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 typedef void (bio_destructor_t) (struct bio *); 20 21 #ifdef CONFIG_BLOCK 22 /* 23 * main unit of I/O for the block layer and lower layers (ie drivers and 24 * stacking drivers) 25 */ 26 struct bio { 27 struct bio *bi_next; /* request queue link */ 28 struct block_device *bi_bdev; 29 int bi_error; 30 unsigned int bi_rw; /* bottom bits req flags, 31 * top bits REQ_OP 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 * sizeof(unsigned int) - REQ_OP_BITS) 92 #define bio_op(bio) ((bio)->bi_rw >> BIO_OP_SHIFT) 93 94 #define bio_set_op_attrs(bio, op, op_flags) do { \ 95 WARN_ON(op >= (1 << REQ_OP_BITS)); \ 96 (bio)->bi_rw &= ((1 << BIO_OP_SHIFT) - 1); \ 97 (bio)->bi_rw |= ((unsigned int) (op) << BIO_OP_SHIFT); \ 98 (bio)->bi_rw |= op_flags; \ 99 } while (0) 100 101 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs) 102 103 /* 104 * bio flags 105 */ 106 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */ 107 #define BIO_CLONED 2 /* doesn't own data */ 108 #define BIO_BOUNCED 3 /* bio is a bounce bio */ 109 #define BIO_USER_MAPPED 4 /* contains user pages */ 110 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */ 111 #define BIO_QUIET 6 /* Make BIO Quiet */ 112 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */ 113 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */ 114 115 /* 116 * Flags starting here get preserved by bio_reset() - this includes 117 * BVEC_POOL_IDX() 118 */ 119 #define BIO_RESET_BITS 10 120 121 /* 122 * We support 6 different bvec pools, the last one is magic in that it 123 * is backed by a mempool. 124 */ 125 #define BVEC_POOL_NR 6 126 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1) 127 128 /* 129 * Top 4 bits of bio flags indicate the pool the bvecs came from. We add 130 * 1 to the actual index so that 0 indicates that there are no bvecs to be 131 * freed. 132 */ 133 #define BVEC_POOL_BITS (4) 134 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS) 135 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET) 136 137 #endif /* CONFIG_BLOCK */ 138 139 /* 140 * Request flags. For use in the cmd_flags field of struct request, and in 141 * bi_rw of struct bio. Note that some flags are only valid in either one. 142 */ 143 enum rq_flag_bits { 144 /* common flags */ 145 __REQ_FAILFAST_DEV, /* no driver retries of device errors */ 146 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ 147 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ 148 149 __REQ_SYNC, /* request is sync (sync write or read) */ 150 __REQ_META, /* metadata io request */ 151 __REQ_PRIO, /* boost priority in cfq */ 152 153 __REQ_NOIDLE, /* don't anticipate more IO after this one */ 154 __REQ_INTEGRITY, /* I/O includes block integrity payload */ 155 __REQ_FUA, /* forced unit access */ 156 __REQ_PREFLUSH, /* request for cache flush */ 157 158 /* bio only flags */ 159 __REQ_RAHEAD, /* read ahead, can fail anytime */ 160 __REQ_THROTTLED, /* This bio has already been subjected to 161 * throttling rules. Don't do it again. */ 162 163 /* request only flags */ 164 __REQ_SORTED, /* elevator knows about this request */ 165 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 166 __REQ_NOMERGE, /* don't touch this for merging */ 167 __REQ_STARTED, /* drive already may have started this one */ 168 __REQ_DONTPREP, /* don't call prep for this one */ 169 __REQ_QUEUED, /* uses queueing */ 170 __REQ_ELVPRIV, /* elevator private data attached */ 171 __REQ_FAILED, /* set if the request failed */ 172 __REQ_QUIET, /* don't worry about errors */ 173 __REQ_PREEMPT, /* set for "ide_preempt" requests and also 174 for requests for which the SCSI "quiesce" 175 state must be ignored. */ 176 __REQ_ALLOCED, /* request came from our alloc pool */ 177 __REQ_COPY_USER, /* contains copies of user pages */ 178 __REQ_FLUSH_SEQ, /* request for flush sequence */ 179 __REQ_IO_STAT, /* account I/O stat */ 180 __REQ_MIXED_MERGE, /* merge of different types, fail separately */ 181 __REQ_PM, /* runtime pm request */ 182 __REQ_HASHED, /* on IO scheduler merge hash */ 183 __REQ_MQ_INFLIGHT, /* track inflight for MQ */ 184 __REQ_NR_BITS, /* stops here */ 185 }; 186 187 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV) 188 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT) 189 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER) 190 #define REQ_SYNC (1ULL << __REQ_SYNC) 191 #define REQ_META (1ULL << __REQ_META) 192 #define REQ_PRIO (1ULL << __REQ_PRIO) 193 #define REQ_NOIDLE (1ULL << __REQ_NOIDLE) 194 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY) 195 196 #define REQ_FAILFAST_MASK \ 197 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) 198 #define REQ_COMMON_MASK \ 199 (REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | REQ_NOIDLE | \ 200 REQ_PREFLUSH | REQ_FUA | REQ_INTEGRITY | REQ_NOMERGE) 201 #define REQ_CLONE_MASK REQ_COMMON_MASK 202 203 /* This mask is used for both bio and request merge checking */ 204 #define REQ_NOMERGE_FLAGS \ 205 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_PREFLUSH | REQ_FUA | REQ_FLUSH_SEQ) 206 207 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD) 208 #define REQ_THROTTLED (1ULL << __REQ_THROTTLED) 209 210 #define REQ_SORTED (1ULL << __REQ_SORTED) 211 #define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER) 212 #define REQ_FUA (1ULL << __REQ_FUA) 213 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE) 214 #define REQ_STARTED (1ULL << __REQ_STARTED) 215 #define REQ_DONTPREP (1ULL << __REQ_DONTPREP) 216 #define REQ_QUEUED (1ULL << __REQ_QUEUED) 217 #define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV) 218 #define REQ_FAILED (1ULL << __REQ_FAILED) 219 #define REQ_QUIET (1ULL << __REQ_QUIET) 220 #define REQ_PREEMPT (1ULL << __REQ_PREEMPT) 221 #define REQ_ALLOCED (1ULL << __REQ_ALLOCED) 222 #define REQ_COPY_USER (1ULL << __REQ_COPY_USER) 223 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH) 224 #define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ) 225 #define REQ_IO_STAT (1ULL << __REQ_IO_STAT) 226 #define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE) 227 #define REQ_PM (1ULL << __REQ_PM) 228 #define REQ_HASHED (1ULL << __REQ_HASHED) 229 #define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT) 230 231 enum req_op { 232 REQ_OP_READ, 233 REQ_OP_WRITE, 234 REQ_OP_DISCARD, /* request to discard sectors */ 235 REQ_OP_SECURE_ERASE, /* request to securely erase sectors */ 236 REQ_OP_WRITE_SAME, /* write same block many times */ 237 REQ_OP_FLUSH, /* request for cache flush */ 238 }; 239 240 #define REQ_OP_BITS 3 241 242 typedef unsigned int blk_qc_t; 243 #define BLK_QC_T_NONE -1U 244 #define BLK_QC_T_SHIFT 16 245 246 static inline bool blk_qc_t_valid(blk_qc_t cookie) 247 { 248 return cookie != BLK_QC_T_NONE; 249 } 250 251 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num) 252 { 253 return tag | (queue_num << BLK_QC_T_SHIFT); 254 } 255 256 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie) 257 { 258 return cookie >> BLK_QC_T_SHIFT; 259 } 260 261 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie) 262 { 263 return cookie & ((1u << BLK_QC_T_SHIFT) - 1); 264 } 265 266 #endif /* __LINUX_BLK_TYPES_H */ 267