2 files changed, 47 insertions, 0 deletions

diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c
index 5a743ac141ab..5d5a4c8c8496 100644
--- a/fs/ceph/debugfs.c
+++ b/fs/ceph/debugfs.c
@@ -158,10 +158,47 @@ static int dentry_lru_show(struct seq_file *s, void *ptr)
         return 0;
 }
 
+static int mds_sessions_show(struct seq_file *s, void *ptr)
+{
+        struct ceph_fs_client *fsc = s->private;
+        struct ceph_mds_client *mdsc = fsc->mdsc;
+        struct ceph_auth_client *ac = fsc->client->monc.auth;
+        struct ceph_options *opt = fsc->client->options;
+        int mds = -1;
+
+        mutex_lock(&mdsc->mutex);
+
+        /* The 'num' portion of an 'entity name' */
+        seq_printf(s, "global_id %llu\n", ac->global_id);
+
+        /* The -o name mount argument */
+        seq_printf(s, "name \"%s\"\n", opt->name ? opt->name : "");
+
+        /* The list of MDS session rank+state */
+        for (mds = 0; mds < mdsc->max_sessions; mds++) {
+                struct ceph_mds_session *session =
+                        __ceph_lookup_mds_session(mdsc, mds);
+                if (!session) {
+                        continue;
+                }
+                mutex_unlock(&mdsc->mutex);
+                seq_printf(s, "mds.%d %s\n",
+                                session->s_mds,
+                                ceph_session_state_name(session->s_state));
+
+                ceph_put_mds_session(session);
+                mutex_lock(&mdsc->mutex);
+        }
+        mutex_unlock(&mdsc->mutex);
+
+        return 0;
+}
+
 CEPH_DEFINE_SHOW_FUNC(mdsmap_show)
 CEPH_DEFINE_SHOW_FUNC(mdsc_show)
 CEPH_DEFINE_SHOW_FUNC(caps_show)
 CEPH_DEFINE_SHOW_FUNC(dentry_lru_show)
+CEPH_DEFINE_SHOW_FUNC(mds_sessions_show)
 
 
 /*
@@ -193,6 +230,7 @@ void ceph_fs_debugfs_cleanup(struct ceph_fs_client *fsc)
         debugfs_remove(fsc->debugfs_bdi);
         debugfs_remove(fsc->debugfs_congestion_kb);
         debugfs_remove(fsc->debugfs_mdsmap);
+        debugfs_remove(fsc->debugfs_mds_sessions);
         debugfs_remove(fsc->debugfs_caps);
         debugfs_remove(fsc->debugfs_mdsc);
         debugfs_remove(fsc->debugfs_dentry_lru);
@@ -231,6 +269,14 @@ int ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
         if (!fsc->debugfs_mdsmap)
                 goto out;
 
+        fsc->debugfs_mds_sessions = debugfs_create_file("mds_sessions",
+                                        0600,
+                                        fsc->client->debugfs_dir,
+                                        fsc,
+                                        &mds_sessions_show_fops);
+        if (!fsc->debugfs_mds_sessions)
+                goto out;
+
         fsc->debugfs_mdsc = debugfs_create_file("mdsc",
                                                 0600,
                                                 fsc->client->debugfs_dir,
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index f62a09863ff1..b82f507979b8 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -95,6 +95,7 @@ struct ceph_fs_client {
         struct dentry *debugfs_congestion_kb;
         struct dentry *debugfs_bdi;
         struct dentry *debugfs_mdsc, *debugfs_mdsmap;
+        struct dentry *debugfs_mds_sessions;
 #endif
 
 #ifdef CONFIG_CEPH_FSCACHE