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-rw-r--r--kernel/drivers/md/dm-bio-record.h40
1 files changed, 40 insertions, 0 deletions
diff --git a/kernel/drivers/md/dm-bio-record.h b/kernel/drivers/md/dm-bio-record.h
new file mode 100644
index 000000000..dd3646111
--- /dev/null
+++ b/kernel/drivers/md/dm-bio-record.h
@@ -0,0 +1,40 @@
+/*
+ * 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 {
+ struct block_device *bi_bdev;
+ unsigned long bi_flags;
+ struct bvec_iter bi_iter;
+};
+
+static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
+{
+ bd->bi_bdev = bio->bi_bdev;
+ bd->bi_flags = bio->bi_flags;
+ bd->bi_iter = bio->bi_iter;
+}
+
+static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
+{
+ bio->bi_bdev = bd->bi_bdev;
+ bio->bi_flags = bd->bi_flags;
+ bio->bi_iter = bd->bi_iter;
+}
+
+#endif