[lustre-devel] [PATCH 21/24] lustre: lnet: add "lnetctl discover"

[James Simmons]

> From: Sonia Sharma <sonia.sharma at intel.com>
> 
> Add a "discover" subcommand to lnetctl
> 
> jt_discover() in lnetctl.c calls lustre_lnet_discover_nid()
> to implement "lnetctl discover". The output is similar to
> "lnetctl ping" command.
> This patch also does some clean up in linlnetconfig.c
> For parameters under global settings, the common code
> for them is pulled in functions ioctl_set_value() and
> ioctl_show_global_values().

Reviewed-by: James Simmons <jsimmons at infradead.org>
 
> WC-bug-id: https://jira.whamcloud.com/browse/LU-9480
> Signed-off-by: Sonia Sharma <sonia.sharma at intel.com>
> Signed-off-by: Amir Shehata <amir.shehata at intel.com>
> Signed-off-by: Olaf Weber <olaf at sgi.com>
> Reviewed-on: https://review.whamcloud.com/25793
> Signed-off-by: NeilBrown <neilb at suse.com>
> ---
>  .../lustre/include/uapi/linux/lnet/libcfs_ioctl.h  |    2 
>  drivers/staging/lustre/lnet/lnet/api-ni.c          |  100 ++++++++++++++++++++
>  2 files changed, 101 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/lustre/include/uapi/linux/lnet/libcfs_ioctl.h b/drivers/staging/lustre/include/uapi/linux/lnet/libcfs_ioctl.h
> index 3d89202bd396..60bc9713923e 100644
> --- a/drivers/staging/lustre/include/uapi/linux/lnet/libcfs_ioctl.h
> +++ b/drivers/staging/lustre/include/uapi/linux/lnet/libcfs_ioctl.h
> @@ -113,7 +113,7 @@ struct libcfs_debug_ioctl_data {
>  #define IOC_LIBCFS_DEL_PEER		   _IOWR('e', 74, IOCTL_LIBCFS_TYPE)
>  #define IOC_LIBCFS_ADD_PEER		   _IOWR('e', 75, IOCTL_LIBCFS_TYPE)
>  #define IOC_LIBCFS_GET_PEER		   _IOWR('e', 76, IOCTL_LIBCFS_TYPE)
> -/* ioctl 77 is free for use */
> +#define IOC_LIBCFS_DISCOVER                _IOWR('e', 77, IOCTL_LIBCFS_TYPE)
>  #define IOC_LIBCFS_ADD_INTERFACE	   _IOWR('e', 78, IOCTL_LIBCFS_TYPE)
>  #define IOC_LIBCFS_DEL_INTERFACE	   _IOWR('e', 79, IOCTL_LIBCFS_TYPE)
>  #define IOC_LIBCFS_GET_INTERFACE	   _IOWR('e', 80, IOCTL_LIBCFS_TYPE)
> diff --git a/drivers/staging/lustre/lnet/lnet/api-ni.c b/drivers/staging/lustre/lnet/lnet/api-ni.c
> index 37f47bd1511f..0511c6acb9b1 100644
> --- a/drivers/staging/lustre/lnet/lnet/api-ni.c
> +++ b/drivers/staging/lustre/lnet/lnet/api-ni.c
> @@ -104,6 +104,9 @@ static atomic_t lnet_dlc_seq_no = ATOMIC_INIT(0);
>  static int lnet_ping(struct lnet_process_id id, signed long timeout,
>  		     struct lnet_process_id __user *ids, int n_ids);
>  
> +static int lnet_discover(struct lnet_process_id id, __u32 force,
> +			 struct lnet_process_id __user *ids, int n_ids);
> +
>  static int
>  discovery_set(const char *val, const struct kernel_param *kp)
>  {
> @@ -3225,6 +3228,25 @@ LNetCtl(unsigned int cmd, void *arg)
>  		return 0;
>  	}
>  
> +	case IOC_LIBCFS_DISCOVER: {
> +		struct lnet_ioctl_ping_data *discover = arg;
> +		struct lnet_peer *lp;
> +
> +		rc = lnet_discover(discover->ping_id, discover->op_param,
> +				   discover->ping_buf,
> +				   discover->ping_count);
> +		if (rc < 0)
> +			return rc;
> +		lp = lnet_find_peer(discover->ping_id.nid);
> +		if (lp) {
> +			discover->ping_id.nid = lp->lp_primary_nid;
> +			discover->mr_info = lnet_peer_is_multi_rail(lp);
> +		}
> +
> +		discover->ping_count = rc;
> +		return 0;
> +	}
> +
>  	default:
>  		ni = lnet_net2ni_addref(data->ioc_net);
>  		if (!ni)
> @@ -3461,3 +3483,81 @@ static int lnet_ping(struct lnet_process_id id, signed long timeout,
>  	lnet_ping_buffer_decref(pbuf);
>  	return rc;
>  }
> +
> +static int
> +lnet_discover(struct lnet_process_id id, __u32 force,
> +	      struct lnet_process_id __user *ids,
> +	      int n_ids)
> +{
> +	struct lnet_peer_ni *lpni;
> +	struct lnet_peer_ni *p;
> +	struct lnet_peer *lp;
> +	struct lnet_process_id *buf;
> +	int cpt;
> +	int i;
> +	int rc;
> +	int max_intf = lnet_interfaces_max;
> +
> +	if (n_ids <= 0 ||
> +	    id.nid == LNET_NID_ANY ||
> +	    n_ids > max_intf)
> +		return -EINVAL;
> +
> +	if (id.pid == LNET_PID_ANY)
> +		id.pid = LNET_PID_LUSTRE;
> +
> +	buf = kcalloc(n_ids, sizeof(*buf), GFP_KERNEL);
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	cpt = lnet_net_lock_current();
> +	lpni = lnet_nid2peerni_locked(id.nid, LNET_NID_ANY, cpt);
> +	if (IS_ERR(lpni)) {
> +		rc = PTR_ERR(lpni);
> +		goto out;
> +	}
> +
> +	/*
> +	 * Clearing the NIDS_UPTODATE flag ensures the peer will
> +	 * be discovered, provided discovery has not been disabled.
> +	 */
> +	lp = lpni->lpni_peer_net->lpn_peer;
> +	spin_lock(&lp->lp_lock);
> +	lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
> +	/* If the force flag is set, force a PING and PUSH as well. */
> +	if (force)
> +		lp->lp_state |= LNET_PEER_FORCE_PING | LNET_PEER_FORCE_PUSH;
> +	spin_unlock(&lp->lp_lock);
> +	rc = lnet_discover_peer_locked(lpni, cpt, true);
> +	if (rc)
> +		goto out_decref;
> +
> +	/* Peer may have changed. */
> +	lp = lpni->lpni_peer_net->lpn_peer;
> +	if (lp->lp_nnis < n_ids)
> +		n_ids = lp->lp_nnis;
> +
> +	i = 0;
> +	p = NULL;
> +	while ((p = lnet_get_next_peer_ni_locked(lp, NULL, p)) != NULL) {
> +		buf[i].pid = id.pid;
> +		buf[i].nid = p->lpni_nid;
> +		if (++i >= n_ids)
> +			break;
> +	}
> +
> +	lnet_net_unlock(cpt);
> +
> +	rc = -EFAULT;
> +	if (copy_to_user(ids, buf, n_ids * sizeof(*buf)))
> +		goto out_relock;
> +	rc = n_ids;
> +out_relock:
> +	lnet_net_lock(cpt);
> +out_decref:
> +	lnet_peer_ni_decref_locked(lpni);
> +out:
> +	lnet_net_unlock(cpt);
> +	kfree(buf);
> +	return rc;
> +}
> 
> 
>