From: Nikos Tsironis <ntsironis@xxxxxxxxxxx> commit c8e846ff93d5eaa5384f6f325a1687ac5921aade upstream. dm-era doesn't support changing the data block size of existing devices, so check explicitly that the requested block size for a new target matches the one stored in the metadata. Fixes: eec40579d84873 ("dm: add era target") Cc: stable@xxxxxxxxxxxxxxx # v3.15+ Signed-off-by: Nikos Tsironis <ntsironis@xxxxxxxxxxx> Reviewed-by: Ming-Hung Tsai <mtsai@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/dm-era-target.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/md/dm-era-target.c +++ b/drivers/md/dm-era-target.c @@ -564,6 +564,15 @@ static int open_metadata(struct era_meta } disk = dm_block_data(sblock); + + /* Verify the data block size hasn't changed */ + if (le32_to_cpu(disk->data_block_size) != md->block_size) { + DMERR("changing the data block size (from %u to %llu) is not supported", + le32_to_cpu(disk->data_block_size), md->block_size); + r = -EINVAL; + goto bad; + } + r = dm_tm_open_with_sm(md->bm, SUPERBLOCK_LOCATION, disk->metadata_space_map_root, sizeof(disk->metadata_space_map_root), @@ -575,7 +584,6 @@ static int open_metadata(struct era_meta setup_infos(md); - md->block_size = le32_to_cpu(disk->data_block_size); md->nr_blocks = le32_to_cpu(disk->nr_blocks); md->current_era = le32_to_cpu(disk->current_era);