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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
21/* these are the possible values of struct btrfs_delayed_ref_node->action */
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 */
25#define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */
26
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 */
36struct btrfs_delayed_ref_node {
37 /*data/tree ref use list, stored in ref_head->ref_list. */
38 struct list_head list;
39 /*
40 * If action is BTRFS_ADD_DELAYED_REF, also link this node to
41 * ref_head->ref_add_list, then we do not need to iterate the
42 * whole ref_head->ref_list to find BTRFS_ADD_DELAYED_REF nodes.
43 */
44 struct list_head add_list;
45
46 /* the starting bytenr of the extent */
47 u64 bytenr;
48
49 /* the size of the extent */
50 u64 num_bytes;
51
52 /* seq number to keep track of insertion order */
53 u64 seq;
54
55 /* ref count on this data structure */
56 atomic_t refs;
57
58 /*
59 * how many refs is this entry adding or deleting. For
60 * head refs, this may be a negative number because it is keeping
61 * track of the total mods done to the reference count.
62 * For individual refs, this will always be a positive number
63 *
64 * It may be more than one, since it is possible for a single
65 * parent to have more than one ref on an extent
66 */
67 int ref_mod;
68
69 unsigned int action:8;
70 unsigned int type:8;
71 /* is this node still in the rbtree? */
72 unsigned int is_head:1;
73 unsigned int in_tree:1;
74};
75
76struct btrfs_delayed_extent_op {
77 struct btrfs_disk_key key;
78 u8 level;
79 bool update_key;
80 bool update_flags;
81 bool is_data;
82 u64 flags_to_set;
83};
84
85/*
86 * the head refs are used to hold a lock on a given extent, which allows us
87 * to make sure that only one process is running the delayed refs
88 * at a time for a single extent. They also store the sum of all the
89 * reference count modifications we've queued up.
90 */
91struct btrfs_delayed_ref_head {
92 struct btrfs_delayed_ref_node node;
93
94 /*
95 * the mutex is held while running the refs, and it is also
96 * held when checking the sum of reference modifications.
97 */
98 struct mutex mutex;
99
100 spinlock_t lock;
101 struct list_head ref_list;
102 /* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */
103 struct list_head ref_add_list;
104
105 struct rb_node href_node;
106
107 struct btrfs_delayed_extent_op *extent_op;
108
109 /*
110 * This is used to track the final ref_mod from all the refs associated
111 * with this head ref, this is not adjusted as delayed refs are run,
112 * this is meant to track if we need to do the csum accounting or not.
113 */
114 int total_ref_mod;
115
116 /*
117 * For qgroup reserved space freeing.
118 *
119 * ref_root and reserved will be recorded after
120 * BTRFS_ADD_DELAYED_EXTENT is called.
121 * And will be used to free reserved qgroup space at
122 * run_delayed_refs() time.
123 */
124 u64 qgroup_ref_root;
125 u64 qgroup_reserved;
126
127 /*
128 * when a new extent is allocated, it is just reserved in memory
129 * The actual extent isn't inserted into the extent allocation tree
130 * until the delayed ref is processed. must_insert_reserved is
131 * used to flag a delayed ref so the accounting can be updated
132 * when a full insert is done.
133 *
134 * It is possible the extent will be freed before it is ever
135 * inserted into the extent allocation tree. In this case
136 * we need to update the in ram accounting to properly reflect
137 * the free has happened.
138 */
139 unsigned int must_insert_reserved:1;
140 unsigned int is_data:1;
141 unsigned int processing:1;
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
159struct btrfs_delayed_ref_root {
160 /* head ref rbtree */
161 struct rb_root href_root;
162
163 /* dirty extent records */
164 struct rb_root dirty_extent_root;
165
166 /* this spin lock protects the rbtree and the entries inside */
167 spinlock_t lock;
168
169 /* how many delayed ref updates we've queued, used by the
170 * throttling code
171 */
172 atomic_t num_entries;
173
174 /* total number of head nodes in tree */
175 unsigned long num_heads;
176
177 /* total number of head nodes ready for processing */
178 unsigned long num_heads_ready;
179
180 u64 pending_csums;
181
182 /*
183 * set when the tree is flushing before a transaction commit,
184 * used by the throttling code to decide if new updates need
185 * to be run right away
186 */
187 int flushing;
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
200extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
201extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
202extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
203extern struct kmem_cache *btrfs_delayed_extent_op_cachep;
204
205int btrfs_delayed_ref_init(void);
206void btrfs_delayed_ref_exit(void);
207
208static inline struct btrfs_delayed_extent_op *
209btrfs_alloc_delayed_extent_op(void)
210{
211 return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS);
212}
213
214static inline void
215btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op)
216{
217 if (op)
218 kmem_cache_free(btrfs_delayed_extent_op_cachep, op);
219}
220
221static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
222{
223 WARN_ON(atomic_read(&ref->refs) == 0);
224 if (atomic_dec_and_test(&ref->refs)) {
225 WARN_ON(ref->in_tree);
226 switch (ref->type) {
227 case BTRFS_TREE_BLOCK_REF_KEY:
228 case BTRFS_SHARED_BLOCK_REF_KEY:
229 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
230 break;
231 case BTRFS_EXTENT_DATA_REF_KEY:
232 case BTRFS_SHARED_DATA_REF_KEY:
233 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
234 break;
235 case 0:
236 kmem_cache_free(btrfs_delayed_ref_head_cachep, ref);
237 break;
238 default:
239 BUG();
240 }
241 }
242}
243
244int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
245 struct btrfs_trans_handle *trans,
246 u64 bytenr, u64 num_bytes, u64 parent,
247 u64 ref_root, int level, int action,
248 struct btrfs_delayed_extent_op *extent_op);
249int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
250 struct btrfs_trans_handle *trans,
251 u64 bytenr, u64 num_bytes,
252 u64 parent, u64 ref_root,
253 u64 owner, u64 offset, u64 reserved, int action,
254 struct btrfs_delayed_extent_op *extent_op);
255int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
256 struct btrfs_trans_handle *trans,
257 u64 bytenr, u64 num_bytes,
258 struct btrfs_delayed_extent_op *extent_op);
259void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
260 struct btrfs_fs_info *fs_info,
261 struct btrfs_delayed_ref_root *delayed_refs,
262 struct btrfs_delayed_ref_head *head);
263
264struct btrfs_delayed_ref_head *
265btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
266int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
267 struct btrfs_delayed_ref_head *head);
268static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
269{
270 mutex_unlock(&head->mutex);
271}
272
273
274struct btrfs_delayed_ref_head *
275btrfs_select_ref_head(struct btrfs_trans_handle *trans);
276
277int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
278 struct btrfs_delayed_ref_root *delayed_refs,
279 u64 seq);
280
281/*
282 * a node might live in a head or a regular ref, this lets you
283 * test for the proper type to use.
284 */
285static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node)
286{
287 return node->is_head;
288}
289
290/*
291 * helper functions to cast a node into its container
292 */
293static inline struct btrfs_delayed_tree_ref *
294btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
295{
296 WARN_ON(btrfs_delayed_ref_is_head(node));
297 return container_of(node, struct btrfs_delayed_tree_ref, node);
298}
299
300static inline struct btrfs_delayed_data_ref *
301btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node)
302{
303 WARN_ON(btrfs_delayed_ref_is_head(node));
304 return container_of(node, struct btrfs_delayed_data_ref, node);
305}
306
307static inline struct btrfs_delayed_ref_head *
308btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node)
309{
310 WARN_ON(!btrfs_delayed_ref_is_head(node));
311 return container_of(node, struct btrfs_delayed_ref_head, node);
312}
313#endif
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
21/* these are the possible values of struct btrfs_delayed_ref_node->action */
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 */
25#define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */
26
27struct btrfs_delayed_ref_node {
28 struct rb_node rb_node;
29
30 /* the starting bytenr of the extent */
31 u64 bytenr;
32
33 /* the size of the extent */
34 u64 num_bytes;
35
36 /* seq number to keep track of insertion order */
37 u64 seq;
38
39 /* ref count on this data structure */
40 atomic_t refs;
41
42 /*
43 * how many refs is this entry adding or deleting. For
44 * head refs, this may be a negative number because it is keeping
45 * track of the total mods done to the reference count.
46 * For individual refs, this will always be a positive number
47 *
48 * It may be more than one, since it is possible for a single
49 * parent to have more than one ref on an extent
50 */
51 int ref_mod;
52
53 unsigned int action:8;
54 unsigned int type:8;
55 /* is this node still in the rbtree? */
56 unsigned int is_head:1;
57 unsigned int in_tree:1;
58};
59
60struct btrfs_delayed_extent_op {
61 struct btrfs_disk_key key;
62 u64 flags_to_set;
63 int level;
64 unsigned int update_key:1;
65 unsigned int update_flags:1;
66 unsigned int is_data:1;
67};
68
69/*
70 * the head refs are used to hold a lock on a given extent, which allows us
71 * to make sure that only one process is running the delayed refs
72 * at a time for a single extent. They also store the sum of all the
73 * reference count modifications we've queued up.
74 */
75struct btrfs_delayed_ref_head {
76 struct btrfs_delayed_ref_node node;
77
78 /*
79 * the mutex is held while running the refs, and it is also
80 * held when checking the sum of reference modifications.
81 */
82 struct mutex mutex;
83
84 spinlock_t lock;
85 struct rb_root ref_root;
86
87 struct rb_node href_node;
88
89 struct btrfs_delayed_extent_op *extent_op;
90 /*
91 * when a new extent is allocated, it is just reserved in memory
92 * The actual extent isn't inserted into the extent allocation tree
93 * until the delayed ref is processed. must_insert_reserved is
94 * used to flag a delayed ref so the accounting can be updated
95 * when a full insert is done.
96 *
97 * It is possible the extent will be freed before it is ever
98 * inserted into the extent allocation tree. In this case
99 * we need to update the in ram accounting to properly reflect
100 * the free has happened.
101 */
102 unsigned int must_insert_reserved:1;
103 unsigned int is_data:1;
104 unsigned int processing:1;
105};
106
107struct btrfs_delayed_tree_ref {
108 struct btrfs_delayed_ref_node node;
109 u64 root;
110 u64 parent;
111 int level;
112};
113
114struct btrfs_delayed_data_ref {
115 struct btrfs_delayed_ref_node node;
116 u64 root;
117 u64 parent;
118 u64 objectid;
119 u64 offset;
120};
121
122struct btrfs_delayed_ref_root {
123 /* head ref rbtree */
124 struct rb_root href_root;
125
126 /* this spin lock protects the rbtree and the entries inside */
127 spinlock_t lock;
128
129 /* how many delayed ref updates we've queued, used by the
130 * throttling code
131 */
132 atomic_t num_entries;
133
134 /* total number of head nodes in tree */
135 unsigned long num_heads;
136
137 /* total number of head nodes ready for processing */
138 unsigned long num_heads_ready;
139
140 /*
141 * set when the tree is flushing before a transaction commit,
142 * used by the throttling code to decide if new updates need
143 * to be run right away
144 */
145 int flushing;
146
147 u64 run_delayed_start;
148};
149
150extern struct kmem_cache *btrfs_delayed_ref_head_cachep;
151extern struct kmem_cache *btrfs_delayed_tree_ref_cachep;
152extern struct kmem_cache *btrfs_delayed_data_ref_cachep;
153extern struct kmem_cache *btrfs_delayed_extent_op_cachep;
154
155int btrfs_delayed_ref_init(void);
156void btrfs_delayed_ref_exit(void);
157
158static inline struct btrfs_delayed_extent_op *
159btrfs_alloc_delayed_extent_op(void)
160{
161 return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS);
162}
163
164static inline void
165btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op)
166{
167 if (op)
168 kmem_cache_free(btrfs_delayed_extent_op_cachep, op);
169}
170
171static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
172{
173 WARN_ON(atomic_read(&ref->refs) == 0);
174 if (atomic_dec_and_test(&ref->refs)) {
175 WARN_ON(ref->in_tree);
176 switch (ref->type) {
177 case BTRFS_TREE_BLOCK_REF_KEY:
178 case BTRFS_SHARED_BLOCK_REF_KEY:
179 kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref);
180 break;
181 case BTRFS_EXTENT_DATA_REF_KEY:
182 case BTRFS_SHARED_DATA_REF_KEY:
183 kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
184 break;
185 case 0:
186 kmem_cache_free(btrfs_delayed_ref_head_cachep, ref);
187 break;
188 default:
189 BUG();
190 }
191 }
192}
193
194int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
195 struct btrfs_trans_handle *trans,
196 u64 bytenr, u64 num_bytes, u64 parent,
197 u64 ref_root, int level, int action,
198 struct btrfs_delayed_extent_op *extent_op,
199 int for_cow);
200int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
201 struct btrfs_trans_handle *trans,
202 u64 bytenr, u64 num_bytes,
203 u64 parent, u64 ref_root,
204 u64 owner, u64 offset, int action,
205 struct btrfs_delayed_extent_op *extent_op,
206 int for_cow);
207int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
208 struct btrfs_trans_handle *trans,
209 u64 bytenr, u64 num_bytes,
210 struct btrfs_delayed_extent_op *extent_op);
211void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans,
212 struct btrfs_fs_info *fs_info,
213 struct btrfs_delayed_ref_root *delayed_refs,
214 struct btrfs_delayed_ref_head *head);
215
216struct btrfs_delayed_ref_head *
217btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
218int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
219 struct btrfs_delayed_ref_head *head);
220static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head)
221{
222 mutex_unlock(&head->mutex);
223}
224
225
226struct btrfs_delayed_ref_head *
227btrfs_select_ref_head(struct btrfs_trans_handle *trans);
228
229int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info,
230 struct btrfs_delayed_ref_root *delayed_refs,
231 u64 seq);
232
233/*
234 * delayed refs with a ref_seq > 0 must be held back during backref walking.
235 * this only applies to items in one of the fs-trees. for_cow items never need
236 * to be held back, so they won't get a ref_seq number.
237 */
238static inline int need_ref_seq(int for_cow, u64 rootid)
239{
240 if (for_cow)
241 return 0;
242
243 if (rootid == BTRFS_FS_TREE_OBJECTID)
244 return 1;
245
246 if ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID)
247 return 1;
248
249 return 0;
250}
251
252/*
253 * a node might live in a head or a regular ref, this lets you
254 * test for the proper type to use.
255 */
256static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node)
257{
258 return node->is_head;
259}
260
261/*
262 * helper functions to cast a node into its container
263 */
264static inline struct btrfs_delayed_tree_ref *
265btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
266{
267 WARN_ON(btrfs_delayed_ref_is_head(node));
268 return container_of(node, struct btrfs_delayed_tree_ref, node);
269}
270
271static inline struct btrfs_delayed_data_ref *
272btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node)
273{
274 WARN_ON(btrfs_delayed_ref_is_head(node));
275 return container_of(node, struct btrfs_delayed_data_ref, node);
276}
277
278static inline struct btrfs_delayed_ref_head *
279btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node)
280{
281 WARN_ON(!btrfs_delayed_ref_is_head(node));
282 return container_of(node, struct btrfs_delayed_ref_head, node);
283}
284#endif