fs/btrfs/block-group.h - linux - Git at Google

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

 #ifndef BTRFS_BLOCK_GROUP_H
 #define BTRFS_BLOCK_GROUP_H

 #include <linux/atomic.h>
 #include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/refcount.h>
 #include <linux/wait.h>
 #include <linux/sizes.h>
 #include <linux/rwsem.h>
 #include <linux/rbtree.h>
 #include <uapi/linux/btrfs_tree.h>
 #include "free-space-cache.h"

 struct btrfs_chunk_map;
 struct btrfs_fs_info;
 struct btrfs_inode;
 struct btrfs_trans_handle;

 enum btrfs_disk_cache_state {
 	BTRFS_DC_WRITTEN,
 	BTRFS_DC_ERROR,
 	BTRFS_DC_CLEAR,
 	BTRFS_DC_SETUP,
 };

 enum btrfs_block_group_size_class {
 	/* Unset */
 	BTRFS_BG_SZ_NONE,
 	/* 0 < size <= 128K */
 	BTRFS_BG_SZ_SMALL,
 	/* 128K < size <= 8M */
 	BTRFS_BG_SZ_MEDIUM,
 	/* 8M < size < BG_LENGTH */
 	BTRFS_BG_SZ_LARGE,
 };

 /*
  * This describes the state of the block_group for async discard.  This is due
  * to the two pass nature of it where extent discarding is prioritized over
  * bitmap discarding.  BTRFS_DISCARD_RESET_CURSOR is set when we are resetting
  * between lists to prevent contention for discard state variables
  * (eg. discard_cursor).
  */
 enum btrfs_discard_state {
 	BTRFS_DISCARD_EXTENTS,
 	BTRFS_DISCARD_BITMAPS,
 	BTRFS_DISCARD_RESET_CURSOR,
 };

 /*
  * Control flags for do_chunk_alloc's force field CHUNK_ALLOC_NO_FORCE means to
  * only allocate a chunk if we really need one.
  *
  * CHUNK_ALLOC_LIMITED means to only try and allocate one if we have very few
  * chunks already allocated.  This is used as part of the clustering code to
  * help make sure we have a good pool of storage to cluster in, without filling
  * the FS with empty chunks
  *
  * CHUNK_ALLOC_FORCE means it must try to allocate one
  *
  * CHUNK_ALLOC_FORCE_FOR_EXTENT like CHUNK_ALLOC_FORCE but called from
  * find_free_extent() that also activaes the zone
  */
 enum btrfs_chunk_alloc_enum {
 	CHUNK_ALLOC_NO_FORCE,
 	CHUNK_ALLOC_LIMITED,
 	CHUNK_ALLOC_FORCE,
 	CHUNK_ALLOC_FORCE_FOR_EXTENT,
 };

 /* Block group flags set at runtime */
 enum btrfs_block_group_flags {
 	BLOCK_GROUP_FLAG_IREF,
 	BLOCK_GROUP_FLAG_REMOVED,
 	BLOCK_GROUP_FLAG_TO_COPY,
 	BLOCK_GROUP_FLAG_RELOCATING_REPAIR,
 	BLOCK_GROUP_FLAG_CHUNK_ITEM_INSERTED,
 	BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
 	BLOCK_GROUP_FLAG_ZONED_DATA_RELOC,
 	/* Does the block group need to be added to the free space tree? */
 	BLOCK_GROUP_FLAG_NEEDS_FREE_SPACE,
 	/* Indicate that the block group is placed on a sequential zone */
 	BLOCK_GROUP_FLAG_SEQUENTIAL_ZONE,
 	/*
 	 * Indicate that block group is in the list of new block groups of a
 	 * transaction.
 	 */
 	BLOCK_GROUP_FLAG_NEW,
 };

 enum btrfs_caching_type {
 	BTRFS_CACHE_NO,
 	BTRFS_CACHE_STARTED,
 	BTRFS_CACHE_FINISHED,
 	BTRFS_CACHE_ERROR,
 };

 struct btrfs_caching_control {
 	struct list_head list;
 	struct mutex mutex;
 	wait_queue_head_t wait;
 	struct btrfs_work work;
 	struct btrfs_block_group *block_group;
 	/* Track progress of caching during allocation. */
 	atomic_t progress;
 	refcount_t count;
 };

 /* Once caching_thread() finds this much free space, it will wake up waiters. */
 #define CACHING_CTL_WAKE_UP SZ_2M

 struct btrfs_block_group {
 	struct btrfs_fs_info *fs_info;
 	struct btrfs_inode *inode;
 	spinlock_t lock;
 	u64 start;
 	u64 length;
 	u64 pinned;
 	u64 reserved;
 	u64 used;
 	u64 delalloc_bytes;
 	u64 bytes_super;
 	u64 flags;
 	u64 cache_generation;
 	u64 global_root_id;

 	/*
 	 * The last committed used bytes of this block group, if the above @used
 	 * is still the same as @commit_used, we don't need to update block
 	 * group item of this block group.
 	 */
 	u64 commit_used;
 	/*
 	 * If the free space extent count exceeds this number, convert the block
 	 * group to bitmaps.
 	 */
 	u32 bitmap_high_thresh;

 	/*
 	 * If the free space extent count drops below this number, convert the
 	 * block group back to extents.
 	 */
 	u32 bitmap_low_thresh;

 	/*
 	 * It is just used for the delayed data space allocation because
 	 * only the data space allocation and the relative metadata update
 	 * can be done cross the transaction.
 	 */
 	struct rw_semaphore data_rwsem;

 	/* For raid56, this is a full stripe, without parity */
 	unsigned long full_stripe_len;
 	unsigned long runtime_flags;

 	unsigned int ro;

 	int disk_cache_state;

 	/* Cache tracking stuff */
 	int cached;
 	struct btrfs_caching_control *caching_ctl;

 	struct btrfs_space_info *space_info;

 	/* Free space cache stuff */
 	struct btrfs_free_space_ctl *free_space_ctl;

 	/* Block group cache stuff */
 	struct rb_node cache_node;

 	/* For block groups in the same raid type */
 	struct list_head list;

 	refcount_t refs;

 	/*
 	 * List of struct btrfs_free_clusters for this block group.
 	 * Today it will only have one thing on it, but that may change
 	 */
 	struct list_head cluster_list;

 	/*
 	 * Used for several lists:
 	 *
 	 * 1) struct btrfs_fs_info::unused_bgs
 	 * 2) struct btrfs_fs_info::reclaim_bgs
 	 * 3) struct btrfs_transaction::deleted_bgs
 	 * 4) struct btrfs_trans_handle::new_bgs
 	 */
 	struct list_head bg_list;

 	/* For read-only block groups */
 	struct list_head ro_list;

 	/*
 	 * When non-zero it means the block group's logical address and its
 	 * device extents can not be reused for future block group allocations
 	 * until the counter goes down to 0. This is to prevent them from being
 	 * reused while some task is still using the block group after it was
 	 * deleted - we want to make sure they can only be reused for new block
 	 * groups after that task is done with the deleted block group.
 	 */
 	atomic_t frozen;

 	/* For discard operations */
 	struct list_head discard_list;
 	int discard_index;
 	u64 discard_eligible_time;
 	u64 discard_cursor;
 	enum btrfs_discard_state discard_state;

 	/* For dirty block groups */
 	struct list_head dirty_list;
 	struct list_head io_list;

 	struct btrfs_io_ctl io_ctl;

 	/*
 	 * Incremented when doing extent allocations and holding a read lock
 	 * on the space_info's groups_sem semaphore.
 	 * Decremented when an ordered extent that represents an IO against this
 	 * block group's range is created (after it's added to its inode's
 	 * root's list of ordered extents) or immediately after the allocation
 	 * if it's a metadata extent or fallocate extent (for these cases we
 	 * don't create ordered extents).
 	 */
 	atomic_t reservations;

 	/*
 	 * Incremented while holding the spinlock *lock* by a task checking if
 	 * it can perform a nocow write (incremented if the value for the *ro*
 	 * field is 0). Decremented by such tasks once they create an ordered
 	 * extent or before that if some error happens before reaching that step.
 	 * This is to prevent races between block group relocation and nocow
 	 * writes through direct IO.
 	 */
 	atomic_t nocow_writers;

 	/* Lock for free space tree operations. */
 	struct mutex free_space_lock;

 	/*
 	 * Number of extents in this block group used for swap files.
 	 * All accesses protected by the spinlock 'lock'.
 	 */
 	int swap_extents;

 	/*
 	 * Allocation offset for the block group to implement sequential
 	 * allocation. This is used only on a zoned filesystem.
 	 */
 	u64 alloc_offset;
 	u64 zone_unusable;
 	u64 zone_capacity;
 	u64 meta_write_pointer;
 	struct btrfs_chunk_map *physical_map;
 	struct list_head active_bg_list;
 	struct work_struct zone_finish_work;
 	struct extent_buffer *last_eb;
 	enum btrfs_block_group_size_class size_class;
 	u64 reclaim_mark;
 };

 static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
 {
 	return (block_group->start + block_group->length);
 }

 static inline bool btrfs_is_block_group_used(const struct btrfs_block_group *bg)
 {
 	lockdep_assert_held(&bg->lock);

 	return (bg->used > 0 || bg->reserved > 0 || bg->pinned > 0);
 }

 static inline bool btrfs_is_block_group_data_only(
 					struct btrfs_block_group *block_group)
 {
 	/*
 	 * In mixed mode the fragmentation is expected to be high, lowering the
 	 * efficiency, so only proper data block groups are considered.
 	 */
 	return (block_group->flags & BTRFS_BLOCK_GROUP_DATA) &&
 	       !(block_group->flags & BTRFS_BLOCK_GROUP_METADATA);
 }

 #ifdef CONFIG_BTRFS_DEBUG
 int btrfs_should_fragment_free_space(struct btrfs_block_group *block_group);
 #endif

 struct btrfs_block_group *btrfs_lookup_first_block_group(
 		struct btrfs_fs_info *info, u64 bytenr);
 struct btrfs_block_group *btrfs_lookup_block_group(
 		struct btrfs_fs_info *info, u64 bytenr);
 struct btrfs_block_group *btrfs_next_block_group(
 		struct btrfs_block_group *cache);
 void btrfs_get_block_group(struct btrfs_block_group *cache);
 void btrfs_put_block_group(struct btrfs_block_group *cache);
 void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
 					const u64 start);
 void btrfs_wait_block_group_reservations(struct btrfs_block_group *bg);
 struct btrfs_block_group *btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info,
 						  u64 bytenr);
 void btrfs_dec_nocow_writers(struct btrfs_block_group *bg);
 void btrfs_wait_nocow_writers(struct btrfs_block_group *bg);
 void btrfs_wait_block_group_cache_progress(struct btrfs_block_group *cache,
 				           u64 num_bytes);
 int btrfs_cache_block_group(struct btrfs_block_group *cache, bool wait);
 struct btrfs_caching_control *btrfs_get_caching_control(
 		struct btrfs_block_group *cache);
 int btrfs_add_new_free_space(struct btrfs_block_group *block_group,
 			     u64 start, u64 end, u64 *total_added_ret);
 struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
 				struct btrfs_fs_info *fs_info,
 				const u64 chunk_offset);
 int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 			     struct btrfs_chunk_map *map);
 void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
 void btrfs_mark_bg_unused(struct btrfs_block_group *bg);
 void btrfs_reclaim_bgs_work(struct work_struct *work);
 void btrfs_reclaim_bgs(struct btrfs_fs_info *fs_info);
 void btrfs_mark_bg_to_reclaim(struct btrfs_block_group *bg);
 int btrfs_read_block_groups(struct btrfs_fs_info *info);
 struct btrfs_block_group *btrfs_make_block_group(struct btrfs_trans_handle *trans,
 						 u64 type,
 						 u64 chunk_offset, u64 size);
 void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_inc_block_group_ro(struct btrfs_block_group *cache,
 			     bool do_chunk_alloc);
 void btrfs_dec_block_group_ro(struct btrfs_block_group *cache);
 int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
 int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
 			     u64 bytenr, u64 num_bytes, bool alloc);
 int btrfs_add_reserved_bytes(struct btrfs_block_group *cache,
 			     u64 ram_bytes, u64 num_bytes, int delalloc,
 			     bool force_wrong_size_class);
 void btrfs_free_reserved_bytes(struct btrfs_block_group *cache,
 			       u64 num_bytes, int delalloc);
 int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 		      enum btrfs_chunk_alloc_enum force);
 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
 void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
 void btrfs_reserve_chunk_metadata(struct btrfs_trans_handle *trans,
 				  bool is_item_insertion);
 u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
 		     u64 physical, u64 **logical, int *naddrs, int *stripe_len);

 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
 {
 	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
 }

 static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
 {
 	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
 }

 static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
 {
 	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
 }

 static inline int btrfs_block_group_done(struct btrfs_block_group *cache)
 {
 	smp_mb();
 	return cache->cached == BTRFS_CACHE_FINISHED ||
 		cache->cached == BTRFS_CACHE_ERROR;
 }

 void btrfs_freeze_block_group(struct btrfs_block_group *cache);
 void btrfs_unfreeze_block_group(struct btrfs_block_group *cache);

 bool btrfs_inc_block_group_swap_extents(struct btrfs_block_group *bg);
 void btrfs_dec_block_group_swap_extents(struct btrfs_block_group *bg, int amount);

 enum btrfs_block_group_size_class btrfs_calc_block_group_size_class(u64 size);
 int btrfs_use_block_group_size_class(struct btrfs_block_group *bg,
 				     enum btrfs_block_group_size_class size_class,
 				     bool force_wrong_size_class);
 bool btrfs_block_group_should_use_size_class(struct btrfs_block_group *bg);

 #endif /* BTRFS_BLOCK_GROUP_H */
	/* SPDX-License-Identifier: GPL-2.0 */

	#ifndef BTRFS_BLOCK_GROUP_H
	#define BTRFS_BLOCK_GROUP_H

	#include <linux/atomic.h>
	#include <linux/mutex.h>
	#include <linux/list.h>
	#include <linux/spinlock.h>
	#include <linux/refcount.h>
	#include <linux/wait.h>
	#include <linux/sizes.h>
	#include <linux/rwsem.h>
	#include <linux/rbtree.h>
	#include <uapi/linux/btrfs_tree.h>
	#include "free-space-cache.h"

	struct btrfs_chunk_map;
	struct btrfs_fs_info;
	struct btrfs_inode;
	struct btrfs_trans_handle;

	enum btrfs_disk_cache_state {
	BTRFS_DC_WRITTEN,
	BTRFS_DC_ERROR,
	BTRFS_DC_CLEAR,
	BTRFS_DC_SETUP,
	};

	enum btrfs_block_group_size_class {
	/* Unset */
	BTRFS_BG_SZ_NONE,
	/* 0 < size <= 128K */
	BTRFS_BG_SZ_SMALL,
	/* 128K < size <= 8M */
	BTRFS_BG_SZ_MEDIUM,
	/* 8M < size < BG_LENGTH */
	BTRFS_BG_SZ_LARGE,
	};

	/*
	* This describes the state of the block_group for async discard. This is due
	* to the two pass nature of it where extent discarding is prioritized over
	* bitmap discarding. BTRFS_DISCARD_RESET_CURSOR is set when we are resetting
	* between lists to prevent contention for discard state variables
	* (eg. discard_cursor).
	*/
	enum btrfs_discard_state {
	BTRFS_DISCARD_EXTENTS,
	BTRFS_DISCARD_BITMAPS,
	BTRFS_DISCARD_RESET_CURSOR,
	};

	/*
	* Control flags for do_chunk_alloc's force field CHUNK_ALLOC_NO_FORCE means to
	* only allocate a chunk if we really need one.
	*
	* CHUNK_ALLOC_LIMITED means to only try and allocate one if we have very few
	* chunks already allocated. This is used as part of the clustering code to
	* help make sure we have a good pool of storage to cluster in, without filling
	* the FS with empty chunks
	*
	* CHUNK_ALLOC_FORCE means it must try to allocate one
	*
	* CHUNK_ALLOC_FORCE_FOR_EXTENT like CHUNK_ALLOC_FORCE but called from
	* find_free_extent() that also activaes the zone
	*/
	enum btrfs_chunk_alloc_enum {
	CHUNK_ALLOC_NO_FORCE,
	CHUNK_ALLOC_LIMITED,
	CHUNK_ALLOC_FORCE,
	CHUNK_ALLOC_FORCE_FOR_EXTENT,
	};

	/* Block group flags set at runtime */
	enum btrfs_block_group_flags {
	BLOCK_GROUP_FLAG_IREF,
	BLOCK_GROUP_FLAG_REMOVED,
	BLOCK_GROUP_FLAG_TO_COPY,
	BLOCK_GROUP_FLAG_RELOCATING_REPAIR,
	BLOCK_GROUP_FLAG_CHUNK_ITEM_INSERTED,
	BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE,
	BLOCK_GROUP_FLAG_ZONED_DATA_RELOC,
	/* Does the block group need to be added to the free space tree? */
	BLOCK_GROUP_FLAG_NEEDS_FREE_SPACE,
	/* Indicate that the block group is placed on a sequential zone */
	BLOCK_GROUP_FLAG_SEQUENTIAL_ZONE,
	/*
	* Indicate that block group is in the list of new block groups of a
	* transaction.
	*/
	BLOCK_GROUP_FLAG_NEW,
	};

	enum btrfs_caching_type {
	BTRFS_CACHE_NO,
	BTRFS_CACHE_STARTED,
	BTRFS_CACHE_FINISHED,
	BTRFS_CACHE_ERROR,
	};

	struct btrfs_caching_control {
	struct list_head list;
	struct mutex mutex;
	wait_queue_head_t wait;
	struct btrfs_work work;
	struct btrfs_block_group *block_group;
	/* Track progress of caching during allocation. */
	atomic_t progress;
	refcount_t count;
	};

	/* Once caching_thread() finds this much free space, it will wake up waiters. */
	#define CACHING_CTL_WAKE_UP SZ_2M

	struct btrfs_block_group {
	struct btrfs_fs_info *fs_info;
	struct btrfs_inode *inode;
	spinlock_t lock;
	u64 start;
	u64 length;
	u64 pinned;
	u64 reserved;
	u64 used;
	u64 delalloc_bytes;
	u64 bytes_super;
	u64 flags;
	u64 cache_generation;
	u64 global_root_id;

	/*
	* The last committed used bytes of this block group, if the above @used
	* is still the same as @commit_used, we don't need to update block
	* group item of this block group.
	*/
	u64 commit_used;
	/*
	* If the free space extent count exceeds this number, convert the block
	* group to bitmaps.
	*/
	u32 bitmap_high_thresh;

	/*
	* If the free space extent count drops below this number, convert the
	* block group back to extents.
	*/
	u32 bitmap_low_thresh;

	/*
	* It is just used for the delayed data space allocation because
	* only the data space allocation and the relative metadata update
	* can be done cross the transaction.
	*/
	struct rw_semaphore data_rwsem;

	/* For raid56, this is a full stripe, without parity */
	unsigned long full_stripe_len;
	unsigned long runtime_flags;

	unsigned int ro;

	int disk_cache_state;

	/* Cache tracking stuff */
	int cached;
	struct btrfs_caching_control *caching_ctl;

	struct btrfs_space_info *space_info;

	/* Free space cache stuff */
	struct btrfs_free_space_ctl *free_space_ctl;

	/* Block group cache stuff */
	struct rb_node cache_node;

	/* For block groups in the same raid type */
	struct list_head list;

	refcount_t refs;

	/*
	* List of struct btrfs_free_clusters for this block group.
	* Today it will only have one thing on it, but that may change
	*/
	struct list_head cluster_list;

	/*
	* Used for several lists:
	*
	* 1) struct btrfs_fs_info::unused_bgs
	* 2) struct btrfs_fs_info::reclaim_bgs
	* 3) struct btrfs_transaction::deleted_bgs
	* 4) struct btrfs_trans_handle::new_bgs
	*/
	struct list_head bg_list;

	/* For read-only block groups */
	struct list_head ro_list;

	/*
	* When non-zero it means the block group's logical address and its
	* device extents can not be reused for future block group allocations
	* until the counter goes down to 0. This is to prevent them from being
	* reused while some task is still using the block group after it was
	* deleted - we want to make sure they can only be reused for new block
	* groups after that task is done with the deleted block group.
	*/
	atomic_t frozen;

	/* For discard operations */
	struct list_head discard_list;
	int discard_index;
	u64 discard_eligible_time;
	u64 discard_cursor;
	enum btrfs_discard_state discard_state;

	/* For dirty block groups */
	struct list_head dirty_list;
	struct list_head io_list;

	struct btrfs_io_ctl io_ctl;

	/*
	* Incremented when doing extent allocations and holding a read lock
	* on the space_info's groups_sem semaphore.
	* Decremented when an ordered extent that represents an IO against this
	* block group's range is created (after it's added to its inode's
	* root's list of ordered extents) or immediately after the allocation
	* if it's a metadata extent or fallocate extent (for these cases we
	* don't create ordered extents).
	*/
	atomic_t reservations;

	/*
	* Incremented while holding the spinlock lock by a task checking if
	* it can perform a nocow write (incremented if the value for the ro
	* field is 0). Decremented by such tasks once they create an ordered
	* extent or before that if some error happens before reaching that step.
	* This is to prevent races between block group relocation and nocow
	* writes through direct IO.
	*/
	atomic_t nocow_writers;

	/* Lock for free space tree operations. */
	struct mutex free_space_lock;

	/*
	* Number of extents in this block group used for swap files.
	* All accesses protected by the spinlock 'lock'.
	*/
	int swap_extents;

	/*
	* Allocation offset for the block group to implement sequential
	* allocation. This is used only on a zoned filesystem.
	*/
	u64 alloc_offset;
	u64 zone_unusable;
	u64 zone_capacity;
	u64 meta_write_pointer;
	struct btrfs_chunk_map *physical_map;
	struct list_head active_bg_list;
	struct work_struct zone_finish_work;
	struct extent_buffer *last_eb;
	enum btrfs_block_group_size_class size_class;
	u64 reclaim_mark;
	};

	static inline u64 btrfs_block_group_end(struct btrfs_block_group *block_group)
	{
	return (block_group->start + block_group->length);
	}

	static inline bool btrfs_is_block_group_used(const struct btrfs_block_group *bg)
	{
	lockdep_assert_held(&bg->lock);

	return (bg->used > 0 \|\| bg->reserved > 0 \|\| bg->pinned > 0);
	}

	static inline bool btrfs_is_block_group_data_only(
	struct btrfs_block_group *block_group)
	{
	/*
	* In mixed mode the fragmentation is expected to be high, lowering the
	* efficiency, so only proper data block groups are considered.
	*/
	return (block_group->flags & BTRFS_BLOCK_GROUP_DATA) &&
	!(block_group->flags & BTRFS_BLOCK_GROUP_METADATA);
	}

	#ifdef CONFIG_BTRFS_DEBUG
	int btrfs_should_fragment_free_space(struct btrfs_block_group *block_group);
	#endif

	struct btrfs_block_group *btrfs_lookup_first_block_group(
	struct btrfs_fs_info *info, u64 bytenr);
	struct btrfs_block_group *btrfs_lookup_block_group(
	struct btrfs_fs_info *info, u64 bytenr);
	struct btrfs_block_group *btrfs_next_block_group(
	struct btrfs_block_group *cache);
	void btrfs_get_block_group(struct btrfs_block_group *cache);
	void btrfs_put_block_group(struct btrfs_block_group *cache);
	void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
	const u64 start);
	void btrfs_wait_block_group_reservations(struct btrfs_block_group *bg);
	struct btrfs_block_group btrfs_inc_nocow_writers(struct btrfs_fs_info fs_info,
	u64 bytenr);
	void btrfs_dec_nocow_writers(struct btrfs_block_group *bg);
	void btrfs_wait_nocow_writers(struct btrfs_block_group *bg);
	void btrfs_wait_block_group_cache_progress(struct btrfs_block_group *cache,
	u64 num_bytes);
	int btrfs_cache_block_group(struct btrfs_block_group *cache, bool wait);
	struct btrfs_caching_control *btrfs_get_caching_control(
	struct btrfs_block_group *cache);
	int btrfs_add_new_free_space(struct btrfs_block_group *block_group,
	u64 start, u64 end, u64 *total_added_ret);
	struct btrfs_trans_handle *btrfs_start_trans_remove_block_group(
	struct btrfs_fs_info *fs_info,
	const u64 chunk_offset);
	int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
	struct btrfs_chunk_map *map);
	void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info);
	void btrfs_mark_bg_unused(struct btrfs_block_group *bg);
	void btrfs_reclaim_bgs_work(struct work_struct *work);
	void btrfs_reclaim_bgs(struct btrfs_fs_info *fs_info);
	void btrfs_mark_bg_to_reclaim(struct btrfs_block_group *bg);
	int btrfs_read_block_groups(struct btrfs_fs_info *info);
	struct btrfs_block_group btrfs_make_block_group(struct btrfs_trans_handle trans,
	u64 type,
	u64 chunk_offset, u64 size);
	void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans);
	int btrfs_inc_block_group_ro(struct btrfs_block_group *cache,
	bool do_chunk_alloc);
	void btrfs_dec_block_group_ro(struct btrfs_block_group *cache);
	int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans);
	int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans);
	int btrfs_setup_space_cache(struct btrfs_trans_handle *trans);
	int btrfs_update_block_group(struct btrfs_trans_handle *trans,
	u64 bytenr, u64 num_bytes, bool alloc);
	int btrfs_add_reserved_bytes(struct btrfs_block_group *cache,
	u64 ram_bytes, u64 num_bytes, int delalloc,
	bool force_wrong_size_class);
	void btrfs_free_reserved_bytes(struct btrfs_block_group *cache,
	u64 num_bytes, int delalloc);
	int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
	enum btrfs_chunk_alloc_enum force);
	int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type);
	void check_system_chunk(struct btrfs_trans_handle *trans, const u64 type);
	void btrfs_reserve_chunk_metadata(struct btrfs_trans_handle *trans,
	bool is_item_insertion);
	u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags);
	void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
	int btrfs_free_block_groups(struct btrfs_fs_info *info);
	int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
	u64 physical, u64 *logical, int naddrs, int *stripe_len);

	static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
	{
	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA);
	}

	static inline u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info)
	{
	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA);
	}

	static inline u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info)
	{
	return btrfs_get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
	}

	static inline int btrfs_block_group_done(struct btrfs_block_group *cache)
	{
	smp_mb();
	return cache->cached == BTRFS_CACHE_FINISHED \|\|
	cache->cached == BTRFS_CACHE_ERROR;
	}

	void btrfs_freeze_block_group(struct btrfs_block_group *cache);
	void btrfs_unfreeze_block_group(struct btrfs_block_group *cache);

	bool btrfs_inc_block_group_swap_extents(struct btrfs_block_group *bg);
	void btrfs_dec_block_group_swap_extents(struct btrfs_block_group *bg, int amount);

	enum btrfs_block_group_size_class btrfs_calc_block_group_size_class(u64 size);
	int btrfs_use_block_group_size_class(struct btrfs_block_group *bg,
	enum btrfs_block_group_size_class size_class,
	bool force_wrong_size_class);
	bool btrfs_block_group_should_use_size_class(struct btrfs_block_group *bg);

	#endif /* BTRFS_BLOCK_GROUP_H */