Re: PROBLEM: drivers/scsi/sd.c - Incorrect Reporting of Blocks and Capacity of Large SCSI Disk Arrays

| From: "James Bourne" <[e-mail]>
|
| drivers/scsi/sd.c - Incorrect Reporting of Blocks and Capacity of Large 
| SCSI Disk Arrays
|
| This problem exists on both a custom 2.4.20 kernel and on a stock RedHat 
| 2.4.18-19.8.0smp kernel. This problem report pertains to the latter kernel.
|
| For example:
|
| SCSI device sdb: -562247552 512-byte hdwr sectors (4294679426 MB)
|  sdb: sdb1
| SCSI device sdc: -1997908992 512-byte hdwr sectors (76582 MB)
|  sdc: sdc1
|
| Array Capacity
|    Total unformatted capacity for Array 1: 1962814MB (1916.81GB, 1.87TB)
|    Total unformatted capacity for Array 2: 1261809MB (1232.23GB, 1.20TB)
-----

Please try the patch below.
Andries

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Subject: Re: using 2 TB  in real life
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> SCSI device sdb: -320126976 512-byte hdwr sectors (-163904 MB)

Yes, the code in 2.4.20 works up to 30 bits.
A slight modification works up to 31 bits.
[This is cosmetic only.]

Andries

--- /linux/2.4/linux-2.4.20/linux/drivers/scsi/sd.c	Sat Aug  3 02:39:44 2002
+++ ./sd.c	Fri Dec 13 00:12:00 2002
@@ -1001,7 +1001,7 @@
 			 */
 			int m;
 			int hard_sector = sector_size;
-			int sz = rscsi_disks[i].capacity * (hard_sector/256);
+			unsigned int sz = (rscsi_disks[i].capacity/2) * (hard_sector/256);
 
 			/* There are 16 minors allocated for each major device */
 			for (m = i << 4; m < ((i + 1) << 4); m++) {
@@ -1009,9 +1009,9 @@
 			}
 
 			printk("SCSI device %s: "
-			       "%d %d-byte hdwr sectors (%d MB)\n",
+			       "%u %d-byte hdwr sectors (%u MB)\n",
 			       nbuff, rscsi_disks[i].capacity,
-			       hard_sector, (sz/2 - sz/1250 + 974)/1950);
+			       hard_sector, (sz - sz/625 + 974)/1950);
 		}
 
 		/* Rescale capacity to 512-byte units */