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..522c836ad
--- /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;
+}