From: John McKell <mckellj@iomega.com>
To: Paul Bristow <paul@paulbristow.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fix blockdev --getro for sr, sd, ide-floppy devs (with patch this time)
Date: 20 Jan 2004 15:41:23 -0700 [thread overview]
Message-ID: <1074638483.3350.2.camel@lintest.iomegacorp.com> (raw)
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 */
reply other threads:[~2004-01-20 22:41 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1074638483.3350.2.camel@lintest.iomegacorp.com \
--to=mckellj@iomega.com \
--cc=linux-kernel@vger.kernel.org \
--cc=paul@paulbristow.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®