rcu: improve RCU CPU stall-warning messages
[safe/jmp/linux-2.6] / kernel / power / swap.c
index 917aba1..66824d7 100644 (file)
@@ -13,8 +13,6 @@
 
 #include <linux/module.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/swap.h>
 #include <linux/swapops.h>
 #include <linux/pm.h>
+#include <linux/slab.h>
 
 #include "power.h"
 
-extern char resume_file[];
-
 #define SWSUSP_SIG     "S1SUSPEND"
 
 struct swsusp_header {
@@ -42,6 +39,107 @@ 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
  */
@@ -63,17 +161,17 @@ static struct block_device *resume_bdev;
 static int submit(int rw, pgoff_t page_off, struct page *page,
                        struct bio **bio_chain)
 {
+       const int bio_rw = rw | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
        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;
 
        if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
-               printk("swsusp: ERROR: adding page to bio at %ld\n", page_off);
+               printk(KERN_ERR "PM: Adding page to bio failed at %ld\n",
+                       page_off);
                bio_put(bio);
                return -EFAULT;
        }
@@ -82,7 +180,7 @@ static int submit(int rw, pgoff_t page_off, struct page *page,
        bio_get(bio);
 
        if (bio_chain == NULL) {
-               submit_bio(rw | (1 << BIO_RW_SYNC), bio);
+               submit_bio(bio_rw, bio);
                wait_on_page_locked(page);
                if (rw == READ)
                        bio_set_pages_dirty(bio);
@@ -92,7 +190,7 @@ static int submit(int rw, pgoff_t page_off, struct page *page,
                        get_page(page); /* These pages are freed later */
                bio->bi_private = *bio_chain;
                *bio_chain = bio;
-               submit_bio(rw | (1 << BIO_RW_SYNC), bio);
+               submit_bio(bio_rw, bio);
        }
        return 0;
 }
@@ -153,7 +251,7 @@ static int mark_swapfiles(sector_t start, unsigned int flags)
                error = bio_write_page(swsusp_resume_block,
                                        swsusp_header, NULL);
        } else {
-               printk(KERN_ERR "swsusp: Swap header not found!\n");
+               printk(KERN_ERR "PM: Swap header not found!\n");
                error = -ENODEV;
        }
        return error;
@@ -174,13 +272,13 @@ static int swsusp_swap_check(void) /* This is called before saving image */
                return res;
 
        root_swap = res;
-       res = blkdev_get(resume_bdev, FMODE_WRITE, O_RDWR);
+       res = blkdev_get(resume_bdev, FMODE_WRITE);
        if (res)
                return res;
 
        res = set_blocksize(resume_bdev, PAGE_SIZE);
        if (res < 0)
-               blkdev_put(resume_bdev);
+               blkdev_put(resume_bdev, FMODE_WRITE);
 
        return res;
 }
@@ -318,40 +416,41 @@ static int save_image(struct swap_map_handle *handle,
 {
        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_to_write);
+       printk(KERN_INFO "PM: 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 {
+       while (1) {
                ret = snapshot_read_next(snapshot, PAGE_SIZE);
-               if (ret > 0) {
-                       error = swap_write_page(handle, data_of(*snapshot),
-                                               &bio);
-                       if (error)
-                               break;
-                       if (!(nr_pages % m))
-                               printk("\b\b\b\b%3d%%", nr_pages / m);
-                       nr_pages++;
-               }
-       } while (ret > 0);
+               if (ret <= 0)
+                       break;
+               ret = swap_write_page(handle, data_of(*snapshot), &bio);
+               if (ret)
+                       break;
+               if (!(nr_pages % m))
+                       printk(KERN_CONT "\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");
+       if (!ret)
+               ret = err2;
+       if (!ret)
+               printk(KERN_CONT "\b\b\b\bdone\n");
+       else
+               printk(KERN_CONT "\n");
        swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
-       return error;
+       return ret;
 }
 
 /**
@@ -365,7 +464,7 @@ 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);
+       pr_debug("PM: Free swap pages: %u\n", free_swap);
        return free_swap > nr_pages + PAGES_FOR_IO;
 }
 
@@ -388,7 +487,7 @@ int swsusp_write(unsigned int flags)
 
        error = swsusp_swap_check();
        if (error) {
-               printk(KERN_ERR "swsusp: Cannot find swap device, try "
+               printk(KERN_ERR "PM: Cannot find swap device, try "
                                "swapon -a.\n");
                return error;
        }
@@ -402,7 +501,7 @@ int swsusp_write(unsigned int flags)
        }
        header = (struct swsusp_info *)data_of(snapshot);
        if (!enough_swap(header->pages)) {
-               printk(KERN_ERR "swsusp: Not enough free swap\n");
+               printk(KERN_ERR "PM: Not enough free swap\n");
                error = -ENOSPC;
                goto out;
        }
@@ -417,7 +516,7 @@ int swsusp_write(unsigned int flags)
 
                if (!error) {
                        flush_swap_writer(&handle);
-                       printk("S");
+                       printk(KERN_INFO "PM: S");
                        error = mark_swapfiles(start, flags);
                        printk("|\n");
                }
@@ -427,7 +526,7 @@ int swsusp_write(unsigned int flags)
 
        release_swap_writer(&handle);
  out:
-       swsusp_close();
+       swsusp_close(FMODE_WRITE);
        return error;
 }
 
@@ -507,7 +606,8 @@ static int load_image(struct swap_map_handle *handle,
        int err2;
        unsigned nr_pages;
 
-       printk("Loading image data pages (%u pages) ...     ", nr_to_read);
+       printk(KERN_INFO "PM: Loading image data pages (%u pages) ...     ",
+               nr_to_read);
        m = nr_to_read / 100;
        if (!m)
                m = 1;
@@ -538,7 +638,8 @@ static int load_image(struct swap_map_handle *handle,
                snapshot_write_finalize(snapshot);
                if (!snapshot_image_loaded(snapshot))
                        error = -ENODATA;
-       }
+       } else
+               printk("\n");
        swsusp_show_speed(&start, &stop, nr_to_read, "Read");
        return error;
 }
@@ -557,10 +658,6 @@ int swsusp_read(unsigned int *flags_p)
        struct swsusp_info *header;
 
        *flags_p = swsusp_header->flags;
-       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);
@@ -574,12 +671,10 @@ int swsusp_read(unsigned int *flags_p)
                error = load_image(&handle, &snapshot, header->pages - 1);
        release_swap_reader(&handle);
 
-       blkdev_put(resume_bdev);
-
        if (!error)
-               pr_debug("swsusp: Reading resume file was successful\n");
+               pr_debug("PM: Image successfully loaded\n");
        else
-               pr_debug("swsusp: Error %d resuming\n", error);
+               pr_debug("PM: Error %d resuming\n", error);
        return error;
 }
 
@@ -598,7 +693,7 @@ int swsusp_check(void)
                error = bio_read_page(swsusp_resume_block,
                                        swsusp_header, NULL);
                if (error)
-                       return error;
+                       goto put;
 
                if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) {
                        memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
@@ -606,18 +701,20 @@ int swsusp_check(void)
                        error = bio_write_page(swsusp_resume_block,
                                                swsusp_header, NULL);
                } else {
-                       return -EINVAL;
+                       error = -EINVAL;
                }
+
+put:
                if (error)
-                       blkdev_put(resume_bdev);
+                       blkdev_put(resume_bdev, FMODE_READ);
                else
-                       pr_debug("swsusp: Signature found, resuming\n");
+                       pr_debug("PM: Signature found, resuming\n");
        } else {
                error = PTR_ERR(resume_bdev);
        }
 
        if (error)
-               pr_debug("swsusp: Error %d check for resume file\n", error);
+               pr_debug("PM: Error %d checking image file\n", error);
 
        return error;
 }
@@ -626,14 +723,14 @@ int swsusp_check(void)
  *     swsusp_close - close swap device.
  */
 
-void swsusp_close(void)
+void swsusp_close(fmode_t mode)
 {
        if (IS_ERR(resume_bdev)) {
-               pr_debug("swsusp: block device not initialised\n");
+               pr_debug("PM: Image device not initialised\n");
                return;
        }
 
-       blkdev_put(resume_bdev);
+       blkdev_put(resume_bdev, mode);
 }
 
 static int swsusp_header_init(void)