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: 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>

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: 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>
David Howells
1 parent 0dfc41d1ef
Showing 6 changed files with 277 additions and 0 deletions Side-by-side Diff
fs/Kconfig
fs/Makefile
fs/fscache/Kconfig
fs/fscache/Makefile
fs/fscache/internal.h
fs/fscache/main.c
@@ -66,6 +66,12 @@
 	bool
 	select FS_POSIX_ACL
  
+menu "Caches"
+
+source "fs/fscache/Kconfig"
+
+endmenu
+
 if BLOCK
 menu "CD-ROM/DVD Filesystems"
  
@@ -63,6 +63,7 @@
 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/
+
+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.
+#
+# Makefile for general filesystem caching code
+#
+
+fscache-y := \
+	main.o
+
+obj-$(CONFIG_FSCACHE) := fscache.o
+/* 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 */
+/* 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();
+	if (ret < 0)
+		goto error_slow_work;
+
+	printk(KERN_NOTICE "FS-Cache: Loaded\n");
+	return 0;
+
+error_slow_work:
+	return ret;
+}
+
+fs_initcall(fscache_init);
+
+/*
+ * clean up on module removal
+ */
+static void __exit fscache_exit(void)
+{
+	_enter("");
+
+	slow_work_unregister_user();
+	printk(KERN_NOTICE "FS-Cache: Unloaded\n");
+}
+
+module_exit(fscache_exit);
...	...	@@ -66,6 +66,12 @@
66	66	bool
67	67	select FS_POSIX_ACL
68	68
	69	+menu "Caches"
	70	+
	71	+source "fs/fscache/Kconfig"
	72	+
	73	+endmenu
	74	+
69	75	if BLOCK
70	76	menu "CD-ROM/DVD Filesystems"
71	77
...	...	@@ -63,6 +63,7 @@
63	63	obj-$(CONFIG_DLM) += dlm/
64	64
65	65	# Do not add any filesystems before this line
	66	+obj-$(CONFIG_FSCACHE) += fscache/
66	67	obj-$(CONFIG_REISERFS_FS) += reiserfs/
67	68	obj-$(CONFIG_EXT3_FS) += ext3/ # Before ext2 so root fs can be ext3
68	69	obj-$(CONFIG_EXT2_FS) += ext2/
	1	+
	2	+config FSCACHE
	3	+ tristate "General filesystem local caching manager"
	4	+ depends on EXPERIMENTAL
	5	+ select SLOW_WORK
	6	+ help
	7	+ This option enables a generic filesystem caching manager that can be
	8	+ used by various network and other filesystems to cache data locally.
	9	+ Different sorts of caches can be plugged in, depending on the
	10	+ resources available.
	11	+
	12	+ See Documentation/filesystems/caching/fscache.txt for more information.
	13	+
	14	+config FSCACHE_DEBUG
	15	+ bool "Debug FS-Cache"
	16	+ depends on FSCACHE
	17	+ help
	18	+ This permits debugging to be dynamically enabled in the local caching
	19	+ management module. If this is set, the debugging output may be
	20	+ enabled by setting bits in /sys/modules/fscache/parameter/debug.
	21	+
	22	+ See Documentation/filesystems/caching/fscache.txt for more information.
	1	+#
	2	+# Makefile for general filesystem caching code
	3	+#
	4	+
	5	+fscache-y := \
	6	+ main.o
	7	+
	8	+obj-$(CONFIG_FSCACHE) := fscache.o
	1	+/* Internal definitions for FS-Cache
	2	+ *
	3	+ * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
	4	+ * Written by David Howells (dhowells@redhat.com)
	5	+ *
	6	+ * This program is free software; you can redistribute it and/or
	7	+ * modify it under the terms of the GNU General Public License
	8	+ * as published by the Free Software Foundation; either version
	9	+ * 2 of the License, or (at your option) any later version.
	10	+ */
	11	+
	12	+/*
	13	+ * Lock order, in the order in which multiple locks should be obtained:
	14	+ * - fscache_addremove_sem
	15	+ * - cookie->lock
	16	+ * - cookie->parent->lock
	17	+ * - cache->object_list_lock
	18	+ * - object->lock
	19	+ * - object->parent->lock
	20	+ * - fscache_thread_lock
	21	+ *
	22	+ */
	23	+
	24	+#include <linux/fscache-cache.h>
	25	+#include <linux/sched.h>
	26	+
	27	+#define FSCACHE_MIN_THREADS 4
	28	+#define FSCACHE_MAX_THREADS 32
	29	+
	30	+/*
	31	+ * fsc-main.c
	32	+ */
	33	+extern unsigned fscache_defer_lookup;
	34	+extern unsigned fscache_defer_create;
	35	+extern unsigned fscache_debug;
	36	+extern struct kobject *fscache_root;
	37	+
	38	+/*****************************************************************************/
	39	+/*
	40	+ * debug tracing
	41	+ */
	42	+#define dbgprintk(FMT, ...) \
	43	+ printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
	44	+
	45	+/* make sure we maintain the format strings, even when debugging is disabled */
	46	+static inline __attribute__((format(printf, 1, 2)))
	47	+void _dbprintk(const char *fmt, ...)
	48	+{
	49	+}
	50	+
	51	+#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
	52	+#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
	53	+#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
	54	+
	55	+#define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
	56	+
	57	+#ifdef __KDEBUG
	58	+#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
	59	+#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
	60	+#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
	61	+
	62	+#elif defined(CONFIG_FSCACHE_DEBUG)
	63	+#define _enter(FMT, ...) \
	64	+do { \
	65	+ if (__do_kdebug(ENTER)) \
	66	+ kenter(FMT, ##__VA_ARGS__); \
	67	+} while (0)
	68	+
	69	+#define _leave(FMT, ...) \
	70	+do { \
	71	+ if (__do_kdebug(LEAVE)) \
	72	+ kleave(FMT, ##__VA_ARGS__); \
	73	+} while (0)
	74	+
	75	+#define _debug(FMT, ...) \
	76	+do { \
	77	+ if (__do_kdebug(DEBUG)) \
	78	+ kdebug(FMT, ##__VA_ARGS__); \
	79	+} while (0)
	80	+
	81	+#else
	82	+#define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
	83	+#define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
	84	+#define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
	85	+#endif
	86	+
	87	+/*
	88	+ * determine whether a particular optional debugging point should be logged
	89	+ * - we need to go through three steps to persuade cpp to correctly join the
	90	+ * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
	91	+ */
	92	+#define ____do_kdebug(LEVEL, POINT) \
	93	+ unlikely((fscache_debug & \
	94	+ (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
	95	+#define ___do_kdebug(LEVEL, POINT) \
	96	+ ____do_kdebug(LEVEL, POINT)
	97	+#define __do_kdebug(POINT) \
	98	+ ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
	99	+
	100	+#define FSCACHE_DEBUG_CACHE 0
	101	+#define FSCACHE_DEBUG_COOKIE 1
	102	+#define FSCACHE_DEBUG_PAGE 2
	103	+#define FSCACHE_DEBUG_OPERATION 3
	104	+
	105	+#define FSCACHE_POINT_ENTER 1
	106	+#define FSCACHE_POINT_LEAVE 2
	107	+#define FSCACHE_POINT_DEBUG 4
	108	+
	109	+#ifndef FSCACHE_DEBUG_LEVEL
	110	+#define FSCACHE_DEBUG_LEVEL CACHE
	111	+#endif
	112	+
	113	+/*
	114	+ * assertions
	115	+ */
	116	+#if 1 /* defined(__KDEBUGALL) */
	117	+
	118	+#define ASSERT(X) \
	119	+do { \
	120	+ if (unlikely(!(X))) { \
	121	+ printk(KERN_ERR "\n"); \
	122	+ printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
	123	+ BUG(); \
	124	+ } \
	125	+} while (0)
	126	+
	127	+#define ASSERTCMP(X, OP, Y) \
	128	+do { \
	129	+ if (unlikely(!((X) OP (Y)))) { \
	130	+ printk(KERN_ERR "\n"); \
	131	+ printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
	132	+ printk(KERN_ERR "%lx " #OP " %lx is false\n", \
	133	+ (unsigned long)(X), (unsigned long)(Y)); \
	134	+ BUG(); \
	135	+ } \
	136	+} while (0)
	137	+
	138	+#define ASSERTIF(C, X) \
	139	+do { \
	140	+ if (unlikely((C) && !(X))) { \
	141	+ printk(KERN_ERR "\n"); \
	142	+ printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
	143	+ BUG(); \
	144	+ } \
	145	+} while (0)
	146	+
	147	+#define ASSERTIFCMP(C, X, OP, Y) \
	148	+do { \
	149	+ if (unlikely((C) && !((X) OP (Y)))) { \
	150	+ printk(KERN_ERR "\n"); \
	151	+ printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
	152	+ printk(KERN_ERR "%lx " #OP " %lx is false\n", \
	153	+ (unsigned long)(X), (unsigned long)(Y)); \
	154	+ BUG(); \
	155	+ } \
	156	+} while (0)
	157	+
	158	+#else
	159	+
	160	+#define ASSERT(X) do {} while (0)
	161	+#define ASSERTCMP(X, OP, Y) do {} while (0)
	162	+#define ASSERTIF(C, X) do {} while (0)
	163	+#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
	164	+
	165	+#endif /* assert or not */
	1	+/* General filesystem local caching manager
	2	+ *
	3	+ * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
	4	+ * Written by David Howells (dhowells@redhat.com)
	5	+ *
	6	+ * This program is free software; you can redistribute it and/or
	7	+ * modify it under the terms of the GNU General Public License
	8	+ * as published by the Free Software Foundation; either version
	9	+ * 2 of the License, or (at your option) any later version.
	10	+ */
	11	+
	12	+#define FSCACHE_DEBUG_LEVEL CACHE
	13	+#include <linux/module.h>
	14	+#include <linux/init.h>
	15	+#include <linux/sched.h>
	16	+#include <linux/completion.h>
	17	+#include <linux/slab.h>
	18	+#include "internal.h"
	19	+
	20	+MODULE_DESCRIPTION("FS Cache Manager");
	21	+MODULE_AUTHOR("Red Hat, Inc.");
	22	+MODULE_LICENSE("GPL");
	23	+
	24	+unsigned fscache_defer_lookup = 1;
	25	+module_param_named(defer_lookup, fscache_defer_lookup, uint,
	26	+ S_IWUSR \| S_IRUGO);
	27	+MODULE_PARM_DESC(fscache_defer_lookup,
	28	+ "Defer cookie lookup to background thread");
	29	+
	30	+unsigned fscache_defer_create = 1;
	31	+module_param_named(defer_create, fscache_defer_create, uint,
	32	+ S_IWUSR \| S_IRUGO);
	33	+MODULE_PARM_DESC(fscache_defer_create,
	34	+ "Defer cookie creation to background thread");
	35	+
	36	+unsigned fscache_debug;
	37	+module_param_named(debug, fscache_debug, uint,
	38	+ S_IWUSR \| S_IRUGO);
	39	+MODULE_PARM_DESC(fscache_debug,
	40	+ "FS-Cache debugging mask");
	41	+
	42	+struct kobject *fscache_root;
	43	+
	44	+/*
	45	+ * initialise the fs caching module
	46	+ */
	47	+static int __init fscache_init(void)
	48	+{
	49	+ int ret;
	50	+
	51	+ ret = slow_work_register_user();
	52	+ if (ret < 0)
	53	+ goto error_slow_work;
	54	+
	55	+ printk(KERN_NOTICE "FS-Cache: Loaded\n");
	56	+ return 0;
	57	+
	58	+error_slow_work:
	59	+ return ret;
	60	+}
	61	+
	62	+fs_initcall(fscache_init);
	63	+
	64	+/*
	65	+ * clean up on module removal
	66	+ */
	67	+static void __exit fscache_exit(void)
	68	+{
	69	+ _enter("");
	70	+
	71	+ slow_work_unregister_user();
	72	+ printk(KERN_NOTICE "FS-Cache: Unloaded\n");
	73	+}
	74	+
	75	+module_exit(fscache_exit);