linux/fs/cachefiles/io.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* kiocb-using read/write
 *
 * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#include <linux/mount.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/uio.h>
#include <linux/bio.h>
#include <linux/falloc.h>
#include <linux/sched/mm.h>
#include <trace/events/fscache.h>
#include "internal.h"

struct cachefiles_kiocb { … };

static inline void cachefiles_put_kiocb(struct cachefiles_kiocb *ki)
{ … }

/*
 * Handle completion of a read from the cache.
 */
static void cachefiles_read_complete(struct kiocb *iocb, long ret)
{ … }

/*
 * Initiate a read from the cache.
 */
static int cachefiles_read(struct netfs_cache_resources *cres,
			   loff_t start_pos,
			   struct iov_iter *iter,
			   enum netfs_read_from_hole read_hole,
			   netfs_io_terminated_t term_func,
			   void *term_func_priv)
{ … }

/*
 * Query the occupancy of the cache in a region, returning where the next chunk
 * of data starts and how long it is.
 */
static int cachefiles_query_occupancy(struct netfs_cache_resources *cres,
				      loff_t start, size_t len, size_t granularity,
				      loff_t *_data_start, size_t *_data_len)
{ … }

/*
 * Handle completion of a write to the cache.
 */
static void cachefiles_write_complete(struct kiocb *iocb, long ret)
{ … }

/*
 * Initiate a write to the cache.
 */
int __cachefiles_write(struct cachefiles_object *object,
		       struct file *file,
		       loff_t start_pos,
		       struct iov_iter *iter,
		       netfs_io_terminated_t term_func,
		       void *term_func_priv)
{ … }

static int cachefiles_write(struct netfs_cache_resources *cres,
			    loff_t start_pos,
			    struct iov_iter *iter,
			    netfs_io_terminated_t term_func,
			    void *term_func_priv)
{ … }

static inline enum netfs_io_source
cachefiles_do_prepare_read(struct netfs_cache_resources *cres,
			   loff_t start, size_t *_len, loff_t i_size,
			   unsigned long *_flags, ino_t netfs_ino)
{ … }

/*
 * Prepare a read operation, shortening it to a cached/uncached
 * boundary as appropriate.
 */
static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq,
						    unsigned long long i_size)
{ … }

/*
 * Prepare an on-demand read operation, shortening it to a cached/uncached
 * boundary as appropriate.
 */
static enum netfs_io_source
cachefiles_prepare_ondemand_read(struct netfs_cache_resources *cres,
				 loff_t start, size_t *_len, loff_t i_size,
				 unsigned long *_flags, ino_t ino)
{ … }

/*
 * Prepare for a write to occur.
 */
int __cachefiles_prepare_write(struct cachefiles_object *object,
			       struct file *file,
			       loff_t *_start, size_t *_len, size_t upper_len,
			       bool no_space_allocated_yet)
{ … }

static int cachefiles_prepare_write(struct netfs_cache_resources *cres,
				    loff_t *_start, size_t *_len, size_t upper_len,
				    loff_t i_size, bool no_space_allocated_yet)
{ … }

static void cachefiles_prepare_write_subreq(struct netfs_io_subrequest *subreq)
{ … }

static void cachefiles_issue_write(struct netfs_io_subrequest *subreq)
{ … }

/*
 * Clean up an operation.
 */
static void cachefiles_end_operation(struct netfs_cache_resources *cres)
{ … }

static const struct netfs_cache_ops cachefiles_netfs_cache_ops = …;

/*
 * Open the cache file when beginning a cache operation.
 */
bool cachefiles_begin_operation(struct netfs_cache_resources *cres,
				enum fscache_want_state want_state)
{ … }