On Sat, May 22, 2021 at 2:04 AM Sagi Grimberg [off-list ref] wrote:

quoted

quoted

quoted

+static inline int nvmet_tcp_inline_data_size(struct nvmet_tcp_cmd *cmd)
+{
+     struct nvmet_tcp_queue *queue = cmd->queue;
+     struct nvme_command *nvme_cmd = cmd->req.cmd;
+     int inline_data_size = NVME_TCP_ADMIN_CCSZ;
+     u16 qid = 0;
+
+     if (likely(queue->nvme_sq.ctrl)) {
+             /* The connect admin/io queue has been executed. */
+             qid = queue->nvme_sq.qid;
+             if (qid)
+                     inline_data_size = cmd->req.port->inline_data_size;
+     } else if (nvme_cmd->connect.qid)
+             inline_data_size = cmd->req.port->inline_data_size;

How can a connection to an I/O queue arrive without having the ctrl
reference installed? Is this for the failure case?

Hi Sagi,
AFAIK after the host finishes setting up the admin queue,
it connects to the io queue and sends the io-connect command. At this
point the nvmet_tcp_queue is firstly allocated and does not have a valid
queue->nvme_sq.ctrl. It is assigned after io-connect in nvmet_install_queue().
So this function tries to find the correct queue number before or after a
fabrics connect command.

Why do you need the inline_data_size before the connect? its only
relevant for nvme I/O..

From my observation, the host always sends an admin-connect command with
nvmf_connect_data as inline data (by setting sg type to NVME_SGL_FMT_DATA_DESC).
This is fixed from the host side.

For io-connect command, the host sends nvmf_connect_data according
to ioccsz. If the size of nvmf_connect_data is smaller than ioccsz*16
it is sent as inline data. ioccsz is obtained by identifying the controller and
is controlled by param_inline_data_size from the target side.

If param_inline_data_size is set to zero, admin-connect will not
be received by target correctly. As target side thought there is
no inline data (by looking param_inline_data_size), but in fact
admin-connect has inline data.

This patch is trying to make param_inline_data_size only affect io-queue.
and admin-queue always allow 8k inline data. This is what the host
side do currently and also what the specification says AFAIK.

Thanks,
Hou

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