From owner-svn-src-head@freebsd.org Wed Jun 14 03:45:27 2017 Return-Path: Delivered-To: svn-src-head@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 6AC12C7905B; Wed, 14 Jun 2017 03:45:27 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::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 39D7D77B2C; Wed, 14 Jun 2017 03:45:27 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v5E3jQmp053600; Wed, 14 Jun 2017 03:45:26 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v5E3jQnW053599; Wed, 14 Jun 2017 03:45:26 GMT (envelope-from markj@FreeBSD.org) Message-Id: <201706140345.v5E3jQnW053599@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Wed, 14 Jun 2017 03:45:26 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r319932 - head/sys/dev/md 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: 2.1.23 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: Wed, 14 Jun 2017 03:45:27 -0000 Author: markj Date: Wed Jun 14 03:45:26 2017 New Revision: 319932 URL: https://svnweb.freebsd.org/changeset/base/319932 Log: Fix handling of subpage BIO_WRITE and BIO_DELETE requests on swap MDs. Such requests would previously mark the entire page as valid, which was incorrect since nothing guaranteed that the page's contents had been initialized. This change also modifies subpage BIO_DELETEs so that the entire page is marked dirty, rather than only a subrange. There is no benefit to creating partially dirty swap pages. Reviewed by: alc, kib (previous version) MFC after: 3 days Modified: head/sys/dev/md/md.c Modified: head/sys/dev/md/md.c ============================================================================== --- head/sys/dev/md/md.c Wed Jun 14 02:46:38 2017 (r319931) +++ head/sys/dev/md/md.c Wed Jun 14 03:45:26 2017 (r319932) @@ -972,6 +972,16 @@ unmapped_step: return (error); } +static void +md_swap_page_free(vm_page_t m) +{ + + vm_page_xunbusy(m); + vm_page_lock(m); + vm_page_free(m); + vm_page_unlock(m); +} + static int mdstart_swap(struct md_s *sc, struct bio *bp) { @@ -1044,15 +1054,17 @@ mdstart_swap(struct md_s *sc, struct bio *bp) cpu_flush_dcache(p, len); } } else if (bp->bio_cmd == BIO_WRITE) { - if (len != PAGE_SIZE && m->valid != VM_PAGE_BITS_ALL) + if (len == PAGE_SIZE || m->valid == VM_PAGE_BITS_ALL) + rv = VM_PAGER_OK; + else rv = vm_pager_get_pages(sc->object, &m, 1, NULL, NULL); - else - rv = VM_PAGER_OK; if (rv == VM_PAGER_ERROR) { vm_page_xunbusy(m); break; - } + } else if (rv == VM_PAGER_FAIL) + pmap_zero_page(m); + if ((bp->bio_flags & BIO_UNMAPPED) != 0) { pmap_copy_pages(bp->bio_ma, ma_offs, &m, offs, len); @@ -1062,34 +1074,40 @@ mdstart_swap(struct md_s *sc, struct bio *bp) } else { physcopyin(p, VM_PAGE_TO_PHYS(m) + offs, len); } + m->valid = VM_PAGE_BITS_ALL; + vm_page_dirty(m); + vm_pager_page_unswapped(m); } else if (bp->bio_cmd == BIO_DELETE) { - if (len != PAGE_SIZE && m->valid != VM_PAGE_BITS_ALL) + if (len == PAGE_SIZE || m->valid == VM_PAGE_BITS_ALL) + rv = VM_PAGER_OK; + else rv = vm_pager_get_pages(sc->object, &m, 1, NULL, NULL); - else - rv = VM_PAGER_OK; if (rv == VM_PAGER_ERROR) { vm_page_xunbusy(m); break; - } - if (len != PAGE_SIZE) { - pmap_zero_page_area(m, offs, len); - vm_page_clear_dirty(m, offs, len); - m->valid = VM_PAGE_BITS_ALL; - } else + } else if (rv == VM_PAGER_FAIL) { + md_swap_page_free(m); + m = NULL; + } else { + /* Page is valid. */ + if (len != PAGE_SIZE) { + pmap_zero_page_area(m, offs, len); + vm_page_dirty(m); + } vm_pager_page_unswapped(m); + if (len == PAGE_SIZE) { + md_swap_page_free(m); + m = NULL; + } + } } - vm_page_xunbusy(m); - vm_page_lock(m); - if (bp->bio_cmd == BIO_DELETE && len == PAGE_SIZE) - vm_page_free(m); - else + if (m != NULL) { + vm_page_xunbusy(m); + vm_page_lock(m); vm_page_activate(m); - vm_page_unlock(m); - if (bp->bio_cmd == BIO_WRITE) { - vm_page_dirty(m); - vm_pager_page_unswapped(m); + vm_page_unlock(m); } /* Actions on further pages start at offset 0 */