pci:v00001AF4d00001050sv00001AF4sd00001100bc03sc00i00
     €БА„\mЇїВД -†    /* SPDX-License-Identifier: GPL-2.0-or-later */
/* Network filesystem support services.
 *
 * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * See:
 *
 *	Documentation/filesystems/netfs_library.rst
 *
 * for a description of the network filesystem interface declared here.
 */

#ifndef _LINUX_NETFS_H
#define _LINUX_NETFS_H

#include <linux/workqueue.h>
#include <linux/fs.h>
#include <linux/pagemap.h>

enum netfs_sreq_ref_trace;

/*
 * Overload PG_private_2 to give us PG_fscache - this is used to indicate that
 * a page is currently backed by a local disk cache
 */
#define folio_test_fscache(folio)	folio_test_private_2(folio)
#define PageFsCache(page)		PagePrivate2((page))
#define SetPageFsCache(page)		SetPagePrivate2((page))
#define ClearPageFsCache(page)		ClearPagePrivate2((page))
#define TestSetPageFsCache(page)	TestSetPagePrivate2((page))
#define TestClearPageFsCache(page)	TestClearPagePrivate2((page))

/**
 * folio_start_fscache - Start an fscache write on a folio.
 * @folio: The folio.
 *
 * Call this function before writing a folio to a local cache.  Starting a
 * second write before the first one finishes is not allowed.
 */
static inline void folio_start_fscache(struct folio *folio)
{
	VM_BUG_ON_FOLIO(folio_test_private_2(folio), folio);
	folio_get(folio);
	folio_set_private_2(folio);
}

/**
 * folio_end_fscache - End an fscache write on a folio.
 * @folio: The folio.
 *
 * Call this function after the folio has been written to the local cache.
 * This will wake any sleepers waiting on this folio.
 */
static inline void folio_end_fscache(struct folio *folio)
{
	folio_end_private_2(folio);
}

/**
 * folio_wait_fscache - Wait for an fscache write on this folio to end.
 * @folio: The folio.
 *
 * If this folio is currently being written to a local cache, wait for
 * the write to finish.  Another write may start after this one finishes,
 * unless the caller holds the folio lock.
 */
static inline void folio_wait_fscache(struct folio *folio)
{
	folio_wait_private_2(folio);
}

/**
 * folio_wait_fscache_killable - Wait for an fscache write on this folio to end.
 * @folio: The folio.
 *
 * If this folio is currently being written to a local cache, wait
 * for the write to finish or for a fatal signal to be received.
 * Another write may start after this one finishes, unless the caller
 * holds the folio lock.
 *
 * Return:
 * - 0 if successful.
 * - -EINTR if a fatal signal was encountered.
 */
static inline int folio_wait_fscache_killable(struct folio *folio)
{
	return folio_wait_private_2_killable(folio);
}

static inline void set_page_fscache(struct page *page)
{
	folio_start_fscache(page_folio(page));
}

static inline void end_page_fscache(struct page *page)
{
	folio_end_private_2(page_folio(page));
}

static inline void wait_on_page_fscache(struct page *page)
{
	folio_wait_private_2(page_folio(page));
}

static inline int wait_on_page_fscache_killable(struct page *page)
{
	return folio_wait_private_2_killable(page_folio(page));
}

enum netfs_io_source {
	NETFS_FILL_WITH_ZEROES,
	NETFS_DOWNLOAD_FROM_SERVER,
	NETFS_READ_FROM_CACHE,
	NETFS_INVALID_READ,
} __mode(byte);

typedef void (*netfs_io_terminated_t)(void *priv, ssize_t transferred_or_error,
				      bool was_async);

/*
 * Per-inode context.  This wraps the VFS inode.
 */
struct netfs_inode {
	struct inode		inode;		/* The VFS inode */
	const struct netfs_request_ops *ops;
#if IS_ENABLED(CONFIG_FSCACHE)
	struct fscache_cookie	*cache;
#endif
	loff_t			remote_i_size;	/* Size of the remote file */
};

/*
 * Resources required to do operations on a cache.
 */
struct netfs_cache_resources {
	const struct netfs_cache_ops	*ops;
	void				*cache_priv;
	void				*cache_priv2;
	unsigned int			debug_id;	/* Cookie debug ID */
	unsigned int			inval_counter;	/* object->inval_counter at begin_op */
};

/*
 * Descriptor for a single component subrequest.
 */
struct netfs_io_subrequest {
	struct netfs_io_request *rreq;		/* Supervising I/