From: Pavel Begunkov <asml.silence@gmail.com>
Date: Wed, 27 Oct 2021 13:21:08 +0100
Subject: [PATCH] block: kill unused polling bits in __blkdev_direct_IO()
Git-commit: 25d207dc22271c2232df2d610ce4be6e125d1de8
Patch-mainline: v5.16-rc1
References: jsc#PED-1183

With addition of __blkdev_direct_IO_async(), __blkdev_direct_IO() now
serves only multio-bio I/O, which we don't poll. Now we can remove
anything related to I/O polling from it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b8c597a6b7ee612df394853bfd24726aee5b898e.1635337135.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 block/fops.c | 20 +++-----------------
 1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/block/fops.c b/block/fops.c
index 092e5079e827..983e993c9a4b 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -190,7 +190,6 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	struct blk_plug plug;
 	struct blkdev_dio *dio;
 	struct bio *bio;
-	bool do_poll = (iocb->ki_flags & IOCB_HIPRI);
 	bool is_read = (iov_iter_rw(iter) == READ), is_sync;
 	loff_t pos = iocb->ki_pos;
 	int ret = 0;
@@ -216,12 +215,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 	if (is_read && iter_is_iovec(iter))
 		dio->flags |= DIO_SHOULD_DIRTY;
 
-	/*
-	 * Don't plug for HIPRI/polled IO, as those should go straight
-	 * to issue
-	 */
-	if (!(iocb->ki_flags & IOCB_HIPRI))
-		blk_start_plug(&plug);
+	blk_start_plug(&plug);
 
 	for (;;) {
 		bio_set_dev(bio, bdev);
@@ -254,11 +248,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 
 		nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
 		if (!nr_pages) {
-			if (do_poll)
-				bio_set_polled(bio, iocb);
 			submit_bio(bio);
-			if (do_poll)
-				WRITE_ONCE(iocb->private, bio);
 			break;
 		}
 		if (!(dio->flags & DIO_MULTI_BIO)) {
@@ -271,7 +261,6 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 				bio_get(bio);
 			dio->flags |= DIO_MULTI_BIO;
 			atomic_set(&dio->ref, 2);
-			do_poll = false;
 		} else {
 			atomic_inc(&dio->ref);
 		}
@@ -280,8 +269,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 		bio = bio_alloc(GFP_KERNEL, nr_pages);
 	}
 
-	if (!(iocb->ki_flags & IOCB_HIPRI))
-		blk_finish_plug(&plug);
+	blk_finish_plug(&plug);
 
 	if (!is_sync)
 		return -EIOCBQUEUED;
@@ -290,9 +278,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		if (!READ_ONCE(dio->waiter))
 			break;
-
-		if (!do_poll || !bio_poll(bio, NULL, 0))
-			blk_io_schedule();
+		blk_io_schedule();
 	}
 	__set_current_state(TASK_RUNNING);
 
-- 
2.35.3