Re: [PATCH] scsi: allow persistent reservations without CAP_SYS_RAWIO

From: Paolo Bonzini
Date: Tue Jun 12 2012 - 13:13:48 EST


Il 12/06/2012 19:08, John Stoffel ha scritto:
> Paolo> Persistent reservations commands cannot be issued right now
> Paolo> without giving CAP_SYS_RAWIO to the process who wishes to send
> Paolo> them. This is a bit heavy-handed, allow these two commands.
>
> This seems like a bad idea, now anyone can just put in a SCSI
> reservation on a system and then you have to hunt around trying to
> figure it out.

What's the difference from anyone destroying data on a disk? You still
need write access to the block device node. Also, you could already do
the same if you have root permissions on your _local_ machine.

(BTW, please reply to these objections where I already stated them, in
the answer to James Bottomley).

> What's the motivation here? What's the use case this solves?

I would like to give access to persistent reservations to VMs, without
having to run qemu as root. One alternative is to run a userspace iSCSI
initiator, but of course that would only work with iSCSI.

Paolo
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