iomap: cleanup up iomap_dio_bio_end_io()

Make the logic a bit easier to follow:

1) Add a release_bio out path, as everybody needs to touch that, and
   have our bio ref check jump there if it's non-zero.
2) Add a kiocb local variable.
3) Add comments for each of the three conditions (sync, inline, or
   async workqueue punt).

No functional changes in this patch.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2023-07-19 09:34:27 -06:00
parent ccff6d117d
commit 3486237c6f
1 changed files with 30 additions and 14 deletions

View File

@ -152,27 +152,43 @@ void iomap_dio_bio_end_io(struct bio *bio)
{
struct iomap_dio *dio = bio->bi_private;
bool should_dirty = (dio->flags & IOMAP_DIO_DIRTY);
struct kiocb *iocb = dio->iocb;
if (bio->bi_status)
iomap_dio_set_error(dio, blk_status_to_errno(bio->bi_status));
if (!atomic_dec_and_test(&dio->ref))
goto release_bio;
if (atomic_dec_and_test(&dio->ref)) {
if (dio->wait_for_completion) {
struct task_struct *waiter = dio->submit.waiter;
WRITE_ONCE(dio->submit.waiter, NULL);
blk_wake_io_task(waiter);
} else if (dio->flags & IOMAP_DIO_WRITE) {
struct inode *inode = file_inode(dio->iocb->ki_filp);
/*
* Synchronous dio, task itself will handle any completion work
* that needs after IO. All we need to do is wake the task.
*/
if (dio->wait_for_completion) {
struct task_struct *waiter = dio->submit.waiter;
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);
}
WRITE_ONCE(dio->submit.waiter, NULL);
blk_wake_io_task(waiter);
goto release_bio;
}
/* Read completion can always complete inline. */
if (!(dio->flags & IOMAP_DIO_WRITE)) {
WRITE_ONCE(iocb->private, NULL);
iomap_dio_complete_work(&dio->aio.work);
goto release_bio;
}
/*
* Async DIO completion that requires filesystem level completion work
* gets punted to a work queue to complete as the operation may require
* more IO to be issued to finalise filesystem metadata changes or
* guarantee data integrity.
*/
WRITE_ONCE(iocb->private, NULL);
INIT_WORK(&dio->aio.work, iomap_dio_complete_work);
queue_work(file_inode(iocb->ki_filp)->i_sb->s_dio_done_wq,
&dio->aio.work);
release_bio:
if (should_dirty) {
bio_check_pages_dirty(bio);
} else {