path: root/include/linux/pagemap.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_PAGEMAP_H
#define _LINUX_PAGEMAP_H

/*
 * Copyright 1995 Linus Torvalds
 */
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/highmem.h>
#include <linux/compiler.h>
#include <linux/uaccess.h>
#include <linux/gfp.h>
#include <linux/bitops.h>
#include <linux/hardirq.h> /* for in_interrupt() */
#include <linux/hugetlb_inline.h>

struct folio_batch;

unsigned long invalidate_mapping_pages(struct address_space *mapping,
					pgoff_t start, pgoff_t end);

static inline void invalidate_remote_inode(struct inode *inode)
{
	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
	    S_ISLNK(inode->i_mode))
		invalidate_mapping_pages(inode->i_mapping, 0, -1);
}
int invalidate_inode_pages2(struct address_space *mapping);
int invalidate_inode_pages2_range(struct address_space *mapping,
		pgoff_t start, pgoff_t end);
int kiocb_invalidate_pages(struct kiocb *iocb, size_t count);
void kiocb_invalidate_post_direct_write(struct kiocb *iocb, size_t count);

int write_inode_now(struct inode *, int sync);
int filemap_fdatawrite(struct address_space *);
int filemap_flush(struct address_space *);
int filemap_fdatawait_keep_errors(struct address_space *mapping);
int filemap_fdatawait_range(struct address_space *, loff_t lstart, loff_t lend);
int filemap_fdatawait_range_keep_errors(struct address_space *mapping,
		loff_t start_byte, loff_t end_byte);
int filemap_invalidate_inode(struct inode *inode, bool flush,
			     loff_t start, loff_t end);

static inline int filemap_fdatawait(struct address_space *mapping)
{
	return filemap_fdatawait_range(mapping, 0, LLONG_MAX);
}

bool filemap_range_has_page(struct address_space *, loff_t lstart, loff_t lend);
int filemap_write_and_wait_range(struct address_space *mapping,
		loff_t lstart, loff_t lend);
int __filemap_fdatawrite_range(struct address_space *mapping,
		loff_t start, loff_t end, int sync_mode);
int filemap_fdatawrite_range(struct address_space *mapping,
		loff_t start, loff_t end);
int filemap_check_errors(struct address_space *mapping);
void __filemap_set_wb_err(struct address_space *mapping, int err);
int filemap_fdatawrite_wbc(struct address_space *mapping,
			   struct writeback_control *wbc);
int kiocb_write_and_wait(struct kiocb *iocb, size_t count);

static inline int filemap_write_and_wait(struct address_space *mapping)
{
	return filemap_write_and_wait_range(mapping, 0, LLONG_MAX);
}

/**
 * filemap_set_wb_err - set a writeback error on an address_space
 * @mapping: mapping in which to set writeback error
 * @err: error to be set in mapping
 *
 * When writeback fails in some way, we must record that error so that
 * userspace can be informed when fsync and the like are called.  We endeavor
 * to report errors on any file that was open at the time of the error.  Some
 * internal callers also need to know when writeback errors have occurred.
 *
 * When a writeback error occurs, most filesystems will want to call
 * filemap_set_wb_err to record the error in the mapping so that it will be
 * automatically reported whenever fsync is called on the file.
 */
static inline void filemap_set_wb_err(struct address_space *mapping, int err)
{
	/* Fastpath for common case of no error */
	if (unlikely(err))
		__filemap_set_wb_err(mapping, err);
}

/**
 * filemap_check_wb_err - has an error occurred since the mark was sampled?
 * @mapping: mapping to check for writeback errors
 * @since: previously-sampled errseq_t
 *
 * Grab the errseq_t value from the mapping, and see if it has changed "since"
 * the given value was sampled.
 *
 * If it has then report the latest error set, otherwise return 0.
 */
static inline int filemap_check_wb_err(struct address_space *mapping,
					errseq_t since)
{
	return errseq_check(&mapping->wb_err, since);
}

/**
 * filemap_sample_wb_err - sample the current errseq_t to test for later errors
 * @mapping: mapping to be sampled
 *
 * Writeback errors are always reported relative to a particular sample point
 * in the past. This function provides those sample points.
 */
static inline errseq_t filemap_sample_wb_err(struct address_space *mapping)
{
	return errseq_sample(&mapping->wb_err);
}

/**
 * file_sample_sb_err - sample the current errseq_t to test for later errors
 * @file: file pointer to be sampled
 *
 * Grab the most current superblock-level errseq_t value for the given
 * struct file.
 */
static inline errseq_t file_sample_sb_err(struct file *file)
{
	return errseq_sample(&file->f_path.dentry->d_sb->s_wb_err);
}

/*
 * Flush file data before changing attributes.  Caller must hold any locks
 * required to prevent further writes to this file until we're done setting
 * flags.
 */
static inline int inode_drain_writes(struct inode *inode)
{
	inode_dio_wait(inode);
	return filemap_write_and_wait(inode->i_mapping);
}

static inline bool mapping_empty(struct address_space *mapping)
{
	return xa_empty(&mapping->i_pages);
}

/*
 * mapping_shrinkable - test if page cache state allows inode reclaim
 * @mapping: the page cache mapping
 *
 * This checks the mapping's cache state for the pupose of inode
 * reclaim and LRU management.
 *
 * The caller is expected to hold the i_lock, but is not required to
 * hold the i_pages lock, which usually protects cache state. That's
 * because the i_lock and the list_lru lock that protect the inode and
 * its LRU state don't nest inside the irq-safe i_pages lock.
 *
 * Cache deletions are performed under the i_lock, which ensures that
 * when an inode goes empty, it will reliably get queued on the LRU.
 *
 * Cache additions do not acquire the i_lock and may race with this
 * check, in which case we'll report the inode as shrinkable when it
 * has cache pages. This is okay: the shrinker also checks the
 * refcount and the referenced bit, which will be elevated or set in
 * the process of adding new cache pages to an inode.
 */
static inline bool mapping_shrinkable(struct address_space *mapping)
{
	void *head;

	/*
	 * On highmem systems, there could be lowmem pressure f