From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 670256B004D for ; Mon, 8 Jun 2009 11:22:21 -0400 (EDT) In-reply-to: <20090608162913.GL8633@ZenIV.linux.org.uk> (message from Al Viro on Mon, 8 Jun 2009 17:29:13 +0100) Subject: Re: [PATCH 0/23] File descriptor hot-unplug support v2 References: <20090606080334.GA15204@ZenIV.linux.org.uk> <20090608162913.GL8633@ZenIV.linux.org.uk> Message-Id: From: Miklos Szeredi Date: Mon, 08 Jun 2009 18:44:41 +0200 Sender: owner-linux-mm@kvack.org To: viro@ZenIV.linux.org.uk Cc: miklos@szeredi.hu, ebiederm@xmission.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, hugh@veritas.com, tj@kernel.org, adobriyan@gmail.com, torvalds@linux-foundation.org, alan@lxorguk.ukuu.org.uk, gregkh@suse.de, npiggin@suse.de, akpm@linux-foundation.org, hch@infradead.org List-ID: On Mon, 8 Jun 2009, Al Viro wrote: > On Mon, Jun 08, 2009 at 11:41:19AM +0200, Miklos Szeredi wrote: > > On Sat, 6 Jun 2009, Al Viro wrote: > > > Frankly, I very much suspect that force-umount is another case like that; > > > we'll need a *lot* of interesting cooperation from fs for that to work and > > > to be useful. I'd be delighted to be proven incorrect on that one, so > > > if you have anything serious in that direction, please share the details. > > > > Umm, not sure why we'd need cooperation from the fs. Simply wait for > > the operation to exit the filesystem or driver. If it's a blocking > > operation, send a signal to interrupt it. > > And making sure that operations *are* interruptible (and that we can cope > with $BIGNUM new failure exits correctly) does not qualify as cooperation? I'm still not getting what the problem is. AFAICS file operations are either a) non-interruptible but finish within a short time or b) may block indefinitely but are interruptible (or at least killable). Anything else is already problematic, resulting in processes "stuck in D state". Can you give a more concrete example about your worries? Thanks, Miklos -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org