From owner-cvs-all@FreeBSD.ORG Sun Oct 19 13:57:13 2003 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0B11516A4BF for ; Sun, 19 Oct 2003 13:57:12 -0700 (PDT) Received: from mail26c.sbc-webhosting.com (mail26b.sbc-webhosting.com [216.173.237.165]) by mx1.FreeBSD.org (Postfix) with SMTP id 1CCC143FE0 for ; Sun, 19 Oct 2003 13:57:10 -0700 (PDT) (envelope-from alc@imimic.com) Received: from www.imimic.com (64.143.12.21)0-0653847020; Sun, 19 Oct 2003 16:57:00 -0400 (EDT) Sender: alc@FreeBSD.ORG Message-ID: <3F92FA9D.F25F3CFB@imimic.com> Date: Sun, 19 Oct 2003 15:57:01 -0500 From: "Alan L. Cox" Organization: iMimic Networking, Inc. X-Mailer: Mozilla 4.8 [en] (X11; U; Linux 2.4.2 i686) X-Accept-Language: en MIME-Version: 1.0 To: David Malone References: <200310192041.h9JKf712075632@repoman.freebsd.org> Content-Type: text/plain; charset=x-user-defined Content-Transfer-Encoding: 7bit X-Loop-Detect: 1 cc: cvs-src@FreeBSD.org cc: src-committers@FreeBSD.org cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/dev/streams streams.csrc/sys/kernkern_descrip.c src/sys/opencrypto cryptodev.c X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 19 Oct 2003 20:57:13 -0000 David Malone wrote: > > dwmalone 2003/10/19 13:41:07 PDT > > FreeBSD src repository > > Modified files: > sys/dev/streams streams.c > sys/kern kern_descrip.c kern_event.c sys_pipe.c > uipc_syscalls.c vfs_syscalls.c > sys/opencrypto cryptodev.c > Log: > falloc allocates a file structure and adds it to the file descriptor > table, acquiring the necessary locks as it works. It usually returns > two references to the new descriptor: one in the descriptor table > and one via a pointer argument. > > As falloc releases the FILEDESC lock before returning, there is a > potential for a process to close the reference in the file descriptor > table before falloc's caller gets to use the file. I don't think this > can happen in practice at the moment, because Giant indirectly protects > closes. > > To stop the file being completly closed in this situation, this change > makes falloc set the refcount to two when both references are returned. > This makes life easier for several of falloc's callers, because the > first thing they previously did was grab an extra reference on the > file. > This reminds me that we still hold Giant around pipe(2) because it isn't declared MPSAFE in the syscall table. Is this still necessary? Additionally, we declare dup2(2) to be MPSAFE, but not dup(2). Given their implementations that seems odd. Regards, Alan