1 files changed, 144 insertions, 0 deletions
diff --git a/kernel/power/tuxonice_extent.c b/kernel/power/tuxonice_extent.c
new file mode 100644
index 000000000..3b558b220
--- /dev/null
+++ b/kernel/power/tuxonice_extent.c
@@ -0,0 +1,144 @@
+/*
+ * kernel/power/tuxonice_extent.c
+ *
+ * Copyright (C) 2003-2015 Nigel Cunningham (nigel at nigelcunningham com au)
+ *
+ * Distributed under GPLv2.
+ *
+ * These functions encapsulate the manipulation of storage metadata.
+ */
+
+#include <linux/suspend.h>
+#include "tuxonice_modules.h"
+#include "tuxonice_extent.h"
+#include "tuxonice_alloc.h"
+#include "tuxonice_ui.h"
+#include "tuxonice.h"
+
+/**
+ * toi_get_extent - return a free extent
+ *
+ * May fail, returning NULL instead.
+ **/
+static struct hibernate_extent *toi_get_extent(void)
+{
+	return (struct hibernate_extent *) toi_kzalloc(2,
+			sizeof(struct hibernate_extent), TOI_ATOMIC_GFP);
+}
+
+/**
+ * toi_put_extent_chain - free a chain of extents starting from value 'from'
+ * @chain:	Chain to free.
+ *
+ * Note that 'from' is an extent value, and may be part way through an extent.
+ * In this case, the extent should be truncated (if necessary) and following
+ * extents freed.
+ **/
+void toi_put_extent_chain_from(struct hibernate_extent_chain *chain, unsigned long from)
+{
+	struct hibernate_extent *this;
+
+	this = chain->first;
+
+	while (this) {
+		struct hibernate_extent *next = this->next;
+
+                // Delete the whole extent?
+                if (this->start >= from) {
+                    chain->size -= (this->end - this->start + 1);
+                    if (chain->first == this)
+                        chain->first = next;
+                    if (chain->last_touched == this)
+                        chain->last_touched = NULL;
+                    if (chain->current_extent == this)
+                        chain->current_extent = NULL;
+                    toi_kfree(2, this, sizeof(*this));
+                    chain->num_extents--;
+                } else if (this->end >= from) {
+                    // Delete part of the extent
+                    chain->size -= (this->end - from + 1);
+                    this->start = from;
+                }
+		this = next;
+	}
+}
+
+/**
+ * toi_put_extent_chain - free a whole chain of extents
+ * @chain:	Chain to free.
+ **/
+void toi_put_extent_chain(struct hibernate_extent_chain *chain)
+{
+    toi_put_extent_chain_from(chain, 0);
+}
+
+/**
+ * toi_add_to_extent_chain - add an extent to an existing chain
+ * @chain:	Chain to which the extend should be added
+ * @start:	Start of the extent (first physical block)
+ * @end:	End of the extent (last physical block)
+ *
+ * The chain information is updated if the insertion is successful.
+ **/
+int toi_add_to_extent_chain(struct hibernate_extent_chain *chain,
+		unsigned long start, unsigned long end)
+{
+	struct hibernate_extent *new_ext = NULL, *cur_ext = NULL;
+
+	toi_message(TOI_IO, TOI_VERBOSE, 0,
+		"Adding extent %lu-%lu to chain %p.\n", start, end, chain);
+
+	/* Find the right place in the chain */
+	if (chain->last_touched && chain->last_touched->start < start)
+		cur_ext = chain->last_touched;
+	else if (chain->first && chain->first->start < start)
+		cur_ext = chain->first;
+
+	if (cur_ext) {
+		while (cur_ext->next && cur_ext->next->start < start)
+			cur_ext = cur_ext->next;
+
+		if (cur_ext->end == (start - 1)) {
+			struct hibernate_extent *next_ext = cur_ext->next;
+			cur_ext->end = end;
+
+			/* Merge with the following one? */
+			if (next_ext && cur_ext->end + 1 == next_ext->start) {
+				cur_ext->end = next_ext->end;
+				cur_ext->next = next_ext->next;
+				toi_kfree(2, next_ext, sizeof(*next_ext));
+				chain->num_extents--;
+			}
+
+			chain->last_touched = cur_ext;
+			chain->size += (end - start + 1);
+
+			return 0;
+		}
+	}
+
+	new_ext = toi_get_extent();
+	if (!new_ext) {
+		printk(KERN_INFO "Error unable to append a new extent to the "
+				"chain.\n");
+		return -ENOMEM;
+	}
+
+	chain->num_extents++;
+	chain->size += (end - start + 1);
+	new_ext->start = start;
+	new_ext->end = end;
+
+	chain->last_touched = new_ext;
+
+	if (cur_ext) {
+		new_ext->next = cur_ext->next;
+		cur_ext->next = new_ext;
+	} else {
+		if (chain->first)
+			new_ext->next = chain->first;
+		chain->first = new_ext;
+	}
+
+	return 0;
+}