[Xen-devel] [PATCH] tools/xc: print messages from xc_save with xc_report

[Olaf Hering <olaf@xxxxxxxxx>]

# HG changeset patch
# User Olaf Hering <olaf@xxxxxxxxx>
# Date 1360958742 -3600
# Node ID 83a05c99299d60197fbb7eac219054b371d61eff
# Parent  6ff99ddc4c41af31863393cd2239bc03fb63642c
tools/xc: print messages from xc_save with xc_report

Make use of xc_report in xc_save to log also pid if some error occoured.
Rework code in switch_qemu_logdirty, fix memleak.

Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>

diff -r 6ff99ddc4c41 -r 83a05c99299d tools/libxc/xc_private.h
--- a/tools/libxc/xc_private.h
+++ b/tools/libxc/xc_private.h
@@ -119,6 +119,7 @@ void xc_report_progress_step(xc_interfac
 
 /* anamorphic macros:  struct xc_interface *xch  must be in scope */
 
+#define WPRINTF(_f, _a...) xc_report(xch, xch->error_handler, XTL_WARN,0, _f , 
## _a)
 #define IPRINTF(_f, _a...) xc_report(xch, xch->error_handler, XTL_INFO,0, _f , 
## _a)
 #define DPRINTF(_f, _a...) xc_report(xch, xch->error_handler, XTL_DETAIL,0, _f 
, ## _a)
 #define DBGPRINTF(_f, _a...) xc_report(xch, xch->error_handler, XTL_DEBUG,0, 
_f , ## _a)
diff -r 6ff99ddc4c41 -r 83a05c99299d tools/xcutils/xc_restore.c
--- a/tools/xcutils/xc_restore.c
+++ b/tools/xcutils/xc_restore.c
@@ -56,6 +56,7 @@ main(int argc, char **argv)
 
     if ( ret == 0 )
     {
+       /* xend expects this output, part of protocol */
        printf("store-mfn %li\n", store_mfn);
         if ( !hvm )
             printf("console-mfn %li\n", console_mfn);
diff -r 6ff99ddc4c41 -r 83a05c99299d tools/xcutils/xc_save.c
--- a/tools/xcutils/xc_save.c
+++ b/tools/xcutils/xc_save.c
@@ -7,6 +7,7 @@
  *
  */
 
+#define _GNU_SOURCE
 #include <err.h>
 #include <stdlib.h>
 #include <stdint.h>
@@ -19,6 +20,7 @@
 #include <fcntl.h>
 #include <err.h>
 
+#include <xc_private.h>
 #include <xenstore.h>
 #include <xenctrl.h>
 #include <xenguest.h>
@@ -51,16 +53,17 @@ static int compat_suspend(void)
  * receive the acknowledgement from the subscribe event channel. */
 static int evtchn_suspend(void)
 {
+    xc_interface *xch = si.xch;
     int rc;
 
     rc = xc_evtchn_notify(si.xce, si.suspend_evtchn);
     if (rc < 0) {
-        warnx("failed to notify suspend request channel: %d", rc);
+        WPRINTF("failed to notify suspend request channel: %d", rc);
         return 0;
     }
 
     if (xc_await_suspend(si.xch, si.xce, si.suspend_evtchn) < 0) {
-        warnx("suspend failed");
+        WPRINTF("suspend failed");
         return 0;
     }
 
@@ -104,61 +107,66 @@ static int suspend(void* data)
 
 static int switch_qemu_logdirty(int domid, unsigned int enable, void *data)
 {
+    xc_interface *xch = si.xch;
     struct xs_handle *xs;
-    char *path, *p, *ret_str, *cmd_str, **watch;
+    char *path, *p, *ret_str, **watch;
+    const char *cmd_str;
     unsigned int len;
+    int ret, again;
     struct timeval tv;
     fd_set fdset;
 
-    if ((xs = xs_daemon_open()) == NULL)
-        errx(1, "Couldn't contact xenstore");
-    if (!(path = strdup("/local/domain/0/device-model/")))
-        errx(1, "can't get domain path in store");
-    if (!(path = realloc(path, strlen(path) 
-                         + 10 
-                         + strlen("/logdirty/cmd") + 1)))
-        errx(1, "no memory for constructing xenstore path");
-    snprintf(path + strlen(path), 11, "%i", domid);
-    strcat(path, "/logdirty/");
-    p = path + strlen(path);
+    if ((xs = xs_daemon_open()) == NULL) {
+        PERROR("Couldn't contact xenstore");
+        exit(1);
+    }
 
+    ret = asprintf(&path, "/local/domain/0/device-model/%i/logdirty/ret", 
domid);
+    if (ret < 0) {
+        ERROR("no memory for constructing xenstore path");
+        exit(1);
+    }
+    p = path + ret - 3;
 
     /* Watch for qemu's return value */
-    strcpy(p, "ret");
-    if (!xs_watch(xs, path, "qemu-logdirty-ret"))
-        errx(1, "can't set watch in store (%s)\n", path);
+    if (!xs_watch(xs, path, "qemu-logdirty-ret")) {
+        PERROR("can't set watch in store (%s)", path);
+        exit(1);
+    }
 
-    if (!(cmd_str = strdup( enable == 0 ? "disable" : "enable")))
-        errx(1, "can't get logdirty cmd path in store");
+    cmd_str = enable ? "enable" : "disable";
 
-    /* Tell qemu that we want it to start logging dirty page to Xen */
+    /* Tell qemu that we want it to start logging dirty pages to Xen */
     strcpy(p, "cmd");
-    if (!xs_write(xs, XBT_NULL, path, cmd_str, strlen(cmd_str)))
-        errx(1, "can't write  to store path (%s)\n",
-             path);
+    if (!xs_write(xs, XBT_NULL, path, cmd_str, strlen(cmd_str))) {
+        PERROR("can't write to store path (%s)", path);
+        exit(1);
+    }
 
-    /* Wait a while for qemu to signal that it has service logdirty command */
- read_again:
-    tv.tv_sec = 5;
-    tv.tv_usec = 0;
-    FD_ZERO(&fdset);
-    FD_SET(xs_fileno(xs), &fdset);
+    /* Wait a while for qemu to signal that it has serviced logdirty command */
+    do {
+        tv.tv_sec = 5;
+        tv.tv_usec = 0;
+        FD_ZERO(&fdset);
+        FD_SET(xs_fileno(xs), &fdset);
+        errno = 0;
 
-    if ((select(xs_fileno(xs) + 1, &fdset, NULL, NULL, &tv)) != 1)
-        errx(1, "timed out waiting for qemu logdirty response.\n");
-
-    watch = xs_read_watch(xs, &len);
-    free(watch);
-
-    strcpy(p, "ret");
-    ret_str = xs_read(xs, XBT_NULL, path, &len);
-    if (ret_str == NULL || strcmp(ret_str, cmd_str))
+        if ((select(xs_fileno(xs) + 1, &fdset, NULL, NULL, &tv)) != 1) {
+            PERROR("timed out waiting for qemu logdirty response.");
+            exit(1);
+        }
+    
+        watch = xs_read_watch(xs, &len);
+        free(watch);
+    
+        strcpy(p, "ret");
+        ret_str = xs_read(xs, XBT_NULL, path, &len);
+        again = ret_str == NULL || strcmp(ret_str, cmd_str);
+        free(ret_str);
         /* Watch fired but value is not yet right */
-        goto read_again;
+    } while (again);
 
     free(path);
-    free(cmd_str);
-    free(ret_str);
 
     return 0;
 }
@@ -166,6 +174,7 @@ static int switch_qemu_logdirty(int domi
 int
 main(int argc, char **argv)
 {
+    xc_interface *xch;
     unsigned int maxit, max_f, lflags;
     int io_fd, ret, port;
     struct save_callbacks callbacks;
@@ -186,26 +195,26 @@ main(int argc, char **argv)
     lvl = si.flags & XCFLAGS_DEBUG ? XTL_DEBUG: XTL_DETAIL;
     lflags = XTL_STDIOSTREAM_SHOW_PID | XTL_STDIOSTREAM_HIDE_PROGRESS;
     l = (xentoollog_logger *)xtl_createlogger_stdiostream(stderr, lvl, lflags);
-    si.xch = xc_interface_open(l, 0, 0);
+    xch = si.xch = xc_interface_open(l, 0, 0);
     if (!si.xch)
         errx(1, "failed to open control interface");
 
     si.xce = xc_evtchn_open(NULL, 0);
     if (si.xce == NULL)
-        warnx("failed to open event channel handle");
+        WPRINTF("failed to open event channel handle");
     else
     {
         port = xs_suspend_evtchn_port(si.domid);
 
         if (port < 0)
-            warnx("failed to get the suspend evtchn port\n");
+            WPRINTF("failed to get the suspend evtchn port\n");
         else
         {
             si.suspend_evtchn =
               xc_suspend_evtchn_init(si.xch, si.xce, si.domid, port);
 
             if (si.suspend_evtchn < 0)
-                warnx("suspend event channel initialization failed, "
+                WPRINTF("suspend event channel initialization failed, "
                        "using slow path");
         }
     }

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