---

yaml
---
r: 54267
b: refs/heads/master
c: d1d241c
h: refs/heads/master
i:
  54265: cf88a9d
  54263: 6d1d611
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 726162b5dad154a90dad51c0185b891312de5757
+refs/heads/master: d1d241cc2c5feec057c370aa71637380b1b945d5

trunk/kernel/power/power.h

@@ -143,30 +143,9 @@ struct resume_swap_area {
 /* If unset, the snapshot device cannot be open. */
 extern atomic_t snapshot_device_available;
 
-/**
- *	The bitmap is used for tracing allocated swap pages
- *
- *	The entire bitmap consists of a number of bitmap_page
- *	structures linked with the help of the .next member.
- *	Thus each page can be allocated individually, so we only
- *	need to make 0-order memory allocations to create
- *	the bitmap.
- */
-
-#define BITMAP_PAGE_SIZE	(PAGE_SIZE - sizeof(void *))
-#define BITMAP_PAGE_CHUNKS	(BITMAP_PAGE_SIZE / sizeof(long))
-#define BITS_PER_CHUNK		(sizeof(long) * 8)
-#define BITMAP_PAGE_BITS	(BITMAP_PAGE_CHUNKS * BITS_PER_CHUNK)
-
-struct bitmap_page {
-	unsigned long		chunks[BITMAP_PAGE_CHUNKS];
-	struct bitmap_page	*next;
-};
-
-extern void free_bitmap(struct bitmap_page *bitmap);
-extern struct bitmap_page *alloc_bitmap(unsigned int nr_bits);
-extern sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap);
-extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
+extern sector_t alloc_swapdev_block(int swap);
+extern void free_all_swap_pages(int swap);
+extern int swsusp_swap_in_use(void);
 
 extern int swsusp_check(void);
 extern int swsusp_shrink_memory(void);

trunk/kernel/power/swap.c

@@ -243,7 +243,6 @@ struct swap_map_page {
 struct swap_map_handle {
 	struct swap_map_page *cur;
 	sector_t cur_swap;
-	struct bitmap_page *bitmap;
 	unsigned int k;
 };
 
@@ -252,22 +251,14 @@ static void release_swap_writer(struct swap_map_handle *handle)
 	if (handle->cur)
 		free_page((unsigned long)handle->cur);
 	handle->cur = NULL;
-	if (handle->bitmap)
-		free_bitmap(handle->bitmap);
-	handle->bitmap = NULL;
 }
 
 static int get_swap_writer(struct swap_map_handle *handle)
 {
 	handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 	if (!handle->cur)
 		return -ENOMEM;
-	handle->bitmap = alloc_bitmap(count_swap_pages(root_swap, 0));
-	if (!handle->bitmap) {
-		release_swap_writer(handle);
-		return -ENOMEM;
-	}
-	handle->cur_swap = alloc_swapdev_block(root_swap, handle->bitmap);
+	handle->cur_swap = alloc_swapdev_block(root_swap);
 	if (!handle->cur_swap) {
 		release_swap_writer(handle);
 		return -ENOSPC;
@@ -284,7 +275,7 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf,
 
 	if (!handle->cur)
 		return -EINVAL;
-	offset = alloc_swapdev_block(root_swap, handle->bitmap);
+	offset = alloc_swapdev_block(root_swap);
 	error = write_page(buf, offset, bio_chain);
 	if (error)
 		return error;
@@ -293,7 +284,7 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf,
 		error = wait_on_bio_chain(bio_chain);
 		if (error)
 			goto out;
-		offset = alloc_swapdev_block(root_swap, handle->bitmap);
+		offset = alloc_swapdev_block(root_swap);
 		if (!offset)
 			return -ENOSPC;
 		handle->cur->next_swap = offset;
@@ -430,7 +421,8 @@ int swsusp_write(void)
 		}
 	}
 	if (error)
-		free_all_swap_pages(root_swap, handle.bitmap);
+		free_all_swap_pages(root_swap);
+
 	release_swap_writer(&handle);
  out:
 	swsusp_close();

trunk/kernel/power/swsusp.c

@@ -50,6 +50,7 @@
 #include <linux/syscalls.h>
 #include <linux/highmem.h>
 #include <linux/time.h>
+#include <linux/rbtree.h>
 
 #include "power.h"
 
@@ -74,96 +75,104 @@ static inline unsigned int count_highmem_pages(void) { return 0; }
 /**
  *	The following functions are used for tracing the allocated
  *	swap pages, so that they can be freed in case of an error.
- *
- *	The functions operate on a linked bitmap structure defined
- *	in power.h
  */
 
-void free_bitmap(struct bitmap_page *bitmap)
-{
-	struct bitmap_page *bp;
+struct swsusp_extent {
+	struct rb_node node;
+	unsigned long start;
+	unsigned long end;
+};
 
-	while (bitmap) {
-		bp = bitmap->next;
-		free_page((unsigned long)bitmap);
-		bitmap = bp;
-	}
-}
+static struct rb_root swsusp_extents = RB_ROOT;
 
-struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
+static int swsusp_extents_insert(unsigned long swap_offset)
 {
-	struct bitmap_page *bitmap, *bp;
-	unsigned int n;
-
-	if (!nr_bits)
-		return NULL;
-
-	bitmap = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
-	bp = bitmap;
-	for (n = BITMAP_PAGE_BITS; n < nr_bits; n += BITMAP_PAGE_BITS) {
-		bp->next = (struct bitmap_page *)get_zeroed_page(GFP_KERNEL);
-		bp = bp->next;
-		if (!bp) {
-			free_bitmap(bitmap);
-			return NULL;
+	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;
 		}
 	}
-	return bitmap;
-}
-
-static int bitmap_set(struct bitmap_page *bitmap, unsigned long bit)
-{
-	unsigned int n;
-
-	n = BITMAP_PAGE_BITS;
-	while (bitmap && n <= bit) {
-		n += BITMAP_PAGE_BITS;
-		bitmap = bitmap->next;
-	}
-	if (!bitmap)
-		return -EINVAL;
-	n -= BITMAP_PAGE_BITS;
-	bit -= n;
-	n = 0;
-	while (bit >= BITS_PER_CHUNK) {
-		bit -= BITS_PER_CHUNK;
-		n++;
-	}
-	bitmap->chunks[n] |= (1UL << bit);
+	/* 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;
 }
 
-sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap)
+/**
+ *	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 (bitmap_set(bitmap, offset))
+		if (swsusp_extents_insert(offset))
 			swap_free(swp_entry(swap, offset));
 		else
 			return swapdev_block(swap, offset);
 	}
 	return 0;
 }
 
-void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
+/**
+ *	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)
 {
-	unsigned int bit, n;
-	unsigned long test;
-
-	bit = 0;
-	while (bitmap) {
-		for (n = 0; n < BITMAP_PAGE_CHUNKS; n++)
-			for (test = 1UL; test; test <<= 1) {
-				if (bitmap->chunks[n] & test)
-					swap_free(swp_entry(swap, bit));
-				bit++;
-			}
-		bitmap = bitmap->next;
+	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);
+}
+
 /**
  *	swsusp_show_speed - print the time elapsed between two events represented by
  *	@start and @stop

trunk/kernel/power/user.c

@@ -33,7 +33,6 @@
 static struct snapshot_data {
 	struct snapshot_handle handle;
 	int swap;
-	struct bitmap_page *bitmap;
 	int mode;
 	char frozen;
 	char ready;
@@ -69,7 +68,6 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 		data->swap = -1;
 		data->mode = O_WRONLY;
 	}
-	data->bitmap = NULL;
 	data->frozen = 0;
 	data->ready = 0;
 	data->platform_suspend = 0;
@@ -84,8 +82,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
 	swsusp_free();
 	free_basic_memory_bitmaps();
 	data = filp->private_data;
-	free_all_swap_pages(data->swap, data->bitmap);
-	free_bitmap(data->bitmap);
+	free_all_swap_pages(data->swap);
 	if (data->frozen) {
 		mutex_lock(&pm_mutex);
 		thaw_processes();
@@ -300,14 +297,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
 			error = -ENODEV;
 			break;
 		}
-		if (!data->bitmap) {
-			data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0));
-			if (!data->bitmap) {
-				error = -ENOMEM;
-				break;
-			}
-		}
-		offset = alloc_swapdev_block(data->swap, data->bitmap);
+		offset = alloc_swapdev_block(data->swap);
 		if (offset) {
 			offset <<= PAGE_SHIFT;
 			error = put_user(offset, (sector_t __user *)arg);
@@ -321,13 +311,11 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
 			error = -ENODEV;
 			break;
 		}
-		free_all_swap_pages(data->swap, data->bitmap);
-		free_bitmap(data->bitmap);
-		data->bitmap = NULL;
+		free_all_swap_pages(data->swap);
 		break;
 
 	case SNAPSHOT_SET_SWAP_FILE:
-		if (!data->bitmap) {
+		if (!swsusp_swap_in_use()) {
 			/*
 			 * User space encodes device types as two-byte values,
 			 * so we need to recode them
@@ -426,7 +414,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
 		break;
 
 	case SNAPSHOT_SET_SWAP_AREA:
-		if (data->bitmap) {
+		if (swsusp_swap_in_use()) {
 			error = -EPERM;
 		} else {
 			struct resume_swap_area swap_area;