- 根目录:
- kernel
- power
- swap.c
/*
* 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@ucw.cz>
* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
* Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
*
* This file is released under the GPLv2.
*
*/
#include <linux/module.h>
#include <linux/file.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/genhd.h>
#include <linux/device.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/lzo.h>
#include <linux/vmalloc.h>
#include <linux/cpumask.h>
#include <linux/atomic.h>
#include <linux/kthread.h>
#include <linux/crc32.h>
#include "power.h"
#define HIBERNATE_SIG "S1SUSPEND"
/*
* 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_ENTRIES 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 pick up all swap_map_page structures into a list.
*/
#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
/*
* Number of free pages that are not high.
*/
static inline unsigned long low_free_pages(void)
{
return nr_free_pages() - nr_free_highpages();
}
/*
* Number of pages required to be kept free while writing the image. Always
* half of all available low pages before the writing starts.
*/
static inline unsigned long reqd_free_pages(void)
{
return low_free_pages() / 2;
}
struct swap_map_page {
sector_t entries[MAP_PAGE_ENTRIES];
sector_t next_swap;
};
struct swap_map_page_list {
struct swap_map_page *map;
struct swap_map_page_list *next;
};
/**
* The swap_map_handle structure is used for handling swap in
* a file-alike way
*/
struct swap_map_handle {
struct swap_map_page *cur;
struct swap_map_page_list *maps;
sector_t cur_swap;
sector_t first_sector;
unsigned int k;
unsigned long reqd_free_pages;
u32 crc32;
};
struct swsusp_header {
char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
sizeof(u32)];
u32 crc32;
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;
/**
* The following functions are used for tracing the allocated
* swap pages, so that they can be freed in case of an error.
*/
struct swsusp_extent {
struct rb_node node;
unsigned long start;
unsigned long end;
};
static struct rb_root swsusp_extents = RB_ROOT;
static int swsusp_extents_insert(unsigned long swap_offset)
{
struct rb_node **new = &(swsusp_extents.rb_node);
struct rb_node *parent = NULL;
struct swsusp_extent *ext;
/* Figure out where to put the new node */
while (*new) {
ext = container_of(*new, struct swsusp_extent, node);
parent = *new;
if (swap_offset < ext->start) {
/* Try to merge */
if (swap_offset == ext->start - 1) {
ext->start--;
return 0;
}
new = &((*new)->rb_left);
} else if (swap_offset > ext->end) {
/* Try to merge */
if (swap_offset == ext->end + 1) {
ext->end++;
return 0;
}
new = &((*new)->rb_right);
} else {
/* It already is in the tree */
return -EINVAL;
}
}
/* Add the new node and rebalance the tree. */
ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
if (!ext)
return -ENOMEM;
ext->start = swap_offset;
ext->end = swap_offset;
rb_link_node(&ext->node, parent, new);
rb_insert_color(&ext->node, &swsusp_extents);
return 0;
}
/**
* alloc_swapdev_block - allocate a swap page and register that it has
* been allocated, so that it can be freed in case of an error.
*/
sector_t alloc_swapdev_block(int swap)
{
unsigned long offset;
offset = swp_offset(get_swap_page_of_type(swap));
if (offset) {
if (swsusp_extents_insert(offset))
swap_free(swp_entry(swap, offset));
else
return swapdev_block(swap, offset);
}
return 0;
}
/**
* free_all_swap_pages - free swap pages allocated for saving image data.
* It also frees the extents used to register which swap entries had been
* allocated.
*/
void free_all_swap_pages(int swap)
{
struct rb_node *node;
while ((node = swsusp_extents.rb_node)) {
struct swsusp_extent *ext;
unsigned long offset;
ext = container_of(node, struct swsusp_extent, node);
rb_erase(node, &swsusp_extents);
for (offset = ext->start; offset <= ext->end; offset++)
swap_free(swp_entry(swap, offset));
kfree(ext);
}
}
int swsusp_swap_in_use(void)
{
return (swsusp_extents.rb_node != NULL);
}
/*
* General things
*/
static unsigned short root_swap = 0xffff;
struct block_device *hib_resume_bdev;
/*
* Saving part
*/
static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
{
int error;
hib_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, HIBERNATE_SIG, 10);
swsusp_header->image = handle->first_sector;
swsusp_header->flags = flags;
if (flags & SF_CRC32_MODE)
swsusp_header->crc32 = handle->crc32;
error = hib_bio_write_page(swsusp_resume_block,
swsusp_header, NULL);
} else {
printk(KERN_ERR "PM: 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)
*
* This is called before saving image
*/
static int swsusp_swap_check(void)
{
int res;
res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
&hib_resume_bdev);
if (res < 0)
return res;
root_swap = res;
res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
if (res)
return res;
res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
if (res < 0)
blkdev_put(hib_resume_bdev, FMODE_WRITE);
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;
int ret;
if (!offset)
return -ENOSPC;
if (bio_chain) {
src = (void *)__get_free_page(__GFP_WAIT | __GFP_NOWARN |
__GFP_NORETRY);
if (src) {
copy_page(src, buf);
} else {
ret = hib_wait_on_bio_chain(bio_chain); /* Free pages */
if (ret)
return ret;
src = (void *)__get_free_page(__GFP_WAIT |
__GFP_NOWARN |
__GFP_NORETRY);
if (src) {
copy_page(src, buf);
} else {
WARN_ON_ONCE(1);
bio_chain = NULL; /* Go synchronous */
src = buf;
}
}
} else {
src = buf;
}
return hib_bio_write_page(offset, src, bio_chain);
}
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)
{
int ret;
ret = swsusp_swap_check();
if (ret) {
if (ret != -ENOSPC)
printk(KERN_ERR "PM: Cannot find swap device, try "
"swapon -a.\n");
return ret;
}
handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
if (!handle->cur) {
ret = -ENOMEM;
goto err_close;
}
handle->cur_swap = alloc_swapdev_block(root_swap);
if (!handle->cur_swap) {
ret = -ENOSPC;
goto err_rel;
}
handle->k = 0;
handle->reqd_free_pages = reqd_free_pages();
handle->first_sector = handle->cur_swap;
return 0;
err_rel:
release_swap_writer(handle);
err_close:
swsusp_close(FMODE_WRITE);
return ret;
}
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) {
offset = alloc_swapdev_block(root_swap);
if (!offset)
return -ENOSPC;
handle->cur->next_swap = offset;
error = write_page(handle->cur, handle->cur_swap, bio_chain);
if (error)
goto out;
clear_page(handle->cur);
handle->cur_swap = offset;
handle->k = 0;
if (bio_chain && low_free_pages() <= handle->reqd_free_pages) {
error = hib_wait_on_bio_chain(bio_chain);
if (error)
goto out;
/*
* Recalculate the number of required free pages, to
* make sure we never take more than half.
*/
handle->reqd_free_pages = reqd_free_pages();
}
}
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;
}
static int swap_writer_finish(struct swap_map_handle *handle,
unsigned int flags, int error)
{
if (!error) {
flush_swap_writer(handle);
printk(KERN_INFO "PM: S");
error = mark_swapfiles(handle, flags);
printk("|\n");
}
if (error)
free_all_swap_pages(root_swap);
release_swap_writer(handle);
swsusp_close(FMODE_WRITE);
return error;
}
/* We need to remember how much compressed data we need to read. */
#define LZO_HEADER sizeof(size_t)
/* Number of pages/bytes we'll compress at one time. */
#define LZO_UNC_PAGES 32
#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
/* Number of pages/bytes we need for compressed data (worst case). */
#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
LZO_HEADER, PAGE_SIZE)
#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
/* Maximum number of threads for compression/decompression. */
#define LZO_THREADS 3
/* Minimum/maximum number of pages for read buffering. */
#define LZO_MIN_RD_PAGES 1024
#define LZO_MAX_RD_PAGES 8192
/**
* 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 nr_pages;
int err2;
struct bio *bio;
struct timeval start;
struct timeval stop;
printk(KERN_INFO "PM: 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);
while (1) {
ret = snapshot_read_next(snapshot);
if (ret <= 0)
break;
ret = swap_write_page(handle, data_of(*snapshot), &bio);
if (ret)
break;
if (!(nr_pages % m))
printk(KERN_CONT "\b\b\b\b%3d%%", nr_pages / m);
nr_pages++;
}
err2 = hib_wait_on_bio_chain(&bio);
do_gettimeofday(&stop);
if (!ret)
ret = err2;
if (!ret)
printk(KERN_CONT "\b\b\b\bdone\n");
else
printk(KERN_CONT "\n");
swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
return ret;
}
/**
* Structure used for CRC32.
*/
struct crc_data {
struct task_struct *thr; /* thread */
atomic_t ready; /* ready to start flag */
atomic_t stop; /* ready to stop flag */
unsigned run_threads; /* nr current threads */
wait_queue_head_t go; /* start crc update */
wait_queue_head_t done; /* crc update done */
u32 *crc32; /* points to handle's crc32 */
size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
unsigned char *unc[LZO_THREADS]; /* uncompressed data */
};
/**
* CRC32 update function that runs in its own thread.
*/
static int crc32_threadfn(void *data)
{
struct crc_data *d = data;
unsigned i;
while (1) {
wait_event(d->go, atomic_read(&d->ready) ||
kthread_should_stop());
if (kthread_should_stop()) {
d->thr = NULL;
atomic_set(&d->stop, 1);
wake_up(&d->done);
break;
}
atomic_set(&d->ready, 0);
for (i = 0; i < d->run_threads; i++)
*d->crc32 = crc32_le(*d->crc32,
d->unc[i], *d->unc_len[i]);
atomic_set(&d->stop, 1);
wake_up(&d->done);
}
return 0;
}
/**
* Structure used for LZO data compression.
*/
struct cmp_data {
struct task_struct *thr; /* thread */
atomic_t ready; /* ready to start flag */
atomic_t stop; /* ready to stop flag */
int ret; /* return code */
wait_queue_head_t go; /* start compression */
wait_queue_head_t done; /* compression done */
size_t unc_len; /* uncompressed length */
size_t cmp_len; /* compressed length */
unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
};
/**
* Compression function that runs in its own thread.
*/
static int lzo_compress_threadfn(void *data)
{
struct cmp_data *d = data;
while (1) {
wait_event(d->go, atomic_read(&d->ready) ||
kthread_should_stop());
if (kthread_should_stop()) {
d->thr = NULL;
d->ret = -1;
atomic_set(&d->stop, 1);
wake_up(&d->done);
break;
}
atomic_set(&d->ready, 0);
d->ret = lzo1x_1_compress(d->unc, d->unc_len,
d->cmp + LZO_HEADER, &d->cmp_len,
d->wrk);
atomic_set(&d->stop, 1);
wake_up(&d->done);
}
return 0;
}
/**
* save_image_lzo - Save the suspend image data compressed with LZO.
* @handle: Swap mam handle to use for saving the image.
* @snapshot: Image to read data from.
* @nr_to_write: Number of pages to save.
*/
static int save_image_lzo(struct swap_map_handle *handle,
struct snapshot_handle *snapshot,
unsigned int nr_to_write)
{
unsigned int m;
int ret = 0;
int nr_pages;
int err2;
struct bio *bio;
struct timeval start;
struct timeval stop;
size_t off;
unsigned thr, run_threads, nr_threads;
unsigned char *page = NULL;
struct cmp_data *data = NULL;
struct crc_data *crc = NULL;
/*
* We'll limit the number of threads for compression to limit memory
* footprint.
*/
nr_threads = num_online_cpus() - 1;
nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
page = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
if (!page) {
printk(KERN_ERR "PM: Failed to allocate LZO page\n");
ret = -ENOMEM;
goto out_clean;
}
data = vmalloc(sizeof(*data) * nr_threads);
if (!data) {
printk(KERN_ERR "PM: Failed to allocate LZO data\n");
ret = -ENOMEM;
goto out_clean;
}
for (thr = 0; thr < nr_threads; thr++)
memset(&data[thr], 0, offsetof(struct cmp_data, go));
crc = kmalloc(sizeof(*crc), GFP_KERNEL);
if (!crc) {
printk(KERN_ERR "PM: Failed to allocate crc\n");
ret = -ENOMEM;
goto out_clean;
}
memset(crc, 0, offsetof(struct crc_data, go));
/*
* Start the compression threads.
*/
for (thr = 0; thr < nr_threads; thr++) {
init_waitqueue_head(&data[thr].go);
init_waitqueue_head(&data[thr].done);
data[thr].thr = kthread_run(lzo_compress_threadfn,
&data[thr],
"image_compress/%u", thr);
if (IS_ERR(data[thr].thr)) {
data[thr].thr = NULL;
printk(KERN_ERR
"PM: Cannot start compression threads\n");
ret = -ENOMEM;
goto out_clean;
}
}
/*
* Start the CRC32 thread.
*/
init_waitqueue_head(&crc->go);
init_waitqueue_head(&crc->done);
handle->crc32 = 0;
crc->crc32 = &handle->crc32;
for (thr = 0; thr < nr_threads; thr++) {
crc->unc[thr] = data[thr].unc;
crc->unc_len[thr] = &data[thr].unc_len;
}
crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
if (IS_ERR(crc->thr)) {
crc->thr = NULL;
printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
ret = -ENOMEM;
goto out_clean;
}
/*
* Adjust the number of required free pages after all allocations have
* been done. We don't want to run out of pages when writing.
*/
handle->reqd_free_pages = reqd_free_pages();
printk(KERN_INFO
"PM: Using %u thread(s) for compression.\n"
"PM: Compressing and saving image data (%u pages) ... ",
nr_threads, nr_to_write);
m = nr_to_write / 100;
if (!m)
m = 1;
nr_pages = 0;
bio = NULL;
do_gettimeofday(&start);
for (;;) {
for (thr = 0; thr < nr_threads; thr++) {
for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
ret = snapshot_read_next(snapshot);
if (ret < 0)
goto out_finish;
if (!ret)
break;
memcpy(data[thr].unc + off,
data_of(*snapshot), PAGE_SIZE);
if (!(nr_pages % m))
printk(KERN_CONT "\b\b\b\b%3d%%",
nr_pages / m);
nr_pages++;
}
if (!off)
break;
data[thr].unc_len = off;
atomic_set(&data[thr].ready, 1);
wake_up(&data[thr].go);
}
if (!thr)
break;
crc->run_threads = thr;
atomic_set(&crc->ready, 1);
wake_up(&crc->go);
for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
wait_event(data[thr].done,
atomic_read(&data[thr].stop));
atomic_set(&data[thr].stop, 0);
ret = data[thr].ret;
if (ret < 0) {
printk(KERN_ERR "PM: LZO compression failed\n");
goto out_finish;
}
if (unlikely(!data[thr].cmp_len ||
data[thr].cmp_len >
lzo1x_worst_compress(data[thr].unc_len))) {
printk(KERN_ERR
"PM: Invalid LZO compressed length\n");
ret = -1;
goto out_finish;
}
*(size_t *)data[thr].cmp = data[thr].cmp_len;
/*
* Given we are writing one page at a time to disk, we
* copy that much from the buffer, although the last
* bit will likely be smaller than full page. This is
* OK - we saved the length of the compressed data, so
* any garbage at the end will be discarded when we
* read it.
*/
for (off = 0;
off < LZO_HEADER + data[thr].cmp_len;
off += PAGE_SIZE) {
memcpy(page, data[thr].cmp + off, PAGE_SIZE);
ret = swap_write_page(handle, page, &bio);
if (ret)
goto out_finish;
}
}
wait_event(crc->done, atomic_read(&crc->stop));
atomic_set(&crc->stop, 0);
}
out_finish:
err2 = hib_wait_on_bio_chain(&bio);
do_gettimeofday(&stop);
if (!ret)
ret = err2;
if (!ret) {
printk(KERN_CONT "\b\b\b\bdone\n");
} else {
printk(KERN_CONT "\n");
}
swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
out_clean:
if (crc) {
if (crc->thr)
kthread_stop(crc->thr);
kfree(crc);
}
if (data) {
for (thr = 0; thr < nr_threads; thr++)
if (data[thr].thr)
kthread_stop(data[thr].thr);
vfree(data);
}
if (page) free_page((unsigned long)page);
return ret;
}
/**
* 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 flags)
{
unsigned int free_swap = count_swap_pages(root_swap, 1);
unsigned int required;
pr_debug("PM: Free swap pages: %u\n", free_swap);
required = PAGES_FOR_IO + nr_pages;
return free_swap > required;
}
/**
* 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;
unsigned long pages;
int error;
pages = snapshot_get_image_size();
error = get_swap_writer(&handle);
if (error) {
printk(KERN_ERR "PM: Cannot get swap writer\n");
return error;
}
if (flags & SF_NOCOMPRESS_MODE) {
if (!enough_swap(pages, flags)) {
printk(KERN_ERR "PM: Not enough free swap\n");
error = -ENOSPC;
goto out_finish;
}
}
memset(&snapshot, 0, sizeof(struct snapshot_handle));
error = snapshot_read_next(&snapshot);
if (error < PAGE_SIZE) {
if (error >= 0)
error = -EFAULT;
goto out_finish;
}
header = (struct swsusp_info *)data_of(snapshot);
error = swap_write_page(&handle, header, NULL);
if (!error) {
error = (flags & SF_NOCOMPRESS_MODE) ?
save_image(&handle, &snapshot, pages - 1) :
save_image_lzo(&handle, &snapshot, pages - 1);
}
out_finish:
error = swap_writer_finish(&handle, flags, error);
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)
{
struct swap_map_page_list *tmp;
while (handle->maps) {
if (handle->maps->map)
free_page((unsigned long)handle->maps->map);
tmp = handle->maps;
handle->maps = handle->maps->next;
kfree(tmp);
}
handle->cur = NULL;
}
static int get_swap_reader(struct swap_map_handle *handle,
unsigned int *flags_p)
{
int error;
struct swap_map_page_list *tmp, *last;
sector_t offset;
*flags_p = swsusp_header->flags;
if (!swsusp_header->image) /* how can this happen? */
return -EINVAL;
handle->cur = NULL;
last = handle->maps = NULL;
offset = swsusp_header->image;
while (offset) {
tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
if (!tmp) {
release_swap_reader(handle);
return -ENOMEM;
}
memset(tmp, 0, sizeof(*tmp));
if (!handle->maps)
handle->maps = tmp;
if (last)
last->next = tmp;
last = tmp;
tmp->map = (struct swap_map_page *)
__get_free_page(__GFP_WAIT | __GFP_HIGH);
if (!tmp->map) {
release_swap_reader(handle);
return -ENOMEM;
}
error = hib_bio_read_page(offset, tmp->map, NULL);
if (error) {
release_swap_reader(handle);
return error;
}
offset = tmp->map->next_swap;
}
handle->k = 0;
handle->cur = handle->maps->map;
return 0;
}
static int swap_read_page(struct swap_map_handle *handle, void *buf,
struct bio **bio_chain)
{
sector_t offset;
int error;
struct swap_map_page_list *tmp;
if (!handle->cur)
return -EINVAL;
offset = handle->cur->entries[handle->k];
if (!offset)
return -EFAULT;
error = hib_bio_read_page(offset, buf, bio_chain);
if (error)
return error;
if (++handle->k >= MAP_PAGE_ENTRIES) {
handle->k = 0;
free_page((unsigned long)handle->maps->map);
tmp = handle->maps;
handle->maps = handle->maps->next;
kfree(tmp);
if (!handle->maps)
release_swap_reader(handle);
else
handle->cur = handle->maps->map;
}
return error;
}
static int swap_reader_finish(struct swap_map_handle *handle)
{
release_swap_reader(handle);
return 0;
}
/**
* 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 ret = 0;
struct timeval start;
struct timeval stop;
struct bio *bio;
int err2;
unsigned nr_pages;
printk(KERN_INFO "PM: 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 ( ; ; ) {
ret = snapshot_write_next(snapshot);
if (ret <= 0)
break;
ret = swap_read_page(handle, data_of(*snapshot), &bio);
if (ret)
break;
if (snapshot->sync_read)
ret = hib_wait_on_bio_chain(&bio);
if (ret)
break;
if (!(nr_pages % m))
printk("\b\b\b\b%3d%%", nr_pages / m);
nr_pages++;
}
err2 = hib_wait_on_bio_chain(&bio);
do_gettimeofday(&stop);
if (!ret)
ret = err2;
if (!ret) {
printk("\b\b\b\bdone\n");
snapshot_write_finalize(snapshot);
if (!snapshot_image_loaded(snapshot))
ret = -ENODATA;
} else
printk("\n");
swsusp_show_speed(&start, &stop, nr_to_read, "Read");
return ret;
}
/**
* Structure used for LZO data decompression.
*/
struct dec_data {
struct task_struct *thr; /* thread */
atomic_t ready; /* ready to start flag */
atomic_t stop; /* ready to stop flag */
int ret; /* return code */
wait_queue_head_t go; /* start decompression */
wait_queue_head_t done; /* decompression done */
size_t unc_len; /* uncompressed length */
size_t cmp_len; /* compressed length */
unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
};
/**
* Deompression function that runs in its own thread.
*/
static int lzo_decompress_threadfn(void *data)
{
struct dec_data *d = data;
while (1) {
wait_event(d->go, atomic_read(&d->ready) ||
kthread_should_stop());
if (kthread_should_stop()) {
d->thr = NULL;
d->ret = -1;
atomic_set(&d->stop, 1);
wake_up(&d->done);
break;
}
atomic_set(&d->ready, 0);
d->unc_len = LZO_UNC_SIZE;
d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
d->unc, &d->unc_len);
atomic_set(&d->stop, 1);
wake_up(&d->done);
}
return 0;
}
/**
* load_image_lzo - Load compressed image data and decompress them with LZO.
* @handle: Swap map handle to use for loading data.
* @snapshot: Image to copy uncompressed data into.
* @nr_to_read: Number of pages to load.
*/
static int load_image_lzo(struct swap_map_handle *handle,
struct snapshot_handle *snapshot,
unsigned int nr_to_read)
{
unsigned int m;
int ret = 0;
int eof = 0;
struct bio *bio;
struct timeval start;
struct timeval stop;
unsigned nr_pages;
size_t off;
unsigned i, thr, run_threads, nr_threads;
unsigned ring = 0, pg = 0, ring_size = 0,
have = 0, want, need, asked = 0;
unsigned long read_pages = 0;
unsigned char **page = NULL;
struct dec_data *data = NULL;
struct crc_data *crc = NULL;
/*
* We'll limit the number of threads for decompression to limit memory
* footprint.
*/
nr_threads = num_online_cpus() - 1;
nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
if (!page) {
printk(KERN_ERR "PM: Failed to allocate LZO page\n");
ret = -ENOMEM;
goto out_clean;
}
data = vmalloc(sizeof(*data) * nr_threads);
if (!data) {
printk(KERN_ERR "PM: Failed to allocate LZO data\n");
ret = -ENOMEM;
goto out_clean;
}
for (thr = 0; thr < nr_threads; thr++)
memset(&data[thr], 0, offsetof(struct dec_data, go));
crc = kmalloc(sizeof(*crc), GFP_KERNEL);
if (!crc) {
printk(KERN_ERR "PM: Failed to allocate crc\n");
ret = -ENOMEM;
goto out_clean;
}
memset(crc, 0, offsetof(struct crc_data, go));
/*
* Start the decompression threads.
*/
for (thr = 0; thr < nr_threads; thr++) {
init_waitqueue_head(&data[thr].go);
init_waitqueue_head(&data[thr].done);
data[thr].thr = kthread_run(lzo_decompress_threadfn,
&data[thr],
"image_decompress/%u", thr);
if (IS_ERR(data[thr].thr)) {
data[thr].thr = NULL;
printk(KERN_ERR
"PM: Cannot start decompression threads\n");
ret = -ENOMEM;
goto out_clean;
}
}
/*
* Start the CRC32 thread.
*/
init_waitqueue_head(&crc->go);
init_waitqueue_head(&crc->done);
handle->crc32 = 0;
crc->crc32 = &handle->crc32;
for (thr = 0; thr < nr_threads; thr++) {
crc->unc[thr] = data[thr].unc;
crc->unc_len[thr] = &data[thr].unc_len;
}
crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
if (IS_ERR(crc->thr)) {
crc->thr = NULL;
printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
ret = -ENOMEM;
goto out_clean;
}
/*
* Set the number of pages for read buffering.
* This is complete guesswork, because we'll only know the real
* picture once prepare_image() is called, which is much later on
* during the image load phase. We'll assume the worst case and
* say that none of the image pages are from high memory.
*/
if (low_free_pages() > snapshot_get_image_size())
read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
for (i = 0; i < read_pages; i++) {
page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
__GFP_WAIT | __GFP_HIGH :
__GFP_WAIT | __GFP_NOWARN |
__GFP_NORETRY);
if (!page[i]) {
if (i < LZO_CMP_PAGES) {
ring_size = i;
printk(KERN_ERR
"PM: Failed to allocate LZO pages\n");
ret = -ENOMEM;
goto out_clean;
} else {
break;
}
}
}
want = ring_size = i;
printk(KERN_INFO
"PM: Using %u thread(s) for decompression.\n"
"PM: Loading and decompressing image data (%u pages) ... ",
nr_threads, nr_to_read);
m = nr_to_read / 100;
if (!m)
m = 1;
nr_pages = 0;
bio = NULL;
do_gettimeofday(&start);
ret = snapshot_write_next(snapshot);
if (ret <= 0)
goto out_finish;
for(;;) {
for (i = 0; !eof && i < want; i++) {
ret = swap_read_page(handle, page[ring], &bio);
if (ret) {
/*
* On real read error, finish. On end of data,
* set EOF flag and just exit the read loop.
*/
if (handle->cur &&
handle->cur->entries[handle->k]) {
goto out_finish;
} else {
eof = 1;
break;
}
}
if (++ring >= ring_size)
ring = 0;
}
asked += i;
want -= i;
/*
* We are out of data, wait for some more.
*/
if (!have) {
if (!asked)
break;
ret = hib_wait_on_bio_chain(&bio);
if (ret)
goto out_finish;
have += asked;
asked = 0;
if (eof)
eof = 2;
}
if (crc->run_threads) {
wait_event(crc->done, atomic_read(&crc->stop));
atomic_set(&crc->stop, 0);
crc->run_threads = 0;
}
for (thr = 0; have && thr < nr_threads; thr++) {
data[thr].cmp_len = *(size_t *)page[pg];
if (unlikely(!data[thr].cmp_len ||
data[thr].cmp_len >
lzo1x_worst_compress(LZO_UNC_SIZE))) {
printk(KERN_ERR
"PM: Invalid LZO compressed length\n");
ret = -1;
goto out_finish;
}
need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
PAGE_SIZE);
if (need > have) {
if (eof > 1) {
ret = -1;
goto out_finish;
}
break;
}
for (off = 0;
off < LZO_HEADER + data[thr].cmp_len;
off += PAGE_SIZE) {
memcpy(data[thr].cmp + off,
page[pg], PAGE_SIZE);
have--;
want++;
if (++pg >= ring_size)
pg = 0;
}
atomic_set(&data[thr].ready, 1);
wake_up(&data[thr].go);
}
/*
* Wait for more data while we are decompressing.
*/
if (have < LZO_CMP_PAGES && asked) {
ret = hib_wait_on_bio_chain(&bio);
if (ret)
goto out_finish;
have += asked;
asked = 0;
if (eof)
eof = 2;
}
for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
wait_event(data[thr].done,
atomic_read(&data[thr].stop));
atomic_set(&data[thr].stop, 0);
ret = data[thr].ret;
if (ret < 0) {
printk(KERN_ERR
"PM: LZO decompression failed\n");
goto out_finish;
}
if (unlikely(!data[thr].unc_len ||
data[thr].unc_len > LZO_UNC_SIZE ||
data[thr].unc_len & (PAGE_SIZE - 1))) {
printk(KERN_ERR
"PM: Invalid LZO uncompressed length\n");
ret = -1;
goto out_finish;
}
for (off = 0;
off < data[thr].unc_len; off += PAGE_SIZE) {
memcpy(data_of(*snapshot),
data[thr].unc + off, PAGE_SIZE);
if (!(nr_pages % m))
printk("\b\b\b\b%3d%%", nr_pages / m);
nr_pages++;
ret = snapshot_write_next(snapshot);
if (ret <= 0) {
crc->run_threads = thr + 1;
atomic_set(&crc->ready, 1);
wake_up(&crc->go);
goto out_finish;
}
}
}
crc->run_threads = thr;
atomic_set(&crc->ready, 1);
wake_up(&crc->go);
}
out_finish:
if (crc->run_threads) {
wait_event(crc->done, atomic_read(&crc->stop));
atomic_set(&crc->stop, 0);
}
do_gettimeofday(&stop);
if (!ret) {
printk("\b\b\b\bdone\n");
snapshot_write_finalize(snapshot);
if (!snapshot_image_loaded(snapshot))
ret = -ENODATA;
if (!ret) {
if (swsusp_header->flags & SF_CRC32_MODE) {
if(handle->crc32 != swsusp_header->crc32) {
printk(KERN_ERR
"PM: Invalid image CRC32!\n");
ret = -ENODATA;
}
}
}
} else
printk("\n");
swsusp_show_speed(&start, &stop, nr_to_read, "Read");
out_clean:
for (i = 0; i < ring_size; i++)
free_page((unsigned long)page[i]);
if (crc) {
if (crc->thr)
kthread_stop(crc->thr);
kfree(crc);
}
if (data) {
for (thr = 0; thr < nr_threads; thr++)
if (data[thr].thr)
kthread_stop(data[thr].thr);
vfree(data);
}
if (page) vfree(page);
return ret;
}
/**
* swsusp_read - read the hibernation image.
* @flags_p: flags passed by the "frozen" kernel in the image header should
* be written into this memory location
*/
int swsusp_read(unsigned int *flags_p)
{
int error;
struct swap_map_handle handle;
struct snapshot_handle snapshot;
struct swsusp_info *header;
memset(&snapshot, 0, sizeof(struct snapshot_handle));
error = snapshot_write_next(&snapshot);
if (error < PAGE_SIZE)
return error < 0 ? error : -EFAULT;
header = (struct swsusp_info *)data_of(snapshot);
error = get_swap_reader(&handle, flags_p);
if (error)
goto end;
if (!error)
error = swap_read_page(&handle, header, NULL);
if (!error) {
error = (*flags_p & SF_NOCOMPRESS_MODE) ?
load_image(&handle, &snapshot, header->pages - 1) :
load_image_lzo(&handle, &snapshot, header->pages - 1);
}
swap_reader_finish(&handle);
end:
if (!error)
pr_debug("PM: Image successfully loaded\n");
else
pr_debug("PM: Error %d resuming\n", error);
return error;
}
/**
* swsusp_check - Check for swsusp signature in the resume device
*/
int swsusp_check(void)
{
int error;
hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
FMODE_READ, NULL);
if (!IS_ERR(hib_resume_bdev)) {
set_blocksize(hib_resume_bdev, PAGE_SIZE);
clear_page(swsusp_header);
error = hib_bio_read_page(swsusp_resume_block,
swsusp_header, NULL);
if (error)
goto put;
if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
/* Reset swap signature now */
error = hib_bio_write_page(swsusp_resume_block,
swsusp_header, NULL);
} else {
error = -EINVAL;
}
put:
if (error)
blkdev_put(hib_resume_bdev, FMODE_READ);
else
pr_debug("PM: Image signature found, resuming\n");
} else {
error = PTR_ERR(hib_resume_bdev);
}
if (error)
pr_debug("PM: Image not found (code %d)\n", error);
return error;
}
/**
* swsusp_close - close swap device.
*/
void swsusp_close(fmode_t mode)
{
if (IS_ERR(hib_resume_bdev)) {
pr_debug("PM: Image device not initialised\n");
return;
}
blkdev_put(hib_resume_bdev, mode);
}
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);