[PATCH] swsusp: low level interface
Introduce the low level interface that can be used for handling the snapshot of the system memory by the in-kernel swap-writing/reading code of swsusp and the userland interface code (to be introduced shortly). Also change the way in which swsusp records the allocated swap pages and, consequently, simplifies the in-kernel swap-writing/reading code (this is necessary for the userland interface too). To this end, it introduces two helper functions in mm/swapfile.c, so that the swsusp code does not refer directly to the swap internals. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Rafael J. Wysocki
committed by
Linus Torvalds
Linus Torvalds
parent
2b322ce210
commit
f577eb30af
@@ -77,6 +77,8 @@
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*/
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unsigned long image_size = 500 * 1024 * 1024;
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int in_suspend __nosavedata = 0;
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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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@@ -98,8 +100,6 @@ static struct swsusp_header {
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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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@@ -129,255 +129,261 @@ static int mark_swapfiles(swp_entry_t start)
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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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* 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 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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int res = swap_type_of(swsusp_resume_device);
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if (!swsusp_resume_device)
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return -ENODEV;
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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 (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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if (res >= 0) {
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root_swap = res;
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return 0;
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}
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spin_unlock(&swap_lock);
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return -ENODEV;
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return res;
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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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* The bitmap is used for tracing allocated swap pages
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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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* 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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static int write_page(unsigned long addr, swp_entry_t *loc)
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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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/**
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* The following functions are used for tracing the allocated
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* swap pages, so that they can be freed in case of an error.
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*
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* The functions operate on a linked bitmap structure defined
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* above
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*/
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static void free_bitmap(struct bitmap_page *bitmap)
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{
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struct bitmap_page *bp;
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while (bitmap) {
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bp = bitmap->next;
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free_page((unsigned long)bitmap);
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bitmap = bp;
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}
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}
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static struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
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{
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struct bitmap_page *bitmap, *bp;
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unsigned int n;
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if (!nr_bits)
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return NULL;
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bitmap = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
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bp = bitmap;
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for (n = BITMAP_PAGE_BITS; n < nr_bits; n += BITMAP_PAGE_BITS) {
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bp->next = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
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bp = bp->next;
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if (!bp) {
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free_bitmap(bitmap);
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return NULL;
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}
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}
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return bitmap;
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}
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static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit)
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{
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unsigned int n;
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n = BITMAP_PAGE_BITS;
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while (bitmap && n <= bit) {
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n += BITMAP_PAGE_BITS;
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bitmap = bitmap->next;
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}
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if (!bitmap)
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return -EINVAL;
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n -= BITMAP_PAGE_BITS;
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bit -= n;
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n = 0;
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while (bit >= BITS_PER_CHUNK) {
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bit -= BITS_PER_CHUNK;
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n++;
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}
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bitmap->chunks[n] |= (1UL << bit);
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return 0;
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}
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static unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
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{
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unsigned long offset;
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offset = swp_offset(get_swap_page_of_type(swap));
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if (offset) {
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if (bitmap_set(bitmap, offset)) {
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swap_free(swp_entry(swap, offset));
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offset = 0;
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}
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}
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return offset;
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}
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static void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
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{
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unsigned int bit, n;
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unsigned long test;
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bit = 0;
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while (bitmap) {
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for (n = 0; n < BITMAP_PAGE_CHUNKS; n++)
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for (test = 1UL; test; test <<= 1) {
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if (bitmap->chunks[n] & test)
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swap_free(swp_entry(swap, bit));
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bit++;
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}
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bitmap = bitmap->next;
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}
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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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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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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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* Swap map-handling functions
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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 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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* 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. 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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* 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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* 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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* 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_SIZE ((PAGE_SIZE - sizeof(swp_entry_t) - sizeof(void *)) \
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/ sizeof(swp_entry_t))
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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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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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unsigned long entries[MAP_PAGE_ENTRIES];
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unsigned long next_swap;
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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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* 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 inline void init_swap_map_handle(struct swap_map_handle *handle,
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struct swap_map_page *map)
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static void release_swap_writer(struct swap_map_handle *handle)
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{
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handle->cur = map;
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handle->k = 0;
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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 inline int swap_map_write_page(struct swap_map_handle *handle,
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unsigned long addr)
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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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error = write_page(addr, handle->cur->entries + handle->k);
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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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if (++handle->k >= MAP_PAGE_SIZE) {
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handle->cur = handle->cur->next;
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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_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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* save_image - save the suspend image data
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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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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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struct pbe *p;
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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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@@ -385,98 +391,22 @@ static int save_image_data(struct pbe *pblist,
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if (!m)
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m = 1;
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nr_pages = 0;
|
||||
for_each_pbe (p, pblist) {
|
||||
error = swap_map_write_page(handle, p->address);
|
||||
if (error)
|
||||
break;
|
||||
if (!(nr_pages % m))
|
||||
printk("\b\b\b\b%3d%%", nr_pages / m);
|
||||
nr_pages++;
|
||||
}
|
||||
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;
|
||||
}
|
||||
|
||||
static void dump_info(void)
|
||||
{
|
||||
pr_debug(" swsusp: Version: %u\n",swsusp_info.version_code);
|
||||
pr_debug(" swsusp: Num Pages: %ld\n",swsusp_info.num_physpages);
|
||||
pr_debug(" swsusp: UTS Sys: %s\n",swsusp_info.uts.sysname);
|
||||
pr_debug(" swsusp: UTS Node: %s\n",swsusp_info.uts.nodename);
|
||||
pr_debug(" swsusp: UTS Release: %s\n",swsusp_info.uts.release);
|
||||
pr_debug(" swsusp: UTS Version: %s\n",swsusp_info.uts.version);
|
||||
pr_debug(" swsusp: UTS Machine: %s\n",swsusp_info.uts.machine);
|
||||
pr_debug(" swsusp: UTS Domain: %s\n",swsusp_info.uts.domainname);
|
||||
pr_debug(" swsusp: CPUs: %d\n",swsusp_info.cpus);
|
||||
pr_debug(" swsusp: Image: %ld Pages\n",swsusp_info.image_pages);
|
||||
pr_debug(" swsusp: Total: %ld Pages\n", swsusp_info.pages);
|
||||
}
|
||||
|
||||
static void init_header(unsigned int nr_pages)
|
||||
{
|
||||
memset(&swsusp_info, 0, sizeof(swsusp_info));
|
||||
swsusp_info.version_code = LINUX_VERSION_CODE;
|
||||
swsusp_info.num_physpages = num_physpages;
|
||||
memcpy(&swsusp_info.uts, &system_utsname, sizeof(system_utsname));
|
||||
|
||||
swsusp_info.cpus = num_online_cpus();
|
||||
swsusp_info.image_pages = nr_pages;
|
||||
swsusp_info.pages = nr_pages +
|
||||
((nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
|
||||
}
|
||||
|
||||
/**
|
||||
* pack_orig_addresses - the .orig_address fields of the PBEs from the
|
||||
* list starting at @pbe are stored in the array @buf[] (1 page)
|
||||
*/
|
||||
|
||||
static inline struct pbe *pack_orig_addresses(unsigned long *buf,
|
||||
struct pbe *pbe)
|
||||
{
|
||||
int j;
|
||||
|
||||
for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
|
||||
buf[j] = pbe->orig_address;
|
||||
pbe = pbe->next;
|
||||
}
|
||||
if (!pbe)
|
||||
for (; j < PAGE_SIZE / sizeof(long); j++)
|
||||
buf[j] = 0;
|
||||
return pbe;
|
||||
}
|
||||
|
||||
/**
|
||||
* save_image_metadata - save the .orig_address fields of the PBEs
|
||||
* from the list @pblist using the swap map handle @handle
|
||||
*/
|
||||
|
||||
static int save_image_metadata(struct pbe *pblist,
|
||||
struct swap_map_handle *handle)
|
||||
{
|
||||
unsigned long *buf;
|
||||
unsigned int n = 0;
|
||||
struct pbe *p;
|
||||
int error = 0;
|
||||
|
||||
printk("Saving image metadata ... ");
|
||||
buf = (unsigned long *)get_zeroed_page(GFP_ATOMIC);
|
||||
if (!buf)
|
||||
return -ENOMEM;
|
||||
p = pblist;
|
||||
while (p) {
|
||||
p = pack_orig_addresses(buf, p);
|
||||
error = swap_map_write_page(handle, (unsigned long)buf);
|
||||
if (error)
|
||||
break;
|
||||
n++;
|
||||
}
|
||||
free_page((unsigned long)buf);
|
||||
if (!error)
|
||||
printk("done (%u pages saved)\n", n);
|
||||
return error;
|
||||
}
|
||||
|
||||
/**
|
||||
* enough_swap - Make sure we have enough swap to save the image.
|
||||
*
|
||||
@@ -486,8 +416,7 @@ static int save_image_metadata(struct pbe *pblist,
|
||||
|
||||
static int enough_swap(unsigned int nr_pages)
|
||||
{
|
||||
unsigned int free_swap = swap_info[root_swap].pages -
|
||||
swap_info[root_swap].inuse_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 +
|
||||
@@ -503,57 +432,44 @@ static int enough_swap(unsigned int nr_pages)
|
||||
* correctly, we'll mark system clean, anyway.)
|
||||
*/
|
||||
|
||||
int swsusp_write(struct pbe *pblist, unsigned int nr_pages)
|
||||
int swsusp_write(void)
|
||||
{
|
||||
struct swap_map_page *swap_map;
|
||||
struct swap_map_handle handle;
|
||||
swp_entry_t start;
|
||||
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;
|
||||
}
|
||||
if (!enough_swap(nr_pages)) {
|
||||
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;
|
||||
}
|
||||
|
||||
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);
|
||||
error = get_swap_writer(&handle);
|
||||
if (!error) {
|
||||
start = handle.cur_swap;
|
||||
error = swap_write_page(&handle, header);
|
||||
}
|
||||
if (!error)
|
||||
error = save_image_metadata(pblist, &handle);
|
||||
if (!error)
|
||||
error = save_image_data(pblist, &handle, nr_pages);
|
||||
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)
|
||||
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);
|
||||
free_all_swap_pages(root_swap, handle.bitmap);
|
||||
release_swap_writer(&handle);
|
||||
return error;
|
||||
|
||||
Free_map_entries:
|
||||
free_swap_map_entries(swap_map);
|
||||
Free_image_entries:
|
||||
free_image_entries(swap_map);
|
||||
goto Free_swap_map;
|
||||
}
|
||||
|
||||
/**
|
||||
@@ -663,45 +579,6 @@ int swsusp_resume(void)
|
||||
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
|
||||
@@ -779,14 +656,14 @@ static int bio_write_page(pgoff_t page_off, void *page)
|
||||
* in a file-alike way
|
||||
*/
|
||||
|
||||
static inline void release_swap_map_reader(struct swap_map_handle *handle)
|
||||
static void release_swap_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,
|
||||
static int get_swap_reader(struct swap_map_handle *handle,
|
||||
swp_entry_t start)
|
||||
{
|
||||
int error;
|
||||
@@ -798,149 +675,80 @@ static inline int get_swap_map_reader(struct swap_map_handle *handle,
|
||||
return -ENOMEM;
|
||||
error = bio_read_page(swp_offset(start), handle->cur);
|
||||
if (error) {
|
||||
release_swap_map_reader(handle);
|
||||
release_swap_reader(handle);
|
||||
return error;
|
||||
}
|
||||
handle->k = 0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int swap_map_read_page(struct swap_map_handle *handle, void *buf)
|
||||
static int swap_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]);
|
||||
offset = handle->cur->entries[handle->k];
|
||||
if (!offset)
|
||||
return -EINVAL;
|
||||
return -EFAULT;
|
||||
error = bio_read_page(offset, buf);
|
||||
if (error)
|
||||
return error;
|
||||
if (++handle->k >= MAP_PAGE_SIZE) {
|
||||
if (++handle->k >= MAP_PAGE_ENTRIES) {
|
||||
handle->k = 0;
|
||||
offset = swp_offset(handle->cur->next_swap);
|
||||
offset = handle->cur->next_swap;
|
||||
if (!offset)
|
||||
release_swap_map_reader(handle);
|
||||
release_swap_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
|
||||
* 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_data(struct pbe *pblist,
|
||||
struct swap_map_handle *handle,
|
||||
unsigned int nr_pages)
|
||||
static int load_image(struct swap_map_handle *handle,
|
||||
struct snapshot_handle *snapshot,
|
||||
unsigned int nr_pages)
|
||||
{
|
||||
int error;
|
||||
unsigned int m;
|
||||
struct pbe *p;
|
||||
int ret;
|
||||
int error = 0;
|
||||
|
||||
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++;
|
||||
}
|
||||
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;
|
||||
}
|
||||
|
||||
/**
|
||||
* 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 swsusp_read(void)
|
||||
{
|
||||
int error;
|
||||
struct pbe *p, *pblist;
|
||||
struct swap_map_handle handle;
|
||||
struct snapshot_handle snapshot;
|
||||
struct swsusp_info *header;
|
||||
unsigned int nr_pages;
|
||||
|
||||
if (IS_ERR(resume_bdev)) {
|
||||
@@ -948,38 +756,19 @@ int swsusp_read(struct pbe **pblist_ptr)
|
||||
return PTR_ERR(resume_bdev);
|
||||
}
|
||||
|
||||
error = get_swap_map_reader(&handle, swsusp_header.image);
|
||||
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_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);
|
||||
error = swap_read_page(&handle, header);
|
||||
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;
|
||||
nr_pages = header->image_pages;
|
||||
error = load_image(&handle, &snapshot, nr_pages);
|
||||
}
|
||||
release_swap_map_reader(&handle);
|
||||
release_swap_reader(&handle);
|
||||
|
||||
blkdev_put(resume_bdev);
|
||||
|
||||
|
||||
Reference in New Issue
Block a user