@@ -200,6 +200,8 @@ static void smbd_destroy_rdma_work(struct work_struct *work)
log_rdma_event(INFO, "wait for all recv to finish\n");
wake_up_interruptible(&info->wait_reassembly_queue);
+ wait_event(info->wait_smbd_recv_pending,
+ info->smbd_recv_pending == 0);
log_rdma_event(INFO, "wait for all send posted to IB to finish\n");
wait_event(info->wait_send_pending,
@@ -1678,6 +1680,9 @@ struct smbd_connection *_smbd_get_connection(
queue_delayed_work(info->workqueue, &info->idle_timer_work,
info->keep_alive_interval*HZ);
+ init_waitqueue_head(&info->wait_smbd_recv_pending);
+ info->smbd_recv_pending = 0;
+
init_waitqueue_head(&info->wait_send_pending);
atomic_set(&info->send_pending, 0);
@@ -1744,3 +1749,227 @@ struct smbd_connection *smbd_get_connection(
}
return ret;
}
+
+/*
+ * Receive data from receive reassembly queue
+ * All the incoming data packets are placed in reassembly queue
+ * buf: the buffer to read data into
+ * size: the length of data to read
+ * return value: actual data read
+ * Note: this implementation copies the data from reassebmly queue to receive
+ * buffers used by upper layer. This is not the optimal code path. A better way
+ * to do it is to not have upper layer allocate its receive buffers but rather
+ * borrow the buffer from reassembly queue, and return it after data is
+ * consumed. But this will require more changes to upper layer code, and also
+ * need to consider packet boundaries while they still being reassembled.
+ */
+int smbd_recv_buf(struct smbd_connection *info, char *buf, unsigned int size)
+{
+ struct smbd_response *response;
+ struct smbd_data_transfer *data_transfer;
+ int to_copy, to_read, data_read, offset;
+ u32 data_length, remaining_data_length, data_offset;
+ int rc;
+ unsigned long flags;
+
+again:
+ if (info->transport_status != SMBD_CONNECTED) {
+ log_read(ERR, "disconnected\n");
+ return -ENODEV;
+ }
+
+ /*
+ * No need to hold the reassembly queue lock all the time as we are
+ * the only one reading from the front of the queue. The transport
+ * may add more entries to the back of the queeu at the same time
+ */
+ log_read(INFO, "size=%d info->reassembly_data_length=%d\n", size,
+ info->reassembly_data_length);
+ if (info->reassembly_data_length >= size) {
+ unsigned long long t1 = rdtsc();
+ int queue_length;
+ int queue_removed = 0;
+
+ /*
+ * Need to make sure reassembly_data_length is read before
+ * reading reassembly_queue_length and calling
+ * _get_first_reassembly. This call is lock free
+ * as we never read at the end of the queue which are being
+ * updated in SOFTIRQ as more data is received
+ */
+ virt_rmb();
+ queue_length = info->reassembly_queue_length;
+ data_read = 0;
+ to_read = size;
+ offset = info->first_entry_offset;
+ while (data_read < size) {
+ response = _get_first_reassembly(info);
+ data_transfer = smbd_response_payload(response);
+ data_length = le32_to_cpu(data_transfer->data_length);
+ remaining_data_length =
+ le32_to_cpu(
+ data_transfer->remaining_data_length);
+ data_offset = le32_to_cpu(data_transfer->data_offset);
+
+ /*
+ * The upper layer expects RFC1002 length at the
+ * beginning of the payload. Return it to indicate
+ * the total length of the packet. This minimize the
+ * change to upper layer packet processing logic. This
+ * will be eventually remove when an intermediate
+ * transport layer is added
+ */
+ if (response->first_segment && size == 4) {
+ unsigned int rfc1002_len =
+ data_length + remaining_data_length;
+ *((__be32 *)buf) = cpu_to_be32(rfc1002_len);
+ data_read = 4;
+ response->first_segment = false;
+ log_read(INFO, "returning rfc1002 length %d\n",
+ rfc1002_len);
+ goto read_rfc1002_done;
+ }
+
+ to_copy = min_t(int, data_length - offset, to_read);
+ memcpy(
+ buf + data_read,
+ (char *)data_transfer + data_offset + offset,
+ to_copy);
+
+ /* move on to the next buffer? */
+ if (to_copy == data_length - offset) {
+ queue_length--;
+ /*
+ * No need to lock if we are not at the
+ * end of the queue
+ */
+ if (!queue_length)
+ spin_lock_irqsave(
+ &info->reassembly_queue_lock,
+ flags);
+ list_del(&response->list);
+ queue_removed++;
+ if (!queue_length)
+ spin_unlock_irqrestore(
+ &info->reassembly_queue_lock,
+ flags);
+
+ info->count_reassembly_queue--;
+ info->count_dequeue_reassembly_queue++;
+ put_receive_buffer(info, response, true);
+ offset = 0;
+ log_read(INFO, "put_receive_buffer offset=0\n");
+ } else
+ offset += to_copy;
+
+ to_read -= to_copy;
+ data_read += to_copy;
+
+ log_read(INFO, "_get_first_reassembly memcpy %d bytes "
+ "data_transfer_length-offset=%d after that "
+ "to_read=%d data_read=%d offset=%d\n",
+ to_copy, data_length - offset,
+ to_read, data_read, offset);
+ }
+
+ spin_lock_irqsave(&info->reassembly_queue_lock, flags);
+ info->reassembly_data_length -= data_read;
+ info->reassembly_queue_length -= queue_removed;
+ spin_unlock_irqrestore(&info->reassembly_queue_lock, flags);
+
+ info->first_entry_offset = offset;
+ log_read(INFO, "returning to thread data_read=%d "
+ "reassembly_data_length=%d first_entry_offset=%d\n",
+ data_read, info->reassembly_data_length,
+ info->first_entry_offset);
+read_rfc1002_done:
+ profiling_add_histogram(rdtsc() - t1, info->smbd_recv_cycles);
+ return data_read;
+ }
+
+ log_read(INFO, "wait_event on more data\n");
+ rc = wait_event_interruptible(
+ info->wait_reassembly_queue,
+ info->reassembly_data_length >= size ||
+ info->transport_status != SMBD_CONNECTED);
+ /* Don't return any data if interrupted */
+ if (rc)
+ return -ENODEV;
+
+ goto again;
+}
+
+/*
+ * Receive a page from receive reassembly queue
+ * page: the page to read data into
+ * to_read: the length of data to read
+ * return value: actual data read
+ */
+int smbd_recv_page(struct smbd_connection *info,
+ struct page *page, unsigned int to_read)
+{
+ int ret;
+ char *to_address;
+
+ /* make sure we have the page ready for read */
+ ret = wait_event_interruptible(
+ info->wait_reassembly_queue,
+ info->reassembly_data_length >= to_read ||
+ info->transport_status != SMBD_CONNECTED);
+ if (ret)
+ return 0;
+
+ /* now we can read from reassembly queue and not sleep */
+ to_address = kmap_atomic(page);
+
+ log_read(INFO, "reading from page=%p address=%p to_read=%d\n",
+ page, to_address, to_read);
+
+ ret = smbd_recv_buf(info, to_address, to_read);
+ kunmap_atomic(to_address);
+
+ return ret;
+}
+
+/*
+ * Receive data from transport
+ * msg: a msghdr point to the buffer, can be ITER_KVEC or ITER_BVEC
+ * return: total bytes read, or 0. SMB Direct will not do partial read.
+ */
+int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
+{
+ char *buf;
+ struct page *page;
+ unsigned int to_read;
+ int rc;
+
+ info->smbd_recv_pending++;
+
+ switch (msg->msg_iter.type) {
+ case READ | ITER_KVEC:
+ buf = msg->msg_iter.kvec->iov_base;
+ to_read = msg->msg_iter.kvec->iov_len;
+ rc = smbd_recv_buf(info, buf, to_read);
+ break;
+
+ case READ | ITER_BVEC:
+ page = msg->msg_iter.bvec->bv_page;
+ to_read = msg->msg_iter.bvec->bv_len;
+ rc = smbd_recv_page(info, page, to_read);
+ break;
+
+ default:
+ /* It's a bug in upper layer to get there */
+ cifs_dbg(VFS, "CIFS: invalid msg type %d\n",
+ msg->msg_iter.type);
+ rc = -EIO;
+ }
+
+ info->smbd_recv_pending--;
+ wake_up(&info->wait_smbd_recv_pending);
+
+ /* SMBDirect will read it all or nothing */
+ if (rc > 0)
+ msg->msg_iter.count = 0;
+ return rc;
+}
@@ -88,6 +88,9 @@ struct smbd_connection {
int fragment_reassembly_remaining;
/* Activity accoutning */
+ /* Pending reqeusts issued from upper layer */
+ int smbd_recv_pending;
+ wait_queue_head_t wait_smbd_recv_pending;
atomic_t send_pending;
wait_queue_head_t wait_send_pending;
@@ -255,6 +258,9 @@ int smbd_reconnect(struct TCP_Server_Info *server);
/* Destroy SMBDirect session */
void smbd_destroy(struct smbd_connection *info);
+/* Interface for carrying upper layer I/O through send/recv */
+int smbd_recv(struct smbd_connection *info, struct msghdr *msg);
+
void profiling_display_histogram(
struct seq_file *m, unsigned long long array[]);
#endif