/* SPDX-License-Identifier: GPL-2.0 */

#ifndef BTRFS_EXTENT_IO_H
#define BTRFS_EXTENT_IO_H

#include <linux/rbtree.h>
#include <linux/refcount.h>
#include "ulist.h"

/* bits for the extent state */
#define EXTENT_DIRTY            (1U << 0)
#define EXTENT_WRITEBACK        (1U << 1)
#define EXTENT_UPTODATE         (1U << 2)
#define EXTENT_LOCKED           (1U << 3)
#define EXTENT_NEW              (1U << 4)
#define EXTENT_DELALLOC         (1U << 5)
#define EXTENT_DEFRAG           (1U << 6)
#define EXTENT_BOUNDARY         (1U << 9)
#define EXTENT_NODATASUM        (1U << 10)
#define EXTENT_CLEAR_META_RESV  (1U << 11)
#define EXTENT_FIRST_DELALLOC   (1U << 12)
#define EXTENT_NEED_WAIT        (1U << 13)
#define EXTENT_DAMAGED          (1U << 14)
#define EXTENT_NORESERVE        (1U << 15)
#define EXTENT_QGROUP_RESERVED  (1U << 16)
#define EXTENT_CLEAR_DATA_RESV  (1U << 17)
#define EXTENT_DELALLOC_NEW     (1U << 18)
#define EXTENT_IOBITS           (EXTENT_LOCKED | EXTENT_WRITEBACK)
#define EXTENT_DO_ACCOUNTING    (EXTENT_CLEAR_META_RESV | \
                                 EXTENT_CLEAR_DATA_RESV)
#define EXTENT_CTLBITS          (EXTENT_DO_ACCOUNTING | EXTENT_FIRST_DELALLOC)

/*
 * flags for bio submission. The high bits indicate the compression
 * type for this bio
 */
#define EXTENT_BIO_COMPRESSED 1
#define EXTENT_BIO_FLAG_SHIFT 16

/* these are bit numbers for test/set bit */
#define EXTENT_BUFFER_UPTODATE 0
#define EXTENT_BUFFER_DIRTY 2
#define EXTENT_BUFFER_CORRUPT 3
#define EXTENT_BUFFER_READAHEAD 4       /* this got triggered by readahead */
#define EXTENT_BUFFER_TREE_REF 5
#define EXTENT_BUFFER_STALE 6
#define EXTENT_BUFFER_WRITEBACK 7
#define EXTENT_BUFFER_READ_ERR 8        /* read IO error */
#define EXTENT_BUFFER_DUMMY 9
#define EXTENT_BUFFER_IN_TREE 10
#define EXTENT_BUFFER_WRITE_ERR 11    /* write IO error */

/* these are flags for __process_pages_contig */
#define PAGE_UNLOCK             (1 << 0)
#define PAGE_CLEAR_DIRTY        (1 << 1)
#define PAGE_SET_WRITEBACK      (1 << 2)
#define PAGE_END_WRITEBACK      (1 << 3)
#define PAGE_SET_PRIVATE2       (1 << 4)
#define PAGE_SET_ERROR          (1 << 5)
#define PAGE_LOCK               (1 << 6)

/*
 * page->private values.  Every page that is controlled by the extent
 * map has page->private set to one.
 */
#define EXTENT_PAGE_PRIVATE 1

/*
 * The extent buffer bitmap operations are done with byte granularity instead of
 * word granularity for two reasons:
 * 1. The bitmaps must be little-endian on disk.
 * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
 *    single word in a bitmap may straddle two pages in the extent buffer.
 */
#define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
#define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
#define BITMAP_FIRST_BYTE_MASK(start) \
        ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
#define BITMAP_LAST_BYTE_MASK(nbits) \
        (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))

struct extent_state;
struct btrfs_root;
struct btrfs_inode;
struct btrfs_io_bio;
struct io_failure_record;

typedef blk_status_t (extent_submit_bio_hook_t)(void *private_data, struct bio *bio,
                                       int mirror_num, unsigned long bio_flags,
                                       u64 bio_offset);

typedef blk_status_t (extent_submit_bio_start_t)(void *private_data,
                struct bio *bio, u64 bio_offset);

typedef blk_status_t (extent_submit_bio_done_t)(void *private_data,
                struct bio *bio, int mirror_num);

struct extent_io_ops {
        /*
         * The following callbacks must be allways defined, the function
         * pointer will be called unconditionally.
         */
        extent_submit_bio_hook_t *submit_bio_hook;
        int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,
                                    struct page *page, u64 start, u64 end,
                                    int mirror);
        int (*merge_bio_hook)(struct page *page, unsigned long offset,
                              size_t size, struct bio *bio,
                              unsigned long bio_flags);
        int (*readpage_io_failed_hook)(struct page *page, int failed_mirror);
        struct btrfs_fs_info *(*tree_fs_info)(void *private_data);
        void (*set_range_writeback)(void *private_data, u64 start, u64 end);

        /*
         * Optional hooks, called if the pointer is not NULL
         */
        int (*fill_delalloc)(void *private_data, struct page *locked_page,
                             u64 start, u64 end, int *page_started,
                             unsigned long *nr_written,
                             struct writeback_control *wbc);

        int (*writepage_start_hook)(struct page *page, u64 start, u64 end);
        void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
                                      struct extent_state *state, int uptodate);
        void (*set_bit_hook)(void *private_data, struct extent_state *state,
                             unsigned *bits);
        void (*clear_bit_hook)(void *private_data,
                        struct extent_state *state,
                        unsigned *bits);
        void (*merge_extent_hook)(void *private_data,
                                  struct extent_state *new,
                                  struct extent_state *other);
        void (*split_extent_hook)(void *private_data,
                                  struct extent_state *orig, u64 split);
        void (*check_extent_io_range)(void *private_data, const char *caller,
                                      u64 start, u64 end);
};

struct extent_io_tree {
        struct rb_root state;
        void *private_data;
        u64 dirty_bytes;
        int track_uptodate;
        spinlock_t lock;
        const struct extent_io_ops *ops;
};

struct extent_state {
        u64 start;
        u64 end; /* inclusive */
        struct rb_node rb_node;

        /* ADD NEW ELEMENTS AFTER THIS */
        wait_queue_head_t wq;
        refcount_t refs;
        unsigned state;

        struct io_failure_record *failrec;

#ifdef CONFIG_BTRFS_DEBUG
        struct list_head leak_list;
#endif
};

#define INLINE_EXTENT_BUFFER_PAGES 16
#define MAX_INLINE_EXTENT_BUFFER_SIZE (INLINE_EXTENT_BUFFER_PAGES * PAGE_SIZE)
struct extent_buffer {
        u64 start;
        unsigned long len;
        unsigned long bflags;
        struct btrfs_fs_info *fs_info;
        spinlock_t refs_lock;
        atomic_t refs;
        atomic_t io_pages;
        int read_mirror;
        struct rcu_head rcu_head;
        pid_t lock_owner;

        /* count of read lock holders on the extent buffer */
        atomic_t write_locks;
        atomic_t read_locks;
        atomic_t blocking_writers;
        atomic_t blocking_readers;
        atomic_t spinning_readers;
        atomic_t spinning_writers;
        short lock_nested;
        /* >= 0 if eb belongs to a log tree, -1 otherwise */
        short log_index;

        /* protects write locks */
        rwlock_t lock;

        /* readers use lock_wq while they wait for the write
         * lock holders to unlock
         */
        wait_queue_head_t write_lock_wq;

        /* writers use read_lock_wq while they wait for readers
         * to unlock
         */
        wait_queue_head_t read_lock_wq;
        struct page *pages[INLINE_EXTENT_BUFFER_PAGES];
#ifdef CONFIG_BTRFS_DEBUG
        struct list_head leak_list;
#endif
};

/*
 * Structure to record how many bytes and which ranges are set/cleared
 */
struct extent_changeset {
        /* How many bytes are set/cleared in this operation */
        unsigned int bytes_changed;

        /* Changed ranges */
        struct ulist range_changed;
};

static inline void extent_changeset_init(struct extent_changeset *changeset)
{
        changeset->bytes_changed = 0;
        ulist_init(&changeset->range_changed);
}

static inline struct extent_changeset *extent_changeset_alloc(void)
{
        struct extent_changeset *ret;

        ret = kmalloc(sizeof(*ret), GFP_KERNEL);
        if (!ret)
                return NULL;

        extent_changeset_init(ret);
        return ret;
}

static inline void extent_changeset_release(struct extent_changeset *changeset)
{
        if (!changeset)
                return;
        changeset->bytes_changed = 0;
        ulist_release(&changeset->range_changed);
}

static inline void extent_changeset_free(struct extent_changeset *changeset)
{
        if (!changeset)
                return;
        extent_changeset_release(changeset);
        kfree(changeset);
}

static inline void extent_set_compress_type(unsigned long *bio_flags,
                                            int compress_type)
{
        *bio_flags |= compress_type << EXTENT_BIO_FLAG_SHIFT;
}

static inline int extent_compress_type(unsigned long bio_flags)
{
        return bio_flags >> EXTENT_BIO_FLAG_SHIFT;
}

struct extent_map_tree;

typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode,
                                          struct page *page,
                                          size_t pg_offset,
                                          u64 start, u64 len,
                                          int create);

void extent_io_tree_init(struct extent_io_tree *tree, void *private_data);
int try_release_extent_mapping(struct page *page, gfp_t mask);
int try_release_extent_buffer(struct page *page);
int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
                     struct extent_state **cached);

static inline int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
{
        return lock_extent_bits(tree, start, end, NULL);
}

int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
                          get_extent_t *get_extent, int mirror_num);
int __init extent_io_init(void);
void __cold extent_io_exit(void);

u64 count_range_bits(struct extent_io_tree *tree,
                     u64 *start, u64 search_end,
                     u64 max_bytes, unsigned bits, int contig);

void free_extent_state(struct extent_state *state);
int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
                   unsigned bits, int filled,
                   struct extent_state *cached_state);
int clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
                unsigned bits, struct extent_changeset *changeset);
int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
                     unsigned bits, int wake, int delete,
                     struct extent_state **cached);
int __clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
                     unsigned bits, int wake, int delete,
                     struct extent_state **cached, gfp_t mask,
                     struct extent_changeset *changeset);

static inline int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end)
{
        return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL);
}

static inline int unlock_extent_cached(struct extent_io_tree *tree, u64 start,
                u64 end, struct extent_state **cached)
{
        return __clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
                                GFP_NOFS, NULL);
}

static inline int unlock_extent_cached_atomic(struct extent_io_tree *tree,
                u64 start, u64 end, struct extent_state **cached)
{
        return __clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, cached,
                                GFP_ATOMIC, NULL);
}

static inline int clear_extent_bits(struct extent_io_tree *tree, u64 start,
                u64 end, unsigned bits)
{
        int wake = 0;

        if (bits & EXTENT_LOCKED)
                wake = 1;

        return clear_extent_bit(tree, start, end, bits, wake, 0, NULL);
}

int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
                           unsigned bits, struct extent_changeset *changeset);
int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
                   unsigned bits, u64 *failed_start,
                   struct extent_state **cached_state, gfp_t mask);

static inline int set_extent_bits(struct extent_io_tree *tree, u64 start,
                u64 end, unsigned bits)
{
        return set_extent_bit(tree, start, end, bits, NULL, NULL, GFP_NOFS);
}

static inline int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
                u64 end, struct extent_state **cached_state)
{
        return __clear_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, 0,
                                cached_state, GFP_NOFS, NULL);
}

static inline int set_extent_dirty(struct extent_io_tree *tree, u64 start,
                u64 end, gfp_t mask)
{
        return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL,
                              NULL, mask);
}

static inline int clear_extent_dirty(struct extent_io_tree *tree, u64 start,
                u64 end)
{
        return clear_extent_bit(tree, start, end,
                                EXTENT_DIRTY | EXTENT_DELALLOC |
                                EXTENT_DO_ACCOUNTING, 0, 0, NULL);
}

int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
                       unsigned bits, unsigned clear_bits,
                       struct extent_state **cached_state);

static inline int set_extent_delalloc(struct extent_io_tree *tree, u64 start,
                                      u64 end, unsigned int extra_bits,
                                      struct extent_state **cached_state)
{
        return set_extent_bit(tree, start, end,
                              EXTENT_DELALLOC | EXTENT_UPTODATE | extra_bits,
                              NULL, cached_state, GFP_NOFS);
}

static inline int set_extent_defrag(struct extent_io_tree *tree, u64 start,
                u64 end, struct extent_state **cached_state)
{
        return set_extent_bit(tree, start, end,
                              EXTENT_DELALLOC | EXTENT_UPTODATE | EXTENT_DEFRAG,
                              NULL, cached_state, GFP_NOFS);
}

static inline int set_extent_new(struct extent_io_tree *tree, u64 start,
                u64 end)
{
        return set_extent_bit(tree, start, end, EXTENT_NEW, NULL, NULL,
                        GFP_NOFS);
}

static inline int set_extent_uptodate(struct extent_io_tree *tree, u64 start,
                u64 end, struct extent_state **cached_state, gfp_t mask)
{
        return set_extent_bit(tree, start, end, EXTENT_UPTODATE, NULL,
                              cached_state, mask);
}

int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
                          u64 *start_ret, u64 *end_ret, unsigned bits,
                          struct extent_state **cached_state);
int extent_invalidatepage(struct extent_io_tree *tree,
                          struct page *page, unsigned long offset);
int extent_write_full_page(struct page *page, struct writeback_control *wbc);
int extent_write_locked_range(struct inode *inode, u64 start, u64 end,
                              int mode);
int extent_writepages(struct address_space *mapping,
                      struct writeback_control *wbc);
int btree_write_cache_pages(struct address_space *mapping,
                            struct writeback_control *wbc);
int extent_readpages(struct address_space *mapping, struct list_head *pages,
                     unsigned nr_pages);
int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                __u64 start, __u64 len);
void set_page_extent_mapped(struct page *page);

struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
                                          u64 start);
struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
                                                  u64 start, unsigned long len);
struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
                                                u64 start);
struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
                                         u64 start);
void free_extent_buffer(struct extent_buffer *eb);
void free_extent_buffer_stale(struct extent_buffer *eb);
#define WAIT_NONE       0
#define WAIT_COMPLETE   1
#define WAIT_PAGE_LOCK  2
int read_extent_buffer_pages(struct extent_io_tree *tree,
                             struct extent_buffer *eb, int wait,
                             int mirror_num);
void wait_on_extent_buffer_writeback(struct extent_buffer *eb);

static inline unsigned long num_extent_pages(u64 start, u64 len)
{
        return ((start + len + PAGE_SIZE - 1) >> PAGE_SHIFT) -
                (start >> PAGE_SHIFT);
}

static inline void extent_buffer_get(struct extent_buffer *eb)
{
        atomic_inc(&eb->refs);
}

static inline int extent_buffer_uptodate(struct extent_buffer *eb)
{
        return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
}

int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
                         unsigned long start, unsigned long len);
void read_extent_buffer(const struct extent_buffer *eb, void *dst,
                        unsigned long start,
                        unsigned long len);
int read_extent_buffer_to_user(const struct extent_buffer *eb,
                               void __user *dst, unsigned long start,
                               unsigned long len);
void write_extent_buffer_fsid(struct extent_buffer *eb, const void *src);
void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
                const void *src);
void write_extent_buffer(struct extent_buffer *eb, const void *src,
                         unsigned long start, unsigned long len);
void copy_extent_buffer_full(struct extent_buffer *dst,
                             struct extent_buffer *src);
void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
                        unsigned long dst_offset, unsigned long src_offset,
                        unsigned long len);
void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
                           unsigned long src_offset, unsigned long len);
void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
                           unsigned long src_offset, unsigned long len);
void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
                           unsigned long len);
int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
                           unsigned long pos);
void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
                              unsigned long pos, unsigned long len);
void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
                                unsigned long pos, unsigned long len);
void clear_extent_buffer_dirty(struct extent_buffer *eb);
int set_extent_buffer_dirty(struct extent_buffer *eb);
void set_extent_buffer_uptodate(struct extent_buffer *eb);
void clear_extent_buffer_uptodate(struct extent_buffer *eb);
int extent_buffer_under_io(struct extent_buffer *eb);
int map_private_extent_buffer(const struct extent_buffer *eb,
                              unsigned long offset, unsigned long min_len,
                              char **map, unsigned long *map_start,
                              unsigned long *map_len);
void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);
void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);
void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
                                 u64 delalloc_end, struct page *locked_page,
                                 unsigned bits_to_clear,
                                 unsigned long page_ops);
struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte);
struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
struct bio *btrfs_bio_clone(struct bio *bio);
struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);

struct btrfs_fs_info;
struct btrfs_inode;

int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
                      u64 length, u64 logical, struct page *page,
                      unsigned int pg_offset, int mirror_num);
int clean_io_failure(struct btrfs_fs_info *fs_info,
                     struct extent_io_tree *failure_tree,
                     struct extent_io_tree *io_tree, u64 start,
                     struct page *page, u64 ino, unsigned int pg_offset);
void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
int repair_eb_io_failure(struct btrfs_fs_info *fs_info,
                         struct extent_buffer *eb, int mirror_num);

/*
 * When IO fails, either with EIO or csum verification fails, we
 * try other mirrors that might have a good copy of the data.  This
 * io_failure_record is used to record state as we go through all the
 * mirrors.  If another mirror has good data, the page is set up to date
 * and things continue.  If a good mirror can't be found, the original
 * bio end_io callback is called to indicate things have failed.
 */
struct io_failure_record {
        struct page *page;
        u64 start;
        u64 len;
        u64 logical;
        unsigned long bio_flags;
        int this_mirror;
        int failed_mirror;
        int in_validation;
};


void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start,
                u64 end);
int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
                                struct io_failure_record **failrec_ret);
bool btrfs_check_repairable(struct inode *inode, unsigned failed_bio_pages,
                            struct io_failure_record *failrec, int fail_mirror);
struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio,
                                    struct io_failure_record *failrec,
                                    struct page *page, int pg_offset, int icsum,
                                    bio_end_io_t *endio_func, void *data);
int free_io_failure(struct extent_io_tree *failure_tree,
                    struct extent_io_tree *io_tree,
                    struct io_failure_record *rec);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
noinline u64 find_lock_delalloc_range(struct inode *inode,
                                      struct extent_io_tree *tree,
                                      struct page *locked_page, u64 *start,
                                      u64 *end, u64 max_bytes);
#endif
struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
                                               u64 start);

#endif