[PATCH] swsusp: add resume_offset command line parameter

Add the kernel command line parameter "resume_offset=" allowing us to specify
the offset, in <PAGE_SIZE> units, from the beginning of the partition pointed
to by the "resume=" parameter at which the swap header is located.

This offset can be determined, for example, by an application using the FIBMAP
ioctl to obtain the swap header's block number for given file.

[akpm@osdl.org: we don't know what type sector_t is]
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>

1 files changed, 10 insertions, 5 deletions

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 1b08f46bbb7e..aa5a9bff01f1 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -161,13 +161,14 @@ static int mark_swapfiles(sector_t start)
 {
         int error;
 
-        bio_read_page(0, &swsusp_header, NULL);
+        bio_read_page(swsusp_resume_block, &swsusp_header, NULL);
         if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
             !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
                 memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
                 memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
                 swsusp_header.image = start;
-                error = bio_write_page(0, &swsusp_header, NULL);
+                error = bio_write_page(swsusp_resume_block,
+                                        &swsusp_header, NULL);
         } else {
                 printk(KERN_ERR "swsusp: Swap header not found!\n");
                 error = -ENODEV;
@@ -184,7 +185,7 @@ static int swsusp_swap_check(void) /* This is called before saving image */
 {
         int res;
 
-        res = swap_type_of(swsusp_resume_device, 0);
+        res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
         if (res < 0)
                 return res;
 
@@ -610,12 +611,16 @@ int swsusp_check(void)
         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, NULL)))
+                error = bio_read_page(swsusp_resume_block,
+                                        &swsusp_header, NULL);
+                if (error)
                         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, NULL);
+                        error = bio_write_page(swsusp_resume_block,
+                                                &swsusp_header, NULL);
                 } else {
                         return -EINVAL;
                 }