diff options
Diffstat (limited to 'fs/fat/cache.c')
| -rw-r--r-- | fs/fat/cache.c | 23 |
1 files changed, 18 insertions, 5 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); |