[CFR][ZFS] Allow async event processing with a R/O root FS

[Justin T. Gibbs]

On 6/15/11 6:15 AM, Pawel Jakub Dawidek wrote:
> On Tue, Jun 14, 2011 at 04:45:06PM -0600, Justin T. Gibbs wrote:
>> Allow ZFS asynchronous event handling to proceed even if the
>> root file system is mounted read-only.  This restriction appears
>> to have been put in place to avoid errors with updating the
>> configuration cache file.  However:
>>
>>    o The majority of asynchronous event handling does not involve
>>      configuration cache file updates.
>>    o The configuration cache file need not be on the root file system,
>>      so the check was not complete.
> Why is that? I keep cache file on the ZFS root file system.
> It is not used by the boot loader, but is loaded by the loader:
>
> 	# tail -7 /boot/defaults/loader.conf
>
You can specify an alternate cache file location that doesn't have to be
on the root file system.  By "the check was not complete", I mean the
"root is R/W" check doesn't ensure that the cache file is located on a
file system mounted R/W.

--
Justin