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[/] [test_project/] [trunk/] [linux_sd_driver/] [kernel/] [power/] [swap.c] - Blame information for rev 62

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/*
 * linux/kernel/power/swap.c
 *
 * This file provides functions for reading the suspend image from
 * and writing it to a swap partition.
 *
 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
 *
 * This file is released under the GPLv2.
 *
 */
 
#include <linux/module.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/version.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/genhd.h>
#include <linux/device.h>
#include <linux/buffer_head.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/pm.h>
 
#include "power.h"
 
extern char resume_file[];
 
#define SWSUSP_SIG      "S1SUSPEND"
 
struct swsusp_header {
        char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)];
        sector_t image;
        unsigned int flags;     /* Flags to pass to the "boot" kernel */
        char    orig_sig[10];
        char    sig[10];
} __attribute__((packed));
 
static struct swsusp_header *swsusp_header;
 
/*
 * General things
 */
 
static unsigned short root_swap = 0xffff;
static struct block_device *resume_bdev;
 
/**
 *      submit - submit BIO request.
 *      @rw:    READ or WRITE.
 *      @off    physical offset of page.
 *      @page:  page we're reading or writing.
 *      @bio_chain: list of pending biod (for async reading)
 *
 *      Straight from the textbook - allocate and initialize the bio.
 *      If we're reading, make sure the page is marked as dirty.
 *      Then submit it and, if @bio_chain == NULL, wait.
 */
static int submit(int rw, pgoff_t page_off, struct page *page,
                        struct bio **bio_chain)
{
        struct bio *bio;
 
        bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
        if (!bio)
                return -ENOMEM;
        bio->bi_sector = page_off * (PAGE_SIZE >> 9);
        bio->bi_bdev = resume_bdev;
        bio->bi_end_io = end_swap_bio_read;
 
        if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
                printk("swsusp: ERROR: adding page to bio at %ld\n", page_off);
                bio_put(bio);
                return -EFAULT;
        }
 
        lock_page(page);
        bio_get(bio);
 
        if (bio_chain == NULL) {
                submit_bio(rw | (1 << BIO_RW_SYNC), bio);
                wait_on_page_locked(page);
                if (rw == READ)
                        bio_set_pages_dirty(bio);
                bio_put(bio);
        } else {
                if (rw == READ)
                        get_page(page); /* These pages are freed later */
                bio->bi_private = *bio_chain;
                *bio_chain = bio;
                submit_bio(rw | (1 << BIO_RW_SYNC), bio);
        }
        return 0;
}
 
static int bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
{
        return submit(READ, page_off, virt_to_page(addr), bio_chain);
}
 
static int bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
{
        return submit(WRITE, page_off, virt_to_page(addr), bio_chain);
}
 
static int wait_on_bio_chain(struct bio **bio_chain)
{
        struct bio *bio;
        struct bio *next_bio;
        int ret = 0;
 
        if (bio_chain == NULL)
                return 0;
 
        bio = *bio_chain;
        if (bio == NULL)
                return 0;
        while (bio) {
                struct page *page;
 
                next_bio = bio->bi_private;
                page = bio->bi_io_vec[0].bv_page;
                wait_on_page_locked(page);
                if (!PageUptodate(page) || PageError(page))
                        ret = -EIO;
                put_page(page);
                bio_put(bio);
                bio = next_bio;
        }
        *bio_chain = NULL;
        return ret;
}
 
/*
 * Saving part
 */
 
static int mark_swapfiles(sector_t start, unsigned int flags)
{
        int error;
 
        bio_read_page(swsusp_resume_block, swsusp_header, NULL);
        if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
            !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
                memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
                memcpy(swsusp_header->sig,SWSUSP_SIG, 10);
                swsusp_header->image = start;
                swsusp_header->flags = flags;
                error = bio_write_page(swsusp_resume_block,
                                        swsusp_header, NULL);
        } else {
                printk(KERN_ERR "swsusp: Swap header not found!\n");
                error = -ENODEV;
        }
        return error;
}
 
/**
 *      swsusp_swap_check - check if the resume device is a swap device
 *      and get its index (if so)
 */
 
static int swsusp_swap_check(void) /* This is called before saving image */
{
        int res;
 
        res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
                        &resume_bdev);
        if (res < 0)
                return res;
 
        root_swap = res;
        res = blkdev_get(resume_bdev, FMODE_WRITE, O_RDWR);
        if (res)
                return res;
 
        res = set_blocksize(resume_bdev, PAGE_SIZE);
        if (res < 0)
                blkdev_put(resume_bdev);
 
        return res;
}
 
/**
 *      write_page - Write one page to given swap location.
 *      @buf:           Address we're writing.
 *      @offset:        Offset of the swap page we're writing to.
 *      @bio_chain:     Link the next write BIO here
 */
 
static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
{
        void *src;
 
        if (!offset)
                return -ENOSPC;
 
        if (bio_chain) {
                src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
                if (src) {
                        memcpy(src, buf, PAGE_SIZE);
                } else {
                        WARN_ON_ONCE(1);
                        bio_chain = NULL;       /* Go synchronous */
                        src = buf;
                }
        } else {
                src = buf;
        }
        return bio_write_page(offset, src, bio_chain);
}
 
/*
 *      The swap map is a data structure used for keeping track of each page
 *      written to a swap partition.  It consists of many swap_map_page
 *      structures that contain each an array of MAP_PAGE_SIZE swap entries.
 *      These structures are stored on the swap and linked together with the
 *      help of the .next_swap member.
 *
 *      The swap map is created during suspend.  The swap map pages are
 *      allocated and populated one at a time, so we only need one memory
 *      page to set up the entire structure.
 *
 *      During resume we also only need to use one swap_map_page structure
 *      at a time.
 */
 
#define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
 
struct swap_map_page {
        sector_t entries[MAP_PAGE_ENTRIES];
        sector_t next_swap;
};
 
/**
 *      The swap_map_handle structure is used for handling swap in
 *      a file-alike way
 */
 
struct swap_map_handle {
        struct swap_map_page *cur;
        sector_t cur_swap;
        unsigned int k;
};
 
static void release_swap_writer(struct swap_map_handle *handle)
{
        if (handle->cur)
                free_page((unsigned long)handle->cur);
        handle->cur = NULL;
}
 
static int get_swap_writer(struct swap_map_handle *handle)
{
        handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
        if (!handle->cur)
                return -ENOMEM;
        handle->cur_swap = alloc_swapdev_block(root_swap);
        if (!handle->cur_swap) {
                release_swap_writer(handle);
                return -ENOSPC;
        }
        handle->k = 0;
        return 0;
}
 
static int swap_write_page(struct swap_map_handle *handle, void *buf,
                                struct bio **bio_chain)
{
        int error = 0;
        sector_t offset;
 
        if (!handle->cur)
                return -EINVAL;
        offset = alloc_swapdev_block(root_swap);
        error = write_page(buf, offset, bio_chain);
        if (error)
                return error;
        handle->cur->entries[handle->k++] = offset;
        if (handle->k >= MAP_PAGE_ENTRIES) {
                error = wait_on_bio_chain(bio_chain);
                if (error)
                        goto out;
                offset = alloc_swapdev_block(root_swap);
                if (!offset)
                        return -ENOSPC;
                handle->cur->next_swap = offset;
                error = write_page(handle->cur, handle->cur_swap, NULL);
                if (error)
                        goto out;
                memset(handle->cur, 0, PAGE_SIZE);
                handle->cur_swap = offset;
                handle->k = 0;
        }
 out:
        return error;
}
 
static int flush_swap_writer(struct swap_map_handle *handle)
{
        if (handle->cur && handle->cur_swap)
                return write_page(handle->cur, handle->cur_swap, NULL);
        else
                return -EINVAL;
}
 
/**
 *      save_image - save the suspend image data
 */
 
static int save_image(struct swap_map_handle *handle,
                      struct snapshot_handle *snapshot,
                      unsigned int nr_to_write)
{
        unsigned int m;
        int ret;
        int error = 0;
        int nr_pages;
        int err2;
        struct bio *bio;
        struct timeval start;
        struct timeval stop;
 
        printk("Saving image data pages (%u pages) ...     ", nr_to_write);
        m = nr_to_write / 100;
        if (!m)
                m = 1;
        nr_pages = 0;
        bio = NULL;
        do_gettimeofday(&start);
        do {
                ret = snapshot_read_next(snapshot, PAGE_SIZE);
                if (ret > 0) {
                        error = swap_write_page(handle, data_of(*snapshot),
                                                &bio);
                        if (error)
                                break;
                        if (!(nr_pages % m))
                                printk("\b\b\b\b%3d%%", nr_pages / m);
                        nr_pages++;
                }
        } while (ret > 0);
        err2 = wait_on_bio_chain(&bio);
        do_gettimeofday(&stop);
        if (!error)
                error = err2;
        if (!error)
                printk("\b\b\b\bdone\n");
        swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
        return error;
}
 
/**
 *      enough_swap - Make sure we have enough swap to save the image.
 *
 *      Returns TRUE or FALSE after checking the total amount of swap
 *      space avaiable from the resume partition.
 */
 
static int enough_swap(unsigned int nr_pages)
{
        unsigned int free_swap = count_swap_pages(root_swap, 1);
 
        pr_debug("swsusp: free swap pages: %u\n", free_swap);
        return free_swap > nr_pages + PAGES_FOR_IO;
}
 
/**
 *      swsusp_write - Write entire image and metadata.
 *      @flags: flags to pass to the "boot" kernel in the image header
 *
 *      It is important _NOT_ to umount filesystems at this point. We want
 *      them synced (in case something goes wrong) but we DO not want to mark
 *      filesystem clean: it is not. (And it does not matter, if we resume
 *      correctly, we'll mark system clean, anyway.)
 */
 
int swsusp_write(unsigned int flags)
{
        struct swap_map_handle handle;
        struct snapshot_handle snapshot;
        struct swsusp_info *header;
        int error;
 
        error = swsusp_swap_check();
        if (error) {
                printk(KERN_ERR "swsusp: Cannot find swap device, try "
                                "swapon -a.\n");
                return error;
        }
        memset(&snapshot, 0, sizeof(struct snapshot_handle));
        error = snapshot_read_next(&snapshot, PAGE_SIZE);
        if (error < PAGE_SIZE) {
                if (error >= 0)
                        error = -EFAULT;
 
                goto out;
        }
        header = (struct swsusp_info *)data_of(snapshot);
        if (!enough_swap(header->pages)) {
                printk(KERN_ERR "swsusp: Not enough free swap\n");
                error = -ENOSPC;
                goto out;
        }
        error = get_swap_writer(&handle);
        if (!error) {
                sector_t start = handle.cur_swap;
 
                error = swap_write_page(&handle, header, NULL);
                if (!error)
                        error = save_image(&handle, &snapshot,
                                        header->pages - 1);
 
                if (!error) {
                        flush_swap_writer(&handle);
                        printk("S");
                        error = mark_swapfiles(start, flags);
                        printk("|\n");
                }
        }
        if (error)
                free_all_swap_pages(root_swap);
 
        release_swap_writer(&handle);
 out:
        swsusp_close();
        return error;
}
 
/**
 *      The following functions allow us to read data using a swap map
 *      in a file-alike way
 */
 
static void release_swap_reader(struct swap_map_handle *handle)
{
        if (handle->cur)
                free_page((unsigned long)handle->cur);
        handle->cur = NULL;
}
 
static int get_swap_reader(struct swap_map_handle *handle, sector_t start)
{
        int error;
 
        if (!start)
                return -EINVAL;
 
        handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH);
        if (!handle->cur)
                return -ENOMEM;
 
        error = bio_read_page(start, handle->cur, NULL);
        if (error) {
                release_swap_reader(handle);
                return error;
        }
        handle->k = 0;
        return 0;
}
 
static int swap_read_page(struct swap_map_handle *handle, void *buf,
                                struct bio **bio_chain)
{
        sector_t offset;
        int error;
 
        if (!handle->cur)
                return -EINVAL;
        offset = handle->cur->entries[handle->k];
        if (!offset)
                return -EFAULT;
        error = bio_read_page(offset, buf, bio_chain);
        if (error)
                return error;
        if (++handle->k >= MAP_PAGE_ENTRIES) {
                error = wait_on_bio_chain(bio_chain);
                handle->k = 0;
                offset = handle->cur->next_swap;
                if (!offset)
                        release_swap_reader(handle);
                else if (!error)
                        error = bio_read_page(offset, handle->cur, NULL);
        }
        return error;
}
 
/**
 *      load_image - load the image using the swap map handle
 *      @handle and the snapshot handle @snapshot
 *      (assume there are @nr_pages pages to load)
 */
 
static int load_image(struct swap_map_handle *handle,
                      struct snapshot_handle *snapshot,
                      unsigned int nr_to_read)
{
        unsigned int m;
        int error = 0;
        struct timeval start;
        struct timeval stop;
        struct bio *bio;
        int err2;
        unsigned nr_pages;
 
        printk("Loading image data pages (%u pages) ...     ", nr_to_read);
        m = nr_to_read / 100;
        if (!m)
                m = 1;
        nr_pages = 0;
        bio = NULL;
        do_gettimeofday(&start);
        for ( ; ; ) {
                error = snapshot_write_next(snapshot, PAGE_SIZE);
                if (error <= 0)
                        break;
                error = swap_read_page(handle, data_of(*snapshot), &bio);
                if (error)
                        break;
                if (snapshot->sync_read)
                        error = wait_on_bio_chain(&bio);
                if (error)
                        break;
                if (!(nr_pages % m))
                        printk("\b\b\b\b%3d%%", nr_pages / m);
                nr_pages++;
        }
        err2 = wait_on_bio_chain(&bio);
        do_gettimeofday(&stop);
        if (!error)
                error = err2;
        if (!error) {
                printk("\b\b\b\bdone\n");
                snapshot_write_finalize(snapshot);
                if (!snapshot_image_loaded(snapshot))
                        error = -ENODATA;
        }
        swsusp_show_speed(&start, &stop, nr_to_read, "Read");
        return error;
}
 
/**
 *      swsusp_read - read the hibernation image.
 *      @flags_p: flags passed by the "frozen" kernel in the image header should
 *                be written into this memeory location
 */
 
int swsusp_read(unsigned int *flags_p)
{
        int error;
        struct swap_map_handle handle;
        struct snapshot_handle snapshot;
        struct swsusp_info *header;
 
        *flags_p = swsusp_header->flags;
        if (IS_ERR(resume_bdev)) {
                pr_debug("swsusp: block device not initialised\n");
                return PTR_ERR(resume_bdev);
        }
 
        memset(&snapshot, 0, sizeof(struct snapshot_handle));
        error = snapshot_write_next(&snapshot, PAGE_SIZE);
        if (error < PAGE_SIZE)
                return error < 0 ? error : -EFAULT;
        header = (struct swsusp_info *)data_of(snapshot);
        error = get_swap_reader(&handle, swsusp_header->image);
        if (!error)
                error = swap_read_page(&handle, header, NULL);
        if (!error)
                error = load_image(&handle, &snapshot, header->pages - 1);
        release_swap_reader(&handle);
 
        blkdev_put(resume_bdev);
 
        if (!error)
                pr_debug("swsusp: Reading resume file was successful\n");
        else
                pr_debug("swsusp: Error %d resuming\n", error);
        return error;
}
 
/**
 *      swsusp_check - Check for swsusp signature in the resume device
 */
 
int swsusp_check(void)
{
        int error;
 
        resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
        if (!IS_ERR(resume_bdev)) {
                set_blocksize(resume_bdev, PAGE_SIZE);
                memset(swsusp_header, 0, PAGE_SIZE);
                error = bio_read_page(swsusp_resume_block,
                                        swsusp_header, NULL);
                if (error)
                        return error;
 
                if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) {
                        memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
                        /* Reset swap signature now */
                        error = bio_write_page(swsusp_resume_block,
                                                swsusp_header, NULL);
                } else {
                        return -EINVAL;
                }
                if (error)
                        blkdev_put(resume_bdev);
                else
                        pr_debug("swsusp: Signature found, resuming\n");
        } else {
                error = PTR_ERR(resume_bdev);
        }
 
        if (error)
                pr_debug("swsusp: Error %d check for resume file\n", error);
 
        return error;
}
 
/**
 *      swsusp_close - close swap device.
 */
 
void swsusp_close(void)
{
        if (IS_ERR(resume_bdev)) {
                pr_debug("swsusp: block device not initialised\n");
                return;
        }
 
        blkdev_put(resume_bdev);
}
 
static int swsusp_header_init(void)
{
        swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
        if (!swsusp_header)
                panic("Could not allocate memory for swsusp_header\n");
        return 0;
}
 
core_initcall(swsusp_header_init);

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[/] [test_project/] [trunk/] [linux_sd_driver/] [kernel/] [power/] [swap.c] - Blame information for rev 62

Line No.	Rev	Author	Line
1	62	marcus.erl	`/*`
2			`* linux/kernel/power/swap.c`
3			`*`
4			`* This file provides functions for reading the suspend image from`
5			`* and writing it to a swap partition.`
6			`*`
7			`* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>`
8			`* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>`
9			`*`
10			`* This file is released under the GPLv2.`
11			`*`
12			`*/`
13
14			`#include <linux/module.h>`
15			`#include <linux/file.h>`
16			`#include <linux/utsname.h>`
17			`#include <linux/version.h>`
18			`#include <linux/delay.h>`
19			`#include <linux/bitops.h>`
20			`#include <linux/genhd.h>`
21			`#include <linux/device.h>`
22			`#include <linux/buffer_head.h>`
23			`#include <linux/bio.h>`
24			`#include <linux/blkdev.h>`
25			`#include <linux/swap.h>`
26			`#include <linux/swapops.h>`
27			`#include <linux/pm.h>`
28
29			`#include "power.h"`
30
31			`extern char resume_file[];`
32
33			`#define SWSUSP_SIG "S1SUSPEND"`
34
35			`struct swsusp_header {`
36			`char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)];`
37			`sector_t image;`
38			`unsigned int flags; /* Flags to pass to the "boot" kernel */`
39			`char orig_sig[10];`
40			`char sig[10];`
41			`} __attribute__((packed));`
42
43			`static struct swsusp_header *swsusp_header;`
44
45			`/*`
46			`* General things`
47			`*/`
48
49			`static unsigned short root_swap = 0xffff;`
50			`static struct block_device *resume_bdev;`
51
52			`/**`
53			`* submit - submit BIO request.`
54			`* @rw: READ or WRITE.`
55			`* @off physical offset of page.`
56			`* @page: page we're reading or writing.`
57			`* @bio_chain: list of pending biod (for async reading)`
58			`*`
59			`* Straight from the textbook - allocate and initialize the bio.`
60			`* If we're reading, make sure the page is marked as dirty.`
61			`* Then submit it and, if @bio_chain == NULL, wait.`
62			`*/`
63			`static int submit(int rw, pgoff_t page_off, struct page *page,`
64			`struct bio **bio_chain)`
65			`{`
66			`struct bio *bio;`
67
68			`bio = bio_alloc(__GFP_WAIT \| __GFP_HIGH, 1);`
69			`if (!bio)`
70			`return -ENOMEM;`
71			`bio->bi_sector = page_off * (PAGE_SIZE >> 9);`
72			`bio->bi_bdev = resume_bdev;`
73			`bio->bi_end_io = end_swap_bio_read;`
74
75			`if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {`
76			`printk("swsusp: ERROR: adding page to bio at %ld\n", page_off);`
77			`bio_put(bio);`
78			`return -EFAULT;`
79			`}`
80
81			`lock_page(page);`
82			`bio_get(bio);`
83
84			`if (bio_chain == NULL) {`
85			`submit_bio(rw \| (1 << BIO_RW_SYNC), bio);`
86			`wait_on_page_locked(page);`
87			`if (rw == READ)`
88			`bio_set_pages_dirty(bio);`
89			`bio_put(bio);`
90			`} else {`
91			`if (rw == READ)`
92			`get_page(page); /* These pages are freed later */`
93			`bio->bi_private = *bio_chain;`
94			`*bio_chain = bio;`
95			`submit_bio(rw \| (1 << BIO_RW_SYNC), bio);`
96			`}`
97			`return 0;`
98			`}`
99
100			`static int bio_read_page(pgoff_t page_off, void addr, struct bio *bio_chain)`
101			`{`
102			`return submit(READ, page_off, virt_to_page(addr), bio_chain);`
103			`}`
104
105			`static int bio_write_page(pgoff_t page_off, void addr, struct bio *bio_chain)`
106			`{`
107			`return submit(WRITE, page_off, virt_to_page(addr), bio_chain);`
108			`}`
109
110			`static int wait_on_bio_chain(struct bio **bio_chain)`
111			`{`
112			`struct bio *bio;`
113			`struct bio *next_bio;`
114			`int ret = 0;`
115
116			`if (bio_chain == NULL)`
117			`return 0;`
118
119			`bio = *bio_chain;`
120			`if (bio == NULL)`
121			`return 0;`
122			`while (bio) {`
123			`struct page *page;`
124
125			`next_bio = bio->bi_private;`
126			`page = bio->bi_io_vec[0].bv_page;`
127			`wait_on_page_locked(page);`
128			`if (!PageUptodate(page) \|\| PageError(page))`
129			`ret = -EIO;`
130			`put_page(page);`
131			`bio_put(bio);`
132			`bio = next_bio;`
133			`}`
134			`*bio_chain = NULL;`
135			`return ret;`
136			`}`
137
138			`/*`
139			`* Saving part`
140			`*/`
141
142			`static int mark_swapfiles(sector_t start, unsigned int flags)`
143			`{`
144			`int error;`
145
146			`bio_read_page(swsusp_resume_block, swsusp_header, NULL);`
147			`if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) \|\|`
148			`!memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {`
149			`memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);`
150			`memcpy(swsusp_header->sig,SWSUSP_SIG, 10);`
151			`swsusp_header->image = start;`
152			`swsusp_header->flags = flags;`
153			`error = bio_write_page(swsusp_resume_block,`
154			`swsusp_header, NULL);`
155			`} else {`
156			`printk(KERN_ERR "swsusp: Swap header not found!\n");`
157			`error = -ENODEV;`
158			`}`
159			`return error;`
160			`}`
161
162			`/**`
163			`* swsusp_swap_check - check if the resume device is a swap device`
164			`* and get its index (if so)`
165			`*/`
166
167			`static int swsusp_swap_check(void) /* This is called before saving image */`
168			`{`
169			`int res;`
170
171			`res = swap_type_of(swsusp_resume_device, swsusp_resume_block,`
172			`&resume_bdev);`
173			`if (res < 0)`
174			`return res;`
175
176			`root_swap = res;`
177			`res = blkdev_get(resume_bdev, FMODE_WRITE, O_RDWR);`
178			`if (res)`
179			`return res;`
180
181			`res = set_blocksize(resume_bdev, PAGE_SIZE);`
182			`if (res < 0)`
183			`blkdev_put(resume_bdev);`
184
185			`return res;`
186			`}`
187
188			`/**`
189			`* write_page - Write one page to given swap location.`
190			`* @buf: Address we're writing.`
191			`* @offset: Offset of the swap page we're writing to.`
192			`* @bio_chain: Link the next write BIO here`
193			`*/`
194
195			`static int write_page(void buf, sector_t offset, struct bio *bio_chain)`
196			`{`
197			`void *src;`
198
199			`if (!offset)`
200			`return -ENOSPC;`
201
202			`if (bio_chain) {`
203			`src = (void *)__get_free_page(__GFP_WAIT \| __GFP_HIGH);`
204			`if (src) {`
205			`memcpy(src, buf, PAGE_SIZE);`
206			`} else {`
207			`WARN_ON_ONCE(1);`
208			`bio_chain = NULL; /* Go synchronous */`
209			`src = buf;`
210			`}`
211			`} else {`
212			`src = buf;`
213			`}`
214			`return bio_write_page(offset, src, bio_chain);`
215			`}`
216
217			`/*`
218			`* The swap map is a data structure used for keeping track of each page`
219			`* written to a swap partition. It consists of many swap_map_page`
220			`* structures that contain each an array of MAP_PAGE_SIZE swap entries.`
221			`* These structures are stored on the swap and linked together with the`
222			`* help of the .next_swap member.`
223			`*`
224			`* The swap map is created during suspend. The swap map pages are`
225			`* allocated and populated one at a time, so we only need one memory`
226			`* page to set up the entire structure.`
227			`*`
228			`* During resume we also only need to use one swap_map_page structure`
229			`* at a time.`
230			`*/`
231
232			`#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)`
233
234			`struct swap_map_page {`
235			`sector_t entries[MAP_PAGE_ENTRIES];`
236			`sector_t next_swap;`
237			`};`
238
239			`/**`
240			`* The swap_map_handle structure is used for handling swap in`
241			`* a file-alike way`
242			`*/`
243
244			`struct swap_map_handle {`
245			`struct swap_map_page *cur;`
246			`sector_t cur_swap;`
247			`unsigned int k;`
248			`};`
249
250			`static void release_swap_writer(struct swap_map_handle *handle)`
251			`{`
252			`if (handle->cur)`
253			`free_page((unsigned long)handle->cur);`
254			`handle->cur = NULL;`
255			`}`
256
257			`static int get_swap_writer(struct swap_map_handle *handle)`
258			`{`
259			`handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);`
260			`if (!handle->cur)`
261			`return -ENOMEM;`
262			`handle->cur_swap = alloc_swapdev_block(root_swap);`
263			`if (!handle->cur_swap) {`
264			`release_swap_writer(handle);`
265			`return -ENOSPC;`
266			`}`
267			`handle->k = 0;`
268			`return 0;`
269			`}`
270
271			`static int swap_write_page(struct swap_map_handle handle, void buf,`
272			`struct bio **bio_chain)`
273			`{`
274			`int error = 0;`
275			`sector_t offset;`
276
277			`if (!handle->cur)`
278			`return -EINVAL;`
279			`offset = alloc_swapdev_block(root_swap);`
280			`error = write_page(buf, offset, bio_chain);`
281			`if (error)`
282			`return error;`
283			`handle->cur->entries[handle->k++] = offset;`
284			`if (handle->k >= MAP_PAGE_ENTRIES) {`
285			`error = wait_on_bio_chain(bio_chain);`
286			`if (error)`
287			`goto out;`
288			`offset = alloc_swapdev_block(root_swap);`
289			`if (!offset)`
290			`return -ENOSPC;`
291			`handle->cur->next_swap = offset;`
292			`error = write_page(handle->cur, handle->cur_swap, NULL);`
293			`if (error)`
294			`goto out;`
295			`memset(handle->cur, 0, PAGE_SIZE);`
296			`handle->cur_swap = offset;`
297			`handle->k = 0;`
298			`}`
299			`out:`
300			`return error;`
301			`}`
302
303			`static int flush_swap_writer(struct swap_map_handle *handle)`
304			`{`
305			`if (handle->cur && handle->cur_swap)`
306			`return write_page(handle->cur, handle->cur_swap, NULL);`
307			`else`
308			`return -EINVAL;`
309			`}`
310
311			`/**`
312			`* save_image - save the suspend image data`
313			`*/`
314
315			`static int save_image(struct swap_map_handle *handle,`
316			`struct snapshot_handle *snapshot,`
317			`unsigned int nr_to_write)`
318			`{`
319			`unsigned int m;`
320			`int ret;`
321			`int error = 0;`
322			`int nr_pages;`
323			`int err2;`
324			`struct bio *bio;`
325			`struct timeval start;`
326			`struct timeval stop;`
327
328			`printk("Saving image data pages (%u pages) ... ", nr_to_write);`
329			`m = nr_to_write / 100;`
330			`if (!m)`
331			`m = 1;`
332			`nr_pages = 0;`
333			`bio = NULL;`
334			`do_gettimeofday(&start);`
335			`do {`
336			`ret = snapshot_read_next(snapshot, PAGE_SIZE);`
337			`if (ret > 0) {`
338			`error = swap_write_page(handle, data_of(*snapshot),`
339			`&bio);`
340			`if (error)`
341			`break;`
342			`if (!(nr_pages % m))`
343			`printk("\b\b\b\b%3d%%", nr_pages / m);`
344			`nr_pages++;`
345			`}`
346			`} while (ret > 0);`
347			`err2 = wait_on_bio_chain(&bio);`
348			`do_gettimeofday(&stop);`
349			`if (!error)`
350			`error = err2;`
351			`if (!error)`
352			`printk("\b\b\b\bdone\n");`
353			`swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");`
354			`return error;`
355			`}`
356
357			`/**`
358			`* enough_swap - Make sure we have enough swap to save the image.`
359			`*`
360			`* Returns TRUE or FALSE after checking the total amount of swap`
361			`* space avaiable from the resume partition.`
362			`*/`
363
364			`static int enough_swap(unsigned int nr_pages)`
365			`{`
366			`unsigned int free_swap = count_swap_pages(root_swap, 1);`
367
368			`pr_debug("swsusp: free swap pages: %u\n", free_swap);`
369			`return free_swap > nr_pages + PAGES_FOR_IO;`
370			`}`
371
372			`/**`
373			`* swsusp_write - Write entire image and metadata.`
374			`* @flags: flags to pass to the "boot" kernel in the image header`
375			`*`
376			`* It is important _NOT_ to umount filesystems at this point. We want`
377			`* them synced (in case something goes wrong) but we DO not want to mark`
378			`* filesystem clean: it is not. (And it does not matter, if we resume`
379			`* correctly, we'll mark system clean, anyway.)`
380			`*/`
381
382			`int swsusp_write(unsigned int flags)`
383			`{`
384			`struct swap_map_handle handle;`
385			`struct snapshot_handle snapshot;`
386			`struct swsusp_info *header;`
387			`int error;`
388
389			`error = swsusp_swap_check();`
390			`if (error) {`
391			`printk(KERN_ERR "swsusp: Cannot find swap device, try "`
392			`"swapon -a.\n");`
393			`return error;`
394			`}`
395			`memset(&snapshot, 0, sizeof(struct snapshot_handle));`
396			`error = snapshot_read_next(&snapshot, PAGE_SIZE);`
397			`if (error < PAGE_SIZE) {`
398			`if (error >= 0)`
399			`error = -EFAULT;`
400
401			`goto out;`
402			`}`
403			`header = (struct swsusp_info *)data_of(snapshot);`
404			`if (!enough_swap(header->pages)) {`
405			`printk(KERN_ERR "swsusp: Not enough free swap\n");`
406			`error = -ENOSPC;`
407			`goto out;`
408			`}`
409			`error = get_swap_writer(&handle);`
410			`if (!error) {`
411			`sector_t start = handle.cur_swap;`
412
413			`error = swap_write_page(&handle, header, NULL);`
414			`if (!error)`
415			`error = save_image(&handle, &snapshot,`
416			`header->pages - 1);`
417
418			`if (!error) {`
419			`flush_swap_writer(&handle);`
420			`printk("S");`
421			`error = mark_swapfiles(start, flags);`
422			`printk("\|\n");`
423			`}`
424			`}`
425			`if (error)`
426			`free_all_swap_pages(root_swap);`
427
428			`release_swap_writer(&handle);`
429			`out:`
430			`swsusp_close();`
431			`return error;`
432			`}`
433
434			`/**`
435			`* The following functions allow us to read data using a swap map`
436			`* in a file-alike way`
437			`*/`
438
439			`static void release_swap_reader(struct swap_map_handle *handle)`
440			`{`
441			`if (handle->cur)`
442			`free_page((unsigned long)handle->cur);`
443			`handle->cur = NULL;`
444			`}`
445
446			`static int get_swap_reader(struct swap_map_handle *handle, sector_t start)`
447			`{`
448			`int error;`
449
450			`if (!start)`
451			`return -EINVAL;`
452
453			`handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT \| __GFP_HIGH);`
454			`if (!handle->cur)`
455			`return -ENOMEM;`
456
457			`error = bio_read_page(start, handle->cur, NULL);`
458			`if (error) {`
459			`release_swap_reader(handle);`
460			`return error;`
461			`}`
462			`handle->k = 0;`
463			`return 0;`
464			`}`
465
466			`static int swap_read_page(struct swap_map_handle handle, void buf,`
467			`struct bio **bio_chain)`
468			`{`
469			`sector_t offset;`
470			`int error;`
471
472			`if (!handle->cur)`
473			`return -EINVAL;`
474			`offset = handle->cur->entries[handle->k];`
475			`if (!offset)`
476			`return -EFAULT;`
477			`error = bio_read_page(offset, buf, bio_chain);`
478			`if (error)`
479			`return error;`
480			`if (++handle->k >= MAP_PAGE_ENTRIES) {`
481			`error = wait_on_bio_chain(bio_chain);`
482			`handle->k = 0;`
483			`offset = handle->cur->next_swap;`
484			`if (!offset)`
485			`release_swap_reader(handle);`
486			`else if (!error)`
487			`error = bio_read_page(offset, handle->cur, NULL);`
488			`}`
489			`return error;`
490			`}`
491
492			`/**`
493			`* load_image - load the image using the swap map handle`
494			`* @handle and the snapshot handle @snapshot`
495			`* (assume there are @nr_pages pages to load)`
496			`*/`
497
498			`static int load_image(struct swap_map_handle *handle,`
499			`struct snapshot_handle *snapshot,`
500			`unsigned int nr_to_read)`
501			`{`
502			`unsigned int m;`
503			`int error = 0;`
504			`struct timeval start;`
505			`struct timeval stop;`
506			`struct bio *bio;`
507			`int err2;`
508			`unsigned nr_pages;`
509
510			`printk("Loading image data pages (%u pages) ... ", nr_to_read);`
511			`m = nr_to_read / 100;`
512			`if (!m)`
513			`m = 1;`
514			`nr_pages = 0;`
515			`bio = NULL;`
516			`do_gettimeofday(&start);`
517			`for ( ; ; ) {`
518			`error = snapshot_write_next(snapshot, PAGE_SIZE);`
519			`if (error <= 0)`
520			`break;`
521			`error = swap_read_page(handle, data_of(*snapshot), &bio);`
522			`if (error)`
523			`break;`
524			`if (snapshot->sync_read)`
525			`error = wait_on_bio_chain(&bio);`
526			`if (error)`
527			`break;`
528			`if (!(nr_pages % m))`
529			`printk("\b\b\b\b%3d%%", nr_pages / m);`
530			`nr_pages++;`
531			`}`
532			`err2 = wait_on_bio_chain(&bio);`
533			`do_gettimeofday(&stop);`
534			`if (!error)`
535			`error = err2;`
536			`if (!error) {`
537			`printk("\b\b\b\bdone\n");`
538			`snapshot_write_finalize(snapshot);`
539			`if (!snapshot_image_loaded(snapshot))`
540			`error = -ENODATA;`
541			`}`
542			`swsusp_show_speed(&start, &stop, nr_to_read, "Read");`
543			`return error;`
544			`}`
545
546			`/**`
547			`* swsusp_read - read the hibernation image.`
548			`* @flags_p: flags passed by the "frozen" kernel in the image header should`
549			`* be written into this memeory location`
550			`*/`
551
552			`int swsusp_read(unsigned int *flags_p)`
553			`{`
554			`int error;`
555			`struct swap_map_handle handle;`
556			`struct snapshot_handle snapshot;`
557			`struct swsusp_info *header;`
558
559			`*flags_p = swsusp_header->flags;`
560			`if (IS_ERR(resume_bdev)) {`
561			`pr_debug("swsusp: block device not initialised\n");`
562			`return PTR_ERR(resume_bdev);`
563			`}`
564
565			`memset(&snapshot, 0, sizeof(struct snapshot_handle));`
566			`error = snapshot_write_next(&snapshot, PAGE_SIZE);`
567			`if (error < PAGE_SIZE)`
568			`return error < 0 ? error : -EFAULT;`
569			`header = (struct swsusp_info *)data_of(snapshot);`
570			`error = get_swap_reader(&handle, swsusp_header->image);`
571			`if (!error)`
572			`error = swap_read_page(&handle, header, NULL);`
573			`if (!error)`
574			`error = load_image(&handle, &snapshot, header->pages - 1);`
575			`release_swap_reader(&handle);`
576
577			`blkdev_put(resume_bdev);`
578
579			`if (!error)`
580			`pr_debug("swsusp: Reading resume file was successful\n");`
581			`else`
582			`pr_debug("swsusp: Error %d resuming\n", error);`
583			`return error;`
584			`}`
585
586			`/**`
587			`* swsusp_check - Check for swsusp signature in the resume device`
588			`*/`
589
590			`int swsusp_check(void)`
591			`{`
592			`int error;`
593
594			`resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);`
595			`if (!IS_ERR(resume_bdev)) {`
596			`set_blocksize(resume_bdev, PAGE_SIZE);`
597			`memset(swsusp_header, 0, PAGE_SIZE);`
598			`error = bio_read_page(swsusp_resume_block,`
599			`swsusp_header, NULL);`
600			`if (error)`
601			`return error;`
602
603			`if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) {`
604			`memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);`
605			`/* Reset swap signature now */`
606			`error = bio_write_page(swsusp_resume_block,`
607			`swsusp_header, NULL);`
608			`} else {`
609			`return -EINVAL;`
610			`}`
611			`if (error)`
612			`blkdev_put(resume_bdev);`
613			`else`
614			`pr_debug("swsusp: Signature found, resuming\n");`
615			`} else {`
616			`error = PTR_ERR(resume_bdev);`
617			`}`
618
619			`if (error)`
620			`pr_debug("swsusp: Error %d check for resume file\n", error);`
621
622			`return error;`
623			`}`
624
625			`/**`
626			`* swsusp_close - close swap device.`
627			`*/`
628
629			`void swsusp_close(void)`
630			`{`
631			`if (IS_ERR(resume_bdev)) {`
632			`pr_debug("swsusp: block device not initialised\n");`
633			`return;`
634			`}`
635
636			`blkdev_put(resume_bdev);`
637			`}`
638
639			`static int swsusp_header_init(void)`
640			`{`
641			`swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);`
642			`if (!swsusp_header)`
643			`panic("Could not allocate memory for swsusp_header\n");`
644			`return 0;`
645			`}`
646
647			`core_initcall(swsusp_header_init);`