* [PATCH v2 1/1] IB/iSER-Target: Release connection resources properly when receiving RDMA_CM_EVENT_DEVICE_REMOVAL
@ 2016-08-02 8:46 Raju Rangoju
[not found] ` <20160802084635.14414-1-rajur-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
0 siblings, 1 reply; 2+ messages in thread
From: Raju Rangoju @ 2016-08-02 8:46 UTC (permalink / raw)
To: linux-rdma-u79uwXL29TY76Z2rM5mHXA
Cc: sagi-NQWnxTmZq1alnMjI0IkVqw,
swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW, Raju Rangoju
When the low level driver exercises the hot unplug they would call
rdma_cm cma_remove_one which would fire DEVICE_REMOVAL event to all cma
consumers. Now, if consumer doesn't make sure they destroy all IB
objects created on that IB device instance prior to finalizing all
processing of DEVICE_REMOVAL callback, rdma_cm will let the lld to
de-register with IB core and destroy the IB device instance. And if the
consumer calls (say) ib_dereg_mr(), it will crash since that dev object
is NULL.
In the current implementation, iser-target just initiates the cleanup
and returns from DEVICE_REMOVAL callback. This deferred work creates a
race between iser-target cleaning IB objects(say MR) and lld destroying
IB device instance.
This patch includes the following fixes
-> make sure that consumer frees all IB objects associated with device
instance
-> return non-zero from the callback to destroy the rdma_cm id
Signed-off-by: Raju Rangoju <rajur-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
---
Changes since v1:
- Added S.O.B note
drivers/infiniband/ulp/isert/ib_isert.c | 23 ++++++++++++++++++++---
drivers/infiniband/ulp/isert/ib_isert.h | 2 ++
2 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index a990c04..3dfd903 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -405,6 +405,7 @@ isert_init_conn(struct isert_conn *isert_conn)
INIT_LIST_HEAD(&isert_conn->node);
init_completion(&isert_conn->login_comp);
init_completion(&isert_conn->login_req_comp);
+ init_waitqueue_head(&isert_conn->rem_wait);
kref_init(&isert_conn->kref);
mutex_init(&isert_conn->mutex);
INIT_WORK(&isert_conn->release_work, isert_release_work);
@@ -580,7 +581,8 @@ isert_connect_release(struct isert_conn *isert_conn)
BUG_ON(!device);
isert_free_rx_descriptors(isert_conn);
- if (isert_conn->cm_id)
+ if (isert_conn->cm_id &&
+ !isert_conn->dev_removed)
rdma_destroy_id(isert_conn->cm_id);
if (isert_conn->qp) {
@@ -595,7 +597,10 @@ isert_connect_release(struct isert_conn *isert_conn)
isert_device_put(device);
- kfree(isert_conn);
+ if (isert_conn->dev_removed)
+ wake_up_interruptible(&isert_conn->rem_wait);
+ else
+ kfree(isert_conn);
}
static void
@@ -755,6 +760,7 @@ static int
isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
{
struct isert_np *isert_np = cma_id->context;
+ struct isert_conn *isert_conn;
int ret = 0;
isert_info("%s (%d): status %d id %p np %p\n",
@@ -775,10 +781,21 @@ isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
break;
case RDMA_CM_EVENT_ADDR_CHANGE: /* FALLTHRU */
case RDMA_CM_EVENT_DISCONNECTED: /* FALLTHRU */
- case RDMA_CM_EVENT_DEVICE_REMOVAL: /* FALLTHRU */
case RDMA_CM_EVENT_TIMEWAIT_EXIT: /* FALLTHRU */
ret = isert_disconnected_handler(cma_id, event->event);
break;
+ case RDMA_CM_EVENT_DEVICE_REMOVAL:
+ isert_conn = cma_id->qp->qp_context;
+ isert_conn->dev_removed = true;
+ isert_disconnected_handler(cma_id, event->event);
+ wait_event_interruptible(isert_conn->rem_wait,
+ isert_conn->state == ISER_CONN_DOWN);
+ kfree(isert_conn);
+ /*
+ * return non-zero from the callback to destroy
+ * the rdma cm id
+ */
+ return 1;
case RDMA_CM_EVENT_REJECTED: /* FALLTHRU */
case RDMA_CM_EVENT_UNREACHABLE: /* FALLTHRU */
case RDMA_CM_EVENT_CONNECT_ERROR:
diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
index e512ba9..d0c5c2c 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -159,6 +159,8 @@ struct isert_conn {
struct work_struct release_work;
bool logout_posted;
bool snd_w_inv;
+ wait_queue_head_t rem_wait;
+ bool dev_removed;
};
#define ISERT_MAX_CQ 64
--
2.8.3
--
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2 1/1] IB/iSER-Target: Release connection resources properly when receiving RDMA_CM_EVENT_DEVICE_REMOVAL
[not found] ` <20160802084635.14414-1-rajur-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
@ 2016-08-02 9:15 ` Sagi Grimberg
0 siblings, 0 replies; 2+ messages in thread
From: Sagi Grimberg @ 2016-08-02 9:15 UTC (permalink / raw)
To: Raju Rangoju, linux-rdma-u79uwXL29TY76Z2rM5mHXA
Cc: swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW, target-devel,
Nicholas A. Bellinger
> When the low level driver exercises the hot unplug they would call
> rdma_cm cma_remove_one which would fire DEVICE_REMOVAL event to all cma
> consumers. Now, if consumer doesn't make sure they destroy all IB
> objects created on that IB device instance prior to finalizing all
> processing of DEVICE_REMOVAL callback, rdma_cm will let the lld to
> de-register with IB core and destroy the IB device instance. And if the
> consumer calls (say) ib_dereg_mr(), it will crash since that dev object
> is NULL.
>
> In the current implementation, iser-target just initiates the cleanup
> and returns from DEVICE_REMOVAL callback. This deferred work creates a
> race between iser-target cleaning IB objects(say MR) and lld destroying
> IB device instance.
>
> This patch includes the following fixes
> -> make sure that consumer frees all IB objects associated with device
> instance
> -> return non-zero from the callback to destroy the rdma_cm id
>
> Signed-off-by: Raju Rangoju <rajur-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
> ---
> Changes since v1:
> - Added S.O.B note
Hi Raju,
I forgot to mention it, but iser-target patches usually go via the
scsi target tree. CCing target-devel and Nic.
And, you forgot my ack tag:
Acked-by: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
>
> drivers/infiniband/ulp/isert/ib_isert.c | 23 ++++++++++++++++++++---
> drivers/infiniband/ulp/isert/ib_isert.h | 2 ++
> 2 files changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
> index a990c04..3dfd903 100644
> --- a/drivers/infiniband/ulp/isert/ib_isert.c
> +++ b/drivers/infiniband/ulp/isert/ib_isert.c
> @@ -405,6 +405,7 @@ isert_init_conn(struct isert_conn *isert_conn)
> INIT_LIST_HEAD(&isert_conn->node);
> init_completion(&isert_conn->login_comp);
> init_completion(&isert_conn->login_req_comp);
> + init_waitqueue_head(&isert_conn->rem_wait);
> kref_init(&isert_conn->kref);
> mutex_init(&isert_conn->mutex);
> INIT_WORK(&isert_conn->release_work, isert_release_work);
> @@ -580,7 +581,8 @@ isert_connect_release(struct isert_conn *isert_conn)
> BUG_ON(!device);
>
> isert_free_rx_descriptors(isert_conn);
> - if (isert_conn->cm_id)
> + if (isert_conn->cm_id &&
> + !isert_conn->dev_removed)
> rdma_destroy_id(isert_conn->cm_id);
>
> if (isert_conn->qp) {
> @@ -595,7 +597,10 @@ isert_connect_release(struct isert_conn *isert_conn)
>
> isert_device_put(device);
>
> - kfree(isert_conn);
> + if (isert_conn->dev_removed)
> + wake_up_interruptible(&isert_conn->rem_wait);
> + else
> + kfree(isert_conn);
> }
>
> static void
> @@ -755,6 +760,7 @@ static int
> isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
> {
> struct isert_np *isert_np = cma_id->context;
> + struct isert_conn *isert_conn;
> int ret = 0;
>
> isert_info("%s (%d): status %d id %p np %p\n",
> @@ -775,10 +781,21 @@ isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
> break;
> case RDMA_CM_EVENT_ADDR_CHANGE: /* FALLTHRU */
> case RDMA_CM_EVENT_DISCONNECTED: /* FALLTHRU */
> - case RDMA_CM_EVENT_DEVICE_REMOVAL: /* FALLTHRU */
> case RDMA_CM_EVENT_TIMEWAIT_EXIT: /* FALLTHRU */
> ret = isert_disconnected_handler(cma_id, event->event);
> break;
> + case RDMA_CM_EVENT_DEVICE_REMOVAL:
> + isert_conn = cma_id->qp->qp_context;
> + isert_conn->dev_removed = true;
> + isert_disconnected_handler(cma_id, event->event);
> + wait_event_interruptible(isert_conn->rem_wait,
> + isert_conn->state == ISER_CONN_DOWN);
> + kfree(isert_conn);
> + /*
> + * return non-zero from the callback to destroy
> + * the rdma cm id
> + */
> + return 1;
> case RDMA_CM_EVENT_REJECTED: /* FALLTHRU */
> case RDMA_CM_EVENT_UNREACHABLE: /* FALLTHRU */
> case RDMA_CM_EVENT_CONNECT_ERROR:
> diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
> index e512ba9..d0c5c2c 100644
> --- a/drivers/infiniband/ulp/isert/ib_isert.h
> +++ b/drivers/infiniband/ulp/isert/ib_isert.h
> @@ -159,6 +159,8 @@ struct isert_conn {
> struct work_struct release_work;
> bool logout_posted;
> bool snd_w_inv;
> + wait_queue_head_t rem_wait;
> + bool dev_removed;
> };
>
> #define ISERT_MAX_CQ 64
>
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2016-08-02 8:46 [PATCH v2 1/1] IB/iSER-Target: Release connection resources properly when receiving RDMA_CM_EVENT_DEVICE_REMOVAL Raju Rangoju
[not found] ` <20160802084635.14414-1-rajur-ut6Up61K2wZBDgjK7y7TUQ@public.gmane.org>
2016-08-02 9:15 ` Sagi Grimberg
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