Re: [linus:master] [xfs] 304a68b9c6: WARNING:at_fs/iomap/buffered-io.c:#iomap_write_delalloc_release

[Dave Chinner <david@fromorbit.com>]

On Tue, Feb 28, 2023 at 04:40:01PM +0800, kernel test robot wrote:
> Greeting,
> 
> FYI, we noticed WARNING:at_fs/iomap/buffered-io.c:#iomap_write_delalloc_release due to commit (built with gcc-11):
> 
> commit: 304a68b9c63bbfc1f6e159d68e8892fc54a06067 ("xfs: use iomap_valid method to detect stale cached iomaps")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> 
> [test failed on linux-next/master 058f4df42121baadbb8a980c06011e912784dbd2]
> in testcase: xfstests
> version: xfstests-i386-5a5e419-1_20220926
> with following parameters:
> 
> 	disk: 4HDD
> 	fs: xfs
> 	test: generic-group-32

Which fstest was running at the time this warning was thrown?

> 
> test-description: xfstests is a regression test suite for xfs and other files ystems.
> test-url: git://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git
> 
> on test machine: 8 threads Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz (Skylake) with 28G memory
> 
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
> 
> 
> [   78.565703][   T59] ------------[ cut here ]------------
> [ 78.570983][ T59] WARNING: CPU: 4 PID: 59 at fs/iomap/buffered-io.c:984 iomap_write_delalloc_release (buffered-io.c:?) 

Well, that's useless without the function offset or line number to
tell us what warning in that function triggered.

> [   78.581265][   T59] Modules linked in: loop(E) dm_flakey(E) xfs(E) dm_mod(E) intel_rapl_msr(E) intel_rapl_common(E) btrfs(E) blake2b_generic(E) xor(E) raid6_pq(E) zstd_compress(E) x86_pkg_temp_thermal(E) libcrc32c(E) intel_powerclamp(E) crc32c_generic(E) coretemp(E) sd_mod(E) t10_pi(E) ipmi_devintf(E) kvm_intel(E) ipmi_msghandler(E) i915(E) crc64_rocksoft_generic(E) kvm(E) irqbypass(E) crc64_rocksoft(E) crc64(E) drm_buddy(E) crc32_pclmul(E) crc32c_intel(E) aesni_intel(E) crypto_simd(E) drm_display_helper(E) cryptd(E) cec(E) mei_wdt(E) wmi_bmof(E) rapl(E) ahci(E) evdev(E) ttm(E) xhci_pci(E) intel_cstate(E) xhci_hcd(E) libahci(E) i2c_i801(E) mei_me(E) drm_kms_helper(E) syscopyarea(E) intel_uncore(E) usbcore(E) i2c_smbus(E) sysfillrect(E) libata(E) mei(E) sysimgblt(E) intel_pch_thermal(E) fb_sys_fops(E) usb_common(E) video(E) fan(E) thermal(E) wmi(E) acpi_pad(E) button(E) fuse(E) drm(E) configfs(E) autofs4(E)
> [   78.661092][   T59] CPU: 4 PID: 59 Comm: kworker/u16:2 Tainted: G            E      6.1.0-rc4-00008-g304a68b9c63b #1

This looks like a broken kernel install. Why are all the modules
tainted?

> [   78.671542][   T59] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.2.8 01/26/2016
> [   78.679578][   T59] Workqueue: loop0 loop_rootcg_workfn [loop]
> [ 78.685393][ T59] EIP: iomap_write_delalloc_release (buffered-io.c:?) 
> [ 78.691449][ T59] Code: e8 cf 94 ed ff f0 ff 4b 1c 74 45 8b 45 e0 8b 40 20 83 c0 10 e8 ab 93 d8 ff 8d 65 f4 89 f0 5b 5e 5f 5d c3 0f 0b e9 f9 fd ff ff <0f> 0b e9 e0 fd ff ff 0f 0b 8b 45 cc 8b 4d f0 8b 55 d0 39 c8 89 d0
> All code
> ========
>    0:	e8 cf 94 ed ff       	callq  0xffffffffffed94d4
>    5:	f0 ff 4b 1c          	lock decl 0x1c(%rbx)
>    9:	74 45                	je     0x50
>    b:	8b 45 e0             	mov    -0x20(%rbp),%eax
>    e:	8b 40 20             	mov    0x20(%rax),%eax
>   11:	83 c0 10             	add    $0x10,%eax
>   14:	e8 ab 93 d8 ff       	callq  0xffffffffffd893c4
>   19:	8d 65 f4             	lea    -0xc(%rbp),%esp
>   1c:	89 f0                	mov    %esi,%eax
>   1e:	5b                   	pop    %rbx
>   1f:	5e                   	pop    %rsi
>   20:	5f                   	pop    %rdi
>   21:	5d                   	pop    %rbp
>   22:	c3                   	retq   
>   23:	0f 0b                	ud2    
>   25:	e9 f9 fd ff ff       	jmpq   0xfffffffffffffe23
>   2a:*	0f 0b                	ud2    		<-- trapping instruction
>   2c:	e9 e0 fd ff ff       	jmpq   0xfffffffffffffe11
>   31:	0f 0b                	ud2    
>   33:	8b 45 cc             	mov    -0x34(%rbp),%eax
>   36:	8b 4d f0             	mov    -0x10(%rbp),%ecx
>   39:	8b 55 d0             	mov    -0x30(%rbp),%edx
>   3c:	39 c8                	cmp    %ecx,%eax
>   3e:	89 d0                	mov    %edx,%eax
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	0f 0b                	ud2    
>    2:	e9 e0 fd ff ff       	jmpq   0xfffffffffffffde7
>    7:	0f 0b                	ud2    
>    9:	8b 45 cc             	mov    -0x34(%rbp),%eax
>    c:	8b 4d f0             	mov    -0x10(%rbp),%ecx
>    f:	8b 55 d0             	mov    -0x30(%rbp),%edx
>   12:	39 c8                	cmp    %ecx,%eax
>   14:	89 d0                	mov    %edx,%eax
> [   78.710792][   T59] EAX: 2335a000 EBX: 00000004 ECX: fffffffc EDX: 00000004
> [   78.717707][   T59] ESI: 2335b000 EDI: 00000000 EBP: c3187c24 ESP: c3187bf0
> [   78.724624][   T59] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010297
> [   78.732056][   T59] CR0: 80050033 CR2: b7da00b0 CR3: 02350000 CR4: 003506f0
> [   78.738971][   T59] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
> [   78.745887][   T59] DR6: fffe0ff0 DR7: 00000400
> [   78.750389][   T59] Call Trace:
> [ 78.753508][ T59] iomap_file_buffered_write_punch_delalloc (??:?) 
> [ 78.760183][ T59] ? xfs_buffered_write_iomap_end (xfs_iomap.c:?) xfs
> [ 78.766541][ T59] xfs_buffered_write_iomap_end (xfs_iomap.c:?) xfs

What's with all the broken/missing function offsets and
file/line numbers in the stack trace?

Please fix your tooling - this report isn't useful with all the
offset/line number information being broken like this

Cheers,

Dave.

-- 
Dave Chinner
david@fromorbit.com