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

#ifndef BTRFS_ORDERED_DATA_H
#define BTRFS_ORDERED_DATA_H

#include <linux/types.h>
#include <linux/list.h>
#include <linux/refcount.h>
#include <linux/completion.h>
#include <linux/rbtree.h>
#include <linux/wait.h>
#include "async-thread.h"

struct inode;
struct page;
struct extent_state;
struct btrfs_block_group;
struct btrfs_inode;
struct btrfs_root;
struct btrfs_fs_info;

struct btrfs_ordered_sum {
        /*
         * Logical start address and length for of the blocks covered by
         * the sums array.
         */
        u64 logical;
        u32 len;

        struct list_head list;
        /* last field is a variable length array of csums */
        u8 sums[];
};

/*
 * Bits for btrfs_ordered_extent::flags.
 *
 * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
 * It is used to make sure metadata is inserted into the tree only once
 * per extent.
 *
 * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
 * rbtree, just before waking any waiters.  It is used to indicate the
 * IO is done and any metadata is inserted into the tree.
 */
enum {
        /*
         * Different types for ordered extents, one and only one of the 4 types
         * need to be set when creating ordered extent.
         *
         * REGULAR:     For regular non-compressed COW write
         * NOCOW:       For NOCOW write into existing non-hole extent
         * PREALLOC:    For NOCOW write into preallocated extent
         * COMPRESSED:  For compressed COW write
         */
        BTRFS_ORDERED_REGULAR,
        BTRFS_ORDERED_NOCOW,
        BTRFS_ORDERED_PREALLOC,
        BTRFS_ORDERED_COMPRESSED,

        /*
         * Extra bit for direct io, can only be set for
         * REGULAR/NOCOW/PREALLOC. No direct io for compressed extent.
         */
        BTRFS_ORDERED_DIRECT,

        /* Extra status bits for ordered extents */

        /* set when all the pages are written */
        BTRFS_ORDERED_IO_DONE,
        /* set when removed from the tree */
        BTRFS_ORDERED_COMPLETE,
        /* We had an io error when writing this out */
        BTRFS_ORDERED_IOERR,
        /* Set when we have to truncate an extent */
        BTRFS_ORDERED_TRUNCATED,
        /* Used during fsync to track already logged extents */
        BTRFS_ORDERED_LOGGED,
        /* We have already logged all the csums of the ordered extent */
        BTRFS_ORDERED_LOGGED_CSUM,
        /* We wait for this extent to complete in the current transaction */
        BTRFS_ORDERED_PENDING,
        /* BTRFS_IOC_ENCODED_WRITE */
        BTRFS_ORDERED_ENCODED,
};

/* BTRFS_ORDERED_* flags that specify the type of the extent. */
#define BTRFS_ORDERED_TYPE_FLAGS ((1UL << BTRFS_ORDERED_REGULAR) |      \
                                  (1UL << BTRFS_ORDERED_NOCOW) |        \
                                  (1UL << BTRFS_ORDERED_PREALLOC) |     \
                                  (1UL << BTRFS_ORDERED_COMPRESSED) |   \
                                  (1UL << BTRFS_ORDERED_DIRECT) |       \
                                  (1UL << BTRFS_ORDERED_ENCODED))

struct btrfs_ordered_extent {
        /* logical offset in the file */
        u64 file_offset;

        /*
         * These fields directly correspond to the same fields in
         * btrfs_file_extent_item.
         */
        u64 num_bytes;
        u64 ram_bytes;
        u64 disk_bytenr;
        u64 disk_num_bytes;
        u64 offset;

        /* number of bytes that still need writing */
        u64 bytes_left;

        /*
         * If we get truncated we need to adjust the file extent we enter for
         * this ordered extent so that we do not expose stale data.
         */
        u64 truncated_len;

        /* flags (described above) */
        unsigned long flags;

        /* compression algorithm */
        int compress_type;

        /* Qgroup reserved space */
        int qgroup_rsv;

        /* reference count */
        refcount_t refs;

        /* the inode we belong to */
        struct btrfs_inode *inode;

        /* list of checksums for insertion when the extent io is done */
        struct list_head list;

        /* used for fast fsyncs */
        struct list_head log_list;

        /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
        wait_queue_head_t wait;

        /* our friendly rbtree entry */
        struct rb_node rb_node;

        /* a per root list of all the pending ordered extents */
        struct list_head root_extent_list;

        struct btrfs_work work;

        struct completion completion;
        struct btrfs_work flush_work;
        struct list_head work_list;

        struct list_head bioc_list;
};

int btrfs_finish_one_ordered(struct btrfs_ordered_extent *ordered_extent);
int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);

void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
                                struct btrfs_ordered_extent *entry);
void btrfs_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
                                 struct folio *folio, u64 file_offset, u64 len,
                                 bool uptodate);
void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
                                    struct folio *folio, u64 file_offset,
                                    u64 num_bytes, bool uptodate);
bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
                                    struct btrfs_ordered_extent **cached,
                                    u64 file_offset, u64 io_size);

/*
 * This represents details about the target file extent item of a write operation.
 */
struct btrfs_file_extent {
        u64 disk_bytenr;
        u64 disk_num_bytes;
        u64 num_bytes;
        u64 ram_bytes;
        u64 offset;
        u8 compression;
};

struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
                        struct btrfs_inode *inode, u64 file_offset,
                        const struct btrfs_file_extent *file_extent, unsigned long flags);
void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
                           struct btrfs_ordered_sum *sum);
struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
                                                         u64 file_offset);
void btrfs_start_ordered_extent_nowriteback(struct btrfs_ordered_extent *entry,
                                u64 nowriteback_start, u32 nowriteback_len);
static inline void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry)
{
        return btrfs_start_ordered_extent_nowriteback(entry, 0, 0);
}

int btrfs_wait_ordered_range(struct btrfs_inode *inode, u64 start, u64 len);
struct btrfs_ordered_extent *
btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset);
struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
                        struct btrfs_inode *inode, u64 file_offset, u64 len);
struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
                struct btrfs_inode *inode,
                u64 file_offset,
                u64 len);
void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
                                           struct list_head *list);
u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
                               const struct btrfs_block_group *bg);
void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
                              const struct btrfs_block_group *bg);
void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
                                        u64 end,
                                        struct extent_state **cached_state);
bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
                                  struct extent_state **cached_state);
struct btrfs_ordered_extent *btrfs_split_ordered_extent(
                        struct btrfs_ordered_extent *ordered, u64 len);
void btrfs_mark_ordered_extent_error(struct btrfs_ordered_extent *ordered);
int __init ordered_data_init(void);
void __cold ordered_data_exit(void);

#endif