diff options
Diffstat (limited to 'drivers/md/dm-bio-list.h')
-rw-r--r-- | drivers/md/dm-bio-list.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/drivers/md/dm-bio-list.h b/drivers/md/dm-bio-list.h new file mode 100644 index 0000000..d4509be --- /dev/null +++ b/drivers/md/dm-bio-list.h @@ -0,0 +1,107 @@ +/* + * 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> + +#ifdef CONFIG_BLOCK + +struct bio_list { + struct bio *head; + struct bio *tail; +}; + +static inline int bio_list_empty(const struct bio_list *bl) +{ + return bl->head == NULL; +} + +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; 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 /* CONFIG_BLOCK */ +#endif |