[RFC PATCH v11 11/19] dm verity: set DM_TARGET_SINGLETON feature flag

Fan Wu
2023-10-04T22:10:04Z

The device-mapper has a flag to mark targets as singleton, which is a
required flag for immutable targets. Without this flag, multiple
dm-verity targets can be added to a mapped device, which has no
practical use cases and will let dm_table_get_immutable_target return
NULL. This patch adds the missing flag, restricting only one
dm-verity target per mapped device.

Signed-off-by: Fan Wu <wufan@linux.microsoft.com>

---
v1-v10:
+ Not present
---
drivers/md/dm-verity-target.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index 26adcfea0302..80673b66c194 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -1503,7 +1503,7 @@ int dm_verity_get_root_digest(struct dm_target *ti, u8 **root_digest, unsigned i

static struct target_type verity_target = {
.name = "verity",
- .features = DM_TARGET_IMMUTABLE,
+ .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE,
.version = {1, 9, 0},
.module = THIS_MODULE,
.ctr = verity_ctr,
--
2.25.1