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a8534adb74
Restore the compatibility with the older code and make it possible to suspend if the kernel command line doesn't contain the "resume=" argument Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1038 lines
26 KiB
C
1038 lines
26 KiB
C
/*
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* linux/kernel/power/swsusp.c
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*
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* This file provides code to write suspend image to swap and read it back.
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*
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* Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
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* Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
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*
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* This file is released under the GPLv2.
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*
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* I'd like to thank the following people for their work:
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*
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* Pavel Machek <pavel@ucw.cz>:
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* Modifications, defectiveness pointing, being with me at the very beginning,
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* suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17.
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*
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* Steve Doddi <dirk@loth.demon.co.uk>:
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* Support the possibility of hardware state restoring.
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*
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* Raph <grey.havens@earthling.net>:
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* Support for preserving states of network devices and virtual console
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* (including X and svgatextmode)
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*
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* Kurt Garloff <garloff@suse.de>:
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* Straightened the critical function in order to prevent compilers from
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* playing tricks with local variables.
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*
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* Andreas Mohr <a.mohr@mailto.de>
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*
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* Alex Badea <vampire@go.ro>:
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* Fixed runaway init
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*
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* Rafael J. Wysocki <rjw@sisk.pl>
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* Added the swap map data structure and reworked the handling of swap
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*
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* More state savers are welcome. Especially for the scsi layer...
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*
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* For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/suspend.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/spinlock.h>
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#include <linux/genhd.h>
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#include <linux/kernel.h>
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#include <linux/major.h>
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#include <linux/swap.h>
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#include <linux/pm.h>
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#include <linux/device.h>
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#include <linux/buffer_head.h>
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#include <linux/swapops.h>
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#include <linux/bootmem.h>
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#include <linux/syscalls.h>
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#include <linux/highmem.h>
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#include <linux/bio.h>
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#include <asm/uaccess.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/io.h>
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#include "power.h"
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/*
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* Preferred image size in bytes (tunable via /sys/power/image_size).
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* When it is set to N, swsusp will do its best to ensure the image
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* size will not exceed N bytes, but if that is impossible, it will
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* try to create the smallest image possible.
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*/
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unsigned long image_size = 500 * 1024 * 1024;
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#ifdef CONFIG_HIGHMEM
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unsigned int count_highmem_pages(void);
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int save_highmem(void);
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int restore_highmem(void);
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#else
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static int save_highmem(void) { return 0; }
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static int restore_highmem(void) { return 0; }
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static unsigned int count_highmem_pages(void) { return 0; }
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#endif
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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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static struct swsusp_info swsusp_info;
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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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* Check whether the swap device is the specified resume
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* device, irrespective of whether they are specified by
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* identical names.
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*
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* (Thus, device inode aliasing is allowed. You can say /dev/hda4
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* instead of /dev/ide/host0/bus0/target0/lun0/part4 [if using devfs]
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* and they'll be considered the same device. This is *necessary* for
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* devfs, since the resume code can only recognize the form /dev/hda4,
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* but the suspend code would see the long name.)
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*/
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static inline int is_resume_device(const struct swap_info_struct *swap_info)
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{
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struct file *file = swap_info->swap_file;
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struct inode *inode = file->f_dentry->d_inode;
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return S_ISBLK(inode->i_mode) &&
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swsusp_resume_device == MKDEV(imajor(inode), iminor(inode));
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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 i;
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spin_lock(&swap_lock);
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for (i = 0; i < MAX_SWAPFILES; i++) {
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if (!(swap_info[i].flags & SWP_WRITEOK))
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continue;
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if (!swsusp_resume_device || is_resume_device(swap_info + i)) {
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spin_unlock(&swap_lock);
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root_swap = i;
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return 0;
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}
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}
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spin_unlock(&swap_lock);
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return -ENODEV;
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}
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/**
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* write_page - Write one page to a fresh swap location.
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* @addr: Address we're writing.
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* @loc: Place to store the entry we used.
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*
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* Allocate a new swap entry and 'sync' it. Note we discard -EIO
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* errors. That is an artifact left over from swsusp. It did not
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* check the return of rw_swap_page_sync() at all, since most pages
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* written back to swap would return -EIO.
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* This is a partial improvement, since we will at least return other
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* errors, though we need to eventually fix the damn code.
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*/
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static int write_page(unsigned long addr, swp_entry_t *loc)
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{
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swp_entry_t entry;
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int error = -ENOSPC;
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entry = get_swap_page_of_type(root_swap);
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if (swp_offset(entry)) {
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error = rw_swap_page_sync(WRITE, entry, virt_to_page(addr));
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if (!error || error == -EIO)
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*loc = entry;
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}
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return error;
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}
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/**
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* Swap map-handling functions
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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 the swap. It consists of many swap_map_page structures
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* that contain each an array of MAP_PAGE_SIZE swap entries.
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* These structures are linked together with the help of either the
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* .next (in memory) or the .next_swap (in swap) member.
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*
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* The swap map is created during suspend. At that time we need to keep
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* it in memory, because we have to free all of the allocated swap
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* entries if an error occurs. The memory needed is preallocated
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* so that we know in advance if there's enough of it.
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*
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* The first swap_map_page structure is filled with the swap entries that
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* correspond to the first MAP_PAGE_SIZE data pages written to swap and
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* so on. After the all of the data pages have been written, the order
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* of the swap_map_page structures in the map is reversed so that they
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* can be read from swap in the original order. This causes the data
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* pages to be loaded in exactly the same order in which they have been
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* saved.
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*
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* During resume we only need to use one swap_map_page structure
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* at a time, which means that we only need to use two memory pages for
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* reading the image - one for reading the swap_map_page structures
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* and the second for reading the data pages from swap.
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*/
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#define MAP_PAGE_SIZE ((PAGE_SIZE - sizeof(swp_entry_t) - sizeof(void *)) \
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/ sizeof(swp_entry_t))
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struct swap_map_page {
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swp_entry_t entries[MAP_PAGE_SIZE];
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swp_entry_t next_swap;
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struct swap_map_page *next;
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};
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static inline void free_swap_map(struct swap_map_page *swap_map)
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{
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struct swap_map_page *swp;
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while (swap_map) {
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swp = swap_map->next;
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free_page((unsigned long)swap_map);
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swap_map = swp;
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}
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}
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static struct swap_map_page *alloc_swap_map(unsigned int nr_pages)
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{
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struct swap_map_page *swap_map, *swp;
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unsigned n = 0;
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if (!nr_pages)
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return NULL;
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pr_debug("alloc_swap_map(): nr_pages = %d\n", nr_pages);
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swap_map = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
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swp = swap_map;
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for (n = MAP_PAGE_SIZE; n < nr_pages; n += MAP_PAGE_SIZE) {
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swp->next = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
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swp = swp->next;
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if (!swp) {
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free_swap_map(swap_map);
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return NULL;
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}
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}
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return swap_map;
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}
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/**
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* reverse_swap_map - reverse the order of pages in the swap map
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* @swap_map
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*/
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static inline struct swap_map_page *reverse_swap_map(struct swap_map_page *swap_map)
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{
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struct swap_map_page *prev, *next;
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prev = NULL;
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while (swap_map) {
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next = swap_map->next;
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swap_map->next = prev;
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prev = swap_map;
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swap_map = next;
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}
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return prev;
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}
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/**
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* free_swap_map_entries - free the swap entries allocated to store
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* the swap map @swap_map (this is only called in case of an error)
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*/
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static inline void free_swap_map_entries(struct swap_map_page *swap_map)
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{
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while (swap_map) {
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if (swap_map->next_swap.val)
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swap_free(swap_map->next_swap);
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swap_map = swap_map->next;
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}
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}
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/**
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* save_swap_map - save the swap map used for tracing the data pages
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* stored in the swap
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*/
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static int save_swap_map(struct swap_map_page *swap_map, swp_entry_t *start)
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{
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swp_entry_t entry = (swp_entry_t){0};
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int error;
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while (swap_map) {
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swap_map->next_swap = entry;
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if ((error = write_page((unsigned long)swap_map, &entry)))
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return error;
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swap_map = swap_map->next;
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}
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*start = entry;
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return 0;
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}
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/**
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* free_image_entries - free the swap entries allocated to store
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* the image data pages (this is only called in case of an error)
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*/
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static inline void free_image_entries(struct swap_map_page *swp)
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{
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unsigned k;
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while (swp) {
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for (k = 0; k < MAP_PAGE_SIZE; k++)
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if (swp->entries[k].val)
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swap_free(swp->entries[k]);
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swp = swp->next;
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}
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}
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/**
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* The swap_map_handle structure is used for handling the swap map 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 int k;
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};
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static inline void init_swap_map_handle(struct swap_map_handle *handle,
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struct swap_map_page *map)
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{
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handle->cur = map;
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handle->k = 0;
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}
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static inline int swap_map_write_page(struct swap_map_handle *handle,
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unsigned long addr)
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{
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int error;
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error = write_page(addr, handle->cur->entries + handle->k);
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if (error)
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return error;
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if (++handle->k >= MAP_PAGE_SIZE) {
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handle->cur = handle->cur->next;
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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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/**
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* save_image_data - save the data pages pointed to by the PBEs
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* from the list @pblist using the swap map handle @handle
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* (assume there are @nr_pages data pages to save)
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*/
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static int save_image_data(struct pbe *pblist,
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struct swap_map_handle *handle,
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unsigned int nr_pages)
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{
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unsigned int m;
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struct pbe *p;
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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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for_each_pbe (p, pblist) {
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error = swap_map_write_page(handle, p->address);
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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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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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static void dump_info(void)
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{
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pr_debug(" swsusp: Version: %u\n",swsusp_info.version_code);
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pr_debug(" swsusp: Num Pages: %ld\n",swsusp_info.num_physpages);
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pr_debug(" swsusp: UTS Sys: %s\n",swsusp_info.uts.sysname);
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pr_debug(" swsusp: UTS Node: %s\n",swsusp_info.uts.nodename);
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pr_debug(" swsusp: UTS Release: %s\n",swsusp_info.uts.release);
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pr_debug(" swsusp: UTS Version: %s\n",swsusp_info.uts.version);
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pr_debug(" swsusp: UTS Machine: %s\n",swsusp_info.uts.machine);
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pr_debug(" swsusp: UTS Domain: %s\n",swsusp_info.uts.domainname);
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pr_debug(" swsusp: CPUs: %d\n",swsusp_info.cpus);
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pr_debug(" swsusp: Image: %ld Pages\n",swsusp_info.image_pages);
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pr_debug(" swsusp: Total: %ld Pages\n", swsusp_info.pages);
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}
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static void init_header(unsigned int nr_pages)
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{
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memset(&swsusp_info, 0, sizeof(swsusp_info));
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swsusp_info.version_code = LINUX_VERSION_CODE;
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swsusp_info.num_physpages = num_physpages;
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memcpy(&swsusp_info.uts, &system_utsname, sizeof(system_utsname));
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swsusp_info.cpus = num_online_cpus();
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swsusp_info.image_pages = nr_pages;
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swsusp_info.pages = nr_pages +
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((nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
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}
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/**
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* pack_orig_addresses - the .orig_address fields of the PBEs from the
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* list starting at @pbe are stored in the array @buf[] (1 page)
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*/
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static inline struct pbe *pack_orig_addresses(unsigned long *buf,
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struct pbe *pbe)
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{
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int j;
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for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
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buf[j] = pbe->orig_address;
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pbe = pbe->next;
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}
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if (!pbe)
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for (; j < PAGE_SIZE / sizeof(long); j++)
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buf[j] = 0;
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return pbe;
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}
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/**
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* save_image_metadata - save the .orig_address fields of the PBEs
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* from the list @pblist using the swap map handle @handle
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*/
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static int save_image_metadata(struct pbe *pblist,
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struct swap_map_handle *handle)
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{
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unsigned long *buf;
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unsigned int n = 0;
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struct pbe *p;
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int error = 0;
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printk("Saving image metadata ... ");
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buf = (unsigned long *)get_zeroed_page(GFP_ATOMIC);
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if (!buf)
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return -ENOMEM;
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p = pblist;
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while (p) {
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p = pack_orig_addresses(buf, p);
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error = swap_map_write_page(handle, (unsigned long)buf);
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if (error)
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break;
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n++;
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}
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free_page((unsigned long)buf);
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if (!error)
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printk("done (%u pages saved)\n", 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 = swap_info[root_swap].pages -
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swap_info[root_swap].inuse_pages;
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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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*
|
|
* 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(struct pbe *pblist, unsigned int nr_pages)
|
|
{
|
|
struct swap_map_page *swap_map;
|
|
struct swap_map_handle handle;
|
|
swp_entry_t start;
|
|
int error;
|
|
|
|
if ((error = swsusp_swap_check())) {
|
|
printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n");
|
|
return error;
|
|
}
|
|
if (!enough_swap(nr_pages)) {
|
|
printk(KERN_ERR "swsusp: Not enough free swap\n");
|
|
return -ENOSPC;
|
|
}
|
|
|
|
init_header(nr_pages);
|
|
swap_map = alloc_swap_map(swsusp_info.pages);
|
|
if (!swap_map)
|
|
return -ENOMEM;
|
|
init_swap_map_handle(&handle, swap_map);
|
|
|
|
error = swap_map_write_page(&handle, (unsigned long)&swsusp_info);
|
|
if (!error)
|
|
error = save_image_metadata(pblist, &handle);
|
|
if (!error)
|
|
error = save_image_data(pblist, &handle, nr_pages);
|
|
if (error)
|
|
goto Free_image_entries;
|
|
|
|
swap_map = reverse_swap_map(swap_map);
|
|
error = save_swap_map(swap_map, &start);
|
|
if (error)
|
|
goto Free_map_entries;
|
|
|
|
dump_info();
|
|
printk( "S" );
|
|
error = mark_swapfiles(start);
|
|
printk( "|\n" );
|
|
if (error)
|
|
goto Free_map_entries;
|
|
|
|
Free_swap_map:
|
|
free_swap_map(swap_map);
|
|
return error;
|
|
|
|
Free_map_entries:
|
|
free_swap_map_entries(swap_map);
|
|
Free_image_entries:
|
|
free_image_entries(swap_map);
|
|
goto Free_swap_map;
|
|
}
|
|
|
|
/**
|
|
* swsusp_shrink_memory - Try to free as much memory as needed
|
|
*
|
|
* ... but do not OOM-kill anyone
|
|
*
|
|
* Notice: all userland should be stopped before it is called, or
|
|
* livelock is possible.
|
|
*/
|
|
|
|
#define SHRINK_BITE 10000
|
|
|
|
int swsusp_shrink_memory(void)
|
|
{
|
|
long size, tmp;
|
|
struct zone *zone;
|
|
unsigned long pages = 0;
|
|
unsigned int i = 0;
|
|
char *p = "-\\|/";
|
|
|
|
printk("Shrinking memory... ");
|
|
do {
|
|
size = 2 * count_highmem_pages();
|
|
size += size / 50 + count_data_pages();
|
|
size += (size + PBES_PER_PAGE - 1) / PBES_PER_PAGE +
|
|
PAGES_FOR_IO;
|
|
tmp = size;
|
|
for_each_zone (zone)
|
|
if (!is_highmem(zone))
|
|
tmp -= zone->free_pages;
|
|
if (tmp > 0) {
|
|
tmp = shrink_all_memory(SHRINK_BITE);
|
|
if (!tmp)
|
|
return -ENOMEM;
|
|
pages += tmp;
|
|
} else if (size > image_size / PAGE_SIZE) {
|
|
tmp = shrink_all_memory(SHRINK_BITE);
|
|
pages += tmp;
|
|
}
|
|
printk("\b%c", p[i++%4]);
|
|
} while (tmp > 0);
|
|
printk("\bdone (%lu pages freed)\n", pages);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int swsusp_suspend(void)
|
|
{
|
|
int error;
|
|
|
|
if ((error = arch_prepare_suspend()))
|
|
return error;
|
|
local_irq_disable();
|
|
/* At this point, device_suspend() has been called, but *not*
|
|
* device_power_down(). We *must* device_power_down() now.
|
|
* Otherwise, drivers for some devices (e.g. interrupt controllers)
|
|
* become desynchronized with the actual state of the hardware
|
|
* at resume time, and evil weirdness ensues.
|
|
*/
|
|
if ((error = device_power_down(PMSG_FREEZE))) {
|
|
printk(KERN_ERR "Some devices failed to power down, aborting suspend\n");
|
|
goto Enable_irqs;
|
|
}
|
|
|
|
if ((error = save_highmem())) {
|
|
printk(KERN_ERR "swsusp: Not enough free pages for highmem\n");
|
|
goto Restore_highmem;
|
|
}
|
|
|
|
save_processor_state();
|
|
if ((error = swsusp_arch_suspend()))
|
|
printk(KERN_ERR "Error %d suspending\n", error);
|
|
/* Restore control flow magically appears here */
|
|
restore_processor_state();
|
|
Restore_highmem:
|
|
restore_highmem();
|
|
device_power_up();
|
|
Enable_irqs:
|
|
local_irq_enable();
|
|
return error;
|
|
}
|
|
|
|
int swsusp_resume(void)
|
|
{
|
|
int error;
|
|
local_irq_disable();
|
|
if (device_power_down(PMSG_FREEZE))
|
|
printk(KERN_ERR "Some devices failed to power down, very bad\n");
|
|
/* We'll ignore saved state, but this gets preempt count (etc) right */
|
|
save_processor_state();
|
|
error = swsusp_arch_resume();
|
|
/* Code below is only ever reached in case of failure. Otherwise
|
|
* execution continues at place where swsusp_arch_suspend was called
|
|
*/
|
|
BUG_ON(!error);
|
|
/* The only reason why swsusp_arch_resume() can fail is memory being
|
|
* very tight, so we have to free it as soon as we can to avoid
|
|
* subsequent failures
|
|
*/
|
|
swsusp_free();
|
|
restore_processor_state();
|
|
restore_highmem();
|
|
touch_softlockup_watchdog();
|
|
device_power_up();
|
|
local_irq_enable();
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* mark_unsafe_pages - mark the pages that cannot be used for storing
|
|
* the image during resume, because they conflict with the pages that
|
|
* had been used before suspend
|
|
*/
|
|
|
|
static void mark_unsafe_pages(struct pbe *pblist)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long zone_pfn;
|
|
struct pbe *p;
|
|
|
|
if (!pblist) /* a sanity check */
|
|
return;
|
|
|
|
/* Clear page flags */
|
|
for_each_zone (zone) {
|
|
for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
|
|
if (pfn_valid(zone_pfn + zone->zone_start_pfn))
|
|
ClearPageNosaveFree(pfn_to_page(zone_pfn +
|
|
zone->zone_start_pfn));
|
|
}
|
|
|
|
/* Mark orig addresses */
|
|
for_each_pbe (p, pblist)
|
|
SetPageNosaveFree(virt_to_page(p->orig_address));
|
|
|
|
}
|
|
|
|
static void copy_page_backup_list(struct pbe *dst, struct pbe *src)
|
|
{
|
|
/* We assume both lists contain the same number of elements */
|
|
while (src) {
|
|
dst->orig_address = src->orig_address;
|
|
dst = dst->next;
|
|
src = src->next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 inline void release_swap_map_reader(struct swap_map_handle *handle)
|
|
{
|
|
if (handle->cur)
|
|
free_page((unsigned long)handle->cur);
|
|
handle->cur = NULL;
|
|
}
|
|
|
|
static inline int get_swap_map_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_map_reader(handle);
|
|
return error;
|
|
}
|
|
handle->k = 0;
|
|
return 0;
|
|
}
|
|
|
|
static inline int swap_map_read_page(struct swap_map_handle *handle, void *buf)
|
|
{
|
|
unsigned long offset;
|
|
int error;
|
|
|
|
if (!handle->cur)
|
|
return -EINVAL;
|
|
offset = swp_offset(handle->cur->entries[handle->k]);
|
|
if (!offset)
|
|
return -EINVAL;
|
|
error = bio_read_page(offset, buf);
|
|
if (error)
|
|
return error;
|
|
if (++handle->k >= MAP_PAGE_SIZE) {
|
|
handle->k = 0;
|
|
offset = swp_offset(handle->cur->next_swap);
|
|
if (!offset)
|
|
release_swap_map_reader(handle);
|
|
else
|
|
error = bio_read_page(offset, handle->cur);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
static int check_header(void)
|
|
{
|
|
char *reason = NULL;
|
|
|
|
dump_info();
|
|
if (swsusp_info.version_code != LINUX_VERSION_CODE)
|
|
reason = "kernel version";
|
|
if (swsusp_info.num_physpages != num_physpages)
|
|
reason = "memory size";
|
|
if (strcmp(swsusp_info.uts.sysname,system_utsname.sysname))
|
|
reason = "system type";
|
|
if (strcmp(swsusp_info.uts.release,system_utsname.release))
|
|
reason = "kernel release";
|
|
if (strcmp(swsusp_info.uts.version,system_utsname.version))
|
|
reason = "version";
|
|
if (strcmp(swsusp_info.uts.machine,system_utsname.machine))
|
|
reason = "machine";
|
|
if (reason) {
|
|
printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason);
|
|
return -EPERM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* load_image_data - load the image data using the swap map handle
|
|
* @handle and store them using the page backup list @pblist
|
|
* (assume there are @nr_pages pages to load)
|
|
*/
|
|
|
|
static int load_image_data(struct pbe *pblist,
|
|
struct swap_map_handle *handle,
|
|
unsigned int nr_pages)
|
|
{
|
|
int error;
|
|
unsigned int m;
|
|
struct pbe *p;
|
|
|
|
if (!pblist)
|
|
return -EINVAL;
|
|
printk("Loading image data pages (%u pages) ... ", nr_pages);
|
|
m = nr_pages / 100;
|
|
if (!m)
|
|
m = 1;
|
|
nr_pages = 0;
|
|
p = pblist;
|
|
while (p) {
|
|
error = swap_map_read_page(handle, (void *)p->address);
|
|
if (error)
|
|
break;
|
|
p = p->next;
|
|
if (!(nr_pages % m))
|
|
printk("\b\b\b\b%3d%%", nr_pages / m);
|
|
nr_pages++;
|
|
}
|
|
if (!error)
|
|
printk("\b\b\b\bdone\n");
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* unpack_orig_addresses - copy the elements of @buf[] (1 page) to
|
|
* the PBEs in the list starting at @pbe
|
|
*/
|
|
|
|
static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
|
|
struct pbe *pbe)
|
|
{
|
|
int j;
|
|
|
|
for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
|
|
pbe->orig_address = buf[j];
|
|
pbe = pbe->next;
|
|
}
|
|
return pbe;
|
|
}
|
|
|
|
/**
|
|
* load_image_metadata - load the image metadata using the swap map
|
|
* handle @handle and put them into the PBEs in the list @pblist
|
|
*/
|
|
|
|
static int load_image_metadata(struct pbe *pblist, struct swap_map_handle *handle)
|
|
{
|
|
struct pbe *p;
|
|
unsigned long *buf;
|
|
unsigned int n = 0;
|
|
int error = 0;
|
|
|
|
printk("Loading image metadata ... ");
|
|
buf = (unsigned long *)get_zeroed_page(GFP_ATOMIC);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
p = pblist;
|
|
while (p) {
|
|
error = swap_map_read_page(handle, buf);
|
|
if (error)
|
|
break;
|
|
p = unpack_orig_addresses(buf, p);
|
|
n++;
|
|
}
|
|
free_page((unsigned long)buf);
|
|
if (!error)
|
|
printk("done (%u pages loaded)\n", n);
|
|
return error;
|
|
}
|
|
|
|
int swsusp_read(struct pbe **pblist_ptr)
|
|
{
|
|
int error;
|
|
struct pbe *p, *pblist;
|
|
struct swap_map_handle handle;
|
|
unsigned int nr_pages;
|
|
|
|
if (IS_ERR(resume_bdev)) {
|
|
pr_debug("swsusp: block device not initialised\n");
|
|
return PTR_ERR(resume_bdev);
|
|
}
|
|
|
|
error = get_swap_map_reader(&handle, swsusp_header.image);
|
|
if (!error)
|
|
error = swap_map_read_page(&handle, &swsusp_info);
|
|
if (!error)
|
|
error = check_header();
|
|
if (error)
|
|
return error;
|
|
nr_pages = swsusp_info.image_pages;
|
|
p = alloc_pagedir(nr_pages, GFP_ATOMIC, 0);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
error = load_image_metadata(p, &handle);
|
|
if (!error) {
|
|
mark_unsafe_pages(p);
|
|
pblist = alloc_pagedir(nr_pages, GFP_ATOMIC, 1);
|
|
if (pblist)
|
|
copy_page_backup_list(pblist, p);
|
|
free_pagedir(p);
|
|
if (!pblist)
|
|
error = -ENOMEM;
|
|
|
|
/* Allocate memory for the image and read the data from swap */
|
|
if (!error)
|
|
error = alloc_data_pages(pblist, GFP_ATOMIC, 1);
|
|
if (!error) {
|
|
release_eaten_pages();
|
|
error = load_image_data(pblist, &handle, nr_pages);
|
|
}
|
|
if (!error)
|
|
*pblist_ptr = pblist;
|
|
}
|
|
release_swap_map_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);
|
|
}
|