From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([59.151.112.132]:51945 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753685AbbLROMj (ORCPT ); Fri, 18 Dec 2015 09:12:39 -0500 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 9EA10409255C for ; Fri, 18 Dec 2015 22:12:12 +0800 (CST) From: Zhao Lei To: CC: Zhao Lei Subject: [PATCH 2/3] btrfs: reduce additional fs_info->reada_lock in reada_find_zone Date: Fri, 18 Dec 2015 22:10:20 +0800 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: We can avoid additional locking-acquirment and one pair of kref_get/put by combine two condition. Signed-off-by: Zhao Lei --- fs/btrfs/reada.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c index 6fb9c37..d8116fe 100644 --- a/fs/btrfs/reada.c +++ b/fs/btrfs/reada.c @@ -260,18 +260,14 @@ static struct reada_zone *reada_find_zone(struct btrfs_fs_info *fs_info, spin_lock(&fs_info->reada_lock); ret = radix_tree_gang_lookup(&dev->reada_zones, (void **)&zone, logical >> PAGE_CACHE_SHIFT, 1); - if (ret == 1) + if (ret == 1 && logical >= zone->start && logical <= zone->end) { kref_get(&zone->refcnt); - spin_unlock(&fs_info->reada_lock); - - if (ret == 1) { - if (logical >= zone->start && logical <= zone->end) - return zone; - spin_lock(&fs_info->reada_lock); - kref_put(&zone->refcnt, reada_zone_release); spin_unlock(&fs_info->reada_lock); + return zone; } + spin_unlock(&fs_info->reada_lock); + cache = btrfs_lookup_block_group(fs_info, logical); if (!cache) return NULL; -- 1.8.5.1