btrfs: merge REQ_OP and REQ_ flags to one parameter in submit_extent_page

The function submit_extent_page has 15(!) parameters right now, op and
op_flags are effectively one value stored to bio::bi_opf, no need to
pass them separately. So it's 14 parameters now.
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/extent_io.c

@@ -2756,8 +2756,10 @@ static int merge_bio(struct extent_io_tree *tree, struct page *page,
 
 }
 
-static int submit_extent_page(unsigned int op, unsigned int op_flags,
-			      struct extent_io_tree *tree,
+/*
+ * @opf:	bio REQ_OP_* and REQ_* flags as one value
+ */
+static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
 			      struct writeback_control *wbc,
 			      struct page *page, sector_t sector,
 			      size_t size, unsigned long offset,
@@ -2804,7 +2806,7 @@ static int submit_extent_page(unsigned int op, unsigned int op_flags,
 	bio->bi_end_io = end_io_func;
 	bio->bi_private = tree;
 	bio->bi_write_hint = page->mapping->host->i_write_hint;
-	bio_set_op_attrs(bio, op, op_flags);
+	bio->bi_opf = opf;
 	if (wbc) {
 		wbc_init_bio(wbc, bio);
 		wbc_account_io(wbc, page, page_size);
@@ -3059,7 +3061,7 @@ static int __do_readpage(struct extent_io_tree *tree,
 			continue;
 		}
 
-		ret = submit_extent_page(REQ_OP_READ, read_flags, tree, NULL,
+		ret = submit_extent_page(REQ_OP_READ | read_flags, tree, NULL,
 					 page, sector, disk_io_size, pg_offset,
 					 bdev, bio,
 					 end_bio_extent_readpage, mirror_num,
@@ -3428,7 +3430,7 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
 			       page->index, cur, end);
 		}
 
-		ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
+		ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
 					 page, sector, iosize, pg_offset,
 					 bdev, &epd->bio,
 					 end_bio_extent_writepage,
@@ -3746,7 +3748,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
 
 		clear_page_dirty_for_io(p);
 		set_page_writeback(p);
-		ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
+		ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
 					 p, offset >> 9, PAGE_SIZE, 0, bdev,
 					 &epd->bio,
 					 end_bio_extent_buffer_writepage,