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 10 struct bio_set; 11 struct bio; 12 struct bio_integrity_payload; 13 struct page; 14 struct block_device; 15 struct io_context; 16 struct cgroup_subsys_state; 17 typedef void (bio_end_io_t) (struct bio *, int); 18 typedef void (bio_destructor_t) (struct bio *); 19 20 /* 21 * was unsigned short, but we might as well be ready for > 64kB I/O pages 22 */ 23 struct bio_vec { 24 struct page *bv_page; 25 unsigned int bv_len; 26 unsigned int bv_offset; 27 }; 28 29 #ifdef CONFIG_BLOCK 30 31 struct bvec_iter { 32 sector_t bi_sector; /* device address in 512 byte 33 sectors */ 34 unsigned int bi_size; /* residual I/O count */ 35 36 unsigned int bi_idx; /* current index into bvl_vec */ 37 38 unsigned int bi_bvec_done; /* number of bytes completed in 39 current bvec */ 40 }; 41 42 /* 43 * main unit of I/O for the block layer and lower layers (ie drivers and 44 * stacking drivers) 45 */ 46 struct bio { 47 struct bio *bi_next; /* request queue link */ 48 struct block_device *bi_bdev; 49 unsigned long bi_flags; /* status, command, etc */ 50 unsigned long bi_rw; /* bottom bits READ/WRITE, 51 * top bits priority 52 */ 53 54 struct bvec_iter bi_iter; 55 56 /* Number of segments in this BIO after 57 * physical address coalescing is performed. 58 */ 59 unsigned int bi_phys_segments; 60 61 /* 62 * To keep track of the max segment size, we account for the 63 * sizes of the first and last mergeable segments in this bio. 64 */ 65 unsigned int bi_seg_front_size; 66 unsigned int bi_seg_back_size; 67 68 atomic_t bi_remaining; 69 70 bio_end_io_t *bi_end_io; 71 72 void *bi_private; 73 #ifdef CONFIG_BLK_CGROUP 74 /* 75 * Optional ioc and css associated with this bio. Put on bio 76 * release. Read comment on top of bio_associate_current(). 77 */ 78 struct io_context *bi_ioc; 79 struct cgroup_subsys_state *bi_css; 80 #endif 81 union { 82 #if defined(CONFIG_BLK_DEV_INTEGRITY) 83 struct bio_integrity_payload *bi_integrity; /* data integrity */ 84 #endif 85 }; 86 87 unsigned short bi_vcnt; /* how many bio_vec's */ 88 89 /* 90 * Everything starting with bi_max_vecs will be preserved by bio_reset() 91 */ 92 93 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */ 94 95 atomic_t bi_cnt; /* pin count */ 96 97 struct bio_vec *bi_io_vec; /* the actual vec list */ 98 99 struct bio_set *bi_pool; 100 101 /* 102 * We can inline a number of vecs at the end of the bio, to avoid 103 * double allocations for a small number of bio_vecs. This member 104 * MUST obviously be kept at the very end of the bio. 105 */ 106 struct bio_vec bi_inline_vecs[0]; 107 }; 108 109 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs) 110 111 /* 112 * bio flags 113 */ 114 #define BIO_UPTODATE 0 /* ok after I/O completion */ 115 #define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */ 116 #define BIO_EOF 2 /* out-out-bounds error */ 117 #define BIO_SEG_VALID 3 /* bi_phys_segments valid */ 118 #define BIO_CLONED 4 /* doesn't own data */ 119 #define BIO_BOUNCED 5 /* bio is a bounce bio */ 120 #define BIO_USER_MAPPED 6 /* contains user pages */ 121 #define BIO_EOPNOTSUPP 7 /* not supported */ 122 #define BIO_NULL_MAPPED 8 /* contains invalid user pages */ 123 #define BIO_QUIET 9 /* Make BIO Quiet */ 124 #define BIO_SNAP_STABLE 10 /* bio data must be snapshotted during write */ 125 126 /* 127 * Flags starting here get preserved by bio_reset() - this includes 128 * BIO_POOL_IDX() 129 */ 130 #define BIO_RESET_BITS 13 131 #define BIO_OWNS_VEC 13 /* bio_free() should free bvec */ 132 133 #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) 134 135 /* 136 * top 4 bits of bio flags indicate the pool this bio came from 137 */ 138 #define BIO_POOL_BITS (4) 139 #define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1) 140 #define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS) 141 #define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET) 142 #define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET) 143 144 #endif /* CONFIG_BLOCK */ 145 146 /* 147 * Request flags. For use in the cmd_flags field of struct request, and in 148 * bi_rw of struct bio. Note that some flags are only valid in either one. 149 */ 150 enum rq_flag_bits { 151 /* common flags */ 152 __REQ_WRITE, /* not set, read. set, write */ 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 __REQ_DISCARD, /* request to discard sectors */ 161 __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */ 162 __REQ_WRITE_SAME, /* write same block many times */ 163 164 __REQ_NOIDLE, /* don't anticipate more IO after this one */ 165 __REQ_INTEGRITY, /* I/O includes block integrity payload */ 166 __REQ_FUA, /* forced unit access */ 167 __REQ_FLUSH, /* request for cache flush */ 168 169 /* bio only flags */ 170 __REQ_RAHEAD, /* read ahead, can fail anytime */ 171 __REQ_THROTTLED, /* This bio has already been subjected to 172 * throttling rules. Don't do it again. */ 173 174 /* request only flags */ 175 __REQ_SORTED, /* elevator knows about this request */ 176 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 177 __REQ_NOMERGE, /* don't touch this for merging */ 178 __REQ_STARTED, /* drive already may have started this one */ 179 __REQ_DONTPREP, /* don't call prep for this one */ 180 __REQ_QUEUED, /* uses queueing */ 181 __REQ_ELVPRIV, /* elevator private data attached */ 182 __REQ_FAILED, /* set if the request failed */ 183 __REQ_QUIET, /* don't worry about errors */ 184 __REQ_PREEMPT, /* set for "ide_preempt" requests and also 185 for requests for which the SCSI "quiesce" 186 state must be ignored. */ 187 __REQ_ALLOCED, /* request came from our alloc pool */ 188 __REQ_COPY_USER, /* contains copies of user pages */ 189 __REQ_FLUSH_SEQ, /* request for flush sequence */ 190 __REQ_IO_STAT, /* account I/O stat */ 191 __REQ_MIXED_MERGE, /* merge of different types, fail separately */ 192 __REQ_PM, /* runtime pm request */ 193 __REQ_HASHED, /* on IO scheduler merge hash */ 194 __REQ_MQ_INFLIGHT, /* track inflight for MQ */ 195 __REQ_NR_BITS, /* stops here */ 196 }; 197 198 #define REQ_WRITE (1ULL << __REQ_WRITE) 199 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV) 200 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT) 201 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER) 202 #define REQ_SYNC (1ULL << __REQ_SYNC) 203 #define REQ_META (1ULL << __REQ_META) 204 #define REQ_PRIO (1ULL << __REQ_PRIO) 205 #define REQ_DISCARD (1ULL << __REQ_DISCARD) 206 #define REQ_WRITE_SAME (1ULL << __REQ_WRITE_SAME) 207 #define REQ_NOIDLE (1ULL << __REQ_NOIDLE) 208 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY) 209 210 #define REQ_FAILFAST_MASK \ 211 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) 212 #define REQ_COMMON_MASK \ 213 (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \ 214 REQ_DISCARD | REQ_WRITE_SAME | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | \ 215 REQ_SECURE | REQ_INTEGRITY) 216 #define REQ_CLONE_MASK REQ_COMMON_MASK 217 218 #define BIO_NO_ADVANCE_ITER_MASK (REQ_DISCARD|REQ_WRITE_SAME) 219 220 /* This mask is used for both bio and request merge checking */ 221 #define REQ_NOMERGE_FLAGS \ 222 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA) 223 224 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD) 225 #define REQ_THROTTLED (1ULL << __REQ_THROTTLED) 226 227 #define REQ_SORTED (1ULL << __REQ_SORTED) 228 #define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER) 229 #define REQ_FUA (1ULL << __REQ_FUA) 230 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE) 231 #define REQ_STARTED (1ULL << __REQ_STARTED) 232 #define REQ_DONTPREP (1ULL << __REQ_DONTPREP) 233 #define REQ_QUEUED (1ULL << __REQ_QUEUED) 234 #define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV) 235 #define REQ_FAILED (1ULL << __REQ_FAILED) 236 #define REQ_QUIET (1ULL << __REQ_QUIET) 237 #define REQ_PREEMPT (1ULL << __REQ_PREEMPT) 238 #define REQ_ALLOCED (1ULL << __REQ_ALLOCED) 239 #define REQ_COPY_USER (1ULL << __REQ_COPY_USER) 240 #define REQ_FLUSH (1ULL << __REQ_FLUSH) 241 #define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ) 242 #define REQ_IO_STAT (1ULL << __REQ_IO_STAT) 243 #define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE) 244 #define REQ_SECURE (1ULL << __REQ_SECURE) 245 #define REQ_PM (1ULL << __REQ_PM) 246 #define REQ_HASHED (1ULL << __REQ_HASHED) 247 #define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT) 248 249 #endif /* __LINUX_BLK_TYPES_H */ 250