NFSv4: Use the open stateid if the delegation has the wrong mode

Fix nfs4_select_rw_stateid() so that it chooses the open stateid
(or an all-zero stateid) if the delegation does not match the selected
read/write mode.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 1eb17285c99a..b7796950eceb 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1024,12 +1024,16 @@ out:
 
 static int nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
 {
+        const nfs4_stateid *src;
         int ret;
         int seq;
 
         do {
+                src = &zero_stateid;
                 seq = read_seqbegin(&state->seqlock);
-                nfs4_stateid_copy(dst, &state->stateid);
+                if (test_bit(NFS_OPEN_STATE, &state->flags))
+                        src = &state->open_stateid;
+                nfs4_stateid_copy(dst, src);
                 ret = 0;
                 smp_rmb();
                 if (!list_empty(&state->owner->so_seqid.list))