0ba699347e
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>
111 lines
1.8 KiB
C
111 lines
1.8 KiB
C
/*
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* Copyright (C) 2004 Red Hat UK Ltd.
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*
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* This file is released under the GPL.
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*/
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#ifndef DM_BIO_LIST_H
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#define DM_BIO_LIST_H
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#include <linux/bio.h>
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#include <linux/prefetch.h>
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struct bio_list {
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struct bio *head;
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struct bio *tail;
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};
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static inline int bio_list_empty(const struct bio_list *bl)
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{
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return bl->head == NULL;
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}
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#define BIO_LIST_INIT { .head = NULL, .tail = NULL }
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#define BIO_LIST(bl) \
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struct bio_list bl = BIO_LIST_INIT
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static inline void bio_list_init(struct bio_list *bl)
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{
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bl->head = bl->tail = NULL;
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}
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#define bio_list_for_each(bio, bl) \
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for (bio = (bl)->head; bio && ({ prefetch(bio->bi_next); 1; }); \
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bio = bio->bi_next)
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static inline unsigned bio_list_size(const struct bio_list *bl)
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{
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unsigned sz = 0;
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struct bio *bio;
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bio_list_for_each(bio, bl)
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sz++;
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return sz;
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}
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static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
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{
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bio->bi_next = NULL;
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if (bl->tail)
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bl->tail->bi_next = bio;
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else
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bl->head = bio;
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bl->tail = bio;
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}
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static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
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{
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if (!bl2->head)
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return;
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if (bl->tail)
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bl->tail->bi_next = bl2->head;
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else
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bl->head = bl2->head;
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bl->tail = bl2->tail;
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}
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static inline void bio_list_merge_head(struct bio_list *bl,
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struct bio_list *bl2)
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{
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if (!bl2->head)
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return;
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if (bl->head)
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bl2->tail->bi_next = bl->head;
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else
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bl->tail = bl2->tail;
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bl->head = bl2->head;
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}
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static inline struct bio *bio_list_pop(struct bio_list *bl)
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{
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struct bio *bio = bl->head;
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if (bio) {
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bl->head = bl->head->bi_next;
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if (!bl->head)
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bl->tail = NULL;
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bio->bi_next = NULL;
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}
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return bio;
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}
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static inline struct bio *bio_list_get(struct bio_list *bl)
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{
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struct bio *bio = bl->head;
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bl->head = bl->tail = NULL;
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return bio;
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}
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#endif
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