On Wednesday 08 January 2020 13:19:19 Jan Kara wrote:
> Free space on filesystems with metadata or virtual partition maps
> currently gets misreported. This is because these partitions are just
> remapped onto underlying real partitions from which keep track of free
> blocks. Take this remapping into account when counting free blocks as
> well.
>
> Reported-by: Pali Rohár <pali.rohar@xxxxxxxxx>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
> ---
> fs/udf/super.c | 19 ++++++++++++++-----
> 1 file changed, 14 insertions(+), 5 deletions(-)
>
> I plan to take this patch to my tree.
>
> diff --git a/fs/udf/super.c b/fs/udf/super.c
> index 8c28e93e9b73..b89e420a4b85 100644
> --- a/fs/udf/super.c
> +++ b/fs/udf/super.c
> @@ -2492,17 +2492,26 @@ static unsigned int udf_count_free_table(struct super_block *sb,
> static unsigned int udf_count_free(struct super_block *sb)
> {
> unsigned int accum = 0;
> - struct udf_sb_info *sbi;
> + struct udf_sb_info *sbi = UDF_SB(sb);
> struct udf_part_map *map;
> + unsigned int part = sbi->s_partition;
> + int ptype = sbi->s_partmaps[part].s_partition_type;
> +
> + if (ptype == UDF_METADATA_MAP25) {
> + part = sbi->s_partmaps[part].s_type_specific.s_metadata.
> + s_phys_partition_ref;
> + } else if (ptype == UDF_VIRTUAL_MAP15 || ptype == UDF_VIRTUAL_MAP20) {
> + part = UDF_I(sbi->s_vat_inode)->i_location.
> + partitionReferenceNum;
Hello! I do not think that it make sense to report "free blocks" for
discs with Virtual partition. By definition of VAT, all blocks prior to
VAT are already "read-only" and therefore these blocks cannot be use for
writing new data by any implementation. And because VAT is stored on the
last block, in our model all blocks are "occupied".
> + }
>
> - sbi = UDF_SB(sb);
> if (sbi->s_lvid_bh) {
> struct logicalVolIntegrityDesc *lvid =
> (struct logicalVolIntegrityDesc *)
> sbi->s_lvid_bh->b_data;
> - if (le32_to_cpu(lvid->numOfPartitions) > sbi->s_partition) {
> + if (le32_to_cpu(lvid->numOfPartitions) > part) {
> accum = le32_to_cpu(
> - lvid->freeSpaceTable[sbi->s_partition]);
> + lvid->freeSpaceTable[part]);
And in any case freeSpaceTable should not be used for discs with VAT.
And we should ignore its value for discs with VAT.
UDF 2.60 2.2.6.2: Free Space Table values be maintained ... except ...
for a virtual partition ...
And same applies for "partition with Access Type pseudo-overwritable".
> if (accum == 0xFFFFFFFF)
> accum = 0;
> }
> @@ -2511,7 +2520,7 @@ static unsigned int udf_count_free(struct super_block *sb)
> if (accum)
> return accum;
>
> - map = &sbi->s_partmaps[sbi->s_partition];
> + map = &sbi->s_partmaps[part];
> if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
> accum += udf_count_free_bitmap(sb,
> map->s_uspace.s_bitmap);
--
Pali Rohár
pali.rohar@xxxxxxxxx
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