[dm-devel] [PATCH] dm-integrity: correctly calculate the size of metadata area

[Mikulas Patocka]

When we use separate devices for data and metadata, dm-integrity would
incorrectly calculate the size of the metadata device as if it had
512-byte block size - and it would refuse activation with larger block
size and smaller metadata device.

This patch fixes it so that it takes actual block size into account.

It fixes https://gitlab.com/cryptsetup/cryptsetup/issues/450

Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
Cc: stable at vger.kernel.org	# v4.19+
Fixes: 356d9d52e122 ("dm integrity: allow separate metadata device")

---
 drivers/md/dm-integrity.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6/drivers/md/dm-integrity.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-integrity.c	2019-05-07 18:57:04.000000000 +0200
+++ linux-2.6/drivers/md/dm-integrity.c	2019-05-07 20:26:44.000000000 +0200
@@ -2568,7 +2568,7 @@ static int calculate_device_limits(struc
 		if (last_sector < ic->start || last_sector >= ic->meta_device_sectors)
 			return -EINVAL;
 	} else {
-		__u64 meta_size = ic->provided_data_sectors * ic->tag_size;
+		__u64 meta_size = (ic->provided_data_sectors >> ic->sb->log2_sectors_per_block) * ic->tag_size;
 		meta_size = (meta_size + ((1U << (ic->log2_buffer_sectors + SECTOR_SHIFT)) - 1))
 				>> (ic->log2_buffer_sectors + SECTOR_SHIFT);
 		meta_size <<= ic->log2_buffer_sectors;
@@ -3439,7 +3439,7 @@ try_smaller_buffer:
 	DEBUG_print("	journal_sections %u\n", (unsigned)le32_to_cpu(ic->sb->journal_sections));
 	DEBUG_print("	journal_entries %u\n", ic->journal_entries);
 	DEBUG_print("	log2_interleave_sectors %d\n", ic->sb->log2_interleave_sectors);
-	DEBUG_print("	device_sectors 0x%llx\n", (unsigned long long)ic->device_sectors);
+	DEBUG_print("	data_device_sectors 0x%llx\n", (unsigned long long)ic->data_device_sectors);
 	DEBUG_print("	initial_sectors 0x%x\n", ic->initial_sectors);
 	DEBUG_print("	metadata_run 0x%x\n", ic->metadata_run);
 	DEBUG_print("	log2_metadata_run %d\n", ic->log2_metadata_run);