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/types.h>
11#include <linux/bio.h>
12#include <linux/workqueue.h>
13#include "tree-checker.h"
14
15struct btrfs_bio;
16struct btrfs_fs_info;
17struct btrfs_inode;
18
19#define BTRFS_BIO_INLINE_CSUM_SIZE	64
20
21/*
22 * Maximum number of sectors for a single bio to limit the size of the
23 * checksum array.  This matches the number of bio_vecs per bio and thus the
24 * I/O size for buffered I/O.
25 */
26#define BTRFS_MAX_BIO_SECTORS		(256)
27
28typedef void (*btrfs_bio_end_io_t)(struct btrfs_bio *bbio);
29
30/*
31 * Highlevel btrfs I/O structure.  It is allocated by btrfs_bio_alloc and
32 * passed to btrfs_submit_bio for mapping to the physical devices.
33 */
34struct btrfs_bio {
35	/*
36	 * Inode and offset into it that this I/O operates on.
37	 * Only set for data I/O.
38	 */
39	struct btrfs_inode *inode;
40	u64 file_offset;
41
42	union {
43		/*
44		 * For data reads: checksumming and original I/O information.
45		 * (for internal use in the btrfs_submit_bio machinery only)
46		 */
47		struct {
48			u8 *csum;
49			u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
50			struct bvec_iter saved_iter;
51		};
52
53		/*
54		 * For data writes:
55		 * - ordered extent covering the bio
56		 * - pointer to the checksums for this bio
57		 * - original physical address from the allocator
58		 *   (for zone append only)
59		 */
60		struct {
61			struct btrfs_ordered_extent *ordered;
62			struct btrfs_ordered_sum *sums;
63			u64 orig_physical;
64		};
65
66		/* For metadata reads: parentness verification. */
67		struct btrfs_tree_parent_check parent_check;
68	};
69
70	/* End I/O information supplied to btrfs_bio_alloc */
71	btrfs_bio_end_io_t end_io;
72	void *private;
73
74	/* For internal use in read end I/O handling */
75	unsigned int mirror_num;
76	atomic_t pending_ios;
77	struct work_struct end_io_work;
78
79	/* File system that this I/O operates on. */
80	struct btrfs_fs_info *fs_info;
81
82	/*
83	 * This member must come last, bio_alloc_bioset will allocate enough
84	 * bytes for entire btrfs_bio but relies on bio being last.
85	 */
86	struct bio bio;
87};
88
89static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
90{
91	return container_of(bio, struct btrfs_bio, bio);
92}
93
94int __init btrfs_bioset_init(void);
95void __cold btrfs_bioset_exit(void);
96
97void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_fs_info *fs_info,
98		    btrfs_bio_end_io_t end_io, void *private);
99struct btrfs_bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
100				  struct btrfs_fs_info *fs_info,
101				  btrfs_bio_end_io_t end_io, void *private);
102void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status);
103
104/* Submit using blkcg_punt_bio_submit. */
105#define REQ_BTRFS_CGROUP_PUNT			REQ_FS_PRIVATE
106
107void btrfs_submit_bio(struct btrfs_bio *bbio, int mirror_num);
108void btrfs_submit_repair_write(struct btrfs_bio *bbio, int mirror_num, bool dev_replace);
109int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
110			    u64 length, u64 logical, struct folio *folio,
111			    unsigned int folio_offset, int mirror_num);
112
113#endif
114