swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 3c2993b8c6143d8a5793746a54eba8f86f95240f authored by Linus Torvalds on 04 June 2017, 23:47:43 UTC
Linux 4.12-rc4
Linux 4.12-rc4
Tip revision: 3c2993b
blk_types.h
/*
* 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>
#include <linux/bvec.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 *);
struct blk_issue_stat {
u64 stat;
};
/*
* 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;
int bi_error;
unsigned int bi_opf; /* bottom bits req flags,
* top bits REQ_OP. Use
* accessors.
*/
unsigned short bi_flags; /* status, etc and bvec pool number */
unsigned short bi_ioprio;
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;
#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
void *bi_cg_private;
struct blk_issue_stat bi_issue_stat;
#endif
#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_SEG_VALID 1 /* bi_phys_segments valid */
#define BIO_CLONED 2 /* doesn't own data */
#define BIO_BOUNCED 3 /* bio is a bounce bio */
#define BIO_USER_MAPPED 4 /* contains user pages */
#define BIO_NULL_MAPPED 5 /* contains invalid user pages */
#define BIO_QUIET 6 /* Make BIO Quiet */
#define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
#define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
#define BIO_THROTTLED 9 /* This bio has already been subjected to
* throttling rules. Don't do it again. */
#define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
* of this bio. */
/* See BVEC_POOL_OFFSET below before adding new flags */
/*
* We support 6 different bvec pools, the last one is magic in that it
* is backed by a mempool.
*/
#define BVEC_POOL_NR 6
#define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
/*
* Top 3 bits of bio flags indicate the pool the bvecs came from. We add
* 1 to the actual index so that 0 indicates that there are no bvecs to be
* freed.
*/
#define BVEC_POOL_BITS (3)
#define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
#define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
#if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
# error "BVEC_POOL_BITS is too small"
#endif
/*
* Flags starting here get preserved by bio_reset() - this includes
* only BVEC_POOL_IDX()
*/
#define BIO_RESET_BITS BVEC_POOL_OFFSET
/*
* Operations and flags common to the bio and request structures.
* We use 8 bits for encoding the operation, and the remaining 24 for flags.
*
* The least significant bit of the operation number indicates the data
* transfer direction:
*
* - if the least significant bit is set transfers are TO the device
* - if the least significant bit is not set transfers are FROM the device
*
* If a operation does not transfer data the least significant bit has no
* meaning.
*/
#define REQ_OP_BITS 8
#define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
#define REQ_FLAG_BITS 24
enum req_opf {
/* read sectors from the device */
REQ_OP_READ = 0,
/* write sectors to the device */
REQ_OP_WRITE = 1,
/* flush the volatile write cache */
REQ_OP_FLUSH = 2,
/* discard sectors */
REQ_OP_DISCARD = 3,
/* get zone information */
REQ_OP_ZONE_REPORT = 4,
/* securely erase sectors */
REQ_OP_SECURE_ERASE = 5,
/* seset a zone write pointer */
REQ_OP_ZONE_RESET = 6,
/* write the same sector many times */
REQ_OP_WRITE_SAME = 7,
/* write the zero filled sector many times */
REQ_OP_WRITE_ZEROES = 9,
/* SCSI passthrough using struct scsi_request */
REQ_OP_SCSI_IN = 32,
REQ_OP_SCSI_OUT = 33,
/* Driver private requests */
REQ_OP_DRV_IN = 34,
REQ_OP_DRV_OUT = 35,
REQ_OP_LAST,
};
enum req_flag_bits {
__REQ_FAILFAST_DEV = /* no driver retries of device errors */
REQ_OP_BITS,
__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_NOMERGE, /* don't touch this for merging */
__REQ_IDLE, /* anticipate more IO after this one */
__REQ_INTEGRITY, /* I/O includes block integrity payload */
__REQ_FUA, /* forced unit access */
__REQ_PREFLUSH, /* request for cache flush */
__REQ_RAHEAD, /* read ahead, can fail anytime */
__REQ_BACKGROUND, /* background IO */
/* command specific flags for REQ_OP_WRITE_ZEROES: */
__REQ_NOUNMAP, /* do not free blocks when zeroing */
__REQ_NR_BITS, /* stops here */
};
#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_NOMERGE (1ULL << __REQ_NOMERGE)
#define REQ_IDLE (1ULL << __REQ_IDLE)
#define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
#define REQ_FUA (1ULL << __REQ_FUA)
#define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
#define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
#define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
#define REQ_FAILFAST_MASK \
(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
#define REQ_NOMERGE_FLAGS \
(REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
#define bio_op(bio) \
((bio)->bi_opf & REQ_OP_MASK)
#define req_op(req) \
((req)->cmd_flags & REQ_OP_MASK)
/* obsolete, don't use in new code */
static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
unsigned op_flags)
{
bio->bi_opf = op | op_flags;
}
static inline bool op_is_write(unsigned int op)
{
return (op & 1);
}
/*
* Check if the bio or request is one that needs special treatment in the
* flush state machine.
*/
static inline bool op_is_flush(unsigned int op)
{
return op & (REQ_FUA | REQ_PREFLUSH);
}
/*
* Reads are always treated as synchronous, as are requests with the FUA or
* PREFLUSH flag. Other operations may be marked as synchronous using the
* REQ_SYNC flag.
*/
static inline bool op_is_sync(unsigned int op)
{
return (op & REQ_OP_MASK) == REQ_OP_READ ||
(op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
}
typedef unsigned int blk_qc_t;
#define BLK_QC_T_NONE -1U
#define BLK_QC_T_SHIFT 16
#define BLK_QC_T_INTERNAL (1U << 31)
static inline bool blk_qc_t_valid(blk_qc_t cookie)
{
return cookie != BLK_QC_T_NONE;
}
static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,
bool internal)
{
blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT);
if (internal)
ret |= BLK_QC_T_INTERNAL;
return ret;
}
static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
{
return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
}
static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
{
return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
}
static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
{
return (cookie & BLK_QC_T_INTERNAL) != 0;
}
struct blk_rq_stat {
s64 mean;
u64 min;
u64 max;
s32 nr_samples;
s32 nr_batch;
u64 batch;
};
#endif /* __LINUX_BLK_TYPES_H */