aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--kernel/power/power.h27
-rw-r--r--kernel/power/swap.c18
-rw-r--r--kernel/power/swsusp.c137
-rw-r--r--kernel/power/user.c22
4 files changed, 86 insertions, 118 deletions
diff --git a/kernel/power/power.h b/kernel/power/power.h
index a64d3f22de97..a3e47cbdaf31 100644
--- a/kernel/power/power.h
+++ b/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);
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index b18c155cbb60..e83ed9945a80 100644
--- a/kernel/power/swap.c
+++ b/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;
};
@@ -252,9 +251,6 @@ 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)
@@ -262,12 +258,7 @@ 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();
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index 175370824f37..1109023d8358 100644
--- a/kernel/power/swsusp.c
+++ b/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"
@@ -74,72 +75,69 @@ 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);
@@ -147,23 +145,34 @@ sector_t alloc_swapdev_block(int swap, struct bitmap_page *bitmap)
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
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 72dbfd01408e..ad4e10208cde 100644
--- a/kernel/power/user.c
+++ b/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;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.