Re: [PATCH] block: tolerate 0 byte discard_granularity in __blkdev_issue_discard()

From: Coly Li
Date: Tue Aug 04 2020 - 10:35:58 EST


On 2020/8/4 22:31, Johannes Thumshirn wrote:
> On 04/08/2020 16:23, Coly Li wrote:
>> This is the procedure to reproduce the panic,
>> # modprobe scsi_debug delay=0 dev_size_mb=2048 max_queue=1
>> # losetup -f /dev/nvme0n1 --direct-io=on
>> # blkdiscard /dev/loop0 -o 0 -l 0x200
>
> losetup -f /dev/sdX isn't it?
>

In my case, I use a NVMe SSD as the backing device of the loop device.
Because I don't have a scsi lun.

And loading scsi_debug module seems necessary, otherwise the discard
process just hang and I cannot see the kernel panic (I don't know why yet).

Coly Li