit 2 ---->| * * Replay code should thus check for all the valid tails in the FC area. * * Fast Commit Replay Idempotence * ------------------------------ * * Fast commits tags are idempotent in nature provided the recovery code follows * certain rules. The guiding principle that the commit path follows while * committing is that it stores the result of a particular operation instead of * storing the procedure. * * Let's consider this rename operation: 'mv /a /b'. Let's assume dirent '/a' * was associated with inode 10. During fast commit, instead of storing this * operation as a procedure "rename a to b", we store the resulting file system * state as a "series" of outcomes: * * - Link dirent b to inode 10 * - Unlink dirent a * - Inode <10> with valid refcount * * Now when recovery code runs, it needs "enforce" this state on the file * system. This is what guarantees idempotence of fast commit replay. * * Let's take an example of a procedure that is not idempotent and see how fast * commits make it idempotent. Consider following sequence of operations: * * rm A; mv B A; read A * (x) (y) (z) * * (x), (y) and (z) are the points at which we can crash. If we store this * sequence of operations as is then the replay is not idempotent. Let's say * while in replay, we crash at (z). During the second replay, file A (which was * actually created as a result of "mv B A" operation) would get deleted. Thus, * file named A would be absent when we try to read A. So, this sequence of * operations is not idempotent. However, as mentioned above, instead of storing * the procedure fast commits store the outcome of each procedure. Thus the fast * commit log for above procedure would be as follows: * * (Let's assume dirent A was linked to inode 10 and dirent B was linked to * inode 11 before the replay) * * [Unlink A] [Link A to inode 11] [Unlink B] [Inode 11] * (w) (x) (y) (z) * * If we crash at (z), we will have file A linked to inode 11. During the second * replay, we will remove file A (inode 11). But we will create it back and make * it point to inode 11. We won't find B, so we'll just skip that step. At this * point, the refcount for inode 11 is not reliable, but that gets fixed by the * replay of last inode 11 tag. Crashes at points (w), (x) and (y) get handled * similarly. Thus, by converting a non-idempotent procedure into a series of * idempotent outcomes, fast commits ensured idempotence during the replay. * * TODOs * ----- * * 0) Fast commit replay path hardening: Fast commit replay code should use * journal handles to make sure all the updates it does during the replay * path are atomic. With that if we crash during fast commit replay, after * trying to do recovery again, we will find a file system where fast commit * area is invalid (because new full commit would be found). In order to deal * with that, fast commit replay code should ensure that the "FC_REPLAY" * superblock state is persisted before starting the replay, so that after * the crash, fast commit recovery code can look at that flag and perform * fast commit recovery even if that area is invalidated by later full * commits. * * 1) Fast commit's commit path locks the entire file system during fast * commit. This has significant performance penalty. Instead of that, we * should use ext4_fc_start/stop_update functions to start inode level * updates from ext4_journal_start/stop. Once we do that we can drop file * system locking during commit path. * * 2) Handle more ineligible cases. */ #include static struct kmem_cache *ext4_fc_dentry_cachep; static void ext4_end_buffer_io_sync(struct buffer_head *bh, int uptodate) { BUFFER_TRACE(bh, ""); if (uptodate) { ext4_debug("%s: Block %lld up-to-date", __func__, bh->b_blocknr); set_buffer_uptodate(bh); } else { ext4_debug("%s: Block %lld not up-to-date", __func__, bh->b_blocknr); clear_buffer_uptodate(bh); } unlock_buffer(bh); } static inline void ext4_fc_reset_inode(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); ei->i_fc_lblk_start = 0; ei->i_fc_lblk_len = 0; } void ext4_fc_init_inode(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); ext4_fc_reset_inode(inode); ext4_clear_inode_state(inode, EXT4_STATE_FC_COMMITTING); INIT_LIST_HEAD(&ei->i_fc_list); INIT_LIST_HEAD(&ei->i_fc_dilist); init_waitqueue_head(&ei->i_fc_wait); atomic_set(&ei->i_fc_updates, 0); } /* This function must be called with sbi->s_fc_lock held. */ static void ext4_fc_wait_committing_inode(struct inode *inode) __releases(&EXT4_SB(inode->i_sb)->s_fc_lock) { wait_queue_head_t *wq; struct ext4_inode_info *ei = EXT4_I(inode); #if (BITS_PER_LONG < 64) DEFINE_WAIT_BIT(wait, &ei->i_state_flags, EXT4_STATE_FC_COMMITTING); wq = bit_waitqueue(&ei->i_state_flags, EXT4_STATE_FC_COMMITTING); #else DEFINE_WAIT_BIT(wait, &ei->i_flags, EXT4_STATE_FC_COMMITTING); wq = bit_waitqueue(&ei->i_flags, EXT4_STATE_FC_COMMITTING); #endif lockdep_assert_held(&EXT4_SB(inode->i_sb)->s_fc_lock); prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock); schedule(); finish_wait(wq, &wait.wq_entry); } /* * Inform Ext4's fast about start of an inode update * * This function is called by the high level call VFS callbacks before * performing any inode update. This function blocks if there's an ongoing * fast commit on the inode in question. */ void ext4_fc_start_update(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) || (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)) return; restart: spin_lock(&EXT4_SB(inode->i_sb)->s_fc_lock); if (list_empty(&ei->i_fc_list)) goto out; if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) { ext4_fc_wait_committing_inode(inode); goto restart; } out: atomic_inc(&ei->i_fc_updates); spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock); } /* * Stop inode update and wake up waiting fast commits if any. */ void ext4_fc_stop_update(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) || (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)) return; if (atomic_dec_and_test(&ei->i_fc_updates)) wake_up_all(&ei->i_fc_wait); } /* * Remove inode from fast commit list. If the inode is being committed * we wait until inode commit is done. */ void ext4_fc_del(struct inode *inode) { struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_fc_dentry_update *fc_dentry; if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) || (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)) return; restart: spin_lock(&EXT4_SB(inode->i_sb)->s_fc_lock); if (list_empty(&ei->i_fc_list) && list_empty(&ei->i_fc_dilist)) { spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock); return; } if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) { ext4_fc_wait_committing_inode(inode); goto restart; } if (!list_empty(&ei->i_fc_list)) list_del_init(&ei->i_fc_list); /* * Since this inode is getting removed, let's also remove all FC * dentry create references, since it is not needed to log it anyways. */ if (list_empty(&ei->i_fc_dilist)) { spin_unlock(&sbi->s_fc_lock); return; } fc_dentry = list_first_entry(&ei->i_fc_dilist, struct ext4_fc_dentry_update, fcd_dilist); WARN_ON(fc_dentry->fcd_op != EXT4_FC_TAG_CREAT); list_del_init(&fc_dentry->fcd_list); list_del_init(&fc_dentry->fcd_dilist); WARN_ON(!list_empty(&ei->i_fc_dilist)); spin_unlock(&sbi->s_fc_lock); if (fc_dentry->fcd_name.name && fc_dentry->fcd_name.len > DNAME_INLINE_LEN) kfree(fc_dentry->fcd_name.name); kmem_cache_free(ext4_fc_dentry_cachep, fc_dentry); return; } /* * Mark file system as fast commit ineligible, and record latest * ineligible transaction tid. This means until the recorded * transaction, commit operation would result in a full jbd2 commit. */ void ext4_fc_mark_ineligible(struct super_block *sb, int reason, handle_t *handle) { struct ext4_sb_info *sbi = EXT4_SB(sb); tid_t tid; if (!test_opt2(sb, JOURNAL_FAST_COMMIT) || (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)) return; ext4_set_mount_flag(sb, EXT4_MF_FC_INELIGIBLE); if (handle && !IS_ERR(handle)) tid = handle->h_transaction->t_tid; else { read_lock(&sbi->s_journal->j_state_lock); tid = sbi->s_journal->j_running_transaction ? sbi->s_journal->j_running_transaction->t_tid : 0; read_unlock(&sbi->s_journal->j_state_lock); } spin_lock(&sbi->s_fc_lock); if (sbi->s_fc_ineligible_tid < tid) sbi->s_fc_ineligible_tid = tid; spin_unlock(&sbi->s_fc_lock); WARN_ON(reason >= EXT4_FC_REASON_MAX); sbi->s_fc_stats.fc_ineligible_reason_count[reason]++; } /* * Generic fast commit tracking function. If this is the first time this we are * called after a full commit, we initialize fast commit fields and then call * __fc_track_fn() with update = 0. If we have already been called after a full * commit, we pass update = 1. Based on that, the track function can determine * if it needs to track a field for the first time or if it needs to just * update the previously tracked value. * * If enqueue is set, this function enqueues the inode in fast commit list. */ static int ext4_fc_track_template( handle_t *handle, struct inode *inode, int (*__fc_track_fn)(struct inode *, void *, bool), void *args, int enqueue) { bool update = false; struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); tid_t tid = 0; int ret; tid = handle->h_transaction->t_tid; mutex_lock(&ei->i_fc_lock); if (tid == ei->i_sync_tid) { update = true; } else { ext4_fc_reset_inode(inode); ei->i_sync_tid = tid; } ret = __fc_track_fn(inode, args, update); mutex_unlock(&ei->i_fc_lock); if (!enqueue) return ret; spin_lock(&sbi->s_fc_lock); if (list_empty(&EXT4_I(inode)->i_fc_list)) list_add_tail(&EXT4_I(inode)->i_fc_list, (sbi->s_journal->j_flags & JBD2_FULL_COMMIT_ONGOING || sbi->s_journal->j_flags & JBD2_FAST_COMMIT_ONGOING) ? &sbi->s_fc_q[FC_Q_STAGING] : &sbi->s_fc_q[FC_Q_MAIN]); spin_unlock(&sbi->s_fc_lock); return ret; } struct __track_dentry_update_args { struct dentry *dentry; int op; }; /* __track_fn for directory entry updates. Called with ei->i_fc_lock. */ static int __track_dentry_update(struct inode *inode, void *arg, bool update) { struct ext4_fc_dentry_update *node; struct ext4_inode_info *ei = EXT4_I(inode); struct __track_dentry_update_args *dentry_update = (struct __track_dentry_update_args *)arg; struct dentry *dentry = dentry_update->dentry; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); mutex_unlock(&ei->i_fc_lock); node = kmem_cache_alloc(ext4_fc_dentry_cachep, GFP_NOFS); if (!node) { ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_NOMEM, NULL); mutex_lock(&ei->i_fc_lock); return -ENOMEM; } node->fcd_op = dentry_update->op; node->fcd_parent = dentry->d_parent->d_inode->i_ino; node->fcd_ino = inode->i_ino; if (dentry->d_name.len > DNAME_INLINE_LEN) { node->fcd_name.name = kmalloc(dentry->d_name.len, GFP_NOFS); if (!node->fcd_name.name) { kmem_cache_free(ext4_fc_dentry_cachep, node); ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_NOMEM, NULL); mutex_lock(&ei->i_fc_lock); return -ENOMEM; } memcpy((u8 *)node->fcd_name.name, dentry->d_name.name, dentry->d_name.len); } else { memcpy(node->fcd_iname, dentry->d_name.name, dentry->d_name.len); node->fcd_name.name = node->fcd_iname; } node->fcd_name.len = dentry->d_name.len; INIT_LIST_HEAD(&node->fcd_dilist); spin_lock(&sbi->s_fc_lock); if (sbi->s_journal->j_flags & JBD2_FULL_COMMIT_ONGOING || sbi->s_journal->j_flags & JBD2_FAST_COMMIT_ONGOING) list_add_tail(&node->fcd_list, &sbi->s_fc_dentry_q[FC_Q_STAGING]); else list_add_tail(&node->fcd_list, &sbi->s_fc_dentry_q[FC_Q_MAIN]); /* * This helps us keep a track of all fc_dentry updates which is part of * this ext4 inode. So in case the inode is getting unlinked, before * even we get a chance to fsync, we could remove all fc_dentry * references while evicting the inode in ext4_fc_del(). * Also with this, we don't need to loop over all the inodes in * sbi->s_fc_q to get the corresponding inode in * ext4_fc_commit_dentry_updates(). */ if (dentry_update->op == EXT4_FC_TAG_CREAT) { WARN_ON(!list_empty(&ei->i_fc_dilist)); list_add_tail(&node->fcd_dilist, &ei->i_fc_dilist); } spin_unlock(&sbi->s_fc_lock); mutex_lock(&ei->i_fc_lock); return 0; } void __ext4_fc_track_unlink(handle_t *handle, struct inode *inode, struct dentry *dentry) { struct __track_dentry_update_args args; int ret; args.dentry = dentry; args.op = EXT4_FC_TAG_UNLINK; ret = ext4_fc_track_template(handle, inode, __track_dentry_update, (void *)&args, 0); trace_ext4_fc_track_unlink(inode, dentry, ret); } void ext4_fc_track_unlink(handle_t *handle, struct dentry *dentry) { struct inode *inode = d_inode(dentry); struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) || (sbi->s_mount_state & EXT4_FC_REPLAY)) return; if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE)) return; __ext4_fc_track_unlink(handle, inode, dentry); } void __ext4_fc_track_link(handle_t *handle, struct inode *inode, struct dentry *dentry) { struct __track_dentry_update_args args; int ret; args.dentry = dentry; args.op = EXT4_FC_TAG_LINK; ret = ext4_fc_track_template(handle, inode, __track_dentry_update, (void *)&args, 0); trace_ext4_fc_track_link(inode, dentry, ret); } void ext4_fc_track_link(handle_t *handle, struct dentry *dentry) { struct inode *inode = d_inode(dentry); struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) || (sbi->s_mount_state & EXT4_FC_REPLAY)) return; if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE)) return; __ext4_fc_track_link(handle, inode, dentry); } void __ext4_fc_track_create(handle_t *handle, struct inode *inode, struct dentry *dentry) { struct __track_dentry_update_args args; int ret; args.dentry = dentry; args.op = EXT4_FC_TAG_CREAT; ret = ext4_fc_track_template(handle, inode, __track_dentry_update, (void *)&args, 0); trace_ext4_fc_track_create(inode, dentry, ret); } void ext4_fc_track_create(handle_t *handle, struct dentry *dentry) { struct inode *inode = d_inode(dentry); struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) || (sbi->s_mount_state & EXT4_FC_REPLAY)) return; if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE)) return; __ext4_fc_track_create(handle, inode, dentry); } /* __track_fn for inode tracking */ static int __track_inode(struct inode *inode, void *arg, bool update) { if (update) return -EEXIST; EXT4_I(inode)->i_fc_lblk_len = 0; return 0; } void ext4_fc_track_inode(handle_t *handle, struct inode *inode) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); int ret; if (S_ISDIR(inode->i_mode)) return; if (ext4_should_journal_data(inode)) { ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_INODE_JOURNAL_DATA, handle); return; } if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) || (sbi->s_mount_state & EXT4_FC_REPLAY)) return; if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE)) return; ret = ext4_fc_track_template(handle, inode, __track_inode, NULL, 1); trace_ext4_fc_track_inode(inode, ret); } struct __track_range_args { ext4_lblk_t start, end; }; /* __track_fn for tracking data updates */ static int __track_range(struct inode *inode, void *arg, bool update) { struct ext4_inode_info *ei = EXT4_I(inode); ext4_lblk_t oldstart; struct __track_range_args *__arg = (struct __track_range_args *)arg; if (inode->i_ino < EXT4_FIRST_INO(inode->i_sb)) { ext4_debug("Special inode %ld being modified\n", inode->i_ino); return -ECANCELED; } oldstart = ei->i_fc_lblk_start; if (update && ei->i_fc_lblk_len > 0) { ei->i_fc_lblk_start = min(ei->i_fc_lblk_start, __arg->start); ei->i_fc_lblk_len = max(oldstart + ei->i_fc_lblk_len - 1, __arg->end) - ei->i_fc_lblk_start + 1; } else { ei->i_fc_lblk_start = __arg->start; ei->i_fc_lblk_len = __arg->end - __arg->start + 1; } return 0; } void ext4_fc_track_range(handle_t *handle, struct inode *inode, ext4_lblk_t start, ext4_lblk_t end) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct __track_range_args args; int ret; if (S_ISDIR(inode->i_mode)) return; if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) || (sbi->s_mount_state & EXT4_FC_REPLAY)) return; if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE)) return; args.start = start; args.end = end; ret = ext4_fc_track_template(handle, inode, __track_range, &args, 1); trace_ext4_fc_track_range(inode, start, end, ret); } static void ext4_fc_submit_bh(struct super_block *sb, bool is_tail) { int write_flags = REQ_SYNC; struct buffer_head *bh = EXT4_SB(sb)->s_fc_bh; /* Add REQ_FUA | REQ_PREFLUSH only its tail */ if (test_opt(sb, BARRIER) && is_tail) write_flags |= REQ_FUA | REQ_PREFLUSH; lock_buffer(bh); set_buffer_dirty(bh); set_buffer_uptodate(bh); bh->b_end_io = ext4_end_buffer_io_sync; submit_bh(REQ_OP_WRITE, write_flags, bh); EXT4_SB(sb)->s_fc_bh = NULL; } /* Ext4 commit path routines */ /* memzero and update CRC */ static void *ext4_fc_memzero(struct super_block *sb, void *dst, int len, u32 *crc) { void *ret; ret = memset(dst, 0, len); if (crc) *crc = ext4_chksum(EXT4_SB(sb), *crc, dst, len); return ret; } /* * Allocate len bytes on a fast commit buffer. * * During the commit time this function is used to manage fast commit * block space. We don't split a fast commit log onto different * blocks. So this function makes sure that if there's not enough space * on the current block, the remaining space in the current block is * marked as unused by adding EXT4_FC_TAG_PAD tag. In that case, * new block is from jbd2 and CRC is updated to reflect the padding * we added. */ static u8 *ext4_fc_reserve_space(struct super_block *sb, int len, u32 *crc) { struct ext4_fc_tl *tl; struct ext4_sb_info *sbi = EXT4_SB(sb); struct buffer_head *bh; int bsize = sbi->s_journal->j_blocksize; int ret, off = sbi->s_fc_bytes % bsize; int pad_len; /* * After allocating len, we should have space at least for a 0 byte * padding. */ if (len + sizeof(struct ext4_fc_tl) > bsize) return NULL; if (bsize - off - 1 > len + sizeof(struct ext4_fc_tl)) { /* * Only allocate from current buffer if we have enough space for * this request AND we have space to add a zero byte padding. */ if (!sbi->s_fc_bh) { ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh); if (ret) return NULL; sbi->s_fc_bh = bh; } sbi->s_fc_bytes += len; return sbi->s_fc_bh->b_data + off; } /* Need to add PAD tag */ tl = (struct ext4_fc_tl *)(sbi->s_fc_bh->b_data + off); tl->fc_tag = cpu_to_le16(EXT4_FC_TAG_PAD); pad_len = bsize - off - 1 - sizeof(struct ext4_fc_tl); tl->fc_len = cpu_to_le16(pad_len); if (crc) *crc = ext4_chksum(sbi, *crc, tl, sizeof(*tl)); if (pad_len > 0) ext4_fc_memzero(sb, tl + 1, pad_len, crc); ext4_fc_submit_bh(sb, false); ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh); if (ret) return NULL; sbi->s_fc_bh = bh; sbi->s_fc_bytes = (sbi->s_fc_bytes / bsize + 1) * bsize + len; return sbi->s_fc_bh->b_data; } /* memcpy to fc reserved space and update CRC */ static void *ext4_fc_memcpy(struct super_block *sb, void *dst, const void *src, int len, u32 *crc) { if (crc) *crc = ext4_chksum(EXT4_SB(sb), *crc, src, len); return memcpy(dst, src, len); } /* * Complete a fast commit by writing tail tag. * * Writing tail tag marks the end of a fast commit. In order to guarantee * atomicity, after writing tail tag, even if there's space remaining * in the block, next commit shouldn't use it. That's why tail tag * has the length as that of the remaining space on the block. */ static int ext4_fc_write_tail(struct super_block *sb, u32 crc) { struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_fc_tl tl; struct ext4_fc_tail tail; int off, bsize = sbi->s_journal->j_blocksize; u8 *dst; /* * ext4_fc_reserve_space takes care of allocating an extra block if * there's no enough space on this block for accommodating this tail. */ dst = ext4_fc_reserve_space(sb, sizeof(tl) + sizeof(tail), &crc); if (!dst) return -ENOSPC; off = sbi->s_fc_bytes % bsize; tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_TAIL); tl.fc_len = cpu_to_le16(bsize - off - 1 + sizeof(struct ext4_fc_tail)); sbi->s_fc_bytes = round_up(sbi->s_fc_bytes, bsize); ext4_fc_memcpy(sb, dst, &tl, sizeof(tl), &crc); dst += sizeof(tl); tail.fc_tid = cpu_to_le32(sbi->s_journal->j_running_transaction->t_tid); ext4_fc_memcpy(sb, dst, &tail.fc_tid, sizeof(tail.fc_tid), &crc); dst += sizeof(tail.fc_tid); tail.fc_crc = cpu_to_le32(crc); ext4_fc_memcpy(sb, dst, &tail.fc_crc, sizeof(tail.fc_crc), NULL); ext4_fc_submit_bh(sb, true); return 0; } /* * Adds tag, length, value and updates CRC. Returns true if tlv was added. * Returns false if there's not enough space. */ static bool ext4_fc_add_tlv(struct super_block *sb, u16 tag, u16 len, u8 *val, u32 *crc) { struct ext4_fc_tl tl; u8 *dst; dst = ext4_fc_reserve_space(sb, sizeof(tl) + len, crc); if (!dst) return false; tl.fc_tag = cpu_to_le16(tag); tl.fc_len = cpu_to_le16(len); ext4_fc_memcpy(sb, dst, &tl, sizeof(tl), crc); ext4_fc_memcpy(sb, dst + sizeof(tl), val, len, crc); return true; } /* Same as above, but adds dentry tlv. */ static bool ext4_fc_add_dentry_tlv(struct super_block *sb, u32 *crc, struct ext4_fc_dentry_update *fc_dentry) { struct ext4_fc_dentry_info fcd; struct ext4_fc_tl tl; int dlen = fc_dentry->fcd_name.len; u8 *dst = ext4_fc_reserve_space(sb, sizeof(tl) + sizeof(fcd) + dlen, crc); if (!dst) return false; fcd.fc_parent_ino = cpu_to_le32(fc_dentry->fcd_parent); fcd.fc_ino = cpu_to_le32(fc_dentry->fcd_ino); tl.fc_tag = cpu_to_le16(fc_dentry->fcd_op); tl.fc_len = cpu_to_le16(sizeof(fcd) + dlen); ext4_fc_memcpy(sb, dst, &tl, sizeof(tl), crc); dst += sizeof(tl); ext4_fc_memcpy(sb, dst, &fcd, sizeof(fcd), crc); dst += sizeof(fcd); ext4_fc_memcpy(sb, dst, fc_dentry->fcd_name.name, dlen, crc); return true; } /* * Writes inode in the fast commit space under TLV with tag @tag. * Returns 0 on success, error on failure. */ static int ext4_fc_write_inode(struct inode *inode, u32 *crc) { struct ext4_inode_info *ei = EXT4_I(inode); int inode_len = EXT4_GOOD_OLD_INODE_SIZE; int ret; struct ext4_iloc iloc; struct ext4_fc_inode fc_inode; struct ext4_fc_tl tl; u8 *dst; ret = ext4_get_inode_loc(inode, &iloc); if (ret) return ret; if (ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA)) inode_len = EXT4_INODE_SIZE(inode->i_sb); else if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) inode_len += ei->i_extra_isize; fc_inode.fc_ino = cpu_to_le32(inode->i_ino); tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_INODE); tl.fc_len = cpu_to_le16(inode_len + sizeof(fc_inode.fc_ino)); dst = ext4_fc_reserve_space(inode->i_sb, sizeof(tl) + inode_len + sizeof(fc_inode.fc_ino), crc); if (!dst) return -ECANCELED; if (!ext4_fc_memcpy(inode->i_sb, dst, &tl, sizeof(tl), crc)) return -ECANCELED; dst += sizeof(tl); if (!ext4_fc_memcpy(inode->i_sb, dst, &fc_inode, sizeof(fc_inode), crc)) return -ECANCELED; dst += sizeof(fc_inode); if (!ext4_fc_memcpy(inode->i_sb, dst, (u8 *)ext4_raw_inode(&iloc), inode_len, crc)) return -ECANCELED; return 0; } /* * Writes updated data ranges for the inode in question. Updates CRC. * Returns 0 on success, error otherwise. */ static int ext4_fc_write_inode_data(struct inode *inode, u32 *crc) { ext4_lblk_t old_blk_size, cur_lblk_off, new_blk_size; struct ext4_inode_info *ei = EXT4_I(inode); struct ext4_map_blocks map; struct ext4_fc_add_range fc_ext; struct ext4_fc_del_range lrange; struct ext4_extent *ex; int ret; mutex_lock(&ei->i_fc_lock); if (ei->i_fc_lblk_len == 0) { mutex_unlock(&ei->i_fc_lock); return 0; } old_blk_size = ei->i_fc_lblk_start; new_blk_size = ei->i_fc_lblk_start + ei->i_fc_lblk_len - 1; ei->i_fc_lblk_len = 0; mutex_unlock(&ei->i_fc_lock); cur_lblk_off = old_blk_size; jbd_debug(1, "%s: will try writing %d to %d for inode %ld\n", __func__, cur_lblk_off, new_blk_size, inode->i_ino); while (cur_lblk_off <= new_blk_size) { map.m_lblk = cur_lblk_off; map.m_len = new_blk_size - cur_lblk_off + 1; ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret < 0) return -ECANCELED; if (map.m_len == 0) { cur_lblk_off++; continue; } if (ret == 0) { lrange.fc_ino = cpu_to_le32(inode->i_ino); lrange.fc_lblk = cpu_to_le32(map.m_lblk); lrange.fc_len = cpu_to_le32(map.m_len); if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_DEL_RANGE, sizeof(lrange), (u8 *)&lrange, crc)) return -ENOSPC; } else { unsigned int max = (map.m_flags & EXT4_MAP_UNWRITTEN) ? EXT_UNWRITTEN_MAX_LEN : EXT_INIT_MAX_LEN; /* Limit the number of blocks in one extent */ map.m_len = min(max, map.m_len); fc_ext.fc_ino = cpu_to_le32(inode->i_ino); ex = (struct ext4_extent *)&fc_ext.fc_ex; ex->ee_block = cpu_to_le32(map.m_lblk); ex->ee_len = cpu_to_le16(map.m_len); ext4_ext_store_pblock(ex, map.m_pblk); if (map.m_flags & EXT4_MAP_UNWRITTEN) ext4_ext_mark_unwritten(ex); else ext4_ext_mark_initialized(ex); if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_ADD_RANGE, sizeof(fc_ext), (u8 *)&fc_ext, crc)) return -ENOSPC; } cur_lblk_off += map.m_len; } return 0; } /* Submit data for all the fast commit inodes */ static int ext4_fc_submit_inode_data_all(journal_t *journal) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_inode_info *ei; int ret = 0; spin_lock(&sbi->s_fc_lock); list_for_each_entry(ei, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) { ext4_set_inode_state(&ei->vfs_inode, EXT4_STATE_FC_COMMITTING); while (atomic_read(&ei->i_fc_updates)) { DEFINE_WAIT(wait); prepare_to_wait(&ei->i_fc_wait, &wait, TASK_UNINTERRUPTIBLE); if (atomic_read(&ei->i_fc_updates)) { spin_unlock(&sbi->s_fc_lock); schedule(); spin_lock(&sbi->s_fc_lock); } finish_wait(&ei->i_fc_wait, &wait); } spin_unlock(&sbi->s_fc_lock); ret = jbd2_submit_inode_data(ei->jinode); if (ret) return ret; spin_lock(&sbi->s_fc_lock); } spin_unlock(&sbi->s_fc_lock); return ret; } /* Wait for completion of data for all the fast commit inodes */ static int ext4_fc_wait_inode_data_all(journal_t *journal) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_inode_info *pos, *n; int ret = 0; spin_lock(&sbi->s_fc_lock); list_for_each_entry_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) { if (!ext4_test_inode_state(&pos->vfs_inode, EXT4_STATE_FC_COMMITTING)) continue; spin_unlock(&sbi->s_fc_lock); ret = jbd2_wait_inode_data(journal, pos->jinode); if (ret) return ret; spin_lock(&sbi->s_fc_lock); } spin_unlock(&sbi->s_fc_lock); return 0; } /* Commit all the directory entry updates */ static int ext4_fc_commit_dentry_updates(journal_t *journal, u32 *crc) __acquires(&sbi->s_fc_lock) __releases(&sbi->s_fc_lock) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_fc_dentry_update *fc_dentry, *fc_dentry_n; struct inode *inode; struct ext4_inode_info *ei; int ret; if (list_empty(&sbi->s_fc_dentry_q[FC_Q_MAIN])) return 0; list_for_each_entry_safe(fc_dentry, fc_dentry_n, &sbi->s_fc_dentry_q[FC_Q_MAIN], fcd_list) { if (fc_dentry->fcd_op != EXT4_FC_TAG_CREAT) { spin_unlock(&sbi->s_fc_lock); if (!ext4_fc_add_dentry_tlv(sb, crc, fc_dentry)) { ret = -ENOSPC; goto lock_and_exit; } spin_lock(&sbi->s_fc_lock); continue; } /* * With fcd_dilist we need not loop in sbi->s_fc_q to get the * corresponding inode pointer */ WARN_ON(list_empty(&fc_dentry->fcd_dilist)); ei = list_first_entry(&fc_dentry->fcd_dilist, struct ext4_inode_info, i_fc_dilist); inode = &ei->vfs_inode; WARN_ON(inode->i_ino != fc_dentry->fcd_ino); spin_unlock(&sbi->s_fc_lock); /* * We first write the inode and then the create dirent. This * allows the recovery code to create an unnamed inode first * and then link it to a directory entry. This allows us * to use namei.c routines almost as is and simplifies * the recovery code. */ ret = ext4_fc_write_inode(inode, crc); if (ret) goto lock_and_exit; ret = ext4_fc_write_inode_data(inode, crc); if (ret) goto lock_and_exit; if (!ext4_fc_add_dentry_tlv(sb, crc, fc_dentry)) { ret = -ENOSPC; goto lock_and_exit; } spin_lock(&sbi->s_fc_lock); } return 0; lock_and_exit: spin_lock(&sbi->s_fc_lock); return ret; } static int ext4_fc_perform_commit(journal_t *journal) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_inode_info *iter; struct ext4_fc_head head; struct inode *inode; struct blk_plug plug; int ret = 0; u32 crc = 0; ret = ext4_fc_submit_inode_data_all(journal); if (ret) return ret; ret = ext4_fc_wait_inode_data_all(journal); if (ret) return ret; /* * If file system device is different from journal device, issue a cache * flush before we start writing fast commit blocks. */ if (journal->j_fs_dev != journal->j_dev) blkdev_issue_flush(journal->j_fs_dev); blk_start_plug(&plug); if (sbi->s_fc_bytes == 0) { /* * Add a head tag only if this is the first fast commit * in this TID. */ head.fc_features = cpu_to_le32(EXT4_FC_SUPPORTED_FEATURES); head.fc_tid = cpu_to_le32( sbi->s_journal->j_running_transaction->t_tid); if (!ext4_fc_add_tlv(sb, EXT4_FC_TAG_HEAD, sizeof(head), (u8 *)&head, &crc)) { ret = -ENOSPC; goto out; } } spin_lock(&sbi->s_fc_lock); ret = ext4_fc_commit_dentry_updates(journal, &crc); if (ret) { spin_unlock(&sbi->s_fc_lock); goto out; } list_for_each_entry(iter, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) { inode = &iter->vfs_inode; if (!ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) continue; spin_unlock(&sbi->s_fc_lock); ret = ext4_fc_write_inode_data(inode, &crc); if (ret) goto out; ret = ext4_fc_write_inode(inode, &crc); if (ret) goto out; spin_lock(&sbi->s_fc_lock); } spin_unlock(&sbi->s_fc_lock); ret = ext4_fc_write_tail(sb, crc); out: blk_finish_plug(&plug); return ret; } static void ext4_fc_update_stats(struct super_block *sb, int status, u64 commit_time, int nblks) { struct ext4_fc_stats *stats = &EXT4_SB(sb)->s_fc_stats; jbd_debug(1, "Fast commit ended with status = %d", status); if (status == EXT4_FC_STATUS_OK) { stats->fc_num_commits++; stats->fc_numblks += nblks; if (likely(stats->s_fc_avg_commit_time)) stats->s_fc_avg_commit_time = (commit_time + stats->s_fc_avg_commit_time * 3) / 4; else stats->s_fc_avg_commit_time = commit_time; } else if (status == EXT4_FC_STATUS_FAILED || status == EXT4_FC_STATUS_INELIGIBLE) { if (status == EXT4_FC_STATUS_FAILED) stats->fc_failed_commits++; stats->fc_ineligible_commits++; } else { stats->fc_skipped_commits++; } trace_ext4_fc_commit_stop(sb, nblks, status); } /* * The main commit entry point. Performs a fast commit for transaction * commit_tid if needed. If it's not possible to perform a fast commit * due to various reasons, we fall back to full commit. Returns 0 * on success, error otherwise. */ int ext4_fc_commit(journal_t *journal, tid_t commit_tid) { struct super_block *sb = (struct super_block *)(journal->j_private); struct ext4_sb_info *sbi = EXT4_SB(sb); int nblks = 0, ret, bsize = journal->j_blocksize; int subtid = atomic_read(&sbi->s_fc_subtid); int status = EXT4_FC_STATUS_OK, fc_bufs_before = 0; ktime_t start_time, commit_time; if (!test_opt2(sb, JOURNAL_FAST_COMMIT)) return jbd2_complete_transaction(journal, commit_tid); trace_ext4_fc_commit_start(sb); start_time = ktime_get(); restart_fc: ret = jbd2_fc_begin_commit(journal, commit_tid); if (ret == -EALREADY) { /* There was an ongoing commit, check if we need to restart */ if (atomic_read(&sbi->s_fc_subtid) <= subtid && commit_tid > journal->j_commit_sequence) goto restart_fc; ext4_fc_update_stats(sb, EXT4_FC_STATUS_SKIPPED, 0, 0); return 0; } else if (ret) { /* * Commit couldn't start. Just update stats and perform a * full commit. */ ext4_fc_update_stats(sb, EXT4_FC_STATUS_FAILED, 0, 0); return jbd2_complete_transaction(journal, commit_tid); } /* * After establishing journal barrier via jbd2_fc_begin_commit(), check * if we are fast commit ineligible. */ if (ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE)) { status = EXT4_FC_STATUS_INELIGIBLE; goto fallback; } fc_bufs_before = (sbi->s_fc_bytes + bsize - 1) / bsize; ret = ext4_fc_perform_commit(journal); if (ret < 0) { status = EXT4_FC_STATUS_FAILED; goto fallback; } nblks = (sbi->s_fc_bytes + bsize - 1) / bsize - fc_bufs_before; ret = jbd2_fc_wait_bufs(journal, nblks); if (ret < 0) { status = EXT4_FC_STATUS_FAILED; goto fallback; } atomic_inc(&sbi->s_fc_subtid); ret = jbd2_fc_end_commit(journal); /* * weight the commit time higher than the average time so we * don't react too strongly to vast changes in the commit time */ commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time)); ext4_fc_update_stats(sb, status, commit_time, nblks); return ret; fallback: ret = jbd2_fc_end_commit_fallback(journal); ext4_fc_update_stats(sb, status, 0, 0); return ret; } /* * Fast commit cleanup routine. This is called after every fast commit and * full commit. full is true if we are called after a full commit. */ static void ext4_fc_cleanup(journal_t *journal, int full, tid_t tid) { struct super_block *sb = journal->j_private; struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_inode_info *iter, *iter_n; struct ext4_fc_dentry_update *fc_dentry; if (full && sbi->s_fc_bh) sbi->s_fc_bh = NULL; trace_ext4_fc_cleanup(journal, full, tid); jbd2_fc_release_bufs(journal); spin_lock(&sbi->s_fc_lock); list_for_each_entry_safe(iter, iter_n, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) { list_del_init(&iter->i_fc_list); ext4_clear_inode_state(&iter->vfs_inode, EXT4_STATE_FC_COMMITTING); if (iter->i_sync_tid <= tid) ext4_fc_reset_inode(&iter->vfs_inode); /* Make sure EXT4_STATE_FC_COMMITTING bit is clear */ smp_mb(); #if (BITS_PER_LONG < 64) wake_up_bit(&iter->i_state_flags, EXT4_STATE_FC_COMMITTING); #else wake_up_bit(&iter->i_flags, EXT4_STATE_FC_COMMITTING); #endif } while (!list_empty(&sbi->s_fc_dentry_q[FC_Q_MAIN])) { fc_dentry = list_first_entry(&sbi->s_fc_dentry_q[FC_Q_MAIN], struct ext4_fc_dentry_update, fcd_list); list_del_init(&fc_dentry->fcd_list); list_del_init(&fc_dentry->fcd_dilist); spin_unlock(&sbi->s_fc_lock); if (fc_dentry->fcd_name.name && fc_dentry->fcd_name.len > DNAME_INLINE_LEN) kfree(fc_dentry->fcd_name.name); kmem_cache_free(ext4_fc_dentry_cachep, fc_dentry); spin_lock(&sbi->s_fc_lock); } list_splice_init(&sbi->s_fc_dentry_q[FC_Q_STAGING], &sbi->s_fc_dentry_q[FC_Q_MAIN]); list_splice_init(&sbi->s_fc_q[FC_Q_STAGING], &sbi->s_fc_q[FC_Q_MAIN]); if (tid >= sbi->s_fc_ineligible_tid) { sbi->s_fc_ineligible_tid = 0; ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE); } if (full) sbi->s_fc_bytes = 0; spin_unlock(&sbi->s_fc_lock); trace_ext4_fc_stats(sb); } /* Ext4 Replay Path Routines */ /* Helper struct for dentry replay routines */ struct dentry_info_args { int parent_ino, dname_len, ino, inode_len; char *dname; }; static inline void tl_to_darg(struct dentry_info_args *darg, struct ext4_fc_tl *tl, u8 *val) { struct ext4_fc_dentry_info fcd; memcpy(&fcd, val, sizeof(fcd)); darg->parent_ino = le32_to_cpu(fcd.fc_parent_ino); darg->ino = le32_to_cpu(fcd.fc_ino); darg->dname = val + offsetof(struct ext4_fc_dentry_info, fc_dname); darg->dname_len = le16_to_cpu(tl->fc_len) - sizeof(struct ext4_fc_dentry_info); } /* Unlink replay function */ static int ext4_fc_replay_unlink(struct super_block *sb, struct ext4_fc_tl *tl, u8 *val) { struct inode *inode, *old_parent; struct qstr entry; struct dentry_info_args darg; int ret = 0; tl_to_darg(&darg, tl, val); trace_ext4_fc_replay(sb, EXT4_FC_TAG_UNLINK, darg.ino, darg.parent_ino, darg.dname_len); entry.name = darg.dname; entry.len = darg.dname_len; inode = ext4_iget(sb, darg.ino, EXT4_IGET_NORMAL); if (IS_ERR(inode)) { jbd_debug(1, "Inode %d not found", darg.ino); return 0; } old_parent = ext4_iget(sb, darg.parent_ino, EXT4_IGET_NORMAL); if (IS_ERR(old_parent)) { jbd_debug(1, "Dir with inode %d not found", darg.parent_ino); iput(inode); return 0; } ret = __ext4_unlink(NULL, old_parent, &entry, inode); /* -ENOENT ok coz it might not exist anymore. */ if (ret == -ENOENT) ret = 0; iput(old_parent); iput(inode); return ret; } static int ext4_fc_replay_link_internal(struct super_block *sb, struct dentry_info_args *darg, struct inode *inode) { struct inode *dir = NULL; struct dentry *dentry_dir = NULL, *dentry_inode = NULL; struct qstr qstr_dname = QSTR_INIT(darg->dname, darg->dname_len); int ret = 0; dir = ext4_iget(sb, darg->parent_ino, EXT4_IGET_NORMAL); if (IS_ERR(dir)) { jbd_debug(1, "Dir with inode %d not found.", darg->parent_ino); dir = NULL; goto out; } dentry_dir = d_obtain_alias(dir); if (IS_ERR(dentry_dir)) { jbd_debug(1, "Failed to obtain dentry"); dentry_dir = NULL; goto out; } dentry_inode = d_alloc(dentry_dir, &qstr_dname); if (!dentry_inode) { jbd_debug(1, "Inode dentry not created."); ret = -ENOMEM; goto out; } ret = __ext4_link(dir, inode, dentry_inode); /* * It's possible that link already existed since data blocks * for the dir in question got persisted before we crashed OR * we replayed this tag and crashed before the entire replay * could complete. */ if (ret && ret != -EEXIST) { jbd_debug(1, "Failed to link\n"); goto out; } ret = 0; out: if (dentry_dir) { d_drop(dentry_dir); dput(dentry_dir); } else if (dir) { iput(dir); } if (dentry_inode) { d_drop(dentry_inode); dput(dentry_inode); } return ret; } /* Link replay function */ static int ext4_fc_replay_link(struct super_block *sb, struct ext4_fc_tl *tl, u8 *val) { struct inode *inode; struct dentry_info_args darg; int ret = 0; tl_to_darg(&darg, tl, val); trace_ext4_fc_replay(sb, EXT4_FC_TAG_LINK, darg.ino, darg.parent_ino, darg.dname_len); inode = ext4_iget(sb, darg.ino, EXT4_IGET_NORMAL); if (IS_ERR(inode)) { jbd_debug(1, "Inode not found."); return 0; } ret = ext4_fc_replay_link_internal(sb, &darg, inode); iput(inode); return ret; } /* * Record all the modified inodes during replay. We use this later to setup * block bitmaps correctly. */ static int ext4_fc_record_modified_inode(struct super_block *sb, int ino) { struct ext4_fc_replay_state *state; int i; state = &EXT4_SB(sb)->s_fc_replay_state; for (i = 0; i < state->fc_modified_inodes_used; i++) if (state->fc_modified_inodes[i] == ino) return 0; if (state->fc_modified_inodes_used == state->fc_modified_inodes_size) { state->fc_modified_inodes = krealloc( state->fc_modified_inodes, sizeof(int) * (state->fc_modified_inodes_size + EXT4_FC_REPLAY_REALLOC_INCREMENT), GFP_KERNEL); if (!state->fc_modified_inodes) return -ENOMEM; state->fc_modified_inodes_size += EXT4_FC_REPLAY_REALLOC_INCREMENT; } state->fc_modified_inodes[state->fc_modified_inodes_used++] = ino; return 0; } /* * Inode replay function */ static int ext4_fc_replay_inode(struct super_block *sb, struct ext4_fc_tl *tl, u8 *val) { struct ext4_fc_inode fc_inode; struct ext4_inode *raw_inode; struct ext4_inode *raw_fc_inode; struct inode *inode = NULL; struct ext4_iloc iloc; int inode_len, ino, ret, tag = le16_to_cpu(tl->fc_tag); struct ext4_extent_header *eh; memcpy(&fc_inode, val, sizeof(fc_inode)); ino = le32_to_cpu(fc_inode.fc_ino); trace_ext4_fc_replay(sb, tag, ino, 0, 0); inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL); if (!IS_ERR(inode)) { ext4_ext_clear_bb(inode); iput(inode); } inode = NULL; ret = ext4_fc_record_modified_inode(sb, ino); if (ret) goto out; raw_fc_inode = (struct ext4_inode *) (val + offsetof(struct ext4_fc_inode, fc_raw_inode)); ret = ext4_get_fc_inode_loc(sb, ino, &iloc); if (ret) goto out; inode_len = le16_to_cpu(tl->fc_len) - sizeof(struct ext4_fc_inode); raw_inode = ext4_raw_inode(&iloc); memcpy(raw_inode, raw_fc_inode, offsetof(struct ext4_inode, i_block)); memcpy(&raw_inode->i_generation, &raw_fc_inode->i_generation, inode_len - offsetof(struct ext4_inode, i_generation)); if (le32_to_cpu(raw_inode->i_flags) & EXT4_EXTENTS_FL) { eh = (struct ext4_extent_header *)(&raw_inode->i_block[0]); if (eh->eh_magic != EXT4_EXT_MAGIC) { memset(eh, 0, sizeof(*eh)); eh->eh_magic = EXT4_EXT_MAGIC; eh->eh_max = cpu_to_le16( (sizeof(raw_inode->i_block) - sizeof(struct ext4_extent_header)) / sizeof(struct ext4_extent)); } } else if (le32_to_cpu(raw_inode->i_flags) & EXT4_INLINE_DATA_FL) { memcpy(raw_inode->i_block, raw_fc_inode->i_block, sizeof(raw_inode->i_block)); } /* Immediately update the inode on disk. */ ret = ext4_handle_dirty_metadata(NULL, NULL, iloc.bh); if (ret) goto out; ret = sync_dirty_buffer(iloc.bh); if (ret) goto out; ret = ext4_mark_inode_used(sb, ino); if (ret) goto out; /* Given that we just wrote the inode on disk, this SHOULD succeed. */ inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL); if (IS_ERR(inode)) { jbd_debug(1, "Inode not found."); return -EFSCORRUPTED; } /* * Our allocator could have made different decisions than before * crashing. This should be fixed but until then, we calculate * the number of blocks the inode. */ if (!ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA)) ext4_ext_replay_set_iblocks(inode); inode->i_generation = le32_to_cpu(ext4_raw_inode(&iloc)->i_generation); ext4_reset_inode_seed(inode); ext4_inode_csum_set(inode, ext4_raw_inode(&iloc), EXT4_I(inode)); ret = ext4_handle_dirty_metadata(NULL, NULL, iloc.bh); sync_dirty_buffer(iloc.bh); brelse(iloc.bh); out: iput(inode); if (!ret) blkdev_issue_flush(sb->s_bdev); return 0; } /* * Dentry create replay function. * * EXT4_FC_TAG_CREAT is preceded by EXT4_FC_TAG_INODE_FULL. Which means, the * inode for which we are trying to create a dentry here, should already have * been replayed before we start here. */ static int ext4_fc_replay_create(struct super_block *sb, struct ext4_fc_tl *tl, u8 *val) { int ret = 0; struct inode *inode = NULL; struct inode *dir = NULL; struct dentry_info_args darg; tl_to_darg(&darg, tl, val); trace_ext4_fc_replay(sb, EXT4_FC_TAG_CREAT, darg.ino, darg.parent_ino, darg.dname_len); /* This takes care of update group descriptor and other metadata */ ret = ext4_mark_inode_used(sb, darg.ino); if (ret) goto out; inode = ext4_iget(sb, darg.ino, EXT4_IGET_NORMAL); if (IS_ERR(inode)) { jbd_debug(1, "inode %d not found.", darg.ino); inode = NULL; ret = -EINVAL; goto out; } if (S_ISDIR(inode->i_mode)) { /* * If we are creating a directory, we need to make sure that the * dot and dot dot dirents are setup properly. */ dir = ext4_iget(sb, darg.parent_ino, EXT4_IGET_NORMAL); if (IS_ERR(dir)) { jbd_debug(1, "Dir %d not found.", darg.ino); goto out; } ret = ext4_init_new_dir(NULL, dir, inode); iput(dir); if (ret) { ret = 0; goto out; } } ret = ext4_fc_replay_link_internal(sb, &darg, inode); if (ret) goto out; set_nlink(inode, 1); ext4_mark_inode_dirty(NULL, inode); out: if (inode) iput(inode); return ret; } /* * Record physical disk regions which are in use as per fast commit area, * and used by inodes during replay phase. Our simple replay phase * allocator excludes these regions from allocation. */ int ext4_fc_record_regions(struct super_block *sb, int ino, ext4_lblk_t lblk, ext4_fsblk_t pblk, int len, int replay) { struct ext4_fc_replay_state *state; struct ext4_fc_alloc_region *region; state = &EXT4_SB(sb)->s_fc_replay_state; /* * during replay phase, the fc_regions_valid may not same as * fc_regions_used, update it when do new additions. */ if (replay && state->fc_regions_used != state->fc_regions_valid) state->fc_regions_used = state->fc_regions_valid; if (state->fc_regions_used == state->fc_regions_size) { state->fc_regions_size += EXT4_FC_REPLAY_REALLOC_INCREMENT; state->fc_regions = krealloc( state->fc_regions, state->fc_regions_size * sizeof(struct ext4_fc_alloc_region), GFP_KERNEL); if (!state->fc_regions) return -ENOMEM; } region = &state->fc_regions[state->fc_regions_used++]; region->ino = ino; region->lblk = lblk; region->pblk = pblk; region->len = len; if (replay) state->fc_regions_valid++; return 0; } /* Replay add range tag */ static int ext4_fc_replay_add_range(struct super_block *sb, struct ext4_fc_tl *tl, u8 *val) { struct ext4_fc_add_range fc_add_ex; struct ext4_extent newex, *ex; struct inode *inode; ext4_lblk_t start, cur; int remaining, len; ext4_fsblk_t start_pblk; struct ext4_map_blocks map; struct ext4_ext_path *path = NULL; int ret; memcpy(&fc_add_ex, val, sizeof(fc_add_ex)); ex = (struct ext4_extent *)&fc_add_ex.fc_ex; trace_ext4_fc_replay(sb, EXT4_FC_TAG_ADD_RANGE, le32_to_cpu(fc_add_ex.fc_ino), le32_to_cpu(ex->ee_block), ext4_ext_get_actual_len(ex)); inode = ext4_iget(sb, le32_to_cpu(fc_add_ex.fc_ino), EXT4_IGET_NORMAL); if (IS_ERR(inode)) { jbd_debug(1, "Inode not found."); return 0; } ret = ext4_fc_record_modified_inode(sb, inode->i_ino); if (ret) goto out; start = le32_to_cpu(ex->ee_block); start_pblk = ext4_ext_pblock(ex); len = ext4_ext_get_actual_len(ex); cur = start; remaining = len; jbd_debug(1, "ADD_RANGE, lblk %d, pblk %lld, len %d, unwritten %d, inode %ld\n", start, start_pblk, len, ext4_ext_is_unwritten(ex), inode->i_ino); while (remaining > 0) { map.m_lblk = cur; map.m_len = remaining; map.m_pblk = 0; ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret < 0) goto out; if (ret == 0) { /* Range is not mapped */ path = ext4_find_extent(inode, cur, NULL, 0); if (IS_ERR(path)) goto out; memset(&newex, 0, sizeof(newex)); newex.ee_block = cpu_to_le32(cur); ext4_ext_store_pblock( &newex, start_pblk + cur - start); newex.ee_len = cpu_to_le16(map.m_len); if (ext4_ext_is_unwritten(ex)) ext4_ext_mark_unwritten(&newex); down_write(&EXT4_I(inode)->i_data_sem); ret = ext4_ext_insert_extent( NULL, inode, &path, &newex, 0); up_write((&EXT4_I(inode)->i_data_sem)); ext4_ext_drop_refs(path); kfree(path); if (ret) goto out; goto next; } if (start_pblk + cur - start != map.m_pblk) { /* * Logical to physical mapping changed. This can happen * if this range was removed and then reallocated to * map to new physical blocks during a fast commit. */ ret = ext4_ext_replay_update_ex(inode, cur, map.m_len, ext4_ext_is_unwritten(ex), start_pblk + cur - start); if (ret) goto out; /* * Mark the old blocks as free since they aren't used * anymore. We maintain an array of all the modified * inodes. In case these blocks are still used at either * a different logical range in the same inode or in * some different inode, we will mark them as allocated * at the end of the FC replay using our array of * modified inodes. */ ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, 0); goto next; } /* Range is mapped and needs a state change */ jbd_debug(1, "Converting from %ld to %d %lld", map.m_flags & EXT4_MAP_UNWRITTEN, ext4_ext_is_unwritten(ex), map.m_pblk); ret = ext4_ext_replay_update_ex(inode, cur, map.m_len, ext4_ext_is_unwritten(ex), map.m_pblk); if (ret) goto out; /* * We may have split the extent tree while toggling the state. * Try to shrink the extent tree now. */ ext4_ext_replay_shrink_inode(inode, start + len); next: cur += map.m_len; remaining -= map.m_len; } ext4_ext_replay_shrink_inode(inode, i_size_read(inode) >> sb->s_blocksize_bits); out: iput(inode); return 0; } /* Replay DEL_RANGE tag */ static int ext4_fc_replay_del_range(struct super_block *sb, struct ext4_fc_tl *tl, u8 *val) { struct inode *inode; struct ext4_fc_del_range lrange; struct ext4_map_blocks map; ext4_lblk_t cur, remaining; int ret; memcpy(&lrange, val, sizeof(lrange)); cur = le32_to_cpu(lrange.fc_lblk); remaining = le32_to_cpu(lrange.fc_len); trace_ext4_fc_replay(sb, EXT4_FC_TAG_DEL_RANGE, le32_to_cpu(lrange.fc_ino), cur, remaining); inode = ext4_iget(sb, le32_to_cpu(lrange.fc_ino), EXT4_IGET_NORMAL); if (IS_ERR(inode)) { jbd_debug(1, "Inode %d not found", le32_to_cpu(lrange.fc_ino)); return 0; } ret = ext4_fc_record_modified_inode(sb, inode->i_ino); if (ret) goto out; jbd_debug(1, "DEL_RANGE, inode %ld, lblk %d, len %d\n", inode->i_ino, le32_to_cpu(lrange.fc_lblk), le32_to_cpu(lrange.fc_len)); while (remaining > 0) { map.m_lblk = cur; map.m_len = remaining; ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret < 0) goto out; if (ret > 0) { remaining -= ret; cur += ret; ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, 0); } else { remaining -= map.m_len; cur += map.m_len; } } down_write(&EXT4_I(inode)->i_data_sem); ret = ext4_ext_remove_space(inode, le32_to_cpu(lrange.fc_lblk), le32_to_cpu(lrange.fc_lblk) + le32_to_cpu(lrange.fc_len) - 1); up_write(&EXT4_I(inode)->i_data_sem); if (ret) goto out; ext4_ext_replay_shrink_inode(inode, i_size_read(inode) >> sb->s_blocksize_bits); ext4_mark_inode_dirty(NULL, inode); out: iput(inode); return 0; } static void ext4_fc_set_bitmaps_and_counters(struct super_block *sb) { struct ext4_fc_replay_state *state; struct inode *inode; struct ext4_ext_path *path = NULL; struct ext4_map_blocks map; int i, ret, j; ext4_lblk_t cur, end; state = &EXT4_SB(sb)->s_fc_replay_state; for (i = 0; i < state->fc_modified_inodes_used; i++) { inode = ext4_iget(sb, state->fc_modified_inodes[i], EXT4_IGET_NORMAL); if (IS_ERR(inode)) { jbd_debug(1, "Inode %d not found.", state->fc_modified_inodes[i]); continue; } cur = 0; end = EXT_MAX_BLOCKS; if (ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA)) { iput(inode); continue; } while (cur < end) { map.m_lblk = cur; map.m_len = end - cur; ret = ext4_map_blocks(NULL, inode, &map, 0); if (ret < 0) break; if (ret > 0) { path = ext4_find_extent(inode, map.m_lblk, NULL, 0); if (!IS_ERR(path)) { for (j = 0; j < path->p_depth; j++) ext4_mb_mark_bb(inode->i_sb, path[j].p_block, 1, 1); ext4_ext_drop_refs(path); kfree(path); } cur += ret; ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, 1); } else { cur = cur + (map.m_len ? map.m_len : 1); } } iput(inode); } } /* * Check if block is in excluded regions for block allocation. The simple * allocator that runs during replay phase is calls this function to see * if it is okay to use a block. */ bool ext4_fc_replay_check_excluded(struct super_block *sb, ext4_fsblk_t blk) { int i; struct ext4_fc_replay_state *state; state = &EXT4_SB(sb)->s_fc_replay_state; for (i = 0; i < state->fc_regions_valid; i++) { if (state->fc_regions[i].ino == 0 || state->fc_regions[i].len == 0) continue; if (in_range(blk, state->fc_regions[i].pblk, state->fc_regions[i].len)) return true; } return false; } /* Cleanup function called after replay */ void ext4_fc_replay_cleanup(struct super_block *sb) { struct ext4_sb_info *sbi = EXT4_SB(sb); sbi->s_mount_state &= ~EXT4_FC_REPLAY; kfree(sbi->s_fc_replay_state.fc_regions); kfree(sbi->s_fc_replay_state.fc_modified_inodes); } /* * Recovery Scan phase handler * * This function is called during the scan phase and is responsible * for doing following things: * - Make sure the fast commit area has valid tags for replay * - Count number of tags that need to be replayed by the replay handler * - Verify CRC * - Create a list of excluded blocks for allocation during replay phase * * This function returns JBD2_FC_REPLAY_CONTINUE to indicate that SCAN is * incomplete and JBD2 should send more blocks. It returns JBD2_FC_REPLAY_STOP * to indicate that scan has finished and JBD2 can now start replay phase. * It returns a negative error to indicate that there was an error. At the end * of a successful scan phase, sbi->s_fc_replay_state.fc_replay_num_tags is set * to indicate the number of tags that need to replayed during the replay phase. */ static int ext4_fc_replay_scan(journal_t *journal, struct buffer_head *bh, int off, tid_t expected_tid) { struct super_block *sb = journal->j_private; struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_fc_replay_state *state; int ret = JBD2_FC_REPLAY_CONTINUE; struct ext4_fc_add_range ext; struct ext4_fc_tl tl; struct ext4_fc_tail tail; __u8 *start, *end, *cur, *val; struct ext4_fc_head head; struct ext4_extent *ex; state = &sbi->s_fc_replay_state; start = (u8 *)bh->b_data; end = (__u8 *)bh->b_data + journal->j_blocksize - 1; if (state->fc_replay_expected_off == 0) { state->fc_cur_tag = 0; state->fc_replay_num_tags = 0; state->fc_crc = 0; state->fc_regions = NULL; state->fc_regions_valid = state->fc_regions_used = state->fc_regions_size = 0; /* Check if we can stop early */ if (le16_to_cpu(((struct ext4_fc_tl *)start)->fc_tag) != EXT4_FC_TAG_HEAD) return 0; } if (off != state->fc_replay_expected_off) { ret = -EFSCORRUPTED; goto out_err; } state->fc_replay_expected_off++; for (cur = start; cur < end; cur = cur + sizeof(tl) + le16_to_cpu(tl.fc_len)) { memcpy(&tl, cur, sizeof(tl)); val = cur + sizeof(tl); jbd_debug(3, "Scan phase, tag:%s, blk %lld\n", tag2str(le16_to_cpu(tl.fc_tag)), bh->b_blocknr); switch (le16_to_cpu(tl.fc_tag)) { case EXT4_FC_TAG_ADD_RANGE: memcpy(&ext, val, sizeof(ext)); ex = (struct ext4_extent *)&ext.fc_ex; ret = ext4_fc_record_regions(sb, le32_to_cpu(ext.fc_ino), le32_to_cpu(ex->ee_block), ext4_ext_pblock(ex), ext4_ext_get_actual_len(ex), 0); if (ret < 0) break; ret = JBD2_FC_REPLAY_CONTINUE; fallthrough; case EXT4_FC_TAG_DEL_RANGE: case EXT4_FC_TAG_LINK: case EXT4_FC_TAG_UNLINK: case EXT4_FC_TAG_CREAT: case EXT4_FC_TAG_INODE: case EXT4_FC_TAG_PAD: state->fc_cur_tag++; state->fc_crc = ext4_chksum(sbi, state->fc_crc, cur, sizeof(tl) + le16_to_cpu(tl.fc_len)); break; case EXT4_FC_TAG_TAIL: state->fc_cur_tag++; memcpy(&tail, val, sizeof(tail)); state->fc_crc = ext4_chksum(sbi, state->fc_crc, cur, sizeof(tl) + offsetof(struct ext4_fc_tail, fc_crc)); if (le32_to_cpu(tail.fc_tid) == expected_tid && le32_to_cpu(tail.fc_crc) == state->fc_crc) { state->fc_replay_num_tags = state->fc_cur_tag; state->fc_regions_valid = state->fc_regions_used; } else { ret = state->fc_replay_num_tags ? JBD2_FC_REPLAY_STOP : -EFSBADCRC; } state->fc_crc = 0; break; case EXT4_FC_TAG_HEAD: memcpy(&head, val, sizeof(head)); if (le32_to_cpu(head.fc_features) & ~EXT4_FC_SUPPORTED_FEATURES) { ret = -EOPNOTSUPP; break; } if (le32_to_cpu(head.fc_tid) != expected_tid) { ret = JBD2_FC_REPLAY_STOP; break; } state->fc_cur_tag++; state->fc_crc = ext4_chksum(sbi, state->fc_crc, cur, sizeof(tl) + le16_to_cpu(tl.fc_len)); break; default: ret = state->fc_replay_num_tags ? JBD2_FC_REPLAY_STOP : -ECANCELED; } if (ret < 0 || ret == JBD2_FC_REPLAY_STOP) break; } out_err: trace_ext4_fc_replay_scan(sb, ret, off); return ret; } /* * Main recovery path entry point. * The meaning of return codes is similar as above. */ static int ext4_fc_replay(journal_t *journal, struct buffer_head *bh, enum passtype pass, int off, tid_t expected_tid) { struct super_block *sb = journal->j_private; struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_fc_tl tl; __u8 *start, *end, *cur, *val; int ret = JBD2_FC_REPLAY_CONTINUE; struct ext4_fc_replay_state *state = &sbi->s_fc_replay_state; struct ext4_fc_tail tail; if (pass == PASS_SCAN) { state->fc_current_pass = PASS_SCAN; return ext4_fc_replay_scan(journal, bh, off, expected_tid); } if (state->fc_current_pass != pass) { state->fc_current_pass = pass; sbi->s_mount_state |= EXT4_FC_REPLAY; } if (!sbi->s_fc_replay_state.fc_replay_num_tags) { jbd_debug(1, "Replay stops\n"); ext4_fc_set_bitmaps_and_counters(sb); return 0; } #ifdef CONFIG_EXT4_DEBUG if (sbi->s_fc_debug_max_replay && off >= sbi->s_fc_debug_max_replay) { pr_warn("Dropping fc block %d because max_replay set\n", off); return JBD2_FC_REPLAY_STOP; } #endif start = (u8 *)bh->b_data; end = (__u8 *)bh->b_data + journal->j_blocksize - 1; for (cur = start; cur < end; cur = cur + sizeof(tl) + le16_to_cpu(tl.fc_len)) { memcpy(&tl, cur, sizeof(tl)); val = cur + sizeof(tl); if (state->fc_replay_num_tags == 0) { ret = JBD2_FC_REPLAY_STOP; ext4_fc_set_bitmaps_and_counters(sb); break; } jbd_debug(3, "Replay phase, tag:%s\n", tag2str(le16_to_cpu(tl.fc_tag))); state->fc_replay_num_tags--; switch (le16_to_cpu(tl.fc_tag)) { case EXT4_FC_TAG_LINK: ret = ext4_fc_replay_link(sb, &tl, val); break; case EXT4_FC_TAG_UNLINK: ret = ext4_fc_replay_unlink(sb, &tl, val); break; case EXT4_FC_TAG_ADD_RANGE: ret = ext4_fc_replay_add_range(sb, &tl, val); break; case EXT4_FC_TAG_CREAT: ret = ext4_fc_replay_create(sb, &tl, val); break; case EXT4_FC_TAG_DEL_RANGE: ret = ext4_fc_replay_del_range(sb, &tl, val); break; case EXT4_FC_TAG_INODE: ret = ext4_fc_replay_inode(sb, &tl, val); break; case EXT4_FC_TAG_PAD: trace_ext4_fc_replay(sb, EXT4_FC_TAG_PAD, 0, le16_to_cpu(tl.fc_len), 0); break; case EXT4_FC_TAG_TAIL: trace_ext4_fc_replay(sb, EXT4_FC_TAG_TAIL, 0, le16_to_cpu(tl.fc_len), 0); memcpy(&tail, val, sizeof(tail)); WARN_ON(le32_to_cpu(tail.fc_tid) != expected_tid); break; case EXT4_FC_TAG_HEAD: break; default: trace_ext4_fc_replay(sb, le16_to_cpu(tl.fc_tag), 0, le16_to_cpu(tl.fc_len), 0); ret = -ECANCELED; break; } if (ret < 0) break; ret = JBD2_FC_REPLAY_CONTINUE; } return ret; } void ext4_fc_init(struct super_block *sb, journal_t *journal) { /* * We set replay callback even if fast commit disabled because we may * could still have fast commit blocks that need to be replayed even if * fast commit has now been turned off. */ journal->j_fc_replay_callback = ext4_fc_replay; if (!test_opt2(sb, JOURNAL_FAST_COMMIT)) return; journal->j_fc_cleanup_callback = ext4_fc_cleanup; } static const char *fc_ineligible_reasons[] = { "Extended attributes changed", "Cross rename", "Journal flag changed", "Insufficient memory", "Swap boot", "Resize", "Dir renamed", "Falloc range op", "Data journalling", "FC Commit Failed" }; int ext4_fc_info_show(struct seq_file *seq, void *v) { struct ext4_sb_info *sbi = EXT4_SB((struct super_block *)seq->private); struct ext4_fc_stats *stats = &sbi->s_fc_stats; int i; if (v != SEQ_START_TOKEN) return 0; seq_printf(seq, "fc stats:\n%ld commits\n%ld ineligible\n%ld numblks\n%lluus avg_commit_time\n", stats->fc_num_commits, stats->fc_ineligible_commits, stats->fc_numblks, div_u64(stats->s_fc_avg_commit_time, 1000)); seq_puts(seq, "Ineligible reasons:\n"); for (i = 0; i < EXT4_FC_REASON_MAX; i++) seq_printf(seq, "\"%s\":\t%d\n", fc_ineligible_reasons[i], stats->fc_ineligible_reason_count[i]); return 0; } int __init ext4_fc_init_dentry_cache(void) { ext4_fc_dentry_cachep = KMEM_CACHE(ext4_fc_dentry_update, SLAB_RECLAIM_ACCOUNT); if (ext4_fc_dentry_cachep == NULL) return -ENOMEM; return 0; } void ext4_fc_destroy_dentry_cache(void) { kmem_cache_destroy(ext4_fc_dentry_cachep); }