diff options
| -rw-r--r-- | fs/fat/cache.c | 23 | ||||
| -rw-r--r-- | fs/fat/dir.c | 2 | ||||
| -rw-r--r-- | fs/fat/fat.h | 6 | ||||
| -rw-r--r-- | fs/fat/inode.c | 4 |
4 files changed, 25 insertions, 10 deletions
diff --git a/fs/fat/cache.c b/fs/fat/cache.c index 589edde9053c..b42602298087 100644 --- a/fs/fat/cache.c +++ b/fs/fat/cache.c @@ -293,10 +293,12 @@ static int fat_bmap_cluster(struct inode *inode, int cluster) } int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, - unsigned long *mapped_blocks) + unsigned long *mapped_blocks, int create) { struct super_block *sb = inode->i_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); + const unsigned long blocksize = sb->s_blocksize; + const unsigned char blocksize_bits = sb->s_blocksize_bits; sector_t last_block; int cluster, offset; @@ -309,10 +311,21 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, } return 0; } - last_block = (MSDOS_I(inode)->mmu_private + (sb->s_blocksize - 1)) - >> sb->s_blocksize_bits; - if (sector >= last_block) - return 0; + + last_block = (i_size_read(inode) + (blocksize - 1)) >> blocksize_bits; + if (sector >= last_block) { + if (!create) + return 0; + + /* + * ->mmu_private can access on only allocation path. + * (caller must hold ->i_mutex) + */ + last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1)) + >> blocksize_bits; + if (sector >= last_block) + return 0; + } cluster = sector >> (sbi->cluster_bits - sb->s_blocksize_bits); offset = sector & (sbi->sec_per_clus - 1); diff --git a/fs/fat/dir.c b/fs/fat/dir.c index 140fc39e2307..2ecaa17acdb5 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -77,7 +77,7 @@ next: *bh = NULL; iblock = *pos >> sb->s_blocksize_bits; - err = fat_bmap(dir, iblock, &phys, &mapped_blocks); + err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0); if (err || !phys) return -1; /* beyond EOF or error */ diff --git a/fs/fat/fat.h b/fs/fat/fat.h index a69f7f9757c0..4efc5038ed29 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -91,7 +91,9 @@ struct msdos_inode_info { /* for avoiding the race between fat_free() and fat_get_cluster() */ unsigned int cache_valid_id; - loff_t mmu_private; + /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */ + loff_t mmu_private; /* physically allocated size */ + int i_start; /* first cluster or 0 */ int i_logstart; /* logical first cluster */ int i_attrs; /* unused attribute bits */ @@ -222,7 +224,7 @@ extern void fat_cache_inval_inode(struct inode *inode); extern int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus); extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, - unsigned long *mapped_blocks); + unsigned long *mapped_blocks, int create); /* fat/dir.c */ extern const struct file_operations fat_dir_operations; diff --git a/fs/fat/inode.c b/fs/fat/inode.c index be88208b83a6..9e37ad93c730 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -64,7 +64,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock, sector_t phys; int err, offset; - err = fat_bmap(inode, iblock, &phys, &mapped_blocks); + err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create); if (err) return err; if (phys) { @@ -94,7 +94,7 @@ 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); + err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create); if (err) return err; |