]>
Commit | Line | Data |
---|---|---|
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 */ | |
25 | ||
26 | struct btrfs_delayed_ref_node { | |
27 | struct rb_node rb_node; | |
28 | ||
29 | /* the starting bytenr of the extent */ | |
30 | u64 bytenr; | |
31 | ||
32 | /* the parent our backref will point to */ | |
33 | u64 parent; | |
34 | ||
35 | /* the size of the extent */ | |
36 | u64 num_bytes; | |
37 | ||
38 | /* ref count on this data structure */ | |
39 | atomic_t refs; | |
40 | ||
41 | /* | |
42 | * how many refs is this entry adding or deleting. For | |
43 | * head refs, this may be a negative number because it is keeping | |
44 | * track of the total mods done to the reference count. | |
45 | * For individual refs, this will always be a positive number | |
46 | * | |
47 | * It may be more than one, since it is possible for a single | |
48 | * parent to have more than one ref on an extent | |
49 | */ | |
50 | int ref_mod; | |
51 | ||
52 | /* is this node still in the rbtree? */ | |
53 | unsigned int in_tree:1; | |
54 | }; | |
55 | ||
56 | /* | |
57 | * the head refs are used to hold a lock on a given extent, which allows us | |
58 | * to make sure that only one process is running the delayed refs | |
59 | * at a time for a single extent. They also store the sum of all the | |
60 | * reference count modifications we've queued up. | |
61 | */ | |
62 | struct btrfs_delayed_ref_head { | |
63 | struct btrfs_delayed_ref_node node; | |
64 | ||
65 | /* | |
66 | * the mutex is held while running the refs, and it is also | |
67 | * held when checking the sum of reference modifications. | |
68 | */ | |
69 | struct mutex mutex; | |
70 | ||
c3e69d58 CM |
71 | struct list_head cluster; |
72 | ||
56bec294 CM |
73 | /* |
74 | * when a new extent is allocated, it is just reserved in memory | |
75 | * The actual extent isn't inserted into the extent allocation tree | |
76 | * until the delayed ref is processed. must_insert_reserved is | |
77 | * used to flag a delayed ref so the accounting can be updated | |
78 | * when a full insert is done. | |
79 | * | |
80 | * It is possible the extent will be freed before it is ever | |
81 | * inserted into the extent allocation tree. In this case | |
82 | * we need to update the in ram accounting to properly reflect | |
83 | * the free has happened. | |
84 | */ | |
85 | unsigned int must_insert_reserved:1; | |
86 | }; | |
87 | ||
88 | struct btrfs_delayed_ref { | |
89 | struct btrfs_delayed_ref_node node; | |
90 | ||
91 | /* the root objectid our ref will point to */ | |
92 | u64 root; | |
93 | ||
94 | /* the generation for the backref */ | |
95 | u64 generation; | |
96 | ||
97 | /* owner_objectid of the backref */ | |
98 | u64 owner_objectid; | |
99 | ||
100 | /* operation done by this entry in the rbtree */ | |
101 | u8 action; | |
102 | ||
103 | /* if pin == 1, when the extent is freed it will be pinned until | |
104 | * transaction commit | |
105 | */ | |
106 | unsigned int pin:1; | |
107 | }; | |
108 | ||
109 | struct btrfs_delayed_ref_root { | |
110 | struct rb_root root; | |
111 | ||
112 | /* this spin lock protects the rbtree and the entries inside */ | |
113 | spinlock_t lock; | |
114 | ||
115 | /* how many delayed ref updates we've queued, used by the | |
116 | * throttling code | |
117 | */ | |
118 | unsigned long num_entries; | |
119 | ||
c3e69d58 CM |
120 | /* total number of head nodes in tree */ |
121 | unsigned long num_heads; | |
122 | ||
123 | /* total number of head nodes ready for processing */ | |
124 | unsigned long num_heads_ready; | |
125 | ||
56bec294 CM |
126 | /* |
127 | * set when the tree is flushing before a transaction commit, | |
128 | * used by the throttling code to decide if new updates need | |
129 | * to be run right away | |
130 | */ | |
131 | int flushing; | |
c3e69d58 CM |
132 | |
133 | u64 run_delayed_start; | |
56bec294 CM |
134 | }; |
135 | ||
136 | static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref) | |
137 | { | |
138 | WARN_ON(atomic_read(&ref->refs) == 0); | |
139 | if (atomic_dec_and_test(&ref->refs)) { | |
140 | WARN_ON(ref->in_tree); | |
141 | kfree(ref); | |
142 | } | |
143 | } | |
144 | ||
145 | int btrfs_add_delayed_ref(struct btrfs_trans_handle *trans, | |
146 | u64 bytenr, u64 num_bytes, u64 parent, u64 ref_root, | |
147 | u64 ref_generation, u64 owner_objectid, int action, | |
148 | int pin); | |
149 | ||
1887be66 CM |
150 | struct btrfs_delayed_ref_head * |
151 | btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr); | |
56bec294 | 152 | int btrfs_delayed_ref_pending(struct btrfs_trans_handle *trans, u64 bytenr); |
56bec294 CM |
153 | int btrfs_lookup_extent_ref(struct btrfs_trans_handle *trans, |
154 | struct btrfs_root *root, u64 bytenr, | |
155 | u64 num_bytes, u32 *refs); | |
156 | int btrfs_update_delayed_ref(struct btrfs_trans_handle *trans, | |
157 | u64 bytenr, u64 num_bytes, u64 orig_parent, | |
158 | u64 parent, u64 orig_ref_root, u64 ref_root, | |
159 | u64 orig_ref_generation, u64 ref_generation, | |
160 | u64 owner_objectid, int pin); | |
c3e69d58 CM |
161 | int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans, |
162 | struct btrfs_delayed_ref_head *head); | |
163 | int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans, | |
164 | struct list_head *cluster, u64 search_start); | |
56bec294 CM |
165 | /* |
166 | * a node might live in a head or a regular ref, this lets you | |
167 | * test for the proper type to use. | |
168 | */ | |
169 | static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node) | |
170 | { | |
171 | return node->parent == (u64)-1; | |
172 | } | |
173 | ||
174 | /* | |
175 | * helper functions to cast a node into its container | |
176 | */ | |
177 | static inline struct btrfs_delayed_ref * | |
178 | btrfs_delayed_node_to_ref(struct btrfs_delayed_ref_node *node) | |
179 | { | |
180 | WARN_ON(btrfs_delayed_ref_is_head(node)); | |
181 | return container_of(node, struct btrfs_delayed_ref, node); | |
182 | ||
183 | } | |
184 | ||
185 | static inline struct btrfs_delayed_ref_head * | |
186 | btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node) | |
187 | { | |
188 | WARN_ON(!btrfs_delayed_ref_is_head(node)); | |
189 | return container_of(node, struct btrfs_delayed_ref_head, node); | |
190 | ||
191 | } | |
192 | #endif |