Received-SPF: pass (google.com: domain of linux-kernel+bounces-45415-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
From: Fan Wu <wufan@linux.microsoft.com>
To: corbet@lwn.net,
	zohar@linux.ibm.com,
	jmorris@namei.org,
	serge@hallyn.com,
	tytso@mit.edu,
	ebiggers@kernel.org,
	axboe@kernel.dk,
	agk@redhat.com,
	snitzer@kernel.org,
	eparis@redhat.com,
	paul@paul-moore.com
Cc: linux-doc@vger.kernel.org,
	linux-integrity@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	linux-fscrypt@vger.kernel.org,
	linux-block@vger.kernel.org,
	dm-devel@lists.linux.dev,
	audit@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Fan Wu <wufan@linux.microsoft.com>
Subject: [RFC PATCH v12 12/20] dm verity: set DM_TARGET_SINGLETON feature flag
Date: Tue, 30 Jan 2024 14:37:00 -0800
Message-Id: <1706654228-17180-13-git-send-email-wufan@linux.microsoft.com>
In-Reply-To: <1706654228-17180-1-git-send-email-wufan@linux.microsoft.com>
References: <1706654228-17180-1-git-send-email-wufan@linux.microsoft.com>
Precedence: bulk

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

v11:
  + Introduced

v12:
  + No changes
---
 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 14e58ae70521..66a850c02be4 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -1507,7 +1507,7 @@ 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,
-- 
2.43.0