[PATCH v3 4/4] IB/sa: Route SA pathrecord query through netlink

kaike.wan-ral2JQCrhuEAvxtiuMwx3w
2015-06-04T12:26:49Z

From: Kaike Wan <kaike.wan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

This patch routes a SA pathrecord query to netlink first and processes the
response appropriately. If a failure is returned, the request will be sent
through IB. The decision whether to route the request to netlink first is
determined by the presence of a listener for the local service netlink
multicast group. If the user-space local service netlink multicast group
listener is not present, the request will be sent through IB, just like
what is currently being done.

Signed-off-by: Kaike Wan <kaike.wan-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: John Fleck <john.fleck-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Sean Hefty <sean.hefty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
drivers/infiniband/core/sa_query.c | 488 +++++++++++++++++++++++++++++++++++-
1 files changed, 487 insertions(+), 1 deletions(-)

diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index 17e1cf7..205a419 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -45,12 +45,21 @@
#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 <uapi/rdma/ib_user_sa.h>
+#include <rdma/ib_marshall.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
+#define IB_SA_LOCAL_SVC_TIMEOUT_MAX 200000
+static int sa_local_svc_timeout_ms = IB_SA_LOCAL_SVC_TIMEOUT_DEFAULT;
+
struct ib_sa_sm_ah {
struct ib_ah *ah;
struct kref ref;
@@ -80,8 +89,25 @@ struct ib_sa_query {
struct ib_mad_send_buf *mad_buf;
struct ib_sa_sm_ah *sm_ah;
int id;
+ u32 flags;
+ void *input;
};

+#define IB_SA_ENABLE_LOCAL_SERVICE 0x00000001
+#define IB_SA_CANCEL 0x00000002
+
+#define IB_SA_LOCAL_SVC_ENABLED(query) \
+ ((query)->flags & IB_SA_ENABLE_LOCAL_SERVICE)
+#define IB_SA_ENABLE_LOCAL_SVC(query) \
+ ((query)->flags |= IB_SA_ENABLE_LOCAL_SERVICE)
+#define IB_SA_DISABLE_LOCAL_SVC(query) \
+ ((query)->flags &= ~IB_SA_ENABLE_LOCAL_SERVICE)
+
+#define IB_SA_QUERY_CANCELLED(query) \
+ ((query)->flags & IB_SA_CANCEL)
+#define IB_SA_CANCEL_QUERY(query) \
+ ((query)->flags |= IB_SA_CANCEL)
+
struct ib_sa_service_query {
void (*callback)(int, struct ib_sa_service_rec *, void *);
void *context;
@@ -106,6 +132,26 @@ struct ib_sa_mcmember_query {
struct ib_sa_query sa_query;
};

+struct ib_nl_request_info {
+ struct list_head list;
+ u32 seq;
+ unsigned long timeout;
+ struct ib_sa_query *query;
+};
+
+struct ib_nl_attr_info {
+ u16 type;
+ u16 len; /* Attribute payload length */
+ void *input;
+ void (*set_attr)(struct sk_buff *skb, struct ib_nl_attr_info *info);
+};
+
+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 +427,405 @@ static const struct ib_field guidinfo_rec_table[] = {
.size_bits = 512 },
};

+static int ib_nl_send_msg(int opcode, struct ib_nl_attr_info *attrs,
+ int num_attrs, u32 seq)
+{
+ struct sk_buff *skb = NULL;
+ struct nlmsghdr *nlh;
+ void *data;
+ int ret = 0;
+ int i, len = 0;
+
+ for (i = 0; i < num_attrs; i++)
+ len += nla_total_size(attrs[i].len);
+
+ if (len <= 0)
+ return -EMSGSIZE;
+
+ skb = nlmsg_new(len, GFP_KERNEL);
+ if (!skb) {
+ pr_err("alloc failed ret=%d\n", ret);
+ return -ENOMEM;
+ }
+
+ /* Put nlmsg header only for now */
+ data = ibnl_put_msg(skb, &nlh, seq, 0, RDMA_NL_SA,
+ opcode, GFP_KERNEL);
+ if (!data) {
+ kfree_skb(skb);
+ return -EMSGSIZE;
+ }
+
+ /* Add attributes */
+ for (i = 0; i < num_attrs; i++)
+ attrs[i].set_attr(skb, &attrs[i]);
+
+ /* Repair the nlmsg header length */
+ nlmsg_end(skb, nlh);
+
+ ret = ibnl_multicast(skb, nlh, RDMA_NL_GROUP_LS, 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 void ib_nl_set_path_rec_attr(struct sk_buff *skb,
+ struct ib_nl_attr_info *info)
+{
+ struct nlattr *nla;
+ struct rdma_nla_ls_path_rec *nla_rec;
+
+ nla = (struct nlattr *) skb_put(skb, nla_total_size(info->len));
+ nla->nla_type = info->type;
+ nla->nla_len = nla_attr_size(info->len);
+ memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(info->len));
+
+ nla_rec = (struct rdma_nla_ls_path_rec *) nla_data(nla);
+ nla_rec->flags = LS_NLA_PATH_F_USER;
+
+ /*
+ * We know that the input is of type struct ib_sa_path_rec while
+ * the output is of type struct ib_user_path_rec.
+ */
+ ib_copy_path_rec_to_user((struct ib_user_path_rec *) nla_rec->path_rec,
+ (struct ib_sa_path_rec *) info->input);
+}
+
+static int ib_nl_send_request(struct ib_nl_request_info *rinfo)
+{
+ struct ib_nl_attr_info info;
+ int opcode;
+ struct ib_sa_mad *mad;
+ unsigned long flags;
+ unsigned long delay;
+ int ret;
+
+ mad = rinfo->query->mad_buf->mad;
+ switch (mad->mad_hdr.attr_id) {
+ case cpu_to_be16(IB_SA_ATTR_PATH_REC):
+ opcode = RDMA_NL_LS_OP_RESOLVE;
+ info.type = LS_NLA_TYPE_PATH_RECORD;
+ info.len = sizeof(struct rdma_nla_ls_path_rec) +
+ sizeof(struct ib_user_path_rec);
+ info.input = rinfo->query->input;
+ info.set_attr = ib_nl_set_path_rec_attr;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&ib_nl_request_lock, flags);
+ ret = ib_nl_send_msg(opcode, &info, 1, rinfo->seq);
+ if (ret <= 0) {
+ ret = -EIO;
+ goto request_out;
+ } else {
+ ret = 0;
+ }
+
+ delay = msecs_to_jiffies(sa_local_svc_timeout_ms);
+ 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;
+ int ret;
+
+ rinfo = ib_nl_alloc_request(query);
+ if (IS_ERR(rinfo))
+ return -ENOMEM;
+
+ ret = ib_nl_send_request(rinfo);
+ if (ret)
+ kfree(rinfo);
+
+ return ret;
+}
+
+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 void send_handler(struct ib_mad_agent *agent,
+ struct ib_mad_send_wc *mad_send_wc);
+
+static void ib_nl_process_good_resolve_rsp(struct ib_sa_query *query,
+ const struct nlmsghdr *nlh)
+{
+ struct ib_mad_send_wc mad_send_wc;
+ struct ib_sa_mad *mad = NULL;
+ const struct nlattr *attr;
+ struct rdma_nla_ls_path_rec *rec;
+ struct ib_user_path_rec *user_rec;
+ struct ib_sa_path_rec sa_rec;
+ struct ib_sa_path_query *path_query =
+ container_of(query, struct ib_sa_path_query, sa_query);
+
+ if (query->callback) {
+ attr = (const struct nlattr *) nlmsg_data(nlh);
+ rec = (struct rdma_nla_ls_path_rec *) nla_data(attr);
+ if (rec->flags & LS_NLA_PATH_F_USER) {
+ user_rec = (struct ib_user_path_rec *)
+ rec->path_rec;
+ memset(&sa_rec, 0, sizeof(sa_rec));
+ ib_copy_path_rec_from_user(&sa_rec, user_rec);
+ path_query->callback(0, &sa_rec, path_query->context);
+ } else {
+ mad = query->mad_buf->mad;
+ mad->mad_hdr.method |= IB_MGMT_METHOD_RESP;
+ memcpy(mad->data, rec->path_rec,
+ nla_len(attr) - sizeof(*rec));
+ query->callback(query, 0, mad);
+ }
+ }
+
+ 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 inline int ib_nl_is_good_resolve_resp(const struct nlmsghdr *nlh)
+{
+ const struct nlattr *attr;
+ struct rdma_nla_ls_path_rec *rec;
+ struct ib_path_rec_data rec_data;
+
+ if (nlh->nlmsg_flags & RDMA_NL_LS_F_ERR)
+ return 0;
+
+ if (!(nlh->nlmsg_flags & RDMA_NL_LS_F_OK))
+ return 0;
+
+ if (nlmsg_len(nlh) < nla_attr_size(sizeof(*rec)))
+ return 0;
+
+ attr = (const struct nlattr *) nlmsg_data(nlh);
+ if (attr->nla_type != LS_NLA_TYPE_PATH_RECORD)
+ return 0;
+
+ rec = (struct rdma_nla_ls_path_rec *) nla_data(attr);
+ if (((rec->flags & LS_NLA_PATH_F_USER) &&
+ nla_len(attr) < sizeof(struct ib_user_path_rec)) ||
+ (!(rec->flags & LS_NLA_PATH_F_USER) &&
+ nla_len(attr) < sizeof(rec_data.path_rec)))
+ return 0;
+
+ return 1;
+}
+
+static int ib_nl_handle_set_timeout(struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ const struct nlmsghdr *nlh = (struct nlmsghdr *)cb->nlh;
+ int timeout, delta, abs_delta;
+ const struct nlattr *attr;
+ struct rdma_nla_ls_timeout *to_attr;
+ unsigned long flags;
+ struct ib_nl_request_info *rinfo;
+ long delay = 0;
+
+ if (nlmsg_len(nlh) < nla_attr_size(sizeof(*to_attr)))
+ goto settimeout_out;
+
+ attr = (const struct nlattr *) nlmsg_data(nlh);
+ if (attr->nla_type != LS_NLA_TYPE_TIMEOUT ||
+ nla_len(attr) != sizeof(*to_attr))
+ goto settimeout_out;
+
+ to_attr = (struct rdma_nla_ls_timeout *) nla_data(attr);
+ timeout = (int) to_attr->timeout;
+ if (timeout < IB_SA_LOCAL_SVC_TIMEOUT_MIN)
+ timeout = IB_SA_LOCAL_SVC_TIMEOUT_MIN;
+ if (timeout > IB_SA_LOCAL_SVC_TIMEOUT_MAX)
+ timeout = IB_SA_LOCAL_SVC_TIMEOUT_MAX;
+
+ delta = timeout - sa_local_svc_timeout_ms;
+ if (delta < 0)
+ abs_delta = -delta;
+ else
+ abs_delta = delta;
+
+ if (delta != 0) {
+ spin_lock_irqsave(&ib_nl_request_lock, flags);
+ sa_local_svc_timeout_ms = timeout;
+ list_for_each_entry(rinfo, &ib_nl_request_list, list) {
+ if (delta < 0 && abs_delta > rinfo->timeout)
+ rinfo->timeout = 0;
+ else
+ rinfo->timeout += delta;
+
+ /* Get the new delay from the first entry */
+ if (!delay) {
+ delay = rinfo->timeout - jiffies;
+ if (delay <= 0)
+ delay = 1;
+ }
+ }
+ if (delay)
+ mod_delayed_work(ib_nl_wq, &ib_nl_timed_work,
+ (unsigned long)delay);
+ spin_unlock_irqrestore(&ib_nl_request_lock, flags);
+ }
+
+settimeout_out:
+ return skb->len;
+}
+
+static int ib_nl_handle_resolve_resp(struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ const struct nlmsghdr *nlh = (struct nlmsghdr *)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 (nlh->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 (!ib_nl_is_good_resolve_resp(nlh)) {
+ /* 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_resolve_rsp(query, nlh);
+ }
+
+ kfree(rinfo);
+resp_out:
+ return skb->len;
+}
+
+static struct ibnl_client_cbs ib_sa_cb_table[] = {
+ [RDMA_NL_LS_OP_RESOLVE] = {
+ .dump = ib_nl_handle_resolve_resp,
+ .module = THIS_MODULE },
+ [RDMA_NL_LS_OP_SET_TIMEOUT] = {
+ .dump = ib_nl_handle_set_timeout,
+ .module = THIS_MODULE },
+};
+
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 +947,13 @@ 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 +1089,14 @@ 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_LS)) {
+ 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);
@@ -766,6 +1225,9 @@ int ib_sa_path_rec_get(struct ib_sa_client *client,

*sa_query = &query->sa_query;

+ IB_SA_ENABLE_LOCAL_SVC(&query->sa_query);
+ query->sa_query.input = rec;
+
ret = send_mad(&query->sa_query, timeout_ms, gfp_mask);
if (ret < 0)
goto err2;
@@ -1250,6 +1712,8 @@ static int __init ib_sa_init(void)

get_random_bytes(&tid, sizeof tid);

+ atomic_set(&ib_nl_sa_request_seq, 0);
+
ret = ib_register_client(&sa_client);
if (ret) {
printk(KERN_ERR "Couldn't register ib_sa client\n");
@@ -1262,7 +1726,25 @@ static int __init ib_sa_init(void)
goto err2;
}

+ ib_nl_wq = create_singlethread_workqueue("ib_nl_sa_wq");
+ if (!ib_nl_wq) {
+ ret = -ENOMEM;
+ goto err3;
+ }
+
+ if (ibnl_add_client(RDMA_NL_SA, RDMA_NL_LS_NUM_OPS,
+ ib_sa_cb_table)) {
+ pr_err("Failed to add netlink callback\n");
+ ret = -EINVAL;
+ goto err4;
+ }
+ INIT_DELAYED_WORK(&ib_nl_timed_work, ib_nl_request_timeout);
+
return 0;
+err4:
+ destroy_workqueue(ib_nl_wq);
+err3:
+ mcast_cleanup();
err2:
ib_unregister_client(&sa_client);
err1:
@@ -1271,6 +1753,10 @@ err1:

static void __exit ib_sa_cleanup(void)
{
+ ibnl_remove_client(RDMA_NL_SA);
+ cancel_delayed_work(&ib_nl_timed_work);
+ flush_workqueue(ib_nl_wq);
+ destroy_workqueue(ib_nl_wq);
mcast_cleanup();
ib_unregister_client(&sa_client);
idr_destroy(&query_idr);
--
1.7.1