ceph: unregister bdi before kill_anon_super releases device name
Sage Weil [Tue, 4 May 2010 23:14:46 +0000 (16:14 -0700)]
Unregister and destroy the bdi in put_super, after mount is r/o, but before
put_anon_super releases the device name.

For symmetry, bdi_destroy in destroy_client (we bdi_init in create_client).

Only set s_bdi if bdi_register succeeds, since we use it to decide whether
to bdi_unregister.

Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/super.c

index f888cf4..110857b 100644 (file)
@@ -47,10 +47,20 @@ const char *ceph_file_part(const char *s, int len)
  */
 static void ceph_put_super(struct super_block *s)
 {
-       struct ceph_client *cl = ceph_client(s);
+       struct ceph_client *client = ceph_sb_to_client(s);
 
        dout("put_super\n");
-       ceph_mdsc_close_sessions(&cl->mdsc);
+       ceph_mdsc_close_sessions(&client->mdsc);
+
+       /*
+        * ensure we release the bdi before put_anon_super releases
+        * the device name.
+        */
+       if (s->s_bdi == &client->backing_dev_info) {
+               bdi_unregister(&client->backing_dev_info);
+               s->s_bdi = NULL;
+       }
+
        return;
 }
 
@@ -636,6 +646,8 @@ static void ceph_destroy_client(struct ceph_client *client)
        destroy_workqueue(client->pg_inv_wq);
        destroy_workqueue(client->trunc_wq);
 
+       bdi_destroy(&client->backing_dev_info);
+
        if (client->msgr)
                ceph_messenger_destroy(client->msgr);
        mempool_destroy(client->wb_pagevec_pool);
@@ -876,14 +888,14 @@ static int ceph_register_bdi(struct super_block *sb, struct ceph_client *client)
 {
        int err;
 
-       sb->s_bdi = &client->backing_dev_info;
-
        /* set ra_pages based on rsize mount option? */
        if (client->mount_args->rsize >= PAGE_CACHE_SIZE)
                client->backing_dev_info.ra_pages =
                        (client->mount_args->rsize + PAGE_CACHE_SIZE - 1)
                        >> PAGE_SHIFT;
        err = bdi_register_dev(&client->backing_dev_info, sb->s_dev);
+       if (!err)
+               sb->s_bdi = &client->backing_dev_info;
        return err;
 }
 
@@ -957,9 +969,6 @@ static void ceph_kill_sb(struct super_block *s)
        dout("kill_sb %p\n", s);
        ceph_mdsc_pre_umount(&client->mdsc);
        kill_anon_super(s);    /* will call put_super after sb is r/o */
-       if (s->s_bdi == &client->backing_dev_info)
-               bdi_unregister(&client->backing_dev_info);
-       bdi_destroy(&client->backing_dev_info);
        ceph_destroy_client(client);
 }