ocfs2: Fix some casting errors related to file writes

ocfs2_align_clusters_to_page_index() needs to cast the clusters shift to
pgoff_t and ocfs2_file_buffered_write() needs loff_t when calculating
destination start for memcpy.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/ocfs2/file.c

@@ -1959,7 +1959,7 @@ static ssize_t ocfs2_file_buffered_write(struct file *file, loff_t *ppos,
 		}
 
 		dst = kmap_atomic(page, KM_USER0);
-		memcpy(dst + (pos & (PAGE_CACHE_SIZE - 1)), buf, bytes);
+		memcpy(dst + (pos & (loff_t)(PAGE_CACHE_SIZE - 1)), buf, bytes);
 		kunmap_atomic(dst, KM_USER0);
 		flush_dcache_page(page);
 		ocfs2_put_write_source(user_page);

fs/ocfs2/ocfs2.h

@@ -494,16 +494,16 @@ static inline unsigned int ocfs2_page_index_to_clusters(struct super_block *sb,
 /*
  * Find the 1st page index which covers the given clusters.
  */
-static inline unsigned long ocfs2_align_clusters_to_page_index(struct super_block *sb,
+static inline pgoff_t ocfs2_align_clusters_to_page_index(struct super_block *sb,
 							u32 clusters)
 {
 	unsigned int cbits = OCFS2_SB(sb)->s_clustersize_bits;
-	unsigned long index = clusters;
+        pgoff_t index = clusters;
 
 	if (PAGE_CACHE_SHIFT > cbits) {
-		index = clusters >> (PAGE_CACHE_SHIFT - cbits);
+		index = (pgoff_t)clusters >> (PAGE_CACHE_SHIFT - cbits);
 	} else if (PAGE_CACHE_SHIFT < cbits) {
-		index = clusters << (cbits - PAGE_CACHE_SHIFT);
+		index = (pgoff_t)clusters << (cbits - PAGE_CACHE_SHIFT);
 	}
 
 	return index;