From e8659a1973313543e4549289f8829115a69ecb04 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Fri, 3 Jan 2014 14:10:25 +1100 Subject: [PATCH] fat: zero out seek range on _fat_get_block For normal buffered write operations, normally if we try to write to an offset > than file size, it does a cont_expand_zero till that offset. Now, in case of fallocated regions, since the blocks are already allocated. So, make it zero out that buffers for those blocks till the seek'ed offset. Signed-off-by: Namjae Jeon Signed-off-by: Amit Sahrawat Cc: OGAWA Hirofumi Signed-off-by: Andrew Morton --- fs/fat/cache.c | 3 ++- fs/fat/inode.c | 15 +++++++++++++-- 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/fat/cache.c b/fs/fat/cache.c index a132666920e6..c56bd7e4af92 100644 --- a/fs/fat/cache.c +++ b/fs/fat/cache.c @@ -334,7 +334,8 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, */ last_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1)) >> blocksize_bits; - if (sector >= last_block) + if (sector >= last_block && + MSDOS_I(inode)->mmu_private == MSDOS_I(inode)->i_disksize) return 0; } diff --git a/fs/fat/inode.c b/fs/fat/inode.c index fb388001decb..7a547ee0d567 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -61,15 +61,26 @@ 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, disk_block; int err, offset; + const unsigned long blocksize = sb->s_blocksize; + const unsigned char blocksize_bits = sb->s_blocksize_bits; err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create); if (err) return err; if (phys) { - map_bh(bh_result, sb, phys); *max_blocks = min(mapped_blocks, *max_blocks); + last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1)) + >> blocksize_bits; + disk_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1)) + >> blocksize_bits; + if (iblock >= last_block && iblock <= disk_block) { + MSDOS_I(inode)->mmu_private += + *max_blocks << blocksize_bits; + set_buffer_new(bh_result); + } + map_bh(bh_result, sb, phys); return 0; } if (!create) -- 2.39.5