linux/fs/fscache/proc.c
David Howells 7394daa8c6 FS-Cache: Add use of /proc and presentation of statistics
Make FS-Cache create its /proc interface and present various statistical
information through it.  Also provide the functions for updating this
information.

These features are enabled by:

	CONFIG_FSCACHE_PROC
	CONFIG_FSCACHE_STATS
	CONFIG_FSCACHE_HISTOGRAM

The /proc directory for FS-Cache is also exported so that caching modules can
add their own statistics there too.

The FS-Cache module is loadable at this point, and the statistics files can be
examined by userspace:

	cat /proc/fs/fscache/stats
	cat /proc/fs/fscache/histogram

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03 16:42:37 +01:00

68 lines
1.5 KiB
C

/* FS-Cache statistics viewing interface
*
* 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 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 OPERATION
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "internal.h"
/*
* initialise the /proc/fs/fscache/ directory
*/
int __init fscache_proc_init(void)
{
_enter("");
if (!proc_mkdir("fs/fscache", NULL))
goto error_dir;
#ifdef CONFIG_FSCACHE_STATS
if (!proc_create("fs/fscache/stats", S_IFREG | 0444, NULL,
&fscache_stats_fops))
goto error_stats;
#endif
#ifdef CONFIG_FSCACHE_HISTOGRAM
if (!proc_create("fs/fscache/histogram", S_IFREG | 0444, NULL,
&fscache_histogram_fops))
goto error_histogram;
#endif
_leave(" = 0");
return 0;
#ifdef CONFIG_FSCACHE_HISTOGRAM
error_histogram:
#endif
#ifdef CONFIG_FSCACHE_STATS
remove_proc_entry("fs/fscache/stats", NULL);
error_stats:
#endif
remove_proc_entry("fs/fscache", NULL);
error_dir:
_leave(" = -ENOMEM");
return -ENOMEM;
}
/*
* clean up the /proc/fs/fscache/ directory
*/
void fscache_proc_cleanup(void)
{
#ifdef CONFIG_FSCACHE_HISTOGRAM
remove_proc_entry("fs/fscache/histogram", NULL);
#endif
#ifdef CONFIG_FSCACHE_STATS
remove_proc_entry("fs/fscache/stats", NULL);
#endif
remove_proc_entry("fs/fscache", NULL);
}