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// SPDX-License-Identifier: GPL-2.0-or-later
/* FS-Cache interface to CacheFiles
*
* Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/slab.h>
#include <linux/mount.h>
#include <linux/xattr.h>
#include <linux/file.h>
#include <linux/falloc.h>
#include <trace/events/fscache.h>
#include "internal.h"
static atomic_t cachefiles_object_debug_id;
/*
* Allocate a cache object record.
*/
static
struct cachefiles_object *cachefiles_alloc_object(struct fscache_cookie *cookie)
{
struct fscache_volume *vcookie = cookie->volume;
struct cachefiles_volume *volume = vcookie->cache_priv;
struct cachefiles_object *object;
_enter("{%s},%x,", vcookie->key, cookie->debug_id);
object = kmem_cache_zalloc(cachefiles_object_jar, GFP_KERNEL);
if (!object)
return NULL;
refcount_set(&object->ref, 1);
spin_lock_init(&object->lock);
INIT_LIST_HEAD(&object->cache_link);
object->volume = volume;
object->debug_id = atomic_inc_return(&cachefiles_object_debug_id);
object->cookie = fscache_get_cookie(cookie, fscache_cookie_get_attach_object);
fscache_count_object(vcookie->cache);
trace_cachefiles_ref(object->debug_id, cookie->debug_id, 1,
cachefiles_obj_new);
return object;
}
/*
* Note that an object has been seen.
*/
void cachefiles_see_object(struct cachefiles_object *object,
enum cachefiles_obj_ref_trace why)
{
trace_cachefiles_ref(object->debug_id, object->cookie->debug_id,
refcount_read(&object->ref), why);
}
/*
* Increment the usage count on an object;
*/
struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
enum cachefiles_obj_ref_trace why)
{
int r;
__refcount_inc(&object->ref, &r);
trace_cachefiles_ref(object->debug_id, object->cookie->debug_id, r, why);
return object;
}
/*
* dispose of a reference to an object
*/
void cachefiles_put_object(struct cachefiles_object *object,
enum cachefiles_obj_ref_trace why)
{
unsigned int object_debug_id = object->debug_id;
unsigned int cookie_debug_id = object->cookie->debug_id;
struct fscache_cache *cache;
bool done;
int r;
done = __refcount_dec_and_test(&object->ref, &r);
trace_cachefiles_ref(object_debug_id, cookie_debug_id, r, why);
if (done) {
_debug("- kill object OBJ%x", object_debug_id);
ASSERTCMP(object->file, ==, NULL);
kfree(object->d_name);
cache = object->volume->cache->cache;
fscache_put_cookie(object->cookie, fscache_cookie_put_object);
object->cookie = NULL;
kmem_cache_free(cachefiles_object_jar, object);
fscache_uncount_object(cache);
}
_leave("");
}
const struct fscache_cache_ops cachefiles_cache_ops = {
.name = "cachefiles",
.acquire_volume = cachefiles_acquire_volume,
.free_volume = cachefiles_free_volume,
};
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