[Suspend2][ 19/20] [Suspend2] Prepare an image.

[Nigel Cunningham <nigel@suspend2.net>]

Attempt to prepare everything for suspending. This section of the code does
most of the work - freezing processes, allocating storage, freeing memory
and so on. Once it is complete, we are either going to abort or jump
straight into writing the image.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/prepare_image.c |   63 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 63 insertions(+), 0 deletions(-)

diff --git a/kernel/power/prepare_image.c b/kernel/power/prepare_image.c
index 893ba72..10159e5 100644
--- a/kernel/power/prepare_image.c
+++ b/kernel/power/prepare_image.c
@@ -622,3 +622,66 @@ static int eat_memory(void)
 	return 0;
 }
 
+/* prepare_image
+ *
+ * Entry point to the whole image preparation section.
+ *
+ * We do four things:
+ * - Freeze processes;
+ * - Ensure image size constraints are met;
+ * - Complete all the preparation for saving the image,
+ *   including allocation of storage. The only memory
+ *   that should be needed when we're finished is that
+ *   for actually storing the image (and we know how
+ *   much is needed for that because the modules tell
+ *   us).
+ * - Make sure that all dirty buffers are written out.
+ */
+#define MAX_TRIES 4
+int suspend_prepare_image(void)
+{
+	int result = 1, tries = 0;
+
+	are_frozen = 0;
+
+	header_space_allocated = 0;
+
+	if (attempt_to_freeze())
+		return 1;
+
+	if (!extra_pd1_pages_allowance)
+		get_extra_pd1_allowance();
+
+	storage_available = suspend_active_writer->storage_available();
+
+	if (!storage_available) {
+		printk(KERN_ERR "You need some storage available to be able to suspend.\n");
+		set_result_state(SUSPEND_ABORTED);
+		set_result_state(SUSPEND_NOSTORAGE_AVAILABLE);
+		return 1;
+	}
+
+	do {
+		suspend_prepare_status(CLEAR_BAR, "Preparing Image.");
+	
+		if (eat_memory() || test_result_state(SUSPEND_ABORTED))
+			break;
+
+		result = update_image();
+
+		suspend_cond_pause(0, NULL);
+		
+		tries++;
+
+	} while ((result) && (tries < MAX_TRIES) && (!test_result_state(SUSPEND_ABORTED)) &&
+		(!test_result_state(SUSPEND_UNABLE_TO_FREE_ENOUGH_MEMORY)));
+
+	if (tries == MAX_TRIES) {
+		abort_suspend("Unable to successfully prepare the image.\n");
+		display_stats(1, 0);
+	}
+
+	suspend_cond_pause(1, "Image preparation complete.");
+
+	return result;
+}

--
Nigel Cunningham		nigel at suspend2 dot net