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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 CM |
26 | |
27 | struct btrfs_delayed_ref_node { | |
28 | struct rb_node rb_node; | |
29 | ||
30 | /* the starting bytenr of the extent */ | |
31 | u64 bytenr; | |
32 | ||
56bec294 CM |
33 | /* the size of the extent */ |
34 | u64 num_bytes; | |
35 | ||
00f04b88 AJ |
36 | /* seq number to keep track of insertion order */ |
37 | u64 seq; | |
38 | ||
56bec294 CM |
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 | ||
5d4f98a2 YZ |
53 | unsigned int action:8; |
54 | unsigned int type:8; | |
56bec294 | 55 | /* is this node still in the rbtree? */ |
5d4f98a2 | 56 | unsigned int is_head:1; |
56bec294 CM |
57 | unsigned int in_tree:1; |
58 | }; | |
59 | ||
5d4f98a2 YZ |
60 | struct btrfs_delayed_extent_op { |
61 | struct btrfs_disk_key key; | |
62 | u64 flags_to_set; | |
b1c79e09 | 63 | int level; |
5d4f98a2 YZ |
64 | unsigned int update_key:1; |
65 | unsigned int update_flags:1; | |
66 | unsigned int is_data:1; | |
67 | }; | |
68 | ||
56bec294 CM |
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 | */ | |
75 | struct 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 | ||
d7df2c79 JB |
84 | spinlock_t lock; |
85 | struct rb_root ref_root; | |
c3e69d58 | 86 | |
c46effa6 LB |
87 | struct rb_node href_node; |
88 | ||
5d4f98a2 | 89 | struct btrfs_delayed_extent_op *extent_op; |
56bec294 CM |
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; | |
5d4f98a2 | 103 | unsigned int is_data:1; |
d7df2c79 | 104 | unsigned int processing:1; |
56bec294 CM |
105 | }; |
106 | ||
5d4f98a2 | 107 | struct btrfs_delayed_tree_ref { |
56bec294 | 108 | struct btrfs_delayed_ref_node node; |
eebe063b AJ |
109 | u64 root; |
110 | u64 parent; | |
5d4f98a2 YZ |
111 | int level; |
112 | }; | |
56bec294 | 113 | |
5d4f98a2 YZ |
114 | struct btrfs_delayed_data_ref { |
115 | struct btrfs_delayed_ref_node node; | |
eebe063b AJ |
116 | u64 root; |
117 | u64 parent; | |
5d4f98a2 YZ |
118 | u64 objectid; |
119 | u64 offset; | |
56bec294 CM |
120 | }; |
121 | ||
122 | struct btrfs_delayed_ref_root { | |
c46effa6 LB |
123 | /* head ref rbtree */ |
124 | struct rb_root href_root; | |
125 | ||
56bec294 CM |
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 | */ | |
d7df2c79 | 132 | atomic_t num_entries; |
56bec294 | 133 | |
c3e69d58 CM |
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 | ||
56bec294 CM |
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; | |
c3e69d58 CM |
146 | |
147 | u64 run_delayed_start; | |
56bec294 CM |
148 | }; |
149 | ||
78a6184a MX |
150 | extern struct kmem_cache *btrfs_delayed_ref_head_cachep; |
151 | extern struct kmem_cache *btrfs_delayed_tree_ref_cachep; | |
152 | extern struct kmem_cache *btrfs_delayed_data_ref_cachep; | |
153 | extern struct kmem_cache *btrfs_delayed_extent_op_cachep; | |
154 | ||
155 | int btrfs_delayed_ref_init(void); | |
156 | void btrfs_delayed_ref_exit(void); | |
157 | ||
158 | static inline struct btrfs_delayed_extent_op * | |
159 | btrfs_alloc_delayed_extent_op(void) | |
160 | { | |
161 | return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS); | |
162 | } | |
163 | ||
164 | static inline void | |
165 | btrfs_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 | ||
56bec294 CM |
171 | static 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); | |
78a6184a MX |
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 | } | |
56bec294 CM |
191 | } |
192 | } | |
193 | ||
66d7e7f0 AJ |
194 | int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info, |
195 | struct btrfs_trans_handle *trans, | |
5d4f98a2 YZ |
196 | u64 bytenr, u64 num_bytes, u64 parent, |
197 | u64 ref_root, int level, int action, | |
66d7e7f0 AJ |
198 | struct btrfs_delayed_extent_op *extent_op, |
199 | int for_cow); | |
200 | int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info, | |
201 | struct btrfs_trans_handle *trans, | |
5d4f98a2 YZ |
202 | u64 bytenr, u64 num_bytes, |
203 | u64 parent, u64 ref_root, | |
204 | u64 owner, u64 offset, int action, | |
66d7e7f0 AJ |
205 | struct btrfs_delayed_extent_op *extent_op, |
206 | int for_cow); | |
207 | int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info, | |
208 | struct btrfs_trans_handle *trans, | |
5d4f98a2 YZ |
209 | u64 bytenr, u64 num_bytes, |
210 | struct btrfs_delayed_extent_op *extent_op); | |
ae1e206b JB |
211 | void 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); | |
56bec294 | 215 | |
1887be66 CM |
216 | struct btrfs_delayed_ref_head * |
217 | btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr); | |
c3e69d58 CM |
218 | int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans, |
219 | struct btrfs_delayed_ref_head *head); | |
093486c4 MX |
220 | static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head) |
221 | { | |
222 | mutex_unlock(&head->mutex); | |
223 | } | |
224 | ||
d7df2c79 JB |
225 | |
226 | struct btrfs_delayed_ref_head * | |
227 | btrfs_select_ref_head(struct btrfs_trans_handle *trans); | |
00f04b88 | 228 | |
097b8a7c JS |
229 | int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, |
230 | struct btrfs_delayed_ref_root *delayed_refs, | |
00f04b88 AJ |
231 | u64 seq); |
232 | ||
546adb0d JS |
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 | */ | |
238 | static 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 | ||
56bec294 CM |
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 | */ | |
256 | static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node) | |
257 | { | |
5d4f98a2 | 258 | return node->is_head; |
56bec294 CM |
259 | } |
260 | ||
261 | /* | |
262 | * helper functions to cast a node into its container | |
263 | */ | |
5d4f98a2 YZ |
264 | static inline struct btrfs_delayed_tree_ref * |
265 | btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node) | |
56bec294 CM |
266 | { |
267 | WARN_ON(btrfs_delayed_ref_is_head(node)); | |
5d4f98a2 YZ |
268 | return container_of(node, struct btrfs_delayed_tree_ref, node); |
269 | } | |
56bec294 | 270 | |
5d4f98a2 YZ |
271 | static inline struct btrfs_delayed_data_ref * |
272 | btrfs_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); | |
56bec294 CM |
276 | } |
277 | ||
278 | static inline struct btrfs_delayed_ref_head * | |
279 | btrfs_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); | |
56bec294 CM |
283 | } |
284 | #endif |