[PATCH] mm: use blk_io_schedule() for avoiding task hung in sync io

From: Xianting Tian
Date: Mon Aug 03 2020 - 09:38:13 EST

swap_readpage() does the sync io for one page, the io is not big, normally,
the io can be finished quickly, but it may take long time or wait forever
in case of io failure or discard.
This patch is to use blk_io_schedule() instead of io_schedule() to avoid
task hung and crash(when set /proc/sys/kernel/hung_task_panic) in case of
above exception occur.
We have prevented task hung in submit_bio_wait(), blk_execute_rq() and

Signed-off-by: Xianting Tian <xianting_tian@xxxxxxx>
mm/page_io.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/page_io.c b/mm/page_io.c
index e8726f3..5d52f7b 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -424,7 +424,7 @@ int swap_readpage(struct page *page, bool synchronous)

if (!blk_poll(disk->queue, qc, true))
- io_schedule();
+ blk_io_schedule();