From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from szxga04-in.huawei.com ([45.249.212.190]:8489 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935497AbdJRCOj (ORCPT ); Tue, 17 Oct 2017 22:14:39 -0400 Subject: Re: [f2fs-dev] [PATCH] f2fs: return error number for quota_write To: Jaegeuk Kim , Chao Yu CC: , , References: <20171012231500.19489-1-jaegeuk@kernel.org> <20171016230444.GA94030@jaegeuk-macbookpro.roam.corp.google.com> <79d07284-167a-3b12-bed3-cea138ab4eb7@kernel.org> <20171017181749.GB10794@jaegeuk-macbookpro.roam.corp.google.com> From: Chao Yu Message-ID: Date: Wed, 18 Oct 2017 10:13:12 +0800 MIME-Version: 1.0 In-Reply-To: <20171017181749.GB10794@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 2017/10/18 2:17, Jaegeuk Kim wrote: > On 10/17, Chao Yu wrote: >> >> >> On 2017/10/17 7:04, Jaegeuk Kim wrote: >>> On 10/16, Chao Yu wrote: >>>> Hi Jaegeuk, >>>> >>>> On 2017/10/13 7:15, Jaegeuk Kim wrote: >>>>> This patch returns an error number to quota_write in order for quota to handle >>>>> it correctly. >>>> >>>> We should return error number like __generic_file_write_iter, right? it >>>> needs to return written bytes if we have written one page or more, otherwise >>>> return error number feedbacked from write_begin. >>>> >>>> So how about reverting 4f31d26b0c17 ("f2fs: return wrong error number on >>>> f2fs_quota_write")? >>> >>> I thought like that, but realized the code change is somewhat different between >>> them. >> >> Hmm... main structure of codes here is copied from other file systems, is there >> the same problem in *_quota_write of other file systems? >> >> BTW, it looks making below judgment condition being useless. >> >> if (len == towrite) >> return 0; > > We need this to avoid needless inode updates. :P For err = 0 and len == towrite case, it more likes a bug of quota that passing 0 in @len. :(, Oh, still didn't get that why there is difference in between reverting and this fixing. Can you please explain more about this? Thanks, > > Thanks, > >> >> Thanks, >> >>> >>> Thanks, >>> >>>> >>>> Thanks, >>>> >>>>> >>>>> Signed-off-by: Jaegeuk Kim >>>>> --- >>>>> fs/f2fs/super.c | 5 ++++- >>>>> 1 file changed, 4 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c >>>>> index 2feecf5e7f4c..840a0876005b 100644 >>>>> --- a/fs/f2fs/super.c >>>>> +++ b/fs/f2fs/super.c >>>>> @@ -1397,8 +1397,11 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type, >>>>> >>>>> err = a_ops->write_begin(NULL, mapping, off, tocopy, 0, >>>>> &page, NULL); >>>>> - if (unlikely(err)) >>>>> + if (unlikely(err)) { >>>>> + if (len == towrite) >>>>> + return err; >>>>> break; >>>>> + } >>>>> >>>>> kaddr = kmap_atomic(page); >>>>> memcpy(kaddr + offset, data, tocopy); >>>>> >>> >>> ------------------------------------------------------------------------------ >>> Check out the vibrant tech community on one of the world's most >>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot >>> _______________________________________________ >>> Linux-f2fs-devel mailing list >>> Linux-f2fs-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel >>> > > . >