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
 14struct btrfs_bio;
 15struct 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
 26typedef 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 */
 32struct 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		 * - ordered extent covering the bio
 54		 * - pointer to the checksums for this bio
 55		 * - original physical address from the allocator
 56		 *   (for zone append only)
 57		 */
 58		struct {
 59			struct btrfs_ordered_extent *ordered;
 60			struct btrfs_ordered_sum *sums;
 61			u64 orig_physical;
 62		};
 63
 64		/* For metadata reads: parentness verification. */
 65		struct btrfs_tree_parent_check parent_check;
 66	};
 67
 68	/* End I/O information supplied to btrfs_bio_alloc */
 69	btrfs_bio_end_io_t end_io;
 70	void *private;
 71
 72	/* For internal use in read end I/O handling */
 73	unsigned int mirror_num;
 74	atomic_t pending_ios;
 75	struct work_struct end_io_work;
 76
 77	/* File system that this I/O operates on. */
 78	struct btrfs_fs_info *fs_info;
 79
 80	/*
 81	 * This member must come last, bio_alloc_bioset will allocate enough
 82	 * bytes for entire btrfs_bio but relies on bio being last.
 83	 */
 84	struct bio bio;
 85};
 86
 87static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
 88{
 89	return container_of(bio, struct btrfs_bio, bio);
 90}
 91
 92int __init btrfs_bioset_init(void);
 93void __cold btrfs_bioset_exit(void);
 94
 95void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_fs_info *fs_info,
 96		    btrfs_bio_end_io_t end_io, void *private);
 97struct btrfs_bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
 98				  struct btrfs_fs_info *fs_info,
 99				  btrfs_bio_end_io_t end_io, void *private);
100void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status);
101
102/* Submit using blkcg_punt_bio_submit. */
103#define REQ_BTRFS_CGROUP_PUNT			REQ_FS_PRIVATE
104
105void btrfs_submit_bio(struct btrfs_bio *bbio, int mirror_num);
106void btrfs_submit_repair_write(struct btrfs_bio *bbio, int mirror_num, bool dev_replace);
107int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
108			    u64 length, u64 logical, struct folio *folio,
109			    unsigned int folio_offset, int mirror_num);
110
111#endif