// SPDX-License-Identifier: GPL-2.0-only /* * QNX6 file system, Linux implementation. * * Version : 1.0.0 * * History : * * 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release. * 16-02-2012 pagemap extension by Al Viro * */ #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/highuid.h> #include <linux/pagemap.h> #include <linux/buffer_head.h> #include <linux/writeback.h> #include <linux/statfs.h> #include <linux/parser.h> #include <linux/seq_file.h> #include <linux/mount.h> #include <linux/crc32.h> #include <linux/mpage.h> #include "qnx6.h" static const struct super_operations qnx6_sops; static void qnx6_put_super(struct super_block *sb); static struct inode *qnx6_alloc_inode(struct super_block *sb); static void qnx6_free_inode(struct inode *inode); static int qnx6_remount(struct super_block *sb, int *flags, char *data); static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf); static int qnx6_show_options(struct seq_file *seq, struct dentry *root); static const struct super_operations qnx6_sops = { .alloc_inode = qnx6_alloc_inode, .free_inode = qnx6_free_inode, .put_super = qnx6_put_super, .statfs = qnx6_statfs, .remount_fs = qnx6_remount, .show_options = qnx6_show_options, }; static int qnx6_show_options(struct seq_file *seq, struct dentry *root) { struct super_block *sb = root->d_sb; struct qnx6_sb_info *sbi = QNX6_SB(sb); if (sbi->s_mount_opt & QNX6_MOUNT_MMI_FS) seq_puts(seq, ",mmi_fs"); return 0; } static int qnx6_remount(struct super_block *sb, int *flags, char *data) { sync_filesystem(sb); *flags |= SB_RDONLY; return 0; } static unsigned qnx6_get_devblock(struct super_block *sb, __fs32 block) { struct qnx6_sb_info *sbi = QNX6_SB(sb); return fs32_to_cpu(sbi, block) + sbi->s_blks_off; } static unsigned qnx6_block_map(struct inode *inode, unsigned iblock); static int qnx6_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh, int create) { unsigned phys; pr_debug("qnx6_get_block inode=[%ld] iblock=[%ld]\n", inode->i_ino, (unsigned long)iblock); phys = qnx6_block_map(inode, iblock); if (phys) { /* logical block is before EOF */ map_bh(bh, inode->i_sb, phys); } return 0; } static int qnx6_check_blockptr(__fs32 ptr) { if (ptr == ~(__fs32)0) { pr_err("hit unused blockpointer.\n"); return 0; } return 1; } static int qnx6_read_folio(struct file *file, struct folio *folio) { return mpage_read_folio(folio, qnx6_get_block); } static void qnx6_readahead(struct readahead_control *rac) { mpage_readahead(rac, qnx6_get_block); } /* * returns the block number for the no-th element in the tree * inodebits requred as there are multiple inodes in one inode block */ static unsigned qnx6_block_map(struct inode *inode, unsigned no) { struct super_block *s = inode->i_sb; struct qnx6_sb_info *sbi = QNX6_SB(s); struct qnx6_inode_info *ei = QNX6_I(inode); unsigned block = 0; struct buffer_head *bh; __fs32 ptr; int levelptr; int ptrbits = sbi->s_ptrbits; int bitdelta; u32 mask = (1 << ptrbits) - 1; int depth = ei->di_filelevels; int i; bitdelta = ptrbits * depth; levelptr = no >> bitdelta; if (levelptr > QNX6_NO_DIRECT_POINTERS - 1) { pr_err("Requested file block number (%u) too big.", no); return 0; } block = qnx6_get_devblock(s, ei->di_block_ptr[levelptr]); for (i = 0; i < depth; i++) { bh = sb_bread(s, block); if (!bh) { pr_err("Error reading block (%u)\n", block); return 0; } bitdelta -= ptrbits; levelptr = (no >> bitdelta) & mask; ptr = ((__fs32 *)bh->b_data)[levelptr]; if (!qnx6_check_blockptr(ptr)) return 0; block = qnx6_get_devblock(s, ptr); brelse(bh); } return block; } static int qnx6_statfs(struct dentry *dentry, struct kstatfs *buf) { struct super_block *sb = dentry->d_sb; struct qnx6_sb_info *sbi = QNX6_SB(sb); u64 id = huge_encode_dev(sb->s_bdev->bd_dev); buf->f_type = sb->s_magic; buf->f_bsize = sb->s_blocksize; buf->f_blocks = fs32_to_cpu(sbi, sbi->sb->sb_num_blocks); buf->f_bfree = fs32_to_cpu(sbi, sbi->sb->sb_free_blocks); buf->f_files = fs32_to_cpu(sbi, sbi->sb->sb_num_inodes); buf->f_ffree = fs32_to_cpu(sbi, sbi->sb->sb_free_inodes); buf->f_bavail = buf->f_bfree; buf->f_namelen = QNX6_LONG_NAME_MAX; buf->f_fsid = u64_to_fsid(id); return 0; } /* * Check the root directory of the filesystem to make sure * it really _is_ a qnx6 filesystem, and to check the size * of the directory entry. */ static const char *qnx6_checkroot(struct super_block *s) { static char match_root[2][3] = {".\0\0", "..\0"}; int i, error = 0; struct qnx6_dir_entry *dir_entry; struct inode *root = d_inode(s->s_root); struct address_space *mapping = root->i_mapping; struct page *page = read_mapping_page(mapping, 0, NULL); if (IS_ERR(page)) return "error reading root directory"; kmap(page); dir_entry = page_address(page); for (i = 0; i < 2; i++) { /* maximum 3 bytes - due to match_root limitation */ if (strncmp(dir_entry[i].de_fname, match_root[i], 3)) error = 1; } qnx6_put_page(page); if (error) return "error reading root directory."; return NULL; } #ifdef CONFIG_QNX6FS_DEBUG void qnx6_superblock_debug(struct qnx6_super_block *sb, struct super_block *s) { struct qnx6_sb_info *sbi = QNX6_SB(s); pr_debug("magic: %08x\n", fs32_to_cpu(sbi, sb->sb_magic)); pr_debug("checksum: %08x\n", fs32_to_cpu(sbi, sb->sb_checksum)); pr_debug("serial: %llx\n", fs64_to_cpu(sbi, sb->sb_serial)); pr_debug("flags: %08x\n", fs32_to_cpu(sbi, sb->sb_flags)); pr_debug("blocksize: %08x\n", fs32_to_cpu(sbi, sb->sb_blocksize)); pr_debug("num_inodes: %08x\n", fs32_to_cpu(sbi, sb->sb_num_inodes)); pr_debug("free_inodes: %08x\n", fs32_to_cpu(sbi, sb->sb_free_inodes)); pr_debug("num_blocks: %08x\n", fs32_to_cpu(sbi, sb->sb_num_blocks)); pr_debug("free_blocks: %08x\n", fs32_to_cpu(sbi, sb->sb_free_blocks)); pr_debug("inode_levels: %02x\n", sb->Inode.levels); } #endif enum { Opt_mmifs, Opt_err }; static const match_table_t tokens = { {Opt_mmifs, "mmi_fs"}, {Opt_err, NULL} }; static int qnx6_parse_options(char *options, struct super_block *sb) { char *p; struct qnx6_sb_info *sbi = QNX6_SB(sb); substring_t args[MAX_OPT_ARGS]; if (!options) return 1; while ((p = strsep(&options, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { case Opt_mmifs: set_opt(sbi->s_mount_opt, MMI_FS); break; default: return 0; } } return 1; } static struct buffer_head *qnx6_check_first_superblock(struct super_block *s, int offset, int silent) { struct qnx6_sb_info *sbi = QNX6_SB(s); struct buffer_head *bh; struct qnx6_super_block *sb; /* Check the superblock signatures start with the first superblock */ bh = sb_bread(s, offset); if (!bh) { pr_err("unable to read the first superblock\n"); return NULL; } sb = (struct qnx6_super_block *)bh->b_data; if (fs32_to_cpu(sbi, sb->sb_magic) != QNX6_SUPER_MAGIC) { sbi->s_bytesex = BYTESEX_BE; if (fs32_to_cpu(sbi, sb->sb_magic) == QNX6_SUPER_MAGIC) { /* we got a big endian fs */ pr_debug("fs got different endianness.\n"); return bh; } else sbi->s_bytesex = BYTESEX_LE; if (!silent) { if (offset == 0) { pr_err("wrong signature (magic) in superblock #1.\n"); } else { pr_info("wrong signature (magic) at position (0x%lx) - will try alternative position (0x0000).\n", offset * s->s_blocksize); } } brelse(bh); return NULL; } return bh; } static struct inode *qnx6_private_inode(struct super_block *s, struct qnx6_root_node *p); static int qnx6_fill_super(struct super_block *s, void *data, int silent) { struct buffer_head *bh1 = NULL, *bh2 = NULL; struct qnx6_super_block *sb1 = NULL, *sb2 = NULL; struct qnx6_sb_info *sbi; struct inode *root; const char *errmsg; struct qnx6_sb_info *qs; int ret = -EINVAL; u64 offset; int bootblock_offset = QNX6_BOOTBLOCK_SIZE; qs = kzalloc(sizeof(struct qnx6_sb_info), GFP_KERNEL); if (!qs) return -ENOMEM; s->s_fs_info = qs; /* Superblock always is 512 Byte long */ if (!sb_set_blocksize(s, QNX6_SUPERBLOCK_SIZE)) { pr_err("unable to set blocksize\n"); goto outnobh; } /* parse the mount-options */ if (!qnx6_parse_options((char *) data, s)) { pr_err("invalid mount options.\n"); goto outnobh; } if (test_opt(s, MMI_FS)) { sb1 = qnx6_mmi_fill_super(s, silent); if (sb1) goto mmi_success; else goto outnobh; } sbi = QNX6_SB(s); sbi->s_bytesex = BYTESEX_LE; /* Check the superblock signatures start with the first superblock */ bh1 = qnx6_check_first_superblock(s, bootblock_offset / QNX6_SUPERBLOCK_SIZE, silent); if (!bh1) { /* try again without bootblock offset */ bh1 = qnx6_check_first_superblock(s, 0, silent); if (!bh1) { pr_err("unable to read the first superblock\n"); goto outnobh; } /* seems that no bootblock at partition start */ bootblock_offset = 0; } sb1 = (struct qnx6_super_block *)bh1->b_data; #ifdef CONFIG_QNX6FS_DEBUG qnx6_superblock_debug(sb1, s); #endif /* checksum check - start at byte 8 and end at byte 512 */ if (fs32_to_cpu(sbi, sb1->sb_checksum) != crc32_be(0, (char *)(bh1->b_data + 8), 504)) { pr_err("superblock #1 checksum error\n"); goto out; } /* set new blocksize */ if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) { pr_err("unable to set blocksize\n"); goto out; } /* blocksize invalidates bh - pull it back in */ brelse(bh1); bh1 = sb_bread(s, bootblock_offset >> s->s_blocksize_bits); if (!bh1) goto outnobh; sb1 = (struct qnx6_super_block *)bh1->b_data; /* calculate second superblock blocknumber */ offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) + (bootblock_offset >> s->s_blocksize_bits) + (QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits); /* set bootblock offset */ sbi->s_blks_off = (bootblock_offset >> s->s_blocksize_bits) + (QNX6_SUPERBLOCK_AREA >> s->s_blocksize_bits); /* next the second superblock */ bh2 = sb_bread(s, offset); if (!bh2) { pr_err("unable to read the second superblock\n"); goto out; } sb2 = (struct qnx6_super_block *)bh2->b_data; if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) { if (!silent) pr_err("wrong signature (magic) in superblock #2.\n"); goto out; } /* checksum check - start at byte 8 and end at byte 512 */ if (fs32_to_cpu(sbi, sb2->sb_checksum) != crc32_be(0, (char *)(bh2->b_data + 8), 504)) { pr_err("superblock #2 checksum error\n"); goto out; } if (fs64_to_cpu(sbi, sb1->sb_serial) >= fs64_to_cpu(sbi, sb2->sb_serial)) { /* superblock #1 active */ sbi->sb_buf = bh1; sbi->sb = (struct qnx6_super_block *)bh1->b_data; brelse(bh2); pr_info("superblock #1 active\n"); } else { /* superblock #2 active */ sbi->sb_buf = bh2; sbi->sb = (struct qnx6_super_block *)bh2->b_data; brelse(bh1); pr_info("superblock #2 active\n"); } mmi_success: /* sanity check - limit maximum indirect pointer levels */ if (sb1->Inode.levels > QNX6_PTR_MAX_LEVELS) { pr_err("too many inode levels (max %i, sb %i)\n", QNX6_PTR_MAX_LEVELS, sb1->Inode.levels); goto out; } if (sb1->Longfile.levels > QNX6_PTR_MAX_LEVELS) { pr_err("too many longfilename levels (max %i, sb %i)\n", QNX6_PTR_MAX_LEVELS, sb1->Longfile.levels); goto out; } s->s_op = &qnx6_sops; s->s_magic = QNX6_SUPER_MAGIC; s->s_flags |= SB_RDONLY; /* Yup, read-only yet */ s->s_time_min = 0; s->s_time_max = U32_MAX; /* ease the later tree level calculations */ sbi = QNX6_SB(s); sbi->s_ptrbits = ilog2(s->s_blocksize / 4); sbi->inodes = qnx6_private_inode(s, &sb1->Inode); if (!sbi->inodes) goto out; sbi->longfile = qnx6_private_inode(s, &sb1->Longfile); if (!sbi->longfile) goto out1; /* prefetch root inode */ root = qnx6_iget(s, QNX6_ROOT_INO); if (IS_ERR(root)) { pr_err("get inode failed\n"); ret = PTR_ERR(root); goto out2; } ret = -ENOMEM; s->s_root = d_make_root(root); if (!s->s_root) goto out2; ret = -EINVAL; errmsg = qnx6_checkroot(s); if (errmsg != NULL) { if (!silent) pr_err("%s\n", errmsg); goto out3; } return 0; out3: dput(s->s_root); s->s_root = NULL; out2: iput(sbi->longfile); out1: iput(sbi->inodes); out: brelse(bh1); brelse(bh2); outnobh: kfree(qs); s->s_fs_info = NULL; return ret; } static void qnx6_put_super(struct super_block *sb) { struct qnx6_sb_info *qs = QNX6_SB(sb); brelse(qs->sb_buf); iput(qs->longfile); iput(qs->inodes); kfree(qs); sb->s_fs_info = NULL; return; } static sector_t qnx6_bmap(struct address_space *mapping, sector_t block) { return generic_block_bmap(mapping, block, qnx6_get_block); } static const struct address_space_operations qnx6_aops = { .read_folio = qnx6_read_folio, .readahead = qnx6_readahead, .bmap = qnx6_bmap }; static struct inode *qnx6_private_inode(struct super_block *s, struct qnx6_root_node *p) { struct inode *inode = new_inode(s); if (inode) { struct qnx6_inode_info *ei = QNX6_I(inode); struct qnx6_sb_info *sbi = QNX6_SB(s); inode->i_size = fs64_to_cpu(sbi, p->size); memcpy(ei->di_block_ptr, p->ptr, sizeof(p->ptr)); ei->di_filelevels = p->levels; inode->i_mode = S_IFREG | S_IRUSR; /* probably wrong */ inode->i_mapping->a_ops = &qnx6_aops; } return inode; } struct inode *qnx6_iget(struct super_block *sb, unsigned ino) { struct qnx6_sb_info *sbi = QNX6_SB(sb); struct qnx6_inode_entry *raw_inode; struct inode *inode; struct qnx6_inode_info *ei; struct address_space *mapping; struct page *page; u32 n, offs; inode = iget_locked(sb, ino); if (!inode) return ERR_PTR(-ENOMEM); if (!(inode->i_state & I_NEW)) return inode; ei = QNX6_I(inode); inode->i_mode = 0; if (ino == 0) { pr_err("bad inode number on dev %s: %u is out of range\n", sb->s_id, ino); iget_failed(inode); return ERR_PTR(-EIO); } n = (ino - 1) >> (PAGE_SHIFT - QNX6_INODE_SIZE_BITS); offs = (ino - 1) & (~PAGE_MASK >> QNX6_INODE_SIZE_BITS); mapping = sbi->inodes->i_mapping; page = read_mapping_page(mapping, n, NULL); if (IS_ERR(page)) { pr_err("major problem: unable to read inode from dev %s\n", sb->s_id); iget_failed(inode); return ERR_CAST(page); } kmap(page); raw_inode = ((struct qnx6_inode_entry *)page_address(page)) + offs; inode->i_mode = fs16_to_cpu(sbi, raw_inode->di_mode); i_uid_write(inode, (uid_t)fs32_to_cpu(sbi, raw_inode->di_uid)); i_gid_write(inode, (gid_t)fs32_to_cpu(sbi, raw_inode->di_gid)); inode->i_size = fs64_to_cpu(sbi, raw_inode->di_size); inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->di_mtime); inode->i_mtime.tv_nsec = 0; inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->di_atime); inode->i_atime.tv_nsec = 0; inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->di_ctime); inode->i_ctime.tv_nsec = 0; /* calc blocks based on 512 byte blocksize */ inode->i_blocks = (inode->i_size + 511) >> 9; memcpy(&ei->di_block_ptr, &raw_inode->di_block_ptr, sizeof(raw_inode->di_block_ptr)); ei->di_filelevels = raw_inode->di_filelevels; if (S_ISREG(inode->i_mode)) { inode->i_fop = &generic_ro_fops; inode->i_mapping->a_ops = &qnx6_aops; } else if (S_ISDIR(inode->i_mode)) { inode->i_op = &qnx6_dir_inode_operations; inode->i_fop = &qnx6_dir_operations; inode->i_mapping->a_ops = &qnx6_aops; } else if (S_ISLNK(inode->i_mode)) { inode->i_op = &page_symlink_inode_operations; inode_nohighmem(inode); inode->i_mapping->a_ops = &qnx6_aops; } else init_special_inode(inode, inode->i_mode, 0); qnx6_put_page(page); unlock_new_inode(inode); return inode; } static struct kmem_cache *qnx6_inode_cachep; static struct inode *qnx6_alloc_inode(struct super_block *sb) { struct qnx6_inode_info *ei; ei = alloc_inode_sb(sb, qnx6_inode_cachep, GFP_KERNEL); if (!ei) return NULL; return &ei->vfs_inode; } static void qnx6_free_inode(struct inode *inode) { kmem_cache_free(qnx6_inode_cachep, QNX6_I(inode)); } static void init_once(void *foo) { struct qnx6_inode_info *ei = (struct qnx6_inode_info *) foo; inode_init_once(&ei->vfs_inode); } static int init_inodecache(void) { qnx6_inode_cachep = kmem_cache_create("qnx6_inode_cache", sizeof(struct qnx6_inode_info), 0, (SLAB_RECLAIM_ACCOUNT| SLAB_MEM_SPREAD|SLAB_ACCOUNT), init_once); if (!qnx6_inode_cachep) return -ENOMEM; return 0; } static void destroy_inodecache(void) { /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); kmem_cache_destroy(qnx6_inode_cachep); } static struct dentry *qnx6_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { return mount_bdev(fs_type, flags, dev_name, data, qnx6_fill_super); } static struct file_system_type qnx6_fs_type = { .owner = THIS_MODULE, .name = "qnx6", .mount = qnx6_mount, .kill_sb = kill_block_super, .fs_flags = FS_REQUIRES_DEV, }; MODULE_ALIAS_FS("qnx6"); static int __init init_qnx6_fs(void) { int err; err = init_inodecache(); if (err) return err; err = register_filesystem(&qnx6_fs_type); if (err) { destroy_inodecache(); return err; } pr_info("QNX6 filesystem 1.0.0 registered.\n"); return 0; } static void __exit exit_qnx6_fs(void) { unregister_filesystem(&qnx6_fs_type); destroy_inodecache(); } module_init(init_qnx6_fs) module_exit(exit_qnx6_fs) MODULE_LICENSE("GPL");