linux/fs/cachefiles/interface.c

// 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 ([email protected])
 */

#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)
{ … }

/*
 * Note that an object has been seen.
 */
void cachefiles_see_object(struct cachefiles_object *object,
			   enum cachefiles_obj_ref_trace why)
{ … }

/*
 * Increment the usage count on an object;
 */
struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
						 enum cachefiles_obj_ref_trace why)
{ … }

/*
 * dispose of a reference to an object
 */
void cachefiles_put_object(struct cachefiles_object *object,
			   enum cachefiles_obj_ref_trace why)
{ … }

/*
 * Adjust the size of a cache file if necessary to match the DIO size.  We keep
 * the EOF marker a multiple of DIO blocks so that we don't fall back to doing
 * non-DIO for a partial block straddling the EOF, but we also have to be
 * careful of someone expanding the file and accidentally accreting the
 * padding.
 */
static int cachefiles_adjust_size(struct cachefiles_object *object)
{ … }

/*
 * Attempt to look up the nominated node in this cache
 */
static bool cachefiles_lookup_cookie(struct fscache_cookie *cookie)
{ … }

/*
 * Shorten the backing object to discard any dirty data and free up
 * any unused granules.
 */
static bool cachefiles_shorten_object(struct cachefiles_object *object,
				      struct file *file, loff_t new_size)
{ … }

/*
 * Resize the backing object.
 */
static void cachefiles_resize_cookie(struct netfs_cache_resources *cres,
				     loff_t new_size)
{ … }

/*
 * Commit changes to the object as we drop it.
 */
static void cachefiles_commit_object(struct cachefiles_object *object,
				     struct cachefiles_cache *cache)
{ … }

/*
 * Finalise and object and close the VFS structs that we have.
 */
static void cachefiles_clean_up_object(struct cachefiles_object *object,
				       struct cachefiles_cache *cache)
{ … }

/*
 * Withdraw caching for a cookie.
 */
static void cachefiles_withdraw_cookie(struct fscache_cookie *cookie)
{ … }

/*
 * Invalidate the storage associated with a cookie.
 */
static bool cachefiles_invalidate_cookie(struct fscache_cookie *cookie)
{ … }

const struct fscache_cache_ops cachefiles_cache_ops = …;