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 #ifdef CONFIG_BLOCK 21 /* 22 * main unit of I/O for the block layer and lower layers (ie drivers and 23 * stacking drivers) 24 */ 25 struct bio { 26 struct bio *bi_next; /* request queue link */ 27 struct block_device *bi_bdev; 28 int bi_error; 29 unsigned int bi_opf; /* bottom bits req flags, 30 * top bits REQ_OP. Use 31 * accessors. 32 */ 33 unsigned short bi_flags; /* status, command, etc */ 34 unsigned short bi_ioprio; 35 36 struct bvec_iter bi_iter; 37 38 /* Number of segments in this BIO after 39 * physical address coalescing is performed. 40 */ 41 unsigned int bi_phys_segments; 42 43 /* 44 * To keep track of the max segment size, we account for the 45 * sizes of the first and last mergeable segments in this bio. 46 */ 47 unsigned int bi_seg_front_size; 48 unsigned int bi_seg_back_size; 49 50 atomic_t __bi_remaining; 51 52 bio_end_io_t *bi_end_io; 53 54 void *bi_private; 55 #ifdef CONFIG_BLK_CGROUP 56 /* 57 * Optional ioc and css associated with this bio. Put on bio 58 * release. Read comment on top of bio_associate_current(). 59 */ 60 struct io_context *bi_ioc; 61 struct cgroup_subsys_state *bi_css; 62 #endif 63 union { 64 #if defined(CONFIG_BLK_DEV_INTEGRITY) 65 struct bio_integrity_payload *bi_integrity; /* data integrity */ 66 #endif 67 }; 68 69 unsigned short bi_vcnt; /* how many bio_vec's */ 70 71 /* 72 * Everything starting with bi_max_vecs will be preserved by bio_reset() 73 */ 74 75 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */ 76 77 atomic_t __bi_cnt; /* pin count */ 78 79 struct bio_vec *bi_io_vec; /* the actual vec list */ 80 81 struct bio_set *bi_pool; 82 83 /* 84 * We can inline a number of vecs at the end of the bio, to avoid 85 * double allocations for a small number of bio_vecs. This member 86 * MUST obviously be kept at the very end of the bio. 87 */ 88 struct bio_vec bi_inline_vecs[0]; 89 }; 90 91 #define BIO_OP_SHIFT (8 * FIELD_SIZEOF(struct bio, bi_opf) - REQ_OP_BITS) 92 #define bio_flags(bio) ((bio)->bi_opf & ((1 << BIO_OP_SHIFT) - 1)) 93 #define bio_op(bio) ((bio)->bi_opf >> BIO_OP_SHIFT) 94 95 #define bio_set_op_attrs(bio, op, op_flags) do { \ 96 if (__builtin_constant_p(op)) \ 97 BUILD_BUG_ON((op) + 0U >= (1U << REQ_OP_BITS)); \ 98 else \ 99 WARN_ON_ONCE((op) + 0U >= (1U << REQ_OP_BITS)); \ 100 if (__builtin_constant_p(op_flags)) \ 101 BUILD_BUG_ON((op_flags) + 0U >= (1U << BIO_OP_SHIFT)); \ 102 else \ 103 WARN_ON_ONCE((op_flags) + 0U >= (1U << BIO_OP_SHIFT)); \ 104 (bio)->bi_opf = bio_flags(bio); \ 105 (bio)->bi_opf |= (((op) + 0U) << BIO_OP_SHIFT); \ 106 (bio)->bi_opf |= (op_flags); \ 107 } while (0) 108 109 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs) 110 111 /* 112 * bio flags 113 */ 114 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */ 115 #define BIO_CLONED 2 /* doesn't own data */ 116 #define BIO_BOUNCED 3 /* bio is a bounce bio */ 117 #define BIO_USER_MAPPED 4 /* contains user pages */ 118 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */ 119 #define BIO_QUIET 6 /* Make BIO Quiet */ 120 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */ 121 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */ 122 123 /* 124 * Flags starting here get preserved by bio_reset() - this includes 125 * BVEC_POOL_IDX() 126 */ 127 #define BIO_RESET_BITS 10 128 129 /* 130 * We support 6 different bvec pools, the last one is magic in that it 131 * is backed by a mempool. 132 */ 133 #define BVEC_POOL_NR 6 134 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1) 135 136 /* 137 * Top 4 bits of bio flags indicate the pool the bvecs came from. We add 138 * 1 to the actual index so that 0 indicates that there are no bvecs to be 139 * freed. 140 */ 141 #define BVEC_POOL_BITS (4) 142 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS) 143 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET) 144 145 #endif /* CONFIG_BLOCK */ 146 147 /* 148 * Request flags. For use in the cmd_flags field of struct request, and in 149 * bi_opf of struct bio. Note that some flags are only valid in either one. 150 */ 151 enum rq_flag_bits { 152 /* common flags */ 153 __REQ_FAILFAST_DEV, /* no driver retries of device errors */ 154 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ 155 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ 156 157 __REQ_SYNC, /* request is sync (sync write or read) */ 158 __REQ_META, /* metadata io request */ 159 __REQ_PRIO, /* boost priority in cfq */ 160 161 __REQ_NOIDLE, /* don't anticipate more IO after this one */ 162 __REQ_INTEGRITY, /* I/O includes block integrity payload */ 163 __REQ_FUA, /* forced unit access */ 164 __REQ_PREFLUSH, /* request for cache flush */ 165 166 /* bio only flags */ 167 __REQ_RAHEAD, /* read ahead, can fail anytime */ 168 __REQ_THROTTLED, /* This bio has already been subjected to 169 * throttling rules. Don't do it again. */ 170 171 /* request only flags */ 172 __REQ_SORTED, /* elevator knows about this request */ 173 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 174 __REQ_NOMERGE, /* don't touch this for merging */ 175 __REQ_STARTED, /* drive already may have started this one */ 176 __REQ_DONTPREP, /* don't call prep for this one */ 177 __REQ_QUEUED, /* uses queueing */ 178 __REQ_ELVPRIV, /* elevator private data attached */ 179 __REQ_FAILED, /* set if the request failed */ 180 __REQ_QUIET, /* don't worry about errors */ 181 __REQ_PREEMPT, /* set for "ide_preempt" requests and also 182 for requests for which the SCSI "quiesce" 183 state must be ignored. */ 184 __REQ_ALLOCED, /* request came from our alloc pool */ 185 __REQ_COPY_USER, /* contains copies of user pages */ 186 __REQ_FLUSH_SEQ, /* request for flush sequence */ 187 __REQ_IO_STAT, /* account I/O stat */ 188 __REQ_MIXED_MERGE, /* merge of different types, fail separately */ 189 __REQ_PM, /* runtime pm request */ 190 __REQ_HASHED, /* on IO scheduler merge hash */ 191 __REQ_MQ_INFLIGHT, /* track inflight for MQ */ 192 __REQ_NR_BITS, /* stops here */ 193 }; 194 195 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV) 196 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT) 197 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER) 198 #define REQ_SYNC (1ULL << __REQ_SYNC) 199 #define REQ_META (1ULL << __REQ_META) 200 #define REQ_PRIO (1ULL << __REQ_PRIO) 201 #define REQ_NOIDLE (1ULL << __REQ_NOIDLE) 202 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY) 203 204 #define REQ_FAILFAST_MASK \ 205 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) 206 #define REQ_COMMON_MASK \ 207 (REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | REQ_NOIDLE | \ 208 REQ_PREFLUSH | REQ_FUA | REQ_INTEGRITY | REQ_NOMERGE) 209 #define REQ_CLONE_MASK REQ_COMMON_MASK 210 211 /* This mask is used for both bio and request merge checking */ 212 #define REQ_NOMERGE_FLAGS \ 213 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_PREFLUSH | REQ_FUA | REQ_FLUSH_SEQ) 214 215 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD) 216 #define REQ_THROTTLED (1ULL << __REQ_THROTTLED) 217 218 #define REQ_SORTED (1ULL << __REQ_SORTED) 219 #define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER) 220 #define REQ_FUA (1ULL << __REQ_FUA) 221 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE) 222 #define REQ_STARTED (1ULL << __REQ_STARTED) 223 #define REQ_DONTPREP (1ULL << __REQ_DONTPREP) 224 #define REQ_QUEUED (1ULL << __REQ_QUEUED) 225 #define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV) 226 #define REQ_FAILED (1ULL << __REQ_FAILED) 227 #define REQ_QUIET (1ULL << __REQ_QUIET) 228 #define REQ_PREEMPT (1ULL << __REQ_PREEMPT) 229 #define REQ_ALLOCED (1ULL << __REQ_ALLOCED) 230 #define REQ_COPY_USER (1ULL << __REQ_COPY_USER) 231 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH) 232 #define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ) 233 #define REQ_IO_STAT (1ULL << __REQ_IO_STAT) 234 #define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE) 235 #define REQ_PM (1ULL << __REQ_PM) 236 #define REQ_HASHED (1ULL << __REQ_HASHED) 237 #define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT) 238 239 enum req_op { 240 REQ_OP_READ, 241 REQ_OP_WRITE, 242 REQ_OP_DISCARD, /* request to discard sectors */ 243 REQ_OP_SECURE_ERASE, /* request to securely erase sectors */ 244 REQ_OP_WRITE_SAME, /* write same block many times */ 245 REQ_OP_FLUSH, /* request for cache flush */ 246 }; 247 248 #define REQ_OP_BITS 3 249 250 typedef unsigned int blk_qc_t; 251 #define BLK_QC_T_NONE -1U 252 #define BLK_QC_T_SHIFT 16 253 254 static inline bool blk_qc_t_valid(blk_qc_t cookie) 255 { 256 return cookie != BLK_QC_T_NONE; 257 } 258 259 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num) 260 { 261 return tag | (queue_num << BLK_QC_T_SHIFT); 262 } 263 264 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie) 265 { 266 return cookie >> BLK_QC_T_SHIFT; 267 } 268 269 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie) 270 { 271 return cookie & ((1u << BLK_QC_T_SHIFT) - 1); 272 } 273 274 #endif /* __LINUX_BLK_TYPES_H */ 275