Commit a4a81383 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: qgroup: use qgroup_iterator to replace tmp ulist in qgroup_update_refcnt() 



For function qgroup_update_refcnt(), we use @tmp list to iterate all the
involved qgroups of a subvolume.

It's a perfect match for qgroup_iterator facility, as that @tmp ulist
has a very limited lifespan (just inside the while() loop).

By migrating to qgroup_iterator, we can get rid of the GFP_ATOMIC memory
allocation and no error handling is needed.

Reviewed-by: default avatarBoris Burkov <boris@bur.io>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent a0bdc04b

fs/btrfs/qgroup.c

+11 −28
Original line number Diff line number Diff line
@@ -2423,13 +2423,11 @@ int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans, 
 * Walk all of the roots that points to the bytenr and adjust their refcnts.

 */

static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info,

				struct ulist *roots, struct ulist *tmp,

				struct ulist *qgroups, u64 seq, int update_old)

				struct ulist *roots, struct ulist *qgroups,

				u64 seq, int update_old)

{

	struct ulist_node *unode;

	struct ulist_iterator uiter;

	struct ulist_node *tmp_unode;

	struct ulist_iterator tmp_uiter;

	struct btrfs_qgroup *qg;

	int ret = 0;
@@ -2437,40 +2435,35 @@ static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info, 
		return 0;

	ULIST_ITER_INIT(&uiter);

	while ((unode = ulist_next(roots, &uiter))) {

		LIST_HEAD(tmp);



		qg = find_qgroup_rb(fs_info, unode->val);

		if (!qg)

			continue;



		ulist_reinit(tmp);

		ret = ulist_add(qgroups, qg->qgroupid, qgroup_to_aux(qg),

				GFP_ATOMIC);

		if (ret < 0)

			return ret;

		ret = ulist_add(tmp, qg->qgroupid, qgroup_to_aux(qg), GFP_ATOMIC);

		if (ret < 0)

			return ret;

		ULIST_ITER_INIT(&tmp_uiter);

		while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {

		qgroup_iterator_add(&tmp, qg);

		list_for_each_entry(qg, &tmp, iterator) {

			struct btrfs_qgroup_list *glist;



			qg = unode_aux_to_qgroup(tmp_unode);

			if (update_old)

				btrfs_qgroup_update_old_refcnt(qg, seq, 1);

			else

				btrfs_qgroup_update_new_refcnt(qg, seq, 1);



			list_for_each_entry(glist, &qg->groups, next_group) {

				ret = ulist_add(qgroups, glist->group->qgroupid,

						qgroup_to_aux(glist->group),

						GFP_ATOMIC);

				if (ret < 0)

					return ret;

				ret = ulist_add(tmp, glist->group->qgroupid,

						qgroup_to_aux(glist->group),

						GFP_ATOMIC);

				if (ret < 0)

					return ret;

				qgroup_iterator_add(&tmp, glist->group);

			}

		}

		qgroup_iterator_clean(&tmp);

	}

	return 0;

}
@@ -2635,7 +2628,6 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, 
{

	struct btrfs_fs_info *fs_info = trans->fs_info;

	struct ulist *qgroups = NULL;

	struct ulist *tmp = NULL;

	u64 seq;

	u64 nr_new_roots = 0;

	u64 nr_old_roots = 0;
@@ -2674,12 +2666,6 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, 
		ret = -ENOMEM;

		goto out_free;

	}

	tmp = ulist_alloc(GFP_NOFS);

	if (!tmp) {

		ret = -ENOMEM;

		goto out_free;

	}



	mutex_lock(&fs_info->qgroup_rescan_lock);

	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {

		if (fs_info->qgroup_rescan_progress.objectid <= bytenr) {
@@ -2694,14 +2680,12 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, 
	seq = fs_info->qgroup_seq;



	/* Update old refcnts using old_roots */

	ret = qgroup_update_refcnt(fs_info, old_roots, tmp, qgroups, seq,

				   UPDATE_OLD);

	ret = qgroup_update_refcnt(fs_info, old_roots, qgroups, seq, UPDATE_OLD);

	if (ret < 0)

		goto out;



	/* Update new refcnts using new_roots */

	ret = qgroup_update_refcnt(fs_info, new_roots, tmp, qgroups, seq,

				   UPDATE_NEW);

	ret = qgroup_update_refcnt(fs_info, new_roots, qgroups, seq, UPDATE_NEW);

	if (ret < 0)

		goto out;
@@ -2715,7 +2699,6 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, 
out:

	spin_unlock(&fs_info->qgroup_lock);

out_free:

	ulist_free(tmp);

	ulist_free(qgroups);

	ulist_free(old_roots);

	ulist_free(new_roots);