treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
[sfrench/cifs-2.6.git] / fs / cifs / smbdirect.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) 2017, Microsoft Corporation.
4  *
5  *   Author(s): Long Li <longli@microsoft.com>
6  */
7 #include <linux/module.h>
8 #include <linux/highmem.h>
9 #include "smbdirect.h"
10 #include "cifs_debug.h"
11 #include "cifsproto.h"
12 #include "smb2proto.h"
13
14 static struct smbd_response *get_empty_queue_buffer(
15                 struct smbd_connection *info);
16 static struct smbd_response *get_receive_buffer(
17                 struct smbd_connection *info);
18 static void put_receive_buffer(
19                 struct smbd_connection *info,
20                 struct smbd_response *response);
21 static int allocate_receive_buffers(struct smbd_connection *info, int num_buf);
22 static void destroy_receive_buffers(struct smbd_connection *info);
23
24 static void put_empty_packet(
25                 struct smbd_connection *info, struct smbd_response *response);
26 static void enqueue_reassembly(
27                 struct smbd_connection *info,
28                 struct smbd_response *response, int data_length);
29 static struct smbd_response *_get_first_reassembly(
30                 struct smbd_connection *info);
31
32 static int smbd_post_recv(
33                 struct smbd_connection *info,
34                 struct smbd_response *response);
35
36 static int smbd_post_send_empty(struct smbd_connection *info);
37 static int smbd_post_send_data(
38                 struct smbd_connection *info,
39                 struct kvec *iov, int n_vec, int remaining_data_length);
40 static int smbd_post_send_page(struct smbd_connection *info,
41                 struct page *page, unsigned long offset,
42                 size_t size, int remaining_data_length);
43
44 static void destroy_mr_list(struct smbd_connection *info);
45 static int allocate_mr_list(struct smbd_connection *info);
46
47 /* SMBD version number */
48 #define SMBD_V1 0x0100
49
50 /* Port numbers for SMBD transport */
51 #define SMB_PORT        445
52 #define SMBD_PORT       5445
53
54 /* Address lookup and resolve timeout in ms */
55 #define RDMA_RESOLVE_TIMEOUT    5000
56
57 /* SMBD negotiation timeout in seconds */
58 #define SMBD_NEGOTIATE_TIMEOUT  120
59
60 /* SMBD minimum receive size and fragmented sized defined in [MS-SMBD] */
61 #define SMBD_MIN_RECEIVE_SIZE           128
62 #define SMBD_MIN_FRAGMENTED_SIZE        131072
63
64 /*
65  * Default maximum number of RDMA read/write outstanding on this connection
66  * This value is possibly decreased during QP creation on hardware limit
67  */
68 #define SMBD_CM_RESPONDER_RESOURCES     32
69
70 /* Maximum number of retries on data transfer operations */
71 #define SMBD_CM_RETRY                   6
72 /* No need to retry on Receiver Not Ready since SMBD manages credits */
73 #define SMBD_CM_RNR_RETRY               0
74
75 /*
76  * User configurable initial values per SMBD transport connection
77  * as defined in [MS-SMBD] 3.1.1.1
78  * Those may change after a SMBD negotiation
79  */
80 /* The local peer's maximum number of credits to grant to the peer */
81 int smbd_receive_credit_max = 255;
82
83 /* The remote peer's credit request of local peer */
84 int smbd_send_credit_target = 255;
85
86 /* The maximum single message size can be sent to remote peer */
87 int smbd_max_send_size = 1364;
88
89 /*  The maximum fragmented upper-layer payload receive size supported */
90 int smbd_max_fragmented_recv_size = 1024 * 1024;
91
92 /*  The maximum single-message size which can be received */
93 int smbd_max_receive_size = 8192;
94
95 /* The timeout to initiate send of a keepalive message on idle */
96 int smbd_keep_alive_interval = 120;
97
98 /*
99  * User configurable initial values for RDMA transport
100  * The actual values used may be lower and are limited to hardware capabilities
101  */
102 /* Default maximum number of SGEs in a RDMA write/read */
103 int smbd_max_frmr_depth = 2048;
104
105 /* If payload is less than this byte, use RDMA send/recv not read/write */
106 int rdma_readwrite_threshold = 4096;
107
108 /* Transport logging functions
109  * Logging are defined as classes. They can be OR'ed to define the actual
110  * logging level via module parameter smbd_logging_class
111  * e.g. cifs.smbd_logging_class=0xa0 will log all log_rdma_recv() and
112  * log_rdma_event()
113  */
114 #define LOG_OUTGOING                    0x1
115 #define LOG_INCOMING                    0x2
116 #define LOG_READ                        0x4
117 #define LOG_WRITE                       0x8
118 #define LOG_RDMA_SEND                   0x10
119 #define LOG_RDMA_RECV                   0x20
120 #define LOG_KEEP_ALIVE                  0x40
121 #define LOG_RDMA_EVENT                  0x80
122 #define LOG_RDMA_MR                     0x100
123 static unsigned int smbd_logging_class;
124 module_param(smbd_logging_class, uint, 0644);
125 MODULE_PARM_DESC(smbd_logging_class,
126         "Logging class for SMBD transport 0x0 to 0x100");
127
128 #define ERR             0x0
129 #define INFO            0x1
130 static unsigned int smbd_logging_level = ERR;
131 module_param(smbd_logging_level, uint, 0644);
132 MODULE_PARM_DESC(smbd_logging_level,
133         "Logging level for SMBD transport, 0 (default): error, 1: info");
134
135 #define log_rdma(level, class, fmt, args...)                            \
136 do {                                                                    \
137         if (level <= smbd_logging_level || class & smbd_logging_class)  \
138                 cifs_dbg(VFS, "%s:%d " fmt, __func__, __LINE__, ##args);\
139 } while (0)
140
141 #define log_outgoing(level, fmt, args...) \
142                 log_rdma(level, LOG_OUTGOING, fmt, ##args)
143 #define log_incoming(level, fmt, args...) \
144                 log_rdma(level, LOG_INCOMING, fmt, ##args)
145 #define log_read(level, fmt, args...)   log_rdma(level, LOG_READ, fmt, ##args)
146 #define log_write(level, fmt, args...)  log_rdma(level, LOG_WRITE, fmt, ##args)
147 #define log_rdma_send(level, fmt, args...) \
148                 log_rdma(level, LOG_RDMA_SEND, fmt, ##args)
149 #define log_rdma_recv(level, fmt, args...) \
150                 log_rdma(level, LOG_RDMA_RECV, fmt, ##args)
151 #define log_keep_alive(level, fmt, args...) \
152                 log_rdma(level, LOG_KEEP_ALIVE, fmt, ##args)
153 #define log_rdma_event(level, fmt, args...) \
154                 log_rdma(level, LOG_RDMA_EVENT, fmt, ##args)
155 #define log_rdma_mr(level, fmt, args...) \
156                 log_rdma(level, LOG_RDMA_MR, fmt, ##args)
157
158 static void smbd_disconnect_rdma_work(struct work_struct *work)
159 {
160         struct smbd_connection *info =
161                 container_of(work, struct smbd_connection, disconnect_work);
162
163         if (info->transport_status == SMBD_CONNECTED) {
164                 info->transport_status = SMBD_DISCONNECTING;
165                 rdma_disconnect(info->id);
166         }
167 }
168
169 static void smbd_disconnect_rdma_connection(struct smbd_connection *info)
170 {
171         queue_work(info->workqueue, &info->disconnect_work);
172 }
173
174 /* Upcall from RDMA CM */
175 static int smbd_conn_upcall(
176                 struct rdma_cm_id *id, struct rdma_cm_event *event)
177 {
178         struct smbd_connection *info = id->context;
179
180         log_rdma_event(INFO, "event=%d status=%d\n",
181                 event->event, event->status);
182
183         switch (event->event) {
184         case RDMA_CM_EVENT_ADDR_RESOLVED:
185         case RDMA_CM_EVENT_ROUTE_RESOLVED:
186                 info->ri_rc = 0;
187                 complete(&info->ri_done);
188                 break;
189
190         case RDMA_CM_EVENT_ADDR_ERROR:
191                 info->ri_rc = -EHOSTUNREACH;
192                 complete(&info->ri_done);
193                 break;
194
195         case RDMA_CM_EVENT_ROUTE_ERROR:
196                 info->ri_rc = -ENETUNREACH;
197                 complete(&info->ri_done);
198                 break;
199
200         case RDMA_CM_EVENT_ESTABLISHED:
201                 log_rdma_event(INFO, "connected event=%d\n", event->event);
202                 info->transport_status = SMBD_CONNECTED;
203                 wake_up_interruptible(&info->conn_wait);
204                 break;
205
206         case RDMA_CM_EVENT_CONNECT_ERROR:
207         case RDMA_CM_EVENT_UNREACHABLE:
208         case RDMA_CM_EVENT_REJECTED:
209                 log_rdma_event(INFO, "connecting failed event=%d\n", event->event);
210                 info->transport_status = SMBD_DISCONNECTED;
211                 wake_up_interruptible(&info->conn_wait);
212                 break;
213
214         case RDMA_CM_EVENT_DEVICE_REMOVAL:
215         case RDMA_CM_EVENT_DISCONNECTED:
216                 /* This happenes when we fail the negotiation */
217                 if (info->transport_status == SMBD_NEGOTIATE_FAILED) {
218                         info->transport_status = SMBD_DISCONNECTED;
219                         wake_up(&info->conn_wait);
220                         break;
221                 }
222
223                 info->transport_status = SMBD_DISCONNECTED;
224                 wake_up_interruptible(&info->disconn_wait);
225                 wake_up_interruptible(&info->wait_reassembly_queue);
226                 wake_up_interruptible_all(&info->wait_send_queue);
227                 break;
228
229         default:
230                 break;
231         }
232
233         return 0;
234 }
235
236 /* Upcall from RDMA QP */
237 static void
238 smbd_qp_async_error_upcall(struct ib_event *event, void *context)
239 {
240         struct smbd_connection *info = context;
241
242         log_rdma_event(ERR, "%s on device %s info %p\n",
243                 ib_event_msg(event->event), event->device->name, info);
244
245         switch (event->event) {
246         case IB_EVENT_CQ_ERR:
247         case IB_EVENT_QP_FATAL:
248                 smbd_disconnect_rdma_connection(info);
249
250         default:
251                 break;
252         }
253 }
254
255 static inline void *smbd_request_payload(struct smbd_request *request)
256 {
257         return (void *)request->packet;
258 }
259
260 static inline void *smbd_response_payload(struct smbd_response *response)
261 {
262         return (void *)response->packet;
263 }
264
265 /* Called when a RDMA send is done */
266 static void send_done(struct ib_cq *cq, struct ib_wc *wc)
267 {
268         int i;
269         struct smbd_request *request =
270                 container_of(wc->wr_cqe, struct smbd_request, cqe);
271
272         log_rdma_send(INFO, "smbd_request %p completed wc->status=%d\n",
273                 request, wc->status);
274
275         if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) {
276                 log_rdma_send(ERR, "wc->status=%d wc->opcode=%d\n",
277                         wc->status, wc->opcode);
278                 smbd_disconnect_rdma_connection(request->info);
279         }
280
281         for (i = 0; i < request->num_sge; i++)
282                 ib_dma_unmap_single(request->info->id->device,
283                         request->sge[i].addr,
284                         request->sge[i].length,
285                         DMA_TO_DEVICE);
286
287         if (request->has_payload) {
288                 if (atomic_dec_and_test(&request->info->send_payload_pending))
289                         wake_up(&request->info->wait_send_payload_pending);
290         } else {
291                 if (atomic_dec_and_test(&request->info->send_pending))
292                         wake_up(&request->info->wait_send_pending);
293         }
294
295         mempool_free(request, request->info->request_mempool);
296 }
297
298 static void dump_smbd_negotiate_resp(struct smbd_negotiate_resp *resp)
299 {
300         log_rdma_event(INFO, "resp message min_version %u max_version %u "
301                 "negotiated_version %u credits_requested %u "
302                 "credits_granted %u status %u max_readwrite_size %u "
303                 "preferred_send_size %u max_receive_size %u "
304                 "max_fragmented_size %u\n",
305                 resp->min_version, resp->max_version, resp->negotiated_version,
306                 resp->credits_requested, resp->credits_granted, resp->status,
307                 resp->max_readwrite_size, resp->preferred_send_size,
308                 resp->max_receive_size, resp->max_fragmented_size);
309 }
310
311 /*
312  * Process a negotiation response message, according to [MS-SMBD]3.1.5.7
313  * response, packet_length: the negotiation response message
314  * return value: true if negotiation is a success, false if failed
315  */
316 static bool process_negotiation_response(
317                 struct smbd_response *response, int packet_length)
318 {
319         struct smbd_connection *info = response->info;
320         struct smbd_negotiate_resp *packet = smbd_response_payload(response);
321
322         if (packet_length < sizeof(struct smbd_negotiate_resp)) {
323                 log_rdma_event(ERR,
324                         "error: packet_length=%d\n", packet_length);
325                 return false;
326         }
327
328         if (le16_to_cpu(packet->negotiated_version) != SMBD_V1) {
329                 log_rdma_event(ERR, "error: negotiated_version=%x\n",
330                         le16_to_cpu(packet->negotiated_version));
331                 return false;
332         }
333         info->protocol = le16_to_cpu(packet->negotiated_version);
334
335         if (packet->credits_requested == 0) {
336                 log_rdma_event(ERR, "error: credits_requested==0\n");
337                 return false;
338         }
339         info->receive_credit_target = le16_to_cpu(packet->credits_requested);
340
341         if (packet->credits_granted == 0) {
342                 log_rdma_event(ERR, "error: credits_granted==0\n");
343                 return false;
344         }
345         atomic_set(&info->send_credits, le16_to_cpu(packet->credits_granted));
346
347         atomic_set(&info->receive_credits, 0);
348
349         if (le32_to_cpu(packet->preferred_send_size) > info->max_receive_size) {
350                 log_rdma_event(ERR, "error: preferred_send_size=%d\n",
351                         le32_to_cpu(packet->preferred_send_size));
352                 return false;
353         }
354         info->max_receive_size = le32_to_cpu(packet->preferred_send_size);
355
356         if (le32_to_cpu(packet->max_receive_size) < SMBD_MIN_RECEIVE_SIZE) {
357                 log_rdma_event(ERR, "error: max_receive_size=%d\n",
358                         le32_to_cpu(packet->max_receive_size));
359                 return false;
360         }
361         info->max_send_size = min_t(int, info->max_send_size,
362                                         le32_to_cpu(packet->max_receive_size));
363
364         if (le32_to_cpu(packet->max_fragmented_size) <
365                         SMBD_MIN_FRAGMENTED_SIZE) {
366                 log_rdma_event(ERR, "error: max_fragmented_size=%d\n",
367                         le32_to_cpu(packet->max_fragmented_size));
368                 return false;
369         }
370         info->max_fragmented_send_size =
371                 le32_to_cpu(packet->max_fragmented_size);
372         info->rdma_readwrite_threshold =
373                 rdma_readwrite_threshold > info->max_fragmented_send_size ?
374                 info->max_fragmented_send_size :
375                 rdma_readwrite_threshold;
376
377
378         info->max_readwrite_size = min_t(u32,
379                         le32_to_cpu(packet->max_readwrite_size),
380                         info->max_frmr_depth * PAGE_SIZE);
381         info->max_frmr_depth = info->max_readwrite_size / PAGE_SIZE;
382
383         return true;
384 }
385
386 /*
387  * Check and schedule to send an immediate packet
388  * This is used to extend credtis to remote peer to keep the transport busy
389  */
390 static void check_and_send_immediate(struct smbd_connection *info)
391 {
392         if (info->transport_status != SMBD_CONNECTED)
393                 return;
394
395         info->send_immediate = true;
396
397         /*
398          * Promptly send a packet if our peer is running low on receive
399          * credits
400          */
401         if (atomic_read(&info->receive_credits) <
402                 info->receive_credit_target - 1)
403                 queue_delayed_work(
404                         info->workqueue, &info->send_immediate_work, 0);
405 }
406
407 static void smbd_post_send_credits(struct work_struct *work)
408 {
409         int ret = 0;
410         int use_receive_queue = 1;
411         int rc;
412         struct smbd_response *response;
413         struct smbd_connection *info =
414                 container_of(work, struct smbd_connection,
415                         post_send_credits_work);
416
417         if (info->transport_status != SMBD_CONNECTED) {
418                 wake_up(&info->wait_receive_queues);
419                 return;
420         }
421
422         if (info->receive_credit_target >
423                 atomic_read(&info->receive_credits)) {
424                 while (true) {
425                         if (use_receive_queue)
426                                 response = get_receive_buffer(info);
427                         else
428                                 response = get_empty_queue_buffer(info);
429                         if (!response) {
430                                 /* now switch to emtpy packet queue */
431                                 if (use_receive_queue) {
432                                         use_receive_queue = 0;
433                                         continue;
434                                 } else
435                                         break;
436                         }
437
438                         response->type = SMBD_TRANSFER_DATA;
439                         response->first_segment = false;
440                         rc = smbd_post_recv(info, response);
441                         if (rc) {
442                                 log_rdma_recv(ERR,
443                                         "post_recv failed rc=%d\n", rc);
444                                 put_receive_buffer(info, response);
445                                 break;
446                         }
447
448                         ret++;
449                 }
450         }
451
452         spin_lock(&info->lock_new_credits_offered);
453         info->new_credits_offered += ret;
454         spin_unlock(&info->lock_new_credits_offered);
455
456         atomic_add(ret, &info->receive_credits);
457
458         /* Check if we can post new receive and grant credits to peer */
459         check_and_send_immediate(info);
460 }
461
462 static void smbd_recv_done_work(struct work_struct *work)
463 {
464         struct smbd_connection *info =
465                 container_of(work, struct smbd_connection, recv_done_work);
466
467         /*
468          * We may have new send credits granted from remote peer
469          * If any sender is blcoked on lack of credets, unblock it
470          */
471         if (atomic_read(&info->send_credits))
472                 wake_up_interruptible(&info->wait_send_queue);
473
474         /*
475          * Check if we need to send something to remote peer to
476          * grant more credits or respond to KEEP_ALIVE packet
477          */
478         check_and_send_immediate(info);
479 }
480
481 /* Called from softirq, when recv is done */
482 static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
483 {
484         struct smbd_data_transfer *data_transfer;
485         struct smbd_response *response =
486                 container_of(wc->wr_cqe, struct smbd_response, cqe);
487         struct smbd_connection *info = response->info;
488         int data_length = 0;
489
490         log_rdma_recv(INFO, "response=%p type=%d wc status=%d wc opcode %d "
491                       "byte_len=%d pkey_index=%x\n",
492                 response, response->type, wc->status, wc->opcode,
493                 wc->byte_len, wc->pkey_index);
494
495         if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_RECV) {
496                 log_rdma_recv(INFO, "wc->status=%d opcode=%d\n",
497                         wc->status, wc->opcode);
498                 smbd_disconnect_rdma_connection(info);
499                 goto error;
500         }
501
502         ib_dma_sync_single_for_cpu(
503                 wc->qp->device,
504                 response->sge.addr,
505                 response->sge.length,
506                 DMA_FROM_DEVICE);
507
508         switch (response->type) {
509         /* SMBD negotiation response */
510         case SMBD_NEGOTIATE_RESP:
511                 dump_smbd_negotiate_resp(smbd_response_payload(response));
512                 info->full_packet_received = true;
513                 info->negotiate_done =
514                         process_negotiation_response(response, wc->byte_len);
515                 complete(&info->negotiate_completion);
516                 break;
517
518         /* SMBD data transfer packet */
519         case SMBD_TRANSFER_DATA:
520                 data_transfer = smbd_response_payload(response);
521                 data_length = le32_to_cpu(data_transfer->data_length);
522
523                 /*
524                  * If this is a packet with data playload place the data in
525                  * reassembly queue and wake up the reading thread
526                  */
527                 if (data_length) {
528                         if (info->full_packet_received)
529                                 response->first_segment = true;
530
531                         if (le32_to_cpu(data_transfer->remaining_data_length))
532                                 info->full_packet_received = false;
533                         else
534                                 info->full_packet_received = true;
535
536                         enqueue_reassembly(
537                                 info,
538                                 response,
539                                 data_length);
540                 } else
541                         put_empty_packet(info, response);
542
543                 if (data_length)
544                         wake_up_interruptible(&info->wait_reassembly_queue);
545
546                 atomic_dec(&info->receive_credits);
547                 info->receive_credit_target =
548                         le16_to_cpu(data_transfer->credits_requested);
549                 atomic_add(le16_to_cpu(data_transfer->credits_granted),
550                         &info->send_credits);
551
552                 log_incoming(INFO, "data flags %d data_offset %d "
553                         "data_length %d remaining_data_length %d\n",
554                         le16_to_cpu(data_transfer->flags),
555                         le32_to_cpu(data_transfer->data_offset),
556                         le32_to_cpu(data_transfer->data_length),
557                         le32_to_cpu(data_transfer->remaining_data_length));
558
559                 /* Send a KEEP_ALIVE response right away if requested */
560                 info->keep_alive_requested = KEEP_ALIVE_NONE;
561                 if (le16_to_cpu(data_transfer->flags) &
562                                 SMB_DIRECT_RESPONSE_REQUESTED) {
563                         info->keep_alive_requested = KEEP_ALIVE_PENDING;
564                 }
565
566                 queue_work(info->workqueue, &info->recv_done_work);
567                 return;
568
569         default:
570                 log_rdma_recv(ERR,
571                         "unexpected response type=%d\n", response->type);
572         }
573
574 error:
575         put_receive_buffer(info, response);
576 }
577
578 static struct rdma_cm_id *smbd_create_id(
579                 struct smbd_connection *info,
580                 struct sockaddr *dstaddr, int port)
581 {
582         struct rdma_cm_id *id;
583         int rc;
584         __be16 *sport;
585
586         id = rdma_create_id(&init_net, smbd_conn_upcall, info,
587                 RDMA_PS_TCP, IB_QPT_RC);
588         if (IS_ERR(id)) {
589                 rc = PTR_ERR(id);
590                 log_rdma_event(ERR, "rdma_create_id() failed %i\n", rc);
591                 return id;
592         }
593
594         if (dstaddr->sa_family == AF_INET6)
595                 sport = &((struct sockaddr_in6 *)dstaddr)->sin6_port;
596         else
597                 sport = &((struct sockaddr_in *)dstaddr)->sin_port;
598
599         *sport = htons(port);
600
601         init_completion(&info->ri_done);
602         info->ri_rc = -ETIMEDOUT;
603
604         rc = rdma_resolve_addr(id, NULL, (struct sockaddr *)dstaddr,
605                 RDMA_RESOLVE_TIMEOUT);
606         if (rc) {
607                 log_rdma_event(ERR, "rdma_resolve_addr() failed %i\n", rc);
608                 goto out;
609         }
610         wait_for_completion_interruptible_timeout(
611                 &info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
612         rc = info->ri_rc;
613         if (rc) {
614                 log_rdma_event(ERR, "rdma_resolve_addr() completed %i\n", rc);
615                 goto out;
616         }
617
618         info->ri_rc = -ETIMEDOUT;
619         rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
620         if (rc) {
621                 log_rdma_event(ERR, "rdma_resolve_route() failed %i\n", rc);
622                 goto out;
623         }
624         wait_for_completion_interruptible_timeout(
625                 &info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
626         rc = info->ri_rc;
627         if (rc) {
628                 log_rdma_event(ERR, "rdma_resolve_route() completed %i\n", rc);
629                 goto out;
630         }
631
632         return id;
633
634 out:
635         rdma_destroy_id(id);
636         return ERR_PTR(rc);
637 }
638
639 /*
640  * Test if FRWR (Fast Registration Work Requests) is supported on the device
641  * This implementation requries FRWR on RDMA read/write
642  * return value: true if it is supported
643  */
644 static bool frwr_is_supported(struct ib_device_attr *attrs)
645 {
646         if (!(attrs->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS))
647                 return false;
648         if (attrs->max_fast_reg_page_list_len == 0)
649                 return false;
650         return true;
651 }
652
653 static int smbd_ia_open(
654                 struct smbd_connection *info,
655                 struct sockaddr *dstaddr, int port)
656 {
657         int rc;
658
659         info->id = smbd_create_id(info, dstaddr, port);
660         if (IS_ERR(info->id)) {
661                 rc = PTR_ERR(info->id);
662                 goto out1;
663         }
664
665         if (!frwr_is_supported(&info->id->device->attrs)) {
666                 log_rdma_event(ERR,
667                         "Fast Registration Work Requests "
668                         "(FRWR) is not supported\n");
669                 log_rdma_event(ERR,
670                         "Device capability flags = %llx "
671                         "max_fast_reg_page_list_len = %u\n",
672                         info->id->device->attrs.device_cap_flags,
673                         info->id->device->attrs.max_fast_reg_page_list_len);
674                 rc = -EPROTONOSUPPORT;
675                 goto out2;
676         }
677         info->max_frmr_depth = min_t(int,
678                 smbd_max_frmr_depth,
679                 info->id->device->attrs.max_fast_reg_page_list_len);
680         info->mr_type = IB_MR_TYPE_MEM_REG;
681         if (info->id->device->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG)
682                 info->mr_type = IB_MR_TYPE_SG_GAPS;
683
684         info->pd = ib_alloc_pd(info->id->device, 0);
685         if (IS_ERR(info->pd)) {
686                 rc = PTR_ERR(info->pd);
687                 log_rdma_event(ERR, "ib_alloc_pd() returned %d\n", rc);
688                 goto out2;
689         }
690
691         return 0;
692
693 out2:
694         rdma_destroy_id(info->id);
695         info->id = NULL;
696
697 out1:
698         return rc;
699 }
700
701 /*
702  * Send a negotiation request message to the peer
703  * The negotiation procedure is in [MS-SMBD] 3.1.5.2 and 3.1.5.3
704  * After negotiation, the transport is connected and ready for
705  * carrying upper layer SMB payload
706  */
707 static int smbd_post_send_negotiate_req(struct smbd_connection *info)
708 {
709         struct ib_send_wr send_wr;
710         int rc = -ENOMEM;
711         struct smbd_request *request;
712         struct smbd_negotiate_req *packet;
713
714         request = mempool_alloc(info->request_mempool, GFP_KERNEL);
715         if (!request)
716                 return rc;
717
718         request->info = info;
719
720         packet = smbd_request_payload(request);
721         packet->min_version = cpu_to_le16(SMBD_V1);
722         packet->max_version = cpu_to_le16(SMBD_V1);
723         packet->reserved = 0;
724         packet->credits_requested = cpu_to_le16(info->send_credit_target);
725         packet->preferred_send_size = cpu_to_le32(info->max_send_size);
726         packet->max_receive_size = cpu_to_le32(info->max_receive_size);
727         packet->max_fragmented_size =
728                 cpu_to_le32(info->max_fragmented_recv_size);
729
730         request->num_sge = 1;
731         request->sge[0].addr = ib_dma_map_single(
732                                 info->id->device, (void *)packet,
733                                 sizeof(*packet), DMA_TO_DEVICE);
734         if (ib_dma_mapping_error(info->id->device, request->sge[0].addr)) {
735                 rc = -EIO;
736                 goto dma_mapping_failed;
737         }
738
739         request->sge[0].length = sizeof(*packet);
740         request->sge[0].lkey = info->pd->local_dma_lkey;
741
742         ib_dma_sync_single_for_device(
743                 info->id->device, request->sge[0].addr,
744                 request->sge[0].length, DMA_TO_DEVICE);
745
746         request->cqe.done = send_done;
747
748         send_wr.next = NULL;
749         send_wr.wr_cqe = &request->cqe;
750         send_wr.sg_list = request->sge;
751         send_wr.num_sge = request->num_sge;
752         send_wr.opcode = IB_WR_SEND;
753         send_wr.send_flags = IB_SEND_SIGNALED;
754
755         log_rdma_send(INFO, "sge addr=%llx length=%x lkey=%x\n",
756                 request->sge[0].addr,
757                 request->sge[0].length, request->sge[0].lkey);
758
759         request->has_payload = false;
760         atomic_inc(&info->send_pending);
761         rc = ib_post_send(info->id->qp, &send_wr, NULL);
762         if (!rc)
763                 return 0;
764
765         /* if we reach here, post send failed */
766         log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc);
767         atomic_dec(&info->send_pending);
768         ib_dma_unmap_single(info->id->device, request->sge[0].addr,
769                 request->sge[0].length, DMA_TO_DEVICE);
770
771         smbd_disconnect_rdma_connection(info);
772
773 dma_mapping_failed:
774         mempool_free(request, info->request_mempool);
775         return rc;
776 }
777
778 /*
779  * Extend the credits to remote peer
780  * This implements [MS-SMBD] 3.1.5.9
781  * The idea is that we should extend credits to remote peer as quickly as
782  * it's allowed, to maintain data flow. We allocate as much receive
783  * buffer as possible, and extend the receive credits to remote peer
784  * return value: the new credtis being granted.
785  */
786 static int manage_credits_prior_sending(struct smbd_connection *info)
787 {
788         int new_credits;
789
790         spin_lock(&info->lock_new_credits_offered);
791         new_credits = info->new_credits_offered;
792         info->new_credits_offered = 0;
793         spin_unlock(&info->lock_new_credits_offered);
794
795         return new_credits;
796 }
797
798 /*
799  * Check if we need to send a KEEP_ALIVE message
800  * The idle connection timer triggers a KEEP_ALIVE message when expires
801  * SMB_DIRECT_RESPONSE_REQUESTED is set in the message flag to have peer send
802  * back a response.
803  * return value:
804  * 1 if SMB_DIRECT_RESPONSE_REQUESTED needs to be set
805  * 0: otherwise
806  */
807 static int manage_keep_alive_before_sending(struct smbd_connection *info)
808 {
809         if (info->keep_alive_requested == KEEP_ALIVE_PENDING) {
810                 info->keep_alive_requested = KEEP_ALIVE_SENT;
811                 return 1;
812         }
813         return 0;
814 }
815
816 /*
817  * Build and prepare the SMBD packet header
818  * This function waits for avaialbe send credits and build a SMBD packet
819  * header. The caller then optional append payload to the packet after
820  * the header
821  * intput values
822  * size: the size of the payload
823  * remaining_data_length: remaining data to send if this is part of a
824  * fragmented packet
825  * output values
826  * request_out: the request allocated from this function
827  * return values: 0 on success, otherwise actual error code returned
828  */
829 static int smbd_create_header(struct smbd_connection *info,
830                 int size, int remaining_data_length,
831                 struct smbd_request **request_out)
832 {
833         struct smbd_request *request;
834         struct smbd_data_transfer *packet;
835         int header_length;
836         int rc;
837
838         /* Wait for send credits. A SMBD packet needs one credit */
839         rc = wait_event_interruptible(info->wait_send_queue,
840                 atomic_read(&info->send_credits) > 0 ||
841                 info->transport_status != SMBD_CONNECTED);
842         if (rc)
843                 return rc;
844
845         if (info->transport_status != SMBD_CONNECTED) {
846                 log_outgoing(ERR, "disconnected not sending\n");
847                 return -EAGAIN;
848         }
849         atomic_dec(&info->send_credits);
850
851         request = mempool_alloc(info->request_mempool, GFP_KERNEL);
852         if (!request) {
853                 rc = -ENOMEM;
854                 goto err;
855         }
856
857         request->info = info;
858
859         /* Fill in the packet header */
860         packet = smbd_request_payload(request);
861         packet->credits_requested = cpu_to_le16(info->send_credit_target);
862         packet->credits_granted =
863                 cpu_to_le16(manage_credits_prior_sending(info));
864         info->send_immediate = false;
865
866         packet->flags = 0;
867         if (manage_keep_alive_before_sending(info))
868                 packet->flags |= cpu_to_le16(SMB_DIRECT_RESPONSE_REQUESTED);
869
870         packet->reserved = 0;
871         if (!size)
872                 packet->data_offset = 0;
873         else
874                 packet->data_offset = cpu_to_le32(24);
875         packet->data_length = cpu_to_le32(size);
876         packet->remaining_data_length = cpu_to_le32(remaining_data_length);
877         packet->padding = 0;
878
879         log_outgoing(INFO, "credits_requested=%d credits_granted=%d "
880                 "data_offset=%d data_length=%d remaining_data_length=%d\n",
881                 le16_to_cpu(packet->credits_requested),
882                 le16_to_cpu(packet->credits_granted),
883                 le32_to_cpu(packet->data_offset),
884                 le32_to_cpu(packet->data_length),
885                 le32_to_cpu(packet->remaining_data_length));
886
887         /* Map the packet to DMA */
888         header_length = sizeof(struct smbd_data_transfer);
889         /* If this is a packet without payload, don't send padding */
890         if (!size)
891                 header_length = offsetof(struct smbd_data_transfer, padding);
892
893         request->num_sge = 1;
894         request->sge[0].addr = ib_dma_map_single(info->id->device,
895                                                  (void *)packet,
896                                                  header_length,
897                                                  DMA_TO_DEVICE);
898         if (ib_dma_mapping_error(info->id->device, request->sge[0].addr)) {
899                 mempool_free(request, info->request_mempool);
900                 rc = -EIO;
901                 goto err;
902         }
903
904         request->sge[0].length = header_length;
905         request->sge[0].lkey = info->pd->local_dma_lkey;
906
907         *request_out = request;
908         return 0;
909
910 err:
911         atomic_inc(&info->send_credits);
912         return rc;
913 }
914
915 static void smbd_destroy_header(struct smbd_connection *info,
916                 struct smbd_request *request)
917 {
918
919         ib_dma_unmap_single(info->id->device,
920                             request->sge[0].addr,
921                             request->sge[0].length,
922                             DMA_TO_DEVICE);
923         mempool_free(request, info->request_mempool);
924         atomic_inc(&info->send_credits);
925 }
926
927 /* Post the send request */
928 static int smbd_post_send(struct smbd_connection *info,
929                 struct smbd_request *request, bool has_payload)
930 {
931         struct ib_send_wr send_wr;
932         int rc, i;
933
934         for (i = 0; i < request->num_sge; i++) {
935                 log_rdma_send(INFO,
936                         "rdma_request sge[%d] addr=%llu length=%u\n",
937                         i, request->sge[i].addr, request->sge[i].length);
938                 ib_dma_sync_single_for_device(
939                         info->id->device,
940                         request->sge[i].addr,
941                         request->sge[i].length,
942                         DMA_TO_DEVICE);
943         }
944
945         request->cqe.done = send_done;
946
947         send_wr.next = NULL;
948         send_wr.wr_cqe = &request->cqe;
949         send_wr.sg_list = request->sge;
950         send_wr.num_sge = request->num_sge;
951         send_wr.opcode = IB_WR_SEND;
952         send_wr.send_flags = IB_SEND_SIGNALED;
953
954         if (has_payload) {
955                 request->has_payload = true;
956                 atomic_inc(&info->send_payload_pending);
957         } else {
958                 request->has_payload = false;
959                 atomic_inc(&info->send_pending);
960         }
961
962         rc = ib_post_send(info->id->qp, &send_wr, NULL);
963         if (rc) {
964                 log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc);
965                 if (has_payload) {
966                         if (atomic_dec_and_test(&info->send_payload_pending))
967                                 wake_up(&info->wait_send_payload_pending);
968                 } else {
969                         if (atomic_dec_and_test(&info->send_pending))
970                                 wake_up(&info->wait_send_pending);
971                 }
972                 smbd_disconnect_rdma_connection(info);
973                 rc = -EAGAIN;
974         } else
975                 /* Reset timer for idle connection after packet is sent */
976                 mod_delayed_work(info->workqueue, &info->idle_timer_work,
977                         info->keep_alive_interval*HZ);
978
979         return rc;
980 }
981
982 static int smbd_post_send_sgl(struct smbd_connection *info,
983         struct scatterlist *sgl, int data_length, int remaining_data_length)
984 {
985         int num_sgs;
986         int i, rc;
987         struct smbd_request *request;
988         struct scatterlist *sg;
989
990         rc = smbd_create_header(
991                 info, data_length, remaining_data_length, &request);
992         if (rc)
993                 return rc;
994
995         num_sgs = sgl ? sg_nents(sgl) : 0;
996         for_each_sg(sgl, sg, num_sgs, i) {
997                 request->sge[i+1].addr =
998                         ib_dma_map_page(info->id->device, sg_page(sg),
999                                sg->offset, sg->length, DMA_TO_DEVICE);
1000                 if (ib_dma_mapping_error(
1001                                 info->id->device, request->sge[i+1].addr)) {
1002                         rc = -EIO;
1003                         request->sge[i+1].addr = 0;
1004                         goto dma_mapping_failure;
1005                 }
1006                 request->sge[i+1].length = sg->length;
1007                 request->sge[i+1].lkey = info->pd->local_dma_lkey;
1008                 request->num_sge++;
1009         }
1010
1011         rc = smbd_post_send(info, request, data_length);
1012         if (!rc)
1013                 return 0;
1014
1015 dma_mapping_failure:
1016         for (i = 1; i < request->num_sge; i++)
1017                 if (request->sge[i].addr)
1018                         ib_dma_unmap_single(info->id->device,
1019                                             request->sge[i].addr,
1020                                             request->sge[i].length,
1021                                             DMA_TO_DEVICE);
1022         smbd_destroy_header(info, request);
1023         return rc;
1024 }
1025
1026 /*
1027  * Send a page
1028  * page: the page to send
1029  * offset: offset in the page to send
1030  * size: length in the page to send
1031  * remaining_data_length: remaining data to send in this payload
1032  */
1033 static int smbd_post_send_page(struct smbd_connection *info, struct page *page,
1034                 unsigned long offset, size_t size, int remaining_data_length)
1035 {
1036         struct scatterlist sgl;
1037
1038         sg_init_table(&sgl, 1);
1039         sg_set_page(&sgl, page, size, offset);
1040
1041         return smbd_post_send_sgl(info, &sgl, size, remaining_data_length);
1042 }
1043
1044 /*
1045  * Send an empty message
1046  * Empty message is used to extend credits to peer to for keep live
1047  * while there is no upper layer payload to send at the time
1048  */
1049 static int smbd_post_send_empty(struct smbd_connection *info)
1050 {
1051         info->count_send_empty++;
1052         return smbd_post_send_sgl(info, NULL, 0, 0);
1053 }
1054
1055 /*
1056  * Send a data buffer
1057  * iov: the iov array describing the data buffers
1058  * n_vec: number of iov array
1059  * remaining_data_length: remaining data to send following this packet
1060  * in segmented SMBD packet
1061  */
1062 static int smbd_post_send_data(
1063         struct smbd_connection *info, struct kvec *iov, int n_vec,
1064         int remaining_data_length)
1065 {
1066         int i;
1067         u32 data_length = 0;
1068         struct scatterlist sgl[SMBDIRECT_MAX_SGE];
1069
1070         if (n_vec > SMBDIRECT_MAX_SGE) {
1071                 cifs_dbg(VFS, "Can't fit data to SGL, n_vec=%d\n", n_vec);
1072                 return -ENOMEM;
1073         }
1074
1075         sg_init_table(sgl, n_vec);
1076         for (i = 0; i < n_vec; i++) {
1077                 data_length += iov[i].iov_len;
1078                 sg_set_buf(&sgl[i], iov[i].iov_base, iov[i].iov_len);
1079         }
1080
1081         return smbd_post_send_sgl(info, sgl, data_length, remaining_data_length);
1082 }
1083
1084 /*
1085  * Post a receive request to the transport
1086  * The remote peer can only send data when a receive request is posted
1087  * The interaction is controlled by send/receive credit system
1088  */
1089 static int smbd_post_recv(
1090                 struct smbd_connection *info, struct smbd_response *response)
1091 {
1092         struct ib_recv_wr recv_wr;
1093         int rc = -EIO;
1094
1095         response->sge.addr = ib_dma_map_single(
1096                                 info->id->device, response->packet,
1097                                 info->max_receive_size, DMA_FROM_DEVICE);
1098         if (ib_dma_mapping_error(info->id->device, response->sge.addr))
1099                 return rc;
1100
1101         response->sge.length = info->max_receive_size;
1102         response->sge.lkey = info->pd->local_dma_lkey;
1103
1104         response->cqe.done = recv_done;
1105
1106         recv_wr.wr_cqe = &response->cqe;
1107         recv_wr.next = NULL;
1108         recv_wr.sg_list = &response->sge;
1109         recv_wr.num_sge = 1;
1110
1111         rc = ib_post_recv(info->id->qp, &recv_wr, NULL);
1112         if (rc) {
1113                 ib_dma_unmap_single(info->id->device, response->sge.addr,
1114                                     response->sge.length, DMA_FROM_DEVICE);
1115                 smbd_disconnect_rdma_connection(info);
1116                 log_rdma_recv(ERR, "ib_post_recv failed rc=%d\n", rc);
1117         }
1118
1119         return rc;
1120 }
1121
1122 /* Perform SMBD negotiate according to [MS-SMBD] 3.1.5.2 */
1123 static int smbd_negotiate(struct smbd_connection *info)
1124 {
1125         int rc;
1126         struct smbd_response *response = get_receive_buffer(info);
1127
1128         response->type = SMBD_NEGOTIATE_RESP;
1129         rc = smbd_post_recv(info, response);
1130         log_rdma_event(INFO,
1131                 "smbd_post_recv rc=%d iov.addr=%llx iov.length=%x "
1132                 "iov.lkey=%x\n",
1133                 rc, response->sge.addr,
1134                 response->sge.length, response->sge.lkey);
1135         if (rc)
1136                 return rc;
1137
1138         init_completion(&info->negotiate_completion);
1139         info->negotiate_done = false;
1140         rc = smbd_post_send_negotiate_req(info);
1141         if (rc)
1142                 return rc;
1143
1144         rc = wait_for_completion_interruptible_timeout(
1145                 &info->negotiate_completion, SMBD_NEGOTIATE_TIMEOUT * HZ);
1146         log_rdma_event(INFO, "wait_for_completion_timeout rc=%d\n", rc);
1147
1148         if (info->negotiate_done)
1149                 return 0;
1150
1151         if (rc == 0)
1152                 rc = -ETIMEDOUT;
1153         else if (rc == -ERESTARTSYS)
1154                 rc = -EINTR;
1155         else
1156                 rc = -ENOTCONN;
1157
1158         return rc;
1159 }
1160
1161 static void put_empty_packet(
1162                 struct smbd_connection *info, struct smbd_response *response)
1163 {
1164         spin_lock(&info->empty_packet_queue_lock);
1165         list_add_tail(&response->list, &info->empty_packet_queue);
1166         info->count_empty_packet_queue++;
1167         spin_unlock(&info->empty_packet_queue_lock);
1168
1169         queue_work(info->workqueue, &info->post_send_credits_work);
1170 }
1171
1172 /*
1173  * Implement Connection.FragmentReassemblyBuffer defined in [MS-SMBD] 3.1.1.1
1174  * This is a queue for reassembling upper layer payload and present to upper
1175  * layer. All the inncoming payload go to the reassembly queue, regardless of
1176  * if reassembly is required. The uuper layer code reads from the queue for all
1177  * incoming payloads.
1178  * Put a received packet to the reassembly queue
1179  * response: the packet received
1180  * data_length: the size of payload in this packet
1181  */
1182 static void enqueue_reassembly(
1183         struct smbd_connection *info,
1184         struct smbd_response *response,
1185         int data_length)
1186 {
1187         spin_lock(&info->reassembly_queue_lock);
1188         list_add_tail(&response->list, &info->reassembly_queue);
1189         info->reassembly_queue_length++;
1190         /*
1191          * Make sure reassembly_data_length is updated after list and
1192          * reassembly_queue_length are updated. On the dequeue side
1193          * reassembly_data_length is checked without a lock to determine
1194          * if reassembly_queue_length and list is up to date
1195          */
1196         virt_wmb();
1197         info->reassembly_data_length += data_length;
1198         spin_unlock(&info->reassembly_queue_lock);
1199         info->count_reassembly_queue++;
1200         info->count_enqueue_reassembly_queue++;
1201 }
1202
1203 /*
1204  * Get the first entry at the front of reassembly queue
1205  * Caller is responsible for locking
1206  * return value: the first entry if any, NULL if queue is empty
1207  */
1208 static struct smbd_response *_get_first_reassembly(struct smbd_connection *info)
1209 {
1210         struct smbd_response *ret = NULL;
1211
1212         if (!list_empty(&info->reassembly_queue)) {
1213                 ret = list_first_entry(
1214                         &info->reassembly_queue,
1215                         struct smbd_response, list);
1216         }
1217         return ret;
1218 }
1219
1220 static struct smbd_response *get_empty_queue_buffer(
1221                 struct smbd_connection *info)
1222 {
1223         struct smbd_response *ret = NULL;
1224         unsigned long flags;
1225
1226         spin_lock_irqsave(&info->empty_packet_queue_lock, flags);
1227         if (!list_empty(&info->empty_packet_queue)) {
1228                 ret = list_first_entry(
1229                         &info->empty_packet_queue,
1230                         struct smbd_response, list);
1231                 list_del(&ret->list);
1232                 info->count_empty_packet_queue--;
1233         }
1234         spin_unlock_irqrestore(&info->empty_packet_queue_lock, flags);
1235
1236         return ret;
1237 }
1238
1239 /*
1240  * Get a receive buffer
1241  * For each remote send, we need to post a receive. The receive buffers are
1242  * pre-allocated in advance.
1243  * return value: the receive buffer, NULL if none is available
1244  */
1245 static struct smbd_response *get_receive_buffer(struct smbd_connection *info)
1246 {
1247         struct smbd_response *ret = NULL;
1248         unsigned long flags;
1249
1250         spin_lock_irqsave(&info->receive_queue_lock, flags);
1251         if (!list_empty(&info->receive_queue)) {
1252                 ret = list_first_entry(
1253                         &info->receive_queue,
1254                         struct smbd_response, list);
1255                 list_del(&ret->list);
1256                 info->count_receive_queue--;
1257                 info->count_get_receive_buffer++;
1258         }
1259         spin_unlock_irqrestore(&info->receive_queue_lock, flags);
1260
1261         return ret;
1262 }
1263
1264 /*
1265  * Return a receive buffer
1266  * Upon returning of a receive buffer, we can post new receive and extend
1267  * more receive credits to remote peer. This is done immediately after a
1268  * receive buffer is returned.
1269  */
1270 static void put_receive_buffer(
1271         struct smbd_connection *info, struct smbd_response *response)
1272 {
1273         unsigned long flags;
1274
1275         ib_dma_unmap_single(info->id->device, response->sge.addr,
1276                 response->sge.length, DMA_FROM_DEVICE);
1277
1278         spin_lock_irqsave(&info->receive_queue_lock, flags);
1279         list_add_tail(&response->list, &info->receive_queue);
1280         info->count_receive_queue++;
1281         info->count_put_receive_buffer++;
1282         spin_unlock_irqrestore(&info->receive_queue_lock, flags);
1283
1284         queue_work(info->workqueue, &info->post_send_credits_work);
1285 }
1286
1287 /* Preallocate all receive buffer on transport establishment */
1288 static int allocate_receive_buffers(struct smbd_connection *info, int num_buf)
1289 {
1290         int i;
1291         struct smbd_response *response;
1292
1293         INIT_LIST_HEAD(&info->reassembly_queue);
1294         spin_lock_init(&info->reassembly_queue_lock);
1295         info->reassembly_data_length = 0;
1296         info->reassembly_queue_length = 0;
1297
1298         INIT_LIST_HEAD(&info->receive_queue);
1299         spin_lock_init(&info->receive_queue_lock);
1300         info->count_receive_queue = 0;
1301
1302         INIT_LIST_HEAD(&info->empty_packet_queue);
1303         spin_lock_init(&info->empty_packet_queue_lock);
1304         info->count_empty_packet_queue = 0;
1305
1306         init_waitqueue_head(&info->wait_receive_queues);
1307
1308         for (i = 0; i < num_buf; i++) {
1309                 response = mempool_alloc(info->response_mempool, GFP_KERNEL);
1310                 if (!response)
1311                         goto allocate_failed;
1312
1313                 response->info = info;
1314                 list_add_tail(&response->list, &info->receive_queue);
1315                 info->count_receive_queue++;
1316         }
1317
1318         return 0;
1319
1320 allocate_failed:
1321         while (!list_empty(&info->receive_queue)) {
1322                 response = list_first_entry(
1323                                 &info->receive_queue,
1324                                 struct smbd_response, list);
1325                 list_del(&response->list);
1326                 info->count_receive_queue--;
1327
1328                 mempool_free(response, info->response_mempool);
1329         }
1330         return -ENOMEM;
1331 }
1332
1333 static void destroy_receive_buffers(struct smbd_connection *info)
1334 {
1335         struct smbd_response *response;
1336
1337         while ((response = get_receive_buffer(info)))
1338                 mempool_free(response, info->response_mempool);
1339
1340         while ((response = get_empty_queue_buffer(info)))
1341                 mempool_free(response, info->response_mempool);
1342 }
1343
1344 /*
1345  * Check and send an immediate or keep alive packet
1346  * The condition to send those packets are defined in [MS-SMBD] 3.1.1.1
1347  * Connection.KeepaliveRequested and Connection.SendImmediate
1348  * The idea is to extend credits to server as soon as it becomes available
1349  */
1350 static void send_immediate_work(struct work_struct *work)
1351 {
1352         struct smbd_connection *info = container_of(
1353                                         work, struct smbd_connection,
1354                                         send_immediate_work.work);
1355
1356         if (info->keep_alive_requested == KEEP_ALIVE_PENDING ||
1357             info->send_immediate) {
1358                 log_keep_alive(INFO, "send an empty message\n");
1359                 smbd_post_send_empty(info);
1360         }
1361 }
1362
1363 /* Implement idle connection timer [MS-SMBD] 3.1.6.2 */
1364 static void idle_connection_timer(struct work_struct *work)
1365 {
1366         struct smbd_connection *info = container_of(
1367                                         work, struct smbd_connection,
1368                                         idle_timer_work.work);
1369
1370         if (info->keep_alive_requested != KEEP_ALIVE_NONE) {
1371                 log_keep_alive(ERR,
1372                         "error status info->keep_alive_requested=%d\n",
1373                         info->keep_alive_requested);
1374                 smbd_disconnect_rdma_connection(info);
1375                 return;
1376         }
1377
1378         log_keep_alive(INFO, "about to send an empty idle message\n");
1379         smbd_post_send_empty(info);
1380
1381         /* Setup the next idle timeout work */
1382         queue_delayed_work(info->workqueue, &info->idle_timer_work,
1383                         info->keep_alive_interval*HZ);
1384 }
1385
1386 /*
1387  * Destroy the transport and related RDMA and memory resources
1388  * Need to go through all the pending counters and make sure on one is using
1389  * the transport while it is destroyed
1390  */
1391 void smbd_destroy(struct TCP_Server_Info *server)
1392 {
1393         struct smbd_connection *info = server->smbd_conn;
1394         struct smbd_response *response;
1395         unsigned long flags;
1396
1397         if (!info) {
1398                 log_rdma_event(INFO, "rdma session already destroyed\n");
1399                 return;
1400         }
1401
1402         log_rdma_event(INFO, "destroying rdma session\n");
1403         if (info->transport_status != SMBD_DISCONNECTED) {
1404                 rdma_disconnect(server->smbd_conn->id);
1405                 log_rdma_event(INFO, "wait for transport being disconnected\n");
1406                 wait_event_interruptible(
1407                         info->disconn_wait,
1408                         info->transport_status == SMBD_DISCONNECTED);
1409         }
1410
1411         log_rdma_event(INFO, "destroying qp\n");
1412         ib_drain_qp(info->id->qp);
1413         rdma_destroy_qp(info->id);
1414
1415         log_rdma_event(INFO, "cancelling idle timer\n");
1416         cancel_delayed_work_sync(&info->idle_timer_work);
1417         log_rdma_event(INFO, "cancelling send immediate work\n");
1418         cancel_delayed_work_sync(&info->send_immediate_work);
1419
1420         log_rdma_event(INFO, "wait for all send posted to IB to finish\n");
1421         wait_event(info->wait_send_pending,
1422                 atomic_read(&info->send_pending) == 0);
1423         wait_event(info->wait_send_payload_pending,
1424                 atomic_read(&info->send_payload_pending) == 0);
1425
1426         /* It's not posssible for upper layer to get to reassembly */
1427         log_rdma_event(INFO, "drain the reassembly queue\n");
1428         do {
1429                 spin_lock_irqsave(&info->reassembly_queue_lock, flags);
1430                 response = _get_first_reassembly(info);
1431                 if (response) {
1432                         list_del(&response->list);
1433                         spin_unlock_irqrestore(
1434                                 &info->reassembly_queue_lock, flags);
1435                         put_receive_buffer(info, response);
1436                 } else
1437                         spin_unlock_irqrestore(
1438                                 &info->reassembly_queue_lock, flags);
1439         } while (response);
1440         info->reassembly_data_length = 0;
1441
1442         log_rdma_event(INFO, "free receive buffers\n");
1443         wait_event(info->wait_receive_queues,
1444                 info->count_receive_queue + info->count_empty_packet_queue
1445                         == info->receive_credit_max);
1446         destroy_receive_buffers(info);
1447
1448         /*
1449          * For performance reasons, memory registration and deregistration
1450          * are not locked by srv_mutex. It is possible some processes are
1451          * blocked on transport srv_mutex while holding memory registration.
1452          * Release the transport srv_mutex to allow them to hit the failure
1453          * path when sending data, and then release memory registartions.
1454          */
1455         log_rdma_event(INFO, "freeing mr list\n");
1456         wake_up_interruptible_all(&info->wait_mr);
1457         while (atomic_read(&info->mr_used_count)) {
1458                 mutex_unlock(&server->srv_mutex);
1459                 msleep(1000);
1460                 mutex_lock(&server->srv_mutex);
1461         }
1462         destroy_mr_list(info);
1463
1464         ib_free_cq(info->send_cq);
1465         ib_free_cq(info->recv_cq);
1466         ib_dealloc_pd(info->pd);
1467         rdma_destroy_id(info->id);
1468
1469         /* free mempools */
1470         mempool_destroy(info->request_mempool);
1471         kmem_cache_destroy(info->request_cache);
1472
1473         mempool_destroy(info->response_mempool);
1474         kmem_cache_destroy(info->response_cache);
1475
1476         info->transport_status = SMBD_DESTROYED;
1477
1478         destroy_workqueue(info->workqueue);
1479         kfree(info);
1480 }
1481
1482 /*
1483  * Reconnect this SMBD connection, called from upper layer
1484  * return value: 0 on success, or actual error code
1485  */
1486 int smbd_reconnect(struct TCP_Server_Info *server)
1487 {
1488         log_rdma_event(INFO, "reconnecting rdma session\n");
1489
1490         if (!server->smbd_conn) {
1491                 log_rdma_event(INFO, "rdma session already destroyed\n");
1492                 goto create_conn;
1493         }
1494
1495         /*
1496          * This is possible if transport is disconnected and we haven't received
1497          * notification from RDMA, but upper layer has detected timeout
1498          */
1499         if (server->smbd_conn->transport_status == SMBD_CONNECTED) {
1500                 log_rdma_event(INFO, "disconnecting transport\n");
1501                 smbd_destroy(server);
1502         }
1503
1504 create_conn:
1505         log_rdma_event(INFO, "creating rdma session\n");
1506         server->smbd_conn = smbd_get_connection(
1507                 server, (struct sockaddr *) &server->dstaddr);
1508         log_rdma_event(INFO, "created rdma session info=%p\n",
1509                 server->smbd_conn);
1510
1511         return server->smbd_conn ? 0 : -ENOENT;
1512 }
1513
1514 static void destroy_caches_and_workqueue(struct smbd_connection *info)
1515 {
1516         destroy_receive_buffers(info);
1517         destroy_workqueue(info->workqueue);
1518         mempool_destroy(info->response_mempool);
1519         kmem_cache_destroy(info->response_cache);
1520         mempool_destroy(info->request_mempool);
1521         kmem_cache_destroy(info->request_cache);
1522 }
1523
1524 #define MAX_NAME_LEN    80
1525 static int allocate_caches_and_workqueue(struct smbd_connection *info)
1526 {
1527         char name[MAX_NAME_LEN];
1528         int rc;
1529
1530         scnprintf(name, MAX_NAME_LEN, "smbd_request_%p", info);
1531         info->request_cache =
1532                 kmem_cache_create(
1533                         name,
1534                         sizeof(struct smbd_request) +
1535                                 sizeof(struct smbd_data_transfer),
1536                         0, SLAB_HWCACHE_ALIGN, NULL);
1537         if (!info->request_cache)
1538                 return -ENOMEM;
1539
1540         info->request_mempool =
1541                 mempool_create(info->send_credit_target, mempool_alloc_slab,
1542                         mempool_free_slab, info->request_cache);
1543         if (!info->request_mempool)
1544                 goto out1;
1545
1546         scnprintf(name, MAX_NAME_LEN, "smbd_response_%p", info);
1547         info->response_cache =
1548                 kmem_cache_create(
1549                         name,
1550                         sizeof(struct smbd_response) +
1551                                 info->max_receive_size,
1552                         0, SLAB_HWCACHE_ALIGN, NULL);
1553         if (!info->response_cache)
1554                 goto out2;
1555
1556         info->response_mempool =
1557                 mempool_create(info->receive_credit_max, mempool_alloc_slab,
1558                        mempool_free_slab, info->response_cache);
1559         if (!info->response_mempool)
1560                 goto out3;
1561
1562         scnprintf(name, MAX_NAME_LEN, "smbd_%p", info);
1563         info->workqueue = create_workqueue(name);
1564         if (!info->workqueue)
1565                 goto out4;
1566
1567         rc = allocate_receive_buffers(info, info->receive_credit_max);
1568         if (rc) {
1569                 log_rdma_event(ERR, "failed to allocate receive buffers\n");
1570                 goto out5;
1571         }
1572
1573         return 0;
1574
1575 out5:
1576         destroy_workqueue(info->workqueue);
1577 out4:
1578         mempool_destroy(info->response_mempool);
1579 out3:
1580         kmem_cache_destroy(info->response_cache);
1581 out2:
1582         mempool_destroy(info->request_mempool);
1583 out1:
1584         kmem_cache_destroy(info->request_cache);
1585         return -ENOMEM;
1586 }
1587
1588 /* Create a SMBD connection, called by upper layer */
1589 static struct smbd_connection *_smbd_get_connection(
1590         struct TCP_Server_Info *server, struct sockaddr *dstaddr, int port)
1591 {
1592         int rc;
1593         struct smbd_connection *info;
1594         struct rdma_conn_param conn_param;
1595         struct ib_qp_init_attr qp_attr;
1596         struct sockaddr_in *addr_in = (struct sockaddr_in *) dstaddr;
1597         struct ib_port_immutable port_immutable;
1598         u32 ird_ord_hdr[2];
1599
1600         info = kzalloc(sizeof(struct smbd_connection), GFP_KERNEL);
1601         if (!info)
1602                 return NULL;
1603
1604         info->transport_status = SMBD_CONNECTING;
1605         rc = smbd_ia_open(info, dstaddr, port);
1606         if (rc) {
1607                 log_rdma_event(INFO, "smbd_ia_open rc=%d\n", rc);
1608                 goto create_id_failed;
1609         }
1610
1611         if (smbd_send_credit_target > info->id->device->attrs.max_cqe ||
1612             smbd_send_credit_target > info->id->device->attrs.max_qp_wr) {
1613                 log_rdma_event(ERR,
1614                         "consider lowering send_credit_target = %d. "
1615                         "Possible CQE overrun, device "
1616                         "reporting max_cpe %d max_qp_wr %d\n",
1617                         smbd_send_credit_target,
1618                         info->id->device->attrs.max_cqe,
1619                         info->id->device->attrs.max_qp_wr);
1620                 goto config_failed;
1621         }
1622
1623         if (smbd_receive_credit_max > info->id->device->attrs.max_cqe ||
1624             smbd_receive_credit_max > info->id->device->attrs.max_qp_wr) {
1625                 log_rdma_event(ERR,
1626                         "consider lowering receive_credit_max = %d. "
1627                         "Possible CQE overrun, device "
1628                         "reporting max_cpe %d max_qp_wr %d\n",
1629                         smbd_receive_credit_max,
1630                         info->id->device->attrs.max_cqe,
1631                         info->id->device->attrs.max_qp_wr);
1632                 goto config_failed;
1633         }
1634
1635         info->receive_credit_max = smbd_receive_credit_max;
1636         info->send_credit_target = smbd_send_credit_target;
1637         info->max_send_size = smbd_max_send_size;
1638         info->max_fragmented_recv_size = smbd_max_fragmented_recv_size;
1639         info->max_receive_size = smbd_max_receive_size;
1640         info->keep_alive_interval = smbd_keep_alive_interval;
1641
1642         if (info->id->device->attrs.max_send_sge < SMBDIRECT_MAX_SGE) {
1643                 log_rdma_event(ERR,
1644                         "warning: device max_send_sge = %d too small\n",
1645                         info->id->device->attrs.max_send_sge);
1646                 log_rdma_event(ERR, "Queue Pair creation may fail\n");
1647         }
1648         if (info->id->device->attrs.max_recv_sge < SMBDIRECT_MAX_SGE) {
1649                 log_rdma_event(ERR,
1650                         "warning: device max_recv_sge = %d too small\n",
1651                         info->id->device->attrs.max_recv_sge);
1652                 log_rdma_event(ERR, "Queue Pair creation may fail\n");
1653         }
1654
1655         info->send_cq = NULL;
1656         info->recv_cq = NULL;
1657         info->send_cq = ib_alloc_cq(info->id->device, info,
1658                         info->send_credit_target, 0, IB_POLL_SOFTIRQ);
1659         if (IS_ERR(info->send_cq)) {
1660                 info->send_cq = NULL;
1661                 goto alloc_cq_failed;
1662         }
1663
1664         info->recv_cq = ib_alloc_cq(info->id->device, info,
1665                         info->receive_credit_max, 0, IB_POLL_SOFTIRQ);
1666         if (IS_ERR(info->recv_cq)) {
1667                 info->recv_cq = NULL;
1668                 goto alloc_cq_failed;
1669         }
1670
1671         memset(&qp_attr, 0, sizeof(qp_attr));
1672         qp_attr.event_handler = smbd_qp_async_error_upcall;
1673         qp_attr.qp_context = info;
1674         qp_attr.cap.max_send_wr = info->send_credit_target;
1675         qp_attr.cap.max_recv_wr = info->receive_credit_max;
1676         qp_attr.cap.max_send_sge = SMBDIRECT_MAX_SGE;
1677         qp_attr.cap.max_recv_sge = SMBDIRECT_MAX_SGE;
1678         qp_attr.cap.max_inline_data = 0;
1679         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
1680         qp_attr.qp_type = IB_QPT_RC;
1681         qp_attr.send_cq = info->send_cq;
1682         qp_attr.recv_cq = info->recv_cq;
1683         qp_attr.port_num = ~0;
1684
1685         rc = rdma_create_qp(info->id, info->pd, &qp_attr);
1686         if (rc) {
1687                 log_rdma_event(ERR, "rdma_create_qp failed %i\n", rc);
1688                 goto create_qp_failed;
1689         }
1690
1691         memset(&conn_param, 0, sizeof(conn_param));
1692         conn_param.initiator_depth = 0;
1693
1694         conn_param.responder_resources =
1695                 info->id->device->attrs.max_qp_rd_atom
1696                         < SMBD_CM_RESPONDER_RESOURCES ?
1697                 info->id->device->attrs.max_qp_rd_atom :
1698                 SMBD_CM_RESPONDER_RESOURCES;
1699         info->responder_resources = conn_param.responder_resources;
1700         log_rdma_mr(INFO, "responder_resources=%d\n",
1701                 info->responder_resources);
1702
1703         /* Need to send IRD/ORD in private data for iWARP */
1704         info->id->device->ops.get_port_immutable(
1705                 info->id->device, info->id->port_num, &port_immutable);
1706         if (port_immutable.core_cap_flags & RDMA_CORE_PORT_IWARP) {
1707                 ird_ord_hdr[0] = info->responder_resources;
1708                 ird_ord_hdr[1] = 1;
1709                 conn_param.private_data = ird_ord_hdr;
1710                 conn_param.private_data_len = sizeof(ird_ord_hdr);
1711         } else {
1712                 conn_param.private_data = NULL;
1713                 conn_param.private_data_len = 0;
1714         }
1715
1716         conn_param.retry_count = SMBD_CM_RETRY;
1717         conn_param.rnr_retry_count = SMBD_CM_RNR_RETRY;
1718         conn_param.flow_control = 0;
1719
1720         log_rdma_event(INFO, "connecting to IP %pI4 port %d\n",
1721                 &addr_in->sin_addr, port);
1722
1723         init_waitqueue_head(&info->conn_wait);
1724         init_waitqueue_head(&info->disconn_wait);
1725         init_waitqueue_head(&info->wait_reassembly_queue);
1726         rc = rdma_connect(info->id, &conn_param);
1727         if (rc) {
1728                 log_rdma_event(ERR, "rdma_connect() failed with %i\n", rc);
1729                 goto rdma_connect_failed;
1730         }
1731
1732         wait_event_interruptible(
1733                 info->conn_wait, info->transport_status != SMBD_CONNECTING);
1734
1735         if (info->transport_status != SMBD_CONNECTED) {
1736                 log_rdma_event(ERR, "rdma_connect failed port=%d\n", port);
1737                 goto rdma_connect_failed;
1738         }
1739
1740         log_rdma_event(INFO, "rdma_connect connected\n");
1741
1742         rc = allocate_caches_and_workqueue(info);
1743         if (rc) {
1744                 log_rdma_event(ERR, "cache allocation failed\n");
1745                 goto allocate_cache_failed;
1746         }
1747
1748         init_waitqueue_head(&info->wait_send_queue);
1749         INIT_DELAYED_WORK(&info->idle_timer_work, idle_connection_timer);
1750         INIT_DELAYED_WORK(&info->send_immediate_work, send_immediate_work);
1751         queue_delayed_work(info->workqueue, &info->idle_timer_work,
1752                 info->keep_alive_interval*HZ);
1753
1754         init_waitqueue_head(&info->wait_send_pending);
1755         atomic_set(&info->send_pending, 0);
1756
1757         init_waitqueue_head(&info->wait_send_payload_pending);
1758         atomic_set(&info->send_payload_pending, 0);
1759
1760         INIT_WORK(&info->disconnect_work, smbd_disconnect_rdma_work);
1761         INIT_WORK(&info->recv_done_work, smbd_recv_done_work);
1762         INIT_WORK(&info->post_send_credits_work, smbd_post_send_credits);
1763         info->new_credits_offered = 0;
1764         spin_lock_init(&info->lock_new_credits_offered);
1765
1766         rc = smbd_negotiate(info);
1767         if (rc) {
1768                 log_rdma_event(ERR, "smbd_negotiate rc=%d\n", rc);
1769                 goto negotiation_failed;
1770         }
1771
1772         rc = allocate_mr_list(info);
1773         if (rc) {
1774                 log_rdma_mr(ERR, "memory registration allocation failed\n");
1775                 goto allocate_mr_failed;
1776         }
1777
1778         return info;
1779
1780 allocate_mr_failed:
1781         /* At this point, need to a full transport shutdown */
1782         smbd_destroy(server);
1783         return NULL;
1784
1785 negotiation_failed:
1786         cancel_delayed_work_sync(&info->idle_timer_work);
1787         destroy_caches_and_workqueue(info);
1788         info->transport_status = SMBD_NEGOTIATE_FAILED;
1789         init_waitqueue_head(&info->conn_wait);
1790         rdma_disconnect(info->id);
1791         wait_event(info->conn_wait,
1792                 info->transport_status == SMBD_DISCONNECTED);
1793
1794 allocate_cache_failed:
1795 rdma_connect_failed:
1796         rdma_destroy_qp(info->id);
1797
1798 create_qp_failed:
1799 alloc_cq_failed:
1800         if (info->send_cq)
1801                 ib_free_cq(info->send_cq);
1802         if (info->recv_cq)
1803                 ib_free_cq(info->recv_cq);
1804
1805 config_failed:
1806         ib_dealloc_pd(info->pd);
1807         rdma_destroy_id(info->id);
1808
1809 create_id_failed:
1810         kfree(info);
1811         return NULL;
1812 }
1813
1814 struct smbd_connection *smbd_get_connection(
1815         struct TCP_Server_Info *server, struct sockaddr *dstaddr)
1816 {
1817         struct smbd_connection *ret;
1818         int port = SMBD_PORT;
1819
1820 try_again:
1821         ret = _smbd_get_connection(server, dstaddr, port);
1822
1823         /* Try SMB_PORT if SMBD_PORT doesn't work */
1824         if (!ret && port == SMBD_PORT) {
1825                 port = SMB_PORT;
1826                 goto try_again;
1827         }
1828         return ret;
1829 }
1830
1831 /*
1832  * Receive data from receive reassembly queue
1833  * All the incoming data packets are placed in reassembly queue
1834  * buf: the buffer to read data into
1835  * size: the length of data to read
1836  * return value: actual data read
1837  * Note: this implementation copies the data from reassebmly queue to receive
1838  * buffers used by upper layer. This is not the optimal code path. A better way
1839  * to do it is to not have upper layer allocate its receive buffers but rather
1840  * borrow the buffer from reassembly queue, and return it after data is
1841  * consumed. But this will require more changes to upper layer code, and also
1842  * need to consider packet boundaries while they still being reassembled.
1843  */
1844 static int smbd_recv_buf(struct smbd_connection *info, char *buf,
1845                 unsigned int size)
1846 {
1847         struct smbd_response *response;
1848         struct smbd_data_transfer *data_transfer;
1849         int to_copy, to_read, data_read, offset;
1850         u32 data_length, remaining_data_length, data_offset;
1851         int rc;
1852
1853 again:
1854         /*
1855          * No need to hold the reassembly queue lock all the time as we are
1856          * the only one reading from the front of the queue. The transport
1857          * may add more entries to the back of the queue at the same time
1858          */
1859         log_read(INFO, "size=%d info->reassembly_data_length=%d\n", size,
1860                 info->reassembly_data_length);
1861         if (info->reassembly_data_length >= size) {
1862                 int queue_length;
1863                 int queue_removed = 0;
1864
1865                 /*
1866                  * Need to make sure reassembly_data_length is read before
1867                  * reading reassembly_queue_length and calling
1868                  * _get_first_reassembly. This call is lock free
1869                  * as we never read at the end of the queue which are being
1870                  * updated in SOFTIRQ as more data is received
1871                  */
1872                 virt_rmb();
1873                 queue_length = info->reassembly_queue_length;
1874                 data_read = 0;
1875                 to_read = size;
1876                 offset = info->first_entry_offset;
1877                 while (data_read < size) {
1878                         response = _get_first_reassembly(info);
1879                         data_transfer = smbd_response_payload(response);
1880                         data_length = le32_to_cpu(data_transfer->data_length);
1881                         remaining_data_length =
1882                                 le32_to_cpu(
1883                                         data_transfer->remaining_data_length);
1884                         data_offset = le32_to_cpu(data_transfer->data_offset);
1885
1886                         /*
1887                          * The upper layer expects RFC1002 length at the
1888                          * beginning of the payload. Return it to indicate
1889                          * the total length of the packet. This minimize the
1890                          * change to upper layer packet processing logic. This
1891                          * will be eventually remove when an intermediate
1892                          * transport layer is added
1893                          */
1894                         if (response->first_segment && size == 4) {
1895                                 unsigned int rfc1002_len =
1896                                         data_length + remaining_data_length;
1897                                 *((__be32 *)buf) = cpu_to_be32(rfc1002_len);
1898                                 data_read = 4;
1899                                 response->first_segment = false;
1900                                 log_read(INFO, "returning rfc1002 length %d\n",
1901                                         rfc1002_len);
1902                                 goto read_rfc1002_done;
1903                         }
1904
1905                         to_copy = min_t(int, data_length - offset, to_read);
1906                         memcpy(
1907                                 buf + data_read,
1908                                 (char *)data_transfer + data_offset + offset,
1909                                 to_copy);
1910
1911                         /* move on to the next buffer? */
1912                         if (to_copy == data_length - offset) {
1913                                 queue_length--;
1914                                 /*
1915                                  * No need to lock if we are not at the
1916                                  * end of the queue
1917                                  */
1918                                 if (queue_length)
1919                                         list_del(&response->list);
1920                                 else {
1921                                         spin_lock_irq(
1922                                                 &info->reassembly_queue_lock);
1923                                         list_del(&response->list);
1924                                         spin_unlock_irq(
1925                                                 &info->reassembly_queue_lock);
1926                                 }
1927                                 queue_removed++;
1928                                 info->count_reassembly_queue--;
1929                                 info->count_dequeue_reassembly_queue++;
1930                                 put_receive_buffer(info, response);
1931                                 offset = 0;
1932                                 log_read(INFO, "put_receive_buffer offset=0\n");
1933                         } else
1934                                 offset += to_copy;
1935
1936                         to_read -= to_copy;
1937                         data_read += to_copy;
1938
1939                         log_read(INFO, "_get_first_reassembly memcpy %d bytes "
1940                                 "data_transfer_length-offset=%d after that "
1941                                 "to_read=%d data_read=%d offset=%d\n",
1942                                 to_copy, data_length - offset,
1943                                 to_read, data_read, offset);
1944                 }
1945
1946                 spin_lock_irq(&info->reassembly_queue_lock);
1947                 info->reassembly_data_length -= data_read;
1948                 info->reassembly_queue_length -= queue_removed;
1949                 spin_unlock_irq(&info->reassembly_queue_lock);
1950
1951                 info->first_entry_offset = offset;
1952                 log_read(INFO, "returning to thread data_read=%d "
1953                         "reassembly_data_length=%d first_entry_offset=%d\n",
1954                         data_read, info->reassembly_data_length,
1955                         info->first_entry_offset);
1956 read_rfc1002_done:
1957                 return data_read;
1958         }
1959
1960         log_read(INFO, "wait_event on more data\n");
1961         rc = wait_event_interruptible(
1962                 info->wait_reassembly_queue,
1963                 info->reassembly_data_length >= size ||
1964                         info->transport_status != SMBD_CONNECTED);
1965         /* Don't return any data if interrupted */
1966         if (rc)
1967                 return rc;
1968
1969         if (info->transport_status != SMBD_CONNECTED) {
1970                 log_read(ERR, "disconnected\n");
1971                 return 0;
1972         }
1973
1974         goto again;
1975 }
1976
1977 /*
1978  * Receive a page from receive reassembly queue
1979  * page: the page to read data into
1980  * to_read: the length of data to read
1981  * return value: actual data read
1982  */
1983 static int smbd_recv_page(struct smbd_connection *info,
1984                 struct page *page, unsigned int page_offset,
1985                 unsigned int to_read)
1986 {
1987         int ret;
1988         char *to_address;
1989         void *page_address;
1990
1991         /* make sure we have the page ready for read */
1992         ret = wait_event_interruptible(
1993                 info->wait_reassembly_queue,
1994                 info->reassembly_data_length >= to_read ||
1995                         info->transport_status != SMBD_CONNECTED);
1996         if (ret)
1997                 return ret;
1998
1999         /* now we can read from reassembly queue and not sleep */
2000         page_address = kmap_atomic(page);
2001         to_address = (char *) page_address + page_offset;
2002
2003         log_read(INFO, "reading from page=%p address=%p to_read=%d\n",
2004                 page, to_address, to_read);
2005
2006         ret = smbd_recv_buf(info, to_address, to_read);
2007         kunmap_atomic(page_address);
2008
2009         return ret;
2010 }
2011
2012 /*
2013  * Receive data from transport
2014  * msg: a msghdr point to the buffer, can be ITER_KVEC or ITER_BVEC
2015  * return: total bytes read, or 0. SMB Direct will not do partial read.
2016  */
2017 int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
2018 {
2019         char *buf;
2020         struct page *page;
2021         unsigned int to_read, page_offset;
2022         int rc;
2023
2024         if (iov_iter_rw(&msg->msg_iter) == WRITE) {
2025                 /* It's a bug in upper layer to get there */
2026                 cifs_dbg(VFS, "CIFS: invalid msg iter dir %u\n",
2027                          iov_iter_rw(&msg->msg_iter));
2028                 rc = -EINVAL;
2029                 goto out;
2030         }
2031
2032         switch (iov_iter_type(&msg->msg_iter)) {
2033         case ITER_KVEC:
2034                 buf = msg->msg_iter.kvec->iov_base;
2035                 to_read = msg->msg_iter.kvec->iov_len;
2036                 rc = smbd_recv_buf(info, buf, to_read);
2037                 break;
2038
2039         case ITER_BVEC:
2040                 page = msg->msg_iter.bvec->bv_page;
2041                 page_offset = msg->msg_iter.bvec->bv_offset;
2042                 to_read = msg->msg_iter.bvec->bv_len;
2043                 rc = smbd_recv_page(info, page, page_offset, to_read);
2044                 break;
2045
2046         default:
2047                 /* It's a bug in upper layer to get there */
2048                 cifs_dbg(VFS, "CIFS: invalid msg type %d\n",
2049                          iov_iter_type(&msg->msg_iter));
2050                 rc = -EINVAL;
2051         }
2052
2053 out:
2054         /* SMBDirect will read it all or nothing */
2055         if (rc > 0)
2056                 msg->msg_iter.count = 0;
2057         return rc;
2058 }
2059
2060 /*
2061  * Send data to transport
2062  * Each rqst is transported as a SMBDirect payload
2063  * rqst: the data to write
2064  * return value: 0 if successfully write, otherwise error code
2065  */
2066 int smbd_send(struct TCP_Server_Info *server,
2067         int num_rqst, struct smb_rqst *rqst_array)
2068 {
2069         struct smbd_connection *info = server->smbd_conn;
2070         struct kvec vec;
2071         int nvecs;
2072         int size;
2073         unsigned int buflen, remaining_data_length;
2074         int start, i, j;
2075         int max_iov_size =
2076                 info->max_send_size - sizeof(struct smbd_data_transfer);
2077         struct kvec *iov;
2078         int rc;
2079         struct smb_rqst *rqst;
2080         int rqst_idx;
2081
2082         if (info->transport_status != SMBD_CONNECTED) {
2083                 rc = -EAGAIN;
2084                 goto done;
2085         }
2086
2087         /*
2088          * Add in the page array if there is one. The caller needs to set
2089          * rq_tailsz to PAGE_SIZE when the buffer has multiple pages and
2090          * ends at page boundary
2091          */
2092         remaining_data_length = 0;
2093         for (i = 0; i < num_rqst; i++)
2094                 remaining_data_length += smb_rqst_len(server, &rqst_array[i]);
2095
2096         if (remaining_data_length + sizeof(struct smbd_data_transfer) >
2097                 info->max_fragmented_send_size) {
2098                 log_write(ERR, "payload size %d > max size %d\n",
2099                         remaining_data_length, info->max_fragmented_send_size);
2100                 rc = -EINVAL;
2101                 goto done;
2102         }
2103
2104         log_write(INFO, "num_rqst=%d total length=%u\n",
2105                         num_rqst, remaining_data_length);
2106
2107         rqst_idx = 0;
2108 next_rqst:
2109         rqst = &rqst_array[rqst_idx];
2110         iov = rqst->rq_iov;
2111
2112         cifs_dbg(FYI, "Sending smb (RDMA): idx=%d smb_len=%lu\n",
2113                 rqst_idx, smb_rqst_len(server, rqst));
2114         for (i = 0; i < rqst->rq_nvec; i++)
2115                 dump_smb(iov[i].iov_base, iov[i].iov_len);
2116
2117
2118         log_write(INFO, "rqst_idx=%d nvec=%d rqst->rq_npages=%d rq_pagesz=%d "
2119                 "rq_tailsz=%d buflen=%lu\n",
2120                 rqst_idx, rqst->rq_nvec, rqst->rq_npages, rqst->rq_pagesz,
2121                 rqst->rq_tailsz, smb_rqst_len(server, rqst));
2122
2123         start = i = 0;
2124         buflen = 0;
2125         while (true) {
2126                 buflen += iov[i].iov_len;
2127                 if (buflen > max_iov_size) {
2128                         if (i > start) {
2129                                 remaining_data_length -=
2130                                         (buflen-iov[i].iov_len);
2131                                 log_write(INFO, "sending iov[] from start=%d "
2132                                         "i=%d nvecs=%d "
2133                                         "remaining_data_length=%d\n",
2134                                         start, i, i-start,
2135                                         remaining_data_length);
2136                                 rc = smbd_post_send_data(
2137                                         info, &iov[start], i-start,
2138                                         remaining_data_length);
2139                                 if (rc)
2140                                         goto done;
2141                         } else {
2142                                 /* iov[start] is too big, break it */
2143                                 nvecs = (buflen+max_iov_size-1)/max_iov_size;
2144                                 log_write(INFO, "iov[%d] iov_base=%p buflen=%d"
2145                                         " break to %d vectors\n",
2146                                         start, iov[start].iov_base,
2147                                         buflen, nvecs);
2148                                 for (j = 0; j < nvecs; j++) {
2149                                         vec.iov_base =
2150                                                 (char *)iov[start].iov_base +
2151                                                 j*max_iov_size;
2152                                         vec.iov_len = max_iov_size;
2153                                         if (j == nvecs-1)
2154                                                 vec.iov_len =
2155                                                         buflen -
2156                                                         max_iov_size*(nvecs-1);
2157                                         remaining_data_length -= vec.iov_len;
2158                                         log_write(INFO,
2159                                                 "sending vec j=%d iov_base=%p"
2160                                                 " iov_len=%zu "
2161                                                 "remaining_data_length=%d\n",
2162                                                 j, vec.iov_base, vec.iov_len,
2163                                                 remaining_data_length);
2164                                         rc = smbd_post_send_data(
2165                                                 info, &vec, 1,
2166                                                 remaining_data_length);
2167                                         if (rc)
2168                                                 goto done;
2169                                 }
2170                                 i++;
2171                                 if (i == rqst->rq_nvec)
2172                                         break;
2173                         }
2174                         start = i;
2175                         buflen = 0;
2176                 } else {
2177                         i++;
2178                         if (i == rqst->rq_nvec) {
2179                                 /* send out all remaining vecs */
2180                                 remaining_data_length -= buflen;
2181                                 log_write(INFO,
2182                                         "sending iov[] from start=%d i=%d "
2183                                         "nvecs=%d remaining_data_length=%d\n",
2184                                         start, i, i-start,
2185                                         remaining_data_length);
2186                                 rc = smbd_post_send_data(info, &iov[start],
2187                                         i-start, remaining_data_length);
2188                                 if (rc)
2189                                         goto done;
2190                                 break;
2191                         }
2192                 }
2193                 log_write(INFO, "looping i=%d buflen=%d\n", i, buflen);
2194         }
2195
2196         /* now sending pages if there are any */
2197         for (i = 0; i < rqst->rq_npages; i++) {
2198                 unsigned int offset;
2199
2200                 rqst_page_get_length(rqst, i, &buflen, &offset);
2201                 nvecs = (buflen + max_iov_size - 1) / max_iov_size;
2202                 log_write(INFO, "sending pages buflen=%d nvecs=%d\n",
2203                         buflen, nvecs);
2204                 for (j = 0; j < nvecs; j++) {
2205                         size = max_iov_size;
2206                         if (j == nvecs-1)
2207                                 size = buflen - j*max_iov_size;
2208                         remaining_data_length -= size;
2209                         log_write(INFO, "sending pages i=%d offset=%d size=%d"
2210                                 " remaining_data_length=%d\n",
2211                                 i, j*max_iov_size+offset, size,
2212                                 remaining_data_length);
2213                         rc = smbd_post_send_page(
2214                                 info, rqst->rq_pages[i],
2215                                 j*max_iov_size + offset,
2216                                 size, remaining_data_length);
2217                         if (rc)
2218                                 goto done;
2219                 }
2220         }
2221
2222         rqst_idx++;
2223         if (rqst_idx < num_rqst)
2224                 goto next_rqst;
2225
2226 done:
2227         /*
2228          * As an optimization, we don't wait for individual I/O to finish
2229          * before sending the next one.
2230          * Send them all and wait for pending send count to get to 0
2231          * that means all the I/Os have been out and we are good to return
2232          */
2233
2234         wait_event(info->wait_send_payload_pending,
2235                 atomic_read(&info->send_payload_pending) == 0);
2236
2237         return rc;
2238 }
2239
2240 static void register_mr_done(struct ib_cq *cq, struct ib_wc *wc)
2241 {
2242         struct smbd_mr *mr;
2243         struct ib_cqe *cqe;
2244
2245         if (wc->status) {
2246                 log_rdma_mr(ERR, "status=%d\n", wc->status);
2247                 cqe = wc->wr_cqe;
2248                 mr = container_of(cqe, struct smbd_mr, cqe);
2249                 smbd_disconnect_rdma_connection(mr->conn);
2250         }
2251 }
2252
2253 /*
2254  * The work queue function that recovers MRs
2255  * We need to call ib_dereg_mr() and ib_alloc_mr() before this MR can be used
2256  * again. Both calls are slow, so finish them in a workqueue. This will not
2257  * block I/O path.
2258  * There is one workqueue that recovers MRs, there is no need to lock as the
2259  * I/O requests calling smbd_register_mr will never update the links in the
2260  * mr_list.
2261  */
2262 static void smbd_mr_recovery_work(struct work_struct *work)
2263 {
2264         struct smbd_connection *info =
2265                 container_of(work, struct smbd_connection, mr_recovery_work);
2266         struct smbd_mr *smbdirect_mr;
2267         int rc;
2268
2269         list_for_each_entry(smbdirect_mr, &info->mr_list, list) {
2270                 if (smbdirect_mr->state == MR_INVALIDATED)
2271                         ib_dma_unmap_sg(
2272                                 info->id->device, smbdirect_mr->sgl,
2273                                 smbdirect_mr->sgl_count,
2274                                 smbdirect_mr->dir);
2275                 else if (smbdirect_mr->state == MR_ERROR) {
2276
2277                         /* recover this MR entry */
2278                         rc = ib_dereg_mr(smbdirect_mr->mr);
2279                         if (rc) {
2280                                 log_rdma_mr(ERR,
2281                                         "ib_dereg_mr failed rc=%x\n",
2282                                         rc);
2283                                 smbd_disconnect_rdma_connection(info);
2284                                 continue;
2285                         }
2286
2287                         smbdirect_mr->mr = ib_alloc_mr(
2288                                 info->pd, info->mr_type,
2289                                 info->max_frmr_depth);
2290                         if (IS_ERR(smbdirect_mr->mr)) {
2291                                 log_rdma_mr(ERR,
2292                                         "ib_alloc_mr failed mr_type=%x "
2293                                         "max_frmr_depth=%x\n",
2294                                         info->mr_type,
2295                                         info->max_frmr_depth);
2296                                 smbd_disconnect_rdma_connection(info);
2297                                 continue;
2298                         }
2299                 } else
2300                         /* This MR is being used, don't recover it */
2301                         continue;
2302
2303                 smbdirect_mr->state = MR_READY;
2304
2305                 /* smbdirect_mr->state is updated by this function
2306                  * and is read and updated by I/O issuing CPUs trying
2307                  * to get a MR, the call to atomic_inc_return
2308                  * implicates a memory barrier and guarantees this
2309                  * value is updated before waking up any calls to
2310                  * get_mr() from the I/O issuing CPUs
2311                  */
2312                 if (atomic_inc_return(&info->mr_ready_count) == 1)
2313                         wake_up_interruptible(&info->wait_mr);
2314         }
2315 }
2316
2317 static void destroy_mr_list(struct smbd_connection *info)
2318 {
2319         struct smbd_mr *mr, *tmp;
2320
2321         cancel_work_sync(&info->mr_recovery_work);
2322         list_for_each_entry_safe(mr, tmp, &info->mr_list, list) {
2323                 if (mr->state == MR_INVALIDATED)
2324                         ib_dma_unmap_sg(info->id->device, mr->sgl,
2325                                 mr->sgl_count, mr->dir);
2326                 ib_dereg_mr(mr->mr);
2327                 kfree(mr->sgl);
2328                 kfree(mr);
2329         }
2330 }
2331
2332 /*
2333  * Allocate MRs used for RDMA read/write
2334  * The number of MRs will not exceed hardware capability in responder_resources
2335  * All MRs are kept in mr_list. The MR can be recovered after it's used
2336  * Recovery is done in smbd_mr_recovery_work. The content of list entry changes
2337  * as MRs are used and recovered for I/O, but the list links will not change
2338  */
2339 static int allocate_mr_list(struct smbd_connection *info)
2340 {
2341         int i;
2342         struct smbd_mr *smbdirect_mr, *tmp;
2343
2344         INIT_LIST_HEAD(&info->mr_list);
2345         init_waitqueue_head(&info->wait_mr);
2346         spin_lock_init(&info->mr_list_lock);
2347         atomic_set(&info->mr_ready_count, 0);
2348         atomic_set(&info->mr_used_count, 0);
2349         init_waitqueue_head(&info->wait_for_mr_cleanup);
2350         /* Allocate more MRs (2x) than hardware responder_resources */
2351         for (i = 0; i < info->responder_resources * 2; i++) {
2352                 smbdirect_mr = kzalloc(sizeof(*smbdirect_mr), GFP_KERNEL);
2353                 if (!smbdirect_mr)
2354                         goto out;
2355                 smbdirect_mr->mr = ib_alloc_mr(info->pd, info->mr_type,
2356                                         info->max_frmr_depth);
2357                 if (IS_ERR(smbdirect_mr->mr)) {
2358                         log_rdma_mr(ERR, "ib_alloc_mr failed mr_type=%x "
2359                                 "max_frmr_depth=%x\n",
2360                                 info->mr_type, info->max_frmr_depth);
2361                         goto out;
2362                 }
2363                 smbdirect_mr->sgl = kcalloc(
2364                                         info->max_frmr_depth,
2365                                         sizeof(struct scatterlist),
2366                                         GFP_KERNEL);
2367                 if (!smbdirect_mr->sgl) {
2368                         log_rdma_mr(ERR, "failed to allocate sgl\n");
2369                         ib_dereg_mr(smbdirect_mr->mr);
2370                         goto out;
2371                 }
2372                 smbdirect_mr->state = MR_READY;
2373                 smbdirect_mr->conn = info;
2374
2375                 list_add_tail(&smbdirect_mr->list, &info->mr_list);
2376                 atomic_inc(&info->mr_ready_count);
2377         }
2378         INIT_WORK(&info->mr_recovery_work, smbd_mr_recovery_work);
2379         return 0;
2380
2381 out:
2382         kfree(smbdirect_mr);
2383
2384         list_for_each_entry_safe(smbdirect_mr, tmp, &info->mr_list, list) {
2385                 ib_dereg_mr(smbdirect_mr->mr);
2386                 kfree(smbdirect_mr->sgl);
2387                 kfree(smbdirect_mr);
2388         }
2389         return -ENOMEM;
2390 }
2391
2392 /*
2393  * Get a MR from mr_list. This function waits until there is at least one
2394  * MR available in the list. It may access the list while the
2395  * smbd_mr_recovery_work is recovering the MR list. This doesn't need a lock
2396  * as they never modify the same places. However, there may be several CPUs
2397  * issueing I/O trying to get MR at the same time, mr_list_lock is used to
2398  * protect this situation.
2399  */
2400 static struct smbd_mr *get_mr(struct smbd_connection *info)
2401 {
2402         struct smbd_mr *ret;
2403         int rc;
2404 again:
2405         rc = wait_event_interruptible(info->wait_mr,
2406                 atomic_read(&info->mr_ready_count) ||
2407                 info->transport_status != SMBD_CONNECTED);
2408         if (rc) {
2409                 log_rdma_mr(ERR, "wait_event_interruptible rc=%x\n", rc);
2410                 return NULL;
2411         }
2412
2413         if (info->transport_status != SMBD_CONNECTED) {
2414                 log_rdma_mr(ERR, "info->transport_status=%x\n",
2415                         info->transport_status);
2416                 return NULL;
2417         }
2418
2419         spin_lock(&info->mr_list_lock);
2420         list_for_each_entry(ret, &info->mr_list, list) {
2421                 if (ret->state == MR_READY) {
2422                         ret->state = MR_REGISTERED;
2423                         spin_unlock(&info->mr_list_lock);
2424                         atomic_dec(&info->mr_ready_count);
2425                         atomic_inc(&info->mr_used_count);
2426                         return ret;
2427                 }
2428         }
2429
2430         spin_unlock(&info->mr_list_lock);
2431         /*
2432          * It is possible that we could fail to get MR because other processes may
2433          * try to acquire a MR at the same time. If this is the case, retry it.
2434          */
2435         goto again;
2436 }
2437
2438 /*
2439  * Register memory for RDMA read/write
2440  * pages[]: the list of pages to register memory with
2441  * num_pages: the number of pages to register
2442  * tailsz: if non-zero, the bytes to register in the last page
2443  * writing: true if this is a RDMA write (SMB read), false for RDMA read
2444  * need_invalidate: true if this MR needs to be locally invalidated after I/O
2445  * return value: the MR registered, NULL if failed.
2446  */
2447 struct smbd_mr *smbd_register_mr(
2448         struct smbd_connection *info, struct page *pages[], int num_pages,
2449         int offset, int tailsz, bool writing, bool need_invalidate)
2450 {
2451         struct smbd_mr *smbdirect_mr;
2452         int rc, i;
2453         enum dma_data_direction dir;
2454         struct ib_reg_wr *reg_wr;
2455
2456         if (num_pages > info->max_frmr_depth) {
2457                 log_rdma_mr(ERR, "num_pages=%d max_frmr_depth=%d\n",
2458                         num_pages, info->max_frmr_depth);
2459                 return NULL;
2460         }
2461
2462         smbdirect_mr = get_mr(info);
2463         if (!smbdirect_mr) {
2464                 log_rdma_mr(ERR, "get_mr returning NULL\n");
2465                 return NULL;
2466         }
2467         smbdirect_mr->need_invalidate = need_invalidate;
2468         smbdirect_mr->sgl_count = num_pages;
2469         sg_init_table(smbdirect_mr->sgl, num_pages);
2470
2471         log_rdma_mr(INFO, "num_pages=0x%x offset=0x%x tailsz=0x%x\n",
2472                         num_pages, offset, tailsz);
2473
2474         if (num_pages == 1) {
2475                 sg_set_page(&smbdirect_mr->sgl[0], pages[0], tailsz, offset);
2476                 goto skip_multiple_pages;
2477         }
2478
2479         /* We have at least two pages to register */
2480         sg_set_page(
2481                 &smbdirect_mr->sgl[0], pages[0], PAGE_SIZE - offset, offset);
2482         i = 1;
2483         while (i < num_pages - 1) {
2484                 sg_set_page(&smbdirect_mr->sgl[i], pages[i], PAGE_SIZE, 0);
2485                 i++;
2486         }
2487         sg_set_page(&smbdirect_mr->sgl[i], pages[i],
2488                 tailsz ? tailsz : PAGE_SIZE, 0);
2489
2490 skip_multiple_pages:
2491         dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2492         smbdirect_mr->dir = dir;
2493         rc = ib_dma_map_sg(info->id->device, smbdirect_mr->sgl, num_pages, dir);
2494         if (!rc) {
2495                 log_rdma_mr(ERR, "ib_dma_map_sg num_pages=%x dir=%x rc=%x\n",
2496                         num_pages, dir, rc);
2497                 goto dma_map_error;
2498         }
2499
2500         rc = ib_map_mr_sg(smbdirect_mr->mr, smbdirect_mr->sgl, num_pages,
2501                 NULL, PAGE_SIZE);
2502         if (rc != num_pages) {
2503                 log_rdma_mr(ERR,
2504                         "ib_map_mr_sg failed rc = %d num_pages = %x\n",
2505                         rc, num_pages);
2506                 goto map_mr_error;
2507         }
2508
2509         ib_update_fast_reg_key(smbdirect_mr->mr,
2510                 ib_inc_rkey(smbdirect_mr->mr->rkey));
2511         reg_wr = &smbdirect_mr->wr;
2512         reg_wr->wr.opcode = IB_WR_REG_MR;
2513         smbdirect_mr->cqe.done = register_mr_done;
2514         reg_wr->wr.wr_cqe = &smbdirect_mr->cqe;
2515         reg_wr->wr.num_sge = 0;
2516         reg_wr->wr.send_flags = IB_SEND_SIGNALED;
2517         reg_wr->mr = smbdirect_mr->mr;
2518         reg_wr->key = smbdirect_mr->mr->rkey;
2519         reg_wr->access = writing ?
2520                         IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
2521                         IB_ACCESS_REMOTE_READ;
2522
2523         /*
2524          * There is no need for waiting for complemtion on ib_post_send
2525          * on IB_WR_REG_MR. Hardware enforces a barrier and order of execution
2526          * on the next ib_post_send when we actaully send I/O to remote peer
2527          */
2528         rc = ib_post_send(info->id->qp, &reg_wr->wr, NULL);
2529         if (!rc)
2530                 return smbdirect_mr;
2531
2532         log_rdma_mr(ERR, "ib_post_send failed rc=%x reg_wr->key=%x\n",
2533                 rc, reg_wr->key);
2534
2535         /* If all failed, attempt to recover this MR by setting it MR_ERROR*/
2536 map_mr_error:
2537         ib_dma_unmap_sg(info->id->device, smbdirect_mr->sgl,
2538                 smbdirect_mr->sgl_count, smbdirect_mr->dir);
2539
2540 dma_map_error:
2541         smbdirect_mr->state = MR_ERROR;
2542         if (atomic_dec_and_test(&info->mr_used_count))
2543                 wake_up(&info->wait_for_mr_cleanup);
2544
2545         smbd_disconnect_rdma_connection(info);
2546
2547         return NULL;
2548 }
2549
2550 static void local_inv_done(struct ib_cq *cq, struct ib_wc *wc)
2551 {
2552         struct smbd_mr *smbdirect_mr;
2553         struct ib_cqe *cqe;
2554
2555         cqe = wc->wr_cqe;
2556         smbdirect_mr = container_of(cqe, struct smbd_mr, cqe);
2557         smbdirect_mr->state = MR_INVALIDATED;
2558         if (wc->status != IB_WC_SUCCESS) {
2559                 log_rdma_mr(ERR, "invalidate failed status=%x\n", wc->status);
2560                 smbdirect_mr->state = MR_ERROR;
2561         }
2562         complete(&smbdirect_mr->invalidate_done);
2563 }
2564
2565 /*
2566  * Deregister a MR after I/O is done
2567  * This function may wait if remote invalidation is not used
2568  * and we have to locally invalidate the buffer to prevent data is being
2569  * modified by remote peer after upper layer consumes it
2570  */
2571 int smbd_deregister_mr(struct smbd_mr *smbdirect_mr)
2572 {
2573         struct ib_send_wr *wr;
2574         struct smbd_connection *info = smbdirect_mr->conn;
2575         int rc = 0;
2576
2577         if (smbdirect_mr->need_invalidate) {
2578                 /* Need to finish local invalidation before returning */
2579                 wr = &smbdirect_mr->inv_wr;
2580                 wr->opcode = IB_WR_LOCAL_INV;
2581                 smbdirect_mr->cqe.done = local_inv_done;
2582                 wr->wr_cqe = &smbdirect_mr->cqe;
2583                 wr->num_sge = 0;
2584                 wr->ex.invalidate_rkey = smbdirect_mr->mr->rkey;
2585                 wr->send_flags = IB_SEND_SIGNALED;
2586
2587                 init_completion(&smbdirect_mr->invalidate_done);
2588                 rc = ib_post_send(info->id->qp, wr, NULL);
2589                 if (rc) {
2590                         log_rdma_mr(ERR, "ib_post_send failed rc=%x\n", rc);
2591                         smbd_disconnect_rdma_connection(info);
2592                         goto done;
2593                 }
2594                 wait_for_completion(&smbdirect_mr->invalidate_done);
2595                 smbdirect_mr->need_invalidate = false;
2596         } else
2597                 /*
2598                  * For remote invalidation, just set it to MR_INVALIDATED
2599                  * and defer to mr_recovery_work to recover the MR for next use
2600                  */
2601                 smbdirect_mr->state = MR_INVALIDATED;
2602
2603         /*
2604          * Schedule the work to do MR recovery for future I/Os
2605          * MR recovery is slow and we don't want it to block the current I/O
2606          */
2607         queue_work(info->workqueue, &info->mr_recovery_work);
2608
2609 done:
2610         if (atomic_dec_and_test(&info->mr_used_count))
2611                 wake_up(&info->wait_for_mr_cleanup);
2612
2613         return rc;
2614 }