From: Parav Pandit <parav@mellanox.com>
Date: Tue, 12 Feb 2019 14:23:58 -0600
Subject: devlink: Return right error code in case of errors for region read
Patch-mainline: v5.1-rc1
Git-commit: fdd41ec21e150113e8fe169783db9b2030f5491b
References: bsc#1109837

devlink_nl_cmd_region_read_dumpit() misses to return right error code on
most error conditions.
Return the right error code on such errors.

Fixes: 4e54795a27f5 ("devlink: Add support for region snapshot read command")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/core/devlink.c |   26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -3521,26 +3521,34 @@ static int devlink_nl_cmd_region_read_du
 		goto out;
 
 	devlink = devlink_get_from_attrs(sock_net(cb->skb->sk), attrs);
-	if (IS_ERR(devlink))
+	if (IS_ERR(devlink)) {
+		err = PTR_ERR(devlink);
 		goto out;
+	}
 
 	mutex_lock(&devlink_mutex);
 	mutex_lock(&devlink->lock);
 
 	if (!attrs[DEVLINK_ATTR_REGION_NAME] ||
-	    !attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID])
+	    !attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID]) {
+		err = -EINVAL;
 		goto out_unlock;
+	}
 
 	region_name = nla_data(attrs[DEVLINK_ATTR_REGION_NAME]);
 	region = devlink_region_get_by_name(devlink, region_name);
-	if (!region)
+	if (!region) {
+		err = -EINVAL;
 		goto out_unlock;
+	}
 
 	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 			  &devlink_nl_family, NLM_F_ACK | NLM_F_MULTI,
 			  DEVLINK_CMD_REGION_READ);
-	if (!hdr)
+	if (!hdr) {
+		err = -EMSGSIZE;
 		goto out_unlock;
+	}
 
 	err = devlink_nl_put_handle(skb, devlink);
 	if (err)
@@ -3551,8 +3559,10 @@ static int devlink_nl_cmd_region_read_du
 		goto nla_put_failure;
 
 	chunks_attr = nla_nest_start(skb, DEVLINK_ATTR_REGION_CHUNKS);
-	if (!chunks_attr)
+	if (!chunks_attr) {
+		err = -EMSGSIZE;
 		goto nla_put_failure;
+	}
 
 	if (attrs[DEVLINK_ATTR_REGION_CHUNK_ADDR] &&
 	    attrs[DEVLINK_ATTR_REGION_CHUNK_LEN]) {
@@ -3575,8 +3585,10 @@ static int devlink_nl_cmd_region_read_du
 		goto nla_put_failure;
 
 	/* Check if there was any progress done to prevent infinite loop */
-	if (ret_offset == start_offset)
+	if (ret_offset == start_offset) {
+		err = -EINVAL;
 		goto nla_put_failure;
+	}
 
 	*((u64 *)&cb->args[0]) = ret_offset;
 
@@ -3593,7 +3605,7 @@ out_unlock:
 	mutex_unlock(&devlink->lock);
 	mutex_unlock(&devlink_mutex);
 out:
-	return 0;
+	return err;
 }
 
 static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {