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* [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully
@ 2021-08-02  9:14 Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 1/8] nvme-fc: Update hardware queues before using them Daniel Wagner
                   ` (7 more replies)
  0 siblings, 8 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02  9:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, Daniel Wagner

Hi,

This update version makes sure the unfreeze call is done when
recreating the queues. I was able to reproduce hanging I/Os when we go
into error recovery mode for FC and TCP [1]. Unfortunatly, I don't
have access to a RDMA setup to verify but as the code is identically
to the TCP, RDMA looks to like to suffer from the same problem.

Thanks,
Daniel

[1] https://lore.kernel.org/linux-nvme/20210730094907.5vg7qebggttibogz@beryllium.lan/
    https://lore.kernel.org/linux-nvme/20210730113415.wezsrvxv5cu4yz4x@beryllium.lan/


v1:
 - https://lore.kernel.org/linux-nvme/20210625101649.49296-1-dwagner@suse.de/
v2:
 - https://lore.kernel.org/linux-nvme/20210708092755.15660-1-dwagner@suse.de/
 - reviewed tags collected
 - added 'update hardware queues' for all transport
 - added fix for fc hanger in nvme_wait_freeze_timeout
v3:
 - https://lore.kernel.org/linux-nvme/20210720124353.127959-1-dwagner@suse.de/
 - dropped 'nvme-fc: Freeze queues before destroying them'
 - added James' two patches
v4:
 - added 'nvme-*: Unfreeze queues on reconnect'
 - added Hannes' reviewed tags
 

Daniel Wagner (5):
  nvme-fc: Update hardware queues before using them
  nvme-rdma: Update number of hardware queues before using them
  nvme-fc: Wait with a timeout for queue to freeze
  nvme-tcp: Unfreeze queues on reconnect
  nvme-rdma: Unfreeze queues on reconnect

Hannes Reinecke (1):
  nvme-tcp: Update number of hardware queues before using them

James Smart (2):
  nvme-fc: avoid race between time out and tear down
  nvme-fc: fix controller reset hang during traffic

 drivers/nvme/host/fc.c   | 28 +++++++++++++++++++---------
 drivers/nvme/host/rdma.c | 15 ++++++++-------
 drivers/nvme/host/tcp.c  | 18 +++++++++---------
 3 files changed, 36 insertions(+), 25 deletions(-)

-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v4 1/8] nvme-fc: Update hardware queues before using them
  2021-08-02  9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
@ 2021-08-02  9:14 ` Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 2/8] nvme-tcp: Update number of " Daniel Wagner
                   ` (6 subsequent siblings)
  7 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02  9:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, Daniel Wagner, James Smart

In case the number of hardware queues changes, do the update the
tagset and ctx to hctx first before using the mapping to recreate and
connnect the IO queues.

Reviewed-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/fc.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 7f462af1b02a..8a903769364f 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2951,14 +2951,6 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
 	if (ctrl->ctrl.queue_count == 1)
 		return 0;
 
-	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
-	if (ret)
-		goto out_free_io_queues;
-
-	ret = nvme_fc_connect_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
-	if (ret)
-		goto out_delete_hw_queues;
-
 	if (prior_ioq_cnt != nr_io_queues) {
 		dev_info(ctrl->ctrl.device,
 			"reconnect: revising io queue count from %d to %d\n",
@@ -2968,6 +2960,14 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
 		nvme_unfreeze(&ctrl->ctrl);
 	}
 
+	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
+	if (ret)
+		goto out_free_io_queues;
+
+	ret = nvme_fc_connect_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
+	if (ret)
+		goto out_delete_hw_queues;
+
 	return 0;
 
 out_delete_hw_queues:
-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them
  2021-08-02  9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 1/8] nvme-fc: Update hardware queues before using them Daniel Wagner
@ 2021-08-02  9:14 ` Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 3/8] nvme-rdma: " Daniel Wagner
                   ` (5 subsequent siblings)
  7 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02  9:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, Daniel Wagner

From: Hannes Reinecke <hare@suse.de>

When the number of hardware queues changes during resetting we should
update the tagset first before using it.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/tcp.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 0a97ba02f61e..32268f24f62a 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1789,6 +1789,7 @@ static void nvme_tcp_destroy_io_queues(struct nvme_ctrl *ctrl, bool remove)
 static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new)
 {
 	int ret;
+	u32 prior_q_cnt = ctrl->queue_count;
 
 	ret = nvme_tcp_alloc_io_queues(ctrl);
 	if (ret)
@@ -1806,14 +1807,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new)
 			ret = PTR_ERR(ctrl->connect_q);
 			goto out_free_tag_set;
 		}
-	}
-
-	ret = nvme_tcp_start_io_queues(ctrl);
-	if (ret)
-		goto out_cleanup_connect_q;
-
-	if (!new) {
-		nvme_start_queues(ctrl);
+	} else if (prior_q_cnt != ctrl->queue_count) {
 		if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) {
 			/*
 			 * If we timed out waiting for freeze we are likely to
@@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new)
 		nvme_unfreeze(ctrl);
 	}
 
+	ret = nvme_tcp_start_io_queues(ctrl);
+	if (ret)
+		goto out_cleanup_connect_q;
+
 	return 0;
 
 out_wait_freeze_timed_out:
-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v4 3/8] nvme-rdma: Update number of hardware queues before using them
  2021-08-02  9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 1/8] nvme-fc: Update hardware queues before using them Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 2/8] nvme-tcp: Update number of " Daniel Wagner
@ 2021-08-02  9:14 ` Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 4/8] nvme-fc: Wait with a timeout for queue to freeze Daniel Wagner
                   ` (4 subsequent siblings)
  7 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02  9:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, Daniel Wagner

When the number of hardware queues changes during resetting we should
update the tagset first before using it.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/rdma.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 69ae67652f38..de2a8950d282 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -965,6 +965,7 @@ static void nvme_rdma_destroy_io_queues(struct nvme_rdma_ctrl *ctrl,
 static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
 {
 	int ret;
+	u32 prior_q_cnt = ctrl->ctrl.queue_count;
 
 	ret = nvme_rdma_alloc_io_queues(ctrl);
 	if (ret)
@@ -982,13 +983,7 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
 			ret = PTR_ERR(ctrl->ctrl.connect_q);
 			goto out_free_tag_set;
 		}
-	}
-
-	ret = nvme_rdma_start_io_queues(ctrl);
-	if (ret)
-		goto out_cleanup_connect_q;
-
-	if (!new) {
+	} else if (prior_q_cnt != ctrl->ctrl.queue_count) {
 		nvme_start_queues(&ctrl->ctrl);
 		if (!nvme_wait_freeze_timeout(&ctrl->ctrl, NVME_IO_TIMEOUT)) {
 			/*
@@ -1004,6 +999,10 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new)
 		nvme_unfreeze(&ctrl->ctrl);
 	}
 
+	ret = nvme_rdma_start_io_queues(ctrl);
+	if (ret)
+		goto out_cleanup_connect_q;
+
 	return 0;
 
 out_wait_freeze_timed_out:
-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v4 4/8] nvme-fc: Wait with a timeout for queue to freeze
  2021-08-02  9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
                   ` (2 preceding siblings ...)
  2021-08-02  9:14 ` [PATCH v4 3/8] nvme-rdma: " Daniel Wagner
@ 2021-08-02  9:14 ` Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 5/8] nvme-fc: avoid race between time out and tear down Daniel Wagner
                   ` (3 subsequent siblings)
  7 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02  9:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, Daniel Wagner, James Smart

Do not wait indifinitly for all queues to freeze. Instead use a
timeout and abort the operation if we get stuck.

Reviewed-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/fc.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 8a903769364f..dbb8ad816df8 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2955,7 +2955,14 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
 		dev_info(ctrl->ctrl.device,
 			"reconnect: revising io queue count from %d to %d\n",
 			prior_ioq_cnt, nr_io_queues);
-		nvme_wait_freeze(&ctrl->ctrl);
+		if (!nvme_wait_freeze_timeout(&ctrl->ctrl, NVME_IO_TIMEOUT)) {
+			/*
+			 * If we timed out waiting for freeze we are likely to
+			 * be stuck.  Fail the controller initialization just
+			 * to be safe.
+			 */
+			return -ENODEV;
+		}
 		blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues);
 		nvme_unfreeze(&ctrl->ctrl);
 	}
-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v4 5/8] nvme-fc: avoid race between time out and tear down
  2021-08-02  9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
                   ` (3 preceding siblings ...)
  2021-08-02  9:14 ` [PATCH v4 4/8] nvme-fc: Wait with a timeout for queue to freeze Daniel Wagner
@ 2021-08-02  9:14 ` Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic Daniel Wagner
                   ` (2 subsequent siblings)
  7 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02  9:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, James Smart, Chao Leng,
	Daniel Wagner

From: James Smart <jsmart2021@gmail.com>

To avoid race between time out and tear down, in tear down process,
first we quiesce the queue, and then delete the timer and cancel
the time out work for the queue.

This patch merges the admin and io sync ops into the queue teardown logic
as shown in the RDMA patch 3017013dcc "nvme-rdma: avoid race between time
out and tear down". There is no teardown_lock in nvme-fc.

Signed-off-by: James Smart <jsmart2021@gmail.com>
CC: Chao Leng <lengchao@huawei.com>
Tested-by: Daniel Wagner <dwagner@suse.de>
[dwagner: updated commit id referenced in commit message]
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/nvme/host/fc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index dbb8ad816df8..133b87db4f1d 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2487,6 +2487,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
 	 */
 	if (ctrl->ctrl.queue_count > 1) {
 		nvme_stop_queues(&ctrl->ctrl);
+		nvme_sync_io_queues(&ctrl->ctrl);
 		blk_mq_tagset_busy_iter(&ctrl->tag_set,
 				nvme_fc_terminate_exchange, &ctrl->ctrl);
 		blk_mq_tagset_wait_completed_request(&ctrl->tag_set);
@@ -2510,6 +2511,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
 	 * clean up the admin queue. Same thing as above.
 	 */
 	blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
+	blk_sync_queue(ctrl->ctrl.admin_q);
 	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 				nvme_fc_terminate_exchange, &ctrl->ctrl);
 	blk_mq_tagset_wait_completed_request(&ctrl->admin_tag_set);
-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-02  9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
                   ` (4 preceding siblings ...)
  2021-08-02  9:14 ` [PATCH v4 5/8] nvme-fc: avoid race between time out and tear down Daniel Wagner
@ 2021-08-02  9:14 ` Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 7/8] nvme-tcp: Unfreeze queues on reconnect Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 8/8] nvme-rdma: " Daniel Wagner
  7 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02  9:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, James Smart, Daniel Wagner

From: James Smart <jsmart2021@gmail.com>

commit fe35ec58f0d3 ("block: update hctx map when use multiple maps")
exposed an issue where we may hang trying to wait for queue freeze
during I/O. We call blk_mq_update_nr_hw_queues which may attempt to freeze
the queue. However we never started queue freeze when starting the
reset, which means that we have inflight pending requests that entered the
queue that we will not complete once the queue is quiesced.

So start a freeze before we quiesce the queue, and unfreeze the queue
after we successfully connected the I/O queues (the unfreeze is already
present in the code). blk_mq_update_nr_hw_queues will be called only
after we are sure that the queue was already frozen.

This follows to how the pci driver handles resets.

This patch added logic introduced in commit 9f98772ba307 "nvme-rdma: fix
controller reset hang during traffic".

Signed-off-by: James Smart <jsmart2021@gmail.com>
CC: Sagi Grimberg <sagi@grimberg.me>
[dwagner: call nvme_unfreeze() unconditionally in
          nvme_fc_recreate_io_queues() to match the nvme_start_freeze()]
Tested-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/fc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 133b87db4f1d..b292af0fd655 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2486,6 +2486,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
 	 * (but with error status).
 	 */
 	if (ctrl->ctrl.queue_count > 1) {
+		nvme_start_freeze(&ctrl->ctrl);
 		nvme_stop_queues(&ctrl->ctrl);
 		nvme_sync_io_queues(&ctrl->ctrl);
 		blk_mq_tagset_busy_iter(&ctrl->tag_set,
@@ -2966,8 +2967,8 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
 			return -ENODEV;
 		}
 		blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues);
-		nvme_unfreeze(&ctrl->ctrl);
 	}
+	nvme_unfreeze(&ctrl->ctrl);
 
 	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
 	if (ret)
-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v4 7/8] nvme-tcp: Unfreeze queues on reconnect
  2021-08-02  9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
                   ` (5 preceding siblings ...)
  2021-08-02  9:14 ` [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic Daniel Wagner
@ 2021-08-02  9:14 ` Daniel Wagner
  2021-08-02  9:14 ` [PATCH v4 8/8] nvme-rdma: " Daniel Wagner
  7 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02  9:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, Daniel Wagner

During the queue teardown in nvme_tcp_teardown_io_queues() freeze is
called unconditionally. When we reconnect we need to pair the freeze
with an unfreeze to avoid hanging I/Os. For newly created connection
this is not needed.

Fixes: 2875b0aecabe ("nvme-tcp: fix controller reset hang during traffic")
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/tcp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 32268f24f62a..097f7dd10ed3 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1819,9 +1819,11 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new)
 		}
 		blk_mq_update_nr_hw_queues(ctrl->tagset,
 			ctrl->queue_count - 1);
-		nvme_unfreeze(ctrl);
 	}
 
+	if (!new)
+		nvme_unfreeze(ctrl);
+
 	ret = nvme_tcp_start_io_queues(ctrl);
 	if (ret)
 		goto out_cleanup_connect_q;
-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v4 8/8] nvme-rdma: Unfreeze queues on reconnect
  2021-08-02  9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
                   ` (6 preceding siblings ...)
  2021-08-02  9:14 ` [PATCH v4 7/8] nvme-tcp: Unfreeze queues on reconnect Daniel Wagner
@ 2021-08-02  9:14 ` Daniel Wagner
  7 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02  9:14 UTC (permalink / raw)
  To: linux-kernel
  Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, Daniel Wagner

During the queue teardown in nvme_rdma_teardown_io_queues() freeze is
called unconditionally. When we reconnect we need to pair the freeze
with an unfreeze to avoid hanging I/Os. For newly created connection
this is not needed.

Fixes: 9f98772ba307 ("nvme-rdma: fix controller reset hang during traffic")
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/rdma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index de2a8950d282..21a8a5353af0 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -901,6 +901,8 @@ static int nvme_rdma_configure_admin_queue(struct nvme_rdma_ctrl *ctrl,
 			error = PTR_ERR(ctrl->ctrl.admin_q);
 			goto out_cleanup_fabrics_q;
 		}
+	} else {
+		nvme_unfreeze(&ctrl->ctrl);
 	}
 
 	error = nvme_rdma_start_queue(ctrl, 0);
-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-18 11:43       ` Daniel Wagner
@ 2021-08-18 11:49         ` Daniel Wagner
  0 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-18 11:49 UTC (permalink / raw)
  To: James Smart
  Cc: Hannes Reinecke, linux-nvme, linux-kernel, James Smart,
	Keith Busch, Ming Lei, Sagi Grimberg, Wen Xiong

On Wed, Aug 18, 2021 at 01:43:09PM +0200, Daniel Wagner wrote:
> On Thu, Aug 12, 2021 at 01:03:07PM -0700, James Smart wrote:
> > try this. Moves the location of the freeze and will always pair with the
> > unfreeze.
> 
> Yes, this works. Do you send a proper patch out or should I just pick up
> this patch and add a commit message?

Forget it, the commit message is still the same. Let me respin this series.

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-12 20:03     ` James Smart
@ 2021-08-18 11:43       ` Daniel Wagner
  2021-08-18 11:49         ` Daniel Wagner
  0 siblings, 1 reply; 18+ messages in thread
From: Daniel Wagner @ 2021-08-18 11:43 UTC (permalink / raw)
  To: James Smart
  Cc: Hannes Reinecke, linux-nvme, linux-kernel, James Smart,
	Keith Busch, Ming Lei, Sagi Grimberg, Wen Xiong

On Thu, Aug 12, 2021 at 01:03:07PM -0700, James Smart wrote:
> try this. Moves the location of the freeze and will always pair with the
> unfreeze.

Yes, this works. Do you send a proper patch out or should I just pick up
this patch and add a commit message?

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-04  7:23   ` Hannes Reinecke
  2021-08-04  8:08     ` Daniel Wagner
@ 2021-08-12 20:03     ` James Smart
  2021-08-18 11:43       ` Daniel Wagner
  1 sibling, 1 reply; 18+ messages in thread
From: James Smart @ 2021-08-12 20:03 UTC (permalink / raw)
  To: Hannes Reinecke, Daniel Wagner, linux-nvme
  Cc: linux-kernel, James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Wen Xiong

On 8/4/2021 12:23 AM, Hannes Reinecke wrote:
> On 8/2/21 1:26 PM, Daniel Wagner wrote:
>> From: James Smart <jsmart2021@gmail.com>
>>
>> commit fe35ec58f0d3 ("block: update hctx map when use multiple maps")
>> exposed an issue where we may hang trying to wait for queue freeze
>> during I/O. We call blk_mq_update_nr_hw_queues which may attempt to freeze
>> the queue. However we never started queue freeze when starting the
>> reset, which means that we have inflight pending requests that entered the
>> queue that we will not complete once the queue is quiesced.
>>
>> So start a freeze before we quiesce the queue, and unfreeze the queue
>> after we successfully connected the I/O queues (the unfreeze is already
>> present in the code). blk_mq_update_nr_hw_queues will be called only
>> after we are sure that the queue was already frozen.
>>
>> This follows to how the pci driver handles resets.
>>
>> This patch added logic introduced in commit 9f98772ba307 "nvme-rdma: fix
>> controller reset hang during traffic".
>>
>> Signed-off-by: James Smart <jsmart2021@gmail.com>
>> CC: Sagi Grimberg <sagi@grimberg.me>
>> [dwagner: call nvme_unfreeze() unconditionally in
>>            nvme_fc_recreate_io_queues() to match the nvme_start_freeze()]
>> Tested-by: Daniel Wagner <dwagner@suse.de>
>> Reviewed-by: Daniel Wagner <dwagner@suse.de>
>> ---
>>   drivers/nvme/host/fc.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
>> index 133b87db4f1d..b292af0fd655 100644
>> --- a/drivers/nvme/host/fc.c
>> +++ b/drivers/nvme/host/fc.c
>> @@ -2486,6 +2486,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
>>   	 * (but with error status).
>>   	 */
>>   	if (ctrl->ctrl.queue_count > 1) {
>> +		nvme_start_freeze(&ctrl->ctrl);
>>   		nvme_stop_queues(&ctrl->ctrl);
>>   		nvme_sync_io_queues(&ctrl->ctrl);
>>   		blk_mq_tagset_busy_iter(&ctrl->tag_set,
>> @@ -2966,8 +2967,8 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
>>   			return -ENODEV;
>>   		}
>>   		blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues);
>> -		nvme_unfreeze(&ctrl->ctrl);
>>   	}
>> +	nvme_unfreeze(&ctrl->ctrl);
>>   
>>   	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
>>   	if (ret)
>>
> There still is now an imbalance, as we're always calling
> 'nvme_unfreeze()' (irrespective on the number of queues), but will only
> call 'nvme_start_freeze()' if we have more than one queue.
> 
> This might lead to an imbalance on the mq_freeze_depth counter.
> Wouldn't it be better to move the call to 'nvme_start_freeze()' out of
> the if() condition to avoid the imbalance?
> 
> Cheers,

Daniel,

try this. Moves the location of the freeze and will always pair with the 
unfreeze.

--- fc.c	2021-08-12 12:33:33.273278611 -0700
+++ fc.c.new	2021-08-12 13:01:16.185817238 -0700
@@ -2965,9 +2965,10 @@ nvme_fc_recreate_io_queues(struct nvme_f
  			prior_ioq_cnt, nr_io_queues);
  		nvme_wait_freeze(&ctrl->ctrl);
  		blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues);
-		nvme_unfreeze(&ctrl->ctrl);
  	}

+	nvme_unfreeze(&ctrl->ctrl);
+
  	return 0;

  out_delete_hw_queues:
@@ -3206,6 +3207,9 @@ nvme_fc_delete_association(struct nvme_f
  	ctrl->iocnt = 0;
  	spin_unlock_irqrestore(&ctrl->lock, flags);

+	if (ctrl->ctrl.queue_count > 1)
+		nvme_start_freeze(&ctrl->ctrl);
+
  	__nvme_fc_abort_outstanding_ios(ctrl, false);

  	/* kill the aens as they are a separate path */


^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-11  1:05       ` Sagi Grimberg
@ 2021-08-11 10:30         ` Daniel Wagner
  0 siblings, 0 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-11 10:30 UTC (permalink / raw)
  To: Sagi Grimberg
  Cc: Hannes Reinecke, linux-nvme, linux-kernel, James Smart,
	Keith Busch, Ming Lei, Wen Xiong, James Smart

On Tue, Aug 10, 2021 at 06:05:04PM -0700, Sagi Grimberg wrote:
> Why is there a conditional freeze?

The freeze only happens if I/O queues have been created/started. If I
understand this correctly, this is the corner case we were only able to
establish the admin queue and fail later to setup the I/O queues.

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-04  8:08     ` Daniel Wagner
@ 2021-08-11  1:05       ` Sagi Grimberg
  2021-08-11 10:30         ` Daniel Wagner
  0 siblings, 1 reply; 18+ messages in thread
From: Sagi Grimberg @ 2021-08-11  1:05 UTC (permalink / raw)
  To: Daniel Wagner, Hannes Reinecke
  Cc: linux-nvme, linux-kernel, James Smart, Keith Busch, Ming Lei,
	Wen Xiong, James Smart


> On Wed, Aug 04, 2021 at 09:23:49AM +0200, Hannes Reinecke wrote:
>> There still is now an imbalance, as we're always calling
>> 'nvme_unfreeze()' (irrespective on the number of queues), but will only
>> call 'nvme_start_freeze()' if we have more than one queue.
>>
>> This might lead to an imbalance on the mq_freeze_depth counter.
>> Wouldn't it be better to move the call to 'nvme_start_freeze()' out of
>> the if() condition to avoid the imbalance?
> 
> What about something like nmve_is_frozen() which would avoid the tracking
> of the queue state open coded as it is right?

Why is there a conditional freeze?

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-04  7:23   ` Hannes Reinecke
@ 2021-08-04  8:08     ` Daniel Wagner
  2021-08-11  1:05       ` Sagi Grimberg
  2021-08-12 20:03     ` James Smart
  1 sibling, 1 reply; 18+ messages in thread
From: Daniel Wagner @ 2021-08-04  8:08 UTC (permalink / raw)
  To: Hannes Reinecke
  Cc: linux-nvme, linux-kernel, James Smart, Keith Busch, Ming Lei,
	Sagi Grimberg, Wen Xiong, James Smart

On Wed, Aug 04, 2021 at 09:23:49AM +0200, Hannes Reinecke wrote:
> There still is now an imbalance, as we're always calling
> 'nvme_unfreeze()' (irrespective on the number of queues), but will only
> call 'nvme_start_freeze()' if we have more than one queue.
> 
> This might lead to an imbalance on the mq_freeze_depth counter.
> Wouldn't it be better to move the call to 'nvme_start_freeze()' out of
> the if() condition to avoid the imbalance?

What about something like nmve_is_frozen() which would avoid the tracking
of the queue state open coded as it is right?

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-02 11:26 ` [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic Daniel Wagner
  2021-08-02 19:39   ` Himanshu Madhani
@ 2021-08-04  7:23   ` Hannes Reinecke
  2021-08-04  8:08     ` Daniel Wagner
  2021-08-12 20:03     ` James Smart
  1 sibling, 2 replies; 18+ messages in thread
From: Hannes Reinecke @ 2021-08-04  7:23 UTC (permalink / raw)
  To: Daniel Wagner, linux-nvme
  Cc: linux-kernel, James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Wen Xiong, James Smart

On 8/2/21 1:26 PM, Daniel Wagner wrote:
> From: James Smart <jsmart2021@gmail.com>
> 
> commit fe35ec58f0d3 ("block: update hctx map when use multiple maps")
> exposed an issue where we may hang trying to wait for queue freeze
> during I/O. We call blk_mq_update_nr_hw_queues which may attempt to freeze
> the queue. However we never started queue freeze when starting the
> reset, which means that we have inflight pending requests that entered the
> queue that we will not complete once the queue is quiesced.
> 
> So start a freeze before we quiesce the queue, and unfreeze the queue
> after we successfully connected the I/O queues (the unfreeze is already
> present in the code). blk_mq_update_nr_hw_queues will be called only
> after we are sure that the queue was already frozen.
> 
> This follows to how the pci driver handles resets.
> 
> This patch added logic introduced in commit 9f98772ba307 "nvme-rdma: fix
> controller reset hang during traffic".
> 
> Signed-off-by: James Smart <jsmart2021@gmail.com>
> CC: Sagi Grimberg <sagi@grimberg.me>
> [dwagner: call nvme_unfreeze() unconditionally in
>           nvme_fc_recreate_io_queues() to match the nvme_start_freeze()]
> Tested-by: Daniel Wagner <dwagner@suse.de>
> Reviewed-by: Daniel Wagner <dwagner@suse.de>
> ---
>  drivers/nvme/host/fc.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> index 133b87db4f1d..b292af0fd655 100644
> --- a/drivers/nvme/host/fc.c
> +++ b/drivers/nvme/host/fc.c
> @@ -2486,6 +2486,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
>  	 * (but with error status).
>  	 */
>  	if (ctrl->ctrl.queue_count > 1) {
> +		nvme_start_freeze(&ctrl->ctrl);
>  		nvme_stop_queues(&ctrl->ctrl);
>  		nvme_sync_io_queues(&ctrl->ctrl);
>  		blk_mq_tagset_busy_iter(&ctrl->tag_set,
> @@ -2966,8 +2967,8 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
>  			return -ENODEV;
>  		}
>  		blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues);
> -		nvme_unfreeze(&ctrl->ctrl);
>  	}
> +	nvme_unfreeze(&ctrl->ctrl);
>  
>  	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
>  	if (ret)
> 
There still is now an imbalance, as we're always calling
'nvme_unfreeze()' (irrespective on the number of queues), but will only
call 'nvme_start_freeze()' if we have more than one queue.

This might lead to an imbalance on the mq_freeze_depth counter.
Wouldn't it be better to move the call to 'nvme_start_freeze()' out of
the if() condition to avoid the imbalance?

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		           Kernel Storage Architect
hare@suse.de			                  +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Felix Imendörffer

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-02 11:26 ` [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic Daniel Wagner
@ 2021-08-02 19:39   ` Himanshu Madhani
  2021-08-04  7:23   ` Hannes Reinecke
  1 sibling, 0 replies; 18+ messages in thread
From: Himanshu Madhani @ 2021-08-02 19:39 UTC (permalink / raw)
  To: Daniel Wagner, linux-nvme
  Cc: linux-kernel, James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, James Smart



On 8/2/21 6:26 AM, Daniel Wagner wrote:
> From: James Smart <jsmart2021@gmail.com>
> 
> commit fe35ec58f0d3 ("block: update hctx map when use multiple maps")
> exposed an issue where we may hang trying to wait for queue freeze
> during I/O. We call blk_mq_update_nr_hw_queues which may attempt to freeze
> the queue. However we never started queue freeze when starting the
> reset, which means that we have inflight pending requests that entered the
> queue that we will not complete once the queue is quiesced.
> 
> So start a freeze before we quiesce the queue, and unfreeze the queue
> after we successfully connected the I/O queues (the unfreeze is already
> present in the code). blk_mq_update_nr_hw_queues will be called only
> after we are sure that the queue was already frozen.
> 
> This follows to how the pci driver handles resets.
> 
> This patch added logic introduced in commit 9f98772ba307 "nvme-rdma: fix
> controller reset hang during traffic".
> 
> Signed-off-by: James Smart <jsmart2021@gmail.com>
> CC: Sagi Grimberg <sagi@grimberg.me>
> [dwagner: call nvme_unfreeze() unconditionally in
>            nvme_fc_recreate_io_queues() to match the nvme_start_freeze()]
> Tested-by: Daniel Wagner <dwagner@suse.de>
> Reviewed-by: Daniel Wagner <dwagner@suse.de>
> ---
>   drivers/nvme/host/fc.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> index 133b87db4f1d..b292af0fd655 100644
> --- a/drivers/nvme/host/fc.c
> +++ b/drivers/nvme/host/fc.c
> @@ -2486,6 +2486,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
>   	 * (but with error status).
>   	 */
>   	if (ctrl->ctrl.queue_count > 1) {
> +		nvme_start_freeze(&ctrl->ctrl);
>   		nvme_stop_queues(&ctrl->ctrl);
>   		nvme_sync_io_queues(&ctrl->ctrl);
>   		blk_mq_tagset_busy_iter(&ctrl->tag_set,
> @@ -2966,8 +2967,8 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
>   			return -ENODEV;
>   		}
>   		blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues);
> -		nvme_unfreeze(&ctrl->ctrl);
>   	}
> +	nvme_unfreeze(&ctrl->ctrl);
>   
>   	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
>   	if (ret)
> 

Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>

-- 
Himanshu Madhani                                Oracle Linux Engineering

^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic
  2021-08-02 11:26 [PATCH RESEND v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
@ 2021-08-02 11:26 ` Daniel Wagner
  2021-08-02 19:39   ` Himanshu Madhani
  2021-08-04  7:23   ` Hannes Reinecke
  0 siblings, 2 replies; 18+ messages in thread
From: Daniel Wagner @ 2021-08-02 11:26 UTC (permalink / raw)
  To: linux-nvme
  Cc: linux-kernel, James Smart, Keith Busch, Ming Lei, Sagi Grimberg,
	Hannes Reinecke, Wen Xiong, James Smart, Daniel Wagner

From: James Smart <jsmart2021@gmail.com>

commit fe35ec58f0d3 ("block: update hctx map when use multiple maps")
exposed an issue where we may hang trying to wait for queue freeze
during I/O. We call blk_mq_update_nr_hw_queues which may attempt to freeze
the queue. However we never started queue freeze when starting the
reset, which means that we have inflight pending requests that entered the
queue that we will not complete once the queue is quiesced.

So start a freeze before we quiesce the queue, and unfreeze the queue
after we successfully connected the I/O queues (the unfreeze is already
present in the code). blk_mq_update_nr_hw_queues will be called only
after we are sure that the queue was already frozen.

This follows to how the pci driver handles resets.

This patch added logic introduced in commit 9f98772ba307 "nvme-rdma: fix
controller reset hang during traffic".

Signed-off-by: James Smart <jsmart2021@gmail.com>
CC: Sagi Grimberg <sagi@grimberg.me>
[dwagner: call nvme_unfreeze() unconditionally in
          nvme_fc_recreate_io_queues() to match the nvme_start_freeze()]
Tested-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/host/fc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 133b87db4f1d..b292af0fd655 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2486,6 +2486,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)
 	 * (but with error status).
 	 */
 	if (ctrl->ctrl.queue_count > 1) {
+		nvme_start_freeze(&ctrl->ctrl);
 		nvme_stop_queues(&ctrl->ctrl);
 		nvme_sync_io_queues(&ctrl->ctrl);
 		blk_mq_tagset_busy_iter(&ctrl->tag_set,
@@ -2966,8 +2967,8 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
 			return -ENODEV;
 		}
 		blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues);
-		nvme_unfreeze(&ctrl->ctrl);
 	}
+	nvme_unfreeze(&ctrl->ctrl);
 
 	ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1);
 	if (ret)
-- 
2.29.2


^ permalink raw reply	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2021-08-18 11:49 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-02  9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
2021-08-02  9:14 ` [PATCH v4 1/8] nvme-fc: Update hardware queues before using them Daniel Wagner
2021-08-02  9:14 ` [PATCH v4 2/8] nvme-tcp: Update number of " Daniel Wagner
2021-08-02  9:14 ` [PATCH v4 3/8] nvme-rdma: " Daniel Wagner
2021-08-02  9:14 ` [PATCH v4 4/8] nvme-fc: Wait with a timeout for queue to freeze Daniel Wagner
2021-08-02  9:14 ` [PATCH v4 5/8] nvme-fc: avoid race between time out and tear down Daniel Wagner
2021-08-02  9:14 ` [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic Daniel Wagner
2021-08-02  9:14 ` [PATCH v4 7/8] nvme-tcp: Unfreeze queues on reconnect Daniel Wagner
2021-08-02  9:14 ` [PATCH v4 8/8] nvme-rdma: " Daniel Wagner
2021-08-02 11:26 [PATCH RESEND v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner
2021-08-02 11:26 ` [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic Daniel Wagner
2021-08-02 19:39   ` Himanshu Madhani
2021-08-04  7:23   ` Hannes Reinecke
2021-08-04  8:08     ` Daniel Wagner
2021-08-11  1:05       ` Sagi Grimberg
2021-08-11 10:30         ` Daniel Wagner
2021-08-12 20:03     ` James Smart
2021-08-18 11:43       ` Daniel Wagner
2021-08-18 11:49         ` Daniel Wagner

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