btrfs: use mutex in btrfs_resume_balance_async

While the spinlock does not cause problems, using the mutex is more
correct and consistent with others. The global status of balance is eg.
checked from btrfs_pause_balance or btrfs_cancel_balance with mutex.

Resuming balance happens during mount or ro->rw remount. In the former
case, no other user of the balance_ctl exists, in the latter, balance
cannot run until the ro/rw transition is finished.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2018-03-21 02:29:13 +01:00
parent 008ef0969d
commit 1354e1a13e

View file

@ -3959,12 +3959,12 @@ int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
{
struct task_struct *tsk;
spin_lock(&fs_info->balance_lock);
mutex_lock(&fs_info->balance_mutex);
if (!fs_info->balance_ctl) {
spin_unlock(&fs_info->balance_lock);
mutex_unlock(&fs_info->balance_mutex);
return 0;
}
spin_unlock(&fs_info->balance_lock);
mutex_unlock(&fs_info->balance_mutex);
if (btrfs_test_opt(fs_info, SKIP_BALANCE)) {
btrfs_info(fs_info, "force skipping balance");