From: Michal Privoznik <mprivozn@redhat.com>
Date: Fri, 23 Oct 2015 11:21:22 +0000 (+0200)
Subject: locking: Add io_timeout to sanlock
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=bd3e16a3cf89303c3ec5281c818acce418b75f50;p=people%2Fliuw%2Flibxenctrl-split%2Flibvirt.git

locking: Add io_timeout to sanlock

https://bugzilla.redhat.com/show_bug.cgi?id=1251190

So, if domain loses access to storage, sanlock tries to kill it
after some timeout. So far, the default is 80 seconds. But for
some scenarios this might not be enough. We should allow users to
adjust the timeout according to their needs.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---

diff --git a/m4/virt-sanlock.m4 b/m4/virt-sanlock.m4
index c7c0186f8..d2a607d04 100644
--- a/m4/virt-sanlock.m4
+++ b/m4/virt-sanlock.m4
@@ -46,6 +46,13 @@ AC_DEFUN([LIBVIRT_CHECK_SANLOCK],[
         [whether sanlock supports sanlock_inq_lockspace])
     fi
 
+    AC_CHECK_LIB([sanlock_client], [sanlock_add_lockspace_timeout],
+                 [sanlock_add_lockspace_timeout=yes], [sanlock_add_lockspace_timeout=no])
+    if test "x$sanlock_add_lockspace_timeout" = "xyes" ; then
+      AC_DEFINE_UNQUOTED([HAVE_SANLOCK_ADD_LOCKSPACE_TIMEOUT], 1,
+        [whether Sanlock supports sanlock_add_lockspace_timeout])
+    fi
+
     CPPFLAGS="$old_cppflags"
     LIBS="$old_libs"
   fi
diff --git a/src/locking/libvirt_sanlock.aug b/src/locking/libvirt_sanlock.aug
index a78a4445c..88435902d 100644
--- a/src/locking/libvirt_sanlock.aug
+++ b/src/locking/libvirt_sanlock.aug
@@ -22,6 +22,7 @@ module Libvirt_sanlock =
              | int_entry "host_id"
              | bool_entry "require_lease_for_disks"
              | bool_entry "ignore_readonly_and_shared_disks"
+             | int_entry "io_timeout"
              | str_entry "user"
              | str_entry "group"
    let comment = [ label "#comment" . del /#[ \t]*/ "# " .  store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ]
diff --git a/src/locking/lock_driver_sanlock.c b/src/locking/lock_driver_sanlock.c
index e052875e2..3069b82f5 100644
--- a/src/locking/lock_driver_sanlock.c
+++ b/src/locking/lock_driver_sanlock.c
@@ -73,6 +73,7 @@ struct _virLockManagerSanlockDriver {
     int hostID;
     bool autoDiskLease;
     char *autoDiskLeasePath;
+    unsigned int io_timeout;
 
     /* under which permissions does sanlock run */
     uid_t user;
@@ -151,6 +152,10 @@ static int virLockManagerSanlockLoadConfig(const char *configFile)
     else
         driver->requireLeaseForDisks = !driver->autoDiskLease;
 
+    p = virConfGetValue(conf, "io_timeout");
+    CHECK_TYPE("io_timeout", VIR_CONF_ULONG);
+    if (p) driver->io_timeout = p->l;
+
     p = virConfGetValue(conf, "user");
     CHECK_TYPE("user", VIR_CONF_STRING);
     if (p) {
@@ -338,7 +343,17 @@ static int virLockManagerSanlockSetupLockspace(void)
      * or we can fallback to polling.
      */
  retry:
-    if ((rv = sanlock_add_lockspace(&ls, 0)) < 0) {
+#ifdef HAVE_SANLOCK_ADD_LOCKSPACE_TIMEOUT
+    rv = sanlock_add_lockspace_timeout(&ls, 0, driver->io_timeout);
+#else
+    if (driver->io_timeout) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("unable to use io_timeout with this version of sanlock"));
+        goto error;
+    }
+    rv = sanlock_add_lockspace(&ls, 0);
+#endif
+    if (rv < 0) {
         if (-rv == EINPROGRESS && --retries) {
 #ifdef HAVE_SANLOCK_INQ_LOCKSPACE
             /* we have this function which blocks until lockspace change the
@@ -404,6 +419,7 @@ static int virLockManagerSanlockInit(unsigned int version,
     driver->requireLeaseForDisks = true;
     driver->hostID = 0;
     driver->autoDiskLease = false;
+    driver->io_timeout = 0;
     driver->user = (uid_t) -1;
     driver->group = (gid_t) -1;
     if (VIR_STRDUP(driver->autoDiskLeasePath, LOCALSTATEDIR "/lib/libvirt/sanlock") < 0) {
diff --git a/src/locking/sanlock.conf b/src/locking/sanlock.conf
index e5566efec..3a1a51c5f 100644
--- a/src/locking/sanlock.conf
+++ b/src/locking/sanlock.conf
@@ -53,6 +53,13 @@
 #
 #require_lease_for_disks = 1
 
+#
+# Sanlock is able to kill qemu processes on IO timeout. By its internal
+# implementation, the current default is 80 seconds. If you need to adjust
+# the value change the following variable. Value of zero means use the
+# default sanlock timeout.
+#io_timeout = 0
+
 #
 # The combination of user and group under which the sanlock
 # daemon runs. Libvirt will chown created files (like
diff --git a/src/locking/test_libvirt_sanlock.aug.in b/src/locking/test_libvirt_sanlock.aug.in
index ef98ea637..7f66f8192 100644
--- a/src/locking/test_libvirt_sanlock.aug.in
+++ b/src/locking/test_libvirt_sanlock.aug.in
@@ -6,5 +6,6 @@ module Test_libvirt_sanlock =
 { "disk_lease_dir" = "/var/lib/libvirt/sanlock" }
 { "host_id" = "1" }
 { "require_lease_for_disks" = "1" }
+{ "io_timeout" = "0" }
 { "user" = "root" }
 { "group" = "root" }