Re: [PATCH] scsi:Prevent deletion of SCSI block device in use

["Ewan D. Milne" <emilne@redhat.com>]

On Tue, 2016-09-13 at 22:08 +0530, Gurunath, Vasundhara wrote:
> From: "Gurunath, Vasundhara" <vasundhara.gurunath@hpe.com>
> 
> SCSI block device can be removed, using write to sysfs
> delete file as below:
> echo 1 > /sys/block/sdX/device/delete
> If the device is in use by applications, or part of
> system configuration such as boot device, removal can
> result in application disruptions or system down time.
> 
> An additional write option ? is added to SCSI sysfs
> interface as below, in order to prevent accidental
> deletion of devices in use.
> echo ? > /sys/block/sdX/device/delete
> 
> In the absence of any usage, this option proceeds with
> device deletion.  If the device is open, deletion is
> prevented, and active Open and IO counts at the time of
> deletion is logged. Information logged during latest
> delete attempt can be obtained by issuing a read to the
> delete file as below:
> cat  /sys/block/sdX/device/delete
> 

This looks like debugging code added to find some culprit
who deleted a device they weren't supposed to, and make it
more difficult for them.

I don't think we'd want this in normal usage.

-Ewan