diff options
Diffstat (limited to 'include/linux/blk_types.h')
| -rw-r--r-- | include/linux/blk_types.h | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h new file mode 100644 index 000000000..9bd89b1e7 --- /dev/null +++ b/include/linux/blk_types.h @@ -0,0 +1,254 @@ +/* + * Block data types and constants. Directly include this file only to + * break include dependency loop. + */ +#ifndef __LINUX_BLK_TYPES_H +#define __LINUX_BLK_TYPES_H + +#include <linux/types.h> + +struct bio_set; +struct bio; +struct bio_integrity_payload; +struct page; +struct block_device; +struct io_context; +struct cgroup_subsys_state; +typedef void (bio_end_io_t) (struct bio *, int); +typedef void (bio_destructor_t) (struct bio *); + +/* + * was unsigned short, but we might as well be ready for > 64kB I/O pages + */ +struct bio_vec { + struct page *bv_page; + unsigned int bv_len; + unsigned int bv_offset; +}; + +#ifdef CONFIG_BLOCK + +struct bvec_iter { + sector_t bi_sector; /* device address in 512 byte + sectors */ + unsigned int bi_size; /* residual I/O count */ + + unsigned int bi_idx; /* current index into bvl_vec */ + + unsigned int bi_bvec_done; /* number of bytes completed in + current bvec */ +}; + +/* + * main unit of I/O for the block layer and lower layers (ie drivers and + * stacking drivers) + */ +struct bio { + struct bio *bi_next; /* request queue link */ + struct block_device *bi_bdev; + unsigned long bi_flags; /* status, command, etc */ + unsigned long bi_rw; /* bottom bits READ/WRITE, + * top bits priority + */ + + struct bvec_iter bi_iter; + + /* Number of segments in this BIO after + * physical address coalescing is performed. + */ + unsigned int bi_phys_segments; + + /* + * To keep track of the max segment size, we account for the + * sizes of the first and last mergeable segments in this bio. + */ + unsigned int bi_seg_front_size; + unsigned int bi_seg_back_size; + + atomic_t bi_remaining; + + bio_end_io_t *bi_end_io; + + void *bi_private; +#ifdef CONFIG_BLK_CGROUP + /* + * Optional ioc and css associated with this bio. Put on bio + * release. Read comment on top of bio_associate_current(). + */ + struct io_context *bi_ioc; + struct cgroup_subsys_state *bi_css; +#endif + union { +#if defined(CONFIG_BLK_DEV_INTEGRITY) + struct bio_integrity_payload *bi_integrity; /* data integrity */ +#endif + }; + + unsigned short bi_vcnt; /* how many bio_vec's */ + + /* + * Everything starting with bi_max_vecs will be preserved by bio_reset() + */ + + unsigned short bi_max_vecs; /* max bvl_vecs we can hold */ + + atomic_t bi_cnt; /* pin count */ + + struct bio_vec *bi_io_vec; /* the actual vec list */ + + struct bio_set *bi_pool; + + /* + * We can inline a number of vecs at the end of the bio, to avoid + * double allocations for a small number of bio_vecs. This member + * MUST obviously be kept at the very end of the bio. + */ + struct bio_vec bi_inline_vecs[0]; +}; + +#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs) + +/* + * bio flags + */ +#define BIO_UPTODATE 0 /* ok after I/O completion */ +#define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */ +#define BIO_EOF 2 /* out-out-bounds error */ +#define BIO_SEG_VALID 3 /* bi_phys_segments valid */ +#define BIO_CLONED 4 /* doesn't own data */ +#define BIO_BOUNCED 5 /* bio is a bounce bio */ +#define BIO_USER_MAPPED 6 /* contains user pages */ +#define BIO_EOPNOTSUPP 7 /* not supported */ +#define BIO_NULL_MAPPED 8 /* contains invalid user pages */ +#define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */ +#define BIO_QUIET 10 /* Make BIO Quiet */ +#define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */ +#define BIO_SNAP_STABLE 12 /* bio data must be snapshotted during write */ +#define BIO_TOI 13 /* bio is TuxOnIce submitted */ + +/* + * Flags starting here get preserved by bio_reset() - this includes + * BIO_POOL_IDX() + */ +#define BIO_RESET_BITS 14 +#define BIO_OWNS_VEC 14 /* bio_free() should free bvec */ + +#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) + +/* + * top 4 bits of bio flags indicate the pool this bio came from + */ +#define BIO_POOL_BITS (4) +#define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1) +#define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS) +#define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET) +#define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET) + +#endif /* CONFIG_BLOCK */ + +/* + * Request flags. For use in the cmd_flags field of struct request, and in + * bi_rw of struct bio. Note that some flags are only valid in either one. + */ +enum rq_flag_bits { + /* common flags */ + __REQ_WRITE, /* not set, read. set, write */ + __REQ_FAILFAST_DEV, /* no driver retries of device errors */ + __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */ + __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */ + + __REQ_SYNC, /* request is sync (sync write or read) */ + __REQ_META, /* metadata io request */ + __REQ_PRIO, /* boost priority in cfq */ + __REQ_DISCARD, /* request to discard sectors */ + __REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */ + __REQ_WRITE_SAME, /* write same block many times */ + + __REQ_NOIDLE, /* don't anticipate more IO after this one */ + __REQ_INTEGRITY, /* I/O includes block integrity payload */ + __REQ_FUA, /* forced unit access */ + __REQ_FLUSH, /* request for cache flush */ + + /* bio only flags */ + __REQ_RAHEAD, /* read ahead, can fail anytime */ + __REQ_THROTTLED, /* This bio has already been subjected to + * throttling rules. Don't do it again. */ + + /* request only flags */ + __REQ_SORTED, /* elevator knows about this request */ + __REQ_SOFTBARRIER, /* may not be passed by ioscheduler */ + __REQ_NOMERGE, /* don't touch this for merging */ + __REQ_STARTED, /* drive already may have started this one */ + __REQ_DONTPREP, /* don't call prep for this one */ + __REQ_QUEUED, /* uses queueing */ + __REQ_ELVPRIV, /* elevator private data attached */ + __REQ_FAILED, /* set if the request failed */ + __REQ_QUIET, /* don't worry about errors */ + __REQ_PREEMPT, /* set for "ide_preempt" requests and also + for requests for which the SCSI "quiesce" + state must be ignored. */ + __REQ_ALLOCED, /* request came from our alloc pool */ + __REQ_COPY_USER, /* contains copies of user pages */ + __REQ_FLUSH_SEQ, /* request for flush sequence */ + __REQ_IO_STAT, /* account I/O stat */ + __REQ_MIXED_MERGE, /* merge of different types, fail separately */ + __REQ_PM, /* runtime pm request */ + __REQ_HASHED, /* on IO scheduler merge hash */ + __REQ_MQ_INFLIGHT, /* track inflight for MQ */ + __REQ_NO_TIMEOUT, /* requests may never expire */ + __REQ_NR_BITS, /* stops here */ +}; + +#define REQ_WRITE (1ULL << __REQ_WRITE) +#define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV) +#define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT) +#define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER) +#define REQ_SYNC (1ULL << __REQ_SYNC) +#define REQ_META (1ULL << __REQ_META) +#define REQ_PRIO (1ULL << __REQ_PRIO) +#define REQ_DISCARD (1ULL << __REQ_DISCARD) +#define REQ_WRITE_SAME (1ULL << __REQ_WRITE_SAME) +#define REQ_NOIDLE (1ULL << __REQ_NOIDLE) +#define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY) + +#define REQ_FAILFAST_MASK \ + (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER) +#define REQ_COMMON_MASK \ + (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \ + REQ_DISCARD | REQ_WRITE_SAME | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | \ + REQ_SECURE | REQ_INTEGRITY) +#define REQ_CLONE_MASK REQ_COMMON_MASK + +#define BIO_NO_ADVANCE_ITER_MASK (REQ_DISCARD|REQ_WRITE_SAME) + +/* This mask is used for both bio and request merge checking */ +#define REQ_NOMERGE_FLAGS \ + (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA | REQ_FLUSH_SEQ) + +#define REQ_RAHEAD (1ULL << __REQ_RAHEAD) +#define REQ_THROTTLED (1ULL << __REQ_THROTTLED) + +#define REQ_SORTED (1ULL << __REQ_SORTED) +#define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER) +#define REQ_FUA (1ULL << __REQ_FUA) +#define REQ_NOMERGE (1ULL << __REQ_NOMERGE) +#define REQ_STARTED (1ULL << __REQ_STARTED) +#define REQ_DONTPREP (1ULL << __REQ_DONTPREP) +#define REQ_QUEUED (1ULL << __REQ_QUEUED) +#define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV) +#define REQ_FAILED (1ULL << __REQ_FAILED) +#define REQ_QUIET (1ULL << __REQ_QUIET) +#define REQ_PREEMPT (1ULL << __REQ_PREEMPT) +#define REQ_ALLOCED (1ULL << __REQ_ALLOCED) +#define REQ_COPY_USER (1ULL << __REQ_COPY_USER) +#define REQ_FLUSH (1ULL << __REQ_FLUSH) +#define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ) +#define REQ_IO_STAT (1ULL << __REQ_IO_STAT) +#define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE) +#define REQ_SECURE (1ULL << __REQ_SECURE) +#define REQ_PM (1ULL << __REQ_PM) +#define REQ_HASHED (1ULL << __REQ_HASHED) +#define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT) +#define REQ_NO_TIMEOUT (1ULL << __REQ_NO_TIMEOUT) + +#endif /* __LINUX_BLK_TYPES_H */ |