drivers/md/dm-bio-list.h

   1 /*
   2  * Copyright (C) 2004 Red Hat UK Ltd.
   3  *
   4  * This file is released under the GPL.
   5  */
   6
   7 #ifndef DM_BIO_LIST_H
   8 #define DM_BIO_LIST_H
   9
  10 #include <linux/bio.h>
  11
  12 struct bio_list {
  13         struct bio *head;
  14         struct bio *tail;
  15 };
  16
  17 static inline void bio_list_init(struct bio_list *bl)
  18 {
  19         bl->head = bl->tail = NULL;
  20 }
  21
  22 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
  23 {
  24         bio->bi_next = NULL;
  25
  26         if (bl->tail)
  27                 bl->tail->bi_next = bio;
  28         else
  29                 bl->head = bio;
  30
  31         bl->tail = bio;
  32 }
  33
  34 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
  35 {
  36         if (bl->tail)
  37                 bl->tail->bi_next = bl2->head;
  38         else
  39                 bl->head = bl2->head;
  40
  41         bl->tail = bl2->tail;
  42 }
  43
  44 static inline struct bio *bio_list_pop(struct bio_list *bl)
  45 {
  46         struct bio *bio = bl->head;
  47
  48         if (bio) {
  49                 bl->head = bl->head->bi_next;
  50                 if (!bl->head)
  51                         bl->tail = NULL;
  52
  53                 bio->bi_next = NULL;
  54         }
  55
  56         return bio;
  57 }
  58
  59 static inline struct bio *bio_list_get(struct bio_list *bl)
  60 {
  61         struct bio *bio = bl->head;
  62
  63         bl->head = bl->tail = NULL;
  64
  65         return bio;
  66 }
  67
  68 #endif