[Drbd-dev] [PATCH v2 0/2] drbd bugfix and cleanup

[Drbd-dev] [PATCH v2 0/2] drbd bugfix and cleanup

[Wang ShaoBo]

drbd bugfix and cleanup.

v2:
  - add new patch for removing useless memset().

Wang ShaoBo (2):
  drbd: remove call to memset before free device/resource/connection
  drbd: destroy workqueue when drbd device was freed

 drivers/block/drbd/drbd_main.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

-- 
2.25.1

[Drbd-dev] [PATCH v2 1/2] drbd: remove call to memset before free device/resource/connection

[Wang ShaoBo]

This revert c2258ffc56f2 ("drbd: poison free'd device, resource and
connection structs"), add memset is odd here for debugging, there are
some methods to accurately show what happened, such as kdump.

Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
---
 drivers/block/drbd/drbd_main.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 8532b839a343..78cae4e75af1 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2217,7 +2217,6 @@ void drbd_destroy_device(struct kref *kref)
 		kref_put(&peer_device->connection->kref, drbd_destroy_connection);
 		kfree(peer_device);
 	}
-	memset(device, 0xfd, sizeof(*device));
 	kfree(device);
 	kref_put(&resource->kref, drbd_destroy_resource);
 }
@@ -2309,7 +2308,6 @@ void drbd_destroy_resource(struct kref *kref)
 	idr_destroy(&resource->devices);
 	free_cpumask_var(resource->cpu_mask);
 	kfree(resource->name);
-	memset(resource, 0xf2, sizeof(*resource));
 	kfree(resource);
 }
 
@@ -2650,7 +2648,6 @@ void drbd_destroy_connection(struct kref *kref)
 	drbd_free_socket(&connection->data);
 	kfree(connection->int_dig_in);
 	kfree(connection->int_dig_vv);
-	memset(connection, 0xfc, sizeof(*connection));
 	kfree(connection);
 	kref_put(&resource->kref, drbd_destroy_resource);
 }
-- 
2.25.1

[Drbd-dev] [PATCH v2 2/2] drbd: destroy workqueue when drbd device was freed

[Wang ShaoBo]

A submitter workqueue is dynamically allocated by init_submitter()
called by drbd_create_device(), we should destroy it when this
device is not needed or destroyed.

Fixes: 113fef9e20e0 ("drbd: prepare to queue write requests on a submit worker")
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
---
 drivers/block/drbd/drbd_main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 78cae4e75af1..2d6b6d1c5ff4 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2217,6 +2217,8 @@ void drbd_destroy_device(struct kref *kref)
 		kref_put(&peer_device->connection->kref, drbd_destroy_connection);
 		kfree(peer_device);
 	}
+	if (device->submit.wq)
+		destroy_workqueue(device->submit.wq);
 	kfree(device);
 	kref_put(&resource->kref, drbd_destroy_resource);
 }
@@ -2807,6 +2809,8 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
 	put_disk(disk);
 out_no_disk:
 	kref_put(&resource->kref, drbd_destroy_resource);
+	if (device->submit.wq)
+		destroy_workqueue(device->submit.wq);
 	kfree(device);
 	return err;
 }
-- 
2.25.1

Re: [Drbd-dev] [PATCH v2 2/2] drbd: destroy workqueue when drbd device was freed

[Christoph Böhmwalder]

Am 22.11.22 um 04:04 schrieb Wang ShaoBo:
> A submitter workqueue is dynamically allocated by init_submitter()
> called by drbd_create_device(), we should destroy it when this
> device is not needed or destroyed.
> 
> Fixes: 113fef9e20e0 ("drbd: prepare to queue write requests on a submit worker")
> Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
> ---
>  drivers/block/drbd/drbd_main.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
> index 78cae4e75af1..2d6b6d1c5ff4 100644
> --- a/drivers/block/drbd/drbd_main.c
> +++ b/drivers/block/drbd/drbd_main.c
> @@ -2217,6 +2217,8 @@ void drbd_destroy_device(struct kref *kref)
>  		kref_put(&peer_device->connection->kref, drbd_destroy_connection);
>  		kfree(peer_device);
>  	}
> +	if (device->submit.wq)
> +		destroy_workqueue(device->submit.wq);
>  	kfree(device);
>  	kref_put(&resource->kref, drbd_destroy_resource);
>  }
> @@ -2807,6 +2809,8 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
>  	put_disk(disk);
>  out_no_disk:
>  	kref_put(&resource->kref, drbd_destroy_resource);
> +	if (device->submit.wq)
> +		destroy_workqueue(device->submit.wq);
>  	kfree(device);
>  	return err;
>  }

Thanks, that is better.

Just one more nitpick: in drbd_create_device, we usually order the
allocations/frees in a "last in, first out" fashion. That is, data
should be released in the reverse order that it was allocated. This also
helps with error handling, which is what the out_* labels are used for.

So maybe we can put that destroy_workqueue() under its own out_* label
and make sure it gets freed first in the cleanup section (since it gets
allocated last).

-- 
Christoph Böhmwalder
LINBIT | Keeping the Digital World Running
DRBD HA —  Disaster Recovery — Software defined Storage