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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->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 unsigned int update_key:1;
64 unsigned int update_flags:1;
65 unsigned int is_data:1;
66};
67
68/*
69 * the head refs are used to hold a lock on a given extent, which allows us
70 * to make sure that only one process is running the delayed refs
71 * at a time for a single extent. They also store the sum of all the
72 * reference count modifications we've queued up.
73 */
74struct btrfs_delayed_ref_head {
75 struct btrfs_delayed_ref_node node;
76
77 /*
78 * the mutex is held while running the refs, and it is also
79 * held when checking the sum of reference modifications.
80 */
81 struct mutex mutex;
82
83 struct list_head cluster;
84
85 struct btrfs_delayed_extent_op *extent_op;
86 /*
87 * when a new extent is allocated, it is just reserved in memory
88 * The actual extent isn't inserted into the extent allocation tree
89 * until the delayed ref is processed. must_insert_reserved is
90 * used to flag a delayed ref so the accounting can be updated
91 * when a full insert is done.
92 *
93 * It is possible the extent will be freed before it is ever
94 * inserted into the extent allocation tree. In this case
95 * we need to update the in ram accounting to properly reflect
96 * the free has happened.
97 */
98 unsigned int must_insert_reserved:1;
99 unsigned int is_data:1;
100};
101
102struct btrfs_delayed_tree_ref {
103 struct btrfs_delayed_ref_node node;
104 u64 root;
105 u64 parent;
106 int level;
107};
108
109struct btrfs_delayed_data_ref {
110 struct btrfs_delayed_ref_node node;
111 u64 root;
112 u64 parent;
113 u64 objectid;
114 u64 offset;
115};
116
117struct btrfs_delayed_ref_root {
118 struct rb_root root;
119
120 /* this spin lock protects the rbtree and the entries inside */
121 spinlock_t lock;
122
123 /* how many delayed ref updates we've queued, used by the
124 * throttling code
125 */
126 unsigned long num_entries;
127
128 /* total number of head nodes in tree */
129 unsigned long num_heads;
130
131 /* total number of head nodes ready for processing */
132 unsigned long num_heads_ready;
133
134 /*
135 * set when the tree is flushing before a transaction commit,
136 * used by the throttling code to decide if new updates need
137 * to be run right away
138 */
139 int flushing;
140
141 u64 run_delayed_start;
142
143 /*
144 * seq number of delayed refs. We need to know if a backref was being
145 * added before the currently processed ref or afterwards.
146 */
147 u64 seq;
148
149 /*
150 * seq_list holds a list of all seq numbers that are currently being
151 * added to the list. While walking backrefs (btrfs_find_all_roots,
152 * qgroups), which might take some time, no newer ref must be processed,
153 * as it might influence the outcome of the walk.
154 */
155 struct list_head seq_head;
156
157 /*
158 * when the only refs we have in the list must not be processed, we want
159 * to wait for more refs to show up or for the end of backref walking.
160 */
161 wait_queue_head_t seq_wait;
162};
163
164static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref)
165{
166 WARN_ON(atomic_read(&ref->refs) == 0);
167 if (atomic_dec_and_test(&ref->refs)) {
168 WARN_ON(ref->in_tree);
169 kfree(ref);
170 }
171}
172
173int btrfs_add_delayed_tree_ref(struct btrfs_fs_info *fs_info,
174 struct btrfs_trans_handle *trans,
175 u64 bytenr, u64 num_bytes, u64 parent,
176 u64 ref_root, int level, int action,
177 struct btrfs_delayed_extent_op *extent_op,
178 int for_cow);
179int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
180 struct btrfs_trans_handle *trans,
181 u64 bytenr, u64 num_bytes,
182 u64 parent, u64 ref_root,
183 u64 owner, u64 offset, int action,
184 struct btrfs_delayed_extent_op *extent_op,
185 int for_cow);
186int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
187 struct btrfs_trans_handle *trans,
188 u64 bytenr, u64 num_bytes,
189 struct btrfs_delayed_extent_op *extent_op);
190
191struct btrfs_delayed_ref_head *
192btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
193int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
194 struct btrfs_delayed_ref_head *head);
195int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
196 struct list_head *cluster, u64 search_start);
197
198static inline u64 inc_delayed_seq(struct btrfs_delayed_ref_root *delayed_refs)
199{
200 assert_spin_locked(&delayed_refs->lock);
201 ++delayed_refs->seq;
202 return delayed_refs->seq;
203}
204
205static inline void
206btrfs_get_delayed_seq(struct btrfs_delayed_ref_root *delayed_refs,
207 struct seq_list *elem)
208{
209 assert_spin_locked(&delayed_refs->lock);
210 elem->seq = delayed_refs->seq;
211 list_add_tail(&elem->list, &delayed_refs->seq_head);
212}
213
214static inline void
215btrfs_put_delayed_seq(struct btrfs_delayed_ref_root *delayed_refs,
216 struct seq_list *elem)
217{
218 spin_lock(&delayed_refs->lock);
219 list_del(&elem->list);
220 wake_up(&delayed_refs->seq_wait);
221 spin_unlock(&delayed_refs->lock);
222}
223
224int btrfs_check_delayed_seq(struct btrfs_delayed_ref_root *delayed_refs,
225 u64 seq);
226
227/*
228 * a node might live in a head or a regular ref, this lets you
229 * test for the proper type to use.
230 */
231static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node)
232{
233 return node->is_head;
234}
235
236/*
237 * helper functions to cast a node into its container
238 */
239static inline struct btrfs_delayed_tree_ref *
240btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
241{
242 WARN_ON(btrfs_delayed_ref_is_head(node));
243 return container_of(node, struct btrfs_delayed_tree_ref, node);
244}
245
246static inline struct btrfs_delayed_data_ref *
247btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node)
248{
249 WARN_ON(btrfs_delayed_ref_is_head(node));
250 return container_of(node, struct btrfs_delayed_data_ref, node);
251}
252
253static inline struct btrfs_delayed_ref_head *
254btrfs_delayed_node_to_head(struct btrfs_delayed_ref_node *node)
255{
256 WARN_ON(!btrfs_delayed_ref_is_head(node));
257 return container_of(node, struct btrfs_delayed_ref_head, node);
258}
259#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->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 /* 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
50 unsigned int action:8;
51 unsigned int type:8;
52 /* is this node still in the rbtree? */
53 unsigned int is_head:1;
54 unsigned int in_tree:1;
55};
56
57struct 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
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 */
71struct 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
80 struct list_head cluster;
81
82 struct btrfs_delayed_extent_op *extent_op;
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;
96 unsigned int is_data:1;
97};
98
99struct btrfs_delayed_tree_ref {
100 struct btrfs_delayed_ref_node node;
101 union {
102 u64 root;
103 u64 parent;
104 };
105 int level;
106};
107
108struct 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;
116};
117
118struct 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
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
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;
141
142 u64 run_delayed_start;
143};
144
145static 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
154int 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);
158int 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);
163int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
164 u64 bytenr, u64 num_bytes,
165 struct btrfs_delayed_extent_op *extent_op);
166
167struct btrfs_delayed_ref_head *
168btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr);
169int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
170 struct btrfs_delayed_ref_head *head);
171int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
172 struct list_head *cluster, u64 search_start);
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 */
177static int btrfs_delayed_ref_is_head(struct btrfs_delayed_ref_node *node)
178{
179 return node->is_head;
180}
181
182/*
183 * helper functions to cast a node into its container
184 */
185static inline struct btrfs_delayed_tree_ref *
186btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
187{
188 WARN_ON(btrfs_delayed_ref_is_head(node));
189 return container_of(node, struct btrfs_delayed_tree_ref, node);
190}
191
192static inline struct btrfs_delayed_data_ref *
193btrfs_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);
197}
198
199static inline struct btrfs_delayed_ref_head *
200btrfs_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);
204}
205#endif