550 lines
16 KiB
C
550 lines
16 KiB
C
/*
|
|
* 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>
|
|
|
|
/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
|
|
#include <linux/blk_types.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)
|
|
|
|
/*
|
|
* 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_empty_barrier(bio) \
|
|
((bio->bi_rw & REQ_HARDBARRIER) && \
|
|
!bio_has_data(bio) && \
|
|
!(bio->bi_rw & REQ_DISCARD))
|
|
|
|
static inline unsigned int bio_cur_bytes(struct bio *bio)
|
|
{
|
|
if (bio->bi_vcnt)
|
|
return bio_iovec(bio)->bv_len;
|
|
else /* dataless requests such as discard */
|
|
return bio->bi_size;
|
|
}
|
|
|
|
static inline void *bio_data(struct bio *bio)
|
|
{
|
|
if (bio->bi_vcnt)
|
|
return page_address(bio_page(bio)) + bio_offset(bio);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static inline int bio_has_allocated_vec(struct bio *bio)
|
|
{
|
|
return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
|
|
/* Default implementation of BIOVEC_PHYS_MERGEABLE */
|
|
#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
|
|
((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
|
|
|
|
/*
|
|
* allow arch override, for eg virtualized architectures (put in asm/io.h)
|
|
*/
|
|
#ifndef BIOVEC_PHYS_MERGEABLE
|
|
#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
|
|
__BIOVEC_PHYS_MERGEABLE(vec1, 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, queue_segment_boundary((q)))
|
|
#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 */
|
|
|
|
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 */
|
|
|
|
unsigned int bip_size;
|
|
|
|
unsigned short bip_slab; /* slab the bip 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 */
|
|
struct bio_vec bip_vec[0]; /* embedded bvec array */
|
|
};
|
|
#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(unsigned int, unsigned 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);
|
|
|
|
#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
|
|
# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
|
|
#endif
|
|
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
|
|
extern void bio_flush_dcache_pages(struct bio *bi);
|
|
#else
|
|
static inline void bio_flush_dcache_pages(struct bio *bi)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
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 void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
|
|
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
|
|
#define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
|
|
|
|
struct bio_set {
|
|
struct kmem_cache *bio_slab;
|
|
unsigned int front_pad;
|
|
|
|
mempool_t *bio_pool;
|
|
#if defined(CONFIG_BLK_DEV_INTEGRITY)
|
|
mempool_t *bio_integrity_pool;
|
|
#endif
|
|
mempool_t *bvec_pool;
|
|
};
|
|
|
|
struct biovec_slab {
|
|
int nr_vecs;
|
|
char *name;
|
|
struct kmem_cache *slab;
|
|
};
|
|
|
|
extern struct bio_set *fs_bio_set;
|
|
extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
|
|
|
|
/*
|
|
* 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 never ever reenable interrupts between a bvec_kmap_irq and
|
|
* bvec_kunmap_irq!
|
|
*/
|
|
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
|
|
static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
|
|
{
|
|
return page_address(bvec->bv_page) + bvec->bv_offset;
|
|
}
|
|
|
|
static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
|
|
{
|
|
*flags = 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;
|
|
}
|
|
|
|
/*
|
|
* BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
|
|
*
|
|
* A bio_list anchors a singly-linked list of bios chained through the bi_next
|
|
* member of the bio. The bio_list also caches the last list member to allow
|
|
* fast access to the tail.
|
|
*/
|
|
struct bio_list {
|
|
struct bio *head;
|
|
struct bio *tail;
|
|
};
|
|
|
|
static inline int bio_list_empty(const struct bio_list *bl)
|
|
{
|
|
return bl->head == NULL;
|
|
}
|
|
|
|
static inline void bio_list_init(struct bio_list *bl)
|
|
{
|
|
bl->head = bl->tail = NULL;
|
|
}
|
|
|
|
#define bio_list_for_each(bio, bl) \
|
|
for (bio = (bl)->head; bio; bio = bio->bi_next)
|
|
|
|
static inline unsigned bio_list_size(const struct bio_list *bl)
|
|
{
|
|
unsigned sz = 0;
|
|
struct bio *bio;
|
|
|
|
bio_list_for_each(bio, bl)
|
|
sz++;
|
|
|
|
return sz;
|
|
}
|
|
|
|
static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
|
|
{
|
|
bio->bi_next = NULL;
|
|
|
|
if (bl->tail)
|
|
bl->tail->bi_next = bio;
|
|
else
|
|
bl->head = bio;
|
|
|
|
bl->tail = bio;
|
|
}
|
|
|
|
static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
|
|
{
|
|
bio->bi_next = bl->head;
|
|
|
|
bl->head = bio;
|
|
|
|
if (!bl->tail)
|
|
bl->tail = bio;
|
|
}
|
|
|
|
static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
|
|
{
|
|
if (!bl2->head)
|
|
return;
|
|
|
|
if (bl->tail)
|
|
bl->tail->bi_next = bl2->head;
|
|
else
|
|
bl->head = bl2->head;
|
|
|
|
bl->tail = bl2->tail;
|
|
}
|
|
|
|
static inline void bio_list_merge_head(struct bio_list *bl,
|
|
struct bio_list *bl2)
|
|
{
|
|
if (!bl2->head)
|
|
return;
|
|
|
|
if (bl->head)
|
|
bl2->tail->bi_next = bl->head;
|
|
else
|
|
bl->tail = bl2->tail;
|
|
|
|
bl->head = bl2->head;
|
|
}
|
|
|
|
static inline struct bio *bio_list_peek(struct bio_list *bl)
|
|
{
|
|
return bl->head;
|
|
}
|
|
|
|
static inline struct bio *bio_list_pop(struct bio_list *bl)
|
|
{
|
|
struct bio *bio = bl->head;
|
|
|
|
if (bio) {
|
|
bl->head = bl->head->bi_next;
|
|
if (!bl->head)
|
|
bl->tail = NULL;
|
|
|
|
bio->bi_next = NULL;
|
|
}
|
|
|
|
return bio;
|
|
}
|
|
|
|
static inline struct bio *bio_list_get(struct bio_list *bl)
|
|
{
|
|
struct bio *bio = bl->head;
|
|
|
|
bl->head = bl->tail = NULL;
|
|
|
|
return bio;
|
|
}
|
|
|
|
#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_for_each_integrity_vec(_bvl, _bio, _iter) \
|
|
for_each_bio(_bio) \
|
|
bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
|
|
|
|
#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 *, gfp_t, 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(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, d) (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(a) do { } while (0)
|
|
|
|
#endif /* CONFIG_BLK_DEV_INTEGRITY */
|
|
|
|
#endif /* CONFIG_BLOCK */
|
|
#endif /* __LINUX_BIO_H */
|