+/* Check if a block is allocated or not */
+static int osd_is_mapped(struct inode *inode, obd_size offset)
+{
+ sector_t (*fs_bmap)(struct address_space *, sector_t);
+
+ fs_bmap = inode->i_mapping->a_ops->bmap;
+
+ /* We can't know if we are overwriting or not */
+ if (unlikely(fs_bmap == NULL))
+ return 0;
+
+ if (i_size_read(inode) == 0)
+ return 0;
+
+ /* Beyond EOF, must not be mapped */
+ if (((i_size_read(inode) - 1) >> inode->i_blkbits) <
+ (offset >> inode->i_blkbits))
+ return 0;
+
+ if (fs_bmap(inode->i_mapping, offset >> inode->i_blkbits) == 0)
+ return 0;
+
+ return 1;
+}
+