[PATCH 3.12 082/127] IB/cm: Mark stale CM id's whenever the mad agent was unregistered

From: Jiri Slaby
Date: Fri Nov 25 2016 - 03:43:13 EST

From: Mark Bloch <markb@xxxxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 9db0ff53cb9b43ed75bacd42a89c1a0ab048b2b0 upstream.

When there is a CM id object that has port assigned to it, it means that
the cm-id asked for the specific port that it should go by it, but if
that port was removed (hot-unplug event) the cm-id was not updated.
In order to fix that the port keeps a list of all the cm-id's that are
planning to go by it, whenever the port is removed it marks all of them
as invalid.

This commit fixes a kernel panic which happens when running traffic between
guests and we force reboot a guest mid traffic, it triggers a kernel panic:

Call Trace:
[<ffffffff815271fa>] ? panic+0xa7/0x16f
[<ffffffff8152b534>] ? oops_end+0xe4/0x100
[<ffffffff8104a00b>] ? no_context+0xfb/0x260
[<ffffffff81084db2>] ? del_timer_sync+0x22/0x30
[<ffffffff8104a295>] ? __bad_area_nosemaphore+0x125/0x1e0
[<ffffffff81084240>] ? process_timeout+0x0/0x10
[<ffffffff8104a363>] ? bad_area_nosemaphore+0x13/0x20
[<ffffffff8104aabf>] ? __do_page_fault+0x31f/0x480
[<ffffffff81065df0>] ? default_wake_function+0x0/0x20
[<ffffffffa0752675>] ? free_msg+0x55/0x70 [mlx5_core]
[<ffffffffa0753434>] ? cmd_exec+0x124/0x840 [mlx5_core]
[<ffffffff8105a924>] ? find_busiest_group+0x244/0x9f0
[<ffffffff8152d45e>] ? do_page_fault+0x3e/0xa0
[<ffffffff8152a815>] ? page_fault+0x25/0x30
[<ffffffffa024da25>] ? cm_alloc_msg+0x35/0xc0 [ib_cm]
[<ffffffffa024e821>] ? ib_send_cm_dreq+0xb1/0x1e0 [ib_cm]
[<ffffffffa024f836>] ? cm_destroy_id+0x176/0x320 [ib_cm]
[<ffffffffa024fb00>] ? ib_destroy_cm_id+0x10/0x20 [ib_cm]
[<ffffffffa034f527>] ? ipoib_cm_free_rx_reap_list+0xa7/0x110 [ib_ipoib]
[<ffffffffa034f590>] ? ipoib_cm_rx_reap+0x0/0x20 [ib_ipoib]
[<ffffffffa034f5a5>] ? ipoib_cm_rx_reap+0x15/0x20 [ib_ipoib]
[<ffffffff81094d20>] ? worker_thread+0x170/0x2a0
[<ffffffff8109b2a0>] ? autoremove_wake_function+0x0/0x40
[<ffffffff81094bb0>] ? worker_thread+0x0/0x2a0
[<ffffffff8109aef6>] ? kthread+0x96/0xa0
[<ffffffff8100c20a>] ? child_rip+0xa/0x20
[<ffffffff8109ae60>] ? kthread+0x0/0xa0
[<ffffffff8100c200>] ? child_rip+0x0/0x20

Fixes: a977049dacde ("[PATCH] IB: Add the kernel CM implementation")
Signed-off-by: Mark Bloch <markb@xxxxxxxxxxxx>
Signed-off-by: Erez Shitrit <erezsh@xxxxxxxxxxxx>
Reviewed-by: Maor Gottlieb <maorg@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/infiniband/core/cm.c | 127 +++++++++++++++++++++++++++++++++++++------
1 file changed, 111 insertions(+), 16 deletions(-)

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index c410217fbe89..951a4f6a3b11 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -79,6 +79,8 @@ static struct ib_cm {
__be32 random_id_operand;
struct list_head timewait_list;
struct workqueue_struct *wq;
+ /* Sync on cm change port state */
+ spinlock_t state_lock;
} cm;

/* Counter indexes ordered by attribute ID */
@@ -160,6 +162,8 @@ struct cm_port {
struct ib_mad_agent *mad_agent;
struct kobject port_obj;
u8 port_num;
+ struct list_head cm_priv_prim_list;
+ struct list_head cm_priv_altr_list;
struct cm_counter_group counter_group[CM_COUNTER_GROUPS];
};

@@ -237,6 +241,12 @@ struct cm_id_private {
u8 service_timeout;
u8 target_ack_delay;

+ struct list_head prim_list;
+ struct list_head altr_list;
+ /* Indicates that the send port mad is registered and av is set */
+ int prim_send_port_not_ready;
+ int altr_send_port_not_ready;
+
struct list_head work_list;
atomic_t work_count;
};
@@ -255,19 +265,46 @@ static int cm_alloc_msg(struct cm_id_private *cm_id_priv,
struct ib_mad_agent *mad_agent;
struct ib_mad_send_buf *m;
struct ib_ah *ah;
+ struct cm_av *av;
+ unsigned long flags, flags2;
+ int ret = 0;

+ /* don't let the port to be released till the agent is down */
+ spin_lock_irqsave(&cm.state_lock, flags2);
+ spin_lock_irqsave(&cm.lock, flags);
+ if (!cm_id_priv->prim_send_port_not_ready)
+ av = &cm_id_priv->av;
+ else if (!cm_id_priv->altr_send_port_not_ready &&
+ (cm_id_priv->alt_av.port))
+ av = &cm_id_priv->alt_av;
+ else {
+ pr_info("%s: not valid CM id\n", __func__);
+ ret = -ENODEV;
+ spin_unlock_irqrestore(&cm.lock, flags);
+ goto out;
+ }
+ spin_unlock_irqrestore(&cm.lock, flags);
+ /* Make sure the port haven't released the mad yet */
mad_agent = cm_id_priv->av.port->mad_agent;
- ah = ib_create_ah(mad_agent->qp->pd, &cm_id_priv->av.ah_attr);
- if (IS_ERR(ah))
- return PTR_ERR(ah);
+ if (!mad_agent) {
+ pr_info("%s: not a valid MAD agent\n", __func__);
+ ret = -ENODEV;
+ goto out;
+ }
+ ah = ib_create_ah(mad_agent->qp->pd, &av->ah_attr);
+ if (IS_ERR(ah)) {
+ ret = PTR_ERR(ah);
+ goto out;
+ }

m = ib_create_send_mad(mad_agent, cm_id_priv->id.remote_cm_qpn,
- cm_id_priv->av.pkey_index,
+ av->pkey_index,
0, IB_MGMT_MAD_HDR, IB_MGMT_MAD_DATA,
GFP_ATOMIC);
if (IS_ERR(m)) {
ib_destroy_ah(ah);
- return PTR_ERR(m);
+ ret = PTR_ERR(m);
+ goto out;
}

/* Timeout set by caller if response is expected. */
@@ -277,7 +314,10 @@ static int cm_alloc_msg(struct cm_id_private *cm_id_priv,
atomic_inc(&cm_id_priv->refcount);
m->context[0] = cm_id_priv;
*msg = m;
- return 0;
+
+out:
+ spin_unlock_irqrestore(&cm.state_lock, flags2);
+ return ret;
}

static int cm_alloc_response_msg(struct cm_port *port,
@@ -346,7 +386,8 @@ static void cm_init_av_for_response(struct cm_port *port, struct ib_wc *wc,
grh, &av->ah_attr);
}

-static int cm_init_av_by_path(struct ib_sa_path_rec *path, struct cm_av *av)
+static int cm_init_av_by_path(struct ib_sa_path_rec *path, struct cm_av *av,
+ struct cm_id_private *cm_id_priv)
{
struct cm_device *cm_dev;
struct cm_port *port = NULL;
@@ -376,7 +417,18 @@ static int cm_init_av_by_path(struct ib_sa_path_rec *path, struct cm_av *av)
ib_init_ah_from_path(cm_dev->ib_device, port->port_num, path,
&av->ah_attr);
av->timeout = path->packet_life_time + 1;
- return 0;
+
+ spin_lock_irqsave(&cm.lock, flags);
+ if (&cm_id_priv->av == av)
+ list_add_tail(&cm_id_priv->prim_list, &port->cm_priv_prim_list);
+ else if (&cm_id_priv->alt_av == av)
+ list_add_tail(&cm_id_priv->altr_list, &port->cm_priv_altr_list);
+ else
+ ret = -EINVAL;
+
+ spin_unlock_irqrestore(&cm.lock, flags);
+
+ return ret;
}

static int cm_alloc_id(struct cm_id_private *cm_id_priv)
@@ -716,6 +768,8 @@ struct ib_cm_id *ib_create_cm_id(struct ib_device *device,
spin_lock_init(&cm_id_priv->lock);
init_completion(&cm_id_priv->comp);
INIT_LIST_HEAD(&cm_id_priv->work_list);
+ INIT_LIST_HEAD(&cm_id_priv->prim_list);
+ INIT_LIST_HEAD(&cm_id_priv->altr_list);
atomic_set(&cm_id_priv->work_count, -1);
atomic_set(&cm_id_priv->refcount, 1);
return &cm_id_priv->id;
@@ -914,6 +968,15 @@ retest:
break;
}

+ spin_lock_irq(&cm.lock);
+ if (!list_empty(&cm_id_priv->altr_list) &&
+ (!cm_id_priv->altr_send_port_not_ready))
+ list_del(&cm_id_priv->altr_list);
+ if (!list_empty(&cm_id_priv->prim_list) &&
+ (!cm_id_priv->prim_send_port_not_ready))
+ list_del(&cm_id_priv->prim_list);
+ spin_unlock_irq(&cm.lock);
+
cm_free_id(cm_id->local_id);
cm_deref_id(cm_id_priv);
wait_for_completion(&cm_id_priv->comp);
@@ -1137,12 +1200,13 @@ int ib_send_cm_req(struct ib_cm_id *cm_id,
goto out;
}

- ret = cm_init_av_by_path(param->primary_path, &cm_id_priv->av);
+ ret = cm_init_av_by_path(param->primary_path, &cm_id_priv->av,
+ cm_id_priv);
if (ret)
goto error1;
if (param->alternate_path) {
ret = cm_init_av_by_path(param->alternate_path,
- &cm_id_priv->alt_av);
+ &cm_id_priv->alt_av, cm_id_priv);
if (ret)
goto error1;
}
@@ -1562,7 +1626,8 @@ static int cm_req_handler(struct cm_work *work)

cm_process_routed_req(req_msg, work->mad_recv_wc->wc);
cm_format_paths_from_req(req_msg, &work->path[0], &work->path[1]);
- ret = cm_init_av_by_path(&work->path[0], &cm_id_priv->av);
+ ret = cm_init_av_by_path(&work->path[0], &cm_id_priv->av,
+ cm_id_priv);
if (ret) {
ib_get_cached_gid(work->port->cm_dev->ib_device,
work->port->port_num, 0, &work->path[0].sgid);
@@ -1572,7 +1637,8 @@ static int cm_req_handler(struct cm_work *work)
goto rejected;
}
if (req_msg->alt_local_lid) {
- ret = cm_init_av_by_path(&work->path[1], &cm_id_priv->alt_av);
+ ret = cm_init_av_by_path(&work->path[1], &cm_id_priv->alt_av,
+ cm_id_priv);
if (ret) {
ib_send_cm_rej(cm_id, IB_CM_REJ_INVALID_ALT_GID,
&work->path[0].sgid,
@@ -2627,7 +2693,8 @@ int ib_send_cm_lap(struct ib_cm_id *cm_id,
goto out;
}

- ret = cm_init_av_by_path(alternate_path, &cm_id_priv->alt_av);
+ ret = cm_init_av_by_path(alternate_path, &cm_id_priv->alt_av,
+ cm_id_priv);
if (ret)
goto out;
cm_id_priv->alt_av.timeout =
@@ -2739,7 +2806,8 @@ static int cm_lap_handler(struct cm_work *work)
cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
work->mad_recv_wc->recv_buf.grh,
&cm_id_priv->av);
- cm_init_av_by_path(param->alternate_path, &cm_id_priv->alt_av);
+ cm_init_av_by_path(param->alternate_path, &cm_id_priv->alt_av,
+ cm_id_priv);
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
@@ -2931,7 +2999,7 @@ int ib_send_cm_sidr_req(struct ib_cm_id *cm_id,
return -EINVAL;

cm_id_priv = container_of(cm_id, struct cm_id_private, id);
- ret = cm_init_av_by_path(param->path, &cm_id_priv->av);
+ ret = cm_init_av_by_path(param->path, &cm_id_priv->av, cm_id_priv);
if (ret)
goto out;

@@ -3352,7 +3420,9 @@ out:
static int cm_migrate(struct ib_cm_id *cm_id)
{
struct cm_id_private *cm_id_priv;
+ struct cm_av tmp_av;
unsigned long flags;
+ int tmp_send_port_not_ready;
int ret = 0;

cm_id_priv = container_of(cm_id, struct cm_id_private, id);
@@ -3361,7 +3431,14 @@ static int cm_migrate(struct ib_cm_id *cm_id)
(cm_id->lap_state == IB_CM_LAP_UNINIT ||
cm_id->lap_state == IB_CM_LAP_IDLE)) {
cm_id->lap_state = IB_CM_LAP_IDLE;
+ /* Swap address vector */
+ tmp_av = cm_id_priv->av;
cm_id_priv->av = cm_id_priv->alt_av;
+ cm_id_priv->alt_av = tmp_av;
+ /* Swap port send ready state */
+ tmp_send_port_not_ready = cm_id_priv->prim_send_port_not_ready;
+ cm_id_priv->prim_send_port_not_ready = cm_id_priv->altr_send_port_not_ready;
+ cm_id_priv->altr_send_port_not_ready = tmp_send_port_not_ready;
} else
ret = -EINVAL;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
@@ -3767,6 +3844,9 @@ static void cm_add_one(struct ib_device *ib_device)
port->cm_dev = cm_dev;
port->port_num = i;

+ INIT_LIST_HEAD(&port->cm_priv_prim_list);
+ INIT_LIST_HEAD(&port->cm_priv_altr_list);
+
ret = cm_create_port_fs(port);
if (ret)
goto error1;
@@ -3813,6 +3893,8 @@ static void cm_remove_one(struct ib_device *ib_device)
{
struct cm_device *cm_dev;
struct cm_port *port;
+ struct cm_id_private *cm_id_priv;
+ struct ib_mad_agent *cur_mad_agent;
struct ib_port_modify port_modify = {
.clr_port_cap_mask = IB_PORT_CM_SUP
};
@@ -3830,10 +3912,22 @@ static void cm_remove_one(struct ib_device *ib_device)
for (i = 1; i <= ib_device->phys_port_cnt; i++) {
port = cm_dev->port[i-1];
ib_modify_port(ib_device, port->port_num, 0, &port_modify);
- ib_unregister_mad_agent(port->mad_agent);
+ /* Mark all the cm_id's as not valid */
+ spin_lock_irq(&cm.lock);
+ list_for_each_entry(cm_id_priv, &port->cm_priv_altr_list, altr_list)
+ cm_id_priv->altr_send_port_not_ready = 1;
+ list_for_each_entry(cm_id_priv, &port->cm_priv_prim_list, prim_list)
+ cm_id_priv->prim_send_port_not_ready = 1;
+ spin_unlock_irq(&cm.lock);
flush_workqueue(cm.wq);
+ spin_lock_irq(&cm.state_lock);
+ cur_mad_agent = port->mad_agent;
+ port->mad_agent = NULL;
+ spin_unlock_irq(&cm.state_lock);
+ ib_unregister_mad_agent(cur_mad_agent);
cm_remove_port_fs(port);
}
+
device_unregister(cm_dev->device);
kfree(cm_dev);
}
@@ -3846,6 +3940,7 @@ static int __init ib_cm_init(void)
INIT_LIST_HEAD(&cm.device_list);
rwlock_init(&cm.device_lock);
spin_lock_init(&cm.lock);
+ spin_lock_init(&cm.state_lock);
cm.listen_service_table = RB_ROOT;
cm.listen_service_id = be64_to_cpu(IB_CM_ASSIGN_SERVICE_ID);
cm.remote_id_table = RB_ROOT;
--
2.10.2