Commit e6249cdd authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

block: add blk_io_schedule() for avoiding task hung in sync dio 



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.

Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
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: default avatarJens Axboe <axboe@kernel.dk>
parent 27eb3af9

fs/block_dev.c

+2 −2
Original line number Diff line number Diff line
@@ -255,7 +255,7 @@ __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);
@@ -449,7 +449,7 @@ __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);

fs/direct-io.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

fs/iomap/direct-io.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

	}

include/linux/blkdev.h

+12 −0
Original line number Diff line number Diff line
@@ -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

CRA Git | Maintained and supported by SUSTech CRA and CCSE