From 0c9b36e0d72c0648d5274adf9b7a2141e1085208 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Mon, 13 Feb 2017 15:42:30 -0800 Subject: [PATCH] Btrfs: try to avoid acquiring free space ctl's lock We don't need to take the lock if the block group has not been cached. Signed-off-by: Liu Bo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent-tree.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 0992cd1..85109de 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7714,18 +7714,20 @@ unclustered_alloc: last_ptr->fragmented = 1; spin_unlock(&last_ptr->lock); } - spin_lock(&block_group->free_space_ctl->tree_lock); - if (cached && - block_group->free_space_ctl->free_space < - num_bytes + empty_cluster + empty_size) { - if (block_group->free_space_ctl->free_space > - max_extent_size) - max_extent_size = - block_group->free_space_ctl->free_space; - spin_unlock(&block_group->free_space_ctl->tree_lock); - goto loop; + if (cached) { + struct btrfs_free_space_ctl *ctl = + block_group->free_space_ctl; + + spin_lock(&ctl->tree_lock); + if (ctl->free_space < + num_bytes + empty_cluster + empty_size) { + if (ctl->free_space > max_extent_size) + max_extent_size = ctl->free_space; + spin_unlock(&ctl->tree_lock); + goto loop; + } + spin_unlock(&ctl->tree_lock); } - spin_unlock(&block_group->free_space_ctl->tree_lock); offset = btrfs_find_space_for_alloc(block_group, search_start, num_bytes, empty_size, -- 2.7.4