/******************************************************************************
*******************************************************************************
**
** 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 v.2.
**
*******************************************************************************
******************************************************************************/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/smp_lock.h>
#include "../../lm_interface.h"
struct nolock_lockspace {
unsigned int nl_lvb_size;
};
struct lm_lockops nolock_ops;
/**
* nolock_mount - mount a nolock lockspace
* @table_name: the name of the space to mount
* @host_data: host specific data
* @cb: the callback
* @fsdata:
* @min_lvb_size:
* @flags:
* @lockstruct: the structure of crap to fill in
*
* Returns: 0 on success, -EXXX on failure
*/
static int nolock_mount(char *table_name, char *host_data,
lm_callback_t cb, lm_fsdata_t *fsdata,
unsigned int min_lvb_size, int flags,
struct lm_lockstruct *lockstruct)
{
char *c;
unsigned int jid;
struct nolock_lockspace *nl;
/* If there is a "jid=" in the hostdata, return that jid.
Otherwise, return zero. */
c = strstr(host_data, "jid=");
if (!c)
jid = 0;
else {
c += 4;
sscanf(c, "%u", &jid);
}
nl = kmalloc(sizeof(struct nolock_lockspace), GFP_KERNEL);
if (!nl)
return -ENOMEM;
memset(nl, 0, sizeof(struct nolock_lockspace));
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 = (lm_lockspace_t *)nl;
lockstruct->ls_ops = &nolock_ops;
lockstruct->ls_flags = LM_LSFLAG_LOCAL;
return 0;
}
/**
* nolock_others_may_mount - unmount a lock space
* @lockspace: the lockspace to unmount
*
*/
static void nolock_others_may_mount(lm_lockspace_t *lockspace)
{
}
/**
* nolock_unmount - unmount a lock space
* @lockspace: the lockspace to unmount
*
*/
static void nolock_unmount(lm_lockspace_t *lockspace)
{
struct nolock_lockspace *nl = (struct nolock_lockspace *)lockspace;
kfree(nl);
}
/**
* nolock_withdraw - withdraw from a lock space
* @lockspace: the lockspace
*
*/
static void nolock_withdraw(lm_lockspace_t *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(lm_lockspace_t *lockspace, struct lm_lockname *name,
lm_lock_t **lockp)
{
*lockp = (lm_lock_t *)lockspace;
return 0;
}
/**
* nolock_put_lock - get rid of a lock structure
* @lock: the lock to throw away
*
*/
static void nolock_put_lock(lm_lock_t *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(lm_lock_t *lock, unsigned int cur_state,
unsigned int req_state, unsigned int flags)
{
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(lm_lock_t *lock, unsigned int cur_state)
{
return 0;
}
/**
* nolock_cancel - cancel a request on a lock
* @lock: the lock to cancel request for
*
*/
static void nolock_cancel(lm_lock_t *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(lm_lock_t *lock, char **lvbp)
{
struct nolock_lockspace *nl = (struct nolock_lockspace *)lock;
int error = 0;
*lvbp = kmalloc(nl->nl_lvb_size, GFP_KERNEL);
if (*lvbp)
memset(*lvbp, 0, nl->nl_lvb_size);
else
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(lm_lock_t *lock, char *lvb)
{
kfree(lvb);
}
/**
* nolock_sync_lvb - sync out the value of a lvb
* @lock: the lock the LVB is associated with
* @lvb: the lock value block
*
*/
static void nolock_sync_lvb(lm_lock_t *lock, char *lvb)
{
}
/**
* nolock_plock_get -
* @lockspace: the lockspace
* @name:
* @file:
* @fl:
*
* Returns: errno
*/
static int nolock_plock_get(lm_lockspace_t *lockspace, struct lm_lockname *name,
struct file *file, struct file_lock *fl)
{
struct file_lock *tmp;
lock_kernel();
tmp = posix_test_lock(file, fl);
fl->fl_type = F_UNLCK;
if (tmp)
memcpy(fl, tmp, sizeof(struct file_lock));
unlock_kernel();
return 0;
}
/**
* nolock_plock -
* @lockspace: the lockspace
* @name:
* @file:
* @cmd:
* @fl:
*
* Returns: errno
*/
static int nolock_plock(lm_lockspace_t *lockspace, struct lm_lockname *name,
struct file *file, int cmd, struct file_lock *fl)
{
int error;
lock_kernel();
error = posix_lock_file_wait(file, fl);
unlock_kernel();
return error;
}
/**
* nolock_punlock -
* @lockspace: the lockspace
* @name:
* @file:
* @fl:
*
* Returns: errno
*/
static int nolock_punlock(lm_lockspace_t *lockspace, struct lm_lockname *name,
struct file *file, struct file_lock *fl)
{
int error;
lock_kernel();
error = posix_lock_file_wait(file, fl);
unlock_kernel();
return error;
}
/**
* nolock_recovery_done - reset the expired locks for a given jid
* @lockspace: the lockspace
* @jid: the jid
*
*/
static void nolock_recovery_done(lm_lockspace_t *lockspace, unsigned int jid,
unsigned int message)
{
}
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_sync_lvb = nolock_sync_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,
};
/**
* init_nolock - Initialize the nolock module
*
* Returns: 0 on success, -EXXX on failure
*/
int __init init_nolock(void)
{
int error;
error = lm_register_proto(&nolock_ops);
if (error) {
printk("lock_nolock: can't register protocol: %d\n", error);
return error;
}
printk("Lock_Nolock (built %s %s) installed\n", __DATE__, __TIME__);
return 0;
}
/**
* exit_nolock - cleanup the nolock module
*
*/
void __exit exit_nolock(void)
{
lm_unregister_proto(&nolock_ops);
}
module_init(init_nolock);
module_exit(exit_nolock);
MODULE_DESCRIPTION("GFS Nolock Locking Module");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
