udf: refactor udf_next_aext() to handle error

Since udf_current_aext() has error handling, udf_next_aext() should have
error handling too. Besides, when too many indirect extents found in one
inode, return -EFSCORRUPTED; when reading block failed, return -EIO.

Signed-off-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20241001115425.266556-3-zhaomzhao@126.com

fs/udf/balloc.c

@@ -370,6 +370,7 @@ static void udf_table_free_blocks(struct super_block *sb,
 	struct extent_position oepos, epos;
 	int8_t etype;
 	struct udf_inode_info *iinfo;
+	int ret = 0;
 
 	mutex_lock(&sbi->s_alloc_mutex);
 	iinfo = UDF_I(table);
@@ -383,8 +384,12 @@ static void udf_table_free_blocks(struct super_block *sb,
 	epos.block = oepos.block = iinfo->i_location;
 	epos.bh = oepos.bh = NULL;
 
-	while (count &&
-	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
+	while (count) {
+		ret = udf_next_aext(table, &epos, &eloc, &elen, &etype, 1);
+		if (ret < 0)
+			goto error_return;
+		if (ret == 0)
+			break;
 		if (((eloc.logicalBlockNum +
 			(elen >> sb->s_blocksize_bits)) == start)) {
 			if ((0x3FFFFFFF - elen) <
@@ -459,11 +464,8 @@ static void udf_table_free_blocks(struct super_block *sb,
 			adsize = sizeof(struct short_ad);
 		else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 			adsize = sizeof(struct long_ad);
-		else {
-			brelse(oepos.bh);
-			brelse(epos.bh);
+		else
 			goto error_return;
-		}
 
 		if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 			/* Steal a block from the extent being free'd */
@@ -479,10 +481,10 @@ static void udf_table_free_blocks(struct super_block *sb,
 			__udf_add_aext(table, &epos, &eloc, elen, 1);
 	}
 
+error_return:
 	brelse(epos.bh);
 	brelse(oepos.bh);
 
-error_return:
 	mutex_unlock(&sbi->s_alloc_mutex);
 	return;
 }
@@ -498,6 +500,7 @@ static int udf_table_prealloc_blocks(struct super_block *sb,
 	struct extent_position epos;
 	int8_t etype = -1;
 	struct udf_inode_info *iinfo;
+	int ret = 0;
 
 	if (first_block >= sbi->s_partmaps[partition].s_partition_len)
 		return 0;
@@ -516,11 +519,14 @@ static int udf_table_prealloc_blocks(struct super_block *sb,
 	epos.bh = NULL;
 	eloc.logicalBlockNum = 0xFFFFFFFF;
 
-	while (first_block != eloc.logicalBlockNum &&
-	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
+	while (first_block != eloc.logicalBlockNum) {
+		ret = udf_next_aext(table, &epos, &eloc, &elen, &etype, 1);
+		if (ret < 0)
+			goto err_out;
+		if (ret == 0)
+			break;
 		udf_debug("eloc=%u, elen=%u, first_block=%u\n",
 			  eloc.logicalBlockNum, elen, first_block);
-		; /* empty loop body */
 	}
 
 	if (first_block == eloc.logicalBlockNum) {
@@ -539,6 +545,7 @@ static int udf_table_prealloc_blocks(struct super_block *sb,
 		alloc_count = 0;
 	}
 
+err_out:
 	brelse(epos.bh);
 
 	if (alloc_count)
@@ -560,6 +567,7 @@ static udf_pblk_t udf_table_new_block(struct super_block *sb,
 	struct extent_position epos, goal_epos;
 	int8_t etype;
 	struct udf_inode_info *iinfo = UDF_I(table);
+	int ret = 0;
 
 	*err = -ENOSPC;
 
@@ -583,8 +591,10 @@ static udf_pblk_t udf_table_new_block(struct super_block *sb,
 	epos.block = iinfo->i_location;
 	epos.bh = goal_epos.bh = NULL;
 
-	while (spread &&
-	       (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
+	while (spread) {
+		ret = udf_next_aext(table, &epos, &eloc, &elen, &etype, 1);
+		if (ret <= 0)
+			break;
 		if (goal >= eloc.logicalBlockNum) {
 			if (goal < eloc.logicalBlockNum +
 					(elen >> sb->s_blocksize_bits))
@@ -612,9 +622,11 @@ static udf_pblk_t udf_table_new_block(struct super_block *sb,
 
 	brelse(epos.bh);
 
-	if (spread == 0xFFFFFFFF) {
+	if (ret < 0 || spread == 0xFFFFFFFF) {
 		brelse(goal_epos.bh);
 		mutex_unlock(&sbi->s_alloc_mutex);
+		if (ret < 0)
+			*err = ret;
 		return 0;
 	}
 

fs/udf/directory.c

@@ -166,13 +166,19 @@ static struct buffer_head *udf_fiiter_bread_blk(struct udf_fileident_iter *iter)
  */
 static int udf_fiiter_advance_blk(struct udf_fileident_iter *iter)
 {
+	int8_t etype = -1;
+	int err = 0;
+
 	iter->loffset++;
 	if (iter->loffset < DIV_ROUND_UP(iter->elen, 1<<iter->dir->i_blkbits))
 		return 0;
 
 	iter->loffset = 0;
-	if (udf_next_aext(iter->dir, &iter->epos, &iter->eloc, &iter->elen, 1)
-			!= (EXT_RECORDED_ALLOCATED >> 30)) {
+	err = udf_next_aext(iter->dir, &iter->epos, &iter->eloc,
+			    &iter->elen, &etype, 1);
+	if (err < 0)
+		return err;
+	else if (err == 0 || etype != (EXT_RECORDED_ALLOCATED >> 30)) {
 		if (iter->pos == iter->dir->i_size) {
 			iter->elen = 0;
 			return 0;