new helper: ihold()

Clones an existing reference to inode; caller must already hold one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/aio.c b/fs/aio.c
index 9e319a0..8c8f6c5 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1553,10 +1553,9 @@
 	 *
 	 * When we're called, we always have a reference
 	 * on the file, so we must always have a reference
-	 * on the inode, so igrab must always just
-	 * bump the count and move on.
+	 * on the inode, so ihold() is safe here.
 	 */
-	atomic_inc(&mapping->host->i_count);
+	ihold(mapping->host);
 	abe->mapping = mapping;
 	hlist_add_head(&abe->list, &batch_hash[bucket]);
 	return;