md: Unify mddev destruction paths

Previously, mddev_put() had a couple different paths for freeing a
mddev, due to the fact that the kobject wasn't initialized when the
mddev was first allocated. If we move the kobject_init() to when it's
first allocated and just use kobject_add() later, we can clean all this
up.

This also removes a hack in mddev_put() to avoid freeing biosets under a
spinlock, which involved copying biosets on the stack after the reset
bioset_init() changes.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 18 insertions, 35 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index fc692b7128bb..22203eba1e6e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -84,6 +84,8 @@ static void autostart_arrays(int part);
 static LIST_HEAD(pers_list);
 static DEFINE_SPINLOCK(pers_lock);
 
+static struct kobj_type md_ktype;
+
 struct md_cluster_operations *md_cluster_ops;
 EXPORT_SYMBOL(md_cluster_ops);
 struct module *md_cluster_mod;
@@ -510,11 +512,6 @@ static void mddev_delayed_delete(struct work_struct *ws);
 
 static void mddev_put(struct mddev *mddev)
 {
-        struct bio_set bs, sync_bs;
-
-        memset(&bs, 0, sizeof(bs));
-        memset(&sync_bs, 0, sizeof(sync_bs));
-
         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
                 return;
         if (!mddev->raid_disks && list_empty(&mddev->disks) &&
@@ -522,30 +519,23 @@ static void mddev_put(struct mddev *mddev)
                 /* Array is not configured at all, and not held active,
                  * so destroy it */
                 list_del_init(&mddev->all_mddevs);
-                bs = mddev->bio_set;
-                sync_bs = mddev->sync_set;
-                memset(&mddev->bio_set, 0, sizeof(mddev->bio_set));
-                memset(&mddev->sync_set, 0, sizeof(mddev->sync_set));
-                if (mddev->gendisk) {
-                        /* We did a probe so need to clean up.  Call
-                         * queue_work inside the spinlock so that
-                         * flush_workqueue() after mddev_find will
-                         * succeed in waiting for the work to be done.
-                         */
-                        INIT_WORK(&mddev->del_work, mddev_delayed_delete);
-                        queue_work(md_misc_wq, &mddev->del_work);
-                } else
-                        kfree(mddev);
+
+                /*
+                 * Call queue_work inside the spinlock so that
+                 * flush_workqueue() after mddev_find will succeed in waiting
+                 * for the work to be done.
+                 */
+                INIT_WORK(&mddev->del_work, mddev_delayed_delete);
+                queue_work(md_misc_wq, &mddev->del_work);
         }
         spin_unlock(&all_mddevs_lock);
-        bioset_exit(&bs);
-        bioset_exit(&sync_bs);
 }
 
 static void md_safemode_timeout(struct timer_list *t);
 
 void mddev_init(struct mddev *mddev)
 {
+        kobject_init(&mddev->kobj, &md_ktype);
         mutex_init(&mddev->open_mutex);
         mutex_init(&mddev->reconfig_mutex);
         mutex_init(&mddev->bitmap_info.mutex);
@@ -5215,6 +5205,8 @@ static void md_free(struct kobject *ko)
                 put_disk(mddev->gendisk);
         percpu_ref_exit(&mddev->writes_pending);
 
+        bioset_exit(&mddev->bio_set);
+        bioset_exit(&mddev->sync_set);
         kfree(mddev);
 }
 
@@ -5348,8 +5340,7 @@ static int md_alloc(dev_t dev, char *name)
         mutex_lock(&mddev->open_mutex);
         add_disk(disk);
 
-        error = kobject_init_and_add(&mddev->kobj, &md_ktype,
-                                     &disk_to_dev(disk)->kobj, "%s", "md");
+        error = kobject_add(&mddev->kobj, &disk_to_dev(disk)->kobj, "%s", "md");
         if (error) {
                 /* This isn't possible, but as kobject_init_and_add is marked
                  * __must_check, we must do something with the result
@@ -5506,7 +5497,7 @@ int md_run(struct mddev *mddev)
         if (!bioset_initialized(&mddev->sync_set)) {
                 err = bioset_init(&mddev->sync_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
                 if (err)
-                        goto abort;
+                        return err;
         }
 
         spin_lock(&pers_lock);
@@ -5519,8 +5510,7 @@ int md_run(struct mddev *mddev)
                 else
                         pr_warn("md: personality for level %s is not loaded!\n",
                                 mddev->clevel);
-                err = -EINVAL;
-                goto abort;
+                return -EINVAL;
         }
         spin_unlock(&pers_lock);
         if (mddev->level != pers->level) {
@@ -5533,8 +5523,7 @@ int md_run(struct mddev *mddev)
             pers->start_reshape == NULL) {
                 /* This personality cannot handle reshaping... */
                 module_put(pers->owner);
-                err = -EINVAL;
-                goto abort;
+                return -EINVAL;
         }
 
         if (pers->sync_request) {
@@ -5603,7 +5592,7 @@ int md_run(struct mddev *mddev)
                 mddev->private = NULL;
                 module_put(pers->owner);
                 bitmap_destroy(mddev);
-                goto abort;
+                return err;
         }
         if (mddev->queue) {
                 bool nonrot = true;
@@ -5665,12 +5654,6 @@ int md_run(struct mddev *mddev)
         sysfs_notify_dirent_safe(mddev->sysfs_action);
         sysfs_notify(&mddev->kobj, NULL, "degraded");
         return 0;
-
-abort:
-        bioset_exit(&mddev->bio_set);
-        bioset_exit(&mddev->sync_set);
-
-        return err;
 }
 EXPORT_SYMBOL_GPL(md_run);