diff options
Diffstat (limited to 'fs/fat')
| -rw-r--r-- | fs/fat/dir.c | 17 | ||||
| -rw-r--r-- | fs/fat/fatent.c | 3 | ||||
| -rw-r--r-- | fs/fat/inode.c | 12 |
3 files changed, 27 insertions, 5 deletions
diff --git a/fs/fat/dir.c b/fs/fat/dir.c index 1bda2ab6745b..054acd9fd033 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -88,9 +88,7 @@ static int fat__get_entry(struct inode *dir, loff_t *pos, int err, offset; next: - if (*bh) - brelse(*bh); - + brelse(*bh); *bh = NULL; iblock = *pos >> sb->s_blocksize_bits; err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0, false); @@ -1100,8 +1098,11 @@ static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used, err = -ENOMEM; goto error; } + /* Avoid race with userspace read via bdev */ + lock_buffer(bhs[n]); memset(bhs[n]->b_data, 0, sb->s_blocksize); set_buffer_uptodate(bhs[n]); + unlock_buffer(bhs[n]); mark_buffer_dirty_inode(bhs[n], dir); n++; @@ -1158,6 +1159,8 @@ int fat_alloc_new_dir(struct inode *dir, struct timespec64 *ts) fat_time_unix2fat(sbi, ts, &time, &date, &time_cs); de = (struct msdos_dir_entry *)bhs[0]->b_data; + /* Avoid race with userspace read via bdev */ + lock_buffer(bhs[0]); /* filling the new directory slots ("." and ".." entries) */ memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME); memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME); @@ -1180,6 +1183,7 @@ int fat_alloc_new_dir(struct inode *dir, struct timespec64 *ts) de[0].size = de[1].size = 0; memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de)); set_buffer_uptodate(bhs[0]); + unlock_buffer(bhs[0]); mark_buffer_dirty_inode(bhs[0], dir); err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE); @@ -1237,11 +1241,14 @@ static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots, /* fill the directory entry */ copy = min(size, sb->s_blocksize); + /* Avoid race with userspace read via bdev */ + lock_buffer(bhs[n]); memcpy(bhs[n]->b_data, slots, copy); - slots += copy; - size -= copy; set_buffer_uptodate(bhs[n]); + unlock_buffer(bhs[n]); mark_buffer_dirty_inode(bhs[n], dir); + slots += copy; + size -= copy; if (!size) break; n++; diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c index 265983635f2b..3647c65a0f48 100644 --- a/fs/fat/fatent.c +++ b/fs/fat/fatent.c @@ -388,8 +388,11 @@ static int fat_mirror_bhs(struct super_block *sb, struct buffer_head **bhs, err = -ENOMEM; goto error; } + /* Avoid race with userspace read via bdev */ + lock_buffer(c_bh); memcpy(c_bh->b_data, bhs[n]->b_data, sb->s_blocksize); set_buffer_uptodate(c_bh); + unlock_buffer(c_bh); mark_buffer_dirty_inode(c_bh, sbi->fat_inode); if (sb->s_flags & SB_SYNCHRONOUS) err = sync_dirty_buffer(c_bh); diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 05689198f5af..5f04c5c810fb 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -31,6 +31,11 @@ #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. @@ -1605,6 +1610,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, int debug; long error; char buf[50]; + struct timespec64 ts; /* * GFP_KERNEL is ok here, because while we do hold the @@ -1698,6 +1704,12 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 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; |