+static int udf_extend_file(struct inode *inode, loff_t newsize)
+{
+
+ struct extent_position epos;
+ struct kernel_lb_addr eloc;
+ uint32_t elen;
+ int8_t etype;
+ struct super_block *sb = inode->i_sb;
+ sector_t first_block = newsize >> sb->s_blocksize_bits, offset;
+ int adsize;
+ struct udf_inode_info *iinfo = UDF_I(inode);
+ struct kernel_long_ad extent;
+ int err;
+
+ if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
+ adsize = sizeof(struct short_ad);
+ else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
+ adsize = sizeof(struct long_ad);
+ else
+ BUG();
+
+ etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
+
+ /* File has extent covering the new size (could happen when extending
+ * inside a block)? */
+ if (etype != -1)
+ return 0;
+ if (newsize & (sb->s_blocksize - 1))
+ offset++;
+ /* Extended file just to the boundary of the last file block? */
+ if (offset == 0)
+ return 0;
+
+ /* Truncate is extending the file by 'offset' blocks */
+ if ((!epos.bh && epos.offset == udf_file_entry_alloc_offset(inode)) ||
+ (epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
+ /* File has no extents at all or has empty last
+ * indirect extent! Create a fake extent... */
+ extent.extLocation.logicalBlockNum = 0;
+ extent.extLocation.partitionReferenceNum = 0;
+ extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
+ } else {
+ epos.offset -= adsize;
+ etype = udf_next_aext(inode, &epos, &extent.extLocation,
+ &extent.extLength, 0);
+ extent.extLength |= etype << 30;
+ }
+ err = udf_do_extend_file(inode, &epos, &extent, offset);
+ if (err < 0)
+ goto out;
+ err = 0;
+ iinfo->i_lenExtents = newsize;
+out:
+ brelse(epos.bh);
+ return err;
+}
+