Strictly require libudev if udev_sync is used.

This prevents some confusion when libudev was not found so udev_sync was disabled
automatically. Configure was successful though giving only a tiny warning.

Also, if "dmsetup udevcreatecookie" is used, never return 0x000000 as a result if
udev is not running and keep the output blank.

WHATS_NEW_DM

@@ -1,5 +1,6 @@
 Version 1.02.46 - 
 ================================
+  Strictly require libudev if udev_sync is used.
   Add support for ioctl's DM_UEVENT_GENERATED_FLAG.
 
 Version 1.02.45 - 9th March 2010

configure.in

@@ -650,6 +650,7 @@ UDEV_SYNC=$enableval, UDEV_SYNC=no)
 AC_MSG_RESULT($UDEV_SYNC)
 
 if test x$UDEV_SYNC = xyes; then
+	AC_CHECK_LIB(udev, udev_queue_get_udev_is_active, UDEV_LIBS="-ludev", AC_MSG_ERROR(bailing out... libudev library is required))
 	AC_DEFINE([UDEV_SYNC_SUPPORT], 1, [Define to 1 to enable synchronisation with udev processing.])
 fi
 
@@ -659,23 +660,6 @@ AC_ARG_ENABLE(udev_rules, [  --enable-udev_rules     Install rule files needed f
 UDEV_RULES=$enableval, UDEV_RULES=$UDEV_SYNC)
 AC_MSG_RESULT($UDEV_RULES)
 
-################################################################################
-dnl -- Check for libudev's udev_queue_get_udev_is_active function when udev synchronisation is enabled
-
-if test x$UDEV_SYNC = xyes; then
-	AC_CHECK_LIB(udev, udev_queue_get_udev_is_active, HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE=yes,
-		HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE=no)
-
-		if test x$HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE = xyes; then
-			AC_DEFINE([HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE], 1,
-			  [Define to 1 if libudev's udev_queue_get_udev_is_active function is available.])
-			UDEV_LIBS="-ludev"
-		else
-			UDEV_LIBS=
-			AC_MSG_WARN(It won't be possible to get udev state. We will assume that udev is not running.)
-		fi
-fi
-
 ################################################################################
 dnl -- Compatibility mode
 AC_ARG_ENABLE(compat,   [  --enable-compat         Enable support for old device-mapper versions],

libdm/libdm-common.c

@@ -29,11 +29,9 @@
 #  include <sys/types.h>
 #  include <sys/ipc.h>
 #  include <sys/sem.h>
-#ifdef HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE
 #  define LIBUDEV_I_KNOW_THE_API_IS_SUBJECT_TO_CHANGE
 #  include <libudev.h>
 #endif
-#endif
 
 #ifdef linux
 #  include <linux/fs.h>
@@ -922,16 +920,6 @@ int dm_udev_wait(uint32_t cookie)
 
 static int _check_udev_is_running(void)
 {
-
-#  ifndef HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE
-
-	log_debug("Could not get udev state because libudev library "
-		  "was not found and it was not compiled in. "
-		  "Assuming udev is not running.");
-	return 0;
-
-#  else	/* HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE */
-
 	struct udev *udev;
 	struct udev_queue *udev_queue;
 	int r;
@@ -956,9 +944,6 @@ static int _check_udev_is_running(void)
 bad:
 	log_error("Could not get udev state. Assuming udev is not running.");
 	return 0;
-
-#  endif	/* HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE */
-
 }
 
 void dm_udev_set_sync_support(int sync_with_udev)
@@ -1170,8 +1155,10 @@ int dm_udev_create_cookie(uint32_t *cookie)
 {
 	int semid;
 
-	if (!dm_udev_get_sync_support())
+	if (!dm_udev_get_sync_support()) {
+		*cookie = 0;
 		return 1;
+	}
 
 	return _udev_notify_sem_create(cookie, &semid);
 }

tools/dmsetup.c

@@ -45,11 +45,9 @@
 #  include <sys/types.h>
 #  include <sys/ipc.h>
 #  include <sys/sem.h>
-#ifdef HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE
 #  define LIBUDEV_I_KNOW_THE_API_IS_SUBJECT_TO_CHANGE
 #  include <libudev.h>
 #endif
-#endif
 
 /* FIXME Unused so far */
 #undef HAVE_SYS_STATVFS_H
@@ -931,12 +929,10 @@ static int _udevcookies(int argc __attribute((unused)), char **argv __attribute(
 #else	/* UDEV_SYNC_SUPPORT */
 static int _set_up_udev_support(const char *dev_dir)
 {
-#ifdef HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE
 	struct udev *udev;
 	const char *udev_dev_dir;
 	size_t udev_dev_dir_len;
 	int dirs_diff;
-#endif
 	const char *env;
 
 	if (_switches[NOUDEVSYNC_ARG])
@@ -955,7 +951,6 @@ static int _set_up_udev_support(const char *dev_dir)
 			  " defined by --udevcookie option.",
 			  _udev_cookie);
 
-#ifdef HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE
 	if (!(udev = udev_new()) ||
 	    !(udev_dev_dir = udev_get_dev_path(udev)) ||
 	    !*udev_dev_dir) {
@@ -995,7 +990,6 @@ static int _set_up_udev_support(const char *dev_dir)
 	}
 
 	udev_unref(udev);
-#endif
 	return 1;
 }
 
@@ -1007,6 +1001,7 @@ static int _udevcreatecookie(int argc, char **argv,
 	if (!dm_udev_create_cookie(&cookie))
 		return 0;
 
+	if (cookie)
 		printf("0x%08" PRIX32 "\n", cookie);
 
 	return 1;

tools/lvmcmdline.c

@@ -42,7 +42,7 @@ extern char *optarg;
 #  define OPTIND_INIT 1
 #endif
 
-#ifdef HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE
+#ifdef UDEV_SYNC_SUPPORT
 #  define LIBUDEV_I_KNOW_THE_API_IS_SUBJECT_TO_CHANGE
 #  include <libudev.h>
 #endif
@@ -919,7 +919,7 @@ static void _apply_settings(struct cmd_context *cmd)
 
 static int _set_udev_checking(struct cmd_context *cmd)
 {
-#ifdef HAVE_UDEV_QUEUE_GET_UDEV_IS_ACTIVE
+#ifdef UDEV_SYNC
 	struct udev *udev;
 	const char *udev_dev_dir;
 	size_t udev_dev_dir_len;