diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index 4423bd96b..396e168c0 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -707,11 +707,30 @@ out:
 	return res;
 }
 
+/* scst_vdisk_mutex supposed to be held */
+static struct scst_vdisk_dev *vdev_find(const char *name)
+{
+	struct scst_vdisk_dev *res, *vv;
+
+	TRACE_ENTRY();
+
+	res = NULL;
+	list_for_each_entry(vv, &vdev_list, vdev_list_entry) {
+		if (strcmp(vv->name, name) == 0) {
+			res = vv;
+			break;
+		}
+	}
+
+	TRACE_EXIT_HRES((unsigned long)res);
+	return res;
+}
+
 static int vdisk_attach(struct scst_device *dev)
 {
 	int res = 0;
 	loff_t err;
-	struct scst_vdisk_dev *virt_dev = NULL, *vv;
+	struct scst_vdisk_dev *virt_dev;
 
 	TRACE_ENTRY();
 
@@ -727,13 +746,7 @@ static int vdisk_attach(struct scst_device *dev)
 	 * scst_vdisk_mutex must be already taken before
 	 * scst_register_virtual_device()
 	 */
-	list_for_each_entry(vv, &vdev_list, vdev_list_entry) {
-		if (strcmp(vv->name, dev->virt_name) == 0) {
-			virt_dev = vv;
-			break;
-		}
-	}
-
+	virt_dev = vdev_find(dev->virt_name);
 	if (virt_dev == NULL) {
 		PRINT_ERROR("Device %s not found", dev->virt_name);
 		res = -EINVAL;
@@ -3366,10 +3379,14 @@ out:
 static int vdev_create(struct scst_dev_type *devt,
 	const char *name, struct scst_vdisk_dev **res_virt_dev)
 {
-	int res = 0;
+	int res;
 	struct scst_vdisk_dev *virt_dev;
 	uint64_t dev_id_num;
 
+	res = -EEXIST;
+	if (vdev_find(name))
+		goto out;
+
 	virt_dev = kzalloc(sizeof(*virt_dev), GFP_KERNEL);
 	if (virt_dev == NULL) {
 		PRINT_ERROR("Allocation of virtual device %s failed",
@@ -3406,6 +3423,7 @@ static int vdev_create(struct scst_dev_type *devt,
 	TRACE_DBG("usn %s", virt_dev->usn);
 
 	*res_virt_dev = virt_dev;
+	res = 0;
 
 out:
 	return res;
@@ -3422,25 +3440,6 @@ static void vdev_destroy(struct scst_vdisk_dev *virt_dev)
 	return;
 }
 
-/* scst_vdisk_mutex supposed to be held */
-static struct scst_vdisk_dev *vdev_find(const char *name)
-{
-	struct scst_vdisk_dev *res, *vv;
-
-	TRACE_ENTRY();
-
-	res = NULL;
-	list_for_each_entry(vv, &vdev_list, vdev_list_entry) {
-		if (strcmp(vv->name, name) == 0) {
-			res = vv;
-			break;
-		}
-	}
-
-	TRACE_EXIT_HRES((unsigned long)res);
-	return res;
-}
-
 #ifndef CONFIG_SCST_PROC
 
 static int vdev_parse_add_dev_params(struct scst_vdisk_dev *virt_dev,
@@ -4661,7 +4660,7 @@ static int vdisk_write_proc(char *buffer, char **start, off_t offset,
 {
 	int res = 0, action;
 	char *p, *name, *filename, *i_buf, *t10_dev_id;
-	struct scst_vdisk_dev *virt_dev, *vv;
+	struct scst_vdisk_dev *virt_dev;
 	uint32_t block_size = DEF_DISK_BLOCKSIZE;
 	int block_shift = DEF_DISK_BLOCKSIZE_SHIFT;
 	size_t slen;
@@ -4724,21 +4723,6 @@ static int vdisk_write_proc(char *buffer, char **start, off_t offset,
 
 	if (action == 1) {
 		/* open */
-		virt_dev = NULL;
-		list_for_each_entry(vv, &vdev_list,
-					vdev_list_entry) {
-			if (strcmp(vv->name, name) == 0) {
-				virt_dev = vv;
-				break;
-			}
-		}
-		if (virt_dev) {
-			PRINT_ERROR("Virtual device with name "
-				   "%s already exist", name);
-			res = -EINVAL;
-			goto out_up;
-		}
-
 		while (isspace(*p) && *p != '\0')
 			p++;
 		filename = p;
@@ -4862,14 +4846,7 @@ static int vdisk_write_proc(char *buffer, char **start, off_t offset,
 			vdev_get_filename(virt_dev), virt_dev->virt_id,
 			virt_dev->block_size);
 	} else if (action == 0) {	/* close */
-		virt_dev = NULL;
-		list_for_each_entry(vv, &vdev_list,
-					vdev_list_entry) {
-			if (strcmp(vv->name, name) == 0) {
-				virt_dev = vv;
-				break;
-			}
-		}
+		virt_dev = vdev_find(name);
 		if (virt_dev == NULL) {
 			PRINT_ERROR("Device %s not found", name);
 			res = -EINVAL;
@@ -4877,14 +4854,7 @@ static int vdisk_write_proc(char *buffer, char **start, off_t offset,
 		}
 		vdev_del_device(virt_dev);
 	} else if (action == 2) {	/* resync_size */
-		virt_dev = NULL;
-		list_for_each_entry(vv, &vdev_list,
-					vdev_list_entry) {
-			if (strcmp(vv->name, name) == 0) {
-				virt_dev = vv;
-				break;
-			}
-		}
+		virt_dev = vdev_find(name);
 		if (virt_dev == NULL) {
 			PRINT_ERROR("Device %s not found", name);
 			res = -EINVAL;
@@ -4895,14 +4865,7 @@ static int vdisk_write_proc(char *buffer, char **start, off_t offset,
 		if (res != 0)
 			goto out_up;
 	} else if (action == 3) {	/* set T10 device id */
-		virt_dev = NULL;
-		list_for_each_entry(vv, &vdev_list,
-					vdev_list_entry) {
-			if (strcmp(vv->name, name) == 0) {
-				virt_dev = vv;
-				break;
-			}
-		}
+		virt_dev = vdev_find(name);
 		if (virt_dev == NULL) {
 			PRINT_ERROR("Device %s not found", name);
 			res = -EINVAL;
@@ -4993,25 +4956,11 @@ out:
 /* scst_vdisk_mutex supposed to be held */
 static int vcdrom_open(char *p, char *name)
 {
-	struct scst_vdisk_dev *virt_dev, *vv;
+	struct scst_vdisk_dev *virt_dev;
 	char *filename;
 	int res = 0;
 	int cdrom_empty;
 
-	virt_dev = NULL;
-	list_for_each_entry(vv, &vdev_list, vdev_list_entry) {
-		if (strcmp(vv->name, name) == 0) {
-			virt_dev = vv;
-			break;
-		}
-	}
-	if (virt_dev) {
-		PRINT_ERROR("Virtual device with name "
-		       "%s already exist", name);
-		res = -EINVAL;
-		goto out;
-	}
-
 	while (isspace(*p) && *p != '\0')
 		p++;
 	filename = p;
@@ -5076,17 +5025,10 @@ out_free_vdev:
 /* scst_vdisk_mutex supposed to be held */
 static int vcdrom_close(char *name)
 {
-	struct scst_vdisk_dev *virt_dev, *vv;
+	struct scst_vdisk_dev *virt_dev;
 	int res = 0;
 
-	virt_dev = NULL;
-	list_for_each_entry(vv, &vdev_list, vdev_list_entry) {
-		if (strcmp(vv->name, name) == 0) {
-			virt_dev = vv;
-			break;
-		}
-	}
-
+	virt_dev = vdev_find(name);
 	if (virt_dev == NULL) {
 		PRINT_ERROR("Virtual device with name "
 		       "%s not found", name);
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 514a07991..37043611f 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -4009,11 +4009,18 @@ void scst_free_session(struct scst_session *sess)
 
 	scst_sess_free_tgt_devs(sess);
 
-#ifndef CONFIG_SCST_PROC
 	mutex_unlock(&scst_mutex);
+
+#ifndef CONFIG_SCST_PROC
 	scst_sess_sysfs_del(sess);
-	mutex_lock(&scst_mutex);
 #endif
+	if (sess->unreg_done_fn) {
+		TRACE_DBG("Calling unreg_done_fn(%p)", sess);
+		sess->unreg_done_fn(sess);
+		TRACE_DBG("%s", "unreg_done_fn() returned");
+	}
+
+	mutex_lock(&scst_mutex);
 
 	/*
 	 * The lists delete must be after sysfs del. Otherwise it would break
@@ -4064,11 +4071,6 @@ void scst_free_session_callback(struct scst_session *sess)
 	sess->shut_phase = SCST_SESS_SPH_UNREG_DONE_CALLING;
 	mutex_unlock(&scst_mutex);
 
-	if (sess->unreg_done_fn) {
-		TRACE_DBG("Calling unreg_done_fn(%p)", sess);
-		sess->unreg_done_fn(sess);
-		TRACE_DBG("%s", "unreg_done_fn() returned");
-	}
 	scst_free_session(sess);
 
 	if (c)
diff --git a/scst/src/scst_pres.c b/scst/src/scst_pres.c
index 689ffa691..6a207cfab 100644
--- a/scst/src/scst_pres.c
+++ b/scst/src/scst_pres.c
@@ -1183,7 +1183,8 @@ static int scst_pr_check_pr_path(void)
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 39)
 	res = path_lookup(SCST_PR_DIR, 0, &nd);
-	scst_pr_path_put(&nd);
+	if (res == 0)
+		scst_pr_path_put(&nd);
 #else
 	res = kern_path(SCST_PR_DIR, 0, &path);
 	if (res == 0)