Initialisation and clean up routines for reading the image header.
Signed-off-by: Nigel Cunningham <[email protected]>
kernel/power/suspend_swap.c | 116 +++++++++++++++++++++++++++++++++++++++++++
1 files changed, 116 insertions(+), 0 deletions(-)
diff --git a/kernel/power/suspend_swap.c b/kernel/power/suspend_swap.c
index b005f8b..9d806a5 100644
--- a/kernel/power/suspend_swap.c
+++ b/kernel/power/suspend_swap.c
@@ -634,3 +634,119 @@ static int swapwriter_write_header_clean
return result;
}
+/* ------------------------- HEADER READING ------------------------- */
+
+/*
+ * read_header_init()
+ *
+ * Description:
+ * 1. Attempt to read the device specified with resume2=.
+ * 2. Check the contents of the swap header for our signature.
+ * 3. Warn, ignore, reset and/or continue as appropriate.
+ * 4. If continuing, read the swapwriter configuration section
+ * of the header and set up block device info so we can read
+ * the rest of the header & image.
+ *
+ * Returns:
+ * May not return if user choose to reboot at a warning.
+ * -EINVAL if cannot resume at this time. Booting should continue
+ * normally.
+ */
+
+static int swapwriter_read_header_init(void)
+{
+ int i;
+
+ BUG_ON(!resume_block_device);
+ BUG_ON(!resume_dev_t);
+
+ suspend_header_bytes_used = 0;
+
+ suspend_writer_buffer = (char *) get_zeroed_page(GFP_ATOMIC);
+
+ BUG_ON(!suspend_writer_buffer);
+
+ if (!header_dev_t) {
+ printk("read_header_init called when we haven't "
+ "verified there is an image!\n");
+ return -EINVAL;
+ }
+
+ /*
+ * If the header is not on the resume_dev_t, get the resume device first.
+ */
+ if (header_dev_t != resume_dev_t) {
+ header_block_device = open_bdev(MAX_SWAPFILES + 1,
+ header_dev_t);
+
+ if (IS_ERR(header_block_device))
+ return PTR_ERR(header_block_device);
+ } else
+ header_block_device = resume_block_device;
+
+ /*
+ * Read swapwriter configuration.
+ * Headerblock size taken into account already.
+ */
+ suspend_bio_ops.bdev_page_io(READ, header_block_device,
+ headerblock << 3,
+ virt_to_page((unsigned long) suspend_writer_buffer));
+
+ memcpy(&suspend_writer_posn_save, suspend_writer_buffer, 3 * sizeof(struct extent_iterate_saved_state));
+
+ suspend_writer_buffer_posn = 3 * sizeof(struct extent_iterate_saved_state);
+ suspend_header_bytes_used += 3 * sizeof(struct extent_iterate_saved_state);
+
+ memcpy(&devinfo, suspend_writer_buffer + suspend_writer_buffer_posn, sizeof(devinfo));
+
+ suspend_writer_buffer_posn += sizeof(devinfo);
+ suspend_header_bytes_used += sizeof(devinfo);
+
+ /* Restore device info */
+ for (i = 0; i < MAX_SWAPFILES; i++) {
+ dev_t thisdevice = devinfo[i].dev_t;
+ struct block_device *result;
+
+ devinfo[i].bdev = NULL;
+
+ if (!thisdevice)
+ continue;
+
+ if (thisdevice == resume_dev_t) {
+ devinfo[i].bdev = resume_block_device;
+ bdev_info_list[i] = bdev_info_list[MAX_SWAPFILES];
+ BUG_ON(!bdev_info_list[i]);
+ bdev_info_list[MAX_SWAPFILES] = NULL;
+ continue;
+ }
+
+ if (thisdevice == header_dev_t) {
+ devinfo[i].bdev = header_block_device;
+ bdev_info_list[i] = bdev_info_list[MAX_SWAPFILES + 1];
+ BUG_ON(!bdev_info_list[i]);
+ bdev_info_list[MAX_SWAPFILES + 1] = NULL;
+ continue;
+ }
+
+ result = open_bdev(i, thisdevice);
+ if (IS_ERR(result)) {
+ close_bdevs();
+ return PTR_ERR(result);
+ }
+ }
+
+ suspend_extent_state_goto_start(&suspend_writer_posn);
+ suspend_bio_ops.set_extra_page_forward();
+
+ for (i = 0; i < MAX_SWAPFILES; i++)
+ suspend_load_extent_chain(&block_chain[i]);
+
+ return 0;
+}
+
+static int swapwriter_read_header_cleanup(void)
+{
+ free_page((unsigned long) suspend_writer_buffer);
+ return 0;
+}
+
--
Nigel Cunningham nigel at suspend2 dot net
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