Re: [PATCH v4 0/2] [SCSI] Asynchronous event notification infrastructure

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



James Bottomley wrote:
Ah, OK; I haven't communicated what we need very clearly.  We need a way
to see if the event is supported by the device, as well as a way to turn
it off.  For some of the events (possibly not the SATA AN one, since I
know all SATA devices will be well behaved) there's going to be a need
to deal with berserk or broken devices that become trigger happy, so
turning off the event will be a useful (and possibly essential) way of
coping.


That's possible with the presented interface[1]:

	# see if event is supported
	cat $path/evt_media_change

	# turn off event to deal with broken/beserk devices
	echo 0 > $path/evt_media_change

Some sillyhead can always do

	echo 1 > $path/evt_some_event_my_device_does_not_support

but that will be obviously be a no-op because their device simply will not send such events.

Granted ls(1) is no longer a method for viewing supported-at-boot-time list of events -- ls(1) in the presented interface lists what events the _kernel_ supports, and cat(1) is used to discover which events are actually enabled.

I think that is the only difference between our two positions: [if I understand you correctly] you want ls(1) to be able to list the device's supported events. However, I feel that is inconsistent: for your proposal, userspace must perform two checks in order to determine a feature's availability: 1) does the file exist? 2) is the file context non-zero?

Regards,

	Jeff


[1] modulo my comment from the original email in this thread:
* I was slack and did not bother to implement the 'set' operation
  for the attributes.  This can easily be done at a later time in a
  separate patch.

-
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Samba]     [Device Mapper]
  Powered by Linux