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[PATCH] OCFS2: The Second Oracle Cluster Filesystem

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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 2005-12-15 14:31:23 -08:00 committed by Joel Becker
parent 6714d8e86b
commit 8df08c89c6
8 changed files with 1617 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Documentation/filesystems/00-INDEX
View File

@ -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

130
Documentation/filesystems/dlmfs.txt Normal file
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@ -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.

4
fs/ocfs2/dlm/Makefile
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@ -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

640
fs/ocfs2/dlm/dlmfs.c Normal file
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@ -0,0 +1,640 @@
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* dlmfs.c
*
* Code which implements the kernel side of a minimal userspace
* interface to our DLM. This file handles the virtual file system
* used for communication with userspace. Credit should go to ramfs,
* which was a template for the fs side of this module.
*
* Copyright (C) 2003, 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.
*/
/* Simple VFS hooks based on: */
/*
* Resizable simple ram filesystem for Linux.
*
* Copyright (C) 2000 Linus Torvalds.
* 2000 Transmeta Corp.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
#include <asm/uaccess.h>
#include "cluster/nodemanager.h"
#include "cluster/heartbeat.h"
#include "cluster/tcp.h"
#include "dlmapi.h"
#include "userdlm.h"
#include "dlmfsver.h"
#define MLOG_MASK_PREFIX ML_DLMFS
#include "cluster/masklog.h"
static struct super_operations dlmfs_ops;
static struct file_operations dlmfs_file_operations;
static struct inode_operations dlmfs_dir_inode_operations;
static struct inode_operations dlmfs_root_inode_operations;
static struct inode_operations dlmfs_file_inode_operations;
static kmem_cache_t *dlmfs_inode_cache;
struct workqueue_struct *user_dlm_worker;
/*
* decodes a set of open flags into a valid lock level and a set of flags.
* returns < 0 if we have invalid flags
* flags which mean something to us:
* O_RDONLY -> PRMODE level
* O_WRONLY -> EXMODE level
*
* O_NONBLOCK -> LKM_NOQUEUE
*/
static int dlmfs_decode_open_flags(int open_flags,
int *level,
int *flags)
{
if (open_flags & (O_WRONLY|O_RDWR))
*level = LKM_EXMODE;
else
*level = LKM_PRMODE;
*flags = 0;
if (open_flags & O_NONBLOCK)
*flags |= LKM_NOQUEUE;
return 0;
}
static int dlmfs_file_open(struct inode *inode,
struct file *file)
{
int status, level, flags;
struct dlmfs_filp_private *fp = NULL;
struct dlmfs_inode_private *ip;
if (S_ISDIR(inode->i_mode))
BUG();
mlog(0, "open called on inode %lu, flags 0x%x\n", inode->i_ino,
file->f_flags);
status = dlmfs_decode_open_flags(file->f_flags, &level, &flags);
if (status < 0)
goto bail;
/* We don't want to honor O_APPEND at read/write time as it
* doesn't make sense for LVB writes. */
file->f_flags &= ~O_APPEND;
fp = kmalloc(sizeof(*fp), GFP_KERNEL);
if (!fp) {
status = -ENOMEM;
goto bail;
}
fp->fp_lock_level = level;
ip = DLMFS_I(inode);
status = user_dlm_cluster_lock(&ip->ip_lockres, level, flags);
if (status < 0) {
/* this is a strange error to return here but I want
* to be able userspace to be able to distinguish a
* valid lock request from one that simply couldn't be
* granted. */
if (flags & LKM_NOQUEUE && status == -EAGAIN)
status = -ETXTBSY;
kfree(fp);
goto bail;
}
file->private_data = fp;
bail:
return status;
}
static int dlmfs_file_release(struct inode *inode,
struct file *file)
{
int level, status;
struct dlmfs_inode_private *ip = DLMFS_I(inode);
struct dlmfs_filp_private *fp =
(struct dlmfs_filp_private *) file->private_data;
if (S_ISDIR(inode->i_mode))
BUG();
mlog(0, "close called on inode %lu\n", inode->i_ino);
status = 0;
if (fp) {
level = fp->fp_lock_level;
if (level != LKM_IVMODE)
user_dlm_cluster_unlock(&ip->ip_lockres, level);
kfree(fp);
file->private_data = NULL;
}
return 0;
}
static ssize_t dlmfs_file_read(struct file *filp,
char __user *buf,
size_t count,
loff_t *ppos)
{
int bytes_left;
ssize_t readlen;
char *lvb_buf;
struct inode *inode = filp->f_dentry->d_inode;
mlog(0, "inode %lu, count = %zu, *ppos = %llu\n",
inode->i_ino, count, *ppos);
if (*ppos >= i_size_read(inode))
return 0;
if (!count)
return 0;
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
/* don't read past the lvb */
if ((count + *ppos) > i_size_read(inode))
readlen = i_size_read(inode) - *ppos;
else
readlen = count - *ppos;
lvb_buf = kmalloc(readlen, GFP_KERNEL);
if (!lvb_buf)
return -ENOMEM;
user_dlm_read_lvb(inode, lvb_buf, readlen);
bytes_left = __copy_to_user(buf, lvb_buf, readlen);
readlen -= bytes_left;
kfree(lvb_buf);
*ppos = *ppos + readlen;
mlog(0, "read %zd bytes\n", readlen);
return readlen;
}
static ssize_t dlmfs_file_write(struct file *filp,
const char __user *buf,
size_t count,
loff_t *ppos)
{
int bytes_left;
ssize_t writelen;
char *lvb_buf;
struct inode *inode = filp->f_dentry->d_inode;
mlog(0, "inode %lu, count = %zu, *ppos = %llu\n",
inode->i_ino, count, *ppos);
if (*ppos >= i_size_read(inode))
return -ENOSPC;
if (!count)
return 0;
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
/* don't write past the lvb */
if ((count + *ppos) > i_size_read(inode))
writelen = i_size_read(inode) - *ppos;
else
writelen = count - *ppos;
lvb_buf = kmalloc(writelen, GFP_KERNEL);
if (!lvb_buf)
return -ENOMEM;
bytes_left = copy_from_user(lvb_buf, buf, writelen);
writelen -= bytes_left;
if (writelen)
user_dlm_write_lvb(inode, lvb_buf, writelen);
kfree(lvb_buf);
*ppos = *ppos + writelen;
mlog(0, "wrote %zd bytes\n", writelen);
return writelen;
}
static void dlmfs_init_once(void *foo,
kmem_cache_t *cachep,
unsigned long flags)
{
struct dlmfs_inode_private *ip =
(struct dlmfs_inode_private *) foo;
if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
SLAB_CTOR_CONSTRUCTOR) {
ip->ip_dlm = NULL;
ip->ip_parent = NULL;
inode_init_once(&ip->ip_vfs_inode);
}
}
static struct inode *dlmfs_alloc_inode(struct super_block *sb)
{
struct dlmfs_inode_private *ip;
ip = kmem_cache_alloc(dlmfs_inode_cache, SLAB_NOFS);
if (!ip)
return NULL;
return &ip->ip_vfs_inode;
}
static void dlmfs_destroy_inode(struct inode *inode)
{
kmem_cache_free(dlmfs_inode_cache, DLMFS_I(inode));
}
static void dlmfs_clear_inode(struct inode *inode)
{
int status;
struct dlmfs_inode_private *ip;
if (!inode)
return;
mlog(0, "inode %lu\n", inode->i_ino);
ip = DLMFS_I(inode);
if (S_ISREG(inode->i_mode)) {
status = user_dlm_destroy_lock(&ip->ip_lockres);
if (status < 0)
mlog_errno(status);
iput(ip->ip_parent);
goto clear_fields;
}
mlog(0, "we're a directory, ip->ip_dlm = 0x%p\n", ip->ip_dlm);
/* we must be a directory. If required, lets unregister the
* dlm context now. */
if (ip->ip_dlm)
user_dlm_unregister_context(ip->ip_dlm);
clear_fields:
ip->ip_parent = NULL;
ip->ip_dlm = NULL;
}
static struct backing_dev_info dlmfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
};
static struct inode *dlmfs_get_root_inode(struct super_block *sb)
{
struct inode *inode = new_inode(sb);
int mode = S_IFDIR | 0755;
struct dlmfs_inode_private *ip;
if (inode) {
ip = DLMFS_I(inode);
inode->i_mode = mode;
inode->i_uid = current->fsuid;
inode->i_gid = current->fsgid;
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->i_nlink++;
inode->i_fop = &simple_dir_operations;
inode->i_op = &dlmfs_root_inode_operations;
}
return inode;
}
static struct inode *dlmfs_get_inode(struct inode *parent,
struct dentry *dentry,
int mode)
{
struct super_block *sb = parent->i_sb;
struct inode * inode = new_inode(sb);
struct dlmfs_inode_private *ip;
if (!inode)
return NULL;
inode->i_mode = mode;
inode->i_uid = current->fsuid;
inode->i_gid = current->fsgid;
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_mapping->backing_dev_info = &dlmfs_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
ip = DLMFS_I(inode);
ip->ip_dlm = DLMFS_I(parent)->ip_dlm;
switch (mode & S_IFMT) {
default:
/* for now we don't support anything other than
* directories and regular files. */
BUG();
break;
case S_IFREG:
inode->i_op = &dlmfs_file_inode_operations;
inode->i_fop = &dlmfs_file_operations;
i_size_write(inode, DLM_LVB_LEN);
user_dlm_lock_res_init(&ip->ip_lockres, dentry);
/* released at clear_inode time, this insures that we
* get to drop the dlm reference on each lock *before*
* we call the unregister code for releasing parent
* directories. */
ip->ip_parent = igrab(parent);
BUG_ON(!ip->ip_parent);
break;
case S_IFDIR:
inode->i_op = &dlmfs_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
/* directory inodes start off with i_nlink ==
* 2 (for "." entry) */
inode->i_nlink++;
break;
}
if (parent->i_mode & S_ISGID) {
inode->i_gid = parent->i_gid;
if (S_ISDIR(mode))
inode->i_mode |= S_ISGID;
}
return inode;
}
/*
* File creation. Allocate an inode, and we're done..
*/
/* SMP-safe */
static int dlmfs_mkdir(struct inode * dir,
struct dentry * dentry,
int mode)
{
int status;
struct inode *inode = NULL;
struct qstr *domain = &dentry->d_name;
struct dlmfs_inode_private *ip;
struct dlm_ctxt *dlm;
mlog(0, "mkdir %.*s\n", domain->len, domain->name);
/* verify that we have a proper domain */
if (domain->len >= O2NM_MAX_NAME_LEN) {
status = -EINVAL;
mlog(ML_ERROR, "invalid domain name for directory.\n");
goto bail;
}
inode = dlmfs_get_inode(dir, dentry, mode | S_IFDIR);
if (!inode) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
ip = DLMFS_I(inode);
dlm = user_dlm_register_context(domain);
if (IS_ERR(dlm)) {
status = PTR_ERR(dlm);
mlog(ML_ERROR, "Error %d could not register domain \"%.*s\"\n",
status, domain->len, domain->name);
goto bail;
}
ip->ip_dlm = dlm;
dir->i_nlink++;
d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
status = 0;
bail:
if (status < 0)
iput(inode);
return status;
}
static int dlmfs_create(struct inode *dir,
struct dentry *dentry,
int mode,
struct nameidata *nd)
{
int status = 0;
struct inode *inode;
struct qstr *name = &dentry->d_name;
mlog(0, "create %.*s\n", name->len, name->name);
/* verify name is valid and doesn't contain any dlm reserved
* characters */
if (name->len >= USER_DLM_LOCK_ID_MAX_LEN ||
name->name[0] == '$') {
status = -EINVAL;
mlog(ML_ERROR, "invalid lock name, %.*s\n", name->len,
name->name);
goto bail;
}
inode = dlmfs_get_inode(dir, dentry, mode | S_IFREG);
if (!inode) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
bail:
return status;
}
static int dlmfs_unlink(struct inode *dir,
struct dentry *dentry)
{
int status;
struct inode *inode = dentry->d_inode;
mlog(0, "unlink inode %lu\n", inode->i_ino);
/* if there are no current holders, or none that are waiting
* to acquire a lock, this basically destroys our lockres. */
status = user_dlm_destroy_lock(&DLMFS_I(inode)->ip_lockres);
if (status < 0) {
mlog(ML_ERROR, "unlink %.*s, error %d from destroy\n",
dentry->d_name.len, dentry->d_name.name, status);
goto bail;
}
status = simple_unlink(dir, dentry);
bail:
return status;
}
static int dlmfs_fill_super(struct super_block * sb,
void * data,
int silent)
{
struct inode * inode;
struct dentry * root;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = DLMFS_MAGIC;
sb->s_op = &dlmfs_ops;
inode = dlmfs_get_root_inode(sb);
if (!inode)
return -ENOMEM;
root = d_alloc_root(inode);
if (!root) {
iput(inode);
return -ENOMEM;
}
sb->s_root = root;
return 0;
}
static struct file_operations dlmfs_file_operations = {
.open = dlmfs_file_open,
.release = dlmfs_file_release,
.read = dlmfs_file_read,
.write = dlmfs_file_write,
};
static struct inode_operations dlmfs_dir_inode_operations = {
.create = dlmfs_create,
.lookup = simple_lookup,
.unlink = dlmfs_unlink,
};
/* this way we can restrict mkdir to only the toplevel of the fs. */
static struct inode_operations dlmfs_root_inode_operations = {
.lookup = simple_lookup,
.mkdir = dlmfs_mkdir,
.rmdir = simple_rmdir,
};
static struct super_operations dlmfs_ops = {
.statfs = simple_statfs,
.alloc_inode = dlmfs_alloc_inode,
.destroy_inode = dlmfs_destroy_inode,
.clear_inode = dlmfs_clear_inode,
.drop_inode = generic_delete_inode,
};
static struct inode_operations dlmfs_file_inode_operations = {
.getattr = simple_getattr,
};
static struct super_block *dlmfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return get_sb_nodev(fs_type, flags, data, dlmfs_fill_super);
}
static struct file_system_type dlmfs_fs_type = {
.owner = THIS_MODULE,
.name = "ocfs2_dlmfs",
.get_sb = dlmfs_get_sb,
.kill_sb = kill_litter_super,
};
static int __init init_dlmfs_fs(void)
{
int status;
int cleanup_inode = 0, cleanup_worker = 0;
dlmfs_print_version();
dlmfs_inode_cache = kmem_cache_create("dlmfs_inode_cache",
sizeof(struct dlmfs_inode_private),
0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
dlmfs_init_once, NULL);
if (!dlmfs_inode_cache)
return -ENOMEM;
cleanup_inode = 1;
user_dlm_worker = create_singlethread_workqueue("user_dlm");
if (!user_dlm_worker) {
status = -ENOMEM;
goto bail;
}
cleanup_worker = 1;
status = register_filesystem(&dlmfs_fs_type);
bail:
if (status) {
if (cleanup_inode)
kmem_cache_destroy(dlmfs_inode_cache);
if (cleanup_worker)
destroy_workqueue(user_dlm_worker);
} else
printk("OCFS2 User DLM kernel interface loaded\n");
return status;
}
static void __exit exit_dlmfs_fs(void)
{
unregister_filesystem(&dlmfs_fs_type);
flush_workqueue(user_dlm_worker);
destroy_workqueue(user_dlm_worker);
if (kmem_cache_destroy(dlmfs_inode_cache))
printk(KERN_INFO "dlmfs_inode_cache: not all structures "
"were freed\n");
}
MODULE_AUTHOR("Oracle");
MODULE_LICENSE("GPL");
module_init(init_dlmfs_fs)
module_exit(exit_dlmfs_fs)

42
fs/ocfs2/dlm/dlmfsver.c Normal file
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@ -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);

31
fs/ocfs2/dlm/dlmfsver.h Normal file
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/* -*- 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 */

658
fs/ocfs2/dlm/userdlm.c Normal file
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/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* userdlm.c
*
* Code which implements the kernel side of a minimal userspace
* interface to our DLM.
*
* Many of the functions here are pared down versions of dlmglue.c
* functions.
*
* Copyright (C) 2003, 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.
*/
#include <asm/signal.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/crc32.h>
#include "cluster/nodemanager.h"
#include "cluster/heartbeat.h"
#include "cluster/tcp.h"
#include "dlmapi.h"
#include "userdlm.h"
#define MLOG_MASK_PREFIX ML_DLMFS
#include "cluster/masklog.h"
static inline int user_check_wait_flag(struct user_lock_res *lockres,
int flag)
{
int ret;
spin_lock(&lockres->l_lock);
ret = lockres->l_flags & flag;
spin_unlock(&lockres->l_lock);
return ret;
}
static inline void user_wait_on_busy_lock(struct user_lock_res *lockres)
{
wait_event(lockres->l_event,
!user_check_wait_flag(lockres, USER_LOCK_BUSY));
}
static inline void user_wait_on_blocked_lock(struct user_lock_res *lockres)
{
wait_event(lockres->l_event,
!user_check_wait_flag(lockres, USER_LOCK_BLOCKED));
}
/* I heart container_of... */
static inline struct dlm_ctxt *
dlm_ctxt_from_user_lockres(struct user_lock_res *lockres)
{
struct dlmfs_inode_private *ip;
ip = container_of(lockres,
struct dlmfs_inode_private,
ip_lockres);
return ip->ip_dlm;
}
static struct inode *
user_dlm_inode_from_user_lockres(struct user_lock_res *lockres)
{
struct dlmfs_inode_private *ip;
ip = container_of(lockres,
struct dlmfs_inode_private,
ip_lockres);
return &ip->ip_vfs_inode;
}
static inline void user_recover_from_dlm_error(struct user_lock_res *lockres)
{
spin_lock(&lockres->l_lock);
lockres->l_flags &= ~USER_LOCK_BUSY;
spin_unlock(&lockres->l_lock);
}
#define user_log_dlm_error(_func, _stat, _lockres) do { \
mlog(ML_ERROR, "Dlm error \"%s\" while calling %s on " \
"resource %s: %s\n", dlm_errname(_stat), _func, \
_lockres->l_name, dlm_errmsg(_stat)); \
} while (0)
/* WARNING: This function lives in a world where the only three lock
* levels are EX, PR, and NL. It *will* have to be adjusted when more
* lock types are added. */
static inline int user_highest_compat_lock_level(int level)
{
int new_level = LKM_EXMODE;
if (level == LKM_EXMODE)
new_level = LKM_NLMODE;
else if (level == LKM_PRMODE)
new_level = LKM_PRMODE;
return new_level;
}
static void user_ast(void *opaque)
{
struct user_lock_res *lockres = opaque;
struct dlm_lockstatus *lksb;
mlog(0, "AST fired for lockres %s\n", lockres->l_name);
spin_lock(&lockres->l_lock);
lksb = &(lockres->l_lksb);
if (lksb->status != DLM_NORMAL) {
mlog(ML_ERROR, "lksb status value of %u on lockres %s\n",
lksb->status, lockres->l_name);
spin_unlock(&lockres->l_lock);
return;
}
/* we're downconverting. */
if (lockres->l_requested < lockres->l_level) {
if (lockres->l_requested <=
user_highest_compat_lock_level(lockres->l_blocking)) {
lockres->l_blocking = LKM_NLMODE;
lockres->l_flags &= ~USER_LOCK_BLOCKED;
}
}
lockres->l_level = lockres->l_requested;
lockres->l_requested = LKM_IVMODE;
lockres->l_flags |= USER_LOCK_ATTACHED;
lockres->l_flags &= ~USER_LOCK_BUSY;
spin_unlock(&lockres->l_lock);
wake_up(&lockres->l_event);
}
static inline void user_dlm_grab_inode_ref(struct user_lock_res *lockres)
{
struct inode *inode;
inode = user_dlm_inode_from_user_lockres(lockres);
if (!igrab(inode))
BUG();
}
static void user_dlm_unblock_lock(void *opaque);
static void __user_dlm_queue_lockres(struct user_lock_res *lockres)
{
if (!(lockres->l_flags & USER_LOCK_QUEUED)) {
user_dlm_grab_inode_ref(lockres);
INIT_WORK(&lockres->l_work, user_dlm_unblock_lock,
lockres);
queue_work(user_dlm_worker, &lockres->l_work);
lockres->l_flags |= USER_LOCK_QUEUED;
}
}
static void __user_dlm_cond_queue_lockres(struct user_lock_res *lockres)
{
int queue = 0;
if (!(lockres->l_flags & USER_LOCK_BLOCKED))
return;
switch (lockres->l_blocking) {
case LKM_EXMODE:
if (!lockres->l_ex_holders && !lockres->l_ro_holders)
queue = 1;
break;
case LKM_PRMODE:
if (!lockres->l_ex_holders)
queue = 1;
break;
default:
BUG();
}
if (queue)
__user_dlm_queue_lockres(lockres);
}
static void user_bast(void *opaque, int level)
{
struct user_lock_res *lockres = opaque;
mlog(0, "Blocking AST fired for lockres %s. Blocking level %d\n",
lockres->l_name, level);
spin_lock(&lockres->l_lock);
lockres->l_flags |= USER_LOCK_BLOCKED;
if (level > lockres->l_blocking)
lockres->l_blocking = level;
__user_dlm_queue_lockres(lockres);
spin_unlock(&lockres->l_lock);
wake_up(&lockres->l_event);
}
static void user_unlock_ast(void *opaque, enum dlm_status status)
{
struct user_lock_res *lockres = opaque;
mlog(0, "UNLOCK AST called on lock %s\n", lockres->l_name);
if (status != DLM_NORMAL)
mlog(ML_ERROR, "Dlm returns status %d\n", status);
spin_lock(&lockres->l_lock);
if (lockres->l_flags & USER_LOCK_IN_TEARDOWN)
lockres->l_level = LKM_IVMODE;
else {
lockres->l_requested = LKM_IVMODE; /* cancel an
* upconvert
* request. */
lockres->l_flags &= ~USER_LOCK_IN_CANCEL;
/* we want the unblock thread to look at it again
* now. */
__user_dlm_queue_lockres(lockres);
}
lockres->l_flags &= ~USER_LOCK_BUSY;
spin_unlock(&lockres->l_lock);
wake_up(&lockres->l_event);
}
static inline void user_dlm_drop_inode_ref(struct user_lock_res *lockres)
{
struct inode *inode;
inode = user_dlm_inode_from_user_lockres(lockres);
iput(inode);
}
static void user_dlm_unblock_lock(void *opaque)
{
int new_level, status;
struct user_lock_res *lockres = (struct user_lock_res *) opaque;
struct dlm_ctxt *dlm = dlm_ctxt_from_user_lockres(lockres);
mlog(0, "processing lockres %s\n", lockres->l_name);
spin_lock(&lockres->l_lock);
BUG_ON(!(lockres->l_flags & USER_LOCK_BLOCKED));
BUG_ON(!(lockres->l_flags & USER_LOCK_QUEUED));
/* notice that we don't clear USER_LOCK_BLOCKED here. That's
* for user_ast to do. */
lockres->l_flags &= ~USER_LOCK_QUEUED;
if (lockres->l_flags & USER_LOCK_IN_TEARDOWN) {
mlog(0, "lock is in teardown so we do nothing\n");
spin_unlock(&lockres->l_lock);
goto drop_ref;
}
if (lockres->l_flags & USER_LOCK_BUSY) {
mlog(0, "BUSY flag detected...\n");
if (lockres->l_flags & USER_LOCK_IN_CANCEL) {
spin_unlock(&lockres->l_lock);
goto drop_ref;
}
lockres->l_flags |= USER_LOCK_IN_CANCEL;
spin_unlock(&lockres->l_lock);
status = dlmunlock(dlm,
&lockres->l_lksb,
LKM_CANCEL,
user_unlock_ast,
lockres);
if (status == DLM_CANCELGRANT) {
/* If we got this, then the ast was fired
* before we could cancel. We cleanup our
* state, and restart the function. */
spin_lock(&lockres->l_lock);
lockres->l_flags &= ~USER_LOCK_IN_CANCEL;
spin_unlock(&lockres->l_lock);
} else if (status != DLM_NORMAL)
user_log_dlm_error("dlmunlock", status, lockres);
goto drop_ref;
}
/* If there are still incompat holders, we can exit safely
* without worrying about re-queueing this lock as that will
* happen on the last call to user_cluster_unlock. */
if ((lockres->l_blocking == LKM_EXMODE)
&& (lockres->l_ex_holders || lockres->l_ro_holders)) {
spin_unlock(&lockres->l_lock);
mlog(0, "can't downconvert for ex: ro = %u, ex = %u\n",
lockres->l_ro_holders, lockres->l_ex_holders);
goto drop_ref;
}
if ((lockres->l_blocking == LKM_PRMODE)
&& lockres->l_ex_holders) {
spin_unlock(&lockres->l_lock);
mlog(0, "can't downconvert for pr: ex = %u\n",
lockres->l_ex_holders);
goto drop_ref;
}
/* yay, we can downconvert now. */
new_level = user_highest_compat_lock_level(lockres->l_blocking);
lockres->l_requested = new_level;
lockres->l_flags |= USER_LOCK_BUSY;
mlog(0, "Downconvert lock from %d to %d\n",
lockres->l_level, new_level);
spin_unlock(&lockres->l_lock);
/* need lock downconvert request now... */
status = dlmlock(dlm,
new_level,
&lockres->l_lksb,
LKM_CONVERT|LKM_VALBLK,
lockres->l_name,
user_ast,
lockres,
user_bast);
if (status != DLM_NORMAL) {
user_log_dlm_error("dlmlock", status, lockres);
user_recover_from_dlm_error(lockres);
}
drop_ref:
user_dlm_drop_inode_ref(lockres);
}
static inline void user_dlm_inc_holders(struct user_lock_res *lockres,
int level)
{
switch(level) {
case LKM_EXMODE:
lockres->l_ex_holders++;
break;
case LKM_PRMODE:
lockres->l_ro_holders++;
break;
default:
BUG();
}
}
/* predict what lock level we'll be dropping down to on behalf
* of another node, and return true if the currently wanted
* level will be compatible with it. */
static inline int
user_may_continue_on_blocked_lock(struct user_lock_res *lockres,
int wanted)
{
BUG_ON(!(lockres->l_flags & USER_LOCK_BLOCKED));
return wanted <= user_highest_compat_lock_level(lockres->l_blocking);
}
int user_dlm_cluster_lock(struct user_lock_res *lockres,
int level,
int lkm_flags)
{
int status, local_flags;
struct dlm_ctxt *dlm = dlm_ctxt_from_user_lockres(lockres);
if (level != LKM_EXMODE &&
level != LKM_PRMODE) {
mlog(ML_ERROR, "lockres %s: invalid request!\n",
lockres->l_name);
status = -EINVAL;
goto bail;
}
mlog(0, "lockres %s: asking for %s lock, passed flags = 0x%x\n",
lockres->l_name,
(level == LKM_EXMODE) ? "LKM_EXMODE" : "LKM_PRMODE",
lkm_flags);
again:
if (signal_pending(current)) {
status = -ERESTARTSYS;
goto bail;
}
spin_lock(&lockres->l_lock);
/* We only compare against the currently granted level
* here. If the lock is blocked waiting on a downconvert,
* we'll get caught below. */
if ((lockres->l_flags & USER_LOCK_BUSY) &&
(level > lockres->l_level)) {
/* is someone sitting in dlm_lock? If so, wait on
* them. */
spin_unlock(&lockres->l_lock);
user_wait_on_busy_lock(lockres);
goto again;
}
if ((lockres->l_flags & USER_LOCK_BLOCKED) &&
(!user_may_continue_on_blocked_lock(lockres, level))) {
/* is the lock is currently blocked on behalf of
* another node */
spin_unlock(&lockres->l_lock);
user_wait_on_blocked_lock(lockres);
goto again;
}
if (level > lockres->l_level) {
local_flags = lkm_flags | LKM_VALBLK;
if (lockres->l_level != LKM_IVMODE)
local_flags |= LKM_CONVERT;
lockres->l_requested = level;
lockres->l_flags |= USER_LOCK_BUSY;
spin_unlock(&lockres->l_lock);
BUG_ON(level == LKM_IVMODE);
BUG_ON(level == LKM_NLMODE);
mlog(0, "lock %s, get lock from %d to level = %d\n",
lockres->l_name, lockres->l_level, level);
/* call dlm_lock to upgrade lock now */
status = dlmlock(dlm,
level,
&lockres->l_lksb,
local_flags,
lockres->l_name,
user_ast,
lockres,
user_bast);
if (status != DLM_NORMAL) {
if ((lkm_flags & LKM_NOQUEUE) &&
(status == DLM_NOTQUEUED))
status = -EAGAIN;
else {
user_log_dlm_error("dlmlock", status, lockres);
status = -EINVAL;
}
user_recover_from_dlm_error(lockres);
goto bail;
}
mlog(0, "lock %s, successfull return from dlmlock\n",
lockres->l_name);
user_wait_on_busy_lock(lockres);
goto again;
}
user_dlm_inc_holders(lockres, level);
spin_unlock(&lockres->l_lock);
mlog(0, "lockres %s: Got %s lock!\n", lockres->l_name,
(level == LKM_EXMODE) ? "LKM_EXMODE" : "LKM_PRMODE");
status = 0;
bail:
return status;
}
static inline void user_dlm_dec_holders(struct user_lock_res *lockres,
int level)
{
switch(level) {
case LKM_EXMODE:
BUG_ON(!lockres->l_ex_holders);
lockres->l_ex_holders--;
break;
case LKM_PRMODE:
BUG_ON(!lockres->l_ro_holders);
lockres->l_ro_holders--;
break;
default:
BUG();
}
}
void user_dlm_cluster_unlock(struct user_lock_res *lockres,
int level)
{
if (level != LKM_EXMODE &&
level != LKM_PRMODE) {
mlog(ML_ERROR, "lockres %s: invalid request!\n", lockres->l_name);
return;
}
mlog(0, "lockres %s: dropping %s lock\n", lockres->l_name,
(level == LKM_EXMODE) ? "LKM_EXMODE" : "LKM_PRMODE");
spin_lock(&lockres->l_lock);
user_dlm_dec_holders(lockres, level);
__user_dlm_cond_queue_lockres(lockres);
spin_unlock(&lockres->l_lock);
}
void user_dlm_write_lvb(struct inode *inode,
const char *val,
unsigned int len)
{
struct user_lock_res *lockres = &DLMFS_I(inode)->ip_lockres;
char *lvb = lockres->l_lksb.lvb;
BUG_ON(len > DLM_LVB_LEN);
spin_lock(&lockres->l_lock);
BUG_ON(lockres->l_level < LKM_EXMODE);
memcpy(lvb, val, len);
spin_unlock(&lockres->l_lock);
}
void user_dlm_read_lvb(struct inode *inode,
char *val,
unsigned int len)
{
struct user_lock_res *lockres = &DLMFS_I(inode)->ip_lockres;
char *lvb = lockres->l_lksb.lvb;
BUG_ON(len > DLM_LVB_LEN);
spin_lock(&lockres->l_lock);
BUG_ON(lockres->l_level < LKM_PRMODE);
memcpy(val, lvb, len);
spin_unlock(&lockres->l_lock);
}
void user_dlm_lock_res_init(struct user_lock_res *lockres,
struct dentry *dentry)
{
memset(lockres, 0, sizeof(*lockres));
spin_lock_init(&lockres->l_lock);
init_waitqueue_head(&lockres->l_event);
lockres->l_level = LKM_IVMODE;
lockres->l_requested = LKM_IVMODE;
lockres->l_blocking = LKM_IVMODE;
/* should have been checked before getting here. */
BUG_ON(dentry->d_name.len >= USER_DLM_LOCK_ID_MAX_LEN);
memcpy(lockres->l_name,
dentry->d_name.name,
dentry->d_name.len);
}
int user_dlm_destroy_lock(struct user_lock_res *lockres)
{
int status = -EBUSY;
struct dlm_ctxt *dlm = dlm_ctxt_from_user_lockres(lockres);
mlog(0, "asked to destroy %s\n", lockres->l_name);
spin_lock(&lockres->l_lock);
while (lockres->l_flags & USER_LOCK_BUSY) {
spin_unlock(&lockres->l_lock);
mlog(0, "lock %s is busy\n", lockres->l_name);
user_wait_on_busy_lock(lockres);
spin_lock(&lockres->l_lock);
}
if (lockres->l_ro_holders || lockres->l_ex_holders) {
spin_unlock(&lockres->l_lock);
mlog(0, "lock %s has holders\n", lockres->l_name);
goto bail;
}
status = 0;
if (!(lockres->l_flags & USER_LOCK_ATTACHED)) {
spin_unlock(&lockres->l_lock);
mlog(0, "lock %s is not attached\n", lockres->l_name);
goto bail;
}
lockres->l_flags &= ~USER_LOCK_ATTACHED;
lockres->l_flags |= USER_LOCK_BUSY;
lockres->l_flags |= USER_LOCK_IN_TEARDOWN;
spin_unlock(&lockres->l_lock);
mlog(0, "unlocking lockres %s\n", lockres->l_name);
status = dlmunlock(dlm,
&lockres->l_lksb,
LKM_VALBLK,
user_unlock_ast,
lockres);
if (status != DLM_NORMAL) {
user_log_dlm_error("dlmunlock", status, lockres);
status = -EINVAL;
goto bail;
}
user_wait_on_busy_lock(lockres);
status = 0;
bail:
return status;
}
struct dlm_ctxt *user_dlm_register_context(struct qstr *name)
{
struct dlm_ctxt *dlm;
u32 dlm_key;
char *domain;
domain = kmalloc(name->len + 1, GFP_KERNEL);
if (!domain) {
mlog_errno(-ENOMEM);
return ERR_PTR(-ENOMEM);
}
dlm_key = crc32_le(0, name->name, name->len);
snprintf(domain, name->len + 1, "%.*s", name->len, name->name);
dlm = dlm_register_domain(domain, dlm_key);
if (IS_ERR(dlm))
mlog_errno(PTR_ERR(dlm));
kfree(domain);
return dlm;
}
void user_dlm_unregister_context(struct dlm_ctxt *dlm)
{
dlm_unregister_domain(dlm);
}

111
fs/ocfs2/dlm/userdlm.h Normal file
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/* -*- 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 */