1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fs/ext4/extents_status.h
4 *
5 * Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
6 * Modified by
7 * Allison Henderson <achender@linux.vnet.ibm.com>
8 * Zheng Liu <wenqing.lz@taobao.com>
9 *
10 */
11
12#ifndef _EXT4_EXTENTS_STATUS_H
13#define _EXT4_EXTENTS_STATUS_H
14
15/*
16 * Turn on ES_DEBUG__ to get lots of info about extent status operations.
17 */
18#ifdef ES_DEBUG__
19#define es_debug(fmt, ...) printk(fmt, ##__VA_ARGS__)
20#else
21#define es_debug(fmt, ...) no_printk(fmt, ##__VA_ARGS__)
22#endif
23
24/*
25 * With ES_AGGRESSIVE_TEST defined, the result of es caching will be
26 * checked with old map_block's result.
27 */
28#define ES_AGGRESSIVE_TEST__
29
30/*
31 * These flags live in the high bits of extent_status.es_pblk
32 */
33enum {
34 ES_WRITTEN_B,
35 ES_UNWRITTEN_B,
36 ES_DELAYED_B,
37 ES_HOLE_B,
38 ES_REFERENCED_B,
39 ES_FLAGS
40};
41
42#define ES_SHIFT (sizeof(ext4_fsblk_t)*8 - ES_FLAGS)
43#define ES_MASK (~((ext4_fsblk_t)0) << ES_SHIFT)
44
45/*
46 * Besides EXTENT_STATUS_REFERENCED, all these extent type masks
47 * are exclusive, only one type can be set at a time.
48 */
49#define EXTENT_STATUS_WRITTEN (1 << ES_WRITTEN_B)
50#define EXTENT_STATUS_UNWRITTEN (1 << ES_UNWRITTEN_B)
51#define EXTENT_STATUS_DELAYED (1 << ES_DELAYED_B)
52#define EXTENT_STATUS_HOLE (1 << ES_HOLE_B)
53#define EXTENT_STATUS_REFERENCED (1 << ES_REFERENCED_B)
54
55#define ES_TYPE_MASK ((ext4_fsblk_t)(EXTENT_STATUS_WRITTEN | \
56 EXTENT_STATUS_UNWRITTEN | \
57 EXTENT_STATUS_DELAYED | \
58 EXTENT_STATUS_HOLE))
59
60#define ES_TYPE_VALID(type) ((type) && !((type) & ((type) - 1)))
61
62struct ext4_sb_info;
63struct ext4_extent;
64
65struct extent_status {
66 struct rb_node rb_node;
67 ext4_lblk_t es_lblk; /* first logical block extent covers */
68 ext4_lblk_t es_len; /* length of extent in block */
69 ext4_fsblk_t es_pblk; /* first physical block */
70};
71
72struct ext4_es_tree {
73 struct rb_root root;
74 struct extent_status *cache_es; /* recently accessed extent */
75};
76
77struct ext4_es_stats {
78 unsigned long es_stats_shrunk;
79 struct percpu_counter es_stats_cache_hits;
80 struct percpu_counter es_stats_cache_misses;
81 u64 es_stats_scan_time;
82 u64 es_stats_max_scan_time;
83 struct percpu_counter es_stats_all_cnt;
84 struct percpu_counter es_stats_shk_cnt;
85};
86
87/*
88 * Pending cluster reservations for bigalloc file systems
89 *
90 * A cluster with a pending reservation is a logical cluster shared by at
91 * least one extent in the extents status tree with delayed and unwritten
92 * status and at least one other written or unwritten extent. The
93 * reservation is said to be pending because a cluster reservation would
94 * have to be taken in the event all blocks in the cluster shared with
95 * written or unwritten extents were deleted while the delayed and
96 * unwritten blocks remained.
97 *
98 * The set of pending cluster reservations is an auxiliary data structure
99 * used with the extents status tree to implement reserved cluster/block
100 * accounting for bigalloc file systems. The set is kept in memory and
101 * records all pending cluster reservations.
102 *
103 * Its primary function is to avoid the need to read extents from the
104 * disk when invalidating pages as a result of a truncate, punch hole, or
105 * collapse range operation. Page invalidation requires a decrease in the
106 * reserved cluster count if it results in the removal of all delayed
107 * and unwritten extents (blocks) from a cluster that is not shared with a
108 * written or unwritten extent, and no decrease otherwise. Determining
109 * whether the cluster is shared can be done by searching for a pending
110 * reservation on it.
111 *
112 * Secondarily, it provides a potentially faster method for determining
113 * whether the reserved cluster count should be increased when a physical
114 * cluster is deallocated as a result of a truncate, punch hole, or
115 * collapse range operation. The necessary information is also present
116 * in the extents status tree, but might be more rapidly accessed in
117 * the pending reservation set in many cases due to smaller size.
118 *
119 * The pending cluster reservation set is implemented as a red-black tree
120 * with the goal of minimizing per page search time overhead.
121 */
122
123struct pending_reservation {
124 struct rb_node rb_node;
125 ext4_lblk_t lclu;
126};
127
128struct ext4_pending_tree {
129 struct rb_root root;
130};
131
132extern int __init ext4_init_es(void);
133extern void ext4_exit_es(void);
134extern void ext4_es_init_tree(struct ext4_es_tree *tree);
135
136extern void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
137 ext4_lblk_t len, ext4_fsblk_t pblk,
138 unsigned int status,
139 bool delalloc_reserve_used);
140extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
141 ext4_lblk_t len, ext4_fsblk_t pblk,
142 unsigned int status);
143extern void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
144 ext4_lblk_t len);
145extern void ext4_es_find_extent_range(struct inode *inode,
146 int (*match_fn)(struct extent_status *es),
147 ext4_lblk_t lblk, ext4_lblk_t end,
148 struct extent_status *es);
149extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
150 ext4_lblk_t *next_lblk,
151 struct extent_status *es, u64 *pseq);
152extern bool ext4_es_scan_range(struct inode *inode,
153 int (*matching_fn)(struct extent_status *es),
154 ext4_lblk_t lblk, ext4_lblk_t end);
155extern bool ext4_es_scan_clu(struct inode *inode,
156 int (*matching_fn)(struct extent_status *es),
157 ext4_lblk_t lblk);
158
159static inline unsigned int ext4_es_status(struct extent_status *es)
160{
161 return es->es_pblk >> ES_SHIFT;
162}
163
164static inline unsigned int ext4_es_type(struct extent_status *es)
165{
166 return (es->es_pblk >> ES_SHIFT) & ES_TYPE_MASK;
167}
168
169static inline int ext4_es_is_written(struct extent_status *es)
170{
171 return (ext4_es_type(es) & EXTENT_STATUS_WRITTEN) != 0;
172}
173
174static inline int ext4_es_is_unwritten(struct extent_status *es)
175{
176 return (ext4_es_type(es) & EXTENT_STATUS_UNWRITTEN) != 0;
177}
178
179static inline int ext4_es_is_delayed(struct extent_status *es)
180{
181 return (ext4_es_type(es) & EXTENT_STATUS_DELAYED) != 0;
182}
183
184static inline int ext4_es_is_hole(struct extent_status *es)
185{
186 return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0;
187}
188
189static inline int ext4_es_is_mapped(struct extent_status *es)
190{
191 return (ext4_es_is_written(es) || ext4_es_is_unwritten(es));
192}
193
194static inline void ext4_es_set_referenced(struct extent_status *es)
195{
196 es->es_pblk |= ((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT;
197}
198
199static inline void ext4_es_clear_referenced(struct extent_status *es)
200{
201 es->es_pblk &= ~(((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT);
202}
203
204static inline int ext4_es_is_referenced(struct extent_status *es)
205{
206 return (ext4_es_status(es) & EXTENT_STATUS_REFERENCED) != 0;
207}
208
209static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
210{
211 return es->es_pblk & ~ES_MASK;
212}
213
214static inline ext4_fsblk_t ext4_es_show_pblock(struct extent_status *es)
215{
216 ext4_fsblk_t pblock = ext4_es_pblock(es);
217 return pblock == ~ES_MASK ? 0 : pblock;
218}
219
220static inline void ext4_es_store_pblock(struct extent_status *es,
221 ext4_fsblk_t pb)
222{
223 ext4_fsblk_t block;
224
225 block = (pb & ~ES_MASK) | (es->es_pblk & ES_MASK);
226 es->es_pblk = block;
227}
228
229static inline void ext4_es_store_pblock_status(struct extent_status *es,
230 ext4_fsblk_t pb,
231 unsigned int status)
232{
233 WARN_ON_ONCE(!ES_TYPE_VALID(status & ES_TYPE_MASK));
234
235 es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) |
236 (pb & ~ES_MASK);
237}
238
239extern int ext4_es_register_shrinker(struct ext4_sb_info *sbi);
240extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
241
242extern int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v);
243
244extern int __init ext4_init_pending(void);
245extern void ext4_exit_pending(void);
246extern void ext4_init_pending_tree(struct ext4_pending_tree *tree);
247extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk);
248extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk);
249extern void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk,
250 ext4_lblk_t len, bool lclu_allocated,
251 bool end_allocated);
252extern void ext4_clear_inode_es(struct inode *inode);
253
254#endif /* _EXT4_EXTENTS_STATUS_H */
255

source code of linux/fs/ext4/extents_status.h