From: Ming Lei <ming.lei@redhat.com>
Date: Sun, 3 May 2020 09:54:22 +0800
Subject: [PATCH] block: add blk_io_schedule() for avoiding task hung in sync
dio
Git-commit: e6249cdd46e43a7d3bdb8cce5fe24565d6c11e94
Patch-Mainline: v5.8-rc1
References: bsc#1175995,jsc#SLE-15608
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: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart 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: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
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 7cbb7b79935e..ebd1507789d2 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -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);
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
--
2.16.4