1 /*
2 * This file provides functions for block I/O operations on swap/file.
3 *
4 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
5 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
6 *
7 * This file is released under the GPLv2.
8 */
9
10 #include <linux/bio.h>
11 #include <linux/kernel.h>
12 #include <linux/pagemap.h>
13 #include <linux/swap.h>
14
15 #include "power.h"
16
17 /**
18 * submit - submit BIO request.
19 * @rw: READ or WRITE.
20 * @off physical offset of page.
21 * @page: page we're reading or writing.
22 * @bio_chain: list of pending biod (for async reading)
23 *
24 * Straight from the textbook - allocate and initialize the bio.
25 * If we're reading, make sure the page is marked as dirty.
26 * Then submit it and, if @bio_chain == NULL, wait.
27 */
submit(int rw,struct block_device * bdev,sector_t sector,struct page * page,struct bio ** bio_chain)28 static int submit(int rw, struct block_device *bdev, sector_t sector,
29 struct page *page, struct bio **bio_chain)
30 {
31 const int bio_rw = rw | REQ_SYNC;
32 struct bio *bio;
33
34 bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
35 bio->bi_sector = sector;
36 bio->bi_bdev = bdev;
37 bio->bi_end_io = end_swap_bio_read;
38
39 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
40 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
41 (unsigned long long)sector);
42 bio_put(bio);
43 return -EFAULT;
44 }
45
46 lock_page(page);
47 bio_get(bio);
48
49 if (bio_chain == NULL) {
50 submit_bio(bio_rw, bio);
51 wait_on_page_locked(page);
52 if (rw == READ)
53 bio_set_pages_dirty(bio);
54 bio_put(bio);
55 } else {
56 if (rw == READ)
57 get_page(page); /* These pages are freed later */
58 bio->bi_private = *bio_chain;
59 *bio_chain = bio;
60 submit_bio(bio_rw, bio);
61 }
62 return 0;
63 }
64
hib_bio_read_page(pgoff_t page_off,void * addr,struct bio ** bio_chain)65 int hib_bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
66 {
67 return submit(READ, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
68 virt_to_page(addr), bio_chain);
69 }
70
hib_bio_write_page(pgoff_t page_off,void * addr,struct bio ** bio_chain)71 int hib_bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
72 {
73 return submit(WRITE, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
74 virt_to_page(addr), bio_chain);
75 }
76
hib_wait_on_bio_chain(struct bio ** bio_chain)77 int hib_wait_on_bio_chain(struct bio **bio_chain)
78 {
79 struct bio *bio;
80 struct bio *next_bio;
81 int ret = 0;
82
83 if (bio_chain == NULL)
84 return 0;
85
86 bio = *bio_chain;
87 if (bio == NULL)
88 return 0;
89 while (bio) {
90 struct page *page;
91
92 next_bio = bio->bi_private;
93 page = bio->bi_io_vec[0].bv_page;
94 wait_on_page_locked(page);
95 if (!PageUptodate(page) || PageError(page))
96 ret = -EIO;
97 put_page(page);
98 bio_put(bio);
99 bio = next_bio;
100 }
101 *bio_chain = NULL;
102 return ret;
103 }
104