bcache: Fix a lockdep splat in an error path

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index c70521fe57a60597b71b7a3b210664e3d52be784..5136e11eadb09658e0721363ffb0a7ea2d9f2163 100644 (file)
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1873,7 +1873,10 @@ static void register_cache(struct cache_sb *sb, struct page *sb_page,
        if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache"))
                goto err;
 
+       mutex_lock(&bch_register_lock);
        err = register_cache_set(ca);
+       mutex_unlock(&bch_register_lock);
+
        if (err)
                goto err;
 
@@ -1935,8 +1938,6 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
        if (!try_module_get(THIS_MODULE))
                return -EBUSY;
 
-       mutex_lock(&bch_register_lock);
-
        if (!(path = kstrndup(buffer, size, GFP_KERNEL)) ||
            !(sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL)))
                goto err;
@@ -1969,7 +1970,9 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
                if (!dc)
                        goto err_close;
 
+               mutex_lock(&bch_register_lock);
                register_bdev(sb, sb_page, bdev, dc);
+               mutex_unlock(&bch_register_lock);
        } else {
                struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
                if (!ca)
@@ -1982,7 +1985,6 @@ out:
                put_page(sb_page);
        kfree(sb);
        kfree(path);
-       mutex_unlock(&bch_register_lock);
        module_put(THIS_MODULE);
        return ret;