1 files changed, 13 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 8ae5abfe6ba2..27d74a294515 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -279,6 +279,7 @@ do_open_fhandle(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, str
 {
         struct svc_fh *current_fh = &cstate->current_fh;
         __be32 status;
+        int accmode = 0;
 
         /* We don't know the target directory, and therefore can not
         * set the change info
@@ -290,9 +291,19 @@ do_open_fhandle(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, str
 
         open->op_truncate = (open->op_iattr.ia_valid & ATTR_SIZE) &&
                 (open->op_iattr.ia_size == 0);
+        /*
+         * In the delegation case, the client is telling us about an
+         * open that it *already* performed locally, some time ago.  We
+         * should let it succeed now if possible.
+         *
+         * In the case of a CLAIM_FH open, on the other hand, the client
+         * may be counting on us to enforce permissions (the Linux 4.1
+         * client uses this for normal opens, for example).
+         */
+        if (open->op_claim_type == NFS4_OPEN_CLAIM_DELEG_CUR_FH)
+                accmode = NFSD_MAY_OWNER_OVERRIDE;
 
-        status = do_open_permission(rqstp, current_fh, open,
-                                    NFSD_MAY_OWNER_OVERRIDE);
+        status = do_open_permission(rqstp, current_fh, open, accmode);
 
         return status;
 }