PM / Hibernate: Separate block_io
Move block I/O operations to a separate file. It is because it will
be used later not only by the swap writer.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/kernel/power/block_io.c b/kernel/power/block_io.c
new file mode 100644
index 0000000..2a2f8ae
--- /dev/null
+++ b/kernel/power/block_io.c
@@ -0,0 +1,103 @@
+/*
+ * This file provides functions for block I/O operations on swap/file.
+ *
+ * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
+ * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/bio.h>
+#include <linux/kernel.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+
+#include "power.h"
+
+/**
+ * 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, struct block_device *bdev, sector_t sector,
+ 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);
+ bio->bi_sector = sector;
+ bio->bi_bdev = bdev;
+ bio->bi_end_io = end_swap_bio_read;
+
+ if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
+ printk(KERN_ERR "PM: Adding page to bio failed at %ld\n",
+ sector);
+ bio_put(bio);
+ return -EFAULT;
+ }
+
+ lock_page(page);
+ bio_get(bio);
+
+ if (bio_chain == NULL) {
+ submit_bio(bio_rw, 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(bio_rw, bio);
+ }
+ return 0;
+}
+
+int hib_bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
+{
+ return submit(READ, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
+ virt_to_page(addr), bio_chain);
+}
+
+int hib_bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain)
+{
+ return submit(WRITE, hib_resume_bdev, page_off * (PAGE_SIZE >> 9),
+ virt_to_page(addr), bio_chain);
+}
+
+int hib_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;
+}