Re: [RFC/RFT][PATCH -mm 0/5] swsusp: userland interface (rev. 2)
From: Rafael J. Wysocki
Date: Fri Jan 06 2006 - 18:38:04 EST
Hi,
On Friday, 6 January 2006 23:44, Pavel Machek wrote:
> > > > This is the second "preview release" of the swsusp userland interface patches.
> > > > They have changed quite a bit since the previous post, as I tried to make the
> > > > interface more robust against some potential user space bugs (or outright
> > > > attempts to abuse it).
> > >
> > > Works for me, thanks.
> > >
> > > Perhaps it is time to get 1/4 and 3/4 into -mm? You get my signed-off
> > > on them...
> >
> > OK, I'll prepare them in a while.
>
> Thanks.
I had to remake the 3/4 a bit, as it depended on some changes to power.h
and swsusp.c done in the 2/4. Nothing particularly invasive, basically some
definitions go to power.h and some function headers change, but please
have a look if the patch is still OK (appended).
> > > 2/4 needs to allocate official major/minor. 1/13 would be nice :-).
> >
> > Well, you said you liked the patch with a misc device (ie. major = 10).
> >
> > Actually the code is somewhat simpler in that case so I'd prefer it.
> >
> > Now, if we used a misc device, which minor would be suitable? 231?
>
> If code is simpler, lets stick with misc. You have to obtain minor by
> mailing device@xxxxxxxxxx, see Doc*/devices.txt.
OK, I'll try.
> > > 4/4... I'm not sure. It would be nice to make swsusp.c disappear. It
> > > is really wrong name. That means we need to only delete from it for a
> > > while...
> >
> > Anyway I think it would be nice to move the code that does not really belong
> > to the snapshot and is used by both the user interface and disk.c/swap.c to
> > a separate file. I have no preference as far as the name of the file is
> > concerned, though.
>
> Ok, lets keep it as it is. We can always rename file in future. [I
> don't quite understand your reasons for movement, through. Highmem is
> part of snapshot we need to make; it is saved in a very different way
> than rest of memory, but that is implementation detail...]
I'm seeing this a bit differently. In my view highmem is handled very much
like devices: save_highmem() turns it "off", restore_highmem() turns it "on"
back again, they are even called next to device_power_up/down().
Besides, the highmem-related code is only invoked from
swsusp_suspend/resume() and swsusp_shrink_memory(), so in swsusp.c it
can be made static or even static inline (eg. save_highmem() is called only
once, and so is count_highmem_pages()).
Greetings,
Rafael
kernel/power/Makefile | 2
kernel/power/power.h | 35 ++
kernel/power/swap.c | 556 ++++++++++++++++++++++++++++++++++++++++++++++
kernel/power/swsusp.c | 596 ++------------------------------------------------
4 files changed, 617 insertions(+), 572 deletions(-)
Index: linux-2.6.15-mm1/kernel/power/Makefile
===================================================================
--- linux-2.6.15-mm1.orig/kernel/power/Makefile 2006-01-06 23:23:05.000000000 +0100
+++ linux-2.6.15-mm1/kernel/power/Makefile 2006-01-06 23:27:19.000000000 +0100
@@ -5,7 +5,7 @@ endif
obj-y := main.o process.o console.o
obj-$(CONFIG_PM_LEGACY) += pm.o
-obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o
+obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o swap.o
obj-$(CONFIG_SUSPEND_SMP) += smp.o
Index: linux-2.6.15-mm1/kernel/power/power.h
===================================================================
--- linux-2.6.15-mm1.orig/kernel/power/power.h 2006-01-06 23:24:18.000000000 +0100
+++ linux-2.6.15-mm1/kernel/power/power.h 2006-01-06 23:29:36.000000000 +0100
@@ -53,8 +53,8 @@ extern struct pbe *pagedir_nosave;
/* Preferred image size in MB (default 500) */
extern unsigned int image_size;
-
extern int in_suspend;
+extern dev_t swsusp_resume_device;
extern asmlinkage int swsusp_arch_suspend(void);
extern asmlinkage int swsusp_arch_resume(void);
@@ -77,3 +77,36 @@ struct snapshot_handle {
extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
int snapshot_image_loaded(struct snapshot_handle *handle);
+
+/**
+ * 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 unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap);
+extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
+
+extern int swsusp_get_swap_index_of(dev_t device);
+extern int swsusp_get_swap_index(void);
+extern unsigned int swsusp_total_swap(unsigned int swap);
+extern unsigned int swsusp_available_swap(unsigned int swap);
+extern int swsusp_shrink_memory(void);
+extern int swsusp_suspend(void);
+extern int swsusp_resume(void);
Index: linux-2.6.15-mm1/kernel/power/swap.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15-mm1/kernel/power/swap.c 2006-01-06 23:27:19.000000000 +0100
@@ -0,0 +1,556 @@
+/*
+ * linux/kernel/power/swap.c
+ *
+ * This file provides functions for reading the suspend image from
+ * and writing it to a swap partition.
+ *
+ * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@xxxxxxx>
+ * Copyright (C) 2005 Rafael J. Wysocki <rjw@xxxxxxx>
+ *
+ * This file is released under the GPLv2.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/smp_lock.h>
+#include <linux/file.h>
+#include <linux/utsname.h>
+#include <linux/version.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+#include <linux/genhd.h>
+#include <linux/device.h>
+#include <linux/buffer_head.h>
+#include <linux/bio.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/pm.h>
+
+#include "power.h"
+
+extern char resume_file[];
+
+#define SWSUSP_SIG "S1SUSPEND"
+
+static struct swsusp_header {
+ char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)];
+ swp_entry_t image;
+ char orig_sig[10];
+ char sig[10];
+} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
+
+/*
+ * Saving part...
+ */
+
+static unsigned short root_swap = 0xffff;
+
+/**
+ * mark_swapfiles - change the signature of the resume partition
+ * and store the swap address of given entry in the partition's
+ * header (the entry should point to the first image page in the
+ * swap)
+ */
+
+static int mark_swapfiles(swp_entry_t start)
+{
+ int error;
+
+ rw_swap_page_sync(READ,
+ swp_entry(root_swap, 0),
+ virt_to_page((unsigned long)&swsusp_header));
+ if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
+ !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
+ memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
+ memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
+ swsusp_header.image = start;
+ error = rw_swap_page_sync(WRITE,
+ swp_entry(root_swap, 0),
+ virt_to_page((unsigned long)
+ &swsusp_header));
+ } else {
+ pr_debug("swsusp: Partition is not swap space.\n");
+ error = -ENODEV;
+ }
+ return error;
+}
+
+/**
+ * swsusp_swap_check - check if the resume partition is available
+ */
+
+static int swsusp_swap_check(void) /* This is called before saving image */
+{
+ int res = swsusp_get_swap_index();
+
+ if (res >= 0) {
+ root_swap = res;
+ return 0;
+ }
+ return res;
+}
+
+/**
+ * write_page - Write one page to given swap location.
+ * @buf: Address we're writing.
+ * @offset: Offset of the swap page we're writing to.
+ */
+
+static int write_page(void *buf, unsigned long offset)
+{
+ swp_entry_t entry;
+ int error = -ENOSPC;
+
+ if (offset) {
+ entry = swp_entry(root_swap, offset);
+ error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf));
+ }
+ return error;
+}
+
+/*
+ * The swap map is a data structure used for keeping track of each page
+ * written to a swap partition. It consists of many swap_map_page
+ * structures that contain each an array of MAP_PAGE_SIZE swap entries.
+ * These structures are stored on the swap and linked together with the
+ * help of the .next_swap member.
+ *
+ * The swap map is created during suspend. The swap map pages are
+ * allocated and populated one at a time, so we only need one memory
+ * page to set up the entire structure.
+ *
+ * During resume we also only need to use one swap_map_page structure
+ * at a time.
+ */
+
+#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(long) - 1)
+
+struct swap_map_page {
+ unsigned long entries[MAP_PAGE_ENTRIES];
+ unsigned long next_swap;
+};
+
+/**
+ * The swap_map_handle structure is used for handling swap in
+ * a file-alike way
+ */
+
+struct swap_map_handle {
+ struct swap_map_page *cur;
+ unsigned long cur_swap;
+ struct bitmap_page *bitmap;
+ unsigned int k;
+};
+
+static inline 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 inline 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(swsusp_total_swap(root_swap));
+ if (!handle->bitmap) {
+ release_swap_writer(handle);
+ return -ENOMEM;
+ }
+ handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap);
+ if (!handle->cur_swap) {
+ release_swap_writer(handle);
+ return -ENOSPC;
+ }
+ handle->k = 0;
+ return 0;
+}
+
+static inline int swap_write_page(struct swap_map_handle *handle, void *buf)
+{
+ int error;
+ unsigned long offset;
+
+ if (!handle->cur)
+ return -EINVAL;
+ offset = alloc_swap_page(root_swap, handle->bitmap);
+ error = write_page(buf, offset);
+ if (error)
+ return error;
+ handle->cur->entries[handle->k++] = offset;
+ if (handle->k >= MAP_PAGE_ENTRIES) {
+ offset = alloc_swap_page(root_swap, handle->bitmap);
+ if (!offset)
+ return -ENOSPC;
+ handle->cur->next_swap = offset;
+ error = write_page(handle->cur, handle->cur_swap);
+ if (error)
+ return error;
+ memset(handle->cur, 0, PAGE_SIZE);
+ handle->cur_swap = offset;
+ handle->k = 0;
+ }
+ return 0;
+}
+
+static inline int flush_swap_writer(struct swap_map_handle *handle)
+{
+ if (handle->cur && handle->cur_swap)
+ return write_page(handle->cur, handle->cur_swap);
+ else
+ return -EINVAL;
+}
+
+/**
+ * save_image - save the suspend image data
+ */
+
+static int save_image(struct swap_map_handle *handle,
+ struct snapshot_handle *snapshot,
+ unsigned int nr_pages)
+{
+ unsigned int m;
+ int ret;
+ int error = 0;
+
+ printk("Saving image data pages (%u pages) ... ", nr_pages);
+ m = nr_pages / 100;
+ if (!m)
+ m = 1;
+ nr_pages = 0;
+ do {
+ ret = snapshot_read_next(snapshot, PAGE_SIZE);
+ if (ret > 0) {
+ error = swap_write_page(handle, data_of(*snapshot));
+ if (error)
+ break;
+ if (!(nr_pages % m))
+ printk("\b\b\b\b%3d%%", nr_pages / m);
+ nr_pages++;
+ }
+ } while (ret > 0);
+ if (!error)
+ printk("\b\b\b\bdone\n");
+ return error;
+}
+
+/**
+ * enough_swap - Make sure we have enough swap to save the image.
+ *
+ * Returns TRUE or FALSE after checking the total amount of swap
+ * space avaiable from the resume partition.
+ */
+
+static int enough_swap(unsigned int nr_pages)
+{
+ unsigned int free_swap = swsusp_available_swap(root_swap);
+
+ pr_debug("swsusp: free swap pages: %u\n", free_swap);
+ return free_swap > (nr_pages + PAGES_FOR_IO +
+ (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
+}
+
+/**
+ * swsusp_write - Write entire image and metadata.
+ *
+ * It is important _NOT_ to umount filesystems at this point. We want
+ * them synced (in case something goes wrong) but we DO not want to mark
+ * filesystem clean: it is not. (And it does not matter, if we resume
+ * correctly, we'll mark system clean, anyway.)
+ */
+
+int swsusp_write(void)
+{
+ struct swap_map_handle handle;
+ struct snapshot_handle snapshot;
+ struct swsusp_info *header;
+ unsigned long start;
+ int error;
+
+ if ((error = swsusp_swap_check())) {
+ printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n");
+ return error;
+ }
+ memset(&snapshot, 0, sizeof(struct snapshot_handle));
+ error = snapshot_read_next(&snapshot, PAGE_SIZE);
+ if (error < PAGE_SIZE)
+ return error < 0 ? error : -EFAULT;
+ header = (struct swsusp_info *)data_of(snapshot);
+ if (!enough_swap(header->pages)) {
+ printk(KERN_ERR "swsusp: Not enough free swap\n");
+ return -ENOSPC;
+ }
+ error = get_swap_writer(&handle);
+ if (!error) {
+ start = handle.cur_swap;
+ error = swap_write_page(&handle, header);
+ }
+ if (!error)
+ error = save_image(&handle, &snapshot, header->pages - 1);
+ if (!error) {
+ flush_swap_writer(&handle);
+ printk("S");
+ error = mark_swapfiles(swp_entry(root_swap, start));
+ printk("|\n");
+ }
+ if (error)
+ free_all_swap_pages(root_swap, handle.bitmap);
+ release_swap_writer(&handle);
+ return error;
+}
+
+/*
+ * Using bio to read from swap.
+ * This code requires a bit more work than just using buffer heads
+ * but, it is the recommended way for 2.5/2.6.
+ * The following are to signal the beginning and end of I/O. Bios
+ * finish asynchronously, while we want them to happen synchronously.
+ * A simple atomic_t, and a wait loop take care of this problem.
+ */
+
+static atomic_t io_done = ATOMIC_INIT(0);
+
+static int end_io(struct bio *bio, unsigned int num, int err)
+{
+ if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
+ panic("I/O error reading memory image");
+ atomic_set(&io_done, 0);
+ return 0;
+}
+
+static struct block_device *resume_bdev;
+
+/**
+ * submit - submit BIO request.
+ * @rw: READ or WRITE.
+ * @off physical offset of page.
+ * @page: page we're reading or writing.
+ *
+ * Straight from the textbook - allocate and initialize the bio.
+ * If we're writing, make sure the page is marked as dirty.
+ * Then submit it and wait.
+ */
+
+static int submit(int rw, pgoff_t page_off, void *page)
+{
+ int error = 0;
+ struct bio *bio;
+
+ bio = bio_alloc(GFP_ATOMIC, 1);
+ if (!bio)
+ return -ENOMEM;
+ bio->bi_sector = page_off * (PAGE_SIZE >> 9);
+ bio_get(bio);
+ bio->bi_bdev = resume_bdev;
+ bio->bi_end_io = end_io;
+
+ if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
+ printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
+ error = -EFAULT;
+ goto Done;
+ }
+
+ if (rw == WRITE)
+ bio_set_pages_dirty(bio);
+
+ atomic_set(&io_done, 1);
+ submit_bio(rw | (1 << BIO_RW_SYNC), bio);
+ while (atomic_read(&io_done))
+ yield();
+
+ Done:
+ bio_put(bio);
+ return error;
+}
+
+static int bio_read_page(pgoff_t page_off, void *page)
+{
+ return submit(READ, page_off, page);
+}
+
+static int bio_write_page(pgoff_t page_off, void *page)
+{
+ return submit(WRITE, page_off, page);
+}
+
+/**
+ * The following functions allow us to read data using a swap map
+ * in a file-alike way
+ */
+
+static inline void release_swap_reader(struct swap_map_handle *handle)
+{
+ if (handle->cur)
+ free_page((unsigned long)handle->cur);
+ handle->cur = NULL;
+}
+
+static inline int get_swap_reader(struct swap_map_handle *handle,
+ swp_entry_t start)
+{
+ int error;
+
+ if (!swp_offset(start))
+ return -EINVAL;
+ handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
+ if (!handle->cur)
+ return -ENOMEM;
+ error = bio_read_page(swp_offset(start), handle->cur);
+ if (error) {
+ release_swap_reader(handle);
+ return error;
+ }
+ handle->k = 0;
+ return 0;
+}
+
+static inline int swap_read_page(struct swap_map_handle *handle, void *buf)
+{
+ unsigned long offset;
+ int error;
+
+ if (!handle->cur)
+ return -EINVAL;
+ offset = handle->cur->entries[handle->k];
+ if (!offset)
+ return -EFAULT;
+ error = bio_read_page(offset, buf);
+ if (error)
+ return error;
+ if (++handle->k >= MAP_PAGE_ENTRIES) {
+ handle->k = 0;
+ offset = handle->cur->next_swap;
+ if (!offset)
+ release_swap_reader(handle);
+ else
+ error = bio_read_page(offset, handle->cur);
+ }
+ return error;
+}
+
+/**
+ * load_image - load the image using the swap map handle
+ * @handle and the snapshot handle @snapshot
+ * (assume there are @nr_pages pages to load)
+ */
+
+static int load_image(struct swap_map_handle *handle,
+ struct snapshot_handle *snapshot,
+ unsigned int nr_pages)
+{
+ unsigned int m;
+ int ret;
+ int error = 0;
+
+ printk("Loading image data pages (%u pages) ... ", nr_pages);
+ m = nr_pages / 100;
+ if (!m)
+ m = 1;
+ nr_pages = 0;
+ do {
+ ret = snapshot_write_next(snapshot, PAGE_SIZE);
+ if (ret > 0) {
+ error = swap_read_page(handle, data_of(*snapshot));
+ if (error)
+ break;
+ if (!(nr_pages % m))
+ printk("\b\b\b\b%3d%%", nr_pages / m);
+ nr_pages++;
+ }
+ } while (ret > 0);
+ if (!error)
+ printk("\b\b\b\bdone\n");
+ if (!snapshot_image_loaded(snapshot))
+ error = -ENODATA;
+ return error;
+}
+
+int swsusp_read(void)
+{
+ int error;
+ struct swap_map_handle handle;
+ struct snapshot_handle snapshot;
+ struct swsusp_info *header;
+ unsigned int nr_pages;
+
+ if (IS_ERR(resume_bdev)) {
+ pr_debug("swsusp: block device not initialised\n");
+ return PTR_ERR(resume_bdev);
+ }
+
+ memset(&snapshot, 0, sizeof(struct snapshot_handle));
+ error = snapshot_write_next(&snapshot, PAGE_SIZE);
+ if (error < PAGE_SIZE)
+ return error < 0 ? error : -EFAULT;
+ header = (struct swsusp_info *)data_of(snapshot);
+ error = get_swap_reader(&handle, swsusp_header.image);
+ if (!error)
+ error = swap_read_page(&handle, header);
+ if (!error) {
+ nr_pages = header->image_pages;
+ error = load_image(&handle, &snapshot, nr_pages);
+ }
+ release_swap_reader(&handle);
+
+ blkdev_put(resume_bdev);
+
+ if (!error)
+ pr_debug("swsusp: Reading resume file was successful\n");
+ else
+ pr_debug("swsusp: Error %d resuming\n", error);
+ return error;
+}
+
+/**
+ * swsusp_check - Check for swsusp signature in the resume device
+ */
+
+int swsusp_check(void)
+{
+ int error;
+
+ resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
+ if (!IS_ERR(resume_bdev)) {
+ set_blocksize(resume_bdev, PAGE_SIZE);
+ memset(&swsusp_header, 0, sizeof(swsusp_header));
+ if ((error = bio_read_page(0, &swsusp_header)))
+ return error;
+ if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
+ memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
+ /* Reset swap signature now */
+ error = bio_write_page(0, &swsusp_header);
+ } else {
+ return -EINVAL;
+ }
+ if (error)
+ blkdev_put(resume_bdev);
+ else
+ pr_debug("swsusp: Signature found, resuming\n");
+ } else {
+ error = PTR_ERR(resume_bdev);
+ }
+
+ if (error)
+ pr_debug("swsusp: Error %d check for resume file\n", error);
+
+ return error;
+}
+
+/**
+ * swsusp_close - close swap device.
+ */
+
+void swsusp_close(void)
+{
+ if (IS_ERR(resume_bdev)) {
+ pr_debug("swsusp: block device not initialised\n");
+ return;
+ }
+
+ blkdev_put(resume_bdev);
+}
Index: linux-2.6.15-mm1/kernel/power/swsusp.c
===================================================================
--- linux-2.6.15-mm1.orig/kernel/power/swsusp.c 2006-01-06 23:24:18.000000000 +0100
+++ linux-2.6.15-mm1/kernel/power/swsusp.c 2006-01-06 23:27:19.000000000 +0100
@@ -31,41 +31,24 @@
* Fixed runaway init
*
* Rafael J. Wysocki <rjw@xxxxxxx>
- * Added the swap map data structure and reworked the handling of swap
+ * Reworked the handling of swap and added the user interface
*
* More state savers are welcome. Especially for the scsi layer...
*
* For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
*/
-#include <linux/module.h>
#include <linux/mm.h>
#include <linux/suspend.h>
-#include <linux/smp_lock.h>
-#include <linux/file.h>
-#include <linux/utsname.h>
-#include <linux/version.h>
-#include <linux/delay.h>
-#include <linux/bitops.h>
#include <linux/spinlock.h>
-#include <linux/genhd.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/swap.h>
#include <linux/pm.h>
-#include <linux/device.h>
-#include <linux/buffer_head.h>
#include <linux/swapops.h>
#include <linux/bootmem.h>
#include <linux/syscalls.h>
#include <linux/highmem.h>
-#include <linux/bio.h>
-
-#include <asm/uaccess.h>
-#include <asm/mmu_context.h>
-#include <asm/pgtable.h>
-#include <asm/tlbflush.h>
-#include <asm/io.h>
#include "power.h"
@@ -89,82 +72,42 @@ static int restore_highmem(void) { retur
static unsigned int count_highmem_pages(void) { return 0; }
#endif
-extern char resume_file[];
-
-#define SWSUSP_SIG "S1SUSPEND"
-
-static struct swsusp_header {
- char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)];
- swp_entry_t image;
- char orig_sig[10];
- char sig[10];
-} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
-
-/*
- * Saving part...
- */
-
-static unsigned short root_swap = 0xffff;
-
-static int mark_swapfiles(swp_entry_t start)
-{
- int error;
-
- rw_swap_page_sync(READ,
- swp_entry(root_swap, 0),
- virt_to_page((unsigned long)&swsusp_header));
- if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
- !memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
- memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
- memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
- swsusp_header.image = start;
- error = rw_swap_page_sync(WRITE,
- swp_entry(root_swap, 0),
- virt_to_page((unsigned long)
- &swsusp_header));
- } else {
- pr_debug("swsusp: Partition is not swap space.\n");
- error = -ENODEV;
- }
- return error;
-}
-
/**
- * Check whether the swap device is the specified resume
- * device, irrespective of whether they are specified by
- * identical names.
+ * is_device - check whether the specified device is a swap device,
+ * irrespective of whether they are specified by identical names.
*
- * (Thus, device inode aliasing is allowed. You can say /dev/hda4
- * instead of /dev/ide/host0/bus0/target0/lun0/part4 [eg. for devfs]
- * and they'll be considered the same device. This was *necessary* for
- * devfs, since the resume code could only recognize the form /dev/hda4,
- * but the suspend code would see the long name.)
+ * (Thus, device inode aliasing is allowed. You can say /dev/hda4
+ * instead of /dev/ide/host0/bus0/target0/lun0/part4 [eg. for devfs]
+ * and they'll be considered the same device. This was *necessary* for
+ * devfs, since the resume code could only recognize the form /dev/hda4,
+ * but the suspend code would see the long name.)
*/
-static inline int is_resume_device(const struct swap_info_struct *swap_info)
+static inline int is_device(const struct swap_info_struct *swap_info,
+ dev_t device)
{
struct file *file = swap_info->swap_file;
struct inode *inode = file->f_dentry->d_inode;
return S_ISBLK(inode->i_mode) &&
- swsusp_resume_device == MKDEV(imajor(inode), iminor(inode));
+ device == MKDEV(imajor(inode), iminor(inode));
}
/**
- * swsusp_get_swap_index - find the index of the resume device
+ * swsusp_get_swap_index_of - find the index of the given device
*/
-int swsusp_get_swap_index(void)
+int swsusp_get_swap_index_of(dev_t device)
{
int i;
- if (!swsusp_resume_device)
- return -ENODEV;
+ if (!device)
+ return -EINVAL;
spin_lock(&swap_lock);
for (i = 0; i < MAX_SWAPFILES; i++) {
if (!(swap_info[i].flags & SWP_WRITEOK))
continue;
- if (is_resume_device(swap_info + i)) {
+ if (is_device(swap_info + i, device)) {
spin_unlock(&swap_lock);
return i;
}
@@ -173,46 +116,24 @@ int swsusp_get_swap_index(void)
return -ENODEV;
}
-static int swsusp_swap_check(void) /* This is called before saving image */
-{
- int res = swsusp_get_swap_index();
-
- if (res >= 0) {
- root_swap = res;
- return 0;
- }
- return res;
-}
-
/**
- * 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.
+ * swsusp_get_swap_index - find the index of the resume device
*/
-#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;
-};
+int swsusp_get_swap_index(void)
+{
+ return swsusp_get_swap_index_of(swsusp_resume_device);
+}
/**
* 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
- * above
+ * in power.h
*/
-static void free_bitmap(struct bitmap_page *bitmap)
+void free_bitmap(struct bitmap_page *bitmap)
{
struct bitmap_page *bp;
@@ -223,7 +144,7 @@ static void free_bitmap(struct bitmap_pa
}
}
-static struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
+struct bitmap_page *alloc_bitmap(unsigned int nr_bits)
{
struct bitmap_page *bitmap, *bp;
unsigned int n;
@@ -266,7 +187,7 @@ static inline int bitmap_set(struct bitm
return 0;
}
-static unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
+unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap)
{
unsigned long offset;
@@ -280,7 +201,7 @@ static unsigned long alloc_swap_page(int
return offset;
}
-static void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
+void free_all_swap_pages(int swap, struct bitmap_page *bitmap)
{
unsigned int bit, n;
unsigned long test;
@@ -298,24 +219,6 @@ static void free_all_swap_pages(int swap
}
/**
- * write_page - Write one page to given swap location.
- * @buf: Address we're writing.
- * @offset: Offset of the swap page we're writing to.
- */
-
-static int write_page(void *buf, unsigned long offset)
-{
- swp_entry_t entry;
- int error = -ENOSPC;
-
- if (offset) {
- entry = swp_entry(root_swap, offset);
- error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf));
- }
- return error;
-}
-
-/**
* swsusp_total_swap - check the total amount of swap
* space in the resume partition/file
*/
@@ -333,137 +236,6 @@ unsigned int swsusp_total_swap(unsigned
return n;
}
-/*
- * The swap map is a data structure used for keeping track of each page
- * written to a swap partition. It consists of many swap_map_page
- * structures that contain each an array of MAP_PAGE_SIZE swap entries.
- * These structures are stored on the swap and linked together with the
- * help of the .next_swap member.
- *
- * The swap map is created during suspend. The swap map pages are
- * allocated and populated one at a time, so we only need one memory
- * page to set up the entire structure.
- *
- * During resume we also only need to use one swap_map_page structure
- * at a time.
- */
-
-#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(long) - 1)
-
-struct swap_map_page {
- unsigned long entries[MAP_PAGE_ENTRIES];
- unsigned long next_swap;
-};
-
-/**
- * The swap_map_handle structure is used for handling swap in
- * a file-alike way
- */
-
-struct swap_map_handle {
- struct swap_map_page *cur;
- unsigned long cur_swap;
- struct bitmap_page *bitmap;
- unsigned int k;
-};
-
-static inline 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 inline 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(swsusp_total_swap(root_swap));
- if (!handle->bitmap) {
- release_swap_writer(handle);
- return -ENOMEM;
- }
- handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap);
- if (!handle->cur_swap) {
- release_swap_writer(handle);
- return -ENOSPC;
- }
- handle->k = 0;
- return 0;
-}
-
-static inline int swap_write_page(struct swap_map_handle *handle, void *buf)
-{
- int error;
- unsigned long offset;
-
- if (!handle->cur)
- return -EINVAL;
- offset = alloc_swap_page(root_swap, handle->bitmap);
- error = write_page(buf, offset);
- if (error)
- return error;
- handle->cur->entries[handle->k++] = offset;
- if (handle->k >= MAP_PAGE_ENTRIES) {
- offset = alloc_swap_page(root_swap, handle->bitmap);
- if (!offset)
- return -ENOSPC;
- handle->cur->next_swap = offset;
- error = write_page(handle->cur, handle->cur_swap);
- if (error)
- return error;
- memset(handle->cur, 0, PAGE_SIZE);
- handle->cur_swap = offset;
- handle->k = 0;
- }
- return 0;
-}
-
-static inline int flush_swap_writer(struct swap_map_handle *handle)
-{
- if (handle->cur && handle->cur_swap)
- return write_page(handle->cur, handle->cur_swap);
- else
- return -EINVAL;
-}
-
-/**
- * save_image - save the suspend image data
- */
-
-static int save_image(struct swap_map_handle *handle,
- struct snapshot_handle *snapshot,
- unsigned int nr_pages)
-{
- unsigned int m;
- int ret;
- int error = 0;
-
- printk("Saving image data pages (%u pages) ... ", nr_pages);
- m = nr_pages / 100;
- if (!m)
- m = 1;
- nr_pages = 0;
- do {
- ret = snapshot_read_next(snapshot, PAGE_SIZE);
- if (ret > 0) {
- error = swap_write_page(handle, data_of(*snapshot));
- if (error)
- break;
- if (!(nr_pages % m))
- printk("\b\b\b\b%3d%%", nr_pages / m);
- nr_pages++;
- }
- } while (ret > 0);
- if (!error)
- printk("\b\b\b\bdone\n");
- return error;
-}
-
/**
* swsusp_available_swap - check the total amount of swap
* space avaiable from given swap partition/file
@@ -484,71 +256,6 @@ unsigned int swsusp_available_swap(unsig
}
/**
- * enough_swap - Make sure we have enough swap to save the image.
- *
- * Returns TRUE or FALSE after checking the total amount of swap
- * space avaiable from the resume partition.
- */
-
-static int enough_swap(unsigned int nr_pages)
-{
- unsigned int free_swap = swsusp_available_swap(root_swap);
-
- pr_debug("swsusp: free swap pages: %u\n", free_swap);
- return free_swap > (nr_pages + PAGES_FOR_IO +
- (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
-}
-
-/**
- * swsusp_write - Write entire image and metadata.
- *
- * It is important _NOT_ to umount filesystems at this point. We want
- * them synced (in case something goes wrong) but we DO not want to mark
- * filesystem clean: it is not. (And it does not matter, if we resume
- * correctly, we'll mark system clean, anyway.)
- */
-
-int swsusp_write(void)
-{
- struct swap_map_handle handle;
- struct snapshot_handle snapshot;
- struct swsusp_info *header;
- unsigned long start;
- int error;
-
- if ((error = swsusp_swap_check())) {
- printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n");
- return error;
- }
- memset(&snapshot, 0, sizeof(struct snapshot_handle));
- error = snapshot_read_next(&snapshot, PAGE_SIZE);
- if (error < PAGE_SIZE)
- return error < 0 ? error : -EFAULT;
- header = (struct swsusp_info *)data_of(snapshot);
- if (!enough_swap(header->pages)) {
- printk(KERN_ERR "swsusp: Not enough free swap\n");
- return -ENOSPC;
- }
- error = get_swap_writer(&handle);
- if (!error) {
- start = handle.cur_swap;
- error = swap_write_page(&handle, header);
- }
- if (!error)
- error = save_image(&handle, &snapshot, header->pages - 1);
- if (!error) {
- flush_swap_writer(&handle);
- printk("S");
- error = mark_swapfiles(swp_entry(root_swap, start));
- printk("|\n");
- }
- if (error)
- free_all_swap_pages(root_swap, handle.bitmap);
- release_swap_writer(&handle);
- return error;
-}
-
-/**
* swsusp_shrink_memory - Try to free as much memory as needed
*
* ... but do not OOM-kill anyone
@@ -654,254 +361,3 @@ int swsusp_resume(void)
local_irq_enable();
return error;
}
-
-/*
- * Using bio to read from swap.
- * This code requires a bit more work than just using buffer heads
- * but, it is the recommended way for 2.5/2.6.
- * The following are to signal the beginning and end of I/O. Bios
- * finish asynchronously, while we want them to happen synchronously.
- * A simple atomic_t, and a wait loop take care of this problem.
- */
-
-static atomic_t io_done = ATOMIC_INIT(0);
-
-static int end_io(struct bio *bio, unsigned int num, int err)
-{
- if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
- panic("I/O error reading memory image");
- atomic_set(&io_done, 0);
- return 0;
-}
-
-static struct block_device *resume_bdev;
-
-/**
- * submit - submit BIO request.
- * @rw: READ or WRITE.
- * @off physical offset of page.
- * @page: page we're reading or writing.
- *
- * Straight from the textbook - allocate and initialize the bio.
- * If we're writing, make sure the page is marked as dirty.
- * Then submit it and wait.
- */
-
-static int submit(int rw, pgoff_t page_off, void *page)
-{
- int error = 0;
- struct bio *bio;
-
- bio = bio_alloc(GFP_ATOMIC, 1);
- if (!bio)
- return -ENOMEM;
- bio->bi_sector = page_off * (PAGE_SIZE >> 9);
- bio_get(bio);
- bio->bi_bdev = resume_bdev;
- bio->bi_end_io = end_io;
-
- if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) {
- printk("swsusp: ERROR: adding page to bio at %ld\n",page_off);
- error = -EFAULT;
- goto Done;
- }
-
- if (rw == WRITE)
- bio_set_pages_dirty(bio);
-
- atomic_set(&io_done, 1);
- submit_bio(rw | (1 << BIO_RW_SYNC), bio);
- while (atomic_read(&io_done))
- yield();
-
- Done:
- bio_put(bio);
- return error;
-}
-
-static int bio_read_page(pgoff_t page_off, void *page)
-{
- return submit(READ, page_off, page);
-}
-
-static int bio_write_page(pgoff_t page_off, void *page)
-{
- return submit(WRITE, page_off, page);
-}
-
-/**
- * The following functions allow us to read data using a swap map
- * in a file-alike way
- */
-
-static inline void release_swap_reader(struct swap_map_handle *handle)
-{
- if (handle->cur)
- free_page((unsigned long)handle->cur);
- handle->cur = NULL;
-}
-
-static inline int get_swap_reader(struct swap_map_handle *handle,
- swp_entry_t start)
-{
- int error;
-
- if (!swp_offset(start))
- return -EINVAL;
- handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
- if (!handle->cur)
- return -ENOMEM;
- error = bio_read_page(swp_offset(start), handle->cur);
- if (error) {
- release_swap_reader(handle);
- return error;
- }
- handle->k = 0;
- return 0;
-}
-
-static inline int swap_read_page(struct swap_map_handle *handle, void *buf)
-{
- unsigned long offset;
- int error;
-
- if (!handle->cur)
- return -EINVAL;
- offset = handle->cur->entries[handle->k];
- if (!offset)
- return -EFAULT;
- error = bio_read_page(offset, buf);
- if (error)
- return error;
- if (++handle->k >= MAP_PAGE_ENTRIES) {
- handle->k = 0;
- offset = handle->cur->next_swap;
- if (!offset)
- release_swap_reader(handle);
- else
- error = bio_read_page(offset, handle->cur);
- }
- return error;
-}
-
-/**
- * load_image - load the image using the swap map handle
- * @handle and the snapshot handle @snapshot
- * (assume there are @nr_pages pages to load)
- */
-
-static int load_image(struct swap_map_handle *handle,
- struct snapshot_handle *snapshot,
- unsigned int nr_pages)
-{
- unsigned int m;
- int ret;
- int error = 0;
-
- printk("Loading image data pages (%u pages) ... ", nr_pages);
- m = nr_pages / 100;
- if (!m)
- m = 1;
- nr_pages = 0;
- do {
- ret = snapshot_write_next(snapshot, PAGE_SIZE);
- if (ret > 0) {
- error = swap_read_page(handle, data_of(*snapshot));
- if (error)
- break;
- if (!(nr_pages % m))
- printk("\b\b\b\b%3d%%", nr_pages / m);
- nr_pages++;
- }
- } while (ret > 0);
- if (!error)
- printk("\b\b\b\bdone\n");
- if (!snapshot_image_loaded(snapshot))
- error = -ENODATA;
- return error;
-}
-
-int swsusp_read(void)
-{
- int error;
- struct swap_map_handle handle;
- struct snapshot_handle snapshot;
- struct swsusp_info *header;
- unsigned int nr_pages;
-
- if (IS_ERR(resume_bdev)) {
- pr_debug("swsusp: block device not initialised\n");
- return PTR_ERR(resume_bdev);
- }
-
- memset(&snapshot, 0, sizeof(struct snapshot_handle));
- error = snapshot_write_next(&snapshot, PAGE_SIZE);
- if (error < PAGE_SIZE)
- return error < 0 ? error : -EFAULT;
- header = (struct swsusp_info *)data_of(snapshot);
- error = get_swap_reader(&handle, swsusp_header.image);
- if (!error)
- error = swap_read_page(&handle, header);
- if (!error) {
- nr_pages = header->image_pages;
- error = load_image(&handle, &snapshot, nr_pages);
- }
- release_swap_reader(&handle);
-
- blkdev_put(resume_bdev);
-
- if (!error)
- pr_debug("swsusp: Reading resume file was successful\n");
- else
- pr_debug("swsusp: Error %d resuming\n", error);
- return error;
-}
-
-/**
- * swsusp_check - Check for swsusp signature in the resume device
- */
-
-int swsusp_check(void)
-{
- int error;
-
- resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
- if (!IS_ERR(resume_bdev)) {
- set_blocksize(resume_bdev, PAGE_SIZE);
- memset(&swsusp_header, 0, sizeof(swsusp_header));
- if ((error = bio_read_page(0, &swsusp_header)))
- return error;
- if (!memcmp(SWSUSP_SIG, swsusp_header.sig, 10)) {
- memcpy(swsusp_header.sig, swsusp_header.orig_sig, 10);
- /* Reset swap signature now */
- error = bio_write_page(0, &swsusp_header);
- } else {
- return -EINVAL;
- }
- if (error)
- blkdev_put(resume_bdev);
- else
- pr_debug("swsusp: Signature found, resuming\n");
- } else {
- error = PTR_ERR(resume_bdev);
- }
-
- if (error)
- pr_debug("swsusp: Error %d check for resume file\n", error);
-
- return error;
-}
-
-/**
- * swsusp_close - close swap device.
- */
-
-void swsusp_close(void)
-{
- if (IS_ERR(resume_bdev)) {
- pr_debug("swsusp: block device not initialised\n");
- return;
- }
-
- blkdev_put(resume_bdev);
-}
-
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