1 files changed, 57 insertions, 38 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 8a3d2594b807..ecaad40e7ef4 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2845,31 +2845,48 @@ out:
 
 static int balance_kthread(void *data)
 {
-        struct btrfs_balance_control *bctl =
-                        (struct btrfs_balance_control *)data;
-        struct btrfs_fs_info *fs_info = bctl->fs_info;
+        struct btrfs_fs_info *fs_info = data;
         int ret = 0;
 
         mutex_lock(&fs_info->volume_mutex);
         mutex_lock(&fs_info->balance_mutex);
 
-        set_balance_control(bctl);
-
-        if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
-                printk(KERN_INFO "btrfs: force skipping balance\n");
-        } else {
+        if (fs_info->balance_ctl) {
                 printk(KERN_INFO "btrfs: continuing balance\n");
-                ret = btrfs_balance(bctl, NULL);
+                ret = btrfs_balance(fs_info->balance_ctl, NULL);
         }
 
         mutex_unlock(&fs_info->balance_mutex);
         mutex_unlock(&fs_info->volume_mutex);
+
         return ret;
 }
 
-int btrfs_recover_balance(struct btrfs_root *tree_root)
+int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
 {
         struct task_struct *tsk;
+
+        spin_lock(&fs_info->balance_lock);
+        if (!fs_info->balance_ctl) {
+                spin_unlock(&fs_info->balance_lock);
+                return 0;
+        }
+        spin_unlock(&fs_info->balance_lock);
+
+        if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
+                printk(KERN_INFO "btrfs: force skipping balance\n");
+                return 0;
+        }
+
+        tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
+        if (IS_ERR(tsk))
+                return PTR_ERR(tsk);
+
+        return 0;
+}
+
+int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
+{
         struct btrfs_balance_control *bctl;
         struct btrfs_balance_item *item;
         struct btrfs_disk_balance_args disk_bargs;
@@ -2882,29 +2899,30 @@ int btrfs_recover_balance(struct btrfs_root *tree_root)
         if (!path)
                 return -ENOMEM;
 
-        bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
-        if (!bctl) {
-                ret = -ENOMEM;
-                goto out;
-        }
-
         key.objectid = BTRFS_BALANCE_OBJECTID;
         key.type = BTRFS_BALANCE_ITEM_KEY;
         key.offset = 0;
 
-        ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
+        ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
         if (ret < 0)
-                goto out_bctl;
+                goto out;
         if (ret > 0) { /* ret = -ENOENT; */
                 ret = 0;
-                goto out_bctl;
+                goto out;
+        }
+
+        bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
+        if (!bctl) {
+                ret = -ENOMEM;
+                goto out;
         }
 
         leaf = path->nodes[0];
         item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
 
-        bctl->fs_info = tree_root->fs_info;
-        bctl->flags = btrfs_balance_flags(leaf, item) | BTRFS_BALANCE_RESUME;
+        bctl->fs_info = fs_info;
+        bctl->flags = btrfs_balance_flags(leaf, item);
+        bctl->flags |= BTRFS_BALANCE_RESUME;
 
         btrfs_balance_data(leaf, item, &disk_bargs);
         btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
@@ -2913,14 +2931,13 @@ int btrfs_recover_balance(struct btrfs_root *tree_root)
         btrfs_balance_sys(leaf, item, &disk_bargs);
         btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
 
-        tsk = kthread_run(balance_kthread, bctl, "btrfs-balance");
-        if (IS_ERR(tsk))
-                ret = PTR_ERR(tsk);
-        else
-                goto out;
+        mutex_lock(&fs_info->volume_mutex);
+        mutex_lock(&fs_info->balance_mutex);
 
-out_bctl:
-        kfree(bctl);
+        set_balance_control(bctl);
+
+        mutex_unlock(&fs_info->balance_mutex);
+        mutex_unlock(&fs_info->volume_mutex);
 out:
         btrfs_free_path(path);
         return ret;
@@ -4061,16 +4078,18 @@ static void btrfs_end_bio(struct bio *bio, int err)
 
                         BUG_ON(stripe_index >= bbio->num_stripes);
                         dev = bbio->stripes[stripe_index].dev;
-                        if (bio->bi_rw & WRITE)
-                                btrfs_dev_stat_inc(dev,
-                                                   BTRFS_DEV_STAT_WRITE_ERRS);
-                        else
-                                btrfs_dev_stat_inc(dev,
-                                                   BTRFS_DEV_STAT_READ_ERRS);
-                        if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
-                                btrfs_dev_stat_inc(dev,
-                                                   BTRFS_DEV_STAT_FLUSH_ERRS);
-                        btrfs_dev_stat_print_on_error(dev);
+                        if (dev->bdev) {
+                                if (bio->bi_rw & WRITE)
+                                        btrfs_dev_stat_inc(dev,
+                                                BTRFS_DEV_STAT_WRITE_ERRS);
+                                else
+                                        btrfs_dev_stat_inc(dev,
+                                                BTRFS_DEV_STAT_READ_ERRS);
+                                if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
+                                        btrfs_dev_stat_inc(dev,
+                                                BTRFS_DEV_STAT_FLUSH_ERRS);
+                                btrfs_dev_stat_print_on_error(dev);
+                        }
                 }
         }