netfs, fscache: Move fs/fscache/* into fs/netfs/

There's a problem with dependencies between netfslib and fscache as each
wants to access some functions of the other. Deal with this by moving
fs/fscache/* into fs/netfs/ and renaming those files to begin with
"fscache-".

For the moment, the moved files are changed as little as possible and an
fscache module is still built. A subsequent patch will integrate them.

Signed-off-by: David Howells <[e-mail]>
Reviewed-by: Jeff Layton <[e-mail]>
cc: Christian Brauner <[e-mail]>
cc: [e-mail]
cc: [e-mail]

MAINTAINERS

···
 F:	fs/iomap/
 F:	include/linux/iomap.h
 
+FILESYSTEMS [NETFS LIBRARY]
+M:	David Howells <[e-mail]>
+L:	[e-mail] (moderated for non-subscribers)
+L:	[e-mail]
+S:	Supported
+F:	Documentation/filesystems/caching/
+F:	Documentation/filesystems/netfs_library.rst
+F:	fs/netfs/
+F:	include/linux/fscache*.h
+F:	include/linux/netfs.h
+F:	include/trace/events/fscache.h
+F:	include/trace/events/netfs.h
+
 FINTEK F75375S HARDWARE MONITOR AND FAN CONTROLLER DRIVER
 M:	Riku Voipio <[e-mail]>
 L:	[e-mail]
···
 F:	Documentation/power/freezing-of-tasks.rst
 F:	include/linux/freezer.h
 F:	kernel/freezer.c
-
-FS-CACHE: LOCAL CACHING FOR NETWORK FILESYSTEMS
-M:	David Howells <[e-mail]>
-L:	[e-mail] (moderated for non-subscribers)
-S:	Supported
-F:	Documentation/filesystems/caching/
-F:	fs/fscache/
-F:	include/linux/fscache*.h
 
 FSCRYPT: FILE SYSTEM LEVEL ENCRYPTION SUPPORT
 M:	Eric Biggers <[e-mail]>

fs/Kconfig

···
 menu "Caches"
 
 source "fs/netfs/Kconfig"
-source "fs/fscache/Kconfig"
 source "fs/cachefiles/Kconfig"
 
 endmenu

fs/Makefile

···
  
 # Do not add any filesystems before this line
 obj-$(CONFIG_NETFS_SUPPORT)	+= netfs/
-obj-$(CONFIG_FSCACHE)		+= fscache/
 obj-$(CONFIG_REISERFS_FS)	+= reiserfs/
 obj-$(CONFIG_EXT4_FS)		+= ext4/
 # We place ext4 before ext2 so that clean ext3 root fs's do NOT mount using the

fs/fscache/Kconfig

···
-# SPDX-License-Identifier: GPL-2.0-only
-
-config FSCACHE
-	tristate "General filesystem local caching manager"
-	select NETFS_SUPPORT
-	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.rst for more information.
-
-config FSCACHE_STATS
-	bool "Gather statistical information on local caching"
-	depends on FSCACHE && PROC_FS
-	select NETFS_STATS
-	help
-	  This option causes statistical information to be gathered on local
-	  caching and exported through file:
-
-		/proc/fs/fscache/stats
-
-	  The gathering of statistics adds a certain amount of overhead to
-	  execution as there are a quite a few stats gathered, and on a
-	  multi-CPU system these may be on cachelines that keep bouncing
-	  between CPUs.  On the other hand, the stats are very useful for
-	  debugging purposes.  Saying 'Y' here is recommended.
-
-	  See Documentation/filesystems/caching/fscache.rst 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.rst for more information.

fs/fscache/Makefile

···
-# SPDX-License-Identifier: GPL-2.0
-#
-# Makefile for general filesystem caching code
-#
-
-fscache-y := \
-	cache.o \
-	cookie.o \
-	io.o \
-	main.o \
-	volume.o
-
-fscache-$(CONFIG_PROC_FS) += proc.o
-fscache-$(CONFIG_FSCACHE_STATS) += stats.o
-
-obj-$(CONFIG_FSCACHE) := fscache.o

fs/netfs/Kconfig

···
 	  multi-CPU system these may be on cachelines that keep bouncing
 	  between CPUs.  On the other hand, the stats are very useful for
 	  debugging purposes.  Saying 'Y' here is recommended.
+
+config FSCACHE
+	tristate "General filesystem local caching manager"
+	select NETFS_SUPPORT
+	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.rst for more information.
+
+config FSCACHE_STATS
+	bool "Gather statistical information on local caching"
+	depends on FSCACHE && PROC_FS
+	select NETFS_STATS
+	help
+	  This option causes statistical information to be gathered on local
+	  caching and exported through file:
+
+		/proc/fs/fscache/stats
+
+	  The gathering of statistics adds a certain amount of overhead to
+	  execution as there are a quite a few stats gathered, and on a
+	  multi-CPU system these may be on cachelines that keep bouncing
+	  between CPUs.  On the other hand, the stats are very useful for
+	  debugging purposes.  Saying 'Y' here is recommended.
+
+	  See Documentation/filesystems/caching/fscache.rst 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.rst for more information.

fs/netfs/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
 
+fscache-y := \
+	fscache_cache.o \
+	fscache_cookie.o \
+	fscache_io.o \
+	fscache_main.o \
+	fscache_volume.o
+
+fscache-$(CONFIG_PROC_FS) += fscache_proc.o
+fscache-$(CONFIG_FSCACHE_STATS) += fscache_stats.o
+
+obj-$(CONFIG_FSCACHE) := fscache.o
+
 netfs-y := \
 	buffered_read.o \
 	io.o \
···
 
 netfs-$(CONFIG_NETFS_STATS) += stats.o
 
-obj-$(CONFIG_NETFS_SUPPORT) := netfs.o
+obj-$(CONFIG_NETFS_SUPPORT) += netfs.o

fs/netfs/internal.h

···
  * Written by David Howells ([e-mail])
  */
 
+#include <linux/slab.h>
+#include <linux/seq_file.h>
 #include <linux/netfs.h>
 #include <linux/fscache.h>
 #include <trace/events/netfs.h>
+#include "fscache_internal.h"
 
 #ifdef pr_fmt
 #undef pr_fmt
···
 /*
  * debug tracing
  */
+#if 0
 #define dbgprintk(FMT, ...) \
 	printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 
···
 #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
 #endif

fs/netfs/main.c

···
 #include <linux/module.h>
 #include <linux/export.h>
 #include "internal.h"
-#define CREATE_TRACE_POINTS
-#include <trace/events/netfs.h>
+//#define CREATE_TRACE_POINTS
+//#include <trace/events/netfs.h>
 
 MODULE_DESCRIPTION("Network fs support");
 MODULE_AUTHOR("Red Hat, Inc.");
···
 unsigned netfs_debug;
 module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO);
 MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
+