virsh: Use vshWatchJob in cmdDump

This patch alters dumping code, so we can report progress
and allow cancel via ^C.

tools/virsh.c

@@ -3092,26 +3092,36 @@ static const vshCmdOptDef opts_dump[] = {
     {"reset", VSH_OT_BOOL, 0, N_("reset the domain after core dump")},
     {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
     {"file", VSH_OT_DATA, VSH_OFLAG_REQ, N_("where to dump the core")},
+    {"verbose", VSH_OT_BOOL, 0, N_("display the progress of dump")},
     {NULL, 0, 0, NULL}
 };
 
-static bool
-cmdDump(vshControl *ctl, const vshCmd *cmd)
+static void
+doDump(void *opaque)
 {
-    virDomainPtr dom;
+    char ret = '1';
+    vshCtrlData *data = opaque;
+    vshControl *ctl = data->ctl;
+    const vshCmd *cmd = data->cmd;
+    virDomainPtr dom = NULL;
+    sigset_t sigmask, oldsigmask;
     const char *name = NULL;
     const char *to = NULL;
-    bool ret = false;
     unsigned int flags = 0;
 
+    sigemptyset(&sigmask);
+    sigaddset(&sigmask, SIGINT);
+    if (pthread_sigmask(SIG_BLOCK, &sigmask, &oldsigmask) < 0)
+        goto out_sig;
+
     if (!vshConnectionUsability(ctl, ctl->conn))
-        return false;
+        goto out;
 
     if (vshCommandOptString(cmd, "file", &to) <= 0)
-        return false;
+        goto out;
 
     if (!(dom = vshCommandOptDomain(ctl, cmd, &name)))
-        return false;
+        goto out;
 
     if (vshCommandOptBool (cmd, "live"))
         flags |= VIR_DUMP_LIVE;
@@ -3124,14 +3134,63 @@ cmdDump(vshControl *ctl, const vshCmd *cmd)
 
     if (virDomainCoreDump(dom, to, flags) < 0) {
         vshError(ctl, _("Failed to core dump domain %s to %s"), name, to);
-        goto cleanup;
+        goto out;
     }
 
-    vshPrint(ctl, _("Domain %s dumped to %s\n"), name, to);
-    ret = true;
+    ret = '0';
+out:
+    pthread_sigmask(SIG_SETMASK, &oldsigmask, NULL);
+out_sig:
+    if (dom)
+        virDomainFree (dom);
+    ignore_value(safewrite(data->writefd, &ret, sizeof(ret)));
+}
+
+static bool
+cmdDump(vshControl *ctl, const vshCmd *cmd)
+{
+    virDomainPtr dom;
+    int p[2] = { -1, -1};
+    bool ret = false;
+    bool verbose = false;
+    const char *name = NULL;
+    const char *to = NULL;
+    vshCtrlData data;
+    virThread workerThread;
+
+    if (!(dom = vshCommandOptDomain(ctl, cmd, &name)))
+        return false;
+
+    if (vshCommandOptString(cmd, "file", &to) <= 0)
+        return false;
+
+    if (vshCommandOptBool (cmd, "verbose"))
+        verbose = true;
+
+    if (pipe(p) < 0)
+        goto cleanup;
+
+    data.ctl = ctl;
+    data.cmd = cmd;
+    data.writefd = p[1];
+
+    if (virThreadCreate(&workerThread,
+                        true,
+                        doDump,
+                        &data) < 0)
+        goto cleanup;
+
+    ret = vshWatchJob(ctl, dom, verbose, p[0], 0, NULL, NULL, _("Dump"));
+
+    virThreadJoin(&workerThread);
+
+    if (ret)
+        vshPrint(ctl, _("\nDomain %s dumped to %s\n"), name, to);
 
 cleanup:
     virDomainFree(dom);
+    VIR_FORCE_CLOSE(p[0]);
+    VIR_FORCE_CLOSE(p[1]);
     return ret;
 }
 

tools/virsh.pod

@@ -682,7 +682,7 @@ the I<format> argument must be B<qemu-argv>. For Xen hypervisor, the
 I<format> argument may be B<xen-xm> or B<xen-sxpr>.
 
 =item B<dump> I<domain-id> I<corefilepath> [I<--bypass-cache>]
-{ [I<--live>] | [I<--crash>] | [I<--reset>] }
+{ [I<--live>] | [I<--crash>] | [I<--reset>] } [I<--verbose>]
 
 Dumps the core of a domain to a file for analysis.
 If I<--live> is specified, the domain continues to run until the core
@@ -695,9 +695,9 @@ If I<--bypass-cache> is specified, the save will avoid the file system
 cache, although this may slow down the operation.
 
 The progress may be monitored using B<domjobinfo> virsh command and canceled
-with B<domjobabort> command (sent by another virsh instance). Interrupting
-(usually with C<Ctrl-C>) the virsh process which runs B<dump> command is not
-enough to actually cancel the operation.
+with B<domjobabort> command (sent by another virsh instance). Another option
+is to send SIGINT (usually with C<Ctrl-C>) to the virsh process running
+B<dump> command. I<--verbose> displays the progress of dump.
 
 NOTE: Some hypervisors may require the user to manually ensure proper
 permissions on file and path specified by argument I<corefilepath>.