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v6.13.7
  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Copyright (C) 2008 Oracle.  All rights reserved.
  4 */
  5
  6#ifndef BTRFS_DELAYED_REF_H
  7#define BTRFS_DELAYED_REF_H
  8
  9#include <linux/types.h>
 10#include <linux/refcount.h>
 11#include <linux/list.h>
 12#include <linux/rbtree.h>
 13#include <linux/mutex.h>
 14#include <linux/spinlock.h>
 15#include <linux/slab.h>
 16#include <uapi/linux/btrfs_tree.h>
 17
 18struct btrfs_trans_handle;
 19struct btrfs_fs_info;
 20
 21/* these are the possible values of struct btrfs_delayed_ref_node->action */
 22enum btrfs_delayed_ref_action {
 23	/* Add one backref to the tree */
 24	BTRFS_ADD_DELAYED_REF = 1,
 25	/* Delete one backref from the tree */
 26	BTRFS_DROP_DELAYED_REF,
 27	/* Record a full extent allocation */
 28	BTRFS_ADD_DELAYED_EXTENT,
 29	/* Not changing ref count on head ref */
 30	BTRFS_UPDATE_DELAYED_HEAD,
 31} __packed;
 32
 33struct btrfs_data_ref {
 34	/* For EXTENT_DATA_REF */
 35
 36	/* Inode which refers to this data extent */
 37	u64 objectid;
 38
 39	/*
 40	 * file_offset - extent_offset
 41	 *
 42	 * file_offset is the key.offset of the EXTENT_DATA key.
 43	 * extent_offset is btrfs_file_extent_offset() of the EXTENT_DATA data.
 44	 */
 45	u64 offset;
 46};
 47
 48struct btrfs_tree_ref {
 49	/*
 50	 * Level of this tree block.
 51	 *
 52	 * Shared for skinny (TREE_BLOCK_REF) and normal tree ref.
 53	 */
 54	int level;
 55
 56	/* For non-skinny metadata, no special member needed */
 57};
 58
 59struct btrfs_delayed_ref_node {
 60	struct rb_node ref_node;
 61	/*
 62	 * If action is BTRFS_ADD_DELAYED_REF, also link this node to
 63	 * ref_head->ref_add_list, then we do not need to iterate the
 64	 * refs rbtree in the corresponding delayed ref head
 65	 * (struct btrfs_delayed_ref_head::ref_tree).
 66	 */
 67	struct list_head add_list;
 68
 69	/* the starting bytenr of the extent */
 70	u64 bytenr;
 71
 72	/* the size of the extent */
 73	u64 num_bytes;
 74
 75	/* seq number to keep track of insertion order */
 76	u64 seq;
 77
 78	/* The ref_root for this ref */
 79	u64 ref_root;
 80
 81	/*
 82	 * The parent for this ref, if this isn't set the ref_root is the
 83	 * reference owner.
 84	 */
 85	u64 parent;
 86
 87	/* ref count on this data structure */
 88	refcount_t refs;
 89
 90	/*
 91	 * how many refs is this entry adding or deleting.  For
 92	 * head refs, this may be a negative number because it is keeping
 93	 * track of the total mods done to the reference count.
 94	 * For individual refs, this will always be a positive number
 95	 *
 96	 * It may be more than one, since it is possible for a single
 97	 * parent to have more than one ref on an extent
 98	 */
 99	int ref_mod;
100
101	unsigned int action:8;
102	unsigned int type:8;
103
104	union {
105		struct btrfs_tree_ref tree_ref;
106		struct btrfs_data_ref data_ref;
107	};
108};
109
110struct btrfs_delayed_extent_op {
111	struct btrfs_disk_key key;
 
112	bool update_key;
113	bool update_flags;
114	u64 flags_to_set;
115};
116
117/*
118 * the head refs are used to hold a lock on a given extent, which allows us
119 * to make sure that only one process is running the delayed refs
120 * at a time for a single extent.  They also store the sum of all the
121 * reference count modifications we've queued up.
122 */
123struct btrfs_delayed_ref_head {
124	u64 bytenr;
125	u64 num_bytes;
126	/*
 
 
 
 
 
 
127	 * the mutex is held while running the refs, and it is also
128	 * held when checking the sum of reference modifications.
129	 */
130	struct mutex mutex;
131
132	refcount_t refs;
133
134	/* Protects 'ref_tree' and 'ref_add_list'. */
135	spinlock_t lock;
136	struct rb_root_cached ref_tree;
137	/* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
138	struct list_head ref_add_list;
139
140	struct btrfs_delayed_extent_op *extent_op;
141
142	/*
143	 * This is used to track the final ref_mod from all the refs associated
144	 * with this head ref, this is not adjusted as delayed refs are run,
145	 * this is meant to track if we need to do the csum accounting or not.
146	 */
147	int total_ref_mod;
148
149	/*
150	 * This is the current outstanding mod references for this bytenr.  This
151	 * is used with lookup_extent_info to get an accurate reference count
152	 * for a bytenr, so it is adjusted as delayed refs are run so that any
153	 * on disk reference count + ref_mod is accurate.
154	 */
155	int ref_mod;
156
157	/*
158	 * The root that triggered the allocation when must_insert_reserved is
159	 * set to true.
160	 */
161	u64 owning_root;
162
163	/*
164	 * Track reserved bytes when setting must_insert_reserved.  On success
165	 * or cleanup, we will need to free the reservation.
166	 */
167	u64 reserved_bytes;
168
169	/* Tree block level, for metadata only. */
170	u8 level;
171
172	/*
173	 * when a new extent is allocated, it is just reserved in memory
174	 * The actual extent isn't inserted into the extent allocation tree
175	 * until the delayed ref is processed.  must_insert_reserved is
176	 * used to flag a delayed ref so the accounting can be updated
177	 * when a full insert is done.
178	 *
179	 * It is possible the extent will be freed before it is ever
180	 * inserted into the extent allocation tree.  In this case
181	 * we need to update the in ram accounting to properly reflect
182	 * the free has happened.
183	 */
184	bool must_insert_reserved;
185
186	bool is_data;
187	bool is_system;
188	bool processing;
189	/*
190	 * Indicate if it's currently in the data structure that tracks head
191	 * refs (struct btrfs_delayed_ref_root::head_refs).
192	 */
193	bool tracked;
 
 
 
 
 
 
 
 
 
 
194};
195
196enum btrfs_delayed_ref_flags {
197	/* Indicate that we are flushing delayed refs for the commit */
198	BTRFS_DELAYED_REFS_FLUSHING,
199};
200
201struct btrfs_delayed_ref_root {
202	/*
203	 * Track head references.
204	 * The keys correspond to the logical address of the extent ("bytenr")
205	 * right shifted by fs_info->sectorsize_bits. This is both to get a more
206	 * dense index space (optimizes xarray structure) and because indexes in
207	 * xarrays are of "unsigned long" type, meaning they are 32 bits wide on
208	 * 32 bits platforms, limiting the extent range to 4G which is too low
209	 * and makes it unusable (truncated index values) on 32 bits platforms.
210	 * Protected by the spinlock 'lock' defined below.
211	 */
212	struct xarray head_refs;
213
214	/*
215	 * Track dirty extent records.
216	 * The keys correspond to the logical address of the extent ("bytenr")
217	 * right shifted by fs_info->sectorsize_bits, for same reasons as above.
218	 */
219	struct xarray dirty_extents;
220
221	/*
222	 * Protects the xarray head_refs, its entries and the following fields:
223	 * num_heads, num_heads_ready, pending_csums and run_delayed_start.
224	 */
225	spinlock_t lock;
226
227	/* Total number of head refs, protected by the spinlock 'lock'. */
 
 
 
 
 
228	unsigned long num_heads;
229
230	/*
231	 * Total number of head refs ready for processing, protected by the
232	 * spinlock 'lock'.
233	 */
234	unsigned long num_heads_ready;
235
236	/*
237	 * Track space reserved for deleting csums of data extents.
238	 * Protected by the spinlock 'lock'.
239	 */
240	u64 pending_csums;
241
242	unsigned long flags;
243
244	/*
245	 * Track from which bytenr to start searching ref heads.
246	 * Protected by the spinlock 'lock'.
247	 */
248	u64 run_delayed_start;
249
250	/*
251	 * To make qgroup to skip given root.
252	 * This is for snapshot, as btrfs_qgroup_inherit() will manually
253	 * modify counters for snapshot and its source, so we should skip
254	 * the snapshot in new_root/old_roots or it will get calculated twice
255	 */
256	u64 qgroup_to_skip;
257};
258
259enum btrfs_ref_type {
260	BTRFS_REF_NOT_SET,
261	BTRFS_REF_DATA,
262	BTRFS_REF_METADATA,
263	BTRFS_REF_LAST,
264} __packed;
265
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
266struct btrfs_ref {
267	enum btrfs_ref_type type;
268	enum btrfs_delayed_ref_action action;
269
270	/*
271	 * Whether this extent should go through qgroup record.
272	 *
273	 * Normally false, but for certain cases like delayed subtree scan,
274	 * setting this flag can hugely reduce qgroup overhead.
275	 */
276	bool skip_qgroup;
277
278#ifdef CONFIG_BTRFS_FS_REF_VERIFY
279	/* Through which root is this modification. */
280	u64 real_root;
281#endif
282	u64 bytenr;
283	u64 num_bytes;
284	u64 owning_root;
285
286	/*
287	 * The root that owns the reference for this reference, this will be set
288	 * or ->parent will be set, depending on what type of reference this is.
289	 */
290	u64 ref_root;
291
292	/* Bytenr of the parent tree block */
293	u64 parent;
294	union {
295		struct btrfs_data_ref data_ref;
296		struct btrfs_tree_ref tree_ref;
297	};
298};
299
300extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
301extern struct kmem_cache *btrfs_delayed_ref_node_cachep;
 
302extern struct kmem_cache *btrfs_delayed_extent_op_cachep;
303
304int __init btrfs_delayed_ref_init(void);
305void __cold btrfs_delayed_ref_exit(void);
306
307static inline u64 btrfs_calc_delayed_ref_bytes(const struct btrfs_fs_info *fs_info,
308					       int num_delayed_refs)
309{
310	u64 num_bytes;
311
312	num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_delayed_refs);
313
314	/*
315	 * We have to check the mount option here because we could be enabling
316	 * the free space tree for the first time and don't have the compat_ro
317	 * option set yet.
318	 *
319	 * We need extra reservations if we have the free space tree because
320	 * we'll have to modify that tree as well.
321	 */
322	if (btrfs_test_opt(fs_info, FREE_SPACE_TREE))
323		num_bytes *= 2;
324
325	return num_bytes;
326}
327
328static inline u64 btrfs_calc_delayed_ref_csum_bytes(const struct btrfs_fs_info *fs_info,
329						    int num_csum_items)
330{
331	/*
332	 * Deleting csum items does not result in new nodes/leaves and does not
333	 * require changing the free space tree, only the csum tree, so this is
334	 * all we need.
335	 */
336	return btrfs_calc_metadata_size(fs_info, num_csum_items);
337}
338
339void btrfs_init_tree_ref(struct btrfs_ref *generic_ref, int level, u64 mod_root,
340			 bool skip_qgroup);
341void btrfs_init_data_ref(struct btrfs_ref *generic_ref, u64 ino, u64 offset,
342			 u64 mod_root, bool skip_qgroup);
 
 
343
344static inline struct btrfs_delayed_extent_op *
345btrfs_alloc_delayed_extent_op(void)
346{
347	return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS);
348}
349
350static inline void
351btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op)
352{
353	if (op)
354		kmem_cache_free(btrfs_delayed_extent_op_cachep, op);
355}
356
357void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref);
358
359static inline u64 btrfs_ref_head_to_space_flags(
360				struct btrfs_delayed_ref_head *head_ref)
361{
362	if (head_ref->is_data)
363		return BTRFS_BLOCK_GROUP_DATA;
364	else if (head_ref->is_system)
365		return BTRFS_BLOCK_GROUP_SYSTEM;
366	return BTRFS_BLOCK_GROUP_METADATA;
367}
368
369static inline void btrfs_put_delayed_ref_head(struct btrfs_delayed_ref_head *head)
370{
371	if (refcount_dec_and_test(&head->refs))
372		kmem_cache_free(btrfs_delayed_ref_head_cachep, head);
373}
374
375int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
376			       struct btrfs_ref *generic_ref,
377			       struct btrfs_delayed_extent_op *extent_op);
378int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
379			       struct btrfs_ref *generic_ref,
380			       u64 reserved);
381int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
382				u64 bytenr, u64 num_bytes, u8 level,
383				struct btrfs_delayed_extent_op *extent_op);
384void btrfs_merge_delayed_refs(struct btrfs_fs_info *fs_info,
385			      struct btrfs_delayed_ref_root *delayed_refs,
386			      struct btrfs_delayed_ref_head *head);
387
388struct btrfs_delayed_ref_head *
389btrfs_find_delayed_ref_head(const struct btrfs_fs_info *fs_info,
390			    struct btrfs_delayed_ref_root *delayed_refs,
391			    u64 bytenr);
 
 
392static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
393{
394	mutex_unlock(&head->mutex);
395}
396void btrfs_delete_ref_head(const struct btrfs_fs_info *fs_info,
397			   struct btrfs_delayed_ref_root *delayed_refs,
398			   struct btrfs_delayed_ref_head *head);
399
400struct btrfs_delayed_ref_head *btrfs_select_ref_head(
401		const struct btrfs_fs_info *fs_info,
402		struct btrfs_delayed_ref_root *delayed_refs);
403void btrfs_unselect_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
404			     struct btrfs_delayed_ref_head *head);
405
406int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq);
407
408void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr_refs, int nr_csums);
409void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans);
410void btrfs_inc_delayed_refs_rsv_bg_inserts(struct btrfs_fs_info *fs_info);
411void btrfs_dec_delayed_refs_rsv_bg_inserts(struct btrfs_fs_info *fs_info);
412void btrfs_inc_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info);
413void btrfs_dec_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info);
414int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
415				  enum btrfs_reserve_flush_enum flush);
 
 
416bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info);
417bool btrfs_find_delayed_tree_ref(struct btrfs_delayed_ref_head *head,
418				 u64 root, u64 parent);
419void btrfs_destroy_delayed_refs(struct btrfs_transaction *trans);
420
421static inline u64 btrfs_delayed_ref_owner(struct btrfs_delayed_ref_node *node)
422{
423	if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
424	    node->type == BTRFS_SHARED_DATA_REF_KEY)
425		return node->data_ref.objectid;
426	return node->tree_ref.level;
427}
428
429static inline u64 btrfs_delayed_ref_offset(struct btrfs_delayed_ref_node *node)
430{
431	if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
432	    node->type == BTRFS_SHARED_DATA_REF_KEY)
433		return node->data_ref.offset;
434	return 0;
435}
436
437static inline u8 btrfs_ref_type(struct btrfs_ref *ref)
 
438{
439	ASSERT(ref->type == BTRFS_REF_DATA || ref->type == BTRFS_REF_METADATA);
440
441	if (ref->type == BTRFS_REF_DATA) {
442		if (ref->parent)
443			return BTRFS_SHARED_DATA_REF_KEY;
444		else
445			return BTRFS_EXTENT_DATA_REF_KEY;
446	} else {
447		if (ref->parent)
448			return BTRFS_SHARED_BLOCK_REF_KEY;
449		else
450			return BTRFS_TREE_BLOCK_REF_KEY;
451	}
452
453	return 0;
454}
455
456#endif
v6.9.4
  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Copyright (C) 2008 Oracle.  All rights reserved.
  4 */
  5
  6#ifndef BTRFS_DELAYED_REF_H
  7#define BTRFS_DELAYED_REF_H
  8
  9#include <linux/types.h>
 10#include <linux/refcount.h>
 11#include <linux/list.h>
 12#include <linux/rbtree.h>
 13#include <linux/mutex.h>
 14#include <linux/spinlock.h>
 15#include <linux/slab.h>
 16#include <uapi/linux/btrfs_tree.h>
 17
 18struct btrfs_trans_handle;
 19struct btrfs_fs_info;
 20
 21/* these are the possible values of struct btrfs_delayed_ref_node->action */
 22enum btrfs_delayed_ref_action {
 23	/* Add one backref to the tree */
 24	BTRFS_ADD_DELAYED_REF = 1,
 25	/* Delete one backref from the tree */
 26	BTRFS_DROP_DELAYED_REF,
 27	/* Record a full extent allocation */
 28	BTRFS_ADD_DELAYED_EXTENT,
 29	/* Not changing ref count on head ref */
 30	BTRFS_UPDATE_DELAYED_HEAD,
 31} __packed;
 32
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 33struct btrfs_delayed_ref_node {
 34	struct rb_node ref_node;
 35	/*
 36	 * If action is BTRFS_ADD_DELAYED_REF, also link this node to
 37	 * ref_head->ref_add_list, then we do not need to iterate the
 38	 * whole ref_head->ref_list to find BTRFS_ADD_DELAYED_REF nodes.
 
 39	 */
 40	struct list_head add_list;
 41
 42	/* the starting bytenr of the extent */
 43	u64 bytenr;
 44
 45	/* the size of the extent */
 46	u64 num_bytes;
 47
 48	/* seq number to keep track of insertion order */
 49	u64 seq;
 50
 
 
 
 
 
 
 
 
 
 51	/* ref count on this data structure */
 52	refcount_t refs;
 53
 54	/*
 55	 * how many refs is this entry adding or deleting.  For
 56	 * head refs, this may be a negative number because it is keeping
 57	 * track of the total mods done to the reference count.
 58	 * For individual refs, this will always be a positive number
 59	 *
 60	 * It may be more than one, since it is possible for a single
 61	 * parent to have more than one ref on an extent
 62	 */
 63	int ref_mod;
 64
 65	unsigned int action:8;
 66	unsigned int type:8;
 
 
 
 
 
 67};
 68
 69struct btrfs_delayed_extent_op {
 70	struct btrfs_disk_key key;
 71	u8 level;
 72	bool update_key;
 73	bool update_flags;
 74	u64 flags_to_set;
 75};
 76
 77/*
 78 * the head refs are used to hold a lock on a given extent, which allows us
 79 * to make sure that only one process is running the delayed refs
 80 * at a time for a single extent.  They also store the sum of all the
 81 * reference count modifications we've queued up.
 82 */
 83struct btrfs_delayed_ref_head {
 84	u64 bytenr;
 85	u64 num_bytes;
 86	/*
 87	 * For insertion into struct btrfs_delayed_ref_root::href_root.
 88	 * Keep it in the same cache line as 'bytenr' for more efficient
 89	 * searches in the rbtree.
 90	 */
 91	struct rb_node href_node;
 92	/*
 93	 * the mutex is held while running the refs, and it is also
 94	 * held when checking the sum of reference modifications.
 95	 */
 96	struct mutex mutex;
 97
 98	refcount_t refs;
 99
100	/* Protects 'ref_tree' and 'ref_add_list'. */
101	spinlock_t lock;
102	struct rb_root_cached ref_tree;
103	/* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
104	struct list_head ref_add_list;
105
106	struct btrfs_delayed_extent_op *extent_op;
107
108	/*
109	 * This is used to track the final ref_mod from all the refs associated
110	 * with this head ref, this is not adjusted as delayed refs are run,
111	 * this is meant to track if we need to do the csum accounting or not.
112	 */
113	int total_ref_mod;
114
115	/*
116	 * This is the current outstanding mod references for this bytenr.  This
117	 * is used with lookup_extent_info to get an accurate reference count
118	 * for a bytenr, so it is adjusted as delayed refs are run so that any
119	 * on disk reference count + ref_mod is accurate.
120	 */
121	int ref_mod;
122
123	/*
124	 * The root that triggered the allocation when must_insert_reserved is
125	 * set to true.
126	 */
127	u64 owning_root;
128
129	/*
130	 * Track reserved bytes when setting must_insert_reserved.  On success
131	 * or cleanup, we will need to free the reservation.
132	 */
133	u64 reserved_bytes;
134
 
 
 
135	/*
136	 * when a new extent is allocated, it is just reserved in memory
137	 * The actual extent isn't inserted into the extent allocation tree
138	 * until the delayed ref is processed.  must_insert_reserved is
139	 * used to flag a delayed ref so the accounting can be updated
140	 * when a full insert is done.
141	 *
142	 * It is possible the extent will be freed before it is ever
143	 * inserted into the extent allocation tree.  In this case
144	 * we need to update the in ram accounting to properly reflect
145	 * the free has happened.
146	 */
147	bool must_insert_reserved;
148
149	bool is_data;
150	bool is_system;
151	bool processing;
152};
153
154struct btrfs_delayed_tree_ref {
155	struct btrfs_delayed_ref_node node;
156	u64 root;
157	u64 parent;
158	int level;
159};
160
161struct btrfs_delayed_data_ref {
162	struct btrfs_delayed_ref_node node;
163	u64 root;
164	u64 parent;
165	u64 objectid;
166	u64 offset;
167};
168
169enum btrfs_delayed_ref_flags {
170	/* Indicate that we are flushing delayed refs for the commit */
171	BTRFS_DELAYED_REFS_FLUSHING,
172};
173
174struct btrfs_delayed_ref_root {
175	/* head ref rbtree */
176	struct rb_root_cached href_root;
 
 
 
 
 
 
 
 
 
177
178	/* dirty extent records */
179	struct rb_root dirty_extent_root;
 
 
 
 
180
181	/* this spin lock protects the rbtree and the entries inside */
 
 
 
182	spinlock_t lock;
183
184	/* how many delayed ref updates we've queued, used by the
185	 * throttling code
186	 */
187	atomic_t num_entries;
188
189	/* total number of head nodes in tree */
190	unsigned long num_heads;
191
192	/* total number of head nodes ready for processing */
 
 
 
193	unsigned long num_heads_ready;
194
 
 
 
 
195	u64 pending_csums;
196
197	unsigned long flags;
198
 
 
 
 
199	u64 run_delayed_start;
200
201	/*
202	 * To make qgroup to skip given root.
203	 * This is for snapshot, as btrfs_qgroup_inherit() will manually
204	 * modify counters for snapshot and its source, so we should skip
205	 * the snapshot in new_root/old_roots or it will get calculated twice
206	 */
207	u64 qgroup_to_skip;
208};
209
210enum btrfs_ref_type {
211	BTRFS_REF_NOT_SET,
212	BTRFS_REF_DATA,
213	BTRFS_REF_METADATA,
214	BTRFS_REF_LAST,
215} __packed;
216
217struct btrfs_data_ref {
218	/* For EXTENT_DATA_REF */
219
220	/* Root which owns this data reference. */
221	u64 ref_root;
222
223	/* Inode which refers to this data extent */
224	u64 ino;
225
226	/*
227	 * file_offset - extent_offset
228	 *
229	 * file_offset is the key.offset of the EXTENT_DATA key.
230	 * extent_offset is btrfs_file_extent_offset() of the EXTENT_DATA data.
231	 */
232	u64 offset;
233};
234
235struct btrfs_tree_ref {
236	/*
237	 * Level of this tree block
238	 *
239	 * Shared for skinny (TREE_BLOCK_REF) and normal tree ref.
240	 */
241	int level;
242
243	/*
244	 * Root which owns this tree block reference.
245	 *
246	 * For TREE_BLOCK_REF (skinny metadata, either inline or keyed)
247	 */
248	u64 ref_root;
249
250	/* For non-skinny metadata, no special member needed */
251};
252
253struct btrfs_ref {
254	enum btrfs_ref_type type;
255	enum btrfs_delayed_ref_action action;
256
257	/*
258	 * Whether this extent should go through qgroup record.
259	 *
260	 * Normally false, but for certain cases like delayed subtree scan,
261	 * setting this flag can hugely reduce qgroup overhead.
262	 */
263	bool skip_qgroup;
264
265#ifdef CONFIG_BTRFS_FS_REF_VERIFY
266	/* Through which root is this modification. */
267	u64 real_root;
268#endif
269	u64 bytenr;
270	u64 len;
271	u64 owning_root;
272
 
 
 
 
 
 
273	/* Bytenr of the parent tree block */
274	u64 parent;
275	union {
276		struct btrfs_data_ref data_ref;
277		struct btrfs_tree_ref tree_ref;
278	};
279};
280
281extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
282extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
283extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
284extern struct kmem_cache *btrfs_delayed_extent_op_cachep;
285
286int __init btrfs_delayed_ref_init(void);
287void __cold btrfs_delayed_ref_exit(void);
288
289static inline u64 btrfs_calc_delayed_ref_bytes(const struct btrfs_fs_info *fs_info,
290					       int num_delayed_refs)
291{
292	u64 num_bytes;
293
294	num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_delayed_refs);
295
296	/*
297	 * We have to check the mount option here because we could be enabling
298	 * the free space tree for the first time and don't have the compat_ro
299	 * option set yet.
300	 *
301	 * We need extra reservations if we have the free space tree because
302	 * we'll have to modify that tree as well.
303	 */
304	if (btrfs_test_opt(fs_info, FREE_SPACE_TREE))
305		num_bytes *= 2;
306
307	return num_bytes;
308}
309
310static inline u64 btrfs_calc_delayed_ref_csum_bytes(const struct btrfs_fs_info *fs_info,
311						    int num_csum_items)
312{
313	/*
314	 * Deleting csum items does not result in new nodes/leaves and does not
315	 * require changing the free space tree, only the csum tree, so this is
316	 * all we need.
317	 */
318	return btrfs_calc_metadata_size(fs_info, num_csum_items);
319}
320
321void btrfs_init_generic_ref(struct btrfs_ref *generic_ref, int action, u64 bytenr,
322			    u64 len, u64 parent, u64 owning_root);
323void btrfs_init_tree_ref(struct btrfs_ref *generic_ref, int level, u64 root,
324			 u64 mod_root, bool skip_qgroup);
325void btrfs_init_data_ref(struct btrfs_ref *generic_ref, u64 ref_root, u64 ino,
326			 u64 offset, u64 mod_root, bool skip_qgroup);
327
328static inline struct btrfs_delayed_extent_op *
329btrfs_alloc_delayed_extent_op(void)
330{
331	return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS);
332}
333
334static inline void
335btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op)
336{
337	if (op)
338		kmem_cache_free(btrfs_delayed_extent_op_cachep, op);
339}
340
341void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref);
342
343static inline u64 btrfs_ref_head_to_space_flags(
344				struct btrfs_delayed_ref_head *head_ref)
345{
346	if (head_ref->is_data)
347		return BTRFS_BLOCK_GROUP_DATA;
348	else if (head_ref->is_system)
349		return BTRFS_BLOCK_GROUP_SYSTEM;
350	return BTRFS_BLOCK_GROUP_METADATA;
351}
352
353static inline void btrfs_put_delayed_ref_head(struct btrfs_delayed_ref_head *head)
354{
355	if (refcount_dec_and_test(&head->refs))
356		kmem_cache_free(btrfs_delayed_ref_head_cachep, head);
357}
358
359int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
360			       struct btrfs_ref *generic_ref,
361			       struct btrfs_delayed_extent_op *extent_op);
362int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
363			       struct btrfs_ref *generic_ref,
364			       u64 reserved);
365int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
366				u64 bytenr, u64 num_bytes,
367				struct btrfs_delayed_extent_op *extent_op);
368void btrfs_merge_delayed_refs(struct btrfs_fs_info *fs_info,
369			      struct btrfs_delayed_ref_root *delayed_refs,
370			      struct btrfs_delayed_ref_head *head);
371
372struct btrfs_delayed_ref_head *
373btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
 
374			    u64 bytenr);
375int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
376			   struct btrfs_delayed_ref_head *head);
377static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
378{
379	mutex_unlock(&head->mutex);
380}
381void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
 
382			   struct btrfs_delayed_ref_head *head);
383
384struct btrfs_delayed_ref_head *btrfs_select_ref_head(
 
385		struct btrfs_delayed_ref_root *delayed_refs);
 
 
386
387int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq);
388
389void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr_refs, int nr_csums);
390void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans);
391void btrfs_inc_delayed_refs_rsv_bg_inserts(struct btrfs_fs_info *fs_info);
392void btrfs_dec_delayed_refs_rsv_bg_inserts(struct btrfs_fs_info *fs_info);
393void btrfs_inc_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info);
394void btrfs_dec_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info);
395int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
396				  enum btrfs_reserve_flush_enum flush);
397void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
398				       u64 num_bytes);
399bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info);
 
 
 
400
401/*
402 * helper functions to cast a node into its container
403 */
404static inline struct btrfs_delayed_tree_ref *
405btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
 
 
 
 
406{
407	return container_of(node, struct btrfs_delayed_tree_ref, node);
 
 
 
408}
409
410static inline struct btrfs_delayed_data_ref *
411btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node)
412{
413	return container_of(node, struct btrfs_delayed_data_ref, node);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
414}
415
416#endif