From: Jianyun Gao <[email protected]>
When dax_range_compare_iter() returns a negative error code (e.g. -EIO),
dax_dedupe_file_range_compare() incorrectly returns 'ret' which holds the
positive return value from iomap_iter() indicating more iterations remain.
This positive value leaks to the caller, where vfs_dedupe_file_range()
interprets it as success (bytes_deduped = len), causing userspace to
incorrectly believe deduplication completed.
Return 'status' instead to propagate the actual error code.
Fixes: 0e79e3736d54 ("fsdax: dedupe: iter two files at the same time")
Cc: [email protected]
Signed-off-by: Jianyun Gao <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: "Darrick J. Wong" <[email protected]>
---
Changes in v3:
- Fix the Fixes tag to point to the commit that actually introduced
the bug (0e79e3736d54), not the one that renamed the variable
- Add Reviewed-by from Darrick J. Wong
Link:
https://lore.kernel.org/lkml/[email protected]/ # v2
fs/dax.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/dax.c b/fs/dax.c
index 6ba50142eeb2..1f6a4fbb97bd 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -2261,7 +2261,7 @@ int dax_dedupe_file_range_compare(struct inode *src,
loff_t srcoff,
status = dax_range_compare_iter(&src_iter, &dst_iter,
min(src_iter.len, dst_iter.len), same);
if (status < 0)
- return ret;
+ return status;
src_iter.status = dst_iter.status = status;
}
return ret;
--
2.34.1
