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1 | /* | |
2 | * Block data types and constants. Directly include this file only to | |
3 | * break include dependency loop. | |
4 | */ | |
5 | #ifndef __LINUX_BLK_TYPES_H | |
6 | #define __LINUX_BLK_TYPES_H | |
7 | ||
8 | #ifdef CONFIG_BLOCK | |
9 | ||
10 | #include <linux/types.h> | |
11 | ||
12 | struct bio_set; | |
13 | struct bio; | |
14 | struct bio_integrity_payload; | |
15 | struct page; | |
16 | struct block_device; | |
17 | typedef void (bio_end_io_t) (struct bio *, int); | |
18 | typedef void (bio_destructor_t) (struct bio *); | |
19 | ||
20 | /* | |
21 | * was unsigned short, but we might as well be ready for > 64kB I/O pages | |
22 | */ | |
23 | struct bio_vec { | |
24 | struct page *bv_page; | |
25 | unsigned int bv_len; | |
26 | unsigned int bv_offset; | |
27 | }; | |
28 | ||
29 | /* | |
30 | * main unit of I/O for the block layer and lower layers (ie drivers and | |
31 | * stacking drivers) | |
32 | */ | |
33 | struct bio { | |
34 | sector_t bi_sector; /* device address in 512 byte | |
35 | sectors */ | |
36 | struct bio *bi_next; /* request queue link */ | |
37 | struct block_device *bi_bdev; | |
38 | unsigned long bi_flags; /* status, command, etc */ | |
39 | unsigned long bi_rw; /* bottom bits READ/WRITE, | |
40 | * top bits priority | |
41 | */ | |
42 | ||
43 | unsigned short bi_vcnt; /* how many bio_vec's */ | |
44 | unsigned short bi_idx; /* current index into bvl_vec */ | |
45 | ||
46 | /* Number of segments in this BIO after | |
47 | * physical address coalescing is performed. | |
48 | */ | |
49 | unsigned int bi_phys_segments; | |
50 | ||
51 | unsigned int bi_size; /* residual I/O count */ | |
52 | ||
53 | /* | |
54 | * To keep track of the max segment size, we account for the | |
55 | * sizes of the first and last mergeable segments in this bio. | |
56 | */ | |
57 | unsigned int bi_seg_front_size; | |
58 | unsigned int bi_seg_back_size; | |
59 | ||
60 | unsigned int bi_max_vecs; /* max bvl_vecs we can hold */ | |
61 | ||
62 | unsigned int bi_comp_cpu; /* completion CPU */ | |
63 | ||
64 | atomic_t bi_cnt; /* pin count */ | |
65 | ||
66 | struct bio_vec *bi_io_vec; /* the actual vec list */ | |
67 | ||
68 | bio_end_io_t *bi_end_io; | |
69 | ||
70 | void *bi_private; | |
71 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
72 | struct bio_integrity_payload *bi_integrity; /* data integrity */ | |
73 | #endif | |
74 | ||
75 | bio_destructor_t *bi_destructor; /* destructor */ | |
76 | ||
77 | /* | |
78 | * We can inline a number of vecs at the end of the bio, to avoid | |
79 | * double allocations for a small number of bio_vecs. This member | |
80 | * MUST obviously be kept at the very end of the bio. | |
81 | */ | |
82 | struct bio_vec bi_inline_vecs[0]; | |
83 | }; | |
84 | ||
85 | /* | |
86 | * bio flags | |
87 | */ | |
88 | #define BIO_UPTODATE 0 /* ok after I/O completion */ | |
89 | #define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */ | |
90 | #define BIO_EOF 2 /* out-out-bounds error */ | |
91 | #define BIO_SEG_VALID 3 /* bi_phys_segments valid */ | |
92 | #define BIO_CLONED 4 /* doesn't own data */ | |
93 | #define BIO_BOUNCED 5 /* bio is a bounce bio */ | |
94 | #define BIO_USER_MAPPED 6 /* contains user pages */ | |
95 | #define BIO_EOPNOTSUPP 7 /* not supported */ | |
96 | #define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */ | |
97 | #define BIO_NULL_MAPPED 9 /* contains invalid user pages */ | |
98 | #define BIO_FS_INTEGRITY 10 /* fs owns integrity data, not block layer */ | |
99 | #define BIO_QUIET 11 /* Make BIO Quiet */ | |
100 | #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) | |
101 | ||
102 | /* | |
103 | * top 4 bits of bio flags indicate the pool this bio came from | |
104 | */ | |
105 | #define BIO_POOL_BITS (4) | |
106 | #define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1) | |
107 | #define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS) | |
108 | #define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET) | |
109 | #define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET) | |
110 | ||
111 | #endif /* CONFIG_BLOCK */ | |
112 | ||
113 | /* | |
114 | * Request flags. For use in the cmd_flags field of struct request, and in | |
115 | * bi_rw of struct bio. Note that some flags are only valid in either one. | |
116 | */ | |
117 | enum rq_flag_bits { | |
118 | /* common flags */ | |
119 | __REQ_WRITE, /* not set, read. set, write */ | |
120 | __REQ_FAILFAST_DEV, /* no driver retries of device errors */ | |
121 | __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ | |
122 | __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ | |
123 | ||
124 | __REQ_HARDBARRIER, /* may not be passed by drive either */ | |
125 | __REQ_SYNC, /* request is sync (sync write or read) */ | |
126 | __REQ_META, /* metadata io request */ | |
127 | __REQ_DISCARD, /* request to discard sectors */ | |
128 | __REQ_NOIDLE, /* don't anticipate more IO after this one */ | |
129 | ||
130 | /* bio only flags */ | |
131 | __REQ_UNPLUG, /* unplug the immediately after submission */ | |
132 | __REQ_RAHEAD, /* read ahead, can fail anytime */ | |
133 | ||
134 | /* request only flags */ | |
135 | __REQ_SORTED, /* elevator knows about this request */ | |
136 | __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ | |
137 | __REQ_FUA, /* forced unit access */ | |
138 | __REQ_NOMERGE, /* don't touch this for merging */ | |
139 | __REQ_STARTED, /* drive already may have started this one */ | |
140 | __REQ_DONTPREP, /* don't call prep for this one */ | |
141 | __REQ_QUEUED, /* uses queueing */ | |
142 | __REQ_ELVPRIV, /* elevator private data attached */ | |
143 | __REQ_FAILED, /* set if the request failed */ | |
144 | __REQ_QUIET, /* don't worry about errors */ | |
145 | __REQ_PREEMPT, /* set for "ide_preempt" requests */ | |
146 | __REQ_ALLOCED, /* request came from our alloc pool */ | |
147 | __REQ_COPY_USER, /* contains copies of user pages */ | |
148 | __REQ_INTEGRITY, /* integrity metadata has been remapped */ | |
149 | __REQ_FLUSH, /* request for cache flush */ | |
150 | __REQ_IO_STAT, /* account I/O stat */ | |
151 | __REQ_MIXED_MERGE, /* merge of different types, fail separately */ | |
152 | __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */ | |
153 | __REQ_NR_BITS, /* stops here */ | |
154 | }; | |
155 | ||
156 | #define REQ_WRITE (1 << __REQ_WRITE) | |
157 | #define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV) | |
158 | #define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT) | |
159 | #define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER) | |
160 | #define REQ_HARDBARRIER (1 << __REQ_HARDBARRIER) | |
161 | #define REQ_SYNC (1 << __REQ_SYNC) | |
162 | #define REQ_META (1 << __REQ_META) | |
163 | #define REQ_DISCARD (1 << __REQ_DISCARD) | |
164 | #define REQ_NOIDLE (1 << __REQ_NOIDLE) | |
165 | ||
166 | #define REQ_FAILFAST_MASK \ | |
167 | (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) | |
168 | #define REQ_COMMON_MASK \ | |
169 | (REQ_WRITE | REQ_FAILFAST_MASK | REQ_HARDBARRIER | REQ_SYNC | \ | |
170 | REQ_META| REQ_DISCARD | REQ_NOIDLE) | |
171 | ||
172 | #define REQ_UNPLUG (1 << __REQ_UNPLUG) | |
173 | #define REQ_RAHEAD (1 << __REQ_RAHEAD) | |
174 | ||
175 | #define REQ_SORTED (1 << __REQ_SORTED) | |
176 | #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) | |
177 | #define REQ_FUA (1 << __REQ_FUA) | |
178 | #define REQ_NOMERGE (1 << __REQ_NOMERGE) | |
179 | #define REQ_STARTED (1 << __REQ_STARTED) | |
180 | #define REQ_DONTPREP (1 << __REQ_DONTPREP) | |
181 | #define REQ_QUEUED (1 << __REQ_QUEUED) | |
182 | #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) | |
183 | #define REQ_FAILED (1 << __REQ_FAILED) | |
184 | #define REQ_QUIET (1 << __REQ_QUIET) | |
185 | #define REQ_PREEMPT (1 << __REQ_PREEMPT) | |
186 | #define REQ_ALLOCED (1 << __REQ_ALLOCED) | |
187 | #define REQ_COPY_USER (1 << __REQ_COPY_USER) | |
188 | #define REQ_INTEGRITY (1 << __REQ_INTEGRITY) | |
189 | #define REQ_FLUSH (1 << __REQ_FLUSH) | |
190 | #define REQ_IO_STAT (1 << __REQ_IO_STAT) | |
191 | #define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE) | |
192 | #define REQ_SECURE (1 << __REQ_SECURE) | |
193 | ||
194 | #endif /* __LINUX_BLK_TYPES_H */ |