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 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 /* 30 * main unit of I/O for the block layer and lower layers (ie drivers and 31 * stacking drivers) 32 */ 33 struct bio { 34 sector_t bi_sector; /* device address in 512 byte 35 sectors */ 36 struct bio *bi_next; /* request queue link */ 37 struct block_device *bi_bdev; 38 unsigned long bi_flags; /* status, command, etc */ 39 unsigned long bi_rw; /* bottom bits READ/WRITE, 40 * top bits priority 41 */ 42 43 unsigned short bi_vcnt; /* how many bio_vec's */ 44 unsigned short bi_idx; /* current index into bvl_vec */ 45 46 /* Number of segments in this BIO after 47 * physical address coalescing is performed. 48 */ 49 unsigned int bi_phys_segments; 50 51 unsigned int bi_size; /* residual I/O count */ 52 53 /* 54 * To keep track of the max segment size, we account for the 55 * sizes of the first and last mergeable segments in this bio. 56 */ 57 unsigned int bi_seg_front_size; 58 unsigned int bi_seg_back_size; 59 60 unsigned int bi_max_vecs; /* max bvl_vecs we can hold */ 61 62 atomic_t bi_cnt; /* pin count */ 63 64 struct bio_vec *bi_io_vec; /* the actual vec list */ 65 66 bio_end_io_t *bi_end_io; 67 68 void *bi_private; 69 #if defined(CONFIG_BLK_DEV_INTEGRITY) 70 struct bio_integrity_payload *bi_integrity; /* data integrity */ 71 #endif 72 73 bio_destructor_t *bi_destructor; /* destructor */ 74 75 /* 76 * We can inline a number of vecs at the end of the bio, to avoid 77 * double allocations for a small number of bio_vecs. This member 78 * MUST obviously be kept at the very end of the bio. 79 */ 80 struct bio_vec bi_inline_vecs[0]; 81 }; 82 83 /* 84 * bio flags 85 */ 86 #define BIO_UPTODATE 0 /* ok after I/O completion */ 87 #define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */ 88 #define BIO_EOF 2 /* out-out-bounds error */ 89 #define BIO_SEG_VALID 3 /* bi_phys_segments valid */ 90 #define BIO_CLONED 4 /* doesn't own data */ 91 #define BIO_BOUNCED 5 /* bio is a bounce bio */ 92 #define BIO_USER_MAPPED 6 /* contains user pages */ 93 #define BIO_EOPNOTSUPP 7 /* not supported */ 94 #define BIO_NULL_MAPPED 8 /* contains invalid user pages */ 95 #define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */ 96 #define BIO_QUIET 10 /* Make BIO Quiet */ 97 #define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */ 98 #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) 99 100 /* 101 * top 4 bits of bio flags indicate the pool this bio came from 102 */ 103 #define BIO_POOL_BITS (4) 104 #define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1) 105 #define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS) 106 #define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET) 107 #define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET) 108 109 #endif /* CONFIG_BLOCK */ 110 111 /* 112 * Request flags. For use in the cmd_flags field of struct request, and in 113 * bi_rw of struct bio. Note that some flags are only valid in either one. 114 */ 115 enum rq_flag_bits { 116 /* common flags */ 117 __REQ_WRITE, /* not set, read. set, write */ 118 __REQ_FAILFAST_DEV, /* no driver retries of device errors */ 119 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ 120 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ 121 122 __REQ_SYNC, /* request is sync (sync write or read) */ 123 __REQ_META, /* metadata io request */ 124 __REQ_PRIO, /* boost priority in cfq */ 125 __REQ_DISCARD, /* request to discard sectors */ 126 __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */ 127 128 __REQ_NOIDLE, /* don't anticipate more IO after this one */ 129 __REQ_FUA, /* forced unit access */ 130 __REQ_FLUSH, /* request for cache flush */ 131 132 /* bio only flags */ 133 __REQ_RAHEAD, /* read ahead, can fail anytime */ 134 __REQ_THROTTLED, /* This bio has already been subjected to 135 * throttling rules. Don't do it again. */ 136 137 /* request only flags */ 138 __REQ_SORTED, /* elevator knows about this request */ 139 __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ 140 __REQ_NOMERGE, /* don't touch this for merging */ 141 __REQ_STARTED, /* drive already may have started this one */ 142 __REQ_DONTPREP, /* don't call prep for this one */ 143 __REQ_QUEUED, /* uses queueing */ 144 __REQ_ELVPRIV, /* elevator private data attached */ 145 __REQ_FAILED, /* set if the request failed */ 146 __REQ_QUIET, /* don't worry about errors */ 147 __REQ_PREEMPT, /* set for "ide_preempt" requests */ 148 __REQ_ALLOCED, /* request came from our alloc pool */ 149 __REQ_COPY_USER, /* contains copies of user pages */ 150 __REQ_FLUSH_SEQ, /* request for flush sequence */ 151 __REQ_IO_STAT, /* account I/O stat */ 152 __REQ_MIXED_MERGE, /* merge of different types, fail separately */ 153 __REQ_NR_BITS, /* stops here */ 154 }; 155 156 #define REQ_WRITE (1 << __REQ_WRITE) 157 #define REQ_FAILFAST_DEV (1 << __REQ_FAILFAST_DEV) 158 #define REQ_FAILFAST_TRANSPORT (1 << __REQ_FAILFAST_TRANSPORT) 159 #define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER) 160 #define REQ_SYNC (1 << __REQ_SYNC) 161 #define REQ_META (1 << __REQ_META) 162 #define REQ_PRIO (1 << __REQ_PRIO) 163 #define REQ_DISCARD (1 << __REQ_DISCARD) 164 #define REQ_NOIDLE (1 << __REQ_NOIDLE) 165 166 #define REQ_FAILFAST_MASK \ 167 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) 168 #define REQ_COMMON_MASK \ 169 (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \ 170 REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE) 171 #define REQ_CLONE_MASK REQ_COMMON_MASK 172 173 #define REQ_RAHEAD (1 << __REQ_RAHEAD) 174 #define REQ_THROTTLED (1 << __REQ_THROTTLED) 175 176 #define REQ_SORTED (1 << __REQ_SORTED) 177 #define REQ_SOFTBARRIER (1 << __REQ_SOFTBARRIER) 178 #define REQ_FUA (1 << __REQ_FUA) 179 #define REQ_NOMERGE (1 << __REQ_NOMERGE) 180 #define REQ_STARTED (1 << __REQ_STARTED) 181 #define REQ_DONTPREP (1 << __REQ_DONTPREP) 182 #define REQ_QUEUED (1 << __REQ_QUEUED) 183 #define REQ_ELVPRIV (1 << __REQ_ELVPRIV) 184 #define REQ_FAILED (1 << __REQ_FAILED) 185 #define REQ_QUIET (1 << __REQ_QUIET) 186 #define REQ_PREEMPT (1 << __REQ_PREEMPT) 187 #define REQ_ALLOCED (1 << __REQ_ALLOCED) 188 #define REQ_COPY_USER (1 << __REQ_COPY_USER) 189 #define REQ_FLUSH (1 << __REQ_FLUSH) 190 #define REQ_FLUSH_SEQ (1 << __REQ_FLUSH_SEQ) 191 #define REQ_IO_STAT (1 << __REQ_IO_STAT) 192 #define REQ_MIXED_MERGE (1 << __REQ_MIXED_MERGE) 193 #define REQ_SECURE (1 << __REQ_SECURE) 194 195 #endif /* __LINUX_BLK_TYPES_H */ 196