[PATCH 1/5] btrfs: pass unaligned length to btrfs_cmp_data()

Mark Fasheh
2015-06-22T22:47:52Z

In the case that we dedupe the tail of a file, we might expand the dedupe
len out to the end of our last block. We don't want to compare data past
i_size however, so pass the original length to btrfs_cmp_data().

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: David Sterba <dsterba@suse.cz>
---
fs/btrfs/ioctl.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 2d24ff4..2deea1f 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2933,7 +2933,8 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
goto out_unlock;
}

- ret = btrfs_cmp_data(src, loff, dst, dst_loff, len);
+ /* pass original length for comparison so we stay within i_size */
+ ret = btrfs_cmp_data(src, loff, dst, dst_loff, olen);
if (ret == 0)
ret = btrfs_clone(src, dst, loff, olen, len, dst_loff);

--
2.1.2

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