Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965219AbdCJJgI (ORCPT ); Fri, 10 Mar 2017 04:36:08 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:42956 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964827AbdCJJgE (ORCPT ); Fri, 10 Mar 2017 04:36:04 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Damien Le Moal , Jaegeuk Kim Subject: [PATCH 4.10 147/167] f2fs: avoid to issue redundant discard commands Date: Fri, 10 Mar 2017 10:09:50 +0100 Message-Id: <20170310084004.481629012@linuxfoundation.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170310083956.767605269@linuxfoundation.org> References: <20170310083956.767605269@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1353 Lines: 49 4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jaegeuk Kim commit 8b107f5b97772c7c0c218302e9a4d15b4edf50b4 upstream. If segs_per_sec is over 1 like under SMR, previously f2fs issues discard commands redundantly on the same section, since we didn't move end position for the previous discard command. E.g., start end | | prefree_bitmap = [01111100111100] And, after issue discard for this section, end start | | prefree_bitmap = [01111100111100] Select this section again by searching from (end + 1), start end | | prefree_bitmap = [01111100111100] Fixes: 36abef4e796d38 ("f2fs: introduce mode=lfs mount option") Cc: Damien Le Moal Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/segment.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -935,6 +935,8 @@ next: start = start_segno + sbi->segs_per_sec; if (start < end) goto next; + else + end = start - 1; } mutex_unlock(&dirty_i->seglist_lock);