From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753185AbdIEWll (ORCPT ); Tue, 5 Sep 2017 18:41:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:47138 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751413AbdIEWli (ORCPT ); Tue, 5 Sep 2017 18:41:38 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC75821A19 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=jaegeuk@kernel.org Date: Tue, 5 Sep 2017 15:41:37 -0700 From: Jaegeuk Kim To: Andreas Dilger Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, stable@vger.kernel.org Subject: Re: [PATCH] f2fs: fix wrong bfree and bavail Message-ID: <20170905224137.GA49767@jaegeuk-macbookpro.roam.corp.google.com> References: <20170905210653.46186-1-jaegeuk@kernel.org> <3A56CCE1-34B3-4EBA-9871-DAF175AB89BD@dilger.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3A56CCE1-34B3-4EBA-9871-DAF175AB89BD@dilger.ca> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/05, Andreas Dilger wrote: > On Sep 5, 2017, at 3:06 PM, Jaegeuk Kim wrote: > > > > This patch fixes bavail and bfree finally. > > > > long f_bfree; /* free blocks in fs */ > > long f_bavail; /* free blocks avail to non-superuser */ > > > > So, bfree represents all the reserved blocks, while bavail does the space only > > visible to normal user. > > > > Fix: 3e6d0b4d9c1c ("f2fs: fix incorrect f_bfree calculation in ->statfs") > > Cc: # 4.8+ > > Signed-off-by: Jaegeuk Kim > > --- > > fs/f2fs/super.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > > index 7e29db227910..17cca4cb93af 100644 > > --- a/fs/f2fs/super.c > > +++ b/fs/f2fs/super.c > > @@ -955,8 +955,8 @@ static int f2fs_statfs(struct dentry *dentry, struct kstatfs *buf) > > buf->f_bsize = sbi->blocksize; > > > > buf->f_blocks = total_count - start_count; > > - buf->f_bfree = user_block_count - valid_user_blocks(sbi) + ovp_count; > > - buf->f_bavail = user_block_count - valid_user_blocks(sbi) - > > + buf->f_bfree = user_block_count - valid_user_blocks(sbi); > > + buf->f_bavail = user_block_count - valid_user_blocks(sbi) - ovp_count - > > sbi->reserved_blocks; > > To keep the statfs data more consistent, you could use: > > buf->f_bavail = buf->f_bfree - ovp_count - sbi->reserved_blocks; > > That avoids the extra subtraction, and avoids (minor) issues if these values > change while this syscall is running. Much better. Thank you so much for correcting me. > > Cheers, Andreas > > > > >