From: R.E.Wolff@BitWizard.nl (Rogier Wolff)
To: mingo@redhat.com,
Linux kernel mailing list <linux-kernel@vger.kernel.org>,
viro@math.psu.edu
Subject: RAID superblock....
Date: Sun, 10 Mar 2002 14:28:57 +0100 (MET) [thread overview]
Message-ID: <200203101328.OAA15987@cave.bitwizard.nl> (raw)
Hi,
The MD code I see doing:
488 sb_offset = calc_dev_sboffset(rdev->dev, rdev->mddev, 1);
489 rdev->sb_offset = sb_offset;
490 fsync_dev(dev);
491 set_blocksize (dev, MD_SB_BYTES);
492 bh = bread (dev, sb_offset / MD_SB_BLOCKS, MD_SB_BYTES);
where sb_offset is calculated as:
290 if (blk_size[MAJOR(dev)])
291 size = blk_size[MAJOR(dev)][MINOR(dev)];
Now, for aguments sake, I have a 4k disk. I'd expect the size to be 4
(1k blocks, according to the comment near the definition of blk_size).
Thus the "bread" would effectively try to read the block at offset 4k.
That would be past the end of my mini-disk, right?
I would have expected a "-1" in there somewhere, to get the last block
of the dev, and not the block just past the end of the drive.
Anyway on the old machine, I still cannot find the raid superblock by
hand, but the drives now mount, so the kernel must have been able to
locate them somehow......
The machine is still running 2.4.16 + IDE patches for 48 bit
addressing.
The working machine is an 850MHz PIII w/384Mb RAM, the non-working
machine is an AMD 1800+ MP w/1G RAM (with another one of those
processors sitting idle close by)...
Roger.
--
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
* There are old pilots, and there are bold pilots.
* There are also old, bald pilots.
next reply other threads:[~2002-03-10 13:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-03-10 13:28 Rogier Wolff [this message]
2002-03-10 23:34 ` RAID superblock Neil Brown
-- strict thread matches above, loose matches on Subject: below --
2004-09-08 17:41 raid superblock rich turner
[not found] <20001025171255.26384.qmail@web6104.mail.yahoo.com>
[not found] ` <Pine.LNX.4.21.0010261534490.9868-100000@server.serve.me.nl>
2000-10-26 16:19 ` RAID superblock Wakko Warner
2000-10-29 10:40 ` Peter Samuelson
2000-10-29 13:36 ` Igmar Palsenberg
2000-10-29 12:52 ` Wakko Warner
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=200203101328.OAA15987@cave.bitwizard.nl \
--to=r.e.wolff@bitwizard.nl \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=viro@math.psu.edu \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.