/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 * Copyright (C) 2022 Christoph Hellwig.
 */

#ifndef BTRFS_BIO_H
#define BTRFS_BIO_H

#include <linux/types.h>
#include <linux/bio.h>
#include <linux/workqueue.h>
#include "tree-checker.h"

struct btrfs_bio;
struct btrfs_fs_info;
struct btrfs_inode;

#define BTRFS_BIO_INLINE_CSUM_SIZE      64

typedef void (*btrfs_bio_end_io_t)(struct btrfs_bio *bbio);

/*
 * Highlevel btrfs I/O structure.  It is allocated by btrfs_bio_alloc and
 * passed to btrfs_submit_bbio() for mapping to the physical devices.
 */
struct btrfs_bio {
        /*
         * Inode and offset into it that this I/O operates on.
         *
         * If the inode is a data one, csum verification and read-repair
         * will be done automatically.
         * If the inode is a metadata one, everything is handled by the caller.
         */
        struct btrfs_inode *inode;
        u64 file_offset;

        union {
                /*
                 * For data reads: checksumming and original I/O information.
                 * (for internal use in the btrfs_submit_bbio() machinery only)
                 */
                struct {
                        u8 *csum;
                        u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
                        struct bvec_iter saved_iter;
                };

                /*
                 * For data writes:
                 * - ordered extent covering the bio
                 * - pointer to the checksums for this bio
                 * - original physical address from the allocator
                 *   (for zone append only)
                 * - original logical address, used for checksumming fscrypt bios
                 */
                struct {
                        struct btrfs_ordered_extent *ordered;
                        struct btrfs_ordered_sum *sums;
                        struct work_struct csum_work;
                        struct completion csum_done;
                        struct bvec_iter csum_saved_iter;
                        u64 orig_physical;
                        u64 orig_logical;
                };

                /* For metadata reads: parentness verification. */
                struct btrfs_tree_parent_check parent_check;
        };

        /* For internal use in read end I/O handling */
        struct work_struct end_io_work;

        /* End I/O information supplied to btrfs_bio_alloc */
        btrfs_bio_end_io_t end_io;
        void *private;

        atomic_t pending_ios;
        u16 mirror_num;

        /* Save the first error status of split bio. */
        blk_status_t status;

        /* Use the commit root to look up csums (data read bio only). */
        bool csum_search_commit_root:1;

        /*
         * Since scrub will reuse btree inode, we need this flag to distinguish
         * scrub bios.
         */
        bool is_scrub:1;

        /* Whether the bio is coming from copy_remapped_data_io(). */
        bool is_remap:1;

        /* Whether the csum generation for data write is async. */
        bool async_csum:1;

        /* Whether the bio is written using zone append. */
        bool can_use_append:1;

        /*
         * This member must come last, bio_alloc_bioset will allocate enough
         * bytes for entire btrfs_bio but relies on bio being last.
         */
        struct bio bio;
};

static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
{
        return container_of(bio, struct btrfs_bio, bio);
}

int __init btrfs_bioset_init(void);
void __cold btrfs_bioset_exit(void);

void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_inode *inode, u64 file_offset,
                    btrfs_bio_end_io_t end_io, void *private);
struct btrfs_bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
                                  struct btrfs_inode *inode, u64 file_offset,
                                  btrfs_bio_end_io_t end_io, void *private);
void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status);

/* Submit using blkcg_punt_bio_submit. */
#define REQ_BTRFS_CGROUP_PUNT                   REQ_FS_PRIVATE

void btrfs_submit_bbio(struct btrfs_bio *bbio, int mirror_num);
void btrfs_submit_repair_write(struct btrfs_bio *bbio, int mirror_num, bool dev_replace);
int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 fileoff,
                            u32 length, u64 logical, const phys_addr_t paddrs[],
                            unsigned int step, int mirror_num);

#endif