xref: /openbmc/linux/drivers/nvme/target/tcp.c (revision 2cf1c348)
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_send_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_tcp_recv_ddgst(struct ahash_request *hash,
417 		struct nvmet_tcp_cmd *cmd)
418 {
419 	struct scatterlist sg;
420 	struct kvec *iov;
421 	int i;
422 
423 	crypto_ahash_init(hash);
424 	for (i = 0, iov = cmd->iov; i < cmd->nr_mapped; i++, iov++) {
425 		sg_init_one(&sg, iov->iov_base, iov->iov_len);
426 		ahash_request_set_crypt(hash, &sg, NULL, iov->iov_len);
427 		crypto_ahash_update(hash);
428 	}
429 	ahash_request_set_crypt(hash, NULL, (void *)&cmd->exp_ddgst, 0);
430 	crypto_ahash_final(hash);
431 }
432 
433 static void nvmet_setup_c2h_data_pdu(struct nvmet_tcp_cmd *cmd)
434 {
435 	struct nvme_tcp_data_pdu *pdu = cmd->data_pdu;
436 	struct nvmet_tcp_queue *queue = cmd->queue;
437 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
438 	u8 ddgst = nvmet_tcp_ddgst_len(cmd->queue);
439 
440 	cmd->offset = 0;
441 	cmd->state = NVMET_TCP_SEND_DATA_PDU;
442 
443 	pdu->hdr.type = nvme_tcp_c2h_data;
444 	pdu->hdr.flags = NVME_TCP_F_DATA_LAST | (queue->nvme_sq.sqhd_disabled ?
445 						NVME_TCP_F_DATA_SUCCESS : 0);
446 	pdu->hdr.hlen = sizeof(*pdu);
447 	pdu->hdr.pdo = pdu->hdr.hlen + hdgst;
448 	pdu->hdr.plen =
449 		cpu_to_le32(pdu->hdr.hlen + hdgst +
450 				cmd->req.transfer_len + ddgst);
451 	pdu->command_id = cmd->req.cqe->command_id;
452 	pdu->data_length = cpu_to_le32(cmd->req.transfer_len);
453 	pdu->data_offset = cpu_to_le32(cmd->wbytes_done);
454 
455 	if (queue->data_digest) {
456 		pdu->hdr.flags |= NVME_TCP_F_DDGST;
457 		nvmet_tcp_send_ddgst(queue->snd_hash, cmd);
458 	}
459 
460 	if (cmd->queue->hdr_digest) {
461 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
462 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
463 	}
464 }
465 
466 static void nvmet_setup_r2t_pdu(struct nvmet_tcp_cmd *cmd)
467 {
468 	struct nvme_tcp_r2t_pdu *pdu = cmd->r2t_pdu;
469 	struct nvmet_tcp_queue *queue = cmd->queue;
470 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
471 
472 	cmd->offset = 0;
473 	cmd->state = NVMET_TCP_SEND_R2T;
474 
475 	pdu->hdr.type = nvme_tcp_r2t;
476 	pdu->hdr.flags = 0;
477 	pdu->hdr.hlen = sizeof(*pdu);
478 	pdu->hdr.pdo = 0;
479 	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
480 
481 	pdu->command_id = cmd->req.cmd->common.command_id;
482 	pdu->ttag = nvmet_tcp_cmd_tag(cmd->queue, cmd);
483 	pdu->r2t_length = cpu_to_le32(cmd->req.transfer_len - cmd->rbytes_done);
484 	pdu->r2t_offset = cpu_to_le32(cmd->rbytes_done);
485 	if (cmd->queue->hdr_digest) {
486 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
487 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
488 	}
489 }
490 
491 static void nvmet_setup_response_pdu(struct nvmet_tcp_cmd *cmd)
492 {
493 	struct nvme_tcp_rsp_pdu *pdu = cmd->rsp_pdu;
494 	struct nvmet_tcp_queue *queue = cmd->queue;
495 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
496 
497 	cmd->offset = 0;
498 	cmd->state = NVMET_TCP_SEND_RESPONSE;
499 
500 	pdu->hdr.type = nvme_tcp_rsp;
501 	pdu->hdr.flags = 0;
502 	pdu->hdr.hlen = sizeof(*pdu);
503 	pdu->hdr.pdo = 0;
504 	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
505 	if (cmd->queue->hdr_digest) {
506 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
507 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
508 	}
509 }
510 
511 static void nvmet_tcp_process_resp_list(struct nvmet_tcp_queue *queue)
512 {
513 	struct llist_node *node;
514 	struct nvmet_tcp_cmd *cmd;
515 
516 	for (node = llist_del_all(&queue->resp_list); node; node = node->next) {
517 		cmd = llist_entry(node, struct nvmet_tcp_cmd, lentry);
518 		list_add(&cmd->entry, &queue->resp_send_list);
519 		queue->send_list_len++;
520 	}
521 }
522 
523 static struct nvmet_tcp_cmd *nvmet_tcp_fetch_cmd(struct nvmet_tcp_queue *queue)
524 {
525 	queue->snd_cmd = list_first_entry_or_null(&queue->resp_send_list,
526 				struct nvmet_tcp_cmd, entry);
527 	if (!queue->snd_cmd) {
528 		nvmet_tcp_process_resp_list(queue);
529 		queue->snd_cmd =
530 			list_first_entry_or_null(&queue->resp_send_list,
531 					struct nvmet_tcp_cmd, entry);
532 		if (unlikely(!queue->snd_cmd))
533 			return NULL;
534 	}
535 
536 	list_del_init(&queue->snd_cmd->entry);
537 	queue->send_list_len--;
538 
539 	if (nvmet_tcp_need_data_out(queue->snd_cmd))
540 		nvmet_setup_c2h_data_pdu(queue->snd_cmd);
541 	else if (nvmet_tcp_need_data_in(queue->snd_cmd))
542 		nvmet_setup_r2t_pdu(queue->snd_cmd);
543 	else
544 		nvmet_setup_response_pdu(queue->snd_cmd);
545 
546 	return queue->snd_cmd;
547 }
548 
549 static void nvmet_tcp_queue_response(struct nvmet_req *req)
550 {
551 	struct nvmet_tcp_cmd *cmd =
552 		container_of(req, struct nvmet_tcp_cmd, req);
553 	struct nvmet_tcp_queue	*queue = cmd->queue;
554 	struct nvme_sgl_desc *sgl;
555 	u32 len;
556 
557 	if (unlikely(cmd == queue->cmd)) {
558 		sgl = &cmd->req.cmd->common.dptr.sgl;
559 		len = le32_to_cpu(sgl->length);
560 
561 		/*
562 		 * Wait for inline data before processing the response.
563 		 * Avoid using helpers, this might happen before
564 		 * nvmet_req_init is completed.
565 		 */
566 		if (queue->rcv_state == NVMET_TCP_RECV_PDU &&
567 		    len && len <= cmd->req.port->inline_data_size &&
568 		    nvme_is_write(cmd->req.cmd))
569 			return;
570 	}
571 
572 	llist_add(&cmd->lentry, &queue->resp_list);
573 	queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &cmd->queue->io_work);
574 }
575 
576 static void nvmet_tcp_execute_request(struct nvmet_tcp_cmd *cmd)
577 {
578 	if (unlikely(cmd->flags & NVMET_TCP_F_INIT_FAILED))
579 		nvmet_tcp_queue_response(&cmd->req);
580 	else
581 		cmd->req.execute(&cmd->req);
582 }
583 
584 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
585 {
586 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
587 	int left = sizeof(*cmd->data_pdu) - cmd->offset + hdgst;
588 	int ret;
589 
590 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->data_pdu),
591 			offset_in_page(cmd->data_pdu) + cmd->offset,
592 			left, MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST);
593 	if (ret <= 0)
594 		return ret;
595 
596 	cmd->offset += ret;
597 	left -= ret;
598 
599 	if (left)
600 		return -EAGAIN;
601 
602 	cmd->state = NVMET_TCP_SEND_DATA;
603 	cmd->offset  = 0;
604 	return 1;
605 }
606 
607 static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
608 {
609 	struct nvmet_tcp_queue *queue = cmd->queue;
610 	int ret;
611 
612 	while (cmd->cur_sg) {
613 		struct page *page = sg_page(cmd->cur_sg);
614 		u32 left = cmd->cur_sg->length - cmd->offset;
615 		int flags = MSG_DONTWAIT;
616 
617 		if ((!last_in_batch && cmd->queue->send_list_len) ||
618 		    cmd->wbytes_done + left < cmd->req.transfer_len ||
619 		    queue->data_digest || !queue->nvme_sq.sqhd_disabled)
620 			flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
621 
622 		ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
623 					left, flags);
624 		if (ret <= 0)
625 			return ret;
626 
627 		cmd->offset += ret;
628 		cmd->wbytes_done += ret;
629 
630 		/* Done with sg?*/
631 		if (cmd->offset == cmd->cur_sg->length) {
632 			cmd->cur_sg = sg_next(cmd->cur_sg);
633 			cmd->offset = 0;
634 		}
635 	}
636 
637 	if (queue->data_digest) {
638 		cmd->state = NVMET_TCP_SEND_DDGST;
639 		cmd->offset = 0;
640 	} else {
641 		if (queue->nvme_sq.sqhd_disabled) {
642 			cmd->queue->snd_cmd = NULL;
643 			nvmet_tcp_put_cmd(cmd);
644 		} else {
645 			nvmet_setup_response_pdu(cmd);
646 		}
647 	}
648 
649 	if (queue->nvme_sq.sqhd_disabled)
650 		nvmet_tcp_free_cmd_buffers(cmd);
651 
652 	return 1;
653 
654 }
655 
656 static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
657 		bool last_in_batch)
658 {
659 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
660 	int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
661 	int flags = MSG_DONTWAIT;
662 	int ret;
663 
664 	if (!last_in_batch && cmd->queue->send_list_len)
665 		flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
666 	else
667 		flags |= MSG_EOR;
668 
669 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
670 		offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
671 	if (ret <= 0)
672 		return ret;
673 	cmd->offset += ret;
674 	left -= ret;
675 
676 	if (left)
677 		return -EAGAIN;
678 
679 	nvmet_tcp_free_cmd_buffers(cmd);
680 	cmd->queue->snd_cmd = NULL;
681 	nvmet_tcp_put_cmd(cmd);
682 	return 1;
683 }
684 
685 static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
686 {
687 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
688 	int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
689 	int flags = MSG_DONTWAIT;
690 	int ret;
691 
692 	if (!last_in_batch && cmd->queue->send_list_len)
693 		flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
694 	else
695 		flags |= MSG_EOR;
696 
697 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
698 		offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
699 	if (ret <= 0)
700 		return ret;
701 	cmd->offset += ret;
702 	left -= ret;
703 
704 	if (left)
705 		return -EAGAIN;
706 
707 	cmd->queue->snd_cmd = NULL;
708 	return 1;
709 }
710 
711 static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
712 {
713 	struct nvmet_tcp_queue *queue = cmd->queue;
714 	int left = NVME_TCP_DIGEST_LENGTH - cmd->offset;
715 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
716 	struct kvec iov = {
717 		.iov_base = (u8 *)&cmd->exp_ddgst + cmd->offset,
718 		.iov_len = left
719 	};
720 	int ret;
721 
722 	if (!last_in_batch && cmd->queue->send_list_len)
723 		msg.msg_flags |= MSG_MORE;
724 	else
725 		msg.msg_flags |= MSG_EOR;
726 
727 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
728 	if (unlikely(ret <= 0))
729 		return ret;
730 
731 	cmd->offset += ret;
732 	left -= ret;
733 
734 	if (left)
735 		return -EAGAIN;
736 
737 	if (queue->nvme_sq.sqhd_disabled) {
738 		cmd->queue->snd_cmd = NULL;
739 		nvmet_tcp_put_cmd(cmd);
740 	} else {
741 		nvmet_setup_response_pdu(cmd);
742 	}
743 	return 1;
744 }
745 
746 static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
747 		bool last_in_batch)
748 {
749 	struct nvmet_tcp_cmd *cmd = queue->snd_cmd;
750 	int ret = 0;
751 
752 	if (!cmd || queue->state == NVMET_TCP_Q_DISCONNECTING) {
753 		cmd = nvmet_tcp_fetch_cmd(queue);
754 		if (unlikely(!cmd))
755 			return 0;
756 	}
757 
758 	if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
759 		ret = nvmet_try_send_data_pdu(cmd);
760 		if (ret <= 0)
761 			goto done_send;
762 	}
763 
764 	if (cmd->state == NVMET_TCP_SEND_DATA) {
765 		ret = nvmet_try_send_data(cmd, last_in_batch);
766 		if (ret <= 0)
767 			goto done_send;
768 	}
769 
770 	if (cmd->state == NVMET_TCP_SEND_DDGST) {
771 		ret = nvmet_try_send_ddgst(cmd, last_in_batch);
772 		if (ret <= 0)
773 			goto done_send;
774 	}
775 
776 	if (cmd->state == NVMET_TCP_SEND_R2T) {
777 		ret = nvmet_try_send_r2t(cmd, last_in_batch);
778 		if (ret <= 0)
779 			goto done_send;
780 	}
781 
782 	if (cmd->state == NVMET_TCP_SEND_RESPONSE)
783 		ret = nvmet_try_send_response(cmd, last_in_batch);
784 
785 done_send:
786 	if (ret < 0) {
787 		if (ret == -EAGAIN)
788 			return 0;
789 		return ret;
790 	}
791 
792 	return 1;
793 }
794 
795 static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
796 		int budget, int *sends)
797 {
798 	int i, ret = 0;
799 
800 	for (i = 0; i < budget; i++) {
801 		ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
802 		if (unlikely(ret < 0)) {
803 			nvmet_tcp_socket_error(queue, ret);
804 			goto done;
805 		} else if (ret == 0) {
806 			break;
807 		}
808 		(*sends)++;
809 	}
810 done:
811 	return ret;
812 }
813 
814 static void nvmet_prepare_receive_pdu(struct nvmet_tcp_queue *queue)
815 {
816 	queue->offset = 0;
817 	queue->left = sizeof(struct nvme_tcp_hdr);
818 	queue->cmd = NULL;
819 	queue->rcv_state = NVMET_TCP_RECV_PDU;
820 }
821 
822 static void nvmet_tcp_free_crypto(struct nvmet_tcp_queue *queue)
823 {
824 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(queue->rcv_hash);
825 
826 	ahash_request_free(queue->rcv_hash);
827 	ahash_request_free(queue->snd_hash);
828 	crypto_free_ahash(tfm);
829 }
830 
831 static int nvmet_tcp_alloc_crypto(struct nvmet_tcp_queue *queue)
832 {
833 	struct crypto_ahash *tfm;
834 
835 	tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
836 	if (IS_ERR(tfm))
837 		return PTR_ERR(tfm);
838 
839 	queue->snd_hash = ahash_request_alloc(tfm, GFP_KERNEL);
840 	if (!queue->snd_hash)
841 		goto free_tfm;
842 	ahash_request_set_callback(queue->snd_hash, 0, NULL, NULL);
843 
844 	queue->rcv_hash = ahash_request_alloc(tfm, GFP_KERNEL);
845 	if (!queue->rcv_hash)
846 		goto free_snd_hash;
847 	ahash_request_set_callback(queue->rcv_hash, 0, NULL, NULL);
848 
849 	return 0;
850 free_snd_hash:
851 	ahash_request_free(queue->snd_hash);
852 free_tfm:
853 	crypto_free_ahash(tfm);
854 	return -ENOMEM;
855 }
856 
857 
858 static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
859 {
860 	struct nvme_tcp_icreq_pdu *icreq = &queue->pdu.icreq;
861 	struct nvme_tcp_icresp_pdu *icresp = &queue->pdu.icresp;
862 	struct msghdr msg = {};
863 	struct kvec iov;
864 	int ret;
865 
866 	if (le32_to_cpu(icreq->hdr.plen) != sizeof(struct nvme_tcp_icreq_pdu)) {
867 		pr_err("bad nvme-tcp pdu length (%d)\n",
868 			le32_to_cpu(icreq->hdr.plen));
869 		nvmet_tcp_fatal_error(queue);
870 	}
871 
872 	if (icreq->pfv != NVME_TCP_PFV_1_0) {
873 		pr_err("queue %d: bad pfv %d\n", queue->idx, icreq->pfv);
874 		return -EPROTO;
875 	}
876 
877 	if (icreq->hpda != 0) {
878 		pr_err("queue %d: unsupported hpda %d\n", queue->idx,
879 			icreq->hpda);
880 		return -EPROTO;
881 	}
882 
883 	queue->hdr_digest = !!(icreq->digest & NVME_TCP_HDR_DIGEST_ENABLE);
884 	queue->data_digest = !!(icreq->digest & NVME_TCP_DATA_DIGEST_ENABLE);
885 	if (queue->hdr_digest || queue->data_digest) {
886 		ret = nvmet_tcp_alloc_crypto(queue);
887 		if (ret)
888 			return ret;
889 	}
890 
891 	memset(icresp, 0, sizeof(*icresp));
892 	icresp->hdr.type = nvme_tcp_icresp;
893 	icresp->hdr.hlen = sizeof(*icresp);
894 	icresp->hdr.pdo = 0;
895 	icresp->hdr.plen = cpu_to_le32(icresp->hdr.hlen);
896 	icresp->pfv = cpu_to_le16(NVME_TCP_PFV_1_0);
897 	icresp->maxdata = cpu_to_le32(0x400000); /* 16M arbitrary limit */
898 	icresp->cpda = 0;
899 	if (queue->hdr_digest)
900 		icresp->digest |= NVME_TCP_HDR_DIGEST_ENABLE;
901 	if (queue->data_digest)
902 		icresp->digest |= NVME_TCP_DATA_DIGEST_ENABLE;
903 
904 	iov.iov_base = icresp;
905 	iov.iov_len = sizeof(*icresp);
906 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
907 	if (ret < 0)
908 		goto free_crypto;
909 
910 	queue->state = NVMET_TCP_Q_LIVE;
911 	nvmet_prepare_receive_pdu(queue);
912 	return 0;
913 free_crypto:
914 	if (queue->hdr_digest || queue->data_digest)
915 		nvmet_tcp_free_crypto(queue);
916 	return ret;
917 }
918 
919 static void nvmet_tcp_handle_req_failure(struct nvmet_tcp_queue *queue,
920 		struct nvmet_tcp_cmd *cmd, struct nvmet_req *req)
921 {
922 	size_t data_len = le32_to_cpu(req->cmd->common.dptr.sgl.length);
923 	int ret;
924 
925 	/*
926 	 * This command has not been processed yet, hence we are trying to
927 	 * figure out if there is still pending data left to receive. If
928 	 * we don't, we can simply prepare for the next pdu and bail out,
929 	 * otherwise we will need to prepare a buffer and receive the
930 	 * stale data before continuing forward.
931 	 */
932 	if (!nvme_is_write(cmd->req.cmd) || !data_len ||
933 	    data_len > cmd->req.port->inline_data_size) {
934 		nvmet_prepare_receive_pdu(queue);
935 		return;
936 	}
937 
938 	ret = nvmet_tcp_map_data(cmd);
939 	if (unlikely(ret)) {
940 		pr_err("queue %d: failed to map data\n", queue->idx);
941 		nvmet_tcp_fatal_error(queue);
942 		return;
943 	}
944 
945 	queue->rcv_state = NVMET_TCP_RECV_DATA;
946 	nvmet_tcp_map_pdu_iovec(cmd);
947 	cmd->flags |= NVMET_TCP_F_INIT_FAILED;
948 }
949 
950 static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
951 {
952 	struct nvme_tcp_data_pdu *data = &queue->pdu.data;
953 	struct nvmet_tcp_cmd *cmd;
954 
955 	if (likely(queue->nr_cmds))
956 		cmd = &queue->cmds[data->ttag];
957 	else
958 		cmd = &queue->connect;
959 
960 	if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
961 		pr_err("ttag %u unexpected data offset %u (expected %u)\n",
962 			data->ttag, le32_to_cpu(data->data_offset),
963 			cmd->rbytes_done);
964 		/* FIXME: use path and transport errors */
965 		nvmet_req_complete(&cmd->req,
966 			NVME_SC_INVALID_FIELD | NVME_SC_DNR);
967 		return -EPROTO;
968 	}
969 
970 	cmd->pdu_len = le32_to_cpu(data->data_length);
971 	cmd->pdu_recv = 0;
972 	nvmet_tcp_map_pdu_iovec(cmd);
973 	queue->cmd = cmd;
974 	queue->rcv_state = NVMET_TCP_RECV_DATA;
975 
976 	return 0;
977 }
978 
979 static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
980 {
981 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
982 	struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
983 	struct nvmet_req *req;
984 	int ret;
985 
986 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
987 		if (hdr->type != nvme_tcp_icreq) {
988 			pr_err("unexpected pdu type (%d) before icreq\n",
989 				hdr->type);
990 			nvmet_tcp_fatal_error(queue);
991 			return -EPROTO;
992 		}
993 		return nvmet_tcp_handle_icreq(queue);
994 	}
995 
996 	if (hdr->type == nvme_tcp_h2c_data) {
997 		ret = nvmet_tcp_handle_h2c_data_pdu(queue);
998 		if (unlikely(ret))
999 			return ret;
1000 		return 0;
1001 	}
1002 
1003 	queue->cmd = nvmet_tcp_get_cmd(queue);
1004 	if (unlikely(!queue->cmd)) {
1005 		/* This should never happen */
1006 		pr_err("queue %d: out of commands (%d) send_list_len: %d, opcode: %d",
1007 			queue->idx, queue->nr_cmds, queue->send_list_len,
1008 			nvme_cmd->common.opcode);
1009 		nvmet_tcp_fatal_error(queue);
1010 		return -ENOMEM;
1011 	}
1012 
1013 	req = &queue->cmd->req;
1014 	memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
1015 
1016 	if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
1017 			&queue->nvme_sq, &nvmet_tcp_ops))) {
1018 		pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
1019 			req->cmd, req->cmd->common.command_id,
1020 			req->cmd->common.opcode,
1021 			le32_to_cpu(req->cmd->common.dptr.sgl.length));
1022 
1023 		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
1024 		return 0;
1025 	}
1026 
1027 	ret = nvmet_tcp_map_data(queue->cmd);
1028 	if (unlikely(ret)) {
1029 		pr_err("queue %d: failed to map data\n", queue->idx);
1030 		if (nvmet_tcp_has_inline_data(queue->cmd))
1031 			nvmet_tcp_fatal_error(queue);
1032 		else
1033 			nvmet_req_complete(req, ret);
1034 		ret = -EAGAIN;
1035 		goto out;
1036 	}
1037 
1038 	if (nvmet_tcp_need_data_in(queue->cmd)) {
1039 		if (nvmet_tcp_has_inline_data(queue->cmd)) {
1040 			queue->rcv_state = NVMET_TCP_RECV_DATA;
1041 			nvmet_tcp_map_pdu_iovec(queue->cmd);
1042 			return 0;
1043 		}
1044 		/* send back R2T */
1045 		nvmet_tcp_queue_response(&queue->cmd->req);
1046 		goto out;
1047 	}
1048 
1049 	queue->cmd->req.execute(&queue->cmd->req);
1050 out:
1051 	nvmet_prepare_receive_pdu(queue);
1052 	return ret;
1053 }
1054 
1055 static const u8 nvme_tcp_pdu_sizes[] = {
1056 	[nvme_tcp_icreq]	= sizeof(struct nvme_tcp_icreq_pdu),
1057 	[nvme_tcp_cmd]		= sizeof(struct nvme_tcp_cmd_pdu),
1058 	[nvme_tcp_h2c_data]	= sizeof(struct nvme_tcp_data_pdu),
1059 };
1060 
1061 static inline u8 nvmet_tcp_pdu_size(u8 type)
1062 {
1063 	size_t idx = type;
1064 
1065 	return (idx < ARRAY_SIZE(nvme_tcp_pdu_sizes) &&
1066 		nvme_tcp_pdu_sizes[idx]) ?
1067 			nvme_tcp_pdu_sizes[idx] : 0;
1068 }
1069 
1070 static inline bool nvmet_tcp_pdu_valid(u8 type)
1071 {
1072 	switch (type) {
1073 	case nvme_tcp_icreq:
1074 	case nvme_tcp_cmd:
1075 	case nvme_tcp_h2c_data:
1076 		/* fallthru */
1077 		return true;
1078 	}
1079 
1080 	return false;
1081 }
1082 
1083 static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
1084 {
1085 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
1086 	int len;
1087 	struct kvec iov;
1088 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1089 
1090 recv:
1091 	iov.iov_base = (void *)&queue->pdu + queue->offset;
1092 	iov.iov_len = queue->left;
1093 	len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1094 			iov.iov_len, msg.msg_flags);
1095 	if (unlikely(len < 0))
1096 		return len;
1097 
1098 	queue->offset += len;
1099 	queue->left -= len;
1100 	if (queue->left)
1101 		return -EAGAIN;
1102 
1103 	if (queue->offset == sizeof(struct nvme_tcp_hdr)) {
1104 		u8 hdgst = nvmet_tcp_hdgst_len(queue);
1105 
1106 		if (unlikely(!nvmet_tcp_pdu_valid(hdr->type))) {
1107 			pr_err("unexpected pdu type %d\n", hdr->type);
1108 			nvmet_tcp_fatal_error(queue);
1109 			return -EIO;
1110 		}
1111 
1112 		if (unlikely(hdr->hlen != nvmet_tcp_pdu_size(hdr->type))) {
1113 			pr_err("pdu %d bad hlen %d\n", hdr->type, hdr->hlen);
1114 			return -EIO;
1115 		}
1116 
1117 		queue->left = hdr->hlen - queue->offset + hdgst;
1118 		goto recv;
1119 	}
1120 
1121 	if (queue->hdr_digest &&
1122 	    nvmet_tcp_verify_hdgst(queue, &queue->pdu, hdr->hlen)) {
1123 		nvmet_tcp_fatal_error(queue); /* fatal */
1124 		return -EPROTO;
1125 	}
1126 
1127 	if (queue->data_digest &&
1128 	    nvmet_tcp_check_ddgst(queue, &queue->pdu)) {
1129 		nvmet_tcp_fatal_error(queue); /* fatal */
1130 		return -EPROTO;
1131 	}
1132 
1133 	return nvmet_tcp_done_recv_pdu(queue);
1134 }
1135 
1136 static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
1137 {
1138 	struct nvmet_tcp_queue *queue = cmd->queue;
1139 
1140 	nvmet_tcp_recv_ddgst(queue->rcv_hash, cmd);
1141 	queue->offset = 0;
1142 	queue->left = NVME_TCP_DIGEST_LENGTH;
1143 	queue->rcv_state = NVMET_TCP_RECV_DDGST;
1144 }
1145 
1146 static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
1147 {
1148 	struct nvmet_tcp_cmd  *cmd = queue->cmd;
1149 	int ret;
1150 
1151 	while (msg_data_left(&cmd->recv_msg)) {
1152 		ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
1153 			cmd->recv_msg.msg_flags);
1154 		if (ret <= 0)
1155 			return ret;
1156 
1157 		cmd->pdu_recv += ret;
1158 		cmd->rbytes_done += ret;
1159 	}
1160 
1161 	nvmet_tcp_unmap_pdu_iovec(cmd);
1162 	if (queue->data_digest) {
1163 		nvmet_tcp_prep_recv_ddgst(cmd);
1164 		return 0;
1165 	}
1166 
1167 	if (cmd->rbytes_done == cmd->req.transfer_len)
1168 		nvmet_tcp_execute_request(cmd);
1169 
1170 	nvmet_prepare_receive_pdu(queue);
1171 	return 0;
1172 }
1173 
1174 static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
1175 {
1176 	struct nvmet_tcp_cmd *cmd = queue->cmd;
1177 	int ret;
1178 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1179 	struct kvec iov = {
1180 		.iov_base = (void *)&cmd->recv_ddgst + queue->offset,
1181 		.iov_len = queue->left
1182 	};
1183 
1184 	ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1185 			iov.iov_len, msg.msg_flags);
1186 	if (unlikely(ret < 0))
1187 		return ret;
1188 
1189 	queue->offset += ret;
1190 	queue->left -= ret;
1191 	if (queue->left)
1192 		return -EAGAIN;
1193 
1194 	if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) {
1195 		pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n",
1196 			queue->idx, cmd->req.cmd->common.command_id,
1197 			queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
1198 			le32_to_cpu(cmd->exp_ddgst));
1199 		nvmet_tcp_finish_cmd(cmd);
1200 		nvmet_tcp_fatal_error(queue);
1201 		ret = -EPROTO;
1202 		goto out;
1203 	}
1204 
1205 	if (cmd->rbytes_done == cmd->req.transfer_len)
1206 		nvmet_tcp_execute_request(cmd);
1207 
1208 	ret = 0;
1209 out:
1210 	nvmet_prepare_receive_pdu(queue);
1211 	return ret;
1212 }
1213 
1214 static int nvmet_tcp_try_recv_one(struct nvmet_tcp_queue *queue)
1215 {
1216 	int result = 0;
1217 
1218 	if (unlikely(queue->rcv_state == NVMET_TCP_RECV_ERR))
1219 		return 0;
1220 
1221 	if (queue->rcv_state == NVMET_TCP_RECV_PDU) {
1222 		result = nvmet_tcp_try_recv_pdu(queue);
1223 		if (result != 0)
1224 			goto done_recv;
1225 	}
1226 
1227 	if (queue->rcv_state == NVMET_TCP_RECV_DATA) {
1228 		result = nvmet_tcp_try_recv_data(queue);
1229 		if (result != 0)
1230 			goto done_recv;
1231 	}
1232 
1233 	if (queue->rcv_state == NVMET_TCP_RECV_DDGST) {
1234 		result = nvmet_tcp_try_recv_ddgst(queue);
1235 		if (result != 0)
1236 			goto done_recv;
1237 	}
1238 
1239 done_recv:
1240 	if (result < 0) {
1241 		if (result == -EAGAIN)
1242 			return 0;
1243 		return result;
1244 	}
1245 	return 1;
1246 }
1247 
1248 static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
1249 		int budget, int *recvs)
1250 {
1251 	int i, ret = 0;
1252 
1253 	for (i = 0; i < budget; i++) {
1254 		ret = nvmet_tcp_try_recv_one(queue);
1255 		if (unlikely(ret < 0)) {
1256 			nvmet_tcp_socket_error(queue, ret);
1257 			goto done;
1258 		} else if (ret == 0) {
1259 			break;
1260 		}
1261 		(*recvs)++;
1262 	}
1263 done:
1264 	return ret;
1265 }
1266 
1267 static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
1268 {
1269 	spin_lock(&queue->state_lock);
1270 	if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
1271 		queue->state = NVMET_TCP_Q_DISCONNECTING;
1272 		schedule_work(&queue->release_work);
1273 	}
1274 	spin_unlock(&queue->state_lock);
1275 }
1276 
1277 static inline void nvmet_tcp_arm_queue_deadline(struct nvmet_tcp_queue *queue)
1278 {
1279 	queue->poll_end = jiffies + usecs_to_jiffies(idle_poll_period_usecs);
1280 }
1281 
1282 static bool nvmet_tcp_check_queue_deadline(struct nvmet_tcp_queue *queue,
1283 		int ops)
1284 {
1285 	if (!idle_poll_period_usecs)
1286 		return false;
1287 
1288 	if (ops)
1289 		nvmet_tcp_arm_queue_deadline(queue);
1290 
1291 	return !time_after(jiffies, queue->poll_end);
1292 }
1293 
1294 static void nvmet_tcp_io_work(struct work_struct *w)
1295 {
1296 	struct nvmet_tcp_queue *queue =
1297 		container_of(w, struct nvmet_tcp_queue, io_work);
1298 	bool pending;
1299 	int ret, ops = 0;
1300 
1301 	do {
1302 		pending = false;
1303 
1304 		ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
1305 		if (ret > 0)
1306 			pending = true;
1307 		else if (ret < 0)
1308 			return;
1309 
1310 		ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
1311 		if (ret > 0)
1312 			pending = true;
1313 		else if (ret < 0)
1314 			return;
1315 
1316 	} while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
1317 
1318 	/*
1319 	 * Requeue the worker if idle deadline period is in progress or any
1320 	 * ops activity was recorded during the do-while loop above.
1321 	 */
1322 	if (nvmet_tcp_check_queue_deadline(queue, ops) || pending)
1323 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1324 }
1325 
1326 static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
1327 		struct nvmet_tcp_cmd *c)
1328 {
1329 	u8 hdgst = nvmet_tcp_hdgst_len(queue);
1330 
1331 	c->queue = queue;
1332 	c->req.port = queue->port->nport;
1333 
1334 	c->cmd_pdu = page_frag_alloc(&queue->pf_cache,
1335 			sizeof(*c->cmd_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1336 	if (!c->cmd_pdu)
1337 		return -ENOMEM;
1338 	c->req.cmd = &c->cmd_pdu->cmd;
1339 
1340 	c->rsp_pdu = page_frag_alloc(&queue->pf_cache,
1341 			sizeof(*c->rsp_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1342 	if (!c->rsp_pdu)
1343 		goto out_free_cmd;
1344 	c->req.cqe = &c->rsp_pdu->cqe;
1345 
1346 	c->data_pdu = page_frag_alloc(&queue->pf_cache,
1347 			sizeof(*c->data_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1348 	if (!c->data_pdu)
1349 		goto out_free_rsp;
1350 
1351 	c->r2t_pdu = page_frag_alloc(&queue->pf_cache,
1352 			sizeof(*c->r2t_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1353 	if (!c->r2t_pdu)
1354 		goto out_free_data;
1355 
1356 	c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1357 
1358 	list_add_tail(&c->entry, &queue->free_list);
1359 
1360 	return 0;
1361 out_free_data:
1362 	page_frag_free(c->data_pdu);
1363 out_free_rsp:
1364 	page_frag_free(c->rsp_pdu);
1365 out_free_cmd:
1366 	page_frag_free(c->cmd_pdu);
1367 	return -ENOMEM;
1368 }
1369 
1370 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c)
1371 {
1372 	page_frag_free(c->r2t_pdu);
1373 	page_frag_free(c->data_pdu);
1374 	page_frag_free(c->rsp_pdu);
1375 	page_frag_free(c->cmd_pdu);
1376 }
1377 
1378 static int nvmet_tcp_alloc_cmds(struct nvmet_tcp_queue *queue)
1379 {
1380 	struct nvmet_tcp_cmd *cmds;
1381 	int i, ret = -EINVAL, nr_cmds = queue->nr_cmds;
1382 
1383 	cmds = kcalloc(nr_cmds, sizeof(struct nvmet_tcp_cmd), GFP_KERNEL);
1384 	if (!cmds)
1385 		goto out;
1386 
1387 	for (i = 0; i < nr_cmds; i++) {
1388 		ret = nvmet_tcp_alloc_cmd(queue, cmds + i);
1389 		if (ret)
1390 			goto out_free;
1391 	}
1392 
1393 	queue->cmds = cmds;
1394 
1395 	return 0;
1396 out_free:
1397 	while (--i >= 0)
1398 		nvmet_tcp_free_cmd(cmds + i);
1399 	kfree(cmds);
1400 out:
1401 	return ret;
1402 }
1403 
1404 static void nvmet_tcp_free_cmds(struct nvmet_tcp_queue *queue)
1405 {
1406 	struct nvmet_tcp_cmd *cmds = queue->cmds;
1407 	int i;
1408 
1409 	for (i = 0; i < queue->nr_cmds; i++)
1410 		nvmet_tcp_free_cmd(cmds + i);
1411 
1412 	nvmet_tcp_free_cmd(&queue->connect);
1413 	kfree(cmds);
1414 }
1415 
1416 static void nvmet_tcp_restore_socket_callbacks(struct nvmet_tcp_queue *queue)
1417 {
1418 	struct socket *sock = queue->sock;
1419 
1420 	write_lock_bh(&sock->sk->sk_callback_lock);
1421 	sock->sk->sk_data_ready =  queue->data_ready;
1422 	sock->sk->sk_state_change = queue->state_change;
1423 	sock->sk->sk_write_space = queue->write_space;
1424 	sock->sk->sk_user_data = NULL;
1425 	write_unlock_bh(&sock->sk->sk_callback_lock);
1426 }
1427 
1428 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
1429 {
1430 	nvmet_req_uninit(&cmd->req);
1431 	nvmet_tcp_unmap_pdu_iovec(cmd);
1432 	nvmet_tcp_free_cmd_buffers(cmd);
1433 }
1434 
1435 static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
1436 {
1437 	struct nvmet_tcp_cmd *cmd = queue->cmds;
1438 	int i;
1439 
1440 	for (i = 0; i < queue->nr_cmds; i++, cmd++) {
1441 		if (nvmet_tcp_need_data_in(cmd))
1442 			nvmet_req_uninit(&cmd->req);
1443 
1444 		nvmet_tcp_unmap_pdu_iovec(cmd);
1445 		nvmet_tcp_free_cmd_buffers(cmd);
1446 	}
1447 
1448 	if (!queue->nr_cmds && nvmet_tcp_need_data_in(&queue->connect)) {
1449 		/* failed in connect */
1450 		nvmet_tcp_finish_cmd(&queue->connect);
1451 	}
1452 }
1453 
1454 static void nvmet_tcp_release_queue_work(struct work_struct *w)
1455 {
1456 	struct page *page;
1457 	struct nvmet_tcp_queue *queue =
1458 		container_of(w, struct nvmet_tcp_queue, release_work);
1459 
1460 	mutex_lock(&nvmet_tcp_queue_mutex);
1461 	list_del_init(&queue->queue_list);
1462 	mutex_unlock(&nvmet_tcp_queue_mutex);
1463 
1464 	nvmet_tcp_restore_socket_callbacks(queue);
1465 	cancel_work_sync(&queue->io_work);
1466 	/* stop accepting incoming data */
1467 	queue->rcv_state = NVMET_TCP_RECV_ERR;
1468 
1469 	nvmet_tcp_uninit_data_in_cmds(queue);
1470 	nvmet_sq_destroy(&queue->nvme_sq);
1471 	cancel_work_sync(&queue->io_work);
1472 	sock_release(queue->sock);
1473 	nvmet_tcp_free_cmds(queue);
1474 	if (queue->hdr_digest || queue->data_digest)
1475 		nvmet_tcp_free_crypto(queue);
1476 	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1477 
1478 	page = virt_to_head_page(queue->pf_cache.va);
1479 	__page_frag_cache_drain(page, queue->pf_cache.pagecnt_bias);
1480 	kfree(queue);
1481 }
1482 
1483 static void nvmet_tcp_data_ready(struct sock *sk)
1484 {
1485 	struct nvmet_tcp_queue *queue;
1486 
1487 	read_lock_bh(&sk->sk_callback_lock);
1488 	queue = sk->sk_user_data;
1489 	if (likely(queue))
1490 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1491 	read_unlock_bh(&sk->sk_callback_lock);
1492 }
1493 
1494 static void nvmet_tcp_write_space(struct sock *sk)
1495 {
1496 	struct nvmet_tcp_queue *queue;
1497 
1498 	read_lock_bh(&sk->sk_callback_lock);
1499 	queue = sk->sk_user_data;
1500 	if (unlikely(!queue))
1501 		goto out;
1502 
1503 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
1504 		queue->write_space(sk);
1505 		goto out;
1506 	}
1507 
1508 	if (sk_stream_is_writeable(sk)) {
1509 		clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1510 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1511 	}
1512 out:
1513 	read_unlock_bh(&sk->sk_callback_lock);
1514 }
1515 
1516 static void nvmet_tcp_state_change(struct sock *sk)
1517 {
1518 	struct nvmet_tcp_queue *queue;
1519 
1520 	read_lock_bh(&sk->sk_callback_lock);
1521 	queue = sk->sk_user_data;
1522 	if (!queue)
1523 		goto done;
1524 
1525 	switch (sk->sk_state) {
1526 	case TCP_FIN_WAIT1:
1527 	case TCP_CLOSE_WAIT:
1528 	case TCP_CLOSE:
1529 		/* FALLTHRU */
1530 		nvmet_tcp_schedule_release_queue(queue);
1531 		break;
1532 	default:
1533 		pr_warn("queue %d unhandled state %d\n",
1534 			queue->idx, sk->sk_state);
1535 	}
1536 done:
1537 	read_unlock_bh(&sk->sk_callback_lock);
1538 }
1539 
1540 static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
1541 {
1542 	struct socket *sock = queue->sock;
1543 	struct inet_sock *inet = inet_sk(sock->sk);
1544 	int ret;
1545 
1546 	ret = kernel_getsockname(sock,
1547 		(struct sockaddr *)&queue->sockaddr);
1548 	if (ret < 0)
1549 		return ret;
1550 
1551 	ret = kernel_getpeername(sock,
1552 		(struct sockaddr *)&queue->sockaddr_peer);
1553 	if (ret < 0)
1554 		return ret;
1555 
1556 	/*
1557 	 * Cleanup whatever is sitting in the TCP transmit queue on socket
1558 	 * close. This is done to prevent stale data from being sent should
1559 	 * the network connection be restored before TCP times out.
1560 	 */
1561 	sock_no_linger(sock->sk);
1562 
1563 	if (so_priority > 0)
1564 		sock_set_priority(sock->sk, so_priority);
1565 
1566 	/* Set socket type of service */
1567 	if (inet->rcv_tos > 0)
1568 		ip_sock_set_tos(sock->sk, inet->rcv_tos);
1569 
1570 	ret = 0;
1571 	write_lock_bh(&sock->sk->sk_callback_lock);
1572 	if (sock->sk->sk_state != TCP_ESTABLISHED) {
1573 		/*
1574 		 * If the socket is already closing, don't even start
1575 		 * consuming it
1576 		 */
1577 		ret = -ENOTCONN;
1578 	} else {
1579 		sock->sk->sk_user_data = queue;
1580 		queue->data_ready = sock->sk->sk_data_ready;
1581 		sock->sk->sk_data_ready = nvmet_tcp_data_ready;
1582 		queue->state_change = sock->sk->sk_state_change;
1583 		sock->sk->sk_state_change = nvmet_tcp_state_change;
1584 		queue->write_space = sock->sk->sk_write_space;
1585 		sock->sk->sk_write_space = nvmet_tcp_write_space;
1586 		if (idle_poll_period_usecs)
1587 			nvmet_tcp_arm_queue_deadline(queue);
1588 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1589 	}
1590 	write_unlock_bh(&sock->sk->sk_callback_lock);
1591 
1592 	return ret;
1593 }
1594 
1595 static int nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
1596 		struct socket *newsock)
1597 {
1598 	struct nvmet_tcp_queue *queue;
1599 	int ret;
1600 
1601 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1602 	if (!queue)
1603 		return -ENOMEM;
1604 
1605 	INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
1606 	INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
1607 	queue->sock = newsock;
1608 	queue->port = port;
1609 	queue->nr_cmds = 0;
1610 	spin_lock_init(&queue->state_lock);
1611 	queue->state = NVMET_TCP_Q_CONNECTING;
1612 	INIT_LIST_HEAD(&queue->free_list);
1613 	init_llist_head(&queue->resp_list);
1614 	INIT_LIST_HEAD(&queue->resp_send_list);
1615 
1616 	queue->idx = ida_simple_get(&nvmet_tcp_queue_ida, 0, 0, GFP_KERNEL);
1617 	if (queue->idx < 0) {
1618 		ret = queue->idx;
1619 		goto out_free_queue;
1620 	}
1621 
1622 	ret = nvmet_tcp_alloc_cmd(queue, &queue->connect);
1623 	if (ret)
1624 		goto out_ida_remove;
1625 
1626 	ret = nvmet_sq_init(&queue->nvme_sq);
1627 	if (ret)
1628 		goto out_free_connect;
1629 
1630 	nvmet_prepare_receive_pdu(queue);
1631 
1632 	mutex_lock(&nvmet_tcp_queue_mutex);
1633 	list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
1634 	mutex_unlock(&nvmet_tcp_queue_mutex);
1635 
1636 	ret = nvmet_tcp_set_queue_sock(queue);
1637 	if (ret)
1638 		goto out_destroy_sq;
1639 
1640 	return 0;
1641 out_destroy_sq:
1642 	mutex_lock(&nvmet_tcp_queue_mutex);
1643 	list_del_init(&queue->queue_list);
1644 	mutex_unlock(&nvmet_tcp_queue_mutex);
1645 	nvmet_sq_destroy(&queue->nvme_sq);
1646 out_free_connect:
1647 	nvmet_tcp_free_cmd(&queue->connect);
1648 out_ida_remove:
1649 	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1650 out_free_queue:
1651 	kfree(queue);
1652 	return ret;
1653 }
1654 
1655 static void nvmet_tcp_accept_work(struct work_struct *w)
1656 {
1657 	struct nvmet_tcp_port *port =
1658 		container_of(w, struct nvmet_tcp_port, accept_work);
1659 	struct socket *newsock;
1660 	int ret;
1661 
1662 	while (true) {
1663 		ret = kernel_accept(port->sock, &newsock, O_NONBLOCK);
1664 		if (ret < 0) {
1665 			if (ret != -EAGAIN)
1666 				pr_warn("failed to accept err=%d\n", ret);
1667 			return;
1668 		}
1669 		ret = nvmet_tcp_alloc_queue(port, newsock);
1670 		if (ret) {
1671 			pr_err("failed to allocate queue\n");
1672 			sock_release(newsock);
1673 		}
1674 	}
1675 }
1676 
1677 static void nvmet_tcp_listen_data_ready(struct sock *sk)
1678 {
1679 	struct nvmet_tcp_port *port;
1680 
1681 	read_lock_bh(&sk->sk_callback_lock);
1682 	port = sk->sk_user_data;
1683 	if (!port)
1684 		goto out;
1685 
1686 	if (sk->sk_state == TCP_LISTEN)
1687 		schedule_work(&port->accept_work);
1688 out:
1689 	read_unlock_bh(&sk->sk_callback_lock);
1690 }
1691 
1692 static int nvmet_tcp_add_port(struct nvmet_port *nport)
1693 {
1694 	struct nvmet_tcp_port *port;
1695 	__kernel_sa_family_t af;
1696 	int ret;
1697 
1698 	port = kzalloc(sizeof(*port), GFP_KERNEL);
1699 	if (!port)
1700 		return -ENOMEM;
1701 
1702 	switch (nport->disc_addr.adrfam) {
1703 	case NVMF_ADDR_FAMILY_IP4:
1704 		af = AF_INET;
1705 		break;
1706 	case NVMF_ADDR_FAMILY_IP6:
1707 		af = AF_INET6;
1708 		break;
1709 	default:
1710 		pr_err("address family %d not supported\n",
1711 				nport->disc_addr.adrfam);
1712 		ret = -EINVAL;
1713 		goto err_port;
1714 	}
1715 
1716 	ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
1717 			nport->disc_addr.trsvcid, &port->addr);
1718 	if (ret) {
1719 		pr_err("malformed ip/port passed: %s:%s\n",
1720 			nport->disc_addr.traddr, nport->disc_addr.trsvcid);
1721 		goto err_port;
1722 	}
1723 
1724 	port->nport = nport;
1725 	INIT_WORK(&port->accept_work, nvmet_tcp_accept_work);
1726 	if (port->nport->inline_data_size < 0)
1727 		port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
1728 
1729 	ret = sock_create(port->addr.ss_family, SOCK_STREAM,
1730 				IPPROTO_TCP, &port->sock);
1731 	if (ret) {
1732 		pr_err("failed to create a socket\n");
1733 		goto err_port;
1734 	}
1735 
1736 	port->sock->sk->sk_user_data = port;
1737 	port->data_ready = port->sock->sk->sk_data_ready;
1738 	port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
1739 	sock_set_reuseaddr(port->sock->sk);
1740 	tcp_sock_set_nodelay(port->sock->sk);
1741 	if (so_priority > 0)
1742 		sock_set_priority(port->sock->sk, so_priority);
1743 
1744 	ret = kernel_bind(port->sock, (struct sockaddr *)&port->addr,
1745 			sizeof(port->addr));
1746 	if (ret) {
1747 		pr_err("failed to bind port socket %d\n", ret);
1748 		goto err_sock;
1749 	}
1750 
1751 	ret = kernel_listen(port->sock, 128);
1752 	if (ret) {
1753 		pr_err("failed to listen %d on port sock\n", ret);
1754 		goto err_sock;
1755 	}
1756 
1757 	nport->priv = port;
1758 	pr_info("enabling port %d (%pISpc)\n",
1759 		le16_to_cpu(nport->disc_addr.portid), &port->addr);
1760 
1761 	return 0;
1762 
1763 err_sock:
1764 	sock_release(port->sock);
1765 err_port:
1766 	kfree(port);
1767 	return ret;
1768 }
1769 
1770 static void nvmet_tcp_destroy_port_queues(struct nvmet_tcp_port *port)
1771 {
1772 	struct nvmet_tcp_queue *queue;
1773 
1774 	mutex_lock(&nvmet_tcp_queue_mutex);
1775 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1776 		if (queue->port == port)
1777 			kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1778 	mutex_unlock(&nvmet_tcp_queue_mutex);
1779 }
1780 
1781 static void nvmet_tcp_remove_port(struct nvmet_port *nport)
1782 {
1783 	struct nvmet_tcp_port *port = nport->priv;
1784 
1785 	write_lock_bh(&port->sock->sk->sk_callback_lock);
1786 	port->sock->sk->sk_data_ready = port->data_ready;
1787 	port->sock->sk->sk_user_data = NULL;
1788 	write_unlock_bh(&port->sock->sk->sk_callback_lock);
1789 	cancel_work_sync(&port->accept_work);
1790 	/*
1791 	 * Destroy the remaining queues, which are not belong to any
1792 	 * controller yet.
1793 	 */
1794 	nvmet_tcp_destroy_port_queues(port);
1795 
1796 	sock_release(port->sock);
1797 	kfree(port);
1798 }
1799 
1800 static void nvmet_tcp_delete_ctrl(struct nvmet_ctrl *ctrl)
1801 {
1802 	struct nvmet_tcp_queue *queue;
1803 
1804 	mutex_lock(&nvmet_tcp_queue_mutex);
1805 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1806 		if (queue->nvme_sq.ctrl == ctrl)
1807 			kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1808 	mutex_unlock(&nvmet_tcp_queue_mutex);
1809 }
1810 
1811 static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
1812 {
1813 	struct nvmet_tcp_queue *queue =
1814 		container_of(sq, struct nvmet_tcp_queue, nvme_sq);
1815 
1816 	if (sq->qid == 0) {
1817 		/* Let inflight controller teardown complete */
1818 		flush_scheduled_work();
1819 	}
1820 
1821 	queue->nr_cmds = sq->size * 2;
1822 	if (nvmet_tcp_alloc_cmds(queue))
1823 		return NVME_SC_INTERNAL;
1824 	return 0;
1825 }
1826 
1827 static void nvmet_tcp_disc_port_addr(struct nvmet_req *req,
1828 		struct nvmet_port *nport, char *traddr)
1829 {
1830 	struct nvmet_tcp_port *port = nport->priv;
1831 
1832 	if (inet_addr_is_any((struct sockaddr *)&port->addr)) {
1833 		struct nvmet_tcp_cmd *cmd =
1834 			container_of(req, struct nvmet_tcp_cmd, req);
1835 		struct nvmet_tcp_queue *queue = cmd->queue;
1836 
1837 		sprintf(traddr, "%pISc", (struct sockaddr *)&queue->sockaddr);
1838 	} else {
1839 		memcpy(traddr, nport->disc_addr.traddr, NVMF_TRADDR_SIZE);
1840 	}
1841 }
1842 
1843 static const struct nvmet_fabrics_ops nvmet_tcp_ops = {
1844 	.owner			= THIS_MODULE,
1845 	.type			= NVMF_TRTYPE_TCP,
1846 	.msdbd			= 1,
1847 	.add_port		= nvmet_tcp_add_port,
1848 	.remove_port		= nvmet_tcp_remove_port,
1849 	.queue_response		= nvmet_tcp_queue_response,
1850 	.delete_ctrl		= nvmet_tcp_delete_ctrl,
1851 	.install_queue		= nvmet_tcp_install_queue,
1852 	.disc_traddr		= nvmet_tcp_disc_port_addr,
1853 };
1854 
1855 static int __init nvmet_tcp_init(void)
1856 {
1857 	int ret;
1858 
1859 	nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq", WQ_HIGHPRI, 0);
1860 	if (!nvmet_tcp_wq)
1861 		return -ENOMEM;
1862 
1863 	ret = nvmet_register_transport(&nvmet_tcp_ops);
1864 	if (ret)
1865 		goto err;
1866 
1867 	return 0;
1868 err:
1869 	destroy_workqueue(nvmet_tcp_wq);
1870 	return ret;
1871 }
1872 
1873 static void __exit nvmet_tcp_exit(void)
1874 {
1875 	struct nvmet_tcp_queue *queue;
1876 
1877 	nvmet_unregister_transport(&nvmet_tcp_ops);
1878 
1879 	flush_scheduled_work();
1880 	mutex_lock(&nvmet_tcp_queue_mutex);
1881 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1882 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1883 	mutex_unlock(&nvmet_tcp_queue_mutex);
1884 	flush_scheduled_work();
1885 
1886 	destroy_workqueue(nvmet_tcp_wq);
1887 }
1888 
1889 module_init(nvmet_tcp_init);
1890 module_exit(nvmet_tcp_exit);
1891 
1892 MODULE_LICENSE("GPL v2");
1893 MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */
1894