From owner-svn-src-head@FreeBSD.ORG Thu Sep 5 12:56:09 2013 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 85BA8C7E; Thu, 5 Sep 2013 12:56:09 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 72F762C3C; Thu, 5 Sep 2013 12:56:09 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.7/8.14.7) with ESMTP id r85Cu9dW015709; Thu, 5 Sep 2013 12:56:09 GMT (envelope-from kib@svn.freebsd.org) Received: (from kib@localhost) by svn.freebsd.org (8.14.7/8.14.5/Submit) id r85Cu95u015708; Thu, 5 Sep 2013 12:56:09 GMT (envelope-from kib@svn.freebsd.org) Message-Id: <201309051256.r85Cu95u015708@svn.freebsd.org> From: Konstantin Belousov Date: Thu, 5 Sep 2013 12:56:09 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r255245 - head/sys/kern X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 05 Sep 2013 12:56:09 -0000 Author: kib Date: Thu Sep 5 12:56:08 2013 New Revision: 255245 URL: http://svnweb.freebsd.org/changeset/base/255245 Log: The vm_pageout_flush() functions sbusies pages in the passed pages run. After that, the pager put method is called, usually translated to VOP_WRITE(). For the filesystems which use buffer cache, bufwrite() sbusies the buffer pages again, waiting for the xbusy state to drain. The later is done in vfs_drain_busy_pages(), which is called with the buffer pages already sbusied (by vm_pageout_flush()). Since vfs_drain_busy_pages() can only wait for one page at the time, and during the wait, the object lock is dropped, previous pages in the buffer must be protected from other threads busying them. Up to the moment, it was done by xbusying the pages, that is incompatible with the sbusy state in the new implementation of busy. Switch to sbusy. Reported and tested by: pho Sponsored by: The FreeBSD Foundation Modified: head/sys/kern/vfs_bio.c Modified: head/sys/kern/vfs_bio.c ============================================================================== --- head/sys/kern/vfs_bio.c Thu Sep 5 12:54:40 2013 (r255244) +++ head/sys/kern/vfs_bio.c Thu Sep 5 12:56:08 2013 (r255245) @@ -3994,7 +3994,7 @@ vfs_drain_busy_pages(struct buf *bp) m = bp->b_pages[i]; if (vm_page_xbusied(m)) { for (; last_busied < i; last_busied++) - vm_page_xbusy(bp->b_pages[last_busied]); + vm_page_sbusy(bp->b_pages[last_busied]); while (vm_page_xbusied(m)) { vm_page_lock(m); VM_OBJECT_WUNLOCK(bp->b_bufobj->bo_object); @@ -4004,7 +4004,7 @@ vfs_drain_busy_pages(struct buf *bp) } } for (i = 0; i < last_busied; i++) - vm_page_xunbusy(bp->b_pages[i]); + vm_page_sunbusy(bp->b_pages[i]); } /*