Re: Finding an available fss device

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

On Sun, Aug 12, 2018 at 04:32:49PM +0700, Robert Elz wrote:
> Clearly there's no point locking before testing for FWRITE
> in flag, that's a local var (param) to this function, 

Right, that one is obvious, I was wondering about the 
FSS_ACTIVE test.

> but the "if it is locked it must be active" is not correct I think, there
> might just be some other process doing a FSSIOCGET
> or something at the same time as the attempt to FSSIOCSET.
> The GET needs to lock, to return consistent values, but that does
> not mean that this fss has an active snapshot.

Do you sugest the mutex should be replaced by a  rwlock? 

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost