1 files changed, 185 insertions, 82 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index eb28141d5c37..5d57a285d59b 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -30,7 +30,7 @@
 #include "root-tree.h"
 #include "tree-checker.h"
 
-enum btrfs_qgroup_mode btrfs_qgroup_mode(struct btrfs_fs_info *fs_info)
+enum btrfs_qgroup_mode btrfs_qgroup_mode(const struct btrfs_fs_info *fs_info)
 {
 	if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
 		return BTRFS_QGROUP_MODE_DISABLED;
@@ -39,12 +39,12 @@ enum btrfs_qgroup_mode btrfs_qgroup_mode(struct btrfs_fs_info *fs_info)
 	return BTRFS_QGROUP_MODE_FULL;
 }
 
-bool btrfs_qgroup_enabled(struct btrfs_fs_info *fs_info)
+bool btrfs_qgroup_enabled(const struct btrfs_fs_info *fs_info)
 {
 	return btrfs_qgroup_mode(fs_info) != BTRFS_QGROUP_MODE_DISABLED;
 }
 
-bool btrfs_qgroup_full_accounting(struct btrfs_fs_info *fs_info)
+bool btrfs_qgroup_full_accounting(const struct btrfs_fs_info *fs_info)
 {
 	return btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_FULL;
 }
@@ -107,7 +107,7 @@ static void qgroup_rsv_release(struct btrfs_fs_info *fs_info,
 
 static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
 				     struct btrfs_qgroup *dest,
-				     struct btrfs_qgroup *src)
+				     const struct btrfs_qgroup *src)
 {
 	int i;
 
@@ -117,7 +117,7 @@ static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info,
 
 static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info,
 					 struct btrfs_qgroup *dest,
-					  struct btrfs_qgroup *src)
+					 const struct btrfs_qgroup *src)
 {
 	int i;
 
@@ -141,37 +141,27 @@ static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq,
 	qg->new_refcnt += mod;
 }
 
-static inline u64 btrfs_qgroup_get_old_refcnt(struct btrfs_qgroup *qg, u64 seq)
+static inline u64 btrfs_qgroup_get_old_refcnt(const struct btrfs_qgroup *qg, u64 seq)
 {
 	if (qg->old_refcnt < seq)
 		return 0;
 	return qg->old_refcnt - seq;
 }
 
-static inline u64 btrfs_qgroup_get_new_refcnt(struct btrfs_qgroup *qg, u64 seq)
+static inline u64 btrfs_qgroup_get_new_refcnt(const struct btrfs_qgroup *qg, u64 seq)
 {
 	if (qg->new_refcnt < seq)
 		return 0;
 	return qg->new_refcnt - seq;
 }
 
-/*
- * glue structure to represent the relations between qgroups.
- */
-struct btrfs_qgroup_list {
-	struct list_head next_group;
-	struct list_head next_member;
-	struct btrfs_qgroup *group;
-	struct btrfs_qgroup *member;
-};
-
 static int
 qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 		   int init_flags);
 static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info);
 
 /* must be called with qgroup_ioctl_lock held */
-static struct btrfs_qgroup *find_qgroup_rb(struct btrfs_fs_info *fs_info,
+static struct btrfs_qgroup *find_qgroup_rb(const struct btrfs_fs_info *fs_info,
 					   u64 qgroupid)
 {
 	struct rb_node *n = fs_info->qgroup_tree.rb_node;
@@ -346,7 +336,7 @@ static int del_relation_rb(struct btrfs_fs_info *fs_info,
 }
 
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-int btrfs_verify_qgroup_counts(struct btrfs_fs_info *fs_info, u64 qgroupid,
+int btrfs_verify_qgroup_counts(const struct btrfs_fs_info *fs_info, u64 qgroupid,
 			       u64 rfer, u64 excl)
 {
 	struct btrfs_qgroup *qgroup;
@@ -468,6 +458,7 @@ int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 		}
 		if (!qgroup) {
 			struct btrfs_qgroup *prealloc;
+			struct btrfs_root *tree_root = fs_info->tree_root;
 
 			prealloc = kzalloc(sizeof(*prealloc), GFP_KERNEL);
 			if (!prealloc) {
@@ -475,6 +466,25 @@ int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info)
 				goto out;
 			}
 			qgroup = add_qgroup_rb(fs_info, prealloc, found_key.offset);
+			/*
+			 * If a qgroup exists for a subvolume ID, it is possible
+			 * that subvolume has been deleted, in which case
+			 * re-using that ID would lead to incorrect accounting.
+			 *
+			 * Ensure that we skip any such subvol ids.
+			 *
+			 * We don't need to lock because this is only called
+			 * during mount before we start doing things like creating
+			 * subvolumes.
+			 */
+			if (is_fstree(qgroup->qgroupid) &&
+			    qgroup->qgroupid > tree_root->free_objectid)
+				/*
+				 * Don't need to check against BTRFS_LAST_FREE_OBJECTID,
+				 * as it will get checked on the next call to
+				 * btrfs_get_free_objectid.
+				 */
+				tree_root->free_objectid = qgroup->qgroupid + 1;
 		}
 		ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup);
 		if (ret < 0)
@@ -588,7 +598,7 @@ out:
  * Return false if no reserved space is left.
  * Return true if some reserved space is leaked.
  */
-bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info)
+bool btrfs_check_quota_leak(const struct btrfs_fs_info *fs_info)
 {
 	struct rb_node *node;
 	bool ret = false;
@@ -1314,24 +1324,19 @@ out:
  */
 static int flush_reservations(struct btrfs_fs_info *fs_info)
 {
-	struct btrfs_trans_handle *trans;
 	int ret;
 
 	ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false);
 	if (ret)
 		return ret;
-	btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
-	trans = btrfs_join_transaction(fs_info->tree_root);
-	if (IS_ERR(trans))
-		return PTR_ERR(trans);
-	ret = btrfs_commit_transaction(trans);
+	btrfs_wait_ordered_roots(fs_info, U64_MAX, NULL);
 
-	return ret;
+	return btrfs_commit_current_transaction(fs_info->tree_root);
 }
 
 int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
 {
-	struct btrfs_root *quota_root;
+	struct btrfs_root *quota_root = NULL;
 	struct btrfs_trans_handle *trans = NULL;
 	int ret = 0;
 
@@ -1426,12 +1431,14 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
 	btrfs_tree_lock(quota_root->node);
 	btrfs_clear_buffer_dirty(trans, quota_root->node);
 	btrfs_tree_unlock(quota_root->node);
-	btrfs_free_tree_block(trans, btrfs_root_id(quota_root),
-			      quota_root->node, 0, 1);
+	ret = btrfs_free_tree_block(trans, btrfs_root_id(quota_root),
+				    quota_root->node, 0, 1);
 
-	btrfs_put_root(quota_root);
+	if (ret < 0)
+		btrfs_abort_transaction(trans, ret);
 
 out:
+	btrfs_put_root(quota_root);
 	mutex_unlock(&fs_info->qgroup_ioctl_lock);
 	if (ret && trans)
 		btrfs_end_transaction(trans);
@@ -1552,15 +1559,21 @@ out:
 	return ret;
 }
 
-int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, u64 dst)
+/*
+ * Add relation between @src and @dst qgroup. The @prealloc is allocated by the
+ * callers and transferred here (either used or freed on error).
+ */
+int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, u64 dst,
+			      struct btrfs_qgroup_list *prealloc)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_qgroup *parent;
 	struct btrfs_qgroup *member;
 	struct btrfs_qgroup_list *list;
-	struct btrfs_qgroup_list *prealloc = NULL;
 	int ret = 0;
 
+	ASSERT(prealloc);
+
 	/* Check the level of src and dst first */
 	if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
 		return -EINVAL;
@@ -1585,11 +1598,6 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, u64 dst
 		}
 	}
 
-	prealloc = kzalloc(sizeof(*list), GFP_NOFS);
-	if (!prealloc) {
-		ret = -ENOMEM;
-		goto out;
-	}
 	ret = add_qgroup_relation_item(trans, src, dst);
 	if (ret)
 		goto out;
@@ -1728,13 +1736,55 @@ out:
 	return ret;
 }
 
-static bool qgroup_has_usage(struct btrfs_qgroup *qgroup)
+/*
+ * Return 0 if we can not delete the qgroup (not empty or has children etc).
+ * Return >0 if we can delete the qgroup.
+ * Return <0 for other errors during tree search.
+ */
+static int can_delete_qgroup(struct btrfs_fs_info *fs_info, struct btrfs_qgroup *qgroup)
 {
-	return (qgroup->rfer > 0 || qgroup->rfer_cmpr > 0 ||
-		qgroup->excl > 0 || qgroup->excl_cmpr > 0 ||
-		qgroup->rsv.values[BTRFS_QGROUP_RSV_DATA] > 0 ||
-		qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PREALLOC] > 0 ||
-		qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PERTRANS] > 0);
+	struct btrfs_key key;
+	struct btrfs_path *path;
+	int ret;
+
+	/*
+	 * Squota would never be inconsistent, but there can still be case
+	 * where a dropped subvolume still has qgroup numbers, and squota
+	 * relies on such qgroup for future accounting.
+	 *
+	 * So for squota, do not allow dropping any non-zero qgroup.
+	 */
+	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE &&
+	    (qgroup->rfer || qgroup->excl || qgroup->excl_cmpr || qgroup->rfer_cmpr))
+		return 0;
+
+	/* For higher level qgroup, we can only delete it if it has no child. */
+	if (btrfs_qgroup_level(qgroup->qgroupid)) {
+		if (!list_empty(&qgroup->members))
+			return 0;
+		return 1;
+	}
+
+	/*
+	 * For level-0 qgroups, we can only delete it if it has no subvolume
+	 * for it.
+	 * This means even a subvolume is unlinked but not yet fully dropped,
+	 * we can not delete the qgroup.
+	 */
+	key.objectid = qgroup->qgroupid;
+	key.type = BTRFS_ROOT_ITEM_KEY;
+	key.offset = -1ULL;
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	ret = btrfs_find_root(fs_info->tree_root, &key, path, NULL, NULL);
+	btrfs_free_path(path);
+	/*
+	 * The @ret from btrfs_find_root() exactly matches our definition for
+	 * the return value, thus can be returned directly.
+	 */
+	return ret;
 }
 
 int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
@@ -1756,7 +1806,10 @@ int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
 		goto out;
 	}
 
-	if (is_fstree(qgroupid) && qgroup_has_usage(qgroup)) {
+	ret = can_delete_qgroup(fs_info, qgroup);
+	if (ret < 0)
+		goto out;
+	if (ret == 0) {
 		ret = -EBUSY;
 		goto out;
 	}
@@ -1781,6 +1834,34 @@ int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid)
 	}
 
 	spin_lock(&fs_info->qgroup_lock);
+	/*
+	 * Warn on reserved space. The subvolume should has no child nor
+	 * corresponding subvolume.
+	 * Thus its reserved space should all be zero, no matter if qgroup
+	 * is consistent or the mode.
+	 */
+	WARN_ON(qgroup->rsv.values[BTRFS_QGROUP_RSV_DATA] ||
+		qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PREALLOC] ||
+		qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PERTRANS]);
+	/*
+	 * The same for rfer/excl numbers, but that's only if our qgroup is
+	 * consistent and if it's in regular qgroup mode.
+	 * For simple mode it's not as accurate thus we can hit non-zero values
+	 * very frequently.
+	 */
+	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_FULL &&
+	    !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT)) {
+		if (WARN_ON(qgroup->rfer || qgroup->excl ||
+			    qgroup->rfer_cmpr || qgroup->excl_cmpr)) {
+			btrfs_warn_rl(fs_info,
+"to be deleted qgroup %u/%llu has non-zero numbers, rfer %llu rfer_cmpr %llu excl %llu excl_cmpr %llu",
+				      btrfs_qgroup_level(qgroup->qgroupid),
+				      btrfs_qgroup_subvolid(qgroup->qgroupid),
+				      qgroup->rfer, qgroup->rfer_cmpr,
+				      qgroup->excl, qgroup->excl_cmpr);
+			qgroup_mark_inconsistent(fs_info);
+		}
+	}
 	del_qgroup_rb(fs_info, qgroupid);
 	spin_unlock(&fs_info->qgroup_lock);
 
@@ -1796,6 +1877,41 @@ out:
 	return ret;
 }
 
+int btrfs_qgroup_cleanup_dropped_subvolume(struct btrfs_fs_info *fs_info, u64 subvolid)
+{
+	struct btrfs_trans_handle *trans;
+	int ret;
+
+	if (!is_fstree(subvolid) || !btrfs_qgroup_enabled(fs_info) || !fs_info->quota_root)
+		return 0;
+
+	/*
+	 * Commit current transaction to make sure all the rfer/excl numbers
+	 * get updated.
+	 */
+	trans = btrfs_start_transaction(fs_info->quota_root, 0);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+
+	ret = btrfs_commit_transaction(trans);
+	if (ret < 0)
+		return ret;
+
+	/* Start new trans to delete the qgroup info and limit items. */
+	trans = btrfs_start_transaction(fs_info->quota_root, 2);
+	if (IS_ERR(trans))
+		return PTR_ERR(trans);
+	ret = btrfs_remove_qgroup(trans, subvolid);
+	btrfs_end_transaction(trans);
+	/*
+	 * It's squota and the subvolume still has numbers needed for future
+	 * accounting, in this case we can not delete it.  Just skip it.
+	 */
+	if (ret == -EBUSY)
+		ret = 0;
+	return ret;
+}
+
 int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid,
 		       struct btrfs_qgroup_limit *limit)
 {
@@ -3042,8 +3158,6 @@ int btrfs_qgroup_check_inherit(struct btrfs_fs_info *fs_info,
 			       struct btrfs_qgroup_inherit *inherit,
 			       size_t size)
 {
-	if (!btrfs_qgroup_enabled(fs_info))
-		return 0;
 	if (inherit->flags & ~BTRFS_QGROUP_INHERIT_FLAGS_SUPP)
 		return -EOPNOTSUPP;
 	if (size < sizeof(*inherit) || size > PAGE_SIZE)
@@ -3065,6 +3179,14 @@ int btrfs_qgroup_check_inherit(struct btrfs_fs_info *fs_info,
 		return -EINVAL;
 
 	/*
+	 * Skip the inherit source qgroups check if qgroup is not enabled.
+	 * Qgroup can still be later enabled causing problems, but in that case
+	 * btrfs_qgroup_inherit() would just ignore those invalid ones.
+	 */
+	if (!btrfs_qgroup_enabled(fs_info))
+		return 0;
+
+	/*
 	 * Now check all the remaining qgroups, they should all:
 	 *
 	 * - Exist
@@ -3196,7 +3318,6 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 			 struct btrfs_qgroup_inherit *inherit)
 {
 	int ret = 0;
-	int i;
 	u64 *i_qgroups;
 	bool committing = false;
 	struct btrfs_fs_info *fs_info = trans->fs_info;
@@ -3253,7 +3374,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 		i_qgroups = (u64 *)(inherit + 1);
 		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
 		       2 * inherit->num_excl_copies;
-		for (i = 0; i < nums; ++i) {
+		for (int i = 0; i < nums; i++) {
 			srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
 
 			/*
@@ -3280,7 +3401,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 	 */
 	if (inherit) {
 		i_qgroups = (u64 *)(inherit + 1);
-		for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
+		for (int i = 0; i < inherit->num_qgroups; i++, i_qgroups++) {
 			if (*i_qgroups == 0)
 				continue;
 			ret = add_qgroup_relation_item(trans, objectid,
@@ -3366,7 +3487,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 		goto unlock;
 
 	i_qgroups = (u64 *)(inherit + 1);
-	for (i = 0; i < inherit->num_qgroups; ++i) {
+	for (int i = 0; i < inherit->num_qgroups; i++) {
 		if (*i_qgroups) {
 			ret = add_relation_rb(fs_info, qlist_prealloc[i], objectid,
 					      *i_qgroups);
@@ -3386,7 +3507,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 		++i_qgroups;
 	}
 
-	for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
+	for (int i = 0; i < inherit->num_ref_copies; i++, i_qgroups += 2) {
 		struct btrfs_qgroup *src;
 		struct btrfs_qgroup *dst;
 
@@ -3407,7 +3528,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid,
 		/* Manually tweaking numbers certainly needs a rescan */
 		need_rescan = true;
 	}
-	for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
+	for (int i = 0; i < inherit->num_excl_copies; i++, i_qgroups += 2) {
 		struct btrfs_qgroup *src;
 		struct btrfs_qgroup *dst;
 
@@ -3820,14 +3941,14 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 		/* we're resuming qgroup rescan at mount time */
 		if (!(fs_info->qgroup_flags &
 		      BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
-			btrfs_warn(fs_info,
+			btrfs_debug(fs_info,
 			"qgroup rescan init failed, qgroup rescan is not queued");
 			ret = -EINVAL;
 		} else if (!(fs_info->qgroup_flags &
 			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
-			btrfs_warn(fs_info,
+			btrfs_debug(fs_info,
 			"qgroup rescan init failed, qgroup is not enabled");
-			ret = -EINVAL;
+			ret = -ENOTCONN;
 		}
 
 		if (ret)
@@ -3838,14 +3959,12 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
 
 	if (init_flags) {
 		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
-			btrfs_warn(fs_info,
-				   "qgroup rescan is already in progress");
 			ret = -EINPROGRESS;
 		} else if (!(fs_info->qgroup_flags &
 			     BTRFS_QGROUP_STATUS_FLAG_ON)) {
-			btrfs_warn(fs_info,
+			btrfs_debug(fs_info,
 			"qgroup rescan init failed, qgroup is not enabled");
-			ret = -EINVAL;
+			ret = -ENOTCONN;
 		} else if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED) {
 			/* Quota disable is in progress */
 			ret = -EBUSY;
@@ -3894,7 +4013,6 @@ int
 btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
 {
 	int ret = 0;
-	struct btrfs_trans_handle *trans;
 
 	ret = qgroup_rescan_init(fs_info, 0, 1);
 	if (ret)
@@ -3911,16 +4029,10 @@ btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
 	 * going to clear all tracking information for a clean start.
 	 */
 
-	trans = btrfs_attach_transaction_barrier(fs_info->fs_root);
-	if (IS_ERR(trans) && trans != ERR_PTR(-ENOENT)) {
+	ret = btrfs_commit_current_transaction(fs_info->fs_root);
+	if (ret) {
 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
-		return PTR_ERR(trans);
-	} else if (trans != ERR_PTR(-ENOENT)) {
-		ret = btrfs_commit_transaction(trans);
-		if (ret) {
-			fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN;
-			return ret;
-		}
+		return ret;
 	}
 
 	qgroup_rescan_zero_tracking(fs_info);
@@ -4056,7 +4168,6 @@ static int qgroup_unreserve_range(struct btrfs_inode *inode,
  */
 static int try_flush_qgroup(struct btrfs_root *root)
 {
-	struct btrfs_trans_handle *trans;
 	int ret;
 
 	/* Can't hold an open transaction or we run the risk of deadlocking. */
@@ -4077,17 +4188,9 @@ static int try_flush_qgroup(struct btrfs_root *root)
 	ret = btrfs_start_delalloc_snapshot(root, true);
 	if (ret < 0)
 		goto out;
-	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
+	btrfs_wait_ordered_extents(root, U64_MAX, NULL);
 
-	trans = btrfs_attach_transaction_barrier(root);
-	if (IS_ERR(trans)) {
-		ret = PTR_ERR(trans);
-		if (ret == -ENOENT)
-			ret = 0;
-		goto out;
-	}
-
-	ret = btrfs_commit_transaction(trans);
+	ret = btrfs_commit_current_transaction(root);
 out:
 	clear_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state);
 	wake_up(&root->qgroup_flush_wait);
@@ -4793,7 +4896,7 @@ void btrfs_free_squota_rsv(struct btrfs_fs_info *fs_info, u64 root, u64 rsv_byte
 }
 
 int btrfs_record_squota_delta(struct btrfs_fs_info *fs_info,
-			      struct btrfs_squota_delta *delta)
+			      const struct btrfs_squota_delta *delta)
 {
 	int ret;
 	struct btrfs_qgroup *qgroup;