On 7/28/2020 4:15 PM, Jakub Kicinski wrote:
> Number of .dumpit functions try to ignore -EOPNOTSUPP errors.
> Recent change missed that, and started reporting all errors
> but -EMSGSIZE back from dumps. This leads to situation like
> this:
>
> $ devlink dev info
> devlink answers: Operation not supported
>
> Dump should not report an error just because the last device
> to be queried could not provide an answer.
>
> To fix this and avoid similar confusion make sure we clear
> err properly, and not leave it set to an error if we don't
> terminate the iteration.
>
Makes sense to me.
> Fixes: c62c2cfb801b ("net: devlink: don't ignore errors during dumpit")
> Signed-off-by: Jakub Kicinski <k...@kernel.org>
> ---
> net/core/devlink.c | 24 ++++++++++++++++++------
> 1 file changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/net/core/devlink.c b/net/core/devlink.c
> index 2cafbc808b09..1d38b6651b23 100644
> --- a/net/core/devlink.c
> +++ b/net/core/devlink.c
> @@ -1065,7 +1065,9 @@ static int devlink_nl_cmd_sb_pool_get_dumpit(struct
> sk_buff *msg,
> devlink_sb,
> NETLINK_CB(cb->skb).portid,
> cb->nlh->nlmsg_seq);
> - if (err && err != -EOPNOTSUPP) {
> + if (err == -EOPNOTSUPP) {
> + err = 0;
> + } else if (err) {
> mutex_unlock(&devlink->lock);
> goto out;
> }
> @@ -1266,7 +1268,9 @@ static int
> devlink_nl_cmd_sb_port_pool_get_dumpit(struct sk_buff *msg,
> devlink, devlink_sb,
>
> NETLINK_CB(cb->skb).portid,
> cb->nlh->nlmsg_seq);
> - if (err && err != -EOPNOTSUPP) {
> + if (err == -EOPNOTSUPP) {
> + err = 0;
> + } else if (err) {
> mutex_unlock(&devlink->lock);
> goto out;
> }
> @@ -1498,7 +1502,9 @@ devlink_nl_cmd_sb_tc_pool_bind_get_dumpit(struct
> sk_buff *msg,
> devlink_sb,
>
> NETLINK_CB(cb->skb).portid,
> cb->nlh->nlmsg_seq);
> - if (err && err != -EOPNOTSUPP) {
> + if (err == -EOPNOTSUPP) {
> + err = 0;
> + } else if (err) {
> mutex_unlock(&devlink->lock);
> goto out;
> }
> @@ -3299,7 +3305,9 @@ static int devlink_nl_cmd_param_get_dumpit(struct
> sk_buff *msg,
> NETLINK_CB(cb->skb).portid,
> cb->nlh->nlmsg_seq,
> NLM_F_MULTI);
> - if (err && err != -EOPNOTSUPP) {
> + if (err == -EOPNOTSUPP) {
> + err = 0;
> + } else if (err) {
> mutex_unlock(&devlink->lock);
> goto out;
> }
> @@ -3569,7 +3577,9 @@ static int devlink_nl_cmd_port_param_get_dumpit(struct
> sk_buff *msg,
> NETLINK_CB(cb->skb).portid,
> cb->nlh->nlmsg_seq,
> NLM_F_MULTI);
> - if (err && err != -EOPNOTSUPP) {
> + if (err == -EOPNOTSUPP) {
> + err = 0;
> + } else if (err) {
> mutex_unlock(&devlink->lock);
> goto out;
> }
> @@ -4518,7 +4528,9 @@ static int devlink_nl_cmd_info_get_dumpit(struct
> sk_buff *msg,
> cb->nlh->nlmsg_seq, NLM_F_MULTI,
> cb->extack);
> mutex_unlock(&devlink->lock);
> - if (err && err != -EOPNOTSUPP)
> + if (err == -EOPNOTSUPP)
> + err = 0;
> + else if (err)
> break;
> idx++;
> }
>
