linux/fs/cachefiles/main.c
David Howells a18feb5576 fscache: Add tracepoints
Add some tracepoints to fscache:

 (*) fscache_cookie - Tracks a cookie's usage count.

 (*) fscache_netfs - Logs registration of a network filesystem, including
     the pointer to the cookie allocated.

 (*) fscache_acquire - Logs cookie acquisition.

 (*) fscache_relinquish - Logs cookie relinquishment.

 (*) fscache_enable - Logs enablement of a cookie.

 (*) fscache_disable - Logs disablement of a cookie.

 (*) fscache_osm - Tracks execution of states in the object state machine.

and cachefiles:

 (*) cachefiles_ref - Tracks a cachefiles object's usage count.

 (*) cachefiles_lookup - Logs result of lookup_one_len().

 (*) cachefiles_mkdir - Logs result of vfs_mkdir().

 (*) cachefiles_create - Logs result of vfs_create().

 (*) cachefiles_unlink - Logs calls to vfs_unlink().

 (*) cachefiles_rename - Logs calls to vfs_rename().

 (*) cachefiles_mark_active - Logs an object becoming active.

 (*) cachefiles_wait_active - Logs a wait for an old object to be
     destroyed.

 (*) cachefiles_mark_inactive - Logs an object becoming inactive.

 (*) cachefiles_mark_buried - Logs the burial of an object.

Signed-off-by: David Howells <dhowells@redhat.com>
2018-04-04 13:41:27 +01:00

107 lines
2.4 KiB
C

/* Network filesystem caching backend to use cache files on a premounted
* filesystem
*
* Copyright (C) 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 Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/completion.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/statfs.h>
#include <linux/sysctl.h>
#include <linux/miscdevice.h>
#define CREATE_TRACE_POINTS
#include "internal.h"
unsigned cachefiles_debug;
module_param_named(debug, cachefiles_debug, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask");
MODULE_DESCRIPTION("Mounted-filesystem based cache");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
struct kmem_cache *cachefiles_object_jar;
static struct miscdevice cachefiles_dev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "cachefiles",
.fops = &cachefiles_daemon_fops,
};
static void cachefiles_object_init_once(void *_object)
{
struct cachefiles_object *object = _object;
memset(object, 0, sizeof(*object));
spin_lock_init(&object->work_lock);
}
/*
* initialise the fs caching module
*/
static int __init cachefiles_init(void)
{
int ret;
ret = misc_register(&cachefiles_dev);
if (ret < 0)
goto error_dev;
/* create an object jar */
ret = -ENOMEM;
cachefiles_object_jar =
kmem_cache_create("cachefiles_object_jar",
sizeof(struct cachefiles_object),
0,
SLAB_HWCACHE_ALIGN,
cachefiles_object_init_once);
if (!cachefiles_object_jar) {
pr_notice("Failed to allocate an object jar\n");
goto error_object_jar;
}
ret = cachefiles_proc_init();
if (ret < 0)
goto error_proc;
pr_info("Loaded\n");
return 0;
error_proc:
kmem_cache_destroy(cachefiles_object_jar);
error_object_jar:
misc_deregister(&cachefiles_dev);
error_dev:
pr_err("failed to register: %d\n", ret);
return ret;
}
fs_initcall(cachefiles_init);
/*
* clean up on module removal
*/
static void __exit cachefiles_exit(void)
{
pr_info("Unloading\n");
cachefiles_proc_cleanup();
kmem_cache_destroy(cachefiles_object_jar);
misc_deregister(&cachefiles_dev);
}
module_exit(cachefiles_exit);