From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 64C2A69D37; Fri, 1 Mar 2024 08:30:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709281804; cv=none; b=RY1G6o+Upl8MpDOSrUU/ydtzk3uAb4cm+JffQK1VRImbxM5ev2gBB/q6Urm6s1YlMegX3ND+uceM1rPRTaAxkxSUoSiU3z6qxXWxQjFsgXnriCKKSDWMqVeZKZl0kPcxsnmmmbS7UaG6aXw3DOAK0NzAsJptC0mU8jHUcT8Q5Ac= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709281804; c=relaxed/simple; bh=fIlpR6h9TKlVBoQgObZveQagfzEbrFMz1qvxqhTbQbM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=D39okgR8gH8wSnbetEOCPWgSOnQciDEZE6PTriw/TmH+9C4rBk/RL1AKxbJOm2h+FUC4Dr2PACLGKtrXTkPYv1YjXCx3svTendD8oMTTFekPytqJ4645tF6ThDjWHpeC1gbg0P3nDPTcdJ+dEtaobnScS+5GRuDYSizljBQL51M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GNDSPknY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GNDSPknY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4FF1C433F1; Fri, 1 Mar 2024 08:30:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709281804; bh=fIlpR6h9TKlVBoQgObZveQagfzEbrFMz1qvxqhTbQbM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GNDSPknYvpVPD78pZkm3Hj3Rz2pt57ZBWl5owjmre4MrOMaH2+gNiE2gANIOjPmVf FA4mIfjyUwLEDgY2vmAgkFs/43Jo+SLi+M0ZWQ/0mwfTEqlVvtxSgz/ft070r657ac RehUP94ZSV99ONsF6hruvIaZlyld2lyDVUXRT3qUOrZyPzMkAqFuFZ6IYI2iWf6pYj hW/UQBlf8eTm5IhKj/pIeSpOitOWLHuadquVsGz8p107BdzZuqrMpu6mzXo/VDwjnl Fm0J58tdUM6to+BUED+OHqgI4yxK+T4FRT26ARFcpRg3O/Y+b6K2UMp2zZS89xK56c 1VBFTY0dIePQA== Date: Fri, 1 Mar 2024 09:29:58 +0100 From: Christian Brauner To: Kemeng Shi Cc: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, naresh.kamboju@linaro.org, daniel.diaz@linaro.org, linux@roeck-us.net Subject: Re: [PATCH 1/2] ext4: alloc test super block from sget Message-ID: <20240301-kommst-urzustand-e7eb09ccb5b8@brauner> References: <20240301120816.22581-1-shikemeng@huaweicloud.com> <20240301120816.22581-2-shikemeng@huaweicloud.com> <20240301-neuland-zoomen-4152b34c6fba@brauner> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240301-neuland-zoomen-4152b34c6fba@brauner> On Fri, Mar 01, 2024 at 09:25:59AM +0100, Christian Brauner wrote: > On Fri, Mar 01, 2024 at 08:08:15PM +0800, Kemeng Shi wrote: > > This fix the oops in ext4 unit test which is cuased by NULL sb.s_user_ns > > as following: > > <4>[ 14.344565] map_id_range_down (kernel/user_namespace.c:318) > > <4>[ 14.345378] make_kuid (kernel/user_namespace.c:415) > > <4>[ 14.345998] inode_init_always (include/linux/fs.h:1375 fs/inode.c:174) > > <4>[ 14.346696] alloc_inode (fs/inode.c:268) > > <4>[ 14.347353] new_inode_pseudo (fs/inode.c:1007) > > <4>[ 14.348016] new_inode (fs/inode.c:1033) > > <4>[ 14.348644] ext4_mb_init (fs/ext4/mballoc.c:3404 fs/ext4/mballoc.c:3719) > > <4>[ 14.349312] mbt_kunit_init (fs/ext4/mballoc-test.c:57 > > fs/ext4/mballoc-test.c:314) > > <4>[ 14.349983] kunit_try_run_case (lib/kunit/test.c:388 lib/kunit/test.c:443) > > <4>[ 14.350696] kunit_generic_run_threadfn_adapter (lib/kunit/try-catch.c:30) > > <4>[ 14.351530] kthread (kernel/kthread.c:388) > > <4>[ 14.352168] ret_from_fork (arch/arm64/kernel/entry.S:861) > > <0>[ 14.353385] Code: 52808004 b8236ae7 72be5e44 b90004c4 (38e368a1) > > > > Alloc test super block from sget to properly initialize test super block > > to fix the issue. > > > > Signed-off-by: Kemeng Shi > > Reported-by: Linux Kernel Functional Testing > > Reported-by: Guenter Roeck > > --- > > fs/ext4/mballoc-test.c | 46 ++++++++++++++++++++++++++++-------------- > > 1 file changed, 31 insertions(+), 15 deletions(-) > > > > diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c > > index 12d0b22cabe1..1da52bbf4599 100644 > > --- a/fs/ext4/mballoc-test.c > > +++ b/fs/ext4/mballoc-test.c > > @@ -21,16 +21,27 @@ struct mbt_ctx { > > }; > > > > struct mbt_ext4_super_block { > > - struct super_block sb; > > + struct ext4_super_block es; > > + struct ext4_sb_info sbi; > > struct mbt_ctx mbt_ctx; > > }; > > > > -#define MBT_CTX(_sb) (&(container_of((_sb), struct mbt_ext4_super_block, sb)->mbt_ctx)) > > +#define MBT_SB(_sb) (container_of((_sb)->s_fs_info, struct mbt_ext4_super_block, sbi)) > > +#define MBT_CTX(_sb) (&MBT_SB(_sb)->mbt_ctx) > > #define MBT_GRP_CTX(_sb, _group) (&MBT_CTX(_sb)->grp_ctx[_group]) > > > > static const struct super_operations mbt_sops = { > > }; > > > > +static void mbt_kill_sb(struct super_block *sb) > > +{ > > +} > > + > > +static struct file_system_type mbt_fs_type = { > > + .name = "mballoc test", > > + .kill_sb = mbt_kill_sb, > > +}; > > + > > static int mbt_mb_init(struct super_block *sb) > > { > > int ret; > > @@ -72,43 +83,48 @@ static void mbt_mb_release(struct super_block *sb) > > kfree(sb->s_bdev); > > } > > > > +static int mbt_set(struct super_block *sb, void *data) > > +{ > > + return 0; > > +} > > + > > static struct super_block *mbt_ext4_alloc_super_block(void) > > { > > - struct ext4_super_block *es = kzalloc(sizeof(*es), GFP_KERNEL); > > - struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); > > struct mbt_ext4_super_block *fsb = kzalloc(sizeof(*fsb), GFP_KERNEL); > > + struct super_block *sb = sget(&mbt_fs_type, NULL, mbt_set, 0, NULL); > > + struct ext4_sb_info *sbi; > > > > - if (fsb == NULL || sbi == NULL || es == NULL) > > + if (fsb == NULL || sb == NULL) > > sget() returns error pointer on failure. So you should check for IS_ERR(sb). You also want to unlock that superblock up_write(sb->s_umount) if it succeeded and then call deactivate_super() when you are done with it in mbt_kunit_exit().