qemu_process: Use unique directories for QMP processes

Multiple QEMU processes for QMP commands can operate concurrently.

Use a unique directory under libDir for each QEMU process to avoid
pidfile and unix socket collision between processes.

The pid file name is changed from "capabilities.pidfile" to "qmp.pid"
because we no longer need to avoid a possible clash with a qemu domain
called "capabilities" now that the processes artifacts are stored in
their own unique temporary directories.

"Capabilities" was changed to "qmp" in the pid file name because these
processes are no longer specific to the capabilities usecase and are
more generic in terms of being used for any general purpose QMP message
exchanges with a QEMU process that is not associated with a domain.

Signed-off-by: Chris Venteicher <cventeic@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index ca5911bacd8ce54fd70a9f82cc0e59929ad8d490..820476dbb18d965a65f17f1ffc0e799ad24ec9e5 100644 (file)
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -8358,6 +8358,9 @@ qemuProcessQMPStop(qemuProcessQMPPtr proc)
 
     if (proc->pidfile)
         unlink(proc->pidfile);
+
+    if (proc->uniqDir)
+        rmdir(proc->uniqDir);
 }
 
 
@@ -8376,6 +8379,7 @@ qemuProcessQMPFree(qemuProcessQMPPtr proc)
     qemuProcessQMPStop(proc);
     VIR_FREE(proc->binary);
     VIR_FREE(proc->libDir);
+    VIR_FREE(proc->uniqDir);
     VIR_FREE(proc->monpath);
     VIR_FREE(proc->monarg);
     VIR_FREE(proc->pidfile);
@@ -8430,31 +8434,37 @@ qemuProcessQMPNew(const char *binary,
 static int
 qemuProcessQMPInit(qemuProcessQMPPtr proc)
 {
+    char *template = NULL;
     int ret = -1;
 
     VIR_DEBUG("proc=%p, emulator=%s", proc, proc->binary);
 
-    /* the ".sock" sufix is important to avoid a possible clash with a qemu
-     * domain called "capabilities"
-     */
-    if (virAsprintf(&proc->monpath, "%s/%s", proc->libDir,
-                    "capabilities.monitor.sock") < 0)
+    if (virAsprintf(&template, "%s/qmp-XXXXXX", proc->libDir) < 0)
+        goto cleanup;
+
+    if (!(proc->uniqDir = mkdtemp(template))) {
+        virReportSystemError(errno,
+                             _("Failed to create unique directory with "
+                               "template '%s' for probing QEMU"),
+                             template);
+        goto cleanup;
+    }
+
+    if (virAsprintf(&proc->monpath, "%s/%s", proc->uniqDir,
+                    "qmp.monitor") < 0)
         goto cleanup;
 
     if (virAsprintf(&proc->monarg, "unix:%s,server,nowait", proc->monpath) < 0)
         goto cleanup;
 
-    /* ".pidfile" suffix is used rather than ".pid" to avoid a possible clash
-     * with a qemu domain called "capabilities"
+    /*
      * Normally we'd use runDir for pid files, but because we're using
      * -daemonize we need QEMU to be allowed to create them, rather
      * than libvirtd. So we're using libDir which QEMU can write to
      */
-    if (virAsprintf(&proc->pidfile, "%s/%s", proc->libDir, "capabilities.pidfile") < 0)
+    if (virAsprintf(&proc->pidfile, "%s/%s", proc->uniqDir, "qmp.pid") < 0)
         goto cleanup;
 
-    virPidFileForceCleanupPath(proc->pidfile);
-
     ret = 0;
 
  cleanup:

diff --git a/src/qemu/qemu_process.h b/src/qemu/qemu_process.h
index c435a1972687f6383cf957e1a41fa47cff2ae2d1..3367cd3fe53bd0a30b98cd6978fc4c98f9498a5f 100644 (file)
--- a/src/qemu/qemu_process.h
+++ b/src/qemu/qemu_process.h
@@ -225,6 +225,7 @@ struct _qemuProcessQMP {
     char *monarg;
     char *monpath;
     char *pidfile;
+    char *uniqDir;
     virCommandPtr cmd;
     qemuMonitorPtr mon;
     pid_t pid;