[PATCH] s390: dasd proc entries

The proc_mkdir calls in the dasd driver are not check for NULL pointers.  Add
code to check the pointers and bail out if one of the proc entries could not
be created.

Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/s390/block/dasd_proc.c

@@ -294,23 +294,40 @@ dasd_statistics_write(struct file *file, const char __user *user_buf,
 #endif				/* CONFIG_DASD_PROFILE */
 }
 
+/*
+ * Create dasd proc-fs entries.
+ * In case creation failed, cleanup and return -ENOENT.
+ */
 int
 dasd_proc_init(void)
 {
 	dasd_proc_root_entry = proc_mkdir("dasd", &proc_root);
+	if (!dasd_proc_root_entry)
+		goto out_nodasd;
 	dasd_proc_root_entry->owner = THIS_MODULE;
 	dasd_devices_entry = create_proc_entry("devices",
 					       S_IFREG | S_IRUGO | S_IWUSR,
 					       dasd_proc_root_entry);
+	if (!dasd_devices_entry)
+		goto out_nodevices;
 	dasd_devices_entry->proc_fops = &dasd_devices_file_ops;
 	dasd_devices_entry->owner = THIS_MODULE;
 	dasd_statistics_entry = create_proc_entry("statistics",
 						  S_IFREG | S_IRUGO | S_IWUSR,
 						  dasd_proc_root_entry);
+	if (!dasd_statistics_entry)
+		goto out_nostatistics;
 	dasd_statistics_entry->read_proc = dasd_statistics_read;
 	dasd_statistics_entry->write_proc = dasd_statistics_write;
 	dasd_statistics_entry->owner = THIS_MODULE;
 	return 0;
+
+ out_nostatistics:
+	remove_proc_entry("devices", dasd_proc_root_entry);
+ out_nodevices:
+	remove_proc_entry("dasd", &proc_root);
+ out_nodasd:
+	return -ENOENT;
 }
 
 void