Re: [PATCH 3/3] IB/sa: route SA pathrecord query through netlink

[Or Gerlitz <ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>]

On 5/18/2015 10:00 PM, kaike.wan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org wrote:

Would be good to have consistent setup for patch titles, e.g start with 
capital letter
as you did for patches 1 and 2 ("route SA ..." --> "Route SA...").
> --- a/drivers/infiniband/core/sa_query.c
> +++ b/drivers/infiniband/core/sa_query.c
> @@ -45,12 +45,22 @@
>   #include <uapi/linux/if_ether.h>
>   #include <rdma/ib_pack.h>
>   #include <rdma/ib_cache.h>
> +#include <rdma/rdma_netlink.h>
> +#include <net/netlink.h>
> +#include <rdma/rdma_netlink.h>
>   #include "sa.h"
>   
>   MODULE_AUTHOR("Roland Dreier");
>   MODULE_DESCRIPTION("InfiniBand subnet administration query support");
>   MODULE_LICENSE("Dual BSD/GPL");
>   
> +#define IB_SA_LOCAL_SVC_TIMEOUT_MIN		100
> +#define IB_SA_LOCAL_SVC_TIMEOUT_DEFAULT		2000
> +static int sa_local_svc_timeout_ms = IB_SA_LOCAL_SVC_TIMEOUT_DEFAULT;
> +
> +module_param_named(local_svc_timeout_ms, sa_local_svc_timeout_ms, int, 0644);
> +MODULE_PARM_DESC(local_svc_timeout_ms, "Local service timeout in millisecond");

what's actually the role of the module param? why it belongs here? is 
that really unavoidable to have it?


>   
> +struct ib_nl_request_info {
> +	struct list_head list;
> +	u32 seq;
> +	unsigned long timeout;
> +	struct ib_sa_query *query;
> +};
> +
> +struct rdma_nl_resp_msg {
> +	struct nlmsghdr nl_hdr;
> +	struct ib_sa_mad sa_mad;
> +};

You use ib_nl prefix for request and rdma_nl prefix for response... make 
it consistent.

Also, request and response are too generic, maybe use naming which is a 
bit more informative on what you
are doing here?


> +
> +static LIST_HEAD(ib_nl_request_list);
> +static DEFINE_SPINLOCK(ib_nl_request_lock);
> +static atomic_t ib_nl_sa_request_seq;
> +static struct workqueue_struct *ib_nl_wq;
> +static struct delayed_work ib_nl_timed_work;
> +
>   static void ib_sa_add_one(struct ib_device *device);
>   static void ib_sa_remove_one(struct ib_device *device);
>   
> @@ -381,6 +425,244 @@ static const struct ib_field guidinfo_rec_table[] = {
>   	  .size_bits    = 512 },
>   };
>   
> +static int ib_nl_send_mad(void *mad, int len, u32 seq)
> +{
> +	struct sk_buff *skb = NULL;
> +	struct nlmsghdr *nlh;
> +	void *data;
> +	int ret = 0;
> +
> +	skb = nlmsg_new(len, GFP_KERNEL);
> +	if (!skb) {
> +		pr_err("alloc failed ret=%d\n", ret);
> +		return -ENOMEM;
> +	}
> +
> +	data = ibnl_put_msg(skb, &nlh, seq, len, RDMA_NL_MAD,
> +			    RDMA_NL_MAD_REQUEST, GFP_KERNEL);
> +	if (!data) {
> +		kfree_skb(skb);
> +		return -EMSGSIZE;
> +	}
> +	memcpy(data, mad, len);
> +
> +	ret = ibnl_multicast(skb, nlh, RDMA_NL_GROUP_MAD, GFP_KERNEL);
> +	if (!ret) {
> +		ret = len;
> +	} else {
> +		if (ret != -ESRCH)
> +			pr_err("ibnl_multicast failed l=%d, r=%d\n", len, ret);
> +		ret = 0;
> +	}
> +	return ret;
> +}
> +
> +static struct ib_nl_request_info *
> +ib_nl_alloc_request(struct ib_sa_query *query)
> +{
> +	struct ib_nl_request_info *rinfo;
> +
> +	rinfo = kzalloc(sizeof(*rinfo), GFP_ATOMIC);
> +	if (rinfo == NULL)
> +		return ERR_PTR(-ENOMEM);
> +
> +	INIT_LIST_HEAD(&rinfo->list);
> +	rinfo->seq = (u32)atomic_inc_return(&ib_nl_sa_request_seq);
> +	rinfo->query = query;
> +
> +	return rinfo;
> +}
> +
> +static int ib_nl_send_request(struct ib_nl_request_info *rinfo)
> +{
> +	struct ib_mad_send_buf *send_buf;
> +	unsigned long flags;
> +	unsigned long delay;
> +	int ret;
> +
> +	send_buf = rinfo->query->mad_buf;
> +
> +	delay = msecs_to_jiffies(sa_local_svc_timeout_ms);
> +	spin_lock_irqsave(&ib_nl_request_lock, flags);
> +	ret = ib_nl_send_mad(send_buf->mad,
> +			     (send_buf->data_len + send_buf->hdr_len),
> +			     rinfo->seq);
> +
> +	if (ret != (send_buf->data_len + send_buf->hdr_len)) {
> +		kfree(rinfo);
> +		ret = -EIO;
> +		goto request_out;
> +	} else {
> +		ret = 0;
> +	}
> +
> +	rinfo->timeout = delay + jiffies;
> +	list_add_tail(&rinfo->list, &ib_nl_request_list);
> +	/* Start the timeout if this is the only request */
> +	if (ib_nl_request_list.next == &rinfo->list)
> +		queue_delayed_work(ib_nl_wq, &ib_nl_timed_work, delay);
> +
> +request_out:
> +	spin_unlock_irqrestore(&ib_nl_request_lock, flags);
> +
> +	return ret;
> +}
> +
> +static int ib_nl_make_request(struct ib_sa_query *query)
> +{
> +	struct ib_nl_request_info *rinfo;
> +
> +	rinfo = ib_nl_alloc_request(query);
> +	if (IS_ERR(rinfo))
> +		return -ENOMEM;
> +
> +	return ib_nl_send_request(rinfo);
> +}
> +
> +static int ib_nl_cancel_request(struct ib_sa_query *query)
> +{
> +	unsigned long flags;
> +	struct ib_nl_request_info *rinfo;
> +	int found = 0;
> +
> +	spin_lock_irqsave(&ib_nl_request_lock, flags);
> +	list_for_each_entry(rinfo, &ib_nl_request_list, list) {
> +		/* Let the timeout to take care of the callback */
> +		if (query == rinfo->query) {
> +			IB_SA_CANCEL_QUERY(query);
> +			rinfo->timeout = jiffies;
> +			list_move(&rinfo->list, &ib_nl_request_list);
> +			found = 1;
> +			mod_delayed_work(ib_nl_wq, &ib_nl_timed_work, 1);
> +			break;
> +		}
> +	}
> +	spin_unlock_irqrestore(&ib_nl_request_lock, flags);
> +
> +	return found;
> +}
> +
> +
> +static int ib_nl_handle_mad_resp(struct sk_buff *skb,
> +				 struct netlink_callback *cb);
> +static struct ibnl_client_cbs ib_sa_cb_table[] = {
> +	[RDMA_NL_MAD_REQUEST] = {
> +		.dump = ib_nl_handle_mad_resp,
> +		.module = THIS_MODULE },
> +};
> +
> +static void send_handler(struct ib_mad_agent *agent,
> +			 struct ib_mad_send_wc *mad_send_wc);
> +
> +static void ib_nl_process_good_rsp(struct ib_sa_query *query,
> +				   struct ib_sa_mad *rsp)
> +{
> +	struct ib_mad_send_wc mad_send_wc;
> +
> +	if (query->callback)
> +		query->callback(query, 0, rsp);
> +
> +	mad_send_wc.send_buf = query->mad_buf;
> +	mad_send_wc.status = IB_WC_SUCCESS;
> +	send_handler(query->mad_buf->mad_agent, &mad_send_wc);
> +}
> +
> +static void ib_nl_request_timeout(struct work_struct *work)
> +{
> +	unsigned long flags;
> +	struct ib_nl_request_info *rinfo;
> +	struct ib_sa_query *query;
> +	unsigned long delay;
> +	struct ib_mad_send_wc mad_send_wc;
> +	int ret;
> +
> +	spin_lock_irqsave(&ib_nl_request_lock, flags);
> +	while (!list_empty(&ib_nl_request_list)) {
> +		rinfo = list_entry(ib_nl_request_list.next,
> +				   struct ib_nl_request_info, list);
> +
> +		if (time_after(rinfo->timeout, jiffies)) {
> +			delay = rinfo->timeout - jiffies;
> +			if ((long)delay <= 0)
> +				delay = 1;
> +			queue_delayed_work(ib_nl_wq, &ib_nl_timed_work, delay);
> +			break;
> +		}
> +
> +		list_del(&rinfo->list);
> +		query = rinfo->query;
> +		IB_SA_DISABLE_LOCAL_SVC(query);
> +		/* Hold the lock to protect against query cancellation */
> +		if (IB_SA_QUERY_CANCELLED(query))
> +			ret = -1;
> +		else
> +			ret = ib_post_send_mad(query->mad_buf, NULL);
> +		if (ret) {
> +			mad_send_wc.send_buf = query->mad_buf;
> +			mad_send_wc.status = IB_WC_WR_FLUSH_ERR;
> +			spin_unlock_irqrestore(&ib_nl_request_lock, flags);
> +			send_handler(query->port->agent, &mad_send_wc);
> +			spin_lock_irqsave(&ib_nl_request_lock, flags);
> +		}
> +		kfree(rinfo);
> +	}
> +	spin_unlock_irqrestore(&ib_nl_request_lock, flags);
> +}
> +
> +static int ib_nl_handle_mad_resp(struct sk_buff *skb,
> +				 struct netlink_callback *cb)
> +{
> +	struct rdma_nl_resp_msg *nl_msg = (struct rdma_nl_resp_msg *)cb->nlh;
> +	unsigned long flags;
> +	struct ib_nl_request_info *rinfo;
> +	struct ib_sa_query *query;
> +	struct ib_mad_send_buf *send_buf;
> +	struct ib_mad_send_wc mad_send_wc;
> +	int found = 0;
> +	int ret;
> +
> +	spin_lock_irqsave(&ib_nl_request_lock, flags);
> +	list_for_each_entry(rinfo, &ib_nl_request_list, list) {
> +		/*
> +		 * If the query is cancelled, let the timeout routine
> +		 * take care of it.
> +		 */
> +		if (nl_msg->nl_hdr.nlmsg_seq == rinfo->seq) {
> +			found = !IB_SA_QUERY_CANCELLED(rinfo->query);
> +			if (found)
> +				list_del(&rinfo->list);
> +			break;
> +		}
> +	}
> +
> +	if (!found) {
> +		spin_unlock_irqrestore(&ib_nl_request_lock, flags);
> +		goto resp_out;
> +	}
> +
> +	query = rinfo->query;
> +	send_buf = query->mad_buf;
> +
> +	if (nl_msg->sa_mad.mad_hdr.status != 0) {
> +		/* if the result is a failure, send out the packet via IB */
> +		IB_SA_DISABLE_LOCAL_SVC(query);
> +		ret = ib_post_send_mad(query->mad_buf, NULL);
> +		spin_unlock_irqrestore(&ib_nl_request_lock, flags);
> +		if (ret) {
> +			mad_send_wc.send_buf = send_buf;
> +			mad_send_wc.status = IB_WC_GENERAL_ERR;
> +			send_handler(query->port->agent, &mad_send_wc);
> +		}
> +	} else {
> +		spin_unlock_irqrestore(&ib_nl_request_lock, flags);
> +		ib_nl_process_good_rsp(query, &nl_msg->sa_mad);
> +	}
> +
> +	kfree(rinfo);
> +resp_out:
> +	return skb->len;
> +}
> +
>   static void free_sm_ah(struct kref *kref)
>   {
>   	struct ib_sa_sm_ah *sm_ah = container_of(kref, struct ib_sa_sm_ah, ref);
> @@ -502,7 +784,13 @@ void ib_sa_cancel_query(int id, struct ib_sa_query *query)
>   	mad_buf = query->mad_buf;
>   	spin_unlock_irqrestore(&idr_lock, flags);
>   
> -	ib_cancel_mad(agent, mad_buf);
> +	/*
> +	 * If the query is still on the netlink request list, schedule
> +	 * it to be cancelled by the timeout routine. Otherwise, it has been
> +	 * sent to the MAD layer and has to be cancelled from there.
> +	 */
> +	if (!ib_nl_cancel_request(query))
> +		ib_cancel_mad(agent, mad_buf);
>   }
>   EXPORT_SYMBOL(ib_sa_cancel_query);
>   
> @@ -638,6 +926,14 @@ static int send_mad(struct ib_sa_query *query, int timeout_ms, gfp_t gfp_mask)
>   	query->mad_buf->context[0] = query;
>   	query->id = id;
>   
> +	if (IB_SA_LOCAL_SVC_ENABLED(query)) {
> +		if (!ibnl_chk_listeners(RDMA_NL_GROUP_MAD)) {
> +			if (!ib_nl_make_request(query))
> +				return id;
> +		}
> +		IB_SA_DISABLE_LOCAL_SVC(query);
> +	}
> +
>   	ret = ib_post_send_mad(query->mad_buf, NULL);
>   	if (ret) {
>   		spin_lock_irqsave(&idr_lock, flags);
> @@ -739,7 +1035,7 @@ int ib_sa_path_rec_get(struct ib_sa_client *client,
>   	port  = &sa_dev->port[port_num - sa_dev->start_port];
>   	agent = port->agent;
>   
> -	query = kmalloc(sizeof *query, gfp_mask);
> +	query = kzalloc(sizeof(*query), gfp_mask);
>   	if (!query)
>   		return -ENOMEM;
>   
> @@ -766,6 +1062,8 @@ int ib_sa_path_rec_get(struct ib_sa_client *client,
>   
>   	*sa_query = &query->sa_query;
>   
> +	IB_SA_ENABLE_LOCAL_SVC(&query->sa_query);
> +
>   	ret = send_mad(&query->sa_query, timeout_ms, gfp_mask);
>   	if (ret < 0)
>   		goto err2;
> @@ -861,7 +1159,7 @@ int ib_sa_service_rec_query(struct ib_sa_client *client,
>   	    method != IB_SA_METHOD_DELETE)
>   		return -EINVAL;
>   
> -	query = kmalloc(sizeof *query, gfp_mask);
> +	query = kzalloc(sizeof(*query), gfp_mask);
>   	if (!query)
>   		return -ENOMEM;
>   
> @@ -953,7 +1251,7 @@ int ib_sa_mcmember_rec_query(struct ib_sa_client *client,
>   	port  = &sa_dev->port[port_num - sa_dev->start_port];
>   	agent = port->agent;
>   
> -	query = kmalloc(sizeof *query, gfp_mask);
> +	query = kzalloc(sizeof(*query), gfp_mask);
>   	if (!query)
>   		return -ENOMEM;
>   
> @@ -1050,7 +1348,7 @@ int ib_sa_guid_info_rec_query(struct ib_sa_client *client,
>   	port  = &sa_dev->port[port_num - sa_dev->start_port];
>   	agent = port->agent;
>   
> -	query = kmalloc(sizeof *query, gfp_mask);
> +	query = kzalloc(sizeof(*query), gfp_mask);
>   	if (!query)
>   		return -ENOMEM;

Please move the three kmalloc --> kzalloc changes above (and more of 
their such if exist in the patch) to a pre-patch


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