[GFS2] Remove unused zero_readpage from stuffed_readpage

Stuffed files only consist of a maximum of
(gfs2 block size - sizeof(struct gfs2_dinode)) bytes. Since the
gfs2 block size is always less than page size, we will never see
a call to stuffed_readpage for anything other than the first page
in the file.
Signed-off-by: NRussell Cattelan <cattelan@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

fs/gfs2/ops_address.c

@@ -156,19 +156,6 @@ static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
 	return 0;
 }
 
-static int zero_readpage(struct page *page)
-{
-	void *kaddr;
-
-	kaddr = kmap_atomic(page, KM_USER0);
-	memset(kaddr, 0, PAGE_CACHE_SIZE);
-	kunmap_atomic(kaddr, KM_USER0);
-
-	SetPageUptodate(page);
-
-	return 0;
-}
-
 /**
  * stuffed_readpage - Fill in a Linux page with stuffed file data
  * @ip: the inode
@@ -183,9 +170,7 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 	void *kaddr;
 	int error;
 
-	/* Only the first page of a stuffed file might contain data */
-	if (unlikely(page->index))
-		return zero_readpage(page);
+	BUG_ON(page->index);
 
 	error = gfs2_meta_inode_buffer(ip, &dibh);
 	if (error)
@@ -737,6 +722,9 @@ int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
 			if (!atomic_read(&aspace->i_writecount))
 				return 0;
 
+			if (!(gfp_mask & __GFP_WAIT))
+				return 0;
+
 			if (time_after_eq(jiffies, t)) {
 				stuck_releasepage(bh);
 				/* should we withdraw here? */