Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Content-Type: text/plain;
        charset=utf-8
Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.21\))
Subject: Re: bug with large_dir in 5.12.17
From:   =?utf-8?B?0JHQu9Cw0LPQvtC00LDRgNC10L3QutC+INCQ0YDRgtGR0Lw=?= 
        <artem.blagodarenko@gmail.com>
In-Reply-To: <YQrpmUq/y3T/L2E6@mit.edu>
Date:   Thu, 5 Aug 2021 00:15:41 +0300
Cc:     Carlos Carvalho <carlos@fisica.ufpr.br>,
        linux-ext4@vger.kernel.org, Theodore Tso <tytso@google.com>,
        Andreas Dilger <adilger@dilger.ca>
Content-Transfer-Encoding: quoted-printable
Message-Id: <B24E01FD-F436-4BA5-BDB3-E1CDB2E07EF3@gmail.com>
References: <YPl/boTCfc3rlJLU@fisica.ufpr.br>
 <5FE9762B-6C6B-4A44-AC99-22192B76C060@gmail.com> <YQrpmUq/y3T/L2E6@mit.edu>
To:     Theodore Ts'o <tytso@mit.edu>
Precedence: bulk

Hello Teodore,

Your one-line fix looks good.

I have tested it. 1560000 names created successfully.

But the patch with refactoring doesn=E2=80=99t work. I got this messages

1480000 names created
1520000 names created
ln: failed to access =
'n000000000000000000000000000000000000000000000000000000000000000000000000=
00000000000000000000000000000000000000000000000000000000000000000000000000=
00000000000000000000000000000000000000000000000000000000000000000000000000=
000000000000000000000000001520519': Bad message
ln: failed to access =
'n000000000000000000000000000000000000000000000000000000000000000000000000=
00000000000000000000000000000000000000000000000000000000000000000000000000=
00000000000000000000000000000000000000000000000000000000000000000000000000=
000000000000000000000000001520520': Bad message

[ 7699.212018] EXT4-fs error (device loop0): dx_probe:887: inode #2: =
block 144843: comm ln: Directory index failed checksum
[ 7699.216001] EXT4-fs error (device loop0): dx_probe:887: inode #2: =
block 144843: comm ln: Directory index failed checksum

I have no objections to send your one-line fix, but we need to double =
check refactoring.

Best regards,
Artem Blagodarenko


> On 4 Aug 2021, at 22:25, Theodore Ts'o <tytso@mit.edu> wrote:
>=20
> On Thu, Jul 29, 2021 at 10:23:35PM +0300, =D0=91=D0=BB=D0=B0=D0=B3=D0=BE=
=D0=B4=D0=B0=D1=80=D0=B5=D0=BD=D0=BA=D0=BE =D0=90=D1=80=D1=82=D1=91=D0=BC =
wrote:
>> Hello,
>>=20
>> It looks like the fix b5776e7524afbd4569978ff790864755c438bba7 "ext4: =
fix potential htree index checksum corruption=E2=80=9D introduced this =
regression.
>> I reverted it and my test from previous message passed the dangerous =
level of 1570000 names count.
>> Now test is still in progress. 2520000 names are already created.
>>=20
>> I am searching the way to fix this.
>>=20
>> Best regards,
>> Artem Blagodarenko.
>=20
> Hi Artem, did you have a chance to take a look at some of the possible
> fixes which I floated on this thread?
>=20
> Do you have any objections if I take this and send it to Linus?
>=20
> Thanks,
>=20
> 					- Ted
>=20
> =46rom fa8db30806b4e83981c65f18f98de33f804012d9 Mon Sep 17 00:00:00 =
2001
> From: Theodore Ts'o <tytso@mit.edu>
> Date: Wed, 4 Aug 2021 14:23:55 -0400
> Subject: [PATCH] ext4: fix potential htree correuption when growing =
large_dir
> directories
> MIME-Version: 1.0
> Content-Type: text/plain; charset=3DUTF-8
> Content-Transfer-Encoding: 8bit
>=20
> Commit b5776e7524af ("ext4: fix potential htree index checksum
> corruption) removed a required restart when multiple levels of index
> nodes need to be split.  Fix this to avoid directory htree corruptions
> when using the large_dir feature.
>=20
> Cc: stable@kernel.org # v5.11
> Cc: =D0=91=D0=BB=D0=B0=D0=B3=D0=BE=D0=B4=D0=B0=D1=80=D0=B5=D0=BD=D0=BA=D0=
=BE =D0=90=D1=80=D1=82=D1=91=D0=BC <artem.blagodarenko@gmail.com>
> Fixes: b5776e7524af ("ext4: fix potential htree index checksum =
corruption)
> Reported-by: Denis <denis@voxelsoft.com>
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> ---
> fs/ext4/namei.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>=20
> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
> index 5fd56f616cf0..f3bbcd4efb56 100644
> --- a/fs/ext4/namei.c
> +++ b/fs/ext4/namei.c
> @@ -2517,7 +2517,7 @@ static int ext4_dx_add_entry(handle_t *handle, =
struct ext4_filename *fname,
> 				goto journal_error;
> 			err =3D ext4_handle_dirty_dx_node(handle, dir,
> 							frame->bh);
> -			if (err)
> +			if (restart || err)
> 				goto journal_error;
> 		} else {
> 			struct dx_root *dxroot;
> --=20
> 2.31.0
>=20