[linux-2.6-block.git] / include / linux / 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

#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;
};

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;

	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

	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 */

/*
 * 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 */

#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_PM,		/* runtime pm request */
	__REQ_END,		/* last of chain of requests */
	__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_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

#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)

#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_KERNEL		(1ULL << __REQ_KERNEL)
#define REQ_PM			(1ULL << __REQ_PM)
#define REQ_END			(1ULL << __REQ_END)

#endif /* __LINUX_BLK_TYPES_H */
Commit	Line	Data
7cc01581 TH	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;
852c788f TH	17	struct io_context;
852c788f TH	18	struct cgroup_subsys_state;
7cc01581 TH	19	typedef void (bio_end_io_t) (struct bio *, int);
	20	typedef void (bio_destructor_t) (struct bio *);
	21
	22	/*
	23	* was unsigned short, but we might as well be ready for > 64kB I/O pages
	24	*/
	25	struct bio_vec {
	26	struct page *bv_page;
	27	unsigned int bv_len;
	28	unsigned int bv_offset;
	29	};
	30
4f024f37 KO	31	struct bvec_iter {
	32	sector_t bi_sector; /* device address in 512 byte
	33	sectors */
	34	unsigned int bi_size; /* residual I/O count */
	35
	36	unsigned int bi_idx; /* current index into bvl_vec */
4550dd6c KO	37
	38	unsigned int bi_bvec_done; /* number of bytes completed in
	39	current bvec */
4f024f37 KO	40	};
4f024f37 KO	41
7cc01581 TH	42	/*
	43	* main unit of I/O for the block layer and lower layers (ie drivers and
	44	* stacking drivers)
	45	*/
	46	struct bio {
7cc01581 TH	47	struct bio bi_next; / request queue link */
	48	struct block_device *bi_bdev;
	49	unsigned long bi_flags; /* status, command, etc */
	50	unsigned long bi_rw; /* bottom bits READ/WRITE,
	51	* top bits priority
	52	*/
	53
4f024f37	54	struct bvec_iter bi_iter;
7cc01581 TH	55
	56	/* Number of segments in this BIO after
	57	* physical address coalescing is performed.
	58	*/
	59	unsigned int bi_phys_segments;
	60
7cc01581 TH	61	/*
	62	* To keep track of the max segment size, we account for the
	63	* sizes of the first and last mergeable segments in this bio.
	64	*/
	65	unsigned int bi_seg_front_size;
	66	unsigned int bi_seg_back_size;
	67
7cc01581 TH	68	bio_end_io_t *bi_end_io;
	69
	70	void *bi_private;
852c788f TH	71	#ifdef CONFIG_BLK_CGROUP
	72	/*
	73	* Optional ioc and css associated with this bio. Put on bio
	74	* release. Read comment on top of bio_associate_current().
	75	*/
	76	struct io_context *bi_ioc;
	77	struct cgroup_subsys_state *bi_css;
	78	#endif
7cc01581 TH	79	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	80	struct bio_integrity_payload bi_integrity; / data integrity */
	81	#endif
	82
4f024f37 KO	83	unsigned short bi_vcnt; /* how many bio_vec's */
4f024f37 KO	84
f44b48c7 KO	85	/*
	86	* Everything starting with bi_max_vecs will be preserved by bio_reset()
	87	*/
	88
4f024f37	89	unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
f44b48c7 KO	90
	91	atomic_t bi_cnt; /* pin count */
	92
	93	struct bio_vec bi_io_vec; / the actual vec list */
	94
395c72a7 KO	95	struct bio_set *bi_pool;
395c72a7 KO	96
7cc01581 TH	97	/*
	98	* We can inline a number of vecs at the end of the bio, to avoid
	99	* double allocations for a small number of bio_vecs. This member
	100	* MUST obviously be kept at the very end of the bio.
	101	*/
	102	struct bio_vec bi_inline_vecs[0];
	103	};
	104
f44b48c7 KO	105	#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
f44b48c7 KO	106
7cc01581 TH	107	/*
	108	* bio flags
	109	*/
	110	#define BIO_UPTODATE 0 /* ok after I/O completion */
	111	#define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */
	112	#define BIO_EOF 2 /* out-out-bounds error */
	113	#define BIO_SEG_VALID 3 /* bi_phys_segments valid */
	114	#define BIO_CLONED 4 /* doesn't own data */
	115	#define BIO_BOUNCED 5 /* bio is a bounce bio */
	116	#define BIO_USER_MAPPED 6 /* contains user pages */
	117	#define BIO_EOPNOTSUPP 7 /* not supported */
9562ad9a TM	118	#define BIO_NULL_MAPPED 8 /* contains invalid user pages */
	119	#define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */
	120	#define BIO_QUIET 10 /* Make BIO Quiet */
	121	#define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */
71368511	122	#define BIO_SNAP_STABLE 12 /* bio data must be snapshotted during write */
f44b48c7 KO	123
	124	/*
	125	* Flags starting here get preserved by bio_reset() - this includes
	126	* BIO_POOL_IDX()
	127	*/
71368511	128	#define BIO_RESET_BITS 13
4de13d7a	129	#define BIO_OWNS_VEC 13 /* bio_free() should free bvec */
f44b48c7	130
7cc01581 TH	131	#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
	132
	133	/*
	134	* top 4 bits of bio flags indicate the pool this bio came from
	135	*/
	136	#define BIO_POOL_BITS (4)
	137	#define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1)
	138	#define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS)
	139	#define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
	140	#define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
	141
de75d60d JA	142	#endif /* CONFIG_BLOCK */
de75d60d JA	143
7cc01581 TH	144	/*
	145	* Request flags. For use in the cmd_flags field of struct request, and in
	146	* bi_rw of struct bio. Note that some flags are only valid in either one.
	147	*/
	148	enum rq_flag_bits {
	149	/* common flags */
	150	__REQ_WRITE, /* not set, read. set, write */
	151	__REQ_FAILFAST_DEV, /* no driver retries of device errors */
	152	__REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
	153	__REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
	154
7cc01581 TH	155	__REQ_SYNC, /* request is sync (sync write or read) */
7cc01581 TH	156	__REQ_META, /* metadata io request */
65299a3b	157	__REQ_PRIO, /* boost priority in cfq */
7cc01581	158	__REQ_DISCARD, /* request to discard sectors */
8e4bf844	159	__REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */
4363ac7c	160	__REQ_WRITE_SAME, /* write same block many times */
8e4bf844	161
7cc01581	162	__REQ_NOIDLE, /* don't anticipate more IO after this one */
8e4bf844 MW	163	__REQ_FUA, /* forced unit access */
8e4bf844 MW	164	__REQ_FLUSH, /* request for cache flush */
7cc01581 TH	165
7cc01581 TH	166	/* bio only flags */
7cc01581	167	__REQ_RAHEAD, /* read ahead, can fail anytime */
e43473b7 VG	168	__REQ_THROTTLED, /* This bio has already been subjected to
e43473b7 VG	169	* throttling rules. Don't do it again. */
7cc01581 TH	170
	171	/* request only flags */
	172	__REQ_SORTED, /* elevator knows about this request */
	173	__REQ_SOFTBARRIER, /* may not be passed by ioscheduler */
7cc01581 TH	174	__REQ_NOMERGE, /* don't touch this for merging */
	175	__REQ_STARTED, /* drive already may have started this one */
	176	__REQ_DONTPREP, /* don't call prep for this one */
	177	__REQ_QUEUED, /* uses queueing */
	178	__REQ_ELVPRIV, /* elevator private data attached */
	179	__REQ_FAILED, /* set if the request failed */
	180	__REQ_QUIET, /* don't worry about errors */
	181	__REQ_PREEMPT, /* set for "ide_preempt" requests */
7cc01581 TH	182	__REQ_ALLOCED, /* request came from our alloc pool */
7cc01581 TH	183	__REQ_COPY_USER, /* contains copies of user pages */
414b4ff5	184	__REQ_FLUSH_SEQ, /* request for flush sequence */
7cc01581 TH	185	__REQ_IO_STAT, /* account I/O stat */
7cc01581 TH	186	__REQ_MIXED_MERGE, /* merge of different types, fail separately */
18022c5d	187	__REQ_KERNEL, /* direct IO to kernel pages */
66311274	188	__REQ_PM, /* runtime pm request */
320ae51f	189	__REQ_END, /* last of chain of requests */
7cc01581 TH	190	__REQ_NR_BITS, /* stops here */
	191	};
	192
5953316d JA	193	#define REQ_WRITE (1ULL << __REQ_WRITE)
	194	#define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
	195	#define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
	196	#define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
	197	#define REQ_SYNC (1ULL << __REQ_SYNC)
	198	#define REQ_META (1ULL << __REQ_META)
	199	#define REQ_PRIO (1ULL << __REQ_PRIO)
	200	#define REQ_DISCARD (1ULL << __REQ_DISCARD)
	201	#define REQ_WRITE_SAME (1ULL << __REQ_WRITE_SAME)
	202	#define REQ_NOIDLE (1ULL << __REQ_NOIDLE)
7cc01581 TH	203
	204	#define REQ_FAILFAST_MASK \
	205	(REQ_FAILFAST_DEV \| REQ_FAILFAST_TRANSPORT \| REQ_FAILFAST_DRIVER)
	206	#define REQ_COMMON_MASK \
65299a3b	207	(REQ_WRITE \| REQ_FAILFAST_MASK \| REQ_SYNC \| REQ_META \| REQ_PRIO \| \
4363ac7c MP	208	REQ_DISCARD \| REQ_WRITE_SAME \| REQ_NOIDLE \| REQ_FLUSH \| REQ_FUA \| \
4363ac7c MP	209	REQ_SECURE)
3a2edd0d	210	#define REQ_CLONE_MASK REQ_COMMON_MASK
7cc01581	211
054bdf64 KO	212	#define BIO_NO_ADVANCE_ITER_MASK (REQ_DISCARD\|REQ_WRITE_SAME)
054bdf64 KO	213
e2a60da7 MP	214	/* This mask is used for both bio and request merge checking */
	215	#define REQ_NOMERGE_FLAGS \
	216	(REQ_NOMERGE \| REQ_STARTED \| REQ_SOFTBARRIER \| REQ_FLUSH \| REQ_FUA)
	217
5953316d JA	218	#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
	219	#define REQ_THROTTLED (1ULL << __REQ_THROTTLED)
	220
	221	#define REQ_SORTED (1ULL << __REQ_SORTED)
	222	#define REQ_SOFTBARRIER (1ULL << __REQ_SOFTBARRIER)
	223	#define REQ_FUA (1ULL << __REQ_FUA)
	224	#define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
	225	#define REQ_STARTED (1ULL << __REQ_STARTED)
	226	#define REQ_DONTPREP (1ULL << __REQ_DONTPREP)
	227	#define REQ_QUEUED (1ULL << __REQ_QUEUED)
	228	#define REQ_ELVPRIV (1ULL << __REQ_ELVPRIV)
	229	#define REQ_FAILED (1ULL << __REQ_FAILED)
	230	#define REQ_QUIET (1ULL << __REQ_QUIET)
	231	#define REQ_PREEMPT (1ULL << __REQ_PREEMPT)
	232	#define REQ_ALLOCED (1ULL << __REQ_ALLOCED)
	233	#define REQ_COPY_USER (1ULL << __REQ_COPY_USER)
	234	#define REQ_FLUSH (1ULL << __REQ_FLUSH)
	235	#define REQ_FLUSH_SEQ (1ULL << __REQ_FLUSH_SEQ)
	236	#define REQ_IO_STAT (1ULL << __REQ_IO_STAT)
	237	#define REQ_MIXED_MERGE (1ULL << __REQ_MIXED_MERGE)
	238	#define REQ_SECURE (1ULL << __REQ_SECURE)
	239	#define REQ_KERNEL (1ULL << __REQ_KERNEL)
	240	#define REQ_PM (1ULL << __REQ_PM)
320ae51f	241	#define REQ_END (1ULL << __REQ_END)
7cc01581	242
7cc01581	243	#endif /* __LINUX_BLK_TYPES_H */