> +/*
> + * This is carved within the block_uring_cmd, to avoid dynamic allocation.
> + * Care should be taken not to grow this beyond what is available.
> + */
> +struct uring_cmd_data {
> + union {
> + struct bio *bio;
> + u64 result; /* nvme cmd result */
> + };
> + void *meta; /* kernel-resident buffer */
> + int status; /* nvme cmd status */
> +};
> +
> +inline u64 *ucmd_data_addr(struct io_uring_cmd *ioucmd)
> +{
> + return &(((struct block_uring_cmd *)&ioucmd->pdu)->unused[0]);
> +}
The whole typing is a mess, but this mostly goes back to the series
you're basing this on. Jens, can you send out the series so that
we can do a proper review?
IMHO struct io_uring_cmd needs to stay private in io-uring.c, and
the method needs to get the file and the untyped payload in form
of a void * separately. and block_uring_cmd should be private to
the example ioctl, not exposed to drivers implementing their own
schemes.
> +void ioucmd_task_cb(struct io_uring_cmd *ioucmd)
This should be mark static and have a much more descriptive name
including a nvme_ prefix.
> + /* handle meta update */
> + if (ucd->meta) {
> + void __user *umeta = nvme_to_user_ptr(ptcmd->metadata);
> +
> + if (!ucd->status)
> + if (copy_to_user(umeta, ucd->meta, ptcmd->metadata_len))
> + ucd->status = -EFAULT;
> + kfree(ucd->meta);
> + }
> + /* handle result update */
> + if (put_user(ucd->result, (u32 __user *)&ptcmd->result))
The comments aren't very useful, and the cast here is a warning sign.
Why do you need it?
> + ucd->status = -EFAULT;
> + io_uring_cmd_done(ioucmd, ucd->status);
Shouldn't the io-uring core take care of this io_uring_cmd_done
call?
> +void nvme_end_async_pt(struct request *req, blk_status_t err)
static?
> +{
> + struct io_uring_cmd *ioucmd;
> + struct uring_cmd_data *ucd;
> + struct bio *bio;
> + int ret;
> +
> + ioucmd = req->end_io_data;
> + ucd = (struct uring_cmd_data *) ucmd_data_addr(ioucmd);
> + /* extract bio before reusing the same field for status */
> + bio = ucd->bio;
> +
> + if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
> + ucd->status = -EINTR;
> + else
> + ucd->status = nvme_req(req)->status;
> + ucd->result = le64_to_cpu(nvme_req(req)->result.u64);
> +
> + /* this takes care of setting up task-work */
> + ret = uring_cmd_complete_in_task(ioucmd, ioucmd_task_cb);
> + if (ret < 0)
> + kfree(ucd->meta);
> +
> + /* unmap pages, free bio, nvme command and request */
> + blk_rq_unmap_user(bio);
> + blk_mq_free_request(req);
How can we free the request here if the data is only copied out in
a task_work?
> static int nvme_submit_user_cmd(struct request_queue *q,
> struct nvme_command *cmd, void __user *ubuffer,
> unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
> - u32 meta_seed, u64 *result, unsigned timeout)
> + u32 meta_seed, u64 *result, unsigned int timeout,
> + struct io_uring_cmd *ioucmd)
> {
> bool write = nvme_is_write(cmd);
> struct nvme_ns *ns = q->queuedata;
> @@ -1179,6 +1278,20 @@ static int nvme_submit_user_cmd(struct request_queue *q,
> req->cmd_flags |= REQ_INTEGRITY;
> }
> }
> + if (ioucmd) { /* async handling */
nvme_submit_user_cmd already is a mess. Please split this out into
a separate function. Maybe the logic to map the user buffers can be
split into a little shared helper.
> +int nvme_uring_cmd(struct request_queue *q, struct io_uring_cmd *ioucmd,
> + enum io_uring_cmd_flags flags)
Another comment on the original infrastructure: this really needs to
be a block_device_operations method taking a struct block_device instead
of being tied into blk-mq.
> +EXPORT_SYMBOL_GPL(nvme_uring_cmd);
I don't think this shoud be exported.
