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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 #ifdef CONFIG_BLOCK
13 
14 struct bio_list {
15 	struct bio *head;
16 	struct bio *tail;
17 };
18 
bio_list_empty(const struct bio_list * bl)19 static inline int bio_list_empty(const struct bio_list *bl)
20 {
21 	return bl->head == NULL;
22 }
23 
bio_list_init(struct bio_list * bl)24 static inline void bio_list_init(struct bio_list *bl)
25 {
26 	bl->head = bl->tail = NULL;
27 }
28 
29 #define bio_list_for_each(bio, bl) \
30 	for (bio = (bl)->head; bio; bio = bio->bi_next)
31 
bio_list_size(const struct bio_list * bl)32 static inline unsigned bio_list_size(const struct bio_list *bl)
33 {
34 	unsigned sz = 0;
35 	struct bio *bio;
36 
37 	bio_list_for_each(bio, bl)
38 		sz++;
39 
40 	return sz;
41 }
42 
bio_list_add(struct bio_list * bl,struct bio * bio)43 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
44 {
45 	bio->bi_next = NULL;
46 
47 	if (bl->tail)
48 		bl->tail->bi_next = bio;
49 	else
50 		bl->head = bio;
51 
52 	bl->tail = bio;
53 }
54 
bio_list_merge(struct bio_list * bl,struct bio_list * bl2)55 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
56 {
57 	if (!bl2->head)
58 		return;
59 
60 	if (bl->tail)
61 		bl->tail->bi_next = bl2->head;
62 	else
63 		bl->head = bl2->head;
64 
65 	bl->tail = bl2->tail;
66 }
67 
bio_list_merge_head(struct bio_list * bl,struct bio_list * bl2)68 static inline void bio_list_merge_head(struct bio_list *bl,
69 				       struct bio_list *bl2)
70 {
71 	if (!bl2->head)
72 		return;
73 
74 	if (bl->head)
75 		bl2->tail->bi_next = bl->head;
76 	else
77 		bl->tail = bl2->tail;
78 
79 	bl->head = bl2->head;
80 }
81 
bio_list_pop(struct bio_list * bl)82 static inline struct bio *bio_list_pop(struct bio_list *bl)
83 {
84 	struct bio *bio = bl->head;
85 
86 	if (bio) {
87 		bl->head = bl->head->bi_next;
88 		if (!bl->head)
89 			bl->tail = NULL;
90 
91 		bio->bi_next = NULL;
92 	}
93 
94 	return bio;
95 }
96 
bio_list_get(struct bio_list * bl)97 static inline struct bio *bio_list_get(struct bio_list *bl)
98 {
99 	struct bio *bio = bl->head;
100 
101 	bl->head = bl->tail = NULL;
102 
103 	return bio;
104 }
105 
106 #endif /* CONFIG_BLOCK */
107 #endif
108