> + if ((ret > 0) &&
No need for the braces here.
> + if (dio->is_async && iov_iter_rw(iter) == WRITE) {
> + retval = 0;
> + if ((iocb->ki_filp->f_flags & O_DSYNC) ||
> + IS_SYNC(iocb->ki_filp->f_mapping->host))
> + retval = dio_set_defer_completion(dio);
> + else if (!dio->inode->i_sb->s_dio_done_wq)
> + /*
> + * In case of AIO write racing with buffered read we
> + * need to defer completion. We can't decide this now,
> + * however the workqueue needs to be initialized here.
> + */
> + retval = sb_init_dio_done_wq(dio->inode->i_sb);
So now we initialize the workqueue on the first aio write. Maybe we
should just always initialize it? Especially given that the cost of
a workqueue is rather cheap. I also don't really understand why
we even need the workqueue per-superblock instead of global.
> index 1732228..2f8dbf9 100644
> --- a/fs/iomap.c
> +++ b/fs/iomap.c
> @@ -713,8 +713,16 @@ struct iomap_dio {
> static ssize_t iomap_dio_complete(struct iomap_dio *dio)
> {
> struct kiocb *iocb = dio->iocb;
> + loff_t offset = iocb->ki_pos;
If you introduce this variable please also use it later in the function
instead of iocb->ki_pos. OR remove the variable, which would be fine
with me as well.
> + struct inode *inode = file_inode(iocb->ki_filp);
> ssize_t ret;
>
> + if ((!dio->error) &&
no need for the inner braces.
