Hello! During testing of udfinfo tool (from udftools project) I found that udfinfo's implementation for calculating free space does not work when UDF filesystem has Metadata partition (according to OSTA UDF 2.50). Year ago in udfinfo for calculating free space I used same algorithm as is implemented in kernel UDF driver, function udf_count_free(). So I suspect kernel driver could have it incorrectly implemented too, but I'm not sure. So I'm sending this email to let you know about it. What is the problem? UDF Metadata partition is stored directly on UDF Physical partition and therefore free space calculation needs to be done from Physical one (same applies for Virtual partition). But Metadata partition contains mapping table for logical <--> physical blocks, so reading data needs to be done always from Metadata partition. Also in UDF terminology are two different things: Partition and Partition Map. And "partition number" is a bit misleading as sometimes it refers to "Partition" and sometimes to "Partition Map" what are two different things. Calculation problem in udfinfo I fixed in this commit: https://github.com/pali/udftools/commit/1763c9f899bdbdb68b1a44a8cb5edd5141107043 -- Pali Rohár pali.rohar@xxxxxxxxx
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