1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/md/dm-bio-record.h b/drivers/md/dm-bio-record.h
new file mode 100644
index 000000000000..d3ec217847d6
--- /dev/null
+++ b/drivers/md/dm-bio-record.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef DM_BIO_RECORD_H
+#define DM_BIO_RECORD_H
+
+#include <linux/bio.h>
+
+/*
+ * There are lots of mutable fields in the bio struct that get
+ * changed by the lower levels of the block layer.  Some targets,
+ * such as multipath, may wish to resubmit a bio on error.  The
+ * functions in this file help the target record and restore the
+ * original bio state.
+ */
+struct dm_bio_details {
+        sector_t bi_sector;
+        struct block_device *bi_bdev;
+        unsigned int bi_size;
+        unsigned short bi_idx;
+        unsigned long bi_flags;
+};
+
+static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
+{
+        bd->bi_sector = bio->bi_sector;
+        bd->bi_bdev = bio->bi_bdev;
+        bd->bi_size = bio->bi_size;
+        bd->bi_idx = bio->bi_idx;
+        bd->bi_flags = bio->bi_flags;
+}
+
+static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
+{
+        bio->bi_sector = bd->bi_sector;
+        bio->bi_bdev = bd->bi_bdev;
+        bio->bi_size = bd->bi_size;
+        bio->bi_idx = bd->bi_idx;
+        bio->bi_flags = bd->bi_flags;
+}
+
+#endif