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.

Signed-off-by: Jianyun Gao <[email protected]>
---
 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


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