You've already forked linux-apfs
mirror of
https://github.com/linux-apfs/linux-apfs.git
synced 2026-05-01 15:00:59 -07:00
[PATCH] OCFS2: The Second Oracle Cluster Filesystem
dlmfs: A minimal dlm userspace interface implemented via a virtual file system. Most of the OCFS2 tools make use of this to take cluster locks when doing operations on the file system. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
This commit is contained in:
Mark Fasheh
Joel Becker
@@ -18,6 +18,8 @@ cramfs.txt
|
||||
- info on the cram filesystem for small storage (ROMs etc)
|
||||
devfs/
|
||||
- directory containing devfs documentation.
|
||||
dlmfs.txt
|
||||
- info on the userspace interface to the OCFS2 DLM.
|
||||
ext2.txt
|
||||
- info, mount options and specifications for the Ext2 filesystem.
|
||||
fat_cvf.txt
|
||||
|
||||
@@ -0,0 +1,130 @@
|
||||
dlmfs
|
||||
==================
|
||||
A minimal DLM userspace interface implemented via a virtual file
|
||||
system.
|
||||
|
||||
dlmfs is built with OCFS2 as it requires most of its infrastructure.
|
||||
|
||||
Project web page: http://oss.oracle.com/projects/ocfs2
|
||||
Tools web page: http://oss.oracle.com/projects/ocfs2-tools
|
||||
OCFS2 mailing lists: http://oss.oracle.com/projects/ocfs2/mailman/
|
||||
|
||||
All code copyright 2005 Oracle except when otherwise noted.
|
||||
|
||||
CREDITS
|
||||
=======
|
||||
|
||||
Some code taken from ramfs which is Copyright (C) 2000 Linus Torvalds
|
||||
and Transmeta Corp.
|
||||
|
||||
Mark Fasheh <mark.fasheh@oracle.com>
|
||||
|
||||
Caveats
|
||||
=======
|
||||
- Right now it only works with the OCFS2 DLM, though support for other
|
||||
DLM implementations should not be a major issue.
|
||||
|
||||
Mount options
|
||||
=============
|
||||
None
|
||||
|
||||
Usage
|
||||
=====
|
||||
|
||||
If you're just interested in OCFS2, then please see ocfs2.txt. The
|
||||
rest of this document will be geared towards those who want to use
|
||||
dlmfs for easy to setup and easy to use clustered locking in
|
||||
userspace.
|
||||
|
||||
Setup
|
||||
=====
|
||||
|
||||
dlmfs requires that the OCFS2 cluster infrastructure be in
|
||||
place. Please download ocfs2-tools from the above url and configure a
|
||||
cluster.
|
||||
|
||||
You'll want to start heartbeating on a volume which all the nodes in
|
||||
your lockspace can access. The easiest way to do this is via
|
||||
ocfs2_hb_ctl (distributed with ocfs2-tools). Right now it requires
|
||||
that an OCFS2 file system be in place so that it can automatically
|
||||
find it's heartbeat area, though it will eventually support heartbeat
|
||||
against raw disks.
|
||||
|
||||
Please see the ocfs2_hb_ctl and mkfs.ocfs2 manual pages distributed
|
||||
with ocfs2-tools.
|
||||
|
||||
Once you're heartbeating, DLM lock 'domains' can be easily created /
|
||||
destroyed and locks within them accessed.
|
||||
|
||||
Locking
|
||||
=======
|
||||
|
||||
Users may access dlmfs via standard file system calls, or they can use
|
||||
'libo2dlm' (distributed with ocfs2-tools) which abstracts the file
|
||||
system calls and presents a more traditional locking api.
|
||||
|
||||
dlmfs handles lock caching automatically for the user, so a lock
|
||||
request for an already acquired lock will not generate another DLM
|
||||
call. Userspace programs are assumed to handle their own local
|
||||
locking.
|
||||
|
||||
Two levels of locks are supported - Shared Read, and Exlcusive.
|
||||
Also supported is a Trylock operation.
|
||||
|
||||
For information on the libo2dlm interface, please see o2dlm.h,
|
||||
distributed with ocfs2-tools.
|
||||
|
||||
Lock value blocks can be read and written to a resource via read(2)
|
||||
and write(2) against the fd obtained via your open(2) call. The
|
||||
maximum currently supported LVB length is 64 bytes (though that is an
|
||||
OCFS2 DLM limitation). Through this mechanism, users of dlmfs can share
|
||||
small amounts of data amongst their nodes.
|
||||
|
||||
mkdir(2) signals dlmfs to join a domain (which will have the same name
|
||||
as the resulting directory)
|
||||
|
||||
rmdir(2) signals dlmfs to leave the domain
|
||||
|
||||
Locks for a given domain are represented by regular inodes inside the
|
||||
domain directory. Locking against them is done via the open(2) system
|
||||
call.
|
||||
|
||||
The open(2) call will not return until your lock has been granted or
|
||||
an error has occurred, unless it has been instructed to do a trylock
|
||||
operation. If the lock succeeds, you'll get an fd.
|
||||
|
||||
open(2) with O_CREAT to ensure the resource inode is created - dlmfs does
|
||||
not automatically create inodes for existing lock resources.
|
||||
|
||||
Open Flag Lock Request Type
|
||||
--------- -----------------
|
||||
O_RDONLY Shared Read
|
||||
O_RDWR Exclusive
|
||||
|
||||
Open Flag Resulting Locking Behavior
|
||||
--------- --------------------------
|
||||
O_NONBLOCK Trylock operation
|
||||
|
||||
You must provide exactly one of O_RDONLY or O_RDWR.
|
||||
|
||||
If O_NONBLOCK is also provided and the trylock operation was valid but
|
||||
could not lock the resource then open(2) will return ETXTBUSY.
|
||||
|
||||
close(2) drops the lock associated with your fd.
|
||||
|
||||
Modes passed to mkdir(2) or open(2) are adhered to locally. Chown is
|
||||
supported locally as well. This means you can use them to restrict
|
||||
access to the resources via dlmfs on your local node only.
|
||||
|
||||
The resource LVB may be read from the fd in either Shared Read or
|
||||
Exclusive modes via the read(2) system call. It can be written via
|
||||
write(2) only when open in Exclusive mode.
|
||||
|
||||
Once written, an LVB will be visible to other nodes who obtain Read
|
||||
Only or higher level locks on the resource.
|
||||
|
||||
See Also
|
||||
========
|
||||
http://opendlm.sourceforge.net/cvsmirror/opendlm/docs/dlmbook_final.pdf
|
||||
|
||||
For more information on the VMS distributed locking API.
|
||||
@@ -1,6 +1,8 @@
|
||||
EXTRA_CFLAGS += -Ifs/ocfs2
|
||||
|
||||
obj-$(CONFIG_OCFS2_FS) += ocfs2_dlm.o
|
||||
obj-$(CONFIG_OCFS2_FS) += ocfs2_dlm.o ocfs2_dlmfs.o
|
||||
|
||||
ocfs2_dlm-objs := dlmdomain.o dlmdebug.o dlmthread.o dlmrecovery.o \
|
||||
dlmmaster.o dlmast.o dlmconvert.o dlmlock.o dlmunlock.o dlmver.o
|
||||
|
||||
ocfs2_dlmfs-objs := userdlm.o dlmfs.o dlmfsver.o
|
||||
|
||||
File diff suppressed because it is too large
Load Diff
@@ -0,0 +1,42 @@
|
||||
/* -*- mode: c; c-basic-offset: 8; -*-
|
||||
* vim: noexpandtab sw=8 ts=8 sts=0:
|
||||
*
|
||||
* dlmfsver.c
|
||||
*
|
||||
* version string
|
||||
*
|
||||
* Copyright (C) 2002, 2005 Oracle. All rights reserved.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public
|
||||
* License as published by the Free Software Foundation; either
|
||||
* version 2 of the License, or (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
* General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public
|
||||
* License along with this program; if not, write to the
|
||||
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
* Boston, MA 021110-1307, USA.
|
||||
*/
|
||||
|
||||
#include <linux/module.h>
|
||||
#include <linux/kernel.h>
|
||||
|
||||
#include "dlmfsver.h"
|
||||
|
||||
#define DLM_BUILD_VERSION "1.3.3"
|
||||
|
||||
#define VERSION_STR "OCFS2 DLMFS " DLM_BUILD_VERSION
|
||||
|
||||
void dlmfs_print_version(void)
|
||||
{
|
||||
printk(KERN_INFO "%s\n", VERSION_STR);
|
||||
}
|
||||
|
||||
MODULE_DESCRIPTION(VERSION_STR);
|
||||
|
||||
MODULE_VERSION(DLM_BUILD_VERSION);
|
||||
@@ -0,0 +1,31 @@
|
||||
/* -*- mode: c; c-basic-offset: 8; -*-
|
||||
* vim: noexpandtab sw=8 ts=8 sts=0:
|
||||
*
|
||||
* dlmver.h
|
||||
*
|
||||
* Function prototypes
|
||||
*
|
||||
* Copyright (C) 2005 Oracle. All rights reserved.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public
|
||||
* License as published by the Free Software Foundation; either
|
||||
* version 2 of the License, or (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
* General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public
|
||||
* License along with this program; if not, write to the
|
||||
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
* Boston, MA 021110-1307, USA.
|
||||
*/
|
||||
|
||||
#ifndef DLMFS_VER_H
|
||||
#define DLMFS_VER_H
|
||||
|
||||
void dlmfs_print_version(void);
|
||||
|
||||
#endif /* DLMFS_VER_H */
|
||||
File diff suppressed because it is too large
Load Diff
@@ -0,0 +1,111 @@
|
||||
/* -*- mode: c; c-basic-offset: 8; -*-
|
||||
* vim: noexpandtab sw=8 ts=8 sts=0:
|
||||
*
|
||||
* userdlm.h
|
||||
*
|
||||
* Userspace dlm defines
|
||||
*
|
||||
* Copyright (C) 2002, 2004 Oracle. All rights reserved.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public
|
||||
* License as published by the Free Software Foundation; either
|
||||
* version 2 of the License, or (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
* General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public
|
||||
* License along with this program; if not, write to the
|
||||
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
* Boston, MA 021110-1307, USA.
|
||||
*/
|
||||
|
||||
|
||||
#ifndef USERDLM_H
|
||||
#define USERDLM_H
|
||||
|
||||
#include <linux/module.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/types.h>
|
||||
#include <linux/workqueue.h>
|
||||
|
||||
/* user_lock_res->l_flags flags. */
|
||||
#define USER_LOCK_ATTACHED (0x00000001) /* have we initialized
|
||||
* the lvb */
|
||||
#define USER_LOCK_BUSY (0x00000002) /* we are currently in
|
||||
* dlm_lock */
|
||||
#define USER_LOCK_BLOCKED (0x00000004) /* blocked waiting to
|
||||
* downconvert*/
|
||||
#define USER_LOCK_IN_TEARDOWN (0x00000008) /* we're currently
|
||||
* destroying this
|
||||
* lock. */
|
||||
#define USER_LOCK_QUEUED (0x00000010) /* lock is on the
|
||||
* workqueue */
|
||||
#define USER_LOCK_IN_CANCEL (0x00000020)
|
||||
|
||||
struct user_lock_res {
|
||||
spinlock_t l_lock;
|
||||
|
||||
int l_flags;
|
||||
|
||||
#define USER_DLM_LOCK_ID_MAX_LEN 32
|
||||
char l_name[USER_DLM_LOCK_ID_MAX_LEN];
|
||||
int l_level;
|
||||
unsigned int l_ro_holders;
|
||||
unsigned int l_ex_holders;
|
||||
struct dlm_lockstatus l_lksb;
|
||||
|
||||
int l_requested;
|
||||
int l_blocking;
|
||||
|
||||
wait_queue_head_t l_event;
|
||||
|
||||
struct work_struct l_work;
|
||||
};
|
||||
|
||||
extern struct workqueue_struct *user_dlm_worker;
|
||||
|
||||
void user_dlm_lock_res_init(struct user_lock_res *lockres,
|
||||
struct dentry *dentry);
|
||||
int user_dlm_destroy_lock(struct user_lock_res *lockres);
|
||||
int user_dlm_cluster_lock(struct user_lock_res *lockres,
|
||||
int level,
|
||||
int lkm_flags);
|
||||
void user_dlm_cluster_unlock(struct user_lock_res *lockres,
|
||||
int level);
|
||||
void user_dlm_write_lvb(struct inode *inode,
|
||||
const char *val,
|
||||
unsigned int len);
|
||||
void user_dlm_read_lvb(struct inode *inode,
|
||||
char *val,
|
||||
unsigned int len);
|
||||
struct dlm_ctxt *user_dlm_register_context(struct qstr *name);
|
||||
void user_dlm_unregister_context(struct dlm_ctxt *dlm);
|
||||
|
||||
struct dlmfs_inode_private {
|
||||
struct dlm_ctxt *ip_dlm;
|
||||
|
||||
struct user_lock_res ip_lockres; /* unused for directories. */
|
||||
struct inode *ip_parent;
|
||||
|
||||
struct inode ip_vfs_inode;
|
||||
};
|
||||
|
||||
static inline struct dlmfs_inode_private *
|
||||
DLMFS_I(struct inode *inode)
|
||||
{
|
||||
return container_of(inode,
|
||||
struct dlmfs_inode_private,
|
||||
ip_vfs_inode);
|
||||
}
|
||||
|
||||
struct dlmfs_filp_private {
|
||||
int fp_lock_level;
|
||||
};
|
||||
|
||||
#define DLMFS_MAGIC 0x76a9f425
|
||||
|
||||
#endif /* USERDLM_H */
|
||||
Reference in New Issue
Block a user