[PATCH net-next v3 05/11] devlink: Extend the support querying for region snapshot IDs

[Alex Vesker <valex@mellanox.com>]

Extend the support for DEVLINK_CMD_REGION_GET command to also
return the IDs of the snapshot currently present on the region.
Each reply will include a nested snapshots attribute that
can contain multiple snapshot attributes each with an ID.

Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
 include/uapi/linux/devlink.h |  3 +++
 net/core/devlink.c           | 53 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 28bfa8a..abde4e3 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -267,6 +267,9 @@ enum devlink_attr {
 
 	DEVLINK_ATTR_REGION_NAME,               /* string */
 	DEVLINK_ATTR_REGION_SIZE,               /* u64 */
+	DEVLINK_ATTR_REGION_SNAPSHOTS,          /* nested */
+	DEVLINK_ATTR_REGION_SNAPSHOT,           /* nested */
+	DEVLINK_ATTR_REGION_SNAPSHOT_ID,        /* u32 */
 
 	/* add new attributes above here, update the policy in devlink.c */
 
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 221ddb6..cb75e26 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -3149,6 +3149,55 @@ static void devlink_param_unregister_one(struct devlink *devlink,
 	kfree(param_item);
 }
 
+static int devlink_nl_region_snapshot_id_put(struct sk_buff *msg,
+					     struct devlink *devlink,
+					     struct devlink_snapshot *snapshot)
+{
+	struct nlattr *snap_attr;
+	int err;
+
+	snap_attr = nla_nest_start(msg, DEVLINK_ATTR_REGION_SNAPSHOT);
+	if (!snap_attr)
+		return -EINVAL;
+
+	err = nla_put_u32(msg, DEVLINK_ATTR_REGION_SNAPSHOT_ID, snapshot->id);
+	if (err)
+		goto nla_put_failure;
+
+	nla_nest_end(msg, snap_attr);
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(msg, snap_attr);
+	return err;
+}
+
+static int devlink_nl_region_snapshots_id_put(struct sk_buff *msg,
+					      struct devlink *devlink,
+					      struct devlink_region *region)
+{
+	struct devlink_snapshot *snapshot;
+	struct nlattr *snapshots_attr;
+	int err;
+
+	snapshots_attr = nla_nest_start(msg, DEVLINK_ATTR_REGION_SNAPSHOTS);
+	if (!snapshots_attr)
+		return -EINVAL;
+
+	list_for_each_entry(snapshot, &region->snapshot_list, list) {
+		err = devlink_nl_region_snapshot_id_put(msg, devlink, snapshot);
+		if (err)
+			goto nla_put_failure;
+	}
+
+	nla_nest_end(msg, snapshots_attr);
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(msg, snapshots_attr);
+	return err;
+}
+
 static int devlink_nl_region_fill(struct sk_buff *msg, struct devlink *devlink,
 				  enum devlink_command cmd, u32 portid,
 				  u32 seq, int flags,
@@ -3175,6 +3224,10 @@ static int devlink_nl_region_fill(struct sk_buff *msg, struct devlink *devlink,
 	if (err)
 		goto nla_put_failure;
 
+	err = devlink_nl_region_snapshots_id_put(msg, devlink, region);
+	if (err)
+		goto nla_put_failure;
+
 	genlmsg_end(msg, hdr);
 	return 0;
 
-- 
1.8.3.1