cregit-Linux how code gets into the kernel

Release 4.7 include/linux/blk_types.h

Directory: include/linux
/*
 * 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 *);

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 int		bi_flags;	/* status, command, etc */
	
int			bi_error;
	
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_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 */

/*
 * Flags starting here get preserved by bio_reset() - this includes
 * BIO_POOL_IDX()
 */

#define BIO_RESET_BITS	13

#define BIO_OWNS_VEC	13	
/* bio_free() should free bvec */

/*
 * 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		(32 - 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_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 | REQ_NOMERGE)

#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)


typedef unsigned int blk_qc_t;

#define BLK_QC_T_NONE	-1U

#define BLK_QC_T_SHIFT	16


static inline bool blk_qc_t_valid(blk_qc_t cookie) { return cookie != BLK_QC_T_NONE; }

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static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num) { return tag | (queue_num << BLK_QC_T_SHIFT); }

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static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie) { return cookie >> BLK_QC_T_SHIFT; }

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static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie) { return cookie & ((1u << BLK_QC_T_SHIFT) - 1); }

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#endif /* __LINUX_BLK_TYPES_H */

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tejun heotejun heo38657.02%411.11%
jens axboejens axboe16123.78%1027.78%
kent overstreetkent overstreet6810.04%719.44%
martin k. petersenmartin k. petersen223.25%38.33%
matthew wilcoxmatthew wilcox91.33%12.78%
lin minglin ming60.89%12.78%
christoph hellwigchristoph hellwig60.89%12.78%
vivek goyalvivek goyal60.89%12.78%
adrian hunteradrian hunter30.44%12.78%
al viroal viro30.44%12.78%
shaohua lishaohua li20.30%25.56%
jan karajan kara20.30%12.78%
darrick j. wongdarrick j. wong10.15%12.78%
linus torvaldslinus torvalds10.15%12.78%
bart van asschebart van assche10.15%12.78%
Total677100.00%36100.00%
Directory: include/linux
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