Re: [PATCH net-next v2 05/15] net/smc: Add diagnostic information to smc ib-device

Saeed Mahameed
2020-11-04T01:00:23Z

On Tue, 2020-11-03 at 11:25 +0100, Karsten Graul wrote:
> From: Guvenc Gulce <guvenc@linux.ibm.com>
>
> During smc ib-device creation, add network device name to smc
> ib-device structure. Register for netdevice name changes and
> update ib-device accordingly. This is needed for diagnostic purposes.
>
> Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
> ---
> net/smc/smc_ib.c | 47
> ++++++++++++++++++++++++++++++++++++++++++++++
> net/smc/smc_ib.h | 2 ++
> net/smc/smc_pnet.c | 3 +++
> 3 files changed, 52 insertions(+)
>
> diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c
> index 1c314dbdc7fa..c4a04e868bf0 100644
> --- a/net/smc/smc_ib.c
> +++ b/net/smc/smc_ib.c
> @@ -557,6 +557,52 @@ static void smc_ib_cleanup_per_ibdev(struct
> smc_ib_device *smcibdev)
>
> static struct ib_client smc_ib_client;
>
> +static void smc_copy_netdev_name(struct smc_ib_device *smcibdev, int
> port)
> +{
> + struct ib_device *ibdev = smcibdev->ibdev;
> + struct net_device *ndev;
> +
> + if (ibdev->ops.get_netdev) {

early return to avoid multiple indentation to the right ..

> + ndev = ibdev->ops.get_netdev(ibdev, port + 1);
> + if (ndev) {
> + snprintf((char *)&smcibdev->netdev[port],
> + sizeof(smcibdev->netdev[port]),
> + "%s", ndev->name);

Why do you need typecasting to char* just declare the netdev as char
array ??

> + dev_put(ndev);
> + }
> + }
> +}
> +
> +void smc_ib_ndev_name_change(struct net_device *ndev)
> +{
> + struct smc_ib_device *smcibdev;
> + struct ib_device *libdev;
> + struct net_device *lndev;
> + u8 port_cnt;
> + int i;
> +
> + mutex_lock(&smc_ib_devices.mutex);
> + list_for_each_entry(smcibdev, &smc_ib_devices.list, list) {
> + port_cnt = smcibdev->ibdev->phys_port_cnt;
> + for (i = 0;
> + i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
> + i++) {

Unnecessary ugly line breaks.

> + libdev = smcibdev->ibdev;
> + if (libdev->ops.get_netdev) {

early continue

if (!libdev->ops.get_netdev)
continue;

do stuff

> + lndev = libdev->ops.get_netdev(libdev,
> i + 1);
> + if (lndev)
> + dev_put(lndev);
> + if (lndev == ndev) {

Same

if (!lndev || lndev != ndev)
continue;

> + snprintf((char *)&smcibdev-
> >netdev[i],
> + sizeof(smcibdev-
> >netdev[i]),
> + "%s", ndev->name);
> + }
> + }
> + }
> + }
> + mutex_unlock(&smc_ib_devices.mutex);
> +}
> +
> /* callback function for ib_register_client() */
> static int smc_ib_add_dev(struct ib_device *ibdev)
> {
> @@ -596,6 +642,7 @@ static int smc_ib_add_dev(struct ib_device
> *ibdev)
> if (smc_pnetid_by_dev_port(ibdev->dev.parent, i,
> smcibdev->pnetid[i]))
> smc_pnetid_by_table_ib(smcibdev, i + 1);
> + smc_copy_netdev_name(smcibdev, i);
> pr_warn_ratelimited("smc: ib device %s port %d has
> pnetid "
> "%.16s%s\n",
> smcibdev->ibdev->name, i + 1,
> diff --git a/net/smc/smc_ib.h b/net/smc/smc_ib.h
> index 3e6bfeddd53b..b0868146b46b 100644
> --- a/net/smc/smc_ib.h
> +++ b/net/smc/smc_ib.h
> @@ -54,11 +54,13 @@ struct smc_ib_device {
> /* ib-device infos for smc */
> wait_queue_head_t lnks_deleted; /* wait 4 removal of all
> links*/
> struct mutex mutex; /* protect dev
> setup+cleanup */
> atomic_t lnk_cnt_by_port[SMC_MAX_PORTS];/*#lnk per
> port*/
> + u8 netdev[SMC_MAX_PORTS][IFNAMSIZ];/*
> ndev names */
> };
>
> struct smc_buf_desc;
> struct smc_link;
>
> +void smc_ib_ndev_name_change(struct net_device *ndev);
> int smc_ib_register_client(void) __init;
> void smc_ib_unregister_client(void);
> bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport);
> diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
> index f3c18b991d35..b0f40d73afd6 100644
> --- a/net/smc/smc_pnet.c
> +++ b/net/smc/smc_pnet.c
> @@ -828,6 +828,9 @@ static int smc_pnet_netdev_event(struct
> notifier_block *this,
> case NETDEV_UNREGISTER:
> smc_pnet_remove_by_ndev(event_dev);
> return NOTIFY_OK;
> + case NETDEV_CHANGENAME:
> + smc_ib_ndev_name_change(event_dev);
> + return NOTIFY_OK;
> case NETDEV_REGISTER:
> smc_pnet_add_by_ndev(event_dev);
> return NOTIFY_OK;