NFS client bugfixes for Linux 3.19

Highlights include:
 
 - Stable fix for a NFSv3/lockd race
 - Fixes for several NFSv4.1 client id trunking bugs
 - Remove an incorrect test when checking for delegated opens
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Merge tag 'nfs-for-3.19-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

   - Stable fix for a NFSv3/lockd race
   - Fixes for several NFSv4.1 client id trunking bugs
   - Remove an incorrect test when checking for delegated opens"

* tag 'nfs-for-3.19-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: Remove incorrect check in can_open_delegated()
  NFS: Ignore transport protocol when detecting server trunking
  NFSv4/v4.1: Verify the client owner id during trunking detection
  NFSv4: Cache the NFSv4/v4.1 client owner_id in the struct nfs_client
  NFSv4.1: Fix client id trunking on Linux
  LOCKD: Fix a race when initialising nlmsvc_timeout

fs/lockd/svc.c

@@ -138,10 +138,6 @@ lockd(void *vrqstp)
 
 	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 
-	if (!nlm_timeout)
-		nlm_timeout = LOCKD_DFLT_TIMEO;
-	nlmsvc_timeout = nlm_timeout * HZ;
-
 	/*
 	 * The main request loop. We don't terminate until the last
 	 * NFS mount or NFS daemon has gone away.
@@ -350,6 +346,10 @@ static struct svc_serv *lockd_create_svc(void)
 		printk(KERN_WARNING
 			"lockd_up: no pid, %d users??\n", nlmsvc_users);
 
+	if (!nlm_timeout)
+		nlm_timeout = LOCKD_DFLT_TIMEO;
+	nlmsvc_timeout = nlm_timeout * HZ;
+
 	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, svc_rpcb_cleanup);
 	if (!serv) {
 		printk(KERN_WARNING "lockd_up: create service failed\n");

fs/nfs/nfs4client.c

@@ -228,6 +228,7 @@ static void nfs4_shutdown_client(struct nfs_client *clp)
 	kfree(clp->cl_serverowner);
 	kfree(clp->cl_serverscope);
 	kfree(clp->cl_implid);
+	kfree(clp->cl_owner_id);
 }
 
 void nfs4_free_client(struct nfs_client *clp)
@@ -452,6 +453,14 @@ static void nfs4_swap_callback_idents(struct nfs_client *keep,
 	spin_unlock(&nn->nfs_client_lock);
 }
 
+static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
+		const struct nfs_client *clp2)
+{
+	if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
+		return true;
+	return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
+}
+
 /**
  * nfs40_walk_client_list - Find server that recognizes a client ID
  *
@@ -483,9 +492,6 @@ int nfs40_walk_client_list(struct nfs_client *new,
 		if (pos->rpc_ops != new->rpc_ops)
 			continue;
 
-		if (pos->cl_proto != new->cl_proto)
-			continue;
-
 		if (pos->cl_minorversion != new->cl_minorversion)
 			continue;
 
@@ -510,6 +516,9 @@ int nfs40_walk_client_list(struct nfs_client *new,
 		if (pos->cl_clientid != new->cl_clientid)
 			continue;
 
+		if (!nfs4_match_client_owner_id(pos, new))
+			continue;
+
 		atomic_inc(&pos->cl_count);
 		spin_unlock(&nn->nfs_client_lock);
 
@@ -566,20 +575,14 @@ static bool nfs4_match_clientids(struct nfs_client *a, struct nfs_client *b)
 }
 
 /*
- * Returns true if the server owners match
+ * Returns true if the server major ids match
  */
 static bool
-nfs4_match_serverowners(struct nfs_client *a, struct nfs_client *b)
+nfs4_check_clientid_trunking(struct nfs_client *a, struct nfs_client *b)
 {
 	struct nfs41_server_owner *o1 = a->cl_serverowner;
 	struct nfs41_server_owner *o2 = b->cl_serverowner;
 
-	if (o1->minor_id != o2->minor_id) {
-		dprintk("NFS: --> %s server owner minor IDs do not match\n",
-			__func__);
-		return false;
-	}
-
 	if (o1->major_id_sz != o2->major_id_sz)
 		goto out_major_mismatch;
 	if (memcmp(o1->major_id, o2->major_id, o1->major_id_sz) != 0)
@@ -621,9 +624,6 @@ int nfs41_walk_client_list(struct nfs_client *new,
 		if (pos->rpc_ops != new->rpc_ops)
 			continue;
 
-		if (pos->cl_proto != new->cl_proto)
-			continue;
-
 		if (pos->cl_minorversion != new->cl_minorversion)
 			continue;
 
@@ -654,7 +654,19 @@ int nfs41_walk_client_list(struct nfs_client *new,
 		if (!nfs4_match_clientids(pos, new))
 			continue;
 
-		if (!nfs4_match_serverowners(pos, new))
+		/*
+		 * Note that session trunking is just a special subcase of
+		 * client id trunking. In either case, we want to fall back
+		 * to using the existing nfs_client.
+		 */
+		if (!nfs4_check_clientid_trunking(pos, new))
+			continue;
+
+		/* Unlike NFSv4.0, we know that NFSv4.1 always uses the
+		 * uniform string, however someone might switch the
+		 * uniquifier string on us.
+		 */
+		if (!nfs4_match_client_owner_id(pos, new))
 			continue;
 
 		atomic_inc(&pos->cl_count);

fs/nfs/nfs4proc.c

@@ -1117,8 +1117,6 @@ static int can_open_delegated(struct nfs_delegation *delegation, fmode_t fmode)
 		return 0;
 	if ((delegation->type & fmode) != fmode)
 		return 0;
-	if (test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags))
-		return 0;
 	if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
 		return 0;
 	nfs_mark_delegation_referenced(delegation);
@@ -4917,11 +4915,14 @@ static void nfs4_init_boot_verifier(const struct nfs_client *clp,
 }
 
 static unsigned int
-nfs4_init_nonuniform_client_string(const struct nfs_client *clp,
+nfs4_init_nonuniform_client_string(struct nfs_client *clp,
 				   char *buf, size_t len)
 {
 	unsigned int result;
 
+	if (clp->cl_owner_id != NULL)
+		return strlcpy(buf, clp->cl_owner_id, len);
+
 	rcu_read_lock();
 	result = scnprintf(buf, len, "Linux NFSv4.0 %s/%s %s",
 				clp->cl_ipaddr,
@@ -4930,24 +4931,32 @@ nfs4_init_nonuniform_client_string(const struct nfs_client *clp,
 				rpc_peeraddr2str(clp->cl_rpcclient,
 							RPC_DISPLAY_PROTO));
 	rcu_read_unlock();
+	clp->cl_owner_id = kstrdup(buf, GFP_KERNEL);
 	return result;
 }
 
 static unsigned int
-nfs4_init_uniform_client_string(const struct nfs_client *clp,
+nfs4_init_uniform_client_string(struct nfs_client *clp,
 				char *buf, size_t len)
 {
 	const char *nodename = clp->cl_rpcclient->cl_nodename;
+	unsigned int result;
+
+	if (clp->cl_owner_id != NULL)
+		return strlcpy(buf, clp->cl_owner_id, len);
 
 	if (nfs4_client_id_uniquifier[0] != '\0')
-		return scnprintf(buf, len, "Linux NFSv%u.%u %s/%s",
+		result = scnprintf(buf, len, "Linux NFSv%u.%u %s/%s",
 				clp->rpc_ops->version,
 				clp->cl_minorversion,
 				nfs4_client_id_uniquifier,
 				nodename);
-	return scnprintf(buf, len, "Linux NFSv%u.%u %s",
+	else
+		result = scnprintf(buf, len, "Linux NFSv%u.%u %s",
 				clp->rpc_ops->version, clp->cl_minorversion,
 				nodename);
+	clp->cl_owner_id = kstrdup(buf, GFP_KERNEL);
+	return result;
 }
 
 /*

include/linux/nfs_fs_sb.h

@@ -74,6 +74,9 @@ struct nfs_client {
 	/* idmapper */
 	struct idmap *		cl_idmap;
 
+	/* Client owner identifier */
+	const char *		cl_owner_id;
+
 	/* Our own IP address, as a null-terminated string.
 	 * This is used to generate the mv0 callback address.
 	 */