Re: [PATCH] sg.c to set direction more reliably (was Re: [PATCH] fusion update to current APIs)

[Jeremy Higdon <jeremy@sgi.com>]

On Thu, Aug 26, 2004 at 06:44:40PM +1000, Douglas Gilbert wrote:
> Jeremy,
> Perhaps the first argument of printk() could be prefixed with
> KERN_WARNING to make it a bit more syslog friendly.
> Otherwise ok.
> 
> Doug Gilbert

You're right.  It's fixed in this patch.
James, if you're satisfied, please apply.

thanks,
jeremy

signed-off-by: jeremy@sgi.com

===== drivers/scsi/sg.c 1.95 vs edited =====
--- 1.95/drivers/scsi/sg.c	2004-08-07 19:11:33 -07:00
+++ edited/drivers/scsi/sg.c	2004-08-26 17:19:58 -07:00
@@ -564,6 +564,18 @@
 	hp->usr_ptr = NULL;
 	if (__copy_from_user(cmnd, buf, cmd_size))
 		return -EFAULT;
+	/*
+	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
+	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
+	 * is a non-zero input_size, so emit a warning.
+	 */
+	if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV)
+		printk(KERN_WARNING
+		       "sg_write: cannot infer direction from count %ld "
+		       "and reply_len %d.  Command 0x%x will probably fail. "
+		       "Please fix the application to use proper counts or "
+		       "the sg version 3 interface\n",
+		       count, old_hdr.reply_len, (unsigned int) cmnd[0]);
 	k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 	return (k < 0) ? k : count;
 }