bcache: fix crash with incomplete cache set

commit bf0c55c986540483c34ca640f2eef4c3314388b1 upstream.

Change-Id: I6abde52afe917633480caaf4e2518f42a816d886
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 0f12382aa35d6c939b53967b205639134e181eae..7552207a479bcf999fb69b11bf6a941613d5a365 100644 (file)
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -663,9 +663,13 @@ struct gc_stat {
  * CACHE_SET_STOPPING always gets set first when we're closing down a cache set;
  * we'll continue to run normally for awhile with CACHE_SET_STOPPING set (i.e.
  * flushing dirty data).
+ *
+ * CACHE_SET_RUNNING means all cache devices have been registered and journal
+ * replay is complete.
  */
 #define CACHE_SET_UNREGISTERING                0
 #define        CACHE_SET_STOPPING              1
+#define        CACHE_SET_RUNNING               2
 
 struct cache_set {
        struct closure          cl;

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 3a2ccf9b624be03597130fb4775919e4a2d6f214..f5004c5c4b9624602eaa4fc849f7f959c99ad721 100644 (file)
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1235,6 +1235,9 @@ int bch_flash_dev_create(struct cache_set *c, uint64_t size)
        if (test_bit(CACHE_SET_STOPPING, &c->flags))
                return -EINTR;
 
+       if (!test_bit(CACHE_SET_RUNNING, &c->flags))
+               return -EPERM;
+
        u = uuid_find_empty(c);
        if (!u) {
                pr_err("Can't create volume, no room for UUID");
@@ -1640,6 +1643,7 @@ static void run_cache_set(struct cache_set *c)
 
        flash_devs_run(c);
 
+       set_bit(CACHE_SET_RUNNING, &c->flags);
        return;
 err_unlock_gc:
        closure_set_stopped(&c->gc.cl);