Re: [PATCH 0/5] rbd: avoid snapshot update race

[Josh Durgin <josh.durgin@inktank.com>]

On 04/29/2013 10:52 AM, Alex Elder wrote:
> On 04/27/2013 02:42 PM, Alex Elder wrote:
>> On 04/27/2013 02:37 PM, Alex Elder wrote:
>>> This series ends with a patch that avoids a race involving the
>>> initial read of an rbd image header and a change to the snapshot
>>> context.  The problem occurs because the rbd client sets up its
>>> watch request on the header object *after* the initial header
>>> read, and if the snapshot context changes between them the
>>> kernel client snapshot context will not be up-to-date.
>
> I have similarly updated these patches.  The new versions now
> replace the old ones in the "review/wip-rbd-cleanup-4" branch
> of the ceph-client git repository.
>
> 					-Alex
>> This series is available in the "review/wip-rbd-cleanup-4"
>> in the ceph-client git repository, which is based on branch
>> "review/wip-rbd-cleanup-3".
>>
>> 					-Alex
>>
>>> The fix is to set up the watch before doing the initial
>>> header read.  The recent patches, along with the patches
>>> in this series, make doing things in this order possible.
>>>
>>> 					-Alex
>>>
>>> [PATCH 1/5] rbd: move more initialization into rbd_dev_probe_image()
>>> [PATCH 2/5] rbd: define rbd_header_name()
>>> [PATCH 3/5] rbd: don't clean up watch in device release function
>>> [PATCH 4/5] rbd: don't bother checking whether order changes
>>> [PATCH 5/5] rbd: set up watch in rbd_dev_probe_image()

This series looks good.

Reviewed-by: Josh Durgin <josh.durgin@inktank.com>