PM / Hibernate: Move swap functions to kernel/power/swap.c.

Move hibernation code's functions for allocating and freeing swap
from swsusp.c to swap.c, which is where you'd expect to find them.

Signed-off-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 101 insertions, 0 deletions

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 890f6b11b1d3..0ce9b00f5d33 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -38,6 +38,107 @@ struct swsusp_header {
 
 static struct swsusp_header *swsusp_header;
 
+/**
+ *      The following functions are used for tracing the allocated
+ *      swap pages, so that they can be freed in case of an error.
+ */
+
+struct swsusp_extent {
+        struct rb_node node;
+        unsigned long start;
+        unsigned long end;
+};
+
+static struct rb_root swsusp_extents = RB_ROOT;
+
+static int swsusp_extents_insert(unsigned long swap_offset)
+{
+        struct rb_node **new = &(swsusp_extents.rb_node);
+        struct rb_node *parent = NULL;
+        struct swsusp_extent *ext;
+
+        /* Figure out where to put the new node */
+        while (*new) {
+                ext = container_of(*new, struct swsusp_extent, node);
+                parent = *new;
+                if (swap_offset < ext->start) {
+                        /* Try to merge */
+                        if (swap_offset == ext->start - 1) {
+                                ext->start--;
+                                return 0;
+                        }
+                        new = &((*new)->rb_left);
+                } else if (swap_offset > ext->end) {
+                        /* Try to merge */
+                        if (swap_offset == ext->end + 1) {
+                                ext->end++;
+                                return 0;
+                        }
+                        new = &((*new)->rb_right);
+                } else {
+                        /* It already is in the tree */
+                        return -EINVAL;
+                }
+        }
+        /* Add the new node and rebalance the tree. */
+        ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
+        if (!ext)
+                return -ENOMEM;
+
+        ext->start = swap_offset;
+        ext->end = swap_offset;
+        rb_link_node(&ext->node, parent, new);
+        rb_insert_color(&ext->node, &swsusp_extents);
+        return 0;
+}
+
+/**
+ *      alloc_swapdev_block - allocate a swap page and register that it has
+ *      been allocated, so that it can be freed in case of an error.
+ */
+
+sector_t alloc_swapdev_block(int swap)
+{
+        unsigned long offset;
+
+        offset = swp_offset(get_swap_page_of_type(swap));
+        if (offset) {
+                if (swsusp_extents_insert(offset))
+                        swap_free(swp_entry(swap, offset));
+                else
+                        return swapdev_block(swap, offset);
+        }
+        return 0;
+}
+
+/**
+ *      free_all_swap_pages - free swap pages allocated for saving image data.
+ *      It also frees the extents used to register which swap entres had been
+ *      allocated.
+ */
+
+void free_all_swap_pages(int swap)
+{
+        struct rb_node *node;
+
+        while ((node = swsusp_extents.rb_node)) {
+                struct swsusp_extent *ext;
+                unsigned long offset;
+
+                ext = container_of(node, struct swsusp_extent, node);
+                rb_erase(node, &swsusp_extents);
+                for (offset = ext->start; offset <= ext->end; offset++)
+                        swap_free(swp_entry(swap, offset));
+
+                kfree(ext);
+        }
+}
+
+int swsusp_swap_in_use(void)
+{
+        return (swsusp_extents.rb_node != NULL);
+}
+
 /*
  * General things
  */