android_kernel_motorola_sm6225/drivers/md/dm-bio-list.h
Heinz Mauelshagen 0ba699347e dm: bio list helpers
More bio_list helper functions for new targets (including dm-delay and
dm-loop) to manipulate lists of bios.

Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Bryn Reeves <breeves@redhat.com>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:47 -07:00

111 lines
1.8 KiB
C

/*
* Copyright (C) 2004 Red Hat UK Ltd.
*
* This file is released under the GPL.
*/
#ifndef DM_BIO_LIST_H
#define DM_BIO_LIST_H
#include <linux/bio.h>
#include <linux/prefetch.h>
struct bio_list {
struct bio *head;
struct bio *tail;
};
static inline int bio_list_empty(const struct bio_list *bl)
{
return bl->head == NULL;
}
#define BIO_LIST_INIT { .head = NULL, .tail = NULL }
#define BIO_LIST(bl) \
struct bio_list bl = BIO_LIST_INIT
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 && ({ prefetch(bio->bi_next); 1; }); \
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_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_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;
}
#endif