Re: [PATCH] don't invalidate non-directory mountpoints

[Miklos Szeredi <miklos@szeredi.hu>]

> > > > d_invalidate allowed a non-directory mountpoint to be invalidated,
> > > > which is bad, since the mountpoint becomes unreachable.
> > > > 
> > > > I know it's racy wrt attaching/detaching mount, but AFAICS so is
> > > > everything else that unhashes the dentry.  This seems to be an
> > > > oversight when splitting out vfsmount_lock from dcache_lock.  To be
> > > > fixed.
> > > 
> > > NAK.  That's a wrong way to deal with the problem and it's much older
> > > than vfsmount_lock or dcache_lock (and affects directories too).
> > 
> > Sorry?
> > 
> > Directories are not invalidated if they have any other reference (like
> > a mount, or any subdirectories which may have mounts).
> > 
> > So how does it affect directories?
> 
> The underlying problem is still there - parts of mount tree _can_ go
> unreachable when remote object dies; trying to pin them down is hopeless
> and the only sane way to deal with that is to dissolve the subtrees
> of mount when that happens.

I get it.

Miklos
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/