diff options
Diffstat (limited to 'fs/fat/inode.c')
| -rw-r--r-- | fs/fat/inode.c | 1399 |
1 files changed, 865 insertions, 534 deletions
diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 11b51bb55b42..0b6009cd1844 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * linux/fs/fat/inode.c * @@ -11,23 +12,17 @@ */ #include <linux/module.h> -#include <linux/init.h> -#include <linux/time.h> -#include <linux/slab.h> -#include <linux/seq_file.h> #include <linux/pagemap.h> #include <linux/mpage.h> -#include <linux/buffer_head.h> -#include <linux/mount.h> -#include <linux/aio.h> #include <linux/vfs.h> -#include <linux/parser.h> +#include <linux/seq_file.h> #include <linux/uio.h> -#include <linux/writeback.h> -#include <linux/log2.h> -#include <linux/hash.h> #include <linux/blkdev.h> -#include <asm/unaligned.h> +#include <linux/backing-dev.h> +#include <linux/unaligned.h> +#include <linux/random.h> +#include <linux/iversion.h> +#include <linux/fs_struct.h> #include "fat.h" #ifndef CONFIG_FAT_DEFAULT_IOCHARSET @@ -35,11 +30,78 @@ #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, +}, +}; -static int fat_add_cluster(struct inode *inode) +int fat_add_cluster(struct inode *inode) { int err, cluster; @@ -61,10 +123,10 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock, struct super_block *sb = inode->i_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); unsigned long mapped_blocks; - sector_t phys; + sector_t phys, last_block; int err, offset; - err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create); + err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false); if (err) return err; if (phys) { @@ -81,8 +143,14 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock, return -EIO; } + last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9); offset = (unsigned long)iblock & (sbi->sec_per_clus - 1); - if (!offset) { + /* + * 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) @@ -94,11 +162,17 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock, *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); + 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(!phys); BUG_ON(*max_blocks != mapped_blocks); set_buffer_new(bh_result); map_bh(bh_result, sb, phys); @@ -120,26 +194,20 @@ static int fat_get_block(struct inode *inode, sector_t iblock, return 0; } -static int fat_writepage(struct page *page, struct writeback_control *wbc) -{ - return block_write_full_page(page, fat_get_block, wbc); -} - static int fat_writepages(struct address_space *mapping, struct writeback_control *wbc) { return mpage_writepages(mapping, wbc, fat_get_block); } -static int fat_readpage(struct file *file, struct page *page) +static int fat_read_folio(struct file *file, struct folio *folio) { - return mpage_readpage(page, fat_get_block); + return mpage_read_folio(folio, fat_get_block); } -static int fat_readpages(struct file *file, struct address_space *mapping, - struct list_head *pages, unsigned nr_pages) +static void fat_readahead(struct readahead_control *rac) { - return mpage_readpages(mapping, pages, nr_pages, fat_get_block); + mpage_readahead(rac, fat_get_block); } static void fat_write_failed(struct address_space *mapping, loff_t to) @@ -147,53 +215,54 @@ 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, 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, unsigned flags, - struct page **pagep, void **fsdata) +static int fat_write_begin(const struct kiocb *iocb, + struct address_space *mapping, + loff_t pos, unsigned len, + struct folio **foliop, void **fsdata) { int err; - *pagep = NULL; - err = cont_write_begin(file, mapping, pos, len, flags, - pagep, fsdata, fat_get_block, + err = cont_write_begin(iocb, mapping, pos, len, + foliop, 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) +static int fat_write_end(const struct kiocb *iocb, + struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct folio *folio, void *fsdata) { struct inode *inode = mapping->host; int err; - err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata); + err = generic_write_end(iocb, mapping, pos, len, copied, folio, fsdata); if (err < len) fat_write_failed(mapping, pos + len); if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { - inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; + 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(int rw, struct kiocb *iocb, - const struct iovec *iov, - loff_t offset, unsigned long nr_segs) +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 (rw == WRITE) { + 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. @@ -203,7 +272,7 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb, * * Return 0, and fallback to normal buffered write. */ - loff_t size = offset + iov_length(iov, nr_segs); + loff_t size = offset + count; if (MSDOS_I(inode)->mmu_private < size) return 0; } @@ -212,35 +281,73 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb, * FAT need to use the DIO_LOCKING for avoiding the race * condition of fat_get_block() and ->truncate(). */ - ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, - fat_get_block); - if (ret < 0 && (rw & WRITE)) - fat_write_failed(mapping, offset + iov_length(iov, nr_segs)); + 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); + 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 = { - .readpage = fat_readpage, - .readpages = fat_readpages, - .writepage = fat_writepage, + .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 + .bmap = _fat_bmap, + .migrate_folio = buffer_migrate_folio, }; /* @@ -359,7 +466,7 @@ struct inode *fat_iget(struct super_block *sb, loff_t i_pos) static int is_exec(unsigned char *extension) { - unsigned char *exe_extensions = "EXECOMBAT", *walk; + unsigned char exe_extensions[] = "EXECOMBAT", *walk; for (walk = exe_extensions; *walk; walk += 3) if (!strncmp(extension, walk, 3)) @@ -384,17 +491,36 @@ static int fat_calc_dir_size(struct inode *inode) 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->i_version++; - inode->i_generation = get_seconds(); + inode_inc_iversion(inode); + inode->i_generation = get_random_u32(); if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { inode->i_generation &= ~1; @@ -410,6 +536,10 @@ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) 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, @@ -433,13 +563,18 @@ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) & ~((loff_t)sbi->cluster_size - 1)) >> 9; - fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0); + 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) { - fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime, + 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); - fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0); } else - inode->i_ctime = inode->i_atime = inode->i_mtime; + inode_set_atime_to_ts(inode, fat_truncate_atime(sbi, &mtime)); return 0; } @@ -472,7 +607,7 @@ struct inode *fat_build_inode(struct super_block *sb, goto out; } inode->i_ino = iunique(sb, MSDOS_ROOT_INO); - inode->i_version = 1; + inode_set_iversion(inode, 1); err = fat_fill_inode(inode, de); if (err) { iput(inode); @@ -488,13 +623,43 @@ out: 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(&inode->i_data, 0); + 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); @@ -506,10 +671,10 @@ static void fat_set_state(struct super_block *sb, { struct buffer_head *bh; struct fat_boot_sector *b; - struct msdos_sb_info *sbi = sb->s_fs_info; + struct msdos_sb_info *sbi = MSDOS_SB(sb); /* do not change any thing if mounted read only */ - if ((sb->s_flags & MS_RDONLY) && !force) + if (sb_rdonly(sb) && !force) return; /* do not change state if fs was dirty */ @@ -531,7 +696,7 @@ static void fat_set_state(struct super_block *sb, b = (struct fat_boot_sector *) bh->b_data; - if (sbi->fat_bits == 32) { + if (is_fat32(sbi)) { if (set) b->fat32.state |= FAT_STATE_DIRTY; else @@ -548,6 +713,24 @@ static void fat_set_state(struct super_block *sb, 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); @@ -557,14 +740,7 @@ static void fat_put_super(struct super_block *sb) iput(sbi->fsinfo_inode); iput(sbi->fat_inode); - unload_nls(sbi->nls_disk); - unload_nls(sbi->nls_io); - - if (sbi->options.iocharset != fat_default_iocharset) - kfree(sbi->options.iocharset); - - sb->s_fs_info = NULL; - kfree(sbi); + call_rcu(&sbi->rcu, delayed_free); } static struct kmem_cache *fat_inode_cachep; @@ -572,25 +748,28 @@ static struct kmem_cache *fat_inode_cachep; static struct inode *fat_alloc_inode(struct super_block *sb) { struct msdos_inode_info *ei; - ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS); + 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_i_callback(struct rcu_head *head) +static void fat_free_inode(struct inode *inode) { - struct inode *inode = container_of(head, struct inode, i_rcu); kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); } -static void fat_destroy_inode(struct inode *inode) -{ - call_rcu(&inode->i_rcu, fat_i_callback); -} - static void init_once(void *foo) { struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; @@ -609,7 +788,7 @@ 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_MEM_SPREAD), + SLAB_ACCOUNT), init_once); if (fat_inode_cachep == NULL) return -ENOMEM; @@ -626,15 +805,18 @@ static void __exit fat_destroy_inodecache(void) kmem_cache_destroy(fat_inode_cachep); } -static int fat_remount(struct super_block *sb, int *flags, char *data) +int fat_reconfigure(struct fs_context *fc) { - int new_rdonly; + bool new_rdonly; + struct super_block *sb = fc->root->d_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); - *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME); + fc->sb_flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME); + + sync_filesystem(sb); /* make sure we update state on remount. */ - new_rdonly = *flags & MS_RDONLY; - if (new_rdonly != (sb->s_flags & MS_RDONLY)) { + new_rdonly = fc->sb_flags & SB_RDONLY; + if (new_rdonly != sb_rdonly(sb)) { if (new_rdonly) fat_set_state(sb, 0, 0); else @@ -642,6 +824,7 @@ static int fat_remount(struct super_block *sb, int *flags, char *data) } return 0; } +EXPORT_SYMBOL_GPL(fat_reconfigure); static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) { @@ -661,8 +844,7 @@ static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) buf->f_blocks = sbi->max_cluster - FAT_START_ENT; buf->f_bfree = sbi->free_clusters; buf->f_bavail = sbi->free_clusters; - buf->f_fsid.val[0] = (u32)id; - buf->f_fsid.val[1] = (u32)(id >> 32); + buf->f_fsid = u64_to_fsid(id); buf->f_namelen = (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE; @@ -675,6 +857,7 @@ static int __fat_write_inode(struct inode *inode, int wait) 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; @@ -708,14 +891,16 @@ retry: 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); - fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time, + 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, &inode->i_ctime, &raw_entry->ctime, + + 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); - fat_time_unix2fat(sbi, &inode->i_atime, &atime, - &raw_entry->adate, NULL); } spin_unlock(&sbi->inode_hash_lock); mark_buffer_dirty(bh); @@ -752,13 +937,11 @@ 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, - .destroy_inode = fat_destroy_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, }; @@ -848,366 +1031,304 @@ static int fat_show_options(struct seq_file *m, struct dentry *root) 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_check, 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_dotsOK, + Opt_charset, Opt_shortname, Opt_utf8, Opt_utf8_bool, + Opt_uni_xl, Opt_uni_xl_bool, Opt_nonumtail, Opt_nonumtail_bool, + Opt_obsolete, Opt_flush, Opt_tz, Opt_rodir, Opt_errors, Opt_discard, + Opt_nfs, Opt_nfs_enum, Opt_time_offset, 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_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 struct constant_table fat_param_check[] = { + {"relaxed", 'r'}, + {"r", 'r'}, + {"strict", 's'}, + {"s", 's'}, + {"normal", 'n'}, + {"n", 'n'}, + {} }; -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 struct constant_table fat_param_tz[] = { + {"UTC", 0}, + {} }; -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 const struct constant_table fat_param_errors[] = { + {"continue", FAT_ERRORS_CONT}, + {"panic", FAT_ERRORS_PANIC}, + {"remount-ro", FAT_ERRORS_RO}, + {} }; -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; +static const struct constant_table fat_param_nfs[] = { + {"stale_rw", FAT_NFS_STALE_RW}, + {"nostale_ro", FAT_NFS_NOSTALE_RO}, + {} +}; - 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; - opts->iocharset = fat_default_iocharset; - 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->utf8 = 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; +/* + * These are all obsolete but we still reject invalid options. + * The corresponding values are therefore meaningless. + */ +static const struct constant_table fat_param_conv[] = { + {"binary", 0}, + {"text", 0}, + {"auto", 0}, + {"b", 0}, + {"t", 0}, + {"a", 0}, + {} +}; - if (!options) - goto out; +/* Core options. See below for vfat and msdos extras */ +const struct fs_parameter_spec fat_param_spec[] = { + fsparam_enum ("check", Opt_check, fat_param_check), + fsparam_uid ("uid", Opt_uid), + fsparam_gid ("gid", Opt_gid), + fsparam_u32oct ("umask", Opt_umask), + fsparam_u32oct ("dmask", Opt_dmask), + fsparam_u32oct ("fmask", Opt_fmask), + fsparam_u32oct ("allow_utime", Opt_allow_utime), + fsparam_u32 ("codepage", Opt_codepage), + fsparam_flag ("usefree", Opt_usefree), + fsparam_flag ("nocase", Opt_nocase), + fsparam_flag ("quiet", Opt_quiet), + fsparam_flag ("showexec", Opt_showexec), + fsparam_flag ("debug", Opt_debug), + fsparam_flag ("sys_immutable", Opt_immutable), + fsparam_flag ("flush", Opt_flush), + fsparam_enum ("tz", Opt_tz, fat_param_tz), + fsparam_s32 ("time_offset", Opt_time_offset), + fsparam_enum ("errors", Opt_errors, fat_param_errors), + fsparam_flag ("discard", Opt_discard), + fsparam_flag ("nfs", Opt_nfs), + fsparam_enum ("nfs", Opt_nfs_enum, fat_param_nfs), + fsparam_flag ("dos1xfloppy", Opt_dos1xfloppy), + __fsparam(fs_param_is_enum, "conv", + Opt_obsolete, fs_param_deprecated, fat_param_conv), + __fsparam(fs_param_is_u32, "fat", + Opt_obsolete, fs_param_deprecated, NULL), + __fsparam(fs_param_is_u32, "blocksize", + Opt_obsolete, fs_param_deprecated, NULL), + __fsparam(fs_param_is_string, "cvf_format", + Opt_obsolete, fs_param_deprecated, NULL), + __fsparam(fs_param_is_string, "cvf_options", + Opt_obsolete, fs_param_deprecated, NULL), + __fsparam(NULL, "posix", + Opt_obsolete, fs_param_deprecated, NULL), + {} +}; +EXPORT_SYMBOL_GPL(fat_param_spec); - while ((p = strsep(&options, ",")) != NULL) { - int token; - if (!*p) - continue; +static const struct fs_parameter_spec msdos_param_spec[] = { + fsparam_flag_no ("dots", Opt_dots), + fsparam_bool ("dotsOK", Opt_dotsOK), + {} +}; - 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; - if (option < -12 * 60 || option > 12 * 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; +static const struct constant_table fat_param_shortname[] = { + {"lower", VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95}, + {"win95", VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95}, + {"winnt", VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT}, + {"mixed", VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95}, + {} +}; - /* msdos specific */ - case Opt_dots: - opts->dotsOK = 1; - break; - case Opt_nodots: - opts->dotsOK = 0; - break; +static const struct fs_parameter_spec vfat_param_spec[] = { + fsparam_string ("iocharset", Opt_charset), + fsparam_enum ("shortname", Opt_shortname, fat_param_shortname), + fsparam_flag ("utf8", Opt_utf8), + fsparam_bool ("utf8", Opt_utf8_bool), + fsparam_flag ("uni_xlate", Opt_uni_xl), + fsparam_bool ("uni_xlate", Opt_uni_xl_bool), + fsparam_flag ("nonumtail", Opt_nonumtail), + fsparam_bool ("nonumtail", Opt_nonumtail_bool), + fsparam_flag ("rodir", Opt_rodir), + {} +}; - /* vfat specific */ - case Opt_charset: - if (opts->iocharset != fat_default_iocharset) - kfree(opts->iocharset); - 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; +int fat_parse_param(struct fs_context *fc, struct fs_parameter *param, + bool is_vfat) +{ + struct fat_mount_options *opts = fc->fs_private; + struct fs_parse_result result; + int opt; - /* 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; - } - } + /* remount options have traditionally been ignored */ + if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) + return 0; -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!"); + opt = fs_parse(fc, fat_param_spec, param, &result); + /* If option not found in fat_param_spec, try vfat/msdos options */ + if (opt == -ENOPARAM) { + if (is_vfat) + opt = fs_parse(fc, vfat_param_spec, param, &result); + else + opt = fs_parse(fc, msdos_param_spec, param, &result); } - /* 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 |= MS_RDONLY; - sb->s_export_op = &fat_export_ops_nostale; + if (opt < 0) + return opt; + + switch (opt) { + case Opt_check: + opts->name_check = result.uint_32; + 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: + opts->debug = 1; + break; + case Opt_immutable: + opts->sys_immutable = 1; + break; + case Opt_uid: + opts->fs_uid = result.uid; + break; + case Opt_gid: + opts->fs_gid = result.gid; + break; + case Opt_umask: + opts->fs_fmask = opts->fs_dmask = result.uint_32; + break; + case Opt_dmask: + opts->fs_dmask = result.uint_32; + break; + case Opt_fmask: + opts->fs_fmask = result.uint_32; + break; + case Opt_allow_utime: + opts->allow_utime = result.uint_32 & (S_IWGRP | S_IWOTH); + break; + case Opt_codepage: + opts->codepage = result.uint_32; + break; + case Opt_flush: + opts->flush = 1; + break; + case Opt_time_offset: + /* + * 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 (result.int_32 < -24 * 60 || result.int_32 > 24 * 60) + return -EINVAL; + opts->tz_set = 1; + opts->time_offset = result.int_32; + break; + case Opt_tz: + opts->tz_set = 1; + opts->time_offset = result.uint_32; + break; + case Opt_errors: + opts->errors = result.uint_32; + break; + case Opt_nfs: + opts->nfs = FAT_NFS_STALE_RW; + break; + case Opt_nfs_enum: + opts->nfs = result.uint_32; + break; + case Opt_dos1xfloppy: + opts->dos1xfloppy = 1; + break; + + /* msdos specific */ + case Opt_dots: /* dots / nodots */ + opts->dotsOK = !result.negated; + break; + case Opt_dotsOK: /* dotsOK = yes/no */ + opts->dotsOK = result.boolean; + break; + + /* vfat specific */ + case Opt_charset: + fat_reset_iocharset(opts); + opts->iocharset = param->string; + param->string = NULL; /* Steal string */ + break; + case Opt_shortname: + opts->shortname = result.uint_32; + break; + case Opt_utf8: + opts->utf8 = 1; + break; + case Opt_utf8_bool: + opts->utf8 = result.boolean; + break; + case Opt_uni_xl: + opts->unicode_xlate = 1; + break; + case Opt_uni_xl_bool: + opts->unicode_xlate = result.boolean; + break; + case Opt_nonumtail: + opts->numtail = 0; /* negated option */ + break; + case Opt_nonumtail_bool: + opts->numtail = !result.boolean; /* negated option */ + break; + case Opt_rodir: + opts->rodir = 1; + break; + case Opt_discard: + opts->discard = 1; + break; + + /* obsolete mount options */ + case Opt_obsolete: + printk(KERN_INFO "FAT-fs: \"%s\" option is obsolete, " + "not supported now", param->key); + break; + default: + return -EINVAL; } return 0; } +EXPORT_SYMBOL_GPL(fat_parse_param); static int fat_read_root(struct inode *inode) { - struct super_block *sb = inode->i_sb; - struct msdos_sb_info *sbi = MSDOS_SB(sb); + 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->i_version++; + 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 (sbi->fat_bits == 32) { + if (is_fat32(sbi)) { MSDOS_I(inode)->i_start = sbi->root_cluster; error = fat_calc_dir_size(inode); if (error < 0) @@ -1222,8 +1343,8 @@ static int fat_read_root(struct inode *inode) MSDOS_I(inode)->mmu_private = inode->i_size; fat_save_attrs(inode, ATTR_DIR); - inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; - inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; + 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; @@ -1234,7 +1355,7 @@ static unsigned long calc_fat_clusters(struct super_block *sb) struct msdos_sb_info *sbi = MSDOS_SB(sb); /* Divide first to avoid overflow */ - if (sbi->fat_bits != 12) { + if (!is_fat12(sbi)) { unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; return ent_per_sec * sbi->fat_length; } @@ -1242,27 +1363,194 @@ static unsigned long calc_fat_clusters(struct super_block *sb) 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, +int fat_fill_super(struct super_block *sb, struct fs_context *fc, void (*setup)(struct super_block *)) { + struct fat_mount_options *opts = fc->fs_private; + int silent = fc->sb_flags & SB_SILENT; struct inode *root_inode = NULL, *fat_inode = NULL; struct inode *fsinfo_inode = NULL; struct buffer_head *bh; - struct fat_boot_sector *b; + 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; - unsigned int media; long error; char buf[50]; + struct timespec64 ts; /* * GFP_KERNEL is ok here, because while we do hold the - * supeblock lock, memory pressure can't call back into + * 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! */ @@ -1271,122 +1559,127 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, return -ENOMEM; sb->s_fs_info = sbi; - sb->s_flags |= MS_NODIRATIME; + 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; + /* 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; + } + + /* Apply parsed options to sbi (structure copy) */ + sbi->options = *opts; + /* Transfer ownership of iocharset to sbi->options */ + opts->iocharset = NULL; setup(sb); /* flavour-specific stuff that needs options */ + error = -EINVAL; + if (!sb_min_blocksize(sb, 512)) { + fat_msg(sb, KERN_ERR, "unable to set blocksize"); + goto out_fail; + } 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; } - b = (struct fat_boot_sector *) bh->b_data; - if (!b->reserved) { - if (!silent) - fat_msg(sb, KERN_ERR, "bogus number of reserved sectors"); - brelse(bh); - goto out_invalid; - } - if (!b->fats) { - if (!silent) - fat_msg(sb, KERN_ERR, "bogus number of FAT structure"); - brelse(bh); - goto out_invalid; - } - - /* - * Earlier we checked here that b->secs_track and b->head are nonzero, - * but it turns out valid FAT filesystems can have zero there. - */ + 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); - media = b->media; - if (!fat_valid_media(media)) { - if (!silent) - fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)", - media); - brelse(bh); - goto out_invalid; - } - logical_sector_size = get_unaligned_le16(&b->sector_size); - if (!is_power_of_2(logical_sector_size) - || (logical_sector_size < 512) - || (logical_sector_size > 4096)) { - if (!silent) - fat_msg(sb, KERN_ERR, "bogus logical sector size %u", - logical_sector_size); - brelse(bh); + if (error == -EINVAL) goto out_invalid; - } - sbi->sec_per_clus = b->sec_per_clus; - if (!is_power_of_2(sbi->sec_per_clus)) { - if (!silent) - fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u", - sbi->sec_per_clus); - brelse(bh); - 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); - brelse(bh); goto out_fail; } + if (logical_sector_size > sb->s_blocksize) { - brelse(bh); + 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; } - bh = sb_bread(sb, 0); - if (bh == NULL) { + + /* 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; } - b = (struct fat_boot_sector *) bh->b_data; + 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 = b->fats; + sbi->fats = bpb.fat_fats; sbi->fat_bits = 0; /* Don't know yet */ - sbi->fat_start = le16_to_cpu(b->reserved); - sbi->fat_length = le16_to_cpu(b->fat_length); + 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 && b->fat32.length) { + 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 = le32_to_cpu(b->fat32.length); - sbi->root_cluster = le32_to_cpu(b->fat32.root_cluster); + 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 = le16_to_cpu(b->fat32.info_sector); + sbi->fsinfo_sector = bpb.fat32_info_sector; if (sbi->fsinfo_sector == 0) sbi->fsinfo_sector = 1; @@ -1394,7 +1687,6 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, if (fsinfo_bh == NULL) { fat_msg(sb, KERN_ERR, "bread failed, FSINFO block" " (sector = %lu)", sbi->fsinfo_sector); - brelse(bh); goto out_fail; } @@ -1416,56 +1708,51 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, } /* interpret volume ID as a little endian 32 bit integer */ - if (sbi->fat_bits == 32) - sbi->vol_id = (((u32)b->fat32.vol_id[0]) | - ((u32)b->fat32.vol_id[1] << 8) | - ((u32)b->fat32.vol_id[2] << 16) | - ((u32)b->fat32.vol_id[3] << 24)); + if (is_fat32(sbi)) + sbi->vol_id = bpb.fat32_vol_id; else /* fat 16 or 12 */ - sbi->vol_id = (((u32)b->fat16.vol_id[0]) | - ((u32)b->fat16.vol_id[1] << 8) | - ((u32)b->fat16.vol_id[2] << 16) | - ((u32)b->fat16.vol_id[3] << 24)); + 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 = get_unaligned_le16(&b->dir_entries); + sbi->dir_entries = bpb.fat_dir_entries; if (sbi->dir_entries & (sbi->dir_per_block - 1)) { if (!silent) - fat_msg(sb, KERN_ERR, "bogus directory-entries per block" + fat_msg(sb, KERN_ERR, "bogus number of directory entries" " (%u)", sbi->dir_entries); - brelse(bh); 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 = get_unaligned_le16(&b->sectors); + total_sectors = bpb.fat_sectors; if (total_sectors == 0) - total_sectors = le32_to_cpu(b->total_sect); + total_sectors = bpb.fat_total_sect; total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; - if (sbi->fat_bits != 32) + 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 (sbi->fat_bits == 32) - sbi->dirty = b->fat32.state & FAT_STATE_DIRTY; + if (is_fat32(sbi)) + sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; else /* fat 16 or 12 */ - sbi->dirty = b->fat16.state & FAT_STATE_DIRTY; + 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 (total_clusters > max_fat(sb)) { if (!silent) fat_msg(sb, KERN_ERR, "count of clusters too big (%u)", total_clusters); - brelse(bh); goto out_invalid; } @@ -1478,19 +1765,21 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, if (sbi->prev_free < FAT_START_ENT) sbi->prev_free = FAT_START_ENT; - brelse(bh); - /* 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 FAT's first entry must have same value with - * media-field. But in real world, too many devices is - * writing wrong value. So, removed that validity check. + * 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. * - * if (FAT_FIRST_ENT(sb, media) != first) + * 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; @@ -1515,7 +1804,6 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, fat_inode = new_inode(sb); if (!fat_inode) goto out_fail; - MSDOS_I(fat_inode)->i_pos = 0; sbi->fat_inode = fat_inode; fsinfo_inode = new_inode(sb); @@ -1529,7 +1817,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, if (!root_inode) goto out_fail; root_inode->i_ino = MSDOS_ROOT_INO; - root_inode->i_version = 1; + inode_set_iversion(root_inode, 1); error = fat_read_root(root_inode); if (error < 0) { iput(root_inode); @@ -1544,13 +1832,9 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, goto out_fail; } - if (sbi->options.discard) { - struct request_queue *q = bdev_get_queue(sb->s_bdev); - if (!blk_queue_discard(q)) - fat_msg(sb, KERN_WARNING, - "mounting with \"discard\" option, but " - "the device does not support discard"); - } + 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; @@ -1561,14 +1845,11 @@ out_invalid: fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem"); out_fail: - if (fsinfo_inode) - iput(fsinfo_inode); - if (fat_inode) - iput(fat_inode); + iput(fsinfo_inode); + iput(fat_inode); unload_nls(sbi->nls_io); unload_nls(sbi->nls_disk); - if (sbi->options.iocharset != fat_default_iocharset) - kfree(sbi->options.iocharset); + fat_reset_iocharset(&sbi->options); sb->s_fs_info = NULL; kfree(sbi); return error; @@ -1614,14 +1895,63 @@ int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2) ret = writeback_inode(i1); if (!ret && i2) ret = writeback_inode(i2); - if (!ret) { - struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; - ret = filemap_flush(mapping); - } + if (!ret) + ret = sync_blockdev_nowait(sb->s_bdev); return ret; } EXPORT_SYMBOL_GPL(fat_flush_inodes); +int fat_init_fs_context(struct fs_context *fc, bool is_vfat) +{ + struct fat_mount_options *opts; + + opts = kzalloc(sizeof(*opts), GFP_KERNEL); + if (!opts) + return -ENOMEM; + + 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; + opts->debug = 0; + + opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat; + + fc->fs_private = opts; + /* fc->ops assigned by caller */ + + return 0; +} +EXPORT_SYMBOL_GPL(fat_init_fs_context); + +void fat_free_fc(struct fs_context *fc) +{ + struct fat_mount_options *opts = fc->fs_private; + + if (opts->iocharset != fat_default_iocharset) + kfree(opts->iocharset); + kfree(fc->fs_private); +} +EXPORT_SYMBOL_GPL(fat_free_fc); + static int __init init_fat_fs(void) { int err; @@ -1650,4 +1980,5 @@ static void __exit exit_fat_fs(void) module_init(init_fat_fs) module_exit(exit_fat_fs) +MODULE_DESCRIPTION("Core FAT filesystem support"); MODULE_LICENSE("GPL"); |