X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=fs%2Ffat%2Fcache.c;h=5d384921524d9722c96cd14c9fdcf0a3aab05851;hb=184ca823481c99dadd7d946e5afd4bb921eab30d;hp=93fc62232ec21e795efc938edad43a22d55cac52;hpb=64e22b86854227b4d13a57fa02f26472bc426812;p=karo-tx-linux.git diff --git a/fs/fat/cache.c b/fs/fat/cache.c index 93fc62232ec2..5d384921524d 100644 --- a/fs/fat/cache.c +++ b/fs/fat/cache.c @@ -301,15 +301,59 @@ static int fat_bmap_cluster(struct inode *inode, int cluster) return dclus; } -int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, - unsigned long *mapped_blocks, int create) +int fat_get_mapped_cluster(struct inode *inode, sector_t sector, + sector_t last_block, + unsigned long *mapped_blocks, sector_t *bmap) { struct super_block *sb = inode->i_sb; struct msdos_sb_info *sbi = MSDOS_SB(sb); + int cluster, offset; + + cluster = sector >> (sbi->cluster_bits - sb->s_blocksize_bits); + offset = sector & (sbi->sec_per_clus - 1); + cluster = fat_bmap_cluster(inode, cluster); + if (cluster < 0) + return cluster; + else if (cluster) { + *bmap = fat_clus_to_blknr(sbi, cluster) + offset; + *mapped_blocks = sbi->sec_per_clus - offset; + if (*mapped_blocks > last_block - sector) + *mapped_blocks = last_block - sector; + } + + return 0; +} + +static int is_exceed_eof(struct inode *inode, sector_t sector, + sector_t *last_block, int create) +{ + struct super_block *sb = inode->i_sb; const unsigned long blocksize = sb->s_blocksize; const unsigned char blocksize_bits = sb->s_blocksize_bits; + + *last_block = (i_size_read(inode) + (blocksize - 1)) >> blocksize_bits; + if (sector >= *last_block) { + if (!create) + return 1; + + /* + * ->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 1; + } + + return 0; +} + +int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, + unsigned long *mapped_blocks, int create, bool from_bmap) +{ + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); sector_t last_block; - int cluster, offset; *phys = 0; *mapped_blocks = 0; @@ -321,31 +365,16 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, return 0; } - last_block = (i_size_read(inode) + (blocksize - 1)) >> blocksize_bits; - if (sector >= last_block) { - if (!create) + if (!from_bmap) { + if (is_exceed_eof(inode, sector, &last_block, 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; + } else { + last_block = inode->i_blocks >> + (inode->i_sb->s_blocksize_bits - 9); if (sector >= last_block) return 0; } - cluster = sector >> (sbi->cluster_bits - sb->s_blocksize_bits); - offset = sector & (sbi->sec_per_clus - 1); - cluster = fat_bmap_cluster(inode, cluster); - if (cluster < 0) - return cluster; - else if (cluster) { - *phys = fat_clus_to_blknr(sbi, cluster) + offset; - *mapped_blocks = sbi->sec_per_clus - offset; - if (*mapped_blocks > last_block - sector) - *mapped_blocks = last_block - sector; - } - return 0; + return fat_get_mapped_cluster(inode, sector, last_block, mapped_blocks, + phys); }