aboutsummaryrefslogtreecommitdiff
path: root/qemu-ga.c
diff options
context:
space:
mode:
Diffstat (limited to 'qemu-ga.c')
-rw-r--r--qemu-ga.c120
1 files changed, 115 insertions, 5 deletions
diff --git a/qemu-ga.c b/qemu-ga.c
index 74a1b02..ac29b73 100644
--- a/qemu-ga.c
+++ b/qemu-ga.c
@@ -56,10 +56,22 @@ struct GAState {
GAService service;
#endif
bool delimit_response;
+ bool frozen;
+ GList *blacklist;
};
struct GAState *ga_state;
+/* commands that are safe to issue while filesystems are frozen */
+static const char *ga_freeze_whitelist[] = {
+ "guest-ping",
+ "guest-info",
+ "guest-sync",
+ "guest-fsfreeze-status",
+ "guest-fsfreeze-thaw",
+ NULL
+};
+
#ifdef _WIN32
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
LPVOID ctx);
@@ -68,6 +80,15 @@ VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
static void quit_handler(int sig)
{
+ /* if we're frozen, don't exit unless we're absolutely forced to,
+ * because it's basically impossible for graceful exit to complete
+ * unless all log/pid files are on unfreezable filesystems. there's
+ * also a very likely chance killing the agent before unfreezing
+ * the filesystems is a mistake (or will be viewed as one later).
+ */
+ if (ga_is_frozen(ga_state)) {
+ return;
+ }
g_debug("received signal num %d, quitting", sig);
if (g_main_loop_is_running(ga_state->main_loop)) {
@@ -206,6 +227,87 @@ void ga_set_response_delimited(GAState *s)
s->delimit_response = true;
}
+static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
+{
+ return strcmp(str1, str2);
+}
+
+/* disable commands that aren't safe for fsfreeze */
+static void ga_disable_non_whitelisted(void)
+{
+ char **list_head, **list;
+ bool whitelisted;
+ int i;
+
+ list_head = list = qmp_get_command_list();
+ while (*list != NULL) {
+ whitelisted = false;
+ i = 0;
+ while (ga_freeze_whitelist[i] != NULL) {
+ if (strcmp(*list, ga_freeze_whitelist[i]) == 0) {
+ whitelisted = true;
+ }
+ i++;
+ }
+ if (!whitelisted) {
+ g_debug("disabling command: %s", *list);
+ qmp_disable_command(*list);
+ }
+ g_free(*list);
+ list++;
+ }
+ g_free(list_head);
+}
+
+/* [re-]enable all commands, except those explictly blacklisted by user */
+static void ga_enable_non_blacklisted(GList *blacklist)
+{
+ char **list_head, **list;
+
+ list_head = list = qmp_get_command_list();
+ while (*list != NULL) {
+ if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL &&
+ !qmp_command_is_enabled(*list)) {
+ g_debug("enabling command: %s", *list);
+ qmp_enable_command(*list);
+ }
+ g_free(*list);
+ list++;
+ }
+ g_free(list_head);
+}
+
+bool ga_is_frozen(GAState *s)
+{
+ return s->frozen;
+}
+
+void ga_set_frozen(GAState *s)
+{
+ if (ga_is_frozen(s)) {
+ return;
+ }
+ /* disable all non-whitelisted (for frozen state) commands */
+ ga_disable_non_whitelisted();
+ g_warning("disabling logging due to filesystem freeze");
+ ga_disable_logging(s);
+ s->frozen = true;
+}
+
+void ga_unset_frozen(GAState *s)
+{
+ if (!ga_is_frozen(s)) {
+ return;
+ }
+
+ ga_enable_logging(s);
+ g_warning("logging re-enabled");
+
+ /* enable all disabled, non-blacklisted commands */
+ ga_enable_non_blacklisted(s->blacklist);
+ s->frozen = false;
+}
+
#ifndef _WIN32
static void become_daemon(const char *pidfile)
{
@@ -513,12 +615,13 @@ int main(int argc, char **argv)
{ "blacklist", 1, NULL, 'b' },
#ifdef _WIN32
{ "service", 1, NULL, 's' },
-#endif
+#endif
{ NULL, 0, NULL, 0 }
};
int opt_ind = 0, ch, daemonize = 0, i, j, len;
GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
FILE *log_file = stderr;
+ GList *blacklist = NULL;
GAState *s;
module_call_init(MODULE_INIT_QAPI);
@@ -568,14 +671,12 @@ int main(int argc, char **argv)
for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
if (optarg[i] == ',') {
optarg[i] = 0;
- qmp_disable_command(&optarg[j]);
- g_debug("disabling command: %s", &optarg[j]);
+ blacklist = g_list_append(blacklist, &optarg[j]);
j = i + 1;
}
}
if (j < i) {
- qmp_disable_command(&optarg[j]);
- g_debug("disabling command: %s", &optarg[j]);
+ blacklist = g_list_append(blacklist, &optarg[j]);
}
break;
}
@@ -615,6 +716,15 @@ int main(int argc, char **argv)
g_log_set_default_handler(ga_log, s);
g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
s->logging_enabled = true;
+ s->frozen = false;
+ if (blacklist) {
+ s->blacklist = blacklist;
+ do {
+ g_debug("disabling command: %s", (char *)blacklist->data);
+ qmp_disable_command(blacklist->data);
+ blacklist = g_list_next(blacklist);
+ } while (blacklist);
+ }
s->command_state = ga_command_state_new();
ga_command_state_init(s, s->command_state);
ga_command_state_init_all(s->command_state);