From: Joel Becker <joel.becker@oracle.com>
To: ocfs2-devel@oss.oracle.com
Cc: linux-kernel@vger.kernel.org, mfasheh@suse.com
Subject: [PATCH 0/10] ocfs2_dlmfs improvements
Date: Thu, 4 Feb 2010 16:54:53 -0800 [thread overview]
Message-ID: <1265331303-19881-1-git-send-email-joel.becker@oracle.com> (raw)
ocfs2 ships with its own cluster stack, o2cb. The dlm portion, o2dlm,
is accessible to userspace via a custom filesystem, ocfs2_dlmfs. Files
in this filesytem represent cluster lock resources. Open the file, and
you take the lock. The libo2dlm library wraps this filesystem,
providing a very simplified cluster locking API to userspace programs.
One of the things left out of the simplified interface is the ability to
learn that other nodes want a lock. Notification that another node
wants the lock is called a "blocking asynchronous system trap", or
"bast". Kernel users of o2dlm can register basts as they please, but
programs using libo2dlm and ocfs2_dlmfs cannot. Thus, they must not
hold a lock forever; other nodes will never get the lock.
The first improvement in this series adds poll(2) support to
ocfs2_dlmfs. POLLIN on an open ocfs2_dlmfs flie signals a bast. Now
user programs can hold a lock until they are notified to release it.
Another limitation of ocfs2_dlmfs is its reliance on o2dlm and thus the
entire o2cb cluster stack. The ocfs2 filesystem has a glue layer,
called "stackglue", that allows it to switch between o2cb+o2dlm and the
userspace cluster stacks that work with fs/dlm. This means userspace
programs for ocfs2 have to know about libo2dlm when o2dlm is employed
and libdlm when fs/dlm is employed.
The second improvement is to make ocfs2_dlmfs use stackglue. Instead of
directly calling o2dlm APIs, it uses stackglue to remain agnostic of the
cluster stack. Now a system using a userspace cluster stack and fs/dlm
can mount ocfs2_dlmfs and use libo2dlm. This benefits everyone.
Joel
[Pull]
git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2.git dlmfs-stackglue
[View]
http://git.kernel.org/?p=linux/kernel/git/jlbec/ocfs2.git;a=shortlog;h=refs/heads/dlmfs-stackglue
fs/ocfs2/Makefile | 1 +
fs/ocfs2/dlm/Makefile | 3 +-
fs/ocfs2/dlmfs/Makefile | 5 +
fs/ocfs2/{dlm => dlmfs}/dlmfs.c | 97 ++++++++++----
fs/ocfs2/{dlm => dlmfs}/dlmfsver.c | 0
fs/ocfs2/{dlm => dlmfs}/dlmfsver.h | 0
fs/ocfs2/{dlm => dlmfs}/userdlm.c | 253 ++++++++++++++++++------------------
fs/ocfs2/{dlm => dlmfs}/userdlm.h | 10 +-
fs/ocfs2/dlmglue.c | 198 ++++++++++++++--------------
fs/ocfs2/ocfs2.h | 2 +-
fs/ocfs2/ocfs2_lockingver.h | 2 +
fs/ocfs2/stack_o2cb.c | 37 +++---
fs/ocfs2/stack_user.c | 49 +++-----
fs/ocfs2/stackglue.c | 98 +++++++++-----
fs/ocfs2/stackglue.h | 95 ++++++++------
15 files changed, 464 insertions(+), 386 deletions(-)
next reply other threads:[~2010-02-05 0:55 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-05 0:54 Joel Becker [this message]
2010-02-05 0:54 ` [PATCH 01/10] ocfs2_dlmfs: Add capabilities parameter Joel Becker
2010-02-05 0:54 ` [PATCH 02/10] ocfs2_dlmfs: Use poll() to signify BASTs Joel Becker
2010-02-05 0:54 ` [PATCH 03/10] ocfs2_dlmfs: Move to its own directory Joel Becker
2010-02-05 0:54 ` [PATCH 04/10] ocfs2: Pass lksbs back from stackglue ast/bast functions Joel Becker
2010-02-05 0:54 ` [PATCH 05/10] ocfs2: Attach the connection to the lksb Joel Becker
2010-02-05 0:54 ` [PATCH 06/10] ocfs2: Hang the locking proto on the cluster conn and use it in asts Joel Becker
2010-02-05 0:55 ` [PATCH 07/10] ocfs2: Remove the ast pointers from ocfs2_stack_plugins Joel Becker
2010-02-05 0:55 ` [PATCH 08/10] ocfs2: Pass the locking protocol into ocfs2_cluster_connect() Joel Becker
2010-02-05 0:55 ` [PATCH 09/10] ocfs2_dlmfs: Use the stackglue Joel Becker
2010-02-05 0:55 ` [PATCH 10/10] ocfs2_dlmfs: Enable the use of user cluster stacks Joel Becker
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=1265331303-19881-1-git-send-email-joel.becker@oracle.com \
--to=joel.becker@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mfasheh@suse.com \
--cc=ocfs2-devel@oss.oracle.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).