Re: [patch 7/7] uml ubd: handle readonly status

Jens Axboe
2005-04-26T08:23:15Z

On Mon, Apr 25 2005, Blaisorblade wrote:
> On Monday 25 April 2005 12:16, Jens Axboe wrote:
> > On Sun, Apr 24 2005, blaisorblade@yahoo.it wrote:
> > > @@ -1099,6 +1104,7 @@ static int prepare_request(struct reques
> > > if((rq_data_dir(req) == WRITE) && !dev->openflags.w){
> > > printk("Write attempted on readonly ubd device %s\n",
> > > disk->disk_name);
> > > + WARN_ON(1); /* This should be impossible now */
> > > end_request(req, 0);
> > > return(1);
> > > }
> >
> > I don't think that's a sound change. The WARN_ON() is strictly only
> > really useful for when you need the stack trace for something
> > interesting. As the io happens async, you will get a boring trace that
> > doesn't contain any valuable information.
> Ok, removed, and resending the patch, is the rest ok? I.e. is that
> supposed to work? I gave a walk around and it seemed that the code
> handles set_{disk,device}_ro() even during the open, but I'm no block
> layer expert.

I'd keep the checks for sanity. Although the set_disk/device_ro prevents
regular fs write mounts, a buggy layered drive could still send down a
write by accident.

--
Jens Axboe