xref: /linux/fs/ext4/extents_status.h (revision 55f1b540d893da740a81200450014c45a8103f54)
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 /*
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 
62 struct ext4_sb_info;
63 struct ext4_extent;
64 
65 struct 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 
72 struct ext4_es_tree {
73 	struct rb_root root;
74 	struct extent_status *cache_es;	/* recently accessed extent */
75 };
76 
77 struct 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 
123 struct pending_reservation {
124 	struct rb_node rb_node;
125 	ext4_lblk_t lclu;
126 };
127 
128 struct ext4_pending_tree {
129 	struct rb_root root;
130 };
131 
132 extern int __init ext4_init_es(void);
133 extern void ext4_exit_es(void);
134 extern void ext4_es_init_tree(struct ext4_es_tree *tree);
135 
136 extern 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, int flags);
139 extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
140 				 ext4_lblk_t len, ext4_fsblk_t pblk,
141 				 unsigned int status);
142 extern void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
143 				  ext4_lblk_t len);
144 extern void ext4_es_find_extent_range(struct inode *inode,
145 				      int (*match_fn)(struct extent_status *es),
146 				      ext4_lblk_t lblk, ext4_lblk_t end,
147 				      struct extent_status *es);
148 extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
149 				 ext4_lblk_t *next_lblk,
150 				 struct extent_status *es);
151 extern bool ext4_es_scan_range(struct inode *inode,
152 			       int (*matching_fn)(struct extent_status *es),
153 			       ext4_lblk_t lblk, ext4_lblk_t end);
154 extern bool ext4_es_scan_clu(struct inode *inode,
155 			     int (*matching_fn)(struct extent_status *es),
156 			     ext4_lblk_t lblk);
157 
158 static inline unsigned int ext4_es_status(struct extent_status *es)
159 {
160 	return es->es_pblk >> ES_SHIFT;
161 }
162 
163 static inline unsigned int ext4_es_type(struct extent_status *es)
164 {
165 	return (es->es_pblk >> ES_SHIFT) & ES_TYPE_MASK;
166 }
167 
168 static inline int ext4_es_is_written(struct extent_status *es)
169 {
170 	return (ext4_es_type(es) & EXTENT_STATUS_WRITTEN) != 0;
171 }
172 
173 static inline int ext4_es_is_unwritten(struct extent_status *es)
174 {
175 	return (ext4_es_type(es) & EXTENT_STATUS_UNWRITTEN) != 0;
176 }
177 
178 static inline int ext4_es_is_delayed(struct extent_status *es)
179 {
180 	return (ext4_es_type(es) & EXTENT_STATUS_DELAYED) != 0;
181 }
182 
183 static inline int ext4_es_is_hole(struct extent_status *es)
184 {
185 	return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0;
186 }
187 
188 static inline int ext4_es_is_mapped(struct extent_status *es)
189 {
190 	return (ext4_es_is_written(es) || ext4_es_is_unwritten(es));
191 }
192 
193 static inline void ext4_es_set_referenced(struct extent_status *es)
194 {
195 	es->es_pblk |= ((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT;
196 }
197 
198 static inline void ext4_es_clear_referenced(struct extent_status *es)
199 {
200 	es->es_pblk &= ~(((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT);
201 }
202 
203 static inline int ext4_es_is_referenced(struct extent_status *es)
204 {
205 	return (ext4_es_status(es) & EXTENT_STATUS_REFERENCED) != 0;
206 }
207 
208 static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
209 {
210 	return es->es_pblk & ~ES_MASK;
211 }
212 
213 static inline ext4_fsblk_t ext4_es_show_pblock(struct extent_status *es)
214 {
215 	ext4_fsblk_t pblock = ext4_es_pblock(es);
216 	return pblock == ~ES_MASK ? 0 : pblock;
217 }
218 
219 static inline void ext4_es_store_pblock(struct extent_status *es,
220 					ext4_fsblk_t pb)
221 {
222 	ext4_fsblk_t block;
223 
224 	block = (pb & ~ES_MASK) | (es->es_pblk & ES_MASK);
225 	es->es_pblk = block;
226 }
227 
228 static inline void ext4_es_store_pblock_status(struct extent_status *es,
229 					       ext4_fsblk_t pb,
230 					       unsigned int status)
231 {
232 	WARN_ON_ONCE(!ES_TYPE_VALID(status & ES_TYPE_MASK));
233 
234 	es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) |
235 		      (pb & ~ES_MASK);
236 }
237 
238 extern int ext4_es_register_shrinker(struct ext4_sb_info *sbi);
239 extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
240 
241 extern int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v);
242 
243 extern int __init ext4_init_pending(void);
244 extern void ext4_exit_pending(void);
245 extern void ext4_init_pending_tree(struct ext4_pending_tree *tree);
246 extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk);
247 extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk);
248 extern void ext4_es_insert_delayed_extent(struct inode *inode, ext4_lblk_t lblk,
249 					  ext4_lblk_t len, bool lclu_allocated,
250 					  bool end_allocated);
251 extern void ext4_clear_inode_es(struct inode *inode);
252 
253 #endif /* _EXT4_EXTENTS_STATUS_H */
254