Commit 77443f61 authored by David Howells's avatar David Howells
Browse files

cachefiles: Introduce rewritten driver 



Introduce basic skeleton of the rewritten cachefiles driver including
config options so that it can be enabled for compilation.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819622766.215744.9108359326983195047.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906923341.143852.3856498104256721447.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967130320.1823006.15791456613198441566.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021528993.640689.9069695476048171884.stgit@warthog.procyon.org.uk/ # v4
parent 16a96bdf

fs/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -132,6 +132,7 @@ menu "Caches" 


source "fs/netfs/Kconfig"

source "fs/fscache/Kconfig"

source "fs/cachefiles/Kconfig"



endmenu

fs/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ obj-$(CONFIG_AFS_FS) += afs/ 
obj-$(CONFIG_NILFS2_FS)		+= nilfs2/

obj-$(CONFIG_BEFS_FS)		+= befs/

obj-$(CONFIG_HOSTFS)		+= hostfs/

obj-$(CONFIG_CACHEFILES)	+= cachefiles/

obj-$(CONFIG_DEBUG_FS)		+= debugfs/

obj-$(CONFIG_TRACING)		+= tracefs/

obj-$(CONFIG_OCFS2_FS)		+= ocfs2/

fs/cachefiles/Kconfig

0 → 100644
+21 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0-only



config CACHEFILES

	tristate "Filesystem caching on files"

	depends on FSCACHE && BLOCK

	help

	  This permits use of a mounted filesystem as a cache for other

	  filesystems - primarily networking filesystems - thus allowing fast

	  local disk to enhance the speed of slower devices.



	  See Documentation/filesystems/caching/cachefiles.rst for more

	  information.



config CACHEFILES_DEBUG

	bool "Debug CacheFiles"

	depends on CACHEFILES

	help

	  This permits debugging to be dynamically enabled in the filesystem

	  caching on files module.  If this is set, the debugging output may be

	  enabled by setting bits in /sys/modules/cachefiles/parameter/debug or

	  by including a debugging specifier in /etc/cachefilesd.conf.

fs/cachefiles/Makefile

0 → 100644
+9 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

#

# Makefile for caching in a mounted filesystem

#



cachefiles-y := \

	main.o



obj-$(CONFIG_CACHEFILES) := cachefiles.o

fs/cachefiles/internal.h

0 → 100644
+115 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-or-later */

/* General netfs cache on cache files internal defs

 *

 * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.

 * Written by David Howells (dhowells@redhat.com)

 */



#ifdef pr_fmt

#undef pr_fmt

#endif



#define pr_fmt(fmt) "CacheFiles: " fmt





#include <linux/fscache-cache.h>

#include <linux/cred.h>

#include <linux/security.h>





/*

 * Debug tracing.

 */

extern unsigned cachefiles_debug;

#define CACHEFILES_DEBUG_KENTER	1

#define CACHEFILES_DEBUG_KLEAVE	2

#define CACHEFILES_DEBUG_KDEBUG	4



#define dbgprintk(FMT, ...) \

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



#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__)





#if defined(__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_CACHEFILES_DEBUG)

#define _enter(FMT, ...)				\

do {							\

	if (cachefiles_debug & CACHEFILES_DEBUG_KENTER)	\

		kenter(FMT, ##__VA_ARGS__);		\

} while (0)



#define _leave(FMT, ...)				\

do {							\

	if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE)	\

		kleave(FMT, ##__VA_ARGS__);		\

} while (0)



#define _debug(FMT, ...)				\

do {							\

	if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG)	\

		kdebug(FMT, ##__VA_ARGS__);		\

} while (0)



#else

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

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

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

#endif



#if 1 /* defined(__KDEBUGALL) */



#define ASSERT(X)							\

do {									\

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

		pr_err("\n");						\

		pr_err("Assertion failed\n");		\

		BUG();							\

	}								\

} while (0)



#define ASSERTCMP(X, OP, Y)						\

do {									\

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

		pr_err("\n");						\

		pr_err("Assertion failed\n");		\

		pr_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))) {					\

		pr_err("\n");						\

		pr_err("Assertion failed\n");		\

		BUG();							\

	}								\

} while (0)



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

do {									\

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

		pr_err("\n");						\

		pr_err("Assertion failed\n");		\

		pr_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