From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Howells Subject: Re: [PATCH v12 10/12] namei: aggressively check for nd->root escape on ".." resolution Date: Wed, 04 Sep 2019 23:31:16 +0100 Message-ID: <20592.1567636276@warthog.procyon.org.uk> References: <20190904201933.10736-1-cyphar@cyphar.com> <20190904201933.10736-11-cyphar@cyphar.com> <20190904214856.vnvom7h5xontvngq@yavin.dot.cyphar.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: In-Reply-To: Content-ID: <20591.1567636276.1@warthog.procyon.org.uk> Sender: linux-kernel-owner@vger.kernel.org To: Linus Torvalds Cc: Aleksa Sarai , Al Viro , Jeff Layton , "J. Bruce Fields" , Arnd Bergmann , David Howells , Shuah Khan , Shuah Khan , Ingo Molnar , Peter Zijlstra , Christian Brauner , Jann Horn , Kees Cook , Eric Biederman , Andy Lutomirski , Andrew Morton , Alexei Starovoitov , Tycho Andersen , David Drysdale , Chanho Min , Oleg Nesterov , Rasmus List-Id: linux-arch.vger.kernel.org Linus Torvalds wrote: > > Hinting to userspace to do a retry (with -EAGAIN as you mention in your > > other mail) wouldn't be a bad thing at all, though you'd almost > > certainly get quite a few spurious -EAGAINs -- &{mount,rename}_lock are > > global for the entire machine, after all. > > I'd hope that we have some future (possibly very long-term) > alternative that is not quite system-global, but yes, right now they > are. It ought to be reasonably easy to make them per-sb at least, I think. We don't allow cross-super rename, right? David From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:33580 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729919AbfIDWb2 (ORCPT ); Wed, 4 Sep 2019 18:31:28 -0400 From: David Howells In-Reply-To: References: <20190904201933.10736-1-cyphar@cyphar.com> <20190904201933.10736-11-cyphar@cyphar.com> <20190904214856.vnvom7h5xontvngq@yavin.dot.cyphar.com> Subject: Re: [PATCH v12 10/12] namei: aggressively check for nd->root escape on ".." resolution MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <20591.1567636276.1@warthog.procyon.org.uk> Date: Wed, 04 Sep 2019 23:31:16 +0100 Message-ID: <20592.1567636276@warthog.procyon.org.uk> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Linus Torvalds Cc: Aleksa Sarai , Al Viro , Jeff Layton , "J. Bruce Fields" , Arnd Bergmann , David Howells , Shuah Khan , Shuah Khan , Ingo Molnar , Peter Zijlstra , Christian Brauner , Jann Horn , Kees Cook , Eric Biederman , Andy Lutomirski , Andrew Morton , Alexei Starovoitov , Tycho Andersen , David Drysdale , Chanho Min , Oleg Nesterov , Rasmus Villemoes , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Aleksa Sarai , Linux Containers , alpha , Linux API , linux-arch , Linux ARM , linux-fsdevel , linux-ia64@vger.kernel.org, Linux List Kernel Mailing , "open list:KERNEL SELFTEST FRAMEWORK" , linux-m68k , linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390 , Linux-sh list , linux-xtensa@linux-xtensa.org, sparclinux@vger.kernel.org Message-ID: <20190904223116.vNeSuxFfjnNBAYOwFGitH2Gh0t8ZXTxVqb0hQCC3uDA@z> Linus Torvalds wrote: > > Hinting to userspace to do a retry (with -EAGAIN as you mention in your > > other mail) wouldn't be a bad thing at all, though you'd almost > > certainly get quite a few spurious -EAGAINs -- &{mount,rename}_lock are > > global for the entire machine, after all. > > I'd hope that we have some future (possibly very long-term) > alternative that is not quite system-global, but yes, right now they > are. It ought to be reasonably easy to make them per-sb at least, I think. We don't allow cross-super rename, right? David