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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 | #include <linux/types.h> | |
9 | #include <linux/bvec.h> | |
10 | ||
11 | struct bio_set; | |
12 | struct bio; | |
13 | struct bio_integrity_payload; | |
14 | struct page; | |
15 | struct block_device; | |
16 | struct io_context; | |
17 | struct cgroup_subsys_state; | |
18 | typedef void (bio_end_io_t) (struct bio *); | |
19 | ||
20 | /* | |
21 | * main unit of I/O for the block layer and lower layers (ie drivers and | |
22 | * stacking drivers) | |
23 | */ | |
24 | struct bio { | |
25 | struct bio *bi_next; /* request queue link */ | |
26 | struct block_device *bi_bdev; | |
27 | int bi_error; | |
28 | unsigned int bi_opf; /* bottom bits req flags, | |
29 | * top bits REQ_OP. Use | |
30 | * accessors. | |
31 | */ | |
32 | unsigned short bi_flags; /* status, command, etc */ | |
33 | unsigned short bi_ioprio; | |
34 | ||
35 | struct bvec_iter bi_iter; | |
36 | ||
37 | /* Number of segments in this BIO after | |
38 | * physical address coalescing is performed. | |
39 | */ | |
40 | unsigned int bi_phys_segments; | |
41 | ||
42 | /* | |
43 | * To keep track of the max segment size, we account for the | |
44 | * sizes of the first and last mergeable segments in this bio. | |
45 | */ | |
46 | unsigned int bi_seg_front_size; | |
47 | unsigned int bi_seg_back_size; | |
48 | ||
49 | atomic_t __bi_remaining; | |
50 | ||
51 | bio_end_io_t *bi_end_io; | |
52 | ||
53 | void *bi_private; | |
54 | #ifdef CONFIG_BLK_CGROUP | |
55 | /* | |
56 | * Optional ioc and css associated with this bio. Put on bio | |
57 | * release. Read comment on top of bio_associate_current(). | |
58 | */ | |
59 | struct io_context *bi_ioc; | |
60 | struct cgroup_subsys_state *bi_css; | |
61 | #endif | |
62 | union { | |
63 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
64 | struct bio_integrity_payload *bi_integrity; /* data integrity */ | |
65 | #endif | |
66 | }; | |
67 | ||
68 | unsigned short bi_vcnt; /* how many bio_vec's */ | |
69 | ||
70 | /* | |
71 | * Everything starting with bi_max_vecs will be preserved by bio_reset() | |
72 | */ | |
73 | ||
74 | unsigned short bi_max_vecs; /* max bvl_vecs we can hold */ | |
75 | ||
76 | atomic_t __bi_cnt; /* pin count */ | |
77 | ||
78 | struct bio_vec *bi_io_vec; /* the actual vec list */ | |
79 | ||
80 | struct bio_set *bi_pool; | |
81 | ||
82 | /* | |
83 | * We can inline a number of vecs at the end of the bio, to avoid | |
84 | * double allocations for a small number of bio_vecs. This member | |
85 | * MUST obviously be kept at the very end of the bio. | |
86 | */ | |
87 | struct bio_vec bi_inline_vecs[0]; | |
88 | }; | |
89 | ||
90 | #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs) | |
91 | ||
92 | /* | |
93 | * bio flags | |
94 | */ | |
95 | #define BIO_SEG_VALID 1 /* bi_phys_segments valid */ | |
96 | #define BIO_CLONED 2 /* doesn't own data */ | |
97 | #define BIO_BOUNCED 3 /* bio is a bounce bio */ | |
98 | #define BIO_USER_MAPPED 4 /* contains user pages */ | |
99 | #define BIO_NULL_MAPPED 5 /* contains invalid user pages */ | |
100 | #define BIO_QUIET 6 /* Make BIO Quiet */ | |
101 | #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */ | |
102 | #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */ | |
103 | #define BIO_THROTTLED 9 /* This bio has already been subjected to | |
104 | * throttling rules. Don't do it again. */ | |
105 | ||
106 | /* | |
107 | * Flags starting here get preserved by bio_reset() - this includes | |
108 | * BVEC_POOL_IDX() | |
109 | */ | |
110 | #define BIO_RESET_BITS 10 | |
111 | ||
112 | /* | |
113 | * We support 6 different bvec pools, the last one is magic in that it | |
114 | * is backed by a mempool. | |
115 | */ | |
116 | #define BVEC_POOL_NR 6 | |
117 | #define BVEC_POOL_MAX (BVEC_POOL_NR - 1) | |
118 | ||
119 | /* | |
120 | * Top 4 bits of bio flags indicate the pool the bvecs came from. We add | |
121 | * 1 to the actual index so that 0 indicates that there are no bvecs to be | |
122 | * freed. | |
123 | */ | |
124 | #define BVEC_POOL_BITS (4) | |
125 | #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS) | |
126 | #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET) | |
127 | ||
128 | /* | |
129 | * Operations and flags common to the bio and request structures. | |
130 | * We use 8 bits for encoding the operation, and the remaining 24 for flags. | |
131 | * | |
132 | * The least significant bit of the operation number indicates the data | |
133 | * transfer direction: | |
134 | * | |
135 | * - if the least significant bit is set transfers are TO the device | |
136 | * - if the least significant bit is not set transfers are FROM the device | |
137 | * | |
138 | * If a operation does not transfer data the least significant bit has no | |
139 | * meaning. | |
140 | */ | |
141 | #define REQ_OP_BITS 8 | |
142 | #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1) | |
143 | #define REQ_FLAG_BITS 24 | |
144 | ||
145 | enum req_opf { | |
146 | /* read sectors from the device */ | |
147 | REQ_OP_READ = 0, | |
148 | /* write sectors to the device */ | |
149 | REQ_OP_WRITE = 1, | |
150 | /* flush the volatile write cache */ | |
151 | REQ_OP_FLUSH = 2, | |
152 | /* discard sectors */ | |
153 | REQ_OP_DISCARD = 3, | |
154 | /* get zone information */ | |
155 | REQ_OP_ZONE_REPORT = 4, | |
156 | /* securely erase sectors */ | |
157 | REQ_OP_SECURE_ERASE = 5, | |
158 | /* seset a zone write pointer */ | |
159 | REQ_OP_ZONE_RESET = 6, | |
160 | /* write the same sector many times */ | |
161 | REQ_OP_WRITE_SAME = 7, | |
162 | /* write the zero filled sector many times */ | |
163 | REQ_OP_WRITE_ZEROES = 8, | |
164 | ||
165 | REQ_OP_LAST, | |
166 | }; | |
167 | ||
168 | enum req_flag_bits { | |
169 | __REQ_FAILFAST_DEV = /* no driver retries of device errors */ | |
170 | REQ_OP_BITS, | |
171 | __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ | |
172 | __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ | |
173 | __REQ_SYNC, /* request is sync (sync write or read) */ | |
174 | __REQ_META, /* metadata io request */ | |
175 | __REQ_PRIO, /* boost priority in cfq */ | |
176 | __REQ_NOMERGE, /* don't touch this for merging */ | |
177 | __REQ_IDLE, /* anticipate more IO after this one */ | |
178 | __REQ_INTEGRITY, /* I/O includes block integrity payload */ | |
179 | __REQ_FUA, /* forced unit access */ | |
180 | __REQ_PREFLUSH, /* request for cache flush */ | |
181 | __REQ_RAHEAD, /* read ahead, can fail anytime */ | |
182 | __REQ_BACKGROUND, /* background IO */ | |
183 | __REQ_NR_BITS, /* stops here */ | |
184 | }; | |
185 | ||
186 | #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV) | |
187 | #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT) | |
188 | #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER) | |
189 | #define REQ_SYNC (1ULL << __REQ_SYNC) | |
190 | #define REQ_META (1ULL << __REQ_META) | |
191 | #define REQ_PRIO (1ULL << __REQ_PRIO) | |
192 | #define REQ_NOMERGE (1ULL << __REQ_NOMERGE) | |
193 | #define REQ_IDLE (1ULL << __REQ_IDLE) | |
194 | #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY) | |
195 | #define REQ_FUA (1ULL << __REQ_FUA) | |
196 | #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH) | |
197 | #define REQ_RAHEAD (1ULL << __REQ_RAHEAD) | |
198 | #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND) | |
199 | ||
200 | #define REQ_FAILFAST_MASK \ | |
201 | (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) | |
202 | ||
203 | #define REQ_NOMERGE_FLAGS \ | |
204 | (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA) | |
205 | ||
206 | #define bio_op(bio) \ | |
207 | ((bio)->bi_opf & REQ_OP_MASK) | |
208 | #define req_op(req) \ | |
209 | ((req)->cmd_flags & REQ_OP_MASK) | |
210 | ||
211 | /* obsolete, don't use in new code */ | |
212 | static inline void bio_set_op_attrs(struct bio *bio, unsigned op, | |
213 | unsigned op_flags) | |
214 | { | |
215 | bio->bi_opf = op | op_flags; | |
216 | } | |
217 | ||
218 | static inline bool op_is_write(unsigned int op) | |
219 | { | |
220 | return (op & 1); | |
221 | } | |
222 | ||
223 | /* | |
224 | * Reads are always treated as synchronous, as are requests with the FUA or | |
225 | * PREFLUSH flag. Other operations may be marked as synchronous using the | |
226 | * REQ_SYNC flag. | |
227 | */ | |
228 | static inline bool op_is_sync(unsigned int op) | |
229 | { | |
230 | return (op & REQ_OP_MASK) == REQ_OP_READ || | |
231 | (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH)); | |
232 | } | |
233 | ||
234 | typedef unsigned int blk_qc_t; | |
235 | #define BLK_QC_T_NONE -1U | |
236 | #define BLK_QC_T_SHIFT 16 | |
237 | ||
238 | static inline bool blk_qc_t_valid(blk_qc_t cookie) | |
239 | { | |
240 | return cookie != BLK_QC_T_NONE; | |
241 | } | |
242 | ||
243 | static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num) | |
244 | { | |
245 | return tag | (queue_num << BLK_QC_T_SHIFT); | |
246 | } | |
247 | ||
248 | static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie) | |
249 | { | |
250 | return cookie >> BLK_QC_T_SHIFT; | |
251 | } | |
252 | ||
253 | static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie) | |
254 | { | |
255 | return cookie & ((1u << BLK_QC_T_SHIFT) - 1); | |
256 | } | |
257 | ||
258 | struct blk_issue_stat { | |
259 | u64 time; | |
260 | }; | |
261 | ||
262 | #define BLK_RQ_STAT_BATCH 64 | |
263 | ||
264 | struct blk_rq_stat { | |
265 | s64 mean; | |
266 | u64 min; | |
267 | u64 max; | |
268 | s32 nr_samples; | |
269 | s32 nr_batch; | |
270 | u64 batch; | |
271 | s64 time; | |
272 | }; | |
273 | ||
274 | #endif /* __LINUX_BLK_TYPES_H */ |