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author | 2021-10-12 13:12:24 +0200 | |
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committer | 2021-10-18 06:17:36 -0600 | |
commit | 3e08773c3841e9db7a520908cc2b136a77d275ff (patch) | |
tree | 5dce4a3944899f0eb1370a92130e89134da2a714 /fs/iomap | |
parent | block: define 'struct bvec_iter' as packed (diff) | |
download | linux-3e08773c3841e9db7a520908cc2b136a77d275ff.tar.gz linux-3e08773c3841e9db7a520908cc2b136a77d275ff.tar.bz2 linux-3e08773c3841e9db7a520908cc2b136a77d275ff.zip |
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 'fs/iomap')
-rw-r--r-- | fs/iomap/direct-io.c | 36 |
1 files changed, 12 insertions, 24 deletions
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 236aba256cd1..8efab177011d 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -38,8 +38,7 @@ struct iomap_dio { struct { struct iov_iter *iter; struct task_struct *waiter; - struct request_queue *last_queue; - blk_qc_t cookie; + struct bio *poll_bio; } submit; /* used for aio completion: */ @@ -49,29 +48,20 @@ struct iomap_dio { }; }; -int iomap_dio_iopoll(struct kiocb *kiocb, unsigned int flags) -{ - struct request_queue *q = READ_ONCE(kiocb->private); - - if (!q) - return 0; - return blk_poll(q, READ_ONCE(kiocb->ki_cookie), flags); -} -EXPORT_SYMBOL_GPL(iomap_dio_iopoll); - static void iomap_dio_submit_bio(const struct iomap_iter *iter, struct iomap_dio *dio, struct bio *bio, loff_t pos) { atomic_inc(&dio->ref); - if (dio->iocb->ki_flags & IOCB_HIPRI) + if (dio->iocb->ki_flags & IOCB_HIPRI) { bio_set_polled(bio, dio->iocb); + dio->submit.poll_bio = bio; + } - dio->submit.last_queue = bdev_get_queue(iter->iomap.bdev); if (dio->dops && dio->dops->submit_io) - dio->submit.cookie = dio->dops->submit_io(iter, bio, pos); + dio->dops->submit_io(iter, bio, pos); else - dio->submit.cookie = submit_bio(bio); + submit_bio(bio); } ssize_t iomap_dio_complete(struct iomap_dio *dio) @@ -164,9 +154,11 @@ static void iomap_dio_bio_end_io(struct bio *bio) } else if (dio->flags & IOMAP_DIO_WRITE) { struct inode *inode = file_inode(dio->iocb->ki_filp); + WRITE_ONCE(dio->iocb->private, NULL); INIT_WORK(&dio->aio.work, iomap_dio_complete_work); queue_work(inode->i_sb->s_dio_done_wq, &dio->aio.work); } else { + WRITE_ONCE(dio->iocb->private, NULL); iomap_dio_complete_work(&dio->aio.work); } } @@ -497,8 +489,7 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, dio->submit.iter = iter; dio->submit.waiter = current; - dio->submit.cookie = BLK_QC_T_NONE; - dio->submit.last_queue = NULL; + dio->submit.poll_bio = NULL; if (iov_iter_rw(iter) == READ) { if (iomi.pos >= dio->i_size) @@ -611,8 +602,7 @@ __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->ki_cookie, dio->submit.cookie); - WRITE_ONCE(iocb->private, dio->submit.last_queue); + WRITE_ONCE(iocb->private, dio->submit.poll_bio); /* * We are about to drop our additional submission reference, which @@ -639,10 +629,8 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (!READ_ONCE(dio->submit.waiter)) break; - if (!(iocb->ki_flags & IOCB_HIPRI) || - !dio->submit.last_queue || - !blk_poll(dio->submit.last_queue, - dio->submit.cookie, 0)) + if (!dio->submit.poll_bio || + !bio_poll(dio->submit.poll_bio, 0)) blk_io_schedule(); } __set_current_state(TASK_RUNNING); |