Re: [V2 PATCH] Safeguard against writing to an active device of another node

[Guoqing Jiang <gqJiang@suse.com>]

Goldwyn Rodrigues wrote:
>
>
> On 07/30/2015 03:49 AM, Guoqing Jiang wrote:
>> Modifying an exiting device's superblock or creating a new superblock
>> on an existing device needs to be checked because the device could be
>> in use by another node in another array. So, we check this by taking
>> all superblock locks in userspace so that we don't  step onto an active
>> device used by another node and safeguard against accidental edits.
>> After the edit is complete, we release all locks and the lockspace so
>> that it can be used by the kernel space.
>>
>> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
>> Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
>> ---
>> V2 Changes: use run-time check for dlm library
>
> This may be better done using a structure of function pointers which
> is setup and resolved one-time as opposed to performing symbol
> resolution every time the function is called. You could include
> get_cluster_name as well in it.
Good point, I will send another incremental patch for this.

Thanks,
Guoqing