linux/fs/fscache/main.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

193 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* General filesystem local caching manager
*
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#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 <linux/seq_file.h>
#define CREATE_TRACE_POINTS
#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;
struct workqueue_struct *fscache_object_wq;
struct workqueue_struct *fscache_op_wq;
DEFINE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
/* these values serve as lower bounds, will be adjusted in fscache_init() */
static unsigned fscache_object_max_active = 4;
static unsigned fscache_op_max_active = 2;
#ifdef CONFIG_SYSCTL
static struct ctl_table_header *fscache_sysctl_header;
static int fscache_max_active_sysctl(struct ctl_table *table, int write,
void __user *buffer,
size_t *lenp, loff_t *ppos)
{
struct workqueue_struct **wqp = table->extra1;
unsigned int *datap = table->data;
int ret;
ret = proc_dointvec(table, write, buffer, lenp, ppos);
if (ret == 0)
workqueue_set_max_active(*wqp, *datap);
return ret;
}
static struct ctl_table fscache_sysctls[] = {
{
.procname = "object_max_active",
.data = &fscache_object_max_active,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = fscache_max_active_sysctl,
.extra1 = &fscache_object_wq,
},
{
.procname = "operation_max_active",
.data = &fscache_op_max_active,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = fscache_max_active_sysctl,
.extra1 = &fscache_op_wq,
},
{}
};
static struct ctl_table fscache_sysctls_root[] = {
{
.procname = "fscache",
.mode = 0555,
.child = fscache_sysctls,
},
{}
};
#endif
/*
* initialise the fs caching module
*/
static int __init fscache_init(void)
{
unsigned int nr_cpus = num_possible_cpus();
unsigned int cpu;
int ret;
fscache_object_max_active =
clamp_val(nr_cpus,
fscache_object_max_active, WQ_UNBOUND_MAX_ACTIVE);
ret = -ENOMEM;
fscache_object_wq = alloc_workqueue("fscache_object", WQ_UNBOUND,
fscache_object_max_active);
if (!fscache_object_wq)
goto error_object_wq;
fscache_op_max_active =
clamp_val(fscache_object_max_active / 2,
fscache_op_max_active, WQ_UNBOUND_MAX_ACTIVE);
ret = -ENOMEM;
fscache_op_wq = alloc_workqueue("fscache_operation", WQ_UNBOUND,
fscache_op_max_active);
if (!fscache_op_wq)
goto error_op_wq;
for_each_possible_cpu(cpu)
init_waitqueue_head(&per_cpu(fscache_object_cong_wait, cpu));
ret = fscache_proc_init();
if (ret < 0)
goto error_proc;
#ifdef CONFIG_SYSCTL
ret = -ENOMEM;
fscache_sysctl_header = register_sysctl_table(fscache_sysctls_root);
if (!fscache_sysctl_header)
goto error_sysctl;
#endif
fscache_cookie_jar = kmem_cache_create("fscache_cookie_jar",
sizeof(struct fscache_cookie),
0, 0, NULL);
if (!fscache_cookie_jar) {
pr_notice("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;
pr_notice("Loaded\n");
return 0;
error_kobj:
kmem_cache_destroy(fscache_cookie_jar);
error_cookie_jar:
#ifdef CONFIG_SYSCTL
unregister_sysctl_table(fscache_sysctl_header);
error_sysctl:
#endif
fscache_proc_cleanup();
error_proc:
destroy_workqueue(fscache_op_wq);
error_op_wq:
destroy_workqueue(fscache_object_wq);
error_object_wq:
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);
#ifdef CONFIG_SYSCTL
unregister_sysctl_table(fscache_sysctl_header);
#endif
fscache_proc_cleanup();
destroy_workqueue(fscache_op_wq);
destroy_workqueue(fscache_object_wq);
pr_notice("Unloaded\n");
}
module_exit(fscache_exit);