Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754496AbYCVELs (ORCPT ); Sat, 22 Mar 2008 00:11:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750938AbYCVELh (ORCPT ); Sat, 22 Mar 2008 00:11:37 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:41793 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750877AbYCVELg (ORCPT ); Sat, 22 Mar 2008 00:11:36 -0400 Date: Sat, 22 Mar 2008 04:11:32 +0000 From: Al Viro To: Miklos Szeredi Cc: akpm@linux-foundation.org, linuxram@us.ibm.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Trond.Myklebust@netapp.com, dhowells@redhat.com Subject: Re: [patch 3/6] vfs: mountinfo stable peer group id Message-ID: <20080322041131.GA10722@ZenIV.linux.org.uk> References: <20080313212641.989467982@szeredi.hu> <20080313212735.741834181@szeredi.hu> <20080319114844.GK10722@ZenIV.linux.org.uk> <20080319182005.GP10722@ZenIV.linux.org.uk> <20080320214319.GS10722@ZenIV.linux.org.uk> <20080322034950.GY10722@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080322034950.GY10722@ZenIV.linux.org.uk> User-Agent: Mutt/1.4.2.3i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1506 Lines: 27 On Sat, Mar 22, 2008 at 03:49:50AM +0000, Al Viro wrote: > Shifting increment from mnt_set_mountpoint() and commit_tree() > to theirs callers and collapsing where possible, we get the following: > * decrement in release_mounts() when resetting ->mnt_parent > * increment in propagate_mnt() after call of mnt_set_mountpoint() > * decrement in attach_recursive_mnt() in the loop calling > commit_tree() for clones (on mountpoint of each clone). > * increment in umount_tree() at the point where we update d_mounted. ... except that it'd give a leak in case of mount to shared mountpoint failing halfway through - we'll get double increments since umount_tree() would hit the mountpoints of cloned trees with extra increment, even though reference from root of cloned to its mountpoint is _already_ a ghost. OTOH, we probably don't want to bother with counting those anyway - i.e. it's simply a bad definition and the right one would be along the lines of "number of vfsmounts that are doomed to be eaten by release_mounts() and that have ->mnt_parent pointing to us". IOW, dropping the 2nd and 3rd in the above would do the right thing - anything chewed by umount_tree() *will* go to release_mounts() and ones in flight are what we are interested in... -- 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/