xref: /kernel/linux/linux-6.6/fs/btrfs/bio.h (revision 62306a36)
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
14struct btrfs_bio;
15struct 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
26typedef 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 */
32struct 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
87static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
88{
89	return container_of(bio, struct btrfs_bio, bio);
90}
91
92int __init btrfs_bioset_init(void);
93void __cold btrfs_bioset_exit(void);
94
95void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_fs_info *fs_info,
96		    btrfs_bio_end_io_t end_io, void *private);
97struct 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);
100void 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
105void btrfs_submit_bio(struct btrfs_bio *bbio, int mirror_num);
106void btrfs_submit_repair_write(struct btrfs_bio *bbio, int mirror_num, bool dev_replace);
107int 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