xref: /linux/fs/smb/server/transport_rdma.c (revision 5914d98ff0f7f9ec0e3963dbe2773401b02888ac)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) 2017, Microsoft Corporation.
4  *   Copyright (C) 2018, LG Electronics.
5  *
6  *   Author(s): Long Li <longli@microsoft.com>,
7  *		Hyunchul Lee <hyc.lee@gmail.com>
8  */
9 
10 #define SUBMOD_NAME	"smb_direct"
11 
12 #include <linux/kthread.h>
13 #include <linux/list.h>
14 #include <linux/mempool.h>
15 #include <linux/highmem.h>
16 #include <linux/scatterlist.h>
17 #include <linux/string_choices.h>
18 #include <rdma/ib_verbs.h>
19 #include <rdma/rdma_cm.h>
20 #include <rdma/rw.h>
21 
22 #define __SMBDIRECT_SOCKET_DISCONNECT(__sc) smb_direct_disconnect_rdma_connection(__sc)
23 
24 #include "glob.h"
25 #include "connection.h"
26 #include "smb_common.h"
27 #include "../common/smb2status.h"
28 #include "../common/smbdirect/smbdirect.h"
29 #include "../common/smbdirect/smbdirect_pdu.h"
30 #include "../common/smbdirect/smbdirect_socket.h"
31 #include "transport_rdma.h"
32 
33 #define SMB_DIRECT_PORT_IWARP		5445
34 #define SMB_DIRECT_PORT_INFINIBAND	445
35 
36 #define SMB_DIRECT_VERSION_LE		cpu_to_le16(SMBDIRECT_V1)
37 
38 /* SMB_DIRECT negotiation timeout (for the server) in seconds */
39 #define SMB_DIRECT_NEGOTIATE_TIMEOUT		5
40 
41 /* The timeout to wait for a keepalive message from peer in seconds */
42 #define SMB_DIRECT_KEEPALIVE_SEND_INTERVAL	120
43 
44 /* The timeout to wait for a keepalive message from peer in seconds */
45 #define SMB_DIRECT_KEEPALIVE_RECV_TIMEOUT	5
46 
47 /*
48  * Default maximum number of RDMA read/write outstanding on this connection
49  * This value is possibly decreased during QP creation on hardware limit
50  */
51 #define SMB_DIRECT_CM_INITIATOR_DEPTH		8
52 
53 /* Maximum number of retries on data transfer operations */
54 #define SMB_DIRECT_CM_RETRY			6
55 /* No need to retry on Receiver Not Ready since SMB_DIRECT manages credits */
56 #define SMB_DIRECT_CM_RNR_RETRY		0
57 
58 /*
59  * User configurable initial values per SMB_DIRECT transport connection
60  * as defined in [MS-SMBD] 3.1.1.1
61  * Those may change after a SMB_DIRECT negotiation
62  */
63 
64 /* Set 445 port to SMB Direct port by default */
65 static int smb_direct_port = SMB_DIRECT_PORT_INFINIBAND;
66 
67 /* The local peer's maximum number of credits to grant to the peer */
68 static int smb_direct_receive_credit_max = 255;
69 
70 /* The remote peer's credit request of local peer */
71 static int smb_direct_send_credit_target = 255;
72 
73 /* The maximum single message size can be sent to remote peer */
74 static int smb_direct_max_send_size = 1364;
75 
76 /*  The maximum fragmented upper-layer payload receive size supported */
77 static int smb_direct_max_fragmented_recv_size = 1024 * 1024;
78 
79 /*  The maximum single-message size which can be received */
80 static int smb_direct_max_receive_size = 1364;
81 
82 static int smb_direct_max_read_write_size = SMBD_DEFAULT_IOSIZE;
83 
84 static LIST_HEAD(smb_direct_device_list);
85 static DEFINE_RWLOCK(smb_direct_device_lock);
86 
87 struct smb_direct_device {
88 	struct ib_device	*ib_dev;
89 	struct list_head	list;
90 };
91 
92 static struct smb_direct_listener {
93 	struct rdma_cm_id	*cm_id;
94 } smb_direct_listener;
95 
96 static struct workqueue_struct *smb_direct_wq;
97 
98 struct smb_direct_transport {
99 	struct ksmbd_transport	transport;
100 
101 	struct smbdirect_socket socket;
102 };
103 
104 #define KSMBD_TRANS(t) (&(t)->transport)
105 #define SMBD_TRANS(t)	(container_of(t, \
106 				struct smb_direct_transport, transport))
107 
108 static const struct ksmbd_transport_ops ksmbd_smb_direct_transport_ops;
109 
110 void init_smbd_max_io_size(unsigned int sz)
111 {
112 	sz = clamp_val(sz, SMBD_MIN_IOSIZE, SMBD_MAX_IOSIZE);
113 	smb_direct_max_read_write_size = sz;
114 }
115 
116 unsigned int get_smbd_max_read_write_size(struct ksmbd_transport *kt)
117 {
118 	struct smb_direct_transport *t;
119 	struct smbdirect_socket *sc;
120 	struct smbdirect_socket_parameters *sp;
121 
122 	if (kt->ops != &ksmbd_smb_direct_transport_ops)
123 		return 0;
124 
125 	t = SMBD_TRANS(kt);
126 	sc = &t->socket;
127 	sp = &sc->parameters;
128 
129 	return sp->max_read_write_size;
130 }
131 
132 static inline int get_buf_page_count(void *buf, int size)
133 {
134 	return DIV_ROUND_UP((uintptr_t)buf + size, PAGE_SIZE) -
135 		(uintptr_t)buf / PAGE_SIZE;
136 }
137 
138 static void smb_direct_destroy_pools(struct smbdirect_socket *sc);
139 static void smb_direct_post_recv_credits(struct work_struct *work);
140 static int smb_direct_post_send_data(struct smbdirect_socket *sc,
141 				     struct smbdirect_send_batch *send_ctx,
142 				     struct kvec *iov, int niov,
143 				     int remaining_data_length);
144 
145 static inline void
146 *smbdirect_recv_io_payload(struct smbdirect_recv_io *recvmsg)
147 {
148 	return (void *)recvmsg->packet;
149 }
150 
151 static struct
152 smbdirect_recv_io *get_free_recvmsg(struct smbdirect_socket *sc)
153 {
154 	struct smbdirect_recv_io *recvmsg = NULL;
155 	unsigned long flags;
156 
157 	spin_lock_irqsave(&sc->recv_io.free.lock, flags);
158 	if (!list_empty(&sc->recv_io.free.list)) {
159 		recvmsg = list_first_entry(&sc->recv_io.free.list,
160 					   struct smbdirect_recv_io,
161 					   list);
162 		list_del(&recvmsg->list);
163 	}
164 	spin_unlock_irqrestore(&sc->recv_io.free.lock, flags);
165 	return recvmsg;
166 }
167 
168 static void put_recvmsg(struct smbdirect_socket *sc,
169 			struct smbdirect_recv_io *recvmsg)
170 {
171 	unsigned long flags;
172 
173 	if (likely(recvmsg->sge.length != 0)) {
174 		ib_dma_unmap_single(sc->ib.dev,
175 				    recvmsg->sge.addr,
176 				    recvmsg->sge.length,
177 				    DMA_FROM_DEVICE);
178 		recvmsg->sge.length = 0;
179 	}
180 
181 	spin_lock_irqsave(&sc->recv_io.free.lock, flags);
182 	list_add(&recvmsg->list, &sc->recv_io.free.list);
183 	spin_unlock_irqrestore(&sc->recv_io.free.lock, flags);
184 
185 	queue_work(sc->workqueue, &sc->recv_io.posted.refill_work);
186 }
187 
188 static void enqueue_reassembly(struct smbdirect_socket *sc,
189 			       struct smbdirect_recv_io *recvmsg,
190 			       int data_length)
191 {
192 	unsigned long flags;
193 
194 	spin_lock_irqsave(&sc->recv_io.reassembly.lock, flags);
195 	list_add_tail(&recvmsg->list, &sc->recv_io.reassembly.list);
196 	sc->recv_io.reassembly.queue_length++;
197 	/*
198 	 * Make sure reassembly_data_length is updated after list and
199 	 * reassembly_queue_length are updated. On the dequeue side
200 	 * reassembly_data_length is checked without a lock to determine
201 	 * if reassembly_queue_length and list is up to date
202 	 */
203 	virt_wmb();
204 	sc->recv_io.reassembly.data_length += data_length;
205 	spin_unlock_irqrestore(&sc->recv_io.reassembly.lock, flags);
206 }
207 
208 static struct smbdirect_recv_io *get_first_reassembly(struct smbdirect_socket *sc)
209 {
210 	if (!list_empty(&sc->recv_io.reassembly.list))
211 		return list_first_entry(&sc->recv_io.reassembly.list,
212 				struct smbdirect_recv_io, list);
213 	else
214 		return NULL;
215 }
216 
217 static void smb_direct_disconnect_wake_up_all(struct smbdirect_socket *sc)
218 {
219 	/*
220 	 * Wake up all waiters in all wait queues
221 	 * in order to notice the broken connection.
222 	 */
223 	wake_up_all(&sc->status_wait);
224 	wake_up_all(&sc->send_io.lcredits.wait_queue);
225 	wake_up_all(&sc->send_io.credits.wait_queue);
226 	wake_up_all(&sc->send_io.pending.zero_wait_queue);
227 	wake_up_all(&sc->recv_io.reassembly.wait_queue);
228 	wake_up_all(&sc->rw_io.credits.wait_queue);
229 }
230 
231 static void smb_direct_disconnect_rdma_work(struct work_struct *work)
232 {
233 	struct smbdirect_socket *sc =
234 		container_of(work, struct smbdirect_socket, disconnect_work);
235 
236 	if (sc->first_error == 0)
237 		sc->first_error = -ECONNABORTED;
238 
239 	/*
240 	 * make sure this and other work is not queued again
241 	 * but here we don't block and avoid
242 	 * disable[_delayed]_work_sync()
243 	 */
244 	disable_work(&sc->disconnect_work);
245 	disable_work(&sc->connect.work);
246 	disable_work(&sc->recv_io.posted.refill_work);
247 	disable_delayed_work(&sc->idle.timer_work);
248 	disable_work(&sc->idle.immediate_work);
249 
250 	switch (sc->status) {
251 	case SMBDIRECT_SOCKET_NEGOTIATE_NEEDED:
252 	case SMBDIRECT_SOCKET_NEGOTIATE_RUNNING:
253 	case SMBDIRECT_SOCKET_NEGOTIATE_FAILED:
254 	case SMBDIRECT_SOCKET_CONNECTED:
255 	case SMBDIRECT_SOCKET_ERROR:
256 		sc->status = SMBDIRECT_SOCKET_DISCONNECTING;
257 		rdma_disconnect(sc->rdma.cm_id);
258 		break;
259 
260 	case SMBDIRECT_SOCKET_CREATED:
261 	case SMBDIRECT_SOCKET_RESOLVE_ADDR_NEEDED:
262 	case SMBDIRECT_SOCKET_RESOLVE_ADDR_RUNNING:
263 	case SMBDIRECT_SOCKET_RESOLVE_ADDR_FAILED:
264 	case SMBDIRECT_SOCKET_RESOLVE_ROUTE_NEEDED:
265 	case SMBDIRECT_SOCKET_RESOLVE_ROUTE_RUNNING:
266 	case SMBDIRECT_SOCKET_RESOLVE_ROUTE_FAILED:
267 	case SMBDIRECT_SOCKET_RDMA_CONNECT_NEEDED:
268 	case SMBDIRECT_SOCKET_RDMA_CONNECT_RUNNING:
269 	case SMBDIRECT_SOCKET_RDMA_CONNECT_FAILED:
270 		/*
271 		 * rdma_accept() never reached
272 		 * RDMA_CM_EVENT_ESTABLISHED
273 		 */
274 		sc->status = SMBDIRECT_SOCKET_DISCONNECTED;
275 		break;
276 
277 	case SMBDIRECT_SOCKET_DISCONNECTING:
278 	case SMBDIRECT_SOCKET_DISCONNECTED:
279 	case SMBDIRECT_SOCKET_DESTROYED:
280 		break;
281 	}
282 
283 	/*
284 	 * Wake up all waiters in all wait queues
285 	 * in order to notice the broken connection.
286 	 */
287 	smb_direct_disconnect_wake_up_all(sc);
288 }
289 
290 static void
291 smb_direct_disconnect_rdma_connection(struct smbdirect_socket *sc)
292 {
293 	if (sc->first_error == 0)
294 		sc->first_error = -ECONNABORTED;
295 
296 	/*
297 	 * make sure other work (than disconnect_work) is
298 	 * not queued again but here we don't block and avoid
299 	 * disable[_delayed]_work_sync()
300 	 */
301 	disable_work(&sc->connect.work);
302 	disable_work(&sc->recv_io.posted.refill_work);
303 	disable_work(&sc->idle.immediate_work);
304 	disable_delayed_work(&sc->idle.timer_work);
305 
306 	switch (sc->status) {
307 	case SMBDIRECT_SOCKET_RESOLVE_ADDR_FAILED:
308 	case SMBDIRECT_SOCKET_RESOLVE_ROUTE_FAILED:
309 	case SMBDIRECT_SOCKET_RDMA_CONNECT_FAILED:
310 	case SMBDIRECT_SOCKET_NEGOTIATE_FAILED:
311 	case SMBDIRECT_SOCKET_ERROR:
312 	case SMBDIRECT_SOCKET_DISCONNECTING:
313 	case SMBDIRECT_SOCKET_DISCONNECTED:
314 	case SMBDIRECT_SOCKET_DESTROYED:
315 		/*
316 		 * Keep the current error status
317 		 */
318 		break;
319 
320 	case SMBDIRECT_SOCKET_RESOLVE_ADDR_NEEDED:
321 	case SMBDIRECT_SOCKET_RESOLVE_ADDR_RUNNING:
322 		sc->status = SMBDIRECT_SOCKET_RESOLVE_ADDR_FAILED;
323 		break;
324 
325 	case SMBDIRECT_SOCKET_RESOLVE_ROUTE_NEEDED:
326 	case SMBDIRECT_SOCKET_RESOLVE_ROUTE_RUNNING:
327 		sc->status = SMBDIRECT_SOCKET_RESOLVE_ROUTE_FAILED;
328 		break;
329 
330 	case SMBDIRECT_SOCKET_RDMA_CONNECT_NEEDED:
331 	case SMBDIRECT_SOCKET_RDMA_CONNECT_RUNNING:
332 		sc->status = SMBDIRECT_SOCKET_RDMA_CONNECT_FAILED;
333 		break;
334 
335 	case SMBDIRECT_SOCKET_NEGOTIATE_NEEDED:
336 	case SMBDIRECT_SOCKET_NEGOTIATE_RUNNING:
337 		sc->status = SMBDIRECT_SOCKET_NEGOTIATE_FAILED;
338 		break;
339 
340 	case SMBDIRECT_SOCKET_CREATED:
341 		sc->status = SMBDIRECT_SOCKET_DISCONNECTED;
342 		break;
343 
344 	case SMBDIRECT_SOCKET_CONNECTED:
345 		sc->status = SMBDIRECT_SOCKET_ERROR;
346 		break;
347 	}
348 
349 	/*
350 	 * Wake up all waiters in all wait queues
351 	 * in order to notice the broken connection.
352 	 */
353 	smb_direct_disconnect_wake_up_all(sc);
354 
355 	queue_work(sc->workqueue, &sc->disconnect_work);
356 }
357 
358 static void smb_direct_send_immediate_work(struct work_struct *work)
359 {
360 	struct smbdirect_socket *sc =
361 		container_of(work, struct smbdirect_socket, idle.immediate_work);
362 
363 	if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
364 		return;
365 
366 	smb_direct_post_send_data(sc, NULL, NULL, 0, 0);
367 }
368 
369 static void smb_direct_idle_connection_timer(struct work_struct *work)
370 {
371 	struct smbdirect_socket *sc =
372 		container_of(work, struct smbdirect_socket, idle.timer_work.work);
373 	struct smbdirect_socket_parameters *sp = &sc->parameters;
374 
375 	if (sc->idle.keepalive != SMBDIRECT_KEEPALIVE_NONE) {
376 		smb_direct_disconnect_rdma_connection(sc);
377 		return;
378 	}
379 
380 	if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
381 		return;
382 
383 	/*
384 	 * Now use the keepalive timeout (instead of keepalive interval)
385 	 * in order to wait for a response
386 	 */
387 	sc->idle.keepalive = SMBDIRECT_KEEPALIVE_PENDING;
388 	mod_delayed_work(sc->workqueue, &sc->idle.timer_work,
389 			 msecs_to_jiffies(sp->keepalive_timeout_msec));
390 	queue_work(sc->workqueue, &sc->idle.immediate_work);
391 }
392 
393 static struct smb_direct_transport *alloc_transport(struct rdma_cm_id *cm_id)
394 {
395 	struct smb_direct_transport *t;
396 	struct smbdirect_socket *sc;
397 	struct smbdirect_socket_parameters *sp;
398 	struct ksmbd_conn *conn;
399 
400 	t = kzalloc(sizeof(*t), KSMBD_DEFAULT_GFP);
401 	if (!t)
402 		return NULL;
403 	sc = &t->socket;
404 	smbdirect_socket_init(sc);
405 	sp = &sc->parameters;
406 
407 	sc->workqueue = smb_direct_wq;
408 
409 	INIT_WORK(&sc->disconnect_work, smb_direct_disconnect_rdma_work);
410 
411 	sp->negotiate_timeout_msec = SMB_DIRECT_NEGOTIATE_TIMEOUT * 1000;
412 	sp->initiator_depth = SMB_DIRECT_CM_INITIATOR_DEPTH;
413 	sp->responder_resources = 1;
414 	sp->recv_credit_max = smb_direct_receive_credit_max;
415 	sp->send_credit_target = smb_direct_send_credit_target;
416 	sp->max_send_size = smb_direct_max_send_size;
417 	sp->max_fragmented_recv_size = smb_direct_max_fragmented_recv_size;
418 	sp->max_recv_size = smb_direct_max_receive_size;
419 	sp->max_read_write_size = smb_direct_max_read_write_size;
420 	sp->keepalive_interval_msec = SMB_DIRECT_KEEPALIVE_SEND_INTERVAL * 1000;
421 	sp->keepalive_timeout_msec = SMB_DIRECT_KEEPALIVE_RECV_TIMEOUT * 1000;
422 
423 	sc->rdma.cm_id = cm_id;
424 	cm_id->context = sc;
425 
426 	sc->ib.dev = sc->rdma.cm_id->device;
427 
428 	INIT_DELAYED_WORK(&sc->idle.timer_work, smb_direct_idle_connection_timer);
429 
430 	conn = ksmbd_conn_alloc();
431 	if (!conn)
432 		goto err;
433 
434 	down_write(&conn_list_lock);
435 	hash_add(conn_list, &conn->hlist, 0);
436 	up_write(&conn_list_lock);
437 
438 	conn->transport = KSMBD_TRANS(t);
439 	KSMBD_TRANS(t)->conn = conn;
440 	KSMBD_TRANS(t)->ops = &ksmbd_smb_direct_transport_ops;
441 	return t;
442 err:
443 	kfree(t);
444 	return NULL;
445 }
446 
447 static void smb_direct_free_transport(struct ksmbd_transport *kt)
448 {
449 	kfree(SMBD_TRANS(kt));
450 }
451 
452 static void free_transport(struct smb_direct_transport *t)
453 {
454 	struct smbdirect_socket *sc = &t->socket;
455 	struct smbdirect_recv_io *recvmsg;
456 
457 	disable_work_sync(&sc->disconnect_work);
458 	if (sc->status < SMBDIRECT_SOCKET_DISCONNECTING)
459 		smb_direct_disconnect_rdma_work(&sc->disconnect_work);
460 	if (sc->status < SMBDIRECT_SOCKET_DISCONNECTED)
461 		wait_event(sc->status_wait, sc->status == SMBDIRECT_SOCKET_DISCONNECTED);
462 
463 	/*
464 	 * Wake up all waiters in all wait queues
465 	 * in order to notice the broken connection.
466 	 *
467 	 * Most likely this was already called via
468 	 * smb_direct_disconnect_rdma_work(), but call it again...
469 	 */
470 	smb_direct_disconnect_wake_up_all(sc);
471 
472 	disable_work_sync(&sc->connect.work);
473 	disable_work_sync(&sc->recv_io.posted.refill_work);
474 	disable_delayed_work_sync(&sc->idle.timer_work);
475 	disable_work_sync(&sc->idle.immediate_work);
476 
477 	if (sc->rdma.cm_id)
478 		rdma_lock_handler(sc->rdma.cm_id);
479 
480 	if (sc->ib.qp) {
481 		ib_drain_qp(sc->ib.qp);
482 		sc->ib.qp = NULL;
483 		rdma_destroy_qp(sc->rdma.cm_id);
484 	}
485 
486 	ksmbd_debug(RDMA, "drain the reassembly queue\n");
487 	do {
488 		unsigned long flags;
489 
490 		spin_lock_irqsave(&sc->recv_io.reassembly.lock, flags);
491 		recvmsg = get_first_reassembly(sc);
492 		if (recvmsg) {
493 			list_del(&recvmsg->list);
494 			spin_unlock_irqrestore(&sc->recv_io.reassembly.lock, flags);
495 			put_recvmsg(sc, recvmsg);
496 		} else {
497 			spin_unlock_irqrestore(&sc->recv_io.reassembly.lock, flags);
498 		}
499 	} while (recvmsg);
500 	sc->recv_io.reassembly.data_length = 0;
501 
502 	if (sc->ib.send_cq)
503 		ib_free_cq(sc->ib.send_cq);
504 	if (sc->ib.recv_cq)
505 		ib_free_cq(sc->ib.recv_cq);
506 	if (sc->ib.pd)
507 		ib_dealloc_pd(sc->ib.pd);
508 	if (sc->rdma.cm_id) {
509 		rdma_unlock_handler(sc->rdma.cm_id);
510 		rdma_destroy_id(sc->rdma.cm_id);
511 	}
512 
513 	smb_direct_destroy_pools(sc);
514 	ksmbd_conn_free(KSMBD_TRANS(t)->conn);
515 }
516 
517 static struct smbdirect_send_io
518 *smb_direct_alloc_sendmsg(struct smbdirect_socket *sc)
519 {
520 	struct smbdirect_send_io *msg;
521 
522 	msg = mempool_alloc(sc->send_io.mem.pool, KSMBD_DEFAULT_GFP);
523 	if (!msg)
524 		return ERR_PTR(-ENOMEM);
525 	msg->socket = sc;
526 	INIT_LIST_HEAD(&msg->sibling_list);
527 	msg->num_sge = 0;
528 	return msg;
529 }
530 
531 static void smb_direct_free_sendmsg(struct smbdirect_socket *sc,
532 				    struct smbdirect_send_io *msg)
533 {
534 	int i;
535 
536 	/*
537 	 * The list needs to be empty!
538 	 * The caller should take care of it.
539 	 */
540 	WARN_ON_ONCE(!list_empty(&msg->sibling_list));
541 
542 	if (msg->num_sge > 0) {
543 		ib_dma_unmap_single(sc->ib.dev,
544 				    msg->sge[0].addr, msg->sge[0].length,
545 				    DMA_TO_DEVICE);
546 		for (i = 1; i < msg->num_sge; i++)
547 			ib_dma_unmap_page(sc->ib.dev,
548 					  msg->sge[i].addr, msg->sge[i].length,
549 					  DMA_TO_DEVICE);
550 	}
551 	mempool_free(msg, sc->send_io.mem.pool);
552 }
553 
554 static int smb_direct_check_recvmsg(struct smbdirect_recv_io *recvmsg)
555 {
556 	struct smbdirect_socket *sc = recvmsg->socket;
557 
558 	switch (sc->recv_io.expected) {
559 	case SMBDIRECT_EXPECT_DATA_TRANSFER: {
560 		struct smbdirect_data_transfer *req =
561 			(struct smbdirect_data_transfer *)recvmsg->packet;
562 		struct smb2_hdr *hdr = (struct smb2_hdr *)(recvmsg->packet
563 				+ le32_to_cpu(req->data_offset));
564 		ksmbd_debug(RDMA,
565 			    "CreditGranted: %u, CreditRequested: %u, DataLength: %u, RemainingDataLength: %u, SMB: %x, Command: %u\n",
566 			    le16_to_cpu(req->credits_granted),
567 			    le16_to_cpu(req->credits_requested),
568 			    req->data_length, req->remaining_data_length,
569 			    hdr->ProtocolId, hdr->Command);
570 		return 0;
571 	}
572 	case SMBDIRECT_EXPECT_NEGOTIATE_REQ: {
573 		struct smbdirect_negotiate_req *req =
574 			(struct smbdirect_negotiate_req *)recvmsg->packet;
575 		ksmbd_debug(RDMA,
576 			    "MinVersion: %u, MaxVersion: %u, CreditRequested: %u, MaxSendSize: %u, MaxRecvSize: %u, MaxFragmentedSize: %u\n",
577 			    le16_to_cpu(req->min_version),
578 			    le16_to_cpu(req->max_version),
579 			    le16_to_cpu(req->credits_requested),
580 			    le32_to_cpu(req->preferred_send_size),
581 			    le32_to_cpu(req->max_receive_size),
582 			    le32_to_cpu(req->max_fragmented_size));
583 		if (le16_to_cpu(req->min_version) > 0x0100 ||
584 		    le16_to_cpu(req->max_version) < 0x0100)
585 			return -EOPNOTSUPP;
586 		if (le16_to_cpu(req->credits_requested) <= 0 ||
587 		    le32_to_cpu(req->max_receive_size) <= 128 ||
588 		    le32_to_cpu(req->max_fragmented_size) <=
589 					128 * 1024)
590 			return -ECONNABORTED;
591 
592 		return 0;
593 	}
594 	case SMBDIRECT_EXPECT_NEGOTIATE_REP:
595 		/* client only */
596 		break;
597 	}
598 
599 	/* This is an internal error */
600 	return -EINVAL;
601 }
602 
603 static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
604 {
605 	struct smbdirect_recv_io *recvmsg;
606 	struct smbdirect_socket *sc;
607 	struct smbdirect_socket_parameters *sp;
608 
609 	recvmsg = container_of(wc->wr_cqe, struct smbdirect_recv_io, cqe);
610 	sc = recvmsg->socket;
611 	sp = &sc->parameters;
612 
613 	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_RECV) {
614 		put_recvmsg(sc, recvmsg);
615 		if (wc->status != IB_WC_WR_FLUSH_ERR) {
616 			pr_err("Recv error. status='%s (%d)' opcode=%d\n",
617 			       ib_wc_status_msg(wc->status), wc->status,
618 			       wc->opcode);
619 			smb_direct_disconnect_rdma_connection(sc);
620 		}
621 		return;
622 	}
623 
624 	ksmbd_debug(RDMA, "Recv completed. status='%s (%d)', opcode=%d\n",
625 		    ib_wc_status_msg(wc->status), wc->status,
626 		    wc->opcode);
627 
628 	ib_dma_sync_single_for_cpu(wc->qp->device, recvmsg->sge.addr,
629 				   recvmsg->sge.length, DMA_FROM_DEVICE);
630 
631 	/*
632 	 * Reset timer to the keepalive interval in
633 	 * order to trigger our next keepalive message.
634 	 */
635 	sc->idle.keepalive = SMBDIRECT_KEEPALIVE_NONE;
636 	mod_delayed_work(sc->workqueue, &sc->idle.timer_work,
637 			 msecs_to_jiffies(sp->keepalive_interval_msec));
638 
639 	switch (sc->recv_io.expected) {
640 	case SMBDIRECT_EXPECT_NEGOTIATE_REQ:
641 		/* see smb_direct_negotiate_recv_done */
642 		break;
643 	case SMBDIRECT_EXPECT_DATA_TRANSFER: {
644 		struct smbdirect_data_transfer *data_transfer =
645 			(struct smbdirect_data_transfer *)recvmsg->packet;
646 		u32 remaining_data_length, data_offset, data_length;
647 		u16 old_recv_credit_target;
648 
649 		if (wc->byte_len <
650 		    offsetof(struct smbdirect_data_transfer, padding)) {
651 			put_recvmsg(sc, recvmsg);
652 			smb_direct_disconnect_rdma_connection(sc);
653 			return;
654 		}
655 
656 		remaining_data_length = le32_to_cpu(data_transfer->remaining_data_length);
657 		data_length = le32_to_cpu(data_transfer->data_length);
658 		data_offset = le32_to_cpu(data_transfer->data_offset);
659 		if (wc->byte_len < data_offset ||
660 		    wc->byte_len < (u64)data_offset + data_length) {
661 			put_recvmsg(sc, recvmsg);
662 			smb_direct_disconnect_rdma_connection(sc);
663 			return;
664 		}
665 		if (remaining_data_length > sp->max_fragmented_recv_size ||
666 		    data_length > sp->max_fragmented_recv_size ||
667 		    (u64)remaining_data_length + (u64)data_length >
668 		    (u64)sp->max_fragmented_recv_size) {
669 			put_recvmsg(sc, recvmsg);
670 			smb_direct_disconnect_rdma_connection(sc);
671 			return;
672 		}
673 
674 		if (data_length) {
675 			if (sc->recv_io.reassembly.full_packet_received)
676 				recvmsg->first_segment = true;
677 
678 			if (le32_to_cpu(data_transfer->remaining_data_length))
679 				sc->recv_io.reassembly.full_packet_received = false;
680 			else
681 				sc->recv_io.reassembly.full_packet_received = true;
682 		}
683 
684 		atomic_dec(&sc->recv_io.posted.count);
685 		atomic_dec(&sc->recv_io.credits.count);
686 
687 		old_recv_credit_target = sc->recv_io.credits.target;
688 		sc->recv_io.credits.target =
689 				le16_to_cpu(data_transfer->credits_requested);
690 		sc->recv_io.credits.target =
691 			min_t(u16, sc->recv_io.credits.target, sp->recv_credit_max);
692 		sc->recv_io.credits.target =
693 			max_t(u16, sc->recv_io.credits.target, 1);
694 		atomic_add(le16_to_cpu(data_transfer->credits_granted),
695 			   &sc->send_io.credits.count);
696 
697 		if (le16_to_cpu(data_transfer->flags) &
698 		    SMBDIRECT_FLAG_RESPONSE_REQUESTED)
699 			queue_work(sc->workqueue, &sc->idle.immediate_work);
700 
701 		if (atomic_read(&sc->send_io.credits.count) > 0)
702 			wake_up(&sc->send_io.credits.wait_queue);
703 
704 		if (data_length) {
705 			if (sc->recv_io.credits.target > old_recv_credit_target)
706 				queue_work(sc->workqueue, &sc->recv_io.posted.refill_work);
707 
708 			enqueue_reassembly(sc, recvmsg, (int)data_length);
709 			wake_up(&sc->recv_io.reassembly.wait_queue);
710 		} else
711 			put_recvmsg(sc, recvmsg);
712 
713 		return;
714 	}
715 	case SMBDIRECT_EXPECT_NEGOTIATE_REP:
716 		/* client only */
717 		break;
718 	}
719 
720 	/*
721 	 * This is an internal error!
722 	 */
723 	WARN_ON_ONCE(sc->recv_io.expected != SMBDIRECT_EXPECT_DATA_TRANSFER);
724 	put_recvmsg(sc, recvmsg);
725 	smb_direct_disconnect_rdma_connection(sc);
726 }
727 
728 static void smb_direct_negotiate_recv_work(struct work_struct *work);
729 
730 static void smb_direct_negotiate_recv_done(struct ib_cq *cq, struct ib_wc *wc)
731 {
732 	struct smbdirect_recv_io *recv_io =
733 		container_of(wc->wr_cqe, struct smbdirect_recv_io, cqe);
734 	struct smbdirect_socket *sc = recv_io->socket;
735 	unsigned long flags;
736 
737 	/*
738 	 * reset the common recv_done for later reuse.
739 	 */
740 	recv_io->cqe.done = recv_done;
741 
742 	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_RECV) {
743 		put_recvmsg(sc, recv_io);
744 		if (wc->status != IB_WC_WR_FLUSH_ERR) {
745 			pr_err("Negotiate Recv error. status='%s (%d)' opcode=%d\n",
746 			       ib_wc_status_msg(wc->status), wc->status,
747 			       wc->opcode);
748 			smb_direct_disconnect_rdma_connection(sc);
749 		}
750 		return;
751 	}
752 
753 	ksmbd_debug(RDMA, "Negotiate Recv completed. status='%s (%d)', opcode=%d\n",
754 		    ib_wc_status_msg(wc->status), wc->status,
755 		    wc->opcode);
756 
757 	ib_dma_sync_single_for_cpu(sc->ib.dev,
758 				   recv_io->sge.addr,
759 				   recv_io->sge.length,
760 				   DMA_FROM_DEVICE);
761 
762 	/*
763 	 * This is an internal error!
764 	 */
765 	if (WARN_ON_ONCE(sc->recv_io.expected != SMBDIRECT_EXPECT_NEGOTIATE_REQ)) {
766 		put_recvmsg(sc, recv_io);
767 		smb_direct_disconnect_rdma_connection(sc);
768 		return;
769 	}
770 
771 	/*
772 	 * Don't reset timer to the keepalive interval in
773 	 * this will be done in smb_direct_negotiate_recv_work.
774 	 */
775 
776 	/*
777 	 * Only remember the recv_io if it has enough bytes,
778 	 * this gives smb_direct_negotiate_recv_work enough
779 	 * information in order to disconnect if it was not
780 	 * valid.
781 	 */
782 	sc->recv_io.reassembly.full_packet_received = true;
783 	if (wc->byte_len >= sizeof(struct smbdirect_negotiate_req))
784 		enqueue_reassembly(sc, recv_io, 0);
785 	else
786 		put_recvmsg(sc, recv_io);
787 
788 	/*
789 	 * Some drivers (at least mlx5_ib and irdma in roce mode)
790 	 * might post a recv completion before RDMA_CM_EVENT_ESTABLISHED,
791 	 * we need to adjust our expectation in that case.
792 	 *
793 	 * So we defer further processing of the negotiation
794 	 * to smb_direct_negotiate_recv_work().
795 	 *
796 	 * If we are already in SMBDIRECT_SOCKET_NEGOTIATE_NEEDED
797 	 * we queue the work directly otherwise
798 	 * smb_direct_cm_handler() will do it, when
799 	 * RDMA_CM_EVENT_ESTABLISHED arrived.
800 	 */
801 	spin_lock_irqsave(&sc->connect.lock, flags);
802 	if (!sc->first_error) {
803 		INIT_WORK(&sc->connect.work, smb_direct_negotiate_recv_work);
804 		if (sc->status == SMBDIRECT_SOCKET_NEGOTIATE_NEEDED)
805 			queue_work(sc->workqueue, &sc->connect.work);
806 	}
807 	spin_unlock_irqrestore(&sc->connect.lock, flags);
808 }
809 
810 static void smb_direct_negotiate_recv_work(struct work_struct *work)
811 {
812 	struct smbdirect_socket *sc =
813 		container_of(work, struct smbdirect_socket, connect.work);
814 	const struct smbdirect_socket_parameters *sp = &sc->parameters;
815 	struct smbdirect_recv_io *recv_io;
816 
817 	if (sc->first_error)
818 		return;
819 
820 	ksmbd_debug(RDMA, "Negotiate Recv Work running\n");
821 
822 	/*
823 	 * Reset timer to the keepalive interval in
824 	 * order to trigger our next keepalive message.
825 	 */
826 	sc->idle.keepalive = SMBDIRECT_KEEPALIVE_NONE;
827 	mod_delayed_work(sc->workqueue, &sc->idle.timer_work,
828 			 msecs_to_jiffies(sp->keepalive_interval_msec));
829 
830 	/*
831 	 * If smb_direct_negotiate_recv_done() detected an
832 	 * invalid request we want to disconnect.
833 	 */
834 	recv_io = get_first_reassembly(sc);
835 	if (!recv_io) {
836 		smb_direct_disconnect_rdma_connection(sc);
837 		return;
838 	}
839 
840 	if (SMBDIRECT_CHECK_STATUS_WARN(sc, SMBDIRECT_SOCKET_NEGOTIATE_NEEDED)) {
841 		smb_direct_disconnect_rdma_connection(sc);
842 		return;
843 	}
844 	sc->status = SMBDIRECT_SOCKET_NEGOTIATE_RUNNING;
845 	wake_up(&sc->status_wait);
846 }
847 
848 static int smb_direct_post_recv(struct smbdirect_socket *sc,
849 				struct smbdirect_recv_io *recvmsg)
850 {
851 	struct smbdirect_socket_parameters *sp = &sc->parameters;
852 	struct ib_recv_wr wr;
853 	int ret;
854 
855 	recvmsg->sge.addr = ib_dma_map_single(sc->ib.dev,
856 					      recvmsg->packet,
857 					      sp->max_recv_size,
858 					      DMA_FROM_DEVICE);
859 	ret = ib_dma_mapping_error(sc->ib.dev, recvmsg->sge.addr);
860 	if (ret)
861 		return ret;
862 	recvmsg->sge.length = sp->max_recv_size;
863 	recvmsg->sge.lkey = sc->ib.pd->local_dma_lkey;
864 
865 	wr.wr_cqe = &recvmsg->cqe;
866 	wr.next = NULL;
867 	wr.sg_list = &recvmsg->sge;
868 	wr.num_sge = 1;
869 
870 	ret = ib_post_recv(sc->ib.qp, &wr, NULL);
871 	if (ret) {
872 		pr_err("Can't post recv: %d\n", ret);
873 		ib_dma_unmap_single(sc->ib.dev,
874 				    recvmsg->sge.addr, recvmsg->sge.length,
875 				    DMA_FROM_DEVICE);
876 		recvmsg->sge.length = 0;
877 		smb_direct_disconnect_rdma_connection(sc);
878 		return ret;
879 	}
880 	return ret;
881 }
882 
883 static int smb_direct_read(struct ksmbd_transport *t, char *buf,
884 			   unsigned int size, int unused)
885 {
886 	struct smbdirect_recv_io *recvmsg;
887 	struct smbdirect_data_transfer *data_transfer;
888 	int to_copy, to_read, data_read, offset;
889 	u32 data_length, remaining_data_length, data_offset;
890 	int rc;
891 	struct smb_direct_transport *st = SMBD_TRANS(t);
892 	struct smbdirect_socket *sc = &st->socket;
893 
894 again:
895 	if (sc->status != SMBDIRECT_SOCKET_CONNECTED) {
896 		pr_err("disconnected\n");
897 		return -ENOTCONN;
898 	}
899 
900 	/*
901 	 * No need to hold the reassembly queue lock all the time as we are
902 	 * the only one reading from the front of the queue. The transport
903 	 * may add more entries to the back of the queue at the same time
904 	 */
905 	if (sc->recv_io.reassembly.data_length >= size) {
906 		int queue_length;
907 		int queue_removed = 0;
908 		unsigned long flags;
909 
910 		/*
911 		 * Need to make sure reassembly_data_length is read before
912 		 * reading reassembly_queue_length and calling
913 		 * get_first_reassembly. This call is lock free
914 		 * as we never read at the end of the queue which are being
915 		 * updated in SOFTIRQ as more data is received
916 		 */
917 		virt_rmb();
918 		queue_length = sc->recv_io.reassembly.queue_length;
919 		data_read = 0;
920 		to_read = size;
921 		offset = sc->recv_io.reassembly.first_entry_offset;
922 		while (data_read < size) {
923 			recvmsg = get_first_reassembly(sc);
924 			data_transfer = smbdirect_recv_io_payload(recvmsg);
925 			data_length = le32_to_cpu(data_transfer->data_length);
926 			remaining_data_length =
927 				le32_to_cpu(data_transfer->remaining_data_length);
928 			data_offset = le32_to_cpu(data_transfer->data_offset);
929 
930 			/*
931 			 * The upper layer expects RFC1002 length at the
932 			 * beginning of the payload. Return it to indicate
933 			 * the total length of the packet. This minimize the
934 			 * change to upper layer packet processing logic. This
935 			 * will be eventually remove when an intermediate
936 			 * transport layer is added
937 			 */
938 			if (recvmsg->first_segment && size == 4) {
939 				unsigned int rfc1002_len =
940 					data_length + remaining_data_length;
941 				*((__be32 *)buf) = cpu_to_be32(rfc1002_len);
942 				data_read = 4;
943 				recvmsg->first_segment = false;
944 				ksmbd_debug(RDMA,
945 					    "returning rfc1002 length %d\n",
946 					    rfc1002_len);
947 				goto read_rfc1002_done;
948 			}
949 
950 			to_copy = min_t(int, data_length - offset, to_read);
951 			memcpy(buf + data_read, (char *)data_transfer + data_offset + offset,
952 			       to_copy);
953 
954 			/* move on to the next buffer? */
955 			if (to_copy == data_length - offset) {
956 				queue_length--;
957 				/*
958 				 * No need to lock if we are not at the
959 				 * end of the queue
960 				 */
961 				if (queue_length) {
962 					list_del(&recvmsg->list);
963 				} else {
964 					spin_lock_irqsave(&sc->recv_io.reassembly.lock, flags);
965 					list_del(&recvmsg->list);
966 					spin_unlock_irqrestore(&sc->recv_io.reassembly.lock, flags);
967 				}
968 				queue_removed++;
969 				put_recvmsg(sc, recvmsg);
970 				offset = 0;
971 			} else {
972 				offset += to_copy;
973 			}
974 
975 			to_read -= to_copy;
976 			data_read += to_copy;
977 		}
978 
979 		spin_lock_irqsave(&sc->recv_io.reassembly.lock, flags);
980 		sc->recv_io.reassembly.data_length -= data_read;
981 		sc->recv_io.reassembly.queue_length -= queue_removed;
982 		spin_unlock_irqrestore(&sc->recv_io.reassembly.lock, flags);
983 
984 		sc->recv_io.reassembly.first_entry_offset = offset;
985 		ksmbd_debug(RDMA,
986 			    "returning to thread data_read=%d reassembly_data_length=%d first_entry_offset=%d\n",
987 			    data_read, sc->recv_io.reassembly.data_length,
988 			    sc->recv_io.reassembly.first_entry_offset);
989 read_rfc1002_done:
990 		return data_read;
991 	}
992 
993 	ksmbd_debug(RDMA, "wait_event on more data\n");
994 	rc = wait_event_interruptible(sc->recv_io.reassembly.wait_queue,
995 				      sc->recv_io.reassembly.data_length >= size ||
996 				       sc->status != SMBDIRECT_SOCKET_CONNECTED);
997 	if (rc)
998 		return -EINTR;
999 
1000 	goto again;
1001 }
1002 
1003 static void smb_direct_post_recv_credits(struct work_struct *work)
1004 {
1005 	struct smbdirect_socket *sc =
1006 		container_of(work, struct smbdirect_socket, recv_io.posted.refill_work);
1007 	struct smbdirect_recv_io *recvmsg;
1008 	int credits = 0;
1009 	int ret;
1010 
1011 	if (atomic_read(&sc->recv_io.credits.count) < sc->recv_io.credits.target) {
1012 		while (true) {
1013 			recvmsg = get_free_recvmsg(sc);
1014 			if (!recvmsg)
1015 				break;
1016 
1017 			recvmsg->first_segment = false;
1018 
1019 			ret = smb_direct_post_recv(sc, recvmsg);
1020 			if (ret) {
1021 				pr_err("Can't post recv: %d\n", ret);
1022 				put_recvmsg(sc, recvmsg);
1023 				break;
1024 			}
1025 			credits++;
1026 
1027 			atomic_inc(&sc->recv_io.posted.count);
1028 		}
1029 	}
1030 
1031 	if (credits)
1032 		queue_work(sc->workqueue, &sc->idle.immediate_work);
1033 }
1034 
1035 static void send_done(struct ib_cq *cq, struct ib_wc *wc)
1036 {
1037 	struct smbdirect_send_io *sendmsg, *sibling, *next;
1038 	struct smbdirect_socket *sc;
1039 	int lcredits = 0;
1040 
1041 	sendmsg = container_of(wc->wr_cqe, struct smbdirect_send_io, cqe);
1042 	sc = sendmsg->socket;
1043 
1044 	ksmbd_debug(RDMA, "Send completed. status='%s (%d)', opcode=%d\n",
1045 		    ib_wc_status_msg(wc->status), wc->status,
1046 		    wc->opcode);
1047 
1048 	/*
1049 	 * Free possible siblings and then the main send_io
1050 	 */
1051 	list_for_each_entry_safe(sibling, next, &sendmsg->sibling_list, sibling_list) {
1052 		list_del_init(&sibling->sibling_list);
1053 		smb_direct_free_sendmsg(sc, sibling);
1054 		lcredits += 1;
1055 	}
1056 	/* Note this frees wc->wr_cqe, but not wc */
1057 	smb_direct_free_sendmsg(sc, sendmsg);
1058 	lcredits += 1;
1059 
1060 	if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) {
1061 		pr_err("Send error. status='%s (%d)', opcode=%d\n",
1062 		       ib_wc_status_msg(wc->status), wc->status,
1063 		       wc->opcode);
1064 		smb_direct_disconnect_rdma_connection(sc);
1065 		return;
1066 	}
1067 
1068 	atomic_add(lcredits, &sc->send_io.lcredits.count);
1069 	wake_up(&sc->send_io.lcredits.wait_queue);
1070 
1071 	if (atomic_dec_and_test(&sc->send_io.pending.count))
1072 		wake_up(&sc->send_io.pending.zero_wait_queue);
1073 }
1074 
1075 static int manage_credits_prior_sending(struct smbdirect_socket *sc)
1076 {
1077 	int new_credits;
1078 
1079 	if (atomic_read(&sc->recv_io.credits.count) >= sc->recv_io.credits.target)
1080 		return 0;
1081 
1082 	new_credits = atomic_read(&sc->recv_io.posted.count);
1083 	if (new_credits == 0)
1084 		return 0;
1085 
1086 	new_credits -= atomic_read(&sc->recv_io.credits.count);
1087 	if (new_credits <= 0)
1088 		return 0;
1089 
1090 	atomic_add(new_credits, &sc->recv_io.credits.count);
1091 	return new_credits;
1092 }
1093 
1094 static int manage_keep_alive_before_sending(struct smbdirect_socket *sc)
1095 {
1096 	struct smbdirect_socket_parameters *sp = &sc->parameters;
1097 
1098 	if (sc->idle.keepalive == SMBDIRECT_KEEPALIVE_PENDING) {
1099 		sc->idle.keepalive = SMBDIRECT_KEEPALIVE_SENT;
1100 		/*
1101 		 * Now use the keepalive timeout (instead of keepalive interval)
1102 		 * in order to wait for a response
1103 		 */
1104 		mod_delayed_work(sc->workqueue, &sc->idle.timer_work,
1105 				 msecs_to_jiffies(sp->keepalive_timeout_msec));
1106 		return 1;
1107 	}
1108 	return 0;
1109 }
1110 
1111 static int smb_direct_post_send(struct smbdirect_socket *sc,
1112 				struct ib_send_wr *wr)
1113 {
1114 	int ret;
1115 
1116 	atomic_inc(&sc->send_io.pending.count);
1117 	ret = ib_post_send(sc->ib.qp, wr, NULL);
1118 	if (ret) {
1119 		pr_err("failed to post send: %d\n", ret);
1120 		smb_direct_disconnect_rdma_connection(sc);
1121 	}
1122 	return ret;
1123 }
1124 
1125 static void smb_direct_send_ctx_init(struct smbdirect_send_batch *send_ctx,
1126 				     bool need_invalidate_rkey,
1127 				     unsigned int remote_key)
1128 {
1129 	INIT_LIST_HEAD(&send_ctx->msg_list);
1130 	send_ctx->wr_cnt = 0;
1131 	send_ctx->need_invalidate_rkey = need_invalidate_rkey;
1132 	send_ctx->remote_key = remote_key;
1133 }
1134 
1135 static int smb_direct_flush_send_list(struct smbdirect_socket *sc,
1136 				      struct smbdirect_send_batch *send_ctx,
1137 				      bool is_last)
1138 {
1139 	struct smbdirect_send_io *first, *last;
1140 	int ret;
1141 
1142 	if (list_empty(&send_ctx->msg_list))
1143 		return 0;
1144 
1145 	first = list_first_entry(&send_ctx->msg_list,
1146 				 struct smbdirect_send_io,
1147 				 sibling_list);
1148 	last = list_last_entry(&send_ctx->msg_list,
1149 			       struct smbdirect_send_io,
1150 			       sibling_list);
1151 
1152 	if (send_ctx->need_invalidate_rkey) {
1153 		first->wr.opcode = IB_WR_SEND_WITH_INV;
1154 		first->wr.ex.invalidate_rkey = send_ctx->remote_key;
1155 		send_ctx->need_invalidate_rkey = false;
1156 		send_ctx->remote_key = 0;
1157 	}
1158 
1159 	last->wr.send_flags = IB_SEND_SIGNALED;
1160 	last->wr.wr_cqe = &last->cqe;
1161 
1162 	/*
1163 	 * Remove last from send_ctx->msg_list
1164 	 * and splice the rest of send_ctx->msg_list
1165 	 * to last->sibling_list.
1166 	 *
1167 	 * send_ctx->msg_list is a valid empty list
1168 	 * at the end.
1169 	 */
1170 	list_del_init(&last->sibling_list);
1171 	list_splice_tail_init(&send_ctx->msg_list, &last->sibling_list);
1172 	send_ctx->wr_cnt = 0;
1173 
1174 	ret = smb_direct_post_send(sc, &first->wr);
1175 	if (ret) {
1176 		struct smbdirect_send_io *sibling, *next;
1177 
1178 		list_for_each_entry_safe(sibling, next, &last->sibling_list, sibling_list) {
1179 			list_del_init(&sibling->sibling_list);
1180 			smb_direct_free_sendmsg(sc, sibling);
1181 		}
1182 		smb_direct_free_sendmsg(sc, last);
1183 	}
1184 
1185 	return ret;
1186 }
1187 
1188 static int wait_for_credits(struct smbdirect_socket *sc,
1189 			    wait_queue_head_t *waitq, atomic_t *total_credits,
1190 			    int needed)
1191 {
1192 	int ret;
1193 
1194 	do {
1195 		if (atomic_sub_return(needed, total_credits) >= 0)
1196 			return 0;
1197 
1198 		atomic_add(needed, total_credits);
1199 		ret = wait_event_interruptible(*waitq,
1200 					       atomic_read(total_credits) >= needed ||
1201 					       sc->status != SMBDIRECT_SOCKET_CONNECTED);
1202 
1203 		if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
1204 			return -ENOTCONN;
1205 		else if (ret < 0)
1206 			return ret;
1207 	} while (true);
1208 }
1209 
1210 static int wait_for_send_lcredit(struct smbdirect_socket *sc,
1211 				 struct smbdirect_send_batch *send_ctx)
1212 {
1213 	if (send_ctx && (atomic_read(&sc->send_io.lcredits.count) <= 1)) {
1214 		int ret;
1215 
1216 		ret = smb_direct_flush_send_list(sc, send_ctx, false);
1217 		if (ret)
1218 			return ret;
1219 	}
1220 
1221 	return wait_for_credits(sc,
1222 				&sc->send_io.lcredits.wait_queue,
1223 				&sc->send_io.lcredits.count,
1224 				1);
1225 }
1226 
1227 static int wait_for_send_credits(struct smbdirect_socket *sc,
1228 				 struct smbdirect_send_batch *send_ctx)
1229 {
1230 	int ret;
1231 
1232 	if (send_ctx &&
1233 	    (send_ctx->wr_cnt >= 16 || atomic_read(&sc->send_io.credits.count) <= 1)) {
1234 		ret = smb_direct_flush_send_list(sc, send_ctx, false);
1235 		if (ret)
1236 			return ret;
1237 	}
1238 
1239 	return wait_for_credits(sc, &sc->send_io.credits.wait_queue, &sc->send_io.credits.count, 1);
1240 }
1241 
1242 static int wait_for_rw_credits(struct smbdirect_socket *sc, int credits)
1243 {
1244 	return wait_for_credits(sc,
1245 				&sc->rw_io.credits.wait_queue,
1246 				&sc->rw_io.credits.count,
1247 				credits);
1248 }
1249 
1250 static int calc_rw_credits(struct smbdirect_socket *sc,
1251 			   char *buf, unsigned int len)
1252 {
1253 	return DIV_ROUND_UP(get_buf_page_count(buf, len),
1254 			    sc->rw_io.credits.num_pages);
1255 }
1256 
1257 static int smb_direct_create_header(struct smbdirect_socket *sc,
1258 				    int size, int remaining_data_length,
1259 				    struct smbdirect_send_io **sendmsg_out)
1260 {
1261 	struct smbdirect_socket_parameters *sp = &sc->parameters;
1262 	struct smbdirect_send_io *sendmsg;
1263 	struct smbdirect_data_transfer *packet;
1264 	int header_length;
1265 	int ret;
1266 
1267 	sendmsg = smb_direct_alloc_sendmsg(sc);
1268 	if (IS_ERR(sendmsg))
1269 		return PTR_ERR(sendmsg);
1270 
1271 	/* Fill in the packet header */
1272 	packet = (struct smbdirect_data_transfer *)sendmsg->packet;
1273 	packet->credits_requested = cpu_to_le16(sp->send_credit_target);
1274 	packet->credits_granted = cpu_to_le16(manage_credits_prior_sending(sc));
1275 
1276 	packet->flags = 0;
1277 	if (manage_keep_alive_before_sending(sc))
1278 		packet->flags |= cpu_to_le16(SMBDIRECT_FLAG_RESPONSE_REQUESTED);
1279 
1280 	packet->reserved = 0;
1281 	if (!size)
1282 		packet->data_offset = 0;
1283 	else
1284 		packet->data_offset = cpu_to_le32(24);
1285 	packet->data_length = cpu_to_le32(size);
1286 	packet->remaining_data_length = cpu_to_le32(remaining_data_length);
1287 	packet->padding = 0;
1288 
1289 	ksmbd_debug(RDMA,
1290 		    "credits_requested=%d credits_granted=%d data_offset=%d data_length=%d remaining_data_length=%d\n",
1291 		    le16_to_cpu(packet->credits_requested),
1292 		    le16_to_cpu(packet->credits_granted),
1293 		    le32_to_cpu(packet->data_offset),
1294 		    le32_to_cpu(packet->data_length),
1295 		    le32_to_cpu(packet->remaining_data_length));
1296 
1297 	/* Map the packet to DMA */
1298 	header_length = sizeof(struct smbdirect_data_transfer);
1299 	/* If this is a packet without payload, don't send padding */
1300 	if (!size)
1301 		header_length =
1302 			offsetof(struct smbdirect_data_transfer, padding);
1303 
1304 	sendmsg->sge[0].addr = ib_dma_map_single(sc->ib.dev,
1305 						 (void *)packet,
1306 						 header_length,
1307 						 DMA_TO_DEVICE);
1308 	ret = ib_dma_mapping_error(sc->ib.dev, sendmsg->sge[0].addr);
1309 	if (ret) {
1310 		smb_direct_free_sendmsg(sc, sendmsg);
1311 		return ret;
1312 	}
1313 
1314 	sendmsg->num_sge = 1;
1315 	sendmsg->sge[0].length = header_length;
1316 	sendmsg->sge[0].lkey = sc->ib.pd->local_dma_lkey;
1317 
1318 	*sendmsg_out = sendmsg;
1319 	return 0;
1320 }
1321 
1322 static int get_sg_list(void *buf, int size, struct scatterlist *sg_list, int nentries)
1323 {
1324 	bool high = is_vmalloc_addr(buf);
1325 	struct page *page;
1326 	int offset, len;
1327 	int i = 0;
1328 
1329 	if (size <= 0 || nentries < get_buf_page_count(buf, size))
1330 		return -EINVAL;
1331 
1332 	offset = offset_in_page(buf);
1333 	buf -= offset;
1334 	while (size > 0) {
1335 		len = min_t(int, PAGE_SIZE - offset, size);
1336 		if (high)
1337 			page = vmalloc_to_page(buf);
1338 		else
1339 			page = kmap_to_page(buf);
1340 
1341 		if (!sg_list)
1342 			return -EINVAL;
1343 		sg_set_page(sg_list, page, len, offset);
1344 		sg_list = sg_next(sg_list);
1345 
1346 		buf += PAGE_SIZE;
1347 		size -= len;
1348 		offset = 0;
1349 		i++;
1350 	}
1351 	return i;
1352 }
1353 
1354 static int get_mapped_sg_list(struct ib_device *device, void *buf, int size,
1355 			      struct scatterlist *sg_list, int nentries,
1356 			      enum dma_data_direction dir, int *npages)
1357 {
1358 	*npages = get_sg_list(buf, size, sg_list, nentries);
1359 	if (*npages < 0)
1360 		return -EINVAL;
1361 	return ib_dma_map_sg(device, sg_list, *npages, dir);
1362 }
1363 
1364 static int post_sendmsg(struct smbdirect_socket *sc,
1365 			struct smbdirect_send_batch *send_ctx,
1366 			struct smbdirect_send_io *msg)
1367 {
1368 	int i;
1369 
1370 	for (i = 0; i < msg->num_sge; i++)
1371 		ib_dma_sync_single_for_device(sc->ib.dev,
1372 					      msg->sge[i].addr, msg->sge[i].length,
1373 					      DMA_TO_DEVICE);
1374 
1375 	msg->cqe.done = send_done;
1376 	msg->wr.opcode = IB_WR_SEND;
1377 	msg->wr.sg_list = &msg->sge[0];
1378 	msg->wr.num_sge = msg->num_sge;
1379 	msg->wr.next = NULL;
1380 
1381 	if (send_ctx) {
1382 		msg->wr.wr_cqe = NULL;
1383 		msg->wr.send_flags = 0;
1384 		if (!list_empty(&send_ctx->msg_list)) {
1385 			struct smbdirect_send_io *last;
1386 
1387 			last = list_last_entry(&send_ctx->msg_list,
1388 					       struct smbdirect_send_io,
1389 					       sibling_list);
1390 			last->wr.next = &msg->wr;
1391 		}
1392 		list_add_tail(&msg->sibling_list, &send_ctx->msg_list);
1393 		send_ctx->wr_cnt++;
1394 		return 0;
1395 	}
1396 
1397 	msg->wr.wr_cqe = &msg->cqe;
1398 	msg->wr.send_flags = IB_SEND_SIGNALED;
1399 	return smb_direct_post_send(sc, &msg->wr);
1400 }
1401 
1402 static int smb_direct_post_send_data(struct smbdirect_socket *sc,
1403 				     struct smbdirect_send_batch *send_ctx,
1404 				     struct kvec *iov, int niov,
1405 				     int remaining_data_length)
1406 {
1407 	int i, j, ret;
1408 	struct smbdirect_send_io *msg;
1409 	int data_length;
1410 	struct scatterlist sg[SMBDIRECT_SEND_IO_MAX_SGE - 1];
1411 
1412 	ret = wait_for_send_lcredit(sc, send_ctx);
1413 	if (ret)
1414 		goto lcredit_failed;
1415 
1416 	ret = wait_for_send_credits(sc, send_ctx);
1417 	if (ret)
1418 		goto credit_failed;
1419 
1420 	data_length = 0;
1421 	for (i = 0; i < niov; i++)
1422 		data_length += iov[i].iov_len;
1423 
1424 	ret = smb_direct_create_header(sc, data_length, remaining_data_length,
1425 				       &msg);
1426 	if (ret)
1427 		goto header_failed;
1428 
1429 	for (i = 0; i < niov; i++) {
1430 		struct ib_sge *sge;
1431 		int sg_cnt;
1432 		int npages;
1433 
1434 		sg_init_table(sg, SMBDIRECT_SEND_IO_MAX_SGE - 1);
1435 		sg_cnt = get_mapped_sg_list(sc->ib.dev,
1436 					    iov[i].iov_base, iov[i].iov_len,
1437 					    sg, SMBDIRECT_SEND_IO_MAX_SGE - 1,
1438 					    DMA_TO_DEVICE, &npages);
1439 		if (sg_cnt <= 0) {
1440 			pr_err("failed to map buffer\n");
1441 			ret = -ENOMEM;
1442 			goto err;
1443 		} else if (sg_cnt + msg->num_sge > SMBDIRECT_SEND_IO_MAX_SGE) {
1444 			pr_err("buffer not fitted into sges\n");
1445 			ret = -E2BIG;
1446 			ib_dma_unmap_sg(sc->ib.dev, sg, npages,
1447 					DMA_TO_DEVICE);
1448 			goto err;
1449 		}
1450 
1451 		for (j = 0; j < sg_cnt; j++) {
1452 			sge = &msg->sge[msg->num_sge];
1453 			sge->addr = sg_dma_address(&sg[j]);
1454 			sge->length = sg_dma_len(&sg[j]);
1455 			sge->lkey  = sc->ib.pd->local_dma_lkey;
1456 			msg->num_sge++;
1457 		}
1458 	}
1459 
1460 	ret = post_sendmsg(sc, send_ctx, msg);
1461 	if (ret)
1462 		goto err;
1463 	return 0;
1464 err:
1465 	smb_direct_free_sendmsg(sc, msg);
1466 header_failed:
1467 	atomic_inc(&sc->send_io.credits.count);
1468 credit_failed:
1469 	atomic_inc(&sc->send_io.lcredits.count);
1470 lcredit_failed:
1471 	return ret;
1472 }
1473 
1474 static int smb_direct_writev(struct ksmbd_transport *t,
1475 			     struct kvec *iov, int niovs, int buflen,
1476 			     bool need_invalidate, unsigned int remote_key)
1477 {
1478 	struct smb_direct_transport *st = SMBD_TRANS(t);
1479 	struct smbdirect_socket *sc = &st->socket;
1480 	struct smbdirect_socket_parameters *sp = &sc->parameters;
1481 	size_t remaining_data_length;
1482 	size_t iov_idx;
1483 	size_t iov_ofs;
1484 	size_t max_iov_size = sp->max_send_size -
1485 			sizeof(struct smbdirect_data_transfer);
1486 	int ret;
1487 	struct smbdirect_send_batch send_ctx;
1488 	int error = 0;
1489 
1490 	if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
1491 		return -ENOTCONN;
1492 
1493 	//FIXME: skip RFC1002 header..
1494 	if (WARN_ON_ONCE(niovs <= 1 || iov[0].iov_len != 4))
1495 		return -EINVAL;
1496 	buflen -= 4;
1497 	iov_idx = 1;
1498 	iov_ofs = 0;
1499 
1500 	remaining_data_length = buflen;
1501 	ksmbd_debug(RDMA, "Sending smb (RDMA): smb_len=%u\n", buflen);
1502 
1503 	smb_direct_send_ctx_init(&send_ctx, need_invalidate, remote_key);
1504 	while (remaining_data_length) {
1505 		struct kvec vecs[SMBDIRECT_SEND_IO_MAX_SGE - 1]; /* minus smbdirect hdr */
1506 		size_t possible_bytes = max_iov_size;
1507 		size_t possible_vecs;
1508 		size_t bytes = 0;
1509 		size_t nvecs = 0;
1510 
1511 		/*
1512 		 * For the last message remaining_data_length should be
1513 		 * have been 0 already!
1514 		 */
1515 		if (WARN_ON_ONCE(iov_idx >= niovs)) {
1516 			error = -EINVAL;
1517 			goto done;
1518 		}
1519 
1520 		/*
1521 		 * We have 2 factors which limit the arguments we pass
1522 		 * to smb_direct_post_send_data():
1523 		 *
1524 		 * 1. The number of supported sges for the send,
1525 		 *    while one is reserved for the smbdirect header.
1526 		 *    And we currently need one SGE per page.
1527 		 * 2. The number of negotiated payload bytes per send.
1528 		 */
1529 		possible_vecs = min_t(size_t, ARRAY_SIZE(vecs), niovs - iov_idx);
1530 
1531 		while (iov_idx < niovs && possible_vecs && possible_bytes) {
1532 			struct kvec *v = &vecs[nvecs];
1533 			int page_count;
1534 
1535 			v->iov_base = ((u8 *)iov[iov_idx].iov_base) + iov_ofs;
1536 			v->iov_len = min_t(size_t,
1537 					   iov[iov_idx].iov_len - iov_ofs,
1538 					   possible_bytes);
1539 			page_count = get_buf_page_count(v->iov_base, v->iov_len);
1540 			if (page_count > possible_vecs) {
1541 				/*
1542 				 * If the number of pages in the buffer
1543 				 * is to much (because we currently require
1544 				 * one SGE per page), we need to limit the
1545 				 * length.
1546 				 *
1547 				 * We know possible_vecs is at least 1,
1548 				 * so we always keep the first page.
1549 				 *
1550 				 * We need to calculate the number extra
1551 				 * pages (epages) we can also keep.
1552 				 *
1553 				 * We calculate the number of bytes in the
1554 				 * first page (fplen), this should never be
1555 				 * larger than v->iov_len because page_count is
1556 				 * at least 2, but adding a limitation feels
1557 				 * better.
1558 				 *
1559 				 * Then we calculate the number of bytes (elen)
1560 				 * we can keep for the extra pages.
1561 				 */
1562 				size_t epages = possible_vecs - 1;
1563 				size_t fpofs = offset_in_page(v->iov_base);
1564 				size_t fplen = min_t(size_t, PAGE_SIZE - fpofs, v->iov_len);
1565 				size_t elen = min_t(size_t, v->iov_len - fplen, epages*PAGE_SIZE);
1566 
1567 				v->iov_len = fplen + elen;
1568 				page_count = get_buf_page_count(v->iov_base, v->iov_len);
1569 				if (WARN_ON_ONCE(page_count > possible_vecs)) {
1570 					/*
1571 					 * Something went wrong in the above
1572 					 * logic...
1573 					 */
1574 					error = -EINVAL;
1575 					goto done;
1576 				}
1577 			}
1578 			possible_vecs -= page_count;
1579 			nvecs += 1;
1580 			possible_bytes -= v->iov_len;
1581 			bytes += v->iov_len;
1582 
1583 			iov_ofs += v->iov_len;
1584 			if (iov_ofs >= iov[iov_idx].iov_len) {
1585 				iov_idx += 1;
1586 				iov_ofs = 0;
1587 			}
1588 		}
1589 
1590 		remaining_data_length -= bytes;
1591 
1592 		ret = smb_direct_post_send_data(sc, &send_ctx,
1593 						vecs, nvecs,
1594 						remaining_data_length);
1595 		if (unlikely(ret)) {
1596 			error = ret;
1597 			goto done;
1598 		}
1599 	}
1600 
1601 done:
1602 	ret = smb_direct_flush_send_list(sc, &send_ctx, true);
1603 	if (unlikely(!ret && error))
1604 		ret = error;
1605 
1606 	/*
1607 	 * As an optimization, we don't wait for individual I/O to finish
1608 	 * before sending the next one.
1609 	 * Send them all and wait for pending send count to get to 0
1610 	 * that means all the I/Os have been out and we are good to return
1611 	 */
1612 
1613 	wait_event(sc->send_io.pending.zero_wait_queue,
1614 		   atomic_read(&sc->send_io.pending.count) == 0 ||
1615 		   sc->status != SMBDIRECT_SOCKET_CONNECTED);
1616 	if (sc->status != SMBDIRECT_SOCKET_CONNECTED && ret == 0)
1617 		ret = -ENOTCONN;
1618 
1619 	return ret;
1620 }
1621 
1622 static void smb_direct_free_rdma_rw_msg(struct smb_direct_transport *t,
1623 					struct smbdirect_rw_io *msg,
1624 					enum dma_data_direction dir)
1625 {
1626 	struct smbdirect_socket *sc = &t->socket;
1627 
1628 	rdma_rw_ctx_destroy(&msg->rdma_ctx, sc->ib.qp, sc->ib.qp->port,
1629 			    msg->sgt.sgl, msg->sgt.nents, dir);
1630 	sg_free_table_chained(&msg->sgt, SG_CHUNK_SIZE);
1631 	kfree(msg);
1632 }
1633 
1634 static void read_write_done(struct ib_cq *cq, struct ib_wc *wc,
1635 			    enum dma_data_direction dir)
1636 {
1637 	struct smbdirect_rw_io *msg =
1638 		container_of(wc->wr_cqe, struct smbdirect_rw_io, cqe);
1639 	struct smbdirect_socket *sc = msg->socket;
1640 
1641 	if (wc->status != IB_WC_SUCCESS) {
1642 		msg->error = -EIO;
1643 		pr_err("read/write error. opcode = %d, status = %s(%d)\n",
1644 		       wc->opcode, ib_wc_status_msg(wc->status), wc->status);
1645 		if (wc->status != IB_WC_WR_FLUSH_ERR)
1646 			smb_direct_disconnect_rdma_connection(sc);
1647 	}
1648 
1649 	complete(msg->completion);
1650 }
1651 
1652 static void read_done(struct ib_cq *cq, struct ib_wc *wc)
1653 {
1654 	read_write_done(cq, wc, DMA_FROM_DEVICE);
1655 }
1656 
1657 static void write_done(struct ib_cq *cq, struct ib_wc *wc)
1658 {
1659 	read_write_done(cq, wc, DMA_TO_DEVICE);
1660 }
1661 
1662 static int smb_direct_rdma_xmit(struct smb_direct_transport *t,
1663 				void *buf, int buf_len,
1664 				struct smbdirect_buffer_descriptor_v1 *desc,
1665 				unsigned int desc_len,
1666 				bool is_read)
1667 {
1668 	struct smbdirect_socket *sc = &t->socket;
1669 	struct smbdirect_socket_parameters *sp = &sc->parameters;
1670 	struct smbdirect_rw_io *msg, *next_msg;
1671 	int i, ret;
1672 	DECLARE_COMPLETION_ONSTACK(completion);
1673 	struct ib_send_wr *first_wr;
1674 	LIST_HEAD(msg_list);
1675 	char *desc_buf;
1676 	int credits_needed;
1677 	unsigned int desc_buf_len, desc_num = 0;
1678 
1679 	if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
1680 		return -ENOTCONN;
1681 
1682 	if (buf_len > sp->max_read_write_size)
1683 		return -EINVAL;
1684 
1685 	/* calculate needed credits */
1686 	credits_needed = 0;
1687 	desc_buf = buf;
1688 	for (i = 0; i < desc_len / sizeof(*desc); i++) {
1689 		if (!buf_len)
1690 			break;
1691 
1692 		desc_buf_len = le32_to_cpu(desc[i].length);
1693 		if (!desc_buf_len)
1694 			return -EINVAL;
1695 
1696 		if (desc_buf_len > buf_len) {
1697 			desc_buf_len = buf_len;
1698 			desc[i].length = cpu_to_le32(desc_buf_len);
1699 			buf_len = 0;
1700 		}
1701 
1702 		credits_needed += calc_rw_credits(sc, desc_buf, desc_buf_len);
1703 		desc_buf += desc_buf_len;
1704 		buf_len -= desc_buf_len;
1705 		desc_num++;
1706 	}
1707 
1708 	ksmbd_debug(RDMA, "RDMA %s, len %#x, needed credits %#x\n",
1709 		    str_read_write(is_read), buf_len, credits_needed);
1710 
1711 	ret = wait_for_rw_credits(sc, credits_needed);
1712 	if (ret < 0)
1713 		return ret;
1714 
1715 	/* build rdma_rw_ctx for each descriptor */
1716 	desc_buf = buf;
1717 	for (i = 0; i < desc_num; i++) {
1718 		msg = kzalloc(struct_size(msg, sg_list, SG_CHUNK_SIZE),
1719 			      KSMBD_DEFAULT_GFP);
1720 		if (!msg) {
1721 			ret = -ENOMEM;
1722 			goto out;
1723 		}
1724 
1725 		desc_buf_len = le32_to_cpu(desc[i].length);
1726 
1727 		msg->socket = sc;
1728 		msg->cqe.done = is_read ? read_done : write_done;
1729 		msg->completion = &completion;
1730 
1731 		msg->sgt.sgl = &msg->sg_list[0];
1732 		ret = sg_alloc_table_chained(&msg->sgt,
1733 					     get_buf_page_count(desc_buf, desc_buf_len),
1734 					     msg->sg_list, SG_CHUNK_SIZE);
1735 		if (ret) {
1736 			ret = -ENOMEM;
1737 			goto free_msg;
1738 		}
1739 
1740 		ret = get_sg_list(desc_buf, desc_buf_len,
1741 				  msg->sgt.sgl, msg->sgt.orig_nents);
1742 		if (ret < 0)
1743 			goto free_table;
1744 
1745 		ret = rdma_rw_ctx_init(&msg->rdma_ctx, sc->ib.qp, sc->ib.qp->port,
1746 				       msg->sgt.sgl,
1747 				       get_buf_page_count(desc_buf, desc_buf_len),
1748 				       0,
1749 				       le64_to_cpu(desc[i].offset),
1750 				       le32_to_cpu(desc[i].token),
1751 				       is_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1752 		if (ret < 0) {
1753 			pr_err("failed to init rdma_rw_ctx: %d\n", ret);
1754 			goto free_table;
1755 		}
1756 
1757 		list_add_tail(&msg->list, &msg_list);
1758 		desc_buf += desc_buf_len;
1759 	}
1760 
1761 	/* concatenate work requests of rdma_rw_ctxs */
1762 	first_wr = NULL;
1763 	list_for_each_entry_reverse(msg, &msg_list, list) {
1764 		first_wr = rdma_rw_ctx_wrs(&msg->rdma_ctx, sc->ib.qp, sc->ib.qp->port,
1765 					   &msg->cqe, first_wr);
1766 	}
1767 
1768 	ret = ib_post_send(sc->ib.qp, first_wr, NULL);
1769 	if (ret) {
1770 		pr_err("failed to post send wr for RDMA R/W: %d\n", ret);
1771 		goto out;
1772 	}
1773 
1774 	msg = list_last_entry(&msg_list, struct smbdirect_rw_io, list);
1775 	wait_for_completion(&completion);
1776 	ret = msg->error;
1777 out:
1778 	list_for_each_entry_safe(msg, next_msg, &msg_list, list) {
1779 		list_del(&msg->list);
1780 		smb_direct_free_rdma_rw_msg(t, msg,
1781 					    is_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
1782 	}
1783 	atomic_add(credits_needed, &sc->rw_io.credits.count);
1784 	wake_up(&sc->rw_io.credits.wait_queue);
1785 	return ret;
1786 
1787 free_table:
1788 	sg_free_table_chained(&msg->sgt, SG_CHUNK_SIZE);
1789 free_msg:
1790 	kfree(msg);
1791 	goto out;
1792 }
1793 
1794 static int smb_direct_rdma_write(struct ksmbd_transport *t,
1795 				 void *buf, unsigned int buflen,
1796 				 struct smbdirect_buffer_descriptor_v1 *desc,
1797 				 unsigned int desc_len)
1798 {
1799 	return smb_direct_rdma_xmit(SMBD_TRANS(t), buf, buflen,
1800 				    desc, desc_len, false);
1801 }
1802 
1803 static int smb_direct_rdma_read(struct ksmbd_transport *t,
1804 				void *buf, unsigned int buflen,
1805 				struct smbdirect_buffer_descriptor_v1 *desc,
1806 				unsigned int desc_len)
1807 {
1808 	return smb_direct_rdma_xmit(SMBD_TRANS(t), buf, buflen,
1809 				    desc, desc_len, true);
1810 }
1811 
1812 static void smb_direct_disconnect(struct ksmbd_transport *t)
1813 {
1814 	struct smb_direct_transport *st = SMBD_TRANS(t);
1815 	struct smbdirect_socket *sc = &st->socket;
1816 
1817 	ksmbd_debug(RDMA, "Disconnecting cm_id=%p\n", sc->rdma.cm_id);
1818 
1819 	free_transport(st);
1820 }
1821 
1822 static void smb_direct_shutdown(struct ksmbd_transport *t)
1823 {
1824 	struct smb_direct_transport *st = SMBD_TRANS(t);
1825 	struct smbdirect_socket *sc = &st->socket;
1826 
1827 	ksmbd_debug(RDMA, "smb-direct shutdown cm_id=%p\n", sc->rdma.cm_id);
1828 
1829 	smb_direct_disconnect_rdma_work(&sc->disconnect_work);
1830 }
1831 
1832 static int smb_direct_cm_handler(struct rdma_cm_id *cm_id,
1833 				 struct rdma_cm_event *event)
1834 {
1835 	struct smbdirect_socket *sc = cm_id->context;
1836 	unsigned long flags;
1837 
1838 	ksmbd_debug(RDMA, "RDMA CM event. cm_id=%p event=%s (%d)\n",
1839 		    cm_id, rdma_event_msg(event->event), event->event);
1840 
1841 	switch (event->event) {
1842 	case RDMA_CM_EVENT_ESTABLISHED: {
1843 		/*
1844 		 * Some drivers (at least mlx5_ib and irdma in roce mode)
1845 		 * might post a recv completion before RDMA_CM_EVENT_ESTABLISHED,
1846 		 * we need to adjust our expectation in that case.
1847 		 *
1848 		 * If smb_direct_negotiate_recv_done was called first
1849 		 * it initialized sc->connect.work only for us to
1850 		 * start, so that we turned into
1851 		 * SMBDIRECT_SOCKET_NEGOTIATE_NEEDED, before
1852 		 * smb_direct_negotiate_recv_work() runs.
1853 		 *
1854 		 * If smb_direct_negotiate_recv_done didn't happen
1855 		 * yet. sc->connect.work is still be disabled and
1856 		 * queue_work() is a no-op.
1857 		 */
1858 		if (SMBDIRECT_CHECK_STATUS_DISCONNECT(sc, SMBDIRECT_SOCKET_RDMA_CONNECT_RUNNING))
1859 			break;
1860 		sc->status = SMBDIRECT_SOCKET_NEGOTIATE_NEEDED;
1861 		spin_lock_irqsave(&sc->connect.lock, flags);
1862 		if (!sc->first_error)
1863 			queue_work(sc->workqueue, &sc->connect.work);
1864 		spin_unlock_irqrestore(&sc->connect.lock, flags);
1865 		wake_up(&sc->status_wait);
1866 		break;
1867 	}
1868 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
1869 	case RDMA_CM_EVENT_DISCONNECTED: {
1870 		sc->status = SMBDIRECT_SOCKET_DISCONNECTED;
1871 		smb_direct_disconnect_rdma_work(&sc->disconnect_work);
1872 		if (sc->ib.qp)
1873 			ib_drain_qp(sc->ib.qp);
1874 		break;
1875 	}
1876 	case RDMA_CM_EVENT_CONNECT_ERROR: {
1877 		sc->status = SMBDIRECT_SOCKET_DISCONNECTED;
1878 		smb_direct_disconnect_rdma_work(&sc->disconnect_work);
1879 		break;
1880 	}
1881 	default:
1882 		pr_err("Unexpected RDMA CM event. cm_id=%p, event=%s (%d)\n",
1883 		       cm_id, rdma_event_msg(event->event),
1884 		       event->event);
1885 		break;
1886 	}
1887 	return 0;
1888 }
1889 
1890 static void smb_direct_qpair_handler(struct ib_event *event, void *context)
1891 {
1892 	struct smbdirect_socket *sc = context;
1893 
1894 	ksmbd_debug(RDMA, "Received QP event. cm_id=%p, event=%s (%d)\n",
1895 		    sc->rdma.cm_id, ib_event_msg(event->event), event->event);
1896 
1897 	switch (event->event) {
1898 	case IB_EVENT_CQ_ERR:
1899 	case IB_EVENT_QP_FATAL:
1900 		smb_direct_disconnect_rdma_connection(sc);
1901 		break;
1902 	default:
1903 		break;
1904 	}
1905 }
1906 
1907 static int smb_direct_send_negotiate_response(struct smbdirect_socket *sc,
1908 					      int failed)
1909 {
1910 	struct smbdirect_socket_parameters *sp = &sc->parameters;
1911 	struct smbdirect_send_io *sendmsg;
1912 	struct smbdirect_negotiate_resp *resp;
1913 	int ret;
1914 
1915 	sendmsg = smb_direct_alloc_sendmsg(sc);
1916 	if (IS_ERR(sendmsg))
1917 		return -ENOMEM;
1918 
1919 	resp = (struct smbdirect_negotiate_resp *)sendmsg->packet;
1920 	if (failed) {
1921 		memset(resp, 0, sizeof(*resp));
1922 		resp->min_version = SMB_DIRECT_VERSION_LE;
1923 		resp->max_version = SMB_DIRECT_VERSION_LE;
1924 		resp->status = STATUS_NOT_SUPPORTED;
1925 
1926 		sc->status = SMBDIRECT_SOCKET_NEGOTIATE_FAILED;
1927 	} else {
1928 		resp->status = STATUS_SUCCESS;
1929 		resp->min_version = SMB_DIRECT_VERSION_LE;
1930 		resp->max_version = SMB_DIRECT_VERSION_LE;
1931 		resp->negotiated_version = SMB_DIRECT_VERSION_LE;
1932 		resp->reserved = 0;
1933 		resp->credits_requested =
1934 				cpu_to_le16(sp->send_credit_target);
1935 		resp->credits_granted = cpu_to_le16(manage_credits_prior_sending(sc));
1936 		resp->max_readwrite_size = cpu_to_le32(sp->max_read_write_size);
1937 		resp->preferred_send_size = cpu_to_le32(sp->max_send_size);
1938 		resp->max_receive_size = cpu_to_le32(sp->max_recv_size);
1939 		resp->max_fragmented_size =
1940 				cpu_to_le32(sp->max_fragmented_recv_size);
1941 
1942 		sc->recv_io.expected = SMBDIRECT_EXPECT_DATA_TRANSFER;
1943 		sc->status = SMBDIRECT_SOCKET_CONNECTED;
1944 	}
1945 
1946 	sendmsg->sge[0].addr = ib_dma_map_single(sc->ib.dev,
1947 						 (void *)resp, sizeof(*resp),
1948 						 DMA_TO_DEVICE);
1949 	ret = ib_dma_mapping_error(sc->ib.dev, sendmsg->sge[0].addr);
1950 	if (ret) {
1951 		smb_direct_free_sendmsg(sc, sendmsg);
1952 		return ret;
1953 	}
1954 
1955 	sendmsg->num_sge = 1;
1956 	sendmsg->sge[0].length = sizeof(*resp);
1957 	sendmsg->sge[0].lkey = sc->ib.pd->local_dma_lkey;
1958 
1959 	ret = post_sendmsg(sc, NULL, sendmsg);
1960 	if (ret) {
1961 		smb_direct_free_sendmsg(sc, sendmsg);
1962 		return ret;
1963 	}
1964 
1965 	wait_event(sc->send_io.pending.zero_wait_queue,
1966 		   atomic_read(&sc->send_io.pending.count) == 0 ||
1967 		   sc->status != SMBDIRECT_SOCKET_CONNECTED);
1968 	if (sc->status != SMBDIRECT_SOCKET_CONNECTED)
1969 		return -ENOTCONN;
1970 
1971 	return 0;
1972 }
1973 
1974 static int smb_direct_accept_client(struct smbdirect_socket *sc)
1975 {
1976 	struct smbdirect_socket_parameters *sp = &sc->parameters;
1977 	struct rdma_conn_param conn_param;
1978 	__be32 ird_ord_hdr[2];
1979 	int ret;
1980 
1981 	/*
1982 	 * smb_direct_handle_connect_request()
1983 	 * already negotiated sp->initiator_depth
1984 	 * and sp->responder_resources
1985 	 */
1986 	memset(&conn_param, 0, sizeof(conn_param));
1987 	conn_param.initiator_depth = sp->initiator_depth;
1988 	conn_param.responder_resources = sp->responder_resources;
1989 
1990 	if (sc->rdma.legacy_iwarp) {
1991 		ird_ord_hdr[0] = cpu_to_be32(conn_param.responder_resources);
1992 		ird_ord_hdr[1] = cpu_to_be32(conn_param.initiator_depth);
1993 		conn_param.private_data = ird_ord_hdr;
1994 		conn_param.private_data_len = sizeof(ird_ord_hdr);
1995 	} else {
1996 		conn_param.private_data = NULL;
1997 		conn_param.private_data_len = 0;
1998 	}
1999 	conn_param.retry_count = SMB_DIRECT_CM_RETRY;
2000 	conn_param.rnr_retry_count = SMB_DIRECT_CM_RNR_RETRY;
2001 	conn_param.flow_control = 0;
2002 
2003 	/*
2004 	 * start with the negotiate timeout and SMBDIRECT_KEEPALIVE_PENDING
2005 	 * so that the timer will cause a disconnect.
2006 	 */
2007 	sc->idle.keepalive = SMBDIRECT_KEEPALIVE_PENDING;
2008 	mod_delayed_work(sc->workqueue, &sc->idle.timer_work,
2009 			 msecs_to_jiffies(sp->negotiate_timeout_msec));
2010 
2011 	WARN_ON_ONCE(sc->status != SMBDIRECT_SOCKET_RDMA_CONNECT_NEEDED);
2012 	sc->status = SMBDIRECT_SOCKET_RDMA_CONNECT_RUNNING;
2013 	ret = rdma_accept(sc->rdma.cm_id, &conn_param);
2014 	if (ret) {
2015 		pr_err("error at rdma_accept: %d\n", ret);
2016 		return ret;
2017 	}
2018 	return 0;
2019 }
2020 
2021 static int smb_direct_prepare_negotiation(struct smbdirect_socket *sc)
2022 {
2023 	struct smbdirect_recv_io *recvmsg;
2024 	bool recv_posted = false;
2025 	int ret;
2026 
2027 	WARN_ON_ONCE(sc->status != SMBDIRECT_SOCKET_CREATED);
2028 	sc->status = SMBDIRECT_SOCKET_RDMA_CONNECT_NEEDED;
2029 
2030 	sc->recv_io.expected = SMBDIRECT_EXPECT_NEGOTIATE_REQ;
2031 
2032 	recvmsg = get_free_recvmsg(sc);
2033 	if (!recvmsg)
2034 		return -ENOMEM;
2035 	recvmsg->cqe.done = smb_direct_negotiate_recv_done;
2036 
2037 	ret = smb_direct_post_recv(sc, recvmsg);
2038 	if (ret) {
2039 		pr_err("Can't post recv: %d\n", ret);
2040 		goto out_err;
2041 	}
2042 	recv_posted = true;
2043 
2044 	ret = smb_direct_accept_client(sc);
2045 	if (ret) {
2046 		pr_err("Can't accept client\n");
2047 		goto out_err;
2048 	}
2049 
2050 	return 0;
2051 out_err:
2052 	/*
2053 	 * If the recv was never posted, return it to the free list.
2054 	 * If it was posted, leave it alone so disconnect teardown can
2055 	 * drain the QP and complete it (flush) and the completion path
2056 	 * will unmap it exactly once.
2057 	 */
2058 	if (!recv_posted)
2059 		put_recvmsg(sc, recvmsg);
2060 	return ret;
2061 }
2062 
2063 static int smb_direct_init_params(struct smbdirect_socket *sc)
2064 {
2065 	struct smbdirect_socket_parameters *sp = &sc->parameters;
2066 	int max_send_sges;
2067 	unsigned int maxpages;
2068 
2069 	/* need 3 more sge. because a SMB_DIRECT header, SMB2 header,
2070 	 * SMB2 response could be mapped.
2071 	 */
2072 	max_send_sges = DIV_ROUND_UP(sp->max_send_size, PAGE_SIZE) + 3;
2073 	if (max_send_sges > SMBDIRECT_SEND_IO_MAX_SGE) {
2074 		pr_err("max_send_size %d is too large\n", sp->max_send_size);
2075 		return -EINVAL;
2076 	}
2077 
2078 	atomic_set(&sc->send_io.lcredits.count, sp->send_credit_target);
2079 
2080 	maxpages = DIV_ROUND_UP(sp->max_read_write_size, PAGE_SIZE);
2081 	sc->rw_io.credits.max = rdma_rw_mr_factor(sc->ib.dev,
2082 						  sc->rdma.cm_id->port_num,
2083 						  maxpages);
2084 	sc->rw_io.credits.num_pages = DIV_ROUND_UP(maxpages, sc->rw_io.credits.max);
2085 	/* add one extra in order to handle unaligned pages */
2086 	sc->rw_io.credits.max += 1;
2087 
2088 	sc->recv_io.credits.target = 1;
2089 
2090 	atomic_set(&sc->rw_io.credits.count, sc->rw_io.credits.max);
2091 
2092 	return 0;
2093 }
2094 
2095 static void smb_direct_destroy_pools(struct smbdirect_socket *sc)
2096 {
2097 	struct smbdirect_recv_io *recvmsg;
2098 
2099 	while ((recvmsg = get_free_recvmsg(sc)))
2100 		mempool_free(recvmsg, sc->recv_io.mem.pool);
2101 
2102 	mempool_destroy(sc->recv_io.mem.pool);
2103 	sc->recv_io.mem.pool = NULL;
2104 
2105 	kmem_cache_destroy(sc->recv_io.mem.cache);
2106 	sc->recv_io.mem.cache = NULL;
2107 
2108 	mempool_destroy(sc->send_io.mem.pool);
2109 	sc->send_io.mem.pool = NULL;
2110 
2111 	kmem_cache_destroy(sc->send_io.mem.cache);
2112 	sc->send_io.mem.cache = NULL;
2113 }
2114 
2115 static int smb_direct_create_pools(struct smbdirect_socket *sc)
2116 {
2117 	struct smbdirect_socket_parameters *sp = &sc->parameters;
2118 	char name[80];
2119 	int i;
2120 	struct smbdirect_recv_io *recvmsg;
2121 
2122 	snprintf(name, sizeof(name), "smbdirect_send_io_pool_%p", sc);
2123 	sc->send_io.mem.cache = kmem_cache_create(name,
2124 					     sizeof(struct smbdirect_send_io) +
2125 					      sizeof(struct smbdirect_negotiate_resp),
2126 					     0, SLAB_HWCACHE_ALIGN, NULL);
2127 	if (!sc->send_io.mem.cache)
2128 		return -ENOMEM;
2129 
2130 	sc->send_io.mem.pool = mempool_create(sp->send_credit_target,
2131 					    mempool_alloc_slab, mempool_free_slab,
2132 					    sc->send_io.mem.cache);
2133 	if (!sc->send_io.mem.pool)
2134 		goto err;
2135 
2136 	snprintf(name, sizeof(name), "smbdirect_recv_io_pool_%p", sc);
2137 	sc->recv_io.mem.cache = kmem_cache_create(name,
2138 					     sizeof(struct smbdirect_recv_io) +
2139 					     sp->max_recv_size,
2140 					     0, SLAB_HWCACHE_ALIGN, NULL);
2141 	if (!sc->recv_io.mem.cache)
2142 		goto err;
2143 
2144 	sc->recv_io.mem.pool =
2145 		mempool_create(sp->recv_credit_max, mempool_alloc_slab,
2146 			       mempool_free_slab, sc->recv_io.mem.cache);
2147 	if (!sc->recv_io.mem.pool)
2148 		goto err;
2149 
2150 	for (i = 0; i < sp->recv_credit_max; i++) {
2151 		recvmsg = mempool_alloc(sc->recv_io.mem.pool, KSMBD_DEFAULT_GFP);
2152 		if (!recvmsg)
2153 			goto err;
2154 		recvmsg->socket = sc;
2155 		recvmsg->sge.length = 0;
2156 		list_add(&recvmsg->list, &sc->recv_io.free.list);
2157 	}
2158 
2159 	return 0;
2160 err:
2161 	smb_direct_destroy_pools(sc);
2162 	return -ENOMEM;
2163 }
2164 
2165 static u32 smb_direct_rdma_rw_send_wrs(struct ib_device *dev, const struct ib_qp_init_attr *attr)
2166 {
2167 	/*
2168 	 * This could be split out of rdma_rw_init_qp()
2169 	 * and be a helper function next to rdma_rw_mr_factor()
2170 	 *
2171 	 * We can't check unlikely(rdma_rw_force_mr) here,
2172 	 * but that is most likely 0 anyway.
2173 	 */
2174 	u32 factor;
2175 
2176 	WARN_ON_ONCE(attr->port_num == 0);
2177 
2178 	/*
2179 	 * Each context needs at least one RDMA READ or WRITE WR.
2180 	 *
2181 	 * For some hardware we might need more, eventually we should ask the
2182 	 * HCA driver for a multiplier here.
2183 	 */
2184 	factor = 1;
2185 
2186 	/*
2187 	 * If the device needs MRs to perform RDMA READ or WRITE operations,
2188 	 * we'll need two additional MRs for the registrations and the
2189 	 * invalidation.
2190 	 */
2191 	if (rdma_protocol_iwarp(dev, attr->port_num) || dev->attrs.max_sgl_rd)
2192 		factor += 2;	/* inv + reg */
2193 
2194 	return factor * attr->cap.max_rdma_ctxs;
2195 }
2196 
2197 static int smb_direct_create_qpair(struct smbdirect_socket *sc)
2198 {
2199 	struct smbdirect_socket_parameters *sp = &sc->parameters;
2200 	int ret;
2201 	struct ib_qp_cap qp_cap;
2202 	struct ib_qp_init_attr qp_attr;
2203 	u32 max_send_wr;
2204 	u32 rdma_send_wr;
2205 
2206 	/*
2207 	 * Note that {rdma,ib}_create_qp() will call
2208 	 * rdma_rw_init_qp() if cap->max_rdma_ctxs is not 0.
2209 	 * It will adjust cap->max_send_wr to the required
2210 	 * number of additional WRs for the RDMA RW operations.
2211 	 * It will cap cap->max_send_wr to the device limit.
2212 	 *
2213 	 * +1 for ib_drain_qp
2214 	 */
2215 	qp_cap.max_send_wr = sp->send_credit_target + 1;
2216 	qp_cap.max_recv_wr = sp->recv_credit_max + 1;
2217 	qp_cap.max_send_sge = SMBDIRECT_SEND_IO_MAX_SGE;
2218 	qp_cap.max_recv_sge = SMBDIRECT_RECV_IO_MAX_SGE;
2219 	qp_cap.max_inline_data = 0;
2220 	qp_cap.max_rdma_ctxs = sc->rw_io.credits.max;
2221 
2222 	/*
2223 	 * Find out the number of max_send_wr
2224 	 * after rdma_rw_init_qp() adjusted it.
2225 	 *
2226 	 * We only do it on a temporary variable,
2227 	 * as rdma_create_qp() will trigger
2228 	 * rdma_rw_init_qp() again.
2229 	 */
2230 	memset(&qp_attr, 0, sizeof(qp_attr));
2231 	qp_attr.cap = qp_cap;
2232 	qp_attr.port_num = sc->rdma.cm_id->port_num;
2233 	rdma_send_wr = smb_direct_rdma_rw_send_wrs(sc->ib.dev, &qp_attr);
2234 	max_send_wr = qp_cap.max_send_wr + rdma_send_wr;
2235 
2236 	if (qp_cap.max_send_wr > sc->ib.dev->attrs.max_cqe ||
2237 	    qp_cap.max_send_wr > sc->ib.dev->attrs.max_qp_wr) {
2238 		pr_err("Possible CQE overrun: max_send_wr %d\n",
2239 		       qp_cap.max_send_wr);
2240 		pr_err("device %.*s reporting max_cqe %d max_qp_wr %d\n",
2241 		       IB_DEVICE_NAME_MAX,
2242 		       sc->ib.dev->name,
2243 		       sc->ib.dev->attrs.max_cqe,
2244 		       sc->ib.dev->attrs.max_qp_wr);
2245 		pr_err("consider lowering send_credit_target = %d\n",
2246 		       sp->send_credit_target);
2247 		return -EINVAL;
2248 	}
2249 
2250 	if (qp_cap.max_rdma_ctxs &&
2251 	    (max_send_wr >= sc->ib.dev->attrs.max_cqe ||
2252 	     max_send_wr >= sc->ib.dev->attrs.max_qp_wr)) {
2253 		pr_err("Possible CQE overrun: rdma_send_wr %d + max_send_wr %d = %d\n",
2254 		       rdma_send_wr, qp_cap.max_send_wr, max_send_wr);
2255 		pr_err("device %.*s reporting max_cqe %d max_qp_wr %d\n",
2256 		       IB_DEVICE_NAME_MAX,
2257 		       sc->ib.dev->name,
2258 		       sc->ib.dev->attrs.max_cqe,
2259 		       sc->ib.dev->attrs.max_qp_wr);
2260 		pr_err("consider lowering send_credit_target = %d, max_rdma_ctxs = %d\n",
2261 		       sp->send_credit_target, qp_cap.max_rdma_ctxs);
2262 		return -EINVAL;
2263 	}
2264 
2265 	if (qp_cap.max_recv_wr > sc->ib.dev->attrs.max_cqe ||
2266 	    qp_cap.max_recv_wr > sc->ib.dev->attrs.max_qp_wr) {
2267 		pr_err("Possible CQE overrun: max_recv_wr %d\n",
2268 		       qp_cap.max_recv_wr);
2269 		pr_err("device %.*s reporting max_cqe %d max_qp_wr %d\n",
2270 		       IB_DEVICE_NAME_MAX,
2271 		       sc->ib.dev->name,
2272 		       sc->ib.dev->attrs.max_cqe,
2273 		       sc->ib.dev->attrs.max_qp_wr);
2274 		pr_err("consider lowering receive_credit_max = %d\n",
2275 		       sp->recv_credit_max);
2276 		return -EINVAL;
2277 	}
2278 
2279 	if (qp_cap.max_send_sge > sc->ib.dev->attrs.max_send_sge ||
2280 	    qp_cap.max_recv_sge > sc->ib.dev->attrs.max_recv_sge) {
2281 		pr_err("device %.*s max_send_sge/max_recv_sge = %d/%d too small\n",
2282 		       IB_DEVICE_NAME_MAX,
2283 		       sc->ib.dev->name,
2284 		       sc->ib.dev->attrs.max_send_sge,
2285 		       sc->ib.dev->attrs.max_recv_sge);
2286 		return -EINVAL;
2287 	}
2288 
2289 	sc->ib.pd = ib_alloc_pd(sc->ib.dev, 0);
2290 	if (IS_ERR(sc->ib.pd)) {
2291 		pr_err("Can't create RDMA PD\n");
2292 		ret = PTR_ERR(sc->ib.pd);
2293 		sc->ib.pd = NULL;
2294 		return ret;
2295 	}
2296 
2297 	sc->ib.send_cq = ib_alloc_cq_any(sc->ib.dev, sc,
2298 					 max_send_wr,
2299 					 IB_POLL_WORKQUEUE);
2300 	if (IS_ERR(sc->ib.send_cq)) {
2301 		pr_err("Can't create RDMA send CQ\n");
2302 		ret = PTR_ERR(sc->ib.send_cq);
2303 		sc->ib.send_cq = NULL;
2304 		goto err;
2305 	}
2306 
2307 	sc->ib.recv_cq = ib_alloc_cq_any(sc->ib.dev, sc,
2308 					 qp_cap.max_recv_wr,
2309 					 IB_POLL_WORKQUEUE);
2310 	if (IS_ERR(sc->ib.recv_cq)) {
2311 		pr_err("Can't create RDMA recv CQ\n");
2312 		ret = PTR_ERR(sc->ib.recv_cq);
2313 		sc->ib.recv_cq = NULL;
2314 		goto err;
2315 	}
2316 
2317 	/*
2318 	 * We reset completely here!
2319 	 * As the above use was just temporary
2320 	 * to calc max_send_wr and rdma_send_wr.
2321 	 *
2322 	 * rdma_create_qp() will trigger rdma_rw_init_qp()
2323 	 * again if max_rdma_ctxs is not 0.
2324 	 */
2325 	memset(&qp_attr, 0, sizeof(qp_attr));
2326 	qp_attr.event_handler = smb_direct_qpair_handler;
2327 	qp_attr.qp_context = sc;
2328 	qp_attr.cap = qp_cap;
2329 	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
2330 	qp_attr.qp_type = IB_QPT_RC;
2331 	qp_attr.send_cq = sc->ib.send_cq;
2332 	qp_attr.recv_cq = sc->ib.recv_cq;
2333 	qp_attr.port_num = ~0;
2334 
2335 	ret = rdma_create_qp(sc->rdma.cm_id, sc->ib.pd, &qp_attr);
2336 	if (ret) {
2337 		pr_err("Can't create RDMA QP: %d\n", ret);
2338 		goto err;
2339 	}
2340 
2341 	sc->ib.qp = sc->rdma.cm_id->qp;
2342 	sc->rdma.cm_id->event_handler = smb_direct_cm_handler;
2343 
2344 	return 0;
2345 err:
2346 	if (sc->ib.qp) {
2347 		sc->ib.qp = NULL;
2348 		rdma_destroy_qp(sc->rdma.cm_id);
2349 	}
2350 	if (sc->ib.recv_cq) {
2351 		ib_destroy_cq(sc->ib.recv_cq);
2352 		sc->ib.recv_cq = NULL;
2353 	}
2354 	if (sc->ib.send_cq) {
2355 		ib_destroy_cq(sc->ib.send_cq);
2356 		sc->ib.send_cq = NULL;
2357 	}
2358 	if (sc->ib.pd) {
2359 		ib_dealloc_pd(sc->ib.pd);
2360 		sc->ib.pd = NULL;
2361 	}
2362 	return ret;
2363 }
2364 
2365 static int smb_direct_prepare(struct ksmbd_transport *t)
2366 {
2367 	struct smb_direct_transport *st = SMBD_TRANS(t);
2368 	struct smbdirect_socket *sc = &st->socket;
2369 	struct smbdirect_socket_parameters *sp = &sc->parameters;
2370 	struct smbdirect_recv_io *recvmsg;
2371 	struct smbdirect_negotiate_req *req;
2372 	unsigned long flags;
2373 	int ret;
2374 
2375 	/*
2376 	 * We are waiting to pass the following states:
2377 	 *
2378 	 * SMBDIRECT_SOCKET_RDMA_CONNECT_NEEDED
2379 	 * SMBDIRECT_SOCKET_RDMA_CONNECT_RUNNING
2380 	 * SMBDIRECT_SOCKET_NEGOTIATE_NEEDED
2381 	 *
2382 	 * To finally get to SMBDIRECT_SOCKET_NEGOTIATE_RUNNING
2383 	 * in order to continue below.
2384 	 *
2385 	 * Everything else is unexpected and an error.
2386 	 */
2387 	ksmbd_debug(RDMA, "Waiting for SMB_DIRECT negotiate request\n");
2388 	ret = wait_event_interruptible_timeout(sc->status_wait,
2389 					sc->status != SMBDIRECT_SOCKET_RDMA_CONNECT_NEEDED &&
2390 					sc->status != SMBDIRECT_SOCKET_RDMA_CONNECT_RUNNING &&
2391 					sc->status != SMBDIRECT_SOCKET_NEGOTIATE_NEEDED,
2392 					msecs_to_jiffies(sp->negotiate_timeout_msec));
2393 	if (ret <= 0 || sc->status != SMBDIRECT_SOCKET_NEGOTIATE_RUNNING)
2394 		return ret < 0 ? ret : -ETIMEDOUT;
2395 
2396 	recvmsg = get_first_reassembly(sc);
2397 	if (!recvmsg)
2398 		return -ECONNABORTED;
2399 
2400 	ret = smb_direct_check_recvmsg(recvmsg);
2401 	if (ret)
2402 		goto put;
2403 
2404 	req = (struct smbdirect_negotiate_req *)recvmsg->packet;
2405 	sp->max_recv_size = min_t(int, sp->max_recv_size,
2406 				  le32_to_cpu(req->preferred_send_size));
2407 	sp->max_send_size = min_t(int, sp->max_send_size,
2408 				  le32_to_cpu(req->max_receive_size));
2409 	sp->max_fragmented_send_size =
2410 		le32_to_cpu(req->max_fragmented_size);
2411 	sp->max_fragmented_recv_size =
2412 		(sp->recv_credit_max * sp->max_recv_size) / 2;
2413 	sc->recv_io.credits.target = le16_to_cpu(req->credits_requested);
2414 	sc->recv_io.credits.target = min_t(u16, sc->recv_io.credits.target, sp->recv_credit_max);
2415 	sc->recv_io.credits.target = max_t(u16, sc->recv_io.credits.target, 1);
2416 
2417 put:
2418 	spin_lock_irqsave(&sc->recv_io.reassembly.lock, flags);
2419 	sc->recv_io.reassembly.queue_length--;
2420 	list_del(&recvmsg->list);
2421 	spin_unlock_irqrestore(&sc->recv_io.reassembly.lock, flags);
2422 	put_recvmsg(sc, recvmsg);
2423 
2424 	if (ret == -ECONNABORTED)
2425 		return ret;
2426 
2427 	if (ret)
2428 		goto respond;
2429 
2430 	/*
2431 	 * We negotiated with success, so we need to refill the recv queue.
2432 	 * We do that with sc->idle.immediate_work still being disabled
2433 	 * via smbdirect_socket_init(), so that queue_work(sc->workqueue,
2434 	 * &sc->idle.immediate_work) in smb_direct_post_recv_credits()
2435 	 * is a no-op.
2436 	 *
2437 	 * The message that grants the credits to the client is
2438 	 * the negotiate response.
2439 	 */
2440 	INIT_WORK(&sc->recv_io.posted.refill_work, smb_direct_post_recv_credits);
2441 	smb_direct_post_recv_credits(&sc->recv_io.posted.refill_work);
2442 	if (unlikely(sc->first_error))
2443 		return sc->first_error;
2444 	INIT_WORK(&sc->idle.immediate_work, smb_direct_send_immediate_work);
2445 
2446 respond:
2447 	ret = smb_direct_send_negotiate_response(sc, ret);
2448 
2449 	return ret;
2450 }
2451 
2452 static int smb_direct_connect(struct smbdirect_socket *sc)
2453 {
2454 	struct smbdirect_recv_io *recv_io;
2455 	int ret;
2456 
2457 	ret = smb_direct_init_params(sc);
2458 	if (ret) {
2459 		pr_err("Can't configure RDMA parameters\n");
2460 		return ret;
2461 	}
2462 
2463 	ret = smb_direct_create_pools(sc);
2464 	if (ret) {
2465 		pr_err("Can't init RDMA pool: %d\n", ret);
2466 		return ret;
2467 	}
2468 
2469 	list_for_each_entry(recv_io, &sc->recv_io.free.list, list)
2470 		recv_io->cqe.done = recv_done;
2471 
2472 	ret = smb_direct_create_qpair(sc);
2473 	if (ret) {
2474 		pr_err("Can't accept RDMA client: %d\n", ret);
2475 		return ret;
2476 	}
2477 
2478 	ret = smb_direct_prepare_negotiation(sc);
2479 	if (ret) {
2480 		pr_err("Can't negotiate: %d\n", ret);
2481 		return ret;
2482 	}
2483 	return 0;
2484 }
2485 
2486 static bool rdma_frwr_is_supported(struct ib_device_attr *attrs)
2487 {
2488 	if (!(attrs->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS))
2489 		return false;
2490 	if (attrs->max_fast_reg_page_list_len == 0)
2491 		return false;
2492 	return true;
2493 }
2494 
2495 static int smb_direct_handle_connect_request(struct rdma_cm_id *new_cm_id,
2496 					     struct rdma_cm_event *event)
2497 {
2498 	struct smb_direct_transport *t;
2499 	struct smbdirect_socket *sc;
2500 	struct smbdirect_socket_parameters *sp;
2501 	struct task_struct *handler;
2502 	u8 peer_initiator_depth;
2503 	u8 peer_responder_resources;
2504 	int ret;
2505 
2506 	if (!rdma_frwr_is_supported(&new_cm_id->device->attrs)) {
2507 		ksmbd_debug(RDMA,
2508 			    "Fast Registration Work Requests is not supported. device capabilities=%llx\n",
2509 			    new_cm_id->device->attrs.device_cap_flags);
2510 		return -EPROTONOSUPPORT;
2511 	}
2512 
2513 	t = alloc_transport(new_cm_id);
2514 	if (!t)
2515 		return -ENOMEM;
2516 	sc = &t->socket;
2517 	sp = &sc->parameters;
2518 
2519 	peer_initiator_depth = event->param.conn.initiator_depth;
2520 	peer_responder_resources = event->param.conn.responder_resources;
2521 	if (rdma_protocol_iwarp(new_cm_id->device, new_cm_id->port_num) &&
2522 	    event->param.conn.private_data_len == 8) {
2523 		/*
2524 		 * Legacy clients with only iWarp MPA v1 support
2525 		 * need a private blob in order to negotiate
2526 		 * the IRD/ORD values.
2527 		 */
2528 		const __be32 *ird_ord_hdr = event->param.conn.private_data;
2529 		u32 ird32 = be32_to_cpu(ird_ord_hdr[0]);
2530 		u32 ord32 = be32_to_cpu(ird_ord_hdr[1]);
2531 
2532 		/*
2533 		 * cifs.ko sends the legacy IRD/ORD negotiation
2534 		 * event if iWarp MPA v2 was used.
2535 		 *
2536 		 * Here we check that the values match and only
2537 		 * mark the client as legacy if they don't match.
2538 		 */
2539 		if ((u32)event->param.conn.initiator_depth != ird32 ||
2540 		    (u32)event->param.conn.responder_resources != ord32) {
2541 			/*
2542 			 * There are broken clients (old cifs.ko)
2543 			 * using little endian and also
2544 			 * struct rdma_conn_param only uses u8
2545 			 * for initiator_depth and responder_resources,
2546 			 * so we truncate the value to U8_MAX.
2547 			 *
2548 			 * smb_direct_accept_client() will then
2549 			 * do the real negotiation in order to
2550 			 * select the minimum between client and
2551 			 * server.
2552 			 */
2553 			ird32 = min_t(u32, ird32, U8_MAX);
2554 			ord32 = min_t(u32, ord32, U8_MAX);
2555 
2556 			sc->rdma.legacy_iwarp = true;
2557 			peer_initiator_depth = (u8)ird32;
2558 			peer_responder_resources = (u8)ord32;
2559 		}
2560 	}
2561 
2562 	/*
2563 	 * First set what the we as server are able to support
2564 	 */
2565 	sp->initiator_depth = min_t(u8, sp->initiator_depth,
2566 				   new_cm_id->device->attrs.max_qp_rd_atom);
2567 
2568 	/*
2569 	 * negotiate the value by using the minimum
2570 	 * between client and server if the client provided
2571 	 * non 0 values.
2572 	 */
2573 	if (peer_initiator_depth != 0)
2574 		sp->initiator_depth = min_t(u8, sp->initiator_depth,
2575 					   peer_initiator_depth);
2576 	if (peer_responder_resources != 0)
2577 		sp->responder_resources = min_t(u8, sp->responder_resources,
2578 					       peer_responder_resources);
2579 
2580 	ret = smb_direct_connect(sc);
2581 	if (ret)
2582 		goto out_err;
2583 
2584 	handler = kthread_run(ksmbd_conn_handler_loop,
2585 			      KSMBD_TRANS(t)->conn, "ksmbd:r%u",
2586 			      smb_direct_port);
2587 	if (IS_ERR(handler)) {
2588 		ret = PTR_ERR(handler);
2589 		pr_err("Can't start thread\n");
2590 		goto out_err;
2591 	}
2592 
2593 	return 0;
2594 out_err:
2595 	free_transport(t);
2596 	return ret;
2597 }
2598 
2599 static int smb_direct_listen_handler(struct rdma_cm_id *cm_id,
2600 				     struct rdma_cm_event *event)
2601 {
2602 	switch (event->event) {
2603 	case RDMA_CM_EVENT_CONNECT_REQUEST: {
2604 		int ret = smb_direct_handle_connect_request(cm_id, event);
2605 
2606 		if (ret) {
2607 			pr_err("Can't create transport: %d\n", ret);
2608 			return ret;
2609 		}
2610 
2611 		ksmbd_debug(RDMA, "Received connection request. cm_id=%p\n",
2612 			    cm_id);
2613 		break;
2614 	}
2615 	default:
2616 		pr_err("Unexpected listen event. cm_id=%p, event=%s (%d)\n",
2617 		       cm_id, rdma_event_msg(event->event), event->event);
2618 		break;
2619 	}
2620 	return 0;
2621 }
2622 
2623 static int smb_direct_listen(int port)
2624 {
2625 	int ret;
2626 	struct rdma_cm_id *cm_id;
2627 	struct sockaddr_in sin = {
2628 		.sin_family		= AF_INET,
2629 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2630 		.sin_port		= htons(port),
2631 	};
2632 
2633 	cm_id = rdma_create_id(&init_net, smb_direct_listen_handler,
2634 			       &smb_direct_listener, RDMA_PS_TCP, IB_QPT_RC);
2635 	if (IS_ERR(cm_id)) {
2636 		pr_err("Can't create cm id: %ld\n", PTR_ERR(cm_id));
2637 		return PTR_ERR(cm_id);
2638 	}
2639 
2640 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
2641 	if (ret) {
2642 		pr_err("Can't bind: %d\n", ret);
2643 		goto err;
2644 	}
2645 
2646 	smb_direct_listener.cm_id = cm_id;
2647 
2648 	ret = rdma_listen(cm_id, 10);
2649 	if (ret) {
2650 		pr_err("Can't listen: %d\n", ret);
2651 		goto err;
2652 	}
2653 	return 0;
2654 err:
2655 	smb_direct_listener.cm_id = NULL;
2656 	rdma_destroy_id(cm_id);
2657 	return ret;
2658 }
2659 
2660 static int smb_direct_ib_client_add(struct ib_device *ib_dev)
2661 {
2662 	struct smb_direct_device *smb_dev;
2663 
2664 	/* Set 5445 port if device type is iWARP(No IB) */
2665 	if (ib_dev->node_type != RDMA_NODE_IB_CA)
2666 		smb_direct_port = SMB_DIRECT_PORT_IWARP;
2667 
2668 	if (!rdma_frwr_is_supported(&ib_dev->attrs))
2669 		return 0;
2670 
2671 	smb_dev = kzalloc(sizeof(*smb_dev), KSMBD_DEFAULT_GFP);
2672 	if (!smb_dev)
2673 		return -ENOMEM;
2674 	smb_dev->ib_dev = ib_dev;
2675 
2676 	write_lock(&smb_direct_device_lock);
2677 	list_add(&smb_dev->list, &smb_direct_device_list);
2678 	write_unlock(&smb_direct_device_lock);
2679 
2680 	ksmbd_debug(RDMA, "ib device added: name %s\n", ib_dev->name);
2681 	return 0;
2682 }
2683 
2684 static void smb_direct_ib_client_remove(struct ib_device *ib_dev,
2685 					void *client_data)
2686 {
2687 	struct smb_direct_device *smb_dev, *tmp;
2688 
2689 	write_lock(&smb_direct_device_lock);
2690 	list_for_each_entry_safe(smb_dev, tmp, &smb_direct_device_list, list) {
2691 		if (smb_dev->ib_dev == ib_dev) {
2692 			list_del(&smb_dev->list);
2693 			kfree(smb_dev);
2694 			break;
2695 		}
2696 	}
2697 	write_unlock(&smb_direct_device_lock);
2698 }
2699 
2700 static struct ib_client smb_direct_ib_client = {
2701 	.name	= "ksmbd_smb_direct_ib",
2702 	.add	= smb_direct_ib_client_add,
2703 	.remove	= smb_direct_ib_client_remove,
2704 };
2705 
2706 int ksmbd_rdma_init(void)
2707 {
2708 	int ret;
2709 
2710 	smb_direct_port = SMB_DIRECT_PORT_INFINIBAND;
2711 	smb_direct_listener.cm_id = NULL;
2712 
2713 	ret = ib_register_client(&smb_direct_ib_client);
2714 	if (ret) {
2715 		pr_err("failed to ib_register_client\n");
2716 		return ret;
2717 	}
2718 
2719 	/* When a client is running out of send credits, the credits are
2720 	 * granted by the server's sending a packet using this queue.
2721 	 * This avoids the situation that a clients cannot send packets
2722 	 * for lack of credits
2723 	 */
2724 	smb_direct_wq = alloc_workqueue("ksmbd-smb_direct-wq",
2725 					WQ_HIGHPRI | WQ_MEM_RECLAIM | WQ_PERCPU,
2726 					0);
2727 	if (!smb_direct_wq)
2728 		return -ENOMEM;
2729 
2730 	ret = smb_direct_listen(smb_direct_port);
2731 	if (ret) {
2732 		destroy_workqueue(smb_direct_wq);
2733 		smb_direct_wq = NULL;
2734 		pr_err("Can't listen: %d\n", ret);
2735 		return ret;
2736 	}
2737 
2738 	ksmbd_debug(RDMA, "init RDMA listener. cm_id=%p\n",
2739 		    smb_direct_listener.cm_id);
2740 	return 0;
2741 }
2742 
2743 void ksmbd_rdma_stop_listening(void)
2744 {
2745 	if (!smb_direct_listener.cm_id)
2746 		return;
2747 
2748 	ib_unregister_client(&smb_direct_ib_client);
2749 	rdma_destroy_id(smb_direct_listener.cm_id);
2750 
2751 	smb_direct_listener.cm_id = NULL;
2752 }
2753 
2754 void ksmbd_rdma_destroy(void)
2755 {
2756 	if (smb_direct_wq) {
2757 		destroy_workqueue(smb_direct_wq);
2758 		smb_direct_wq = NULL;
2759 	}
2760 }
2761 
2762 static bool ksmbd_find_rdma_capable_netdev(struct net_device *netdev)
2763 {
2764 	struct smb_direct_device *smb_dev;
2765 	int i;
2766 	bool rdma_capable = false;
2767 
2768 	read_lock(&smb_direct_device_lock);
2769 	list_for_each_entry(smb_dev, &smb_direct_device_list, list) {
2770 		for (i = 0; i < smb_dev->ib_dev->phys_port_cnt; i++) {
2771 			struct net_device *ndev;
2772 
2773 			ndev = ib_device_get_netdev(smb_dev->ib_dev, i + 1);
2774 			if (!ndev)
2775 				continue;
2776 
2777 			if (ndev == netdev) {
2778 				dev_put(ndev);
2779 				rdma_capable = true;
2780 				goto out;
2781 			}
2782 			dev_put(ndev);
2783 		}
2784 	}
2785 out:
2786 	read_unlock(&smb_direct_device_lock);
2787 
2788 	if (rdma_capable == false) {
2789 		struct ib_device *ibdev;
2790 
2791 		ibdev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_UNKNOWN);
2792 		if (ibdev) {
2793 			rdma_capable = rdma_frwr_is_supported(&ibdev->attrs);
2794 			ib_device_put(ibdev);
2795 		}
2796 	}
2797 
2798 	ksmbd_debug(RDMA, "netdev(%s) rdma capable : %s\n",
2799 		    netdev->name, str_true_false(rdma_capable));
2800 
2801 	return rdma_capable;
2802 }
2803 
2804 bool ksmbd_rdma_capable_netdev(struct net_device *netdev)
2805 {
2806 	struct net_device *lower_dev;
2807 	struct list_head *iter;
2808 
2809 	if (ksmbd_find_rdma_capable_netdev(netdev))
2810 		return true;
2811 
2812 	/* check if netdev is bridge or VLAN */
2813 	if (netif_is_bridge_master(netdev) ||
2814 	    netdev->priv_flags & IFF_802_1Q_VLAN)
2815 		netdev_for_each_lower_dev(netdev, lower_dev, iter)
2816 			if (ksmbd_find_rdma_capable_netdev(lower_dev))
2817 				return true;
2818 
2819 	/* check if netdev is IPoIB safely without layer violation */
2820 	if (netdev->type == ARPHRD_INFINIBAND)
2821 		return true;
2822 
2823 	return false;
2824 }
2825 
2826 static const struct ksmbd_transport_ops ksmbd_smb_direct_transport_ops = {
2827 	.prepare	= smb_direct_prepare,
2828 	.disconnect	= smb_direct_disconnect,
2829 	.shutdown	= smb_direct_shutdown,
2830 	.writev		= smb_direct_writev,
2831 	.read		= smb_direct_read,
2832 	.rdma_read	= smb_direct_rdma_read,
2833 	.rdma_write	= smb_direct_rdma_write,
2834 	.free_transport = smb_direct_free_transport,
2835 };
2836