[PATCH V2] block: add blk_io_schedule() for avoiding task hung in sync dio

[PATCH V2] block: add blk_io_schedule() for avoiding task hung in sync dio

[Ming Lei]

Sync dio could be big, or may take long time in discard or in case of
IO failure.

We have prevented task hung in submit_bio_wait() and blk_execute_rq(),
so apply the same trick for prevent task hung from happening in sync dio.

Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent
task hung warning.

Cc: Salman Qazi <sqazi@google.com>
Cc: Jesse Barnes <jsbarnes@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
V2:
	- drop helper of blk_default_io_timeout()


 fs/block_dev.c         |  4 ++--
 fs/direct-io.c         |  2 +-
 fs/iomap/direct-io.c   |  2 +-
 include/linux/blkdev.h | 12 ++++++++++++
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 5eb30a474f6d..3b396f8c967c 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -256,7 +256,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
 			break;
 		if (!(iocb->ki_flags & IOCB_HIPRI) ||
 		    !blk_poll(bdev_get_queue(bdev), qc, true))
-			io_schedule();
+			blk_io_schedule();
 	}
 	__set_current_state(TASK_RUNNING);
 
@@ -450,7 +450,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
 
 		if (!(iocb->ki_flags & IOCB_HIPRI) ||
 		    !blk_poll(bdev_get_queue(bdev), qc, true))
-			io_schedule();
+			blk_io_schedule();
 	}
 	__set_current_state(TASK_RUNNING);
 
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 00b4d15bb811..6d5370eac2a8 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -500,7 +500,7 @@ static struct bio *dio_await_one(struct dio *dio)
 		spin_unlock_irqrestore(&dio->bio_lock, flags);
 		if (!(dio->iocb->ki_flags & IOCB_HIPRI) ||
 		    !blk_poll(dio->bio_disk->queue, dio->bio_cookie, true))
-			io_schedule();
+			blk_io_schedule();
 		/* wake up sets us TASK_RUNNING */
 		spin_lock_irqsave(&dio->bio_lock, flags);
 		dio->waiter = NULL;
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 20dde5aadcdd..fd3bd06fabb6 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -561,7 +561,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 			    !dio->submit.last_queue ||
 			    !blk_poll(dio->submit.last_queue,
 					 dio->submit.cookie, true))
-				io_schedule();
+				blk_io_schedule();
 		}
 		__set_current_state(TASK_RUNNING);
 	}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index f00bd4042295..222eb5f32279 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -27,6 +27,7 @@
 #include <linux/percpu-refcount.h>
 #include <linux/scatterlist.h>
 #include <linux/blkzoned.h>
+#include <linux/sched/sysctl.h>
 
 struct module;
 struct scsi_ioctl_command;
@@ -1827,4 +1828,15 @@ static inline void blk_wake_io_task(struct task_struct *waiter)
 		wake_up_process(waiter);
 }
 
+static inline void blk_io_schedule(void)
+{
+	/* Prevent hang_check timer from firing at us during very long I/O */
+	unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
+
+	if (timeout)
+		io_schedule_timeout(timeout);
+	else
+		io_schedule();
+}
+
 #endif
-- 
2.25.2

Re: [PATCH V2] block: add blk_io_schedule() for avoiding task hung in sync dio

[Bart Van Assche]

On 2020-05-02 18:54, Ming Lei wrote:
> Sync dio could be big, or may take long time in discard or in case of
> IO failure.
> 
> We have prevented task hung in submit_bio_wait() and blk_execute_rq(),
> so apply the same trick for prevent task hung from happening in sync dio.
> 
> Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent
> task hung warning.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH V2] block: add blk_io_schedule() for avoiding task hung in sync dio

[Ming Lei]

On Sun, May 03, 2020 at 09:54:22AM +0800, Ming Lei wrote:
> Sync dio could be big, or may take long time in discard or in case of
> IO failure.
> 
> We have prevented task hung in submit_bio_wait() and blk_execute_rq(),
> so apply the same trick for prevent task hung from happening in sync dio.
> 
> Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent
> task hung warning.
> 
> Cc: Salman Qazi <sqazi@google.com>
> Cc: Jesse Barnes <jsbarnes@google.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Bart Van Assche <bvanassche@acm.org>
> Cc: Hannes Reinecke <hare@suse.de>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> V2:
> 	- drop helper of blk_default_io_timeout()
> 
> 
>  fs/block_dev.c         |  4 ++--
>  fs/direct-io.c         |  2 +-
>  fs/iomap/direct-io.c   |  2 +-
>  include/linux/blkdev.h | 12 ++++++++++++
>  4 files changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 5eb30a474f6d..3b396f8c967c 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -256,7 +256,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
>  			break;
>  		if (!(iocb->ki_flags & IOCB_HIPRI) ||
>  		    !blk_poll(bdev_get_queue(bdev), qc, true))
> -			io_schedule();
> +			blk_io_schedule();
>  	}
>  	__set_current_state(TASK_RUNNING);
>  
> @@ -450,7 +450,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
>  
>  		if (!(iocb->ki_flags & IOCB_HIPRI) ||
>  		    !blk_poll(bdev_get_queue(bdev), qc, true))
> -			io_schedule();
> +			blk_io_schedule();
>  	}
>  	__set_current_state(TASK_RUNNING);
>  
> diff --git a/fs/direct-io.c b/fs/direct-io.c
> index 00b4d15bb811..6d5370eac2a8 100644
> --- a/fs/direct-io.c
> +++ b/fs/direct-io.c
> @@ -500,7 +500,7 @@ static struct bio *dio_await_one(struct dio *dio)
>  		spin_unlock_irqrestore(&dio->bio_lock, flags);
>  		if (!(dio->iocb->ki_flags & IOCB_HIPRI) ||
>  		    !blk_poll(dio->bio_disk->queue, dio->bio_cookie, true))
> -			io_schedule();
> +			blk_io_schedule();
>  		/* wake up sets us TASK_RUNNING */
>  		spin_lock_irqsave(&dio->bio_lock, flags);
>  		dio->waiter = NULL;
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 20dde5aadcdd..fd3bd06fabb6 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -561,7 +561,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
>  			    !dio->submit.last_queue ||
>  			    !blk_poll(dio->submit.last_queue,
>  					 dio->submit.cookie, true))
> -				io_schedule();
> +				blk_io_schedule();
>  		}
>  		__set_current_state(TASK_RUNNING);
>  	}
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index f00bd4042295..222eb5f32279 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -27,6 +27,7 @@
>  #include <linux/percpu-refcount.h>
>  #include <linux/scatterlist.h>
>  #include <linux/blkzoned.h>
> +#include <linux/sched/sysctl.h>
>  
>  struct module;
>  struct scsi_ioctl_command;
> @@ -1827,4 +1828,15 @@ static inline void blk_wake_io_task(struct task_struct *waiter)
>  		wake_up_process(waiter);
>  }
>  
> +static inline void blk_io_schedule(void)
> +{
> +	/* Prevent hang_check timer from firing at us during very long I/O */
> +	unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
> +
> +	if (timeout)
> +		io_schedule_timeout(timeout);
> +	else
> +		io_schedule();
> +}
> +
>  #endif

Hi Jens and Guys,

Ping...

thanks, 
Ming

Re: [PATCH V2] block: add blk_io_schedule() for avoiding task hung in sync dio

[Jens Axboe]

On 5/2/20 7:54 PM, Ming Lei wrote:
> Sync dio could be big, or may take long time in discard or in case of
> IO failure.
> 
> We have prevented task hung in submit_bio_wait() and blk_execute_rq(),
> so apply the same trick for prevent task hung from happening in sync dio.
> 
> Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent
> task hung warning.

Applied, thanks.

-- 
Jens Axboe

Re: [PATCH V2] block: add blk_io_schedule() for avoiding task hung in sync dio

[Satya Tangirala]

On Sun, May 03, 2020 at 09:54:22AM +0800, Ming Lei wrote:
> Sync dio could be big, or may take long time in discard or in case of
> IO failure.
> 
> We have prevented task hung in submit_bio_wait() and blk_execute_rq(),
> so apply the same trick for prevent task hung from happening in sync dio.
> 
> Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent
> task hung warning.
> 
> Cc: Salman Qazi <sqazi@google.com>
> Cc: Jesse Barnes <jsbarnes@google.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Bart Van Assche <bvanassche@acm.org>
> Cc: Hannes Reinecke <hare@suse.de>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> V2:
> 	- drop helper of blk_default_io_timeout()
> 
> 
>  fs/block_dev.c         |  4 ++--
>  fs/direct-io.c         |  2 +-
>  fs/iomap/direct-io.c   |  2 +-
>  include/linux/blkdev.h | 12 ++++++++++++
>  4 files changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 5eb30a474f6d..3b396f8c967c 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -256,7 +256,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
>  			break;
>  		if (!(iocb->ki_flags & IOCB_HIPRI) ||
>  		    !blk_poll(bdev_get_queue(bdev), qc, true))
> -			io_schedule();
> +			blk_io_schedule();
>  	}
>  	__set_current_state(TASK_RUNNING);
>  
> @@ -450,7 +450,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
>  
>  		if (!(iocb->ki_flags & IOCB_HIPRI) ||
>  		    !blk_poll(bdev_get_queue(bdev), qc, true))
> -			io_schedule();
> +			blk_io_schedule();
>  	}
>  	__set_current_state(TASK_RUNNING);
>  
> diff --git a/fs/direct-io.c b/fs/direct-io.c
> index 00b4d15bb811..6d5370eac2a8 100644
> --- a/fs/direct-io.c
> +++ b/fs/direct-io.c
> @@ -500,7 +500,7 @@ static struct bio *dio_await_one(struct dio *dio)
>  		spin_unlock_irqrestore(&dio->bio_lock, flags);
>  		if (!(dio->iocb->ki_flags & IOCB_HIPRI) ||
>  		    !blk_poll(dio->bio_disk->queue, dio->bio_cookie, true))
> -			io_schedule();
> +			blk_io_schedule();
>  		/* wake up sets us TASK_RUNNING */
>  		spin_lock_irqsave(&dio->bio_lock, flags);
>  		dio->waiter = NULL;
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 20dde5aadcdd..fd3bd06fabb6 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -561,7 +561,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
>  			    !dio->submit.last_queue ||
>  			    !blk_poll(dio->submit.last_queue,
>  					 dio->submit.cookie, true))
> -				io_schedule();
> +				blk_io_schedule();
>  		}
>  		__set_current_state(TASK_RUNNING);
>  	}
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index f00bd4042295..222eb5f32279 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -27,6 +27,7 @@
>  #include <linux/percpu-refcount.h>
>  #include <linux/scatterlist.h>
>  #include <linux/blkzoned.h>
> +#include <linux/sched/sysctl.h>
>  
>  struct module;
>  struct scsi_ioctl_command;
> @@ -1827,4 +1828,15 @@ static inline void blk_wake_io_task(struct task_struct *waiter)
>  		wake_up_process(waiter);
>  }
>  
> +static inline void blk_io_schedule(void)
> +{
> +	/* Prevent hang_check timer from firing at us during very long I/O */
> +	unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
> +
> +	if (timeout)
> +		io_schedule_timeout(timeout);
> +	else
> +		io_schedule();
> +}
> +
>  #endif
This won't compile without CONFIG_BLOCK, since this patch includes
linux/sched/sysctl.h only inside the #ifdef CONFIG_BLOCK, while blk_io_schedule
is declared outside the #ifdef CONFIG_BLOCK, but references
sysctl_hung_task_timeout_secs defined in linux/sched/sysctl.h. Afaict, the
function isn't needed without CONFIG_BLOCK, so maybe we should move the
function into the #ifdef CONFIG_BLOCK too?

> -- 
> 2.25.2
> 

Re: [PATCH V2] block: add blk_io_schedule() for avoiding task hung in sync dio

[Ming Lei]

On Thu, May 14, 2020 at 01:11:10AM +0000, Satya Tangirala wrote:
> On Sun, May 03, 2020 at 09:54:22AM +0800, Ming Lei wrote:
> > Sync dio could be big, or may take long time in discard or in case of
> > IO failure.
> > 
> > We have prevented task hung in submit_bio_wait() and blk_execute_rq(),
> > so apply the same trick for prevent task hung from happening in sync dio.
> > 
> > Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent
> > task hung warning.
> > 
> > Cc: Salman Qazi <sqazi@google.com>
> > Cc: Jesse Barnes <jsbarnes@google.com>
> > Cc: Christoph Hellwig <hch@lst.de>
> > Cc: Bart Van Assche <bvanassche@acm.org>
> > Cc: Hannes Reinecke <hare@suse.de>
> > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> > ---
> > V2:
> > 	- drop helper of blk_default_io_timeout()
> > 
> > 
> >  fs/block_dev.c         |  4 ++--
> >  fs/direct-io.c         |  2 +-
> >  fs/iomap/direct-io.c   |  2 +-
> >  include/linux/blkdev.h | 12 ++++++++++++
> >  4 files changed, 16 insertions(+), 4 deletions(-)
> > 
> > diff --git a/fs/block_dev.c b/fs/block_dev.c
> > index 5eb30a474f6d..3b396f8c967c 100644
> > --- a/fs/block_dev.c
> > +++ b/fs/block_dev.c
> > @@ -256,7 +256,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
> >  			break;
> >  		if (!(iocb->ki_flags & IOCB_HIPRI) ||
> >  		    !blk_poll(bdev_get_queue(bdev), qc, true))
> > -			io_schedule();
> > +			blk_io_schedule();
> >  	}
> >  	__set_current_state(TASK_RUNNING);
> >  
> > @@ -450,7 +450,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
> >  
> >  		if (!(iocb->ki_flags & IOCB_HIPRI) ||
> >  		    !blk_poll(bdev_get_queue(bdev), qc, true))
> > -			io_schedule();
> > +			blk_io_schedule();
> >  	}
> >  	__set_current_state(TASK_RUNNING);
> >  
> > diff --git a/fs/direct-io.c b/fs/direct-io.c
> > index 00b4d15bb811..6d5370eac2a8 100644
> > --- a/fs/direct-io.c
> > +++ b/fs/direct-io.c
> > @@ -500,7 +500,7 @@ static struct bio *dio_await_one(struct dio *dio)
> >  		spin_unlock_irqrestore(&dio->bio_lock, flags);
> >  		if (!(dio->iocb->ki_flags & IOCB_HIPRI) ||
> >  		    !blk_poll(dio->bio_disk->queue, dio->bio_cookie, true))
> > -			io_schedule();
> > +			blk_io_schedule();
> >  		/* wake up sets us TASK_RUNNING */
> >  		spin_lock_irqsave(&dio->bio_lock, flags);
> >  		dio->waiter = NULL;
> > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> > index 20dde5aadcdd..fd3bd06fabb6 100644
> > --- a/fs/iomap/direct-io.c
> > +++ b/fs/iomap/direct-io.c
> > @@ -561,7 +561,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> >  			    !dio->submit.last_queue ||
> >  			    !blk_poll(dio->submit.last_queue,
> >  					 dio->submit.cookie, true))
> > -				io_schedule();
> > +				blk_io_schedule();
> >  		}
> >  		__set_current_state(TASK_RUNNING);
> >  	}
> > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> > index f00bd4042295..222eb5f32279 100644
> > --- a/include/linux/blkdev.h
> > +++ b/include/linux/blkdev.h
> > @@ -27,6 +27,7 @@
> >  #include <linux/percpu-refcount.h>
> >  #include <linux/scatterlist.h>
> >  #include <linux/blkzoned.h>
> > +#include <linux/sched/sysctl.h>
> >  
> >  struct module;
> >  struct scsi_ioctl_command;
> > @@ -1827,4 +1828,15 @@ static inline void blk_wake_io_task(struct task_struct *waiter)
> >  		wake_up_process(waiter);
> >  }
> >  
> > +static inline void blk_io_schedule(void)
> > +{
> > +	/* Prevent hang_check timer from firing at us during very long I/O */
> > +	unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
> > +
> > +	if (timeout)
> > +		io_schedule_timeout(timeout);
> > +	else
> > +		io_schedule();
> > +}
> > +
> >  #endif
> This won't compile without CONFIG_BLOCK, since this patch includes

Thanks for the report.

> linux/sched/sysctl.h only inside the #ifdef CONFIG_BLOCK, while blk_io_schedule
> is declared outside the #ifdef CONFIG_BLOCK, but references
> sysctl_hung_task_timeout_secs defined in linux/sched/sysctl.h. Afaict, the
> function isn't needed without CONFIG_BLOCK, so maybe we should move the
> function into the #ifdef CONFIG_BLOCK too?

Given io_schedule() is always available, I'd suggest to move
"#include <linux/sched/sysctl.h>" out of '#ifdef CONFIG_BLOCK', does the
following patch fixes the issue?

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5360696d85ff..bf99a723673b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -4,6 +4,7 @@
 
 #include <linux/sched.h>
 #include <linux/sched/clock.h>
+#include <linux/sched/sysctl.h>
 
 #ifdef CONFIG_BLOCK
 
@@ -27,7 +28,6 @@
 #include <linux/percpu-refcount.h>
 #include <linux/scatterlist.h>
 #include <linux/blkzoned.h>
-#include <linux/sched/sysctl.h>
 
 struct module;
 struct scsi_ioctl_command;

thanks,
Ming

Re: [PATCH V2] block: add blk_io_schedule() for avoiding task hung in sync dio

[Satya Tangirala]

On Thu, May 14, 2020 at 09:17:10AM +0800, Ming Lei wrote:
> On Thu, May 14, 2020 at 01:11:10AM +0000, Satya Tangirala wrote:
> > On Sun, May 03, 2020 at 09:54:22AM +0800, Ming Lei wrote:
> > > Sync dio could be big, or may take long time in discard or in case of
> > > IO failure.
> > > 
> > > We have prevented task hung in submit_bio_wait() and blk_execute_rq(),
> > > so apply the same trick for prevent task hung from happening in sync dio.
> > > 
> > > Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent
> > > task hung warning.
> > > 
> > > Cc: Salman Qazi <sqazi@google.com>
> > > Cc: Jesse Barnes <jsbarnes@google.com>
> > > Cc: Christoph Hellwig <hch@lst.de>
> > > Cc: Bart Van Assche <bvanassche@acm.org>
> > > Cc: Hannes Reinecke <hare@suse.de>
> > > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> > > ---
> > > V2:
> > > 	- drop helper of blk_default_io_timeout()
> > > 
> > > 
> > >  fs/block_dev.c         |  4 ++--
> > >  fs/direct-io.c         |  2 +-
> > >  fs/iomap/direct-io.c   |  2 +-
> > >  include/linux/blkdev.h | 12 ++++++++++++
> > >  4 files changed, 16 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/fs/block_dev.c b/fs/block_dev.c
> > > index 5eb30a474f6d..3b396f8c967c 100644
> > > --- a/fs/block_dev.c
> > > +++ b/fs/block_dev.c
> > > @@ -256,7 +256,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
> > >  			break;
> > >  		if (!(iocb->ki_flags & IOCB_HIPRI) ||
> > >  		    !blk_poll(bdev_get_queue(bdev), qc, true))
> > > -			io_schedule();
> > > +			blk_io_schedule();
> > >  	}
> > >  	__set_current_state(TASK_RUNNING);
> > >  
> > > @@ -450,7 +450,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
> > >  
> > >  		if (!(iocb->ki_flags & IOCB_HIPRI) ||
> > >  		    !blk_poll(bdev_get_queue(bdev), qc, true))
> > > -			io_schedule();
> > > +			blk_io_schedule();
> > >  	}
> > >  	__set_current_state(TASK_RUNNING);
> > >  
> > > diff --git a/fs/direct-io.c b/fs/direct-io.c
> > > index 00b4d15bb811..6d5370eac2a8 100644
> > > --- a/fs/direct-io.c
> > > +++ b/fs/direct-io.c
> > > @@ -500,7 +500,7 @@ static struct bio *dio_await_one(struct dio *dio)
> > >  		spin_unlock_irqrestore(&dio->bio_lock, flags);
> > >  		if (!(dio->iocb->ki_flags & IOCB_HIPRI) ||
> > >  		    !blk_poll(dio->bio_disk->queue, dio->bio_cookie, true))
> > > -			io_schedule();
> > > +			blk_io_schedule();
> > >  		/* wake up sets us TASK_RUNNING */
> > >  		spin_lock_irqsave(&dio->bio_lock, flags);
> > >  		dio->waiter = NULL;
> > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> > > index 20dde5aadcdd..fd3bd06fabb6 100644
> > > --- a/fs/iomap/direct-io.c
> > > +++ b/fs/iomap/direct-io.c
> > > @@ -561,7 +561,7 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> > >  			    !dio->submit.last_queue ||
> > >  			    !blk_poll(dio->submit.last_queue,
> > >  					 dio->submit.cookie, true))
> > > -				io_schedule();
> > > +				blk_io_schedule();
> > >  		}
> > >  		__set_current_state(TASK_RUNNING);
> > >  	}
> > > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> > > index f00bd4042295..222eb5f32279 100644
> > > --- a/include/linux/blkdev.h
> > > +++ b/include/linux/blkdev.h
> > > @@ -27,6 +27,7 @@
> > >  #include <linux/percpu-refcount.h>
> > >  #include <linux/scatterlist.h>
> > >  #include <linux/blkzoned.h>
> > > +#include <linux/sched/sysctl.h>
> > >  
> > >  struct module;
> > >  struct scsi_ioctl_command;
> > > @@ -1827,4 +1828,15 @@ static inline void blk_wake_io_task(struct task_struct *waiter)
> > >  		wake_up_process(waiter);
> > >  }
> > >  
> > > +static inline void blk_io_schedule(void)
> > > +{
> > > +	/* Prevent hang_check timer from firing at us during very long I/O */
> > > +	unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
> > > +
> > > +	if (timeout)
> > > +		io_schedule_timeout(timeout);
> > > +	else
> > > +		io_schedule();
> > > +}
> > > +
> > >  #endif
> > This won't compile without CONFIG_BLOCK, since this patch includes
> 
> Thanks for the report.
> 
> > linux/sched/sysctl.h only inside the #ifdef CONFIG_BLOCK, while blk_io_schedule
> > is declared outside the #ifdef CONFIG_BLOCK, but references
> > sysctl_hung_task_timeout_secs defined in linux/sched/sysctl.h. Afaict, the
> > function isn't needed without CONFIG_BLOCK, so maybe we should move the
> > function into the #ifdef CONFIG_BLOCK too?
> 
> Given io_schedule() is always available, I'd suggest to move
> "#include <linux/sched/sysctl.h>" out of '#ifdef CONFIG_BLOCK', does the
> following patch fixes the issue?
> 
Yeah sure, that works too :).

> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 5360696d85ff..bf99a723673b 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -4,6 +4,7 @@
>  
>  #include <linux/sched.h>
>  #include <linux/sched/clock.h>
> +#include <linux/sched/sysctl.h>
>  
>  #ifdef CONFIG_BLOCK
>  
> @@ -27,7 +28,6 @@
>  #include <linux/percpu-refcount.h>
>  #include <linux/scatterlist.h>
>  #include <linux/blkzoned.h>
> -#include <linux/sched/sysctl.h>
>  
>  struct module;
>  struct scsi_ioctl_command;
> 
> thanks,
> Ming
>