xref: /linux/fs/btrfs/bio.h (revision 06fc46cae9c40f8b6a9525a26cc96bca58ae25c0)
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 	/* Inode and offset into it that this I/O operates on. */
34 	struct btrfs_inode *inode;
35 	u64 file_offset;
36 
37 	union {
38 		/*
39 		 * Data checksumming and original I/O information for internal
40 		 * use in the btrfs_submit_bio machinery.
41 		 */
42 		struct {
43 			u8 *csum;
44 			u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
45 			struct bvec_iter saved_iter;
46 		};
47 
48 		/* For metadata parentness verification. */
49 		struct btrfs_tree_parent_check parent_check;
50 	};
51 
52 	/* End I/O information supplied to btrfs_bio_alloc */
53 	btrfs_bio_end_io_t end_io;
54 	void *private;
55 
56 	/* For internal use in read end I/O handling */
57 	unsigned int mirror_num;
58 	atomic_t pending_ios;
59 	struct work_struct end_io_work;
60 
61 	/*
62 	 * This member must come last, bio_alloc_bioset will allocate enough
63 	 * bytes for entire btrfs_bio but relies on bio being last.
64 	 */
65 	struct bio bio;
66 };
67 
68 static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
69 {
70 	return container_of(bio, struct btrfs_bio, bio);
71 }
72 
73 int __init btrfs_bioset_init(void);
74 void __cold btrfs_bioset_exit(void);
75 
76 void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_inode *inode,
77 		    btrfs_bio_end_io_t end_io, void *private);
78 struct bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
79 			    struct btrfs_inode *inode,
80 			    btrfs_bio_end_io_t end_io, void *private);
81 
82 static inline void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status)
83 {
84 	bbio->bio.bi_status = status;
85 	bbio->end_io(bbio);
86 }
87 
88 /* Bio only refers to one ordered extent. */
89 #define REQ_BTRFS_ONE_ORDERED			REQ_DRV
90 
91 void btrfs_submit_bio(struct bio *bio, int mirror_num);
92 int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
93 			    u64 length, u64 logical, struct page *page,
94 			    unsigned int pg_offset, int mirror_num);
95 
96 #endif
97