Index: uspace/app/bdsh/cmds/modules/mount/mount.c
===================================================================
--- uspace/app/bdsh/cmds/modules/mount/mount.c	(revision 4c7c25135dc43993f0c90327f035578a98ef0c2f)
+++ uspace/app/bdsh/cmds/modules/mount/mount.c	(revision 37b1651de7d2b2fb0e5e2ee69dd1cfbdc338bfe1)
@@ -31,4 +31,5 @@
 #include <vfs/vfs.h>
 #include <errno.h>
+#include <getopt.h>
 #include "config.h"
 #include "util.h"
@@ -40,5 +41,11 @@
 static const char *cmdname = "mount";
 
-/* Dispays help for mount in various levels */
+static struct option const long_options[] = {
+	{ "help", no_argument, 0, 'h' },
+	{ 0, 0, 0, 0 }
+};
+
+
+/* Displays help for mount in various levels */
 void help_cmd_mount(unsigned int level)
 {
@@ -59,10 +66,19 @@
 	unsigned int argc;
 	const char *mopts = "";
-	int rc;
+	int rc, c, opt_ind;
 
 	argc = cli_count_args(argv);
 
+	for (c = 0, optind = 0, opt_ind = 0; c != -1;) {
+		c = getopt_long(argc, argv, "h", long_options, &opt_ind);
+		switch (c) {
+		case 'h':
+			help_cmd_mount(HELP_LONG);
+			return CMD_SUCCESS;
+		}
+	}
+
 	if ((argc < 4) || (argc > 5)) {
-		printf("%s: invalid number of arguments.\n",
+		printf("%s: invalid number of arguments. Try `mount --help'\n",
 		    cmdname);
 		return CMD_FAILURE;
Index: uspace/lib/c/generic/loader.c
===================================================================
--- uspace/lib/c/generic/loader.c	(revision 4c7c25135dc43993f0c90327f035578a98ef0c2f)
+++ uspace/lib/c/generic/loader.c	(revision 37b1651de7d2b2fb0e5e2ee69dd1cfbdc338bfe1)
@@ -160,4 +160,5 @@
 	int rc = async_data_write_start(ldr->phone_id, (void *) pa, pa_len);
 	if (rc != EOK) {
+		free(pa);
 		async_wait_for(req, NULL);
 		return rc;
Index: uspace/lib/c/generic/vfs/vfs.c
===================================================================
--- uspace/lib/c/generic/vfs/vfs.c	(revision 4c7c25135dc43993f0c90327f035578a98ef0c2f)
+++ uspace/lib/c/generic/vfs/vfs.c	(revision 37b1651de7d2b2fb0e5e2ee69dd1cfbdc338bfe1)
@@ -69,4 +69,5 @@
 	char *ncwd_path;
 	char *ncwd_path_nc;
+	size_t total_size; 
 
 	fibril_mutex_lock(&cwd_mutex);
@@ -77,14 +78,16 @@
 			return NULL;
 		}
-		ncwd_path_nc = malloc(cwd_size + 1 + size + 1);
+		total_size = cwd_size + 1 + size + 1;
+		ncwd_path_nc = malloc(total_size);
 		if (!ncwd_path_nc) {
 			fibril_mutex_unlock(&cwd_mutex);
 			return NULL;
 		}
-		str_cpy(ncwd_path_nc, cwd_size + 1 + size + 1, cwd_path);
+		str_cpy(ncwd_path_nc, total_size, cwd_path);
 		ncwd_path_nc[cwd_size] = '/';
 		ncwd_path_nc[cwd_size + 1] = '\0';
 	} else {
-		ncwd_path_nc = malloc(size + 1);
+		total_size = size + 1;
+		ncwd_path_nc = malloc(total_size);
 		if (!ncwd_path_nc) {
 			fibril_mutex_unlock(&cwd_mutex);
@@ -93,5 +96,5 @@
 		ncwd_path_nc[0] = '\0';
 	}
-	str_append(ncwd_path_nc, cwd_size + 1 + size + 1, path);
+	str_append(ncwd_path_nc, total_size, path);
 	ncwd_path = canonify(ncwd_path_nc, retlen);
 	if (!ncwd_path) {
Index: uspace/srv/devmap/devmap.c
===================================================================
--- uspace/srv/devmap/devmap.c	(revision 4c7c25135dc43993f0c90327f035578a98ef0c2f)
+++ uspace/srv/devmap/devmap.c	(revision 37b1651de7d2b2fb0e5e2ee69dd1cfbdc338bfe1)
@@ -123,4 +123,10 @@
 static devmap_handle_t last_handle = 0;
 static devmap_device_t *null_devices[NULL_DEVICES];
+
+/*
+ * Dummy list for null devices. This is necessary so that null devices can
+ * be used just as any other devices, e.g. in devmap_device_unregister_core().
+ */
+static LIST_INITIALIZE(dummy_null_driver_devices);
 
 static devmap_handle_t devmap_create_handle(void)
@@ -953,7 +959,11 @@
 	device->name = dev_name;
 	
-	/* Insert device into list of all devices
-	   and into null devices array */
+	/*
+	 * Insert device into list of all devices and into null devices array.
+	 * Insert device into a dummy list of null driver's devices so that it
+	 * can be safely removed later.
+	 */
 	list_append(&device->devices, &devices_list);
+	list_append(&device->driver_devices, &dummy_null_driver_devices);
 	null_devices[i] = device;
 	
Index: uspace/srv/fs/fat/fat_ops.c
===================================================================
--- uspace/srv/fs/fat/fat_ops.c	(revision 4c7c25135dc43993f0c90327f035578a98ef0c2f)
+++ uspace/srv/fs/fat/fat_ops.c	(revision 37b1651de7d2b2fb0e5e2ee69dd1cfbdc338bfe1)
@@ -325,4 +325,5 @@
 		    uint16_t_le2host(d->firstc));
 		if (rc != EOK) {
+			(void) block_put(b);
 			(void) fat_node_put(FS_NODE(nodep));
 			return rc;
@@ -811,4 +812,5 @@
 	fibril_mutex_unlock(&childp->idx->lock);
 	childp->lnkcnt = 0;
+	childp->refcnt++;	/* keep the node in memory until destroyed */
 	childp->dirty = true;
 	fibril_mutex_unlock(&childp->lock);
@@ -1488,4 +1490,5 @@
 	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
 	fs_node_t *fn;
+	fat_node_t *nodep;
 	int rc;
 
@@ -1499,4 +1502,11 @@
 		return;
 	}
+
+	nodep = FAT_NODE(fn);
+	/*
+	 * We should have exactly two references. One for the above
+	 * call to fat_node_get() and one from fat_unlink().
+	 */
+	assert(nodep->refcnt == 2);
 
 	rc = fat_destroy_node(fn);