PM / Hibernate: Group swap ops

Move all the swap processing into one function. It will make swap
calls from a non-swap code easier.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 63e8062..b0bb217 100644 (file)
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -208,9 +208,10 @@ static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 /**
  *     swsusp_swap_check - check if the resume device is a swap device
  *     and get its index (if so)
+ *
+ *     This is called before saving image
  */
-
-static int swsusp_swap_check(void) /* This is called before saving image */
+static int swsusp_swap_check(void)
 {
        int res;
 
@@ -269,17 +270,33 @@ static void release_swap_writer(struct swap_map_handle *handle)
 
 static int get_swap_writer(struct swap_map_handle *handle)
 {
+       int ret;
+
+       ret = swsusp_swap_check();
+       if (ret) {
+               if (ret != -ENOSPC)
+                       printk(KERN_ERR "PM: Cannot find swap device, try "
+                                       "swapon -a.\n");
+               return ret;
+       }
        handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
-       if (!handle->cur)
-               return -ENOMEM;
+       if (!handle->cur) {
+               ret = -ENOMEM;
+               goto err_close;
+       }
        handle->cur_swap = alloc_swapdev_block(root_swap);
        if (!handle->cur_swap) {
-               release_swap_writer(handle);
-               return -ENOSPC;
+               ret = -ENOSPC;
+               goto err_rel;
        }
        handle->k = 0;
        handle->first_sector = handle->cur_swap;
        return 0;
+err_rel:
+       release_swap_writer(handle);
+err_close:
+       swsusp_close(FMODE_WRITE);
+       return ret;
 }
 
 static int swap_write_page(struct swap_map_handle *handle, void *buf,
@@ -322,6 +339,24 @@ static int flush_swap_writer(struct swap_map_handle *handle)
                return -EINVAL;
 }
 
+static int swap_writer_finish(struct swap_map_handle *handle,
+               unsigned int flags, int error)
+{
+       if (!error) {
+               flush_swap_writer(handle);
+               printk(KERN_INFO "PM: S");
+               error = mark_swapfiles(handle, flags);
+               printk("|\n");
+       }
+
+       if (error)
+               free_all_swap_pages(root_swap);
+       release_swap_writer(handle);
+       swsusp_close(FMODE_WRITE);
+
+       return error;
+}
+
 /**
  *     save_image - save the suspend image data
  */
@@ -399,48 +434,34 @@ int swsusp_write(unsigned int flags)
        struct swap_map_handle handle;
        struct snapshot_handle snapshot;
        struct swsusp_info *header;
+       unsigned long pages;
        int error;
 
-       error = swsusp_swap_check();
+       pages = snapshot_get_image_size();
+       error = get_swap_writer(&handle);
        if (error) {
-               printk(KERN_ERR "PM: Cannot find swap device, try "
-                               "swapon -a.\n");
+               printk(KERN_ERR "PM: Cannot get swap writer\n");
                return error;
        }
+       if (!enough_swap(pages)) {
+               printk(KERN_ERR "PM: Not enough free swap\n");
+               error = -ENOSPC;
+               goto out_finish;
+       }
        memset(&snapshot, 0, sizeof(struct snapshot_handle));
        error = snapshot_read_next(&snapshot);
        if (error < PAGE_SIZE) {
                if (error >= 0)
                        error = -EFAULT;
 
-               goto out;
+               goto out_finish;
        }
        header = (struct swsusp_info *)data_of(snapshot);
-       if (!enough_swap(header->pages)) {
-               printk(KERN_ERR "PM: Not enough free swap\n");
-               error = -ENOSPC;
-               goto out;
-       }
-       error = get_swap_writer(&handle);
-       if (!error) {
-               error = swap_write_page(&handle, header, NULL);
-               if (!error)
-                       error = save_image(&handle, &snapshot,
-                                       header->pages - 1);
-
-               if (!error) {
-                       flush_swap_writer(&handle);
-                       printk(KERN_INFO "PM: S");
-                       error = mark_swapfiles(&handle, flags);
-                       printk("|\n");
-               }
-       }
-       if (error)
-               free_all_swap_pages(root_swap);
-
-       release_swap_writer(&handle);
- out:
-       swsusp_close(FMODE_WRITE);
+       error = swap_write_page(&handle, header, NULL);
+       if (!error)
+               error = save_image(&handle, &snapshot, pages - 1);
+out_finish:
+       error = swap_writer_finish(&handle, flags, error);
        return error;
 }
 
@@ -456,18 +477,21 @@ static void release_swap_reader(struct swap_map_handle *handle)
        handle->cur = NULL;
 }
 
-static int get_swap_reader(struct swap_map_handle *handle, sector_t start)
+static int get_swap_reader(struct swap_map_handle *handle,
+               unsigned int *flags_p)
 {
        int error;
 
-       if (!start)
+       *flags_p = swsusp_header->flags;
+
+       if (!swsusp_header->image) /* how can this happen? */
                return -EINVAL;
 
        handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH);
        if (!handle->cur)
                return -ENOMEM;
 
-       error = hib_bio_read_page(start, handle->cur, NULL);
+       error = hib_bio_read_page(swsusp_header->image, handle->cur, NULL);
        if (error) {
                release_swap_reader(handle);
                return error;
@@ -502,6 +526,13 @@ static int swap_read_page(struct swap_map_handle *handle, void *buf,
        return error;
 }
 
+static int swap_reader_finish(struct swap_map_handle *handle)
+{
+       release_swap_reader(handle);
+
+       return 0;
+}
+
 /**
  *     load_image - load the image using the swap map handle
  *     @handle and the snapshot handle @snapshot
@@ -571,20 +602,20 @@ int swsusp_read(unsigned int *flags_p)
        struct snapshot_handle snapshot;
        struct swsusp_info *header;
 
-       *flags_p = swsusp_header->flags;
-
        memset(&snapshot, 0, sizeof(struct snapshot_handle));
        error = snapshot_write_next(&snapshot);
        if (error < PAGE_SIZE)
                return error < 0 ? error : -EFAULT;
        header = (struct swsusp_info *)data_of(snapshot);
-       error = get_swap_reader(&handle, swsusp_header->image);
+       error = get_swap_reader(&handle, flags_p);
+       if (error)
+               goto end;
        if (!error)
                error = swap_read_page(&handle, header, NULL);
        if (!error)
                error = load_image(&handle, &snapshot, header->pages - 1);
-       release_swap_reader(&handle);
-
+       swap_reader_finish(&handle);
+end:
        if (!error)
                pr_debug("PM: Image successfully loaded\n");
        else