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 #ifdef CONFIG_BLOCK 9 10 #include <linux/types.h> 11 12 struct bio_set; 13 struct bio; 14 struct bio_integrity_payload; 15 struct page; 16 struct block_device; 17 struct io_context; 18 struct cgroup_subsys_state; 19 typedef void (bio_end_io_t) (struct bio *, int); 20 typedef void (bio_destructor_t) (struct bio *); 21 22 /* 23 * was unsigned short, but we might as well be ready for > 64kB I/O pages 24 */ 25 struct bio_vec { 26 struct page *bv_page; 27 unsigned int bv_len; 28 unsigned int bv_offset; 29 }; 30 31 /* 32 * main unit of I/O for the block layer and lower layers (ie drivers and 33 * stacking drivers) 34 */ 35 struct bio { 36 sector_t bi_sector; /* device address in 512 byte 37 sectors */ 38 struct bio *bi_next; /* request queue link */ 39 struct block_device *bi_bdev; 40 unsigned long bi_flags; /* status, command, etc */ 41 unsigned long bi_rw; /* bottom bits READ/WRITE, 42 * top bits priority 43 */ 44 45 unsigned short bi_vcnt; /* how many bio_vec's */ 46 unsigned short bi_idx; /* current index into bvl_vec */ 47 48 /* Number of segments in this BIO after 49 * physical address coalescing is performed. 50 */ 51 unsigned int bi_phys_segments; 52 53 unsigned int bi_size; /* residual I/O count */ 54 55 /* 56 * To keep track of the max segment size, we account for the 57 * sizes of the first and last mergeable segments in this bio. 58 */ 59 unsigned int bi_seg_front_size; 60 unsigned int bi_seg_back_size; 61 62 bio_end_io_t *bi_end_io; 63 64 void *bi_private; 65 #ifdef CONFIG_BLK_CGROUP 66 /* 67 * Optional ioc and css associated with this bio. Put on bio 68 * release. Read comment on top of bio_associate_current(). 69 */ 70 struct io_context *bi_ioc; 71 struct cgroup_subsys_state *bi_css; 72 #endif 73 #if defined(CONFIG_BLK_DEV_INTEGRITY) 74 struct bio_integrity_payload *bi_integrity; /* data integrity */ 75 #endif 76 77 /* 78 * Everything starting with bi_max_vecs will be preserved by bio_reset() 79 */ 80 81 unsigned int bi_max_vecs; /* max bvl_vecs we can hold */ 82 83 atomic_t bi_cnt; /* pin count */ 84 85 struct bio_vec *bi_io_vec; /* the actual vec list */ 86 87 struct bio_set *bi_pool; 88 89 /* 90 * We can inline a number of vecs at the end of the bio, to avoid 91 * double allocations for a small number of bio_vecs. This member 92 * MUST obviously be kept at the very end of the bio. 93 */ 94 struct bio_vec bi_inline_vecs[0]; 95 }; 96 97 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs) 98 99 /* 100 * bio flags 101 */ 102 #define BIO_UPTODATE 0 /* ok after I/O completion */ 103 #define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */ 104 #define BIO_EOF 2 /* out-out-bounds error */ 105 #define BIO_SEG_VALID 3 /* bi_phys_segments valid */ 106 #define BIO_CLONED 4 /* doesn't own data */ 107 #define BIO_BOUNCED 5 /* bio is a bounce bio */ 108 #define BIO_USER_MAPPED 6 /* contains user pages */ 109 #define BIO_EOPNOTSUPP 7 /* not supported */ 110 #define BIO_NULL_MAPPED 8 /* contains invalid user pages */ 111 #define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */ 112 #define BIO_QUIET 10 /* Make BIO Quiet */ 113 #define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */ 114 #define BIO_SNAP_STABLE 12 /* bio data must be snapshotted during write */ 115 116 /* 117 * Flags starting here get preserved by bio_reset() - this includes 118 * BIO_POOL_IDX() 119 */ 120 #define BIO_RESET_BITS 13 121 #define BIO_OWNS_VEC 13 /* bio_free() should free bvec */ 122 123 #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) 124 125 /* 126 * top 4 bits of bio flags indicate the pool this bio came from 127 */ 128 #define BIO_POOL_BITS (4) 129 #define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1) 130 #define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS) 131 #define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET) 132 #define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET) 133 134 #endif /* CONFIG_BLOCK */ 135 136 /* 137 * Request flags. For use in the cmd_flags field of struct request, and in 138 * bi_rw of struct bio. Note that some flags are only valid in either one. 139 */ 140 enum rq_flag_bits { 141 /* common flags */ 142 __REQ_WRITE, /* not set, read. set, write */ 143 __REQ_FAILFAST_DEV, /* no driver retries of device errors */ 144 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ 145 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ 146 147 __REQ_SYNC, /* request is sync (sync write or read) */ 148 __REQ_META, /* metadata io request */ 149 __REQ_PRIO, /* boost priority in cfq */ 150 __REQ_DISCARD, /* request to discard sectors */ 151 __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */ 152 __REQ_WRITE_SAME, /* write same block many times */ 153 154 __REQ_NOIDLE, /* don't anticipate more IO after this one */ 155 __REQ_FUA, /* forced unit access */ 156 __REQ_FLUSH, /* 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 */ 174 __REQ_ALLOCED, /* request came from our alloc pool */ 175 __REQ_COPY_USER, /* contains copies of user pages */ 176 __REQ_FLUSH_SEQ, /* request for flush sequence */ 177 __REQ_IO_STAT, /* account I/O stat */ 178 __REQ_MIXED_MERGE, /* merge of different types, fail separately */ 179 __REQ_KERNEL, /* direct IO to kernel pages */ 180 __REQ_PM, /* runtime pm request */ 181 __REQ_NR_BITS, /* stops here */ 182 }; 183 184 #define REQ_WRITE (1 << __REQ_WRITE) 185 #define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV) 186 #define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT) 187 #define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER) 188 #define REQ_SYNC (1 << __REQ_SYNC) 189 #define REQ_META (1 << __REQ_META) 190 #define REQ_PRIO (1 << __REQ_PRIO) 191 #define REQ_DISCARD (1 << __REQ_DISCARD) 192 #define REQ_WRITE_SAME (1 << __REQ_WRITE_SAME) 193 #define REQ_NOIDLE (1 << __REQ_NOIDLE) 194 195 #define REQ_FAILFAST_MASK \ 196 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) 197 #define REQ_COMMON_MASK \ 198 (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \ 199 REQ_DISCARD | REQ_WRITE_SAME | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | \ 200 REQ_SECURE) 201 #define REQ_CLONE_MASK REQ_COMMON_MASK 202 203 #define BIO_NO_ADVANCE_ITER_MASK (REQ_DISCARD|REQ_WRITE_SAME) 204 205 /* This mask is used for both bio and request merge checking */ 206 #define REQ_NOMERGE_FLAGS \ 207 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA) 208 209 #define REQ_RAHEAD (1 << __REQ_RAHEAD) 210 #define REQ_THROTTLED (1 << __REQ_THROTTLED) 211 212 #define REQ_SORTED (1 << __REQ_SORTED) 213 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) 214 #define REQ_FUA (1 << __REQ_FUA) 215 #define REQ_NOMERGE (1 << __REQ_NOMERGE) 216 #define REQ_STARTED (1 << __REQ_STARTED) 217 #define REQ_DONTPREP (1 << __REQ_DONTPREP) 218 #define REQ_QUEUED (1 << __REQ_QUEUED) 219 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) 220 #define REQ_FAILED (1 << __REQ_FAILED) 221 #define REQ_QUIET (1 << __REQ_QUIET) 222 #define REQ_PREEMPT (1 << __REQ_PREEMPT) 223 #define REQ_ALLOCED (1 << __REQ_ALLOCED) 224 #define REQ_COPY_USER (1 << __REQ_COPY_USER) 225 #define REQ_FLUSH (1 << __REQ_FLUSH) 226 #define REQ_FLUSH_SEQ (1 << __REQ_FLUSH_SEQ) 227 #define REQ_IO_STAT (1 << __REQ_IO_STAT) 228 #define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE) 229 #define REQ_SECURE (1 << __REQ_SECURE) 230 #define REQ_KERNEL (1 << __REQ_KERNEL) 231 #define REQ_PM (1 << __REQ_PM) 232 233 #endif /* __LINUX_BLK_TYPES_H */ 234