Add framework for validation of ioctls. Doesn't do any checks yet.

dmsetup --checks
libdevmapper: dm_task_enable_checks()
lvm.conf: activation/checks=1

4 files changed, 29 insertions, 1 deletions

diff --git a/libdm/ioctl/libdm-iface.c b/libdm/ioctl/libdm-iface.c
index da492018..cfc19b62 100644
--- a/libdm/ioctl/libdm-iface.c
+++ b/libdm/ioctl/libdm-iface.c
@@ -1884,6 +1884,16 @@ no_match:
 	return r;
 }
 
+static int _suspend_with_validation_v4(struct dm_task *dmt)
+{
+	/*
+	 * FIXME Ensure we can't leave any I/O trapped between suspended devices.
+	 */
+	dmt->enable_checks = 0;
+	
+	return dm_task_run(dmt);
+}
+
 static const char *_sanitise_message(char *message)
 {
 	const char *sanitised_message = message ?: "";
@@ -1963,7 +1973,7 @@ static struct dm_ioctl *_do_dm_ioctl(struct dm_task *dmt, unsigned command,
 	}
 
 	log_debug("dm %s %s%s %s%s%s %s%.0d%s%.0d%s"
-		  "%s%c%c%s%s%s%s %.0" PRIu64 " %s [%u]",
+		  "%s%c%c%s%s%s%s%s %.0" PRIu64 " %s [%u]",
 		  _cmd_data_v4[dmt->type].name,
 		  dmt->new_uuid ? "UUID " : "",
 		  dmi->name, dmi->uuid, dmt->newname ? " " : "",
@@ -1980,6 +1990,7 @@ static struct dm_ioctl *_do_dm_ioctl(struct dm_task *dmt, unsigned command,
 		  dmt->skip_lockfs ? "S " : "",
 		  dmt->secure_data ? "W " : "",
 		  dmt->query_inactive_table ? "I " : "",
+		  dmt->enable_checks ? "C" : "",
 		  dmt->sector, _sanitise_message(dmt->message),
 		  dmi->data_size);
 #ifdef DM_IOCTLS
@@ -2054,6 +2065,9 @@ int dm_task_run(struct dm_task *dmt)
 	if ((dmt->type == DM_DEVICE_RELOAD) && dmt->suppress_identical_reload)
 		return _reload_with_suppression_v4(dmt);
 
+	if ((dmt->type == DM_DEVICE_SUSPEND) && dmt->enable_checks)
+		return _suspend_with_validation_v4(dmt);
+
 	if (!_open_control()) {
 		_udev_complete(dmt);
 		return 0;
diff --git a/libdm/ioctl/libdm-targets.h b/libdm/ioctl/libdm-targets.h
index d8cca844..d61ccfda 100644
--- a/libdm/ioctl/libdm-targets.h
+++ b/libdm/ioctl/libdm-targets.h
@@ -65,6 +65,7 @@ struct dm_task {
 	int cookie_set;
 	int new_uuid;
 	int secure_data;
+	int enable_checks;
 
 	char *uuid;
 };
diff --git a/libdm/libdevmapper.h b/libdm/libdevmapper.h
index a3ae8807..340e6e51 100644
--- a/libdm/libdevmapper.h
+++ b/libdm/libdevmapper.h
@@ -190,6 +190,12 @@ int dm_task_skip_lockfs(struct dm_task *dmt);
 int dm_task_query_inactive_table(struct dm_task *dmt);
 int dm_task_suppress_identical_reload(struct dm_task *dmt);
 int dm_task_secure_data(struct dm_task *dmt);
+
+/*
+ * Enable checks for common mistakes such as issuing ioctls in an unsafe order.
+ */
+int dm_task_enable_checks(struct dm_task *dmt);
+
 typedef enum {
 	DM_ADD_NODE_ON_RESUME, /* add /dev/mapper node with dmsetup resume */
 	DM_ADD_NODE_ON_CREATE  /* add /dev/mapper node with dmsetup create */
diff --git a/libdm/libdm-common.c b/libdm/libdm-common.c
index fa6746a0..31a44e72 100644
--- a/libdm/libdm-common.c
+++ b/libdm/libdm-common.c
@@ -395,6 +395,13 @@ int dm_task_set_mode(struct dm_task *dmt, mode_t mode)
 	return 1;
 }
 
+int dm_task_enable_checks(struct dm_task *dmt)
+{
+	dmt->enable_checks = 1;
+
+	return 1;
+}
+
 int dm_task_add_target(struct dm_task *dmt, uint64_t start, uint64_t size,
 		       const char *ttype, const char *params)
 {