nfsd4: handle seqid-mutating open errors from xdr decoding

If a client sets an owner (or group_owner or acl) attribute on open for
create, and the mapping of that owner to an id fails, then we return
BAD_OWNER.  But BAD_OWNER is a seqid-mutating error, so we can't
shortcut the open processing that case: we have to at least look up the
owner so we can find the seqid to bump.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

3 files changed, 28 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index c7e4e8c28827..42c498ce9f0e 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -351,6 +351,10 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         }
         if (status)
                 goto out;
+        if (open->op_xdr_error) {
+                status = open->op_xdr_error;
+                goto out;
+        }
 
         status = nfsd4_check_open_attributes(rqstp, cstate, open);
         if (status)
@@ -417,6 +421,24 @@ out:
 }
 
 /*
+ * OPEN is the only seqid-mutating operation whose decoding can fail
+ * with a seqid-mutating error (specifically, decoding of user names in
+ * the attributes).  Therefore we have to do some processing to look up
+ * the stateowner so that we can bump the seqid.
+ */
+static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_op *op)
+{
+        struct nfsd4_open *open = (struct nfsd4_open *)&op->u;
+
+        if (!seqid_mutating_err(ntohl(op->status)))
+                return op->status;
+        if (nfsd4_has_session(cstate))
+                return op->status;
+        open->op_xdr_error = op->status;
+        return nfsd4_open(rqstp, cstate, open);
+}
+
+/*
  * filehandle-manipulating ops.
  */
 static __be32
@@ -1244,8 +1266,11 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
                  * for example, if there is a miscellaneous XDR error
                  * it will be set to nfserr_bad_xdr.
                  */
-                if (op->status)
+                if (op->status) {
+                        if (op->opnum == OP_OPEN)
+                                op->status = nfsd4_open_omfg(rqstp, cstate, op);
                         goto encode_op;
+                }
 
                 /* We must be able to encode a successful response to
                  * this operation, with enough room left over to encode a
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index a2720071f282..229b3ac246e1 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -804,6 +804,7 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
         open->op_iattr.ia_valid = 0;
         open->op_openowner = NULL;
 
+        open->op_xdr_error = 0;
         /* seqid, share_access, share_deny, clientid, ownerlen */
         READ_BUF(4);
         READ32(open->op_seqid);
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 546f8983ecf1..be0a79d1dbcb 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -237,6 +237,7 @@ struct nfsd4_open {
         u32             op_share_deny;      /* request */
         u32             op_deleg_want;      /* request */
         stateid_t       op_stateid;         /* response */
+        __be32          op_xdr_error;       /* see nfsd4_open_omfg() */
         u32             op_recall;          /* recall */
         struct nfsd4_change_info  op_cinfo; /* response */
         u32             op_rflags;          /* response */