Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751575AbdHRKDD (ORCPT ); Fri, 18 Aug 2017 06:03:03 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:4498 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750929AbdHRKDC (ORCPT ); Fri, 18 Aug 2017 06:03:02 -0400 Subject: Re: [PATCH v2] f2fs: free_user_blocks should use reserved_segments instead To: , , , CC: , , , , References: <1502702552-78497-1-git-send-email-yunlong.song@huawei.com> <1502781273-97035-1-git-send-email-yunlong.song@huawei.com> From: Yunlong Song Message-ID: <624b1f95-1b48-1b2e-4e9a-27d19859b878@huawei.com> Date: Fri, 18 Aug 2017 18:02:13 +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: <1502781273-97035-1-git-send-email-yunlong.song@huawei.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=0001.0A020206.5996BB42.0171,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: efd3ddef4a74656c8b0c84eda33dae46 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1772 Lines: 50 ping... On 2017/8/15 15:14, Yunlong Song wrote: > 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. > > Signed-off-by: Yunlong Song > --- > fs/f2fs/gc.h | 18 +++++++++++++++--- > 1 file changed, 15 insertions(+), 3 deletions(-) > > diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h > index 9325191..542612a 100644 > --- a/fs/f2fs/gc.h > +++ b/fs/f2fs/gc.h > @@ -49,11 +49,23 @@ struct gc_inode_list { > */ > static inline block_t free_user_blocks(struct f2fs_sb_info *sbi) > { > - if (free_segments(sbi) < overprovision_segments(sbi)) > + block_t avail_user_block_count, free_blocks, avail_free_blocks; > + block_t reserved_blocks; > + > + avail_user_block_count = sbi->user_block_count - sbi->reserved_blocks; > + > + if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) > + return 0; > + > + free_blocks = free_segments(sbi) << sbi->log_blocks_per_seg; > + avail_free_blocks = min(free_blocks, avail_user_block_count - > + sbi->total_valid_block_count); > + reserved_blocks = reserved_segments(sbi) << sbi->log_blocks_per_seg; > + > + if (avail_free_blocks < reserved_blocks) > return 0; > else > - return (free_segments(sbi) - overprovision_segments(sbi)) > - << sbi->log_blocks_per_seg; > + return avail_free_blocks - reserved_blocks; > } > > static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi) -- Thanks, Yunlong Song