ufs freeze does not work

[Edward Tomasz Napierała]

As I said, the suspension is released when the ufssuspend file descriptor
gets closed - which is what happens when the calling process exits.  It's
a protection mechanism, to avoid the situation where the process malfunction
(eg a crash) would leave the system in unrecoverable (suspended) state.

You probably want your process to just execute another one, and wait until
it exits.

On 0628T0733, Hongjiang Zhang wrote:
> I run "./freeze -f", the program should freeze the "/" file partition, but I can still write something to "/tmp" folder.
> 
> -----Original Message-----
> From: Edward Tomasz Napierała [mailto:etnapierala at gmail.com] On Behalf Of Edward Tomasz Napierala
> Sent: Tuesday, June 28, 2016 2:55 PM
> To: Hongjiang Zhang <honzhan at microsoft.com>
> Cc: freebsd-fs at freebsd.org
> Subject: Re: ufs freeze does not work
> 
> On 0627T0815, Hongjiang Zhang via freebsd-fs wrote:
> > Hi all,
> > 
> > I wrote a test to freeze ufs, but it does not work even if the ioctl returns successful. What is the problem?
> 
> What do you mean by 'does not work'?  What happens, and what did you expect to happen?
> 
> Regarding your example - remember that the filesystem gets automatically unsuspended as soon as you close the /dev/ufssuspend file descriptor.
>