From bea229ba8b1008450c2bed2b7b015fd300df60d9 Mon Sep 17 00:00:00 2001 From: Shiyang Ruan Date: Thu, 2 Feb 2023 12:33:47 +0000 Subject: [PATCH] fsdax: dax_unshare_iter() should return a valid length commit 388bc034d91d480efa88abc5c8d6e6c8a878b1ab upstream. The copy_mc_to_kernel() will return 0 if it executed successfully. Then the return value should be set to the length it copied. [akpm@linux-foundation.org: don't mess up `ret', per Matthew] Link: https://lkml.kernel.org/r/1675341227-14-1-git-send-email-ruansy.fnst@fujitsu.com Fixes: d984648e428b ("fsdax,xfs: port unshare to fsdax") Signed-off-by: Shiyang Ruan Cc: Darrick J. Wong Cc: Alistair Popple Cc: Dan Williams Cc: Dave Chinner Cc: Jason Gunthorpe Cc: John Hubbard Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/dax.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 7ecad1a28a89..8b1c371d6b28 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1247,8 +1247,9 @@ 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: