xref: /openbmc/linux/fs/btrfs/bio.h (revision cbfce4c7fbde23cc8bcba44822a58c728caf6ec9)
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 		 * - pointer to the checksums for this bio
54 		 * - original physical address from the allocator
55 		 *   (for zone append only)
56 		 */
57 		struct {
58 			struct btrfs_ordered_sum *sums;
59 			u64 orig_physical;
60 		};
61 
62 		/* For metadata reads: parentness verification. */
63 		struct btrfs_tree_parent_check parent_check;
64 	};
65 
66 	/* End I/O information supplied to btrfs_bio_alloc */
67 	btrfs_bio_end_io_t end_io;
68 	void *private;
69 
70 	/* For internal use in read end I/O handling */
71 	unsigned int mirror_num;
72 	atomic_t pending_ios;
73 	struct work_struct end_io_work;
74 
75 	/* File system that this I/O operates on. */
76 	struct btrfs_fs_info *fs_info;
77 
78 	/*
79 	 * This member must come last, bio_alloc_bioset will allocate enough
80 	 * bytes for entire btrfs_bio but relies on bio being last.
81 	 */
82 	struct bio bio;
83 };
84 
85 static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
86 {
87 	return container_of(bio, struct btrfs_bio, bio);
88 }
89 
90 int __init btrfs_bioset_init(void);
91 void __cold btrfs_bioset_exit(void);
92 
93 void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_fs_info *fs_info,
94 		    btrfs_bio_end_io_t end_io, void *private);
95 struct btrfs_bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
96 				  struct btrfs_fs_info *fs_info,
97 				  btrfs_bio_end_io_t end_io, void *private);
98 
99 static inline void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status)
100 {
101 	bbio->bio.bi_status = status;
102 	bbio->end_io(bbio);
103 }
104 
105 /* Bio only refers to one ordered extent. */
106 #define REQ_BTRFS_ONE_ORDERED			REQ_DRV
107 
108 /* Submit using blkcg_punt_bio_submit. */
109 #define REQ_BTRFS_CGROUP_PUNT			REQ_FS_PRIVATE
110 
111 void btrfs_submit_bio(struct btrfs_bio *bbio, int mirror_num);
112 void btrfs_submit_repair_write(struct btrfs_bio *bbio, int mirror_num, bool dev_replace);
113 int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
114 			    u64 length, u64 logical, struct page *page,
115 			    unsigned int pg_offset, int mirror_num);
116 
117 #endif
118