Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754748Ab3JCGOx (ORCPT ); Thu, 3 Oct 2013 02:14:53 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:41535 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754278Ab3JCGOw (ORCPT ); Thu, 3 Oct 2013 02:14:52 -0400 Date: Thu, 3 Oct 2013 07:14:49 +0100 From: Al Viro To: Linus Torvalds Cc: linux-fsdevel , Linux Kernel Mailing List , Miklos Szeredi Subject: Re: [rfc][possible solution] RCU vfsmounts Message-ID: <20131003061449.GA23460@ZenIV.linux.org.uk> References: <20130928202728.GK13318@ZenIV.linux.org.uk> <20130929060601.GL13318@ZenIV.linux.org.uk> <20130929181047.GM13318@ZenIV.linux.org.uk> <20130930194921.GS13318@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130930194921.GS13318@ZenIV.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 962 Lines: 21 On Mon, Sep 30, 2013 at 08:49:21PM +0100, Al Viro wrote: > * btrfs: wants btrfs_root_readonly(BTRFS_I(inode)->root) usable in > ->permission(). Delayed freeing of struct btrfs_root, perhaps? Not needed, actually - it's only checked with MAY_WRITE, and we don't pass that in RCU mode. Anyway, I've slapped what looks like a sufficient set of synchronize_rcu() in affected filesystems and re-pushed. Result is at least supposed to cover all of them. It still might bugger your memory, chew the disks, etc., so it's only for testing on scratch boxen at that point. Still, review and (if you are really brave) testing would be very much appreciated. I'll post the patchset on top of the current mainline in a few. -- 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/