[PATCH 4.9 36/90] gfs2_atomic_open(): fix O_EXCL|O_CREAT handling on cold dcache

[Greg Kroah-Hartman]

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit 21039132650281de06a169cbe8a0f7e5c578fd8b upstream.

with the way fs/namei.c:do_last() had been done, ->atomic_open()
instances needed to recognize the case when existing file got
found with O_EXCL|O_CREAT, either by falling back to finish_no_open()
or failing themselves.  gfs2 one didn't.

Fixes: 6d4ade986f9c (GFS2: Add atomic_open support)
Cc: stable@xxxxxxxxxx # v3.11
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/gfs2/inode.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1248,7 +1248,7 @@ static int gfs2_atomic_open(struct inode
 		if (!(*opened & FILE_OPENED))
 			return finish_no_open(file, d);
 		dput(d);
-		return 0;
+		return excl && (flags & O_CREAT) ? -EEXIST : 0;
 	}
 
 	BUG_ON(d != NULL);