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[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>
This commit is contained in:
Rafael J. Wysocki
Linus Torvalds
parent
f577eb30af
commit
61159a314b
@ -5,7 +5,7 @@ endif
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obj-y := main.o process.o console.o
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obj-$(CONFIG_PM_LEGACY) += pm.o
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obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o
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obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o swap.o
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obj-$(CONFIG_SUSPEND_SMP) += smp.o
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@ -41,8 +41,8 @@ extern struct pbe *pagedir_nosave;
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/* Preferred image size in bytes (default 500 MB) */
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extern unsigned long image_size;
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extern int in_suspend;
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extern dev_t swsusp_resume_device;
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extern asmlinkage int swsusp_arch_suspend(void);
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extern asmlinkage int swsusp_arch_resume(void);
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@ -65,3 +65,32 @@ struct snapshot_handle {
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extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
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extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
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int snapshot_image_loaded(struct snapshot_handle *handle);
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/**
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* The bitmap is used for tracing allocated swap pages
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*
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* The entire bitmap consists of a number of bitmap_page
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* structures linked with the help of the .next member.
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* Thus each page can be allocated individually, so we only
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* need to make 0-order memory allocations to create
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* the bitmap.
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*/
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#define BITMAP_PAGE_SIZE (PAGE_SIZE - sizeof(void *))
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#define BITMAP_PAGE_CHUNKS (BITMAP_PAGE_SIZE / sizeof(long))
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#define BITS_PER_CHUNK (sizeof(long) * 8)
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#define BITMAP_PAGE_BITS (BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK)
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struct bitmap_page {
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unsigned long chunks[BITMAP_PAGE_CHUNKS];
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struct bitmap_page *next;
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};
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extern void free_bitmap(struct bitmap_page *bitmap);
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extern struct bitmap_page *alloc_bitmap(unsigned int nr_bits);
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extern unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap);
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extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
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extern int swsusp_shrink_memory(void);
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extern int swsusp_suspend(void);
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extern int swsusp_resume(void);
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544
kernel/power/swap.c
Normal file
544
kernel/power/swap.c
Normal file
@ -0,0 +1,544 @@
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/*
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* linux/kernel/power/swap.c
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*
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* This file provides functions for reading the suspend image from
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* and writing it to a swap partition.
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*
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* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
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* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
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*
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* This file is released under the GPLv2.
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*
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*/
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#include <linux/module.h>
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#include <linux/smp_lock.h>
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#include <linux/file.h>
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#include <linux/utsname.h>
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#include <linux/version.h>
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#include <linux/delay.h>
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#include <linux/bitops.h>
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#include <linux/genhd.h>
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#include <linux/device.h>
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#include <linux/buffer_head.h>
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#include <linux/bio.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/pm.h>
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#include "power.h"
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extern char resume_file[];
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#define SWSUSP_SIG "S1SUSPEND"
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static struct swsusp_header {
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char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)];
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swp_entry_t image;
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char orig_sig[10];
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char sig[10];
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} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
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/*
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* Saving part...
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*/
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static unsigned short root_swap = 0xffff;
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static int mark_swapfiles(swp_entry_t start)
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{
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int error;
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rw_swap_page_sync(READ,
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swp_entry(root_swap, 0),
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virt_to_page((unsigned long)&swsusp_header));
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if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
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!memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
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memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
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memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
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swsusp_header.image = start;
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error = rw_swap_page_sync(WRITE,
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swp_entry(root_swap, 0),
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virt_to_page((unsigned long)
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&swsusp_header));
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} else {
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pr_debug("swsusp: Partition is not swap space.\n");
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error = -ENODEV;
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}
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return error;
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}
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/**
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* swsusp_swap_check - check if the resume device is a swap device
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* and get its index (if so)
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*/
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static int swsusp_swap_check(void) /* This is called before saving image */
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{
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int res = swap_type_of(swsusp_resume_device);
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if (res >= 0) {
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root_swap = res;
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return 0;
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}
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return res;
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}
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/**
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* write_page - Write one page to given swap location.
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* @buf: Address we're writing.
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* @offset: Offset of the swap page we're writing to.
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*/
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static int write_page(void *buf, unsigned long offset)
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{
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swp_entry_t entry;
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int error = -ENOSPC;
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if (offset) {
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entry = swp_entry(root_swap, offset);
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error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf));
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}
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return error;
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}
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/*
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* The swap map is a data structure used for keeping track of each page
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* written to a swap partition. It consists of many swap_map_page
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* structures that contain each an array of MAP_PAGE_SIZE swap entries.
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* These structures are stored on the swap and linked together with the
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* help of the .next_swap member.
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*
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* The swap map is created during suspend. The swap map pages are
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* allocated and populated one at a time, so we only need one memory
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* page to set up the entire structure.
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*
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* During resume we also only need to use one swap_map_page structure
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* at a time.
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*/
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#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(long) - 1)
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struct swap_map_page {
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unsigned long entries[MAP_PAGE_ENTRIES];
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unsigned long next_swap;
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};
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/**
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* The swap_map_handle structure is used for handling swap in
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* a file-alike way
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*/
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struct swap_map_handle {
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struct swap_map_page *cur;
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unsigned long cur_swap;
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struct bitmap_page *bitmap;
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unsigned int k;
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};
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static void release_swap_writer(struct swap_map_handle *handle)
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{
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if (handle->cur)
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free_page((unsigned long)handle->cur);
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handle->cur = NULL;
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if (handle->bitmap)
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free_bitmap(handle->bitmap);
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handle->bitmap = NULL;
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}
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static int get_swap_writer(struct swap_map_handle *handle)
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{
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handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
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if (!handle->cur)
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return -ENOMEM;
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handle->bitmap = alloc_bitmap(count_swap_pages(root_swap, 0));
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if (!handle->bitmap) {
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release_swap_writer(handle);
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return -ENOMEM;
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}
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handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap);
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if (!handle->cur_swap) {
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release_swap_writer(handle);
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return -ENOSPC;
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}
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handle->k = 0;
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return 0;
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}
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static int swap_write_page(struct swap_map_handle *handle, void *buf)
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{
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int error;
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unsigned long offset;
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if (!handle->cur)
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return -EINVAL;
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offset = alloc_swap_page(root_swap, handle->bitmap);
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error = write_page(buf, offset);
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if (error)
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return error;
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handle->cur->entries[handle->k++] = offset;
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if (handle->k >= MAP_PAGE_ENTRIES) {
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offset = alloc_swap_page(root_swap, handle->bitmap);
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if (!offset)
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return -ENOSPC;
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handle->cur->next_swap = offset;
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error = write_page(handle->cur, handle->cur_swap);
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if (error)
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return error;
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memset(handle->cur, 0, PAGE_SIZE);
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handle->cur_swap = offset;
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handle->k = 0;
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}
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return 0;
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}
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static int flush_swap_writer(struct swap_map_handle *handle)
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{
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if (handle->cur && handle->cur_swap)
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return write_page(handle->cur, handle->cur_swap);
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else
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return -EINVAL;
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}
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/**
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* save_image - save the suspend image data
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*/
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static int save_image(struct swap_map_handle *handle,
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struct snapshot_handle *snapshot,
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unsigned int nr_pages)
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{
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unsigned int m;
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int ret;
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int error = 0;
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printk("Saving image data pages (%u pages) ... ", nr_pages);
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m = nr_pages / 100;
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if (!m)
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m = 1;
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nr_pages = 0;
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do {
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ret = snapshot_read_next(snapshot, PAGE_SIZE);
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if (ret > 0) {
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error = swap_write_page(handle, data_of(*snapshot));
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if (error)
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break;
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if (!(nr_pages % m))
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printk("\b\b\b\b%3d%%", nr_pages / m);
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nr_pages++;
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}
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} while (ret > 0);
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if (!error)
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printk("\b\b\b\bdone\n");
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return error;
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}
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/**
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* enough_swap - Make sure we have enough swap to save the image.
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*
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* Returns TRUE or FALSE after checking the total amount of swap
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* space avaiable from the resume partition.
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*/
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static int enough_swap(unsigned int nr_pages)
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{
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unsigned int free_swap = count_swap_pages(root_swap, 1);
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pr_debug("swsusp: free swap pages: %u\n", free_swap);
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return free_swap > (nr_pages + PAGES_FOR_IO +
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(nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
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}
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/**
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* swsusp_write - Write entire image and metadata.
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*
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* It is important _NOT_ to umount filesystems at this point. We want
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* them synced (in case something goes wrong) but we DO not want to mark
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* filesystem clean: it is not. (And it does not matter, if we resume
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* correctly, we'll mark system clean, anyway.)
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*/
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int swsusp_write(void)
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{
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struct swap_map_handle handle;
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struct snapshot_handle snapshot;
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struct swsusp_info *header;
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unsigned long start;
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int error;
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if ((error = swsusp_swap_check())) {
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printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n");
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return error;
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}
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memset(&snapshot, 0, sizeof(struct snapshot_handle));
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error = snapshot_read_next(&snapshot, PAGE_SIZE);
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if (error < PAGE_SIZE)
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return error < 0 ? error : -EFAULT;
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header = (struct swsusp_info *)data_of(snapshot);
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if (!enough_swap(header->pages)) {
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printk(KERN_ERR "swsusp: Not enough free swap\n");
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return -ENOSPC;
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}
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error = get_swap_writer(&handle);
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if (!error) {
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start = handle.cur_swap;
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error = swap_write_page(&handle, header);
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}
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if (!error)
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error = save_image(&handle, &snapshot, header->pages - 1);
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if (!error) {
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flush_swap_writer(&handle);
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printk("S");
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error = mark_swapfiles(swp_entry(root_swap, start));
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printk("|\n");
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}
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if (error)
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free_all_swap_pages(root_swap, handle.bitmap);
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release_swap_writer(&handle);
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return error;
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}
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/*
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* Using bio to read from swap.
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* This code requires a bit more work than just using buffer heads
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* but, it is the recommended way for 2.5/2.6.
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* The following are to signal the beginning and end of I/O. Bios
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* finish asynchronously, while we want them to happen synchronously.
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* A simple atomic_t, and a wait loop take care of this problem.
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*/
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static atomic_t io_done = ATOMIC_INIT(0);
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static int end_io(struct bio *bio, unsigned int num, int err)
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{
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if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
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panic("I/O error reading memory image");
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atomic_set(&io_done, 0);
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return 0;
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}
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static struct block_device *resume_bdev;
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/**
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* submit - submit BIO request.
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* @rw: READ or WRITE.
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* @off physical offset of page.
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* @page: page we're reading or writing.
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*
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* Straight from the textbook - allocate and initialize the bio.
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* If we're writing, make sure the page is marked as dirty.
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* Then submit it and wait.
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*/
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static int submit(int rw, pgoff_t page_off, void *page)
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{
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int error = 0;
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struct bio *bio;
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bio = bio_alloc(GFP_ATOMIC, 1);
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if (!bio)
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return -ENOMEM;
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bio->bi_sector = page_off * (PAGE_SIZE >> 9);
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bio->bi_bdev = resume_bdev;
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bio->bi_end_io = end_io;
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if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
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printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
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error = -EFAULT;
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goto Done;
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}
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atomic_set(&io_done, 1);
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submit_bio(rw | (1 << BIO_RW_SYNC), bio);
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while (atomic_read(&io_done))
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yield();
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if (rw == READ)
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bio_set_pages_dirty(bio);
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Done:
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bio_put(bio);
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return error;
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}
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static int bio_read_page(pgoff_t page_off, void *page)
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{
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return submit(READ, page_off, page);
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}
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static int bio_write_page(pgoff_t page_off, void *page)
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{
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return submit(WRITE, page_off, page);
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}
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/**
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* The following functions allow us to read data using a swap map
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* in a file-alike way
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*/
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static void release_swap_reader(struct swap_map_handle *handle)
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{
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if (handle->cur)
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free_page((unsigned long)handle->cur);
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handle->cur = NULL;
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}
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static int get_swap_reader(struct swap_map_handle *handle,
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swp_entry_t start)
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{
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int error;
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if (!swp_offset(start))
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return -EINVAL;
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handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
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if (!handle->cur)
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return -ENOMEM;
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error = bio_read_page(swp_offset(start), handle->cur);
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if (error) {
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release_swap_reader(handle);
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return error;
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}
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handle->k = 0;
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return 0;
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}
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static int swap_read_page(struct swap_map_handle *handle, void *buf)
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{
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unsigned long offset;
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int error;
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if (!handle->cur)
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return -EINVAL;
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offset = handle->cur->entries[handle->k];
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if (!offset)
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return -EFAULT;
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error = bio_read_page(offset, buf);
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if (error)
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return error;
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if (++handle->k >= MAP_PAGE_ENTRIES) {
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handle->k = 0;
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offset = handle->cur->next_swap;
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if (!offset)
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release_swap_reader(handle);
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else
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error = bio_read_page(offset, handle->cur);
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}
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return error;
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}
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/**
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* load_image - load the image using the swap map handle
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* @handle and the snapshot handle @snapshot
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* (assume there are @nr_pages pages to load)
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*/
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static int load_image(struct swap_map_handle *handle,
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struct snapshot_handle *snapshot,
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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;
|
||||
|
||||
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)
|
||||
error = load_image(&handle, &snapshot, header->pages - 1);
|
||||
release_swap_reader(&handle);
|
||||
|
||||
blkdev_put(resume_bdev);
|
||||
|
||||
if (!error)
|
||||
pr_debug("swsusp: Reading resume file was successful\n");
|
||||
else
|
||||
pr_debug("swsusp: Error %d resuming\n", error);
|
||||
return error;
|
||||
}
|
||||
|
||||
/**
|
||||
* swsusp_check - Check for swsusp signature in the resume device
|
||||
*/
|
||||
|
||||
int swsusp_check(void)
|
||||
{
|
||||
int error;
|
||||
|
||||
resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
|
||||
if (!IS_ERR(resume_bdev)) {
|
||||
set_blocksize(resume_bdev, PAGE_SIZE);
|
||||
memset(&swsusp_header, 0, 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);
|
||||
}
|
||||
@ -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;
|
||||
@ -258,220 +165,6 @@ 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
|
||||
*
|
||||
@ -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);
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user