udf: Convert empty_dir() to new directory iteration code

Convert empty_dir() to new directory iteration code.
Signed-off-by: Jan Kara <jack@suse.cz>

fs/udf/namei.c

@@ -869,69 +869,19 @@ static int udf_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 
 static int empty_dir(struct inode *dir)
 {
-	struct fileIdentDesc *fi, cfi;
-	struct udf_fileident_bh fibh;
-	loff_t f_pos;
-	loff_t size = udf_ext0_offset(dir) + dir->i_size;
-	udf_pblk_t block;
-	struct kernel_lb_addr eloc;
-	uint32_t elen;
-	sector_t offset;
-	struct extent_position epos = {};
-	struct udf_inode_info *dinfo = UDF_I(dir);
-
-	f_pos = udf_ext0_offset(dir);
-	fibh.soffset = fibh.eoffset = f_pos & (dir->i_sb->s_blocksize - 1);
-
-	if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)
-		fibh.sbh = fibh.ebh = NULL;
-	else if (inode_bmap(dir, f_pos >> dir->i_sb->s_blocksize_bits,
-			      &epos, &eloc, &elen, &offset) ==
-					(EXT_RECORDED_ALLOCATED >> 30)) {
-		block = udf_get_lb_pblock(dir->i_sb, &eloc, offset);
-		if ((++offset << dir->i_sb->s_blocksize_bits) < elen) {
-			if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
-				epos.offset -= sizeof(struct short_ad);
-			else if (dinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
-				epos.offset -= sizeof(struct long_ad);
-		} else
-			offset = 0;
-
-		fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block);
-		if (!fibh.sbh) {
-			brelse(epos.bh);
-			return 0;
-		}
-	} else {
-		brelse(epos.bh);
-		return 0;
-	}
-
-	while (f_pos < size) {
-		fi = udf_fileident_read(dir, &f_pos, &fibh, &cfi, &epos, &eloc,
-					&elen, &offset);
-		if (!fi) {
-			if (fibh.sbh != fibh.ebh)
-				brelse(fibh.ebh);
-			brelse(fibh.sbh);
-			brelse(epos.bh);
-			return 0;
-		}
+	struct udf_fileident_iter iter;
+	int ret;
 
-		if (cfi.lengthFileIdent &&
-		    (cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) == 0) {
-			if (fibh.sbh != fibh.ebh)
-				brelse(fibh.ebh);
-			brelse(fibh.sbh);
-			brelse(epos.bh);
+	for (ret = udf_fiiter_init(&iter, dir, 0);
+	     !ret && iter.pos < dir->i_size;
+	     ret = udf_fiiter_advance(&iter)) {
+		if (iter.fi.lengthFileIdent &&
+		    !(iter.fi.fileCharacteristics & FID_FILE_CHAR_DELETED)) {
+			udf_fiiter_release(&iter);
 			return 0;
 		}
 	}
-
-	if (fibh.sbh != fibh.ebh)
-		brelse(fibh.ebh);
-	brelse(fibh.sbh);
-	brelse(epos.bh);
+	udf_fiiter_release(&iter);
 
 	return 1;
 }