Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753348AbdHOHSd (ORCPT ); Tue, 15 Aug 2017 03:18:33 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:3532 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753127AbdHOHSc (ORCPT ); Tue, 15 Aug 2017 03:18:32 -0400 Subject: Re: [PATCH] f2fs: free_user_blocks should use reserved_segments instead To: Jaegeuk Kim CC: , , , , , , , References: <1502702552-78497-1-git-send-email-yunlong.song@huawei.com> <20170815033258.GD91145@jaegeuk-macbookpro.roam.corp.google.com> From: Yunlong Song Message-ID: <367fde95-a6f6-5600-5eda-df254e4ed03b@huawei.com> Date: Tue, 15 Aug 2017 15:17:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170815033258.GD91145@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.111.220.140] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.5992A036.0007,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 7bb64b74fc9330a287bcfefc3ce32ec1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1529 Lines: 48 Consider this, I have sent another patch v2, please review. The part (overprovision_segments - reserved_segments) can still be used for LFS in some case, e.g., there are lots of invalid block from dirty segments, then the part (overprovision_segments - reserved_segments) can be safely used. So free_use_blocks should use reserved_segments instead, rather than directly use overprovision_segments. BTW, we also add the constraint of sbi->reserved_blocks. On 2017/8/15 11:32, Jaegeuk Kim wrote: > On 08/14, Yunlong Song wrote: >> The part (overprovision_segments - reserved_segments) can still be used for LFS, >> so free_use_blocks should use reserved_segments instead, rather than use >> overprovision_segments. >> >> Signed-off-by: Yunlong Song >> --- >> fs/f2fs/gc.h | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h >> index 9325191..6258305 100644 >> --- a/fs/f2fs/gc.h >> +++ b/fs/f2fs/gc.h >> @@ -49,10 +49,10 @@ struct gc_inode_list { >> */ >> static inline block_t free_user_blocks(struct f2fs_sb_info *sbi) > NAK. This gives user-visible block count. > >> { >> - if (free_segments(sbi) < overprovision_segments(sbi)) >> + if (free_segments(sbi) < reserved_segments(sbi)) >> return 0; >> else >> - return (free_segments(sbi) - overprovision_segments(sbi)) >> + return (free_segments(sbi) - reserved_segments(sbi)) >> << sbi->log_blocks_per_seg; >> } >> >> -- >> 1.8.5.2 > . > -- Thanks, Yunlong Song