Re: next: /dev/root: Can't open blockdev

[Jan Kara]

On Tue 06-02-24 14:41:17, Naresh Kamboju wrote:
> All qemu's mount rootfs failed on Linux next-20230206 tag due to the following
> kernel crash.
> 
> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> 
> Crash log:
> ---------
> <3>[    3.257960] /dev/root: Can't open blockdev
> <4>[    3.258940] VFS: Cannot open root device "/dev/sda" or
> unknown-block(8,0): error -16

Uhuh, -16 is EBUSY so it seems Christian's block device opening changes are
suspect? Do you have some sample kconfig available somewhere?

								Honza

> <4>[    3.259704] Please append a correct "root=" boot option; here
> are the available partitions:
> <4>[    3.261088] 0800         2500336 sda
> <4>[    3.261186]  driver: sd
> <4>[    3.262260] 0b00         1048575 sr0
> <4>[    3.262409]  driver: sr
> <3>[    3.263022] List of all bdev filesystems:
> <3>[    3.263553]  ext3
> <3>[    3.263708]  ext2
> <3>[    3.263994]  ext4
> <3>[    3.264160]  vfat
> <3>[    3.264419]  msdos
> <3>[    3.264589]  iso9660
> <3>[    3.264773]
> <0>[    3.265665] Kernel panic - not syncing: VFS: Unable to mount
> root fs on unknown-block(8,0)
> <4>[    3.266991] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
> 6.8.0-rc3-next-20240206 #1
> <4>[    3.267593] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009),
> BIOS 1.16.3-debian-1.16.3-2 04/01/2014
> <4>[    3.268937] Call Trace:
> <4>[    3.269316]  <TASK>
> <4>[    3.270113]  dump_stack_lvl+0x71/0xb0
> <4>[    3.271837]  dump_stack+0x14/0x20
> <4>[    3.272128]  panic+0x12f/0x2f0
> <4>[    3.272812]  ? _printk+0x5d/0x80
> <4>[    3.273097]  mount_root_generic+0x26e/0x2b0
> <4>[    3.273941]  mount_block_root+0x3f/0x50
> <4>[    3.274212]  mount_root+0x60/0x80
> <4>[    3.274610]  prepare_namespace+0x7a/0xb0
> <4>[    3.276008]  kernel_init_freeable+0x137/0x180
> <4>[    3.276285]  ? __pfx_kernel_init+0x10/0x10
> <4>[    3.276563]  kernel_init+0x1e/0x1a0
> <4>[    3.276837]  ret_from_fork+0x45/0x50
> <4>[    3.277319]  ? __pfx_kernel_init+0x10/0x10
> <4>[    3.278176]  ret_from_fork_asm+0x1a/0x30
> <4>[    3.278560]  </TASK>
> <0>[    3.280750] Kernel Offset: 0x1a800000 from 0xffffffff81000000
> (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
> <0>[    3.281985] ---[ end Kernel panic - not syncing: VFS: Unable to
> mount root fs on unknown-block(8,0) ]---
> 
> 
> Links:
>  - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240206/testrun/22547673/suite/log-parser-test/test/check-kernel-panic/log
>  - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20240206/testrun/22547673/suite/log-parser-test/tests/
> 
> --
> Linaro LKFT
> https://lkft.linaro.org
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR