| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| OGAWA Hirofumi | 4061 | 42.00% | 71 | 23.75% |
| Linus Torvalds (pre-git) | 1366 | 14.13% | 67 | 22.41% |
| Conrad Meyer | 1060 | 10.96% | 1 | 0.33% |
| Namjae Jeon | 355 | 3.67% | 11 | 3.68% |
| Andrew Morton | 317 | 3.28% | 10 | 3.34% |
| Linus Torvalds | 273 | 2.82% | 17 | 5.69% |
| Oleksij Rempel | 238 | 2.46% | 2 | 0.67% |
| Nicholas Piggin | 202 | 2.09% | 4 | 1.34% |
| Steven J. Magnani | 167 | 1.73% | 3 | 1.00% |
| Al Viro | 165 | 1.71% | 16 | 5.35% |
| Christoph Hellwig | 165 | 1.71% | 18 | 6.02% |
| Alexey Fisher | 138 | 1.43% | 2 | 0.67% |
| Chris Mason | 126 | 1.30% | 1 | 0.33% |
| Jan Kara | 111 | 1.15% | 5 | 1.67% |
| Denis Karpov | 100 | 1.03% | 1 | 0.33% |
| Jeff Layton | 85 | 0.88% | 3 | 1.00% |
| Deepa Dinamani | 73 | 0.75% | 2 | 0.67% |
| Artem B. Bityutskiy | 61 | 0.63% | 2 | 0.67% |
| Eric W. Biedermann | 60 | 0.62% | 1 | 0.33% |
| Chung-Chiang Cheng | 45 | 0.47% | 2 | 0.67% |
| Joe Peterson | 40 | 0.41% | 1 | 0.33% |
| Neil Brown | 40 | 0.41% | 1 | 0.33% |
| Coly Li | 27 | 0.28% | 1 | 0.33% |
| Kent Overstreet | 27 | 0.28% | 1 | 0.33% |
| Badari Pulavarty | 24 | 0.25% | 2 | 0.67% |
| Pekka J Enberg | 24 | 0.25% | 1 | 0.33% |
| Carmeli Tamir | 22 | 0.23% | 3 | 1.00% |
| Marco Stornelli | 22 | 0.23% | 1 | 0.33% |
| Matthew Wilcox | 21 | 0.22% | 4 | 1.34% |
| Stephane Kardas | 21 | 0.22% | 1 | 0.33% |
| Miklos Szeredi | 20 | 0.21% | 2 | 0.67% |
| Mike Lockwood | 19 | 0.20% | 1 | 0.33% |
| David Howells | 19 | 0.20% | 3 | 1.00% |
| Dave Hansen | 18 | 0.19% | 1 | 0.33% |
| Frank Sorenson | 17 | 0.18% | 2 | 0.67% |
| Brian Gerst | 14 | 0.14% | 1 | 0.33% |
| Geert Uytterhoeven | 13 | 0.13% | 1 | 0.33% |
| Andries E. Brouwer | 12 | 0.12% | 2 | 0.67% |
| Maciej S. Szmigiero | 11 | 0.11% | 1 | 0.33% |
| Art Haas | 9 | 0.09% | 1 | 0.33% |
| Omar Sandoval | 9 | 0.09% | 1 | 0.33% |
| Paul Wise | 8 | 0.08% | 1 | 0.33% |
| Arnd Bergmann | 7 | 0.07% | 2 | 0.67% |
| Mark Fasheh | 7 | 0.07% | 1 | 0.33% |
| Andi Kleen | 6 | 0.06% | 1 | 0.33% |
| Christoph Lameter | 5 | 0.05% | 2 | 0.67% |
| Dave Reisner | 5 | 0.05% | 1 | 0.33% |
| Alexander Kuleshov | 5 | 0.05% | 2 | 0.67% |
| Kirill A. Shutemov | 4 | 0.04% | 1 | 0.33% |
| Paul Jackson | 3 | 0.03% | 2 | 0.67% |
| Song Muchun | 3 | 0.03% | 1 | 0.33% |
| Steven Whitehouse | 3 | 0.03% | 1 | 0.33% |
| Fred Chou | 3 | 0.03% | 1 | 0.33% |
| Zheng Lv | 2 | 0.02% | 2 | 0.67% |
| Mihai Moldovan | 2 | 0.02% | 1 | 0.33% |
| Panagiotis Issaris | 1 | 0.01% | 1 | 0.33% |
| Alexey Dobriyan | 1 | 0.01% | 1 | 0.33% |
| Vladimir Davydov | 1 | 0.01% | 1 | 0.33% |
| Thomas Gleixner | 1 | 0.01% | 1 | 0.33% |
| Kevin Dankwardt | 1 | 0.01% | 1 | 0.33% |
| Manuel Schölling | 1 | 0.01% | 1 | 0.33% |
| Johannes Weiner | 1 | 0.01% | 1 | 0.33% |
| Jason A. Donenfeld | 1 | 0.01% | 1 | 0.33% |
| Josef 'Jeff' Sipek | 1 | 0.01% | 1 | 0.33% |
| Total | 9669 | 299 |
// SPDX-License-Identifier: GPL-2.0-only /* * linux/fs/fat/inode.c * * Written 1992,1993 by Werner Almesberger * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner * Rewritten for the constant inumbers support by Al Viro * * Fixes: * * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0 */ #include <linux/module.h> #include <linux/pagemap.h> #include <linux/mpage.h> #include <linux/vfs.h> #include <linux/seq_file.h> #include <linux/parser.h> #include <linux/uio.h> #include <linux/blkdev.h> #include <linux/backing-dev.h> #include <asm/unaligned.h> #include <linux/random.h> #include <linux/iversion.h> #include "fat.h" #ifndef CONFIG_FAT_DEFAULT_IOCHARSET /* if user don't select VFAT, this is undefined. */ #define CONFIG_FAT_DEFAULT_IOCHARSET "" #endif #define KB_IN_SECTORS 2 /* DOS dates from 1980/1/1 through 2107/12/31 */ #define FAT_DATE_MIN (0<<9 | 1<<5 | 1) #define FAT_DATE_MAX (127<<9 | 12<<5 | 31) #define FAT_TIME_MAX (23<<11 | 59<<5 | 29) /* * A deserialized copy of the on-disk structure laid out in struct * fat_boot_sector. */ struct fat_bios_param_block { u16 fat_sector_size; u8 fat_sec_per_clus; u16 fat_reserved; u8 fat_fats; u16 fat_dir_entries; u16 fat_sectors; u16 fat_fat_length; u32 fat_total_sect; u8 fat16_state; u32 fat16_vol_id; u32 fat32_length; u32 fat32_root_cluster; u16 fat32_info_sector; u8 fat32_state; u32 fat32_vol_id; }; static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; static struct fat_floppy_defaults { unsigned nr_sectors; unsigned sec_per_clus; unsigned dir_entries; unsigned media; unsigned fat_length; } floppy_defaults[] = { { .nr_sectors = 160 * KB_IN_SECTORS, .sec_per_clus = 1, .dir_entries = 64, .media = 0xFE, .fat_length = 1, }, { .nr_sectors = 180 * KB_IN_SECTORS, .sec_per_clus = 1, .dir_entries = 64, .media = 0xFC, .fat_length = 2, }, { .nr_sectors = 320 * KB_IN_SECTORS, .sec_per_clus = 2, .dir_entries = 112, .media = 0xFF, .fat_length = 1, }, { .nr_sectors = 360 * KB_IN_SECTORS, .sec_per_clus = 2, .dir_entries = 112, .media = 0xFD, .fat_length = 2, }, }; int fat_add_cluster(struct inode *inode) { int err, cluster; err = fat_alloc_clusters(inode, &cluster, 1); if (err) return err; /* FIXME: this cluster should be added after data of this * cluster is writed */ err = fat_chain_add(inode, cluster, 1); if (err) fat_free_clusters(inode, cluster); return err; } static inline int __fat_get_block(struct inode *inode, sector_t iblock, unsigned long *max_blocks, struct buffer_head *bh_result, int create) { struct super_block *sb = inode->i_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); unsigned long mapped_blocks; sector_t phys, last_block; int err, offset; err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); if (err) return err; if (phys) { map_bh(bh_result, sb, phys); *max_blocks = min(mapped_blocks, *max_blocks); return 0; } if (!create) return 0; if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)", MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); return -EIO; } last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9); offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); /* * allocate a cluster according to the following. * 1) no more available blocks * 2) not part of fallocate region */ if (!offset && !(iblock < last_block)) { /* TODO: multiple cluster allocation would be desirable. */ err = fat_add_cluster(inode); if (err) return err; } /* available blocks on this cluster */ mapped_blocks = sbi->sec_per_clus - offset; *max_blocks = min(mapped_blocks, *max_blocks); MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits; err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); if (err) return err; if (!phys) { fat_fs_error(sb, "invalid FAT chain (i_pos %lld, last_block %llu)", MSDOS_I(inode)->i_pos, (unsigned long long)last_block); return -EIO; } BUG_ON(*max_blocks != mapped_blocks); set_buffer_new(bh_result); map_bh(bh_result, sb, phys); return 0; } static int fat_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { struct super_block *sb = inode->i_sb; unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; int err; err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create); if (err) return err; bh_result->b_size = max_blocks << sb->s_blocksize_bits; return 0; } static int fat_writepages(struct address_space *mapping, struct writeback_control *wbc) { return mpage_writepages(mapping, wbc, fat_get_block); } static int fat_read_folio(struct file *file, struct folio *folio) { return mpage_read_folio(folio, fat_get_block); } static void fat_readahead(struct readahead_control *rac) { mpage_readahead(rac, fat_get_block); } static void fat_write_failed(struct address_space *mapping, loff_t to) { struct inode *inode = mapping->host; if (to > inode->i_size) { truncate_pagecache(inode, inode->i_size); fat_truncate_blocks(inode, inode->i_size); } } static int fat_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, struct page **pagep, void **fsdata) { int err; *pagep = NULL; err = cont_write_begin(file, mapping, pos, len, pagep, fsdata, fat_get_block, &MSDOS_I(mapping->host)->mmu_private); if (err < 0) fat_write_failed(mapping, pos + len); return err; } static int fat_write_end(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *pagep, void *fsdata) { struct inode *inode = mapping->host; int err; err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); if (err < len) fat_write_failed(mapping, pos + len); if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { fat_truncate_time(inode, NULL, S_CTIME|S_MTIME); MSDOS_I(inode)->i_attrs |= ATTR_ARCH; mark_inode_dirty(inode); } return err; } static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter) { struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; size_t count = iov_iter_count(iter); loff_t offset = iocb->ki_pos; ssize_t ret; if (iov_iter_rw(iter) == WRITE) { /* * FIXME: blockdev_direct_IO() doesn't use ->write_begin(), * so we need to update the ->mmu_private to block boundary. * * But we must fill the remaining area or hole by nul for * updating ->mmu_private. * * Return 0, and fallback to normal buffered write. */ loff_t size = offset + count; if (MSDOS_I(inode)->mmu_private < size) return 0; } /* * FAT need to use the DIO_LOCKING for avoiding the race * condition of fat_get_block() and ->truncate(). */ ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block); if (ret < 0 && iov_iter_rw(iter) == WRITE) fat_write_failed(mapping, offset + count); return ret; } static int fat_get_block_bmap(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { struct super_block *sb = inode->i_sb; unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; int err; sector_t bmap; unsigned long mapped_blocks; BUG_ON(create != 0); err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true); if (err) return err; if (bmap) { map_bh(bh_result, sb, bmap); max_blocks = min(mapped_blocks, max_blocks); } bh_result->b_size = max_blocks << sb->s_blocksize_bits; return 0; } static sector_t _fat_bmap(struct address_space *mapping, sector_t block) { sector_t blocknr; /* fat_get_cluster() assumes the requested blocknr isn't truncated. */ down_read(&MSDOS_I(mapping->host)->truncate_lock); blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap); up_read(&MSDOS_I(mapping->host)->truncate_lock); return blocknr; } /* * fat_block_truncate_page() zeroes out a mapping from file offset `from' * up to the end of the block which corresponds to `from'. * This is required during truncate to physically zeroout the tail end * of that block so it doesn't yield old data if the file is later grown. * Also, avoid causing failure from fsx for cases of "data past EOF" */ int fat_block_truncate_page(struct inode *inode, loff_t from) { return block_truncate_page(inode->i_mapping, from, fat_get_block); } static const struct address_space_operations fat_aops = { .dirty_folio = block_dirty_folio, .invalidate_folio = block_invalidate_folio, .read_folio = fat_read_folio, .readahead = fat_readahead, .writepages = fat_writepages, .write_begin = fat_write_begin, .write_end = fat_write_end, .direct_IO = fat_direct_IO, .bmap = _fat_bmap, .migrate_folio = buffer_migrate_folio, }; /* * New FAT inode stuff. We do the following: * a) i_ino is constant and has nothing with on-disk location. * b) FAT manages its own cache of directory entries. * c) *This* cache is indexed by on-disk location. * d) inode has an associated directory entry, all right, but * it may be unhashed. * e) currently entries are stored within struct inode. That should * change. * f) we deal with races in the following way: * 1. readdir() and lookup() do FAT-dir-cache lookup. * 2. rename() unhashes the F-d-c entry and rehashes it in * a new place. * 3. unlink() and rmdir() unhash F-d-c entry. * 4. fat_write_inode() checks whether the thing is unhashed. * If it is we silently return. If it isn't we do bread(), * check if the location is still valid and retry if it * isn't. Otherwise we do changes. * 5. Spinlock is used to protect hash/unhash/location check/lookup * 6. fat_evict_inode() unhashes the F-d-c entry. * 7. lookup() and readdir() do igrab() if they find a F-d-c entry * and consider negative result as cache miss. */ static void fat_hash_init(struct super_block *sb) { struct msdos_sb_info *sbi = MSDOS_SB(sb); int i; spin_lock_init(&sbi->inode_hash_lock); for (i = 0; i < FAT_HASH_SIZE; i++) INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); } static inline unsigned long fat_hash(loff_t i_pos) { return hash_32(i_pos, FAT_HASH_BITS); } static void dir_hash_init(struct super_block *sb) { struct msdos_sb_info *sbi = MSDOS_SB(sb); int i; spin_lock_init(&sbi->dir_hash_lock); for (i = 0; i < FAT_HASH_SIZE; i++) INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); } void fat_attach(struct inode *inode, loff_t i_pos) { struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); if (inode->i_ino != MSDOS_ROOT_INO) { struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); spin_lock(&sbi->inode_hash_lock); MSDOS_I(inode)->i_pos = i_pos; hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); spin_unlock(&sbi->inode_hash_lock); } /* If NFS support is enabled, cache the mapping of start cluster * to directory inode. This is used during reconnection of * dentries to the filesystem root. */ if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { struct hlist_head *d_head = sbi->dir_hashtable; d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); spin_lock(&sbi->dir_hash_lock); hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); spin_unlock(&sbi->dir_hash_lock); } } EXPORT_SYMBOL_GPL(fat_attach); void fat_detach(struct inode *inode) { struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); spin_lock(&sbi->inode_hash_lock); MSDOS_I(inode)->i_pos = 0; hlist_del_init(&MSDOS_I(inode)->i_fat_hash); spin_unlock(&sbi->inode_hash_lock); if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { spin_lock(&sbi->dir_hash_lock); hlist_del_init(&MSDOS_I(inode)->i_dir_hash); spin_unlock(&sbi->dir_hash_lock); } } EXPORT_SYMBOL_GPL(fat_detach); struct inode *fat_iget(struct super_block *sb, loff_t i_pos) { struct msdos_sb_info *sbi = MSDOS_SB(sb); struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); struct msdos_inode_info *i; struct inode *inode = NULL; spin_lock(&sbi->inode_hash_lock); hlist_for_each_entry(i, head, i_fat_hash) { BUG_ON(i->vfs_inode.i_sb != sb); if (i->i_pos != i_pos) continue; inode = igrab(&i->vfs_inode); if (inode) break; } spin_unlock(&sbi->inode_hash_lock); return inode; } static int is_exec(unsigned char *extension) { unsigned char exe_extensions[] = "EXECOMBAT", *walk; for (walk = exe_extensions; *walk; walk += 3) if (!strncmp(extension, walk, 3)) return 1; return 0; } static int fat_calc_dir_size(struct inode *inode) { struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); int ret, fclus, dclus; inode->i_size = 0; if (MSDOS_I(inode)->i_start == 0) return 0; ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); if (ret < 0) return ret; inode->i_size = (fclus + 1) << sbi->cluster_bits; return 0; } static int fat_validate_dir(struct inode *dir) { struct super_block *sb = dir->i_sb; if (dir->i_nlink < 2) { /* Directory should have "."/".." entries at least. */ fat_fs_error(sb, "corrupted directory (invalid entries)"); return -EIO; } if (MSDOS_I(dir)->i_start == 0 || MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) { /* Directory should point valid cluster. */ fat_fs_error(sb, "corrupted directory (invalid i_start)"); return -EIO; } return 0; } /* doesn't deal with root inode */ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) { struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); struct timespec64 mtime; int error; MSDOS_I(inode)->i_pos = 0; inode->i_uid = sbi->options.fs_uid; inode->i_gid = sbi->options.fs_gid; inode_inc_iversion(inode); inode->i_generation = get_random_u32(); if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { inode->i_generation &= ~1; inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO); inode->i_op = sbi->dir_ops; inode->i_fop = &fat_dir_operations; MSDOS_I(inode)->i_start = fat_get_start(sbi, de); MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; error = fat_calc_dir_size(inode); if (error < 0) return error; MSDOS_I(inode)->mmu_private = inode->i_size; set_nlink(inode, fat_subdirs(inode)); error = fat_validate_dir(inode); if (error < 0) return error; } else { /* not a directory */ inode->i_generation |= 1; inode->i_mode = fat_make_mode(sbi, de->attr, ((sbi->options.showexec && !is_exec(de->name + 8)) ? S_IRUGO|S_IWUGO : S_IRWXUGO)); MSDOS_I(inode)->i_start = fat_get_start(sbi, de); MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; inode->i_size = le32_to_cpu(de->size); inode->i_op = &fat_file_inode_operations; inode->i_fop = &fat_file_operations; inode->i_mapping->a_ops = &fat_aops; MSDOS_I(inode)->mmu_private = inode->i_size; } if (de->attr & ATTR_SYS) { if (sbi->options.sys_immutable) inode->i_flags |= S_IMMUTABLE; } fat_save_attrs(inode, de->attr); inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) & ~((loff_t)sbi->cluster_size - 1)) >> 9; fat_time_fat2unix(sbi, &mtime, de->time, de->date, 0); inode_set_mtime_to_ts(inode, mtime); inode_set_ctime_to_ts(inode, mtime); if (sbi->options.isvfat) { struct timespec64 atime; fat_time_fat2unix(sbi, &atime, 0, de->adate, 0); inode_set_atime_to_ts(inode, atime); fat_time_fat2unix(sbi, &MSDOS_I(inode)->i_crtime, de->ctime, de->cdate, de->ctime_cs); } else inode_set_atime_to_ts(inode, fat_truncate_atime(sbi, &mtime)); return 0; } static inline void fat_lock_build_inode(struct msdos_sb_info *sbi) { if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) mutex_lock(&sbi->nfs_build_inode_lock); } static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi) { if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) mutex_unlock(&sbi->nfs_build_inode_lock); } struct inode *fat_build_inode(struct super_block *sb, struct msdos_dir_entry *de, loff_t i_pos) { struct inode *inode; int err; fat_lock_build_inode(MSDOS_SB(sb)); inode = fat_iget(sb, i_pos); if (inode) goto out; inode = new_inode(sb); if (!inode) { inode = ERR_PTR(-ENOMEM); goto out; } inode->i_ino = iunique(sb, MSDOS_ROOT_INO); inode_set_iversion(inode, 1); err = fat_fill_inode(inode, de); if (err) { iput(inode); inode = ERR_PTR(err); goto out; } fat_attach(inode, i_pos); insert_inode_hash(inode); out: fat_unlock_build_inode(MSDOS_SB(sb)); return inode; } EXPORT_SYMBOL_GPL(fat_build_inode); static int __fat_write_inode(struct inode *inode, int wait); static void fat_free_eofblocks(struct inode *inode) { /* Release unwritten fallocated blocks on inode eviction. */ if ((inode->i_blocks << 9) > round_up(MSDOS_I(inode)->mmu_private, MSDOS_SB(inode->i_sb)->cluster_size)) { int err; fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private); /* Fallocate results in updating the i_start/iogstart * for the zero byte file. So, make it return to * original state during evict and commit it to avoid * any corruption on the next access to the cluster * chain for the file. */ err = __fat_write_inode(inode, inode_needs_sync(inode)); if (err) { fat_msg(inode->i_sb, KERN_WARNING, "Failed to " "update on disk inode for unused " "fallocated blocks, inode could be " "corrupted. Please run fsck"); } } } static void fat_evict_inode(struct inode *inode) { truncate_inode_pages_final(&inode->i_data); if (!inode->i_nlink) { inode->i_size = 0; fat_truncate_blocks(inode, 0); } else fat_free_eofblocks(inode); invalidate_inode_buffers(inode); clear_inode(inode); fat_cache_inval_inode(inode); fat_detach(inode); } static void fat_set_state(struct super_block *sb, unsigned int set, unsigned int force) { struct buffer_head *bh; struct fat_boot_sector *b; struct msdos_sb_info *sbi = MSDOS_SB(sb); /* do not change any thing if mounted read only */ if (sb_rdonly(sb) && !force) return; /* do not change state if fs was dirty */ if (sbi->dirty) { /* warn only on set (mount). */ if (set) fat_msg(sb, KERN_WARNING, "Volume was not properly " "unmounted. Some data may be corrupt. " "Please run fsck."); return; } bh = sb_bread(sb, 0); if (bh == NULL) { fat_msg(sb, KERN_ERR, "unable to read boot sector " "to mark fs as dirty"); return; } b = (struct fat_boot_sector *) bh->b_data; if (is_fat32(sbi)) { if (set) b->fat32.state |= FAT_STATE_DIRTY; else b->fat32.state &= ~FAT_STATE_DIRTY; } else /* fat 16 and 12 */ { if (set) b->fat16.state |= FAT_STATE_DIRTY; else b->fat16.state &= ~FAT_STATE_DIRTY; } mark_buffer_dirty(bh); sync_dirty_buffer(bh); brelse(bh); } static void fat_reset_iocharset(struct fat_mount_options *opts) { if (opts->iocharset != fat_default_iocharset) { /* Note: opts->iocharset can be NULL here */ kfree(opts->iocharset); opts->iocharset = fat_default_iocharset; } } static void delayed_free(struct rcu_head *p) { struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu); unload_nls(sbi->nls_disk); unload_nls(sbi->nls_io); fat_reset_iocharset(&sbi->options); kfree(sbi); } static void fat_put_super(struct super_block *sb) { struct msdos_sb_info *sbi = MSDOS_SB(sb); fat_set_state(sb, 0, 0); iput(sbi->fsinfo_inode); iput(sbi->fat_inode); call_rcu(&sbi->rcu, delayed_free); } static struct kmem_cache *fat_inode_cachep; static struct inode *fat_alloc_inode(struct super_block *sb) { struct msdos_inode_info *ei; ei = alloc_inode_sb(sb, fat_inode_cachep, GFP_NOFS); if (!ei) return NULL; init_rwsem(&ei->truncate_lock); /* Zeroing to allow iput() even if partial initialized inode. */ ei->mmu_private = 0; ei->i_start = 0; ei->i_logstart = 0; ei->i_attrs = 0; ei->i_pos = 0; ei->i_crtime.tv_sec = 0; ei->i_crtime.tv_nsec = 0; return &ei->vfs_inode; } static void fat_free_inode(struct inode *inode) { kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); } static void init_once(void *foo) { struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; spin_lock_init(&ei->cache_lru_lock); ei->nr_caches = 0; ei->cache_valid_id = FAT_CACHE_VALID + 1; INIT_LIST_HEAD(&ei->cache_lru); INIT_HLIST_NODE(&ei->i_fat_hash); INIT_HLIST_NODE(&ei->i_dir_hash); inode_init_once(&ei->vfs_inode); } static int __init fat_init_inodecache(void) { fat_inode_cachep = kmem_cache_create("fat_inode_cache", sizeof(struct msdos_inode_info), 0, (SLAB_RECLAIM_ACCOUNT| SLAB_ACCOUNT), init_once); if (fat_inode_cachep == NULL) return -ENOMEM; return 0; } static void __exit fat_destroy_inodecache(void) { /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); kmem_cache_destroy(fat_inode_cachep); } static int fat_remount(struct super_block *sb, int *flags, char *data) { bool new_rdonly; struct msdos_sb_info *sbi = MSDOS_SB(sb); *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); sync_filesystem(sb); /* make sure we update state on remount. */ new_rdonly = *flags & SB_RDONLY; if (new_rdonly != sb_rdonly(sb)) { if (new_rdonly) fat_set_state(sb, 0, 0); else fat_set_state(sb, 1, 1); } return 0; } static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) { struct super_block *sb = dentry->d_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); u64 id = huge_encode_dev(sb->s_bdev->bd_dev); /* If the count of free cluster is still unknown, counts it here. */ if (sbi->free_clusters == -1 || !sbi->free_clus_valid) { int err = fat_count_free_clusters(dentry->d_sb); if (err) return err; } buf->f_type = dentry->d_sb->s_magic; buf->f_bsize = sbi->cluster_size; buf->f_blocks = sbi->max_cluster - FAT_START_ENT; buf->f_bfree = sbi->free_clusters; buf->f_bavail = sbi->free_clusters; buf->f_fsid = u64_to_fsid(id); buf->f_namelen = (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; return 0; } static int __fat_write_inode(struct inode *inode, int wait) { struct super_block *sb = inode->i_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); struct buffer_head *bh; struct msdos_dir_entry *raw_entry; struct timespec64 mtime; loff_t i_pos; sector_t blocknr; int err, offset; if (inode->i_ino == MSDOS_ROOT_INO) return 0; retry: i_pos = fat_i_pos_read(sbi, inode); if (!i_pos) return 0; fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset); bh = sb_bread(sb, blocknr); if (!bh) { fat_msg(sb, KERN_ERR, "unable to read inode block " "for updating (i_pos %lld)", i_pos); return -EIO; } spin_lock(&sbi->inode_hash_lock); if (i_pos != MSDOS_I(inode)->i_pos) { spin_unlock(&sbi->inode_hash_lock); brelse(bh); goto retry; } raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset]; if (S_ISDIR(inode->i_mode)) raw_entry->size = 0; else raw_entry->size = cpu_to_le32(inode->i_size); raw_entry->attr = fat_make_attrs(inode); fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart); mtime = inode_get_mtime(inode); fat_time_unix2fat(sbi, &mtime, &raw_entry->time, &raw_entry->date, NULL); if (sbi->options.isvfat) { struct timespec64 ts = inode_get_atime(inode); __le16 atime; fat_time_unix2fat(sbi, &ts, &atime, &raw_entry->adate, NULL); fat_time_unix2fat(sbi, &MSDOS_I(inode)->i_crtime, &raw_entry->ctime, &raw_entry->cdate, &raw_entry->ctime_cs); } spin_unlock(&sbi->inode_hash_lock); mark_buffer_dirty(bh); err = 0; if (wait) err = sync_dirty_buffer(bh); brelse(bh); return err; } static int fat_write_inode(struct inode *inode, struct writeback_control *wbc) { int err; if (inode->i_ino == MSDOS_FSINFO_INO) { struct super_block *sb = inode->i_sb; mutex_lock(&MSDOS_SB(sb)->s_lock); err = fat_clusters_flush(sb); mutex_unlock(&MSDOS_SB(sb)->s_lock); } else err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); return err; } int fat_sync_inode(struct inode *inode) { return __fat_write_inode(inode, 1); } EXPORT_SYMBOL_GPL(fat_sync_inode); static int fat_show_options(struct seq_file *m, struct dentry *root); static const struct super_operations fat_sops = { .alloc_inode = fat_alloc_inode, .free_inode = fat_free_inode, .write_inode = fat_write_inode, .evict_inode = fat_evict_inode, .put_super = fat_put_super, .statfs = fat_statfs, .remount_fs = fat_remount, .show_options = fat_show_options, }; static int fat_show_options(struct seq_file *m, struct dentry *root) { struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb); struct fat_mount_options *opts = &sbi->options; int isvfat = opts->isvfat; if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID)) seq_printf(m, ",uid=%u", from_kuid_munged(&init_user_ns, opts->fs_uid)); if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) seq_printf(m, ",gid=%u", from_kgid_munged(&init_user_ns, opts->fs_gid)); seq_printf(m, ",fmask=%04o", opts->fs_fmask); seq_printf(m, ",dmask=%04o", opts->fs_dmask); if (opts->allow_utime) seq_printf(m, ",allow_utime=%04o", opts->allow_utime); if (sbi->nls_disk) /* strip "cp" prefix from displayed option */ seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]); if (isvfat) { if (sbi->nls_io) seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); switch (opts->shortname) { case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: seq_puts(m, ",shortname=win95"); break; case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: seq_puts(m, ",shortname=winnt"); break; case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: seq_puts(m, ",shortname=mixed"); break; case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: seq_puts(m, ",shortname=lower"); break; default: seq_puts(m, ",shortname=unknown"); break; } } if (opts->name_check != 'n') seq_printf(m, ",check=%c", opts->name_check); if (opts->usefree) seq_puts(m, ",usefree"); if (opts->quiet) seq_puts(m, ",quiet"); if (opts->showexec) seq_puts(m, ",showexec"); if (opts->sys_immutable) seq_puts(m, ",sys_immutable"); if (!isvfat) { if (opts->dotsOK) seq_puts(m, ",dotsOK=yes"); if (opts->nocase) seq_puts(m, ",nocase"); } else { if (opts->utf8) seq_puts(m, ",utf8"); if (opts->unicode_xlate) seq_puts(m, ",uni_xlate"); if (!opts->numtail) seq_puts(m, ",nonumtail"); if (opts->rodir) seq_puts(m, ",rodir"); } if (opts->flush) seq_puts(m, ",flush"); if (opts->tz_set) { if (opts->time_offset) seq_printf(m, ",time_offset=%d", opts->time_offset); else seq_puts(m, ",tz=UTC"); } if (opts->errors == FAT_ERRORS_CONT) seq_puts(m, ",errors=continue"); else if (opts->errors == FAT_ERRORS_PANIC) seq_puts(m, ",errors=panic"); else seq_puts(m, ",errors=remount-ro"); if (opts->nfs == FAT_NFS_NOSTALE_RO) seq_puts(m, ",nfs=nostale_ro"); else if (opts->nfs) seq_puts(m, ",nfs=stale_rw"); if (opts->discard) seq_puts(m, ",discard"); if (opts->dos1xfloppy) seq_puts(m, ",dos1xfloppy"); return 0; } enum { Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage, Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable, Opt_dots, Opt_nodots, Opt_charset, Opt_shortname_lower, Opt_shortname_win95, Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset, Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy, }; static const match_table_t fat_tokens = { {Opt_check_r, "check=relaxed"}, {Opt_check_s, "check=strict"}, {Opt_check_n, "check=normal"}, {Opt_check_r, "check=r"}, {Opt_check_s, "check=s"}, {Opt_check_n, "check=n"}, {Opt_uid, "uid=%u"}, {Opt_gid, "gid=%u"}, {Opt_umask, "umask=%o"}, {Opt_dmask, "dmask=%o"}, {Opt_fmask, "fmask=%o"}, {Opt_allow_utime, "allow_utime=%o"}, {Opt_codepage, "codepage=%u"}, {Opt_usefree, "usefree"}, {Opt_nocase, "nocase"}, {Opt_quiet, "quiet"}, {Opt_showexec, "showexec"}, {Opt_debug, "debug"}, {Opt_immutable, "sys_immutable"}, {Opt_flush, "flush"}, {Opt_tz_utc, "tz=UTC"}, {Opt_time_offset, "time_offset=%d"}, {Opt_err_cont, "errors=continue"}, {Opt_err_panic, "errors=panic"}, {Opt_err_ro, "errors=remount-ro"}, {Opt_discard, "discard"}, {Opt_nfs_stale_rw, "nfs"}, {Opt_nfs_stale_rw, "nfs=stale_rw"}, {Opt_nfs_nostale_ro, "nfs=nostale_ro"}, {Opt_dos1xfloppy, "dos1xfloppy"}, {Opt_obsolete, "conv=binary"}, {Opt_obsolete, "conv=text"}, {Opt_obsolete, "conv=auto"}, {Opt_obsolete, "conv=b"}, {Opt_obsolete, "conv=t"}, {Opt_obsolete, "conv=a"}, {Opt_obsolete, "fat=%u"}, {Opt_obsolete, "blocksize=%u"}, {Opt_obsolete, "cvf_format=%20s"}, {Opt_obsolete, "cvf_options=%100s"}, {Opt_obsolete, "posix"}, {Opt_err, NULL}, }; static const match_table_t msdos_tokens = { {Opt_nodots, "nodots"}, {Opt_nodots, "dotsOK=no"}, {Opt_dots, "dots"}, {Opt_dots, "dotsOK=yes"}, {Opt_err, NULL} }; static const match_table_t vfat_tokens = { {Opt_charset, "iocharset=%s"}, {Opt_shortname_lower, "shortname=lower"}, {Opt_shortname_win95, "shortname=win95"}, {Opt_shortname_winnt, "shortname=winnt"}, {Opt_shortname_mixed, "shortname=mixed"}, {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ {Opt_utf8_no, "utf8=no"}, {Opt_utf8_no, "utf8=false"}, {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ {Opt_utf8_yes, "utf8=yes"}, {Opt_utf8_yes, "utf8=true"}, {Opt_utf8_yes, "utf8"}, {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ {Opt_uni_xl_no, "uni_xlate=no"}, {Opt_uni_xl_no, "uni_xlate=false"}, {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ {Opt_uni_xl_yes, "uni_xlate=yes"}, {Opt_uni_xl_yes, "uni_xlate=true"}, {Opt_uni_xl_yes, "uni_xlate"}, {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ {Opt_nonumtail_no, "nonumtail=no"}, {Opt_nonumtail_no, "nonumtail=false"}, {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ {Opt_nonumtail_yes, "nonumtail=yes"}, {Opt_nonumtail_yes, "nonumtail=true"}, {Opt_nonumtail_yes, "nonumtail"}, {Opt_rodir, "rodir"}, {Opt_err, NULL} }; static int parse_options(struct super_block *sb, char *options, int is_vfat, int silent, int *debug, struct fat_mount_options *opts) { char *p; substring_t args[MAX_OPT_ARGS]; int option; char *iocharset; opts->isvfat = is_vfat; opts->fs_uid = current_uid(); opts->fs_gid = current_gid(); opts->fs_fmask = opts->fs_dmask = current_umask(); opts->allow_utime = -1; opts->codepage = fat_default_codepage; fat_reset_iocharset(opts); if (is_vfat) { opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95; opts->rodir = 0; } else { opts->shortname = 0; opts->rodir = 1; } opts->name_check = 'n'; opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; opts->unicode_xlate = 0; opts->numtail = 1; opts->usefree = opts->nocase = 0; opts->tz_set = 0; opts->nfs = 0; opts->errors = FAT_ERRORS_RO; *debug = 0; opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; if (!options) goto out; while ((p = strsep(&options, ",")) != NULL) { int token; if (!*p) continue; token = match_token(p, fat_tokens, args); if (token == Opt_err) { if (is_vfat) token = match_token(p, vfat_tokens, args); else token = match_token(p, msdos_tokens, args); } switch (token) { case Opt_check_s: opts->name_check = 's'; break; case Opt_check_r: opts->name_check = 'r'; break; case Opt_check_n: opts->name_check = 'n'; break; case Opt_usefree: opts->usefree = 1; break; case Opt_nocase: if (!is_vfat) opts->nocase = 1; else { /* for backward compatibility */ opts->shortname = VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95; } break; case Opt_quiet: opts->quiet = 1; break; case Opt_showexec: opts->showexec = 1; break; case Opt_debug: *debug = 1; break; case Opt_immutable: opts->sys_immutable = 1; break; case Opt_uid: if (match_int(&args[0], &option)) return -EINVAL; opts->fs_uid = make_kuid(current_user_ns(), option); if (!uid_valid(opts->fs_uid)) return -EINVAL; break; case Opt_gid: if (match_int(&args[0], &option)) return -EINVAL; opts->fs_gid = make_kgid(current_user_ns(), option); if (!gid_valid(opts->fs_gid)) return -EINVAL; break; case Opt_umask: if (match_octal(&args[0], &option)) return -EINVAL; opts->fs_fmask = opts->fs_dmask = option; break; case Opt_dmask: if (match_octal(&args[0], &option)) return -EINVAL; opts->fs_dmask = option; break; case Opt_fmask: if (match_octal(&args[0], &option)) return -EINVAL; opts->fs_fmask = option; break; case Opt_allow_utime: if (match_octal(&args[0], &option)) return -EINVAL; opts->allow_utime = option & (S_IWGRP | S_IWOTH); break; case Opt_codepage: if (match_int(&args[0], &option)) return -EINVAL; opts->codepage = option; break; case Opt_flush: opts->flush = 1; break; case Opt_time_offset: if (match_int(&args[0], &option)) return -EINVAL; /* * GMT+-12 zones may have DST corrections so at least * 13 hours difference is needed. Make the limit 24 * just in case someone invents something unusual. */ if (option < -24 * 60 || option > 24 * 60) return -EINVAL; opts->tz_set = 1; opts->time_offset = option; break; case Opt_tz_utc: opts->tz_set = 1; opts->time_offset = 0; break; case Opt_err_cont: opts->errors = FAT_ERRORS_CONT; break; case Opt_err_panic: opts->errors = FAT_ERRORS_PANIC; break; case Opt_err_ro: opts->errors = FAT_ERRORS_RO; break; case Opt_nfs_stale_rw: opts->nfs = FAT_NFS_STALE_RW; break; case Opt_nfs_nostale_ro: opts->nfs = FAT_NFS_NOSTALE_RO; break; case Opt_dos1xfloppy: opts->dos1xfloppy = 1; break; /* msdos specific */ case Opt_dots: opts->dotsOK = 1; break; case Opt_nodots: opts->dotsOK = 0; break; /* vfat specific */ case Opt_charset: fat_reset_iocharset(opts); iocharset = match_strdup(&args[0]); if (!iocharset) return -ENOMEM; opts->iocharset = iocharset; break; case Opt_shortname_lower: opts->shortname = VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95; break; case Opt_shortname_win95: opts->shortname = VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95; break; case Opt_shortname_winnt: opts->shortname = VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT; break; case Opt_shortname_mixed: opts->shortname = VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95; break; case Opt_utf8_no: /* 0 or no or false */ opts->utf8 = 0; break; case Opt_utf8_yes: /* empty or 1 or yes or true */ opts->utf8 = 1; break; case Opt_uni_xl_no: /* 0 or no or false */ opts->unicode_xlate = 0; break; case Opt_uni_xl_yes: /* empty or 1 or yes or true */ opts->unicode_xlate = 1; break; case Opt_nonumtail_no: /* 0 or no or false */ opts->numtail = 1; /* negated option */ break; case Opt_nonumtail_yes: /* empty or 1 or yes or true */ opts->numtail = 0; /* negated option */ break; case Opt_rodir: opts->rodir = 1; break; case Opt_discard: opts->discard = 1; break; /* obsolete mount options */ case Opt_obsolete: fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, " "not supported now", p); break; /* unknown option */ default: if (!silent) { fat_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" " "or missing value", p); } return -EINVAL; } } out: /* UTF-8 doesn't provide FAT semantics */ if (!strcmp(opts->iocharset, "utf8")) { fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset" " for FAT filesystems, filesystem will be " "case sensitive!"); } /* If user doesn't specify allow_utime, it's initialized from dmask. */ if (opts->allow_utime == (unsigned short)-1) opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH); if (opts->unicode_xlate) opts->utf8 = 0; if (opts->nfs == FAT_NFS_NOSTALE_RO) { sb->s_flags |= SB_RDONLY; sb->s_export_op = &fat_export_ops_nostale; } return 0; } static int fat_read_root(struct inode *inode) { struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); int error; MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO; inode->i_uid = sbi->options.fs_uid; inode->i_gid = sbi->options.fs_gid; inode_inc_iversion(inode); inode->i_generation = 0; inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO); inode->i_op = sbi->dir_ops; inode->i_fop = &fat_dir_operations; if (is_fat32(sbi)) { MSDOS_I(inode)->i_start = sbi->root_cluster; error = fat_calc_dir_size(inode); if (error < 0) return error; } else { MSDOS_I(inode)->i_start = 0; inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); } inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) & ~((loff_t)sbi->cluster_size - 1)) >> 9; MSDOS_I(inode)->i_logstart = 0; MSDOS_I(inode)->mmu_private = inode->i_size; fat_save_attrs(inode, ATTR_DIR); inode_set_mtime_to_ts(inode, inode_set_atime_to_ts(inode, inode_set_ctime(inode, 0, 0))); set_nlink(inode, fat_subdirs(inode)+2); return 0; } static unsigned long calc_fat_clusters(struct super_block *sb) { struct msdos_sb_info *sbi = MSDOS_SB(sb); /* Divide first to avoid overflow */ if (!is_fat12(sbi)) { unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; return ent_per_sec * sbi->fat_length; } return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; } static bool fat_bpb_is_zero(struct fat_boot_sector *b) { if (get_unaligned_le16(&b->sector_size)) return false; if (b->sec_per_clus) return false; if (b->reserved) return false; if (b->fats) return false; if (get_unaligned_le16(&b->dir_entries)) return false; if (get_unaligned_le16(&b->sectors)) return false; if (b->media) return false; if (b->fat_length) return false; if (b->secs_track) return false; if (b->heads) return false; return true; } static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b, int silent, struct fat_bios_param_block *bpb) { int error = -EINVAL; /* Read in BPB ... */ memset(bpb, 0, sizeof(*bpb)); bpb->fat_sector_size = get_unaligned_le16(&b->sector_size); bpb->fat_sec_per_clus = b->sec_per_clus; bpb->fat_reserved = le16_to_cpu(b->reserved); bpb->fat_fats = b->fats; bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries); bpb->fat_sectors = get_unaligned_le16(&b->sectors); bpb->fat_fat_length = le16_to_cpu(b->fat_length); bpb->fat_total_sect = le32_to_cpu(b->total_sect); bpb->fat16_state = b->fat16.state; bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id); bpb->fat32_length = le32_to_cpu(b->fat32.length); bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster); bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector); bpb->fat32_state = b->fat32.state; bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id); /* Validate this looks like a FAT filesystem BPB */ if (!bpb->fat_reserved) { if (!silent) fat_msg(sb, KERN_ERR, "bogus number of reserved sectors"); goto out; } if (!bpb->fat_fats) { if (!silent) fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); goto out; } /* * Earlier we checked here that b->secs_track and b->head are nonzero, * but it turns out valid FAT filesystems can have zero there. */ if (!fat_valid_media(b->media)) { if (!silent) fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", (unsigned)b->media); goto out; } if (!is_power_of_2(bpb->fat_sector_size) || (bpb->fat_sector_size < 512) || (bpb->fat_sector_size > 4096)) { if (!silent) fat_msg(sb, KERN_ERR, "bogus logical sector size %u", (unsigned)bpb->fat_sector_size); goto out; } if (!is_power_of_2(bpb->fat_sec_per_clus)) { if (!silent) fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", (unsigned)bpb->fat_sec_per_clus); goto out; } if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) { if (!silent) fat_msg(sb, KERN_ERR, "bogus number of FAT sectors"); goto out; } error = 0; out: return error; } static int fat_read_static_bpb(struct super_block *sb, struct fat_boot_sector *b, int silent, struct fat_bios_param_block *bpb) { static const char *notdos1x = "This doesn't look like a DOS 1.x volume"; sector_t bd_sects = bdev_nr_sectors(sb->s_bdev); struct fat_floppy_defaults *fdefaults = NULL; int error = -EINVAL; unsigned i; /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */ if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) { if (!silent) fat_msg(sb, KERN_ERR, "%s; no bootstrapping code", notdos1x); goto out; } /* * If any value in this region is non-zero, it isn't archaic * DOS. */ if (!fat_bpb_is_zero(b)) { if (!silent) fat_msg(sb, KERN_ERR, "%s; DOS 2.x BPB is non-zero", notdos1x); goto out; } for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) { if (floppy_defaults[i].nr_sectors == bd_sects) { fdefaults = &floppy_defaults[i]; break; } } if (fdefaults == NULL) { if (!silent) fat_msg(sb, KERN_WARNING, "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)", (u64)bd_sects); goto out; } if (!silent) fat_msg(sb, KERN_INFO, "This looks like a DOS 1.x volume; assuming default BPB values"); memset(bpb, 0, sizeof(*bpb)); bpb->fat_sector_size = SECTOR_SIZE; bpb->fat_sec_per_clus = fdefaults->sec_per_clus; bpb->fat_reserved = 1; bpb->fat_fats = 2; bpb->fat_dir_entries = fdefaults->dir_entries; bpb->fat_sectors = fdefaults->nr_sectors; bpb->fat_fat_length = fdefaults->fat_length; error = 0; out: return error; } /* * Read the super block of an MS-DOS FS. */ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, void (*setup)(struct super_block *)) { struct inode *root_inode = NULL, *fat_inode = NULL; struct inode *fsinfo_inode = NULL; struct buffer_head *bh; struct fat_bios_param_block bpb; struct msdos_sb_info *sbi; u16 logical_sector_size; u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; int debug; long error; char buf[50]; struct timespec64 ts; /* * GFP_KERNEL is ok here, because while we do hold the * superblock lock, memory pressure can't call back into * the filesystem, since we're only just about to mount * it and have no inodes etc active! */ sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); if (!sbi) return -ENOMEM; sb->s_fs_info = sbi; sb->s_flags |= SB_NODIRATIME; sb->s_magic = MSDOS_SUPER_MAGIC; sb->s_op = &fat_sops; sb->s_export_op = &fat_export_ops; /* * fat timestamps are complex and truncated by fat itself, so * we set 1 here to be fast */ sb->s_time_gran = 1; mutex_init(&sbi->nfs_build_inode_lock); ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options); if (error) goto out_fail; setup(sb); /* flavour-specific stuff that needs options */ error = -EIO; sb_min_blocksize(sb, 512); bh = sb_bread(sb, 0); if (bh == NULL) { fat_msg(sb, KERN_ERR, "unable to read boot sector"); goto out_fail; } error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, &bpb); if (error == -EINVAL && sbi->options.dos1xfloppy) error = fat_read_static_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, &bpb); brelse(bh); if (error == -EINVAL) goto out_invalid; else if (error) goto out_fail; logical_sector_size = bpb.fat_sector_size; sbi->sec_per_clus = bpb.fat_sec_per_clus; error = -EIO; if (logical_sector_size < sb->s_blocksize) { fat_msg(sb, KERN_ERR, "logical sector size too small for device" " (logical sector size = %u)", logical_sector_size); goto out_fail; } if (logical_sector_size > sb->s_blocksize) { struct buffer_head *bh_resize; if (!sb_set_blocksize(sb, logical_sector_size)) { fat_msg(sb, KERN_ERR, "unable to set blocksize %u", logical_sector_size); goto out_fail; } /* Verify that the larger boot sector is fully readable */ bh_resize = sb_bread(sb, 0); if (bh_resize == NULL) { fat_msg(sb, KERN_ERR, "unable to read boot sector" " (logical sector size = %lu)", sb->s_blocksize); goto out_fail; } brelse(bh_resize); } mutex_init(&sbi->s_lock); sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; sbi->cluster_bits = ffs(sbi->cluster_size) - 1; sbi->fats = bpb.fat_fats; sbi->fat_bits = 0; /* Don't know yet */ sbi->fat_start = bpb.fat_reserved; sbi->fat_length = bpb.fat_fat_length; sbi->root_cluster = 0; sbi->free_clusters = -1; /* Don't know yet */ sbi->free_clus_valid = 0; sbi->prev_free = FAT_START_ENT; sb->s_maxbytes = 0xffffffff; fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0); sb->s_time_min = ts.tv_sec; fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX), cpu_to_le16(FAT_DATE_MAX), 0); sb->s_time_max = ts.tv_sec; if (!sbi->fat_length && bpb.fat32_length) { struct fat_boot_fsinfo *fsinfo; struct buffer_head *fsinfo_bh; /* Must be FAT32 */ sbi->fat_bits = 32; sbi->fat_length = bpb.fat32_length; sbi->root_cluster = bpb.fat32_root_cluster; /* MC - if info_sector is 0, don't multiply by 0 */ sbi->fsinfo_sector = bpb.fat32_info_sector; if (sbi->fsinfo_sector == 0) sbi->fsinfo_sector = 1; fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); if (fsinfo_bh == NULL) { fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" " (sector = %lu)", sbi->fsinfo_sector); goto out_fail; } fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; if (!IS_FSINFO(fsinfo)) { fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: " "0x%08x, 0x%08x (sector = %lu)", le32_to_cpu(fsinfo->signature1), le32_to_cpu(fsinfo->signature2), sbi->fsinfo_sector); } else { if (sbi->options.usefree) sbi->free_clus_valid = 1; sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); } brelse(fsinfo_bh); } /* interpret volume ID as a little endian 32 bit integer */ if (is_fat32(sbi)) sbi->vol_id = bpb.fat32_vol_id; else /* fat 16 or 12 */ sbi->vol_id = bpb.fat16_vol_id; __le32 vol_id_le = cpu_to_le32(sbi->vol_id); super_set_uuid(sb, (void *) &vol_id_le, sizeof(vol_id_le)); sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; sbi->dir_entries = bpb.fat_dir_entries; if (sbi->dir_entries & (sbi->dir_per_block - 1)) { if (!silent) fat_msg(sb, KERN_ERR, "bogus number of directory entries" " (%u)", sbi->dir_entries); goto out_invalid; } rootdir_sectors = sbi->dir_entries * sizeof(struct msdos_dir_entry) / sb->s_blocksize; sbi->data_start = sbi->dir_start + rootdir_sectors; total_sectors = bpb.fat_sectors; if (total_sectors == 0) total_sectors = bpb.fat_total_sect; total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; if (!is_fat32(sbi)) sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ if (is_fat32(sbi)) sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; else /* fat 16 or 12 */ sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; /* check that FAT table does not overflow */ fat_clusters = calc_fat_clusters(sb); total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); if (total_clusters > max_fat(sb)) { if (!silent) fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", total_clusters); goto out_invalid; } sbi->max_cluster = total_clusters + FAT_START_ENT; /* check the free_clusters, it's not necessarily correct */ if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) sbi->free_clusters = -1; /* check the prev_free, it's not necessarily correct */ sbi->prev_free %= sbi->max_cluster; if (sbi->prev_free < FAT_START_ENT) sbi->prev_free = FAT_START_ENT; /* set up enough so that it can read an inode */ fat_hash_init(sb); dir_hash_init(sb); fat_ent_access_init(sb); /* * The low byte of the first FAT entry must have the same value as * the media field of the boot sector. But in real world, too many * devices are writing wrong values. So, removed that validity check. * * The removed check compared the first FAT entry to a value dependent * on the media field like this: * == (0x0F00 | media), for FAT12 * == (0XFF00 | media), for FAT16 * == (0x0FFFFF | media), for FAT32 */ error = -EINVAL; sprintf(buf, "cp%d", sbi->options.codepage); sbi->nls_disk = load_nls(buf); if (!sbi->nls_disk) { fat_msg(sb, KERN_ERR, "codepage %s not found", buf); goto out_fail; } /* FIXME: utf8 is using iocharset for upper/lower conversion */ if (sbi->options.isvfat) { sbi->nls_io = load_nls(sbi->options.iocharset); if (!sbi->nls_io) { fat_msg(sb, KERN_ERR, "IO charset %s not found", sbi->options.iocharset); goto out_fail; } } error = -ENOMEM; fat_inode = new_inode(sb); if (!fat_inode) goto out_fail; sbi->fat_inode = fat_inode; fsinfo_inode = new_inode(sb); if (!fsinfo_inode) goto out_fail; fsinfo_inode->i_ino = MSDOS_FSINFO_INO; sbi->fsinfo_inode = fsinfo_inode; insert_inode_hash(fsinfo_inode); root_inode = new_inode(sb); if (!root_inode) goto out_fail; root_inode->i_ino = MSDOS_ROOT_INO; inode_set_iversion(root_inode, 1); error = fat_read_root(root_inode); if (error < 0) { iput(root_inode); goto out_fail; } error = -ENOMEM; insert_inode_hash(root_inode); fat_attach(root_inode, 0); sb->s_root = d_make_root(root_inode); if (!sb->s_root) { fat_msg(sb, KERN_ERR, "get root inode failed"); goto out_fail; } if (sbi->options.discard && !bdev_max_discard_sectors(sb->s_bdev)) fat_msg(sb, KERN_WARNING, "mounting with \"discard\" option, but the device does not support discard"); fat_set_state(sb, 1, 0); return 0; out_invalid: error = -EINVAL; if (!silent) fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); out_fail: iput(fsinfo_inode); iput(fat_inode); unload_nls(sbi->nls_io); unload_nls(sbi->nls_disk); fat_reset_iocharset(&sbi->options); sb->s_fs_info = NULL; kfree(sbi); return error; } EXPORT_SYMBOL_GPL(fat_fill_super); /* * helper function for fat_flush_inodes. This writes both the inode * and the file data blocks, waiting for in flight data blocks before * the start of the call. It does not wait for any io started * during the call */ static int writeback_inode(struct inode *inode) { int ret; /* if we used wait=1, sync_inode_metadata waits for the io for the * inode to finish. So wait=0 is sent down to sync_inode_metadata * and filemap_fdatawrite is used for the data blocks */ ret = sync_inode_metadata(inode, 0); if (!ret) ret = filemap_fdatawrite(inode->i_mapping); return ret; } /* * write data and metadata corresponding to i1 and i2. The io is * started but we do not wait for any of it to finish. * * filemap_flush is used for the block device, so if there is a dirty * page for a block already in flight, we will not wait and start the * io over again */ int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) { int ret = 0; if (!MSDOS_SB(sb)->options.flush) return 0; if (i1) ret = writeback_inode(i1); if (!ret && i2) ret = writeback_inode(i2); if (!ret) ret = sync_blockdev_nowait(sb->s_bdev); return ret; } EXPORT_SYMBOL_GPL(fat_flush_inodes); static int __init init_fat_fs(void) { int err; err = fat_cache_init(); if (err) return err; err = fat_init_inodecache(); if (err) goto failed; return 0; failed: fat_cache_destroy(); return err; } static void __exit exit_fat_fs(void) { fat_cache_destroy(); fat_destroy_inodecache(); } module_init(init_fat_fs) module_exit(exit_fat_fs) MODULE_LICENSE("GPL");
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