[PATCH] blkfront:finish requests in io-ring with EIO

[PATCH] blkfront:finish requests in io-ring with EIO

[Gordon Gong]

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Subject: [PATCH] blkfront:finished the requests in io-ring with EIO to avoid
 stucking with state of D.

The sequence of xenwatch of blkfront and xenbus_frontend, when the
tdb path of backend is gone, desided that the backend closing->
frontend closing->backend closed->frontend closed normaly or remove
started by xenbus.
---
 drivers/block/xen-blkfront.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 9ea8c25..6582592 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -653,6 +653,26 @@ static void blkif_restart_queue(struct work_struct
*work)
  spin_unlock_irq(&blkif_io_lock);
 }

+static void finish_requests_sync(struct blkfront_info *info)
+{
+ RING_IDX rc, rp;
+ struct blkif_request *ring_req;
+ struct request *req;
+
+ rc = (info->ring.sring)->req_prod;
+ rp = info->ring.req_prod_pvt;
+
+ while(rc != cp) {
+ unsigned long id;
+
+ ring_req = RING_GET_REQUEST(&info->ring, rc);
+ id = ring_req->id;
+ req = info->shadow[id].request;
+ __blk_end_srequest_all(req, -EIO);
+ rc++;
+ }
+}
+
 static void blkif_free(struct blkfront_info *info, int suspend)
 {
  /* Prevent new requests being issued until we fix things up. */
@@ -664,6 +684,9 @@ static void blkif_free(struct blkfront_info *info, int
suspend)
  blk_stop_queue(info->rq);
  /* No more gnttab callback work. */
  gnttab_cancel_free_callback(&info->callback);
+ /* Finished request in io-ring with EIO */
+ finish_requests_sync(info);
+
  spin_unlock_irq(&blkif_io_lock);

  /* Flush gnttab callback work. Must be done with no locks held. */
-- 
1.8.3.1

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From 98e228ab342065ddb7bb0754e55f1566ebe5938b Mon Sep 17 00:00:00 2001
From: Xiaodong Gong <gordongong0350@gmail.com>
Date: Tue, 1 Apr 2014 03:00:39 -0400
Subject: [PATCH] blkfront:finished the requests in io-ring with EIO to avoid
 stucking with state of D.

The sequence of xenwatch of blkfront and xenbus_frontend, when the
tdb path of backend is gone, desided that the backend closing->
frontend closing->backend closed->frontend closed normaly or remove
started by xenbus.
---
 drivers/block/xen-blkfront.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 9ea8c25..6582592 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -653,6 +653,26 @@ static void blkif_restart_queue(struct work_struct *work)
 	spin_unlock_irq(&blkif_io_lock);
 }
 
+static void finish_requests_sync(struct blkfront_info *info)
+{
+	RING_IDX rc, rp;
+	struct blkif_request *ring_req;
+	struct request *req;
+
+	rc = (info->ring.sring)->req_prod;
+	rp = info->ring.req_prod_pvt;
+
+	while(rc != cp) {
+		unsigned long id;
+
+		ring_req = RING_GET_REQUEST(&info->ring, rc);
+		id = ring_req->id;
+		req = info->shadow[id].request;
+		__blk_end_srequest_all(req, -EIO);
+		rc++;
+	}
+}
+
 static void blkif_free(struct blkfront_info *info, int suspend)
 {
 	/* Prevent new requests being issued until we fix things up. */
@@ -664,6 +684,9 @@ static void blkif_free(struct blkfront_info *info, int suspend)
 		blk_stop_queue(info->rq);
 	/* No more gnttab callback work. */
 	gnttab_cancel_free_callback(&info->callback);
+	/* Finished request in io-ring with EIO */
+	finish_requests_sync(info);
+
 	spin_unlock_irq(&blkif_io_lock);
 
 	/* Flush gnttab callback work. Must be done with no locks held. */
-- 
1.8.3.1


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Re: [PATCH] blkfront:finish requests in io-ring with EIO

[Konrad Rzeszutek Wilk]

On Tue, Apr 01, 2014 at 04:25:12PM +0800, Gordon Gong wrote:
> Subject: [PATCH] blkfront:finished the requests in io-ring with EIO to avoid
>  stucking with state of D.

How do you get to this state?
> 
> The sequence of xenwatch of blkfront and xenbus_frontend, when the
> tdb path of backend is gone, desided that the backend closing->
> frontend closing->backend closed->frontend closed normaly or remove
> started by xenbus.
> ---
>  drivers/block/xen-blkfront.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> index 9ea8c25..6582592 100644
> --- a/drivers/block/xen-blkfront.c
> +++ b/drivers/block/xen-blkfront.c
> @@ -653,6 +653,26 @@ static void blkif_restart_queue(struct work_struct
> *work)
>   spin_unlock_irq(&blkif_io_lock);
>  }
> 
> +static void finish_requests_sync(struct blkfront_info *info)
> +{
> + RING_IDX rc, rp;
> + struct blkif_request *ring_req;
> + struct request *req;
> +
> + rc = (info->ring.sring)->req_prod;
> + rp = info->ring.req_prod_pvt;
> +
> + while(rc != cp) {
> + unsigned long id;
> +
> + ring_req = RING_GET_REQUEST(&info->ring, rc);
> + id = ring_req->id;
> + req = info->shadow[id].request;
> + __blk_end_srequest_all(req, -EIO);
> + rc++;
> + }

Something is off with your editor. You should use tabs.
> +}
> +
>  static void blkif_free(struct blkfront_info *info, int suspend)
>  {
>   /* Prevent new requests being issued until we fix things up. */
> @@ -664,6 +684,9 @@ static void blkif_free(struct blkfront_info *info, int
> suspend)
>   blk_stop_queue(info->rq);
>   /* No more gnttab callback work. */
>   gnttab_cancel_free_callback(&info->callback);
> + /* Finished request in io-ring with EIO */
> + finish_requests_sync(info);
> +
>   spin_unlock_irq(&blkif_io_lock);
> 
>   /* Flush gnttab callback work. Must be done with no locks held. */
> -- 
> 1.8.3.1