From: Qu Wenruo Date: Fri, 18 Jul 2014 01:55:43 +0000 (+0800) Subject: btrfs: Return right extent when fiemap gives unaligned offset and len. X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2c91943b5066314a8bb9f0a65584e5e4cd92ea63;p=linux-beck.git btrfs: Return right extent when fiemap gives unaligned offset and len. When page aligned start and len passed to extent_fiemap(), the result is good, but when start and len is not aligned, e.g. start = 1 and len = 4095 is passed to extent_fiemap(), it returns no extent. The problem is that start and len is all rounded down which causes the problem. This patch will round down start and round up (start + len) to return right extent. Reported-by: Chandan Rajendra Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a389820d158b..1c70cff4a9e1 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4213,8 +4213,8 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, return -ENOMEM; path->leave_spinning = 1; - start = ALIGN(start, BTRFS_I(inode)->root->sectorsize); - len = ALIGN(len, BTRFS_I(inode)->root->sectorsize); + start = round_down(start, BTRFS_I(inode)->root->sectorsize); + len = round_up(max, BTRFS_I(inode)->root->sectorsize) - start; /* * lookup the last file extent. We're not using i_size here