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linux-pinenote/kernel/power/swap.c
Markus Elfring 6c45de0d51 PM / hibernate: Deletion of an unnecessary check before the function call "vfree" 
The vfree() function performs also input parameter validation. Thus the test
around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-18 02:49:40 +01:00

1512 lines
36 KiB
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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@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 <linux/ktime.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];
} __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 = rb_entry(*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;
ktime_t start;
ktime_t stop;
printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
nr_to_write);
m = nr_to_write / 10;
if (!m)
m = 1;
nr_pages = 0;
bio = NULL;
start = ktime_get();
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_INFO "PM: Image saving progress: %3d%%\n",
nr_pages / m * 10);
nr_pages++;
}
err2 = hib_wait_on_bio_chain(&bio);
stop = ktime_get();
if (!ret)
ret = err2;
if (!ret)
printk(KERN_INFO "PM: Image saving done.\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 map 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;
ktime_t start;
ktime_t 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)...\n",
nr_threads, nr_to_write);
m = nr_to_write / 10;
if (!m)
m = 1;
nr_pages = 0;
bio = NULL;
start = ktime_get();
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_INFO
"PM: Image saving progress: "
"%3d%%\n",
nr_pages / m * 10);
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);
stop = ktime_get();
if (!ret)
ret = err2;
if (!ret)
printk(KERN_INFO "PM: Image saving done.\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;
ktime_t start;
ktime_t stop;
struct bio *bio;
int err2;
unsigned nr_pages;
printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
nr_to_read);
m = nr_to_read / 10;
if (!m)
m = 1;
nr_pages = 0;
bio = NULL;
start = ktime_get();
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(KERN_INFO "PM: Image loading progress: %3d%%\n",
nr_pages / m * 10);
nr_pages++;
}
err2 = hib_wait_on_bio_chain(&bio);
stop = ktime_get();
if (!ret)
ret = err2;
if (!ret) {
printk(KERN_INFO "PM: Image loading done.\n");
snapshot_write_finalize(snapshot);
if (!snapshot_image_loaded(snapshot))
ret = -ENODATA;
}
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;
ktime_t start;
ktime_t 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)...\n",
nr_threads, nr_to_read);
m = nr_to_read / 10;
if (!m)
m = 1;
nr_pages = 0;
bio = NULL;
start = ktime_get();
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(KERN_INFO
"PM: Image loading progress: "
"%3d%%\n",
nr_pages / m * 10);
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);
}
stop = ktime_get();
if (!ret) {
printk(KERN_INFO "PM: Image loading done.\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;
}
}
}
}
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);
}
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);
}
/**
* swsusp_unmark - Unmark swsusp signature in the resume device
*/
#ifdef CONFIG_SUSPEND
int swsusp_unmark(void)
{
int error;
hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
error = hib_bio_write_page(swsusp_resume_block,
swsusp_header, NULL);
} else {
printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
error = -ENODEV;
}
/*
* We just returned from suspend, we don't need the image any more.
*/
free_all_swap_pages(root_swap);
return error;
}
#endif
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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