Re: [autofs] [PATCH 04/38] autofs4: Save autofs trigger's vfsmountin super block info

[Ian Kent]

On Wed, 2010-06-23 at 11:07 +0900, J. R. Okajima wrote:
> Ian Kent:
> > I may be missing something about this, but why is it safe to use
> > iterate_mounts(), since it doesn't take the vfsmount_lock when
> > traversing the list of mounts?
> 
> The sample code was not correct.
> We need to acquire vfsmount_lock or down_read(namespace_sem).
> 
> Or it may be better to extract the body of iterate_mounts() and create a
> new function __iterate_mounts() such like that.
> 
> __iterate_mounts()
> {
> 	/* equiv to the current iterate_mounts */
> }
> 
> iterate_mount()
> {
> 	down_read(namespace_sem);
> 	or spin_lock(&vfsmount_lock);
> 
> 	__iterate_mount();
> 
> 	spin_unlock(&vfsmount_lock);
> 	or up_read(namespace_sem);
> }

Yep, thought so.
That's a useful enough function to warrant that IMHO.
I'll continue checking its usages before I do it though.

Ian


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