fs/btrfs/bio.h

   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_bbio() 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_bbio() 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_bbio(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