dm integrity: use version 2 for separate metadata

Use version "2" in the superblock when data and metadata devices are
separate, so that the device is not accidentally read by older kernel
version.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index fb5c8ef5b519..1097d8c25577 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -44,7 +44,8 @@
  */
 
 #define SB_MAGIC                        "integrt"
-#define SB_VERSION                      1
+#define SB_VERSION_1                    1
+#define SB_VERSION_2                    2
 #define SB_SECTORS                      8
 #define MAX_SECTORS_PER_BLOCK           8
 
@@ -414,6 +415,14 @@ static void wraparound_section(struct dm_integrity_c *ic, unsigned *sec_ptr)
                 *sec_ptr -= ic->journal_sections;
 }
 
+static void sb_set_version(struct dm_integrity_c *ic)
+{
+        if (ic->meta_dev)
+                ic->sb->version = SB_VERSION_2;
+        else
+                ic->sb->version = SB_VERSION_1;
+}
+
 static int sync_rw_sb(struct dm_integrity_c *ic, int op, int op_flags)
 {
         struct dm_io_request io_req;
@@ -2432,7 +2441,6 @@ static int initialize_superblock(struct dm_integrity_c *ic, unsigned journal_sec
 
         memset(ic->sb, 0, SB_SECTORS << SECTOR_SHIFT);
         memcpy(ic->sb->magic, SB_MAGIC, 8);
-        ic->sb->version = SB_VERSION;
         ic->sb->integrity_tag_size = cpu_to_le16(ic->tag_size);
         ic->sb->log2_sectors_per_block = __ffs(ic->sectors_per_block);
         if (ic->journal_mac_alg.alg_string)
@@ -2489,6 +2497,8 @@ try_smaller_buffer:
 
         ic->sb->provided_data_sectors = cpu_to_le64(ic->provided_data_sectors);
 
+        sb_set_version(ic);
+
         return 0;
 }
 
@@ -3193,7 +3203,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv)
                         should_write_sb = true;
         }
 
-        if (ic->sb->version != SB_VERSION) {
+        if (!ic->sb->version || ic->sb->version > SB_VERSION_2) {
                 r = -EINVAL;
                 ti->error = "Unknown version";
                 goto bad;