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 void bio_list_merge_head(struct bio_list *bl,
  48                                        struct bio_list *bl2)
  49 {
  50         if (!bl2->head)
  51                 return;
  52
  53         if (bl->head)
  54                 bl2->tail->bi_next = bl->head;
  55         else
  56                 bl->tail = bl2->tail;
  57
  58         bl->head = bl2->head;
  59 }
  60
  61 static inline struct bio *bio_list_pop(struct bio_list *bl)
  62 {
  63         struct bio *bio = bl->head;
  64
  65         if (bio) {
  66                 bl->head = bl->head->bi_next;
  67                 if (!bl->head)
  68                         bl->tail = NULL;
  69
  70                 bio->bi_next = NULL;
  71         }
  72
  73         return bio;
  74 }
  75
  76 static inline struct bio *bio_list_get(struct bio_list *bl)
  77 {
  78         struct bio *bio = bl->head;
  79
  80         bl->head = bl->tail = NULL;
  81
  82         return bio;
  83 }
  84
  85 #endif