From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chao Yu <chao2.yu@samsung.com>
Subject: RE: [f2fs-dev] [PATCH] f2fs: avoid to use a NULL point in
 destroy_segment_manager
Date: Wed, 06 Nov 2013 13:59:13 +0800
Message-ID: <000201cedab5$89f0f9d0$9dd2ed70$@samsung.com>
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 <000101cedaae$bb7ed820$327c8860$@samsung.com> <5279D078.8080803@cn.fujitsu.com>
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Cc: '???' <jaegeuk.kim@samsung.com>, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-f2fs-devel@lists.sourceforge.net,
	=?gb2312?B?J8y35q0n?= <shu.tan@samsung.com>
To: 'Gu Zheng' <guz.fnst@cn.fujitsu.com>
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Hi Gu,=20

Thanks for your reviewing!

Regards
Yu

> -----Original Message-----
> From: Gu Zheng [mailto:guz.fnst@cn.fujitsu.com]
> Sent: Wednesday, November 06, 2013 1:16 PM
> To: Chao Yu
> Cc: '???'; linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.or=
g; linux-f2fs-devel@lists.sourceforge.net; '=CC=B7=E6=AD'
> Subject: Re: [f2fs-dev] [PATCH] f2fs: avoid to use a NULL point in de=
stroy_segment_manager
>=20
> On 11/06/2013 01:10 PM, Chao Yu wrote:
>=20
> > 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.o=
rg; linux-f2fs-devel@lists.sourceforge.net; =CC=B7=E6=AD
> >> 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 a=
fter allocating memory fail for f2fs_sm_info.
> >>
> >> Though without this patch it still can work well, because if it fa=
iled
> >> 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 wel=
l.
> >
> > I think it could not work well. Without this patch we may got a seg=
ment
> > fault in DIRTY_I(sbi) at the following code if it failed to allocat=
e
> > f2fs_sm_info memory(sbi->sm_info). Right?
>=20
> Yes, you're right. SIT_I generates sit_info from f2fs_sm_info.
> Sorry for my mistake.:(
>=20
> Regards,
> Gu
>=20
> >
> > static void destroy_dirty_segmap(struct f2fs_sb_info *sbi)
> > {
> > 	struct dirty_seglist_info *dirty_i =3D DIRTY_I(sbi);
> >
> >> IMO, this patch is still a good catch.
> >>
> >> Regards,
> >> Gu
> >>
> >>>
> >>> Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> >>> ---
> >>>  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 =3D SM_I(sbi);
> >>> +	if (!sm_info)
> >>> +		return;
> >>>  	destroy_dirty_segmap(sbi);
> >>>  	destroy_curseg(sbi);
> >>>  	destroy_free_segmap(sbi);
> >
> >
> >
>=20
>=20
> =3D