NFSv4: Fix unnecessary delegation returns in nfs4_do_open

commit 2d0dbc6ae8a5194aaecb9cfffb9053f38fce8b86 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index e9b1eb701a01c11c4f4b7ac00bac5bf2c92438fa..d60c2d870ab0f31108d3af79d5aef1b8f9fafd69 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1861,6 +1861,7 @@ static struct nfs4_state *nfs4_do_open(struct inode *dir, struct dentry *dentry,
        struct nfs4_state *res;
        int status;
 
+       fmode &= FMODE_READ|FMODE_WRITE;
        do {
                status = _nfs4_do_open(dir, dentry, fmode, flags, sattr, cred, &res);
                if (status == 0)