diff options
| author | Christoph Hellwig <hch@lst.de> | 2021-10-12 13:12:24 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-18 06:17:36 -0600 |
| commit | 3e08773c3841e9db7a520908cc2b136a77d275ff (patch) | |
| tree | 5dce4a3944899f0eb1370a92130e89134da2a714 /block/fops.c | |
| parent | 19416123ab3e1348b3532347af221d8f60838431 (diff) | |
block: switch polling to be bio based
Replace the blk_poll interface that requires the caller to keep a queue
and cookie from the submissions with polling based on the bio.
Polling for the bio itself leads to a few advantages:
- the cookie construction can made entirely private in blk-mq.c
- the caller does not need to remember the request_queue and cookie
separately and thus sidesteps their lifetime issues
- keeping the device and the cookie inside the bio allows to trivially
support polling BIOs remapping by stacking drivers
- a lot of code to propagate the cookie back up the submission path can
be removed entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/fops.c')
| -rw-r--r-- | block/fops.c | 25 |
1 files changed, 8 insertions, 17 deletions
diff --git a/block/fops.c b/block/fops.c index db8f2fe68dd2..ce1255529ba2 100644 --- a/block/fops.c +++ b/block/fops.c @@ -61,7 +61,6 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, bool should_dirty = false; struct bio bio; ssize_t ret; - blk_qc_t qc; if ((pos | iov_iter_alignment(iter)) & (bdev_logical_block_size(bdev) - 1)) @@ -102,13 +101,12 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, if (iocb->ki_flags & IOCB_HIPRI) bio_set_polled(&bio, iocb); - qc = submit_bio(&bio); + submit_bio(&bio); for (;;) { set_current_state(TASK_UNINTERRUPTIBLE); if (!READ_ONCE(bio.bi_private)) break; - if (!(iocb->ki_flags & IOCB_HIPRI) || - !blk_poll(bdev_get_queue(bdev), qc, 0)) + if (!(iocb->ki_flags & IOCB_HIPRI) || !bio_poll(&bio, 0)) blk_io_schedule(); } __set_current_state(TASK_RUNNING); @@ -141,14 +139,6 @@ struct blkdev_dio { static struct bio_set blkdev_dio_pool; -static int blkdev_iopoll(struct kiocb *kiocb, unsigned int flags) -{ - 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), flags); -} - static void blkdev_bio_end_io(struct bio *bio) { struct blkdev_dio *dio = bio->bi_private; @@ -162,6 +152,8 @@ static void blkdev_bio_end_io(struct bio *bio) struct kiocb *iocb = dio->iocb; ssize_t ret; + WRITE_ONCE(iocb->private, NULL); + if (likely(!dio->bio.bi_status)) { ret = dio->size; iocb->ki_pos += ret; @@ -200,7 +192,6 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, 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; int ret = 0; if ((pos | iov_iter_alignment(iter)) & @@ -262,9 +253,9 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, if (!nr_pages) { if (do_poll) bio_set_polled(bio, iocb); - qc = submit_bio(bio); + submit_bio(bio); if (do_poll) - WRITE_ONCE(iocb->ki_cookie, qc); + WRITE_ONCE(iocb->private, bio); break; } if (!dio->multi_bio) { @@ -297,7 +288,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, if (!READ_ONCE(dio->waiter)) break; - if (!do_poll || !blk_poll(bdev_get_queue(bdev), qc, 0)) + if (!do_poll || !bio_poll(bio, 0)) blk_io_schedule(); } __set_current_state(TASK_RUNNING); @@ -594,7 +585,7 @@ const struct file_operations def_blk_fops = { .llseek = blkdev_llseek, .read_iter = blkdev_read_iter, .write_iter = blkdev_write_iter, - .iopoll = blkdev_iopoll, + .iopoll = iocb_bio_iopoll, .mmap = generic_file_mmap, .fsync = blkdev_fsync, .unlocked_ioctl = blkdev_ioctl, |