From owner-svn-src-user@FreeBSD.ORG Sat Dec 12 23:52:21 2009 Return-Path: Delivered-To: svn-src-user@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 53CFB1065679; Sat, 12 Dec 2009 23:52:21 +0000 (UTC) (envelope-from kmacy@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id 430B28FC1C; Sat, 12 Dec 2009 23:52:21 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id nBCNqLNL067593; Sat, 12 Dec 2009 23:52:21 GMT (envelope-from kmacy@svn.freebsd.org) Received: (from kmacy@localhost) by svn.freebsd.org (8.14.3/8.14.3/Submit) id nBCNqLg0067591; Sat, 12 Dec 2009 23:52:21 GMT (envelope-from kmacy@svn.freebsd.org) Message-Id: <200912122352.nBCNqLg0067591@svn.freebsd.org> From: Kip Macy Date: Sat, 12 Dec 2009 23:52:21 +0000 (UTC) To: src-committers@freebsd.org, svn-src-user@freebsd.org X-SVN-Group: user MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r200457 - user/kmacy/releng_8_fcs_buf_xen/sys/cddl/contrib/opensolaris/uts/common/fs/zfs X-BeenThere: svn-src-user@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the experimental " user" src tree" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Dec 2009 23:52:21 -0000 Author: kmacy Date: Sat Dec 12 23:52:20 2009 New Revision: 200457 URL: http://svn.freebsd.org/changeset/base/200457 Log: add comment clarifying call to zbio_sync_cache Modified: user/kmacy/releng_8_fcs_buf_xen/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c Modified: user/kmacy/releng_8_fcs_buf_xen/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c ============================================================================== --- user/kmacy/releng_8_fcs_buf_xen/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c Sat Dec 12 23:47:31 2009 (r200456) +++ user/kmacy/releng_8_fcs_buf_xen/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c Sat Dec 12 23:52:20 2009 (r200457) @@ -435,10 +435,15 @@ zio_create(zio_t *pio, spa_t *spa, uint6 else zio->io_child_type = ZIO_CHILD_LOGICAL; - if (bp != NULL) { io_bypass = 0; + /* + * Synchronize buffer with page cache - making sure that + * the page cache only holds the most recent txg's pages. + * This also allows us to skip disk I/O if we hit in the + * page cache. + */ if (((vd == NULL) || (vd->vdev_parent == NULL)) && ((type == ZIO_TYPE_WRITE) || (type == ZIO_TYPE_READ))) io_bypass = zbio_sync_cache(spa, bp, txg, data, size,