Date: Sun, 25 Oct 2020 15:58:07 -0700 From: Cy Schubert <Cy.Schubert@cschubert.com> To: Cy Schubert <Cy.Schubert@cschubert.com>, Oliver Pinter <oliver.pntr@gmail.com>, "src-committers@freebsd.org" <src-committers@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org> Subject: Re: svn commit: r367038 - head/sbin/mount_nullfs Message-ID: <202010252258.09PMw7wK009643@slippy.cwsent.com> In-Reply-To: <20201025213509.GA1671@brick> References: <202010251409.09PE91aS001781@repo.freebsd.org> <CAPjTQNEq2ukvkNoF6bsymTai52XV1tbu3TxW4rrN4n5hASMFqQ@mail.gmail.com> <202010251417.09PEH6tE003403@slippy.cwsent.com> <20201025213509.GA1671@brick>
next in thread | previous in thread | raw e-mail | index | archive | help
In message <20201025213509.GA1671@brick>, Edward Tomasz Napierala writes: > On 1025T0717, Cy Schubert wrote: > > In message <CAPjTQNEq2ukvkNoF6bsymTai52XV1tbu3TxW4rrN4n5hASMFqQ@mail.gmail. > c > > om> > > , Oliver Pinter writes: > > > On Sunday, October 25, 2020, Edward Tomasz Napierala <trasz@freebsd.org> > > > wrote: > > > > > > > Author: trasz > > > > Date: Sun Oct 25 14:09:00 2020 > > > > New Revision: 367038 > > > > URL: https://svnweb.freebsd.org/changeset/base/367038 > > > > > > > > Log: > > > > Remove the check that prevents creating "loops" from mount_nullfs(8). > > > > > > > > > > > The simple question is: why? > > > > I was about to ask that myself. > > > > The why is usually more important than the how. > > Two reasons. > > First, from what I can tell this is an artificial limitation which serves > no purpose. I thought it was to prevent some kind of deadlock between > vnodes, so I asked kib@, and he mentioned removing that very limitation > from the kernel code; thus, it looks to me like a historical leftover. > > Second, I've stumbled upon this when trying to nullfs-mount '/' on > '/compat/ubuntu/bsd/', which would be useful for autochroot functionality, > when (or if) it becomes a thing. Thanks. -- Cheers, Cy Schubert <Cy.Schubert@cschubert.com> FreeBSD UNIX: <cy@FreeBSD.org> Web: https://FreeBSD.org NTP: <cy@nwtime.org> Web: https://nwtime.org The need of the many outweighs the greed of the few.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202010252258.09PMw7wK009643>