Commit 9f3a074d authored by Miao Xie's avatar Miao Xie Committed by Chris Mason
Browse files

Btrfs: don't wait for all the async delalloc when shrinking delalloc 



It was very likely that there were lots of async delalloc pages in the
filesystem, if we waited until all the pages were flushed, we would be
blocked for a long time, and the performance would also drop down.

Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: default avatarJosef Bacik <jbacik@fusionio.com>
Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
parent c61a16a7

fs/btrfs/extent-tree.c

+12 −2
Original line number Diff line number Diff line
@@ -4079,9 +4079,19 @@ static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig, 
		 * We need to wait for the async pages to actually start before

		 * we do anything.

		 */

		wait_event(root->fs_info->async_submit_wait,

			   !atomic_read(&root->fs_info->async_delalloc_pages));

		max_reclaim = atomic_read(&root->fs_info->async_delalloc_pages);

		if (!max_reclaim)

			goto skip_async;



		if (max_reclaim <= nr_pages)

			max_reclaim = 0;

		else

			max_reclaim -= nr_pages;



		wait_event(root->fs_info->async_submit_wait,

			   atomic_read(&root->fs_info->async_delalloc_pages) <=

			   (int)max_reclaim);

skip_async:

		if (!trans)

			flush = BTRFS_RESERVE_FLUSH_ALL;

		else