Commit 099aa972 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

btrfs: use btrfs_try_lock_balance in btrfs_ioctl_balance 



This eliminates 2 labels and makes the code generally more streamlined.
Also rename the 'out_bargs' label to 'out_unlock' since bargs is going
to be freed under the 'out' label. This also fixes a memory leak since
bargs wasn't correctly freed in one of the condition which are now moved
in btrfs_try_lock_balance.

Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 7fb10ed8

fs/btrfs/ioctl.c

+5 −46
Original line number Diff line number Diff line
@@ -4427,7 +4427,7 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) 
	struct btrfs_fs_info *fs_info = root->fs_info;

	struct btrfs_ioctl_balance_args *bargs;

	struct btrfs_balance_control *bctl;

	bool need_unlock; /* for mut. excl. ops lock */

	bool need_unlock = true;

	int ret;



	if (!capable(CAP_SYS_ADMIN))
@@ -4444,53 +4444,12 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg) 
		goto out;

	}



again:

	if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {

		mutex_lock(&fs_info->balance_mutex);

		need_unlock = true;

		goto locked;

	}



	/*

	 * mut. excl. ops lock is locked.  Three possibilities:

	 *   (1) some other op is running

	 *   (2) balance is running

	 *   (3) balance is paused -- special case (think resume)

	 */

	mutex_lock(&fs_info->balance_mutex);

	if (fs_info->balance_ctl) {

		/* this is either (2) or (3) */

		if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {

			mutex_unlock(&fs_info->balance_mutex);

			/*

			 * Lock released to allow other waiters to continue,

			 * we'll reexamine the status again.

			 */

			mutex_lock(&fs_info->balance_mutex);



			if (fs_info->balance_ctl &&

			    !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {

				/* this is (3) */

				need_unlock = false;

				goto locked;

			}



			mutex_unlock(&fs_info->balance_mutex);

			goto again;

		} else {

			/* this is (2) */

			mutex_unlock(&fs_info->balance_mutex);

			ret = -EINPROGRESS;

			goto out;

		}

	} else {

		/* this is (1) */

		mutex_unlock(&fs_info->balance_mutex);

		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;

	ret = btrfs_try_lock_balance(fs_info, &need_unlock);

	if (ret)

		goto out;

	}



locked:

	lockdep_assert_held(&fs_info->balance_mutex);



	if (bargs->flags & BTRFS_BALANCE_RESUME) {

		if (!fs_info->balance_ctl) {

			ret = -ENOTCONN;