--- /dev/null
+/*
+ * 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);
Code Review / kvmfornfv.git / blobdiff