/* SPDX-License-Identifier: GPL-2.0 */
  
  #ifndef BTRFS_SPACE_INFO_H
  #define BTRFS_SPACE_INFO_H
  
  struct btrfs_space_info {
  	spinlock_t lock;
  
  	u64 total_bytes;	/* total bytes in the space,
  				   this doesn't take mirrors into account */
  	u64 bytes_used;		/* total bytes used,
  				   this doesn't take mirrors into account */
  	u64 bytes_pinned;	/* total bytes pinned, will be freed when the
  				   transaction finishes */
  	u64 bytes_reserved;	/* total bytes the allocator has reserved for
  				   current allocations */
  	u64 bytes_may_use;	/* number of bytes that may be used for
  				   delalloc/allocations */
  	u64 bytes_readonly;	/* total bytes that are read only */
  
  	u64 max_extent_size;	/* This will hold the maximum extent size of
  				   the space info if we had an ENOSPC in the
  				   allocator. */
  
  	unsigned int full:1;	/* indicates that we cannot allocate any more
  				   chunks for this space */
  	unsigned int chunk_alloc:1;	/* set if we are allocating a chunk */
  
  	unsigned int flush:1;		/* set if we are trying to make space */
  
  	unsigned int force_alloc;	/* set if we need to force a chunk
  					   alloc for this space */
  
  	u64 disk_used;		/* total bytes used on disk */
  	u64 disk_total;		/* total bytes on disk, takes mirrors into
  				   account */
  
  	u64 flags;
  
  	/*
  	 * bytes_pinned is kept in line with what is actually pinned, as in
  	 * we've called update_block_group and dropped the bytes_used counter
  	 * and increased the bytes_pinned counter.  However this means that
  	 * bytes_pinned does not reflect the bytes that will be pinned once the
  	 * delayed refs are flushed, so this counter is inc'ed every time we
  	 * call btrfs_free_extent so it is a realtime count of what will be
  	 * freed once the transaction is committed.  It will be zeroed every
  	 * time the transaction commits.
  	 */
  	struct percpu_counter total_bytes_pinned;
  
  	struct list_head list;
  	/* Protected by the spinlock 'lock'. */
  	struct list_head ro_bgs;
  	struct list_head priority_tickets;
  	struct list_head tickets;

  
  	/*
  	 * Size of space that needs to be reclaimed in order to satisfy pending
  	 * tickets
  	 */
  	u64 reclaim_size;

  	/*
  	 * tickets_id just indicates the next ticket will be handled, so note
  	 * it's not stored per ticket.
  	 */
  	u64 tickets_id;
  
  	struct rw_semaphore groups_sem;
  	/* for block groups in our same type */
  	struct list_head block_groups[BTRFS_NR_RAID_TYPES];

  
  	struct kobject kobj;
  	struct kobject *block_group_kobjs[BTRFS_NR_RAID_TYPES];
  };

  struct reserve_ticket {

  	u64 bytes;
  	int error;

  	bool steal;

  	struct list_head list;
  	wait_queue_head_t wait;
  };

  static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
  {
  	return ((space_info->flags & BTRFS_BLOCK_GROUP_METADATA) &&
  		(space_info->flags & BTRFS_BLOCK_GROUP_DATA));
  }

  /*
   *
   * Declare a helper function to detect underflow of various space info members
   */

  #define DECLARE_SPACE_INFO_UPDATE(name, trace_name)			\

  static inline void							\
  btrfs_space_info_update_##name(struct btrfs_fs_info *fs_info,		\
  			       struct btrfs_space_info *sinfo,		\
  			       s64 bytes)				\
  {									\

  	const u64 abs_bytes = (bytes < 0) ? -bytes : bytes;		\

  	lockdep_assert_held(&sinfo->lock);				\
  	trace_update_##name(fs_info, sinfo, sinfo->name, bytes);	\

  	trace_btrfs_space_reservation(fs_info, trace_name,		\
  				      sinfo->flags, abs_bytes,		\
  				      bytes > 0);			\

  	if (bytes < 0 && sinfo->name < -bytes) {			\
  		WARN_ON(1);						\
  		sinfo->name = 0;					\
  		return;							\
  	}								\
  	sinfo->name += bytes;						\
  }

  DECLARE_SPACE_INFO_UPDATE(bytes_may_use, "space_info");
  DECLARE_SPACE_INFO_UPDATE(bytes_pinned, "pinned");

  int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
  void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
  			     u64 total_bytes, u64 bytes_used,
  			     u64 bytes_readonly,
  			     struct btrfs_space_info **space_info);
  struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
  					       u64 flags);

  u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,

  			  bool may_use_included);
  void btrfs_clear_space_info_full(struct btrfs_fs_info *info);

  void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
  			   struct btrfs_space_info *info, u64 bytes,
  			   int dump_block_groups);

  int btrfs_reserve_metadata_bytes(struct btrfs_root *root,
  				 struct btrfs_block_rsv *block_rsv,
  				 u64 orig_bytes,
  				 enum btrfs_reserve_flush_enum flush);

  void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
  				struct btrfs_space_info *space_info);

  int btrfs_can_overcommit(struct btrfs_fs_info *fs_info,
  			 struct btrfs_space_info *space_info, u64 bytes,
  			 enum btrfs_reserve_flush_enum flush);

  static inline void btrfs_space_info_free_bytes_may_use(

  				struct btrfs_fs_info *fs_info,
  				struct btrfs_space_info *space_info,
  				u64 num_bytes)
  {
  	spin_lock(&space_info->lock);
  	btrfs_space_info_update_bytes_may_use(fs_info, space_info, -num_bytes);
  	btrfs_try_granting_tickets(fs_info, space_info);
  	spin_unlock(&space_info->lock);
  }

  int btrfs_reserve_data_bytes(struct btrfs_fs_info *fs_info, u64 bytes,
  			     enum btrfs_reserve_flush_enum flush);

  #endif /* BTRFS_SPACE_INFO_H */