Merge tag 'nfsd-5.10-1' of git://linux-nfs.org/~bfields/linux

Pull nfsd fixes from Bruce Fields:
 "This is mainly server-to-server copy and fallout from Chuck's 5.10 rpc
  refactoring"

* tag 'nfsd-5.10-1' of git://linux-nfs.org/~bfields/linux:
  net/sunrpc: fix useless comparison in proc_do_xprt()
  net/sunrpc: return 0 on attempt to write to "transports"
  NFSD: fix missing refcount in nfsd4_copy by nfsd4_do_async_copy
  NFSD: Fix use-after-free warning when doing inter-server copy
  NFSD: MKNOD should return NFSERR_BADTYPE instead of NFSERR_INVAL
  SUNRPC: Fix general protection fault in trace_rpc_xdr_overflow()
  NFSD: NFSv3 PATHCONF Reply is improperly formed

fs/nfsd/nfs3proc.c

@@ -316,10 +316,6 @@ nfsd3_proc_mknod(struct svc_rqst *rqstp)
 	fh_copy(&resp->dirfh, &argp->fh);
 	fh_init(&resp->fh, NFS3_FHSIZE);
 
-	if (argp->ftype == 0 || argp->ftype >= NF3BAD) {
-		resp->status = nfserr_inval;
-		goto out;
-	}
 	if (argp->ftype == NF3CHR || argp->ftype == NF3BLK) {
 		rdev = MKDEV(argp->major, argp->minor);
 		if (MAJOR(rdev) != argp->major ||
@@ -328,7 +324,7 @@ nfsd3_proc_mknod(struct svc_rqst *rqstp)
 			goto out;
 		}
 	} else if (argp->ftype != NF3SOCK && argp->ftype != NF3FIFO) {
-		resp->status = nfserr_inval;
+		resp->status = nfserr_badtype;
 		goto out;
 	}
 

fs/nfsd/nfs3xdr.c

@@ -1114,6 +1114,7 @@ nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p)
 {
 	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
 
+	*p++ = resp->status;
 	*p++ = xdr_zero;	/* no post_op_attr */
 
 	if (resp->status == 0) {

fs/nfsd/nfs4proc.c

@@ -1299,7 +1299,7 @@ nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct nfsd_file *src,
 			struct nfsd_file *dst)
 {
 	nfs42_ssc_close(src->nf_file);
-	nfsd_file_put(src);
+	/* 'src' is freed by nfsd4_do_async_copy */
 	nfsd_file_put(dst);
 	mntput(ss_mnt);
 }
@@ -1486,6 +1486,7 @@ do_callback:
 	cb_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
 	if (!cb_copy)
 		goto out;
+	refcount_set(&cb_copy->refcount, 1);
 	memcpy(&cb_copy->cp_res, &copy->cp_res, sizeof(copy->cp_res));
 	cb_copy->cp_clp = copy->cp_clp;
 	cb_copy->nfserr = copy->nfserr;

include/trace/events/sunrpc.h

@@ -655,10 +655,10 @@ TRACE_EVENT(rpc_xdr_overflow,
 		__field(size_t, tail_len)
 		__field(unsigned int, page_len)
 		__field(unsigned int, len)
-		__string(progname,
-			 xdr->rqst->rq_task->tk_client->cl_program->name)
-		__string(procedure,
-			 xdr->rqst->rq_task->tk_msg.rpc_proc->p_name)
+		__string(progname, xdr->rqst ?
+			 xdr->rqst->rq_task->tk_client->cl_program->name : "unknown")
+		__string(procedure, xdr->rqst ?
+			 xdr->rqst->rq_task->tk_msg.rpc_proc->p_name : "unknown")
 	),
 
 	TP_fast_assign(

net/sunrpc/sysctl.c

@@ -63,19 +63,20 @@ static int proc_do_xprt(struct ctl_table *table, int write,
 			void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char tmpbuf[256];
-	size_t len;
+	ssize_t len;
 
-	if ((*ppos && !write) || !*lenp) {
+	if (write || *ppos) {
 		*lenp = 0;
 		return 0;
 	}
 	len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
-	*lenp = memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
+	len = memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
 
-	if (*lenp < 0) {
+	if (len < 0) {
 		*lenp = 0;
 		return -EINVAL;
 	}
+	*lenp = len;
 	return 0;
 }