From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Yu Subject: Re: [PATCH] f2fs: avoid to use a NULL point in destroy_segment_manager Date: Wed, 06 Nov 2013 13:10:58 +0800 Message-ID: <000101cedaae$bb7ed820$327c8860$@samsung.com> References: <000001ceda8d$5b185bd0$11491370$@samsung.com> <5279BA67.4040906@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="gb2312" Content-Transfer-Encoding: base64 Return-path: Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1VdvPb-0001qO-Fi for linux-f2fs-devel@lists.sourceforge.net; Wed, 06 Nov 2013 05:12:15 +0000 Received: from mailout4.samsung.com ([203.254.224.34]) by sog-mx-2.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1VdvPX-00075r-Lf for linux-f2fs-devel@lists.sourceforge.net; Wed, 06 Nov 2013 05:12:15 +0000 Received: from epcpsbgm2.samsung.com (epcpsbgm2 [203.254.230.27]) by mailout4.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MVT00FXVT453BG0@mailout4.samsung.com> for linux-f2fs-devel@lists.sourceforge.net; Wed, 06 Nov 2013 14:12:05 +0900 (KST) In-reply-to: <5279BA67.4040906@cn.fujitsu.com> Content-language: zh-cn List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: 'Gu Zheng' Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net SGkgR3UsCgo+IC0tLS0tT3JpZ2luYWwgTWVzc2FnZS0tLS0tCj4gRnJvbTogR3UgWmhlbmcgW21h aWx0bzpndXouZm5zdEBjbi5mdWppdHN1LmNvbV0KPiBTZW50OiBXZWRuZXNkYXksIE5vdmVtYmVy IDA2LCAyMDEzIDExOjQxIEFNCj4gVG86IENoYW8gWXUKPiBDYzogPz8/OyBsaW51eC1mc2RldmVs QHZnZXIua2VybmVsLm9yZzsgbGludXgta2VybmVsQHZnZXIua2VybmVsLm9yZzsgbGludXgtZjJm cy1kZXZlbEBsaXN0cy5zb3VyY2Vmb3JnZS5uZXQ7IMy35q0KPiBTdWJqZWN0OiBSZTogW2YyZnMt ZGV2XSBbUEFUQ0hdIGYyZnM6IGF2b2lkIHRvIHVzZSBhIE5VTEwgcG9pbnQgaW4gZGVzdHJveV9z ZWdtZW50X21hbmFnZXIKPiAKPiBPbiAxMS8wNi8yMDEzIDA5OjEyIEFNLCBDaGFvIFl1IHdyb3Rl Ogo+IAo+ID4gQSBOVUxMIHBvaW50IHNob3VsZCBhdm9pZCB0byBiZSB1c2VkIGluIGRlc3Ryb3lf c2VnbWVudF9tYW5hZ2VyIGFmdGVyIGFsbG9jYXRpbmcgbWVtb3J5IGZhaWwgZm9yIGYyZnNfc21f aW5mby4KPiAKPiBUaG91Z2ggd2l0aG91dCB0aGlzIHBhdGNoIGl0IHN0aWxsIGNhbiB3b3JrIHdl bGwsIGJlY2F1c2UgaWYgaXQgZmFpbGVkCj4gdG8gYWxsb2NhdGUgZjJmc19zbV9pbmZvLCB0aGUg c2l0X2luZm8sIGZyZWVfaW5mby4uLiBhbGwgd2VyZSBOVUxMLCBhbmQKPiB0aGUgZGVzdG9yeSBw YXRoKGUuZy4gZGVzdHJveV9kaXJ0eV9zZWdtYXApIGNhbiBkZWFsIHdpdGggdGhlbSB3ZWxsLgoK SSB0aGluayBpdCBjb3VsZCBub3Qgd29yayB3ZWxsLiBXaXRob3V0IHRoaXMgcGF0Y2ggd2UgbWF5 IGdvdCBhIHNlZ21lbnQgCmZhdWx0IGluIERJUlRZX0koc2JpKSBhdCB0aGUgZm9sbG93aW5nIGNv ZGUgaWYgaXQgZmFpbGVkIHRvIGFsbG9jYXRlIApmMmZzX3NtX2luZm8gbWVtb3J5KHNiaS0+c21f aW5mbykuIFJpZ2h0PwoKc3RhdGljIHZvaWQgZGVzdHJveV9kaXJ0eV9zZWdtYXAoc3RydWN0IGYy ZnNfc2JfaW5mbyAqc2JpKQp7CglzdHJ1Y3QgZGlydHlfc2VnbGlzdF9pbmZvICpkaXJ0eV9pID0g RElSVFlfSShzYmkpOwoKPiBJTU8sIHRoaXMgcGF0Y2ggaXMgc3RpbGwgYSBnb29kIGNhdGNoLgo+ IAo+IFJlZ2FyZHMsCj4gR3UKPiAKPiA+Cj4gPiBTaWduZWQtb2ZmLWJ5OiBDaGFvIFl1IDxjaGFv Mi55dUBzYW1zdW5nLmNvbT4KPiA+IC0tLQo+ID4gIGZzL2YyZnMvc2VnbWVudC5jIHwgICAgMiAr Kwo+ID4gIDEgZmlsZSBjaGFuZ2VkLCAyIGluc2VydGlvbnMoKykKPiA+Cj4gPiBkaWZmIC0tZ2l0 IGEvZnMvZjJmcy9zZWdtZW50LmMgYi9mcy9mMmZzL3NlZ21lbnQuYwo+ID4gaW5kZXggM2Q0ZDVm Yy4uZmYzNjNlNgo+ID4gLS0tIGEvZnMvZjJmcy9zZWdtZW50LmMKPiA+ICsrKyBiL2ZzL2YyZnMv c2VnbWVudC5jCj4gPiBAQCAtMTc0NCw2ICsxNzQ0LDggQEAgc3RhdGljIHZvaWQgZGVzdHJveV9z aXRfaW5mbyhzdHJ1Y3QgZjJmc19zYl9pbmZvICpzYmkpCj4gPiAgdm9pZCBkZXN0cm95X3NlZ21l bnRfbWFuYWdlcihzdHJ1Y3QgZjJmc19zYl9pbmZvICpzYmkpCj4gPiAgewo+ID4gIAlzdHJ1Y3Qg ZjJmc19zbV9pbmZvICpzbV9pbmZvID0gU01fSShzYmkpOwo+ID4gKwlpZiAoIXNtX2luZm8pCj4g PiArCQlyZXR1cm47Cj4gPiAgCWRlc3Ryb3lfZGlydHlfc2VnbWFwKHNiaSk7Cj4gPiAgCWRlc3Ry b3lfY3Vyc2VnKHNiaSk7Cj4gPiAgCWRlc3Ryb3lfZnJlZV9zZWdtYXAoc2JpKTsKCgoKLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tCk5vdmVtYmVyIFdlYmluYXJzIGZvciBDLCBDKyssIEZvcnRyYW4gRGV2 ZWxvcGVycwpBY2NlbGVyYXRlIGFwcGxpY2F0aW9uIHBlcmZvcm1hbmNlIHdpdGggc2NhbGFibGUg cHJvZ3JhbW1pbmcgbW9kZWxzLiBFeHBsb3JlCnRlY2huaXF1ZXMgZm9yIHRocmVhZGluZywgZXJy b3IgY2hlY2tpbmcsIHBvcnRpbmcsIGFuZCB0dW5pbmcuIEdldCB0aGUgbW9zdCAKZnJvbSB0aGUg bGF0ZXN0IEludGVsIHByb2Nlc3NvcnMgYW5kIGNvcHJvY2Vzc29ycy4gU2VlIGFic3RyYWN0cyBh bmQgcmVnaXN0ZXIKaHR0cDovL3B1YmFkcy5nLmRvdWJsZWNsaWNrLm5ldC9nYW1wYWQvY2xrP2lk PTYwMTM2MjMxJml1PS80MTQwL29zdGcuY2xrdHJrCl9fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fCkxpbnV4LWYyZnMtZGV2ZWwgbWFpbGluZyBsaXN0CkxpbnV4 LWYyZnMtZGV2ZWxAbGlzdHMuc291cmNlZm9yZ2UubmV0Cmh0dHBzOi8vbGlzdHMuc291cmNlZm9y Z2UubmV0L2xpc3RzL2xpc3RpbmZvL2xpbnV4LWYyZnMtZGV2ZWwK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751007Ab3KFFMN (ORCPT ); Wed, 6 Nov 2013 00:12:13 -0500 Received: from mailout4.samsung.com ([203.254.224.34]:27815 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750769Ab3KFFML convert rfc822-to-8bit (ORCPT ); Wed, 6 Nov 2013 00:12:11 -0500 X-AuditID: cbfee61b-b7fd56d000001fc6-54-5279cfa4bc88 From: Chao Yu To: "'Gu Zheng'" Cc: "'???'" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, =?gb2312?B?J8y35q0n?= References: <000001ceda8d$5b185bd0$11491370$@samsung.com> <5279BA67.4040906@cn.fujitsu.com> In-reply-to: <5279BA67.4040906@cn.fujitsu.com> Subject: RE: [f2fs-dev] [PATCH] f2fs: avoid to use a NULL point in destroy_segment_manager Date: Wed, 06 Nov 2013 13:10:58 +0800 Message-id: <000101cedaae$bb7ed820$327c8860$@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=gb2312 Content-transfer-encoding: 8BIT X-Mailer: Microsoft Outlook 14.0 Thread-index: AQECxHgARzzGwNztGb8VlYqYPj89CQHEf8cam6Gr2uA= Content-language: zh-cn X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrKLMWRmVeSWpSXmKPExsVy+t9jQd2l5yuDDCZMYrF43n6A2eL6rr9M FpcWuVvs2XuSxeLyrjlsFq0LzzM7sHn8PziJ2WP3gs9MHn1bVjF6fN4kF8ASxWWTkpqTWZZa pG+XwJXRfbeTtaCZr2L7rpUsDYybubsYOTkkBEwkHi1uZYewxSQu3FvP1sXIxSEkMJ1R4tzW hcwQzg9GiYWNK1lBqtgEVCSWd/xnArFFBDQkpk3dzwRSxCywk1Fi9/otYEVCArES849PACvi FNCTmL3nJJDNwSEsECOx7b4ASJhFQFWiaf59FhCbV8BS4vCcJiYIW1Dix+R7YHFmoPn9izaw QdjaEk/eXWCFuFRBYsfZ14wQN1hJrJv/iwmiRlxi45FbLBMYhWYhGTULyahZSEbNQtKygJFl FaNoakFyQXFSeq6RXnFibnFpXrpecn7uJkZwZDyT3sG4qsHiEKMAB6MSD2+CfGWQEGtiWXFl 7iFGCQ5mJRHeDfuAQrwpiZVVqUX58UWlOanFhxilOViUxHkPtloHCgmkJ5akZqemFqQWwWSZ ODilGhiDXukdtX0aZ6ev+6NznvED7p1rEt/Ey6SY9t2PbtgT4czWl1jWtOHI75qqAMX4nQlr DA+pTLmcL1gyw3mT1o+zYoeK61Plw9QFFn1Z5SX/R3jHFuvyX/PUrtpbL75iXmbYlVTmMWnC 7ZqlhpG3zRIYeB4c8ohvCZRcfOt4g8LphokRV5nnLlBiKc5INNRiLipOBAAK6oBciAIAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Gu, > -----Original Message----- > From: Gu Zheng [mailto:guz.fnst@cn.fujitsu.com] > Sent: Wednesday, November 06, 2013 11:41 AM > To: Chao Yu > Cc: ???; linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org; linux-f2fs-devel@lists.sourceforge.net; Ì·æ­ > Subject: Re: [f2fs-dev] [PATCH] f2fs: avoid to use a NULL point in destroy_segment_manager > > On 11/06/2013 09:12 AM, Chao Yu wrote: > > > A NULL point should avoid to be used in destroy_segment_manager after allocating memory fail for f2fs_sm_info. > > Though without this patch it still can work well, because if it failed > to allocate f2fs_sm_info, the sit_info, free_info... all were NULL, and > the destory path(e.g. destroy_dirty_segmap) can deal with them well. I think it could not work well. Without this patch we may got a segment fault in DIRTY_I(sbi) at the following code if it failed to allocate f2fs_sm_info memory(sbi->sm_info). Right? static void destroy_dirty_segmap(struct f2fs_sb_info *sbi) { struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); > IMO, this patch is still a good catch. > > Regards, > Gu > > > > > Signed-off-by: Chao Yu > > --- > > fs/f2fs/segment.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > > index 3d4d5fc..ff363e6 > > --- a/fs/f2fs/segment.c > > +++ b/fs/f2fs/segment.c > > @@ -1744,6 +1744,8 @@ static void destroy_sit_info(struct f2fs_sb_info *sbi) > > void destroy_segment_manager(struct f2fs_sb_info *sbi) > > { > > struct f2fs_sm_info *sm_info = SM_I(sbi); > > + if (!sm_info) > > + return; > > destroy_dirty_segmap(sbi); > > destroy_curseg(sbi); > > destroy_free_segmap(sbi);