2 * linux/kernel/power/swsusp.c
4 * This file provides code to write suspend image to swap and read it back.
6 * Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
7 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
9 * This file is released under the GPLv2.
11 * I'd like to thank the following people for their work:
13 * Pavel Machek <pavel@ucw.cz>:
14 * Modifications, defectiveness pointing, being with me at the very beginning,
15 * suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17.
17 * Steve Doddi <dirk@loth.demon.co.uk>:
18 * Support the possibility of hardware state restoring.
20 * Raph <grey.havens@earthling.net>:
21 * Support for preserving states of network devices and virtual console
22 * (including X and svgatextmode)
24 * Kurt Garloff <garloff@suse.de>:
25 * Straightened the critical function in order to prevent compilers from
26 * playing tricks with local variables.
28 * Andreas Mohr <a.mohr@mailto.de>
30 * Alex Badea <vampire@go.ro>:
33 * Andreas Steinmetz <ast@domdv.de>:
34 * Added encrypted suspend option
36 * More state savers are welcome. Especially for the scsi layer...
38 * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
41 #include <linux/module.h>
43 #include <linux/suspend.h>
44 #include <linux/smp_lock.h>
45 #include <linux/file.h>
46 #include <linux/utsname.h>
47 #include <linux/version.h>
48 #include <linux/delay.h>
49 #include <linux/bitops.h>
50 #include <linux/spinlock.h>
51 #include <linux/genhd.h>
52 #include <linux/kernel.h>
53 #include <linux/major.h>
54 #include <linux/swap.h>
56 #include <linux/device.h>
57 #include <linux/buffer_head.h>
58 #include <linux/swapops.h>
59 #include <linux/bootmem.h>
60 #include <linux/syscalls.h>
61 #include <linux/highmem.h>
62 #include <linux/bio.h>
64 #include <asm/uaccess.h>
65 #include <asm/mmu_context.h>
66 #include <asm/pgtable.h>
67 #include <asm/tlbflush.h>
70 #include <linux/random.h>
71 #include <linux/crypto.h>
72 #include <asm/scatterlist.h>
80 extern char resume_file
[];
82 /* Local variables that should not be affected by save */
83 unsigned int nr_copy_pages __nosavedata
= 0;
85 /* Suspend pagedir is allocated before final copy, therefore it
86 must be freed after resume
88 Warning: this is even more evil than it seems. Pagedirs this file
89 talks about are completely different from page directories used by
92 suspend_pagedir_t
*pagedir_nosave __nosavedata
= NULL
;
94 #define SWSUSP_SIG "S1SUSPEND"
96 static struct swsusp_header
{
97 char reserved
[PAGE_SIZE
- 20 - MAXKEY
- MAXIV
- sizeof(swp_entry_t
)];
98 u8 key_iv
[MAXKEY
+MAXIV
];
99 swp_entry_t swsusp_info
;
102 } __attribute__((packed
, aligned(PAGE_SIZE
))) swsusp_header
;
104 static struct swsusp_info swsusp_info
;
110 /* We memorize in swapfile_used what swap devices are used for suspension */
111 #define SWAPFILE_UNUSED 0
112 #define SWAPFILE_SUSPEND 1 /* This is the suspending device */
113 #define SWAPFILE_IGNORED 2 /* Those are other swap devices ignored for suspension */
115 static unsigned short swapfile_used
[MAX_SWAPFILES
];
116 static unsigned short root_swap
;
118 static int write_page(unsigned long addr
, swp_entry_t
*loc
);
119 static int bio_read_page(pgoff_t page_off
, void *page
);
121 static u8 key_iv
[MAXKEY
+MAXIV
];
123 #ifdef CONFIG_SWSUSP_ENCRYPT
125 static int crypto_init(int mode
, void **mem
)
130 struct crypto_tfm
*tfm
;
132 modemsg
= mode
? "suspend not possible" : "resume not possible";
134 tfm
= crypto_alloc_tfm(CIPHER
, CRYPTO_TFM_MODE_CBC
);
136 printk(KERN_ERR
"swsusp: no tfm, %s\n", modemsg
);
141 if(MAXKEY
< crypto_tfm_alg_min_keysize(tfm
)) {
142 printk(KERN_ERR
"swsusp: key buffer too small, %s\n", modemsg
);
148 get_random_bytes(key_iv
, MAXKEY
+MAXIV
);
150 len
= crypto_tfm_alg_max_keysize(tfm
);
154 if (crypto_cipher_setkey(tfm
, key_iv
, len
)) {
155 printk(KERN_ERR
"swsusp: key setup failure, %s\n", modemsg
);
156 error
= -EKEYREJECTED
;
160 len
= crypto_tfm_alg_ivsize(tfm
);
163 printk(KERN_ERR
"swsusp: iv buffer too small, %s\n", modemsg
);
168 crypto_cipher_set_iv(tfm
, key_iv
+MAXKEY
, len
);
174 fail
: crypto_free_tfm(tfm
);
178 static __inline__
void crypto_exit(void *mem
)
180 crypto_free_tfm((struct crypto_tfm
*)mem
);
183 static __inline__
int crypto_write(struct pbe
*p
, void *mem
)
186 struct scatterlist src
, dst
;
188 src
.page
= virt_to_page(p
->address
);
190 src
.length
= PAGE_SIZE
;
191 dst
.page
= virt_to_page((void *)&swsusp_header
);
193 dst
.length
= PAGE_SIZE
;
195 error
= crypto_cipher_encrypt((struct crypto_tfm
*)mem
, &dst
, &src
,
199 error
= write_page((unsigned long)&swsusp_header
,
204 static __inline__
int crypto_read(struct pbe
*p
, void *mem
)
207 struct scatterlist src
, dst
;
209 error
= bio_read_page(swp_offset(p
->swap_address
), (void *)p
->address
);
212 src
.length
= PAGE_SIZE
;
214 dst
.length
= PAGE_SIZE
;
215 src
.page
= dst
.page
= virt_to_page((void *)p
->address
);
217 error
= crypto_cipher_decrypt((struct crypto_tfm
*)mem
, &dst
,
223 static __inline__
int crypto_init(int mode
, void *mem
)
228 static __inline__
void crypto_exit(void *mem
)
232 static __inline__
int crypto_write(struct pbe
*p
, void *mem
)
234 return write_page(p
->address
, &(p
->swap_address
));
237 static __inline__
int crypto_read(struct pbe
*p
, void *mem
)
239 return bio_read_page(swp_offset(p
->swap_address
), (void *)p
->address
);
243 static int mark_swapfiles(swp_entry_t prev
)
247 rw_swap_page_sync(READ
,
248 swp_entry(root_swap
, 0),
249 virt_to_page((unsigned long)&swsusp_header
));
250 if (!memcmp("SWAP-SPACE",swsusp_header
.sig
, 10) ||
251 !memcmp("SWAPSPACE2",swsusp_header
.sig
, 10)) {
252 memcpy(swsusp_header
.orig_sig
,swsusp_header
.sig
, 10);
253 memcpy(swsusp_header
.sig
,SWSUSP_SIG
, 10);
254 memcpy(swsusp_header
.key_iv
, key_iv
, MAXKEY
+MAXIV
);
255 swsusp_header
.swsusp_info
= prev
;
256 error
= rw_swap_page_sync(WRITE
,
257 swp_entry(root_swap
, 0),
258 virt_to_page((unsigned long)
261 pr_debug("swsusp: Partition is not swap space.\n");
268 * Check whether the swap device is the specified resume
269 * device, irrespective of whether they are specified by
272 * (Thus, device inode aliasing is allowed. You can say /dev/hda4
273 * instead of /dev/ide/host0/bus0/target0/lun0/part4 [if using devfs]
274 * and they'll be considered the same device. This is *necessary* for
275 * devfs, since the resume code can only recognize the form /dev/hda4,
276 * but the suspend code would see the long name.)
278 static int is_resume_device(const struct swap_info_struct
*swap_info
)
280 struct file
*file
= swap_info
->swap_file
;
281 struct inode
*inode
= file
->f_dentry
->d_inode
;
283 return S_ISBLK(inode
->i_mode
) &&
284 swsusp_resume_device
== MKDEV(imajor(inode
), iminor(inode
));
287 static int swsusp_swap_check(void) /* This is called before saving image */
291 len
=strlen(resume_file
);
294 spin_lock(&swap_lock
);
295 for (i
=0; i
<MAX_SWAPFILES
; i
++) {
296 if (!(swap_info
[i
].flags
& SWP_WRITEOK
)) {
297 swapfile_used
[i
]=SWAPFILE_UNUSED
;
300 printk(KERN_WARNING
"resume= option should be used to set suspend device" );
301 if (root_swap
== 0xFFFF) {
302 swapfile_used
[i
] = SWAPFILE_SUSPEND
;
305 swapfile_used
[i
] = SWAPFILE_IGNORED
;
307 /* we ignore all swap devices that are not the resume_file */
308 if (is_resume_device(&swap_info
[i
])) {
309 swapfile_used
[i
] = SWAPFILE_SUSPEND
;
312 swapfile_used
[i
] = SWAPFILE_IGNORED
;
317 spin_unlock(&swap_lock
);
318 return (root_swap
!= 0xffff) ? 0 : -ENODEV
;
322 * This is called after saving image so modification
323 * will be lost after resume... and that's what we want.
324 * we make the device unusable. A new call to
325 * lock_swapdevices can unlock the devices.
327 static void lock_swapdevices(void)
331 spin_lock(&swap_lock
);
332 for (i
= 0; i
< MAX_SWAPFILES
; i
++)
333 if (swapfile_used
[i
] == SWAPFILE_IGNORED
) {
334 swap_info
[i
].flags
^= SWP_WRITEOK
;
336 spin_unlock(&swap_lock
);
340 * write_page - Write one page to a fresh swap location.
341 * @addr: Address we're writing.
342 * @loc: Place to store the entry we used.
344 * Allocate a new swap entry and 'sync' it. Note we discard -EIO
345 * errors. That is an artifact left over from swsusp. It did not
346 * check the return of rw_swap_page_sync() at all, since most pages
347 * written back to swap would return -EIO.
348 * This is a partial improvement, since we will at least return other
349 * errors, though we need to eventually fix the damn code.
351 static int write_page(unsigned long addr
, swp_entry_t
*loc
)
356 entry
= get_swap_page();
357 if (swp_offset(entry
) &&
358 swapfile_used
[swp_type(entry
)] == SWAPFILE_SUSPEND
) {
359 error
= rw_swap_page_sync(WRITE
, entry
,
371 * data_free - Free the swap entries used by the saved image.
373 * Walk the list of used swap entries and free each one.
374 * This is only used for cleanup when suspend fails.
376 static void data_free(void)
381 for_each_pbe (p
, pagedir_nosave
) {
382 entry
= p
->swap_address
;
391 * data_write - Write saved image to swap.
393 * Walk the list of pages in the image and sync each one to swap.
395 static int data_write(void)
397 int error
= 0, i
= 0;
398 unsigned int mod
= nr_copy_pages
/ 100;
402 if ((error
= crypto_init(1, &tfm
)))
408 printk( "Writing data to swap (%d pages)... ", nr_copy_pages
);
409 for_each_pbe (p
, pagedir_nosave
) {
411 printk( "\b\b\b\b%3d%%", i
/ mod
);
412 if ((error
= crypto_write(p
, tfm
))) {
418 printk("\b\b\b\bdone\n");
423 static void dump_info(void)
425 pr_debug(" swsusp: Version: %u\n",swsusp_info
.version_code
);
426 pr_debug(" swsusp: Num Pages: %ld\n",swsusp_info
.num_physpages
);
427 pr_debug(" swsusp: UTS Sys: %s\n",swsusp_info
.uts
.sysname
);
428 pr_debug(" swsusp: UTS Node: %s\n",swsusp_info
.uts
.nodename
);
429 pr_debug(" swsusp: UTS Release: %s\n",swsusp_info
.uts
.release
);
430 pr_debug(" swsusp: UTS Version: %s\n",swsusp_info
.uts
.version
);
431 pr_debug(" swsusp: UTS Machine: %s\n",swsusp_info
.uts
.machine
);
432 pr_debug(" swsusp: UTS Domain: %s\n",swsusp_info
.uts
.domainname
);
433 pr_debug(" swsusp: CPUs: %d\n",swsusp_info
.cpus
);
434 pr_debug(" swsusp: Image: %ld Pages\n",swsusp_info
.image_pages
);
435 pr_debug(" swsusp: Pagedir: %ld Pages\n",swsusp_info
.pagedir_pages
);
438 static void init_header(void)
440 memset(&swsusp_info
, 0, sizeof(swsusp_info
));
441 swsusp_info
.version_code
= LINUX_VERSION_CODE
;
442 swsusp_info
.num_physpages
= num_physpages
;
443 memcpy(&swsusp_info
.uts
, &system_utsname
, sizeof(system_utsname
));
445 swsusp_info
.suspend_pagedir
= pagedir_nosave
;
446 swsusp_info
.cpus
= num_online_cpus();
447 swsusp_info
.image_pages
= nr_copy_pages
;
450 static int close_swap(void)
456 error
= write_page((unsigned long)&swsusp_info
, &entry
);
459 error
= mark_swapfiles(entry
);
466 * free_pagedir_entries - Free pages used by the page directory.
468 * This is used during suspend for error recovery.
471 static void free_pagedir_entries(void)
475 for (i
= 0; i
< swsusp_info
.pagedir_pages
; i
++)
476 swap_free(swsusp_info
.pagedir
[i
]);
481 * write_pagedir - Write the array of pages holding the page directory.
482 * @last: Last swap entry we write (needed for header).
485 static int write_pagedir(void)
491 printk( "Writing pagedir...");
492 for_each_pb_page (pbe
, pagedir_nosave
) {
493 if ((error
= write_page((unsigned long)pbe
, &swsusp_info
.pagedir
[n
++])))
497 swsusp_info
.pagedir_pages
= n
;
498 printk("done (%u pages)\n", n
);
503 * write_suspend_image - Write entire image and metadata.
506 static int write_suspend_image(void)
511 if ((error
= data_write()))
514 if ((error
= write_pagedir()))
517 if ((error
= close_swap()))
520 memset(key_iv
, 0, MAXKEY
+MAXIV
);
523 free_pagedir_entries();
530 * enough_swap - Make sure we have enough swap to save the image.
532 * Returns TRUE or FALSE after checking the total amount of swap
535 * FIXME: si_swapinfo(&i) returns all swap devices information.
536 * We should only consider resume_device.
539 int enough_swap(unsigned int nr_pages
)
544 pr_debug("swsusp: available swap: %lu pages\n", i
.freeswap
);
545 return i
.freeswap
> (nr_pages
+ PAGES_FOR_IO
+
546 (nr_pages
+ PBES_PER_PAGE
- 1) / PBES_PER_PAGE
);
550 /* It is important _NOT_ to umount filesystems at this point. We want
551 * them synced (in case something goes wrong) but we DO not want to mark
552 * filesystem clean: it is not. (And it does not matter, if we resume
553 * correctly, we'll mark system clean, anyway.)
555 int swsusp_write(void)
560 error
= write_suspend_image();
561 /* This will unlock ignored swap devices since writing is finished */
569 int swsusp_suspend(void)
572 if ((error
= arch_prepare_suspend()))
575 /* At this point, device_suspend() has been called, but *not*
576 * device_power_down(). We *must* device_power_down() now.
577 * Otherwise, drivers for some devices (e.g. interrupt controllers)
578 * become desynchronized with the actual state of the hardware
579 * at resume time, and evil weirdness ensues.
581 if ((error
= device_power_down(PMSG_FREEZE
))) {
582 printk(KERN_ERR
"Some devices failed to power down, aborting suspend\n");
587 if ((error
= swsusp_swap_check())) {
588 printk(KERN_ERR
"swsusp: cannot find swap device, try swapon -a.\n");
594 save_processor_state();
595 if ((error
= swsusp_arch_suspend()))
596 printk(KERN_ERR
"Error %d suspending\n", error
);
597 /* Restore control flow magically appears here */
598 restore_processor_state();
605 int swsusp_resume(void)
609 if (device_power_down(PMSG_FREEZE
))
610 printk(KERN_ERR
"Some devices failed to power down, very bad\n");
611 /* We'll ignore saved state, but this gets preempt count (etc) right */
612 save_processor_state();
613 error
= swsusp_arch_resume();
614 /* Code below is only ever reached in case of failure. Otherwise
615 * execution continues at place where swsusp_arch_suspend was called
618 /* The only reason why swsusp_arch_resume() can fail is memory being
619 * very tight, so we have to free it as soon as we can to avoid
620 * subsequent failures
623 restore_processor_state();
625 touch_softlockup_watchdog();
632 * On resume, for storing the PBE list and the image,
633 * we can only use memory pages that do not conflict with the pages
634 * which had been used before suspend.
636 * We don't know which pages are usable until we allocate them.
638 * Allocated but unusable (ie eaten) memory pages are marked so that
639 * swsusp_free() can release them
642 unsigned long get_safe_page(gfp_t gfp_mask
)
647 m
= get_zeroed_page(gfp_mask
);
648 if (m
&& PageNosaveFree(virt_to_page(m
)))
649 /* This is for swsusp_free() */
650 SetPageNosave(virt_to_page(m
));
651 } while (m
&& PageNosaveFree(virt_to_page(m
)));
653 /* This is for swsusp_free() */
654 SetPageNosave(virt_to_page(m
));
655 SetPageNosaveFree(virt_to_page(m
));
661 * check_pagedir - We ensure here that pages that the PBEs point to
662 * won't collide with pages where we're going to restore from the loaded
666 static int check_pagedir(struct pbe
*pblist
)
670 /* This is necessary, so that we can free allocated pages
673 for_each_pbe (p
, pblist
)
676 for_each_pbe (p
, pblist
) {
677 p
->address
= get_safe_page(GFP_ATOMIC
);
685 * swsusp_pagedir_relocate - It is possible, that some memory pages
686 * occupied by the list of PBEs collide with pages where we're going to
687 * restore from the loaded pages later. We relocate them here.
690 static struct pbe
*swsusp_pagedir_relocate(struct pbe
*pblist
)
693 unsigned long zone_pfn
;
694 struct pbe
*pbpage
, *tail
, *p
;
698 if (!pblist
) /* a sanity check */
701 pr_debug("swsusp: Relocating pagedir (%lu pages to check)\n",
702 swsusp_info
.pagedir_pages
);
704 /* Clear page flags */
706 for_each_zone (zone
) {
707 for (zone_pfn
= 0; zone_pfn
< zone
->spanned_pages
; ++zone_pfn
)
708 if (pfn_valid(zone_pfn
+ zone
->zone_start_pfn
))
709 ClearPageNosaveFree(pfn_to_page(zone_pfn
+
710 zone
->zone_start_pfn
));
713 /* Mark orig addresses */
715 for_each_pbe (p
, pblist
)
716 SetPageNosaveFree(virt_to_page(p
->orig_address
));
718 tail
= pblist
+ PB_PAGE_SKIP
;
720 /* Relocate colliding pages */
722 for_each_pb_page (pbpage
, pblist
) {
723 if (PageNosaveFree(virt_to_page((unsigned long)pbpage
))) {
724 m
= (void *)get_safe_page(GFP_ATOMIC
| __GFP_COLD
);
727 memcpy(m
, (void *)pbpage
, PAGE_SIZE
);
728 if (pbpage
== pblist
)
729 pblist
= (struct pbe
*)m
;
731 tail
->next
= (struct pbe
*)m
;
732 pbpage
= (struct pbe
*)m
;
734 /* We have to link the PBEs again */
735 for (p
= pbpage
; p
< pbpage
+ PB_PAGE_SKIP
; p
++)
736 if (p
->next
) /* needed to save the end */
741 tail
= pbpage
+ PB_PAGE_SKIP
;
744 /* This is for swsusp_free() */
745 for_each_pb_page (pbpage
, pblist
) {
746 SetPageNosave(virt_to_page(pbpage
));
747 SetPageNosaveFree(virt_to_page(pbpage
));
750 printk("swsusp: Relocated %d pages\n", rel
);
756 * Using bio to read from swap.
757 * This code requires a bit more work than just using buffer heads
758 * but, it is the recommended way for 2.5/2.6.
759 * The following are to signal the beginning and end of I/O. Bios
760 * finish asynchronously, while we want them to happen synchronously.
761 * A simple atomic_t, and a wait loop take care of this problem.
764 static atomic_t io_done
= ATOMIC_INIT(0);
766 static int end_io(struct bio
*bio
, unsigned int num
, int err
)
768 if (!test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
769 panic("I/O error reading memory image");
770 atomic_set(&io_done
, 0);
774 static struct block_device
*resume_bdev
;
777 * submit - submit BIO request.
778 * @rw: READ or WRITE.
779 * @off physical offset of page.
780 * @page: page we're reading or writing.
782 * Straight from the textbook - allocate and initialize the bio.
783 * If we're writing, make sure the page is marked as dirty.
784 * Then submit it and wait.
787 static int submit(int rw
, pgoff_t page_off
, void *page
)
792 bio
= bio_alloc(GFP_ATOMIC
, 1);
795 bio
->bi_sector
= page_off
* (PAGE_SIZE
>> 9);
797 bio
->bi_bdev
= resume_bdev
;
798 bio
->bi_end_io
= end_io
;
800 if (bio_add_page(bio
, virt_to_page(page
), PAGE_SIZE
, 0) < PAGE_SIZE
) {
801 printk("swsusp: ERROR: adding page to bio at %ld\n",page_off
);
807 bio_set_pages_dirty(bio
);
809 atomic_set(&io_done
, 1);
810 submit_bio(rw
| (1 << BIO_RW_SYNC
), bio
);
811 while (atomic_read(&io_done
))
819 static int bio_read_page(pgoff_t page_off
, void *page
)
821 return submit(READ
, page_off
, page
);
824 static int bio_write_page(pgoff_t page_off
, void *page
)
826 return submit(WRITE
, page_off
, page
);
830 * Sanity check if this image makes sense with this kernel/swap context
831 * I really don't think that it's foolproof but more than nothing..
834 static const char *sanity_check(void)
837 if (swsusp_info
.version_code
!= LINUX_VERSION_CODE
)
838 return "kernel version";
839 if (swsusp_info
.num_physpages
!= num_physpages
)
840 return "memory size";
841 if (strcmp(swsusp_info
.uts
.sysname
,system_utsname
.sysname
))
842 return "system type";
843 if (strcmp(swsusp_info
.uts
.release
,system_utsname
.release
))
844 return "kernel release";
845 if (strcmp(swsusp_info
.uts
.version
,system_utsname
.version
))
847 if (strcmp(swsusp_info
.uts
.machine
,system_utsname
.machine
))
850 /* We can't use number of online CPUs when we use hotplug to remove them ;-))) */
851 if (swsusp_info
.cpus
!= num_possible_cpus())
852 return "number of cpus";
858 static int check_header(void)
860 const char *reason
= NULL
;
863 if ((error
= bio_read_page(swp_offset(swsusp_header
.swsusp_info
), &swsusp_info
)))
866 /* Is this same machine? */
867 if ((reason
= sanity_check())) {
868 printk(KERN_ERR
"swsusp: Resume mismatch: %s\n",reason
);
871 nr_copy_pages
= swsusp_info
.image_pages
;
875 static int check_sig(void)
879 memset(&swsusp_header
, 0, sizeof(swsusp_header
));
880 if ((error
= bio_read_page(0, &swsusp_header
)))
882 if (!memcmp(SWSUSP_SIG
, swsusp_header
.sig
, 10)) {
883 memcpy(swsusp_header
.sig
, swsusp_header
.orig_sig
, 10);
884 memcpy(key_iv
, swsusp_header
.key_iv
, MAXKEY
+MAXIV
);
885 memset(swsusp_header
.key_iv
, 0, MAXKEY
+MAXIV
);
888 * Reset swap signature now.
890 error
= bio_write_page(0, &swsusp_header
);
895 pr_debug("swsusp: Signature found, resuming\n");
900 * data_read - Read image pages from swap.
902 * You do not need to check for overlaps, check_pagedir()
906 static int data_read(struct pbe
*pblist
)
911 int mod
= swsusp_info
.image_pages
/ 100;
914 if ((error
= crypto_init(0, &tfm
)))
920 printk("swsusp: Reading image data (%lu pages): ",
921 swsusp_info
.image_pages
);
923 for_each_pbe (p
, pblist
) {
925 printk("\b\b\b\b%3d%%", i
/ mod
);
927 if ((error
= crypto_read(p
, tfm
))) {
934 printk("\b\b\b\bdone\n");
940 * read_pagedir - Read page backup list pages from swap
943 static int read_pagedir(struct pbe
*pblist
)
945 struct pbe
*pbpage
, *p
;
952 printk("swsusp: Reading pagedir (%lu pages)\n",
953 swsusp_info
.pagedir_pages
);
955 for_each_pb_page (pbpage
, pblist
) {
956 unsigned long offset
= swp_offset(swsusp_info
.pagedir
[i
++]);
960 p
= (pbpage
+ PB_PAGE_SKIP
)->next
;
961 error
= bio_read_page(offset
, (void *)pbpage
);
962 (pbpage
+ PB_PAGE_SKIP
)->next
= p
;
969 BUG_ON(i
!= swsusp_info
.pagedir_pages
);
975 static int check_suspend_image(void)
979 if ((error
= check_sig()))
982 if ((error
= check_header()))
988 static int read_suspend_image(void)
993 if (!(p
= alloc_pagedir(nr_copy_pages
)))
996 if ((error
= read_pagedir(p
)))
999 create_pbe_list(p
, nr_copy_pages
);
1001 if (!(pagedir_nosave
= swsusp_pagedir_relocate(p
)))
1004 /* Allocate memory for the image and read the data from swap */
1006 error
= check_pagedir(pagedir_nosave
);
1009 error
= data_read(pagedir_nosave
);
1015 * swsusp_check - Check for saved image in swap
1018 int swsusp_check(void)
1022 resume_bdev
= open_by_devnum(swsusp_resume_device
, FMODE_READ
);
1023 if (!IS_ERR(resume_bdev
)) {
1024 set_blocksize(resume_bdev
, PAGE_SIZE
);
1025 error
= check_suspend_image();
1027 blkdev_put(resume_bdev
);
1029 error
= PTR_ERR(resume_bdev
);
1032 pr_debug("swsusp: resume file found\n");
1034 pr_debug("swsusp: Error %d check for resume file\n", error
);
1039 * swsusp_read - Read saved image from swap.
1042 int swsusp_read(void)
1046 if (IS_ERR(resume_bdev
)) {
1047 pr_debug("swsusp: block device not initialised\n");
1048 return PTR_ERR(resume_bdev
);
1051 error
= read_suspend_image();
1052 blkdev_put(resume_bdev
);
1053 memset(key_iv
, 0, MAXKEY
+MAXIV
);
1056 pr_debug("swsusp: Reading resume file was successful\n");
1058 pr_debug("swsusp: Error %d resuming\n", error
);
1063 * swsusp_close - close swap device.
1066 void swsusp_close(void)
1068 if (IS_ERR(resume_bdev
)) {
1069 pr_debug("swsusp: block device not initialised\n");
1073 blkdev_put(resume_bdev
);