[PATCH] Fix SG_IO timeout jiffy conversion

Commit 85e04e371b5a321b5df2bc3f8e0099a64fb087d7 cleaned up the timeout
conversion, but did it exactly the wrong way.  We get msecs from user
space, and should convert them into jiffies. Not the other way around.

Here is a fix with the overflow check sg.c has added in.  This fixes DVD
burnign with Nero.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
[ "you'll be wanting a comma there" - Andrew ]
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block/scsi_ioctl.c

@@ -223,7 +223,7 @@ static int verify_command(struct file *file, unsigned char *cmd)
 static int sg_io(struct file *file, request_queue_t *q,
 		struct gendisk *bd_disk, struct sg_io_hdr *hdr)
 {
-	unsigned long start_time;
+	unsigned long start_time, timeout;
 	int writing = 0, ret = 0;
 	struct request *rq;
 	char sense[SCSI_SENSE_BUFFERSIZE];
@@ -271,7 +271,8 @@ static int sg_io(struct file *file, request_queue_t *q,
 
 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
 
-	rq->timeout = jiffies_to_msecs(hdr->timeout);
+	timeout = msecs_to_jiffies(hdr->timeout);
+	rq->timeout = (timeout < INT_MAX) ? timeout : INT_MAX;
 	if (!rq->timeout)
 		rq->timeout = q->sg_timeout;
 	if (!rq->timeout)