Commit 215a63d1 authored by Miao Xie's avatar Miao Xie Committed by Chris Mason
Browse files

Btrfs: cleanup the code of used_block_group in find_free_extent() 



used_block_group is just used for the space cluster which doesn't
belong to the current block group, the other place needn't use it.
Or the logic of code seems unclear.

Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 920e4a58

fs/btrfs/extent-tree.c

+13 −20
Original line number Diff line number Diff line
@@ -6159,7 +6159,6 @@ static noinline int find_free_extent(struct btrfs_root *orig_root, 
	struct btrfs_root *root = orig_root->fs_info->extent_root;

	struct btrfs_free_cluster *last_ptr = NULL;

	struct btrfs_block_group_cache *block_group = NULL;

	struct btrfs_block_group_cache *used_block_group;

	u64 search_start = 0;

	u64 max_extent_size = 0;

	int empty_cluster = 2 * 1024 * 1024;
@@ -6220,7 +6219,6 @@ static noinline int find_free_extent(struct btrfs_root *orig_root, 
	if (search_start == hint_byte) {

		block_group = btrfs_lookup_block_group(root->fs_info,

						       search_start);

		used_block_group = block_group;

		/*

		 * we don't want to use the block group if it doesn't match our

		 * allocation bits, or if its not cached.
@@ -6257,7 +6255,6 @@ search: 
		u64 offset;

		int cached;



		used_block_group = block_group;

		btrfs_get_block_group(block_group);

		search_start = block_group->key.objectid;
@@ -6300,6 +6297,7 @@ have_block_group: 
		 * lets look there

		 */

		if (last_ptr) {

			struct btrfs_block_group_cache *used_block_group;

			unsigned long aligned_cluster;

			/*

			 * the refill lock keeps out other
@@ -6310,10 +6308,8 @@ have_block_group: 
			if (used_block_group != block_group &&

			    (!used_block_group ||

			     used_block_group->ro ||

			     !block_group_bits(used_block_group, flags))) {

				used_block_group = block_group;

			     !block_group_bits(used_block_group, flags)))

				goto refill_cluster;

			}



			if (used_block_group != block_group)

				btrfs_get_block_group(used_block_group);
@@ -6328,16 +6324,17 @@ have_block_group: 
				spin_unlock(&last_ptr->refill_lock);

				trace_btrfs_reserve_extent_cluster(root,

					block_group, search_start, num_bytes);

				if (used_block_group != block_group) {

					btrfs_put_block_group(block_group);

					block_group = used_block_group;

				}

				goto checks;

			}



			WARN_ON(last_ptr->block_group != used_block_group);

			if (used_block_group != block_group) {

			if (used_block_group != block_group)

				btrfs_put_block_group(used_block_group);

				used_block_group = block_group;

			}

refill_cluster:

			BUG_ON(used_block_group != block_group);

			/* If we are on LOOP_NO_EMPTY_SIZE, we can't

			 * set up a new clusters, so lets just skip it

			 * and let the allocator find whatever block
@@ -6456,25 +6453,25 @@ unclustered_alloc: 
			goto loop;

		}

checks:

		search_start = stripe_align(root, used_block_group,

		search_start = stripe_align(root, block_group,

					    offset, num_bytes);



		/* move on to the next group */

		if (search_start + num_bytes >

		    used_block_group->key.objectid + used_block_group->key.offset) {

			btrfs_add_free_space(used_block_group, offset, num_bytes);

		    block_group->key.objectid + block_group->key.offset) {

			btrfs_add_free_space(block_group, offset, num_bytes);

			goto loop;

		}



		if (offset < search_start)

			btrfs_add_free_space(used_block_group, offset,

			btrfs_add_free_space(block_group, offset,

					     search_start - offset);

		BUG_ON(offset > search_start);



		ret = btrfs_update_reserved_bytes(used_block_group, num_bytes,

		ret = btrfs_update_reserved_bytes(block_group, num_bytes,

						  alloc_type);

		if (ret == -EAGAIN) {

			btrfs_add_free_space(used_block_group, offset, num_bytes);

			btrfs_add_free_space(block_group, offset, num_bytes);

			goto loop;

		}
@@ -6484,16 +6481,12 @@ checks: 


		trace_btrfs_reserve_extent(orig_root, block_group,

					   search_start, num_bytes);

		if (used_block_group != block_group)

			btrfs_put_block_group(used_block_group);

		btrfs_put_block_group(block_group);

		break;

loop:

		failed_cluster_refill = false;

		failed_alloc = false;

		BUG_ON(index != get_block_group_index(block_group));

		if (used_block_group != block_group)

			btrfs_put_block_group(used_block_group);

		btrfs_put_block_group(block_group);

	}

	up_read(&space_info->groups_sem);

CRA Git | Maintained and supported by SUSTech CRA and CCSE