From owner-svn-src-all@freebsd.org Sun Sep 27 01:06:46 2015 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6E7ACA0A2EA; Sun, 27 Sep 2015 01:06:46 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4588D2D9; Sun, 27 Sep 2015 01:06:46 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.70]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id t8R16kDC087500; Sun, 27 Sep 2015 01:06:46 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id t8R16kIY087499; Sun, 27 Sep 2015 01:06:46 GMT (envelope-from kib@FreeBSD.org) Message-Id: <201509270106.t8R16kIY087499@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Sun, 27 Sep 2015 01:06:46 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r288282 - stable/10/sys/fs/fifofs X-SVN-Group: stable-10 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 27 Sep 2015 01:06:46 -0000 Author: kib Date: Sun Sep 27 01:06:45 2015 New Revision: 288282 URL: https://svnweb.freebsd.org/changeset/base/288282 Log: MFC r288044: Ensure that when a blockable open of fifo returns success, a valid file descriptor opened for complimentary access exists as well. Modified: stable/10/sys/fs/fifofs/fifo_vnops.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/fs/fifofs/fifo_vnops.c ============================================================================== --- stable/10/sys/fs/fifofs/fifo_vnops.c Sat Sep 26 22:57:10 2015 (r288281) +++ stable/10/sys/fs/fifofs/fifo_vnops.c Sun Sep 27 01:06:45 2015 (r288282) @@ -64,6 +64,8 @@ struct fifoinfo { struct pipe *fi_pipe; long fi_readers; long fi_writers; + u_int fi_rgen; + u_int fi_wgen; }; static vop_print_t fifo_print; @@ -137,6 +139,7 @@ fifo_open(ap) struct thread *td; struct fifoinfo *fip; struct pipe *fpipe; + u_int gen; int error, stops_deferred; vp = ap->a_vp; @@ -164,6 +167,7 @@ fifo_open(ap) PIPE_LOCK(fpipe); if (ap->a_mode & FREAD) { fip->fi_readers++; + fip->fi_rgen++; if (fip->fi_readers == 1) { fpipe->pipe_state &= ~PIPE_EOF; if (fip->fi_writers > 0) @@ -179,6 +183,7 @@ fifo_open(ap) return (ENXIO); } fip->fi_writers++; + fip->fi_wgen++; if (fip->fi_writers == 1) { fpipe->pipe_state &= ~PIPE_EOF; if (fip->fi_readers > 0) @@ -187,6 +192,7 @@ fifo_open(ap) } if ((ap->a_mode & O_NONBLOCK) == 0) { if ((ap->a_mode & FREAD) && fip->fi_writers == 0) { + gen = fip->fi_wgen; VOP_UNLOCK(vp, 0); stops_deferred = sigallowstop(); error = msleep(&fip->fi_readers, PIPE_MTX(fpipe), @@ -194,7 +200,7 @@ fifo_open(ap) if (stops_deferred) sigdeferstop(); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); - if (error) { + if (error != 0 && gen == fip->fi_wgen) { fip->fi_readers--; if (fip->fi_readers == 0) { PIPE_LOCK(fpipe); @@ -214,6 +220,7 @@ fifo_open(ap) */ } if ((ap->a_mode & FWRITE) && fip->fi_readers == 0) { + gen = fip->fi_rgen; VOP_UNLOCK(vp, 0); stops_deferred = sigallowstop(); error = msleep(&fip->fi_writers, PIPE_MTX(fpipe), @@ -221,7 +228,7 @@ fifo_open(ap) if (stops_deferred) sigdeferstop(); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); - if (error) { + if (error != 0 && gen == fip->fi_rgen) { fip->fi_writers--; if (fip->fi_writers == 0) { PIPE_LOCK(fpipe);