[PATCH 4.19 007/109] gfs2: Prevent direct-I/O write fallback errors from getting lost

[Sasha Levin]

From: Andreas Gruenbacher <agruenba@xxxxxxxxxx>

[ Upstream commit 43a511c44e58e357a687d61a20cf5ef1dc9e5a7c ]

When a direct I/O write falls entirely and falls back to buffered I/O and the
buffered I/O fails, the write failed with return value 0 instead of the error
number reported by the buffered I/O. Fix that.

Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/gfs2/file.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 143e7d518c5d..7c69486d556f 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -822,8 +822,11 @@ static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		current->backing_dev_info = inode_to_bdi(inode);
 		buffered = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
 		current->backing_dev_info = NULL;
-		if (unlikely(buffered <= 0))
+		if (unlikely(buffered <= 0)) {
+			if (!ret)
+				ret = buffered;
 			goto out_unlock;
+		}
 
 		/*
 		 * We need to ensure that the page cache pages are written to
-- 
2.30.2