[RFC PATCH v2 2/3] Adds support for security checks in the linear target

[Ondrej Kozina <okozina@redhat.com>]

Just a security check implementation for linear target

---
 drivers/md/dm-linear.c |   19 ++++++++++++++++++-
 1 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 3639eea..b04aa00 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -153,9 +153,25 @@ static int linear_iterate_devices(struct dm_target *ti,
 	return fn(ti, lc->dev, lc->start, ti->len, data);
 }
 
+static int linear_security(struct dm_target *ti, unsigned int argc, char **argv)
+{
+	int r;
+
+	if (argc < 1) {
+		ti->error = "dm-linear: Security check: invalid number of parameters";
+		return -EINVAL;
+	}
+
+	r = dm_check_backing_dev_permission(ti, argv[0]);
+	if (r)
+		ti->error = "dm-linear: Security check failed";
+
+	return r;
+}
+
 static struct target_type linear_target = {
 	.name   = "linear",
-	.version = {1, 1, 0},
+	.version = {1, 2, 0},
 	.module = THIS_MODULE,
 	.ctr    = linear_ctr,
 	.dtr    = linear_dtr,
@@ -164,6 +180,7 @@ static struct target_type linear_target = {
 	.ioctl  = linear_ioctl,
 	.merge  = linear_merge,
 	.iterate_devices = linear_iterate_devices,
+	.security = linear_security
 };
 
 int __init dm_linear_init(void)
-- 
1.7.8.6