[PATCH] Allow initrd_load() before software_resume()

[Pascal Brisset <pascal.brisset-ml@wanadoo.fr>]

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This patch adds a boot parameter "resume_initrd".
If present, init will load the initrd before trying to resume.

This makes it posssible to resume from an encrypted suspend image.
The initrd should insmod cryptoloop.o or loop-AES.o and perform
losetup -e so that resume=/dev/loopX makes sense.
Note: software_resume() should not be allowed to complete if
initrd has altered disks (e.g. by flushing journals).

/initrd
|-- bin
|   |-- ash
|   |-- insmod
|   `-- losetup
|-- dev
|   |-- console
|   |-- hdaX
|   |-- loopX
|   |-- null
|   `-- tty
|-- linuxrc
|-- loop.o
`-- lost+found

Resuming works, but suspension seems to fail more frequently when
the swap is encrypted. I am using loop-AES-v1.7d + patch for 2.6.

Is it safe to suspend to loop devices ?

-- Pascal


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diff -ur linux-2.6.0-test1.orig/Documentation/kernel-parameters.txt linux-2.6.0-test1/Documentation/kernel-parameters.txt
--- linux-2.6.0-test1.orig/Documentation/kernel-parameters.txt	2003-07-14 05:39:36.000000000 +0200
+++ linux-2.6.0-test1/Documentation/kernel-parameters.txt	2003-08-01 01:19:46.000000000 +0200
@@ -816,6 +816,8 @@
 
 	resume=		[SWSUSP] Specify the partition device for software suspension
 
+	resume_initrd   [SWSUSP] Run initrd before resuming from software suspension
+
 	riscom8=	[HW,SERIAL]
 			Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
 
diff -ur linux-2.6.0-test1.orig/init/do_mounts.c linux-2.6.0-test1/init/do_mounts.c
--- linux-2.6.0-test1.orig/init/do_mounts.c	2003-07-14 05:32:44.000000000 +0200
+++ linux-2.6.0-test1/init/do_mounts.c	2003-08-01 01:21:44.000000000 +0200
@@ -49,6 +49,15 @@
 __setup("ro", readonly);
 __setup("rw", readwrite);
 
+static int resume_initrd = 0;
+static int __init set_resume_initrd(char *str)
+{
+	resume_initrd = 1;
+	return 1;
+}
+
+__setup("resume_initrd", set_resume_initrd);
+
 static dev_t __init try_name(char *name, int part)
 {
 	char path[64];
@@ -365,12 +374,21 @@
 
 	is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 
-	/* This has to be before mounting root, because even readonly mount of reiserfs would replay
-	   log corrupting stuff */
-	software_resume();
+	/* software_resume() has to be before mounting root, because even
+	   readonly mount of reiserfs would replay log corrupting stuff.
+	   However, users may still want to run initrd first. */
+	if (resume_initrd) {
+		if (initrd_load()) {
+			software_resume();
+			goto out;
+		}
+	}
+	else {
+		software_resume();
 
-	if (initrd_load())
-		goto out;
+		if (initrd_load())
+			goto out;
+	}
 
 	if (is_floppy && rd_doload && rd_load_disk(0))
 		ROOT_DEV = Root_RAM0;