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

From: Greg Kroah-Hartman
Date: Thu Mar 19 2020 - 09:12:28 EST


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);