Re: scsi_id: sending ioctl 2285 to a partition
From: Nelson, Doug
Date: Fri Feb 10 2012 - 12:19:41 EST
On 02/10/2012 12:17 AM, Paolo Bonzini wrote:
On 02/09/2012 10:00 PM, Matthew Wilcox wrote:
On Thu, Feb 09, 2012 at 12:42:00PM -0800, Linus Torvalds wrote:
On Thu, Feb 9, 2012 at 12:29 PM, Matthew
Wilcox<willy@xxxxxxxxxxxxxxx> wrote:
Commit 0bfc96cb77 adds this printk that triggers tens of thousands of
times during a run of "a well-known database benchmark". 0x2285 is
SG_IO.
I'm not sure why scsi_id feels that it needs to repeatedly send a SCSI
INQUIRY to a partition, but there we are.
So is it doing this as root (in which case we end up allowing it) or
as a normal user (in which case we end up disallowing it)?
I'm pretty sure it's doing it as root ... it'll be run by udev, after
all.
What does the rule look like? Here it is like this:
# scsi devices
KERNEL=="sd*[!0-9]|sr*", ENV{ID_SERIAL}!="?*",
IMPORT{program}="scsi_id --export --whitelisted -d $tempnode",
ENV{ID_BUS}="scsi"
The rule I had was not excluding partitions. I'll fix that and try again.
thanks,
doug
which should exclude partitions, and indeed I don't see any such
message. I also have this rule:
# for partitions import parent information
ENV{DEVTYPE}=="partition", IMPORT{parent}="ID_*"
which makes it clear that udev does not need to send INQUIRY to the
partition.
And does it all work well apart from the printk? Because the printk
itself is scheduled to be removed, it's only there to hear about users
that may be doing crazy things that got disallowed by the patches in
question?
If it is being run as root, then the printk is pointless, right?
At the time the printk is removed, access also will be disallowed to
root.
Paolo
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