* Alex Badea <vampire@go.ro>:
* Fixed runaway init
*
+ * Rafael J. Wysocki <rjw@sisk.pl>
+ * Added the swap map data structure and reworked the handling of swap
+ *
* More state savers are welcome. Especially for the scsi layer...
*
* For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
extern char resume_file[];
-/* Local variables that should not be affected by save */
-unsigned int nr_copy_pages __nosavedata = 0;
-
-/* Suspend pagedir is allocated before final copy, therefore it
- must be freed after resume
-
- Warning: this is even more evil than it seems. Pagedirs this file
- talks about are completely different from page directories used by
- MMU hardware.
- */
-suspend_pagedir_t *pagedir_nosave __nosavedata = NULL;
-
#define SWSUSP_SIG "S1SUSPEND"
static struct swsusp_header {
}
/**
- * data_free - Free the swap entries used by the saved image.
+ * Swap map-handling functions
+ *
+ * The swap map is a data structure used for keeping track of each page
+ * written to the swap. It consists of many swap_map_page structures
+ * that contain each an array of MAP_PAGE_SIZE swap entries.
+ * These structures are linked together with the help of either the
+ * .next (in memory) or the .next_swap (in swap) member.
*
- * Walk the list of used swap entries and free each one.
- * This is only used for cleanup when suspend fails.
+ * The swap map is created during suspend. At that time we need to keep
+ * it in memory, because we have to free all of the allocated swap
+ * entries if an error occurs. The memory needed is preallocated
+ * so that we know in advance if there's enough of it.
+ *
+ * The first swap_map_page structure is filled with the swap entries that
+ * correspond to the first MAP_PAGE_SIZE data pages written to swap and
+ * so on. After the all of the data pages have been written, the order
+ * of the swap_map_page structures in the map is reversed so that they
+ * can be read from swap in the original order. This causes the data
+ * pages to be loaded in exactly the same order in which they have been
+ * saved.
+ *
+ * During resume we only need to use one swap_map_page structure
+ * at a time, which means that we only need to use two memory pages for
+ * reading the image - one for reading the swap_map_page structures
+ * and the second for reading the data pages from swap.
*/
-static void data_free(void)
+
+#define MAP_PAGE_SIZE ((PAGE_SIZE - sizeof(swp_entry_t) - sizeof(void *)) \
+ / sizeof(swp_entry_t))
+
+struct swap_map_page {
+ swp_entry_t entries[MAP_PAGE_SIZE];
+ swp_entry_t next_swap;
+ struct swap_map_page *next;
+};
+
+static inline void free_swap_map(struct swap_map_page *swap_map)
{
- swp_entry_t entry;
- struct pbe *p;
+ struct swap_map_page *swp;
- for_each_pbe (p, pagedir_nosave) {
- entry = p->swap_address;
- if (entry.val)
- swap_free(entry);
- else
- break;
+ while (swap_map) {
+ swp = swap_map->next;
+ free_page((unsigned long)swap_map);
+ swap_map = swp;
+ }
+}
+
+static struct swap_map_page *alloc_swap_map(unsigned int nr_pages)
+{
+ struct swap_map_page *swap_map, *swp;
+ unsigned n = 0;
+
+ if (!nr_pages)
+ return NULL;
+
+ pr_debug("alloc_swap_map(): nr_pages = %d\n", nr_pages);
+ swap_map = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
+ swp = swap_map;
+ for (n = MAP_PAGE_SIZE; n < nr_pages; n += MAP_PAGE_SIZE) {
+ swp->next = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
+ swp = swp->next;
+ if (!swp) {
+ free_swap_map(swap_map);
+ return NULL;
+ }
}
+ return swap_map;
}
/**
- * data_write - Write saved image to swap.
- *
- * Walk the list of pages in the image and sync each one to swap.
+ * reverse_swap_map - reverse the order of pages in the swap map
+ * @swap_map
*/
-static int data_write(void)
+
+static inline struct swap_map_page *reverse_swap_map(struct swap_map_page *swap_map)
{
- int error = 0, i = 0;
- unsigned int mod = nr_copy_pages / 100;
- struct pbe *p;
+ struct swap_map_page *prev, *next;
+
+ prev = NULL;
+ while (swap_map) {
+ next = swap_map->next;
+ swap_map->next = prev;
+ prev = swap_map;
+ swap_map = next;
+ }
+ return prev;
+}
- if (!mod)
- mod = 1;
+/**
+ * free_swap_map_entries - free the swap entries allocated to store
+ * the swap map @swap_map (this is only called in case of an error)
+ */
+static inline void free_swap_map_entries(struct swap_map_page *swap_map)
+{
+ while (swap_map) {
+ if (swap_map->next_swap.val)
+ swap_free(swap_map->next_swap);
+ swap_map = swap_map->next;
+ }
+}
- printk( "Writing data to swap (%d pages)... ", nr_copy_pages );
- for_each_pbe (p, pagedir_nosave) {
- if (!(i%mod))
- printk( "\b\b\b\b%3d%%", i / mod );
- if ((error = write_page(p->address, &p->swap_address)))
+/**
+ * save_swap_map - save the swap map used for tracing the data pages
+ * stored in the swap
+ */
+
+static int save_swap_map(struct swap_map_page *swap_map, swp_entry_t *start)
+{
+ swp_entry_t entry = (swp_entry_t){0};
+ int error;
+
+ while (swap_map) {
+ swap_map->next_swap = entry;
+ if ((error = write_page((unsigned long)swap_map, &entry)))
return error;
- i++;
+ swap_map = swap_map->next;
}
- printk("\b\b\b\bdone\n");
+ *start = entry;
+ return 0;
+}
+
+/**
+ * free_image_entries - free the swap entries allocated to store
+ * the image data pages (this is only called in case of an error)
+ */
+
+static inline void free_image_entries(struct swap_map_page *swp)
+{
+ unsigned k;
+
+ while (swp) {
+ for (k = 0; k < MAP_PAGE_SIZE; k++)
+ if (swp->entries[k].val)
+ swap_free(swp->entries[k]);
+ swp = swp->next;
+ }
+}
+
+/**
+ * The swap_map_handle structure is used for handling the swap map in
+ * a file-alike way
+ */
+
+struct swap_map_handle {
+ struct swap_map_page *cur;
+ unsigned int k;
+};
+
+static inline void init_swap_map_handle(struct swap_map_handle *handle,
+ struct swap_map_page *map)
+{
+ handle->cur = map;
+ handle->k = 0;
+}
+
+static inline int swap_map_write_page(struct swap_map_handle *handle,
+ unsigned long addr)
+{
+ int error;
+
+ error = write_page(addr, handle->cur->entries + handle->k);
+ if (error)
+ return error;
+ if (++handle->k >= MAP_PAGE_SIZE) {
+ handle->cur = handle->cur->next;
+ handle->k = 0;
+ }
+ return 0;
+}
+
+/**
+ * save_image_data - save the data pages pointed to by the PBEs
+ * from the list @pblist using the swap map handle @handle
+ * (assume there are @nr_pages data pages to save)
+ */
+
+static int save_image_data(struct pbe *pblist,
+ struct swap_map_handle *handle,
+ unsigned int nr_pages)
+{
+ unsigned int m;
+ struct pbe *p;
+ int error = 0;
+
+ printk("Saving image data pages (%u pages) ... ", nr_pages);
+ m = nr_pages / 100;
+ if (!m)
+ m = 1;
+ 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++;
+ }
+ if (!error)
+ printk("\b\b\b\bdone\n");
return error;
}
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: Pagedir: %ld Pages\n",swsusp_info.pagedir_pages);
+ pr_debug(" swsusp: Total: %ld Pages\n", swsusp_info.pages);
}
-static void init_header(void)
+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.suspend_pagedir = pagedir_nosave;
swsusp_info.cpus = num_online_cpus();
- swsusp_info.image_pages = nr_copy_pages;
+ swsusp_info.image_pages = nr_pages;
+ swsusp_info.pages = nr_pages +
+ ((nr_pages * sizeof(long) + PAGE_SIZE - 1) >> PAGE_SHIFT);
}
static int close_swap(void)
}
/**
- * free_pagedir_entries - Free pages used by the page directory.
- *
- * This is used during suspend for error recovery.
+ * 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 void free_pagedir_entries(void)
+static inline struct pbe *pack_orig_addresses(unsigned long *buf,
+ struct pbe *pbe)
{
- int i;
+ int j;
- for (i = 0; i < swsusp_info.pagedir_pages; i++)
- swap_free(swsusp_info.pagedir[i]);
+ 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;
}
-
/**
- * write_pagedir - Write the array of pages holding the page directory.
- * @last: Last swap entry we write (needed for header).
+ * save_image_metadata - save the .orig_address fields of the PBEs
+ * from the list @pblist using the swap map handle @handle
*/
-static int write_pagedir(void)
+static int save_image_metadata(struct pbe *pblist,
+ struct swap_map_handle *handle)
{
- int error = 0;
+ unsigned long *buf;
unsigned int n = 0;
- struct pbe *pbe;
+ struct pbe *p;
+ int error = 0;
- printk( "Writing pagedir...");
- for_each_pb_page (pbe, pagedir_nosave) {
- if ((error = write_page((unsigned long)pbe, &swsusp_info.pagedir[n++])))
- return error;
+ 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++;
}
-
- swsusp_info.pagedir_pages = n;
- printk("done (%u pages)\n", n);
+ free_page((unsigned long)buf);
+ if (!error)
+ printk("done (%u pages saved)\n", n);
return error;
}
/**
* write_suspend_image - Write entire image and metadata.
- *
*/
-static int write_suspend_image(void)
+static int write_suspend_image(struct pbe *pblist, unsigned int nr_pages)
{
+ struct swap_map_page *swap_map;
+ struct swap_map_handle handle;
int error;
- if (!enough_swap(nr_copy_pages)) {
+ if (!enough_swap(nr_pages)) {
printk(KERN_ERR "swsusp: Not enough free swap\n");
return -ENOSPC;
}
- init_header();
- if ((error = data_write()))
- goto FreeData;
+ init_header(nr_pages);
+ swap_map = alloc_swap_map(swsusp_info.pages);
+ if (!swap_map)
+ return -ENOMEM;
+ init_swap_map_handle(&handle, swap_map);
- if ((error = write_pagedir()))
- goto FreePagedir;
+ error = save_image_metadata(pblist, &handle);
+ if (!error)
+ error = save_image_data(pblist, &handle, nr_pages);
+ if (error)
+ goto Free_image_entries;
- if ((error = close_swap()))
- goto FreePagedir;
- Done:
+ swap_map = reverse_swap_map(swap_map);
+ error = save_swap_map(swap_map, &swsusp_info.start);
+ if (error)
+ goto Free_map_entries;
+
+ error = close_swap();
+ if (error)
+ goto Free_map_entries;
+
+Free_swap_map:
+ free_swap_map(swap_map);
return error;
- FreePagedir:
- free_pagedir_entries();
- FreeData:
- data_free();
- goto Done;
+
+Free_map_entries:
+ free_swap_map_entries(swap_map);
+Free_image_entries:
+ free_image_entries(swap_map);
+ goto Free_swap_map;
}
/* It is important _NOT_ to umount filesystems at this point. We want
* filesystem clean: it is not. (And it does not matter, if we resume
* correctly, we'll mark system clean, anyway.)
*/
-int swsusp_write(void)
+int swsusp_write(struct pbe *pblist, unsigned int nr_pages)
{
int error;
return error;
}
lock_swapdevices();
- error = write_suspend_image();
+ error = write_suspend_image(pblist, nr_pages);
/* This will unlock ignored swap devices since writing is finished */
lock_swapdevices();
return error;
}
-
-
int swsusp_suspend(void)
{
int error;
/* We assume both lists contain the same number of elements */
while (src) {
dst->orig_address = src->orig_address;
- dst->swap_address = src->swap_address;
dst = dst->next;
src = src->next;
}
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;
+}
+
/*
* Sanity check if this image makes sense with this kernel/swap context
* I really don't think that it's foolproof but more than nothing..
return NULL;
}
-
static int check_header(void)
{
const char *reason = NULL;
printk(KERN_ERR "swsusp: Resume mismatch: %s\n",reason);
return -EPERM;
}
- nr_copy_pages = swsusp_info.image_pages;
return error;
}
}
/**
- * data_read - Read image pages from swap.
- *
- * You do not need to check for overlaps, check_pagedir()
- * already did that.
+ * 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 data_read(struct pbe *pblist)
+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;
- int error = 0;
- int i = 0;
- int mod = swsusp_info.image_pages / 100;
-
- if (!mod)
- mod = 1;
-
- printk("swsusp: Reading image data (%lu pages): ",
- swsusp_info.image_pages);
-
- for_each_pbe (p, pblist) {
- if (!(i % mod))
- printk("\b\b\b\b%3d%%", i / mod);
- if ((error = bio_read_page(swp_offset(p->swap_address),
- (void *)p->address)))
- return error;
-
- i++;
+ 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++;
}
- printk("\b\b\b\bdone\n");
+ if (!error)
+ printk("\b\b\b\bdone\n");
return error;
}
/**
- * read_pagedir - Read page backup list pages from swap
+ * unpack_orig_addresses - copy the elements of @buf[] (1 page) to
+ * the PBEs in the list starting at @pbe
*/
-static int read_pagedir(struct pbe *pblist)
+static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
+ struct pbe *pbe)
{
- struct pbe *pbpage, *p;
- unsigned int i = 0;
- int error;
+ int j;
- if (!pblist)
- return -EFAULT;
+ for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
+ pbe->orig_address = buf[j];
+ pbe = pbe->next;
+ }
+ return pbe;
+}
- printk("swsusp: Reading pagedir (%lu pages)\n",
- swsusp_info.pagedir_pages);
+/**
+ * load_image_metadata - load the image metadata using the swap map
+ * handle @handle and put them into the PBEs in the list @pblist
+ */
- for_each_pb_page (pbpage, pblist) {
- unsigned long offset = swp_offset(swsusp_info.pagedir[i++]);
+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;
- error = -EFAULT;
- if (offset) {
- p = (pbpage + PB_PAGE_SKIP)->next;
- error = bio_read_page(offset, (void *)pbpage);
- (pbpage + PB_PAGE_SKIP)->next = p;
- }
+ 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)
- BUG_ON(i != swsusp_info.pagedir_pages);
-
+ printk("done (%u pages loaded)\n", n);
return error;
}
-
static int check_suspend_image(void)
{
int error = 0;
return 0;
}
-static int read_suspend_image(void)
+static int read_suspend_image(struct pbe **pblist_ptr)
{
int error = 0;
- struct pbe *p;
+ struct pbe *p, *pblist;
+ struct swap_map_handle handle;
+ unsigned int nr_pages = swsusp_info.image_pages;
- if (!(p = alloc_pagedir(nr_copy_pages, GFP_ATOMIC, 0)))
+ p = alloc_pagedir(nr_pages, GFP_ATOMIC, 0);
+ if (!p)
return -ENOMEM;
-
- if ((error = read_pagedir(p)))
+ error = get_swap_map_reader(&handle, swsusp_info.start);
+ if (error)
+ /* The PBE list at p will be released by swsusp_free() */
return error;
- create_pbe_list(p, nr_copy_pages);
- mark_unsafe_pages(p);
- pagedir_nosave = alloc_pagedir(nr_copy_pages, GFP_ATOMIC, 1);
- if (pagedir_nosave) {
- create_pbe_list(pagedir_nosave, nr_copy_pages);
- copy_page_backup_list(pagedir_nosave, p);
+ 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)
+ error = load_image_data(pblist, &handle, nr_pages);
+ if (!error)
+ *pblist_ptr = pblist;
}
- free_pagedir(p);
- if (!pagedir_nosave)
- return -ENOMEM;
-
- /* Allocate memory for the image and read the data from swap */
-
- error = alloc_data_pages(pagedir_nosave, GFP_ATOMIC, 1);
-
- if (!error)
- error = data_read(pagedir_nosave);
-
+ release_swap_map_reader(&handle);
return error;
}
* swsusp_read - Read saved image from swap.
*/
-int swsusp_read(void)
+int swsusp_read(struct pbe **pblist_ptr)
{
int error;
return PTR_ERR(resume_bdev);
}
- error = read_suspend_image();
+ error = read_suspend_image(pblist_ptr);
blkdev_put(resume_bdev);
if (!error)
projects / linux-2.6 / commitdiff