fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / kernel / power / swap.c
index 044b8e0..3581f8f 100644 (file)
@@ -22,6 +22,7 @@
 #include <linux/device.h>
 #include <linux/buffer_head.h>
 #include <linux/bio.h>
+#include <linux/blkdev.h>
 #include <linux/swap.h>
 #include <linux/swapops.h>
 #include <linux/pm.h>
@@ -33,36 +34,123 @@ 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 reserved[PAGE_SIZE - 20 - sizeof(sector_t)];
+       sector_t image;
        char    orig_sig[10];
        char    sig[10];
 } __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;
 
 /*
- * Saving part...
+ * General things
  */
 
 static unsigned short root_swap = 0xffff;
+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.
+ *     @bio_chain: list of pending biod (for async reading)
+ *
+ *     Straight from the textbook - allocate and initialize the bio.
+ *     If we're reading, make sure the page is marked as dirty.
+ *     Then submit it and, if @bio_chain == NULL, wait.
+ */
+static int submit(int rw, pgoff_t page_off, struct page *page,
+                       struct bio **bio_chain)
+{
+       struct bio *bio;
+
+       bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
+       if (!bio)
+               return -ENOMEM;
+       bio->bi_sector = page_off * (PAGE_SIZE >> 9);
+       bio->bi_bdev = resume_bdev;
+       bio->bi_end_io = end_swap_bio_read;
 
-static int mark_swapfiles(swp_entry_t start)
+       if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
+               printk("swsusp: ERROR: adding page to bio at %ld\n", page_off);
+               bio_put(bio);
+               return -EFAULT;
+       }
+
+       lock_page(page);
+       bio_get(bio);
+
+       if (bio_chain == NULL) {
+               submit_bio(rw | (1 << BIO_RW_SYNC), bio);
+               wait_on_page_locked(page);
+               if (rw == READ)
+                       bio_set_pages_dirty(bio);
+               bio_put(bio);
+       } else {
+               if (rw == READ)
+                       get_page(page); /* These pages are freed later */
+               bio->bi_private = *bio_chain;
+               *bio_chain = bio;
+               submit_bio(rw | (1 << BIO_RW_SYNC), bio);
+       }
+       return 0;
+}
+
+static int bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
+{
+       return submit(READ, page_off, virt_to_page(addr), bio_chain);
+}
+
+static int bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
+{
+       return submit(WRITE, page_off, virt_to_page(addr), bio_chain);
+}
+
+static int wait_on_bio_chain(struct bio **bio_chain)
+{
+       struct bio *bio;
+       struct bio *next_bio;
+       int ret = 0;
+
+       if (bio_chain == NULL)
+               return 0;
+
+       bio = *bio_chain;
+       if (bio == NULL)
+               return 0;
+       while (bio) {
+               struct page *page;
+
+               next_bio = bio->bi_private;
+               page = bio->bi_io_vec[0].bv_page;
+               wait_on_page_locked(page);
+               if (!PageUptodate(page) || PageError(page))
+                       ret = -EIO;
+               put_page(page);
+               bio_put(bio);
+               bio = next_bio;
+       }
+       *bio_chain = NULL;
+       return ret;
+}
+
+/*
+ * Saving part
+ */
+
+static int mark_swapfiles(sector_t start)
 {
        int error;
 
-       rw_swap_page_sync(READ,
-                         swp_entry(root_swap, 0),
-                         virt_to_page((unsigned long)&swsusp_header));
+       bio_read_page(swsusp_resume_block, &swsusp_header, NULL);
        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));
+               error = bio_write_page(swsusp_resume_block,
+                                       &swsusp_header, NULL);
        } else {
-               pr_debug("swsusp: Partition is not swap space.\n");
+               printk(KERN_ERR "swsusp: Swap header not found!\n");
                error = -ENODEV;
        }
        return error;
@@ -75,12 +163,22 @@ static int mark_swapfiles(swp_entry_t start)
 
 static int swsusp_swap_check(void) /* This is called before saving image */
 {
-       int res = swap_type_of(swsusp_resume_device);
+       int res;
+
+       res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
+                       &resume_bdev);
+       if (res < 0)
+               return res;
+
+       root_swap = res;
+       res = blkdev_get(resume_bdev, FMODE_WRITE, O_RDWR);
+       if (res)
+               return res;
+
+       res = set_blocksize(resume_bdev, PAGE_SIZE);
+       if (res < 0)
+               blkdev_put(resume_bdev);
 
-       if (res >= 0) {
-               root_swap = res;
-               return 0;
-       }
        return res;
 }
 
@@ -88,18 +186,29 @@ static int swsusp_swap_check(void) /* This is called before saving image */
  *     write_page - Write one page to given swap location.
  *     @buf:           Address we're writing.
  *     @offset:        Offset of the swap page we're writing to.
+ *     @bio_chain:     Link the next write BIO here
  */
 
-static int write_page(void *buf, unsigned long offset)
+static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
 {
-       swp_entry_t entry;
-       int error = -ENOSPC;
+       void *src;
 
-       if (offset) {
-               entry = swp_entry(root_swap, offset);
-               error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf));
+       if (!offset)
+               return -ENOSPC;
+
+       if (bio_chain) {
+               src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
+               if (src) {
+                       memcpy(src, buf, PAGE_SIZE);
+               } else {
+                       WARN_ON_ONCE(1);
+                       bio_chain = NULL;       /* Go synchronous */
+                       src = buf;
+               }
+       } else {
+               src = buf;
        }
-       return error;
+       return bio_write_page(offset, src, bio_chain);
 }
 
 /*
@@ -117,11 +226,11 @@ static int write_page(void *buf, unsigned long offset)
  *     at a time.
  */
 
-#define MAP_PAGE_ENTRIES       (PAGE_SIZE / sizeof(long) - 1)
+#define MAP_PAGE_ENTRIES       (PAGE_SIZE / sizeof(sector_t) - 1)
 
 struct swap_map_page {
-       unsigned long           entries[MAP_PAGE_ENTRIES];
-       unsigned long           next_swap;
+       sector_t entries[MAP_PAGE_ENTRIES];
+       sector_t next_swap;
 };
 
 /**
@@ -131,7 +240,7 @@ struct swap_map_page {
 
 struct swap_map_handle {
        struct swap_map_page *cur;
-       unsigned long cur_swap;
+       sector_t cur_swap;
        struct bitmap_page *bitmap;
        unsigned int k;
 };
@@ -156,7 +265,7 @@ static int get_swap_writer(struct swap_map_handle *handle)
                release_swap_writer(handle);
                return -ENOMEM;
        }
-       handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap);
+       handle->cur_swap = alloc_swapdev_block(root_swap, handle->bitmap);
        if (!handle->cur_swap) {
                release_swap_writer(handle);
                return -ENOSPC;
@@ -165,37 +274,42 @@ static int get_swap_writer(struct swap_map_handle *handle)
        return 0;
 }
 
-static int swap_write_page(struct swap_map_handle *handle, void *buf)
+static int swap_write_page(struct swap_map_handle *handle, void *buf,
+                               struct bio **bio_chain)
 {
-       int error;
-       unsigned long offset;
+       int error = 0;
+       sector_t offset;
 
        if (!handle->cur)
                return -EINVAL;
-       offset = alloc_swap_page(root_swap, handle->bitmap);
-       error = write_page(buf, offset);
+       offset = alloc_swapdev_block(root_swap, handle->bitmap);
+       error = write_page(buf, offset, bio_chain);
        if (error)
                return error;
        handle->cur->entries[handle->k++] = offset;
        if (handle->k >= MAP_PAGE_ENTRIES) {
-               offset = alloc_swap_page(root_swap, handle->bitmap);
+               error = wait_on_bio_chain(bio_chain);
+               if (error)
+                       goto out;
+               offset = alloc_swapdev_block(root_swap, handle->bitmap);
                if (!offset)
                        return -ENOSPC;
                handle->cur->next_swap = offset;
-               error = write_page(handle->cur, handle->cur_swap);
+               error = write_page(handle->cur, handle->cur_swap, NULL);
                if (error)
-                       return error;
+                       goto out;
                memset(handle->cur, 0, PAGE_SIZE);
                handle->cur_swap = offset;
                handle->k = 0;
        }
-       return 0;
+ out:
+       return error;
 }
 
 static int flush_swap_writer(struct swap_map_handle *handle)
 {
        if (handle->cur && handle->cur_swap)
-               return write_page(handle->cur, handle->cur_swap);
+               return write_page(handle->cur, handle->cur_swap, NULL);
        else
                return -EINVAL;
 }
@@ -206,21 +320,29 @@ static int flush_swap_writer(struct swap_map_handle *handle)
 
 static int save_image(struct swap_map_handle *handle,
                       struct snapshot_handle *snapshot,
-                      unsigned int nr_pages)
+                      unsigned int nr_to_write)
 {
        unsigned int m;
        int ret;
        int error = 0;
+       int nr_pages;
+       int err2;
+       struct bio *bio;
+       struct timeval start;
+       struct timeval stop;
 
-       printk("Saving image data pages (%u pages) ...     ", nr_pages);
-       m = nr_pages / 100;
+       printk("Saving image data pages (%u pages) ...     ", nr_to_write);
+       m = nr_to_write / 100;
        if (!m)
                m = 1;
        nr_pages = 0;
+       bio = NULL;
+       do_gettimeofday(&start);
        do {
                ret = snapshot_read_next(snapshot, PAGE_SIZE);
                if (ret > 0) {
-                       error = swap_write_page(handle, data_of(*snapshot));
+                       error = swap_write_page(handle, data_of(*snapshot),
+                                               &bio);
                        if (error)
                                break;
                        if (!(nr_pages % m))
@@ -228,8 +350,13 @@ static int save_image(struct swap_map_handle *handle,
                        nr_pages++;
                }
        } while (ret > 0);
+       err2 = wait_on_bio_chain(&bio);
+       do_gettimeofday(&stop);
+       if (!error)
+               error = err2;
        if (!error)
                printk("\b\b\b\bdone\n");
+       swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
        return error;
 }
 
@@ -245,8 +372,7 @@ static int enough_swap(unsigned int nr_pages)
        unsigned int free_swap = count_swap_pages(root_swap, 1);
 
        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);
+       return free_swap > nr_pages + PAGES_FOR_IO;
 }
 
 /**
@@ -263,112 +389,52 @@ 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");
+       error = swsusp_swap_check();
+       if (error) {
+               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;
+       if (error < PAGE_SIZE) {
+               if (error >= 0)
+                       error = -EFAULT;
+
+               goto out;
+       }
        header = (struct swsusp_info *)data_of(snapshot);
        if (!enough_swap(header->pages)) {
                printk(KERN_ERR "swsusp: Not enough free swap\n");
-               return -ENOSPC;
+               error = -ENOSPC;
+               goto out;
        }
        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");
+               sector_t start = handle.cur_swap;
+
+               error = swap_write_page(&handle, header, NULL);
+               if (!error)
+                       error = save_image(&handle, &snapshot,
+                                       header->pages - 1);
+
+               if (!error) {
+                       flush_swap_writer(&handle);
+                       printk("S");
+                       error = mark_swapfiles(start);
+                       printk("|\n");
+               }
        }
        if (error)
                free_all_swap_pages(root_swap, handle.bitmap);
        release_swap_writer(&handle);
+ out:
+       swsusp_close();
        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->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;
-       }
-
-       atomic_set(&io_done, 1);
-       submit_bio(rw | (1 << BIO_RW_SYNC), bio);
-       while (atomic_read(&io_done))
-               yield();
-       if (rw == READ)
-               bio_set_pages_dirty(bio);
- 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
@@ -381,17 +447,18 @@ static void release_swap_reader(struct swap_map_handle *handle)
        handle->cur = NULL;
 }
 
-static int get_swap_reader(struct swap_map_handle *handle,
-                                      swp_entry_t start)
+static int get_swap_reader(struct swap_map_handle *handle, sector_t start)
 {
        int error;
 
-       if (!swp_offset(start))
+       if (!start)
                return -EINVAL;
-       handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC);
+
+       handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH);
        if (!handle->cur)
                return -ENOMEM;
-       error = bio_read_page(swp_offset(start), handle->cur);
+
+       error = bio_read_page(start, handle->cur, NULL);
        if (error) {
                release_swap_reader(handle);
                return error;
@@ -400,9 +467,10 @@ static int get_swap_reader(struct swap_map_handle *handle,
        return 0;
 }
 
-static int swap_read_page(struct swap_map_handle *handle, void *buf)
+static int swap_read_page(struct swap_map_handle *handle, void *buf,
+                               struct bio **bio_chain)
 {
-       unsigned long offset;
+       sector_t offset;
        int error;
 
        if (!handle->cur)
@@ -410,16 +478,17 @@ static int swap_read_page(struct swap_map_handle *handle, void *buf)
        offset = handle->cur->entries[handle->k];
        if (!offset)
                return -EFAULT;
-       error = bio_read_page(offset, buf);
+       error = bio_read_page(offset, buf, bio_chain);
        if (error)
                return error;
        if (++handle->k >= MAP_PAGE_ENTRIES) {
+               error = wait_on_bio_chain(bio_chain);
                handle->k = 0;
                offset = handle->cur->next_swap;
                if (!offset)
                        release_swap_reader(handle);
-               else
-                       error = bio_read_page(offset, handle->cur);
+               else if (!error)
+                       error = bio_read_page(offset, handle->cur, NULL);
        }
        return error;
 }
@@ -432,33 +501,49 @@ static int swap_read_page(struct swap_map_handle *handle, void *buf)
 
 static int load_image(struct swap_map_handle *handle,
                       struct snapshot_handle *snapshot,
-                      unsigned int nr_pages)
+                      unsigned int nr_to_read)
 {
        unsigned int m;
-       int ret;
        int error = 0;
+       struct timeval start;
+       struct timeval stop;
+       struct bio *bio;
+       int err2;
+       unsigned nr_pages;
 
-       printk("Loading image data pages (%u pages) ...     ", nr_pages);
-       m = nr_pages / 100;
+       printk("Loading image data pages (%u pages) ...     ", nr_to_read);
+       m = nr_to_read / 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);
+       bio = NULL;
+       do_gettimeofday(&start);
+       for ( ; ; ) {
+               error = snapshot_write_next(snapshot, PAGE_SIZE);
+               if (error <= 0)
+                       break;
+               error = swap_read_page(handle, data_of(*snapshot), &bio);
+               if (error)
+                       break;
+               if (snapshot->sync_read)
+                       error = wait_on_bio_chain(&bio);
+               if (error)
+                       break;
+               if (!(nr_pages % m))
+                       printk("\b\b\b\b%3d%%", nr_pages / m);
+               nr_pages++;
+       }
+       err2 = wait_on_bio_chain(&bio);
+       do_gettimeofday(&stop);
+       if (!error)
+               error = err2;
        if (!error) {
                printk("\b\b\b\bdone\n");
+               snapshot_write_finalize(snapshot);
                if (!snapshot_image_loaded(snapshot))
                        error = -ENODATA;
        }
+       swsusp_show_speed(&start, &stop, nr_to_read, "Read");
        return error;
 }
 
@@ -481,7 +566,7 @@ int swsusp_read(void)
        header = (struct swsusp_info *)data_of(snapshot);
        error = get_swap_reader(&handle, swsusp_header.image);
        if (!error)
-               error = swap_read_page(&handle, header);
+               error = swap_read_page(&handle, header, NULL);
        if (!error)
                error = load_image(&handle, &snapshot, header->pages - 1);
        release_swap_reader(&handle);
@@ -507,12 +592,16 @@ int swsusp_check(void)
        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)))
+               error = bio_read_page(swsusp_resume_block,
+                                       &swsusp_header, NULL);
+               if (error)
                        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);
+                       error = bio_write_page(swsusp_resume_block,
+                                               &swsusp_header, NULL);
                } else {
                        return -EINVAL;
                }