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

#ifndef BTRFS_EXTENT_IO_TREE_H
#define BTRFS_EXTENT_IO_TREE_H

#include <linux/rbtree.h>
#include <linux/spinlock.h>
#include <linux/refcount.h>
#include <linux/list.h>
#include <linux/wait.h>
#include "misc.h"

struct extent_changeset;
struct btrfs_fs_info;
struct btrfs_inode;

/* Bits for the extent state */
enum {
        ENUM_BIT(EXTENT_DIRTY),
        ENUM_BIT(EXTENT_LOCKED),
        ENUM_BIT(EXTENT_DIO_LOCKED),
        ENUM_BIT(EXTENT_DIRTY_LOG1),
        ENUM_BIT(EXTENT_DIRTY_LOG2),
        ENUM_BIT(EXTENT_DELALLOC),
        ENUM_BIT(EXTENT_DEFRAG),
        ENUM_BIT(EXTENT_BOUNDARY),
        ENUM_BIT(EXTENT_NODATASUM),
        ENUM_BIT(EXTENT_CLEAR_META_RESV),
        ENUM_BIT(EXTENT_NEED_WAIT),
        ENUM_BIT(EXTENT_NORESERVE),
        ENUM_BIT(EXTENT_QGROUP_RESERVED),
        ENUM_BIT(EXTENT_CLEAR_DATA_RESV),
        /*
         * Must be cleared only during ordered extent completion or on error
         * paths if we did not manage to submit bios and create the ordered
         * extents for the range.  Should not be cleared during page release
         * and page invalidation (if there is an ordered extent in flight),
         * that is left for the ordered extent completion.
         */
        ENUM_BIT(EXTENT_DELALLOC_NEW),
        /*
         * Mark that a range is being locked for finishing an ordered extent.
         * Used together with EXTENT_LOCKED.
         */
        ENUM_BIT(EXTENT_FINISHING_ORDERED),
        /*
         * When an ordered extent successfully completes for a region marked as
         * a new delalloc range, use this flag when clearing a new delalloc
         * range to indicate that the VFS' inode number of bytes should be
         * incremented and the inode's new delalloc bytes decremented, in an
         * atomic way to prevent races with stat(2).
         */
        ENUM_BIT(EXTENT_ADD_INODE_BYTES),
        /*
         * Set during truncate when we're clearing an entire range and we just
         * want the extent states to go away.
         */
        ENUM_BIT(EXTENT_CLEAR_ALL_BITS),

        /*
         * This must be last.
         *
         * Bit not representing a state but a request for NOWAIT semantics,
         * e.g. when allocating memory, and must be masked out from the other
         * bits.
         */
        ENUM_BIT(EXTENT_NOWAIT)
};

#define EXTENT_DO_ACCOUNTING    (EXTENT_CLEAR_META_RESV | \
                                 EXTENT_CLEAR_DATA_RESV)
#define EXTENT_CTLBITS          (EXTENT_DO_ACCOUNTING | \
                                 EXTENT_ADD_INODE_BYTES | \
                                 EXTENT_CLEAR_ALL_BITS)

#define EXTENT_LOCK_BITS        (EXTENT_LOCKED | EXTENT_DIO_LOCKED)

/*
 * Redefined bits above which are used only in the device allocation tree,
 * shouldn't be using EXTENT_LOCKED / EXTENT_BOUNDARY / EXTENT_CLEAR_META_RESV
 * / EXTENT_CLEAR_DATA_RESV because they have special meaning to the bit
 * manipulation functions
 */
#define CHUNK_ALLOCATED                         EXTENT_DIRTY
#define CHUNK_TRIMMED                           EXTENT_DEFRAG
#define CHUNK_STATE_MASK                        (CHUNK_ALLOCATED |              \
                                                 CHUNK_TRIMMED)

enum {
        IO_TREE_FS_PINNED_EXTENTS,
        IO_TREE_FS_EXCLUDED_EXTENTS,
        IO_TREE_BTREE_INODE_IO,
        IO_TREE_INODE_IO,
        IO_TREE_RELOC_BLOCKS,
        IO_TREE_TRANS_DIRTY_PAGES,
        IO_TREE_ROOT_DIRTY_LOG_PAGES,
        IO_TREE_INODE_FILE_EXTENT,
        IO_TREE_LOG_CSUM_RANGE,
        IO_TREE_SELFTEST,
        IO_TREE_DEVICE_ALLOC_STATE,
};

struct extent_io_tree {
        struct rb_root state;
        /*
         * The fs_info is needed for trace points, a tree attached to an inode
         * needs the inode.
         *
         * owner == IO_TREE_INODE_IO - then inode is valid and fs_info can be
         *                             accessed as inode->root->fs_info
         */
        union {
                struct btrfs_fs_info *fs_info;
                struct btrfs_inode *inode;
        };

        /* Who owns this io tree, should be one of IO_TREE_* */
        u8 owner;

        spinlock_t lock;
};

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;
        u32 state;

#ifdef CONFIG_BTRFS_DEBUG
        struct list_head leak_list;
#endif
};

const struct btrfs_inode *btrfs_extent_io_tree_to_inode(const struct extent_io_tree *tree);
const struct btrfs_fs_info *btrfs_extent_io_tree_to_fs_info(const struct extent_io_tree *tree);

void btrfs_extent_io_tree_init(struct btrfs_fs_info *fs_info,
                               struct extent_io_tree *tree, unsigned int owner);
void btrfs_extent_io_tree_release(struct extent_io_tree *tree);
int btrfs_lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, u32 bits,
                           struct extent_state **cached);
bool btrfs_try_lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
                                u32 bits, struct extent_state **cached);

static inline int btrfs_lock_extent(struct extent_io_tree *tree, u64 start, u64 end,
                                    struct extent_state **cached)
{
        return btrfs_lock_extent_bits(tree, start, end, EXTENT_LOCKED, cached);
}

static inline bool btrfs_try_lock_extent(struct extent_io_tree *tree, u64 start,
                                         u64 end, struct extent_state **cached)
{
        return btrfs_try_lock_extent_bits(tree, start, end, EXTENT_LOCKED, cached);
}

int __init btrfs_extent_state_init_cachep(void);
void __cold btrfs_extent_state_free_cachep(void);

u64 btrfs_count_range_bits(struct extent_io_tree *tree,
                           u64 *start, u64 search_end,
                           u64 max_bytes, u32 bits, bool contig,
                           struct extent_state **cached_state);

void btrfs_free_extent_state(struct extent_state *state);
bool btrfs_test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, u32 bit,
                          struct extent_state *cached_state);
bool btrfs_test_range_bit_exists(struct extent_io_tree *tree, u64 start, u64 end, u32 bit);
void btrfs_get_range_bits(struct extent_io_tree *tree, u64 start, u64 end, u32 *bits,
                          struct extent_state **cached_state);
int btrfs_clear_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
                                   u32 bits, struct extent_changeset *changeset);
int btrfs_clear_extent_bit_changeset(struct extent_io_tree *tree, u64 start, u64 end,
                                     u32 bits, struct extent_state **cached,
                                     struct extent_changeset *changeset);

static inline int btrfs_clear_extent_bit(struct extent_io_tree *tree, u64 start,
                                         u64 end, u32 bits,
                                         struct extent_state **cached)
{
        return btrfs_clear_extent_bit_changeset(tree, start, end, bits, cached, NULL);
}

static inline int btrfs_unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
                                      struct extent_state **cached)
{
        return btrfs_clear_extent_bit_changeset(tree, start, end, EXTENT_LOCKED,
                                                cached, NULL);
}

int btrfs_set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
                                 u32 bits, struct extent_changeset *changeset);
int btrfs_set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
                         u32 bits, struct extent_state **cached_state);

static inline int btrfs_clear_extent_dirty(struct extent_io_tree *tree, u64 start,
                                           u64 end, struct extent_state **cached)
{
        return btrfs_clear_extent_bit(tree, start, end,
                                      EXTENT_DIRTY | EXTENT_DELALLOC |
                                      EXTENT_DO_ACCOUNTING, cached);
}

int btrfs_convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
                             u32 bits, u32 clear_bits,
                             struct extent_state **cached_state);

bool btrfs_find_first_extent_bit(struct extent_io_tree *tree, u64 start,
                                 u64 *start_ret, u64 *end_ret, u32 bits,
                                 struct extent_state **cached_state);
void btrfs_find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start,
                                       u64 *start_ret, u64 *end_ret, u32 bits);
bool btrfs_find_contiguous_extent_bit(struct extent_io_tree *tree, u64 start,
                                      u64 *start_ret, u64 *end_ret, u32 bits);
bool btrfs_find_delalloc_range(struct extent_io_tree *tree, u64 *start,
                               u64 *end, u64 max_bytes,
                               struct extent_state **cached_state);
static inline int btrfs_lock_dio_extent(struct extent_io_tree *tree, u64 start,
                                        u64 end, struct extent_state **cached)
{
        return btrfs_lock_extent_bits(tree, start, end, EXTENT_DIO_LOCKED, cached);
}

static inline bool btrfs_try_lock_dio_extent(struct extent_io_tree *tree, u64 start,
                                             u64 end, struct extent_state **cached)
{
        return btrfs_try_lock_extent_bits(tree, start, end, EXTENT_DIO_LOCKED, cached);
}

static inline int btrfs_unlock_dio_extent(struct extent_io_tree *tree, u64 start,
                                          u64 end, struct extent_state **cached)
{
        return btrfs_clear_extent_bit_changeset(tree, start, end, EXTENT_DIO_LOCKED,
                                                cached, NULL);
}

struct extent_state *btrfs_next_extent_state(struct extent_io_tree *tree,
                                             struct extent_state *state);

#endif /* BTRFS_EXTENT_IO_TREE_H */