Commit 06b3db1b authored by David Howells's avatar David Howells
Browse files

FS-Cache: Add main configuration option, module entry points and debugging 



Add the main configuration option, allowing FS-Cache to be selected; the
module entry and exit functions and the debugging stuff used by these patches.

The two configuration options added are:

	CONFIG_FSCACHE
	CONFIG_FSCACHE_DEBUG

The first enables the facility, and the second makes the debugging statements
enableable through the "debug" module parameter.  The value of this parameter
is a bitmask as described in:

	Documentation/filesystems/caching/fscache.txt

The module can be loaded at this point, but all it will do at this point in
the patch series is to start up the slow work facility and shut it down again.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarSteve Dickson <steved@redhat.com>
Acked-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Tested-by: default avatarDaire Byrne <Daire.Byrne@framestore.com>
parent 0dfc41d1

fs/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -66,6 +66,12 @@ config GENERIC_ACL 
	bool

	select FS_POSIX_ACL



menu "Caches"



source "fs/fscache/Kconfig"



endmenu



if BLOCK

menu "CD-ROM/DVD Filesystems"

fs/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ obj-$(CONFIG_PROFILING) += dcookies.o 
obj-$(CONFIG_DLM)		+= dlm/

 

# Do not add any filesystems before this line

obj-$(CONFIG_FSCACHE)		+= fscache/

obj-$(CONFIG_REISERFS_FS)	+= reiserfs/

obj-$(CONFIG_EXT3_FS)		+= ext3/ # Before ext2 so root fs can be ext3

obj-$(CONFIG_EXT2_FS)		+= ext2/

fs/fscache/Kconfig

0 → 100644
+22 −0
Original line number Diff line number Diff line 


config FSCACHE

	tristate "General filesystem local caching manager"

	depends on EXPERIMENTAL

	select SLOW_WORK

	help

	  This option enables a generic filesystem caching manager that can be

	  used by various network and other filesystems to cache data locally.

	  Different sorts of caches can be plugged in, depending on the

	  resources available.



	  See Documentation/filesystems/caching/fscache.txt for more information.



config FSCACHE_DEBUG

	bool "Debug FS-Cache"

	depends on FSCACHE

	help

	  This permits debugging to be dynamically enabled in the local caching

	  management module.  If this is set, the debugging output may be

	  enabled by setting bits in /sys/modules/fscache/parameter/debug.



	  See Documentation/filesystems/caching/fscache.txt for more information.

fs/fscache/Makefile

0 → 100644
+8 −0
Original line number Diff line number Diff line 
#

# Makefile for general filesystem caching code

#



fscache-y := \

	main.o



obj-$(CONFIG_FSCACHE) := fscache.o

fs/fscache/internal.h

0 → 100644
+165 −0
Original line number Diff line number Diff line 
/* Internal definitions for FS-Cache

 *

 * 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.

 */



/*

 * Lock order, in the order in which multiple locks should be obtained:

 * - fscache_addremove_sem

 * - cookie->lock

 * - cookie->parent->lock

 * - cache->object_list_lock

 * - object->lock

 * - object->parent->lock

 * - fscache_thread_lock

 *

 */



#include <linux/fscache-cache.h>

#include <linux/sched.h>



#define FSCACHE_MIN_THREADS	4

#define FSCACHE_MAX_THREADS	32



/*

 * fsc-main.c

 */

extern unsigned fscache_defer_lookup;

extern unsigned fscache_defer_create;

extern unsigned fscache_debug;

extern struct kobject *fscache_root;



/*****************************************************************************/

/*

 * debug tracing

 */

#define dbgprintk(FMT, ...) \

	printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)



/* make sure we maintain the format strings, even when debugging is disabled */

static inline __attribute__((format(printf, 1, 2)))

void _dbprintk(const char *fmt, ...)

{

}



#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)

#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)

#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)



#define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)



#ifdef __KDEBUG

#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)

#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)

#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)



#elif defined(CONFIG_FSCACHE_DEBUG)

#define _enter(FMT, ...)			\

do {						\

	if (__do_kdebug(ENTER))			\

		kenter(FMT, ##__VA_ARGS__);	\

} while (0)



#define _leave(FMT, ...)			\

do {						\

	if (__do_kdebug(LEAVE))			\

		kleave(FMT, ##__VA_ARGS__);	\

} while (0)



#define _debug(FMT, ...)			\

do {						\

	if (__do_kdebug(DEBUG))			\

		kdebug(FMT, ##__VA_ARGS__);	\

} while (0)



#else

#define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)

#define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)

#define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)

#endif



/*

 * determine whether a particular optional debugging point should be logged

 * - we need to go through three steps to persuade cpp to correctly join the

 *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix

 */

#define ____do_kdebug(LEVEL, POINT) \

	unlikely((fscache_debug & \

		  (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))

#define ___do_kdebug(LEVEL, POINT) \

	____do_kdebug(LEVEL, POINT)

#define __do_kdebug(POINT) \

	___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)



#define FSCACHE_DEBUG_CACHE	0

#define FSCACHE_DEBUG_COOKIE	1

#define FSCACHE_DEBUG_PAGE	2

#define FSCACHE_DEBUG_OPERATION	3



#define FSCACHE_POINT_ENTER	1

#define FSCACHE_POINT_LEAVE	2

#define FSCACHE_POINT_DEBUG	4



#ifndef FSCACHE_DEBUG_LEVEL

#define FSCACHE_DEBUG_LEVEL CACHE

#endif



/*

 * assertions

 */

#if 1 /* defined(__KDEBUGALL) */



#define ASSERT(X)							\

do {									\

	if (unlikely(!(X))) {						\

		printk(KERN_ERR "\n");					\

		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\

		BUG();							\

	}								\

} while (0)



#define ASSERTCMP(X, OP, Y)						\

do {									\

	if (unlikely(!((X) OP (Y)))) {					\

		printk(KERN_ERR "\n");					\

		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\

		printk(KERN_ERR "%lx " #OP " %lx is false\n",		\

		       (unsigned long)(X), (unsigned long)(Y));		\

		BUG();							\

	}								\

} while (0)



#define ASSERTIF(C, X)							\

do {									\

	if (unlikely((C) && !(X))) {					\

		printk(KERN_ERR "\n");					\

		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\

		BUG();							\

	}								\

} while (0)



#define ASSERTIFCMP(C, X, OP, Y)					\

do {									\

	if (unlikely((C) && !((X) OP (Y)))) {				\

		printk(KERN_ERR "\n");					\

		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\

		printk(KERN_ERR "%lx " #OP " %lx is false\n",		\

		       (unsigned long)(X), (unsigned long)(Y));		\

		BUG();							\

	}								\

} while (0)



#else



#define ASSERT(X)			do {} while (0)

#define ASSERTCMP(X, OP, Y)		do {} while (0)

#define ASSERTIF(C, X)			do {} while (0)

#define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)



#endif /* assert or not */

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