From 1879e856729deba532cbb083ae1e94e0b93cd100 Mon Sep 17 00:00:00 2001
From: Peter Rajnoha <prajnoha@redhat.com>
Date: Thu, 6 Aug 2009 15:00:25 +0000
Subject: [PATCH] Detect udev problems in _rename_dev_node.

---
 libdm/libdm-common.c | 94 ++++++++++++++++++++++++++------------------
 1 file changed, 56 insertions(+), 38 deletions(-)

diff --git a/libdm/libdm-common.c b/libdm/libdm-common.c
index 8eb5548ee..78268ab99 100644
--- a/libdm/libdm-common.c
+++ b/libdm/libdm-common.c
@@ -381,44 +381,6 @@ static int _add_dev_node(const char *dev_name, uint32_t major, uint32_t minor,
 	return 1;
 }
 
-static int _rename_dev_node(const char *old_name, const char *new_name)
-{
-	char oldpath[PATH_MAX];
-	char newpath[PATH_MAX];
-	struct stat info;
-
-	_build_dev_path(oldpath, sizeof(oldpath), old_name);
-	_build_dev_path(newpath, sizeof(newpath), new_name);
-
-	if (stat(newpath, &info) == 0) {
-		if (!S_ISBLK(info.st_mode)) {
-			log_error("A non-block device file at '%s' "
-				  "is already present", newpath);
-			return 0;
-		}
-
-		if (unlink(newpath) < 0) {
-			if (errno == EPERM) {
-				/* devfs, entry has already been renamed */
-				return 1;
-			}
-			log_error("Unable to unlink device node for '%s'",
-				  new_name);
-			return 0;
-		}
-	}
-
-	if (rename(oldpath, newpath) < 0) {
-		log_error("Unable to rename device node from '%s' to '%s'",
-			  old_name, new_name);
-		return 0;
-	}
-
-	log_debug("Renamed %s to %s", oldpath, newpath);
-
-	return 1;
-}
-
 static int _rm_dev_node(const char *dev_name)
 {
 	char path[PATH_MAX];
@@ -442,6 +404,62 @@ static int _rm_dev_node(const char *dev_name)
 	return 1;
 }
 
+static int _rename_dev_node(const char *old_name, const char *new_name)
+{
+	char oldpath[PATH_MAX];
+	char newpath[PATH_MAX];
+	struct stat info;
+
+	_build_dev_path(oldpath, sizeof(oldpath), old_name);
+	_build_dev_path(newpath, sizeof(newpath), new_name);
+
+	if (stat(newpath, &info) == 0) {
+		if (!S_ISBLK(info.st_mode)) {
+			log_error("A non-block device file at '%s' "
+				  "is already present", newpath);
+			return 0;
+		}
+		else if (dm_udev_get_sync_support()) {
+			if (stat(oldpath, &info) < 0 &&
+				 errno == ENOENT)
+				/* assume udev already deleted this */
+				return 1;
+			else {
+				log_warn("The node %s should have been renamed to %s "
+					 "by udev but old node is still present. "
+					 "Falling back to direct old node removal.",
+					 oldpath, newpath);
+				return _rm_dev_node(old_name);
+			}
+		}
+
+		if (unlink(newpath) < 0) {
+			if (errno == EPERM) {
+				/* devfs, entry has already been renamed */
+				return 1;
+			}
+			log_error("Unable to unlink device node for '%s'",
+				  new_name);
+			return 0;
+		}
+	}
+	else if (dm_udev_get_sync_support())
+		log_warn("The node %s should have been renamed to %s "
+			 "by udev but new node is not present. "
+			 "Falling back to direct node rename.",
+			 oldpath, newpath);
+
+	if (rename(oldpath, newpath) < 0) {
+		log_error("Unable to rename device node from '%s' to '%s'",
+			  old_name, new_name);
+		return 0;
+	}
+
+	log_debug("Renamed %s to %s", oldpath, newpath);
+
+	return 1;
+}
+
 #ifdef linux
 static int _open_dev_node(const char *dev_name)
 {