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authorRafael J. Wysocki <rjw@sisk.pl>2006-03-23 12:00:00 +0100
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-23 16:38:07 +0100
commit61159a314bca6408320c3173c1282c64f5cdaa76 (patch)
tree8e1b7627443da0fd52b2fac66366dde9f7871f1e /kernel/power/swsusp.c
parent[PATCH] swsusp: low level interface (diff)
downloadlinux-61159a314bca6408320c3173c1282c64f5cdaa76.tar.xz
linux-61159a314bca6408320c3173c1282c64f5cdaa76.zip
[PATCH] swsusp: separate swap-writing/reading code
Move the swap-writing/reading code of swsusp to a separate file. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to '')
-rw-r--r--kernel/power/swsusp.c568
1 files changed, 6 insertions, 562 deletions
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index 457084f50010..c4016cbbd3e0 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -31,41 +31,24 @@
* Fixed runaway init
*
* Rafael J. Wysocki <rjw@sisk.pl>
- * Added the swap map data structure and reworked the handling of swap
+ * Reworked the freeing of memory and the handling of swap
*
* More state savers are welcome. Especially for the scsi layer...
*
* For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
*/
-#include <linux/module.h>
#include <linux/mm.h>
#include <linux/suspend.h>
-#include <linux/smp_lock.h>
-#include <linux/file.h>
-#include <linux/utsname.h>
-#include <linux/version.h>
-#include <linux/delay.h>
-#include <linux/bitops.h>
#include <linux/spinlock.h>
-#include <linux/genhd.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/swap.h>
#include <linux/pm.h>
-#include <linux/device.h>
-#include <linux/buffer_head.h>
#include <linux/swapops.h>
#include <linux/bootmem.h>
#include <linux/syscalls.h>
#include <linux/highmem.h>
-#include <linux/bio.h>
-
-#include <asm/uaccess.h>
-#include <asm/mmu_context.h>
-#include <asm/pgtable.h>
-#include <asm/tlbflush.h>
-#include <asm/io.h>
#include "power.h"
@@ -89,91 +72,15 @@ static int restore_highmem(void) { return 0; }
static unsigned int count_highmem_pages(void) { return 0; }
#endif
-extern char resume_file[];
-
-#define SWSUSP_SIG "S1SUSPEND"
-
-static struct swsusp_header {
- char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)];
- swp_entry_t image;
- char orig_sig[10];
- char sig[10];
-} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
-
-/*
- * Saving part...
- */
-
-static unsigned short root_swap = 0xffff;
-
-static int mark_swapfiles(swp_entry_t start)
-{
- int error;
-
- rw_swap_page_sync(READ,
- swp_entry(root_swap, 0),
- virt_to_page((unsigned long)&swsusp_header));
- if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
- !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
- memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
- memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
- swsusp_header.image = start;
- error = rw_swap_page_sync(WRITE,
- swp_entry(root_swap, 0),
- virt_to_page((unsigned long)
- &swsusp_header));
- } else {
- pr_debug("swsusp: Partition is not swap space.\n");
- error = -ENODEV;
- }
- return error;
-}
-
-/**
- * swsusp_swap_check - check if the resume device is a swap device
- * and get its index (if so)
- */
-
-static int swsusp_swap_check(void) /* This is called before saving image */
-{
- int res = swap_type_of(swsusp_resume_device);
-
- if (res >= 0) {
- root_swap = res;
- return 0;
- }
- return res;
-}
-
-/**
- * The bitmap is used for tracing allocated swap pages
- *
- * The entire bitmap consists of a number of bitmap_page
- * structures linked with the help of the .next member.
- * Thus each page can be allocated individually, so we only
- * need to make 0-order memory allocations to create
- * the bitmap.
- */
-
-#define BITMAP_PAGE_SIZE (PAGE_SIZE - sizeof(void *))
-#define BITMAP_PAGE_CHUNKS (BITMAP_PAGE_SIZE / sizeof(long))
-#define BITS_PER_CHUNK (sizeof(long) * 8)
-#define BITMAP_PAGE_BITS (BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK)
-
-struct bitmap_page {
- unsigned long chunks[BITMAP_PAGE_CHUNKS];
- struct bitmap_page *next;
-};
-
/**
* The following functions are used for tracing the allocated
* swap pages, so that they can be freed in case of an error.
*
* The functions operate on a linked bitmap structure defined
- * above
+ * in power.h
*/
-static void free_bitmap(struct bitmap_page *bitmap)
+void free_bitmap(struct bitmap_page *bitmap)
{
struct bitmap_page *bp;
@@ -184,7 +91,7 @@ static void free_bitmap(struct bitmap_page *bitmap)
}
}
-static struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
+struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
{
struct bitmap_page *bitmap, *bp;
unsigned int n;
@@ -227,7 +134,7 @@ static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit)
return 0;
}
-static unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
+unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
{
unsigned long offset;
@@ -241,7 +148,7 @@ static unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
return offset;
}
-static void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
+void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
{
unsigned int bit, n;
unsigned long test;
@@ -259,220 +166,6 @@ static void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
}
/**
- * write_page - Write one page to given swap location.
- * @buf: Address we're writing.
- * @offset: Offset of the swap page we're writing to.
- */
-
-static int write_page(void *buf, unsigned long offset)
-{
- swp_entry_t entry;
- int error = -ENOSPC;
-
- if (offset) {
- entry = swp_entry(root_swap, offset);
- error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf));
- }
- return error;
-}
-
-/*
- * The swap map is a data structure used for keeping track of each page
- * written to a swap partition. It consists of many swap_map_page
- * structures that contain each an array of MAP_PAGE_SIZE swap entries.
- * These structures are stored on the swap and linked together with the
- * help of the .next_swap member.
- *
- * The swap map is created during suspend. The swap map pages are
- * allocated and populated one at a time, so we only need one memory
- * page to set up the entire structure.
- *
- * During resume we also only need to use one swap_map_page structure
- * at a time.
- */
-
-#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(long) - 1)
-
-struct swap_map_page {
- unsigned long entries[MAP_PAGE_ENTRIES];
- unsigned long next_swap;
-};
-
-/**
- * The swap_map_handle structure is used for handling swap in
- * a file-alike way
- */
-
-struct swap_map_handle {
- struct swap_map_page *cur;
- unsigned long cur_swap;
- struct bitmap_page *bitmap;
- unsigned int k;
-};
-
-static void release_swap_writer(struct swap_map_handle *handle)
-{
- if (handle->cur)
- free_page((unsigned long)handle->cur);
- handle->cur = NULL;
- if (handle->bitmap)
- free_bitmap(handle->bitmap);
- handle->bitmap = NULL;
-}
-
-static int get_swap_writer(struct swap_map_handle *handle)
-{
- handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
- if (!handle->cur)
- return -ENOMEM;
- handle->bitmap = alloc_bitmap(count_swap_pages(root_swap, 0));
- if (!handle->bitmap) {
- release_swap_writer(handle);
- return -ENOMEM;
- }
- handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap);
- if (!handle->cur_swap) {
- release_swap_writer(handle);
- return -ENOSPC;
- }
- handle->k = 0;
- return 0;
-}
-
-static int swap_write_page(struct swap_map_handle *handle, void *buf)
-{
- int error;
- unsigned long offset;
-
- if (!handle->cur)
- return -EINVAL;
- offset = alloc_swap_page(root_swap, handle->bitmap);
- error = write_page(buf, offset);
- if (error)
- return error;
- handle->cur->entries[handle->k++] = offset;
- if (handle->k >= MAP_PAGE_ENTRIES) {
- offset = alloc_swap_page(root_swap, handle->bitmap);
- if (!offset)
- return -ENOSPC;
- handle->cur->next_swap = offset;
- error = write_page(handle->cur, handle->cur_swap);
- if (error)
- return error;
- memset(handle->cur, 0, PAGE_SIZE);
- handle->cur_swap = offset;
- handle->k = 0;
- }
- return 0;
-}
-
-static int flush_swap_writer(struct swap_map_handle *handle)
-{
- if (handle->cur && handle->cur_swap)
- return write_page(handle->cur, handle->cur_swap);
- else
- return -EINVAL;
-}
-
-/**
- * save_image - save the suspend image data
- */
-
-static int save_image(struct swap_map_handle *handle,
- struct snapshot_handle *snapshot,
- unsigned int nr_pages)
-{
- unsigned int m;
- int ret;
- int error = 0;
-
- printk("Saving image data pages (%u pages) ... ", nr_pages);
- m = nr_pages / 100;
- if (!m)
- m = 1;
- nr_pages = 0;
- do {
- ret = snapshot_read_next(snapshot, PAGE_SIZE);
- if (ret > 0) {
- error = swap_write_page(handle, data_of(*snapshot));
- if (error)
- break;
- if (!(nr_pages % m))
- printk("\b\b\b\b%3d%%", nr_pages / m);
- nr_pages++;
- }
- } while (ret > 0);
- if (!error)
- printk("\b\b\b\bdone\n");
- return error;
-}
-
-/**
- * enough_swap - Make sure we have enough swap to save the image.
- *
- * Returns TRUE or FALSE after checking the total amount of swap
- * space avaiable from the resume partition.
- */
-
-static int enough_swap(unsigned int nr_pages)
-{
- unsigned int free_swap = count_swap_pages(root_swap, 1);
-
- pr_debug("swsusp: free swap pages: %u\n", free_swap);
- return free_swap > (nr_pages + PAGES_FOR_IO +
- (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
-}
-
-/**
- * swsusp_write - Write entire image and metadata.
- *
- * 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(void)
-{
- struct swap_map_handle handle;
- struct snapshot_handle snapshot;
- struct swsusp_info *header;
- unsigned long start;
- int error;
-
- if ((error = swsusp_swap_check())) {
- printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n");
- return error;
- }
- memset(&snapshot, 0, sizeof(struct snapshot_handle));
- error = snapshot_read_next(&snapshot, PAGE_SIZE);
- if (error < PAGE_SIZE)
- return error < 0 ? error : -EFAULT;
- header = (struct swsusp_info *)data_of(snapshot);
- if (!enough_swap(header->pages)) {
- printk(KERN_ERR "swsusp: Not enough free swap\n");
- return -ENOSPC;
- }
- error = get_swap_writer(&handle);
- if (!error) {
- start = handle.cur_swap;
- error = swap_write_page(&handle, header);
- }
- if (!error)
- error = save_image(&handle, &snapshot, header->pages - 1);
- if (!error) {
- flush_swap_writer(&handle);
- printk("S");
- error = mark_swapfiles(swp_entry(root_swap, start));
- printk("|\n");
- }
- if (error)
- free_all_swap_pages(root_swap, handle.bitmap);
- release_swap_writer(&handle);
- return error;
-}
-
-/**
* swsusp_shrink_memory - Try to free as much memory as needed
*
* ... but do not OOM-kill anyone
@@ -578,252 +271,3 @@ int swsusp_resume(void)
local_irq_enable();
return error;
}
-
-/*
- * Using bio to read from swap.
- * This code requires a bit more work than just using buffer heads
- * but, it is the recommended way for 2.5/2.6.
- * The following are to signal the beginning and end of I/O. Bios
- * finish asynchronously, while we want them to happen synchronously.
- * A simple atomic_t, and a wait loop take care of this problem.
- */
-
-static atomic_t io_done = ATOMIC_INIT(0);
-
-static int end_io(struct bio *bio, unsigned int num, int err)
-{
- if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
- panic("I/O error reading memory image");
- atomic_set(&io_done, 0);
- return 0;
-}
-
-static struct block_device *resume_bdev;
-
-/**
- * submit - submit BIO request.
- * @rw: READ or WRITE.
- * @off physical offset of page.
- * @page: page we're reading or writing.
- *
- * Straight from the textbook - allocate and initialize the bio.
- * If we're writing, make sure the page is marked as dirty.
- * Then submit it and wait.
- */
-
-static int submit(int rw, pgoff_t page_off, void *page)
-{
- int error = 0;
- struct bio *bio;
-
- bio = bio_alloc(GFP_ATOMIC, 1);
- if (!bio)
- return -ENOMEM;
- bio->bi_sector = page_off * (PAGE_SIZE >> 9);
- bio->bi_bdev = resume_bdev;
- bio->bi_end_io = end_io;
-
- if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
- printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
- error = -EFAULT;
- goto Done;
- }
-
-
- atomic_set(&io_done, 1);
- submit_bio(rw | (1 << BIO_RW_SYNC), bio);
- while (atomic_read(&io_done))
- yield();
- if (rw == READ)
- bio_set_pages_dirty(bio);
- Done:
- bio_put(bio);
- return error;
-}
-
-static int bio_read_page(pgoff_t page_off, void *page)
-{
- return submit(READ, page_off, page);
-}
-
-static int bio_write_page(pgoff_t page_off, void *page)
-{
- return submit(WRITE, page_off, page);
-}
-
-/**
- * The following functions allow us to read data using a swap map
- * in a file-alike way
- */
-
-static void release_swap_reader(struct swap_map_handle *handle)
-{
- if (handle->cur)
- free_page((unsigned long)handle->cur);
- handle->cur = NULL;
-}
-
-static int get_swap_reader(struct swap_map_handle *handle,
- swp_entry_t start)
-{
- int error;
-
- if (!swp_offset(start))
- return -EINVAL;
- handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
- if (!handle->cur)
- return -ENOMEM;
- error = bio_read_page(swp_offset(start), handle->cur);
- if (error) {
- release_swap_reader(handle);
- return error;
- }
- handle->k = 0;
- return 0;
-}
-
-static int swap_read_page(struct swap_map_handle *handle, void *buf)
-{
- unsigned long offset;
- int error;
-
- if (!handle->cur)
- return -EINVAL;
- offset = handle->cur->entries[handle->k];
- if (!offset)
- return -EFAULT;
- error = bio_read_page(offset, buf);
- if (error)
- return error;
- if (++handle->k >= MAP_PAGE_ENTRIES) {
- handle->k = 0;
- offset = handle->cur->next_swap;
- if (!offset)
- release_swap_reader(handle);
- else
- error = bio_read_page(offset, handle->cur);
- }
- return error;
-}
-
-/**
- * load_image - load the image using the swap map handle
- * @handle and the snapshot handle @snapshot
- * (assume there are @nr_pages pages to load)
- */
-
-static int load_image(struct swap_map_handle *handle,
- struct snapshot_handle *snapshot,
- unsigned int nr_pages)
-{
- unsigned int m;
- int ret;
- int error = 0;
-
- printk("Loading image data pages (%u pages) ... ", nr_pages);
- m = nr_pages / 100;
- if (!m)
- m = 1;
- nr_pages = 0;
- do {
- ret = snapshot_write_next(snapshot, PAGE_SIZE);
- if (ret > 0) {
- error = swap_read_page(handle, data_of(*snapshot));
- if (error)
- break;
- if (!(nr_pages % m))
- printk("\b\b\b\b%3d%%", nr_pages / m);
- nr_pages++;
- }
- } while (ret > 0);
- if (!error)
- printk("\b\b\b\bdone\n");
- if (!snapshot_image_loaded(snapshot))
- error = -ENODATA;
- return error;
-}
-
-int swsusp_read(void)
-{
- int error;
- struct swap_map_handle handle;
- struct snapshot_handle snapshot;
- struct swsusp_info *header;
- unsigned int nr_pages;
-
- if (IS_ERR(resume_bdev)) {
- pr_debug("swsusp: block device not initialised\n");
- return PTR_ERR(resume_bdev);
- }
-
- memset(&snapshot, 0, sizeof(struct snapshot_handle));
- error = snapshot_write_next(&snapshot, PAGE_SIZE);
- if (error < PAGE_SIZE)
- return error < 0 ? error : -EFAULT;
- header = (struct swsusp_info *)data_of(snapshot);
- error = get_swap_reader(&handle, swsusp_header.image);
- if (!error)
- error = swap_read_page(&handle, header);
- if (!error) {
- nr_pages = header->image_pages;
- error = load_image(&handle, &snapshot, nr_pages);
- }
- release_swap_reader(&handle);
-
- blkdev_put(resume_bdev);
-
- if (!error)
- pr_debug("swsusp: Reading resume file was successful\n");
- else
- pr_debug("swsusp: Error %d resuming\n", error);
- return error;
-}
-
-/**
- * swsusp_check - Check for swsusp signature in the resume device
- */
-
-int swsusp_check(void)
-{
- int error;
-
- resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
- if (!IS_ERR(resume_bdev)) {
- set_blocksize(resume_bdev, PAGE_SIZE);
- memset(&swsusp_header, 0, sizeof(swsusp_header));
- if ((error = bio_read_page(0, &swsusp_header)))
- return error;
- if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
- memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
- /* Reset swap signature now */
- error = bio_write_page(0, &swsusp_header);
- } else {
- return -EINVAL;
- }
- if (error)
- blkdev_put(resume_bdev);
- else
- pr_debug("swsusp: Signature found, resuming\n");
- } else {
- error = PTR_ERR(resume_bdev);
- }
-
- if (error)
- pr_debug("swsusp: Error %d check for resume file\n", error);
-
- return error;
-}
-
-/**
- * swsusp_close - close swap device.
- */
-
-void swsusp_close(void)
-{
- if (IS_ERR(resume_bdev)) {
- pr_debug("swsusp: block device not initialised\n");
- return;
- }
-
- blkdev_put(resume_bdev);
-}