btrfs: use bio fields for op and flags

The bio REQ_OP and bi_rw rq_flag_bits are now always setup, so there is
no need to pass around the rq_flag_bits bits too. btrfs users should
should access the bio insead.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 029bd79..cefedab 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -374,7 +374,7 @@
 		page = compressed_pages[pg_index];
 		page->mapping = inode->i_mapping;
 		if (bio->bi_iter.bi_size)
-			ret = io_tree->ops->merge_bio_hook(WRITE, page, 0,
+			ret = io_tree->ops->merge_bio_hook(page, 0,
 							   PAGE_SIZE,
 							   bio, 0);
 		else
@@ -402,7 +402,7 @@
 				BUG_ON(ret); /* -ENOMEM */
 			}
 
-			ret = btrfs_map_bio(root, WRITE, bio, 0, 1);
+			ret = btrfs_map_bio(root, bio, 0, 1);
 			BUG_ON(ret); /* -ENOMEM */
 
 			bio_put(bio);
@@ -433,7 +433,7 @@
 		BUG_ON(ret); /* -ENOMEM */
 	}
 
-	ret = btrfs_map_bio(root, WRITE, bio, 0, 1);
+	ret = btrfs_map_bio(root, bio, 0, 1);
 	BUG_ON(ret); /* -ENOMEM */
 
 	bio_put(bio);
@@ -659,7 +659,7 @@
 		page->index = em_start >> PAGE_SHIFT;
 
 		if (comp_bio->bi_iter.bi_size)
-			ret = tree->ops->merge_bio_hook(READ, page, 0,
+			ret = tree->ops->merge_bio_hook(page, 0,
 							PAGE_SIZE,
 							comp_bio, 0);
 		else
@@ -690,8 +690,7 @@
 			sums += DIV_ROUND_UP(comp_bio->bi_iter.bi_size,
 					     root->sectorsize);
 
-			ret = btrfs_map_bio(root, READ, comp_bio,
-					    mirror_num, 0);
+			ret = btrfs_map_bio(root, comp_bio, mirror_num, 0);
 			if (ret) {
 				bio->bi_error = ret;
 				bio_endio(comp_bio);
@@ -721,7 +720,7 @@
 		BUG_ON(ret); /* -ENOMEM */
 	}
 
-	ret = btrfs_map_bio(root, READ, comp_bio, mirror_num, 0);
+	ret = btrfs_map_bio(root, comp_bio, mirror_num, 0);
 	if (ret) {
 		bio->bi_error = ret;
 		bio_endio(comp_bio);