NFSv4: Fix unnecessary delegation returns in nfs4_do_open

While nfs4_do_open() expects the fmode argument to be restricted to
combinations of FMODE_READ and FMODE_WRITE, both nfs4_atomic_open()
and nfs4_proc_create will pass the nfs_open_context->mode,
which contains the full fmode_t.

This patch ensures that nfs4_do_open strips the other fmode_t bits,
fixing a problem in which the nfs4_do_open call would result in an
unnecessary delegation return.

Reported-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 5881f2cc5d81..f23977e4ac0f 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1902,6 +1902,7 @@ static struct nfs4_state *nfs4_do_open(struct inode *dir,
         struct nfs4_state *res;
         int status;
 
+        fmode &= FMODE_READ|FMODE_WRITE;
         do {
                 status = _nfs4_do_open(dir, dentry, fmode, flags, sattr, cred,
                                        &res, ctx_th);