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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License version 2.
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/lm_interface.h>
struct nolock_lockspace {
unsigned int nl_lvb_size;
};
static const struct lm_lockops nolock_ops;
static int nolock_mount(char *table_name, char *host_data,
lm_callback_t cb, void *cb_data,
unsigned int min_lvb_size, int flags,
struct lm_lockstruct *lockstruct,
struct kobject *fskobj)
{
char *c;
unsigned int jid;
struct nolock_lockspace *nl;
c = strstr(host_data, "jid=");
if (!c)
jid = 0;
else {
c += 4;
sscanf(c, "%u", &jid);
}
nl = kzalloc(sizeof(struct nolock_lockspace), GFP_KERNEL);
if (!nl)
return -ENOMEM;
nl->nl_lvb_size = min_lvb_size;
lockstruct->ls_jid = jid;
lockstruct->ls_first = 1;
lockstruct->ls_lvb_size = min_lvb_size;
lockstruct->ls_lockspace = nl;
lockstruct->ls_ops = &nolock_ops;
lockstruct->ls_flags = LM_LSFLAG_LOCAL;
return 0;
}
static void nolock_others_may_mount(void *lockspace)
{
}
static void nolock_unmount(void *lockspace)
{
struct nolock_lockspace *nl = lockspace;
kfree(nl);
}
static void nolock_withdraw(void *lockspace)
{
}
/**
* nolock_get_lock - get a lm_lock_t given a descripton of the lock
* @lockspace: the lockspace the lock lives in
* @name: the name of the lock
* @lockp: return the lm_lock_t here
*
* Returns: 0 on success, -EXXX on failure
*/
static int nolock_get_lock(void *lockspace, struct lm_lockname *name,
void **lockp)
{
*lockp = lockspace;
return 0;
}
/**
* nolock_put_lock - get rid of a lock structure
* @lock: the lock to throw away
*
*/
static void nolock_put_lock(void *lock)
{
}
/**
* nolock_lock - acquire a lock
* @lock: the lock to manipulate
* @cur_state: the current state
* @req_state: the requested state
* @flags: modifier flags
*
* Returns: A bitmap of LM_OUT_*
*/
static unsigned int nolock_lock(void *lock, unsigned int cur_state,
unsigned int req_state, unsigned int flags)
{
if (req_state == LM_ST_UNLOCKED)
return 0;
return req_state | LM_OUT_CACHEABLE;
}
/**
* nolock_unlock - unlock a lock
* @lock: the lock to manipulate
* @cur_state: the current state
*
* Returns: 0
*/
static unsigned int nolock_unlock(void *lock, unsigned int cur_state)
{
return 0;
}
static void nolock_cancel(void *lock)
{
}
/**
* nolock_hold_lvb - hold on to a lock value block
* @lock: the lock the LVB is associated with
* @lvbp: return the lm_lvb_t here
*
* Returns: 0 on success, -EXXX on failure
*/
static int nolock_hold_lvb(void *lock, char **lvbp)
{
struct nolock_lockspace *nl = lock;
int error = 0;
*lvbp = kzalloc(nl->nl_lvb_size, GFP_NOFS);
if (!*lvbp)
error = -ENOMEM;
return error;
}
/**
* nolock_unhold_lvb - release a LVB
* @lock: the lock the LVB is associated with
* @lvb: the lock value block
*
*/
static void nolock_unhold_lvb(void *lock, char *lvb)
{
kfree(lvb);
}
static int nolock_plock_get(void *lockspace, struct lm_lockname *name,
struct file *file, struct file_lock *fl)
{
posix_test_lock(file, fl);
return 0;
}
static int nolock_plock(void *lockspace, struct lm_lockname *name,
struct file *file, int cmd, struct file_lock *fl)
{
int error;
error = posix_lock_file_wait(file, fl);
return error;
}
static int nolock_punlock(void *lockspace, struct lm_lockname *name,
struct file *file, struct file_lock *fl)
{
int error;
error = posix_lock_file_wait(file, fl);
return error;
}
static void nolock_recovery_done(void *lockspace, unsigned int jid,
unsigned int message)
{
}
static const struct lm_lockops nolock_ops = {
.lm_proto_name = "lock_nolock",
.lm_mount = nolock_mount,
.lm_others_may_mount = nolock_others_may_mount,
.lm_unmount = nolock_unmount,
.lm_withdraw = nolock_withdraw,
.lm_get_lock = nolock_get_lock,
.lm_put_lock = nolock_put_lock,
.lm_lock = nolock_lock,
.lm_unlock = nolock_unlock,
.lm_cancel = nolock_cancel,
.lm_hold_lvb = nolock_hold_lvb,
.lm_unhold_lvb = nolock_unhold_lvb,
.lm_plock_get = nolock_plock_get,
.lm_plock = nolock_plock,
.lm_punlock = nolock_punlock,
.lm_recovery_done = nolock_recovery_done,
.lm_owner = THIS_MODULE,
};
static int __init init_nolock(void)
{
int error;
error = gfs2_register_lockproto(&nolock_ops);
if (error) {
printk(KERN_WARNING
"lock_nolock: can't register protocol: %d\n", error);
return error;
}
printk(KERN_INFO
"Lock_Nolock (built %s %s) installed\n", __DATE__, __TIME__);
return 0;
}
static void __exit exit_nolock(void)
{
gfs2_unregister_lockproto(&nolock_ops);
}
module_init(init_nolock);
module_exit(exit_nolock);
MODULE_DESCRIPTION("GFS Nolock Locking Module");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
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