From 3b7885bf96e03271a9fff41124c38ed7176616e2 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Thu, 6 Nov 2008 21:48:27 -0500 Subject: Btrfs: enforce metadata allocation clustering The allocator uses the last allocation as a starting point for metadata allocations, and tries to allocate in clusters of at least 256k. If the search for a free block fails to find the expected block, this patch forces a new cluster to be found in the free list. Signed-off-by: Chris Mason --- fs/btrfs/extent-tree.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'fs/btrfs/extent-tree.c') diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index ebd8275a1934..b8c6541c33fe 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2195,6 +2195,23 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans, if (search_start + num_bytes > end) goto new_group; + if (last_ptr && *last_ptr && search_start != *last_ptr) { + total_needed += empty_cluster; + *last_ptr = 0; + /* + * if search_start is still in this block group + * then we just re-search this block group + */ + if (search_start >= start && + search_start < end) { + mutex_unlock(&block_group->alloc_mutex); + continue; + } + + /* else we go to the next block group */ + goto new_group; + } + if (exclude_nr > 0 && (search_start + num_bytes > exclude_start && search_start < exclude_start + exclude_nr)) { -- cgit v1.2.2