[mirror_ubuntu-artful-kernel.git] / fs / btrfs / delayed-ref.h

/*
 * Copyright (C) 2008 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */
#ifndef __DELAYED_REF__
#define __DELAYED_REF__

/* these are the possible values of struct btrfs_delayed_ref_node->action */
#define BTRFS_ADD_DELAYED_REF    1 /* add one backref to the tree */
#define BTRFS_DROP_DELAYED_REF   2 /* delete one backref from the tree */
#define BTRFS_ADD_DELAYED_EXTENT 3 /* record a full extent allocation */
#define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */

/*
 * XXX: Qu: I really hate the design that ref_head and tree/data ref shares the
 * same ref_node structure.
 * Ref_head is in a higher logic level than tree/data ref, and duplicated
 * bytenr/num_bytes in ref_node is really a waste or memory, they should be
 * referred from ref_head.
 * This gets more disgusting after we use list to store tree/data ref in
 * ref_head. Must clean this mess up later.
 */
struct btrfs_delayed_ref_node {
	/*
	 * ref_head use rb tree, stored in ref_root->href.
	 * indexed by bytenr
	 */
	struct rb_node rb_node;

	/*data/tree ref use list, stored in ref_head->ref_list. */
	struct list_head list;
	/*
	 * If action is BTRFS_ADD_DELAYED_REF, also link this node to
	 * ref_head->ref_add_list, then we do not need to iterate the
	 * whole ref_head->ref_list to find BTRFS_ADD_DELAYED_REF nodes.
	 */
	struct list_head add_list;

	/* the starting bytenr of the extent */
	u64 bytenr;

	/* the size of the extent */
	u64 num_bytes;

	/* seq number to keep track of insertion order */
	u64 seq;

	/* ref count on this data structure */
	atomic_t refs;

	/*
	 * how many refs is this entry adding or deleting.  For
	 * head refs, this may be a negative number because it is keeping
	 * track of the total mods done to the reference count.
	 * For individual refs, this will always be a positive number
	 *
	 * It may be more than one, since it is possible for a single
	 * parent to have more than one ref on an extent
	 */
	int ref_mod;

	unsigned int action:8;
	unsigned int type:8;
	/* is this node still in the rbtree? */
	unsigned int is_head:1;
	unsigned int in_tree:1;
};

struct btrfs_delayed_extent_op {
	struct btrfs_disk_key key;
	u8 level;
	bool update_key;
	bool update_flags;
	bool is_data;
	u64 flags_to_set;
};

/*
 * the head refs are used to hold a lock on a given extent, which allows us
 * to make sure that only one process is running the delayed refs
 * at a time for a single extent.  They also store the sum of all the
 * reference count modifications we've queued up.
 */
struct btrfs_delayed_ref_head {
	struct btrfs_delayed_ref_node node;

	/*
	 * the mutex is held while running the refs, and it is also
	 * held when checking the sum of reference modifications.
	 */
	struct mutex mutex;

	spinlock_t lock;
	struct list_head ref_list;
	/* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
	struct list_head ref_add_list;

	struct rb_node href_node;

	struct btrfs_delayed_extent_op *extent_op;

	/*
	 * This is used to track the final ref_mod from all the refs associated
	 * with this head ref, this is not adjusted as delayed refs are run,
	 * this is meant to track if we need to do the csum accounting or not.
	 */
	int total_ref_mod;

	/*
	 * For qgroup reserved space freeing.
	 *
	 * ref_root and reserved will be recorded after
	 * BTRFS_ADD_DELAYED_EXTENT is called.
	 * And will be used to free reserved qgroup space at
	 * run_delayed_refs() time.
	 */
	u64 qgroup_ref_root;
	u64 qgroup_reserved;

	/*
	 * when a new extent is allocated, it is just reserved in memory
	 * The actual extent isn't inserted into the extent allocation tree
	 * until the delayed ref is processed.  must_insert_reserved is
	 * used to flag a delayed ref so the accounting can be updated
	 * when a full insert is done.
	 *
	 * It is possible the extent will be freed before it is ever
	 * inserted into the extent allocation tree.  In this case
	 * we need to update the in ram accounting to properly reflect
	 * the free has happened.
	 */
	unsigned int must_insert_reserved:1;
	unsigned int is_data:1;
	unsigned int processing:1;
};

struct btrfs_delayed_tree_ref {
	struct btrfs_delayed_ref_node node;
	u64 root;
	u64 parent;
	int level;
};

struct btrfs_delayed_data_ref {
	struct btrfs_delayed_ref_node node;
	u64 root;
	u64 parent;
	u64 objectid;
	u64 offset;
};

struct btrfs_delayed_ref_root {
	/* head ref rbtree */
	struct rb_root href_root;

	/* dirty extent records */
	struct rb_root dirty_extent_root;

	/* this spin lock protects the rbtree and the entries inside */
	spinlock_t lock;

	/* how many delayed ref updates we've queued, used by the
	 * throttling code
	 */
	atomic_t num_entries;

	/* total number of head nodes in tree */
	unsigned long num_heads;

	/* total number of head nodes ready for processing */
	unsigned long num_heads_ready;

	u64 pending_csums;

	/*
	 * set when the tree is flushing before a transaction commit,
	 * used by the throttling code to decide if new updates need
	 * to be run right away
	 */
	int flushing;

	u64 run_delayed_start;

	/*
	 * To make qgroup to skip given root.
	 * This is for snapshot, as btrfs_qgroup_inherit() will manually
	 * modify counters for snapshot and its source, so we should skip
	 * the snapshot in new_root/old_roots or it will get calculated twice
	 */
	u64 qgroup_to_skip;
};

extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
extern struct kmem_cache *btrfs_delayed_extent_op_cachep;

int btrfs_delayed_ref_init(void);
void btrfs_delayed_ref_exit(void);

static inline struct btrfs_delayed_extent_op *
btrfs_alloc_delayed_extent_op(void)
{
	return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS);
}

static inline void
btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op)
{
	if (op)
		kmem_cache_free(btrfs_delayed_extent_op_cachep, op);
}

static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
{
	WARN_ON(atomic_read(&ref->refs) == 0);
	if (atomic_dec_and_test(&ref->refs)) {
		WARN_ON(ref->in_tree);
		switch (ref->type) {
		case BTRFS_TREE_BLOCK_REF_KEY:
		case BTRFS_SHARED_BLOCK_REF_KEY:
			kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
			break;
		case BTRFS_EXTENT_DATA_REF_KEY:
		case BTRFS_SHARED_DATA_REF_KEY:
			kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
			break;
		case 0:
			kmem_cache_free(btrfs_delayed_ref_head_cachep, ref);
			break;
		default:
			BUG();
		}
	}
}

int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
			       struct btrfs_trans_handle *trans,
			       u64 bytenr, u64 num_bytes, u64 parent,
			       u64 ref_root, int level, int action,
			       struct btrfs_delayed_extent_op *extent_op);
int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
			       struct btrfs_trans_handle *trans,
			       u64 bytenr, u64 num_bytes,
			       u64 parent, u64 ref_root,
			       u64 owner, u64 offset, u64 reserved, int action,
			       struct btrfs_delayed_extent_op *extent_op);
int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
				struct btrfs_trans_handle *trans,
				u64 bytenr, u64 num_bytes,
				struct btrfs_delayed_extent_op *extent_op);
void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
			      struct btrfs_fs_info *fs_info,
			      struct btrfs_delayed_ref_root *delayed_refs,
			      struct btrfs_delayed_ref_head *head);

struct btrfs_delayed_ref_head *
btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
			   struct btrfs_delayed_ref_head *head);
static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
{
	mutex_unlock(&head->mutex);
}


struct btrfs_delayed_ref_head *
btrfs_select_ref_head(struct btrfs_trans_handle *trans);

int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
			    struct btrfs_delayed_ref_root *delayed_refs,
			    u64 seq);

/*
 * a node might live in a head or a regular ref, this lets you
 * test for the proper type to use.
 */
static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node)
{
	return node->is_head;
}

/*
 * helper functions to cast a node into its container
 */
static inline struct btrfs_delayed_tree_ref *
btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
{
	WARN_ON(btrfs_delayed_ref_is_head(node));
	return container_of(node, struct btrfs_delayed_tree_ref, node);
}

static inline struct btrfs_delayed_data_ref *
btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node)
{
	WARN_ON(btrfs_delayed_ref_is_head(node));
	return container_of(node, struct btrfs_delayed_data_ref, node);
}

static inline struct btrfs_delayed_ref_head *
btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node)
{
	WARN_ON(!btrfs_delayed_ref_is_head(node));
	return container_of(node, struct btrfs_delayed_ref_head, node);
}
#endif
Commit	Line	Data
56bec294 CM	1	/*
	2	* Copyright (C) 2008 Oracle. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public
	6	* License v2 as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public
	14	* License along with this program; if not, write to the
	15	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	16	* Boston, MA 021110-1307, USA.
	17	*/
	18	#ifndef __DELAYED_REF__
	19	#define __DELAYED_REF__
	20
44a075bd	21	/* these are the possible values of struct btrfs_delayed_ref_node->action */
56bec294 CM	22	#define BTRFS_ADD_DELAYED_REF 1 /* add one backref to the tree */
	23	#define BTRFS_DROP_DELAYED_REF 2 /* delete one backref from the tree */
	24	#define BTRFS_ADD_DELAYED_EXTENT 3 /* record a full extent allocation */
1a81af4d	25	#define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */
56bec294	26
c6fc2454 QW	27	/*
	28	* XXX: Qu: I really hate the design that ref_head and tree/data ref shares the
	29	* same ref_node structure.
	30	* Ref_head is in a higher logic level than tree/data ref, and duplicated
	31	* bytenr/num_bytes in ref_node is really a waste or memory, they should be
	32	* referred from ref_head.
	33	* This gets more disgusting after we use list to store tree/data ref in
	34	* ref_head. Must clean this mess up later.
	35	*/
56bec294	36	struct btrfs_delayed_ref_node {
c6fc2454 QW	37	/*
	38	* ref_head use rb tree, stored in ref_root->href.
	39	* indexed by bytenr
	40	*/
56bec294 CM	41	struct rb_node rb_node;
56bec294 CM	42
c6fc2454 QW	43	/data/tree ref use list, stored in ref_head->ref_list. /
c6fc2454 QW	44	struct list_head list;
1d57ee94 WX	45	/*
	46	* If action is BTRFS_ADD_DELAYED_REF, also link this node to
	47	* ref_head->ref_add_list, then we do not need to iterate the
	48	* whole ref_head->ref_list to find BTRFS_ADD_DELAYED_REF nodes.
	49	*/
	50	struct list_head add_list;
c6fc2454	51
56bec294 CM	52	/* the starting bytenr of the extent */
	53	u64 bytenr;
	54
56bec294 CM	55	/* the size of the extent */
	56	u64 num_bytes;
	57
00f04b88 AJ	58	/* seq number to keep track of insertion order */
	59	u64 seq;
	60
56bec294 CM	61	/* ref count on this data structure */
	62	atomic_t refs;
	63
	64	/*
	65	* how many refs is this entry adding or deleting. For
	66	* head refs, this may be a negative number because it is keeping
	67	* track of the total mods done to the reference count.
	68	* For individual refs, this will always be a positive number
	69	*
	70	* It may be more than one, since it is possible for a single
	71	* parent to have more than one ref on an extent
	72	*/
	73	int ref_mod;
	74
5d4f98a2 YZ	75	unsigned int action:8;
5d4f98a2 YZ	76	unsigned int type:8;
56bec294	77	/* is this node still in the rbtree? */
5d4f98a2	78	unsigned int is_head:1;
56bec294 CM	79	unsigned int in_tree:1;
	80	};
	81
5d4f98a2 YZ	82	struct btrfs_delayed_extent_op {
5d4f98a2 YZ	83	struct btrfs_disk_key key;
35b3ad50 DS	84	u8 level;
	85	bool update_key;
	86	bool update_flags;
	87	bool is_data;
5d4f98a2	88	u64 flags_to_set;
5d4f98a2 YZ	89	};
5d4f98a2 YZ	90
56bec294 CM	91	/*
	92	* the head refs are used to hold a lock on a given extent, which allows us
	93	* to make sure that only one process is running the delayed refs
	94	* at a time for a single extent. They also store the sum of all the
	95	* reference count modifications we've queued up.
	96	*/
	97	struct btrfs_delayed_ref_head {
	98	struct btrfs_delayed_ref_node node;
	99
	100	/*
	101	* the mutex is held while running the refs, and it is also
	102	* held when checking the sum of reference modifications.
	103	*/
	104	struct mutex mutex;
	105
d7df2c79	106	spinlock_t lock;
c6fc2454	107	struct list_head ref_list;
1d57ee94 WX	108	/* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
1d57ee94 WX	109	struct list_head ref_add_list;
c3e69d58	110
c46effa6 LB	111	struct rb_node href_node;
c46effa6 LB	112
5d4f98a2	113	struct btrfs_delayed_extent_op *extent_op;
1262133b JB	114
	115	/*
	116	* This is used to track the final ref_mod from all the refs associated
	117	* with this head ref, this is not adjusted as delayed refs are run,
	118	* this is meant to track if we need to do the csum accounting or not.
	119	*/
	120	int total_ref_mod;
	121
f64d5ca8 QW	122	/*
	123	* For qgroup reserved space freeing.
	124	*
	125	* ref_root and reserved will be recorded after
	126	* BTRFS_ADD_DELAYED_EXTENT is called.
	127	* And will be used to free reserved qgroup space at
	128	* run_delayed_refs() time.
	129	*/
	130	u64 qgroup_ref_root;
	131	u64 qgroup_reserved;
	132
56bec294 CM	133	/*
	134	* when a new extent is allocated, it is just reserved in memory
	135	* The actual extent isn't inserted into the extent allocation tree
	136	* until the delayed ref is processed. must_insert_reserved is
	137	* used to flag a delayed ref so the accounting can be updated
	138	* when a full insert is done.
	139	*
	140	* It is possible the extent will be freed before it is ever
	141	* inserted into the extent allocation tree. In this case
	142	* we need to update the in ram accounting to properly reflect
	143	* the free has happened.
	144	*/
	145	unsigned int must_insert_reserved:1;
5d4f98a2	146	unsigned int is_data:1;
d7df2c79	147	unsigned int processing:1;
56bec294 CM	148	};
56bec294 CM	149
5d4f98a2	150	struct btrfs_delayed_tree_ref {
56bec294	151	struct btrfs_delayed_ref_node node;
eebe063b AJ	152	u64 root;
eebe063b AJ	153	u64 parent;
5d4f98a2 YZ	154	int level;
5d4f98a2 YZ	155	};
56bec294	156
5d4f98a2 YZ	157	struct btrfs_delayed_data_ref {
5d4f98a2 YZ	158	struct btrfs_delayed_ref_node node;
eebe063b AJ	159	u64 root;
eebe063b AJ	160	u64 parent;
5d4f98a2 YZ	161	u64 objectid;
5d4f98a2 YZ	162	u64 offset;
56bec294 CM	163	};
	164
	165	struct btrfs_delayed_ref_root {
c46effa6 LB	166	/* head ref rbtree */
	167	struct rb_root href_root;
	168
3368d001 QW	169	/* dirty extent records */
	170	struct rb_root dirty_extent_root;
	171
56bec294 CM	172	/* this spin lock protects the rbtree and the entries inside */
	173	spinlock_t lock;
	174
	175	/* how many delayed ref updates we've queued, used by the
	176	* throttling code
	177	*/
d7df2c79	178	atomic_t num_entries;
56bec294	179
c3e69d58 CM	180	/* total number of head nodes in tree */
	181	unsigned long num_heads;
	182
	183	/* total number of head nodes ready for processing */
	184	unsigned long num_heads_ready;
	185
1262133b JB	186	u64 pending_csums;
1262133b JB	187
56bec294 CM	188	/*
	189	* set when the tree is flushing before a transaction commit,
	190	* used by the throttling code to decide if new updates need
	191	* to be run right away
	192	*/
	193	int flushing;
c3e69d58 CM	194
c3e69d58 CM	195	u64 run_delayed_start;
9086db86 QW	196
	197	/*
	198	* To make qgroup to skip given root.
01327610	199	* This is for snapshot, as btrfs_qgroup_inherit() will manually
9086db86 QW	200	* modify counters for snapshot and its source, so we should skip
	201	* the snapshot in new_root/old_roots or it will get calculated twice
	202	*/
	203	u64 qgroup_to_skip;
56bec294 CM	204	};
56bec294 CM	205
78a6184a MX	206	extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
	207	extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
	208	extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
	209	extern struct kmem_cache *btrfs_delayed_extent_op_cachep;
	210
	211	int btrfs_delayed_ref_init(void);
	212	void btrfs_delayed_ref_exit(void);
	213
	214	static inline struct btrfs_delayed_extent_op *
	215	btrfs_alloc_delayed_extent_op(void)
	216	{
	217	return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS);
	218	}
	219
	220	static inline void
	221	btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op)
	222	{
	223	if (op)
	224	kmem_cache_free(btrfs_delayed_extent_op_cachep, op);
	225	}
	226
56bec294 CM	227	static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
	228	{
	229	WARN_ON(atomic_read(&ref->refs) == 0);
	230	if (atomic_dec_and_test(&ref->refs)) {
	231	WARN_ON(ref->in_tree);
78a6184a MX	232	switch (ref->type) {
	233	case BTRFS_TREE_BLOCK_REF_KEY:
	234	case BTRFS_SHARED_BLOCK_REF_KEY:
	235	kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
	236	break;
	237	case BTRFS_EXTENT_DATA_REF_KEY:
	238	case BTRFS_SHARED_DATA_REF_KEY:
	239	kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
	240	break;
	241	case 0:
	242	kmem_cache_free(btrfs_delayed_ref_head_cachep, ref);
	243	break;
	244	default:
	245	BUG();
	246	}
56bec294 CM	247	}
	248	}
	249
66d7e7f0 AJ	250	int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
66d7e7f0 AJ	251	struct btrfs_trans_handle *trans,
5d4f98a2 YZ	252	u64 bytenr, u64 num_bytes, u64 parent,
5d4f98a2 YZ	253	u64 ref_root, int level, int action,
b06c4bf5	254	struct btrfs_delayed_extent_op *extent_op);
66d7e7f0 AJ	255	int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
66d7e7f0 AJ	256	struct btrfs_trans_handle *trans,
5d4f98a2 YZ	257	u64 bytenr, u64 num_bytes,
5d4f98a2 YZ	258	u64 parent, u64 ref_root,
5846a3c2	259	u64 owner, u64 offset, u64 reserved, int action,
b06c4bf5	260	struct btrfs_delayed_extent_op *extent_op);
66d7e7f0 AJ	261	int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
66d7e7f0 AJ	262	struct btrfs_trans_handle *trans,
5d4f98a2 YZ	263	u64 bytenr, u64 num_bytes,
5d4f98a2 YZ	264	struct btrfs_delayed_extent_op *extent_op);
ae1e206b JB	265	void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
	266	struct btrfs_fs_info *fs_info,
	267	struct btrfs_delayed_ref_root *delayed_refs,
	268	struct btrfs_delayed_ref_head *head);
56bec294	269
1887be66 CM	270	struct btrfs_delayed_ref_head *
1887be66 CM	271	btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
c3e69d58 CM	272	int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
c3e69d58 CM	273	struct btrfs_delayed_ref_head *head);
093486c4 MX	274	static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
	275	{
	276	mutex_unlock(&head->mutex);
	277	}
	278
d7df2c79 JB	279
	280	struct btrfs_delayed_ref_head *
	281	btrfs_select_ref_head(struct btrfs_trans_handle *trans);
00f04b88	282
097b8a7c JS	283	int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
097b8a7c JS	284	struct btrfs_delayed_ref_root *delayed_refs,
00f04b88 AJ	285	u64 seq);
00f04b88 AJ	286
56bec294 CM	287	/*
	288	* a node might live in a head or a regular ref, this lets you
	289	* test for the proper type to use.
	290	*/
	291	static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node)
	292	{
5d4f98a2	293	return node->is_head;
56bec294 CM	294	}
	295
	296	/*
	297	* helper functions to cast a node into its container
	298	*/
5d4f98a2 YZ	299	static inline struct btrfs_delayed_tree_ref *
5d4f98a2 YZ	300	btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
56bec294 CM	301	{
56bec294 CM	302	WARN_ON(btrfs_delayed_ref_is_head(node));
5d4f98a2 YZ	303	return container_of(node, struct btrfs_delayed_tree_ref, node);
5d4f98a2 YZ	304	}
56bec294	305
5d4f98a2 YZ	306	static inline struct btrfs_delayed_data_ref *
	307	btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node)
	308	{
	309	WARN_ON(btrfs_delayed_ref_is_head(node));
	310	return container_of(node, struct btrfs_delayed_data_ref, node);
56bec294 CM	311	}
	312
	313	static inline struct btrfs_delayed_ref_head *
	314	btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node)
	315	{
	316	WARN_ON(!btrfs_delayed_ref_is_head(node));
	317	return container_of(node, struct btrfs_delayed_ref_head, node);
56bec294 CM	318	}
56bec294 CM	319	#endif