Re: mount notification question

[Daniel Lezcano <daniel.lezcano@free.fr>]

On 08/06/2010 09:44 AM, Kay Sievers wrote:
> On Fri, Aug 6, 2010 at 03:07, Daniel Lezcano<daniel.lezcano@free.fr>  wrote:
>    
>> On 08/04/2010 08:41 PM, Chris Friesen wrote:
>>      
>>> On 08/02/2010 03:12 PM, Daniel Lezcano wrote:
>>>        
>>>> is there a way to be notified when a mount occurs on the system ?
>>>>          
>>> Have you looked on google?  The link is a bit misleading but they do
>>> give a way to do it (not using inotify).
>>>
>>> http://stackoverflow.com/questions/1113176/how-could-i-detect-when-a-directory-is-mounted-with-inotify
>>>        
>> Thanks a lot for the pointer. I am not sure this solution will work, because
>> it is inadequate for watching a specific location in a container context
>> separated by the mount and the network namespaces. We have multiple mount
>> points at the same place (eg. the mount point inheritance, the container
>> configuration and the init scripts may mount /dev or /var/run several time)
>> and the network namespace separation will make impossible to watch udev
>> event via a netlink socket. I didn't look at the inotify implementation but
>> IMHO, it should be worth to add IN_MOUNT and IN_UNMOUNT events for inotify
>> no ?
>>      
> These events wouldn't work, and they are long removed from the kernel
> and don't exist.
>
> You need to poll() /proc/mounts, and any changes in it will wake you
> up with POLL_ERR. /proc/mounts should be namespace aware.
>    

Ah, great ! I will look for this solution (I suppose I will probably 
have to diff /proc/mounts but anyway ...)

Thanks Kay and Chris for your help.

   -- Daniel