From 71fc3f5e2c00c966e6a2ffebadfbcc6914249d32 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 12 Oct 2021 13:12:12 +0200 Subject: block: don't try to poll multi-bio I/Os in __blkdev_direct_IO If an iocb is split into multiple bios we can't poll for both. So don't even bother to try to poll in that case. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20211012111226.760968-3-hch@lst.de Signed-off-by: Jens Axboe --- block/fops.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) (limited to 'block/fops.c') diff --git a/block/fops.c b/block/fops.c index 7bb9581a146c..15324f2e5a91 100644 --- a/block/fops.c +++ b/block/fops.c @@ -197,7 +197,7 @@ 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 is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0; + bool do_poll = (iocb->ki_flags & IOCB_HIPRI); bool is_read = (iov_iter_rw(iter) == READ), is_sync; loff_t pos = iocb->ki_pos; blk_qc_t qc = BLK_QC_T_NONE; @@ -226,7 +226,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, * Don't plug for HIPRI/polled IO, as those should go straight * to issue */ - if (!is_poll) + if (!(iocb->ki_flags & IOCB_HIPRI)) blk_start_plug(&plug); for (;;) { @@ -260,20 +260,13 @@ 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) { - bool polled = false; - - if (iocb->ki_flags & IOCB_HIPRI) { + if (do_poll) bio_set_polled(bio, iocb); - polled = true; - } - qc = submit_bio(bio); - - if (polled) + if (do_poll) WRITE_ONCE(iocb->ki_cookie, qc); break; } - if (!dio->multi_bio) { /* * AIO needs an extra reference to ensure the dio @@ -284,6 +277,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, bio_get(bio); dio->multi_bio = true; atomic_set(&dio->ref, 2); + do_poll = false; } else { atomic_inc(&dio->ref); } @@ -292,7 +286,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, bio = bio_alloc(GFP_KERNEL, nr_pages); } - if (!is_poll) + if (!(iocb->ki_flags & IOCB_HIPRI)) blk_finish_plug(&plug); if (!is_sync) @@ -303,8 +297,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, if (!READ_ONCE(dio->waiter)) break; - if (!(iocb->ki_flags & IOCB_HIPRI) || - !blk_poll(bdev_get_queue(bdev), qc, true)) + if (!do_poll || !blk_poll(bdev_get_queue(bdev), qc, true)) blk_io_schedule(); } __set_current_state(TASK_RUNNING); -- cgit v1.2.3