Commit dce28769 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: qgroup: use qgroup_iterator_nested to in qgroup_update_refcnt() 



The ulist @qgroups is utilized to record all involved qgroups from both
old and new roots inside btrfs_qgroup_account_extent().

Due to the fact that qgroup_update_refcnt() itself is already utilizing
qgroup_iterator, here we have to introduce another list_head,
btrfs_qgroup::nested_iterator, allowing nested iteration.

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 a4a81383

fs/btrfs/qgroup.c

+35 −42
Original line number Diff line number Diff line
@@ -209,6 +209,7 @@ static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info, 
	INIT_LIST_HEAD(&qgroup->members);

	INIT_LIST_HEAD(&qgroup->dirty);

	INIT_LIST_HEAD(&qgroup->iterator);

	INIT_LIST_HEAD(&qgroup->nested_iterator);



	rb_link_node(&qgroup->node, parent, p);

	rb_insert_color(&qgroup->node, &fs_info->qgroup_tree);
@@ -2417,22 +2418,39 @@ int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans, 
	return ret;

}



static void qgroup_iterator_nested_add(struct list_head *head, struct btrfs_qgroup *qgroup)

{

	if (!list_empty(&qgroup->nested_iterator))

		return;



	list_add_tail(&qgroup->nested_iterator, head);

}



static void qgroup_iterator_nested_clean(struct list_head *head)

{

	while (!list_empty(head)) {

		struct btrfs_qgroup *qgroup;



		qgroup = list_first_entry(head, struct btrfs_qgroup, nested_iterator);

		list_del_init(&qgroup->nested_iterator);

	}

}



#define UPDATE_NEW	0

#define UPDATE_OLD	1

/*

 * 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 *qgroups,

static void qgroup_update_refcnt(struct btrfs_fs_info *fs_info,

				 struct ulist *roots, struct list_head *qgroups,

				 u64 seq, int update_old)

{

	struct ulist_node *unode;

	struct ulist_iterator uiter;

	struct btrfs_qgroup *qg;

	int ret = 0;



	if (!roots)

		return 0;

		return;

	ULIST_ITER_INIT(&uiter);

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

		LIST_HEAD(tmp);
@@ -2441,10 +2459,7 @@ static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info, 
		if (!qg)

			continue;



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

				GFP_ATOMIC);

		if (ret < 0)

			return ret;

		qgroup_iterator_nested_add(qgroups, qg);

		qgroup_iterator_add(&tmp, qg);

		list_for_each_entry(qg, &tmp, iterator) {

			struct btrfs_qgroup_list *glist;
@@ -2455,17 +2470,12 @@ static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info, 
				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;

				qgroup_iterator_nested_add(qgroups, glist->group);

				qgroup_iterator_add(&tmp, glist->group);

			}

		}

		qgroup_iterator_clean(&tmp);

	}

	return 0;

}



/*
@@ -2504,22 +2514,16 @@ static int qgroup_update_refcnt(struct btrfs_fs_info *fs_info, 
 * But this time we don't need to consider other things, the codes and logic

 * is easy to understand now.

 */

static int qgroup_update_counters(struct btrfs_fs_info *fs_info,

				  struct ulist *qgroups,

				  u64 nr_old_roots,

				  u64 nr_new_roots,

				  u64 num_bytes, u64 seq)

static void qgroup_update_counters(struct btrfs_fs_info *fs_info,

				   struct list_head *qgroups, u64 nr_old_roots,

				   u64 nr_new_roots, u64 num_bytes, u64 seq)

{

	struct ulist_node *unode;

	struct ulist_iterator uiter;

	struct btrfs_qgroup *qg;

	u64 cur_new_count, cur_old_count;



	ULIST_ITER_INIT(&uiter);

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

	list_for_each_entry(qg, qgroups, nested_iterator) {

		u64 cur_new_count, cur_old_count;

		bool dirty = false;



		qg = unode_aux_to_qgroup(unode);

		cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);

		cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
@@ -2590,7 +2594,6 @@ static int qgroup_update_counters(struct btrfs_fs_info *fs_info, 
		if (dirty)

			qgroup_dirty(fs_info, qg);

	}

	return 0;

}



/*
@@ -2627,7 +2630,7 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, 
				struct ulist *new_roots)

{

	struct btrfs_fs_info *fs_info = trans->fs_info;

	struct ulist *qgroups = NULL;

	LIST_HEAD(qgroups);

	u64 seq;

	u64 nr_new_roots = 0;

	u64 nr_old_roots = 0;
@@ -2661,11 +2664,6 @@ int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, 
	trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr,

					num_bytes, nr_old_roots, nr_new_roots);



	qgroups = ulist_alloc(GFP_NOFS);

	if (!qgroups) {

		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) {
@@ -2680,26 +2678,21 @@ 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, qgroups, seq, UPDATE_OLD);

	if (ret < 0)

		goto out;

	qgroup_update_refcnt(fs_info, old_roots, &qgroups, seq, UPDATE_OLD);



	/* Update new refcnts using new_roots */

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

	if (ret < 0)

		goto out;

	qgroup_update_refcnt(fs_info, new_roots, &qgroups, seq, UPDATE_NEW);



	qgroup_update_counters(fs_info, qgroups, nr_old_roots, nr_new_roots,

	qgroup_update_counters(fs_info, &qgroups, nr_old_roots, nr_new_roots,

			       num_bytes, seq);



	/*

	 * Bump qgroup_seq to avoid seq overlap

	 */

	fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1;

out:

	spin_unlock(&fs_info->qgroup_lock);

out_free:

	ulist_free(qgroups);

	qgroup_iterator_nested_clean(&qgroups);

	ulist_free(old_roots);

	ulist_free(new_roots);

	return ret;

fs/btrfs/qgroup.h

+18 −0
Original line number Diff line number Diff line
@@ -229,6 +229,24 @@ struct btrfs_qgroup { 
	 * finished.

	 */

	struct list_head iterator;



	/*

	 * For nested iterator usage.

	 *

	 * Here we support at most one level of nested iterator calls like:

	 *

	 *	LIST_HEAD(all_qgroups);

	 *	{

	 *		LIST_HEAD(local_qgroups);

	 *		qgroup_iterator_add(local_qgroups, qg);

	 *		qgroup_iterator_nested_add(all_qgroups, qg);

	 *		do_some_work(local_qgroups);

	 *		qgroup_iterator_clean(local_qgroups);

	 *	}

	 *	do_some_work(all_qgroups);

	 *	qgroup_iterator_nested_clean(all_qgroups);

	 */

	struct list_head nested_iterator;

	struct rb_node node;	  /* tree of qgroups */



	/*