libceph: create messenger with client

This simplifies the init/shutdown paths, and makes client->msgr available
during the rest of the setup process.
Signed-off-by: Sage Weil <sage@newdream.net>

drivers/block/rbd.c

@@ -260,7 +260,7 @@ static struct rbd_client *rbd_client_create(struct ceph_options *opt,
 	kref_init(&rbdc->kref);
 	INIT_LIST_HEAD(&rbdc->node);
 
-	rbdc->client = ceph_create_client(opt, rbdc);
+	rbdc->client = ceph_create_client(opt, rbdc, 0, 0);
 	if (IS_ERR(rbdc->client))
 		goto out_rbdc;
 	opt = NULL; /* Now rbdc->client is responsible for opt */

fs/ceph/super.c

@@ -430,20 +430,23 @@ struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
 					struct ceph_options *opt)
 {
 	struct ceph_fs_client *fsc;
+	const unsigned supported_features =
+		CEPH_FEATURE_FLOCK |
+		CEPH_FEATURE_DIRLAYOUTHASH;
+	const unsigned required_features = 0;
 	int err = -ENOMEM;
 
 	fsc = kzalloc(sizeof(*fsc), GFP_KERNEL);
 	if (!fsc)
 		return ERR_PTR(-ENOMEM);
 
-	fsc->client = ceph_create_client(opt, fsc);
+	fsc->client = ceph_create_client(opt, fsc, supported_features,
+					 required_features);
 	if (IS_ERR(fsc->client)) {
 		err = PTR_ERR(fsc->client);
 		goto fail;
 	}
 	fsc->client->extra_mon_dispatch = extra_mon_dispatch;
-	fsc->client->supported_features |= CEPH_FEATURE_FLOCK |
-		CEPH_FEATURE_DIRLAYOUTHASH;
 	fsc->client->monc.want_mdsmap = 1;
 
 	fsc->mount_options = fsopt;

include/linux/ceph/libceph.h

@@ -215,7 +215,9 @@ extern void ceph_destroy_options(struct ceph_options *opt);
 extern int ceph_compare_options(struct ceph_options *new_opt,
 				struct ceph_client *client);
 extern struct ceph_client *ceph_create_client(struct ceph_options *opt,
-					      void *private);
+					      void *private,
+					      unsigned supported_features,
+					      unsigned required_features);
 extern u64 ceph_client_id(struct ceph_client *client);
 extern void ceph_destroy_client(struct ceph_client *client);
 extern int __ceph_open_session(struct ceph_client *client,

net/ceph/ceph_common.c

@@ -432,9 +432,12 @@ EXPORT_SYMBOL(ceph_client_id);
 /*
  * create a fresh client instance
  */
-struct ceph_client *ceph_create_client(struct ceph_options *opt, void *private)
+struct ceph_client *ceph_create_client(struct ceph_options *opt, void *private,
+				       unsigned supported_features,
+				       unsigned required_features)
 {
 	struct ceph_client *client;
+	struct ceph_entity_addr *myaddr = NULL;
 	int err = -ENOMEM;
 
 	client = kzalloc(sizeof(*client), GFP_KERNEL);
@@ -449,15 +452,27 @@ struct ceph_client *ceph_create_client(struct ceph_options *opt, void *private)
 	client->auth_err = 0;
 
 	client->extra_mon_dispatch = NULL;
-	client->supported_features = CEPH_FEATURE_SUPPORTED_DEFAULT;
-	client->required_features = CEPH_FEATURE_REQUIRED_DEFAULT;
+	client->supported_features = CEPH_FEATURE_SUPPORTED_DEFAULT |
+		supported_features;
+	client->required_features = CEPH_FEATURE_REQUIRED_DEFAULT |
+		required_features;
 
-	client->msgr = NULL;
+	/* msgr */
+	if (ceph_test_opt(client, MYIP))
+		myaddr = &client->options->my_addr;
+	client->msgr = ceph_messenger_create(myaddr,
+					     client->supported_features,
+					     client->required_features);
+	if (IS_ERR(client->msgr)) {
+		err = PTR_ERR(client->msgr);
+		goto fail;
+	}
+	client->msgr->nocrc = ceph_test_opt(client, NOCRC);
 
 	/* subsystems */
 	err = ceph_monc_init(&client->monc, client);
 	if (err < 0)
-		goto fail;
+		goto fail_msgr;
 	err = ceph_osdc_init(&client->osdc, client);
 	if (err < 0)
 		goto fail_monc;
@@ -466,6 +481,8 @@ struct ceph_client *ceph_create_client(struct ceph_options *opt, void *private)
 
 fail_monc:
 	ceph_monc_stop(&client->monc);
+fail_msgr:
+	ceph_messenger_destroy(client->msgr);
 fail:
 	kfree(client);
 	return ERR_PTR(err);
@@ -490,7 +507,6 @@ void ceph_destroy_client(struct ceph_client *client)
 
 	ceph_debugfs_client_cleanup(client);
 
-	if (client->msgr)
 	ceph_messenger_destroy(client->msgr);
 
 	ceph_destroy_options(client->options);
@@ -514,24 +530,9 @@ static int have_mon_and_osd_map(struct ceph_client *client)
  */
 int __ceph_open_session(struct ceph_client *client, unsigned long started)
 {
-	struct ceph_entity_addr *myaddr = NULL;
 	int err;
 	unsigned long timeout = client->options->mount_timeout * HZ;
 
-	/* initialize the messenger */
-	if (client->msgr == NULL) {
-		if (ceph_test_opt(client, MYIP))
-			myaddr = &client->options->my_addr;
-		client->msgr = ceph_messenger_create(myaddr,
-					client->supported_features,
-					client->required_features);
-		if (IS_ERR(client->msgr)) {
-			client->msgr = NULL;
-			return PTR_ERR(client->msgr);
-		}
-		client->msgr->nocrc = ceph_test_opt(client, NOCRC);
-	}
-
 	/* open session, and wait for mon and osd maps */
 	err = ceph_monc_open_session(&client->monc);
 	if (err < 0)