[PATCH V4 15/27] ublk: abort requests filled in event kfifo

Ming Lei posted 27 patches 1 week, 3 days ago
[PATCH V4 15/27] ublk: abort requests filled in event kfifo
Posted by Ming Lei 1 week, 3 days ago
In case of BATCH_IO, any request filled in event kfifo, they don't get
chance to be dispatched any more when releasing ublk char device, so
we have to abort them too.

Add ublk_abort_batch_queue() for aborting this kind of requests.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 2e5e392c939e..849199771f86 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -2241,7 +2241,8 @@ static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma)
 static void __ublk_fail_req(struct ublk_device *ub, struct ublk_io *io,
 		struct request *req)
 {
-	WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE);
+	WARN_ON_ONCE(!ublk_dev_support_batch_io(ub) &&
+			io->flags & UBLK_IO_FLAG_ACTIVE);
 
 	if (ublk_nosrv_should_reissue_outstanding(ub))
 		blk_mq_requeue_request(req, false);
@@ -2251,6 +2252,26 @@ static void __ublk_fail_req(struct ublk_device *ub, struct ublk_io *io,
 	}
 }
 
+/*
+ * Request tag may just be filled to event kfifo, not get chance to
+ * dispatch, abort these requests too
+ */
+static void ublk_abort_batch_queue(struct ublk_device *ub,
+				   struct ublk_queue *ubq)
+{
+	while (true) {
+		struct request *req;
+		short tag;
+
+		if (!kfifo_out(&ubq->evts_fifo, &tag, 1))
+			break;
+
+		req = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], tag);
+		if (req && blk_mq_request_started(req))
+			__ublk_fail_req(ub, &ubq->ios[tag], req);
+	}
+}
+
 /*
  * Called from ublk char device release handler, when any uring_cmd is
  * done, meantime request queue is "quiesced" since all inflight requests
@@ -2269,6 +2290,9 @@ static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq)
 		if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)
 			__ublk_fail_req(ub, io, io->req);
 	}
+
+	if (ublk_support_batch_io(ubq))
+		ublk_abort_batch_queue(ub, ubq);
 }
 
 static void ublk_start_cancel(struct ublk_device *ub)
-- 
2.47.0
Re: [PATCH V4 15/27] ublk: abort requests filled in event kfifo
Posted by Caleb Sander Mateos 6 hours ago
On Thu, Nov 20, 2025 at 6:00 PM Ming Lei <ming.lei@redhat.com> wrote:
>
> In case of BATCH_IO, any request filled in event kfifo, they don't get
> chance to be dispatched any more when releasing ublk char device, so
> we have to abort them too.
>
> Add ublk_abort_batch_queue() for aborting this kind of requests.
>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
>  drivers/block/ublk_drv.c | 26 +++++++++++++++++++++++++-
>  1 file changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index 2e5e392c939e..849199771f86 100644
> --- a/drivers/block/ublk_drv.c
> +++ b/drivers/block/ublk_drv.c
> @@ -2241,7 +2241,8 @@ static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma)
>  static void __ublk_fail_req(struct ublk_device *ub, struct ublk_io *io,
>                 struct request *req)
>  {
> -       WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE);
> +       WARN_ON_ONCE(!ublk_dev_support_batch_io(ub) &&
> +                       io->flags & UBLK_IO_FLAG_ACTIVE);
>
>         if (ublk_nosrv_should_reissue_outstanding(ub))
>                 blk_mq_requeue_request(req, false);
> @@ -2251,6 +2252,26 @@ static void __ublk_fail_req(struct ublk_device *ub, struct ublk_io *io,
>         }
>  }
>
> +/*
> + * Request tag may just be filled to event kfifo, not get chance to
> + * dispatch, abort these requests too
> + */
> +static void ublk_abort_batch_queue(struct ublk_device *ub,
> +                                  struct ublk_queue *ubq)
> +{
> +       while (true) {
> +               struct request *req;
> +               short tag;
> +
> +               if (!kfifo_out(&ubq->evts_fifo, &tag, 1))
> +                       break;

This loop could also be written a bit more simply as while
(kfifo_out(&ubq->evts_fifo, &tag, 1)).

Best,
Caleb

> +
> +               req = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], tag);
> +               if (req && blk_mq_request_started(req))
> +                       __ublk_fail_req(ub, &ubq->ios[tag], req);
> +       }
> +}
> +
>  /*
>   * Called from ublk char device release handler, when any uring_cmd is
>   * done, meantime request queue is "quiesced" since all inflight requests
> @@ -2269,6 +2290,9 @@ static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq)
>                 if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)
>                         __ublk_fail_req(ub, io, io->req);
>         }
> +
> +       if (ublk_support_batch_io(ubq))
> +               ublk_abort_batch_queue(ub, ubq);
>  }
>
>  static void ublk_start_cancel(struct ublk_device *ub)
> --
> 2.47.0
>
Re: [PATCH V4 15/27] ublk: abort requests filled in event kfifo
Posted by Caleb Sander Mateos 6 hours ago
On Thu, Nov 20, 2025 at 6:00 PM Ming Lei <ming.lei@redhat.com> wrote:
>
> In case of BATCH_IO, any request filled in event kfifo, they don't get
> chance to be dispatched any more when releasing ublk char device, so
> we have to abort them too.
>
> Add ublk_abort_batch_queue() for aborting this kind of requests.
>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
>  drivers/block/ublk_drv.c | 26 +++++++++++++++++++++++++-
>  1 file changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index 2e5e392c939e..849199771f86 100644
> --- a/drivers/block/ublk_drv.c
> +++ b/drivers/block/ublk_drv.c
> @@ -2241,7 +2241,8 @@ static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma)
>  static void __ublk_fail_req(struct ublk_device *ub, struct ublk_io *io,
>                 struct request *req)
>  {
> -       WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE);
> +       WARN_ON_ONCE(!ublk_dev_support_batch_io(ub) &&
> +                       io->flags & UBLK_IO_FLAG_ACTIVE);
>
>         if (ublk_nosrv_should_reissue_outstanding(ub))
>                 blk_mq_requeue_request(req, false);
> @@ -2251,6 +2252,26 @@ static void __ublk_fail_req(struct ublk_device *ub, struct ublk_io *io,
>         }
>  }
>
> +/*
> + * Request tag may just be filled to event kfifo, not get chance to
> + * dispatch, abort these requests too
> + */
> +static void ublk_abort_batch_queue(struct ublk_device *ub,
> +                                  struct ublk_queue *ubq)
> +{
> +       while (true) {
> +               struct request *req;
> +               short tag;

unsigned short?

> +
> +               if (!kfifo_out(&ubq->evts_fifo, &tag, 1))
> +                       break;
> +
> +               req = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], tag);
> +               if (req && blk_mq_request_started(req))

If the tag is in the evts_fifo, how would it be possible for the
request not to have been started yet?

Best,
Caleb

> +                       __ublk_fail_req(ub, &ubq->ios[tag], req);
> +       }
> +}
> +
>  /*
>   * Called from ublk char device release handler, when any uring_cmd is
>   * done, meantime request queue is "quiesced" since all inflight requests
> @@ -2269,6 +2290,9 @@ static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq)
>                 if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)
>                         __ublk_fail_req(ub, io, io->req);
>         }
> +
> +       if (ublk_support_batch_io(ubq))
> +               ublk_abort_batch_queue(ub, ubq);
>  }
>
>  static void ublk_start_cancel(struct ublk_device *ub)
> --
> 2.47.0
>
Re: [PATCH V4 15/27] ublk: abort requests filled in event kfifo
Posted by Ming Lei 21 minutes ago
On Mon, Dec 01, 2025 at 10:52:22AM -0800, Caleb Sander Mateos wrote:
> On Thu, Nov 20, 2025 at 6:00 PM Ming Lei <ming.lei@redhat.com> wrote:
> >
> > In case of BATCH_IO, any request filled in event kfifo, they don't get
> > chance to be dispatched any more when releasing ublk char device, so
> > we have to abort them too.
> >
> > Add ublk_abort_batch_queue() for aborting this kind of requests.
> >
> > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> > ---
> >  drivers/block/ublk_drv.c | 26 +++++++++++++++++++++++++-
> >  1 file changed, 25 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> > index 2e5e392c939e..849199771f86 100644
> > --- a/drivers/block/ublk_drv.c
> > +++ b/drivers/block/ublk_drv.c
> > @@ -2241,7 +2241,8 @@ static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma)
> >  static void __ublk_fail_req(struct ublk_device *ub, struct ublk_io *io,
> >                 struct request *req)
> >  {
> > -       WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE);
> > +       WARN_ON_ONCE(!ublk_dev_support_batch_io(ub) &&
> > +                       io->flags & UBLK_IO_FLAG_ACTIVE);
> >
> >         if (ublk_nosrv_should_reissue_outstanding(ub))
> >                 blk_mq_requeue_request(req, false);
> > @@ -2251,6 +2252,26 @@ static void __ublk_fail_req(struct ublk_device *ub, struct ublk_io *io,
> >         }
> >  }
> >
> > +/*
> > + * Request tag may just be filled to event kfifo, not get chance to
> > + * dispatch, abort these requests too
> > + */
> > +static void ublk_abort_batch_queue(struct ublk_device *ub,
> > +                                  struct ublk_queue *ubq)
> > +{
> > +       while (true) {
> > +               struct request *req;
> > +               short tag;
> 
> unsigned short?

OK.

> 
> > +
> > +               if (!kfifo_out(&ubq->evts_fifo, &tag, 1))
> > +                       break;
> > +
> > +               req = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], tag);
> > +               if (req && blk_mq_request_started(req))
> 
> If the tag is in the evts_fifo, how would it be possible for the
> request not to have been started yet?

Good point, the above check can be replaced with warn_on_once().


Thanks,
Ming