[libvirt] [PATCH] locking: Add io_timeout to sanlock

[Michal Privoznik]

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 at redhat.com>
---
 src/locking/libvirt_sanlock.aug         | 1 +
 src/locking/lock_driver_sanlock.c       | 8 +++++++-
 src/locking/sanlock.conf                | 7 +++++++
 src/locking/test_libvirt_sanlock.aug.in | 1 +
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/locking/libvirt_sanlock.aug b/src/locking/libvirt_sanlock.aug
index a78a444..8843590 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 e052875..f1dbbaf 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 +343,7 @@ static int virLockManagerSanlockSetupLockspace(void)
      * or we can fallback to polling.
      */
  retry:
-    if ((rv = sanlock_add_lockspace(&ls, 0)) < 0) {
+    if ((rv = sanlock_add_lockspace_timeout(&ls, 0, driver->io_timeout)) < 0) {
         if (-rv == EINPROGRESS && --retries) {
 #ifdef HAVE_SANLOCK_INQ_LOCKSPACE
             /* we have this function which blocks until lockspace change the
@@ -404,6 +409,7 @@ 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 e5566ef..3a1a51c 100644
--- a/src/locking/sanlock.conf
+++ b/src/locking/sanlock.conf
@@ -54,6 +54,13 @@
 #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
 # content of disk_lease_dir) to make sure sanlock daemon can
diff --git a/src/locking/test_libvirt_sanlock.aug.in b/src/locking/test_libvirt_sanlock.aug.in
index ef98ea6..7f66f81 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" }
-- 
2.4.10