ceph: mount non-default filesystem by name

To mount non-default filesytem, user currently needs to provide mds
namespace ID. This is inconvenience.

This patch makes user be able to mount filesystem by name. If user
wants to mount non-default filesystem. Client first subscribes to
fsmap.user. Subscribe to mdsmap.<ID> after getting ID of filesystem.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

1 files changed, 26 insertions, 12 deletions

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index a5b2275e1573..7736a931376e 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -108,7 +108,6 @@ static int ceph_sync_fs(struct super_block *sb, int wait)
  * mount options
  */
 enum {
-	Opt_mds_namespace,
 	Opt_wsize,
 	Opt_rsize,
 	Opt_rasize,
@@ -121,6 +120,7 @@ enum {
 	Opt_last_int,
 	/* int args above */
 	Opt_snapdirname,
+	Opt_mds_namespace,
 	Opt_last_string,
 	/* string args above */
 	Opt_dirstat,
@@ -144,7 +144,6 @@ enum {
 };
 
 static match_table_t fsopt_tokens = {
-	{Opt_mds_namespace, "mds_namespace=%d"},
 	{Opt_wsize, "wsize=%d"},
 	{Opt_rsize, "rsize=%d"},
 	{Opt_rasize, "rasize=%d"},
@@ -156,6 +155,7 @@ static match_table_t fsopt_tokens = {
 	{Opt_congestion_kb, "write_congestion_kb=%d"},
 	/* int args above */
 	{Opt_snapdirname, "snapdirname=%s"},
+	{Opt_mds_namespace, "mds_namespace=%s"},
 	/* string args above */
 	{Opt_dirstat, "dirstat"},
 	{Opt_nodirstat, "nodirstat"},
@@ -212,11 +212,14 @@ static int parse_fsopt_token(char *c, void *private)
 		if (!fsopt->snapdir_name)
 			return -ENOMEM;
 		break;
-
-		/* misc */
 	case Opt_mds_namespace:
-		fsopt->mds_namespace = intval;
+		fsopt->mds_namespace = kstrndup(argstr[0].from,
+						argstr[0].to-argstr[0].from,
+						GFP_KERNEL);
+		if (!fsopt->mds_namespace)
+			return -ENOMEM;
 		break;
+		/* misc */
 	case Opt_wsize:
 		fsopt->wsize = intval;
 		break;
@@ -302,6 +305,7 @@ static void destroy_mount_options(struct ceph_mount_options *args)
 {
 	dout("destroy_mount_options %p\n", args);
 	kfree(args->snapdir_name);
+	kfree(args->mds_namespace);
 	kfree(args->server_path);
 	kfree(args);
 }
@@ -333,6 +337,9 @@ static int compare_mount_options(struct ceph_mount_options *new_fsopt,
 	ret = strcmp_null(fsopt1->snapdir_name, fsopt2->snapdir_name);
 	if (ret)
 		return ret;
+	ret = strcmp_null(fsopt1->mds_namespace, fsopt2->mds_namespace);
+	if (ret)
+		return ret;
 
 	ret = strcmp_null(fsopt1->server_path, fsopt2->server_path);
 	if (ret)
@@ -376,7 +383,6 @@ static int parse_mount_options(struct ceph_mount_options **pfsopt,
 	fsopt->max_readdir = CEPH_MAX_READDIR_DEFAULT;
 	fsopt->max_readdir_bytes = CEPH_MAX_READDIR_BYTES_DEFAULT;
 	fsopt->congestion_kb = default_congestion_kb();
-	fsopt->mds_namespace = CEPH_FS_CLUSTER_ID_NONE;
 
 	/*
 	 * Distinguish the server list from the path in "dev_name".
@@ -469,8 +475,8 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root)
 		seq_puts(m, ",noacl");
 #endif
 
-	if (fsopt->mds_namespace != CEPH_FS_CLUSTER_ID_NONE)
-		seq_printf(m, ",mds_namespace=%d", fsopt->mds_namespace);
+	if (fsopt->mds_namespace)
+		seq_printf(m, ",mds_namespace=%s", fsopt->mds_namespace);
 	if (fsopt->wsize)
 		seq_printf(m, ",wsize=%d", fsopt->wsize);
 	if (fsopt->rsize != CEPH_RSIZE_DEFAULT)
@@ -509,9 +515,11 @@ static int extra_mon_dispatch(struct ceph_client *client, struct ceph_msg *msg)
 
 	switch (type) {
 	case CEPH_MSG_MDS_MAP:
-		ceph_mdsc_handle_map(fsc->mdsc, msg);
+		ceph_mdsc_handle_mdsmap(fsc->mdsc, msg);
+		return 0;
+	case CEPH_MSG_FS_MAP_USER:
+		ceph_mdsc_handle_fsmap(fsc->mdsc, msg);
 		return 0;
-
 	default:
 		return -1;
 	}
@@ -543,8 +551,14 @@ static struct ceph_fs_client *create_fs_client(struct ceph_mount_options *fsopt,
 		goto fail;
 	}
 	fsc->client->extra_mon_dispatch = extra_mon_dispatch;
-	fsc->client->monc.fs_cluster_id = fsopt->mds_namespace;
-	ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP, 0, true);
+
+	if (fsopt->mds_namespace == NULL) {
+		ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
+				   0, true);
+	} else {
+		ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_FSMAP,
+				   0, false);
+	}
 
 	fsc->mount_options = fsopt;