From: Jim Rees <rees@umich.edu>
To: tao.peng@emc.com
Cc: bhalevy@tonian.com, linux-nfs@vger.kernel.org, honey@citi.umich.edu
Subject: Re: [PATCH 1/6] SQUASHME: pnfs-block: Remove write_begin/end hooks
Date: Thu, 14 Jul 2011 07:25:19 -0400 [thread overview]
Message-ID: <20110714112519.GA619@merit.edu> (raw)
In-Reply-To: <F19688880B763E40B28B2B462677FBF805BEFF0D64@MX09A.corp.emc.com>
tao.peng@emc.com wrote:
> > + * map_block: map a requested I/0 block (isect) into an offset in the LVM
> > + * meta block_device
>
> What's a "meta block_device"?
We can remove the *meta* if you don't like the name.
I've been calling this the "mapped device." It's produced by blkmapd, which
is short for "block map daemon." In the kernel it's consistently called the
"meta device." I'm not crazy about the name either but it needs to be
consistent. Should I change it?
I just noticed too that there are some outdated comments left over from when
the mapping was done in the kernel:
/* For each device returned in dlist, call GETDEVICEINFO, and
* decode the opaque topology encoding to create a flat
* volume topology, matching VOLUME_SIMPLE disk signatures
* to disks in the visible block disk list.
* Construct an LVM meta device from the flat volume topology.
*/
What's really going on here is the devices are just being added to a list.
The device is constructed later by the daemon. I will fix this comment.
next prev parent reply other threads:[~2011-07-14 11:25 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-07 16:26 [PATCH 0/6] pnfs block layout updates Jim Rees
2011-07-07 16:26 ` [PATCH 1/6] SQUASHME: pnfs-block: Remove write_begin/end hooks Jim Rees
2011-07-13 12:52 ` Benny Halevy
2011-07-13 13:43 ` Jim Rees
2011-07-14 5:05 ` tao.peng
2011-07-14 11:25 ` Jim Rees [this message]
2011-07-07 16:26 ` [PATCH 2/6] SQUASHME: pnfs-block: skip sectors already initialized Jim Rees
2011-07-07 16:26 ` [PATCH 3/6] SQUASHME: pnfs: teach layoutcommit handle multiple segments Jim Rees
2011-07-07 16:26 ` [PATCH 4/6] get rid of deprecated xdr macros Jim Rees
2011-07-07 16:26 ` [PATCH 5/6] reindent Jim Rees
2011-07-07 16:26 ` [PATCH 6/6] pnfs-block: mark IO error with NFS_LAYOUT_{RW|RO}_FAILED Jim Rees
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=20110714112519.GA619@merit.edu \
--to=rees@umich.edu \
--cc=bhalevy@tonian.com \
--cc=honey@citi.umich.edu \
--cc=linux-nfs@vger.kernel.org \
--cc=tao.peng@emc.com \
/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;
as well as URLs for NNTP newsgroup(s).