linux-kernel - Re: nfsd changes for 2.6.37

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 27 Oct 2010 17:23:59 +0200
From:	Arnd Bergmann <arnd@...db.de>
To:	Christoph Hellwig <hch@...radead.org>
Cc:	"J. Bruce Fields" <bfields@...ldses.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Bryan Schumaker <bjschuma@...app.com>,
	linux-nfs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: nfsd changes for 2.6.37

On Wednesday 27 October 2010, Christoph Hellwig wrote:
> On Wed, Oct 27, 2010 at 10:55:39AM -0400, J. Bruce Fields wrote:
> > Hm, two problems:
> > 	- We introduce the possibility of fcntl(fd, F_SETLEASE, F_UNLCK)
> > 	  failing with ENOMEM.
> 
> splitt ->setlease into ->add_least and ->delete_lease.  No need to pass
> in a structure for the later.  No need to return one either.

That sounds like a good way to get rid of a lot of special cases, too.

> > 	- fasync_helper(.,.,1,.) sleeps.  Argh.
> 
> That's not new..

It comes back to the original problem with Bruce's patch though:
fcntl_setlease wants to atomically add a lease or fail. If
fasync_helper fails, we want to remove the lease that was
just added before anyone can see it. At the very least we need
to keep the flock from getting freed in another thread while
we call fasync_helper without the lock.

locks_delete_lock is also called with lock_flocks held and calls
fasync_helper...

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