Re: [PATCH v5 03/10] ext4: warn if delalloc counters are not zero on inactive

Zhang Yi
2024-09-25T11:35:01Z

On 2024/9/25 17:52, Lai, Yi wrote:
> Hi,
>
> I have applied your mentioned patch series on top of linux tag v6.11.
> Using the same repro binary, issue cannot be reproduced.
>

Ah, that's great, this series seems had fixed some corner problems
as well, thanks a lot for testing this.

Thanks,
Yi.

> Regards,
> Yi Lai
>
> On Tue, Sep 24, 2024 at 04:38:22PM +0800, Zhang Yi wrote:
>> On 2024/9/24 11:25, Lai, Yi wrote:
>>> Hi Zhang Yi,
>>>
>>> Greetings!
>>>
>>> I used Syzkaller and found that there is WARNING in ext4_destroy_inode.
>>>
>>> After bisection and the first bad commit is:
>>> "
>>> b37c907073e8 ext4: warn if delalloc counters are not zero on inactive
>>> "
>>>
>>> I understand that the commit is to add WARN_ON_ONCE to make error message more visible. I hope the reproduction program will be insightful for you.
>>>
>>
>> Thanks for the report! It seems that this patch worked, it start exposing
>> problems about inconsistent delalloc counter, which were previously hidden.
>> However, the counter updating logic has changed after this series:
>>
>> https://lore.kernel.org/linux-ext4/20240813123452.2824659-1-yi.zhang@huaweicloud.com/
>>
>> Could you reproduce this issue with this series or in the latest upstream
>> kernel?
>>
>> Thanks,
>> Yi.
>>
>>> All detailed into can be found at:
>>> https://github.com/laifryiee/syzkaller_logs/tree/main/240923_043748_ext4_destroy_inode
>>> Syzkaller repro code:
>>> https://github.com/laifryiee/syzkaller_logs/blob/main/240923_043748_ext4_destroy_inode/repro.c
>>> Syzkaller repro syscall steps:
>>> https://github.com/laifryiee/syzkaller_logs/blob/main/240923_043748_ext4_destroy_inode/repro.prog
>>> Syzkaller report:
>>> https://github.com/laifryiee/syzkaller_logs/blob/main/240923_043748_ext4_destroy_inode/repro.report
>>> Kconfig(make olddefconfig):
>>> https://github.com/laifryiee/syzkaller_logs/blob/main/240923_043748_ext4_destroy_inode/kconfig_origin
>>> Bisect info:
>>> https://github.com/laifryiee/syzkaller_logs/blob/main/240923_043748_ext4_destroy_inode/bisect_info.log
>>> bzImage:
>>> https://github.com/laifryiee/syzkaller_logs/raw/main/240923_043748_ext4_destroy_inode/bzImage_98f7e32f20d28ec452afb208f9cffc08448a2652
>>> Issue dmesg:
>>> https://github.com/laifryiee/syzkaller_logs/blob/main/240923_043748_ext4_destroy_inode/98f7e32f20d28ec452afb208f9cffc08448a2652_dmesg.log
>>>
>>> "
>>> [ 25.223775] ------------[ cut here ]------------
>>> [ 25.224177] WARNING: CPU: 0 PID: 740 at fs/ext4/super.c:1464 ext4_destroy_inode+0x1de/0x280
>>> [ 25.224724] Modules linked in:
>>> [ 25.224920] CPU: 0 UID: 0 PID: 740 Comm: repro Not tainted 6.11.0-98f7e32f20d2 #1
>>> [ 25.225393] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
>>> [ 25.226103] RIP: 0010:ext4_destroy_inode+0x1de/0x280
>>> [ 25.226429] Code: 31 ff 44 89 e6 e8 62 ad 45 ff 45 85 e4 75 16 e8 d8 a9 45 ff 48 8d 65 e0 5b 41 5c 41 5d 41 5e 5d c3 cc cc cc cc e8 c2 a9 45 ff <0f> 0b 48 8d 7b 40 4c 8d 83 50 fd ff ff 48 b8 00 00 00 00 00 fc ff
>>> [ 25.227570] RSP: 0018:ff11000023707c08 EFLAGS: 00010293
>>> [ 25.227915] RAX: 0000000000000000 RBX: ff11000022f22a50 RCX: ffffffff822028de
>>> [ 25.228357] RDX: ff110000139a8000 RSI: ffffffff822028fe RDI: 0000000000000005
>>> [ 25.228840] RBP: ff11000023707c30 R08: 0000000000000001 R09: ffe21c00024e24eb
>>> [ 25.229284] R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001
>>> [ 25.229712] R13: ff11000012712000 R14: ff11000022f22ad0 R15: ff1100006c1aa440
>>> [ 25.230168] FS: 00007f1d418a7800(0000) GS:ff1100006c400000(0000) knlGS:0000000000000000
>>> [ 25.230666] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [ 25.230818] EXT4-fs (sda): Inode 151593 (000000004419e1b8): i_reserved_data_blocks (1) not cleared!
>>> [ 25.231037] CR2: 00007f1d416b1ac0 CR3: 00000000140e4004 CR4: 0000000000771ef0
>>> [ 25.232104] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>> [ 25.232546] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
>>> [ 25.233006] PKRU: 55555554
>>> [ 25.233184] Call Trace:
>>> [ 25.233348] <TASK>
>>> [ 25.233489] ? show_regs+0xa8/0xc0
>>> [ 25.233724] ? __warn+0xee/0x380
>>> [ 25.233953] ? report_bug+0x25e/0x4b0
>>> [ 25.234201] ? ext4_destroy_inode+0x1de/0x280
>>> [ 25.234485] ? report_bug+0x2cb/0x4b0
>>> [ 25.234729] ? ext4_destroy_inode+0x1de/0x280
>>> [ 25.235020] ? handle_bug+0xa2/0x130
>>> [ 25.235266] ? exc_invalid_op+0x3c/0x80
>>> [ 25.235513] ? asm_exc_invalid_op+0x1f/0x30
>>> [ 25.235786] ? ext4_destroy_inode+0x1be/0x280
>>> [ 25.236072] ? ext4_destroy_inode+0x1de/0x280
>>> [ 25.236356] ? ext4_destroy_inode+0x1de/0x280
>>> [ 25.236637] ? ext4_destroy_inode+0x1de/0x280
>>> [ 25.236949] ? __pfx_ext4_destroy_inode+0x10/0x10
>>> [ 25.237257] destroy_inode+0xd6/0x1d0
>>> [ 25.237507] evict+0x5a7/0x930
>>> [ 25.237708] ? lock_release+0x441/0x870
>>> [ 25.237975] ? do_raw_spin_lock+0x141/0x280
>>> [ 25.238246] ? __pfx_evict+0x10/0x10
>>> [ 25.238486] ? __pfx_lock_release+0x10/0x10
>>> [ 25.238757] ? lock_release+0x441/0x870
>>> [ 25.239015] ? lock_release+0x441/0x870
>>> [ 25.239266] ? do_raw_spin_unlock+0x15c/0x210
>>> [ 25.239552] iput.part.0+0x543/0x740
>>> [ 25.239788] ? __pfx_ext4_drop_inode+0x10/0x10
>>> [ 25.240081] iput+0x68/0x90
>>> [ 25.240265] do_unlinkat+0x5dc/0x730
>>> [ 25.240503] ? __pfx_do_unlinkat+0x10/0x10
>>> [ 25.240791] ? __sanitizer_cov_trace_const_cmp8+0x1c/0x30
>>> [ 25.241149] ? strncpy_from_user+0x1ef/0x2e0
>>> [ 25.241436] ? __sanitizer_cov_trace_const_cmp4+0x1a/0x20
>>> [ 25.241774] ? getname_flags.part.0+0x1d5/0x570
>>> [ 25.242459] __x64_sys_unlink+0xd1/0x120
>>> [ 25.242749] x64_sys_call+0x2014/0x20d0
>>> [ 25.243031] do_syscall_64+0x6d/0x140
>>> [ 25.243304] entry_SYSCALL_64_after_hwframe+0x76/0x7e
>>> [ 25.243630] RIP: 0033:0x7f1d4163eb7b
>>> [ 25.243878] Code: f0 ff ff 73 01 c3 48 8b 0d a2 b2 1b 00 f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 75 b2 1b 00 f7 d8 64 89 01 48
>>> [ 25.245038] RSP: 002b:00007fffffa2ca48 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
>>> [ 25.245508] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1d4163eb7b
>>> [ 25.245966] RDX: 00007fffffa2ca60 RSI: 00007fffffa2caf0 RDI: 00007fffffa2caf0
>>> [ 25.246412] RBP: 00007fffffa2db30 R08: 0000000000000000 R09: 00007fffffa2c8e0
>>> [ 25.246872] R10: 00007f1d4160b208 R11: 0000000000000206 R12: 00007fffffa2dca8
>>> [ 25.247310] R13: 0000000000402e4b R14: 0000000000404e08 R15: 00007f1d418f2000
>>> [ 25.247759] </TASK>
>>> [ 25.247912] irq event stamp: 5719
>>> [ 25.248127] hardirqs last enabled at (5727): [<ffffffff81458eb4>] console_unlock+0x224/0x240
>>> [ 25.248690] hardirqs last disabled at (5736): [<ffffffff81458e99>] console_unlock+0x209/0x240
>>> [ 25.249236] softirqs last enabled at (5252): [<ffffffff81289d19>] __irq_exit_rcu+0xa9/0x120
>>> [ 25.249768] softirqs last disabled at (5247): [<ffffffff81289d19>] __irq_exit_rcu+0xa9/0x120
>>> [ 25.250311] ---[ end trace 0000000000000000 ]---
>>> [ 25.250602] EXT4-fs (sda): Inode 151586 (00000000f9d6a315): i_reserved_data_blocks (1) not cleared!
>>> [ 25.326263] EXT4-fs (sda): Inode 151578 (00000000d86ad2f9): i_reserved_data_blocks (1) not cleared!
>>> [ 25.680884] EXT4-fs (sda): Inode 151596 (00000000da9177c9): i_reserved_data_blocks (1) not cleared!
>>> [ 25.717550] EXT4-fs (sda): Inode 151573 (0000000088687caa): i_reserved_data_blocks (1) not cleared!
>>> [ 25.726089] EXT4-fs (sda): Inode 151585 (000000005d7aed9a): i_reserved_data_blocks (1) not cleared!
>>> [ 25.838592] EXT4-fs (sda): Inode 151573 (000000004af622df): i_reserved_data_blocks (1) not cleared!
>>> [ 25.955073] EXT4-fs (sda): Inode 151598 (00000000a6e598ec): i_reserved_data_blocks (1) not cleared!
>>> [ 26.525552] EXT4-fs (sda): Inode 151593 (0000000026aef1cd): i_reserved_data_blocks (1) not cleared!
>>> [ 26.554067] EXT4-fs (sda): Inode 151591 (0000000051e990da): i_reserved_data_blocks (1) not cleared!
>>> [ 30.291490] EXT4-fs: 14 callbacks suppressed
>>> [ 30.291510] EXT4-fs (sda): Inode 151591 (0000000050be254a): i_reserved_data_blocks (1) not cleared!
>>> [ 30.301238] EXT4-fs (sda): Inode 151587 (000000004ba9ad70): i_reserved_data_blocks (1) not cleared!
>>> [ 30.414377] EXT4-fs (sda): Inode 151583 (00000000f6751ad3): i_reserved_data_blocks (1) not cleared!
>>> [ 30.417213] EXT4-fs (sda): Inode 151591 (0000000090a0dce3): i_reserved_data_blocks (1) not cleared!
>>> [ 30.537920] EXT4-fs (sda): Inode 151587 (00000000de72acf9): i_reserved_data_blocks (1) not cleared!
>>> [ 30.645791] EXT4-fs (sda): Inode 151580 (00000000a40a052f): i_reserved_data_blocks (1) not cleared!
>>> [ 30.665732] EXT4-fs (sda): Inode 151587 (00000000d9452edd): i_reserved_data_blocks (1) not cleared!
>>> [ 30.670204] EXT4-fs (sda): Inode 151597 (00000000f861d75f): i_reserved_data_blocks (1) not cleared!
>>> [ 31.964931] EXT4-fs (sda): Inode 151589 (000000009baa4064): i_reserved_data_blocks (1) not cleared!
>>> [ 32.101343] EXT4-fs (sda): Inode 151598 (000000003fca6cd5): i_reserved_data_blocks (1) not cleared!
>>> "
>>>
>>> I hope you find it useful.
>>>
>>> Regards,
>>> Yi Lai
>>>
>>> ---
>>>
>>> If you don't need the following environment to reproduce the problem or if you
>>> already have one reproduced environment, please ignore the following information.
>>>
>>> How to reproduce:
>>> git clone https://gitlab.com/xupengfe/repro_vm_env.git
>>> cd repro_vm_env
>>> tar -xvf repro_vm_env.tar.gz
>>> cd repro_vm_env; ./start3.sh // it needs qemu-system-x86_64 and I used v7.1.0
>>> // start3.sh will load bzImage_2241ab53cbb5cdb08a6b2d4688feb13971058f65 v6.2-rc5 kernel
>>> // You could change the bzImage_xxx as you want
>>> // Maybe you need to remove line "-drive if=pflash,format=raw,readonly=on,file=./OVMF_CODE.fd \" for different qemu version
>>> You could use below command to log in, there is no password for root.
>>> ssh -p 10023 root@localhost
>>>
>>> After login vm(virtual machine) successfully, you could transfer reproduced
>>> binary to the vm by below way, and reproduce the problem in vm:
>>> gcc -pthread -o repro repro.c
>>> scp -P 10023 repro root@localhost:/root/
>>>
>>> Get the bzImage for target kernel:
>>> Please use target kconfig and copy it to kernel_src/.config
>>> make olddefconfig
>>> make -jx bzImage //x should equal or less than cpu num your pc has
>>>
>>> Fill the bzImage file into above start3.sh to load the target kernel in vm.
>>>
>>> Tips:
>>> If you already have qemu-system-x86_64, please ignore below info.
>>> If you want to install qemu v7.1.0 version:
>>> git clone https://github.com/qemu/qemu.git
>>> cd qemu
>>> git checkout -f v7.1.0
>>> mkdir build
>>> cd build
>>> yum install -y ninja-build.x86_64
>>> yum -y install libslirp-devel.x86_64
>>> ../configure --target-list=x86_64-softmmu --enable-kvm --enable-vnc --enable-gtk --enable-sdl --enable-usb-redir --enable-slirp
>>> make
>>> make install
>>>
>>> On Fri, May 17, 2024 at 08:39:58PM +0800, Zhang Yi wrote:
>>>> From: Zhang Yi <yi.zhang@huawei.com>
>>>>
>>>> The per-inode i_reserved_data_blocks count the reserved delalloc blocks
>>>> in a regular file, it should be zero when destroying the file. The
>>>> per-fs s_dirtyclusters_counter count all reserved delalloc blocks in a
>>>> filesystem, it also should be zero when umounting the filesystem. Now we
>>>> have only an error message if the i_reserved_data_blocks is not zero,
>>>> which is unable to be simply captured, so add WARN_ON_ONCE to make it
>>>> more visable.
>>>>
>>>> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
>>>> ---
>>>> fs/ext4/super.c | 6 +++++-
>>>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
>>>> index 044135796f2b..b68064c877e3 100644
>>>> --- a/fs/ext4/super.c
>>>> +++ b/fs/ext4/super.c
>>>> @@ -1343,6 +1343,9 @@ static void ext4_put_super(struct super_block *sb)
>>>>
>>>> ext4_group_desc_free(sbi);
>>>> ext4_flex_groups_free(sbi);
>>>> +
>>>> + WARN_ON_ONCE(!(sbi->s_mount_state & EXT4_ERROR_FS) &&
>>>> + percpu_counter_sum(&sbi->s_dirtyclusters_counter));
>>>> ext4_percpu_param_destroy(sbi);
>>>> #ifdef CONFIG_QUOTA
>>>> for (int i = 0; i < EXT4_MAXQUOTAS; i++)
>>>> @@ -1473,7 +1476,8 @@ static void ext4_destroy_inode(struct inode *inode)
>>>> dump_stack();
>>>> }
>>>>
>>>> - if (EXT4_I(inode)->i_reserved_data_blocks)
>>>> + if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ERROR_FS) &&
>>>> + WARN_ON_ONCE(EXT4_I(inode)->i_reserved_data_blocks))
>>>> ext4_msg(inode->i_sb, KERN_ERR,
>>>> "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
>>>> inode->i_ino, EXT4_I(inode),
>>>> --
>>>> 2.39.2
>>>>
>>>
>>