linux/fs/fscache/main.c
David Howells 3d7a641e54 SLOW_WORK: Wait for outstanding work items belonging to a module to clear
Wait for outstanding slow work items belonging to a module to clear when
unregistering that module as a user of the facility.  This prevents the put_ref
code of a work item from being taken away before it returns.

Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:10:23 +00:00

125 lines
2.9 KiB
C

/* General filesystem local caching manager
*
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* 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.
*/
#define FSCACHE_DEBUG_LEVEL CACHE
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/completion.h>
#include <linux/slab.h>
#include "internal.h"
MODULE_DESCRIPTION("FS Cache Manager");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
unsigned fscache_defer_lookup = 1;
module_param_named(defer_lookup, fscache_defer_lookup, uint,
S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(fscache_defer_lookup,
"Defer cookie lookup to background thread");
unsigned fscache_defer_create = 1;
module_param_named(defer_create, fscache_defer_create, uint,
S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(fscache_defer_create,
"Defer cookie creation to background thread");
unsigned fscache_debug;
module_param_named(debug, fscache_debug, uint,
S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(fscache_debug,
"FS-Cache debugging mask");
struct kobject *fscache_root;
/*
* initialise the fs caching module
*/
static int __init fscache_init(void)
{
int ret;
ret = slow_work_register_user(THIS_MODULE);
if (ret < 0)
goto error_slow_work;
ret = fscache_proc_init();
if (ret < 0)
goto error_proc;
fscache_cookie_jar = kmem_cache_create("fscache_cookie_jar",
sizeof(struct fscache_cookie),
0,
0,
fscache_cookie_init_once);
if (!fscache_cookie_jar) {
printk(KERN_NOTICE
"FS-Cache: Failed to allocate a cookie jar\n");
ret = -ENOMEM;
goto error_cookie_jar;
}
fscache_root = kobject_create_and_add("fscache", kernel_kobj);
if (!fscache_root)
goto error_kobj;
printk(KERN_NOTICE "FS-Cache: Loaded\n");
return 0;
error_kobj:
kmem_cache_destroy(fscache_cookie_jar);
error_cookie_jar:
fscache_proc_cleanup();
error_proc:
slow_work_unregister_user(THIS_MODULE);
error_slow_work:
return ret;
}
fs_initcall(fscache_init);
/*
* clean up on module removal
*/
static void __exit fscache_exit(void)
{
_enter("");
kobject_put(fscache_root);
kmem_cache_destroy(fscache_cookie_jar);
fscache_proc_cleanup();
slow_work_unregister_user(THIS_MODULE);
printk(KERN_NOTICE "FS-Cache: Unloaded\n");
}
module_exit(fscache_exit);
/*
* wait_on_bit() sleep function for uninterruptible waiting
*/
int fscache_wait_bit(void *flags)
{
schedule();
return 0;
}
EXPORT_SYMBOL(fscache_wait_bit);
/*
* wait_on_bit() sleep function for interruptible waiting
*/
int fscache_wait_bit_interruptible(void *flags)
{
schedule();
return signal_pending(current);
}
EXPORT_SYMBOL(fscache_wait_bit_interruptible);