btrfs: fix crash when trying to resume balance without the resume flag

[sagit-ice-cold/kernel_xiaomi_msm8998.git] / fs / btrfs / volumes.c

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 6d874b1..ed75d70 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3850,6 +3850,15 @@ int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
                return 0;
        }
 
+       /*
+        * A ro->rw remount sequence should continue with the paused balance
+        * regardless of who pauses it, system or the user as of now, so set
+        * the resume flag.
+        */
+       spin_lock(&fs_info->balance_lock);
+       fs_info->balance_ctl->flags |= BTRFS_BALANCE_RESUME;
+       spin_unlock(&fs_info->balance_lock);
+
        tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
        return PTR_ERR_OR_ZERO(tsk);
 }