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