sg kill local jiffies problems

It has been reported that the change to sg.c in lk 2.6.9-rc1-bk5 to use library jiffy functions breaks sg (albeit under vmware). Evidentally sg devices are no longer recognised after that change.

Reverting that changeset removes the problem. Strange, it is not obvious why.

At some stage I must have detected negative time spans (yeh yeh it never happens) and my versions returned 0 in this case; otherwise the implementations look very similar.

Doug Gilbert

The following patch fixes the problem. It is
against lk 2.6.9-rc1-bk7 (i.e. after "standard"
jiffy_to_millisecs macros replaced sg versions).

Change:
- make sure a (large) user supplied timeout value does not result in a negative timeout passed to the midlevel

Doug Gilbert

@@ -576,6 +576,7 @@
 	sg_io_hdr_t *hp;
 	unsigned char cmnd[sizeof (dummy_cmdp->sr_cmnd)];
 	int timeout;
+	unsigned long ul_timeout;
 
 	if (count < SZ_SG_IO_HDR)
 		return -EINVAL;

@@ -610,7 +611,8 @@
 			return -EBUSY;	/* reserve buffer already being used */
 		}
 	}
-	timeout = msecs_to_jiffies(srp->header.timeout);
+	ul_timeout = msecs_to_jiffies(srp->header.timeout);
+	timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 	if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 		sg_remove_request(sfp, srp);
 		return -EMSGSIZE;