nfsd4: delegation-based open reclaims should bypass permissions

We saw a v4.0 client's create fail as follows:

	- open create succeeds and gets a read delegation
	- client attempts to set mode on new file, gets DELAY while
	  server recalls delegation.
	- client attempts a CLAIM_DELEGATE_CUR open using the
	  delegation, gets error because of new file mode.

This probably can't happen on a recent kernel since we're no longer
giving out delegations on create opens.  Nevertheless, it's a
bug--reclaim opens should bypass permission checks.

Reported-by: Steve Dickson <steved@redhat.com>
Reported-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 1a1ff247bc59..a7cee864e7b2 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -296,7 +296,8 @@ do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, stru
 
         nfsd4_set_open_owner_reply_cache(cstate, open, resfh);
         accmode = NFSD_MAY_NOP;
-        if (open->op_created)
+        if (open->op_created ||
+                        open->op_claim_type == NFS4_OPEN_CLAIM_DELEGATE_CUR)
                 accmode |= NFSD_MAY_OWNER_OVERRIDE;
         status = do_open_permission(rqstp, resfh, open, accmode);
         set_change_info(&open->op_cinfo, current_fh);