147 lines
3.3 KiB
C
147 lines
3.3 KiB
C
/*
|
|
* net/9p/util.c
|
|
*
|
|
* This file contains some helper functions
|
|
*
|
|
* Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
|
|
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
|
|
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2
|
|
* as published by the Free Software Foundation.
|
|
*
|
|
* 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:
|
|
* Free Software Foundation
|
|
* 51 Franklin Street, Fifth Floor
|
|
* Boston, MA 02111-1301 USA
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/parser.h>
|
|
#include <linux/idr.h>
|
|
#include <linux/slab.h>
|
|
#include <net/9p/9p.h>
|
|
|
|
/**
|
|
* struct p9_idpool - per-connection accounting for tag idpool
|
|
* @lock: protects the pool
|
|
* @pool: idr to allocate tag id from
|
|
*
|
|
*/
|
|
|
|
struct p9_idpool {
|
|
spinlock_t lock;
|
|
struct idr pool;
|
|
};
|
|
|
|
/**
|
|
* p9_idpool_create - create a new per-connection id pool
|
|
*
|
|
*/
|
|
|
|
struct p9_idpool *p9_idpool_create(void)
|
|
{
|
|
struct p9_idpool *p;
|
|
|
|
p = kmalloc(sizeof(struct p9_idpool), GFP_KERNEL);
|
|
if (!p)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
spin_lock_init(&p->lock);
|
|
idr_init(&p->pool);
|
|
|
|
return p;
|
|
}
|
|
EXPORT_SYMBOL(p9_idpool_create);
|
|
|
|
/**
|
|
* p9_idpool_destroy - create a new per-connection id pool
|
|
* @p: idpool to destory
|
|
*/
|
|
|
|
void p9_idpool_destroy(struct p9_idpool *p)
|
|
{
|
|
idr_destroy(&p->pool);
|
|
kfree(p);
|
|
}
|
|
EXPORT_SYMBOL(p9_idpool_destroy);
|
|
|
|
/**
|
|
* p9_idpool_get - allocate numeric id from pool
|
|
* @p: pool to allocate from
|
|
*
|
|
* Bugs: This seems to be an awful generic function, should it be in idr.c with
|
|
* the lock included in struct idr?
|
|
*/
|
|
|
|
int p9_idpool_get(struct p9_idpool *p)
|
|
{
|
|
int i = 0;
|
|
int error;
|
|
unsigned long flags;
|
|
|
|
retry:
|
|
if (idr_pre_get(&p->pool, GFP_KERNEL) == 0)
|
|
return 0;
|
|
|
|
spin_lock_irqsave(&p->lock, flags);
|
|
|
|
/* no need to store exactly p, we just need something non-null */
|
|
error = idr_get_new(&p->pool, p, &i);
|
|
spin_unlock_irqrestore(&p->lock, flags);
|
|
|
|
if (error == -EAGAIN)
|
|
goto retry;
|
|
else if (error)
|
|
return -1;
|
|
|
|
P9_DPRINTK(P9_DEBUG_MUX, " id %d pool %p\n", i, p);
|
|
return i;
|
|
}
|
|
EXPORT_SYMBOL(p9_idpool_get);
|
|
|
|
/**
|
|
* p9_idpool_put - release numeric id from pool
|
|
* @id: numeric id which is being released
|
|
* @p: pool to release id into
|
|
*
|
|
* Bugs: This seems to be an awful generic function, should it be in idr.c with
|
|
* the lock included in struct idr?
|
|
*/
|
|
|
|
void p9_idpool_put(int id, struct p9_idpool *p)
|
|
{
|
|
unsigned long flags;
|
|
|
|
P9_DPRINTK(P9_DEBUG_MUX, " id %d pool %p\n", id, p);
|
|
|
|
spin_lock_irqsave(&p->lock, flags);
|
|
idr_remove(&p->pool, id);
|
|
spin_unlock_irqrestore(&p->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(p9_idpool_put);
|
|
|
|
/**
|
|
* p9_idpool_check - check if the specified id is available
|
|
* @id: id to check
|
|
* @p: pool to check
|
|
*/
|
|
|
|
int p9_idpool_check(int id, struct p9_idpool *p)
|
|
{
|
|
return idr_find(&p->pool, id) != NULL;
|
|
}
|
|
EXPORT_SYMBOL(p9_idpool_check);
|
|
|