Commit 850cba06 authored by David Howells's avatar David Howells
Browse files

cachefiles: Delete the cachefiles driver pending rewrite 



Delete the code from the cachefiles driver to make it easier to rewrite and
resubmit in a logical manner.

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/163819577641.215744.12718114397770666596.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906883770.143852.4149714614981373410.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967076066.1823006.7175712134577687753.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021483619.640689.7586546280515844702.stgit@warthog.procyon.org.uk/ # v4
parent 01491a75

fs/Kconfig

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


source "fs/netfs/Kconfig"

source "fs/fscache/Kconfig"

source "fs/cachefiles/Kconfig"



endmenu

fs/Makefile

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Original line number Diff line number Diff line
@@ -125,7 +125,6 @@ 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

deleted100644 → 0
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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

deleted100644 → 0
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Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

#

# Makefile for caching in a mounted filesystem

#



cachefiles-y := \

	bind.o \

	daemon.o \

	interface.o \

	io.o \

	key.o \

	main.o \

	namei.o \

	rdwr.o \

	security.o \

	xattr.o



obj-$(CONFIG_CACHEFILES) := cachefiles.o

fs/cachefiles/bind.c

deleted100644 → 0
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Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-or-later

/* Bind and unbind a cache from the filesystem backing it

 *

 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.

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

 */



#include <linux/module.h>

#include <linux/init.h>

#include <linux/sched.h>

#include <linux/completion.h>

#include <linux/slab.h>

#include <linux/fs.h>

#include <linux/file.h>

#include <linux/namei.h>

#include <linux/mount.h>

#include <linux/statfs.h>

#include <linux/ctype.h>

#include <linux/xattr.h>

#include "internal.h"



static int cachefiles_daemon_add_cache(struct cachefiles_cache *caches);



/*

 * bind a directory as a cache

 */

int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args)

{

	_enter("{%u,%u,%u,%u,%u,%u},%s",

	       cache->frun_percent,

	       cache->fcull_percent,

	       cache->fstop_percent,

	       cache->brun_percent,

	       cache->bcull_percent,

	       cache->bstop_percent,

	       args);



	/* start by checking things over */

	ASSERT(cache->fstop_percent >= 0 &&

	       cache->fstop_percent < cache->fcull_percent &&

	       cache->fcull_percent < cache->frun_percent &&

	       cache->frun_percent  < 100);



	ASSERT(cache->bstop_percent >= 0 &&

	       cache->bstop_percent < cache->bcull_percent &&

	       cache->bcull_percent < cache->brun_percent &&

	       cache->brun_percent  < 100);



	if (*args) {

		pr_err("'bind' command doesn't take an argument\n");

		return -EINVAL;

	}



	if (!cache->rootdirname) {

		pr_err("No cache directory specified\n");

		return -EINVAL;

	}



	/* don't permit already bound caches to be re-bound */

	if (test_bit(CACHEFILES_READY, &cache->flags)) {

		pr_err("Cache already bound\n");

		return -EBUSY;

	}



	/* make sure we have copies of the tag and dirname strings */

	if (!cache->tag) {

		/* the tag string is released by the fops->release()

		 * function, so we don't release it on error here */

		cache->tag = kstrdup("CacheFiles", GFP_KERNEL);

		if (!cache->tag)

			return -ENOMEM;

	}



	/* add the cache */

	return cachefiles_daemon_add_cache(cache);

}



/*

 * add a cache

 */

static int cachefiles_daemon_add_cache(struct cachefiles_cache *cache)

{

	struct cachefiles_object *fsdef;

	struct path path;

	struct kstatfs stats;

	struct dentry *graveyard, *cachedir, *root;

	const struct cred *saved_cred;

	int ret;



	_enter("");



	/* we want to work under the module's security ID */

	ret = cachefiles_get_security_ID(cache);

	if (ret < 0)

		return ret;



	cachefiles_begin_secure(cache, &saved_cred);



	/* allocate the root index object */

	ret = -ENOMEM;



	fsdef = kmem_cache_alloc(cachefiles_object_jar, GFP_KERNEL);

	if (!fsdef)

		goto error_root_object;



	ASSERTCMP(fsdef->backer, ==, NULL);



	atomic_set(&fsdef->usage, 1);

	fsdef->type = FSCACHE_COOKIE_TYPE_INDEX;



	/* look up the directory at the root of the cache */

	ret = kern_path(cache->rootdirname, LOOKUP_DIRECTORY, &path);

	if (ret < 0)

		goto error_open_root;



	cache->mnt = path.mnt;

	root = path.dentry;



	ret = -EINVAL;

	if (mnt_user_ns(path.mnt) != &init_user_ns) {

		pr_warn("File cache on idmapped mounts not supported");

		goto error_unsupported;

	}



	/* check parameters */

	ret = -EOPNOTSUPP;

	if (d_is_negative(root) ||

	    !d_backing_inode(root)->i_op->lookup ||

	    !d_backing_inode(root)->i_op->mkdir ||

	    !(d_backing_inode(root)->i_opflags & IOP_XATTR) ||

	    !root->d_sb->s_op->statfs ||

	    !root->d_sb->s_op->sync_fs)

		goto error_unsupported;



	ret = -EROFS;

	if (sb_rdonly(root->d_sb))

		goto error_unsupported;



	/* determine the security of the on-disk cache as this governs

	 * security ID of files we create */

	ret = cachefiles_determine_cache_security(cache, root, &saved_cred);

	if (ret < 0)

		goto error_unsupported;



	/* get the cache size and blocksize */

	ret = vfs_statfs(&path, &stats);

	if (ret < 0)

		goto error_unsupported;



	ret = -ERANGE;

	if (stats.f_bsize <= 0)

		goto error_unsupported;



	ret = -EOPNOTSUPP;

	if (stats.f_bsize > PAGE_SIZE)

		goto error_unsupported;



	cache->bsize = stats.f_bsize;

	cache->bshift = 0;

	if (stats.f_bsize < PAGE_SIZE)

		cache->bshift = PAGE_SHIFT - ilog2(stats.f_bsize);



	_debug("blksize %u (shift %u)",

	       cache->bsize, cache->bshift);



	_debug("size %llu, avail %llu",

	       (unsigned long long) stats.f_blocks,

	       (unsigned long long) stats.f_bavail);



	/* set up caching limits */

	do_div(stats.f_files, 100);

	cache->fstop = stats.f_files * cache->fstop_percent;

	cache->fcull = stats.f_files * cache->fcull_percent;

	cache->frun  = stats.f_files * cache->frun_percent;



	_debug("limits {%llu,%llu,%llu} files",

	       (unsigned long long) cache->frun,

	       (unsigned long long) cache->fcull,

	       (unsigned long long) cache->fstop);



	stats.f_blocks >>= cache->bshift;

	do_div(stats.f_blocks, 100);

	cache->bstop = stats.f_blocks * cache->bstop_percent;

	cache->bcull = stats.f_blocks * cache->bcull_percent;

	cache->brun  = stats.f_blocks * cache->brun_percent;



	_debug("limits {%llu,%llu,%llu} blocks",

	       (unsigned long long) cache->brun,

	       (unsigned long long) cache->bcull,

	       (unsigned long long) cache->bstop);



	/* get the cache directory and check its type */

	cachedir = cachefiles_get_directory(cache, root, "cache");

	if (IS_ERR(cachedir)) {

		ret = PTR_ERR(cachedir);

		goto error_unsupported;

	}



	fsdef->dentry = cachedir;

	fsdef->fscache.cookie = NULL;



	ret = cachefiles_check_object_type(fsdef);

	if (ret < 0)

		goto error_unsupported;



	/* get the graveyard directory */

	graveyard = cachefiles_get_directory(cache, root, "graveyard");

	if (IS_ERR(graveyard)) {

		ret = PTR_ERR(graveyard);

		goto error_unsupported;

	}



	cache->graveyard = graveyard;



	/* publish the cache */

	fscache_init_cache(&cache->cache,

			   &cachefiles_cache_ops,

			   "%s",

			   fsdef->dentry->d_sb->s_id);



	fscache_object_init(&fsdef->fscache, &fscache_fsdef_index,

			    &cache->cache);



	ret = fscache_add_cache(&cache->cache, &fsdef->fscache, cache->tag);

	if (ret < 0)

		goto error_add_cache;



	/* done */

	set_bit(CACHEFILES_READY, &cache->flags);

	dput(root);



	pr_info("File cache on %s registered\n", cache->cache.identifier);



	/* check how much space the cache has */

	cachefiles_has_space(cache, 0, 0);

	cachefiles_end_secure(cache, saved_cred);

	return 0;



error_add_cache:

	dput(cache->graveyard);

	cache->graveyard = NULL;

error_unsupported:

	mntput(cache->mnt);

	cache->mnt = NULL;

	dput(fsdef->dentry);

	fsdef->dentry = NULL;

	dput(root);

error_open_root:

	kmem_cache_free(cachefiles_object_jar, fsdef);

error_root_object:

	cachefiles_end_secure(cache, saved_cred);

	pr_err("Failed to register: %d\n", ret);

	return ret;

}



/*

 * unbind a cache on fd release

 */

void cachefiles_daemon_unbind(struct cachefiles_cache *cache)

{

	_enter("");



	if (test_bit(CACHEFILES_READY, &cache->flags)) {

		pr_info("File cache on %s unregistering\n",

			cache->cache.identifier);



		fscache_withdraw_cache(&cache->cache);

	}



	dput(cache->graveyard);

	mntput(cache->mnt);



	kfree(cache->rootdirname);

	kfree(cache->secctx);

	kfree(cache->tag);



	_leave("");

}