Btrfs: resume balance on rw (re)mounts properly

This introduces btrfs_resume_balance_async(), which, given that
restriper state was recovered earlier by btrfs_recover_balance(),
resumes balance in btrfs-balance kthread.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3a7961ba161ef1d9279890e30f89f2bad3df26e6..8cc47103a32e0495da87bf68338c48c0c0848a22 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2490,17 +2490,23 @@ retry_root_backup:
                goto fail_trans_kthread;
        }
 
-       if (!(sb->s_flags & MS_RDONLY)) {
-               down_read(&fs_info->cleanup_work_sem);
-               err = btrfs_orphan_cleanup(fs_info->fs_root);
-               if (!err)
-                       err = btrfs_orphan_cleanup(fs_info->tree_root);
+       if (sb->s_flags & MS_RDONLY)
+               return 0;
+
+       down_read(&fs_info->cleanup_work_sem);
+       if ((ret = btrfs_orphan_cleanup(fs_info->fs_root)) ||
+           (ret = btrfs_orphan_cleanup(fs_info->tree_root))) {
                up_read(&fs_info->cleanup_work_sem);
+               close_ctree(tree_root);
+               return ret;
+       }
+       up_read(&fs_info->cleanup_work_sem);
 
-               if (err) {
-                       close_ctree(tree_root);
-                       return err;
-               }
+       ret = btrfs_resume_balance_async(fs_info);
+       if (ret) {
+               printk(KERN_WARNING "btrfs: failed to resume balance\n");
+               close_ctree(tree_root);
+               return ret;
        }
 
        return 0;

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 0eb9a4da069e6cb1e3c4294d4ad02e2ab92da666..e23991574fdf309e6ed95e23985fc5dd0af28e0f 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1187,6 +1187,10 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
                if (ret)
                        goto restore;
 
+               ret = btrfs_resume_balance_async(fs_info);
+               if (ret)
+                       goto restore;
+
                sb->s_flags &= ~MS_RDONLY;
        }
 

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 48943d0f861af5412465aebbd2c6de144ccb2af9..ecaad40e7ef499fedb7667659d9efd955a661eaa 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2845,28 +2845,46 @@ 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_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;

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index e1b1a649fc5adf7cb7ed872ddf3120c9dd47eba1..95f6637614db5932f8d52daba79943514a7ed8da 100644 (file)
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -281,6 +281,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 int btrfs_init_new_device(struct btrfs_root *root, char *path);
 int btrfs_balance(struct btrfs_balance_control *bctl,
                  struct btrfs_ioctl_balance_args *bargs);
+int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
 int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);