Message-ID: <20211220141734.12206-3-joshi.k@xxxxxxxxxxx> On 12/20/21 19:47:23 +0530, Kanchan Joshi wrote: > Introduce handlers for fops->async_cmd(), implementing async passthru on > char device (including the multipath one). > The handlers supports NVME_IOCTL_IO64_CMD. > I commented on these two issues below in more detail at https://github.com/joshkan/nvme-uring-pt/issues > +static void nvme_setup_uring_cmd_data(struct request *rq, > + struct io_uring_cmd *ioucmd, void *meta, > + void __user *meta_buffer, u32 meta_len, bool write) { > + struct nvme_uring_cmd *cmd = nvme_uring_cmd(ioucmd); > + > + /* to free bio on completion, as req->bio will be null at that time */ > + cmd->bio = rq->bio; > + /* meta update is required only for read requests */ > + if (meta && !write) { > + cmd->meta = meta; > + cmd->meta_buffer = meta_buffer; > + cmd->meta_len = meta_len; > + } else { > + cmd->meta = NULL; I believe that not saving meta in cmd->meta will leak it when it's a write. But nvme_pt_task_cb also needs to change to copy to user when cmd->meta_buffer is set instead of cmd->meta. > + > +int nvme_ns_chr_async_cmd(struct io_uring_cmd *ioucmd, > + enum io_uring_cmd_flags flags) > +{ > + struct nvme_ns *ns = container_of(file_inode(ioucmd->file)->i_cdev, > + struct nvme_ns, cdev); > + > + return nvme_ns_async_ioctl(ns, ioucmd); } > + The uring cmd flags are not being passed to nvme_ns_async_ioctl - what if IO_URING_F_NONBLOCK Is set? When it is, I think the nvme_alloc_request() call in nvme_submit_user_cmd() needs to pass in BLK_MQ_REQ_NOWAIT as the flags parameter or move to another thread. Our proto-type does the former requiring user mode to retry on -EWOULDBLOCK and -EBUSY. -- Clay Mayers
