My brain hurts. (Messing with mount.)

[Rob Landley]

On Monday 06 March 2006 8:35 am, Michael S. Zick wrote:
> On Sun March 5 2006 19:07, Rob Landley wrote:
> > There is no mount spec.  Only endless questions.
> >
> >
> > When you supply two arguments, mount doesn't check fstab at all.  With
> > the above fstab entry:
> >   mount walrus.img walrus
> >
> >   The mount is rw, not ro, and I have to say -t ext2 -o loop with the gnu
> >   mount.
>
> That sounds like the known behavior of the kernel - to silently ignore ro

No, it means that the mount command didn't check fstab at all, and thus never 
picked up the -o ro.  (Just like it never picked up the -o loop.)

When I specify just one argument, it gets both.  Nothing to do with the 
kernel.

This is all stuff I have to work through to get a spec for mount.  With two 
arguments, no need to check fstab.  Therefore, the second argument can always 
be converted to an absolute path, and only the first one needs both.

> Prior to recent patches, the attributes noexec, noatime, ro where handled
> "per filesystem" only - not "per inode", any attribute change that resolved
> to an inode would be silently ignored.

A) They were talking about fixing that long ago.

B) This has nothing to do with per filesystem vs per inode.  If I do this:

  mount walrus
  umount walrus
  mount walrus
  umount walrus
  mount walrus.img walrus

The first two mount commands behave identically, the third is different.

> > Dinner time.
>
> Don't spend too long eating - the kernel has patches going in to make it
> change its mount behavior.

Yeah, all Al Viro's namespace work.  That's half the reason I did the rewrite, 
the old mount had no chance of ever supporting that stuff.  The new one isn't 
bothered by it.

> You can get the new functionality with the "BME" patches at
> linux-vserver.org Let me know off-list if you want me to dig out the exact
> link for you.

I'll wait for it to hit a mainstream -pre release.  Right now I'm closing 
mount down for 1.1.1.

> Mike

Rob
-- 
Never bet against the cheap plastic solution.