| // SPDX-License-Identifier: GPL-2.0 | 
 | /* | 
 |  * Copyright (C) 2011 STRATO.  All rights reserved. | 
 |  */ | 
 |  | 
 | #include <linux/sched.h> | 
 | #include <linux/pagemap.h> | 
 | #include <linux/writeback.h> | 
 | #include <linux/blkdev.h> | 
 | #include <linux/rbtree.h> | 
 | #include <linux/slab.h> | 
 | #include <linux/workqueue.h> | 
 | #include <linux/btrfs.h> | 
 | #include <linux/sched/mm.h> | 
 |  | 
 | #include "ctree.h" | 
 | #include "transaction.h" | 
 | #include "disk-io.h" | 
 | #include "locking.h" | 
 | #include "ulist.h" | 
 | #include "backref.h" | 
 | #include "extent_io.h" | 
 | #include "qgroup.h" | 
 | #include "block-group.h" | 
 | #include "sysfs.h" | 
 | #include "tree-mod-log.h" | 
 | #include "fs.h" | 
 | #include "accessors.h" | 
 | #include "extent-tree.h" | 
 | #include "root-tree.h" | 
 | #include "tree-checker.h" | 
 |  | 
 | 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; | 
 | 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE) | 
 | 		return BTRFS_QGROUP_MODE_SIMPLE; | 
 | 	return BTRFS_QGROUP_MODE_FULL; | 
 | } | 
 |  | 
 | 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(const struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	return btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_FULL; | 
 | } | 
 |  | 
 | /* | 
 |  * Helpers to access qgroup reservation | 
 |  * | 
 |  * Callers should ensure the lock context and type are valid | 
 |  */ | 
 |  | 
 | static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup) | 
 | { | 
 | 	u64 ret = 0; | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) | 
 | 		ret += qgroup->rsv.values[i]; | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | #ifdef CONFIG_BTRFS_DEBUG | 
 | static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type) | 
 | { | 
 | 	if (type == BTRFS_QGROUP_RSV_DATA) | 
 | 		return "data"; | 
 | 	if (type == BTRFS_QGROUP_RSV_META_PERTRANS) | 
 | 		return "meta_pertrans"; | 
 | 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC) | 
 | 		return "meta_prealloc"; | 
 | 	return NULL; | 
 | } | 
 | #endif | 
 |  | 
 | static void qgroup_rsv_add(struct btrfs_fs_info *fs_info, | 
 | 			   struct btrfs_qgroup *qgroup, u64 num_bytes, | 
 | 			   enum btrfs_qgroup_rsv_type type) | 
 | { | 
 | 	trace_qgroup_update_reserve(fs_info, qgroup, num_bytes, type); | 
 | 	qgroup->rsv.values[type] += num_bytes; | 
 | } | 
 |  | 
 | static void qgroup_rsv_release(struct btrfs_fs_info *fs_info, | 
 | 			       struct btrfs_qgroup *qgroup, u64 num_bytes, | 
 | 			       enum btrfs_qgroup_rsv_type type) | 
 | { | 
 | 	trace_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type); | 
 | 	if (qgroup->rsv.values[type] >= num_bytes) { | 
 | 		qgroup->rsv.values[type] -= num_bytes; | 
 | 		return; | 
 | 	} | 
 | #ifdef CONFIG_BTRFS_DEBUG | 
 | 	WARN_RATELIMIT(1, | 
 | 		"qgroup %llu %s reserved space underflow, have %llu to free %llu", | 
 | 		qgroup->qgroupid, qgroup_rsv_type_str(type), | 
 | 		qgroup->rsv.values[type], num_bytes); | 
 | #endif | 
 | 	qgroup->rsv.values[type] = 0; | 
 | } | 
 |  | 
 | static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info, | 
 | 				     struct btrfs_qgroup *dest, | 
 | 				     const struct btrfs_qgroup *src) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) | 
 | 		qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i); | 
 | } | 
 |  | 
 | static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info, | 
 | 					 struct btrfs_qgroup *dest, | 
 | 					 const struct btrfs_qgroup *src) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) | 
 | 		qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i); | 
 | } | 
 |  | 
 | static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq, | 
 | 					   int mod) | 
 | { | 
 | 	if (qg->old_refcnt < seq) | 
 | 		qg->old_refcnt = seq; | 
 | 	qg->old_refcnt += mod; | 
 | } | 
 |  | 
 | static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq, | 
 | 					   int mod) | 
 | { | 
 | 	if (qg->new_refcnt < seq) | 
 | 		qg->new_refcnt = seq; | 
 | 	qg->new_refcnt += mod; | 
 | } | 
 |  | 
 | 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(const struct btrfs_qgroup *qg, u64 seq) | 
 | { | 
 | 	if (qg->new_refcnt < seq) | 
 | 		return 0; | 
 | 	return qg->new_refcnt - seq; | 
 | } | 
 |  | 
 | 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(const struct btrfs_fs_info *fs_info, | 
 | 					   u64 qgroupid) | 
 | { | 
 | 	struct rb_node *n = fs_info->qgroup_tree.rb_node; | 
 | 	struct btrfs_qgroup *qgroup; | 
 |  | 
 | 	while (n) { | 
 | 		qgroup = rb_entry(n, struct btrfs_qgroup, node); | 
 | 		if (qgroup->qgroupid < qgroupid) | 
 | 			n = n->rb_left; | 
 | 		else if (qgroup->qgroupid > qgroupid) | 
 | 			n = n->rb_right; | 
 | 		else | 
 | 			return qgroup; | 
 | 	} | 
 | 	return NULL; | 
 | } | 
 |  | 
 | /* | 
 |  * Add qgroup to the filesystem's qgroup tree. | 
 |  * | 
 |  * Must be called with qgroup_lock held and @prealloc preallocated. | 
 |  * | 
 |  * The control on the lifespan of @prealloc would be transferred to this | 
 |  * function, thus caller should no longer touch @prealloc. | 
 |  */ | 
 | static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info, | 
 | 					  struct btrfs_qgroup *prealloc, | 
 | 					  u64 qgroupid) | 
 | { | 
 | 	struct rb_node **p = &fs_info->qgroup_tree.rb_node; | 
 | 	struct rb_node *parent = NULL; | 
 | 	struct btrfs_qgroup *qgroup; | 
 |  | 
 | 	/* Caller must have pre-allocated @prealloc. */ | 
 | 	ASSERT(prealloc); | 
 |  | 
 | 	while (*p) { | 
 | 		parent = *p; | 
 | 		qgroup = rb_entry(parent, struct btrfs_qgroup, node); | 
 |  | 
 | 		if (qgroup->qgroupid < qgroupid) { | 
 | 			p = &(*p)->rb_left; | 
 | 		} else if (qgroup->qgroupid > qgroupid) { | 
 | 			p = &(*p)->rb_right; | 
 | 		} else { | 
 | 			kfree(prealloc); | 
 | 			return qgroup; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	qgroup = prealloc; | 
 | 	qgroup->qgroupid = qgroupid; | 
 | 	INIT_LIST_HEAD(&qgroup->groups); | 
 | 	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); | 
 |  | 
 | 	return qgroup; | 
 | } | 
 |  | 
 | static void __del_qgroup_rb(struct btrfs_fs_info *fs_info, | 
 | 			    struct btrfs_qgroup *qgroup) | 
 | { | 
 | 	struct btrfs_qgroup_list *list; | 
 |  | 
 | 	list_del(&qgroup->dirty); | 
 | 	while (!list_empty(&qgroup->groups)) { | 
 | 		list = list_first_entry(&qgroup->groups, | 
 | 					struct btrfs_qgroup_list, next_group); | 
 | 		list_del(&list->next_group); | 
 | 		list_del(&list->next_member); | 
 | 		kfree(list); | 
 | 	} | 
 |  | 
 | 	while (!list_empty(&qgroup->members)) { | 
 | 		list = list_first_entry(&qgroup->members, | 
 | 					struct btrfs_qgroup_list, next_member); | 
 | 		list_del(&list->next_group); | 
 | 		list_del(&list->next_member); | 
 | 		kfree(list); | 
 | 	} | 
 | } | 
 |  | 
 | /* must be called with qgroup_lock held */ | 
 | static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid) | 
 | { | 
 | 	struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid); | 
 |  | 
 | 	if (!qgroup) | 
 | 		return -ENOENT; | 
 |  | 
 | 	rb_erase(&qgroup->node, &fs_info->qgroup_tree); | 
 | 	__del_qgroup_rb(fs_info, qgroup); | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Add relation specified by two qgroups. | 
 |  * | 
 |  * Must be called with qgroup_lock held, the ownership of @prealloc is | 
 |  * transferred to this function and caller should not touch it anymore. | 
 |  * | 
 |  * Return: 0        on success | 
 |  *         -ENOENT  if one of the qgroups is NULL | 
 |  *         <0       other errors | 
 |  */ | 
 | static int __add_relation_rb(struct btrfs_qgroup_list *prealloc, | 
 | 			     struct btrfs_qgroup *member, | 
 | 			     struct btrfs_qgroup *parent) | 
 | { | 
 | 	if (!member || !parent) { | 
 | 		kfree(prealloc); | 
 | 		return -ENOENT; | 
 | 	} | 
 |  | 
 | 	prealloc->group = parent; | 
 | 	prealloc->member = member; | 
 | 	list_add_tail(&prealloc->next_group, &member->groups); | 
 | 	list_add_tail(&prealloc->next_member, &parent->members); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Add relation specified by two qgroup ids. | 
 |  * | 
 |  * Must be called with qgroup_lock held. | 
 |  * | 
 |  * Return: 0        on success | 
 |  *         -ENOENT  if one of the ids does not exist | 
 |  *         <0       other errors | 
 |  */ | 
 | static int add_relation_rb(struct btrfs_fs_info *fs_info, | 
 | 			   struct btrfs_qgroup_list *prealloc, | 
 | 			   u64 memberid, u64 parentid) | 
 | { | 
 | 	struct btrfs_qgroup *member; | 
 | 	struct btrfs_qgroup *parent; | 
 |  | 
 | 	member = find_qgroup_rb(fs_info, memberid); | 
 | 	parent = find_qgroup_rb(fs_info, parentid); | 
 |  | 
 | 	return __add_relation_rb(prealloc, member, parent); | 
 | } | 
 |  | 
 | /* Must be called with qgroup_lock held */ | 
 | static int del_relation_rb(struct btrfs_fs_info *fs_info, | 
 | 			   u64 memberid, u64 parentid) | 
 | { | 
 | 	struct btrfs_qgroup *member; | 
 | 	struct btrfs_qgroup *parent; | 
 | 	struct btrfs_qgroup_list *list; | 
 |  | 
 | 	member = find_qgroup_rb(fs_info, memberid); | 
 | 	parent = find_qgroup_rb(fs_info, parentid); | 
 | 	if (!member || !parent) | 
 | 		return -ENOENT; | 
 |  | 
 | 	list_for_each_entry(list, &member->groups, next_group) { | 
 | 		if (list->group == parent) { | 
 | 			list_del(&list->next_group); | 
 | 			list_del(&list->next_member); | 
 | 			kfree(list); | 
 | 			return 0; | 
 | 		} | 
 | 	} | 
 | 	return -ENOENT; | 
 | } | 
 |  | 
 | #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS | 
 | int btrfs_verify_qgroup_counts(const struct btrfs_fs_info *fs_info, u64 qgroupid, | 
 | 			       u64 rfer, u64 excl) | 
 | { | 
 | 	struct btrfs_qgroup *qgroup; | 
 |  | 
 | 	qgroup = find_qgroup_rb(fs_info, qgroupid); | 
 | 	if (!qgroup) | 
 | 		return -EINVAL; | 
 | 	if (qgroup->rfer != rfer || qgroup->excl != excl) | 
 | 		return -EINVAL; | 
 | 	return 0; | 
 | } | 
 | #endif | 
 |  | 
 | static void qgroup_mark_inconsistent(struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) | 
 | 		return; | 
 | 	fs_info->qgroup_flags |= (BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT | | 
 | 				  BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN | | 
 | 				  BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING); | 
 | } | 
 |  | 
 | static void qgroup_read_enable_gen(struct btrfs_fs_info *fs_info, | 
 | 				   struct extent_buffer *leaf, int slot, | 
 | 				   struct btrfs_qgroup_status_item *ptr) | 
 | { | 
 | 	ASSERT(btrfs_fs_incompat(fs_info, SIMPLE_QUOTA)); | 
 | 	ASSERT(btrfs_item_size(leaf, slot) >= sizeof(*ptr)); | 
 | 	fs_info->qgroup_enable_gen = btrfs_qgroup_status_enable_gen(leaf, ptr); | 
 | } | 
 |  | 
 | /* | 
 |  * The full config is read in one go, only called from open_ctree() | 
 |  * It doesn't use any locking, as at this point we're still single-threaded | 
 |  */ | 
 | int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	struct btrfs_key key; | 
 | 	struct btrfs_key found_key; | 
 | 	struct btrfs_root *quota_root = fs_info->quota_root; | 
 | 	struct btrfs_path *path = NULL; | 
 | 	struct extent_buffer *l; | 
 | 	int slot; | 
 | 	int ret = 0; | 
 | 	u64 flags = 0; | 
 | 	u64 rescan_progress = 0; | 
 |  | 
 | 	if (!fs_info->quota_root) | 
 | 		return 0; | 
 |  | 
 | 	fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL); | 
 | 	if (!fs_info->qgroup_ulist) { | 
 | 		ret = -ENOMEM; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) { | 
 | 		ret = -ENOMEM; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = btrfs_sysfs_add_qgroups(fs_info); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 | 	/* default this to quota off, in case no status key is found */ | 
 | 	fs_info->qgroup_flags = 0; | 
 |  | 
 | 	/* | 
 | 	 * pass 1: read status, all qgroup infos and limits | 
 | 	 */ | 
 | 	key.objectid = 0; | 
 | 	key.type = 0; | 
 | 	key.offset = 0; | 
 | 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1); | 
 | 	if (ret) | 
 | 		goto out; | 
 |  | 
 | 	while (1) { | 
 | 		struct btrfs_qgroup *qgroup; | 
 |  | 
 | 		slot = path->slots[0]; | 
 | 		l = path->nodes[0]; | 
 | 		btrfs_item_key_to_cpu(l, &found_key, slot); | 
 |  | 
 | 		if (found_key.type == BTRFS_QGROUP_STATUS_KEY) { | 
 | 			struct btrfs_qgroup_status_item *ptr; | 
 |  | 
 | 			ptr = btrfs_item_ptr(l, slot, | 
 | 					     struct btrfs_qgroup_status_item); | 
 |  | 
 | 			if (btrfs_qgroup_status_version(l, ptr) != | 
 | 			    BTRFS_QGROUP_STATUS_VERSION) { | 
 | 				btrfs_err(fs_info, | 
 | 				 "old qgroup version, quota disabled"); | 
 | 				goto out; | 
 | 			} | 
 | 			fs_info->qgroup_flags = btrfs_qgroup_status_flags(l, ptr); | 
 | 			if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE) { | 
 | 				qgroup_read_enable_gen(fs_info, l, slot, ptr); | 
 | 			} else if (btrfs_qgroup_status_generation(l, ptr) != fs_info->generation) { | 
 | 				qgroup_mark_inconsistent(fs_info); | 
 | 				btrfs_err(fs_info, | 
 | 					"qgroup generation mismatch, marked as inconsistent"); | 
 | 			} | 
 | 			rescan_progress = btrfs_qgroup_status_rescan(l, ptr); | 
 | 			goto next1; | 
 | 		} | 
 |  | 
 | 		if (found_key.type != BTRFS_QGROUP_INFO_KEY && | 
 | 		    found_key.type != BTRFS_QGROUP_LIMIT_KEY) | 
 | 			goto next1; | 
 |  | 
 | 		qgroup = find_qgroup_rb(fs_info, found_key.offset); | 
 | 		if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) || | 
 | 		    (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) { | 
 | 			btrfs_err(fs_info, "inconsistent qgroup config"); | 
 | 			qgroup_mark_inconsistent(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) { | 
 | 				ret = -ENOMEM; | 
 | 				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) | 
 | 			goto out; | 
 |  | 
 | 		switch (found_key.type) { | 
 | 		case BTRFS_QGROUP_INFO_KEY: { | 
 | 			struct btrfs_qgroup_info_item *ptr; | 
 |  | 
 | 			ptr = btrfs_item_ptr(l, slot, | 
 | 					     struct btrfs_qgroup_info_item); | 
 | 			qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr); | 
 | 			qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr); | 
 | 			qgroup->excl = btrfs_qgroup_info_excl(l, ptr); | 
 | 			qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr); | 
 | 			/* generation currently unused */ | 
 | 			break; | 
 | 		} | 
 | 		case BTRFS_QGROUP_LIMIT_KEY: { | 
 | 			struct btrfs_qgroup_limit_item *ptr; | 
 |  | 
 | 			ptr = btrfs_item_ptr(l, slot, | 
 | 					     struct btrfs_qgroup_limit_item); | 
 | 			qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr); | 
 | 			qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr); | 
 | 			qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr); | 
 | 			qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr); | 
 | 			qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr); | 
 | 			break; | 
 | 		} | 
 | 		} | 
 | next1: | 
 | 		ret = btrfs_next_item(quota_root, path); | 
 | 		if (ret < 0) | 
 | 			goto out; | 
 | 		if (ret) | 
 | 			break; | 
 | 	} | 
 | 	btrfs_release_path(path); | 
 |  | 
 | 	/* | 
 | 	 * pass 2: read all qgroup relations | 
 | 	 */ | 
 | 	key.objectid = 0; | 
 | 	key.type = BTRFS_QGROUP_RELATION_KEY; | 
 | 	key.offset = 0; | 
 | 	ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0); | 
 | 	if (ret) | 
 | 		goto out; | 
 | 	while (1) { | 
 | 		struct btrfs_qgroup_list *list = NULL; | 
 |  | 
 | 		slot = path->slots[0]; | 
 | 		l = path->nodes[0]; | 
 | 		btrfs_item_key_to_cpu(l, &found_key, slot); | 
 |  | 
 | 		if (found_key.type != BTRFS_QGROUP_RELATION_KEY) | 
 | 			goto next2; | 
 |  | 
 | 		if (found_key.objectid > found_key.offset) { | 
 | 			/* parent <- member, not needed to build config */ | 
 | 			/* FIXME should we omit the key completely? */ | 
 | 			goto next2; | 
 | 		} | 
 |  | 
 | 		list = kzalloc(sizeof(*list), GFP_KERNEL); | 
 | 		if (!list) { | 
 | 			ret = -ENOMEM; | 
 | 			goto out; | 
 | 		} | 
 | 		ret = add_relation_rb(fs_info, list, found_key.objectid, | 
 | 				      found_key.offset); | 
 | 		list = NULL; | 
 | 		if (ret == -ENOENT) { | 
 | 			btrfs_warn(fs_info, | 
 | 				"orphan qgroup relation 0x%llx->0x%llx", | 
 | 				found_key.objectid, found_key.offset); | 
 | 			ret = 0;	/* ignore the error */ | 
 | 		} | 
 | 		if (ret) | 
 | 			goto out; | 
 | next2: | 
 | 		ret = btrfs_next_item(quota_root, path); | 
 | 		if (ret < 0) | 
 | 			goto out; | 
 | 		if (ret) | 
 | 			break; | 
 | 	} | 
 | out: | 
 | 	btrfs_free_path(path); | 
 | 	fs_info->qgroup_flags |= flags; | 
 | 	if (ret >= 0) { | 
 | 		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON) | 
 | 			set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); | 
 | 		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) | 
 | 			ret = qgroup_rescan_init(fs_info, rescan_progress, 0); | 
 | 	} else { | 
 | 		ulist_free(fs_info->qgroup_ulist); | 
 | 		fs_info->qgroup_ulist = NULL; | 
 | 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN; | 
 | 		btrfs_sysfs_del_qgroups(fs_info); | 
 | 	} | 
 |  | 
 | 	return ret < 0 ? ret : 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Called in close_ctree() when quota is still enabled.  This verifies we don't | 
 |  * leak some reserved space. | 
 |  * | 
 |  * Return false if no reserved space is left. | 
 |  * Return true if some reserved space is leaked. | 
 |  */ | 
 | bool btrfs_check_quota_leak(const struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	struct rb_node *node; | 
 | 	bool ret = false; | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED) | 
 | 		return ret; | 
 | 	/* | 
 | 	 * Since we're unmounting, there is no race and no need to grab qgroup | 
 | 	 * lock.  And here we don't go post-order to provide a more user | 
 | 	 * friendly sorted result. | 
 | 	 */ | 
 | 	for (node = rb_first(&fs_info->qgroup_tree); node; node = rb_next(node)) { | 
 | 		struct btrfs_qgroup *qgroup; | 
 | 		int i; | 
 |  | 
 | 		qgroup = rb_entry(node, struct btrfs_qgroup, node); | 
 | 		for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) { | 
 | 			if (qgroup->rsv.values[i]) { | 
 | 				ret = true; | 
 | 				btrfs_warn(fs_info, | 
 | 		"qgroup %hu/%llu has unreleased space, type %d rsv %llu", | 
 | 				   btrfs_qgroup_level(qgroup->qgroupid), | 
 | 				   btrfs_qgroup_subvolid(qgroup->qgroupid), | 
 | 				   i, qgroup->rsv.values[i]); | 
 | 			} | 
 | 		} | 
 | 	} | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(), | 
 |  * first two are in single-threaded paths.And for the third one, we have set | 
 |  * quota_root to be null with qgroup_lock held before, so it is safe to clean | 
 |  * up the in-memory structures without qgroup_lock held. | 
 |  */ | 
 | void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	struct rb_node *n; | 
 | 	struct btrfs_qgroup *qgroup; | 
 |  | 
 | 	while ((n = rb_first(&fs_info->qgroup_tree))) { | 
 | 		qgroup = rb_entry(n, struct btrfs_qgroup, node); | 
 | 		rb_erase(n, &fs_info->qgroup_tree); | 
 | 		__del_qgroup_rb(fs_info, qgroup); | 
 | 		btrfs_sysfs_del_one_qgroup(fs_info, qgroup); | 
 | 		kfree(qgroup); | 
 | 	} | 
 | 	/* | 
 | 	 * We call btrfs_free_qgroup_config() when unmounting | 
 | 	 * filesystem and disabling quota, so we set qgroup_ulist | 
 | 	 * to be null here to avoid double free. | 
 | 	 */ | 
 | 	ulist_free(fs_info->qgroup_ulist); | 
 | 	fs_info->qgroup_ulist = NULL; | 
 | 	btrfs_sysfs_del_qgroups(fs_info); | 
 | } | 
 |  | 
 | static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src, | 
 | 				    u64 dst) | 
 | { | 
 | 	int ret; | 
 | 	struct btrfs_root *quota_root = trans->fs_info->quota_root; | 
 | 	struct btrfs_path *path; | 
 | 	struct btrfs_key key; | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	key.objectid = src; | 
 | 	key.type = BTRFS_QGROUP_RELATION_KEY; | 
 | 	key.offset = dst; | 
 |  | 
 | 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, 0); | 
 |  | 
 | 	btrfs_mark_buffer_dirty(trans, path->nodes[0]); | 
 |  | 
 | 	btrfs_free_path(path); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src, | 
 | 				    u64 dst) | 
 | { | 
 | 	int ret; | 
 | 	struct btrfs_root *quota_root = trans->fs_info->quota_root; | 
 | 	struct btrfs_path *path; | 
 | 	struct btrfs_key key; | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	key.objectid = src; | 
 | 	key.type = BTRFS_QGROUP_RELATION_KEY; | 
 | 	key.offset = dst; | 
 |  | 
 | 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 |  | 
 | 	if (ret > 0) { | 
 | 		ret = -ENOENT; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = btrfs_del_item(trans, quota_root, path); | 
 | out: | 
 | 	btrfs_free_path(path); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int add_qgroup_item(struct btrfs_trans_handle *trans, | 
 | 			   struct btrfs_root *quota_root, u64 qgroupid) | 
 | { | 
 | 	int ret; | 
 | 	struct btrfs_path *path; | 
 | 	struct btrfs_qgroup_info_item *qgroup_info; | 
 | 	struct btrfs_qgroup_limit_item *qgroup_limit; | 
 | 	struct extent_buffer *leaf; | 
 | 	struct btrfs_key key; | 
 |  | 
 | 	if (btrfs_is_testing(quota_root->fs_info)) | 
 | 		return 0; | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	key.objectid = 0; | 
 | 	key.type = BTRFS_QGROUP_INFO_KEY; | 
 | 	key.offset = qgroupid; | 
 |  | 
 | 	/* | 
 | 	 * Avoid a transaction abort by catching -EEXIST here. In that | 
 | 	 * case, we proceed by re-initializing the existing structure | 
 | 	 * on disk. | 
 | 	 */ | 
 |  | 
 | 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, | 
 | 				      sizeof(*qgroup_info)); | 
 | 	if (ret && ret != -EEXIST) | 
 | 		goto out; | 
 |  | 
 | 	leaf = path->nodes[0]; | 
 | 	qgroup_info = btrfs_item_ptr(leaf, path->slots[0], | 
 | 				 struct btrfs_qgroup_info_item); | 
 | 	btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid); | 
 | 	btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0); | 
 | 	btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0); | 
 | 	btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0); | 
 | 	btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0); | 
 |  | 
 | 	btrfs_mark_buffer_dirty(trans, leaf); | 
 |  | 
 | 	btrfs_release_path(path); | 
 |  | 
 | 	key.type = BTRFS_QGROUP_LIMIT_KEY; | 
 | 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, | 
 | 				      sizeof(*qgroup_limit)); | 
 | 	if (ret && ret != -EEXIST) | 
 | 		goto out; | 
 |  | 
 | 	leaf = path->nodes[0]; | 
 | 	qgroup_limit = btrfs_item_ptr(leaf, path->slots[0], | 
 | 				  struct btrfs_qgroup_limit_item); | 
 | 	btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0); | 
 | 	btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0); | 
 | 	btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0); | 
 | 	btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0); | 
 | 	btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0); | 
 |  | 
 | 	btrfs_mark_buffer_dirty(trans, leaf); | 
 |  | 
 | 	ret = 0; | 
 | out: | 
 | 	btrfs_free_path(path); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid) | 
 | { | 
 | 	int ret; | 
 | 	struct btrfs_root *quota_root = trans->fs_info->quota_root; | 
 | 	struct btrfs_path *path; | 
 | 	struct btrfs_key key; | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	key.objectid = 0; | 
 | 	key.type = BTRFS_QGROUP_INFO_KEY; | 
 | 	key.offset = qgroupid; | 
 | 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 |  | 
 | 	if (ret > 0) { | 
 | 		ret = -ENOENT; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = btrfs_del_item(trans, quota_root, path); | 
 | 	if (ret) | 
 | 		goto out; | 
 |  | 
 | 	btrfs_release_path(path); | 
 |  | 
 | 	key.type = BTRFS_QGROUP_LIMIT_KEY; | 
 | 	ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 |  | 
 | 	if (ret > 0) { | 
 | 		ret = -ENOENT; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = btrfs_del_item(trans, quota_root, path); | 
 |  | 
 | out: | 
 | 	btrfs_free_path(path); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int update_qgroup_limit_item(struct btrfs_trans_handle *trans, | 
 | 				    struct btrfs_qgroup *qgroup) | 
 | { | 
 | 	struct btrfs_root *quota_root = trans->fs_info->quota_root; | 
 | 	struct btrfs_path *path; | 
 | 	struct btrfs_key key; | 
 | 	struct extent_buffer *l; | 
 | 	struct btrfs_qgroup_limit_item *qgroup_limit; | 
 | 	int ret; | 
 | 	int slot; | 
 |  | 
 | 	key.objectid = 0; | 
 | 	key.type = BTRFS_QGROUP_LIMIT_KEY; | 
 | 	key.offset = qgroup->qgroupid; | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1); | 
 | 	if (ret > 0) | 
 | 		ret = -ENOENT; | 
 |  | 
 | 	if (ret) | 
 | 		goto out; | 
 |  | 
 | 	l = path->nodes[0]; | 
 | 	slot = path->slots[0]; | 
 | 	qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item); | 
 | 	btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags); | 
 | 	btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer); | 
 | 	btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl); | 
 | 	btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer); | 
 | 	btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl); | 
 |  | 
 | 	btrfs_mark_buffer_dirty(trans, l); | 
 |  | 
 | out: | 
 | 	btrfs_free_path(path); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int update_qgroup_info_item(struct btrfs_trans_handle *trans, | 
 | 				   struct btrfs_qgroup *qgroup) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_root *quota_root = fs_info->quota_root; | 
 | 	struct btrfs_path *path; | 
 | 	struct btrfs_key key; | 
 | 	struct extent_buffer *l; | 
 | 	struct btrfs_qgroup_info_item *qgroup_info; | 
 | 	int ret; | 
 | 	int slot; | 
 |  | 
 | 	if (btrfs_is_testing(fs_info)) | 
 | 		return 0; | 
 |  | 
 | 	key.objectid = 0; | 
 | 	key.type = BTRFS_QGROUP_INFO_KEY; | 
 | 	key.offset = qgroup->qgroupid; | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1); | 
 | 	if (ret > 0) | 
 | 		ret = -ENOENT; | 
 |  | 
 | 	if (ret) | 
 | 		goto out; | 
 |  | 
 | 	l = path->nodes[0]; | 
 | 	slot = path->slots[0]; | 
 | 	qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item); | 
 | 	btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid); | 
 | 	btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer); | 
 | 	btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr); | 
 | 	btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl); | 
 | 	btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr); | 
 |  | 
 | 	btrfs_mark_buffer_dirty(trans, l); | 
 |  | 
 | out: | 
 | 	btrfs_free_path(path); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int update_qgroup_status_item(struct btrfs_trans_handle *trans) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_root *quota_root = fs_info->quota_root; | 
 | 	struct btrfs_path *path; | 
 | 	struct btrfs_key key; | 
 | 	struct extent_buffer *l; | 
 | 	struct btrfs_qgroup_status_item *ptr; | 
 | 	int ret; | 
 | 	int slot; | 
 |  | 
 | 	key.objectid = 0; | 
 | 	key.type = BTRFS_QGROUP_STATUS_KEY; | 
 | 	key.offset = 0; | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1); | 
 | 	if (ret > 0) | 
 | 		ret = -ENOENT; | 
 |  | 
 | 	if (ret) | 
 | 		goto out; | 
 |  | 
 | 	l = path->nodes[0]; | 
 | 	slot = path->slots[0]; | 
 | 	ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item); | 
 | 	btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags & | 
 | 				      BTRFS_QGROUP_STATUS_FLAGS_MASK); | 
 | 	btrfs_set_qgroup_status_generation(l, ptr, trans->transid); | 
 | 	btrfs_set_qgroup_status_rescan(l, ptr, | 
 | 				fs_info->qgroup_rescan_progress.objectid); | 
 |  | 
 | 	btrfs_mark_buffer_dirty(trans, l); | 
 |  | 
 | out: | 
 | 	btrfs_free_path(path); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * called with qgroup_lock held | 
 |  */ | 
 | static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans, | 
 | 				  struct btrfs_root *root) | 
 | { | 
 | 	struct btrfs_path *path; | 
 | 	struct btrfs_key key; | 
 | 	struct extent_buffer *leaf = NULL; | 
 | 	int ret; | 
 | 	int nr = 0; | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	key.objectid = 0; | 
 | 	key.offset = 0; | 
 | 	key.type = 0; | 
 |  | 
 | 	while (1) { | 
 | 		ret = btrfs_search_slot(trans, root, &key, path, -1, 1); | 
 | 		if (ret < 0) | 
 | 			goto out; | 
 | 		leaf = path->nodes[0]; | 
 | 		nr = btrfs_header_nritems(leaf); | 
 | 		if (!nr) | 
 | 			break; | 
 | 		/* | 
 | 		 * delete the leaf one by one | 
 | 		 * since the whole tree is going | 
 | 		 * to be deleted. | 
 | 		 */ | 
 | 		path->slots[0] = 0; | 
 | 		ret = btrfs_del_items(trans, root, path, 0, nr); | 
 | 		if (ret) | 
 | 			goto out; | 
 |  | 
 | 		btrfs_release_path(path); | 
 | 	} | 
 | 	ret = 0; | 
 | out: | 
 | 	btrfs_free_path(path); | 
 | 	return ret; | 
 | } | 
 |  | 
 | int btrfs_quota_enable(struct btrfs_fs_info *fs_info, | 
 | 		       struct btrfs_ioctl_quota_ctl_args *quota_ctl_args) | 
 | { | 
 | 	struct btrfs_root *quota_root; | 
 | 	struct btrfs_root *tree_root = fs_info->tree_root; | 
 | 	struct btrfs_path *path = NULL; | 
 | 	struct btrfs_qgroup_status_item *ptr; | 
 | 	struct extent_buffer *leaf; | 
 | 	struct btrfs_key key; | 
 | 	struct btrfs_key found_key; | 
 | 	struct btrfs_qgroup *qgroup = NULL; | 
 | 	struct btrfs_qgroup *prealloc = NULL; | 
 | 	struct btrfs_trans_handle *trans = NULL; | 
 | 	struct ulist *ulist = NULL; | 
 | 	const bool simple = (quota_ctl_args->cmd == BTRFS_QUOTA_CTL_ENABLE_SIMPLE_QUOTA); | 
 | 	int ret = 0; | 
 | 	int slot; | 
 |  | 
 | 	/* | 
 | 	 * We need to have subvol_sem write locked, to prevent races between | 
 | 	 * concurrent tasks trying to enable quotas, because we will unlock | 
 | 	 * and relock qgroup_ioctl_lock before setting fs_info->quota_root | 
 | 	 * and before setting BTRFS_FS_QUOTA_ENABLED. | 
 | 	 */ | 
 | 	lockdep_assert_held_write(&fs_info->subvol_sem); | 
 |  | 
 | 	if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) { | 
 | 		btrfs_err(fs_info, | 
 | 			  "qgroups are currently unsupported in extent tree v2"); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (fs_info->quota_root) | 
 | 		goto out; | 
 |  | 
 | 	ulist = ulist_alloc(GFP_KERNEL); | 
 | 	if (!ulist) { | 
 | 		ret = -ENOMEM; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = btrfs_sysfs_add_qgroups(fs_info); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 |  | 
 | 	/* | 
 | 	 * Unlock qgroup_ioctl_lock before starting the transaction. This is to | 
 | 	 * avoid lock acquisition inversion problems (reported by lockdep) between | 
 | 	 * qgroup_ioctl_lock and the vfs freeze semaphores, acquired when we | 
 | 	 * start a transaction. | 
 | 	 * After we started the transaction lock qgroup_ioctl_lock again and | 
 | 	 * check if someone else created the quota root in the meanwhile. If so, | 
 | 	 * just return success and release the transaction handle. | 
 | 	 * | 
 | 	 * Also we don't need to worry about someone else calling | 
 | 	 * btrfs_sysfs_add_qgroups() after we unlock and getting an error because | 
 | 	 * that function returns 0 (success) when the sysfs entries already exist. | 
 | 	 */ | 
 | 	mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 |  | 
 | 	/* | 
 | 	 * 1 for quota root item | 
 | 	 * 1 for BTRFS_QGROUP_STATUS item | 
 | 	 * | 
 | 	 * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items | 
 | 	 * per subvolume. However those are not currently reserved since it | 
 | 	 * would be a lot of overkill. | 
 | 	 */ | 
 | 	trans = btrfs_start_transaction(tree_root, 2); | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (IS_ERR(trans)) { | 
 | 		ret = PTR_ERR(trans); | 
 | 		trans = NULL; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	if (fs_info->quota_root) | 
 | 		goto out; | 
 |  | 
 | 	fs_info->qgroup_ulist = ulist; | 
 | 	ulist = NULL; | 
 |  | 
 | 	/* | 
 | 	 * initially create the quota tree | 
 | 	 */ | 
 | 	quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID); | 
 | 	if (IS_ERR(quota_root)) { | 
 | 		ret =  PTR_ERR(quota_root); | 
 | 		btrfs_abort_transaction(trans, ret); | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) { | 
 | 		ret = -ENOMEM; | 
 | 		btrfs_abort_transaction(trans, ret); | 
 | 		goto out_free_root; | 
 | 	} | 
 |  | 
 | 	key.objectid = 0; | 
 | 	key.type = BTRFS_QGROUP_STATUS_KEY; | 
 | 	key.offset = 0; | 
 |  | 
 | 	ret = btrfs_insert_empty_item(trans, quota_root, path, &key, | 
 | 				      sizeof(*ptr)); | 
 | 	if (ret) { | 
 | 		btrfs_abort_transaction(trans, ret); | 
 | 		goto out_free_path; | 
 | 	} | 
 |  | 
 | 	leaf = path->nodes[0]; | 
 | 	ptr = btrfs_item_ptr(leaf, path->slots[0], | 
 | 				 struct btrfs_qgroup_status_item); | 
 | 	btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid); | 
 | 	btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION); | 
 | 	fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON; | 
 | 	if (simple) { | 
 | 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE; | 
 | 		btrfs_set_qgroup_status_enable_gen(leaf, ptr, trans->transid); | 
 | 	} else { | 
 | 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; | 
 | 	} | 
 | 	btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags & | 
 | 				      BTRFS_QGROUP_STATUS_FLAGS_MASK); | 
 | 	btrfs_set_qgroup_status_rescan(leaf, ptr, 0); | 
 |  | 
 | 	btrfs_mark_buffer_dirty(trans, leaf); | 
 |  | 
 | 	key.objectid = 0; | 
 | 	key.type = BTRFS_ROOT_REF_KEY; | 
 | 	key.offset = 0; | 
 |  | 
 | 	btrfs_release_path(path); | 
 | 	ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0); | 
 | 	if (ret > 0) | 
 | 		goto out_add_root; | 
 | 	if (ret < 0) { | 
 | 		btrfs_abort_transaction(trans, ret); | 
 | 		goto out_free_path; | 
 | 	} | 
 |  | 
 | 	while (1) { | 
 | 		slot = path->slots[0]; | 
 | 		leaf = path->nodes[0]; | 
 | 		btrfs_item_key_to_cpu(leaf, &found_key, slot); | 
 |  | 
 | 		if (found_key.type == BTRFS_ROOT_REF_KEY) { | 
 |  | 
 | 			/* Release locks on tree_root before we access quota_root */ | 
 | 			btrfs_release_path(path); | 
 |  | 
 | 			/* We should not have a stray @prealloc pointer. */ | 
 | 			ASSERT(prealloc == NULL); | 
 | 			prealloc = kzalloc(sizeof(*prealloc), GFP_NOFS); | 
 | 			if (!prealloc) { | 
 | 				ret = -ENOMEM; | 
 | 				btrfs_abort_transaction(trans, ret); | 
 | 				goto out_free_path; | 
 | 			} | 
 |  | 
 | 			ret = add_qgroup_item(trans, quota_root, | 
 | 					      found_key.offset); | 
 | 			if (ret) { | 
 | 				btrfs_abort_transaction(trans, ret); | 
 | 				goto out_free_path; | 
 | 			} | 
 |  | 
 | 			qgroup = add_qgroup_rb(fs_info, prealloc, found_key.offset); | 
 | 			prealloc = NULL; | 
 | 			if (IS_ERR(qgroup)) { | 
 | 				ret = PTR_ERR(qgroup); | 
 | 				btrfs_abort_transaction(trans, ret); | 
 | 				goto out_free_path; | 
 | 			} | 
 | 			ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup); | 
 | 			if (ret < 0) { | 
 | 				btrfs_abort_transaction(trans, ret); | 
 | 				goto out_free_path; | 
 | 			} | 
 | 			ret = btrfs_search_slot_for_read(tree_root, &found_key, | 
 | 							 path, 1, 0); | 
 | 			if (ret < 0) { | 
 | 				btrfs_abort_transaction(trans, ret); | 
 | 				goto out_free_path; | 
 | 			} | 
 | 			if (ret > 0) { | 
 | 				/* | 
 | 				 * Shouldn't happen, but in case it does we | 
 | 				 * don't need to do the btrfs_next_item, just | 
 | 				 * continue. | 
 | 				 */ | 
 | 				continue; | 
 | 			} | 
 | 		} | 
 | 		ret = btrfs_next_item(tree_root, path); | 
 | 		if (ret < 0) { | 
 | 			btrfs_abort_transaction(trans, ret); | 
 | 			goto out_free_path; | 
 | 		} | 
 | 		if (ret) | 
 | 			break; | 
 | 	} | 
 |  | 
 | out_add_root: | 
 | 	btrfs_release_path(path); | 
 | 	ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID); | 
 | 	if (ret) { | 
 | 		btrfs_abort_transaction(trans, ret); | 
 | 		goto out_free_path; | 
 | 	} | 
 |  | 
 | 	ASSERT(prealloc == NULL); | 
 | 	prealloc = kzalloc(sizeof(*prealloc), GFP_NOFS); | 
 | 	if (!prealloc) { | 
 | 		ret = -ENOMEM; | 
 | 		goto out_free_path; | 
 | 	} | 
 | 	qgroup = add_qgroup_rb(fs_info, prealloc, BTRFS_FS_TREE_OBJECTID); | 
 | 	prealloc = NULL; | 
 | 	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup); | 
 | 	if (ret < 0) { | 
 | 		btrfs_abort_transaction(trans, ret); | 
 | 		goto out_free_path; | 
 | 	} | 
 |  | 
 | 	fs_info->qgroup_enable_gen = trans->transid; | 
 |  | 
 | 	mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 | 	/* | 
 | 	 * Commit the transaction while not holding qgroup_ioctl_lock, to avoid | 
 | 	 * a deadlock with tasks concurrently doing other qgroup operations, such | 
 | 	 * adding/removing qgroups or adding/deleting qgroup relations for example, | 
 | 	 * because all qgroup operations first start or join a transaction and then | 
 | 	 * lock the qgroup_ioctl_lock mutex. | 
 | 	 * We are safe from a concurrent task trying to enable quotas, by calling | 
 | 	 * this function, since we are serialized by fs_info->subvol_sem. | 
 | 	 */ | 
 | 	ret = btrfs_commit_transaction(trans); | 
 | 	trans = NULL; | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (ret) | 
 | 		goto out_free_path; | 
 |  | 
 | 	/* | 
 | 	 * Set quota enabled flag after committing the transaction, to avoid | 
 | 	 * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot | 
 | 	 * creation. | 
 | 	 */ | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	fs_info->quota_root = quota_root; | 
 | 	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); | 
 | 	if (simple) | 
 | 		btrfs_set_fs_incompat(fs_info, SIMPLE_QUOTA); | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 |  | 
 | 	/* Skip rescan for simple qgroups. */ | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) | 
 | 		goto out_free_path; | 
 |  | 
 | 	ret = qgroup_rescan_init(fs_info, 0, 1); | 
 | 	if (!ret) { | 
 | 	        qgroup_rescan_zero_tracking(fs_info); | 
 | 		fs_info->qgroup_rescan_running = true; | 
 | 	        btrfs_queue_work(fs_info->qgroup_rescan_workers, | 
 | 	                         &fs_info->qgroup_rescan_work); | 
 | 	} else { | 
 | 		/* | 
 | 		 * We have set both BTRFS_FS_QUOTA_ENABLED and | 
 | 		 * BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with | 
 | 		 * -EINPROGRESS. That can happen because someone started the | 
 | 		 * rescan worker by calling quota rescan ioctl before we | 
 | 		 * attempted to initialize the rescan worker. Failure due to | 
 | 		 * quotas disabled in the meanwhile is not possible, because | 
 | 		 * we are holding a write lock on fs_info->subvol_sem, which | 
 | 		 * is also acquired when disabling quotas. | 
 | 		 * Ignore such error, and any other error would need to undo | 
 | 		 * everything we did in the transaction we just committed. | 
 | 		 */ | 
 | 		ASSERT(ret == -EINPROGRESS); | 
 | 		ret = 0; | 
 | 	} | 
 |  | 
 | out_free_path: | 
 | 	btrfs_free_path(path); | 
 | out_free_root: | 
 | 	if (ret) | 
 | 		btrfs_put_root(quota_root); | 
 | out: | 
 | 	if (ret) { | 
 | 		ulist_free(fs_info->qgroup_ulist); | 
 | 		fs_info->qgroup_ulist = NULL; | 
 | 		btrfs_sysfs_del_qgroups(fs_info); | 
 | 	} | 
 | 	mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (ret && trans) | 
 | 		btrfs_end_transaction(trans); | 
 | 	else if (trans) | 
 | 		ret = btrfs_end_transaction(trans); | 
 | 	ulist_free(ulist); | 
 | 	kfree(prealloc); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * It is possible to have outstanding ordered extents which reserved bytes | 
 |  * before we disabled. We need to fully flush delalloc, ordered extents, and a | 
 |  * commit to ensure that we don't leak such reservations, only to have them | 
 |  * come back if we re-enable. | 
 |  * | 
 |  * - enable simple quotas | 
 |  * - reserve space | 
 |  * - release it, store rsv_bytes in OE | 
 |  * - disable quotas | 
 |  * - enable simple quotas (qgroup rsv are all 0) | 
 |  * - OE finishes | 
 |  * - run delayed refs | 
 |  * - free rsv_bytes, resulting in miscounting or even underflow | 
 |  */ | 
 | static int flush_reservations(struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	int ret; | 
 |  | 
 | 	ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false); | 
 | 	if (ret) | 
 | 		return ret; | 
 | 	btrfs_wait_ordered_roots(fs_info, U64_MAX, NULL); | 
 |  | 
 | 	return btrfs_commit_current_transaction(fs_info->tree_root); | 
 | } | 
 |  | 
 | int btrfs_quota_disable(struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	struct btrfs_root *quota_root = NULL; | 
 | 	struct btrfs_trans_handle *trans = NULL; | 
 | 	int ret = 0; | 
 |  | 
 | 	/* | 
 | 	 * We need to have subvol_sem write locked to prevent races with | 
 | 	 * snapshot creation. | 
 | 	 */ | 
 | 	lockdep_assert_held_write(&fs_info->subvol_sem); | 
 |  | 
 | 	/* | 
 | 	 * Relocation will mess with backrefs, so make sure we have the | 
 | 	 * cleaner_mutex held to protect us from relocate. | 
 | 	 */ | 
 | 	lockdep_assert_held(&fs_info->cleaner_mutex); | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (!fs_info->quota_root) | 
 | 		goto out; | 
 |  | 
 | 	/* | 
 | 	 * Unlock the qgroup_ioctl_lock mutex before waiting for the rescan worker to | 
 | 	 * complete. Otherwise we can deadlock because btrfs_remove_qgroup() needs | 
 | 	 * to lock that mutex while holding a transaction handle and the rescan | 
 | 	 * worker needs to commit a transaction. | 
 | 	 */ | 
 | 	mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 |  | 
 | 	/* | 
 | 	 * Request qgroup rescan worker to complete and wait for it. This wait | 
 | 	 * must be done before transaction start for quota disable since it may | 
 | 	 * deadlock with transaction by the qgroup rescan worker. | 
 | 	 */ | 
 | 	clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); | 
 | 	btrfs_qgroup_wait_for_completion(fs_info, false); | 
 |  | 
 | 	/* | 
 | 	 * We have nothing held here and no trans handle, just return the error | 
 | 	 * if there is one. | 
 | 	 */ | 
 | 	ret = flush_reservations(fs_info); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	/* | 
 | 	 * 1 For the root item | 
 | 	 * | 
 | 	 * We should also reserve enough items for the quota tree deletion in | 
 | 	 * btrfs_clean_quota_tree but this is not done. | 
 | 	 * | 
 | 	 * Also, we must always start a transaction without holding the mutex | 
 | 	 * qgroup_ioctl_lock, see btrfs_quota_enable(). | 
 | 	 */ | 
 | 	trans = btrfs_start_transaction(fs_info->tree_root, 1); | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (IS_ERR(trans)) { | 
 | 		ret = PTR_ERR(trans); | 
 | 		trans = NULL; | 
 | 		set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	if (!fs_info->quota_root) | 
 | 		goto out; | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	quota_root = fs_info->quota_root; | 
 | 	fs_info->quota_root = NULL; | 
 | 	fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON; | 
 | 	fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE; | 
 | 	fs_info->qgroup_drop_subtree_thres = BTRFS_MAX_LEVEL; | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 |  | 
 | 	btrfs_free_qgroup_config(fs_info); | 
 |  | 
 | 	ret = btrfs_clean_quota_tree(trans, quota_root); | 
 | 	if (ret) { | 
 | 		btrfs_abort_transaction(trans, ret); | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = btrfs_del_root(trans, "a_root->root_key); | 
 | 	if (ret) { | 
 | 		btrfs_abort_transaction(trans, ret); | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	spin_lock(&fs_info->trans_lock); | 
 | 	list_del("a_root->dirty_list); | 
 | 	spin_unlock(&fs_info->trans_lock); | 
 |  | 
 | 	btrfs_tree_lock(quota_root->node); | 
 | 	btrfs_clear_buffer_dirty(trans, quota_root->node); | 
 | 	btrfs_tree_unlock(quota_root->node); | 
 | 	ret = btrfs_free_tree_block(trans, btrfs_root_id(quota_root), | 
 | 				    quota_root->node, 0, 1); | 
 |  | 
 | 	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); | 
 | 	else if (trans) | 
 | 		ret = btrfs_commit_transaction(trans); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static void qgroup_dirty(struct btrfs_fs_info *fs_info, | 
 | 			 struct btrfs_qgroup *qgroup) | 
 | { | 
 | 	if (list_empty(&qgroup->dirty)) | 
 | 		list_add(&qgroup->dirty, &fs_info->dirty_qgroups); | 
 | } | 
 |  | 
 | static void qgroup_iterator_add(struct list_head *head, struct btrfs_qgroup *qgroup) | 
 | { | 
 | 	if (!list_empty(&qgroup->iterator)) | 
 | 		return; | 
 |  | 
 | 	list_add_tail(&qgroup->iterator, head); | 
 | } | 
 |  | 
 | static void qgroup_iterator_clean(struct list_head *head) | 
 | { | 
 | 	while (!list_empty(head)) { | 
 | 		struct btrfs_qgroup *qgroup; | 
 |  | 
 | 		qgroup = list_first_entry(head, struct btrfs_qgroup, iterator); | 
 | 		list_del_init(&qgroup->iterator); | 
 | 	} | 
 | } | 
 |  | 
 | /* | 
 |  * The easy accounting, we're updating qgroup relationship whose child qgroup | 
 |  * only has exclusive extents. | 
 |  * | 
 |  * In this case, all exclusive extents will also be exclusive for parent, so | 
 |  * excl/rfer just get added/removed. | 
 |  * | 
 |  * So is qgroup reservation space, which should also be added/removed to | 
 |  * parent. | 
 |  * Or when child tries to release reservation space, parent will underflow its | 
 |  * reservation (for relationship adding case). | 
 |  * | 
 |  * Caller should hold fs_info->qgroup_lock. | 
 |  */ | 
 | static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info, u64 ref_root, | 
 | 				    struct btrfs_qgroup *src, int sign) | 
 | { | 
 | 	struct btrfs_qgroup *qgroup; | 
 | 	struct btrfs_qgroup *cur; | 
 | 	LIST_HEAD(qgroup_list); | 
 | 	u64 num_bytes = src->excl; | 
 | 	int ret = 0; | 
 |  | 
 | 	qgroup = find_qgroup_rb(fs_info, ref_root); | 
 | 	if (!qgroup) | 
 | 		goto out; | 
 |  | 
 | 	qgroup_iterator_add(&qgroup_list, qgroup); | 
 | 	list_for_each_entry(cur, &qgroup_list, iterator) { | 
 | 		struct btrfs_qgroup_list *glist; | 
 |  | 
 | 		qgroup->rfer += sign * num_bytes; | 
 | 		qgroup->rfer_cmpr += sign * num_bytes; | 
 |  | 
 | 		WARN_ON(sign < 0 && qgroup->excl < num_bytes); | 
 | 		qgroup->excl += sign * num_bytes; | 
 | 		qgroup->excl_cmpr += sign * num_bytes; | 
 |  | 
 | 		if (sign > 0) | 
 | 			qgroup_rsv_add_by_qgroup(fs_info, qgroup, src); | 
 | 		else | 
 | 			qgroup_rsv_release_by_qgroup(fs_info, qgroup, src); | 
 | 		qgroup_dirty(fs_info, qgroup); | 
 |  | 
 | 		/* Append parent qgroups to @qgroup_list. */ | 
 | 		list_for_each_entry(glist, &qgroup->groups, next_group) | 
 | 			qgroup_iterator_add(&qgroup_list, glist->group); | 
 | 	} | 
 | 	ret = 0; | 
 | out: | 
 | 	qgroup_iterator_clean(&qgroup_list); | 
 | 	return ret; | 
 | } | 
 |  | 
 |  | 
 | /* | 
 |  * Quick path for updating qgroup with only excl refs. | 
 |  * | 
 |  * In that case, just update all parent will be enough. | 
 |  * Or we needs to do a full rescan. | 
 |  * Caller should also hold fs_info->qgroup_lock. | 
 |  * | 
 |  * Return 0 for quick update, return >0 for need to full rescan | 
 |  * and mark INCONSISTENT flag. | 
 |  * Return < 0 for other error. | 
 |  */ | 
 | static int quick_update_accounting(struct btrfs_fs_info *fs_info, | 
 | 				   u64 src, u64 dst, int sign) | 
 | { | 
 | 	struct btrfs_qgroup *qgroup; | 
 | 	int ret = 1; | 
 |  | 
 | 	qgroup = find_qgroup_rb(fs_info, src); | 
 | 	if (!qgroup) | 
 | 		goto out; | 
 | 	if (qgroup->excl == qgroup->rfer) { | 
 | 		ret = __qgroup_excl_accounting(fs_info, dst, qgroup, sign); | 
 | 		if (ret < 0) | 
 | 			goto out; | 
 | 		ret = 0; | 
 | 	} | 
 | out: | 
 | 	if (ret) | 
 | 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * 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; | 
 | 	int ret = 0; | 
 |  | 
 | 	ASSERT(prealloc); | 
 |  | 
 | 	/* Check the level of src and dst first */ | 
 | 	if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst)) | 
 | 		return -EINVAL; | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (!fs_info->quota_root) { | 
 | 		ret = -ENOTCONN; | 
 | 		goto out; | 
 | 	} | 
 | 	member = find_qgroup_rb(fs_info, src); | 
 | 	parent = find_qgroup_rb(fs_info, dst); | 
 | 	if (!member || !parent) { | 
 | 		ret = -EINVAL; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	/* check if such qgroup relation exist firstly */ | 
 | 	list_for_each_entry(list, &member->groups, next_group) { | 
 | 		if (list->group == parent) { | 
 | 			ret = -EEXIST; | 
 | 			goto out; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	ret = add_qgroup_relation_item(trans, src, dst); | 
 | 	if (ret) | 
 | 		goto out; | 
 |  | 
 | 	ret = add_qgroup_relation_item(trans, dst, src); | 
 | 	if (ret) { | 
 | 		del_qgroup_relation_item(trans, src, dst); | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	ret = __add_relation_rb(prealloc, member, parent); | 
 | 	prealloc = NULL; | 
 | 	if (ret < 0) { | 
 | 		spin_unlock(&fs_info->qgroup_lock); | 
 | 		goto out; | 
 | 	} | 
 | 	ret = quick_update_accounting(fs_info, src, dst, 1); | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 | out: | 
 | 	kfree(prealloc); | 
 | 	mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, | 
 | 				 u64 dst) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_qgroup *parent; | 
 | 	struct btrfs_qgroup *member; | 
 | 	struct btrfs_qgroup_list *list; | 
 | 	bool found = false; | 
 | 	int ret = 0; | 
 | 	int ret2; | 
 |  | 
 | 	if (!fs_info->quota_root) { | 
 | 		ret = -ENOTCONN; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	member = find_qgroup_rb(fs_info, src); | 
 | 	parent = find_qgroup_rb(fs_info, dst); | 
 | 	/* | 
 | 	 * The parent/member pair doesn't exist, then try to delete the dead | 
 | 	 * relation items only. | 
 | 	 */ | 
 | 	if (!member || !parent) | 
 | 		goto delete_item; | 
 |  | 
 | 	/* check if such qgroup relation exist firstly */ | 
 | 	list_for_each_entry(list, &member->groups, next_group) { | 
 | 		if (list->group == parent) { | 
 | 			found = true; | 
 | 			break; | 
 | 		} | 
 | 	} | 
 |  | 
 | delete_item: | 
 | 	ret = del_qgroup_relation_item(trans, src, dst); | 
 | 	if (ret < 0 && ret != -ENOENT) | 
 | 		goto out; | 
 | 	ret2 = del_qgroup_relation_item(trans, dst, src); | 
 | 	if (ret2 < 0 && ret2 != -ENOENT) | 
 | 		goto out; | 
 |  | 
 | 	/* At least one deletion succeeded, return 0 */ | 
 | 	if (!ret || !ret2) | 
 | 		ret = 0; | 
 |  | 
 | 	if (found) { | 
 | 		spin_lock(&fs_info->qgroup_lock); | 
 | 		del_relation_rb(fs_info, src, dst); | 
 | 		ret = quick_update_accounting(fs_info, src, dst, -1); | 
 | 		spin_unlock(&fs_info->qgroup_lock); | 
 | 	} | 
 | out: | 
 | 	return ret; | 
 | } | 
 |  | 
 | int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, | 
 | 			      u64 dst) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	int ret = 0; | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	ret = __del_qgroup_relation(trans, src, dst); | 
 | 	mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_root *quota_root; | 
 | 	struct btrfs_qgroup *qgroup; | 
 | 	struct btrfs_qgroup *prealloc = NULL; | 
 | 	int ret = 0; | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED) | 
 | 		return 0; | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (!fs_info->quota_root) { | 
 | 		ret = -ENOTCONN; | 
 | 		goto out; | 
 | 	} | 
 | 	quota_root = fs_info->quota_root; | 
 | 	qgroup = find_qgroup_rb(fs_info, qgroupid); | 
 | 	if (qgroup) { | 
 | 		ret = -EEXIST; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	prealloc = kzalloc(sizeof(*prealloc), GFP_NOFS); | 
 | 	if (!prealloc) { | 
 | 		ret = -ENOMEM; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = add_qgroup_item(trans, quota_root, qgroupid); | 
 | 	if (ret) | 
 | 		goto out; | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	qgroup = add_qgroup_rb(fs_info, prealloc, qgroupid); | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 | 	prealloc = NULL; | 
 |  | 
 | 	ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup); | 
 | out: | 
 | 	mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 | 	kfree(prealloc); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * 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) | 
 | { | 
 | 	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) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_qgroup *qgroup; | 
 | 	struct btrfs_qgroup_list *list; | 
 | 	int ret = 0; | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (!fs_info->quota_root) { | 
 | 		ret = -ENOTCONN; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	qgroup = find_qgroup_rb(fs_info, qgroupid); | 
 | 	if (!qgroup) { | 
 | 		ret = -ENOENT; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = can_delete_qgroup(fs_info, qgroup); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 | 	if (ret == 0) { | 
 | 		ret = -EBUSY; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	/* Check if there are no children of this qgroup */ | 
 | 	if (!list_empty(&qgroup->members)) { | 
 | 		ret = -EBUSY; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = del_qgroup_item(trans, qgroupid); | 
 | 	if (ret && ret != -ENOENT) | 
 | 		goto out; | 
 |  | 
 | 	while (!list_empty(&qgroup->groups)) { | 
 | 		list = list_first_entry(&qgroup->groups, | 
 | 					struct btrfs_qgroup_list, next_group); | 
 | 		ret = __del_qgroup_relation(trans, qgroupid, | 
 | 					    list->group->qgroupid); | 
 | 		if (ret) | 
 | 			goto out; | 
 | 	} | 
 |  | 
 | 	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); | 
 |  | 
 | 	/* | 
 | 	 * Remove the qgroup from sysfs now without holding the qgroup_lock | 
 | 	 * spinlock, since the sysfs_remove_group() function needs to take | 
 | 	 * the mutex kernfs_mutex through kernfs_remove_by_name_ns(). | 
 | 	 */ | 
 | 	btrfs_sysfs_del_one_qgroup(fs_info, qgroup); | 
 | 	kfree(qgroup); | 
 | out: | 
 | 	mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 | 	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) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_qgroup *qgroup; | 
 | 	int ret = 0; | 
 | 	/* Sometimes we would want to clear the limit on this qgroup. | 
 | 	 * To meet this requirement, we treat the -1 as a special value | 
 | 	 * which tell kernel to clear the limit on this qgroup. | 
 | 	 */ | 
 | 	const u64 CLEAR_VALUE = -1; | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (!fs_info->quota_root) { | 
 | 		ret = -ENOTCONN; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	qgroup = find_qgroup_rb(fs_info, qgroupid); | 
 | 	if (!qgroup) { | 
 | 		ret = -ENOENT; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) { | 
 | 		if (limit->max_rfer == CLEAR_VALUE) { | 
 | 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER; | 
 | 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER; | 
 | 			qgroup->max_rfer = 0; | 
 | 		} else { | 
 | 			qgroup->max_rfer = limit->max_rfer; | 
 | 		} | 
 | 	} | 
 | 	if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) { | 
 | 		if (limit->max_excl == CLEAR_VALUE) { | 
 | 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL; | 
 | 			limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL; | 
 | 			qgroup->max_excl = 0; | 
 | 		} else { | 
 | 			qgroup->max_excl = limit->max_excl; | 
 | 		} | 
 | 	} | 
 | 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) { | 
 | 		if (limit->rsv_rfer == CLEAR_VALUE) { | 
 | 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER; | 
 | 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER; | 
 | 			qgroup->rsv_rfer = 0; | 
 | 		} else { | 
 | 			qgroup->rsv_rfer = limit->rsv_rfer; | 
 | 		} | 
 | 	} | 
 | 	if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) { | 
 | 		if (limit->rsv_excl == CLEAR_VALUE) { | 
 | 			qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL; | 
 | 			limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL; | 
 | 			qgroup->rsv_excl = 0; | 
 | 		} else { | 
 | 			qgroup->rsv_excl = limit->rsv_excl; | 
 | 		} | 
 | 	} | 
 | 	qgroup->lim_flags |= limit->flags; | 
 |  | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 |  | 
 | 	ret = update_qgroup_limit_item(trans, qgroup); | 
 | 	if (ret) { | 
 | 		qgroup_mark_inconsistent(fs_info); | 
 | 		btrfs_info(fs_info, "unable to update quota limit for %llu", | 
 | 		       qgroupid); | 
 | 	} | 
 |  | 
 | out: | 
 | 	mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * Inform qgroup to trace one dirty extent, its info is recorded in @record. | 
 |  * So qgroup can account it at transaction committing time. | 
 |  * | 
 |  * No lock version, caller must acquire delayed ref lock and allocated memory, | 
 |  * then call btrfs_qgroup_trace_extent_post() after exiting lock context. | 
 |  * | 
 |  * Return 0 for success insert | 
 |  * Return >0 for existing record, caller can free @record safely. | 
 |  * Error is not possible | 
 |  */ | 
 | int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info, | 
 | 				struct btrfs_delayed_ref_root *delayed_refs, | 
 | 				struct btrfs_qgroup_extent_record *record) | 
 | { | 
 | 	struct rb_node **p = &delayed_refs->dirty_extent_root.rb_node; | 
 | 	struct rb_node *parent_node = NULL; | 
 | 	struct btrfs_qgroup_extent_record *entry; | 
 | 	u64 bytenr = record->bytenr; | 
 |  | 
 | 	if (!btrfs_qgroup_full_accounting(fs_info)) | 
 | 		return 1; | 
 |  | 
 | 	lockdep_assert_held(&delayed_refs->lock); | 
 | 	trace_btrfs_qgroup_trace_extent(fs_info, record); | 
 |  | 
 | 	while (*p) { | 
 | 		parent_node = *p; | 
 | 		entry = rb_entry(parent_node, struct btrfs_qgroup_extent_record, | 
 | 				 node); | 
 | 		if (bytenr < entry->bytenr) { | 
 | 			p = &(*p)->rb_left; | 
 | 		} else if (bytenr > entry->bytenr) { | 
 | 			p = &(*p)->rb_right; | 
 | 		} else { | 
 | 			if (record->data_rsv && !entry->data_rsv) { | 
 | 				entry->data_rsv = record->data_rsv; | 
 | 				entry->data_rsv_refroot = | 
 | 					record->data_rsv_refroot; | 
 | 			} | 
 | 			return 1; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	rb_link_node(&record->node, parent_node, p); | 
 | 	rb_insert_color(&record->node, &delayed_refs->dirty_extent_root); | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Post handler after qgroup_trace_extent_nolock(). | 
 |  * | 
 |  * NOTE: Current qgroup does the expensive backref walk at transaction | 
 |  * committing time with TRANS_STATE_COMMIT_DOING, this blocks incoming | 
 |  * new transaction. | 
 |  * This is designed to allow btrfs_find_all_roots() to get correct new_roots | 
 |  * result. | 
 |  * | 
 |  * However for old_roots there is no need to do backref walk at that time, | 
 |  * since we search commit roots to walk backref and result will always be | 
 |  * correct. | 
 |  * | 
 |  * Due to the nature of no lock version, we can't do backref there. | 
 |  * So we must call btrfs_qgroup_trace_extent_post() after exiting | 
 |  * spinlock context. | 
 |  * | 
 |  * TODO: If we can fix and prove btrfs_find_all_roots() can get correct result | 
 |  * using current root, then we can move all expensive backref walk out of | 
 |  * transaction committing, but not now as qgroup accounting will be wrong again. | 
 |  */ | 
 | int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans, | 
 | 				   struct btrfs_qgroup_extent_record *qrecord) | 
 | { | 
 | 	struct btrfs_backref_walk_ctx ctx = { 0 }; | 
 | 	int ret; | 
 |  | 
 | 	if (!btrfs_qgroup_full_accounting(trans->fs_info)) | 
 | 		return 0; | 
 | 	/* | 
 | 	 * We are always called in a context where we are already holding a | 
 | 	 * transaction handle. Often we are called when adding a data delayed | 
 | 	 * reference from btrfs_truncate_inode_items() (truncating or unlinking), | 
 | 	 * in which case we will be holding a write lock on extent buffer from a | 
 | 	 * subvolume tree. In this case we can't allow btrfs_find_all_roots() to | 
 | 	 * acquire fs_info->commit_root_sem, because that is a higher level lock | 
 | 	 * that must be acquired before locking any extent buffers. | 
 | 	 * | 
 | 	 * So we want btrfs_find_all_roots() to not acquire the commit_root_sem | 
 | 	 * but we can't pass it a non-NULL transaction handle, because otherwise | 
 | 	 * it would not use commit roots and would lock extent buffers, causing | 
 | 	 * a deadlock if it ends up trying to read lock the same extent buffer | 
 | 	 * that was previously write locked at btrfs_truncate_inode_items(). | 
 | 	 * | 
 | 	 * So pass a NULL transaction handle to btrfs_find_all_roots() and | 
 | 	 * explicitly tell it to not acquire the commit_root_sem - if we are | 
 | 	 * holding a transaction handle we don't need its protection. | 
 | 	 */ | 
 | 	ASSERT(trans != NULL); | 
 |  | 
 | 	if (trans->fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING) | 
 | 		return 0; | 
 |  | 
 | 	ctx.bytenr = qrecord->bytenr; | 
 | 	ctx.fs_info = trans->fs_info; | 
 |  | 
 | 	ret = btrfs_find_all_roots(&ctx, true); | 
 | 	if (ret < 0) { | 
 | 		qgroup_mark_inconsistent(trans->fs_info); | 
 | 		btrfs_warn(trans->fs_info, | 
 | "error accounting new delayed refs extent (err code: %d), quota inconsistent", | 
 | 			ret); | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * Here we don't need to get the lock of | 
 | 	 * trans->transaction->delayed_refs, since inserted qrecord won't | 
 | 	 * be deleted, only qrecord->node may be modified (new qrecord insert) | 
 | 	 * | 
 | 	 * So modifying qrecord->old_roots is safe here | 
 | 	 */ | 
 | 	qrecord->old_roots = ctx.roots; | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Inform qgroup to trace one dirty extent, specified by @bytenr and | 
 |  * @num_bytes. | 
 |  * So qgroup can account it at commit trans time. | 
 |  * | 
 |  * Better encapsulated version, with memory allocation and backref walk for | 
 |  * commit roots. | 
 |  * So this can sleep. | 
 |  * | 
 |  * Return 0 if the operation is done. | 
 |  * Return <0 for error, like memory allocation failure or invalid parameter | 
 |  * (NULL trans) | 
 |  */ | 
 | int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr, | 
 | 			      u64 num_bytes) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_qgroup_extent_record *record; | 
 | 	struct btrfs_delayed_ref_root *delayed_refs; | 
 | 	int ret; | 
 |  | 
 | 	if (!btrfs_qgroup_full_accounting(fs_info) || bytenr == 0 || num_bytes == 0) | 
 | 		return 0; | 
 | 	record = kzalloc(sizeof(*record), GFP_NOFS); | 
 | 	if (!record) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	delayed_refs = &trans->transaction->delayed_refs; | 
 | 	record->bytenr = bytenr; | 
 | 	record->num_bytes = num_bytes; | 
 | 	record->old_roots = NULL; | 
 |  | 
 | 	spin_lock(&delayed_refs->lock); | 
 | 	ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record); | 
 | 	spin_unlock(&delayed_refs->lock); | 
 | 	if (ret > 0) { | 
 | 		kfree(record); | 
 | 		return 0; | 
 | 	} | 
 | 	return btrfs_qgroup_trace_extent_post(trans, record); | 
 | } | 
 |  | 
 | /* | 
 |  * Inform qgroup to trace all leaf items of data | 
 |  * | 
 |  * Return 0 for success | 
 |  * Return <0 for error(ENOMEM) | 
 |  */ | 
 | int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans, | 
 | 				  struct extent_buffer *eb) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	int nr = btrfs_header_nritems(eb); | 
 | 	int i, extent_type, ret; | 
 | 	struct btrfs_key key; | 
 | 	struct btrfs_file_extent_item *fi; | 
 | 	u64 bytenr, num_bytes; | 
 |  | 
 | 	/* We can be called directly from walk_up_proc() */ | 
 | 	if (!btrfs_qgroup_full_accounting(fs_info)) | 
 | 		return 0; | 
 |  | 
 | 	for (i = 0; i < nr; i++) { | 
 | 		btrfs_item_key_to_cpu(eb, &key, i); | 
 |  | 
 | 		if (key.type != BTRFS_EXTENT_DATA_KEY) | 
 | 			continue; | 
 |  | 
 | 		fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item); | 
 | 		/* filter out non qgroup-accountable extents  */ | 
 | 		extent_type = btrfs_file_extent_type(eb, fi); | 
 |  | 
 | 		if (extent_type == BTRFS_FILE_EXTENT_INLINE) | 
 | 			continue; | 
 |  | 
 | 		bytenr = btrfs_file_extent_disk_bytenr(eb, fi); | 
 | 		if (!bytenr) | 
 | 			continue; | 
 |  | 
 | 		num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi); | 
 |  | 
 | 		ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes); | 
 | 		if (ret) | 
 | 			return ret; | 
 | 	} | 
 | 	cond_resched(); | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Walk up the tree from the bottom, freeing leaves and any interior | 
 |  * nodes which have had all slots visited. If a node (leaf or | 
 |  * interior) is freed, the node above it will have it's slot | 
 |  * incremented. The root node will never be freed. | 
 |  * | 
 |  * At the end of this function, we should have a path which has all | 
 |  * slots incremented to the next position for a search. If we need to | 
 |  * read a new node it will be NULL and the node above it will have the | 
 |  * correct slot selected for a later read. | 
 |  * | 
 |  * If we increment the root nodes slot counter past the number of | 
 |  * elements, 1 is returned to signal completion of the search. | 
 |  */ | 
 | static int adjust_slots_upwards(struct btrfs_path *path, int root_level) | 
 | { | 
 | 	int level = 0; | 
 | 	int nr, slot; | 
 | 	struct extent_buffer *eb; | 
 |  | 
 | 	if (root_level == 0) | 
 | 		return 1; | 
 |  | 
 | 	while (level <= root_level) { | 
 | 		eb = path->nodes[level]; | 
 | 		nr = btrfs_header_nritems(eb); | 
 | 		path->slots[level]++; | 
 | 		slot = path->slots[level]; | 
 | 		if (slot >= nr || level == 0) { | 
 | 			/* | 
 | 			 * Don't free the root -  we will detect this | 
 | 			 * condition after our loop and return a | 
 | 			 * positive value for caller to stop walking the tree. | 
 | 			 */ | 
 | 			if (level != root_level) { | 
 | 				btrfs_tree_unlock_rw(eb, path->locks[level]); | 
 | 				path->locks[level] = 0; | 
 |  | 
 | 				free_extent_buffer(eb); | 
 | 				path->nodes[level] = NULL; | 
 | 				path->slots[level] = 0; | 
 | 			} | 
 | 		} else { | 
 | 			/* | 
 | 			 * We have a valid slot to walk back down | 
 | 			 * from. Stop here so caller can process these | 
 | 			 * new nodes. | 
 | 			 */ | 
 | 			break; | 
 | 		} | 
 |  | 
 | 		level++; | 
 | 	} | 
 |  | 
 | 	eb = path->nodes[root_level]; | 
 | 	if (path->slots[root_level] >= btrfs_header_nritems(eb)) | 
 | 		return 1; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Helper function to trace a subtree tree block swap. | 
 |  * | 
 |  * The swap will happen in highest tree block, but there may be a lot of | 
 |  * tree blocks involved. | 
 |  * | 
 |  * For example: | 
 |  *  OO = Old tree blocks | 
 |  *  NN = New tree blocks allocated during balance | 
 |  * | 
 |  *           File tree (257)                  Reloc tree for 257 | 
 |  * L2              OO                                NN | 
 |  *               /    \                            /    \ | 
 |  * L1          OO      OO (a)                    OO      NN (a) | 
 |  *            / \     / \                       / \     / \ | 
 |  * L0       OO   OO OO   OO                   OO   OO NN   NN | 
 |  *                  (b)  (c)                          (b)  (c) | 
 |  * | 
 |  * When calling qgroup_trace_extent_swap(), we will pass: | 
 |  * @src_eb = OO(a) | 
 |  * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ] | 
 |  * @dst_level = 0 | 
 |  * @root_level = 1 | 
 |  * | 
 |  * In that case, qgroup_trace_extent_swap() will search from OO(a) to | 
 |  * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty. | 
 |  * | 
 |  * The main work of qgroup_trace_extent_swap() can be split into 3 parts: | 
 |  * | 
 |  * 1) Tree search from @src_eb | 
 |  *    It should acts as a simplified btrfs_search_slot(). | 
 |  *    The key for search can be extracted from @dst_path->nodes[dst_level] | 
 |  *    (first key). | 
 |  * | 
 |  * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty | 
 |  *    NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty. | 
 |  *    They should be marked during previous (@dst_level = 1) iteration. | 
 |  * | 
 |  * 3) Mark file extents in leaves dirty | 
 |  *    We don't have good way to pick out new file extents only. | 
 |  *    So we still follow the old method by scanning all file extents in | 
 |  *    the leave. | 
 |  * | 
 |  * This function can free us from keeping two paths, thus later we only need | 
 |  * to care about how to iterate all new tree blocks in reloc tree. | 
 |  */ | 
 | static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans, | 
 | 				    struct extent_buffer *src_eb, | 
 | 				    struct btrfs_path *dst_path, | 
 | 				    int dst_level, int root_level, | 
 | 				    bool trace_leaf) | 
 | { | 
 | 	struct btrfs_key key; | 
 | 	struct btrfs_path *src_path; | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	u32 nodesize = fs_info->nodesize; | 
 | 	int cur_level = root_level; | 
 | 	int ret; | 
 |  | 
 | 	BUG_ON(dst_level > root_level); | 
 | 	/* Level mismatch */ | 
 | 	if (btrfs_header_level(src_eb) != root_level) | 
 | 		return -EINVAL; | 
 |  | 
 | 	src_path = btrfs_alloc_path(); | 
 | 	if (!src_path) { | 
 | 		ret = -ENOMEM; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	if (dst_level) | 
 | 		btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0); | 
 | 	else | 
 | 		btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0); | 
 |  | 
 | 	/* For src_path */ | 
 | 	atomic_inc(&src_eb->refs); | 
 | 	src_path->nodes[root_level] = src_eb; | 
 | 	src_path->slots[root_level] = dst_path->slots[root_level]; | 
 | 	src_path->locks[root_level] = 0; | 
 |  | 
 | 	/* A simplified version of btrfs_search_slot() */ | 
 | 	while (cur_level >= dst_level) { | 
 | 		struct btrfs_key src_key; | 
 | 		struct btrfs_key dst_key; | 
 |  | 
 | 		if (src_path->nodes[cur_level] == NULL) { | 
 | 			struct extent_buffer *eb; | 
 | 			int parent_slot; | 
 |  | 
 | 			eb = src_path->nodes[cur_level + 1]; | 
 | 			parent_slot = src_path->slots[cur_level + 1]; | 
 |  | 
 | 			eb = btrfs_read_node_slot(eb, parent_slot); | 
 | 			if (IS_ERR(eb)) { | 
 | 				ret = PTR_ERR(eb); | 
 | 				goto out; | 
 | 			} | 
 |  | 
 | 			src_path->nodes[cur_level] = eb; | 
 |  | 
 | 			btrfs_tree_read_lock(eb); | 
 | 			src_path->locks[cur_level] = BTRFS_READ_LOCK; | 
 | 		} | 
 |  | 
 | 		src_path->slots[cur_level] = dst_path->slots[cur_level]; | 
 | 		if (cur_level) { | 
 | 			btrfs_node_key_to_cpu(dst_path->nodes[cur_level], | 
 | 					&dst_key, dst_path->slots[cur_level]); | 
 | 			btrfs_node_key_to_cpu(src_path->nodes[cur_level], | 
 | 					&src_key, src_path->slots[cur_level]); | 
 | 		} else { | 
 | 			btrfs_item_key_to_cpu(dst_path->nodes[cur_level], | 
 | 					&dst_key, dst_path->slots[cur_level]); | 
 | 			btrfs_item_key_to_cpu(src_path->nodes[cur_level], | 
 | 					&src_key, src_path->slots[cur_level]); | 
 | 		} | 
 | 		/* Content mismatch, something went wrong */ | 
 | 		if (btrfs_comp_cpu_keys(&dst_key, &src_key)) { | 
 | 			ret = -ENOENT; | 
 | 			goto out; | 
 | 		} | 
 | 		cur_level--; | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * Now both @dst_path and @src_path have been populated, record the tree | 
 | 	 * blocks for qgroup accounting. | 
 | 	 */ | 
 | 	ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start, | 
 | 					nodesize); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 | 	ret = btrfs_qgroup_trace_extent(trans, dst_path->nodes[dst_level]->start, | 
 | 					nodesize); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 |  | 
 | 	/* Record leaf file extents */ | 
 | 	if (dst_level == 0 && trace_leaf) { | 
 | 		ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]); | 
 | 		if (ret < 0) | 
 | 			goto out; | 
 | 		ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]); | 
 | 	} | 
 | out: | 
 | 	btrfs_free_path(src_path); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * Helper function to do recursive generation-aware depth-first search, to | 
 |  * locate all new tree blocks in a subtree of reloc tree. | 
 |  * | 
 |  * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot) | 
 |  *         reloc tree | 
 |  * L2         NN (a) | 
 |  *          /    \ | 
 |  * L1    OO        NN (b) | 
 |  *      /  \      /  \ | 
 |  * L0  OO  OO    OO  NN | 
 |  *               (c) (d) | 
 |  * If we pass: | 
 |  * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ], | 
 |  * @cur_level = 1 | 
 |  * @root_level = 1 | 
 |  * | 
 |  * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace | 
 |  * above tree blocks along with their counter parts in file tree. | 
 |  * While during search, old tree blocks OO(c) will be skipped as tree block swap | 
 |  * won't affect OO(c). | 
 |  */ | 
 | static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans, | 
 | 					   struct extent_buffer *src_eb, | 
 | 					   struct btrfs_path *dst_path, | 
 | 					   int cur_level, int root_level, | 
 | 					   u64 last_snapshot, bool trace_leaf) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct extent_buffer *eb; | 
 | 	bool need_cleanup = false; | 
 | 	int ret = 0; | 
 | 	int i; | 
 |  | 
 | 	/* Level sanity check */ | 
 | 	if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 || | 
 | 	    root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 || | 
 | 	    root_level < cur_level) { | 
 | 		btrfs_err_rl(fs_info, | 
 | 			"%s: bad levels, cur_level=%d root_level=%d", | 
 | 			__func__, cur_level, root_level); | 
 | 		return -EUCLEAN; | 
 | 	} | 
 |  | 
 | 	/* Read the tree block if needed */ | 
 | 	if (dst_path->nodes[cur_level] == NULL) { | 
 | 		int parent_slot; | 
 | 		u64 child_gen; | 
 |  | 
 | 		/* | 
 | 		 * dst_path->nodes[root_level] must be initialized before | 
 | 		 * calling this function. | 
 | 		 */ | 
 | 		if (cur_level == root_level) { | 
 | 			btrfs_err_rl(fs_info, | 
 | 	"%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d", | 
 | 				__func__, root_level, root_level, cur_level); | 
 | 			return -EUCLEAN; | 
 | 		} | 
 |  | 
 | 		/* | 
 | 		 * We need to get child blockptr/gen from parent before we can | 
 | 		 * read it. | 
 | 		  */ | 
 | 		eb = dst_path->nodes[cur_level + 1]; | 
 | 		parent_slot = dst_path->slots[cur_level + 1]; | 
 | 		child_gen = btrfs_node_ptr_generation(eb, parent_slot); | 
 |  | 
 | 		/* This node is old, no need to trace */ | 
 | 		if (child_gen < last_snapshot) | 
 | 			goto out; | 
 |  | 
 | 		eb = btrfs_read_node_slot(eb, parent_slot); | 
 | 		if (IS_ERR(eb)) { | 
 | 			ret = PTR_ERR(eb); | 
 | 			goto out; | 
 | 		} | 
 |  | 
 | 		dst_path->nodes[cur_level] = eb; | 
 | 		dst_path->slots[cur_level] = 0; | 
 |  | 
 | 		btrfs_tree_read_lock(eb); | 
 | 		dst_path->locks[cur_level] = BTRFS_READ_LOCK; | 
 | 		need_cleanup = true; | 
 | 	} | 
 |  | 
 | 	/* Now record this tree block and its counter part for qgroups */ | 
 | 	ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level, | 
 | 				       root_level, trace_leaf); | 
 | 	if (ret < 0) | 
 | 		goto cleanup; | 
 |  | 
 | 	eb = dst_path->nodes[cur_level]; | 
 |  | 
 | 	if (cur_level > 0) { | 
 | 		/* Iterate all child tree blocks */ | 
 | 		for (i = 0; i < btrfs_header_nritems(eb); i++) { | 
 | 			/* Skip old tree blocks as they won't be swapped */ | 
 | 			if (btrfs_node_ptr_generation(eb, i) < last_snapshot) | 
 | 				continue; | 
 | 			dst_path->slots[cur_level] = i; | 
 |  | 
 | 			/* Recursive call (at most 7 times) */ | 
 | 			ret = qgroup_trace_new_subtree_blocks(trans, src_eb, | 
 | 					dst_path, cur_level - 1, root_level, | 
 | 					last_snapshot, trace_leaf); | 
 | 			if (ret < 0) | 
 | 				goto cleanup; | 
 | 		} | 
 | 	} | 
 |  | 
 | cleanup: | 
 | 	if (need_cleanup) { | 
 | 		/* Clean up */ | 
 | 		btrfs_tree_unlock_rw(dst_path->nodes[cur_level], | 
 | 				     dst_path->locks[cur_level]); | 
 | 		free_extent_buffer(dst_path->nodes[cur_level]); | 
 | 		dst_path->nodes[cur_level] = NULL; | 
 | 		dst_path->slots[cur_level] = 0; | 
 | 		dst_path->locks[cur_level] = 0; | 
 | 	} | 
 | out: | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans, | 
 | 				struct extent_buffer *src_eb, | 
 | 				struct extent_buffer *dst_eb, | 
 | 				u64 last_snapshot, bool trace_leaf) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_path *dst_path = NULL; | 
 | 	int level; | 
 | 	int ret; | 
 |  | 
 | 	if (!btrfs_qgroup_full_accounting(fs_info)) | 
 | 		return 0; | 
 |  | 
 | 	/* Wrong parameter order */ | 
 | 	if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) { | 
 | 		btrfs_err_rl(fs_info, | 
 | 		"%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__, | 
 | 			     btrfs_header_generation(src_eb), | 
 | 			     btrfs_header_generation(dst_eb)); | 
 | 		return -EUCLEAN; | 
 | 	} | 
 |  | 
 | 	if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) { | 
 | 		ret = -EIO; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	level = btrfs_header_level(dst_eb); | 
 | 	dst_path = btrfs_alloc_path(); | 
 | 	if (!dst_path) { | 
 | 		ret = -ENOMEM; | 
 | 		goto out; | 
 | 	} | 
 | 	/* For dst_path */ | 
 | 	atomic_inc(&dst_eb->refs); | 
 | 	dst_path->nodes[level] = dst_eb; | 
 | 	dst_path->slots[level] = 0; | 
 | 	dst_path->locks[level] = 0; | 
 |  | 
 | 	/* Do the generation aware breadth-first search */ | 
 | 	ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level, | 
 | 					      level, last_snapshot, trace_leaf); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 | 	ret = 0; | 
 |  | 
 | out: | 
 | 	btrfs_free_path(dst_path); | 
 | 	if (ret < 0) | 
 | 		qgroup_mark_inconsistent(fs_info); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * Inform qgroup to trace a whole subtree, including all its child tree | 
 |  * blocks and data. | 
 |  * The root tree block is specified by @root_eb. | 
 |  * | 
 |  * Normally used by relocation(tree block swap) and subvolume deletion. | 
 |  * | 
 |  * Return 0 for success | 
 |  * Return <0 for error(ENOMEM or tree search error) | 
 |  */ | 
 | int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans, | 
 | 			       struct extent_buffer *root_eb, | 
 | 			       u64 root_gen, int root_level) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	int ret = 0; | 
 | 	int level; | 
 | 	u8 drop_subptree_thres; | 
 | 	struct extent_buffer *eb = root_eb; | 
 | 	struct btrfs_path *path = NULL; | 
 |  | 
 | 	ASSERT(0 <= root_level && root_level < BTRFS_MAX_LEVEL); | 
 | 	ASSERT(root_eb != NULL); | 
 |  | 
 | 	if (!btrfs_qgroup_full_accounting(fs_info)) | 
 | 		return 0; | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	drop_subptree_thres = fs_info->qgroup_drop_subtree_thres; | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 |  | 
 | 	/* | 
 | 	 * This function only gets called for snapshot drop, if we hit a high | 
 | 	 * node here, it means we are going to change ownership for quite a lot | 
 | 	 * of extents, which will greatly slow down btrfs_commit_transaction(). | 
 | 	 * | 
 | 	 * So here if we find a high tree here, we just skip the accounting and | 
 | 	 * mark qgroup inconsistent. | 
 | 	 */ | 
 | 	if (root_level >= drop_subptree_thres) { | 
 | 		qgroup_mark_inconsistent(fs_info); | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	if (!extent_buffer_uptodate(root_eb)) { | 
 | 		struct btrfs_tree_parent_check check = { | 
 | 			.has_first_key = false, | 
 | 			.transid = root_gen, | 
 | 			.level = root_level | 
 | 		}; | 
 |  | 
 | 		ret = btrfs_read_extent_buffer(root_eb, &check); | 
 | 		if (ret) | 
 | 			goto out; | 
 | 	} | 
 |  | 
 | 	if (root_level == 0) { | 
 | 		ret = btrfs_qgroup_trace_leaf_items(trans, root_eb); | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	/* | 
 | 	 * Walk down the tree.  Missing extent blocks are filled in as | 
 | 	 * we go. Metadata is accounted every time we read a new | 
 | 	 * extent block. | 
 | 	 * | 
 | 	 * When we reach a leaf, we account for file extent items in it, | 
 | 	 * walk back up the tree (adjusting slot pointers as we go) | 
 | 	 * and restart the search process. | 
 | 	 */ | 
 | 	atomic_inc(&root_eb->refs);	/* For path */ | 
 | 	path->nodes[root_level] = root_eb; | 
 | 	path->slots[root_level] = 0; | 
 | 	path->locks[root_level] = 0; /* so release_path doesn't try to unlock */ | 
 | walk_down: | 
 | 	level = root_level; | 
 | 	while (level >= 0) { | 
 | 		if (path->nodes[level] == NULL) { | 
 | 			int parent_slot; | 
 | 			u64 child_bytenr; | 
 |  | 
 | 			/* | 
 | 			 * We need to get child blockptr from parent before we | 
 | 			 * can read it. | 
 | 			  */ | 
 | 			eb = path->nodes[level + 1]; | 
 | 			parent_slot = path->slots[level + 1]; | 
 | 			child_bytenr = btrfs_node_blockptr(eb, parent_slot); | 
 |  | 
 | 			eb = btrfs_read_node_slot(eb, parent_slot); | 
 | 			if (IS_ERR(eb)) { | 
 | 				ret = PTR_ERR(eb); | 
 | 				goto out; | 
 | 			} | 
 |  | 
 | 			path->nodes[level] = eb; | 
 | 			path->slots[level] = 0; | 
 |  | 
 | 			btrfs_tree_read_lock(eb); | 
 | 			path->locks[level] = BTRFS_READ_LOCK; | 
 |  | 
 | 			ret = btrfs_qgroup_trace_extent(trans, child_bytenr, | 
 | 							fs_info->nodesize); | 
 | 			if (ret) | 
 | 				goto out; | 
 | 		} | 
 |  | 
 | 		if (level == 0) { | 
 | 			ret = btrfs_qgroup_trace_leaf_items(trans, | 
 | 							    path->nodes[level]); | 
 | 			if (ret) | 
 | 				goto out; | 
 |  | 
 | 			/* Nonzero return here means we completed our search */ | 
 | 			ret = adjust_slots_upwards(path, root_level); | 
 | 			if (ret) | 
 | 				break; | 
 |  | 
 | 			/* Restart search with new slots */ | 
 | 			goto walk_down; | 
 | 		} | 
 |  | 
 | 		level--; | 
 | 	} | 
 |  | 
 | 	ret = 0; | 
 | out: | 
 | 	btrfs_free_path(path); | 
 |  | 
 | 	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 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; | 
 |  | 
 | 	if (!roots) | 
 | 		return; | 
 | 	ULIST_ITER_INIT(&uiter); | 
 | 	while ((unode = ulist_next(roots, &uiter))) { | 
 | 		LIST_HEAD(tmp); | 
 |  | 
 | 		qg = find_qgroup_rb(fs_info, unode->val); | 
 | 		if (!qg) | 
 | 			continue; | 
 |  | 
 | 		qgroup_iterator_nested_add(qgroups, qg); | 
 | 		qgroup_iterator_add(&tmp, qg); | 
 | 		list_for_each_entry(qg, &tmp, iterator) { | 
 | 			struct btrfs_qgroup_list *glist; | 
 |  | 
 | 			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) { | 
 | 				qgroup_iterator_nested_add(qgroups, glist->group); | 
 | 				qgroup_iterator_add(&tmp, glist->group); | 
 | 			} | 
 | 		} | 
 | 		qgroup_iterator_clean(&tmp); | 
 | 	} | 
 | } | 
 |  | 
 | /* | 
 |  * Update qgroup rfer/excl counters. | 
 |  * Rfer update is easy, codes can explain themselves. | 
 |  * | 
 |  * Excl update is tricky, the update is split into 2 parts. | 
 |  * Part 1: Possible exclusive <-> sharing detect: | 
 |  *	|	A	|	!A	| | 
 |  *  ------------------------------------- | 
 |  *  B	|	*	|	-	| | 
 |  *  ------------------------------------- | 
 |  *  !B	|	+	|	**	| | 
 |  *  ------------------------------------- | 
 |  * | 
 |  * Conditions: | 
 |  * A:	cur_old_roots < nr_old_roots	(not exclusive before) | 
 |  * !A:	cur_old_roots == nr_old_roots	(possible exclusive before) | 
 |  * B:	cur_new_roots < nr_new_roots	(not exclusive now) | 
 |  * !B:	cur_new_roots == nr_new_roots	(possible exclusive now) | 
 |  * | 
 |  * Results: | 
 |  * +: Possible sharing -> exclusive	-: Possible exclusive -> sharing | 
 |  * *: Definitely not changed.		**: Possible unchanged. | 
 |  * | 
 |  * For !A and !B condition, the exception is cur_old/new_roots == 0 case. | 
 |  * | 
 |  * To make the logic clear, we first use condition A and B to split | 
 |  * combination into 4 results. | 
 |  * | 
 |  * Then, for result "+" and "-", check old/new_roots == 0 case, as in them | 
 |  * only on variant maybe 0. | 
 |  * | 
 |  * Lastly, check result **, since there are 2 variants maybe 0, split them | 
 |  * again(2x2). | 
 |  * But this time we don't need to consider other things, the codes and logic | 
 |  * is easy to understand now. | 
 |  */ | 
 | 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 btrfs_qgroup *qg; | 
 |  | 
 | 	list_for_each_entry(qg, qgroups, nested_iterator) { | 
 | 		u64 cur_new_count, cur_old_count; | 
 | 		bool dirty = false; | 
 |  | 
 | 		cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq); | 
 | 		cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq); | 
 |  | 
 | 		trace_qgroup_update_counters(fs_info, qg, cur_old_count, | 
 | 					     cur_new_count); | 
 |  | 
 | 		/* Rfer update part */ | 
 | 		if (cur_old_count == 0 && cur_new_count > 0) { | 
 | 			qg->rfer += num_bytes; | 
 | 			qg->rfer_cmpr += num_bytes; | 
 | 			dirty = true; | 
 | 		} | 
 | 		if (cur_old_count > 0 && cur_new_count == 0) { | 
 | 			qg->rfer -= num_bytes; | 
 | 			qg->rfer_cmpr -= num_bytes; | 
 | 			dirty = true; | 
 | 		} | 
 |  | 
 | 		/* Excl update part */ | 
 | 		/* Exclusive/none -> shared case */ | 
 | 		if (cur_old_count == nr_old_roots && | 
 | 		    cur_new_count < nr_new_roots) { | 
 | 			/* Exclusive -> shared */ | 
 | 			if (cur_old_count != 0) { | 
 | 				qg->excl -= num_bytes; | 
 | 				qg->excl_cmpr -= num_bytes; | 
 | 				dirty = true; | 
 | 			} | 
 | 		} | 
 |  | 
 | 		/* Shared -> exclusive/none case */ | 
 | 		if (cur_old_count < nr_old_roots && | 
 | 		    cur_new_count == nr_new_roots) { | 
 | 			/* Shared->exclusive */ | 
 | 			if (cur_new_count != 0) { | 
 | 				qg->excl += num_bytes; | 
 | 				qg->excl_cmpr += num_bytes; | 
 | 				dirty = true; | 
 | 			} | 
 | 		} | 
 |  | 
 | 		/* Exclusive/none -> exclusive/none case */ | 
 | 		if (cur_old_count == nr_old_roots && | 
 | 		    cur_new_count == nr_new_roots) { | 
 | 			if (cur_old_count == 0) { | 
 | 				/* None -> exclusive/none */ | 
 |  | 
 | 				if (cur_new_count != 0) { | 
 | 					/* None -> exclusive */ | 
 | 					qg->excl += num_bytes; | 
 | 					qg->excl_cmpr += num_bytes; | 
 | 					dirty = true; | 
 | 				} | 
 | 				/* None -> none, nothing changed */ | 
 | 			} else { | 
 | 				/* Exclusive -> exclusive/none */ | 
 |  | 
 | 				if (cur_new_count == 0) { | 
 | 					/* Exclusive -> none */ | 
 | 					qg->excl -= num_bytes; | 
 | 					qg->excl_cmpr -= num_bytes; | 
 | 					dirty = true; | 
 | 				} | 
 | 				/* Exclusive -> exclusive, nothing changed */ | 
 | 			} | 
 | 		} | 
 |  | 
 | 		if (dirty) | 
 | 			qgroup_dirty(fs_info, qg); | 
 | 	} | 
 | } | 
 |  | 
 | /* | 
 |  * Check if the @roots potentially is a list of fs tree roots | 
 |  * | 
 |  * Return 0 for definitely not a fs/subvol tree roots ulist | 
 |  * Return 1 for possible fs/subvol tree roots in the list (considering an empty | 
 |  *          one as well) | 
 |  */ | 
 | static int maybe_fs_roots(struct ulist *roots) | 
 | { | 
 | 	struct ulist_node *unode; | 
 | 	struct ulist_iterator uiter; | 
 |  | 
 | 	/* Empty one, still possible for fs roots */ | 
 | 	if (!roots || roots->nnodes == 0) | 
 | 		return 1; | 
 |  | 
 | 	ULIST_ITER_INIT(&uiter); | 
 | 	unode = ulist_next(roots, &uiter); | 
 | 	if (!unode) | 
 | 		return 1; | 
 |  | 
 | 	/* | 
 | 	 * If it contains fs tree roots, then it must belong to fs/subvol | 
 | 	 * trees. | 
 | 	 * If it contains a non-fs tree, it won't be shared with fs/subvol trees. | 
 | 	 */ | 
 | 	return is_fstree(unode->val); | 
 | } | 
 |  | 
 | int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, | 
 | 				u64 num_bytes, struct ulist *old_roots, | 
 | 				struct ulist *new_roots) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	LIST_HEAD(qgroups); | 
 | 	u64 seq; | 
 | 	u64 nr_new_roots = 0; | 
 | 	u64 nr_old_roots = 0; | 
 | 	int ret = 0; | 
 |  | 
 | 	/* | 
 | 	 * If quotas get disabled meanwhile, the resources need to be freed and | 
 | 	 * we can't just exit here. | 
 | 	 */ | 
 | 	if (!btrfs_qgroup_full_accounting(fs_info) || | 
 | 	    fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING) | 
 | 		goto out_free; | 
 |  | 
 | 	if (new_roots) { | 
 | 		if (!maybe_fs_roots(new_roots)) | 
 | 			goto out_free; | 
 | 		nr_new_roots = new_roots->nnodes; | 
 | 	} | 
 | 	if (old_roots) { | 
 | 		if (!maybe_fs_roots(old_roots)) | 
 | 			goto out_free; | 
 | 		nr_old_roots = old_roots->nnodes; | 
 | 	} | 
 |  | 
 | 	/* Quick exit, either not fs tree roots, or won't affect any qgroup */ | 
 | 	if (nr_old_roots == 0 && nr_new_roots == 0) | 
 | 		goto out_free; | 
 |  | 
 | 	trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr, | 
 | 					num_bytes, nr_old_roots, nr_new_roots); | 
 |  | 
 | 	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) { | 
 | 			mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 | 			ret = 0; | 
 | 			goto out_free; | 
 | 		} | 
 | 	} | 
 | 	mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	seq = fs_info->qgroup_seq; | 
 |  | 
 | 	/* Update old refcnts using old_roots */ | 
 | 	qgroup_update_refcnt(fs_info, old_roots, &qgroups, seq, UPDATE_OLD); | 
 |  | 
 | 	/* Update new refcnts using new_roots */ | 
 | 	qgroup_update_refcnt(fs_info, new_roots, &qgroups, seq, UPDATE_NEW); | 
 |  | 
 | 	qgroup_update_counters(fs_info, &qgroups, nr_old_roots, nr_new_roots, | 
 | 			       num_bytes, seq); | 
 |  | 
 | 	/* | 
 | 	 * We're done using the iterator, release all its qgroups while holding | 
 | 	 * fs_info->qgroup_lock so that we don't race with btrfs_remove_qgroup() | 
 | 	 * and trigger use-after-free accesses to qgroups. | 
 | 	 */ | 
 | 	qgroup_iterator_nested_clean(&qgroups); | 
 |  | 
 | 	/* | 
 | 	 * Bump qgroup_seq to avoid seq overlap | 
 | 	 */ | 
 | 	fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1; | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 | out_free: | 
 | 	ulist_free(old_roots); | 
 | 	ulist_free(new_roots); | 
 | 	return ret; | 
 | } | 
 |  | 
 | int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_qgroup_extent_record *record; | 
 | 	struct btrfs_delayed_ref_root *delayed_refs; | 
 | 	struct ulist *new_roots = NULL; | 
 | 	struct rb_node *node; | 
 | 	u64 num_dirty_extents = 0; | 
 | 	u64 qgroup_to_skip; | 
 | 	int ret = 0; | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) | 
 | 		return 0; | 
 |  | 
 | 	delayed_refs = &trans->transaction->delayed_refs; | 
 | 	qgroup_to_skip = delayed_refs->qgroup_to_skip; | 
 | 	while ((node = rb_first(&delayed_refs->dirty_extent_root))) { | 
 | 		record = rb_entry(node, struct btrfs_qgroup_extent_record, | 
 | 				  node); | 
 |  | 
 | 		num_dirty_extents++; | 
 | 		trace_btrfs_qgroup_account_extents(fs_info, record); | 
 |  | 
 | 		if (!ret && !(fs_info->qgroup_flags & | 
 | 			      BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)) { | 
 | 			struct btrfs_backref_walk_ctx ctx = { 0 }; | 
 |  | 
 | 			ctx.bytenr = record->bytenr; | 
 | 			ctx.fs_info = fs_info; | 
 |  | 
 | 			/* | 
 | 			 * Old roots should be searched when inserting qgroup | 
 | 			 * extent record. | 
 | 			 * | 
 | 			 * But for INCONSISTENT (NO_ACCOUNTING) -> rescan case, | 
 | 			 * we may have some record inserted during | 
 | 			 * NO_ACCOUNTING (thus no old_roots populated), but | 
 | 			 * later we start rescan, which clears NO_ACCOUNTING, | 
 | 			 * leaving some inserted records without old_roots | 
 | 			 * populated. | 
 | 			 * | 
 | 			 * Those cases are rare and should not cause too much | 
 | 			 * time spent during commit_transaction(). | 
 | 			 */ | 
 | 			if (!record->old_roots) { | 
 | 				/* Search commit root to find old_roots */ | 
 | 				ret = btrfs_find_all_roots(&ctx, false); | 
 | 				if (ret < 0) | 
 | 					goto cleanup; | 
 | 				record->old_roots = ctx.roots; | 
 | 				ctx.roots = NULL; | 
 | 			} | 
 |  | 
 | 			/* | 
 | 			 * Use BTRFS_SEQ_LAST as time_seq to do special search, | 
 | 			 * which doesn't lock tree or delayed_refs and search | 
 | 			 * current root. It's safe inside commit_transaction(). | 
 | 			 */ | 
 | 			ctx.trans = trans; | 
 | 			ctx.time_seq = BTRFS_SEQ_LAST; | 
 | 			ret = btrfs_find_all_roots(&ctx, false); | 
 | 			if (ret < 0) | 
 | 				goto cleanup; | 
 | 			new_roots = ctx.roots; | 
 | 			if (qgroup_to_skip) { | 
 | 				ulist_del(new_roots, qgroup_to_skip, 0); | 
 | 				ulist_del(record->old_roots, qgroup_to_skip, | 
 | 					  0); | 
 | 			} | 
 | 			ret = btrfs_qgroup_account_extent(trans, record->bytenr, | 
 | 							  record->num_bytes, | 
 | 							  record->old_roots, | 
 | 							  new_roots); | 
 | 			record->old_roots = NULL; | 
 | 			new_roots = NULL; | 
 | 		} | 
 | 		/* Free the reserved data space */ | 
 | 		btrfs_qgroup_free_refroot(fs_info, | 
 | 				record->data_rsv_refroot, | 
 | 				record->data_rsv, | 
 | 				BTRFS_QGROUP_RSV_DATA); | 
 | cleanup: | 
 | 		ulist_free(record->old_roots); | 
 | 		ulist_free(new_roots); | 
 | 		new_roots = NULL; | 
 | 		rb_erase(node, &delayed_refs->dirty_extent_root); | 
 | 		kfree(record); | 
 |  | 
 | 	} | 
 | 	trace_qgroup_num_dirty_extents(fs_info, trans->transid, | 
 | 				       num_dirty_extents); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * Writes all changed qgroups to disk. | 
 |  * Called by the transaction commit path and the qgroup assign ioctl. | 
 |  */ | 
 | int btrfs_run_qgroups(struct btrfs_trans_handle *trans) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	int ret = 0; | 
 |  | 
 | 	/* | 
 | 	 * In case we are called from the qgroup assign ioctl, assert that we | 
 | 	 * are holding the qgroup_ioctl_lock, otherwise we can race with a quota | 
 | 	 * disable operation (ioctl) and access a freed quota root. | 
 | 	 */ | 
 | 	if (trans->transaction->state != TRANS_STATE_COMMIT_DOING) | 
 | 		lockdep_assert_held(&fs_info->qgroup_ioctl_lock); | 
 |  | 
 | 	if (!fs_info->quota_root) | 
 | 		return ret; | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	while (!list_empty(&fs_info->dirty_qgroups)) { | 
 | 		struct btrfs_qgroup *qgroup; | 
 | 		qgroup = list_first_entry(&fs_info->dirty_qgroups, | 
 | 					  struct btrfs_qgroup, dirty); | 
 | 		list_del_init(&qgroup->dirty); | 
 | 		spin_unlock(&fs_info->qgroup_lock); | 
 | 		ret = update_qgroup_info_item(trans, qgroup); | 
 | 		if (ret) | 
 | 			qgroup_mark_inconsistent(fs_info); | 
 | 		ret = update_qgroup_limit_item(trans, qgroup); | 
 | 		if (ret) | 
 | 			qgroup_mark_inconsistent(fs_info); | 
 | 		spin_lock(&fs_info->qgroup_lock); | 
 | 	} | 
 | 	if (btrfs_qgroup_enabled(fs_info)) | 
 | 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON; | 
 | 	else | 
 | 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON; | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 |  | 
 | 	ret = update_qgroup_status_item(trans); | 
 | 	if (ret) | 
 | 		qgroup_mark_inconsistent(fs_info); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | int btrfs_qgroup_check_inherit(struct btrfs_fs_info *fs_info, | 
 | 			       struct btrfs_qgroup_inherit *inherit, | 
 | 			       size_t size) | 
 | { | 
 | 	if (inherit->flags & ~BTRFS_QGROUP_INHERIT_FLAGS_SUPP) | 
 | 		return -EOPNOTSUPP; | 
 | 	if (size < sizeof(*inherit) || size > PAGE_SIZE) | 
 | 		return -EINVAL; | 
 |  | 
 | 	/* | 
 | 	 * In the past we allowed btrfs_qgroup_inherit to specify to copy | 
 | 	 * rfer/excl numbers directly from other qgroups.  This behavior has | 
 | 	 * been disabled in userspace for a very long time, but here we should | 
 | 	 * also disable it in kernel, as this behavior is known to mark qgroup | 
 | 	 * inconsistent, and a rescan would wipe out the changes anyway. | 
 | 	 * | 
 | 	 * Reject any btrfs_qgroup_inherit with num_ref_copies or num_excl_copies. | 
 | 	 */ | 
 | 	if (inherit->num_ref_copies > 0 || inherit->num_excl_copies > 0) | 
 | 		return -EINVAL; | 
 |  | 
 | 	if (size != struct_size(inherit, qgroups, inherit->num_qgroups)) | 
 | 		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 | 
 | 	 * - Be higher level qgroups. | 
 | 	 */ | 
 | 	for (int i = 0; i < inherit->num_qgroups; i++) { | 
 | 		struct btrfs_qgroup *qgroup; | 
 | 		u64 qgroupid = inherit->qgroups[i]; | 
 |  | 
 | 		if (btrfs_qgroup_level(qgroupid) == 0) | 
 | 			return -EINVAL; | 
 |  | 
 | 		spin_lock(&fs_info->qgroup_lock); | 
 | 		qgroup = find_qgroup_rb(fs_info, qgroupid); | 
 | 		if (!qgroup) { | 
 | 			spin_unlock(&fs_info->qgroup_lock); | 
 | 			return -ENOENT; | 
 | 		} | 
 | 		spin_unlock(&fs_info->qgroup_lock); | 
 | 	} | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int qgroup_auto_inherit(struct btrfs_fs_info *fs_info, | 
 | 			       u64 inode_rootid, | 
 | 			       struct btrfs_qgroup_inherit **inherit) | 
 | { | 
 | 	int i = 0; | 
 | 	u64 num_qgroups = 0; | 
 | 	struct btrfs_qgroup *inode_qg; | 
 | 	struct btrfs_qgroup_list *qg_list; | 
 | 	struct btrfs_qgroup_inherit *res; | 
 | 	size_t struct_sz; | 
 | 	u64 *qgids; | 
 |  | 
 | 	if (*inherit) | 
 | 		return -EEXIST; | 
 |  | 
 | 	inode_qg = find_qgroup_rb(fs_info, inode_rootid); | 
 | 	if (!inode_qg) | 
 | 		return -ENOENT; | 
 |  | 
 | 	num_qgroups = list_count_nodes(&inode_qg->groups); | 
 |  | 
 | 	if (!num_qgroups) | 
 | 		return 0; | 
 |  | 
 | 	struct_sz = struct_size(res, qgroups, num_qgroups); | 
 | 	if (struct_sz == SIZE_MAX) | 
 | 		return -ERANGE; | 
 |  | 
 | 	res = kzalloc(struct_sz, GFP_NOFS); | 
 | 	if (!res) | 
 | 		return -ENOMEM; | 
 | 	res->num_qgroups = num_qgroups; | 
 | 	qgids = res->qgroups; | 
 |  | 
 | 	list_for_each_entry(qg_list, &inode_qg->groups, next_group) | 
 | 		qgids[i++] = qg_list->group->qgroupid; | 
 |  | 
 | 	*inherit = res; | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Check if we can skip rescan when inheriting qgroups.  If @src has a single | 
 |  * @parent, and that @parent is owning all its bytes exclusively, we can skip | 
 |  * the full rescan, by just adding nodesize to the @parent's excl/rfer. | 
 |  * | 
 |  * Return <0 for fatal errors (like srcid/parentid has no qgroup). | 
 |  * Return 0 if a quick inherit is done. | 
 |  * Return >0 if a quick inherit is not possible, and a full rescan is needed. | 
 |  */ | 
 | static int qgroup_snapshot_quick_inherit(struct btrfs_fs_info *fs_info, | 
 | 					 u64 srcid, u64 parentid) | 
 | { | 
 | 	struct btrfs_qgroup *src; | 
 | 	struct btrfs_qgroup *parent; | 
 | 	struct btrfs_qgroup_list *list; | 
 | 	int nr_parents = 0; | 
 |  | 
 | 	src = find_qgroup_rb(fs_info, srcid); | 
 | 	if (!src) | 
 | 		return -ENOENT; | 
 | 	parent = find_qgroup_rb(fs_info, parentid); | 
 | 	if (!parent) | 
 | 		return -ENOENT; | 
 |  | 
 | 	/* | 
 | 	 * Source has no parent qgroup, but our new qgroup would have one. | 
 | 	 * Qgroup numbers would become inconsistent. | 
 | 	 */ | 
 | 	if (list_empty(&src->groups)) | 
 | 		return 1; | 
 |  | 
 | 	list_for_each_entry(list, &src->groups, next_group) { | 
 | 		/* The parent is not the same, quick update is not possible. */ | 
 | 		if (list->group->qgroupid != parentid) | 
 | 			return 1; | 
 | 		nr_parents++; | 
 | 		/* | 
 | 		 * More than one parent qgroup, we can't be sure about accounting | 
 | 		 * consistency. | 
 | 		 */ | 
 | 		if (nr_parents > 1) | 
 | 			return 1; | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * The parent is not exclusively owning all its bytes.  We're not sure | 
 | 	 * if the source has any bytes not fully owned by the parent. | 
 | 	 */ | 
 | 	if (parent->excl != parent->rfer) | 
 | 		return 1; | 
 |  | 
 | 	parent->excl += fs_info->nodesize; | 
 | 	parent->rfer += fs_info->nodesize; | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Copy the accounting information between qgroups. This is necessary | 
 |  * when a snapshot or a subvolume is created. Throwing an error will | 
 |  * cause a transaction abort so we take extra care here to only error | 
 |  * when a readonly fs is a reasonable outcome. | 
 |  */ | 
 | int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid, | 
 | 			 u64 objectid, u64 inode_rootid, | 
 | 			 struct btrfs_qgroup_inherit *inherit) | 
 | { | 
 | 	int ret = 0; | 
 | 	u64 *i_qgroups; | 
 | 	bool committing = false; | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_root *quota_root; | 
 | 	struct btrfs_qgroup *srcgroup; | 
 | 	struct btrfs_qgroup *dstgroup; | 
 | 	struct btrfs_qgroup *prealloc; | 
 | 	struct btrfs_qgroup_list **qlist_prealloc = NULL; | 
 | 	bool free_inherit = false; | 
 | 	bool need_rescan = false; | 
 | 	u32 level_size = 0; | 
 | 	u64 nums; | 
 |  | 
 | 	prealloc = kzalloc(sizeof(*prealloc), GFP_NOFS); | 
 | 	if (!prealloc) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	/* | 
 | 	 * There are only two callers of this function. | 
 | 	 * | 
 | 	 * One in create_subvol() in the ioctl context, which needs to hold | 
 | 	 * the qgroup_ioctl_lock. | 
 | 	 * | 
 | 	 * The other one in create_pending_snapshot() where no other qgroup | 
 | 	 * code can modify the fs as they all need to either start a new trans | 
 | 	 * or hold a trans handler, thus we don't need to hold | 
 | 	 * qgroup_ioctl_lock. | 
 | 	 * This would avoid long and complex lock chain and make lockdep happy. | 
 | 	 */ | 
 | 	spin_lock(&fs_info->trans_lock); | 
 | 	if (trans->transaction->state == TRANS_STATE_COMMIT_DOING) | 
 | 		committing = true; | 
 | 	spin_unlock(&fs_info->trans_lock); | 
 |  | 
 | 	if (!committing) | 
 | 		mutex_lock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (!btrfs_qgroup_enabled(fs_info)) | 
 | 		goto out; | 
 |  | 
 | 	quota_root = fs_info->quota_root; | 
 | 	if (!quota_root) { | 
 | 		ret = -EINVAL; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE && !inherit) { | 
 | 		ret = qgroup_auto_inherit(fs_info, inode_rootid, &inherit); | 
 | 		if (ret) | 
 | 			goto out; | 
 | 		free_inherit = true; | 
 | 	} | 
 |  | 
 | 	if (inherit) { | 
 | 		i_qgroups = (u64 *)(inherit + 1); | 
 | 		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies + | 
 | 		       2 * inherit->num_excl_copies; | 
 | 		for (int i = 0; i < nums; i++) { | 
 | 			srcgroup = find_qgroup_rb(fs_info, *i_qgroups); | 
 |  | 
 | 			/* | 
 | 			 * Zero out invalid groups so we can ignore | 
 | 			 * them later. | 
 | 			 */ | 
 | 			if (!srcgroup || | 
 | 			    ((srcgroup->qgroupid >> 48) <= (objectid >> 48))) | 
 | 				*i_qgroups = 0ULL; | 
 |  | 
 | 			++i_qgroups; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * create a tracking group for the subvol itself | 
 | 	 */ | 
 | 	ret = add_qgroup_item(trans, quota_root, objectid); | 
 | 	if (ret) | 
 | 		goto out; | 
 |  | 
 | 	/* | 
 | 	 * add qgroup to all inherited groups | 
 | 	 */ | 
 | 	if (inherit) { | 
 | 		i_qgroups = (u64 *)(inherit + 1); | 
 | 		for (int i = 0; i < inherit->num_qgroups; i++, i_qgroups++) { | 
 | 			if (*i_qgroups == 0) | 
 | 				continue; | 
 | 			ret = add_qgroup_relation_item(trans, objectid, | 
 | 						       *i_qgroups); | 
 | 			if (ret && ret != -EEXIST) | 
 | 				goto out; | 
 | 			ret = add_qgroup_relation_item(trans, *i_qgroups, | 
 | 						       objectid); | 
 | 			if (ret && ret != -EEXIST) | 
 | 				goto out; | 
 | 		} | 
 | 		ret = 0; | 
 |  | 
 | 		qlist_prealloc = kcalloc(inherit->num_qgroups, | 
 | 					 sizeof(struct btrfs_qgroup_list *), | 
 | 					 GFP_NOFS); | 
 | 		if (!qlist_prealloc) { | 
 | 			ret = -ENOMEM; | 
 | 			goto out; | 
 | 		} | 
 | 		for (int i = 0; i < inherit->num_qgroups; i++) { | 
 | 			qlist_prealloc[i] = kzalloc(sizeof(struct btrfs_qgroup_list), | 
 | 						    GFP_NOFS); | 
 | 			if (!qlist_prealloc[i]) { | 
 | 				ret = -ENOMEM; | 
 | 				goto out; | 
 | 			} | 
 | 		} | 
 | 	} | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 |  | 
 | 	dstgroup = add_qgroup_rb(fs_info, prealloc, objectid); | 
 | 	prealloc = NULL; | 
 |  | 
 | 	if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) { | 
 | 		dstgroup->lim_flags = inherit->lim.flags; | 
 | 		dstgroup->max_rfer = inherit->lim.max_rfer; | 
 | 		dstgroup->max_excl = inherit->lim.max_excl; | 
 | 		dstgroup->rsv_rfer = inherit->lim.rsv_rfer; | 
 | 		dstgroup->rsv_excl = inherit->lim.rsv_excl; | 
 |  | 
 | 		qgroup_dirty(fs_info, dstgroup); | 
 | 	} | 
 |  | 
 | 	if (srcid && btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_FULL) { | 
 | 		srcgroup = find_qgroup_rb(fs_info, srcid); | 
 | 		if (!srcgroup) | 
 | 			goto unlock; | 
 |  | 
 | 		/* | 
 | 		 * We call inherit after we clone the root in order to make sure | 
 | 		 * our counts don't go crazy, so at this point the only | 
 | 		 * difference between the two roots should be the root node. | 
 | 		 */ | 
 | 		level_size = fs_info->nodesize; | 
 | 		dstgroup->rfer = srcgroup->rfer; | 
 | 		dstgroup->rfer_cmpr = srcgroup->rfer_cmpr; | 
 | 		dstgroup->excl = level_size; | 
 | 		dstgroup->excl_cmpr = level_size; | 
 | 		srcgroup->excl = level_size; | 
 | 		srcgroup->excl_cmpr = level_size; | 
 |  | 
 | 		/* inherit the limit info */ | 
 | 		dstgroup->lim_flags = srcgroup->lim_flags; | 
 | 		dstgroup->max_rfer = srcgroup->max_rfer; | 
 | 		dstgroup->max_excl = srcgroup->max_excl; | 
 | 		dstgroup->rsv_rfer = srcgroup->rsv_rfer; | 
 | 		dstgroup->rsv_excl = srcgroup->rsv_excl; | 
 |  | 
 | 		qgroup_dirty(fs_info, dstgroup); | 
 | 		qgroup_dirty(fs_info, srcgroup); | 
 |  | 
 | 		/* | 
 | 		 * If the source qgroup has parent but the new one doesn't, | 
 | 		 * we need a full rescan. | 
 | 		 */ | 
 | 		if (!inherit && !list_empty(&srcgroup->groups)) | 
 | 			need_rescan = true; | 
 | 	} | 
 |  | 
 | 	if (!inherit) | 
 | 		goto unlock; | 
 |  | 
 | 	i_qgroups = (u64 *)(inherit + 1); | 
 | 	for (int i = 0; i < inherit->num_qgroups; i++) { | 
 | 		if (*i_qgroups) { | 
 | 			ret = add_relation_rb(fs_info, qlist_prealloc[i], objectid, | 
 | 					      *i_qgroups); | 
 | 			qlist_prealloc[i] = NULL; | 
 | 			if (ret) | 
 | 				goto unlock; | 
 | 		} | 
 | 		if (srcid) { | 
 | 			/* Check if we can do a quick inherit. */ | 
 | 			ret = qgroup_snapshot_quick_inherit(fs_info, srcid, *i_qgroups); | 
 | 			if (ret < 0) | 
 | 				goto unlock; | 
 | 			if (ret > 0) | 
 | 				need_rescan = true; | 
 | 			ret = 0; | 
 | 		} | 
 | 		++i_qgroups; | 
 | 	} | 
 |  | 
 | 	for (int i = 0; i < inherit->num_ref_copies; i++, i_qgroups += 2) { | 
 | 		struct btrfs_qgroup *src; | 
 | 		struct btrfs_qgroup *dst; | 
 |  | 
 | 		if (!i_qgroups[0] || !i_qgroups[1]) | 
 | 			continue; | 
 |  | 
 | 		src = find_qgroup_rb(fs_info, i_qgroups[0]); | 
 | 		dst = find_qgroup_rb(fs_info, i_qgroups[1]); | 
 |  | 
 | 		if (!src || !dst) { | 
 | 			ret = -EINVAL; | 
 | 			goto unlock; | 
 | 		} | 
 |  | 
 | 		dst->rfer = src->rfer - level_size; | 
 | 		dst->rfer_cmpr = src->rfer_cmpr - level_size; | 
 |  | 
 | 		/* Manually tweaking numbers certainly needs a rescan */ | 
 | 		need_rescan = true; | 
 | 	} | 
 | 	for (int i = 0; i < inherit->num_excl_copies; i++, i_qgroups += 2) { | 
 | 		struct btrfs_qgroup *src; | 
 | 		struct btrfs_qgroup *dst; | 
 |  | 
 | 		if (!i_qgroups[0] || !i_qgroups[1]) | 
 | 			continue; | 
 |  | 
 | 		src = find_qgroup_rb(fs_info, i_qgroups[0]); | 
 | 		dst = find_qgroup_rb(fs_info, i_qgroups[1]); | 
 |  | 
 | 		if (!src || !dst) { | 
 | 			ret = -EINVAL; | 
 | 			goto unlock; | 
 | 		} | 
 |  | 
 | 		dst->excl = src->excl + level_size; | 
 | 		dst->excl_cmpr = src->excl_cmpr + level_size; | 
 | 		need_rescan = true; | 
 | 	} | 
 |  | 
 | unlock: | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 | 	if (!ret) | 
 | 		ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup); | 
 | out: | 
 | 	if (!committing) | 
 | 		mutex_unlock(&fs_info->qgroup_ioctl_lock); | 
 | 	if (need_rescan) | 
 | 		qgroup_mark_inconsistent(fs_info); | 
 | 	if (qlist_prealloc) { | 
 | 		for (int i = 0; i < inherit->num_qgroups; i++) | 
 | 			kfree(qlist_prealloc[i]); | 
 | 		kfree(qlist_prealloc); | 
 | 	} | 
 | 	if (free_inherit) | 
 | 		kfree(inherit); | 
 | 	kfree(prealloc); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes) | 
 | { | 
 | 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) && | 
 | 	    qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer) | 
 | 		return false; | 
 |  | 
 | 	if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) && | 
 | 	    qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl) | 
 | 		return false; | 
 |  | 
 | 	return true; | 
 | } | 
 |  | 
 | static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce, | 
 | 			  enum btrfs_qgroup_rsv_type type) | 
 | { | 
 | 	struct btrfs_qgroup *qgroup; | 
 | 	struct btrfs_fs_info *fs_info = root->fs_info; | 
 | 	u64 ref_root = btrfs_root_id(root); | 
 | 	int ret = 0; | 
 | 	LIST_HEAD(qgroup_list); | 
 |  | 
 | 	if (!is_fstree(ref_root)) | 
 | 		return 0; | 
 |  | 
 | 	if (num_bytes == 0) | 
 | 		return 0; | 
 |  | 
 | 	if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) && | 
 | 	    capable(CAP_SYS_RESOURCE)) | 
 | 		enforce = false; | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	if (!fs_info->quota_root) | 
 | 		goto out; | 
 |  | 
 | 	qgroup = find_qgroup_rb(fs_info, ref_root); | 
 | 	if (!qgroup) | 
 | 		goto out; | 
 |  | 
 | 	qgroup_iterator_add(&qgroup_list, qgroup); | 
 | 	list_for_each_entry(qgroup, &qgroup_list, iterator) { | 
 | 		struct btrfs_qgroup_list *glist; | 
 |  | 
 | 		if (enforce && !qgroup_check_limits(qgroup, num_bytes)) { | 
 | 			ret = -EDQUOT; | 
 | 			goto out; | 
 | 		} | 
 |  | 
 | 		list_for_each_entry(glist, &qgroup->groups, next_group) | 
 | 			qgroup_iterator_add(&qgroup_list, glist->group); | 
 | 	} | 
 |  | 
 | 	ret = 0; | 
 | 	/* | 
 | 	 * no limits exceeded, now record the reservation into all qgroups | 
 | 	 */ | 
 | 	list_for_each_entry(qgroup, &qgroup_list, iterator) | 
 | 		qgroup_rsv_add(fs_info, qgroup, num_bytes, type); | 
 |  | 
 | out: | 
 | 	qgroup_iterator_clean(&qgroup_list); | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * Free @num_bytes of reserved space with @type for qgroup.  (Normally level 0 | 
 |  * qgroup). | 
 |  * | 
 |  * Will handle all higher level qgroup too. | 
 |  * | 
 |  * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup. | 
 |  * This special case is only used for META_PERTRANS type. | 
 |  */ | 
 | void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info, | 
 | 			       u64 ref_root, u64 num_bytes, | 
 | 			       enum btrfs_qgroup_rsv_type type) | 
 | { | 
 | 	struct btrfs_qgroup *qgroup; | 
 | 	LIST_HEAD(qgroup_list); | 
 |  | 
 | 	if (!is_fstree(ref_root)) | 
 | 		return; | 
 |  | 
 | 	if (num_bytes == 0) | 
 | 		return; | 
 |  | 
 | 	if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) { | 
 | 		WARN(1, "%s: Invalid type to free", __func__); | 
 | 		return; | 
 | 	} | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 |  | 
 | 	if (!fs_info->quota_root) | 
 | 		goto out; | 
 |  | 
 | 	qgroup = find_qgroup_rb(fs_info, ref_root); | 
 | 	if (!qgroup) | 
 | 		goto out; | 
 |  | 
 | 	if (num_bytes == (u64)-1) | 
 | 		/* | 
 | 		 * We're freeing all pertrans rsv, get reserved value from | 
 | 		 * level 0 qgroup as real num_bytes to free. | 
 | 		 */ | 
 | 		num_bytes = qgroup->rsv.values[type]; | 
 |  | 
 | 	qgroup_iterator_add(&qgroup_list, qgroup); | 
 | 	list_for_each_entry(qgroup, &qgroup_list, iterator) { | 
 | 		struct btrfs_qgroup_list *glist; | 
 |  | 
 | 		qgroup_rsv_release(fs_info, qgroup, num_bytes, type); | 
 | 		list_for_each_entry(glist, &qgroup->groups, next_group) { | 
 | 			qgroup_iterator_add(&qgroup_list, glist->group); | 
 | 		} | 
 | 	} | 
 | out: | 
 | 	qgroup_iterator_clean(&qgroup_list); | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 | } | 
 |  | 
 | /* | 
 |  * Check if the leaf is the last leaf. Which means all node pointers | 
 |  * are at their last position. | 
 |  */ | 
 | static bool is_last_leaf(struct btrfs_path *path) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) { | 
 | 		if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1) | 
 | 			return false; | 
 | 	} | 
 | 	return true; | 
 | } | 
 |  | 
 | /* | 
 |  * returns < 0 on error, 0 when more leafs are to be scanned. | 
 |  * returns 1 when done. | 
 |  */ | 
 | static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans, | 
 | 			      struct btrfs_path *path) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = trans->fs_info; | 
 | 	struct btrfs_root *extent_root; | 
 | 	struct btrfs_key found; | 
 | 	struct extent_buffer *scratch_leaf = NULL; | 
 | 	u64 num_bytes; | 
 | 	bool done; | 
 | 	int slot; | 
 | 	int ret; | 
 |  | 
 | 	if (!btrfs_qgroup_full_accounting(fs_info)) | 
 | 		return 1; | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_rescan_lock); | 
 | 	extent_root = btrfs_extent_root(fs_info, | 
 | 				fs_info->qgroup_rescan_progress.objectid); | 
 | 	ret = btrfs_search_slot_for_read(extent_root, | 
 | 					 &fs_info->qgroup_rescan_progress, | 
 | 					 path, 1, 0); | 
 |  | 
 | 	btrfs_debug(fs_info, | 
 | 		"current progress key (%llu %u %llu), search_slot ret %d", | 
 | 		fs_info->qgroup_rescan_progress.objectid, | 
 | 		fs_info->qgroup_rescan_progress.type, | 
 | 		fs_info->qgroup_rescan_progress.offset, ret); | 
 |  | 
 | 	if (ret) { | 
 | 		/* | 
 | 		 * The rescan is about to end, we will not be scanning any | 
 | 		 * further blocks. We cannot unset the RESCAN flag here, because | 
 | 		 * we want to commit the transaction if everything went well. | 
 | 		 * To make the live accounting work in this phase, we set our | 
 | 		 * scan progress pointer such that every real extent objectid | 
 | 		 * will be smaller. | 
 | 		 */ | 
 | 		fs_info->qgroup_rescan_progress.objectid = (u64)-1; | 
 | 		btrfs_release_path(path); | 
 | 		mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 | 		return ret; | 
 | 	} | 
 | 	done = is_last_leaf(path); | 
 |  | 
 | 	btrfs_item_key_to_cpu(path->nodes[0], &found, | 
 | 			      btrfs_header_nritems(path->nodes[0]) - 1); | 
 | 	fs_info->qgroup_rescan_progress.objectid = found.objectid + 1; | 
 |  | 
 | 	scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]); | 
 | 	if (!scratch_leaf) { | 
 | 		ret = -ENOMEM; | 
 | 		mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 | 		goto out; | 
 | 	} | 
 | 	slot = path->slots[0]; | 
 | 	btrfs_release_path(path); | 
 | 	mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 |  | 
 | 	for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) { | 
 | 		struct btrfs_backref_walk_ctx ctx = { 0 }; | 
 |  | 
 | 		btrfs_item_key_to_cpu(scratch_leaf, &found, slot); | 
 | 		if (found.type != BTRFS_EXTENT_ITEM_KEY && | 
 | 		    found.type != BTRFS_METADATA_ITEM_KEY) | 
 | 			continue; | 
 | 		if (found.type == BTRFS_METADATA_ITEM_KEY) | 
 | 			num_bytes = fs_info->nodesize; | 
 | 		else | 
 | 			num_bytes = found.offset; | 
 |  | 
 | 		ctx.bytenr = found.objectid; | 
 | 		ctx.fs_info = fs_info; | 
 |  | 
 | 		ret = btrfs_find_all_roots(&ctx, false); | 
 | 		if (ret < 0) | 
 | 			goto out; | 
 | 		/* For rescan, just pass old_roots as NULL */ | 
 | 		ret = btrfs_qgroup_account_extent(trans, found.objectid, | 
 | 						  num_bytes, NULL, ctx.roots); | 
 | 		if (ret < 0) | 
 | 			goto out; | 
 | 	} | 
 | out: | 
 | 	if (scratch_leaf) | 
 | 		free_extent_buffer(scratch_leaf); | 
 |  | 
 | 	if (done && !ret) { | 
 | 		ret = 1; | 
 | 		fs_info->qgroup_rescan_progress.objectid = (u64)-1; | 
 | 	} | 
 | 	return ret; | 
 | } | 
 |  | 
 | static bool rescan_should_stop(struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	if (btrfs_fs_closing(fs_info)) | 
 | 		return true; | 
 | 	if (test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state)) | 
 | 		return true; | 
 | 	if (!btrfs_qgroup_enabled(fs_info)) | 
 | 		return true; | 
 | 	if (fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN) | 
 | 		return true; | 
 | 	return false; | 
 | } | 
 |  | 
 | static void btrfs_qgroup_rescan_worker(struct btrfs_work *work) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info, | 
 | 						     qgroup_rescan_work); | 
 | 	struct btrfs_path *path; | 
 | 	struct btrfs_trans_handle *trans = NULL; | 
 | 	int ret = 0; | 
 | 	bool stopped = false; | 
 | 	bool did_leaf_rescans = false; | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) | 
 | 		return; | 
 |  | 
 | 	path = btrfs_alloc_path(); | 
 | 	if (!path) { | 
 | 		ret = -ENOMEM; | 
 | 		goto out; | 
 | 	} | 
 | 	/* | 
 | 	 * Rescan should only search for commit root, and any later difference | 
 | 	 * should be recorded by qgroup | 
 | 	 */ | 
 | 	path->search_commit_root = 1; | 
 | 	path->skip_locking = 1; | 
 |  | 
 | 	while (!ret && !(stopped = rescan_should_stop(fs_info))) { | 
 | 		trans = btrfs_start_transaction(fs_info->fs_root, 0); | 
 | 		if (IS_ERR(trans)) { | 
 | 			ret = PTR_ERR(trans); | 
 | 			break; | 
 | 		} | 
 |  | 
 | 		ret = qgroup_rescan_leaf(trans, path); | 
 | 		did_leaf_rescans = true; | 
 |  | 
 | 		if (ret > 0) | 
 | 			btrfs_commit_transaction(trans); | 
 | 		else | 
 | 			btrfs_end_transaction(trans); | 
 | 	} | 
 |  | 
 | out: | 
 | 	btrfs_free_path(path); | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_rescan_lock); | 
 | 	if (ret > 0 && | 
 | 	    fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) { | 
 | 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; | 
 | 	} else if (ret < 0 || stopped) { | 
 | 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; | 
 | 	} | 
 | 	mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 |  | 
 | 	/* | 
 | 	 * Only update status, since the previous part has already updated the | 
 | 	 * qgroup info, and only if we did any actual work. This also prevents | 
 | 	 * race with a concurrent quota disable, which has already set | 
 | 	 * fs_info->quota_root to NULL and cleared BTRFS_FS_QUOTA_ENABLED at | 
 | 	 * btrfs_quota_disable(). | 
 | 	 */ | 
 | 	if (did_leaf_rescans) { | 
 | 		trans = btrfs_start_transaction(fs_info->quota_root, 1); | 
 | 		if (IS_ERR(trans)) { | 
 | 			ret = PTR_ERR(trans); | 
 | 			trans = NULL; | 
 | 			btrfs_err(fs_info, | 
 | 				  "fail to start transaction for status update: %d", | 
 | 				  ret); | 
 | 		} | 
 | 	} else { | 
 | 		trans = NULL; | 
 | 	} | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_rescan_lock); | 
 | 	if (!stopped || | 
 | 	    fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN) | 
 | 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN; | 
 | 	if (trans) { | 
 | 		int ret2 = update_qgroup_status_item(trans); | 
 |  | 
 | 		if (ret2 < 0) { | 
 | 			ret = ret2; | 
 | 			btrfs_err(fs_info, "fail to update qgroup status: %d", ret); | 
 | 		} | 
 | 	} | 
 | 	fs_info->qgroup_rescan_running = false; | 
 | 	fs_info->qgroup_flags &= ~BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN; | 
 | 	complete_all(&fs_info->qgroup_rescan_completion); | 
 | 	mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 |  | 
 | 	if (!trans) | 
 | 		return; | 
 |  | 
 | 	btrfs_end_transaction(trans); | 
 |  | 
 | 	if (stopped) { | 
 | 		btrfs_info(fs_info, "qgroup scan paused"); | 
 | 	} else if (fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN) { | 
 | 		btrfs_info(fs_info, "qgroup scan cancelled"); | 
 | 	} else if (ret >= 0) { | 
 | 		btrfs_info(fs_info, "qgroup scan completed%s", | 
 | 			ret > 0 ? " (inconsistency flag cleared)" : ""); | 
 | 	} else { | 
 | 		btrfs_err(fs_info, "qgroup scan failed with %d", ret); | 
 | 	} | 
 | } | 
 |  | 
 | /* | 
 |  * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all | 
 |  * memory required for the rescan context. | 
 |  */ | 
 | static int | 
 | qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid, | 
 | 		   int init_flags) | 
 | { | 
 | 	int ret = 0; | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) { | 
 | 		btrfs_warn(fs_info, "qgroup rescan init failed, running in simple mode"); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	if (!init_flags) { | 
 | 		/* we're resuming qgroup rescan at mount time */ | 
 | 		if (!(fs_info->qgroup_flags & | 
 | 		      BTRFS_QGROUP_STATUS_FLAG_RESCAN)) { | 
 | 			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_debug(fs_info, | 
 | 			"qgroup rescan init failed, qgroup is not enabled"); | 
 | 			ret = -ENOTCONN; | 
 | 		} | 
 |  | 
 | 		if (ret) | 
 | 			return ret; | 
 | 	} | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_rescan_lock); | 
 |  | 
 | 	if (init_flags) { | 
 | 		if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) { | 
 | 			ret = -EINPROGRESS; | 
 | 		} else if (!(fs_info->qgroup_flags & | 
 | 			     BTRFS_QGROUP_STATUS_FLAG_ON)) { | 
 | 			btrfs_debug(fs_info, | 
 | 			"qgroup rescan init failed, qgroup is not enabled"); | 
 | 			ret = -ENOTCONN; | 
 | 		} else if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED) { | 
 | 			/* Quota disable is in progress */ | 
 | 			ret = -EBUSY; | 
 | 		} | 
 |  | 
 | 		if (ret) { | 
 | 			mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 | 			return ret; | 
 | 		} | 
 | 		fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN; | 
 | 	} | 
 |  | 
 | 	memset(&fs_info->qgroup_rescan_progress, 0, | 
 | 		sizeof(fs_info->qgroup_rescan_progress)); | 
 | 	fs_info->qgroup_flags &= ~(BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN | | 
 | 				   BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING); | 
 | 	fs_info->qgroup_rescan_progress.objectid = progress_objectid; | 
 | 	init_completion(&fs_info->qgroup_rescan_completion); | 
 | 	mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 |  | 
 | 	btrfs_init_work(&fs_info->qgroup_rescan_work, | 
 | 			btrfs_qgroup_rescan_worker, NULL); | 
 | 	return 0; | 
 | } | 
 |  | 
 | static void | 
 | qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	struct rb_node *n; | 
 | 	struct btrfs_qgroup *qgroup; | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	/* clear all current qgroup tracking information */ | 
 | 	for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) { | 
 | 		qgroup = rb_entry(n, struct btrfs_qgroup, node); | 
 | 		qgroup->rfer = 0; | 
 | 		qgroup->rfer_cmpr = 0; | 
 | 		qgroup->excl = 0; | 
 | 		qgroup->excl_cmpr = 0; | 
 | 		qgroup_dirty(fs_info, qgroup); | 
 | 	} | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 | } | 
 |  | 
 | int | 
 | btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	int ret = 0; | 
 |  | 
 | 	ret = qgroup_rescan_init(fs_info, 0, 1); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	/* | 
 | 	 * We have set the rescan_progress to 0, which means no more | 
 | 	 * delayed refs will be accounted by btrfs_qgroup_account_ref. | 
 | 	 * However, btrfs_qgroup_account_ref may be right after its call | 
 | 	 * to btrfs_find_all_roots, in which case it would still do the | 
 | 	 * accounting. | 
 | 	 * To solve this, we're committing the transaction, which will | 
 | 	 * ensure we run all delayed refs and only after that, we are | 
 | 	 * going to clear all tracking information for a clean start. | 
 | 	 */ | 
 |  | 
 | 	ret = btrfs_commit_current_transaction(fs_info->fs_root); | 
 | 	if (ret) { | 
 | 		fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN; | 
 | 		return ret; | 
 | 	} | 
 |  | 
 | 	qgroup_rescan_zero_tracking(fs_info); | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_rescan_lock); | 
 | 	fs_info->qgroup_rescan_running = true; | 
 | 	btrfs_queue_work(fs_info->qgroup_rescan_workers, | 
 | 			 &fs_info->qgroup_rescan_work); | 
 | 	mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info, | 
 | 				     bool interruptible) | 
 | { | 
 | 	int running; | 
 | 	int ret = 0; | 
 |  | 
 | 	mutex_lock(&fs_info->qgroup_rescan_lock); | 
 | 	running = fs_info->qgroup_rescan_running; | 
 | 	mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 |  | 
 | 	if (!running) | 
 | 		return 0; | 
 |  | 
 | 	if (interruptible) | 
 | 		ret = wait_for_completion_interruptible( | 
 | 					&fs_info->qgroup_rescan_completion); | 
 | 	else | 
 | 		wait_for_completion(&fs_info->qgroup_rescan_completion); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * this is only called from open_ctree where we're still single threaded, thus | 
 |  * locking is omitted here. | 
 |  */ | 
 | void | 
 | btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info) | 
 | { | 
 | 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) { | 
 | 		mutex_lock(&fs_info->qgroup_rescan_lock); | 
 | 		fs_info->qgroup_rescan_running = true; | 
 | 		btrfs_queue_work(fs_info->qgroup_rescan_workers, | 
 | 				 &fs_info->qgroup_rescan_work); | 
 | 		mutex_unlock(&fs_info->qgroup_rescan_lock); | 
 | 	} | 
 | } | 
 |  | 
 | #define rbtree_iterate_from_safe(node, next, start)				\ | 
 |        for (node = start; node && ({ next = rb_next(node); 1;}); node = next) | 
 |  | 
 | static int qgroup_unreserve_range(struct btrfs_inode *inode, | 
 | 				  struct extent_changeset *reserved, u64 start, | 
 | 				  u64 len) | 
 | { | 
 | 	struct rb_node *node; | 
 | 	struct rb_node *next; | 
 | 	struct ulist_node *entry; | 
 | 	int ret = 0; | 
 |  | 
 | 	node = reserved->range_changed.root.rb_node; | 
 | 	if (!node) | 
 | 		return 0; | 
 | 	while (node) { | 
 | 		entry = rb_entry(node, struct ulist_node, rb_node); | 
 | 		if (entry->val < start) | 
 | 			node = node->rb_right; | 
 | 		else | 
 | 			node = node->rb_left; | 
 | 	} | 
 |  | 
 | 	if (entry->val > start && rb_prev(&entry->rb_node)) | 
 | 		entry = rb_entry(rb_prev(&entry->rb_node), struct ulist_node, | 
 | 				 rb_node); | 
 |  | 
 | 	rbtree_iterate_from_safe(node, next, &entry->rb_node) { | 
 | 		u64 entry_start; | 
 | 		u64 entry_end; | 
 | 		u64 entry_len; | 
 | 		int clear_ret; | 
 |  | 
 | 		entry = rb_entry(node, struct ulist_node, rb_node); | 
 | 		entry_start = entry->val; | 
 | 		entry_end = entry->aux; | 
 | 		entry_len = entry_end - entry_start + 1; | 
 |  | 
 | 		if (entry_start >= start + len) | 
 | 			break; | 
 | 		if (entry_start + entry_len <= start) | 
 | 			continue; | 
 | 		/* | 
 | 		 * Now the entry is in [start, start + len), revert the | 
 | 		 * EXTENT_QGROUP_RESERVED bit. | 
 | 		 */ | 
 | 		clear_ret = clear_extent_bits(&inode->io_tree, entry_start, | 
 | 					      entry_end, EXTENT_QGROUP_RESERVED); | 
 | 		if (!ret && clear_ret < 0) | 
 | 			ret = clear_ret; | 
 |  | 
 | 		ulist_del(&reserved->range_changed, entry->val, entry->aux); | 
 | 		if (likely(reserved->bytes_changed >= entry_len)) { | 
 | 			reserved->bytes_changed -= entry_len; | 
 | 		} else { | 
 | 			WARN_ON(1); | 
 | 			reserved->bytes_changed = 0; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * Try to free some space for qgroup. | 
 |  * | 
 |  * For qgroup, there are only 3 ways to free qgroup space: | 
 |  * - Flush nodatacow write | 
 |  *   Any nodatacow write will free its reserved data space at run_delalloc_range(). | 
 |  *   In theory, we should only flush nodatacow inodes, but it's not yet | 
 |  *   possible, so we need to flush the whole root. | 
 |  * | 
 |  * - Wait for ordered extents | 
 |  *   When ordered extents are finished, their reserved metadata is finally | 
 |  *   converted to per_trans status, which can be freed by later commit | 
 |  *   transaction. | 
 |  * | 
 |  * - Commit transaction | 
 |  *   This would free the meta_per_trans space. | 
 |  *   In theory this shouldn't provide much space, but any more qgroup space | 
 |  *   is needed. | 
 |  */ | 
 | static int try_flush_qgroup(struct btrfs_root *root) | 
 | { | 
 | 	int ret; | 
 |  | 
 | 	/* Can't hold an open transaction or we run the risk of deadlocking. */ | 
 | 	ASSERT(current->journal_info == NULL); | 
 | 	if (WARN_ON(current->journal_info)) | 
 | 		return 0; | 
 |  | 
 | 	/* | 
 | 	 * We don't want to run flush again and again, so if there is a running | 
 | 	 * one, we won't try to start a new flush, but exit directly. | 
 | 	 */ | 
 | 	if (test_and_set_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state)) { | 
 | 		wait_event(root->qgroup_flush_wait, | 
 | 			!test_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state)); | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	ret = btrfs_start_delalloc_snapshot(root, true); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 | 	btrfs_wait_ordered_extents(root, U64_MAX, NULL); | 
 |  | 
 | 	ret = btrfs_commit_current_transaction(root); | 
 | out: | 
 | 	clear_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state); | 
 | 	wake_up(&root->qgroup_flush_wait); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int qgroup_reserve_data(struct btrfs_inode *inode, | 
 | 			struct extent_changeset **reserved_ret, u64 start, | 
 | 			u64 len) | 
 | { | 
 | 	struct btrfs_root *root = inode->root; | 
 | 	struct extent_changeset *reserved; | 
 | 	bool new_reserved = false; | 
 | 	u64 orig_reserved; | 
 | 	u64 to_reserve; | 
 | 	int ret; | 
 |  | 
 | 	if (btrfs_qgroup_mode(root->fs_info) == BTRFS_QGROUP_MODE_DISABLED || | 
 | 	    !is_fstree(btrfs_root_id(root)) || len == 0) | 
 | 		return 0; | 
 |  | 
 | 	/* @reserved parameter is mandatory for qgroup */ | 
 | 	if (WARN_ON(!reserved_ret)) | 
 | 		return -EINVAL; | 
 | 	if (!*reserved_ret) { | 
 | 		new_reserved = true; | 
 | 		*reserved_ret = extent_changeset_alloc(); | 
 | 		if (!*reserved_ret) | 
 | 			return -ENOMEM; | 
 | 	} | 
 | 	reserved = *reserved_ret; | 
 | 	/* Record already reserved space */ | 
 | 	orig_reserved = reserved->bytes_changed; | 
 | 	ret = set_record_extent_bits(&inode->io_tree, start, | 
 | 			start + len -1, EXTENT_QGROUP_RESERVED, reserved); | 
 |  | 
 | 	/* Newly reserved space */ | 
 | 	to_reserve = reserved->bytes_changed - orig_reserved; | 
 | 	trace_btrfs_qgroup_reserve_data(&inode->vfs_inode, start, len, | 
 | 					to_reserve, QGROUP_RESERVE); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 | 	ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA); | 
 | 	if (ret < 0) | 
 | 		goto cleanup; | 
 |  | 
 | 	return ret; | 
 |  | 
 | cleanup: | 
 | 	qgroup_unreserve_range(inode, reserved, start, len); | 
 | out: | 
 | 	if (new_reserved) { | 
 | 		extent_changeset_free(reserved); | 
 | 		*reserved_ret = NULL; | 
 | 	} | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * Reserve qgroup space for range [start, start + len). | 
 |  * | 
 |  * This function will either reserve space from related qgroups or do nothing | 
 |  * if the range is already reserved. | 
 |  * | 
 |  * Return 0 for successful reservation | 
 |  * Return <0 for error (including -EQUOT) | 
 |  * | 
 |  * NOTE: This function may sleep for memory allocation, dirty page flushing and | 
 |  *	 commit transaction. So caller should not hold any dirty page locked. | 
 |  */ | 
 | int btrfs_qgroup_reserve_data(struct btrfs_inode *inode, | 
 | 			struct extent_changeset **reserved_ret, u64 start, | 
 | 			u64 len) | 
 | { | 
 | 	int ret; | 
 |  | 
 | 	ret = qgroup_reserve_data(inode, reserved_ret, start, len); | 
 | 	if (ret <= 0 && ret != -EDQUOT) | 
 | 		return ret; | 
 |  | 
 | 	ret = try_flush_qgroup(inode->root); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 | 	return qgroup_reserve_data(inode, reserved_ret, start, len); | 
 | } | 
 |  | 
 | /* Free ranges specified by @reserved, normally in error path */ | 
 | static int qgroup_free_reserved_data(struct btrfs_inode *inode, | 
 | 				     struct extent_changeset *reserved, | 
 | 				     u64 start, u64 len, u64 *freed_ret) | 
 | { | 
 | 	struct btrfs_root *root = inode->root; | 
 | 	struct ulist_node *unode; | 
 | 	struct ulist_iterator uiter; | 
 | 	struct extent_changeset changeset; | 
 | 	u64 freed = 0; | 
 | 	int ret; | 
 |  | 
 | 	extent_changeset_init(&changeset); | 
 | 	len = round_up(start + len, root->fs_info->sectorsize); | 
 | 	start = round_down(start, root->fs_info->sectorsize); | 
 |  | 
 | 	ULIST_ITER_INIT(&uiter); | 
 | 	while ((unode = ulist_next(&reserved->range_changed, &uiter))) { | 
 | 		u64 range_start = unode->val; | 
 | 		/* unode->aux is the inclusive end */ | 
 | 		u64 range_len = unode->aux - range_start + 1; | 
 | 		u64 free_start; | 
 | 		u64 free_len; | 
 |  | 
 | 		extent_changeset_release(&changeset); | 
 |  | 
 | 		/* Only free range in range [start, start + len) */ | 
 | 		if (range_start >= start + len || | 
 | 		    range_start + range_len <= start) | 
 | 			continue; | 
 | 		free_start = max(range_start, start); | 
 | 		free_len = min(start + len, range_start + range_len) - | 
 | 			   free_start; | 
 | 		/* | 
 | 		 * TODO: To also modify reserved->ranges_reserved to reflect | 
 | 		 * the modification. | 
 | 		 * | 
 | 		 * However as long as we free qgroup reserved according to | 
 | 		 * EXTENT_QGROUP_RESERVED, we won't double free. | 
 | 		 * So not need to rush. | 
 | 		 */ | 
 | 		ret = clear_record_extent_bits(&inode->io_tree, free_start, | 
 | 				free_start + free_len - 1, | 
 | 				EXTENT_QGROUP_RESERVED, &changeset); | 
 | 		if (ret < 0) | 
 | 			goto out; | 
 | 		freed += changeset.bytes_changed; | 
 | 	} | 
 | 	btrfs_qgroup_free_refroot(root->fs_info, btrfs_root_id(root), freed, | 
 | 				  BTRFS_QGROUP_RSV_DATA); | 
 | 	if (freed_ret) | 
 | 		*freed_ret = freed; | 
 | 	ret = 0; | 
 | out: | 
 | 	extent_changeset_release(&changeset); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int __btrfs_qgroup_release_data(struct btrfs_inode *inode, | 
 | 			struct extent_changeset *reserved, u64 start, u64 len, | 
 | 			u64 *released, int free) | 
 | { | 
 | 	struct extent_changeset changeset; | 
 | 	int trace_op = QGROUP_RELEASE; | 
 | 	int ret; | 
 |  | 
 | 	if (btrfs_qgroup_mode(inode->root->fs_info) == BTRFS_QGROUP_MODE_DISABLED) { | 
 | 		extent_changeset_init(&changeset); | 
 | 		return clear_record_extent_bits(&inode->io_tree, start, | 
 | 						start + len - 1, | 
 | 						EXTENT_QGROUP_RESERVED, &changeset); | 
 | 	} | 
 |  | 
 | 	/* In release case, we shouldn't have @reserved */ | 
 | 	WARN_ON(!free && reserved); | 
 | 	if (free && reserved) | 
 | 		return qgroup_free_reserved_data(inode, reserved, start, len, released); | 
 | 	extent_changeset_init(&changeset); | 
 | 	ret = clear_record_extent_bits(&inode->io_tree, start, start + len -1, | 
 | 				       EXTENT_QGROUP_RESERVED, &changeset); | 
 | 	if (ret < 0) | 
 | 		goto out; | 
 |  | 
 | 	if (free) | 
 | 		trace_op = QGROUP_FREE; | 
 | 	trace_btrfs_qgroup_release_data(&inode->vfs_inode, start, len, | 
 | 					changeset.bytes_changed, trace_op); | 
 | 	if (free) | 
 | 		btrfs_qgroup_free_refroot(inode->root->fs_info, | 
 | 				btrfs_root_id(inode->root), | 
 | 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA); | 
 | 	if (released) | 
 | 		*released = changeset.bytes_changed; | 
 | out: | 
 | 	extent_changeset_release(&changeset); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * Free a reserved space range from io_tree and related qgroups | 
 |  * | 
 |  * Should be called when a range of pages get invalidated before reaching disk. | 
 |  * Or for error cleanup case. | 
 |  * if @reserved is given, only reserved range in [@start, @start + @len) will | 
 |  * be freed. | 
 |  * | 
 |  * For data written to disk, use btrfs_qgroup_release_data(). | 
 |  * | 
 |  * NOTE: This function may sleep for memory allocation. | 
 |  */ | 
 | int btrfs_qgroup_free_data(struct btrfs_inode *inode, | 
 | 			   struct extent_changeset *reserved, | 
 | 			   u64 start, u64 len, u64 *freed) | 
 | { | 
 | 	return __btrfs_qgroup_release_data(inode, reserved, start, len, freed, 1); | 
 | } | 
 |  | 
 | /* | 
 |  * Release a reserved space range from io_tree only. | 
 |  * | 
 |  * Should be called when a range of pages get written to disk and corresponding | 
 |  * FILE_EXTENT is inserted into corresponding root. | 
 |  * | 
 |  * Since new qgroup accounting framework will only update qgroup numbers at | 
 |  * commit_transaction() time, its reserved space shouldn't be freed from | 
 |  * related qgroups. | 
 |  * | 
 |  * But we should release the range from io_tree, to allow further write to be | 
 |  * COWed. | 
 |  * | 
 |  * NOTE: This function may sleep for memory allocation. | 
 |  */ | 
 | int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len, u64 *released) | 
 | { | 
 | 	return __btrfs_qgroup_release_data(inode, NULL, start, len, released, 0); | 
 | } | 
 |  | 
 | static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes, | 
 | 			      enum btrfs_qgroup_rsv_type type) | 
 | { | 
 | 	if (type != BTRFS_QGROUP_RSV_META_PREALLOC && | 
 | 	    type != BTRFS_QGROUP_RSV_META_PERTRANS) | 
 | 		return; | 
 | 	if (num_bytes == 0) | 
 | 		return; | 
 |  | 
 | 	spin_lock(&root->qgroup_meta_rsv_lock); | 
 | 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC) | 
 | 		root->qgroup_meta_rsv_prealloc += num_bytes; | 
 | 	else | 
 | 		root->qgroup_meta_rsv_pertrans += num_bytes; | 
 | 	spin_unlock(&root->qgroup_meta_rsv_lock); | 
 | } | 
 |  | 
 | static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes, | 
 | 			     enum btrfs_qgroup_rsv_type type) | 
 | { | 
 | 	if (type != BTRFS_QGROUP_RSV_META_PREALLOC && | 
 | 	    type != BTRFS_QGROUP_RSV_META_PERTRANS) | 
 | 		return 0; | 
 | 	if (num_bytes == 0) | 
 | 		return 0; | 
 |  | 
 | 	spin_lock(&root->qgroup_meta_rsv_lock); | 
 | 	if (type == BTRFS_QGROUP_RSV_META_PREALLOC) { | 
 | 		num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc, | 
 | 				  num_bytes); | 
 | 		root->qgroup_meta_rsv_prealloc -= num_bytes; | 
 | 	} else { | 
 | 		num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans, | 
 | 				  num_bytes); | 
 | 		root->qgroup_meta_rsv_pertrans -= num_bytes; | 
 | 	} | 
 | 	spin_unlock(&root->qgroup_meta_rsv_lock); | 
 | 	return num_bytes; | 
 | } | 
 |  | 
 | int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes, | 
 | 			      enum btrfs_qgroup_rsv_type type, bool enforce) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = root->fs_info; | 
 | 	int ret; | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED || | 
 | 	    !is_fstree(btrfs_root_id(root)) || num_bytes == 0) | 
 | 		return 0; | 
 |  | 
 | 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize)); | 
 | 	trace_qgroup_meta_reserve(root, (s64)num_bytes, type); | 
 | 	ret = qgroup_reserve(root, num_bytes, enforce, type); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 | 	/* | 
 | 	 * Record what we have reserved into root. | 
 | 	 * | 
 | 	 * To avoid quota disabled->enabled underflow. | 
 | 	 * In that case, we may try to free space we haven't reserved | 
 | 	 * (since quota was disabled), so record what we reserved into root. | 
 | 	 * And ensure later release won't underflow this number. | 
 | 	 */ | 
 | 	add_root_meta_rsv(root, num_bytes, type); | 
 | 	return ret; | 
 | } | 
 |  | 
 | int __btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes, | 
 | 				enum btrfs_qgroup_rsv_type type, bool enforce, | 
 | 				bool noflush) | 
 | { | 
 | 	int ret; | 
 |  | 
 | 	ret = btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce); | 
 | 	if ((ret <= 0 && ret != -EDQUOT) || noflush) | 
 | 		return ret; | 
 |  | 
 | 	ret = try_flush_qgroup(root); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 | 	return btrfs_qgroup_reserve_meta(root, num_bytes, type, enforce); | 
 | } | 
 |  | 
 | /* | 
 |  * Per-transaction meta reservation should be all freed at transaction commit | 
 |  * time | 
 |  */ | 
 | void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = root->fs_info; | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED || | 
 | 	    !is_fstree(btrfs_root_id(root))) | 
 | 		return; | 
 |  | 
 | 	/* TODO: Update trace point to handle such free */ | 
 | 	trace_qgroup_meta_free_all_pertrans(root); | 
 | 	/* Special value -1 means to free all reserved space */ | 
 | 	btrfs_qgroup_free_refroot(fs_info, btrfs_root_id(root), (u64)-1, | 
 | 				  BTRFS_QGROUP_RSV_META_PERTRANS); | 
 | } | 
 |  | 
 | void __btrfs_qgroup_free_meta(struct btrfs_root *root, int num_bytes, | 
 | 			      enum btrfs_qgroup_rsv_type type) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = root->fs_info; | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED || | 
 | 	    !is_fstree(btrfs_root_id(root))) | 
 | 		return; | 
 |  | 
 | 	/* | 
 | 	 * reservation for META_PREALLOC can happen before quota is enabled, | 
 | 	 * which can lead to underflow. | 
 | 	 * Here ensure we will only free what we really have reserved. | 
 | 	 */ | 
 | 	num_bytes = sub_root_meta_rsv(root, num_bytes, type); | 
 | 	BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize)); | 
 | 	trace_qgroup_meta_reserve(root, -(s64)num_bytes, type); | 
 | 	btrfs_qgroup_free_refroot(fs_info, btrfs_root_id(root), num_bytes, type); | 
 | } | 
 |  | 
 | static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root, | 
 | 				int num_bytes) | 
 | { | 
 | 	struct btrfs_qgroup *qgroup; | 
 | 	LIST_HEAD(qgroup_list); | 
 |  | 
 | 	if (num_bytes == 0) | 
 | 		return; | 
 | 	if (!fs_info->quota_root) | 
 | 		return; | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	qgroup = find_qgroup_rb(fs_info, ref_root); | 
 | 	if (!qgroup) | 
 | 		goto out; | 
 |  | 
 | 	qgroup_iterator_add(&qgroup_list, qgroup); | 
 | 	list_for_each_entry(qgroup, &qgroup_list, iterator) { | 
 | 		struct btrfs_qgroup_list *glist; | 
 |  | 
 | 		qgroup_rsv_release(fs_info, qgroup, num_bytes, | 
 | 				BTRFS_QGROUP_RSV_META_PREALLOC); | 
 | 		if (!sb_rdonly(fs_info->sb)) | 
 | 			qgroup_rsv_add(fs_info, qgroup, num_bytes, | 
 | 				       BTRFS_QGROUP_RSV_META_PERTRANS); | 
 |  | 
 | 		list_for_each_entry(glist, &qgroup->groups, next_group) | 
 | 			qgroup_iterator_add(&qgroup_list, glist->group); | 
 | 	} | 
 | out: | 
 | 	qgroup_iterator_clean(&qgroup_list); | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 | } | 
 |  | 
 | /* | 
 |  * Convert @num_bytes of META_PREALLOCATED reservation to META_PERTRANS. | 
 |  * | 
 |  * This is called when preallocated meta reservation needs to be used. | 
 |  * Normally after btrfs_join_transaction() call. | 
 |  */ | 
 | void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = root->fs_info; | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED || | 
 | 	    !is_fstree(btrfs_root_id(root))) | 
 | 		return; | 
 | 	/* Same as btrfs_qgroup_free_meta_prealloc() */ | 
 | 	num_bytes = sub_root_meta_rsv(root, num_bytes, | 
 | 				      BTRFS_QGROUP_RSV_META_PREALLOC); | 
 | 	trace_qgroup_meta_convert(root, num_bytes); | 
 | 	qgroup_convert_meta(fs_info, btrfs_root_id(root), num_bytes); | 
 | 	if (!sb_rdonly(fs_info->sb)) | 
 | 		add_root_meta_rsv(root, num_bytes, BTRFS_QGROUP_RSV_META_PERTRANS); | 
 | } | 
 |  | 
 | /* | 
 |  * Check qgroup reserved space leaking, normally at destroy inode | 
 |  * time | 
 |  */ | 
 | void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode) | 
 | { | 
 | 	struct extent_changeset changeset; | 
 | 	struct ulist_node *unode; | 
 | 	struct ulist_iterator iter; | 
 | 	int ret; | 
 |  | 
 | 	extent_changeset_init(&changeset); | 
 | 	ret = clear_record_extent_bits(&inode->io_tree, 0, (u64)-1, | 
 | 			EXTENT_QGROUP_RESERVED, &changeset); | 
 |  | 
 | 	WARN_ON(ret < 0); | 
 | 	if (WARN_ON(changeset.bytes_changed)) { | 
 | 		ULIST_ITER_INIT(&iter); | 
 | 		while ((unode = ulist_next(&changeset.range_changed, &iter))) { | 
 | 			btrfs_warn(inode->root->fs_info, | 
 | 		"leaking qgroup reserved space, ino: %llu, start: %llu, end: %llu", | 
 | 				btrfs_ino(inode), unode->val, unode->aux); | 
 | 		} | 
 | 		btrfs_qgroup_free_refroot(inode->root->fs_info, | 
 | 				btrfs_root_id(inode->root), | 
 | 				changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA); | 
 |  | 
 | 	} | 
 | 	extent_changeset_release(&changeset); | 
 | } | 
 |  | 
 | void btrfs_qgroup_init_swapped_blocks( | 
 | 	struct btrfs_qgroup_swapped_blocks *swapped_blocks) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	spin_lock_init(&swapped_blocks->lock); | 
 | 	for (i = 0; i < BTRFS_MAX_LEVEL; i++) | 
 | 		swapped_blocks->blocks[i] = RB_ROOT; | 
 | 	swapped_blocks->swapped = false; | 
 | } | 
 |  | 
 | /* | 
 |  * Delete all swapped blocks record of @root. | 
 |  * Every record here means we skipped a full subtree scan for qgroup. | 
 |  * | 
 |  * Gets called when committing one transaction. | 
 |  */ | 
 | void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root) | 
 | { | 
 | 	struct btrfs_qgroup_swapped_blocks *swapped_blocks; | 
 | 	int i; | 
 |  | 
 | 	swapped_blocks = &root->swapped_blocks; | 
 |  | 
 | 	spin_lock(&swapped_blocks->lock); | 
 | 	if (!swapped_blocks->swapped) | 
 | 		goto out; | 
 | 	for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | 
 | 		struct rb_root *cur_root = &swapped_blocks->blocks[i]; | 
 | 		struct btrfs_qgroup_swapped_block *entry; | 
 | 		struct btrfs_qgroup_swapped_block *next; | 
 |  | 
 | 		rbtree_postorder_for_each_entry_safe(entry, next, cur_root, | 
 | 						     node) | 
 | 			kfree(entry); | 
 | 		swapped_blocks->blocks[i] = RB_ROOT; | 
 | 	} | 
 | 	swapped_blocks->swapped = false; | 
 | out: | 
 | 	spin_unlock(&swapped_blocks->lock); | 
 | } | 
 |  | 
 | /* | 
 |  * Add subtree roots record into @subvol_root. | 
 |  * | 
 |  * @subvol_root:	tree root of the subvolume tree get swapped | 
 |  * @bg:			block group under balance | 
 |  * @subvol_parent/slot:	pointer to the subtree root in subvolume tree | 
 |  * @reloc_parent/slot:	pointer to the subtree root in reloc tree | 
 |  *			BOTH POINTERS ARE BEFORE TREE SWAP | 
 |  * @last_snapshot:	last snapshot generation of the subvolume tree | 
 |  */ | 
 | int btrfs_qgroup_add_swapped_blocks(struct btrfs_trans_handle *trans, | 
 | 		struct btrfs_root *subvol_root, | 
 | 		struct btrfs_block_group *bg, | 
 | 		struct extent_buffer *subvol_parent, int subvol_slot, | 
 | 		struct extent_buffer *reloc_parent, int reloc_slot, | 
 | 		u64 last_snapshot) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = subvol_root->fs_info; | 
 | 	struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks; | 
 | 	struct btrfs_qgroup_swapped_block *block; | 
 | 	struct rb_node **cur; | 
 | 	struct rb_node *parent = NULL; | 
 | 	int level = btrfs_header_level(subvol_parent) - 1; | 
 | 	int ret = 0; | 
 |  | 
 | 	if (!btrfs_qgroup_full_accounting(fs_info)) | 
 | 		return 0; | 
 |  | 
 | 	if (btrfs_node_ptr_generation(subvol_parent, subvol_slot) > | 
 | 	    btrfs_node_ptr_generation(reloc_parent, reloc_slot)) { | 
 | 		btrfs_err_rl(fs_info, | 
 | 		"%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu", | 
 | 			__func__, | 
 | 			btrfs_node_ptr_generation(subvol_parent, subvol_slot), | 
 | 			btrfs_node_ptr_generation(reloc_parent, reloc_slot)); | 
 | 		return -EUCLEAN; | 
 | 	} | 
 |  | 
 | 	block = kmalloc(sizeof(*block), GFP_NOFS); | 
 | 	if (!block) { | 
 | 		ret = -ENOMEM; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	/* | 
 | 	 * @reloc_parent/slot is still before swap, while @block is going to | 
 | 	 * record the bytenr after swap, so we do the swap here. | 
 | 	 */ | 
 | 	block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot); | 
 | 	block->subvol_generation = btrfs_node_ptr_generation(reloc_parent, | 
 | 							     reloc_slot); | 
 | 	block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot); | 
 | 	block->reloc_generation = btrfs_node_ptr_generation(subvol_parent, | 
 | 							    subvol_slot); | 
 | 	block->last_snapshot = last_snapshot; | 
 | 	block->level = level; | 
 |  | 
 | 	/* | 
 | 	 * If we have bg == NULL, we're called from btrfs_recover_relocation(), | 
 | 	 * no one else can modify tree blocks thus we qgroup will not change | 
 | 	 * no matter the value of trace_leaf. | 
 | 	 */ | 
 | 	if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA) | 
 | 		block->trace_leaf = true; | 
 | 	else | 
 | 		block->trace_leaf = false; | 
 | 	btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot); | 
 |  | 
 | 	/* Insert @block into @blocks */ | 
 | 	spin_lock(&blocks->lock); | 
 | 	cur = &blocks->blocks[level].rb_node; | 
 | 	while (*cur) { | 
 | 		struct btrfs_qgroup_swapped_block *entry; | 
 |  | 
 | 		parent = *cur; | 
 | 		entry = rb_entry(parent, struct btrfs_qgroup_swapped_block, | 
 | 				 node); | 
 |  | 
 | 		if (entry->subvol_bytenr < block->subvol_bytenr) { | 
 | 			cur = &(*cur)->rb_left; | 
 | 		} else if (entry->subvol_bytenr > block->subvol_bytenr) { | 
 | 			cur = &(*cur)->rb_right; | 
 | 		} else { | 
 | 			if (entry->subvol_generation != | 
 | 					block->subvol_generation || | 
 | 			    entry->reloc_bytenr != block->reloc_bytenr || | 
 | 			    entry->reloc_generation != | 
 | 					block->reloc_generation) { | 
 | 				/* | 
 | 				 * Duplicated but mismatch entry found. | 
 | 				 * Shouldn't happen. | 
 | 				 * | 
 | 				 * Marking qgroup inconsistent should be enough | 
 | 				 * for end users. | 
 | 				 */ | 
 | 				WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); | 
 | 				ret = -EEXIST; | 
 | 			} | 
 | 			kfree(block); | 
 | 			goto out_unlock; | 
 | 		} | 
 | 	} | 
 | 	rb_link_node(&block->node, parent, cur); | 
 | 	rb_insert_color(&block->node, &blocks->blocks[level]); | 
 | 	blocks->swapped = true; | 
 | out_unlock: | 
 | 	spin_unlock(&blocks->lock); | 
 | out: | 
 | 	if (ret < 0) | 
 | 		qgroup_mark_inconsistent(fs_info); | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* | 
 |  * Check if the tree block is a subtree root, and if so do the needed | 
 |  * delayed subtree trace for qgroup. | 
 |  * | 
 |  * This is called during btrfs_cow_block(). | 
 |  */ | 
 | int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans, | 
 | 					 struct btrfs_root *root, | 
 | 					 struct extent_buffer *subvol_eb) | 
 | { | 
 | 	struct btrfs_fs_info *fs_info = root->fs_info; | 
 | 	struct btrfs_tree_parent_check check = { 0 }; | 
 | 	struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks; | 
 | 	struct btrfs_qgroup_swapped_block *block; | 
 | 	struct extent_buffer *reloc_eb = NULL; | 
 | 	struct rb_node *node; | 
 | 	bool found = false; | 
 | 	bool swapped = false; | 
 | 	int level = btrfs_header_level(subvol_eb); | 
 | 	int ret = 0; | 
 | 	int i; | 
 |  | 
 | 	if (!btrfs_qgroup_full_accounting(fs_info)) | 
 | 		return 0; | 
 | 	if (!is_fstree(btrfs_root_id(root)) || !root->reloc_root) | 
 | 		return 0; | 
 |  | 
 | 	spin_lock(&blocks->lock); | 
 | 	if (!blocks->swapped) { | 
 | 		spin_unlock(&blocks->lock); | 
 | 		return 0; | 
 | 	} | 
 | 	node = blocks->blocks[level].rb_node; | 
 |  | 
 | 	while (node) { | 
 | 		block = rb_entry(node, struct btrfs_qgroup_swapped_block, node); | 
 | 		if (block->subvol_bytenr < subvol_eb->start) { | 
 | 			node = node->rb_left; | 
 | 		} else if (block->subvol_bytenr > subvol_eb->start) { | 
 | 			node = node->rb_right; | 
 | 		} else { | 
 | 			found = true; | 
 | 			break; | 
 | 		} | 
 | 	} | 
 | 	if (!found) { | 
 | 		spin_unlock(&blocks->lock); | 
 | 		goto out; | 
 | 	} | 
 | 	/* Found one, remove it from @blocks first and update blocks->swapped */ | 
 | 	rb_erase(&block->node, &blocks->blocks[level]); | 
 | 	for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | 
 | 		if (RB_EMPTY_ROOT(&blocks->blocks[i])) { | 
 | 			swapped = true; | 
 | 			break; | 
 | 		} | 
 | 	} | 
 | 	blocks->swapped = swapped; | 
 | 	spin_unlock(&blocks->lock); | 
 |  | 
 | 	check.level = block->level; | 
 | 	check.transid = block->reloc_generation; | 
 | 	check.has_first_key = true; | 
 | 	memcpy(&check.first_key, &block->first_key, sizeof(check.first_key)); | 
 |  | 
 | 	/* Read out reloc subtree root */ | 
 | 	reloc_eb = read_tree_block(fs_info, block->reloc_bytenr, &check); | 
 | 	if (IS_ERR(reloc_eb)) { | 
 | 		ret = PTR_ERR(reloc_eb); | 
 | 		reloc_eb = NULL; | 
 | 		goto free_out; | 
 | 	} | 
 | 	if (!extent_buffer_uptodate(reloc_eb)) { | 
 | 		ret = -EIO; | 
 | 		goto free_out; | 
 | 	} | 
 |  | 
 | 	ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb, | 
 | 			block->last_snapshot, block->trace_leaf); | 
 | free_out: | 
 | 	kfree(block); | 
 | 	free_extent_buffer(reloc_eb); | 
 | out: | 
 | 	if (ret < 0) { | 
 | 		btrfs_err_rl(fs_info, | 
 | 			     "failed to account subtree at bytenr %llu: %d", | 
 | 			     subvol_eb->start, ret); | 
 | 		qgroup_mark_inconsistent(fs_info); | 
 | 	} | 
 | 	return ret; | 
 | } | 
 |  | 
 | void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans) | 
 | { | 
 | 	struct btrfs_qgroup_extent_record *entry; | 
 | 	struct btrfs_qgroup_extent_record *next; | 
 | 	struct rb_root *root; | 
 |  | 
 | 	root = &trans->delayed_refs.dirty_extent_root; | 
 | 	rbtree_postorder_for_each_entry_safe(entry, next, root, node) { | 
 | 		ulist_free(entry->old_roots); | 
 | 		kfree(entry); | 
 | 	} | 
 | 	*root = RB_ROOT; | 
 | } | 
 |  | 
 | void btrfs_free_squota_rsv(struct btrfs_fs_info *fs_info, u64 root, u64 rsv_bytes) | 
 | { | 
 | 	if (btrfs_qgroup_mode(fs_info) != BTRFS_QGROUP_MODE_SIMPLE) | 
 | 		return; | 
 |  | 
 | 	if (!is_fstree(root)) | 
 | 		return; | 
 |  | 
 | 	btrfs_qgroup_free_refroot(fs_info, root, rsv_bytes, BTRFS_QGROUP_RSV_DATA); | 
 | } | 
 |  | 
 | int btrfs_record_squota_delta(struct btrfs_fs_info *fs_info, | 
 | 			      const struct btrfs_squota_delta *delta) | 
 | { | 
 | 	int ret; | 
 | 	struct btrfs_qgroup *qgroup; | 
 | 	struct btrfs_qgroup *qg; | 
 | 	LIST_HEAD(qgroup_list); | 
 | 	u64 root = delta->root; | 
 | 	u64 num_bytes = delta->num_bytes; | 
 | 	const int sign = (delta->is_inc ? 1 : -1); | 
 |  | 
 | 	if (btrfs_qgroup_mode(fs_info) != BTRFS_QGROUP_MODE_SIMPLE) | 
 | 		return 0; | 
 |  | 
 | 	if (!is_fstree(root)) | 
 | 		return 0; | 
 |  | 
 | 	/* If the extent predates enabling quotas, don't count it. */ | 
 | 	if (delta->generation < fs_info->qgroup_enable_gen) | 
 | 		return 0; | 
 |  | 
 | 	spin_lock(&fs_info->qgroup_lock); | 
 | 	qgroup = find_qgroup_rb(fs_info, root); | 
 | 	if (!qgroup) { | 
 | 		ret = -ENOENT; | 
 | 		goto out; | 
 | 	} | 
 |  | 
 | 	ret = 0; | 
 | 	qgroup_iterator_add(&qgroup_list, qgroup); | 
 | 	list_for_each_entry(qg, &qgroup_list, iterator) { | 
 | 		struct btrfs_qgroup_list *glist; | 
 |  | 
 | 		qg->excl += num_bytes * sign; | 
 | 		qg->rfer += num_bytes * sign; | 
 | 		qgroup_dirty(fs_info, qg); | 
 |  | 
 | 		list_for_each_entry(glist, &qg->groups, next_group) | 
 | 			qgroup_iterator_add(&qgroup_list, glist->group); | 
 | 	} | 
 | 	qgroup_iterator_clean(&qgroup_list); | 
 |  | 
 | out: | 
 | 	spin_unlock(&fs_info->qgroup_lock); | 
 | 	return ret; | 
 | } |