From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262707AbUATWl1 (ORCPT ); Tue, 20 Jan 2004 17:41:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265748AbUATWl1 (ORCPT ); Tue, 20 Jan 2004 17:41:27 -0500 Received: from email-out1.iomega.com ([147.178.1.82]:15597 "EHLO email.iomega.com") by vger.kernel.org with ESMTP id S262707AbUATWlY (ORCPT ); Tue, 20 Jan 2004 17:41:24 -0500 Subject: Re: [PATCH] fix blockdev --getro for sr, sd, ide-floppy devs (with patch this time) From: John McKell To: Paul Bristow Cc: linux-kernel@vger.kernel.org Content-Type: text/plain Organization: Iomega Corp. Message-Id: <1074638483.3350.2.camel@lintest.iomegacorp.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-4) Date: 20 Jan 2004 15:41:23 -0700 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 20 Jan 2004 22:41:23.0914 (UTC) FILETIME=[883362A0:01C3DFA6] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This 2.6.1 patch works by setting gendisk->policy to the correct value during initialization as the various drivers decide whether or not the disk is writeable. This patch persuades "blockdev --getro ..." to correctly report the read-only state of a newly inserted disk. This patch applies to sr.c, sd.c and ide-floppy.c. ide-cd.c already has this functionality built into it. Using an Iomega Zip drive as the test case... Without the patch, I always see: $ sudo blockdev --getro /dev/sda 0 $ That's only correct for writeable disks though. Only when the patch is applied do I see a write-protected disk described correctly: $ sudo blockdev --getro /dev/sda 1 $ --John McKell diff -Nurp linux-2.6.1/drivers/ide/ide-floppy.c linux/drivers/ide/ide-floppy.c --- linux-2.6.1/drivers/ide/ide-floppy.c 2004-01-08 23:59:33.000000000 -0700 +++ linux/drivers/ide/ide-floppy.c 2004-01-14 08:46:26.000000000 -0700 @@ -1317,6 +1317,7 @@ static int idefloppy_get_flexible_disk_p } header = (idefloppy_mode_parameter_header_t *) pc.buffer; floppy->wp = header->wp; + set_disk_ro(drive->disk, floppy->wp); page = (idefloppy_flexible_disk_page_t *) (header + 1); page->transfer_rate = ntohs(page->transfer_rate); diff -Nurp linux-2.6.1/drivers/scsi/sd.c linux/drivers/scsi/sd.c --- linux-2.6.1/drivers/scsi/sd.c 2004-01-08 23:59:49.000000000 -0700 +++ linux/drivers/scsi/sd.c 2004-01-14 08:46:26.000000000 -0700 @@ -1089,6 +1089,7 @@ sd_read_write_protect_flag(struct scsi_d int res; struct scsi_mode_data data; + set_disk_ro(sdkp->disk, 0); if (sdkp->device->skip_ms_page_3f) { printk(KERN_NOTICE "%s: assuming Write Enabled\n", diskname); return; @@ -1120,6 +1121,7 @@ sd_read_write_protect_flag(struct scsi_d "%s: test WP failed, assume Write Enabled\n", diskname); } else { sdkp->write_prot = ((data.device_specific & 0x80) != 0); + set_disk_ro(sdkp->disk, sdkp->write_prot); printk(KERN_NOTICE "%s: Write Protect is %s\n", diskname, sdkp->write_prot ? "on" : "off"); printk(KERN_DEBUG "%s: Mode Sense: %02x %02x %02x %02x\n", diff -Nurp linux-2.6.1/drivers/scsi/sr.c linux/drivers/scsi/sr.c --- linux-2.6.1/drivers/scsi/sr.c 2004-01-08 23:59:19.000000000 -0700 +++ linux/drivers/scsi/sr.c 2004-01-14 09:16:18.000000000 -0700 @@ -711,6 +711,9 @@ static void get_capabilities(struct scsi "" }; + /* Set read only initially */ + set_disk_ro(cd->disk, 1); + /* allocate a request for the TEST_UNIT_READY */ SRpnt = scsi_allocate_request(cd->device, GFP_KERNEL); if (!SRpnt) { @@ -790,6 +793,7 @@ static void get_capabilities(struct scsi cd->cdi.mask |= CDC_DVD_RAM; } else { cd->device->writeable = 1; + set_disk_ro(cd->disk, 0); } if ((buffer[n + 3] & 0x10) == 0) /* can't write DVD-R media */