Mon Apr 20 14:11:05 2020 UTC ()
do not retry when xen_shm_map() fails after having returned error for it,
it corrupts the ring; just go to next request

should fix the problem with ZFS causing failscade when req fails,
reported by Brian Buhrow on port-xen


(jdolecek)
diff -r1.81 -r1.82 src/sys/arch/xen/xen/xbdback_xenbus.c
cvs diff -r1.81 -r1.82 src/sys/arch/xen/xen/xbdback_xenbus.c (expand / switch to unified diff)

--- src/sys/arch/xen/xen/xbdback_xenbus.c 2020/04/20 03:00:33 1.81
+++ src/sys/arch/xen/xen/xbdback_xenbus.c 2020/04/20 14:11:04 1.82
@@ -1,14 +1,14 @@ @@ -1,14 +1,14 @@
1/* $NetBSD: xbdback_xenbus.c,v 1.81 2020/04/20 03:00:33 msaitoh Exp $ */ 1/* $NetBSD: xbdback_xenbus.c,v 1.82 2020/04/20 14:11:04 jdolecek Exp $ */
2 2
3/* 3/*
4 * Copyright (c) 2006 Manuel Bouyer. 4 * Copyright (c) 2006 Manuel Bouyer.
5 * 5 *
6 * Redistribution and use in source and binary forms, with or without 6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions 7 * modification, are permitted provided that the following conditions
8 * are met: 8 * are met:
9 * 1. Redistributions of source code must retain the above copyright 9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer. 10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright 11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the 12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution. 13 * documentation and/or other materials provided with the distribution.
14 * 14 *
@@ -16,27 +16,27 @@ @@ -16,27 +16,27 @@
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 * 25 *
26 */ 26 */
27 27
28#include <sys/cdefs.h> 28#include <sys/cdefs.h>
29__KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.81 2020/04/20 03:00:33 msaitoh Exp $"); 29__KERNEL_RCSID(0, "$NetBSD: xbdback_xenbus.c,v 1.82 2020/04/20 14:11:04 jdolecek Exp $");
30 30
31#include <sys/atomic.h> 31#include <sys/atomic.h>
32#include <sys/buf.h> 32#include <sys/buf.h>
33#include <sys/condvar.h> 33#include <sys/condvar.h>
34#include <sys/conf.h> 34#include <sys/conf.h>
35#include <sys/disk.h> 35#include <sys/disk.h>
36#include <sys/device.h> 36#include <sys/device.h>
37#include <sys/fcntl.h> 37#include <sys/fcntl.h>
38#include <sys/kauth.h> 38#include <sys/kauth.h>
39#include <sys/kernel.h> 39#include <sys/kernel.h>
40#include <sys/kmem.h> 40#include <sys/kmem.h>
41#include <sys/kthread.h> 41#include <sys/kthread.h>
42#include <sys/mutex.h> 42#include <sys/mutex.h>
@@ -1794,27 +1794,28 @@ xbdback_map_shm(struct xbdback_io *xbd_i @@ -1794,27 +1794,28 @@ xbdback_map_shm(struct xbdback_io *xbd_i
1794 } 1794 }
1795 printf("\n"); 1795 printf("\n");
1796#endif 1796#endif
1797 xbd_io->xio_mapped = 1; 1797 xbd_io->xio_mapped = 1;
1798 return xbdi; 1798 return xbdi;
1799 default: 1799 default:
1800 if (ratecheck(&xbdi->xbdi_lasterr_time, &xbdback_err_intvl)) { 1800 if (ratecheck(&xbdi->xbdi_lasterr_time, &xbdback_err_intvl)) {
1801 printf("xbdback_map_shm: xen_shm error %d ", error); 1801 printf("xbdback_map_shm: xen_shm error %d ", error);
1802 } 1802 }
1803 xbdback_io_error(xbdi->xbdi_io, error); 1803 xbdback_io_error(xbdi->xbdi_io, error);
1804 SLIST_INSERT_HEAD(&xbdi->xbdi_va_free, xbd_io->xio_xv, xv_next); 1804 SLIST_INSERT_HEAD(&xbdi->xbdi_va_free, xbd_io->xio_xv, xv_next);
1805 xbd_io->xio_xv = NULL; 1805 xbd_io->xio_xv = NULL;
1806 xbdi->xbdi_io = NULL; 1806 xbdi->xbdi_io = NULL;
1807 xbdi->xbdi_cont = xbdi->xbdi_cont_aux; 1807 // do not retry
 1808 xbdi->xbdi_cont = xbdback_co_main_incr;
1808 return xbdi; 1809 return xbdi;
1809 } 1810 }
1810} 1811}
1811 1812
1812/* unmap a request from our virtual address space (request is done) */ 1813/* unmap a request from our virtual address space (request is done) */
1813static void 1814static void
1814xbdback_unmap_shm(struct xbdback_io *xbd_io) 1815xbdback_unmap_shm(struct xbdback_io *xbd_io)
1815{ 1816{
1816 struct xbdback_instance *xbdi = xbd_io->xio_xbdi; 1817 struct xbdback_instance *xbdi = xbd_io->xio_xbdi;
1817 1818
1818#ifdef XENDEBUG_VBD 1819#ifdef XENDEBUG_VBD
1819 int i; 1820 int i;
1820 printf("xbdback_unmap_shm handle "); 1821 printf("xbdback_unmap_shm handle ");