Commit c668690d authored by Naohiro Aota's avatar Naohiro Aota Committed by David Sterba
Browse files

btrfs: factor out do_allocation() for extent allocation 



Factor out do_allocation() from find_free_extent(). This function do an
actual extent allocation in a given block group. The ffe_ctl->policy is
used to determine the actual allocator function to use.

Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent c10859be

fs/btrfs/extent-tree.c

+44 −31
Original line number Diff line number Diff line
@@ -3664,6 +3664,37 @@ static int find_free_extent_unclustered(struct btrfs_block_group *bg, 
	return 0;

}



static int do_allocation_clustered(struct btrfs_block_group *block_group,

				   struct find_free_extent_ctl *ffe_ctl,

				   struct btrfs_block_group **bg_ret)

{

	int ret;



	/* We want to try and use the cluster allocator, so lets look there */

	if (ffe_ctl->last_ptr && ffe_ctl->use_cluster) {

		ret = find_free_extent_clustered(block_group, ffe_ctl->last_ptr,

						 ffe_ctl, bg_ret);

		if (ret >= 0 || ret == -EAGAIN)

			return ret;

		/* ret == -ENOENT case falls through */

	}



	return find_free_extent_unclustered(block_group, ffe_ctl->last_ptr,

					    ffe_ctl);

}



static int do_allocation(struct btrfs_block_group *block_group,

			 struct find_free_extent_ctl *ffe_ctl,

			 struct btrfs_block_group **bg_ret)

{

	switch (ffe_ctl->policy) {

	case BTRFS_EXTENT_ALLOC_CLUSTERED:

		return do_allocation_clustered(block_group, ffe_ctl, bg_ret);

	default:

		BUG();

	}

}



/*

 * Return >0 means caller needs to re-search for free extent

 * Return 0 means we have the needed free extent.
@@ -3931,6 +3962,8 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, 
	down_read(&space_info->groups_sem);

	list_for_each_entry(block_group,

			    &space_info->block_groups[ffe_ctl.index], list) {

		struct btrfs_block_group *bg_ret;



		/* If the block group is read-only, we can skip it entirely. */

		if (unlikely(block_group->ro))

			continue;
@@ -3991,40 +4024,20 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, 
		if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))

			goto loop;



		/*

		 * Ok we want to try and use the cluster allocator, so

		 * lets look there

		 */

		if (ffe_ctl.last_ptr && ffe_ctl.use_cluster) {

			struct btrfs_block_group *cluster_bg = NULL;



			ret = find_free_extent_clustered(block_group,

							 ffe_ctl.last_ptr,

							 &ffe_ctl, &cluster_bg);



		bg_ret = NULL;

		ret = do_allocation(block_group, &ffe_ctl, &bg_ret);

		if (ret == 0) {

				if (cluster_bg && cluster_bg != block_group) {

					btrfs_release_block_group(block_group,

								  delalloc);

					block_group = cluster_bg;

			if (bg_ret && bg_ret != block_group) {

				btrfs_release_block_group(block_group, delalloc);

				block_group = bg_ret;

			}

				goto checks;

		} else if (ret == -EAGAIN) {

			goto have_block_group;

		} else if (ret > 0) {

			goto loop;

		}

			/* ret == -ENOENT case falls through */

		}



		ret = find_free_extent_unclustered(block_group,

						   ffe_ctl.last_ptr, &ffe_ctl);

		if (ret == -EAGAIN)

			goto have_block_group;

		else if (ret > 0)

			goto loop;

		/* ret == 0 case falls through */

checks:

		/* Checks */

		ffe_ctl.search_start = round_up(ffe_ctl.found_offset,

					     fs_info->stripesize);