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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 | ||
21 | /* these are the possible values of struct btrfs_delayed_ref->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 */ | |
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 | ||
36 | /* ref count on this data structure */ | |
37 | atomic_t refs; | |
38 | ||
39 | /* | |
40 | * how many refs is this entry adding or deleting. For | |
41 | * head refs, this may be a negative number because it is keeping | |
42 | * track of the total mods done to the reference count. | |
43 | * For individual refs, this will always be a positive number | |
44 | * | |
45 | * It may be more than one, since it is possible for a single | |
46 | * parent to have more than one ref on an extent | |
47 | */ | |
48 | int ref_mod; | |
49 | ||
5d4f98a2 YZ |
50 | unsigned int action:8; |
51 | unsigned int type:8; | |
56bec294 | 52 | /* is this node still in the rbtree? */ |
5d4f98a2 | 53 | unsigned int is_head:1; |
56bec294 CM |
54 | unsigned int in_tree:1; |
55 | }; | |
56 | ||
5d4f98a2 YZ |
57 | struct btrfs_delayed_extent_op { |
58 | struct btrfs_disk_key key; | |
59 | u64 flags_to_set; | |
60 | unsigned int update_key:1; | |
61 | unsigned int update_flags:1; | |
62 | unsigned int is_data:1; | |
63 | }; | |
64 | ||
56bec294 CM |
65 | /* |
66 | * the head refs are used to hold a lock on a given extent, which allows us | |
67 | * to make sure that only one process is running the delayed refs | |
68 | * at a time for a single extent. They also store the sum of all the | |
69 | * reference count modifications we've queued up. | |
70 | */ | |
71 | struct btrfs_delayed_ref_head { | |
72 | struct btrfs_delayed_ref_node node; | |
73 | ||
74 | /* | |
75 | * the mutex is held while running the refs, and it is also | |
76 | * held when checking the sum of reference modifications. | |
77 | */ | |
78 | struct mutex mutex; | |
79 | ||
c3e69d58 CM |
80 | struct list_head cluster; |
81 | ||
5d4f98a2 | 82 | struct btrfs_delayed_extent_op *extent_op; |
56bec294 CM |
83 | /* |
84 | * when a new extent is allocated, it is just reserved in memory | |
85 | * The actual extent isn't inserted into the extent allocation tree | |
86 | * until the delayed ref is processed. must_insert_reserved is | |
87 | * used to flag a delayed ref so the accounting can be updated | |
88 | * when a full insert is done. | |
89 | * | |
90 | * It is possible the extent will be freed before it is ever | |
91 | * inserted into the extent allocation tree. In this case | |
92 | * we need to update the in ram accounting to properly reflect | |
93 | * the free has happened. | |
94 | */ | |
95 | unsigned int must_insert_reserved:1; | |
5d4f98a2 | 96 | unsigned int is_data:1; |
56bec294 CM |
97 | }; |
98 | ||
5d4f98a2 | 99 | struct btrfs_delayed_tree_ref { |
56bec294 | 100 | struct btrfs_delayed_ref_node node; |
5d4f98a2 YZ |
101 | union { |
102 | u64 root; | |
103 | u64 parent; | |
104 | }; | |
105 | int level; | |
106 | }; | |
56bec294 | 107 | |
5d4f98a2 YZ |
108 | struct btrfs_delayed_data_ref { |
109 | struct btrfs_delayed_ref_node node; | |
110 | union { | |
111 | u64 root; | |
112 | u64 parent; | |
113 | }; | |
114 | u64 objectid; | |
115 | u64 offset; | |
56bec294 CM |
116 | }; |
117 | ||
118 | struct btrfs_delayed_ref_root { | |
119 | struct rb_root root; | |
120 | ||
121 | /* this spin lock protects the rbtree and the entries inside */ | |
122 | spinlock_t lock; | |
123 | ||
124 | /* how many delayed ref updates we've queued, used by the | |
125 | * throttling code | |
126 | */ | |
127 | unsigned long num_entries; | |
128 | ||
c3e69d58 CM |
129 | /* total number of head nodes in tree */ |
130 | unsigned long num_heads; | |
131 | ||
132 | /* total number of head nodes ready for processing */ | |
133 | unsigned long num_heads_ready; | |
134 | ||
56bec294 CM |
135 | /* |
136 | * set when the tree is flushing before a transaction commit, | |
137 | * used by the throttling code to decide if new updates need | |
138 | * to be run right away | |
139 | */ | |
140 | int flushing; | |
c3e69d58 CM |
141 | |
142 | u64 run_delayed_start; | |
56bec294 CM |
143 | }; |
144 | ||
145 | static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref) | |
146 | { | |
147 | WARN_ON(atomic_read(&ref->refs) == 0); | |
148 | if (atomic_dec_and_test(&ref->refs)) { | |
149 | WARN_ON(ref->in_tree); | |
150 | kfree(ref); | |
151 | } | |
152 | } | |
153 | ||
5d4f98a2 YZ |
154 | int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans, |
155 | u64 bytenr, u64 num_bytes, u64 parent, | |
156 | u64 ref_root, int level, int action, | |
157 | struct btrfs_delayed_extent_op *extent_op); | |
158 | int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans, | |
159 | u64 bytenr, u64 num_bytes, | |
160 | u64 parent, u64 ref_root, | |
161 | u64 owner, u64 offset, int action, | |
162 | struct btrfs_delayed_extent_op *extent_op); | |
163 | int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans, | |
164 | u64 bytenr, u64 num_bytes, | |
165 | struct btrfs_delayed_extent_op *extent_op); | |
56bec294 | 166 | |
1887be66 CM |
167 | struct btrfs_delayed_ref_head * |
168 | btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr); | |
c3e69d58 CM |
169 | int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans, |
170 | struct btrfs_delayed_ref_head *head); | |
171 | int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans, | |
172 | struct list_head *cluster, u64 search_start); | |
56bec294 CM |
173 | /* |
174 | * a node might live in a head or a regular ref, this lets you | |
175 | * test for the proper type to use. | |
176 | */ | |
177 | static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node) | |
178 | { | |
5d4f98a2 | 179 | return node->is_head; |
56bec294 CM |
180 | } |
181 | ||
182 | /* | |
183 | * helper functions to cast a node into its container | |
184 | */ | |
5d4f98a2 YZ |
185 | static inline struct btrfs_delayed_tree_ref * |
186 | btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node) | |
56bec294 CM |
187 | { |
188 | WARN_ON(btrfs_delayed_ref_is_head(node)); | |
5d4f98a2 YZ |
189 | return container_of(node, struct btrfs_delayed_tree_ref, node); |
190 | } | |
56bec294 | 191 | |
5d4f98a2 YZ |
192 | static inline struct btrfs_delayed_data_ref * |
193 | btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node) | |
194 | { | |
195 | WARN_ON(btrfs_delayed_ref_is_head(node)); | |
196 | return container_of(node, struct btrfs_delayed_data_ref, node); | |
56bec294 CM |
197 | } |
198 | ||
199 | static inline struct btrfs_delayed_ref_head * | |
200 | btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node) | |
201 | { | |
202 | WARN_ON(!btrfs_delayed_ref_is_head(node)); | |
203 | return container_of(node, struct btrfs_delayed_ref_head, node); | |
56bec294 CM |
204 | } |
205 | #endif |