xref: /openbmc/linux/drivers/nvme/target/tcp.c (revision 92c005a1)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * NVMe over Fabrics TCP target.
4  * Copyright (c) 2018 Lightbits Labs. All rights reserved.
5  */
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/err.h>
11 #include <linux/nvme-tcp.h>
12 #include <net/sock.h>
13 #include <net/tcp.h>
14 #include <linux/inet.h>
15 #include <linux/llist.h>
16 #include <crypto/hash.h>
17 
18 #include "nvmet.h"
19 
20 #define NVMET_TCP_DEF_INLINE_DATA_SIZE	(4 * PAGE_SIZE)
21 
22 /* Define the socket priority to use for connections were it is desirable
23  * that the NIC consider performing optimized packet processing or filtering.
24  * A non-zero value being sufficient to indicate general consideration of any
25  * possible optimization.  Making it a module param allows for alternative
26  * values that may be unique for some NIC implementations.
27  */
28 static int so_priority;
29 module_param(so_priority, int, 0644);
30 MODULE_PARM_DESC(so_priority, "nvmet tcp socket optimize priority");
31 
32 /* Define a time period (in usecs) that io_work() shall sample an activated
33  * queue before determining it to be idle.  This optional module behavior
34  * can enable NIC solutions that support socket optimized packet processing
35  * using advanced interrupt moderation techniques.
36  */
37 static int idle_poll_period_usecs;
38 module_param(idle_poll_period_usecs, int, 0644);
39 MODULE_PARM_DESC(idle_poll_period_usecs,
40 		"nvmet tcp io_work poll till idle time period in usecs");
41 
42 #define NVMET_TCP_RECV_BUDGET		8
43 #define NVMET_TCP_SEND_BUDGET		8
44 #define NVMET_TCP_IO_WORK_BUDGET	64
45 
46 enum nvmet_tcp_send_state {
47 	NVMET_TCP_SEND_DATA_PDU,
48 	NVMET_TCP_SEND_DATA,
49 	NVMET_TCP_SEND_R2T,
50 	NVMET_TCP_SEND_DDGST,
51 	NVMET_TCP_SEND_RESPONSE
52 };
53 
54 enum nvmet_tcp_recv_state {
55 	NVMET_TCP_RECV_PDU,
56 	NVMET_TCP_RECV_DATA,
57 	NVMET_TCP_RECV_DDGST,
58 	NVMET_TCP_RECV_ERR,
59 };
60 
61 enum {
62 	NVMET_TCP_F_INIT_FAILED = (1 << 0),
63 };
64 
65 struct nvmet_tcp_cmd {
66 	struct nvmet_tcp_queue		*queue;
67 	struct nvmet_req		req;
68 
69 	struct nvme_tcp_cmd_pdu		*cmd_pdu;
70 	struct nvme_tcp_rsp_pdu		*rsp_pdu;
71 	struct nvme_tcp_data_pdu	*data_pdu;
72 	struct nvme_tcp_r2t_pdu		*r2t_pdu;
73 
74 	u32				rbytes_done;
75 	u32				wbytes_done;
76 
77 	u32				pdu_len;
78 	u32				pdu_recv;
79 	int				sg_idx;
80 	int				nr_mapped;
81 	struct msghdr			recv_msg;
82 	struct kvec			*iov;
83 	u32				flags;
84 
85 	struct list_head		entry;
86 	struct llist_node		lentry;
87 
88 	/* send state */
89 	u32				offset;
90 	struct scatterlist		*cur_sg;
91 	enum nvmet_tcp_send_state	state;
92 
93 	__le32				exp_ddgst;
94 	__le32				recv_ddgst;
95 };
96 
97 enum nvmet_tcp_queue_state {
98 	NVMET_TCP_Q_CONNECTING,
99 	NVMET_TCP_Q_LIVE,
100 	NVMET_TCP_Q_DISCONNECTING,
101 };
102 
103 struct nvmet_tcp_queue {
104 	struct socket		*sock;
105 	struct nvmet_tcp_port	*port;
106 	struct work_struct	io_work;
107 	struct nvmet_cq		nvme_cq;
108 	struct nvmet_sq		nvme_sq;
109 
110 	/* send state */
111 	struct nvmet_tcp_cmd	*cmds;
112 	unsigned int		nr_cmds;
113 	struct list_head	free_list;
114 	struct llist_head	resp_list;
115 	struct list_head	resp_send_list;
116 	int			send_list_len;
117 	struct nvmet_tcp_cmd	*snd_cmd;
118 
119 	/* recv state */
120 	int			offset;
121 	int			left;
122 	enum nvmet_tcp_recv_state rcv_state;
123 	struct nvmet_tcp_cmd	*cmd;
124 	union nvme_tcp_pdu	pdu;
125 
126 	/* digest state */
127 	bool			hdr_digest;
128 	bool			data_digest;
129 	struct ahash_request	*snd_hash;
130 	struct ahash_request	*rcv_hash;
131 
132 	unsigned long           poll_end;
133 
134 	spinlock_t		state_lock;
135 	enum nvmet_tcp_queue_state state;
136 
137 	struct sockaddr_storage	sockaddr;
138 	struct sockaddr_storage	sockaddr_peer;
139 	struct work_struct	release_work;
140 
141 	int			idx;
142 	struct list_head	queue_list;
143 
144 	struct nvmet_tcp_cmd	connect;
145 
146 	struct page_frag_cache	pf_cache;
147 
148 	void (*data_ready)(struct sock *);
149 	void (*state_change)(struct sock *);
150 	void (*write_space)(struct sock *);
151 };
152 
153 struct nvmet_tcp_port {
154 	struct socket		*sock;
155 	struct work_struct	accept_work;
156 	struct nvmet_port	*nport;
157 	struct sockaddr_storage addr;
158 	void (*data_ready)(struct sock *);
159 };
160 
161 static DEFINE_IDA(nvmet_tcp_queue_ida);
162 static LIST_HEAD(nvmet_tcp_queue_list);
163 static DEFINE_MUTEX(nvmet_tcp_queue_mutex);
164 
165 static struct workqueue_struct *nvmet_tcp_wq;
166 static const struct nvmet_fabrics_ops nvmet_tcp_ops;
167 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
168 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd);
169 static void nvmet_tcp_free_cmd_buffers(struct nvmet_tcp_cmd *cmd);
170 static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd);
171 
172 static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue,
173 		struct nvmet_tcp_cmd *cmd)
174 {
175 	if (unlikely(!queue->nr_cmds)) {
176 		/* We didn't allocate cmds yet, send 0xffff */
177 		return USHRT_MAX;
178 	}
179 
180 	return cmd - queue->cmds;
181 }
182 
183 static inline bool nvmet_tcp_has_data_in(struct nvmet_tcp_cmd *cmd)
184 {
185 	return nvme_is_write(cmd->req.cmd) &&
186 		cmd->rbytes_done < cmd->req.transfer_len;
187 }
188 
189 static inline bool nvmet_tcp_need_data_in(struct nvmet_tcp_cmd *cmd)
190 {
191 	return nvmet_tcp_has_data_in(cmd) && !cmd->req.cqe->status;
192 }
193 
194 static inline bool nvmet_tcp_need_data_out(struct nvmet_tcp_cmd *cmd)
195 {
196 	return !nvme_is_write(cmd->req.cmd) &&
197 		cmd->req.transfer_len > 0 &&
198 		!cmd->req.cqe->status;
199 }
200 
201 static inline bool nvmet_tcp_has_inline_data(struct nvmet_tcp_cmd *cmd)
202 {
203 	return nvme_is_write(cmd->req.cmd) && cmd->pdu_len &&
204 		!cmd->rbytes_done;
205 }
206 
207 static inline struct nvmet_tcp_cmd *
208 nvmet_tcp_get_cmd(struct nvmet_tcp_queue *queue)
209 {
210 	struct nvmet_tcp_cmd *cmd;
211 
212 	cmd = list_first_entry_or_null(&queue->free_list,
213 				struct nvmet_tcp_cmd, entry);
214 	if (!cmd)
215 		return NULL;
216 	list_del_init(&cmd->entry);
217 
218 	cmd->rbytes_done = cmd->wbytes_done = 0;
219 	cmd->pdu_len = 0;
220 	cmd->pdu_recv = 0;
221 	cmd->iov = NULL;
222 	cmd->flags = 0;
223 	return cmd;
224 }
225 
226 static inline void nvmet_tcp_put_cmd(struct nvmet_tcp_cmd *cmd)
227 {
228 	if (unlikely(cmd == &cmd->queue->connect))
229 		return;
230 
231 	list_add_tail(&cmd->entry, &cmd->queue->free_list);
232 }
233 
234 static inline int queue_cpu(struct nvmet_tcp_queue *queue)
235 {
236 	return queue->sock->sk->sk_incoming_cpu;
237 }
238 
239 static inline u8 nvmet_tcp_hdgst_len(struct nvmet_tcp_queue *queue)
240 {
241 	return queue->hdr_digest ? NVME_TCP_DIGEST_LENGTH : 0;
242 }
243 
244 static inline u8 nvmet_tcp_ddgst_len(struct nvmet_tcp_queue *queue)
245 {
246 	return queue->data_digest ? NVME_TCP_DIGEST_LENGTH : 0;
247 }
248 
249 static inline void nvmet_tcp_hdgst(struct ahash_request *hash,
250 		void *pdu, size_t len)
251 {
252 	struct scatterlist sg;
253 
254 	sg_init_one(&sg, pdu, len);
255 	ahash_request_set_crypt(hash, &sg, pdu + len, len);
256 	crypto_ahash_digest(hash);
257 }
258 
259 static int nvmet_tcp_verify_hdgst(struct nvmet_tcp_queue *queue,
260 	void *pdu, size_t len)
261 {
262 	struct nvme_tcp_hdr *hdr = pdu;
263 	__le32 recv_digest;
264 	__le32 exp_digest;
265 
266 	if (unlikely(!(hdr->flags & NVME_TCP_F_HDGST))) {
267 		pr_err("queue %d: header digest enabled but no header digest\n",
268 			queue->idx);
269 		return -EPROTO;
270 	}
271 
272 	recv_digest = *(__le32 *)(pdu + hdr->hlen);
273 	nvmet_tcp_hdgst(queue->rcv_hash, pdu, len);
274 	exp_digest = *(__le32 *)(pdu + hdr->hlen);
275 	if (recv_digest != exp_digest) {
276 		pr_err("queue %d: header digest error: recv %#x expected %#x\n",
277 			queue->idx, le32_to_cpu(recv_digest),
278 			le32_to_cpu(exp_digest));
279 		return -EPROTO;
280 	}
281 
282 	return 0;
283 }
284 
285 static int nvmet_tcp_check_ddgst(struct nvmet_tcp_queue *queue, void *pdu)
286 {
287 	struct nvme_tcp_hdr *hdr = pdu;
288 	u8 digest_len = nvmet_tcp_hdgst_len(queue);
289 	u32 len;
290 
291 	len = le32_to_cpu(hdr->plen) - hdr->hlen -
292 		(hdr->flags & NVME_TCP_F_HDGST ? digest_len : 0);
293 
294 	if (unlikely(len && !(hdr->flags & NVME_TCP_F_DDGST))) {
295 		pr_err("queue %d: data digest flag is cleared\n", queue->idx);
296 		return -EPROTO;
297 	}
298 
299 	return 0;
300 }
301 
302 static void nvmet_tcp_free_cmd_buffers(struct nvmet_tcp_cmd *cmd)
303 {
304 	WARN_ON(unlikely(cmd->nr_mapped > 0));
305 
306 	kfree(cmd->iov);
307 	sgl_free(cmd->req.sg);
308 	cmd->iov = NULL;
309 	cmd->req.sg = NULL;
310 }
311 
312 static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd)
313 {
314 	struct scatterlist *sg;
315 	int i;
316 
317 	sg = &cmd->req.sg[cmd->sg_idx];
318 
319 	for (i = 0; i < cmd->nr_mapped; i++)
320 		kunmap(sg_page(&sg[i]));
321 
322 	cmd->nr_mapped = 0;
323 }
324 
325 static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd)
326 {
327 	struct kvec *iov = cmd->iov;
328 	struct scatterlist *sg;
329 	u32 length, offset, sg_offset;
330 
331 	length = cmd->pdu_len;
332 	cmd->nr_mapped = DIV_ROUND_UP(length, PAGE_SIZE);
333 	offset = cmd->rbytes_done;
334 	cmd->sg_idx = offset / PAGE_SIZE;
335 	sg_offset = offset % PAGE_SIZE;
336 	sg = &cmd->req.sg[cmd->sg_idx];
337 
338 	while (length) {
339 		u32 iov_len = min_t(u32, length, sg->length - sg_offset);
340 
341 		iov->iov_base = kmap(sg_page(sg)) + sg->offset + sg_offset;
342 		iov->iov_len = iov_len;
343 
344 		length -= iov_len;
345 		sg = sg_next(sg);
346 		iov++;
347 		sg_offset = 0;
348 	}
349 
350 	iov_iter_kvec(&cmd->recv_msg.msg_iter, READ, cmd->iov,
351 		cmd->nr_mapped, cmd->pdu_len);
352 }
353 
354 static void nvmet_tcp_fatal_error(struct nvmet_tcp_queue *queue)
355 {
356 	queue->rcv_state = NVMET_TCP_RECV_ERR;
357 	if (queue->nvme_sq.ctrl)
358 		nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
359 	else
360 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
361 }
362 
363 static void nvmet_tcp_socket_error(struct nvmet_tcp_queue *queue, int status)
364 {
365 	if (status == -EPIPE || status == -ECONNRESET)
366 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
367 	else
368 		nvmet_tcp_fatal_error(queue);
369 }
370 
371 static int nvmet_tcp_map_data(struct nvmet_tcp_cmd *cmd)
372 {
373 	struct nvme_sgl_desc *sgl = &cmd->req.cmd->common.dptr.sgl;
374 	u32 len = le32_to_cpu(sgl->length);
375 
376 	if (!len)
377 		return 0;
378 
379 	if (sgl->type == ((NVME_SGL_FMT_DATA_DESC << 4) |
380 			  NVME_SGL_FMT_OFFSET)) {
381 		if (!nvme_is_write(cmd->req.cmd))
382 			return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
383 
384 		if (len > cmd->req.port->inline_data_size)
385 			return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
386 		cmd->pdu_len = len;
387 	}
388 	cmd->req.transfer_len += len;
389 
390 	cmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt);
391 	if (!cmd->req.sg)
392 		return NVME_SC_INTERNAL;
393 	cmd->cur_sg = cmd->req.sg;
394 
395 	if (nvmet_tcp_has_data_in(cmd)) {
396 		cmd->iov = kmalloc_array(cmd->req.sg_cnt,
397 				sizeof(*cmd->iov), GFP_KERNEL);
398 		if (!cmd->iov)
399 			goto err;
400 	}
401 
402 	return 0;
403 err:
404 	nvmet_tcp_free_cmd_buffers(cmd);
405 	return NVME_SC_INTERNAL;
406 }
407 
408 static void nvmet_tcp_calc_ddgst(struct ahash_request *hash,
409 		struct nvmet_tcp_cmd *cmd)
410 {
411 	ahash_request_set_crypt(hash, cmd->req.sg,
412 		(void *)&cmd->exp_ddgst, cmd->req.transfer_len);
413 	crypto_ahash_digest(hash);
414 }
415 
416 static void nvmet_setup_c2h_data_pdu(struct nvmet_tcp_cmd *cmd)
417 {
418 	struct nvme_tcp_data_pdu *pdu = cmd->data_pdu;
419 	struct nvmet_tcp_queue *queue = cmd->queue;
420 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
421 	u8 ddgst = nvmet_tcp_ddgst_len(cmd->queue);
422 
423 	cmd->offset = 0;
424 	cmd->state = NVMET_TCP_SEND_DATA_PDU;
425 
426 	pdu->hdr.type = nvme_tcp_c2h_data;
427 	pdu->hdr.flags = NVME_TCP_F_DATA_LAST | (queue->nvme_sq.sqhd_disabled ?
428 						NVME_TCP_F_DATA_SUCCESS : 0);
429 	pdu->hdr.hlen = sizeof(*pdu);
430 	pdu->hdr.pdo = pdu->hdr.hlen + hdgst;
431 	pdu->hdr.plen =
432 		cpu_to_le32(pdu->hdr.hlen + hdgst +
433 				cmd->req.transfer_len + ddgst);
434 	pdu->command_id = cmd->req.cqe->command_id;
435 	pdu->data_length = cpu_to_le32(cmd->req.transfer_len);
436 	pdu->data_offset = cpu_to_le32(cmd->wbytes_done);
437 
438 	if (queue->data_digest) {
439 		pdu->hdr.flags |= NVME_TCP_F_DDGST;
440 		nvmet_tcp_calc_ddgst(queue->snd_hash, cmd);
441 	}
442 
443 	if (cmd->queue->hdr_digest) {
444 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
445 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
446 	}
447 }
448 
449 static void nvmet_setup_r2t_pdu(struct nvmet_tcp_cmd *cmd)
450 {
451 	struct nvme_tcp_r2t_pdu *pdu = cmd->r2t_pdu;
452 	struct nvmet_tcp_queue *queue = cmd->queue;
453 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
454 
455 	cmd->offset = 0;
456 	cmd->state = NVMET_TCP_SEND_R2T;
457 
458 	pdu->hdr.type = nvme_tcp_r2t;
459 	pdu->hdr.flags = 0;
460 	pdu->hdr.hlen = sizeof(*pdu);
461 	pdu->hdr.pdo = 0;
462 	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
463 
464 	pdu->command_id = cmd->req.cmd->common.command_id;
465 	pdu->ttag = nvmet_tcp_cmd_tag(cmd->queue, cmd);
466 	pdu->r2t_length = cpu_to_le32(cmd->req.transfer_len - cmd->rbytes_done);
467 	pdu->r2t_offset = cpu_to_le32(cmd->rbytes_done);
468 	if (cmd->queue->hdr_digest) {
469 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
470 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
471 	}
472 }
473 
474 static void nvmet_setup_response_pdu(struct nvmet_tcp_cmd *cmd)
475 {
476 	struct nvme_tcp_rsp_pdu *pdu = cmd->rsp_pdu;
477 	struct nvmet_tcp_queue *queue = cmd->queue;
478 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
479 
480 	cmd->offset = 0;
481 	cmd->state = NVMET_TCP_SEND_RESPONSE;
482 
483 	pdu->hdr.type = nvme_tcp_rsp;
484 	pdu->hdr.flags = 0;
485 	pdu->hdr.hlen = sizeof(*pdu);
486 	pdu->hdr.pdo = 0;
487 	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
488 	if (cmd->queue->hdr_digest) {
489 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
490 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
491 	}
492 }
493 
494 static void nvmet_tcp_process_resp_list(struct nvmet_tcp_queue *queue)
495 {
496 	struct llist_node *node;
497 	struct nvmet_tcp_cmd *cmd;
498 
499 	for (node = llist_del_all(&queue->resp_list); node; node = node->next) {
500 		cmd = llist_entry(node, struct nvmet_tcp_cmd, lentry);
501 		list_add(&cmd->entry, &queue->resp_send_list);
502 		queue->send_list_len++;
503 	}
504 }
505 
506 static struct nvmet_tcp_cmd *nvmet_tcp_fetch_cmd(struct nvmet_tcp_queue *queue)
507 {
508 	queue->snd_cmd = list_first_entry_or_null(&queue->resp_send_list,
509 				struct nvmet_tcp_cmd, entry);
510 	if (!queue->snd_cmd) {
511 		nvmet_tcp_process_resp_list(queue);
512 		queue->snd_cmd =
513 			list_first_entry_or_null(&queue->resp_send_list,
514 					struct nvmet_tcp_cmd, entry);
515 		if (unlikely(!queue->snd_cmd))
516 			return NULL;
517 	}
518 
519 	list_del_init(&queue->snd_cmd->entry);
520 	queue->send_list_len--;
521 
522 	if (nvmet_tcp_need_data_out(queue->snd_cmd))
523 		nvmet_setup_c2h_data_pdu(queue->snd_cmd);
524 	else if (nvmet_tcp_need_data_in(queue->snd_cmd))
525 		nvmet_setup_r2t_pdu(queue->snd_cmd);
526 	else
527 		nvmet_setup_response_pdu(queue->snd_cmd);
528 
529 	return queue->snd_cmd;
530 }
531 
532 static void nvmet_tcp_queue_response(struct nvmet_req *req)
533 {
534 	struct nvmet_tcp_cmd *cmd =
535 		container_of(req, struct nvmet_tcp_cmd, req);
536 	struct nvmet_tcp_queue	*queue = cmd->queue;
537 	struct nvme_sgl_desc *sgl;
538 	u32 len;
539 
540 	if (unlikely(cmd == queue->cmd)) {
541 		sgl = &cmd->req.cmd->common.dptr.sgl;
542 		len = le32_to_cpu(sgl->length);
543 
544 		/*
545 		 * Wait for inline data before processing the response.
546 		 * Avoid using helpers, this might happen before
547 		 * nvmet_req_init is completed.
548 		 */
549 		if (queue->rcv_state == NVMET_TCP_RECV_PDU &&
550 		    len && len <= cmd->req.port->inline_data_size &&
551 		    nvme_is_write(cmd->req.cmd))
552 			return;
553 	}
554 
555 	llist_add(&cmd->lentry, &queue->resp_list);
556 	queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &cmd->queue->io_work);
557 }
558 
559 static void nvmet_tcp_execute_request(struct nvmet_tcp_cmd *cmd)
560 {
561 	if (unlikely(cmd->flags & NVMET_TCP_F_INIT_FAILED))
562 		nvmet_tcp_queue_response(&cmd->req);
563 	else
564 		cmd->req.execute(&cmd->req);
565 }
566 
567 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
568 {
569 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
570 	int left = sizeof(*cmd->data_pdu) - cmd->offset + hdgst;
571 	int ret;
572 
573 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->data_pdu),
574 			offset_in_page(cmd->data_pdu) + cmd->offset,
575 			left, MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST);
576 	if (ret <= 0)
577 		return ret;
578 
579 	cmd->offset += ret;
580 	left -= ret;
581 
582 	if (left)
583 		return -EAGAIN;
584 
585 	cmd->state = NVMET_TCP_SEND_DATA;
586 	cmd->offset  = 0;
587 	return 1;
588 }
589 
590 static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
591 {
592 	struct nvmet_tcp_queue *queue = cmd->queue;
593 	int ret;
594 
595 	while (cmd->cur_sg) {
596 		struct page *page = sg_page(cmd->cur_sg);
597 		u32 left = cmd->cur_sg->length - cmd->offset;
598 		int flags = MSG_DONTWAIT;
599 
600 		if ((!last_in_batch && cmd->queue->send_list_len) ||
601 		    cmd->wbytes_done + left < cmd->req.transfer_len ||
602 		    queue->data_digest || !queue->nvme_sq.sqhd_disabled)
603 			flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
604 
605 		ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
606 					left, flags);
607 		if (ret <= 0)
608 			return ret;
609 
610 		cmd->offset += ret;
611 		cmd->wbytes_done += ret;
612 
613 		/* Done with sg?*/
614 		if (cmd->offset == cmd->cur_sg->length) {
615 			cmd->cur_sg = sg_next(cmd->cur_sg);
616 			cmd->offset = 0;
617 		}
618 	}
619 
620 	if (queue->data_digest) {
621 		cmd->state = NVMET_TCP_SEND_DDGST;
622 		cmd->offset = 0;
623 	} else {
624 		if (queue->nvme_sq.sqhd_disabled) {
625 			cmd->queue->snd_cmd = NULL;
626 			nvmet_tcp_put_cmd(cmd);
627 		} else {
628 			nvmet_setup_response_pdu(cmd);
629 		}
630 	}
631 
632 	if (queue->nvme_sq.sqhd_disabled)
633 		nvmet_tcp_free_cmd_buffers(cmd);
634 
635 	return 1;
636 
637 }
638 
639 static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
640 		bool last_in_batch)
641 {
642 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
643 	int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
644 	int flags = MSG_DONTWAIT;
645 	int ret;
646 
647 	if (!last_in_batch && cmd->queue->send_list_len)
648 		flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
649 	else
650 		flags |= MSG_EOR;
651 
652 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
653 		offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
654 	if (ret <= 0)
655 		return ret;
656 	cmd->offset += ret;
657 	left -= ret;
658 
659 	if (left)
660 		return -EAGAIN;
661 
662 	nvmet_tcp_free_cmd_buffers(cmd);
663 	cmd->queue->snd_cmd = NULL;
664 	nvmet_tcp_put_cmd(cmd);
665 	return 1;
666 }
667 
668 static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
669 {
670 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
671 	int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
672 	int flags = MSG_DONTWAIT;
673 	int ret;
674 
675 	if (!last_in_batch && cmd->queue->send_list_len)
676 		flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
677 	else
678 		flags |= MSG_EOR;
679 
680 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
681 		offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
682 	if (ret <= 0)
683 		return ret;
684 	cmd->offset += ret;
685 	left -= ret;
686 
687 	if (left)
688 		return -EAGAIN;
689 
690 	cmd->queue->snd_cmd = NULL;
691 	return 1;
692 }
693 
694 static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
695 {
696 	struct nvmet_tcp_queue *queue = cmd->queue;
697 	int left = NVME_TCP_DIGEST_LENGTH - cmd->offset;
698 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
699 	struct kvec iov = {
700 		.iov_base = (u8 *)&cmd->exp_ddgst + cmd->offset,
701 		.iov_len = left
702 	};
703 	int ret;
704 
705 	if (!last_in_batch && cmd->queue->send_list_len)
706 		msg.msg_flags |= MSG_MORE;
707 	else
708 		msg.msg_flags |= MSG_EOR;
709 
710 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
711 	if (unlikely(ret <= 0))
712 		return ret;
713 
714 	cmd->offset += ret;
715 	left -= ret;
716 
717 	if (left)
718 		return -EAGAIN;
719 
720 	if (queue->nvme_sq.sqhd_disabled) {
721 		cmd->queue->snd_cmd = NULL;
722 		nvmet_tcp_put_cmd(cmd);
723 	} else {
724 		nvmet_setup_response_pdu(cmd);
725 	}
726 	return 1;
727 }
728 
729 static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
730 		bool last_in_batch)
731 {
732 	struct nvmet_tcp_cmd *cmd = queue->snd_cmd;
733 	int ret = 0;
734 
735 	if (!cmd || queue->state == NVMET_TCP_Q_DISCONNECTING) {
736 		cmd = nvmet_tcp_fetch_cmd(queue);
737 		if (unlikely(!cmd))
738 			return 0;
739 	}
740 
741 	if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
742 		ret = nvmet_try_send_data_pdu(cmd);
743 		if (ret <= 0)
744 			goto done_send;
745 	}
746 
747 	if (cmd->state == NVMET_TCP_SEND_DATA) {
748 		ret = nvmet_try_send_data(cmd, last_in_batch);
749 		if (ret <= 0)
750 			goto done_send;
751 	}
752 
753 	if (cmd->state == NVMET_TCP_SEND_DDGST) {
754 		ret = nvmet_try_send_ddgst(cmd, last_in_batch);
755 		if (ret <= 0)
756 			goto done_send;
757 	}
758 
759 	if (cmd->state == NVMET_TCP_SEND_R2T) {
760 		ret = nvmet_try_send_r2t(cmd, last_in_batch);
761 		if (ret <= 0)
762 			goto done_send;
763 	}
764 
765 	if (cmd->state == NVMET_TCP_SEND_RESPONSE)
766 		ret = nvmet_try_send_response(cmd, last_in_batch);
767 
768 done_send:
769 	if (ret < 0) {
770 		if (ret == -EAGAIN)
771 			return 0;
772 		return ret;
773 	}
774 
775 	return 1;
776 }
777 
778 static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
779 		int budget, int *sends)
780 {
781 	int i, ret = 0;
782 
783 	for (i = 0; i < budget; i++) {
784 		ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
785 		if (unlikely(ret < 0)) {
786 			nvmet_tcp_socket_error(queue, ret);
787 			goto done;
788 		} else if (ret == 0) {
789 			break;
790 		}
791 		(*sends)++;
792 	}
793 done:
794 	return ret;
795 }
796 
797 static void nvmet_prepare_receive_pdu(struct nvmet_tcp_queue *queue)
798 {
799 	queue->offset = 0;
800 	queue->left = sizeof(struct nvme_tcp_hdr);
801 	queue->cmd = NULL;
802 	queue->rcv_state = NVMET_TCP_RECV_PDU;
803 }
804 
805 static void nvmet_tcp_free_crypto(struct nvmet_tcp_queue *queue)
806 {
807 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(queue->rcv_hash);
808 
809 	ahash_request_free(queue->rcv_hash);
810 	ahash_request_free(queue->snd_hash);
811 	crypto_free_ahash(tfm);
812 }
813 
814 static int nvmet_tcp_alloc_crypto(struct nvmet_tcp_queue *queue)
815 {
816 	struct crypto_ahash *tfm;
817 
818 	tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
819 	if (IS_ERR(tfm))
820 		return PTR_ERR(tfm);
821 
822 	queue->snd_hash = ahash_request_alloc(tfm, GFP_KERNEL);
823 	if (!queue->snd_hash)
824 		goto free_tfm;
825 	ahash_request_set_callback(queue->snd_hash, 0, NULL, NULL);
826 
827 	queue->rcv_hash = ahash_request_alloc(tfm, GFP_KERNEL);
828 	if (!queue->rcv_hash)
829 		goto free_snd_hash;
830 	ahash_request_set_callback(queue->rcv_hash, 0, NULL, NULL);
831 
832 	return 0;
833 free_snd_hash:
834 	ahash_request_free(queue->snd_hash);
835 free_tfm:
836 	crypto_free_ahash(tfm);
837 	return -ENOMEM;
838 }
839 
840 
841 static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
842 {
843 	struct nvme_tcp_icreq_pdu *icreq = &queue->pdu.icreq;
844 	struct nvme_tcp_icresp_pdu *icresp = &queue->pdu.icresp;
845 	struct msghdr msg = {};
846 	struct kvec iov;
847 	int ret;
848 
849 	if (le32_to_cpu(icreq->hdr.plen) != sizeof(struct nvme_tcp_icreq_pdu)) {
850 		pr_err("bad nvme-tcp pdu length (%d)\n",
851 			le32_to_cpu(icreq->hdr.plen));
852 		nvmet_tcp_fatal_error(queue);
853 	}
854 
855 	if (icreq->pfv != NVME_TCP_PFV_1_0) {
856 		pr_err("queue %d: bad pfv %d\n", queue->idx, icreq->pfv);
857 		return -EPROTO;
858 	}
859 
860 	if (icreq->hpda != 0) {
861 		pr_err("queue %d: unsupported hpda %d\n", queue->idx,
862 			icreq->hpda);
863 		return -EPROTO;
864 	}
865 
866 	queue->hdr_digest = !!(icreq->digest & NVME_TCP_HDR_DIGEST_ENABLE);
867 	queue->data_digest = !!(icreq->digest & NVME_TCP_DATA_DIGEST_ENABLE);
868 	if (queue->hdr_digest || queue->data_digest) {
869 		ret = nvmet_tcp_alloc_crypto(queue);
870 		if (ret)
871 			return ret;
872 	}
873 
874 	memset(icresp, 0, sizeof(*icresp));
875 	icresp->hdr.type = nvme_tcp_icresp;
876 	icresp->hdr.hlen = sizeof(*icresp);
877 	icresp->hdr.pdo = 0;
878 	icresp->hdr.plen = cpu_to_le32(icresp->hdr.hlen);
879 	icresp->pfv = cpu_to_le16(NVME_TCP_PFV_1_0);
880 	icresp->maxdata = cpu_to_le32(0x400000); /* 16M arbitrary limit */
881 	icresp->cpda = 0;
882 	if (queue->hdr_digest)
883 		icresp->digest |= NVME_TCP_HDR_DIGEST_ENABLE;
884 	if (queue->data_digest)
885 		icresp->digest |= NVME_TCP_DATA_DIGEST_ENABLE;
886 
887 	iov.iov_base = icresp;
888 	iov.iov_len = sizeof(*icresp);
889 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
890 	if (ret < 0)
891 		goto free_crypto;
892 
893 	queue->state = NVMET_TCP_Q_LIVE;
894 	nvmet_prepare_receive_pdu(queue);
895 	return 0;
896 free_crypto:
897 	if (queue->hdr_digest || queue->data_digest)
898 		nvmet_tcp_free_crypto(queue);
899 	return ret;
900 }
901 
902 static void nvmet_tcp_handle_req_failure(struct nvmet_tcp_queue *queue,
903 		struct nvmet_tcp_cmd *cmd, struct nvmet_req *req)
904 {
905 	size_t data_len = le32_to_cpu(req->cmd->common.dptr.sgl.length);
906 	int ret;
907 
908 	/*
909 	 * This command has not been processed yet, hence we are trying to
910 	 * figure out if there is still pending data left to receive. If
911 	 * we don't, we can simply prepare for the next pdu and bail out,
912 	 * otherwise we will need to prepare a buffer and receive the
913 	 * stale data before continuing forward.
914 	 */
915 	if (!nvme_is_write(cmd->req.cmd) || !data_len ||
916 	    data_len > cmd->req.port->inline_data_size) {
917 		nvmet_prepare_receive_pdu(queue);
918 		return;
919 	}
920 
921 	ret = nvmet_tcp_map_data(cmd);
922 	if (unlikely(ret)) {
923 		pr_err("queue %d: failed to map data\n", queue->idx);
924 		nvmet_tcp_fatal_error(queue);
925 		return;
926 	}
927 
928 	queue->rcv_state = NVMET_TCP_RECV_DATA;
929 	nvmet_tcp_map_pdu_iovec(cmd);
930 	cmd->flags |= NVMET_TCP_F_INIT_FAILED;
931 }
932 
933 static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
934 {
935 	struct nvme_tcp_data_pdu *data = &queue->pdu.data;
936 	struct nvmet_tcp_cmd *cmd;
937 
938 	if (likely(queue->nr_cmds))
939 		cmd = &queue->cmds[data->ttag];
940 	else
941 		cmd = &queue->connect;
942 
943 	if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
944 		pr_err("ttag %u unexpected data offset %u (expected %u)\n",
945 			data->ttag, le32_to_cpu(data->data_offset),
946 			cmd->rbytes_done);
947 		/* FIXME: use path and transport errors */
948 		nvmet_req_complete(&cmd->req,
949 			NVME_SC_INVALID_FIELD | NVME_SC_DNR);
950 		return -EPROTO;
951 	}
952 
953 	cmd->pdu_len = le32_to_cpu(data->data_length);
954 	cmd->pdu_recv = 0;
955 	nvmet_tcp_map_pdu_iovec(cmd);
956 	queue->cmd = cmd;
957 	queue->rcv_state = NVMET_TCP_RECV_DATA;
958 
959 	return 0;
960 }
961 
962 static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
963 {
964 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
965 	struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
966 	struct nvmet_req *req;
967 	int ret;
968 
969 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
970 		if (hdr->type != nvme_tcp_icreq) {
971 			pr_err("unexpected pdu type (%d) before icreq\n",
972 				hdr->type);
973 			nvmet_tcp_fatal_error(queue);
974 			return -EPROTO;
975 		}
976 		return nvmet_tcp_handle_icreq(queue);
977 	}
978 
979 	if (hdr->type == nvme_tcp_h2c_data) {
980 		ret = nvmet_tcp_handle_h2c_data_pdu(queue);
981 		if (unlikely(ret))
982 			return ret;
983 		return 0;
984 	}
985 
986 	queue->cmd = nvmet_tcp_get_cmd(queue);
987 	if (unlikely(!queue->cmd)) {
988 		/* This should never happen */
989 		pr_err("queue %d: out of commands (%d) send_list_len: %d, opcode: %d",
990 			queue->idx, queue->nr_cmds, queue->send_list_len,
991 			nvme_cmd->common.opcode);
992 		nvmet_tcp_fatal_error(queue);
993 		return -ENOMEM;
994 	}
995 
996 	req = &queue->cmd->req;
997 	memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
998 
999 	if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
1000 			&queue->nvme_sq, &nvmet_tcp_ops))) {
1001 		pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
1002 			req->cmd, req->cmd->common.command_id,
1003 			req->cmd->common.opcode,
1004 			le32_to_cpu(req->cmd->common.dptr.sgl.length));
1005 
1006 		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
1007 		return 0;
1008 	}
1009 
1010 	ret = nvmet_tcp_map_data(queue->cmd);
1011 	if (unlikely(ret)) {
1012 		pr_err("queue %d: failed to map data\n", queue->idx);
1013 		if (nvmet_tcp_has_inline_data(queue->cmd))
1014 			nvmet_tcp_fatal_error(queue);
1015 		else
1016 			nvmet_req_complete(req, ret);
1017 		ret = -EAGAIN;
1018 		goto out;
1019 	}
1020 
1021 	if (nvmet_tcp_need_data_in(queue->cmd)) {
1022 		if (nvmet_tcp_has_inline_data(queue->cmd)) {
1023 			queue->rcv_state = NVMET_TCP_RECV_DATA;
1024 			nvmet_tcp_map_pdu_iovec(queue->cmd);
1025 			return 0;
1026 		}
1027 		/* send back R2T */
1028 		nvmet_tcp_queue_response(&queue->cmd->req);
1029 		goto out;
1030 	}
1031 
1032 	queue->cmd->req.execute(&queue->cmd->req);
1033 out:
1034 	nvmet_prepare_receive_pdu(queue);
1035 	return ret;
1036 }
1037 
1038 static const u8 nvme_tcp_pdu_sizes[] = {
1039 	[nvme_tcp_icreq]	= sizeof(struct nvme_tcp_icreq_pdu),
1040 	[nvme_tcp_cmd]		= sizeof(struct nvme_tcp_cmd_pdu),
1041 	[nvme_tcp_h2c_data]	= sizeof(struct nvme_tcp_data_pdu),
1042 };
1043 
1044 static inline u8 nvmet_tcp_pdu_size(u8 type)
1045 {
1046 	size_t idx = type;
1047 
1048 	return (idx < ARRAY_SIZE(nvme_tcp_pdu_sizes) &&
1049 		nvme_tcp_pdu_sizes[idx]) ?
1050 			nvme_tcp_pdu_sizes[idx] : 0;
1051 }
1052 
1053 static inline bool nvmet_tcp_pdu_valid(u8 type)
1054 {
1055 	switch (type) {
1056 	case nvme_tcp_icreq:
1057 	case nvme_tcp_cmd:
1058 	case nvme_tcp_h2c_data:
1059 		/* fallthru */
1060 		return true;
1061 	}
1062 
1063 	return false;
1064 }
1065 
1066 static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
1067 {
1068 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
1069 	int len;
1070 	struct kvec iov;
1071 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1072 
1073 recv:
1074 	iov.iov_base = (void *)&queue->pdu + queue->offset;
1075 	iov.iov_len = queue->left;
1076 	len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1077 			iov.iov_len, msg.msg_flags);
1078 	if (unlikely(len < 0))
1079 		return len;
1080 
1081 	queue->offset += len;
1082 	queue->left -= len;
1083 	if (queue->left)
1084 		return -EAGAIN;
1085 
1086 	if (queue->offset == sizeof(struct nvme_tcp_hdr)) {
1087 		u8 hdgst = nvmet_tcp_hdgst_len(queue);
1088 
1089 		if (unlikely(!nvmet_tcp_pdu_valid(hdr->type))) {
1090 			pr_err("unexpected pdu type %d\n", hdr->type);
1091 			nvmet_tcp_fatal_error(queue);
1092 			return -EIO;
1093 		}
1094 
1095 		if (unlikely(hdr->hlen != nvmet_tcp_pdu_size(hdr->type))) {
1096 			pr_err("pdu %d bad hlen %d\n", hdr->type, hdr->hlen);
1097 			return -EIO;
1098 		}
1099 
1100 		queue->left = hdr->hlen - queue->offset + hdgst;
1101 		goto recv;
1102 	}
1103 
1104 	if (queue->hdr_digest &&
1105 	    nvmet_tcp_verify_hdgst(queue, &queue->pdu, hdr->hlen)) {
1106 		nvmet_tcp_fatal_error(queue); /* fatal */
1107 		return -EPROTO;
1108 	}
1109 
1110 	if (queue->data_digest &&
1111 	    nvmet_tcp_check_ddgst(queue, &queue->pdu)) {
1112 		nvmet_tcp_fatal_error(queue); /* fatal */
1113 		return -EPROTO;
1114 	}
1115 
1116 	return nvmet_tcp_done_recv_pdu(queue);
1117 }
1118 
1119 static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
1120 {
1121 	struct nvmet_tcp_queue *queue = cmd->queue;
1122 
1123 	nvmet_tcp_calc_ddgst(queue->rcv_hash, cmd);
1124 	queue->offset = 0;
1125 	queue->left = NVME_TCP_DIGEST_LENGTH;
1126 	queue->rcv_state = NVMET_TCP_RECV_DDGST;
1127 }
1128 
1129 static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
1130 {
1131 	struct nvmet_tcp_cmd  *cmd = queue->cmd;
1132 	int ret;
1133 
1134 	while (msg_data_left(&cmd->recv_msg)) {
1135 		ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
1136 			cmd->recv_msg.msg_flags);
1137 		if (ret <= 0)
1138 			return ret;
1139 
1140 		cmd->pdu_recv += ret;
1141 		cmd->rbytes_done += ret;
1142 	}
1143 
1144 	nvmet_tcp_unmap_pdu_iovec(cmd);
1145 	if (queue->data_digest) {
1146 		nvmet_tcp_prep_recv_ddgst(cmd);
1147 		return 0;
1148 	}
1149 
1150 	if (cmd->rbytes_done == cmd->req.transfer_len)
1151 		nvmet_tcp_execute_request(cmd);
1152 
1153 	nvmet_prepare_receive_pdu(queue);
1154 	return 0;
1155 }
1156 
1157 static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
1158 {
1159 	struct nvmet_tcp_cmd *cmd = queue->cmd;
1160 	int ret;
1161 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1162 	struct kvec iov = {
1163 		.iov_base = (void *)&cmd->recv_ddgst + queue->offset,
1164 		.iov_len = queue->left
1165 	};
1166 
1167 	ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1168 			iov.iov_len, msg.msg_flags);
1169 	if (unlikely(ret < 0))
1170 		return ret;
1171 
1172 	queue->offset += ret;
1173 	queue->left -= ret;
1174 	if (queue->left)
1175 		return -EAGAIN;
1176 
1177 	if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) {
1178 		pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n",
1179 			queue->idx, cmd->req.cmd->common.command_id,
1180 			queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
1181 			le32_to_cpu(cmd->exp_ddgst));
1182 		nvmet_tcp_finish_cmd(cmd);
1183 		nvmet_tcp_fatal_error(queue);
1184 		ret = -EPROTO;
1185 		goto out;
1186 	}
1187 
1188 	if (cmd->rbytes_done == cmd->req.transfer_len)
1189 		nvmet_tcp_execute_request(cmd);
1190 
1191 	ret = 0;
1192 out:
1193 	nvmet_prepare_receive_pdu(queue);
1194 	return ret;
1195 }
1196 
1197 static int nvmet_tcp_try_recv_one(struct nvmet_tcp_queue *queue)
1198 {
1199 	int result = 0;
1200 
1201 	if (unlikely(queue->rcv_state == NVMET_TCP_RECV_ERR))
1202 		return 0;
1203 
1204 	if (queue->rcv_state == NVMET_TCP_RECV_PDU) {
1205 		result = nvmet_tcp_try_recv_pdu(queue);
1206 		if (result != 0)
1207 			goto done_recv;
1208 	}
1209 
1210 	if (queue->rcv_state == NVMET_TCP_RECV_DATA) {
1211 		result = nvmet_tcp_try_recv_data(queue);
1212 		if (result != 0)
1213 			goto done_recv;
1214 	}
1215 
1216 	if (queue->rcv_state == NVMET_TCP_RECV_DDGST) {
1217 		result = nvmet_tcp_try_recv_ddgst(queue);
1218 		if (result != 0)
1219 			goto done_recv;
1220 	}
1221 
1222 done_recv:
1223 	if (result < 0) {
1224 		if (result == -EAGAIN)
1225 			return 0;
1226 		return result;
1227 	}
1228 	return 1;
1229 }
1230 
1231 static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
1232 		int budget, int *recvs)
1233 {
1234 	int i, ret = 0;
1235 
1236 	for (i = 0; i < budget; i++) {
1237 		ret = nvmet_tcp_try_recv_one(queue);
1238 		if (unlikely(ret < 0)) {
1239 			nvmet_tcp_socket_error(queue, ret);
1240 			goto done;
1241 		} else if (ret == 0) {
1242 			break;
1243 		}
1244 		(*recvs)++;
1245 	}
1246 done:
1247 	return ret;
1248 }
1249 
1250 static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
1251 {
1252 	spin_lock(&queue->state_lock);
1253 	if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
1254 		queue->state = NVMET_TCP_Q_DISCONNECTING;
1255 		queue_work(nvmet_wq, &queue->release_work);
1256 	}
1257 	spin_unlock(&queue->state_lock);
1258 }
1259 
1260 static inline void nvmet_tcp_arm_queue_deadline(struct nvmet_tcp_queue *queue)
1261 {
1262 	queue->poll_end = jiffies + usecs_to_jiffies(idle_poll_period_usecs);
1263 }
1264 
1265 static bool nvmet_tcp_check_queue_deadline(struct nvmet_tcp_queue *queue,
1266 		int ops)
1267 {
1268 	if (!idle_poll_period_usecs)
1269 		return false;
1270 
1271 	if (ops)
1272 		nvmet_tcp_arm_queue_deadline(queue);
1273 
1274 	return !time_after(jiffies, queue->poll_end);
1275 }
1276 
1277 static void nvmet_tcp_io_work(struct work_struct *w)
1278 {
1279 	struct nvmet_tcp_queue *queue =
1280 		container_of(w, struct nvmet_tcp_queue, io_work);
1281 	bool pending;
1282 	int ret, ops = 0;
1283 
1284 	do {
1285 		pending = false;
1286 
1287 		ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
1288 		if (ret > 0)
1289 			pending = true;
1290 		else if (ret < 0)
1291 			return;
1292 
1293 		ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
1294 		if (ret > 0)
1295 			pending = true;
1296 		else if (ret < 0)
1297 			return;
1298 
1299 	} while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
1300 
1301 	/*
1302 	 * Requeue the worker if idle deadline period is in progress or any
1303 	 * ops activity was recorded during the do-while loop above.
1304 	 */
1305 	if (nvmet_tcp_check_queue_deadline(queue, ops) || pending)
1306 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1307 }
1308 
1309 static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
1310 		struct nvmet_tcp_cmd *c)
1311 {
1312 	u8 hdgst = nvmet_tcp_hdgst_len(queue);
1313 
1314 	c->queue = queue;
1315 	c->req.port = queue->port->nport;
1316 
1317 	c->cmd_pdu = page_frag_alloc(&queue->pf_cache,
1318 			sizeof(*c->cmd_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1319 	if (!c->cmd_pdu)
1320 		return -ENOMEM;
1321 	c->req.cmd = &c->cmd_pdu->cmd;
1322 
1323 	c->rsp_pdu = page_frag_alloc(&queue->pf_cache,
1324 			sizeof(*c->rsp_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1325 	if (!c->rsp_pdu)
1326 		goto out_free_cmd;
1327 	c->req.cqe = &c->rsp_pdu->cqe;
1328 
1329 	c->data_pdu = page_frag_alloc(&queue->pf_cache,
1330 			sizeof(*c->data_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1331 	if (!c->data_pdu)
1332 		goto out_free_rsp;
1333 
1334 	c->r2t_pdu = page_frag_alloc(&queue->pf_cache,
1335 			sizeof(*c->r2t_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1336 	if (!c->r2t_pdu)
1337 		goto out_free_data;
1338 
1339 	c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1340 
1341 	list_add_tail(&c->entry, &queue->free_list);
1342 
1343 	return 0;
1344 out_free_data:
1345 	page_frag_free(c->data_pdu);
1346 out_free_rsp:
1347 	page_frag_free(c->rsp_pdu);
1348 out_free_cmd:
1349 	page_frag_free(c->cmd_pdu);
1350 	return -ENOMEM;
1351 }
1352 
1353 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c)
1354 {
1355 	page_frag_free(c->r2t_pdu);
1356 	page_frag_free(c->data_pdu);
1357 	page_frag_free(c->rsp_pdu);
1358 	page_frag_free(c->cmd_pdu);
1359 }
1360 
1361 static int nvmet_tcp_alloc_cmds(struct nvmet_tcp_queue *queue)
1362 {
1363 	struct nvmet_tcp_cmd *cmds;
1364 	int i, ret = -EINVAL, nr_cmds = queue->nr_cmds;
1365 
1366 	cmds = kcalloc(nr_cmds, sizeof(struct nvmet_tcp_cmd), GFP_KERNEL);
1367 	if (!cmds)
1368 		goto out;
1369 
1370 	for (i = 0; i < nr_cmds; i++) {
1371 		ret = nvmet_tcp_alloc_cmd(queue, cmds + i);
1372 		if (ret)
1373 			goto out_free;
1374 	}
1375 
1376 	queue->cmds = cmds;
1377 
1378 	return 0;
1379 out_free:
1380 	while (--i >= 0)
1381 		nvmet_tcp_free_cmd(cmds + i);
1382 	kfree(cmds);
1383 out:
1384 	return ret;
1385 }
1386 
1387 static void nvmet_tcp_free_cmds(struct nvmet_tcp_queue *queue)
1388 {
1389 	struct nvmet_tcp_cmd *cmds = queue->cmds;
1390 	int i;
1391 
1392 	for (i = 0; i < queue->nr_cmds; i++)
1393 		nvmet_tcp_free_cmd(cmds + i);
1394 
1395 	nvmet_tcp_free_cmd(&queue->connect);
1396 	kfree(cmds);
1397 }
1398 
1399 static void nvmet_tcp_restore_socket_callbacks(struct nvmet_tcp_queue *queue)
1400 {
1401 	struct socket *sock = queue->sock;
1402 
1403 	write_lock_bh(&sock->sk->sk_callback_lock);
1404 	sock->sk->sk_data_ready =  queue->data_ready;
1405 	sock->sk->sk_state_change = queue->state_change;
1406 	sock->sk->sk_write_space = queue->write_space;
1407 	sock->sk->sk_user_data = NULL;
1408 	write_unlock_bh(&sock->sk->sk_callback_lock);
1409 }
1410 
1411 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
1412 {
1413 	nvmet_req_uninit(&cmd->req);
1414 	nvmet_tcp_unmap_pdu_iovec(cmd);
1415 	nvmet_tcp_free_cmd_buffers(cmd);
1416 }
1417 
1418 static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
1419 {
1420 	struct nvmet_tcp_cmd *cmd = queue->cmds;
1421 	int i;
1422 
1423 	for (i = 0; i < queue->nr_cmds; i++, cmd++) {
1424 		if (nvmet_tcp_need_data_in(cmd))
1425 			nvmet_req_uninit(&cmd->req);
1426 
1427 		nvmet_tcp_unmap_pdu_iovec(cmd);
1428 		nvmet_tcp_free_cmd_buffers(cmd);
1429 	}
1430 
1431 	if (!queue->nr_cmds && nvmet_tcp_need_data_in(&queue->connect)) {
1432 		/* failed in connect */
1433 		nvmet_tcp_finish_cmd(&queue->connect);
1434 	}
1435 }
1436 
1437 static void nvmet_tcp_release_queue_work(struct work_struct *w)
1438 {
1439 	struct page *page;
1440 	struct nvmet_tcp_queue *queue =
1441 		container_of(w, struct nvmet_tcp_queue, release_work);
1442 
1443 	mutex_lock(&nvmet_tcp_queue_mutex);
1444 	list_del_init(&queue->queue_list);
1445 	mutex_unlock(&nvmet_tcp_queue_mutex);
1446 
1447 	nvmet_tcp_restore_socket_callbacks(queue);
1448 	cancel_work_sync(&queue->io_work);
1449 	/* stop accepting incoming data */
1450 	queue->rcv_state = NVMET_TCP_RECV_ERR;
1451 
1452 	nvmet_tcp_uninit_data_in_cmds(queue);
1453 	nvmet_sq_destroy(&queue->nvme_sq);
1454 	cancel_work_sync(&queue->io_work);
1455 	sock_release(queue->sock);
1456 	nvmet_tcp_free_cmds(queue);
1457 	if (queue->hdr_digest || queue->data_digest)
1458 		nvmet_tcp_free_crypto(queue);
1459 	ida_free(&nvmet_tcp_queue_ida, queue->idx);
1460 
1461 	page = virt_to_head_page(queue->pf_cache.va);
1462 	__page_frag_cache_drain(page, queue->pf_cache.pagecnt_bias);
1463 	kfree(queue);
1464 }
1465 
1466 static void nvmet_tcp_data_ready(struct sock *sk)
1467 {
1468 	struct nvmet_tcp_queue *queue;
1469 
1470 	read_lock_bh(&sk->sk_callback_lock);
1471 	queue = sk->sk_user_data;
1472 	if (likely(queue))
1473 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1474 	read_unlock_bh(&sk->sk_callback_lock);
1475 }
1476 
1477 static void nvmet_tcp_write_space(struct sock *sk)
1478 {
1479 	struct nvmet_tcp_queue *queue;
1480 
1481 	read_lock_bh(&sk->sk_callback_lock);
1482 	queue = sk->sk_user_data;
1483 	if (unlikely(!queue))
1484 		goto out;
1485 
1486 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
1487 		queue->write_space(sk);
1488 		goto out;
1489 	}
1490 
1491 	if (sk_stream_is_writeable(sk)) {
1492 		clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1493 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1494 	}
1495 out:
1496 	read_unlock_bh(&sk->sk_callback_lock);
1497 }
1498 
1499 static void nvmet_tcp_state_change(struct sock *sk)
1500 {
1501 	struct nvmet_tcp_queue *queue;
1502 
1503 	read_lock_bh(&sk->sk_callback_lock);
1504 	queue = sk->sk_user_data;
1505 	if (!queue)
1506 		goto done;
1507 
1508 	switch (sk->sk_state) {
1509 	case TCP_FIN_WAIT1:
1510 	case TCP_CLOSE_WAIT:
1511 	case TCP_CLOSE:
1512 		/* FALLTHRU */
1513 		nvmet_tcp_schedule_release_queue(queue);
1514 		break;
1515 	default:
1516 		pr_warn("queue %d unhandled state %d\n",
1517 			queue->idx, sk->sk_state);
1518 	}
1519 done:
1520 	read_unlock_bh(&sk->sk_callback_lock);
1521 }
1522 
1523 static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
1524 {
1525 	struct socket *sock = queue->sock;
1526 	struct inet_sock *inet = inet_sk(sock->sk);
1527 	int ret;
1528 
1529 	ret = kernel_getsockname(sock,
1530 		(struct sockaddr *)&queue->sockaddr);
1531 	if (ret < 0)
1532 		return ret;
1533 
1534 	ret = kernel_getpeername(sock,
1535 		(struct sockaddr *)&queue->sockaddr_peer);
1536 	if (ret < 0)
1537 		return ret;
1538 
1539 	/*
1540 	 * Cleanup whatever is sitting in the TCP transmit queue on socket
1541 	 * close. This is done to prevent stale data from being sent should
1542 	 * the network connection be restored before TCP times out.
1543 	 */
1544 	sock_no_linger(sock->sk);
1545 
1546 	if (so_priority > 0)
1547 		sock_set_priority(sock->sk, so_priority);
1548 
1549 	/* Set socket type of service */
1550 	if (inet->rcv_tos > 0)
1551 		ip_sock_set_tos(sock->sk, inet->rcv_tos);
1552 
1553 	ret = 0;
1554 	write_lock_bh(&sock->sk->sk_callback_lock);
1555 	if (sock->sk->sk_state != TCP_ESTABLISHED) {
1556 		/*
1557 		 * If the socket is already closing, don't even start
1558 		 * consuming it
1559 		 */
1560 		ret = -ENOTCONN;
1561 	} else {
1562 		sock->sk->sk_user_data = queue;
1563 		queue->data_ready = sock->sk->sk_data_ready;
1564 		sock->sk->sk_data_ready = nvmet_tcp_data_ready;
1565 		queue->state_change = sock->sk->sk_state_change;
1566 		sock->sk->sk_state_change = nvmet_tcp_state_change;
1567 		queue->write_space = sock->sk->sk_write_space;
1568 		sock->sk->sk_write_space = nvmet_tcp_write_space;
1569 		if (idle_poll_period_usecs)
1570 			nvmet_tcp_arm_queue_deadline(queue);
1571 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1572 	}
1573 	write_unlock_bh(&sock->sk->sk_callback_lock);
1574 
1575 	return ret;
1576 }
1577 
1578 static int nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
1579 		struct socket *newsock)
1580 {
1581 	struct nvmet_tcp_queue *queue;
1582 	int ret;
1583 
1584 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1585 	if (!queue)
1586 		return -ENOMEM;
1587 
1588 	INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
1589 	INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
1590 	queue->sock = newsock;
1591 	queue->port = port;
1592 	queue->nr_cmds = 0;
1593 	spin_lock_init(&queue->state_lock);
1594 	queue->state = NVMET_TCP_Q_CONNECTING;
1595 	INIT_LIST_HEAD(&queue->free_list);
1596 	init_llist_head(&queue->resp_list);
1597 	INIT_LIST_HEAD(&queue->resp_send_list);
1598 
1599 	queue->idx = ida_alloc(&nvmet_tcp_queue_ida, GFP_KERNEL);
1600 	if (queue->idx < 0) {
1601 		ret = queue->idx;
1602 		goto out_free_queue;
1603 	}
1604 
1605 	ret = nvmet_tcp_alloc_cmd(queue, &queue->connect);
1606 	if (ret)
1607 		goto out_ida_remove;
1608 
1609 	ret = nvmet_sq_init(&queue->nvme_sq);
1610 	if (ret)
1611 		goto out_free_connect;
1612 
1613 	nvmet_prepare_receive_pdu(queue);
1614 
1615 	mutex_lock(&nvmet_tcp_queue_mutex);
1616 	list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
1617 	mutex_unlock(&nvmet_tcp_queue_mutex);
1618 
1619 	ret = nvmet_tcp_set_queue_sock(queue);
1620 	if (ret)
1621 		goto out_destroy_sq;
1622 
1623 	return 0;
1624 out_destroy_sq:
1625 	mutex_lock(&nvmet_tcp_queue_mutex);
1626 	list_del_init(&queue->queue_list);
1627 	mutex_unlock(&nvmet_tcp_queue_mutex);
1628 	nvmet_sq_destroy(&queue->nvme_sq);
1629 out_free_connect:
1630 	nvmet_tcp_free_cmd(&queue->connect);
1631 out_ida_remove:
1632 	ida_free(&nvmet_tcp_queue_ida, queue->idx);
1633 out_free_queue:
1634 	kfree(queue);
1635 	return ret;
1636 }
1637 
1638 static void nvmet_tcp_accept_work(struct work_struct *w)
1639 {
1640 	struct nvmet_tcp_port *port =
1641 		container_of(w, struct nvmet_tcp_port, accept_work);
1642 	struct socket *newsock;
1643 	int ret;
1644 
1645 	while (true) {
1646 		ret = kernel_accept(port->sock, &newsock, O_NONBLOCK);
1647 		if (ret < 0) {
1648 			if (ret != -EAGAIN)
1649 				pr_warn("failed to accept err=%d\n", ret);
1650 			return;
1651 		}
1652 		ret = nvmet_tcp_alloc_queue(port, newsock);
1653 		if (ret) {
1654 			pr_err("failed to allocate queue\n");
1655 			sock_release(newsock);
1656 		}
1657 	}
1658 }
1659 
1660 static void nvmet_tcp_listen_data_ready(struct sock *sk)
1661 {
1662 	struct nvmet_tcp_port *port;
1663 
1664 	read_lock_bh(&sk->sk_callback_lock);
1665 	port = sk->sk_user_data;
1666 	if (!port)
1667 		goto out;
1668 
1669 	if (sk->sk_state == TCP_LISTEN)
1670 		queue_work(nvmet_wq, &port->accept_work);
1671 out:
1672 	read_unlock_bh(&sk->sk_callback_lock);
1673 }
1674 
1675 static int nvmet_tcp_add_port(struct nvmet_port *nport)
1676 {
1677 	struct nvmet_tcp_port *port;
1678 	__kernel_sa_family_t af;
1679 	int ret;
1680 
1681 	port = kzalloc(sizeof(*port), GFP_KERNEL);
1682 	if (!port)
1683 		return -ENOMEM;
1684 
1685 	switch (nport->disc_addr.adrfam) {
1686 	case NVMF_ADDR_FAMILY_IP4:
1687 		af = AF_INET;
1688 		break;
1689 	case NVMF_ADDR_FAMILY_IP6:
1690 		af = AF_INET6;
1691 		break;
1692 	default:
1693 		pr_err("address family %d not supported\n",
1694 				nport->disc_addr.adrfam);
1695 		ret = -EINVAL;
1696 		goto err_port;
1697 	}
1698 
1699 	ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
1700 			nport->disc_addr.trsvcid, &port->addr);
1701 	if (ret) {
1702 		pr_err("malformed ip/port passed: %s:%s\n",
1703 			nport->disc_addr.traddr, nport->disc_addr.trsvcid);
1704 		goto err_port;
1705 	}
1706 
1707 	port->nport = nport;
1708 	INIT_WORK(&port->accept_work, nvmet_tcp_accept_work);
1709 	if (port->nport->inline_data_size < 0)
1710 		port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
1711 
1712 	ret = sock_create(port->addr.ss_family, SOCK_STREAM,
1713 				IPPROTO_TCP, &port->sock);
1714 	if (ret) {
1715 		pr_err("failed to create a socket\n");
1716 		goto err_port;
1717 	}
1718 
1719 	port->sock->sk->sk_user_data = port;
1720 	port->data_ready = port->sock->sk->sk_data_ready;
1721 	port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
1722 	sock_set_reuseaddr(port->sock->sk);
1723 	tcp_sock_set_nodelay(port->sock->sk);
1724 	if (so_priority > 0)
1725 		sock_set_priority(port->sock->sk, so_priority);
1726 
1727 	ret = kernel_bind(port->sock, (struct sockaddr *)&port->addr,
1728 			sizeof(port->addr));
1729 	if (ret) {
1730 		pr_err("failed to bind port socket %d\n", ret);
1731 		goto err_sock;
1732 	}
1733 
1734 	ret = kernel_listen(port->sock, 128);
1735 	if (ret) {
1736 		pr_err("failed to listen %d on port sock\n", ret);
1737 		goto err_sock;
1738 	}
1739 
1740 	nport->priv = port;
1741 	pr_info("enabling port %d (%pISpc)\n",
1742 		le16_to_cpu(nport->disc_addr.portid), &port->addr);
1743 
1744 	return 0;
1745 
1746 err_sock:
1747 	sock_release(port->sock);
1748 err_port:
1749 	kfree(port);
1750 	return ret;
1751 }
1752 
1753 static void nvmet_tcp_destroy_port_queues(struct nvmet_tcp_port *port)
1754 {
1755 	struct nvmet_tcp_queue *queue;
1756 
1757 	mutex_lock(&nvmet_tcp_queue_mutex);
1758 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1759 		if (queue->port == port)
1760 			kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1761 	mutex_unlock(&nvmet_tcp_queue_mutex);
1762 }
1763 
1764 static void nvmet_tcp_remove_port(struct nvmet_port *nport)
1765 {
1766 	struct nvmet_tcp_port *port = nport->priv;
1767 
1768 	write_lock_bh(&port->sock->sk->sk_callback_lock);
1769 	port->sock->sk->sk_data_ready = port->data_ready;
1770 	port->sock->sk->sk_user_data = NULL;
1771 	write_unlock_bh(&port->sock->sk->sk_callback_lock);
1772 	cancel_work_sync(&port->accept_work);
1773 	/*
1774 	 * Destroy the remaining queues, which are not belong to any
1775 	 * controller yet.
1776 	 */
1777 	nvmet_tcp_destroy_port_queues(port);
1778 
1779 	sock_release(port->sock);
1780 	kfree(port);
1781 }
1782 
1783 static void nvmet_tcp_delete_ctrl(struct nvmet_ctrl *ctrl)
1784 {
1785 	struct nvmet_tcp_queue *queue;
1786 
1787 	mutex_lock(&nvmet_tcp_queue_mutex);
1788 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1789 		if (queue->nvme_sq.ctrl == ctrl)
1790 			kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1791 	mutex_unlock(&nvmet_tcp_queue_mutex);
1792 }
1793 
1794 static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
1795 {
1796 	struct nvmet_tcp_queue *queue =
1797 		container_of(sq, struct nvmet_tcp_queue, nvme_sq);
1798 
1799 	if (sq->qid == 0) {
1800 		/* Let inflight controller teardown complete */
1801 		flush_workqueue(nvmet_wq);
1802 	}
1803 
1804 	queue->nr_cmds = sq->size * 2;
1805 	if (nvmet_tcp_alloc_cmds(queue))
1806 		return NVME_SC_INTERNAL;
1807 	return 0;
1808 }
1809 
1810 static void nvmet_tcp_disc_port_addr(struct nvmet_req *req,
1811 		struct nvmet_port *nport, char *traddr)
1812 {
1813 	struct nvmet_tcp_port *port = nport->priv;
1814 
1815 	if (inet_addr_is_any((struct sockaddr *)&port->addr)) {
1816 		struct nvmet_tcp_cmd *cmd =
1817 			container_of(req, struct nvmet_tcp_cmd, req);
1818 		struct nvmet_tcp_queue *queue = cmd->queue;
1819 
1820 		sprintf(traddr, "%pISc", (struct sockaddr *)&queue->sockaddr);
1821 	} else {
1822 		memcpy(traddr, nport->disc_addr.traddr, NVMF_TRADDR_SIZE);
1823 	}
1824 }
1825 
1826 static const struct nvmet_fabrics_ops nvmet_tcp_ops = {
1827 	.owner			= THIS_MODULE,
1828 	.type			= NVMF_TRTYPE_TCP,
1829 	.msdbd			= 1,
1830 	.add_port		= nvmet_tcp_add_port,
1831 	.remove_port		= nvmet_tcp_remove_port,
1832 	.queue_response		= nvmet_tcp_queue_response,
1833 	.delete_ctrl		= nvmet_tcp_delete_ctrl,
1834 	.install_queue		= nvmet_tcp_install_queue,
1835 	.disc_traddr		= nvmet_tcp_disc_port_addr,
1836 };
1837 
1838 static int __init nvmet_tcp_init(void)
1839 {
1840 	int ret;
1841 
1842 	nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq", WQ_HIGHPRI, 0);
1843 	if (!nvmet_tcp_wq)
1844 		return -ENOMEM;
1845 
1846 	ret = nvmet_register_transport(&nvmet_tcp_ops);
1847 	if (ret)
1848 		goto err;
1849 
1850 	return 0;
1851 err:
1852 	destroy_workqueue(nvmet_tcp_wq);
1853 	return ret;
1854 }
1855 
1856 static void __exit nvmet_tcp_exit(void)
1857 {
1858 	struct nvmet_tcp_queue *queue;
1859 
1860 	nvmet_unregister_transport(&nvmet_tcp_ops);
1861 
1862 	flush_workqueue(nvmet_wq);
1863 	mutex_lock(&nvmet_tcp_queue_mutex);
1864 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1865 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1866 	mutex_unlock(&nvmet_tcp_queue_mutex);
1867 	flush_workqueue(nvmet_wq);
1868 
1869 	destroy_workqueue(nvmet_tcp_wq);
1870 }
1871 
1872 module_init(nvmet_tcp_init);
1873 module_exit(nvmet_tcp_exit);
1874 
1875 MODULE_LICENSE("GPL v2");
1876 MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */
1877