[deliverable/linux.git] / include / linux / bio.h

/*
 * 2.5 block I/O model
 *
 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public Licens
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
 */
#ifndef __LINUX_BIO_H
#define __LINUX_BIO_H

#include <linux/highmem.h>
#include <linux/mempool.h>
#include <linux/ioprio.h>

#ifdef CONFIG_BLOCK

#include <asm/io.h>

#define BIO_DEBUG

#ifdef BIO_DEBUG
#define BIO_BUG_ON	BUG_ON
#else
#define BIO_BUG_ON
#endif

#define BIO_MAX_PAGES		256
#define BIO_MAX_SIZE		(BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
#define BIO_MAX_SECTORS		(BIO_MAX_SIZE >> 9)

/*
 * 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 bio_set;
struct bio;
struct bio_integrity_payload;
typedef void (bio_end_io_t) (struct bio *, int);
typedef void (bio_destructor_t) (struct bio *);

/*
 * 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 */

	unsigned int		bi_max_vecs;	/* max bvl_vecs we can hold */

	unsigned int		bi_comp_cpu;	/* completion CPU */

	struct bio_vec		*bi_io_vec;	/* the actual vec list */

	bio_end_io_t		*bi_end_io;
	atomic_t		bi_cnt;		/* pin count */

	void			*bi_private;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
	struct bio_integrity_payload *bi_integrity;  /* data integrity */
#endif

	bio_destructor_t	*bi_destructor;	/* destructor */
};

/*
 * 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_CPU_AFFINE	8	/* complete bio on same CPU as submitted */
#define BIO_NULL_MAPPED 9	/* contains invalid user pages */
#define BIO_FS_INTEGRITY 10	/* fs owns integrity data, not block layer */
#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_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)	

/*
 * bio bi_rw flags
 *
 * bit 0 -- data direction
 *	If not set, bio is a read from device. If set, it's a write to device.
 * bit 1 -- rw-ahead when set
 * bit 2 -- barrier
 *	Insert a serialization point in the IO queue, forcing previously
 *	submitted IO to be completed before this oen is issued.
 * bit 3 -- fail fast, don't want low level driver retries
 * bit 4 -- synchronous I/O hint: the block layer will unplug immediately
 *	Note that this does NOT indicate that the IO itself is sync, just
 *	that the block layer will not postpone issue of this IO by plugging.
 * bit 5 -- metadata request
 *	Used for tracing to differentiate metadata and data IO. May also
 *	get some preferential treatment in the IO scheduler
 * bit 6 -- discard sectors
 *	Informs the lower level device that this range of sectors is no longer
 *	used by the file system and may thus be freed by the device. Used
 *	for flash based storage.
 */
#define BIO_RW		0	/* Must match RW in req flags (blkdev.h) */
#define BIO_RW_AHEAD	1	/* Must match FAILFAST in req flags */
#define BIO_RW_BARRIER	2
#define BIO_RW_FAILFAST	3
#define BIO_RW_SYNC	4
#define BIO_RW_META	5
#define BIO_RW_DISCARD	6

/*
 * upper 16 bits of bi_rw define the io priority of this bio
 */
#define BIO_PRIO_SHIFT	(8 * sizeof(unsigned long) - IOPRIO_BITS)
#define bio_prio(bio)	((bio)->bi_rw >> BIO_PRIO_SHIFT)
#define bio_prio_valid(bio)	ioprio_valid(bio_prio(bio))

#define bio_set_prio(bio, prio)		do {			\
	WARN_ON(prio >= (1 << IOPRIO_BITS));			\
	(bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);		\
	(bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);	\
} while (0)

/*
 * various member access, note that bio_data should of course not be used
 * on highmem page vectors
 */
#define bio_iovec_idx(bio, idx)	(&((bio)->bi_io_vec[(idx)]))
#define bio_iovec(bio)		bio_iovec_idx((bio), (bio)->bi_idx)
#define bio_page(bio)		bio_iovec((bio))->bv_page
#define bio_offset(bio)		bio_iovec((bio))->bv_offset
#define bio_segments(bio)	((bio)->bi_vcnt - (bio)->bi_idx)
#define bio_sectors(bio)	((bio)->bi_size >> 9)
#define bio_barrier(bio)	((bio)->bi_rw & (1 << BIO_RW_BARRIER))
#define bio_sync(bio)		((bio)->bi_rw & (1 << BIO_RW_SYNC))
#define bio_failfast(bio)	((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
#define bio_rw_ahead(bio)	((bio)->bi_rw & (1 << BIO_RW_AHEAD))
#define bio_rw_meta(bio)	((bio)->bi_rw & (1 << BIO_RW_META))
#define bio_discard(bio)	((bio)->bi_rw & (1 << BIO_RW_DISCARD))
#define bio_empty_barrier(bio)	(bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))

static inline unsigned int bio_cur_sectors(struct bio *bio)
{
	if (bio->bi_vcnt)
		return bio_iovec(bio)->bv_len >> 9;
	else /* dataless requests such as discard */
		return bio->bi_size >> 9;
}

static inline void *bio_data(struct bio *bio)
{
	if (bio->bi_vcnt)
		return page_address(bio_page(bio)) + bio_offset(bio);

	return NULL;
}

/*
 * will die
 */
#define bio_to_phys(bio)	(page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
#define bvec_to_phys(bv)	(page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)

/*
 * queues that have highmem support enabled may still need to revert to
 * PIO transfers occasionally and thus map high pages temporarily. For
 * permanent PIO fall back, user is probably better off disabling highmem
 * I/O completely on that queue (see ide-dma for example)
 */
#define __bio_kmap_atomic(bio, idx, kmtype)				\
	(kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) +	\
		bio_iovec_idx((bio), (idx))->bv_offset)

#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)

/*
 * merge helpers etc
 */

#define __BVEC_END(bio)		bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
#define __BVEC_START(bio)	bio_iovec_idx((bio), (bio)->bi_idx)

/*
 * allow arch override, for eg virtualized architectures (put in asm/io.h)
 */
#ifndef BIOVEC_PHYS_MERGEABLE
#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
#endif

#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, (q)->seg_boundary_mask)
#define BIO_SEG_BOUNDARY(q, b1, b2) \
	BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))

#define bio_io_error(bio) bio_endio((bio), -EIO)

/*
 * drivers should not use the __ version unless they _really_ want to
 * run through the entire bio and not just pending pieces
 */
#define __bio_for_each_segment(bvl, bio, i, start_idx)			\
	for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx);	\
	     i < (bio)->bi_vcnt;					\
	     bvl++, i++)

#define bio_for_each_segment(bvl, bio, i)				\
	__bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)

/*
 * get a reference to a bio, so it won't disappear. the intended use is
 * something like:
 *
 * bio_get(bio);
 * submit_bio(rw, bio);
 * if (bio->bi_flags ...)
 *	do_something
 * bio_put(bio);
 *
 * without the bio_get(), it could potentially complete I/O before submit_bio
 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
 * runs
 */
#define bio_get(bio)	atomic_inc(&(bio)->bi_cnt)

#if defined(CONFIG_BLK_DEV_INTEGRITY)
/*
 * bio integrity payload
 */
struct bio_integrity_payload {
	struct bio		*bip_bio;	/* parent bio */
	struct bio_vec		*bip_vec;	/* integrity data vector */

	sector_t		bip_sector;	/* virtual start sector */

	void			*bip_buf;	/* generated integrity data */
	bio_end_io_t		*bip_end_io;	/* saved I/O completion fn */

	int			bip_error;	/* saved I/O error */
	unsigned int		bip_size;

	unsigned short		bip_pool;	/* pool the ivec came from */
	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
	unsigned short		bip_idx;	/* current bip_vec index */

	struct work_struct	bip_work;	/* I/O completion */
};
#endif /* CONFIG_BLK_DEV_INTEGRITY */

/*
 * A bio_pair is used when we need to split a bio.
 * This can only happen for a bio that refers to just one
 * page of data, and in the unusual situation when the
 * page crosses a chunk/device boundary
 *
 * The address of the master bio is stored in bio1.bi_private
 * The address of the pool the pair was allocated from is stored
 *   in bio2.bi_private
 */
struct bio_pair {
	struct bio			bio1, bio2;
	struct bio_vec			bv1, bv2;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
	struct bio_integrity_payload	bip1, bip2;
	struct bio_vec			iv1, iv2;
#endif
	atomic_t			cnt;
	int				error;
};
extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
extern void bio_pair_release(struct bio_pair *dbio);

extern struct bio_set *bioset_create(int, int);
extern void bioset_free(struct bio_set *);

extern struct bio *bio_alloc(gfp_t, int);
extern struct bio *bio_kmalloc(gfp_t, int);
extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
extern void bio_put(struct bio *);
extern void bio_free(struct bio *, struct bio_set *);

extern void bio_endio(struct bio *, int);
struct request_queue;
extern int bio_phys_segments(struct request_queue *, struct bio *);

extern void __bio_clone(struct bio *, struct bio *);
extern struct bio *bio_clone(struct bio *, gfp_t);

extern void bio_init(struct bio *);

extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
			   unsigned int, unsigned int);
extern int bio_get_nr_vecs(struct block_device *);
extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
				unsigned long, unsigned int, int, gfp_t);
struct sg_iovec;
struct rq_map_data;
extern struct bio *bio_map_user_iov(struct request_queue *,
				    struct block_device *,
				    struct sg_iovec *, int, int, gfp_t);
extern void bio_unmap_user(struct bio *);
extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
				gfp_t);
extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
				 gfp_t, int);
extern void bio_set_pages_dirty(struct bio *bio);
extern void bio_check_pages_dirty(struct bio *bio);
extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
				 unsigned long, unsigned int, int, gfp_t);
extern struct bio *bio_copy_user_iov(struct request_queue *,
				     struct rq_map_data *, struct sg_iovec *,
				     int, int, gfp_t);
extern int bio_uncopy_user(struct bio *);
void zero_fill_bio(struct bio *bio);
extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
extern unsigned int bvec_nr_vecs(unsigned short idx);

/*
 * Allow queuer to specify a completion CPU for this bio
 */
static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
{
	bio->bi_comp_cpu = cpu;
}

/*
 * bio_set is used to allow other portions of the IO system to
 * allocate their own private memory pools for bio and iovec structures.
 * These memory pools in turn all allocate from the bio_slab
 * and the bvec_slabs[].
 */
#define BIO_POOL_SIZE 2
#define BIOVEC_NR_POOLS 6

struct bio_set {
	mempool_t *bio_pool;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
	mempool_t *bio_integrity_pool;
#endif
	mempool_t *bvec_pools[BIOVEC_NR_POOLS];
};

struct biovec_slab {
	int nr_vecs;
	char *name;
	struct kmem_cache *slab;
};

extern struct bio_set *fs_bio_set;

/*
 * a small number of entries is fine, not going to be performance critical.
 * basically we just need to survive
 */
#define BIO_SPLIT_ENTRIES 2

#ifdef CONFIG_HIGHMEM
/*
 * remember to add offset! and never ever reenable interrupts between a
 * bvec_kmap_irq and bvec_kunmap_irq!!
 *
 * This function MUST be inlined - it plays with the CPU interrupt flags.
 */
static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
{
	unsigned long addr;

	/*
	 * might not be a highmem page, but the preempt/irq count
	 * balancing is a lot nicer this way
	 */
	local_irq_save(*flags);
	addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);

	BUG_ON(addr & ~PAGE_MASK);

	return (char *) addr + bvec->bv_offset;
}

static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
{
	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;

	kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
	local_irq_restore(*flags);
}

#else
#define bvec_kmap_irq(bvec, flags)	(page_address((bvec)->bv_page) + (bvec)->bv_offset)
#define bvec_kunmap_irq(buf, flags)	do { *(flags) = 0; } while (0)
#endif

static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
				   unsigned long *flags)
{
	return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
}
#define __bio_kunmap_irq(buf, flags)	bvec_kunmap_irq(buf, flags)

#define bio_kmap_irq(bio, flags) \
	__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
#define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)

/*
 * Check whether this bio carries any data or not. A NULL bio is allowed.
 */
static inline int bio_has_data(struct bio *bio)
{
	return bio && bio->bi_io_vec != NULL;
}

#if defined(CONFIG_BLK_DEV_INTEGRITY)

#define bip_vec_idx(bip, idx)	(&(bip->bip_vec[(idx)]))
#define bip_vec(bip)		bip_vec_idx(bip, 0)

#define __bip_for_each_vec(bvl, bip, i, start_idx)			\
	for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx);	\
	     i < (bip)->bip_vcnt;					\
	     bvl++, i++)

#define bip_for_each_vec(bvl, bip, i)					\
	__bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)

#define bio_integrity(bio) (bio->bi_integrity != NULL)

extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
extern void bio_integrity_free(struct bio *, struct bio_set *);
extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
extern int bio_integrity_enabled(struct bio *bio);
extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
extern int bio_integrity_prep(struct bio *);
extern void bio_integrity_endio(struct bio *, int);
extern void bio_integrity_advance(struct bio *, unsigned int);
extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
extern int bio_integrity_clone(struct bio *, struct bio *, struct bio_set *);
extern int bioset_integrity_create(struct bio_set *, int);
extern void bioset_integrity_free(struct bio_set *);
extern void bio_integrity_init_slab(void);

#else /* CONFIG_BLK_DEV_INTEGRITY */

#define bio_integrity(a)		(0)
#define bioset_integrity_create(a, b)	(0)
#define bio_integrity_prep(a)		(0)
#define bio_integrity_enabled(a)	(0)
#define bio_integrity_clone(a, b, c)	(0)
#define bioset_integrity_free(a)	do { } while (0)
#define bio_integrity_free(a, b)	do { } while (0)
#define bio_integrity_endio(a, b)	do { } while (0)
#define bio_integrity_advance(a, b)	do { } while (0)
#define bio_integrity_trim(a, b, c)	do { } while (0)
#define bio_integrity_split(a, b, c)	do { } while (0)
#define bio_integrity_set_tag(a, b, c)	do { } while (0)
#define bio_integrity_get_tag(a, b, c)	do { } while (0)
#define bio_integrity_init_slab(a)	do { } while (0)

#endif /* CONFIG_BLK_DEV_INTEGRITY */

#endif /* CONFIG_BLOCK */
#endif /* __LINUX_BIO_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* 2.5 block I/O model
	3	*
	4	* Copyright (C) 2001 Jens Axboe <axboe@suse.de>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public Licens
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
	19	*/
	20	#ifndef __LINUX_BIO_H
	21	#define __LINUX_BIO_H
	22
	23	#include <linux/highmem.h>
	24	#include <linux/mempool.h>
22e2c507	25	#include <linux/ioprio.h>
1da177e4	26
02a5e0ac DH	27	#ifdef CONFIG_BLOCK
02a5e0ac DH	28
1da177e4 LT	29	#include <asm/io.h>
1da177e4 LT	30
1da177e4 LT	31	#define BIO_DEBUG
	32
	33	#ifdef BIO_DEBUG
	34	#define BIO_BUG_ON BUG_ON
	35	#else
	36	#define BIO_BUG_ON
	37	#endif
	38
d84a8477	39	#define BIO_MAX_PAGES 256
1da177e4 LT	40	#define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
	41	#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
	42
	43	/*
	44	* was unsigned short, but we might as well be ready for > 64kB I/O pages
	45	*/
	46	struct bio_vec {
	47	struct page *bv_page;
	48	unsigned int bv_len;
	49	unsigned int bv_offset;
	50	};
	51
	52	struct bio_set;
	53	struct bio;
7ba1ba12	54	struct bio_integrity_payload;
6712ecf8	55	typedef void (bio_end_io_t) (struct bio *, int);
1da177e4 LT	56	typedef void (bio_destructor_t) (struct bio *);
	57
	58	/*
	59	* main unit of I/O for the block layer and lower layers (ie drivers and
	60	* stacking drivers)
	61	*/
	62	struct bio {
2c2345c2 RG	63	sector_t bi_sector; /* device address in 512 byte
2c2345c2 RG	64	sectors */
1da177e4 LT	65	struct bio bi_next; / request queue link */
	66	struct block_device *bi_bdev;
	67	unsigned long bi_flags; /* status, command, etc */
	68	unsigned long bi_rw; /* bottom bits READ/WRITE,
	69	* top bits priority
	70	*/
	71
	72	unsigned short bi_vcnt; /* how many bio_vec's */
	73	unsigned short bi_idx; /* current index into bvl_vec */
	74
	75	/* Number of segments in this BIO after
	76	* physical address coalescing is performed.
	77	*/
5b99c2ff	78	unsigned int bi_phys_segments;
1da177e4	79
1da177e4 LT	80	unsigned int bi_size; /* residual I/O count */
1da177e4 LT	81
1da177e4 LT	82	unsigned int bi_max_vecs; /* max bvl_vecs we can hold */
1da177e4 LT	83
c7c22e4d JA	84	unsigned int bi_comp_cpu; /* completion CPU */
c7c22e4d JA	85
1da177e4 LT	86	struct bio_vec bi_io_vec; / the actual vec list */
	87
	88	bio_end_io_t *bi_end_io;
	89	atomic_t bi_cnt; /* pin count */
	90
	91	void *bi_private;
7ba1ba12 MP	92	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	93	struct bio_integrity_payload bi_integrity; / data integrity */
	94	#endif
1da177e4 LT	95
1da177e4 LT	96	bio_destructor_t bi_destructor; / destructor */
1da177e4 LT	97	};
	98
	99	/*
	100	* bio flags
	101	*/
	102	#define BIO_UPTODATE 0 /* ok after I/O completion */
	103	#define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */
	104	#define BIO_EOF 2 /* out-out-bounds error */
5df97b91	105	#define BIO_SEG_VALID 3 /* bi_phys_segments valid */
1da177e4 LT	106	#define BIO_CLONED 4 /* doesn't own data */
	107	#define BIO_BOUNCED 5 /* bio is a bounce bio */
	108	#define BIO_USER_MAPPED 6 /* contains user pages */
	109	#define BIO_EOPNOTSUPP 7 /* not supported */
c7c22e4d	110	#define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */
81882766	111	#define BIO_NULL_MAPPED 9 /* contains invalid user pages */
74aa8c2c	112	#define BIO_FS_INTEGRITY 10 /* fs owns integrity data, not block layer */
1da177e4 LT	113	#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
	114
	115	/*
	116	* top 4 bits of bio flags indicate the pool this bio came from
	117	*/
	118	#define BIO_POOL_BITS (4)
	119	#define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS)
	120	#define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
	121	#define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
	122
	123	/*
	124	* bio bi_rw flags
	125	*
af563942 JA	126	* bit 0 -- data direction
af563942 JA	127	* If not set, bio is a read from device. If set, it's a write to device.
1da177e4 LT	128	* bit 1 -- rw-ahead when set
1da177e4 LT	129	* bit 2 -- barrier
af563942 JA	130	* Insert a serialization point in the IO queue, forcing previously
af563942 JA	131	* submitted IO to be completed before this oen is issued.
1da177e4 LT	132	* bit 3 -- fail fast, don't want low level driver retries
1da177e4 LT	133	* bit 4 -- synchronous I/O hint: the block layer will unplug immediately
af563942 JA	134	* Note that this does NOT indicate that the IO itself is sync, just
af563942 JA	135	* that the block layer will not postpone issue of this IO by plugging.
fb2dce86	136	* bit 5 -- metadata request
af563942 JA	137	* Used for tracing to differentiate metadata and data IO. May also
af563942 JA	138	* get some preferential treatment in the IO scheduler
fb2dce86	139	* bit 6 -- discard sectors
af563942 JA	140	* Informs the lower level device that this range of sectors is no longer
	141	* used by the file system and may thus be freed by the device. Used
	142	* for flash based storage.
1da177e4	143	*/
d628eaef DW	144	#define BIO_RW 0 /* Must match RW in req flags (blkdev.h) */
d628eaef DW	145	#define BIO_RW_AHEAD 1 /* Must match FAILFAST in req flags */
1da177e4 LT	146	#define BIO_RW_BARRIER 2
	147	#define BIO_RW_FAILFAST 3
	148	#define BIO_RW_SYNC 4
5404bc7a	149	#define BIO_RW_META 5
fb2dce86	150	#define BIO_RW_DISCARD 6
1da177e4	151
22e2c507 JA	152	/*
	153	* upper 16 bits of bi_rw define the io priority of this bio
	154	*/
	155	#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
	156	#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
	157	#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
	158
	159	#define bio_set_prio(bio, prio) do { \
	160	WARN_ON(prio >= (1 << IOPRIO_BITS)); \
	161	(bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
	162	(bio)->bi_rw \|= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
	163	} while (0)
	164
1da177e4 LT	165	/*
	166	* various member access, note that bio_data should of course not be used
	167	* on highmem page vectors
	168	*/
	169	#define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
	170	#define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
	171	#define bio_page(bio) bio_iovec((bio))->bv_page
	172	#define bio_offset(bio) bio_iovec((bio))->bv_offset
	173	#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
	174	#define bio_sectors(bio) ((bio)->bi_size >> 9)
1da177e4 LT	175	#define bio_barrier(bio) ((bio)->bi_rw & (1 << BIO_RW_BARRIER))
	176	#define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNC))
	177	#define bio_failfast(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
	178	#define bio_rw_ahead(bio) ((bio)->bi_rw & (1 << BIO_RW_AHEAD))
5404bc7a	179	#define bio_rw_meta(bio) ((bio)->bi_rw & (1 << BIO_RW_META))
fb2dce86	180	#define bio_discard(bio) ((bio)->bi_rw & (1 << BIO_RW_DISCARD))
e17fc0a1	181	#define bio_empty_barrier(bio) (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
bf2de6f5 JA	182
	183	static inline unsigned int bio_cur_sectors(struct bio *bio)
	184	{
	185	if (bio->bi_vcnt)
	186	return bio_iovec(bio)->bv_len >> 9;
fb2dce86 DW	187	else /* dataless requests such as discard */
fb2dce86 DW	188	return bio->bi_size >> 9;
bf2de6f5 JA	189	}
	190
	191	static inline void bio_data(struct bio bio)
	192	{
	193	if (bio->bi_vcnt)
	194	return page_address(bio_page(bio)) + bio_offset(bio);
	195
	196	return NULL;
	197	}
1da177e4 LT	198
	199	/*
	200	* will die
	201	*/
	202	#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
	203	#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
	204
	205	/*
	206	* queues that have highmem support enabled may still need to revert to
	207	* PIO transfers occasionally and thus map high pages temporarily. For
	208	* permanent PIO fall back, user is probably better off disabling highmem
	209	* I/O completely on that queue (see ide-dma for example)
	210	*/
	211	#define __bio_kmap_atomic(bio, idx, kmtype) \
	212	(kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
	213	bio_iovec_idx((bio), (idx))->bv_offset)
	214
	215	#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
	216
	217	/*
	218	* merge helpers etc
	219	*/
	220
	221	#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
	222	#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
	223
	224	/*
	225	* allow arch override, for eg virtualized architectures (put in asm/io.h)
	226	*/
	227	#ifndef BIOVEC_PHYS_MERGEABLE
	228	#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
	229	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
	230	#endif
	231
1da177e4 LT	232	#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
	233	(((addr1) \| (mask)) == (((addr2) - 1) \| (mask)))
	234	#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
	235	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, (q)->seg_boundary_mask)
	236	#define BIO_SEG_BOUNDARY(q, b1, b2) \
	237	BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
	238
6712ecf8	239	#define bio_io_error(bio) bio_endio((bio), -EIO)
1da177e4 LT	240
	241	/*
	242	* drivers should not use the __ version unless they _really_ want to
	243	* run through the entire bio and not just pending pieces
	244	*/
	245	#define __bio_for_each_segment(bvl, bio, i, start_idx) \
	246	for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
	247	i < (bio)->bi_vcnt; \
	248	bvl++, i++)
	249
	250	#define bio_for_each_segment(bvl, bio, i) \
	251	__bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
	252
	253	/*
	254	* get a reference to a bio, so it won't disappear. the intended use is
	255	* something like:
	256	*
	257	* bio_get(bio);
	258	* submit_bio(rw, bio);
	259	* if (bio->bi_flags ...)
	260	* do_something
	261	* bio_put(bio);
	262	*
	263	* without the bio_get(), it could potentially complete I/O before submit_bio
	264	* returns. and then bio would be freed memory when if (bio->bi_flags ...)
	265	* runs
	266	*/
	267	#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
	268
7ba1ba12 MP	269	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	270	/*
	271	* bio integrity payload
	272	*/
	273	struct bio_integrity_payload {
	274	struct bio bip_bio; / parent bio */
	275	struct bio_vec bip_vec; / integrity data vector */
	276
	277	sector_t bip_sector; /* virtual start sector */
	278
	279	void bip_buf; / generated integrity data */
	280	bio_end_io_t bip_end_io; / saved I/O completion fn */
	281
	282	int bip_error; /* saved I/O error */
	283	unsigned int bip_size;
	284
	285	unsigned short bip_pool; /* pool the ivec came from */
	286	unsigned short bip_vcnt; /* # of integrity bio_vecs */
	287	unsigned short bip_idx; /* current bip_vec index */
	288
	289	struct work_struct bip_work; /* I/O completion */
	290	};
	291	#endif /* CONFIG_BLK_DEV_INTEGRITY */
1da177e4 LT	292
	293	/*
	294	* A bio_pair is used when we need to split a bio.
	295	* This can only happen for a bio that refers to just one
	296	* page of data, and in the unusual situation when the
	297	* page crosses a chunk/device boundary
	298	*
	299	* The address of the master bio is stored in bio1.bi_private
	300	* The address of the pool the pair was allocated from is stored
	301	* in bio2.bi_private
	302	*/
	303	struct bio_pair {
7ba1ba12 MP	304	struct bio bio1, bio2;
	305	struct bio_vec bv1, bv2;
	306	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	307	struct bio_integrity_payload bip1, bip2;
	308	struct bio_vec iv1, iv2;
	309	#endif
	310	atomic_t cnt;
	311	int error;
1da177e4	312	};
6feef531	313	extern struct bio_pair bio_split(struct bio bi, int first_sectors);
1da177e4 LT	314	extern void bio_pair_release(struct bio_pair *dbio);
1da177e4 LT	315
5972511b	316	extern struct bio_set *bioset_create(int, int);
1da177e4 LT	317	extern void bioset_free(struct bio_set *);
1da177e4 LT	318
dd0fc66f	319	extern struct bio *bio_alloc(gfp_t, int);
0a0d96b0	320	extern struct bio *bio_kmalloc(gfp_t, int);
dd0fc66f	321	extern struct bio bio_alloc_bioset(gfp_t, int, struct bio_set );
1da177e4	322	extern void bio_put(struct bio *);
3676347a	323	extern void bio_free(struct bio , struct bio_set );
1da177e4	324
6712ecf8	325	extern void bio_endio(struct bio *, int);
1da177e4 LT	326	struct request_queue;
1da177e4 LT	327	extern int bio_phys_segments(struct request_queue , struct bio );
1da177e4 LT	328
1da177e4 LT	329	extern void __bio_clone(struct bio , struct bio );
dd0fc66f	330	extern struct bio bio_clone(struct bio , gfp_t);
1da177e4 LT	331
	332	extern void bio_init(struct bio *);
	333
	334	extern int bio_add_page(struct bio , struct page , unsigned int,unsigned int);
6e68af66 MC	335	extern int bio_add_pc_page(struct request_queue , struct bio , struct page *,
6e68af66 MC	336	unsigned int, unsigned int);
1da177e4	337	extern int bio_get_nr_vecs(struct block_device *);
ad3316bf	338	extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
1da177e4	339	extern struct bio bio_map_user(struct request_queue , struct block_device *,
a3bce90e	340	unsigned long, unsigned int, int, gfp_t);
f1970baf	341	struct sg_iovec;
152e283f	342	struct rq_map_data;
f1970baf JB	343	extern struct bio bio_map_user_iov(struct request_queue ,
f1970baf JB	344	struct block_device *,
a3bce90e	345	struct sg_iovec *, int, int, gfp_t);
1da177e4	346	extern void bio_unmap_user(struct bio *);
df46b9a4	347	extern struct bio bio_map_kern(struct request_queue , void *, unsigned int,
27496a8c	348	gfp_t);
68154e90 FT	349	extern struct bio bio_copy_kern(struct request_queue , void *, unsigned int,
68154e90 FT	350	gfp_t, int);
1da177e4 LT	351	extern void bio_set_pages_dirty(struct bio *bio);
1da177e4 LT	352	extern void bio_check_pages_dirty(struct bio *bio);
152e283f FT	353	extern struct bio bio_copy_user(struct request_queue , struct rq_map_data *,
	354	unsigned long, unsigned int, int, gfp_t);
	355	extern struct bio bio_copy_user_iov(struct request_queue ,
	356	struct rq_map_data , struct sg_iovec ,
a3bce90e	357	int, int, gfp_t);
1da177e4 LT	358	extern int bio_uncopy_user(struct bio *);
1da177e4 LT	359	void zero_fill_bio(struct bio *bio);
51d654e1	360	extern struct bio_vec bvec_alloc_bs(gfp_t, int, unsigned long , struct bio_set *);
7ba1ba12	361	extern unsigned int bvec_nr_vecs(unsigned short idx);
51d654e1	362
c7c22e4d JA	363	/*
	364	* Allow queuer to specify a completion CPU for this bio
	365	*/
	366	static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
	367	{
	368	bio->bi_comp_cpu = cpu;
	369	}
	370
51d654e1 MP	371	/*
	372	* bio_set is used to allow other portions of the IO system to
	373	* allocate their own private memory pools for bio and iovec structures.
	374	* These memory pools in turn all allocate from the bio_slab
	375	* and the bvec_slabs[].
	376	*/
	377	#define BIO_POOL_SIZE 2
	378	#define BIOVEC_NR_POOLS 6
	379
	380	struct bio_set {
	381	mempool_t *bio_pool;
7ba1ba12 MP	382	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	383	mempool_t *bio_integrity_pool;
	384	#endif
51d654e1 MP	385	mempool_t *bvec_pools[BIOVEC_NR_POOLS];
	386	};
	387
	388	struct biovec_slab {
	389	int nr_vecs;
	390	char *name;
	391	struct kmem_cache *slab;
	392	};
	393
	394	extern struct bio_set *fs_bio_set;
	395
	396	/*
	397	* a small number of entries is fine, not going to be performance critical.
	398	* basically we just need to survive
	399	*/
	400	#define BIO_SPLIT_ENTRIES 2
1da177e4 LT	401
	402	#ifdef CONFIG_HIGHMEM
	403	/*
	404	* remember to add offset! and never ever reenable interrupts between a
	405	* bvec_kmap_irq and bvec_kunmap_irq!!
	406	*
	407	* This function MUST be inlined - it plays with the CPU interrupt flags.
1da177e4	408	*/
c2d08dad	409	static inline char bvec_kmap_irq(struct bio_vec bvec, unsigned long *flags)
1da177e4 LT	410	{
	411	unsigned long addr;
	412
	413	/*
	414	* might not be a highmem page, but the preempt/irq count
	415	* balancing is a lot nicer this way
	416	*/
	417	local_irq_save(*flags);
	418	addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
	419
	420	BUG_ON(addr & ~PAGE_MASK);
	421
	422	return (char *) addr + bvec->bv_offset;
	423	}
	424
c2d08dad	425	static inline void bvec_kunmap_irq(char buffer, unsigned long flags)
1da177e4 LT	426	{
	427	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
	428
	429	kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
	430	local_irq_restore(*flags);
	431	}
	432
	433	#else
	434	#define bvec_kmap_irq(bvec, flags) (page_address((bvec)->bv_page) + (bvec)->bv_offset)
	435	#define bvec_kunmap_irq(buf, flags) do { *(flags) = 0; } while (0)
	436	#endif
	437
c2d08dad	438	static inline char __bio_kmap_irq(struct bio bio, unsigned short idx,
1da177e4 LT	439	unsigned long *flags)
	440	{
	441	return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
	442	}
	443	#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
	444
	445	#define bio_kmap_irq(bio, flags) \
	446	__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
	447	#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
	448
7a67f63b JA	449	/*
	450	* Check whether this bio carries any data or not. A NULL bio is allowed.
	451	*/
	452	static inline int bio_has_data(struct bio *bio)
	453	{
	454	return bio && bio->bi_io_vec != NULL;
	455	}
	456
7ba1ba12 MP	457	#if defined(CONFIG_BLK_DEV_INTEGRITY)
	458
	459	#define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
	460	#define bip_vec(bip) bip_vec_idx(bip, 0)
	461
	462	#define __bip_for_each_vec(bvl, bip, i, start_idx) \
	463	for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
	464	i < (bip)->bip_vcnt; \
	465	bvl++, i++)
	466
	467	#define bip_for_each_vec(bvl, bip, i) \
	468	__bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
	469
8deaf721	470	#define bio_integrity(bio) (bio->bi_integrity != NULL)
7ba1ba12 MP	471
	472	extern struct bio_integrity_payload bio_integrity_alloc_bioset(struct bio , gfp_t, unsigned int, struct bio_set *);
	473	extern struct bio_integrity_payload bio_integrity_alloc(struct bio , gfp_t, unsigned int);
	474	extern void bio_integrity_free(struct bio , struct bio_set );
	475	extern int bio_integrity_add_page(struct bio , struct page , unsigned int, unsigned int);
	476	extern int bio_integrity_enabled(struct bio *bio);
	477	extern int bio_integrity_set_tag(struct bio , void , unsigned int);
	478	extern int bio_integrity_get_tag(struct bio , void , unsigned int);
	479	extern int bio_integrity_prep(struct bio *);
	480	extern void bio_integrity_endio(struct bio *, int);
	481	extern void bio_integrity_advance(struct bio *, unsigned int);
	482	extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
	483	extern void bio_integrity_split(struct bio , struct bio_pair , int);
	484	extern int bio_integrity_clone(struct bio , struct bio , struct bio_set *);
	485	extern int bioset_integrity_create(struct bio_set *, int);
	486	extern void bioset_integrity_free(struct bio_set *);
	487	extern void bio_integrity_init_slab(void);
	488
	489	#else /* CONFIG_BLK_DEV_INTEGRITY */
	490
	491	#define bio_integrity(a) (0)
	492	#define bioset_integrity_create(a, b) (0)
	493	#define bio_integrity_prep(a) (0)
	494	#define bio_integrity_enabled(a) (0)
	495	#define bio_integrity_clone(a, b, c) (0)
	496	#define bioset_integrity_free(a) do { } while (0)
	497	#define bio_integrity_free(a, b) do { } while (0)
	498	#define bio_integrity_endio(a, b) do { } while (0)
	499	#define bio_integrity_advance(a, b) do { } while (0)
	500	#define bio_integrity_trim(a, b, c) do { } while (0)
	501	#define bio_integrity_split(a, b, c) do { } while (0)
	502	#define bio_integrity_set_tag(a, b, c) do { } while (0)
	503	#define bio_integrity_get_tag(a, b, c) do { } while (0)
	504	#define bio_integrity_init_slab(a) do { } while (0)
	505
	506	#endif /* CONFIG_BLK_DEV_INTEGRITY */
	507
02a5e0ac	508	#endif /* CONFIG_BLOCK */
1da177e4	509	#endif /* __LINUX_BIO_H */