From: Matthew Wilcox <matthew@wil.cx>
Date: Sat, 21 Oct 2006 17:24:19 +0000 (-0700)
Subject: [PATCH] cciss: Fix warnings (and bug on 1TB discs)
X-Git-Tag: v2.6.19-rc3~18
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3f7705eab6722ad1a346d748c4aad55755d6c241;p=linux-2.6

[PATCH] cciss: Fix warnings (and bug on 1TB discs)

CCISS was producing warnings about shifts being greater than the size of
the type and pointers being of incompatible type.  Turns out this is
because it's calling do_div on a 32-bit quantity.  Upon further
investigation, the sector_t total_size is being assigned to an int, and
then we're calling do_div on that int.  Obviously, sector_div is called for
here, and I took the chance to refactor the code a little.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Acked-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index dcccaf2782..bc6602606f 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -1923,7 +1923,6 @@ static void cciss_geometry_inquiry(int ctlr, int logvol,
 {
 	int return_code;
 	unsigned long t;
-	unsigned long rem;
 
 	memset(inq_buff, 0, sizeof(InquiryData_struct));
 	if (withirq)
@@ -1939,26 +1938,23 @@ static void cciss_geometry_inquiry(int ctlr, int logvol,
 			printk(KERN_WARNING
 			       "cciss: reading geometry failed, volume "
 			       "does not support reading geometry\n");
-			drv->block_size = block_size;
-			drv->nr_blocks = total_size;
 			drv->heads = 255;
 			drv->sectors = 32;	// Sectors per track
-			t = drv->heads * drv->sectors;
-			drv->cylinders = total_size;
-			rem = do_div(drv->cylinders, t);
 		} else {
-			drv->block_size = block_size;
-			drv->nr_blocks = total_size;
 			drv->heads = inq_buff->data_byte[6];
 			drv->sectors = inq_buff->data_byte[7];
 			drv->cylinders = (inq_buff->data_byte[4] & 0xff) << 8;
 			drv->cylinders += inq_buff->data_byte[5];
 			drv->raid_level = inq_buff->data_byte[8];
-			t = drv->heads * drv->sectors;
-			if (t > 1) {
-				drv->cylinders = total_size;
-				rem = do_div(drv->cylinders, t);
-			}
+		}
+		drv->block_size = block_size;
+		drv->nr_blocks = total_size;
+		t = drv->heads * drv->sectors;
+		if (t > 1) {
+			unsigned rem = sector_div(total_size, t);
+			if (rem)
+				total_size++;
+			drv->cylinders = total_size;
 		}
 	} else {		/* Get geometry failed */
 		printk(KERN_WARNING "cciss: reading geometry failed\n");