Re: Fix for SMP deadlock in autofs4

[Alexander Viro]

On Fri, 20 Apr 2001, Linus Torvalds wrote:

> 
> 
> On Fri, 20 Apr 2001, Jeremy Fitzhardinge wrote:
> >
> > I kept the dget/put out caution and ignorance, but they're clearly
> > problematic.  I'm happy to drop them if holding dcache_lock is enough
> > to keep the tree stable while I traverse it.
> 
> How does this patch look to you people?
> 
> It's untested, but looks fairly obvious. It removes the increment, and
> changes autofs4_expire() to properly bump the count of the returned dentry
> (and callers will dput() it when done). This may be unnecessarily careful,
> but it's the RightThing(tm) to do.

Looks sane for me. However, I would add check for dentry being hashed and
would skip the unhashed ones. Otherwise you can get a directory that
had been removed but is still busy - doesn't look like a right thing to
do. Jeremy?
								Al