Commit 424499db authored by Yan, Zheng's avatar Yan, Zheng Committed by Chris Mason
Browse files

Btrfs: Kill allocate_wait in space_info 



We already have fs_info->chunk_mutex to avoid concurrent
chunk creation.

Signed-off-by: default avatarYan Zheng <zheng.yan@oracle.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent b742bb82

fs/btrfs/ctree.h

+0 −2
Original line number Diff line number Diff line
@@ -701,9 +701,7 @@ struct btrfs_space_info { 
	struct list_head list;



	/* for controlling how we free up space for allocations */

	wait_queue_head_t allocate_wait;

	wait_queue_head_t flush_wait;

	int allocating_chunk;

	int flushing;



	/* for block groups in our same type */

fs/btrfs/extent-tree.c

+58 −74
Original line number Diff line number Diff line
@@ -71,6 +71,9 @@ static int find_next_key(struct btrfs_path *path, int level, 
			 struct btrfs_key *key);

static void dump_space_info(struct btrfs_space_info *info, u64 bytes,

			    int dump_block_groups);

static int maybe_allocate_chunk(struct btrfs_trans_handle *trans,

				struct btrfs_root *root,

				struct btrfs_space_info *sinfo, u64 num_bytes);



static noinline int

block_group_cache_done(struct btrfs_block_group_cache *cache)
@@ -2691,7 +2694,6 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags, 
		INIT_LIST_HEAD(&found->block_groups[i]);

	init_rwsem(&found->groups_sem);

	init_waitqueue_head(&found->flush_wait);

	init_waitqueue_head(&found->allocate_wait);

	spin_lock_init(&found->lock);

	found->flags = flags & (BTRFS_BLOCK_GROUP_DATA |

				BTRFS_BLOCK_GROUP_SYSTEM |
@@ -3004,71 +3006,6 @@ static void flush_delalloc(struct btrfs_root *root, 
	wake_up(&info->flush_wait);

}



static int maybe_allocate_chunk(struct btrfs_root *root,

				 struct btrfs_space_info *info)

{

	struct btrfs_super_block *disk_super = &root->fs_info->super_copy;

	struct btrfs_trans_handle *trans;

	bool wait = false;

	int ret = 0;

	u64 min_metadata;

	u64 free_space;



	free_space = btrfs_super_total_bytes(disk_super);

	/*

	 * we allow the metadata to grow to a max of either 10gb or 5% of the

	 * space in the volume.

	 */

	min_metadata = min((u64)10 * 1024 * 1024 * 1024,

			     div64_u64(free_space * 5, 100));

	if (info->total_bytes >= min_metadata) {

		spin_unlock(&info->lock);

		return 0;

	}



	if (info->full) {

		spin_unlock(&info->lock);

		return 0;

	}



	if (!info->allocating_chunk) {

		info->force_alloc = 1;

		info->allocating_chunk = 1;

	} else {

		wait = true;

	}



	spin_unlock(&info->lock);



	if (wait) {

		wait_event(info->allocate_wait,

			   !info->allocating_chunk);

		return 1;

	}



	trans = btrfs_start_transaction(root, 1);

	if (!trans) {

		ret = -ENOMEM;

		goto out;

	}



	ret = do_chunk_alloc(trans, root->fs_info->extent_root,

			     4096 + 2 * 1024 * 1024,

			     info->flags, 0);

	btrfs_end_transaction(trans, root);

	if (ret)

		goto out;

out:

	spin_lock(&info->lock);

	info->allocating_chunk = 0;

	spin_unlock(&info->lock);

	wake_up(&info->allocate_wait);



	if (ret)

		return 0;

	return 1;

}



/*

 * Reserve metadata space for delalloc.

 */
@@ -3109,7 +3046,8 @@ int btrfs_reserve_metadata_for_delalloc(struct btrfs_root *root, 
		flushed++;



		if (flushed == 1) {

			if (maybe_allocate_chunk(root, meta_sinfo))

			if (maybe_allocate_chunk(NULL, root, meta_sinfo,

						 num_bytes))

				goto again;

			flushed++;

		} else {
@@ -3224,7 +3162,8 @@ int btrfs_reserve_metadata_space(struct btrfs_root *root, int num_items) 
	if (used > meta_sinfo->total_bytes) {

		retries++;

		if (retries == 1) {

			if (maybe_allocate_chunk(root, meta_sinfo))

			if (maybe_allocate_chunk(NULL, root, meta_sinfo,

						 num_bytes))

				goto again;

			retries++;

		} else {
@@ -3421,13 +3360,28 @@ static void force_metadata_allocation(struct btrfs_fs_info *info) 
	rcu_read_unlock();

}



static int should_alloc_chunk(struct btrfs_space_info *sinfo,

			      u64 alloc_bytes)

{

	u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;



	if (sinfo->bytes_used + sinfo->bytes_reserved +

	    alloc_bytes + 256 * 1024 * 1024 < num_bytes)

		return 0;



	if (sinfo->bytes_used + sinfo->bytes_reserved +

	    alloc_bytes < div_factor(num_bytes, 8))

		return 0;



	return 1;

}



static int do_chunk_alloc(struct btrfs_trans_handle *trans,

			  struct btrfs_root *extent_root, u64 alloc_bytes,

			  u64 flags, int force)

{

	struct btrfs_space_info *space_info;

	struct btrfs_fs_info *fs_info = extent_root->fs_info;

	u64 thresh;

	int ret = 0;



	mutex_lock(&fs_info->chunk_mutex);
@@ -3450,11 +3404,7 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans, 
		goto out;

	}



	thresh = space_info->total_bytes - space_info->bytes_readonly;

	thresh = div_factor(thresh, 8);

	if (!force &&

	   (space_info->bytes_used + space_info->bytes_pinned +

	    space_info->bytes_reserved + alloc_bytes) < thresh) {

	if (!force && !should_alloc_chunk(space_info, alloc_bytes)) {

		spin_unlock(&space_info->lock);

		goto out;

	}
@@ -3476,6 +3426,8 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans, 
	spin_lock(&space_info->lock);

	if (ret)

		space_info->full = 1;

	else

		ret = 1;

	space_info->force_alloc = 0;

	spin_unlock(&space_info->lock);

out:
@@ -3483,6 +3435,38 @@ static int do_chunk_alloc(struct btrfs_trans_handle *trans, 
	return ret;

}



static int maybe_allocate_chunk(struct btrfs_trans_handle *trans,

				struct btrfs_root *root,

				struct btrfs_space_info *sinfo, u64 num_bytes)

{

	int ret;

	int end_trans = 0;



	if (sinfo->full)

		return 0;



	spin_lock(&sinfo->lock);

	ret = should_alloc_chunk(sinfo, num_bytes + 2 * 1024 * 1024);

	spin_unlock(&sinfo->lock);

	if (!ret)

		return 0;



	if (!trans) {

		trans = btrfs_join_transaction(root, 1);

		BUG_ON(IS_ERR(trans));

		end_trans = 1;

	}



	ret = do_chunk_alloc(trans, root->fs_info->extent_root,

			     num_bytes + 2 * 1024 * 1024,

			     get_alloc_profile(root, sinfo->flags), 0);



	if (end_trans)

		btrfs_end_transaction(trans, root);



	return ret == 1 ? 1 : 0;

}



static int update_block_group(struct btrfs_trans_handle *trans,

			      struct btrfs_root *root,

			      u64 bytenr, u64 num_bytes, int alloc,