[PATCH] warn once for unknown SCSI command

Warn once for each unknown command sent through SG_IO or the old SCSI
command ioctl.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/block/scsi_ioctl.c

@@ -107,12 +107,13 @@ static int sg_emulated_host(request_queue_t *q, int __user *p)
 
 #define CMD_READ_SAFE	0x01
 #define CMD_WRITE_SAFE	0x02
+#define CMD_WARNED	0x04
 #define safe_for_read(cmd)	[cmd] = CMD_READ_SAFE
 #define safe_for_write(cmd)	[cmd] = CMD_WRITE_SAFE
 
 static int verify_command(struct file *file, unsigned char *cmd)
 {
-	static const unsigned char cmd_type[256] = {
+	static unsigned char cmd_type[256] = {
 
 		/* Basic read-only commands */
 		safe_for_read(TEST_UNIT_READY),
@@ -197,6 +198,11 @@ static int verify_command(struct file *file, unsigned char *cmd)
 			return 0;
 	}
 
+	if (!(type & CMD_WARNED)) {
+		cmd_type[cmd[0]] = CMD_WARNED;
+		printk(KERN_WARNING "scsi: unknown opcode 0x%02x\n", cmd[0]);
+	}
+
 	/* And root can do any command.. */
 	if (capable(CAP_SYS_RAWIO))
 		return 0;