Message-ID: <ZvIxRP0eVkbagUr5@ly-workstation>
Date: Tue, 24 Sep 2024 11:25:56 +0800
From: "Lai, Yi" <yi1.lai@...ux.intel.com>
To: Zhang Yi <yi.zhang@...weicloud.com>
Cc: linux-ext4@...r.kernel.org, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org, tytso@....edu,
	adilger.kernel@...ger.ca, jack@...e.cz, ritesh.list@...il.com,
	yi.zhang@...wei.com, chengzhihao1@...wei.com, yukuai3@...wei.com,
	yi1.lai@...el.com
Subject: Re: [PATCH v5 03/10] ext4: warn if delalloc counters are not zero on
 inactive

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.

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@...alhost

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@...alhost:/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@...wei.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@...wei.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
> 

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