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v6.8
  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/refcount.h>
 
 
 
 
 
 
 
 
 
 10
 11/* these are the possible values of struct btrfs_delayed_ref_node->action */
 12enum btrfs_delayed_ref_action {
 13	/* Add one backref to the tree */
 14	BTRFS_ADD_DELAYED_REF = 1,
 15	/* Delete one backref from the tree */
 16	BTRFS_DROP_DELAYED_REF,
 17	/* Record a full extent allocation */
 18	BTRFS_ADD_DELAYED_EXTENT,
 19	/* Not changing ref count on head ref */
 20	BTRFS_UPDATE_DELAYED_HEAD,
 21} __packed;
 22
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 23struct btrfs_delayed_ref_node {
 24	struct rb_node ref_node;
 25	/*
 26	 * If action is BTRFS_ADD_DELAYED_REF, also link this node to
 27	 * ref_head->ref_add_list, then we do not need to iterate the
 28	 * whole ref_head->ref_list to find BTRFS_ADD_DELAYED_REF nodes.
 
 29	 */
 30	struct list_head add_list;
 31
 32	/* the starting bytenr of the extent */
 33	u64 bytenr;
 34
 35	/* the size of the extent */
 36	u64 num_bytes;
 37
 38	/* seq number to keep track of insertion order */
 39	u64 seq;
 40
 
 
 
 
 
 
 
 
 
 41	/* ref count on this data structure */
 42	refcount_t refs;
 43
 44	/*
 45	 * how many refs is this entry adding or deleting.  For
 46	 * head refs, this may be a negative number because it is keeping
 47	 * track of the total mods done to the reference count.
 48	 * For individual refs, this will always be a positive number
 49	 *
 50	 * It may be more than one, since it is possible for a single
 51	 * parent to have more than one ref on an extent
 52	 */
 53	int ref_mod;
 54
 55	unsigned int action:8;
 56	unsigned int type:8;
 
 
 
 
 
 57};
 58
 59struct btrfs_delayed_extent_op {
 60	struct btrfs_disk_key key;
 61	u8 level;
 62	bool update_key;
 63	bool update_flags;
 64	u64 flags_to_set;
 65};
 66
 67/*
 68 * the head refs are used to hold a lock on a given extent, which allows us
 69 * to make sure that only one process is running the delayed refs
 70 * at a time for a single extent.  They also store the sum of all the
 71 * reference count modifications we've queued up.
 72 */
 73struct btrfs_delayed_ref_head {
 74	u64 bytenr;
 75	u64 num_bytes;
 76	/*
 77	 * For insertion into struct btrfs_delayed_ref_root::href_root.
 78	 * Keep it in the same cache line as 'bytenr' for more efficient
 79	 * searches in the rbtree.
 80	 */
 81	struct rb_node href_node;
 82	/*
 83	 * the mutex is held while running the refs, and it is also
 84	 * held when checking the sum of reference modifications.
 85	 */
 86	struct mutex mutex;
 87
 88	refcount_t refs;
 89
 90	/* Protects 'ref_tree' and 'ref_add_list'. */
 91	spinlock_t lock;
 92	struct rb_root_cached ref_tree;
 93	/* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
 94	struct list_head ref_add_list;
 95
 96	struct btrfs_delayed_extent_op *extent_op;
 97
 98	/*
 99	 * This is used to track the final ref_mod from all the refs associated
100	 * with this head ref, this is not adjusted as delayed refs are run,
101	 * this is meant to track if we need to do the csum accounting or not.
102	 */
103	int total_ref_mod;
104
105	/*
106	 * This is the current outstanding mod references for this bytenr.  This
107	 * is used with lookup_extent_info to get an accurate reference count
108	 * for a bytenr, so it is adjusted as delayed refs are run so that any
109	 * on disk reference count + ref_mod is accurate.
110	 */
111	int ref_mod;
112
113	/*
114	 * The root that triggered the allocation when must_insert_reserved is
115	 * set to true.
116	 */
117	u64 owning_root;
118
119	/*
120	 * Track reserved bytes when setting must_insert_reserved.  On success
121	 * or cleanup, we will need to free the reservation.
122	 */
123	u64 reserved_bytes;
124
 
 
 
125	/*
126	 * when a new extent is allocated, it is just reserved in memory
127	 * The actual extent isn't inserted into the extent allocation tree
128	 * until the delayed ref is processed.  must_insert_reserved is
129	 * used to flag a delayed ref so the accounting can be updated
130	 * when a full insert is done.
131	 *
132	 * It is possible the extent will be freed before it is ever
133	 * inserted into the extent allocation tree.  In this case
134	 * we need to update the in ram accounting to properly reflect
135	 * the free has happened.
136	 */
137	bool must_insert_reserved;
138
139	bool is_data;
140	bool is_system;
141	bool processing;
142};
143
144struct btrfs_delayed_tree_ref {
145	struct btrfs_delayed_ref_node node;
146	u64 root;
147	u64 parent;
148	int level;
149};
150
151struct btrfs_delayed_data_ref {
152	struct btrfs_delayed_ref_node node;
153	u64 root;
154	u64 parent;
155	u64 objectid;
156	u64 offset;
157};
158
159enum btrfs_delayed_ref_flags {
160	/* Indicate that we are flushing delayed refs for the commit */
161	BTRFS_DELAYED_REFS_FLUSHING,
162};
163
164struct btrfs_delayed_ref_root {
165	/* head ref rbtree */
166	struct rb_root_cached href_root;
167
168	/* dirty extent records */
169	struct rb_root dirty_extent_root;
 
 
 
 
 
 
170
171	/* this spin lock protects the rbtree and the entries inside */
172	spinlock_t lock;
 
 
 
 
173
174	/* how many delayed ref updates we've queued, used by the
175	 * throttling code
 
176	 */
177	atomic_t num_entries;
178
179	/* total number of head nodes in tree */
180	unsigned long num_heads;
181
182	/* total number of head nodes ready for processing */
 
 
 
183	unsigned long num_heads_ready;
184
 
 
 
 
185	u64 pending_csums;
186
187	unsigned long flags;
188
 
 
 
 
189	u64 run_delayed_start;
190
191	/*
192	 * To make qgroup to skip given root.
193	 * This is for snapshot, as btrfs_qgroup_inherit() will manually
194	 * modify counters for snapshot and its source, so we should skip
195	 * the snapshot in new_root/old_roots or it will get calculated twice
196	 */
197	u64 qgroup_to_skip;
198};
199
200enum btrfs_ref_type {
201	BTRFS_REF_NOT_SET,
202	BTRFS_REF_DATA,
203	BTRFS_REF_METADATA,
204	BTRFS_REF_LAST,
205} __packed;
206
207struct btrfs_data_ref {
208	/* For EXTENT_DATA_REF */
209
210	/* Root which owns this data reference. */
211	u64 ref_root;
212
213	/* Inode which refers to this data extent */
214	u64 ino;
215
216	/*
217	 * file_offset - extent_offset
218	 *
219	 * file_offset is the key.offset of the EXTENT_DATA key.
220	 * extent_offset is btrfs_file_extent_offset() of the EXTENT_DATA data.
221	 */
222	u64 offset;
223};
224
225struct btrfs_tree_ref {
226	/*
227	 * Level of this tree block
228	 *
229	 * Shared for skinny (TREE_BLOCK_REF) and normal tree ref.
230	 */
231	int level;
232
233	/*
234	 * Root which owns this tree block reference.
235	 *
236	 * For TREE_BLOCK_REF (skinny metadata, either inline or keyed)
237	 */
238	u64 ref_root;
239
240	/* For non-skinny metadata, no special member needed */
241};
242
243struct btrfs_ref {
244	enum btrfs_ref_type type;
245	enum btrfs_delayed_ref_action action;
246
247	/*
248	 * Whether this extent should go through qgroup record.
249	 *
250	 * Normally false, but for certain cases like delayed subtree scan,
251	 * setting this flag can hugely reduce qgroup overhead.
252	 */
253	bool skip_qgroup;
254
255#ifdef CONFIG_BTRFS_FS_REF_VERIFY
256	/* Through which root is this modification. */
257	u64 real_root;
258#endif
259	u64 bytenr;
260	u64 len;
261	u64 owning_root;
262
 
 
 
 
 
 
263	/* Bytenr of the parent tree block */
264	u64 parent;
265	union {
266		struct btrfs_data_ref data_ref;
267		struct btrfs_tree_ref tree_ref;
268	};
269};
270
271extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
272extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
273extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
274extern struct kmem_cache *btrfs_delayed_extent_op_cachep;
275
276int __init btrfs_delayed_ref_init(void);
277void __cold btrfs_delayed_ref_exit(void);
278
279static inline u64 btrfs_calc_delayed_ref_bytes(const struct btrfs_fs_info *fs_info,
280					       int num_delayed_refs)
281{
282	u64 num_bytes;
283
284	num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_delayed_refs);
285
286	/*
287	 * We have to check the mount option here because we could be enabling
288	 * the free space tree for the first time and don't have the compat_ro
289	 * option set yet.
290	 *
291	 * We need extra reservations if we have the free space tree because
292	 * we'll have to modify that tree as well.
293	 */
294	if (btrfs_test_opt(fs_info, FREE_SPACE_TREE))
295		num_bytes *= 2;
296
297	return num_bytes;
298}
299
300static inline u64 btrfs_calc_delayed_ref_csum_bytes(const struct btrfs_fs_info *fs_info,
301						    int num_csum_items)
302{
303	/*
304	 * Deleting csum items does not result in new nodes/leaves and does not
305	 * require changing the free space tree, only the csum tree, so this is
306	 * all we need.
307	 */
308	return btrfs_calc_metadata_size(fs_info, num_csum_items);
309}
310
311static inline void btrfs_init_generic_ref(struct btrfs_ref *generic_ref,
312					  int action, u64 bytenr, u64 len,
313					  u64 parent, u64 owning_root)
314{
315	generic_ref->action = action;
316	generic_ref->bytenr = bytenr;
317	generic_ref->len = len;
318	generic_ref->parent = parent;
319	generic_ref->owning_root = owning_root;
320}
321
322static inline void btrfs_init_tree_ref(struct btrfs_ref *generic_ref, int level,
323				       u64 root, u64 mod_root, bool skip_qgroup)
324{
325#ifdef CONFIG_BTRFS_FS_REF_VERIFY
326	/* If @real_root not set, use @root as fallback */
327	generic_ref->real_root = mod_root ?: root;
328#endif
329	generic_ref->tree_ref.level = level;
330	generic_ref->tree_ref.ref_root = root;
331	generic_ref->type = BTRFS_REF_METADATA;
332	if (skip_qgroup || !(is_fstree(root) &&
333			     (!mod_root || is_fstree(mod_root))))
334		generic_ref->skip_qgroup = true;
335	else
336		generic_ref->skip_qgroup = false;
337
338}
339
340static inline void btrfs_init_data_ref(struct btrfs_ref *generic_ref,
341				u64 ref_root, u64 ino, u64 offset, u64 mod_root,
342				bool skip_qgroup)
343{
344#ifdef CONFIG_BTRFS_FS_REF_VERIFY
345	/* If @real_root not set, use @root as fallback */
346	generic_ref->real_root = mod_root ?: ref_root;
347#endif
348	generic_ref->data_ref.ref_root = ref_root;
349	generic_ref->data_ref.ino = ino;
350	generic_ref->data_ref.offset = offset;
351	generic_ref->type = BTRFS_REF_DATA;
352	if (skip_qgroup || !(is_fstree(ref_root) &&
353			     (!mod_root || is_fstree(mod_root))))
354		generic_ref->skip_qgroup = true;
355	else
356		generic_ref->skip_qgroup = false;
357}
358
359static inline struct btrfs_delayed_extent_op *
360btrfs_alloc_delayed_extent_op(void)
361{
362	return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS);
363}
364
365static inline void
366btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op)
367{
368	if (op)
369		kmem_cache_free(btrfs_delayed_extent_op_cachep, op);
370}
371
372static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
373{
374	if (refcount_dec_and_test(&ref->refs)) {
375		WARN_ON(!RB_EMPTY_NODE(&ref->ref_node));
376		switch (ref->type) {
377		case BTRFS_TREE_BLOCK_REF_KEY:
378		case BTRFS_SHARED_BLOCK_REF_KEY:
379			kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
380			break;
381		case BTRFS_EXTENT_DATA_REF_KEY:
382		case BTRFS_SHARED_DATA_REF_KEY:
383			kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
384			break;
385		default:
386			BUG();
387		}
388	}
389}
390
391static inline u64 btrfs_ref_head_to_space_flags(
392				struct btrfs_delayed_ref_head *head_ref)
393{
394	if (head_ref->is_data)
395		return BTRFS_BLOCK_GROUP_DATA;
396	else if (head_ref->is_system)
397		return BTRFS_BLOCK_GROUP_SYSTEM;
398	return BTRFS_BLOCK_GROUP_METADATA;
399}
400
401static inline void btrfs_put_delayed_ref_head(struct btrfs_delayed_ref_head *head)
402{
403	if (refcount_dec_and_test(&head->refs))
404		kmem_cache_free(btrfs_delayed_ref_head_cachep, head);
405}
406
407int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
408			       struct btrfs_ref *generic_ref,
409			       struct btrfs_delayed_extent_op *extent_op);
410int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
411			       struct btrfs_ref *generic_ref,
412			       u64 reserved);
413int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
414				u64 bytenr, u64 num_bytes,
415				struct btrfs_delayed_extent_op *extent_op);
416void btrfs_merge_delayed_refs(struct btrfs_fs_info *fs_info,
417			      struct btrfs_delayed_ref_root *delayed_refs,
418			      struct btrfs_delayed_ref_head *head);
419
420struct btrfs_delayed_ref_head *
421btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
 
422			    u64 bytenr);
423int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs,
424			   struct btrfs_delayed_ref_head *head);
425static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
426{
427	mutex_unlock(&head->mutex);
428}
429void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs,
 
430			   struct btrfs_delayed_ref_head *head);
431
432struct btrfs_delayed_ref_head *btrfs_select_ref_head(
 
433		struct btrfs_delayed_ref_root *delayed_refs);
 
 
434
435int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq);
436
437void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr_refs, int nr_csums);
438void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans);
439void btrfs_inc_delayed_refs_rsv_bg_inserts(struct btrfs_fs_info *fs_info);
440void btrfs_dec_delayed_refs_rsv_bg_inserts(struct btrfs_fs_info *fs_info);
441void btrfs_inc_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info);
442void btrfs_dec_delayed_refs_rsv_bg_updates(struct btrfs_fs_info *fs_info);
443int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
444				  enum btrfs_reserve_flush_enum flush);
445void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
446				       u64 num_bytes);
447bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info);
 
 
 
448
449/*
450 * helper functions to cast a node into its container
451 */
452static inline struct btrfs_delayed_tree_ref *
453btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
 
 
 
 
454{
455	return container_of(node, struct btrfs_delayed_tree_ref, node);
 
 
 
456}
457
458static inline struct btrfs_delayed_data_ref *
459btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node)
460{
461	return container_of(node, struct btrfs_delayed_data_ref, node);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
462}
463
464#endif
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