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  */
33 enum {
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 
56 struct ext4_sb_info;
57 struct ext4_extent;
58 
59 struct 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 
66 struct ext4_es_tree {
67 	struct rb_root root;
68 	struct extent_status *cache_es;	/* recently accessed extent */
69 };
70 
71 struct 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 
117 struct pending_reservation {
118 	struct rb_node rb_node;
119 	ext4_lblk_t lclu;
120 };
121 
122 struct ext4_pending_tree {
123 	struct rb_root root;
124 };
125 
126 extern int __init ext4_init_es(void);
127 extern void ext4_exit_es(void);
128 extern void ext4_es_init_tree(struct ext4_es_tree *tree);
129 
130 extern 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);
133 extern 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);
136 extern void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
137 				  ext4_lblk_t len);
138 extern 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);
142 extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
143 				 ext4_lblk_t *next_lblk,
144 				 struct extent_status *es);
145 extern 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);
148 extern bool ext4_es_scan_clu(struct inode *inode,
149 			     int (*matching_fn)(struct extent_status *es),
150 			     ext4_lblk_t lblk);
151 
ext4_es_status(struct extent_status * es)152 static inline unsigned int ext4_es_status(struct extent_status *es)
153 {
154 	return es->es_pblk >> ES_SHIFT;
155 }
156 
ext4_es_type(struct extent_status * es)157 static inline unsigned int ext4_es_type(struct extent_status *es)
158 {
159 	return (es->es_pblk & ES_TYPE_MASK) >> ES_SHIFT;
160 }
161 
ext4_es_is_written(struct extent_status * es)162 static inline int ext4_es_is_written(struct extent_status *es)
163 {
164 	return (ext4_es_type(es) & EXTENT_STATUS_WRITTEN) != 0;
165 }
166 
ext4_es_is_unwritten(struct extent_status * es)167 static inline int ext4_es_is_unwritten(struct extent_status *es)
168 {
169 	return (ext4_es_type(es) & EXTENT_STATUS_UNWRITTEN) != 0;
170 }
171 
ext4_es_is_delayed(struct extent_status * es)172 static inline int ext4_es_is_delayed(struct extent_status *es)
173 {
174 	return (ext4_es_type(es) & EXTENT_STATUS_DELAYED) != 0;
175 }
176 
ext4_es_is_hole(struct extent_status * es)177 static inline int ext4_es_is_hole(struct extent_status *es)
178 {
179 	return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0;
180 }
181 
ext4_es_is_mapped(struct extent_status * es)182 static 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 
ext4_es_is_delonly(struct extent_status * es)187 static 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 
ext4_es_set_referenced(struct extent_status * es)192 static 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 
ext4_es_clear_referenced(struct extent_status * es)197 static 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 
ext4_es_is_referenced(struct extent_status * es)202 static inline int ext4_es_is_referenced(struct extent_status *es)
203 {
204 	return (ext4_es_status(es) & EXTENT_STATUS_REFERENCED) != 0;
205 }
206 
ext4_es_pblock(struct extent_status * es)207 static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
208 {
209 	return es->es_pblk & ~ES_MASK;
210 }
211 
ext4_es_show_pblock(struct extent_status * es)212 static 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 
ext4_es_store_pblock(struct extent_status * es,ext4_fsblk_t pb)218 static 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 
ext4_es_store_status(struct extent_status * es,unsigned int status)227 static 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 
ext4_es_store_pblock_status(struct extent_status * es,ext4_fsblk_t pb,unsigned int status)234 static 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 
242 extern int ext4_es_register_shrinker(struct ext4_sb_info *sbi);
243 extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
244 
245 extern int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v);
246 
247 extern int __init ext4_init_pending(void);
248 extern void ext4_exit_pending(void);
249 extern void ext4_init_pending_tree(struct ext4_pending_tree *tree);
250 extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk);
251 extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk);
252 extern void ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
253 					 bool allocated);
254 extern unsigned int ext4_es_delayed_clu(struct inode *inode, ext4_lblk_t lblk,
255 					ext4_lblk_t len);
256 extern void ext4_clear_inode_es(struct inode *inode);
257 
258 #endif /* _EXT4_EXTENTS_STATUS_H */
259