From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:47777 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751485AbdH3Qfq (ORCPT ); Wed, 30 Aug 2017 12:35:46 -0400 From: Nikolay Borisov To: dsterba@suse.cz Cc: linux-btrfs@vger.kernel.org, josef@toxicpanda.com, Nikolay Borisov Subject: [PATCH] btrfs: Remove memory barrier from block_group_cache_done Date: Wed, 30 Aug 2017 19:35:42 +0300 Message-Id: <1504110942-23146-1-git-send-email-nborisov@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: This memory barrier was introduced in 817d52f8dba2 ("Btrfs: async block group caching"), but even at that time it's usage was broken since it didn't pair with anything. There was one situation where the cached member was set to BTRFS_CACHE_FINISHED in a spinlock region which *might* have acted as a pairing barrier. Since there is no clear semantics how it's supposed to work better to just remove it. Signed-off-by: Nikolay Borisov --- fs/btrfs/extent-tree.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 21c78c48e15b..10c2ef1a9fd2 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -112,7 +112,6 @@ static void space_info_add_old_bytes(struct btrfs_fs_info *fs_info, static noinline int block_group_cache_done(struct btrfs_block_group_cache *cache) { - smp_mb(); return cache->cached == BTRFS_CACHE_FINISHED || cache->cached == BTRFS_CACHE_ERROR; } -- 2.7.4