xref: /linux/fs/btrfs/bio.h (revision 6f7e6393d1ce636bb7ec77a7fe7b77458fddf701)
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 typedef void (*btrfs_bio_end_io_t)(struct btrfs_bio *bbio);
22 
23 /*
24  * Highlevel btrfs I/O structure.  It is allocated by btrfs_bio_alloc and
25  * passed to btrfs_submit_bbio() for mapping to the physical devices.
26  */
27 struct btrfs_bio {
28 	/*
29 	 * Inode and offset into it that this I/O operates on.
30 	 *
31 	 * If the inode is a data one, csum verification and read-repair
32 	 * will be done automatically.
33 	 * If the inode is a metadata one, everything is handled by the caller.
34 	 */
35 	struct btrfs_inode *inode;
36 	u64 file_offset;
37 
38 	union {
39 		/*
40 		 * For data reads: checksumming and original I/O information.
41 		 * (for internal use in the btrfs_submit_bbio() machinery only)
42 		 */
43 		struct {
44 			u8 *csum;
45 			u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
46 			struct bvec_iter saved_iter;
47 		};
48 
49 		/*
50 		 * For data writes:
51 		 * - ordered extent covering the bio
52 		 * - pointer to the checksums for this bio
53 		 * - original physical address from the allocator
54 		 *   (for zone append only)
55 		 * - original logical address, used for checksumming fscrypt bios
56 		 */
57 		struct {
58 			struct btrfs_ordered_extent *ordered;
59 			struct btrfs_ordered_sum *sums;
60 			struct work_struct csum_work;
61 			struct completion csum_done;
62 			struct bvec_iter csum_saved_iter;
63 			u64 orig_physical;
64 			u64 orig_logical;
65 		};
66 
67 		/* For metadata reads: parentness verification. */
68 		struct btrfs_tree_parent_check parent_check;
69 	};
70 
71 	/* For internal use in read end I/O handling */
72 	struct work_struct end_io_work;
73 
74 	/* End I/O information supplied to btrfs_bio_alloc */
75 	btrfs_bio_end_io_t end_io;
76 	void *private;
77 
78 	atomic_t pending_ios;
79 	u16 mirror_num;
80 
81 	/* Save the first error status of split bio. */
82 	blk_status_t status;
83 
84 	/* Use the commit root to look up csums (data read bio only). */
85 	bool csum_search_commit_root:1;
86 
87 	/*
88 	 * Since scrub will reuse btree inode, we need this flag to distinguish
89 	 * scrub bios.
90 	 */
91 	bool is_scrub:1;
92 
93 	/* Whether the bio is coming from copy_remapped_data_io(). */
94 	bool is_remap:1;
95 
96 	/* Whether the csum generation for data write is async. */
97 	bool async_csum:1;
98 
99 	/* Whether the bio is written using zone append. */
100 	bool can_use_append:1;
101 
102 	/*
103 	 * This member must come last, bio_alloc_bioset will allocate enough
104 	 * bytes for entire btrfs_bio but relies on bio being last.
105 	 */
106 	struct bio bio;
107 };
108 
109 static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
110 {
111 	return container_of(bio, struct btrfs_bio, bio);
112 }
113 
114 int __init btrfs_bioset_init(void);
115 void __cold btrfs_bioset_exit(void);
116 
117 void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_inode *inode, u64 file_offset,
118 		    btrfs_bio_end_io_t end_io, void *private);
119 struct btrfs_bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
120 				  struct btrfs_inode *inode, u64 file_offset,
121 				  btrfs_bio_end_io_t end_io, void *private);
122 void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status);
123 
124 /* Submit using blkcg_punt_bio_submit. */
125 #define REQ_BTRFS_CGROUP_PUNT			REQ_FS_PRIVATE
126 
127 void btrfs_submit_bbio(struct btrfs_bio *bbio, int mirror_num);
128 void btrfs_submit_repair_write(struct btrfs_bio *bbio, int mirror_num, bool dev_replace);
129 int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 fileoff,
130 			    u32 length, u64 logical, const phys_addr_t paddrs[],
131 			    unsigned int step, int mirror_num);
132 
133 #endif
134