xref: /linux/fs/btrfs/bio.h (revision 8b40a46966d294bc64bad0feb13d3304fde738f2)
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 
15 struct btrfs_bio;
16 struct btrfs_fs_info;
17 struct 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 
28 typedef 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  */
34 struct 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 
89 static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
90 {
91 	return container_of(bio, struct btrfs_bio, bio);
92 }
93 
94 int __init btrfs_bioset_init(void);
95 void __cold btrfs_bioset_exit(void);
96 
97 void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_fs_info *fs_info,
98 		    btrfs_bio_end_io_t end_io, void *private);
99 struct 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);
102 void 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 
107 void btrfs_submit_bio(struct btrfs_bio *bbio, int mirror_num);
108 void btrfs_submit_repair_write(struct btrfs_bio *bbio, int mirror_num, bool dev_replace);
109 int 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