Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 46b665ce authored by Jan Schmidt's avatar Jan Schmidt Committed by Josef Bacik
Browse files

Btrfs: split btrfs_qgroup_account_ref into four functions 



The function is separated into a preparation part and the three accounting
steps mentioned in the qgroups documentation. The goal is to make steps two
and three usable by the rescan functionality. A side effect is that the
function is restructured into readable subunits.

Signed-off-by: default avatarJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
parent 3c76cd84

fs/btrfs/qgroup.c

+148 −105
Original line number Diff line number Diff line
@@ -1185,6 +1185,144 @@ int btrfs_qgroup_record_ref(struct btrfs_trans_handle *trans, 
	return 0;

}



static int qgroup_account_ref_step1(struct btrfs_fs_info *fs_info,

				    struct ulist *roots, struct ulist *tmp,

				    u64 seq)

{

	struct ulist_node *unode;

	struct ulist_iterator uiter;

	struct ulist_node *tmp_unode;

	struct ulist_iterator tmp_uiter;

	struct btrfs_qgroup *qg;

	int ret;



	ULIST_ITER_INIT(&uiter);

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

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

		if (!qg)

			continue;



		ulist_reinit(tmp);

						/* XXX id not needed */

		ret = ulist_add(tmp, qg->qgroupid,

				(u64)(uintptr_t)qg, GFP_ATOMIC);

		if (ret < 0)

			return ret;

		ULIST_ITER_INIT(&tmp_uiter);

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

			struct btrfs_qgroup_list *glist;



			qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;

			if (qg->refcnt < seq)

				qg->refcnt = seq + 1;

			else

				++qg->refcnt;



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

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

						(u64)(uintptr_t)glist->group,

						GFP_ATOMIC);

				if (ret < 0)

					return ret;

			}

		}

	}



	return 0;

}



static int qgroup_account_ref_step2(struct btrfs_fs_info *fs_info,

				    struct ulist *roots, struct ulist *tmp,

				    u64 seq, int sgn, u64 num_bytes,

				    struct btrfs_qgroup *qgroup)

{

	struct ulist_node *unode;

	struct ulist_iterator uiter;

	struct btrfs_qgroup *qg;

	struct btrfs_qgroup_list *glist;

	int ret;



	ulist_reinit(tmp);

	ret = ulist_add(tmp, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);

	if (ret < 0)

		return ret;



	ULIST_ITER_INIT(&uiter);

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

		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;

		if (qg->refcnt < seq) {

			/* not visited by step 1 */

			qg->rfer += sgn * num_bytes;

			qg->rfer_cmpr += sgn * num_bytes;

			if (roots->nnodes == 0) {

				qg->excl += sgn * num_bytes;

				qg->excl_cmpr += sgn * num_bytes;

			}

			qgroup_dirty(fs_info, qg);

		}

		WARN_ON(qg->tag >= seq);

		qg->tag = seq;



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

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

					(uintptr_t)glist->group, GFP_ATOMIC);

			if (ret < 0)

				return ret;

		}

	}



	return 0;

}



static int qgroup_account_ref_step3(struct btrfs_fs_info *fs_info,

				    struct ulist *roots, struct ulist *tmp,

				    u64 seq, int sgn, u64 num_bytes)

{

	struct ulist_node *unode;

	struct ulist_iterator uiter;

	struct btrfs_qgroup *qg;

	struct ulist_node *tmp_unode;

	struct ulist_iterator tmp_uiter;

	int ret;



	ULIST_ITER_INIT(&uiter);

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

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

		if (!qg)

			continue;



		ulist_reinit(tmp);

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

		if (ret < 0)

			return ret;



		ULIST_ITER_INIT(&tmp_uiter);

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

			struct btrfs_qgroup_list *glist;



			qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;

			if (qg->tag == seq)

				continue;



			if (qg->refcnt - seq == roots->nnodes) {

				qg->excl -= sgn * num_bytes;

				qg->excl_cmpr -= sgn * num_bytes;

				qgroup_dirty(fs_info, qg);

			}



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

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

						(uintptr_t)glist->group,

						GFP_ATOMIC);

				if (ret < 0)

					return ret;

			}

		}

	}



	return 0;

}



/*

 * btrfs_qgroup_account_ref is called for every ref that is added to or deleted

 * from the fs. First, all roots referencing the extent are searched, and
@@ -1200,10 +1338,8 @@ int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans, 
	struct btrfs_root *quota_root;

	u64 ref_root;

	struct btrfs_qgroup *qgroup;

	struct ulist_node *unode;

	struct ulist *roots = NULL;

	struct ulist *tmp = NULL;

	struct ulist_iterator uiter;

	u64 seq;

	int ret = 0;

	int sgn;
@@ -1287,119 +1423,26 @@ int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans, 
	seq = fs_info->qgroup_seq;

	fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */



	ULIST_ITER_INIT(&uiter);

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

		struct ulist_node *tmp_unode;

		struct ulist_iterator tmp_uiter;

		struct btrfs_qgroup *qg;



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

		if (!qg)

			continue;



		ulist_reinit(tmp);

						/* XXX id not needed */

		ret = ulist_add(tmp, qg->qgroupid,

				(u64)(uintptr_t)qg, GFP_ATOMIC);

		if (ret < 0)

			goto unlock;

		ULIST_ITER_INIT(&tmp_uiter);

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

			struct btrfs_qgroup_list *glist;



			qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;

			if (qg->refcnt < seq)

				qg->refcnt = seq + 1;

			else

				++qg->refcnt;



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

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

						(u64)(uintptr_t)glist->group,

						GFP_ATOMIC);

				if (ret < 0)

	ret = qgroup_account_ref_step1(fs_info, roots, tmp, seq);

	if (ret)

		goto unlock;

			}

		}

	}



	/*

	 * step 2: walk from the new root

	 */

	ulist_reinit(tmp);

	ret = ulist_add(tmp, qgroup->qgroupid,

			(uintptr_t)qgroup, GFP_ATOMIC);

	if (ret < 0)

		goto unlock;

	ULIST_ITER_INIT(&uiter);

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

		struct btrfs_qgroup *qg;

		struct btrfs_qgroup_list *glist;



		qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;

		if (qg->refcnt < seq) {

			/* not visited by step 1 */

			qg->rfer += sgn * node->num_bytes;

			qg->rfer_cmpr += sgn * node->num_bytes;

			if (roots->nnodes == 0) {

				qg->excl += sgn * node->num_bytes;

				qg->excl_cmpr += sgn * node->num_bytes;

			}

			qgroup_dirty(fs_info, qg);

		}

		WARN_ON(qg->tag >= seq);

		qg->tag = seq;



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

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

					(uintptr_t)glist->group, GFP_ATOMIC);

			if (ret < 0)

	ret = qgroup_account_ref_step2(fs_info, roots, tmp, seq, sgn,

				       node->num_bytes, qgroup);

	if (ret)

		goto unlock;

		}

	}



	/*

	 * step 3: walk again from old refs

	 */

	ULIST_ITER_INIT(&uiter);

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

		struct btrfs_qgroup *qg;

		struct ulist_node *tmp_unode;

		struct ulist_iterator tmp_uiter;



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

		if (!qg)

			continue;



		ulist_reinit(tmp);

		ret = ulist_add(tmp, qg->qgroupid,

				(uintptr_t)qg, GFP_ATOMIC);

		if (ret < 0)

	ret = qgroup_account_ref_step3(fs_info, roots, tmp, seq, sgn,

				       node->num_bytes);

	if (ret)

		goto unlock;

		ULIST_ITER_INIT(&tmp_uiter);

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

			struct btrfs_qgroup_list *glist;



			qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;

			if (qg->tag == seq)

				continue;



			if (qg->refcnt - seq == roots->nnodes) {

				qg->excl -= sgn * node->num_bytes;

				qg->excl_cmpr -= sgn * node->num_bytes;

				qgroup_dirty(fs_info, qg);

			}



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

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

						(uintptr_t)glist->group,

						GFP_ATOMIC);

				if (ret < 0)

					goto unlock;

			}

		}

	}

	ret = 0;

unlock:

	spin_unlock(&fs_info->qgroup_lock);

	ulist_free(roots);