Hi, On 08/24/2016 08:44 PM, David Sterba wrote:
On Fri, Aug 19, 2016 at 05:59:46PM +0800, Wang Xiaoguang wrote:The basic idea is simple. Assume a middle tree node A is shared and its referenceing fs/file tree root ids are 5, 258 and 260, then we only check node A in the tree who has the smallest root id. That means in this case, when checking root tree(5), we check inode A, for root tree 258 and 260, we can just skip it. Notice even with this patch, we still may visit a shared node or leaf multiple times. This happens when a inode metadata occupies multiple leaves. leaf_A leaf_B When checking inode item in leaf_A, assume inode[512] have file extents in leaf_B, and leaf_B is shared. In the case, for inode[512], we must visit leaf_B to have inode item check. After finishing inode[512] check, here we walk down tree root to leaf_B to check whether node or leaf is shared, if some node or leaf is shared, we can just skip it and below nodes or leaf's check. I also fill a disk partition with linux source codes and create 3 snapshots in it. Before this patch, it averagely took 46s to finish one btrfsck execution, with this patch, it averagely took 15s. Signed-off-by: Wang Xiaoguang <wangxg.fnst@xxxxxxxxxxxxxx>Can you please refresh the patch on top of current devel branch? I get too many conflicts to resolve.
This patch is to improve low memory mode fs/file tree check, but it seems Lu Fengqi's low memory fs/file tree check patches are not merged into your devel branch :)
@@ -2001,6 +2081,7 @@ static int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path, path->nodes[*level]->start, *level, 1, &refs, NULL); if (ret < 0) { + fprintf(stderr, "zhaoyan\n");Probably a debugging leftover
:) I'll remove it. Regards, Xiaoguang Wang
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