linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 *  linux/mm/page_io.c

 *

 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds

 *

 *  Swap reorganised 29.12.95, 

 *  Asynchronous swapping added 30.12.95. Stephen Tweedie

 *  Removed race in async swapping. 14.4.1996. Bruno Haible

 *  Add swap of shared pages through the page cache. 20.2.1998. Stephen Tweedie

 *  Always use brw_page, life becomes simpler. 12 May 1998 Eric Biederman

 */

​

#include <linux/mm.h>

#include <linux/kernel_stat.h>

#include <linux/gfp.h>

#include <linux/pagemap.h>

#include <linux/swap.h>

#include <linux/bio.h>

#include <linux/swapops.h>

#include <linux/buffer_head.h>

#include <linux/writeback.h>

#include <linux/frontswap.h>

#include <linux/blkdev.h>

#include <linux/uio.h>

#include <linux/sched/task.h>

#include <asm/pgtable.h>

​

static struct bio *get_swap_bio(gfp_t gfp_flags,

                struct page *page, bio_end_io_t end_io)

{

    int i, nr = hpage_nr_pages(page);

    struct bio *bio;

​

    bio = bio_alloc(gfp_flags, nr);

    if (bio) {

        struct block_device *bdev;

​

        bio->bi_iter.bi_sector = map_swap_page(page, &bdev);

        bio_set_dev(bio, bdev);

        bio->bi_iter.bi_sector <<= PAGE_SHIFT - 9;

        bio->bi_end_io = end_io;

​

        for (i = 0; i < nr; i++)

            bio_add_page(bio, page + i, PAGE_SIZE, 0);

        VM_BUG_ON(bio->bi_iter.bi_size != PAGE_SIZE * nr);

    }

    return bio;

}

​

void end_swap_bio_write(struct bio *bio)

{

    struct page *page = bio_first_page_all(bio);

​

    if (bio->bi_status) {

        SetPageError(page);

        /*

         * We failed to write the page out to swap-space.

         * Re-dirty the page in order to avoid it being reclaimed.

         * Also print a dire warning that things will go BAD (tm)

         * very quickly.

         *

         * Also clear PG_reclaim to avoid rotate_reclaimable_page()