fsdax: dax_unshare_iter() should return a valid length

The copy_mc_to_kernel() will return 0 if it executed successfully. Then the return value should be set to the length it copied. [[email protected]: don't mess up `ret', per Matthew] Link: https://lkml.kernel.org/r/[email protected] Fixes: d984648 ("fsdax,xfs: port unshare to fsdax") Signed-off-by: Shiyang Ruan <[email protected]> Cc: Darrick J. Wong <[email protected]> Cc: Alistair Popple <[email protected]> Cc: Dan Williams <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: John Hubbard <[email protected]> Cc: Matthew Wilcox <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
niw · Feb 4, 2023 · 388bc03 · 388bc03
1 parent aa1e6a9
commit 388bc03
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/fs/dax.c b/fs/dax.c
@@ -1271,8 +1271,9 @@ static s64 dax_unshare_iter(struct iomap_iter *iter)
 	if (ret < 0)
 		goto out_unlock;
 
-	ret = copy_mc_to_kernel(daddr, saddr, length);
-	if (ret)
+	if (copy_mc_to_kernel(daddr, saddr, length) == 0)
+		ret = length;
+	else
 		ret = -EIO;
 
 out_unlock: