@@ -44,14 +44,6 @@ static unsigned int dio_bio_write_op(struct kiocb *iocb)
#define DIO_INLINE_BIO_VECS 4
-static void blkdev_bio_end_io_simple(struct bio *bio)
-{
- struct task_struct *waiter = bio->bi_private;
-
- WRITE_ONCE(bio->bi_private, NULL);
- blk_wake_io_task(waiter);
-}
-
static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
struct iov_iter *iter, unsigned int nr_pages)
{
@@ -83,8 +75,6 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb));
}
bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT;
- bio.bi_private = current;
- bio.bi_end_io = blkdev_bio_end_io_simple;
bio.bi_ioprio = iocb->ki_ioprio;
ret = bio_iov_iter_get_pages(&bio, iter);
@@ -97,18 +87,8 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
if (iocb->ki_flags & IOCB_NOWAIT)
bio.bi_opf |= REQ_NOWAIT;
- if (iocb->ki_flags & IOCB_HIPRI)
- bio_set_polled(&bio, iocb);
- submit_bio(&bio);
- for (;;) {
- set_current_state(TASK_UNINTERRUPTIBLE);
- if (!READ_ONCE(bio.bi_private))
- break;
- if (!(iocb->ki_flags & IOCB_HIPRI) || !bio_poll(&bio, NULL, 0))
- blk_io_schedule();
- }
- __set_current_state(TASK_RUNNING);
+ submit_bio_wait(&bio);
bio_release_pages(&bio, should_dirty);
if (unlikely(bio.bi_status))
@@ -41,7 +41,6 @@ struct iomap_dio {
struct {
struct iov_iter *iter;
struct task_struct *waiter;
- struct bio *poll_bio;
} submit;
/* used for aio completion: */
@@ -56,11 +55,6 @@ static void iomap_dio_submit_bio(const struct iomap_iter *iter,
{
atomic_inc(&dio->ref);
- if (dio->iocb->ki_flags & IOCB_HIPRI) {
- bio_set_polled(bio, dio->iocb);
- dio->submit.poll_bio = bio;
- }
-
if (dio->dops && dio->dops->submit_io)
dio->dops->submit_io(iter, bio, pos);
else
@@ -507,7 +501,6 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
dio->submit.iter = iter;
dio->submit.waiter = current;
- dio->submit.poll_bio = NULL;
if (iov_iter_rw(iter) == READ) {
if (iomi.pos >= dio->i_size)
@@ -626,7 +619,7 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
if (dio->flags & IOMAP_DIO_WRITE_FUA)
dio->flags &= ~IOMAP_DIO_NEED_SYNC;
- WRITE_ONCE(iocb->private, dio->submit.poll_bio);
+ WRITE_ONCE(iocb->private, NULL);
/*
* We are about to drop our additional submission reference, which
@@ -653,9 +646,7 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
if (!READ_ONCE(dio->submit.waiter))
break;
- if (!dio->submit.poll_bio ||
- !bio_poll(dio->submit.poll_bio, NULL, 0))
- blk_io_schedule();
+ blk_io_schedule();
}
__set_current_state(TASK_RUNNING);
}
@@ -360,7 +360,6 @@ int swap_readpage(struct page *page, bool synchronous)
* attempt to access it in the page fault retry time check.
*/
if (synchronous) {
- bio->bi_opf |= REQ_POLLED;
get_task_struct(current);
bio->bi_private = current;
}
@@ -372,8 +371,7 @@ int swap_readpage(struct page *page, bool synchronous)
if (!READ_ONCE(bio->bi_private))
break;
- if (!bio_poll(bio, NULL, 0))
- blk_io_schedule();
+ blk_io_schedule();
}
__set_current_state(TASK_RUNNING);
bio_put(bio);
So far bio is marked as REQ_POLLED if RWF_HIPRI/IOCB_HIPRI is passed from userspace sync io interface, then block layer tries to poll until the bio is completed. But the current implementation calls blk_io_schedule() if bio_poll() returns 0, and this way causes io hang or timeout easily. But looks no one reports this kind of issue, which should have been triggered in normal io poll sanity test or blktests block/007 as observed by Changhui, that means it is very likely that no one uses it or no one cares it. Also after io_uring is invented, io poll for sync dio becomes legacy interface. So ignore RWF_HIPRI hint for sync dio. CC: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Reported-by: Changhui Zhong <czhong@redhat.com> Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- block/fops.c | 22 +--------------------- fs/iomap/direct-io.c | 13 ++----------- mm/page_io.c | 4 +--- 3 files changed, 4 insertions(+), 35 deletions(-)