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#define EXTENT_STATUS_WRITTEN	(1 << ES_WRITTEN_B)
46#define EXTENT_STATUS_UNWRITTEN (1 << ES_UNWRITTEN_B)
47#define EXTENT_STATUS_DELAYED	(1 << ES_DELAYED_B)
48#define EXTENT_STATUS_HOLE	(1 << ES_HOLE_B)
49#define EXTENT_STATUS_REFERENCED	(1 << ES_REFERENCED_B)
50
51#define ES_TYPE_MASK	((ext4_fsblk_t)(EXTENT_STATUS_WRITTEN | \
52			  EXTENT_STATUS_UNWRITTEN | \
53			  EXTENT_STATUS_DELAYED | \
54			  EXTENT_STATUS_HOLE) << ES_SHIFT)
55
56struct ext4_sb_info;
57struct ext4_extent;
58
59struct extent_status {
60	struct rb_node rb_node;
61	ext4_lblk_t es_lblk;	/* first logical block extent covers */
62	ext4_lblk_t es_len;	/* length of extent in block */
63	ext4_fsblk_t es_pblk;	/* first physical block */
64};
65
66struct ext4_es_tree {
67	struct rb_root root;
68	struct extent_status *cache_es;	/* recently accessed extent */
69};
70
71struct ext4_es_stats {
72	unsigned long es_stats_shrunk;
73	struct percpu_counter es_stats_cache_hits;
74	struct percpu_counter es_stats_cache_misses;
75	u64 es_stats_scan_time;
76	u64 es_stats_max_scan_time;
77	struct percpu_counter es_stats_all_cnt;
78	struct percpu_counter es_stats_shk_cnt;
79};
80
81/*
82 * Pending cluster reservations for bigalloc file systems
83 *
84 * A cluster with a pending reservation is a logical cluster shared by at
85 * least one extent in the extents status tree with delayed and unwritten
86 * status and at least one other written or unwritten extent.  The
87 * reservation is said to be pending because a cluster reservation would
88 * have to be taken in the event all blocks in the cluster shared with
89 * written or unwritten extents were deleted while the delayed and
90 * unwritten blocks remained.
91 *
92 * The set of pending cluster reservations is an auxiliary data structure
93 * used with the extents status tree to implement reserved cluster/block
94 * accounting for bigalloc file systems.  The set is kept in memory and
95 * records all pending cluster reservations.
96 *
97 * Its primary function is to avoid the need to read extents from the
98 * disk when invalidating pages as a result of a truncate, punch hole, or
99 * collapse range operation.  Page invalidation requires a decrease in the
100 * reserved cluster count if it results in the removal of all delayed
101 * and unwritten extents (blocks) from a cluster that is not shared with a
102 * written or unwritten extent, and no decrease otherwise.  Determining
103 * whether the cluster is shared can be done by searching for a pending
104 * reservation on it.
105 *
106 * Secondarily, it provides a potentially faster method for determining
107 * whether the reserved cluster count should be increased when a physical
108 * cluster is deallocated as a result of a truncate, punch hole, or
109 * collapse range operation.  The necessary information is also present
110 * in the extents status tree, but might be more rapidly accessed in
111 * the pending reservation set in many cases due to smaller size.
112 *
113 * The pending cluster reservation set is implemented as a red-black tree
114 * with the goal of minimizing per page search time overhead.
115 */
116
117struct pending_reservation {
118	struct rb_node rb_node;
119	ext4_lblk_t lclu;
120};
121
122struct ext4_pending_tree {
123	struct rb_root root;
124};
125
126extern int __init ext4_init_es(void);
127extern void ext4_exit_es(void);
128extern void ext4_es_init_tree(struct ext4_es_tree *tree);
129
130extern void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
131				  ext4_lblk_t len, ext4_fsblk_t pblk,
132				  unsigned int status);
133extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
134				 ext4_lblk_t len, ext4_fsblk_t pblk,
135				 unsigned int status);
136extern void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
137				  ext4_lblk_t len);
138extern void ext4_es_find_extent_range(struct inode *inode,
139				      int (*match_fn)(struct extent_status *es),
140				      ext4_lblk_t lblk, ext4_lblk_t end,
141				      struct extent_status *es);
142extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
143				 ext4_lblk_t *next_lblk,
144				 struct extent_status *es);
145extern bool ext4_es_scan_range(struct inode *inode,
146			       int (*matching_fn)(struct extent_status *es),
147			       ext4_lblk_t lblk, ext4_lblk_t end);
148extern bool ext4_es_scan_clu(struct inode *inode,
149			     int (*matching_fn)(struct extent_status *es),
150			     ext4_lblk_t lblk);
151
152static inline unsigned int ext4_es_status(struct extent_status *es)
153{
154	return es->es_pblk >> ES_SHIFT;
155}
156
157static inline unsigned int ext4_es_type(struct extent_status *es)
158{
159	return (es->es_pblk & ES_TYPE_MASK) >> ES_SHIFT;
160}
161
162static inline int ext4_es_is_written(struct extent_status *es)
163{
164	return (ext4_es_type(es) & EXTENT_STATUS_WRITTEN) != 0;
165}
166
167static inline int ext4_es_is_unwritten(struct extent_status *es)
168{
169	return (ext4_es_type(es) & EXTENT_STATUS_UNWRITTEN) != 0;
170}
171
172static inline int ext4_es_is_delayed(struct extent_status *es)
173{
174	return (ext4_es_type(es) & EXTENT_STATUS_DELAYED) != 0;
175}
176
177static inline int ext4_es_is_hole(struct extent_status *es)
178{
179	return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0;
180}
181
182static inline int ext4_es_is_mapped(struct extent_status *es)
183{
184	return (ext4_es_is_written(es) || ext4_es_is_unwritten(es));
185}
186
187static inline int ext4_es_is_delonly(struct extent_status *es)
188{
189	return (ext4_es_is_delayed(es) && !ext4_es_is_unwritten(es));
190}
191
192static inline void ext4_es_set_referenced(struct extent_status *es)
193{
194	es->es_pblk |= ((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT;
195}
196
197static inline void ext4_es_clear_referenced(struct extent_status *es)
198{
199	es->es_pblk &= ~(((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT);
200}
201
202static inline int ext4_es_is_referenced(struct extent_status *es)
203{
204	return (ext4_es_status(es) & EXTENT_STATUS_REFERENCED) != 0;
205}
206
207static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
208{
209	return es->es_pblk & ~ES_MASK;
210}
211
212static inline ext4_fsblk_t ext4_es_show_pblock(struct extent_status *es)
213{
214	ext4_fsblk_t pblock = ext4_es_pblock(es);
215	return pblock == ~ES_MASK ? 0 : pblock;
216}
217
218static inline void ext4_es_store_pblock(struct extent_status *es,
219					ext4_fsblk_t pb)
220{
221	ext4_fsblk_t block;
222
223	block = (pb & ~ES_MASK) | (es->es_pblk & ES_MASK);
224	es->es_pblk = block;
225}
226
227static inline void ext4_es_store_status(struct extent_status *es,
228					unsigned int status)
229{
230	es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) |
231		      (es->es_pblk & ~ES_MASK);
232}
233
234static inline void ext4_es_store_pblock_status(struct extent_status *es,
235					       ext4_fsblk_t pb,
236					       unsigned int status)
237{
238	es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) |
239		      (pb & ~ES_MASK);
240}
241
242extern int ext4_es_register_shrinker(struct ext4_sb_info *sbi);
243extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
244
245extern int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v);
246
247extern int __init ext4_init_pending(void);
248extern void ext4_exit_pending(void);
249extern void ext4_init_pending_tree(struct ext4_pending_tree *tree);
250extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk);
251extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk);
252extern void ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
253					 bool allocated);
254extern unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
255					ext4_lblk_t len);
256extern void ext4_clear_inode_es(struct inode *inode);
257
258#endif /* _EXT4_EXTENTS_STATUS_H */
259