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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /kernel/power/tuxonice_extent.c
Initial import
Diffstat (limited to 'kernel/power/tuxonice_extent.c')
-rw-r--r--kernel/power/tuxonice_extent.c144
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;
+}