From: Trond Myklebust <Trond.Myklebust@netapp.com>
Date: Wed, 4 Apr 2012 17:51:33 +0000 (-0700)
Subject: NFSv4: Don't use open stateids that have the wrong open mode
X-Git-Tag: next-20120411~58^2~2
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5ec0ed6cd88c65464092533787706d9ecfb85320;p=karo-tx-linux.git

NFSv4: Don't use open stateids that have the wrong open mode

If the client is doing an operation that needs a particular open
mode, then nfs4_select_rw_stateid() should only copy the
open stateid if the latter has the correct open mode.

Otherwise we should just use the zero stateid.

Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 0f43414eb25a..71dcfd4e30f3 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -932,6 +932,13 @@ void nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
 {
 	if (nfs4_copy_delegation_stateid(dst, state->inode, fmode))
 		return;
+
+	fmode &= FMODE_READ|FMODE_WRITE;
+	if ((state->state & fmode) != fmode) {
+		nfs4_stateid_copy(dst, &zero_stateid);
+		return;
+	}
+
 	if (nfs4_copy_lock_stateid(dst, state, fl_owner, fl_pid))
 		return;
 	nfs4_copy_open_stateid(dst, state);