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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
7cc01581 8#include <linux/types.h>
0781e79e 9#include <linux/bvec.h>
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10
11struct bio_set;
12struct bio;
13struct bio_integrity_payload;
14struct page;
15struct block_device;
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16struct io_context;
17struct cgroup_subsys_state;
4246a0b6 18typedef void (bio_end_io_t) (struct bio *);
7cc01581 19
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20/*
21 * Block error status values. See block/blk-core:blk_errors for the details.
22 */
23typedef u8 __bitwise blk_status_t;
24#define BLK_STS_OK 0
25#define BLK_STS_NOTSUPP ((__force blk_status_t)1)
26#define BLK_STS_TIMEOUT ((__force blk_status_t)2)
27#define BLK_STS_NOSPC ((__force blk_status_t)3)
28#define BLK_STS_TRANSPORT ((__force blk_status_t)4)
29#define BLK_STS_TARGET ((__force blk_status_t)5)
30#define BLK_STS_NEXUS ((__force blk_status_t)6)
31#define BLK_STS_MEDIUM ((__force blk_status_t)7)
32#define BLK_STS_PROTECTION ((__force blk_status_t)8)
33#define BLK_STS_RESOURCE ((__force blk_status_t)9)
34#define BLK_STS_IOERR ((__force blk_status_t)10)
35
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36/* hack for device mapper, don't use elsewhere: */
37#define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
38
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39struct blk_issue_stat {
40 u64 stat;
41};
42
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43/*
44 * main unit of I/O for the block layer and lower layers (ie drivers and
45 * stacking drivers)
46 */
47struct bio {
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48 struct bio *bi_next; /* request queue link */
49 struct block_device *bi_bdev;
4e4cbee9 50 blk_status_t bi_status;
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51 unsigned int bi_opf; /* bottom bits req flags,
52 * top bits REQ_OP. Use
53 * accessors.
4e1b2d52 54 */
dbde775c 55 unsigned short bi_flags; /* status, etc and bvec pool number */
43b62ce3 56 unsigned short bi_ioprio;
7cc01581 57
4f024f37 58 struct bvec_iter bi_iter;
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59
60 /* Number of segments in this BIO after
61 * physical address coalescing is performed.
62 */
63 unsigned int bi_phys_segments;
64
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65 /*
66 * To keep track of the max segment size, we account for the
67 * sizes of the first and last mergeable segments in this bio.
68 */
69 unsigned int bi_seg_front_size;
70 unsigned int bi_seg_back_size;
71
c4cf5261 72 atomic_t __bi_remaining;
196d38bc 73
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74 bio_end_io_t *bi_end_io;
75
76 void *bi_private;
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77#ifdef CONFIG_BLK_CGROUP
78 /*
79 * Optional ioc and css associated with this bio. Put on bio
80 * release. Read comment on top of bio_associate_current().
81 */
82 struct io_context *bi_ioc;
83 struct cgroup_subsys_state *bi_css;
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84#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
85 void *bi_cg_private;
b9147dd1 86 struct blk_issue_stat bi_issue_stat;
9e234eea 87#endif
852c788f 88#endif
180b2f95 89 union {
7cc01581 90#if defined(CONFIG_BLK_DEV_INTEGRITY)
180b2f95 91 struct bio_integrity_payload *bi_integrity; /* data integrity */
7cc01581 92#endif
180b2f95 93 };
7cc01581 94
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95 unsigned short bi_vcnt; /* how many bio_vec's */
96
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97 /*
98 * Everything starting with bi_max_vecs will be preserved by bio_reset()
99 */
100
4f024f37 101 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
f44b48c7 102
dac56212 103 atomic_t __bi_cnt; /* pin count */
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104
105 struct bio_vec *bi_io_vec; /* the actual vec list */
106
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107 struct bio_set *bi_pool;
108
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109 /*
110 * We can inline a number of vecs at the end of the bio, to avoid
111 * double allocations for a small number of bio_vecs. This member
112 * MUST obviously be kept at the very end of the bio.
113 */
114 struct bio_vec bi_inline_vecs[0];
115};
116
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117#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
118
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119/*
120 * bio flags
121 */
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122#define BIO_SEG_VALID 1 /* bi_phys_segments valid */
123#define BIO_CLONED 2 /* doesn't own data */
124#define BIO_BOUNCED 3 /* bio is a bounce bio */
125#define BIO_USER_MAPPED 4 /* contains user pages */
126#define BIO_NULL_MAPPED 5 /* contains invalid user pages */
127#define BIO_QUIET 6 /* Make BIO Quiet */
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128#define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
129#define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
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130#define BIO_THROTTLED 9 /* This bio has already been subjected to
131 * throttling rules. Don't do it again. */
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132#define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
133 * of this bio. */
dbde775c 134/* See BVEC_POOL_OFFSET below before adding new flags */
f44b48c7 135
7cc01581 136/*
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137 * We support 6 different bvec pools, the last one is magic in that it
138 * is backed by a mempool.
7cc01581 139 */
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140#define BVEC_POOL_NR 6
141#define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
142
143/*
dbde775c 144 * Top 3 bits of bio flags indicate the pool the bvecs came from. We add
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145 * 1 to the actual index so that 0 indicates that there are no bvecs to be
146 * freed.
147 */
dbde775c 148#define BVEC_POOL_BITS (3)
c0acf12a 149#define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
ed996a52 150#define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
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151#if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
152# error "BVEC_POOL_BITS is too small"
153#endif
154
155/*
156 * Flags starting here get preserved by bio_reset() - this includes
157 * only BVEC_POOL_IDX()
158 */
159#define BIO_RESET_BITS BVEC_POOL_OFFSET
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160
161/*
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162 * Operations and flags common to the bio and request structures.
163 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
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164 *
165 * The least significant bit of the operation number indicates the data
166 * transfer direction:
167 *
168 * - if the least significant bit is set transfers are TO the device
169 * - if the least significant bit is not set transfers are FROM the device
170 *
171 * If a operation does not transfer data the least significant bit has no
172 * meaning.
7cc01581 173 */
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174#define REQ_OP_BITS 8
175#define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
176#define REQ_FLAG_BITS 24
177
178enum req_opf {
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179 /* read sectors from the device */
180 REQ_OP_READ = 0,
181 /* write sectors to the device */
182 REQ_OP_WRITE = 1,
183 /* flush the volatile write cache */
184 REQ_OP_FLUSH = 2,
185 /* discard sectors */
186 REQ_OP_DISCARD = 3,
187 /* get zone information */
188 REQ_OP_ZONE_REPORT = 4,
189 /* securely erase sectors */
190 REQ_OP_SECURE_ERASE = 5,
191 /* seset a zone write pointer */
192 REQ_OP_ZONE_RESET = 6,
193 /* write the same sector many times */
194 REQ_OP_WRITE_SAME = 7,
a6f0788e 195 /* write the zero filled sector many times */
1d62ac13 196 REQ_OP_WRITE_ZEROES = 9,
ef295ecf 197
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198 /* SCSI passthrough using struct scsi_request */
199 REQ_OP_SCSI_IN = 32,
200 REQ_OP_SCSI_OUT = 33,
201 /* Driver private requests */
202 REQ_OP_DRV_IN = 34,
203 REQ_OP_DRV_OUT = 35,
204
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205 REQ_OP_LAST,
206};
207
208enum req_flag_bits {
209 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
210 REQ_OP_BITS,
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211 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
212 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
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213 __REQ_SYNC, /* request is sync (sync write or read) */
214 __REQ_META, /* metadata io request */
65299a3b 215 __REQ_PRIO, /* boost priority in cfq */
bd1c1c21 216 __REQ_NOMERGE, /* don't touch this for merging */
a2b80967 217 __REQ_IDLE, /* anticipate more IO after this one */
180b2f95 218 __REQ_INTEGRITY, /* I/O includes block integrity payload */
8e4bf844 219 __REQ_FUA, /* forced unit access */
28a8f0d3 220 __REQ_PREFLUSH, /* request for cache flush */
188bd2b1 221 __REQ_RAHEAD, /* read ahead, can fail anytime */
1d796d6a 222 __REQ_BACKGROUND, /* background IO */
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223
224 /* command specific flags for REQ_OP_WRITE_ZEROES: */
225 __REQ_NOUNMAP, /* do not free blocks when zeroing */
226
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227 __REQ_NR_BITS, /* stops here */
228};
229
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230#define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
231#define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
232#define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
233#define REQ_SYNC (1ULL << __REQ_SYNC)
234#define REQ_META (1ULL << __REQ_META)
235#define REQ_PRIO (1ULL << __REQ_PRIO)
ef295ecf 236#define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
a2b80967 237#define REQ_IDLE (1ULL << __REQ_IDLE)
180b2f95 238#define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
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239#define REQ_FUA (1ULL << __REQ_FUA)
240#define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
241#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
1d796d6a 242#define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
7cc01581 243
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244#define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
245
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246#define REQ_FAILFAST_MASK \
247 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
7cc01581 248
e2a60da7 249#define REQ_NOMERGE_FLAGS \
e8064021 250 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
e2a60da7 251
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252#define bio_op(bio) \
253 ((bio)->bi_opf & REQ_OP_MASK)
254#define req_op(req) \
255 ((req)->cmd_flags & REQ_OP_MASK)
7cc01581 256
ef295ecf 257/* obsolete, don't use in new code */
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258static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
259 unsigned op_flags)
260{
261 bio->bi_opf = op | op_flags;
262}
c11f0c0b 263
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264static inline bool op_is_write(unsigned int op)
265{
266 return (op & 1);
267}
268
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269/*
270 * Check if the bio or request is one that needs special treatment in the
271 * flush state machine.
272 */
273static inline bool op_is_flush(unsigned int op)
274{
275 return op & (REQ_FUA | REQ_PREFLUSH);
276}
277
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278/*
279 * Reads are always treated as synchronous, as are requests with the FUA or
280 * PREFLUSH flag. Other operations may be marked as synchronous using the
281 * REQ_SYNC flag.
282 */
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283static inline bool op_is_sync(unsigned int op)
284{
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285 return (op & REQ_OP_MASK) == REQ_OP_READ ||
286 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
ef295ecf 287}
c11f0c0b 288
dece1635 289typedef unsigned int blk_qc_t;
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290#define BLK_QC_T_NONE -1U
291#define BLK_QC_T_SHIFT 16
292#define BLK_QC_T_INTERNAL (1U << 31)
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293
294static inline bool blk_qc_t_valid(blk_qc_t cookie)
295{
296 return cookie != BLK_QC_T_NONE;
297}
298
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299static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,
300 bool internal)
dece1635 301{
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302 blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT);
303
304 if (internal)
305 ret |= BLK_QC_T_INTERNAL;
306
307 return ret;
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308}
309
310static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
311{
fd2d3326 312 return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
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313}
314
315static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
316{
e3a7a3bf 317 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
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318}
319
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320static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
321{
322 return (cookie & BLK_QC_T_INTERNAL) != 0;
323}
324
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325struct blk_rq_stat {
326 s64 mean;
327 u64 min;
328 u64 max;
329 s32 nr_samples;
330 s32 nr_batch;
331 u64 batch;
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332};
333
7cc01581 334#endif /* __LINUX_BLK_TYPES_H */