1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 * Copyright (C) 2022 Christoph Hellwig.
5 */
6
7 #ifndef BTRFS_BIO_H
8 #define BTRFS_BIO_H
9
10 #include <linux/bio.h>
11 #include <linux/workqueue.h>
12 #include "tree-checker.h"
13
14 struct btrfs_bio;
15 struct btrfs_fs_info;
16
17 #define BTRFS_BIO_INLINE_CSUM_SIZE 64
18
19 /*
20 * Maximum number of sectors for a single bio to limit the size of the
21 * checksum array. This matches the number of bio_vecs per bio and thus the
22 * I/O size for buffered I/O.
23 */
24 #define BTRFS_MAX_BIO_SECTORS (256)
25
26 typedef void (*btrfs_bio_end_io_t)(struct btrfs_bio *bbio);
27
28 /*
29 * Highlevel btrfs I/O structure. It is allocated by btrfs_bio_alloc and
30 * passed to btrfs_submit_bio for mapping to the physical devices.
31 */
32 struct btrfs_bio {
33 /*
34 * Inode and offset into it that this I/O operates on.
35 * Only set for data I/O.
36 */
37 struct btrfs_inode *inode;
38 u64 file_offset;
39
40 union {
41 /*
42 * For data reads: checksumming and original I/O information.
43 * (for internal use in the btrfs_submit_bio machinery only)
44 */
45 struct {
46 u8 *csum;
47 u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
48 struct bvec_iter saved_iter;
49 };
50
51 /*
52 * For data writes:
53 * - ordered extent covering the bio
54 * - pointer to the checksums for this bio
55 * - original physical address from the allocator
56 * (for zone append only)
57 */
58 struct {
59 struct btrfs_ordered_extent *ordered;
60 struct btrfs_ordered_sum *sums;
61 u64 orig_physical;
62 };
63
64 /* For metadata reads: parentness verification. */
65 struct btrfs_tree_parent_check parent_check;
66 };
67
68 /* End I/O information supplied to btrfs_bio_alloc */
69 btrfs_bio_end_io_t end_io;
70 void *private;
71
72 /* For internal use in read end I/O handling */
73 unsigned int mirror_num;
74 atomic_t pending_ios;
75 struct work_struct end_io_work;
76
77 /* File system that this I/O operates on. */
78 struct btrfs_fs_info *fs_info;
79
80 /*
81 * This member must come last, bio_alloc_bioset will allocate enough
82 * bytes for entire btrfs_bio but relies on bio being last.
83 */
84 struct bio bio;
85 };
86
btrfs_bio(struct bio * bio)87 static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
88 {
89 return container_of(bio, struct btrfs_bio, bio);
90 }
91
92 int __init btrfs_bioset_init(void);
93 void __cold btrfs_bioset_exit(void);
94
95 void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_fs_info *fs_info,
96 btrfs_bio_end_io_t end_io, void *private);
97 struct btrfs_bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
98 struct btrfs_fs_info *fs_info,
99 btrfs_bio_end_io_t end_io, void *private);
100 void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status);
101
102 /* Submit using blkcg_punt_bio_submit. */
103 #define REQ_BTRFS_CGROUP_PUNT REQ_FS_PRIVATE
104
105 void btrfs_submit_bio(struct btrfs_bio *bbio, int mirror_num);
106 void btrfs_submit_repair_write(struct btrfs_bio *bbio, int mirror_num, bool dev_replace);
107 int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
108 u64 length, u64 logical, struct page *page,
109 unsigned int pg_offset, int mirror_num);
110
111 #endif
112