On 3/11/19 10:24 AM, Ming Lei wrote:
> Hi,
>
> It is observed that ext4 is corrupted easily by running some workloads
> on QEMU NVMe, such as:
I cannot reproduce with most recent up-to-date mainline kernel on below qemu
versions:
- qemu-2.10.2
- qemu-3.0.0
>
> 1) mkfs.ext4 /dev/nvme0n1
>
> 2) mount /dev/nvme0n1 /mnt
>
> 3) cd /mnt; git clone
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>
> 4) then the following error message may show up:
>
> [ 1642.271816] EXT4-fs error (device nvme0n1): ext4_mb_generate_buddy:747:
> group 0, block bitmap and bg descriptor inconsistent: 32768 vs 23513 free
> clusters
>
> Or fsck.ext4 will complain after running 'umount /mnt'
>
> The issue disappears by reverting 6e02318eaea53eaafe6 ("nvme: add support for
> the
> Write Zeroes command").
As above commit is for Write Zeros command, I instrument and add printf at the
beginning of nvme_write_zeros() for qemu-2.10.2.
nvme_write_zeros() are only called for 47 times during "mount /dev/nvme0n1
/mnt".
During "git clone" from torvalds' linux.git, there is no call of
nvme_write_zeros().
Perhaps there is some special configuration required to trigger the
nvme_write_zeros() on purpose during "git clone" to involve the
nvme_cmd_write_zeroes on kernel side?
My test nvme image is only about 5GB.
Dongli Zhang
>
> QEMU version:
>
> QEMU emulator version 2.10.2(qemu-2.10.2-1.fc27)
> Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers
>
> Thanks,
> Ming
>
