block: unify flags for struct bio and struct request

Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver.  There were two flags in the bio that were
missing in the requests:  BIO_RW_UNPLUG and BIO_RW_AHEAD.  Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 42e64e4..62ecb66 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -799,12 +799,12 @@
 	int i;
 	int chunk_sects = conf->chunk_mask + 1;
 	const int rw = bio_data_dir(bio);
-	const bool do_sync = bio_rw_flagged(bio, BIO_RW_SYNCIO);
+	const bool do_sync = (bio->bi_rw & REQ_SYNC);
 	struct bio_list bl;
 	unsigned long flags;
 	mdk_rdev_t *blocked_rdev;
 
-	if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) {
+	if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) {
 		md_barrier_request(mddev, bio);
 		return 0;
 	}
@@ -879,7 +879,7 @@
 			mirror->rdev->data_offset;
 		read_bio->bi_bdev = mirror->rdev->bdev;
 		read_bio->bi_end_io = raid10_end_read_request;
-		read_bio->bi_rw = READ | (do_sync << BIO_RW_SYNCIO);
+		read_bio->bi_rw = READ | do_sync;
 		read_bio->bi_private = r10_bio;
 
 		generic_make_request(read_bio);
@@ -947,7 +947,7 @@
 			conf->mirrors[d].rdev->data_offset;
 		mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
 		mbio->bi_end_io	= raid10_end_write_request;
-		mbio->bi_rw = WRITE | (do_sync << BIO_RW_SYNCIO);
+		mbio->bi_rw = WRITE | do_sync;
 		mbio->bi_private = r10_bio;
 
 		atomic_inc(&r10_bio->remaining);
@@ -1716,7 +1716,7 @@
 				raid_end_bio_io(r10_bio);
 				bio_put(bio);
 			} else {
-				const bool do_sync = bio_rw_flagged(r10_bio->master_bio, BIO_RW_SYNCIO);
+				const bool do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC);
 				bio_put(bio);
 				rdev = conf->mirrors[mirror].rdev;
 				if (printk_ratelimit())
@@ -1730,7 +1730,7 @@
 				bio->bi_sector = r10_bio->devs[r10_bio->read_slot].addr
 					+ rdev->data_offset;
 				bio->bi_bdev = rdev->bdev;
-				bio->bi_rw = READ | (do_sync << BIO_RW_SYNCIO);
+				bio->bi_rw = READ | do_sync;
 				bio->bi_private = r10_bio;
 				bio->bi_end_io = raid10_end_read_request;
 				unplug = 1;