104 строки
2.4 KiB
C
104 строки
2.4 KiB
C
/*
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* This file provides functions for block I/O operations on swap/file.
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*
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* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
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* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
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*
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* This file is released under the GPLv2.
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*/
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#include <linux/bio.h>
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#include <linux/kernel.h>
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#include <linux/pagemap.h>
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#include <linux/swap.h>
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#include "power.h"
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/**
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* submit - submit BIO request.
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* @rw: READ or WRITE.
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* @off physical offset of page.
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* @page: page we're reading or writing.
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* @bio_chain: list of pending biod (for async reading)
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*
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* Straight from the textbook - allocate and initialize the bio.
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* If we're reading, make sure the page is marked as dirty.
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* Then submit it and, if @bio_chain == NULL, wait.
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*/
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static int submit(int rw, struct block_device *bdev, sector_t sector,
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struct page *page, struct bio **bio_chain)
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{
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const int bio_rw = rw | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
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struct bio *bio;
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bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
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bio->bi_sector = sector;
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bio->bi_bdev = bdev;
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bio->bi_end_io = end_swap_bio_read;
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if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
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printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
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(unsigned long long)sector);
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bio_put(bio);
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return -EFAULT;
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}
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lock_page(page);
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bio_get(bio);
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if (bio_chain == NULL) {
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submit_bio(bio_rw, bio);
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wait_on_page_locked(page);
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if (rw == READ)
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bio_set_pages_dirty(bio);
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bio_put(bio);
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} else {
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if (rw == READ)
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get_page(page); /* These pages are freed later */
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bio->bi_private = *bio_chain;
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*bio_chain = bio;
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submit_bio(bio_rw, bio);
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}
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return 0;
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}
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int hib_bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
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{
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return submit(READ, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
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virt_to_page(addr), bio_chain);
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}
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int hib_bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
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{
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return submit(WRITE, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
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virt_to_page(addr), bio_chain);
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}
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int hib_wait_on_bio_chain(struct bio **bio_chain)
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{
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struct bio *bio;
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struct bio *next_bio;
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int ret = 0;
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if (bio_chain == NULL)
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return 0;
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bio = *bio_chain;
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if (bio == NULL)
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return 0;
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while (bio) {
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struct page *page;
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next_bio = bio->bi_private;
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page = bio->bi_io_vec[0].bv_page;
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wait_on_page_locked(page);
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if (!PageUptodate(page) || PageError(page))
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ret = -EIO;
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put_page(page);
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bio_put(bio);
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bio = next_bio;
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}
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*bio_chain = NULL;
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return ret;
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}
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