On Tue, Dec 17, 2019 at 6:40 AM Jens Axboe <axboe@xxxxxxxxx> wrote:
>
> We pass a lot of arguments to iomap_apply(), and subsequently to the
> actors that it calls. In preparation for adding one more argument,
> switch them to using a struct iomap_ctx instead. The actor gets a const
> version of that, they are not supposed to change anything in it.
Looks generally like what I expected, but when looking at the patch I
notice that the type of 'len' is crazy and wrong.
It was wrong before too, though:
> -dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
'loff_t length' is not right.
> + loff_t pos = data->pos;
> + loff_t length = pos + data->len;
And WTH is that? "pos + data->len" is not "length", that's end. And this:
> loff_t end = pos + length, done = 0;
What? Now 'end' is 'pos+length', which is 'pos+pos+data->len'.
WHAA?
> @@ -1197,22 +1200,26 @@ dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
> {
> + loff_t ret = 0, done = 0;
More insanity. "ret" shouldn't be loff_t.
dax_iomap_rw() returns a ssize_t.
> + loff_t count = data->len;
More of this crazy things.
> iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,
This was wrong before.
> +struct iomap_ctx {
> + struct inode *inode;
> + loff_t pos;
> + loff_t len;
> + void *priv;
> + unsigned flags;
> +};
Please make 'len' be 'size_t' or something.
If you're on a 32-bit architecture, you shouldn't be writing more than
4GB in a go anyway.
Is there some reason for this horrible case of "let's allow 64-bit sizes?"
Because even if there is, it shouldn't be "loff_t". That's an
_offset_. Not a length.
Linus
