block: wire up block device iopoll method

Just call blk_poll on the iocb cookie, we can derive the block device
from the inode trivially.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 7758adee6efecb3dfc27997e020ab00b67a59850..1fe498b08f1bc4303b5f8e206f149ed08a6eae4c 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -294,6 +294,14 @@ struct blkdev_dio {
 
 static struct bio_set blkdev_dio_pool;
 
+static int blkdev_iopoll(struct kiocb *kiocb, bool wait)
+{
+       struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host);
+       struct request_queue *q = bdev_get_queue(bdev);
+
+       return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait);
+}
+
 static void blkdev_bio_end_io(struct bio *bio)
 {
        struct blkdev_dio *dio = bio->bi_private;
@@ -408,10 +416,17 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
 
                nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES);
                if (!nr_pages) {
-                       if (iocb->ki_flags & IOCB_HIPRI)
+                       bool polled = false;
+
+                       if (iocb->ki_flags & IOCB_HIPRI) {
                                bio->bi_opf |= REQ_HIPRI;
+                               polled = true;
+                       }
 
                        qc = submit_bio(bio);
+
+                       if (polled)
+                               WRITE_ONCE(iocb->ki_cookie, qc);
                        break;
                }
 
@@ -2078,6 +2093,7 @@ const struct file_operations def_blk_fops = {
        .llseek         = block_llseek,
        .read_iter      = blkdev_read_iter,
        .write_iter     = blkdev_write_iter,
+       .iopoll         = blkdev_iopoll,
        .mmap           = generic_file_mmap,
        .fsync          = blkdev_fsync,
        .unlocked_ioctl = block_ioctl,