[libvirt] [PATCH]lxc: improve readability of lxcContainer[Send|Waitfor]Continue

[Chen Hanxiao]

From: Chen Hanxiao <chenhanxiao at cn.fujitsu.com>

Currently, lxcContainer[Send|Waitfor]Continue only tell
us 'fd', but we had to deal with the interaction between
lxc_[container|controller|process].
This patch adds parameters to identify the caller.

Signed-off-by: Chen Hanxiao <chenhanxiao at cn.fujitsu.com>
---
 src/lxc/lxc_container.c  | 16 +++++++++-------
 src/lxc/lxc_container.h  |  4 ++--
 src/lxc/lxc_controller.c |  6 +++---
 src/lxc/lxc_process.c    |  2 +-
 4 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index ed1fe29..c7371ca 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -351,19 +351,20 @@ cleanup:
 /**
  * lxcContainerSendContinue:
  * @control: control FD to child
+ * @caller: function invoker
  *
  * Sends the continue message via the socket pair stored in the vm
  * structure.
  *
  * Returns 0 on success or -1 in case of error
  */
-int lxcContainerSendContinue(int control)
+int lxcContainerSendContinue(int control, const char *caller)
 {
     int rc = -1;
     lxc_message_t msg = LXC_CONTINUE_MSG;
     int writeCount = 0;
 
-    VIR_DEBUG("Send continue on fd %d", control);
+    VIR_DEBUG("Send continue on fd %d by %s", control, caller);
     writeCount = safewrite(control, &msg, sizeof(msg));
     if (writeCount != sizeof(msg)) {
         goto error_out;
@@ -377,6 +378,7 @@ error_out:
 /**
  * lxcContainerWaitForContinue:
  * @control: Control FD from parent
+ * @caller: function invoker
  *
  * This function will wait for the container continue message from the
  * parent process.  It will send this message on the socket pair stored in
@@ -384,14 +386,14 @@ error_out:
  *
  * Returns 0 on success or -1 in case of error
  */
-int lxcContainerWaitForContinue(int control)
+int lxcContainerWaitForContinue(int control, const char *caller)
 {
     lxc_message_t msg;
     int readLen;
 
-    VIR_DEBUG("Wait continue on fd %d", control);
+    VIR_DEBUG("%s wait continue on fd %d", caller, control);
     readLen = saferead(control, &msg, sizeof(msg));
-    VIR_DEBUG("Got continue on fd %d %d", control, readLen);
+    VIR_DEBUG("%s got continue on fd %d %d", caller, control, readLen);
     if (readLen != sizeof(msg)) {
         if (readLen >= 0)
             errno = EIO;
@@ -1813,7 +1815,7 @@ static int lxcContainerChild(void *data)
     /* Wait for controller to finish setup tasks, including
      * things like move of network interfaces, uid/gid mapping
      */
-    if (lxcContainerWaitForContinue(argv->monitor) < 0) {
+    if (lxcContainerWaitForContinue(argv->monitor, __func__) < 0) {
         virReportSystemError(errno, "%s",
                              _("Failed to read the container continue message"));
         goto cleanup;
@@ -1880,7 +1882,7 @@ static int lxcContainerChild(void *data)
     if (lxcContainerDropCapabilities(!!hasReboot) < 0)
         goto cleanup;
 
-    if (lxcContainerSendContinue(argv->handshakefd) < 0) {
+    if (lxcContainerSendContinue(argv->handshakefd, __func__) < 0) {
         virReportSystemError(errno, "%s",
                             _("Failed to send continue signal to controller"));
         goto cleanup;
diff --git a/src/lxc/lxc_container.h b/src/lxc/lxc_container.h
index e74a7d7..77fb2a0 100644
--- a/src/lxc/lxc_container.h
+++ b/src/lxc/lxc_container.h
@@ -49,8 +49,8 @@ enum {
 # define LXC_DEV_MAJ_FUSE    10
 # define LXC_DEV_MIN_FUSE    229
 
-int lxcContainerSendContinue(int control);
-int lxcContainerWaitForContinue(int control);
+int lxcContainerSendContinue(int control, const char *caller);
+int lxcContainerWaitForContinue(int control, const char *caller);
 
 int lxcContainerStart(virDomainDefPtr def,
                       virSecurityManagerPtr securityDriver,
diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c
index 851a773..25dbbec 100644
--- a/src/lxc/lxc_controller.c
+++ b/src/lxc/lxc_controller.c
@@ -319,7 +319,7 @@ static int virLXCControllerConsoleSetNonblocking(virLXCControllerConsolePtr cons
 
 static int virLXCControllerDaemonHandshake(virLXCControllerPtr ctrl)
 {
-    if (lxcContainerSendContinue(ctrl->handshakeFd) < 0) {
+    if (lxcContainerSendContinue(ctrl->handshakeFd, __func__) < 0) {
         virReportSystemError(errno, "%s",
                              _("error sending continue signal to daemon"));
         return -1;
@@ -2176,13 +2176,13 @@ virLXCControllerRun(virLXCControllerPtr ctrl)
     if (virLXCControllerMoveInterfaces(ctrl) < 0)
         goto cleanup;
 
-    if (lxcContainerSendContinue(control[0]) < 0) {
+    if (lxcContainerSendContinue(control[0], __func__) < 0) {
         virReportSystemError(errno, "%s",
                              _("Unable to send container continue message"));
         goto cleanup;
     }
 
-    if (lxcContainerWaitForContinue(containerhandshake[0]) < 0) {
+    if (lxcContainerWaitForContinue(containerhandshake[0], __func__) < 0) {
         virReportSystemError(errno, "%s",
                              _("error receiving signal from container"));
         goto cleanup;
diff --git a/src/lxc/lxc_process.c b/src/lxc/lxc_process.c
index f088e8e..de20dd0 100644
--- a/src/lxc/lxc_process.c
+++ b/src/lxc/lxc_process.c
@@ -1264,7 +1264,7 @@ int virLXCProcessStart(virConnectPtr conn,
     if (virAtomicIntInc(&driver->nactive) == 1 && driver->inhibitCallback)
         driver->inhibitCallback(true, driver->inhibitOpaque);
 
-    if (lxcContainerWaitForContinue(handshakefds[0]) < 0) {
+    if (lxcContainerWaitForContinue(handshakefds[0], __func__) < 0) {
         char out[1024];
 
         if (!(virLXCProcessReadLogOutput(vm, logfile, pos, out, 1024) < 0)) {
-- 
1.8.2.1