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 (!bl2->head)
  37                 return;
  38
  39         if (bl->tail)
  40                 bl->tail->bi_next = bl2->head;
  41         else
  42                 bl->head = bl2->head;
  43
  44         bl->tail = bl2->tail;
  45 }
  46
  47 static inline struct bio *bio_list_pop(struct bio_list *bl)
  48 {
  49         struct bio *bio = bl->head;
  50
  51         if (bio) {
  52                 bl->head = bl->head->bi_next;
  53                 if (!bl->head)
  54                         bl->tail = NULL;
  55
  56                 bio->bi_next = NULL;
  57         }
  58
  59         return bio;
  60 }
  61
  62 static inline struct bio *bio_list_get(struct bio_list *bl)
  63 {
  64         struct bio *bio = bl->head;
  65
  66         bl->head = bl->tail = NULL;
  67
  68         return bio;
  69 }
  70
  71 #endif