Commit 0338dff6 authored Apr 27, 2018 by Gu Jinxiang Committed by David Sterba May 28, 2018

btrfs: do reverse path readahead in btrfs_shrink_device



In btrfs_shrink_device, before btrfs_search_slot, path->reada is set to
READA_FORWARD. But I think READA_BACK is correct.

Since:

 1. key.offset is set to (u64)-1
 2. after btrfs_search_slot, btrfs_previous_item is called

So, for readahead previous items, READA_BACK is the correct one.

Signed-off-by: Gu Jinxiang <gujx@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 4ed0a7a3

fs/btrfs/volumes.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -4414,7 +4414,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
		if (!path)
		return -ENOMEM;

		path->reada = READA_FORWARD;
		path->reada = READA_BACK;

		mutex_lock(&fs_info->chunk_mutex);