1/*
2 *  fs/ext4/extents_status.h
3 *
4 * Written by Yongqiang Yang <xiaoqiangnk@gmail.com>
5 * Modified by
6 *	Allison Henderson <achender@linux.vnet.ibm.com>
7 *	Zheng Liu <wenqing.lz@taobao.com>
8 *
9 */
10
11#ifndef _EXT4_EXTENTS_STATUS_H
12#define _EXT4_EXTENTS_STATUS_H
13
14/*
15 * Turn on ES_DEBUG__ to get lots of info about extent status operations.
16 */
17#ifdef ES_DEBUG__
18#define es_debug(fmt, ...)	printk(fmt, ##__VA_ARGS__)
19#else
20#define es_debug(fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
21#endif
22
23/*
24 * With ES_AGGRESSIVE_TEST defined, the result of es caching will be
25 * checked with old map_block's result.
26 */
27#define ES_AGGRESSIVE_TEST__
28
29/*
30 * These flags live in the high bits of extent_status.es_pblk
31 */
32enum {
33	ES_WRITTEN_B,
34	ES_UNWRITTEN_B,
35	ES_DELAYED_B,
36	ES_HOLE_B,
37	ES_REFERENCED_B,
38	ES_FLAGS
39};
40
41#define ES_SHIFT (sizeof(ext4_fsblk_t)*8 - ES_FLAGS)
42#define ES_MASK (~((ext4_fsblk_t)0) << ES_SHIFT)
43
44#define EXTENT_STATUS_WRITTEN	(1 << ES_WRITTEN_B)
45#define EXTENT_STATUS_UNWRITTEN (1 << ES_UNWRITTEN_B)
46#define EXTENT_STATUS_DELAYED	(1 << ES_DELAYED_B)
47#define EXTENT_STATUS_HOLE	(1 << ES_HOLE_B)
48#define EXTENT_STATUS_REFERENCED	(1 << ES_REFERENCED_B)
49
50#define ES_TYPE_MASK	((ext4_fsblk_t)(EXTENT_STATUS_WRITTEN | \
51			  EXTENT_STATUS_UNWRITTEN | \
52			  EXTENT_STATUS_DELAYED | \
53			  EXTENT_STATUS_HOLE) << ES_SHIFT)
54
55struct ext4_sb_info;
56struct ext4_extent;
57
58struct extent_status {
59	struct rb_node rb_node;
60	ext4_lblk_t es_lblk;	/* first logical block extent covers */
61	ext4_lblk_t es_len;	/* length of extent in block */
62	ext4_fsblk_t es_pblk;	/* first physical block */
63};
64
65struct ext4_es_tree {
66	struct rb_root root;
67	struct extent_status *cache_es;	/* recently accessed extent */
68};
69
70struct ext4_es_stats {
71	unsigned long es_stats_shrunk;
72	unsigned long es_stats_cache_hits;
73	unsigned long es_stats_cache_misses;
74	u64 es_stats_scan_time;
75	u64 es_stats_max_scan_time;
76	struct percpu_counter es_stats_all_cnt;
77	struct percpu_counter es_stats_shk_cnt;
78};
79
80extern int __init ext4_init_es(void);
81extern void ext4_exit_es(void);
82extern void ext4_es_init_tree(struct ext4_es_tree *tree);
83
84extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
85				 ext4_lblk_t len, ext4_fsblk_t pblk,
86				 unsigned int status);
87extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
88				 ext4_lblk_t len, ext4_fsblk_t pblk,
89				 unsigned int status);
90extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
91				 ext4_lblk_t len);
92extern void ext4_es_find_delayed_extent_range(struct inode *inode,
93					ext4_lblk_t lblk, ext4_lblk_t end,
94					struct extent_status *es);
95extern int ext4_es_lookup_extent(struct inode *inode, ext4_lblk_t lblk,
96				 struct extent_status *es);
97
98static inline unsigned int ext4_es_status(struct extent_status *es)
99{
100	return es->es_pblk >> ES_SHIFT;
101}
102
103static inline unsigned int ext4_es_type(struct extent_status *es)
104{
105	return (es->es_pblk & ES_TYPE_MASK) >> ES_SHIFT;
106}
107
108static inline int ext4_es_is_written(struct extent_status *es)
109{
110	return (ext4_es_type(es) & EXTENT_STATUS_WRITTEN) != 0;
111}
112
113static inline int ext4_es_is_unwritten(struct extent_status *es)
114{
115	return (ext4_es_type(es) & EXTENT_STATUS_UNWRITTEN) != 0;
116}
117
118static inline int ext4_es_is_delayed(struct extent_status *es)
119{
120	return (ext4_es_type(es) & EXTENT_STATUS_DELAYED) != 0;
121}
122
123static inline int ext4_es_is_hole(struct extent_status *es)
124{
125	return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0;
126}
127
128static inline void ext4_es_set_referenced(struct extent_status *es)
129{
130	es->es_pblk |= ((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT;
131}
132
133static inline void ext4_es_clear_referenced(struct extent_status *es)
134{
135	es->es_pblk &= ~(((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT);
136}
137
138static inline int ext4_es_is_referenced(struct extent_status *es)
139{
140	return (ext4_es_status(es) & EXTENT_STATUS_REFERENCED) != 0;
141}
142
143static inline ext4_fsblk_t ext4_es_pblock(struct extent_status *es)
144{
145	return es->es_pblk & ~ES_MASK;
146}
147
148static inline void ext4_es_store_pblock(struct extent_status *es,
149					ext4_fsblk_t pb)
150{
151	ext4_fsblk_t block;
152
153	block = (pb & ~ES_MASK) | (es->es_pblk & ES_MASK);
154	es->es_pblk = block;
155}
156
157static inline void ext4_es_store_status(struct extent_status *es,
158					unsigned int status)
159{
160	es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) |
161		      (es->es_pblk & ~ES_MASK);
162}
163
164static inline void ext4_es_store_pblock_status(struct extent_status *es,
165					       ext4_fsblk_t pb,
166					       unsigned int status)
167{
168	es->es_pblk = (((ext4_fsblk_t)status << ES_SHIFT) & ES_MASK) |
169		      (pb & ~ES_MASK);
170}
171
172extern int ext4_es_register_shrinker(struct ext4_sb_info *sbi);
173extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
174
175#endif /* _EXT4_EXTENTS_STATUS_H */
176