/* * 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 #ifdef CONFIG_BLOCK #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;}; /* * main unit of I/O for the block layer and lower layers (ie drivers and * stacking drivers) */struct bio {	sector_t		bi_sector;	/* device address in 512 byte						   sectors */	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						 */ 	unsigned short		bi_vcnt;	/* how many bio_vec's */	unsigned short		bi_idx;		/* current index into bvl_vec */ 	/* Number of segments in this BIO after	 * physical address coalescing is performed.	 */	unsigned int		bi_phys_segments; 	unsigned int		bi_size;	/* residual I/O count */ 	/*	 * 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; 	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#if defined(CONFIG_BLK_DEV_INTEGRITY)	struct bio_integrity_payload *bi_integrity;  /* data integrity */#endif 	/*	 * Everything starting with bi_max_vecs will be preserved by bio_reset()	 */ 	unsigned int		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 */ /* * Flags starting here get preserved by bio_reset() - this includes * BIO_POOL_IDX() */#define BIO_RESET_BITS	12 #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_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 */	__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_KERNEL, 		/* direct IO to kernel pages */	__REQ_NR_BITS,		/* stops here */}; #define REQ_WRITE		(1 << __REQ_WRITE)#define REQ_FAILFAST_DEV	(1 << __REQ_FAILFAST_DEV)#define REQ_FAILFAST_TRANSPORT	(1 << __REQ_FAILFAST_TRANSPORT)#define REQ_FAILFAST_DRIVER	(1 << __REQ_FAILFAST_DRIVER)#define REQ_SYNC		(1 << __REQ_SYNC)#define REQ_META		(1 << __REQ_META)#define REQ_PRIO		(1 << __REQ_PRIO)#define REQ_DISCARD		(1 << __REQ_DISCARD)#define REQ_WRITE_SAME		(1 << __REQ_WRITE_SAME)#define REQ_NOIDLE		(1 << __REQ_NOIDLE) #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)#define REQ_CLONE_MASK		REQ_COMMON_MASK /* 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) #define REQ_RAHEAD		(1 << __REQ_RAHEAD)#define REQ_THROTTLED		(1 << __REQ_THROTTLED) #define REQ_SORTED		(1 << __REQ_SORTED)#define REQ_SOFTBARRIER		(1 << __REQ_SOFTBARRIER)#define REQ_FUA			(1 << __REQ_FUA)#define REQ_NOMERGE		(1 << __REQ_NOMERGE)#define REQ_STARTED		(1 << __REQ_STARTED)#define REQ_DONTPREP		(1 << __REQ_DONTPREP)#define REQ_QUEUED		(1 << __REQ_QUEUED)#define REQ_ELVPRIV		(1 << __REQ_ELVPRIV)#define REQ_FAILED		(1 << __REQ_FAILED)#define REQ_QUIET		(1 << __REQ_QUIET)#define REQ_PREEMPT		(1 << __REQ_PREEMPT)#define REQ_ALLOCED		(1 << __REQ_ALLOCED)#define REQ_COPY_USER		(1 << __REQ_COPY_USER)#define REQ_FLUSH		(1 << __REQ_FLUSH)#define REQ_FLUSH_SEQ		(1 << __REQ_FLUSH_SEQ)#define REQ_IO_STAT		(1 << __REQ_IO_STAT)#define REQ_MIXED_MERGE		(1 << __REQ_MIXED_MERGE)#define REQ_SECURE		(1 << __REQ_SECURE)#define REQ_KERNEL		(1 << __REQ_KERNEL) #endif /* __LINUX_BLK_TYPES_H */