xref: /openbmc/linux/drivers/nvme/target/tcp.c (revision e657c18a)
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 NVMET_TCP_RECV_BUDGET		8
23 #define NVMET_TCP_SEND_BUDGET		8
24 #define NVMET_TCP_IO_WORK_BUDGET	64
25 
26 enum nvmet_tcp_send_state {
27 	NVMET_TCP_SEND_DATA_PDU,
28 	NVMET_TCP_SEND_DATA,
29 	NVMET_TCP_SEND_R2T,
30 	NVMET_TCP_SEND_DDGST,
31 	NVMET_TCP_SEND_RESPONSE
32 };
33 
34 enum nvmet_tcp_recv_state {
35 	NVMET_TCP_RECV_PDU,
36 	NVMET_TCP_RECV_DATA,
37 	NVMET_TCP_RECV_DDGST,
38 	NVMET_TCP_RECV_ERR,
39 };
40 
41 enum {
42 	NVMET_TCP_F_INIT_FAILED = (1 << 0),
43 };
44 
45 struct nvmet_tcp_cmd {
46 	struct nvmet_tcp_queue		*queue;
47 	struct nvmet_req		req;
48 
49 	struct nvme_tcp_cmd_pdu		*cmd_pdu;
50 	struct nvme_tcp_rsp_pdu		*rsp_pdu;
51 	struct nvme_tcp_data_pdu	*data_pdu;
52 	struct nvme_tcp_r2t_pdu		*r2t_pdu;
53 
54 	u32				rbytes_done;
55 	u32				wbytes_done;
56 
57 	u32				pdu_len;
58 	u32				pdu_recv;
59 	int				sg_idx;
60 	int				nr_mapped;
61 	struct msghdr			recv_msg;
62 	struct kvec			*iov;
63 	u32				flags;
64 
65 	struct list_head		entry;
66 	struct llist_node		lentry;
67 
68 	/* send state */
69 	u32				offset;
70 	struct scatterlist		*cur_sg;
71 	enum nvmet_tcp_send_state	state;
72 
73 	__le32				exp_ddgst;
74 	__le32				recv_ddgst;
75 };
76 
77 enum nvmet_tcp_queue_state {
78 	NVMET_TCP_Q_CONNECTING,
79 	NVMET_TCP_Q_LIVE,
80 	NVMET_TCP_Q_DISCONNECTING,
81 };
82 
83 struct nvmet_tcp_queue {
84 	struct socket		*sock;
85 	struct nvmet_tcp_port	*port;
86 	struct work_struct	io_work;
87 	int			cpu;
88 	struct nvmet_cq		nvme_cq;
89 	struct nvmet_sq		nvme_sq;
90 
91 	/* send state */
92 	struct nvmet_tcp_cmd	*cmds;
93 	unsigned int		nr_cmds;
94 	struct list_head	free_list;
95 	struct llist_head	resp_list;
96 	struct list_head	resp_send_list;
97 	int			send_list_len;
98 	struct nvmet_tcp_cmd	*snd_cmd;
99 
100 	/* recv state */
101 	int			offset;
102 	int			left;
103 	enum nvmet_tcp_recv_state rcv_state;
104 	struct nvmet_tcp_cmd	*cmd;
105 	union nvme_tcp_pdu	pdu;
106 
107 	/* digest state */
108 	bool			hdr_digest;
109 	bool			data_digest;
110 	struct ahash_request	*snd_hash;
111 	struct ahash_request	*rcv_hash;
112 
113 	spinlock_t		state_lock;
114 	enum nvmet_tcp_queue_state state;
115 
116 	struct sockaddr_storage	sockaddr;
117 	struct sockaddr_storage	sockaddr_peer;
118 	struct work_struct	release_work;
119 
120 	int			idx;
121 	struct list_head	queue_list;
122 
123 	struct nvmet_tcp_cmd	connect;
124 
125 	struct page_frag_cache	pf_cache;
126 
127 	void (*data_ready)(struct sock *);
128 	void (*state_change)(struct sock *);
129 	void (*write_space)(struct sock *);
130 };
131 
132 struct nvmet_tcp_port {
133 	struct socket		*sock;
134 	struct work_struct	accept_work;
135 	struct nvmet_port	*nport;
136 	struct sockaddr_storage addr;
137 	int			last_cpu;
138 	void (*data_ready)(struct sock *);
139 };
140 
141 static DEFINE_IDA(nvmet_tcp_queue_ida);
142 static LIST_HEAD(nvmet_tcp_queue_list);
143 static DEFINE_MUTEX(nvmet_tcp_queue_mutex);
144 
145 static struct workqueue_struct *nvmet_tcp_wq;
146 static struct nvmet_fabrics_ops nvmet_tcp_ops;
147 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
148 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd);
149 
150 static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue,
151 		struct nvmet_tcp_cmd *cmd)
152 {
153 	return cmd - queue->cmds;
154 }
155 
156 static inline bool nvmet_tcp_has_data_in(struct nvmet_tcp_cmd *cmd)
157 {
158 	return nvme_is_write(cmd->req.cmd) &&
159 		cmd->rbytes_done < cmd->req.transfer_len;
160 }
161 
162 static inline bool nvmet_tcp_need_data_in(struct nvmet_tcp_cmd *cmd)
163 {
164 	return nvmet_tcp_has_data_in(cmd) && !cmd->req.rsp->status;
165 }
166 
167 static inline bool nvmet_tcp_need_data_out(struct nvmet_tcp_cmd *cmd)
168 {
169 	return !nvme_is_write(cmd->req.cmd) &&
170 		cmd->req.transfer_len > 0 &&
171 		!cmd->req.rsp->status;
172 }
173 
174 static inline bool nvmet_tcp_has_inline_data(struct nvmet_tcp_cmd *cmd)
175 {
176 	return nvme_is_write(cmd->req.cmd) && cmd->pdu_len &&
177 		!cmd->rbytes_done;
178 }
179 
180 static inline struct nvmet_tcp_cmd *
181 nvmet_tcp_get_cmd(struct nvmet_tcp_queue *queue)
182 {
183 	struct nvmet_tcp_cmd *cmd;
184 
185 	cmd = list_first_entry_or_null(&queue->free_list,
186 				struct nvmet_tcp_cmd, entry);
187 	if (!cmd)
188 		return NULL;
189 	list_del_init(&cmd->entry);
190 
191 	cmd->rbytes_done = cmd->wbytes_done = 0;
192 	cmd->pdu_len = 0;
193 	cmd->pdu_recv = 0;
194 	cmd->iov = NULL;
195 	cmd->flags = 0;
196 	return cmd;
197 }
198 
199 static inline void nvmet_tcp_put_cmd(struct nvmet_tcp_cmd *cmd)
200 {
201 	if (unlikely(cmd == &cmd->queue->connect))
202 		return;
203 
204 	list_add_tail(&cmd->entry, &cmd->queue->free_list);
205 }
206 
207 static inline u8 nvmet_tcp_hdgst_len(struct nvmet_tcp_queue *queue)
208 {
209 	return queue->hdr_digest ? NVME_TCP_DIGEST_LENGTH : 0;
210 }
211 
212 static inline u8 nvmet_tcp_ddgst_len(struct nvmet_tcp_queue *queue)
213 {
214 	return queue->data_digest ? NVME_TCP_DIGEST_LENGTH : 0;
215 }
216 
217 static inline void nvmet_tcp_hdgst(struct ahash_request *hash,
218 		void *pdu, size_t len)
219 {
220 	struct scatterlist sg;
221 
222 	sg_init_one(&sg, pdu, len);
223 	ahash_request_set_crypt(hash, &sg, pdu + len, len);
224 	crypto_ahash_digest(hash);
225 }
226 
227 static int nvmet_tcp_verify_hdgst(struct nvmet_tcp_queue *queue,
228 	void *pdu, size_t len)
229 {
230 	struct nvme_tcp_hdr *hdr = pdu;
231 	__le32 recv_digest;
232 	__le32 exp_digest;
233 
234 	if (unlikely(!(hdr->flags & NVME_TCP_F_HDGST))) {
235 		pr_err("queue %d: header digest enabled but no header digest\n",
236 			queue->idx);
237 		return -EPROTO;
238 	}
239 
240 	recv_digest = *(__le32 *)(pdu + hdr->hlen);
241 	nvmet_tcp_hdgst(queue->rcv_hash, pdu, len);
242 	exp_digest = *(__le32 *)(pdu + hdr->hlen);
243 	if (recv_digest != exp_digest) {
244 		pr_err("queue %d: header digest error: recv %#x expected %#x\n",
245 			queue->idx, le32_to_cpu(recv_digest),
246 			le32_to_cpu(exp_digest));
247 		return -EPROTO;
248 	}
249 
250 	return 0;
251 }
252 
253 static int nvmet_tcp_check_ddgst(struct nvmet_tcp_queue *queue, void *pdu)
254 {
255 	struct nvme_tcp_hdr *hdr = pdu;
256 	u8 digest_len = nvmet_tcp_hdgst_len(queue);
257 	u32 len;
258 
259 	len = le32_to_cpu(hdr->plen) - hdr->hlen -
260 		(hdr->flags & NVME_TCP_F_HDGST ? digest_len : 0);
261 
262 	if (unlikely(len && !(hdr->flags & NVME_TCP_F_DDGST))) {
263 		pr_err("queue %d: data digest flag is cleared\n", queue->idx);
264 		return -EPROTO;
265 	}
266 
267 	return 0;
268 }
269 
270 static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd)
271 {
272 	struct scatterlist *sg;
273 	int i;
274 
275 	sg = &cmd->req.sg[cmd->sg_idx];
276 
277 	for (i = 0; i < cmd->nr_mapped; i++)
278 		kunmap(sg_page(&sg[i]));
279 }
280 
281 static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd)
282 {
283 	struct kvec *iov = cmd->iov;
284 	struct scatterlist *sg;
285 	u32 length, offset, sg_offset;
286 
287 	length = cmd->pdu_len;
288 	cmd->nr_mapped = DIV_ROUND_UP(length, PAGE_SIZE);
289 	offset = cmd->rbytes_done;
290 	cmd->sg_idx = DIV_ROUND_UP(offset, PAGE_SIZE);
291 	sg_offset = offset % PAGE_SIZE;
292 	sg = &cmd->req.sg[cmd->sg_idx];
293 
294 	while (length) {
295 		u32 iov_len = min_t(u32, length, sg->length - sg_offset);
296 
297 		iov->iov_base = kmap(sg_page(sg)) + sg->offset + sg_offset;
298 		iov->iov_len = iov_len;
299 
300 		length -= iov_len;
301 		sg = sg_next(sg);
302 		iov++;
303 	}
304 
305 	iov_iter_kvec(&cmd->recv_msg.msg_iter, READ, cmd->iov,
306 		cmd->nr_mapped, cmd->pdu_len);
307 }
308 
309 static void nvmet_tcp_fatal_error(struct nvmet_tcp_queue *queue)
310 {
311 	queue->rcv_state = NVMET_TCP_RECV_ERR;
312 	if (queue->nvme_sq.ctrl)
313 		nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
314 	else
315 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
316 }
317 
318 static int nvmet_tcp_map_data(struct nvmet_tcp_cmd *cmd)
319 {
320 	struct nvme_sgl_desc *sgl = &cmd->req.cmd->common.dptr.sgl;
321 	u32 len = le32_to_cpu(sgl->length);
322 
323 	if (!cmd->req.data_len)
324 		return 0;
325 
326 	if (sgl->type == ((NVME_SGL_FMT_DATA_DESC << 4) |
327 			  NVME_SGL_FMT_OFFSET)) {
328 		if (!nvme_is_write(cmd->req.cmd))
329 			return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
330 
331 		if (len > cmd->req.port->inline_data_size)
332 			return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
333 		cmd->pdu_len = len;
334 	}
335 	cmd->req.transfer_len += len;
336 
337 	cmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt);
338 	if (!cmd->req.sg)
339 		return NVME_SC_INTERNAL;
340 	cmd->cur_sg = cmd->req.sg;
341 
342 	if (nvmet_tcp_has_data_in(cmd)) {
343 		cmd->iov = kmalloc_array(cmd->req.sg_cnt,
344 				sizeof(*cmd->iov), GFP_KERNEL);
345 		if (!cmd->iov)
346 			goto err;
347 	}
348 
349 	return 0;
350 err:
351 	sgl_free(cmd->req.sg);
352 	return NVME_SC_INTERNAL;
353 }
354 
355 static void nvmet_tcp_ddgst(struct ahash_request *hash,
356 		struct nvmet_tcp_cmd *cmd)
357 {
358 	ahash_request_set_crypt(hash, cmd->req.sg,
359 		(void *)&cmd->exp_ddgst, cmd->req.transfer_len);
360 	crypto_ahash_digest(hash);
361 }
362 
363 static void nvmet_setup_c2h_data_pdu(struct nvmet_tcp_cmd *cmd)
364 {
365 	struct nvme_tcp_data_pdu *pdu = cmd->data_pdu;
366 	struct nvmet_tcp_queue *queue = cmd->queue;
367 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
368 	u8 ddgst = nvmet_tcp_ddgst_len(cmd->queue);
369 
370 	cmd->offset = 0;
371 	cmd->state = NVMET_TCP_SEND_DATA_PDU;
372 
373 	pdu->hdr.type = nvme_tcp_c2h_data;
374 	pdu->hdr.flags = NVME_TCP_F_DATA_LAST;
375 	pdu->hdr.hlen = sizeof(*pdu);
376 	pdu->hdr.pdo = pdu->hdr.hlen + hdgst;
377 	pdu->hdr.plen =
378 		cpu_to_le32(pdu->hdr.hlen + hdgst +
379 				cmd->req.transfer_len + ddgst);
380 	pdu->command_id = cmd->req.rsp->command_id;
381 	pdu->data_length = cpu_to_le32(cmd->req.transfer_len);
382 	pdu->data_offset = cpu_to_le32(cmd->wbytes_done);
383 
384 	if (queue->data_digest) {
385 		pdu->hdr.flags |= NVME_TCP_F_DDGST;
386 		nvmet_tcp_ddgst(queue->snd_hash, cmd);
387 	}
388 
389 	if (cmd->queue->hdr_digest) {
390 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
391 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
392 	}
393 }
394 
395 static void nvmet_setup_r2t_pdu(struct nvmet_tcp_cmd *cmd)
396 {
397 	struct nvme_tcp_r2t_pdu *pdu = cmd->r2t_pdu;
398 	struct nvmet_tcp_queue *queue = cmd->queue;
399 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
400 
401 	cmd->offset = 0;
402 	cmd->state = NVMET_TCP_SEND_R2T;
403 
404 	pdu->hdr.type = nvme_tcp_r2t;
405 	pdu->hdr.flags = 0;
406 	pdu->hdr.hlen = sizeof(*pdu);
407 	pdu->hdr.pdo = 0;
408 	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
409 
410 	pdu->command_id = cmd->req.cmd->common.command_id;
411 	pdu->ttag = nvmet_tcp_cmd_tag(cmd->queue, cmd);
412 	pdu->r2t_length = cpu_to_le32(cmd->req.transfer_len - cmd->rbytes_done);
413 	pdu->r2t_offset = cpu_to_le32(cmd->rbytes_done);
414 	if (cmd->queue->hdr_digest) {
415 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
416 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
417 	}
418 }
419 
420 static void nvmet_setup_response_pdu(struct nvmet_tcp_cmd *cmd)
421 {
422 	struct nvme_tcp_rsp_pdu *pdu = cmd->rsp_pdu;
423 	struct nvmet_tcp_queue *queue = cmd->queue;
424 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
425 
426 	cmd->offset = 0;
427 	cmd->state = NVMET_TCP_SEND_RESPONSE;
428 
429 	pdu->hdr.type = nvme_tcp_rsp;
430 	pdu->hdr.flags = 0;
431 	pdu->hdr.hlen = sizeof(*pdu);
432 	pdu->hdr.pdo = 0;
433 	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
434 	if (cmd->queue->hdr_digest) {
435 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
436 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
437 	}
438 }
439 
440 static void nvmet_tcp_process_resp_list(struct nvmet_tcp_queue *queue)
441 {
442 	struct llist_node *node;
443 
444 	node = llist_del_all(&queue->resp_list);
445 	if (!node)
446 		return;
447 
448 	while (node) {
449 		struct nvmet_tcp_cmd *cmd = llist_entry(node,
450 					struct nvmet_tcp_cmd, lentry);
451 
452 		list_add(&cmd->entry, &queue->resp_send_list);
453 		node = node->next;
454 		queue->send_list_len++;
455 	}
456 }
457 
458 static struct nvmet_tcp_cmd *nvmet_tcp_fetch_cmd(struct nvmet_tcp_queue *queue)
459 {
460 	queue->snd_cmd = list_first_entry_or_null(&queue->resp_send_list,
461 				struct nvmet_tcp_cmd, entry);
462 	if (!queue->snd_cmd) {
463 		nvmet_tcp_process_resp_list(queue);
464 		queue->snd_cmd =
465 			list_first_entry_or_null(&queue->resp_send_list,
466 					struct nvmet_tcp_cmd, entry);
467 		if (unlikely(!queue->snd_cmd))
468 			return NULL;
469 	}
470 
471 	list_del_init(&queue->snd_cmd->entry);
472 	queue->send_list_len--;
473 
474 	if (nvmet_tcp_need_data_out(queue->snd_cmd))
475 		nvmet_setup_c2h_data_pdu(queue->snd_cmd);
476 	else if (nvmet_tcp_need_data_in(queue->snd_cmd))
477 		nvmet_setup_r2t_pdu(queue->snd_cmd);
478 	else
479 		nvmet_setup_response_pdu(queue->snd_cmd);
480 
481 	return queue->snd_cmd;
482 }
483 
484 static void nvmet_tcp_queue_response(struct nvmet_req *req)
485 {
486 	struct nvmet_tcp_cmd *cmd =
487 		container_of(req, struct nvmet_tcp_cmd, req);
488 	struct nvmet_tcp_queue	*queue = cmd->queue;
489 
490 	llist_add(&cmd->lentry, &queue->resp_list);
491 	queue_work_on(cmd->queue->cpu, nvmet_tcp_wq, &cmd->queue->io_work);
492 }
493 
494 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
495 {
496 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
497 	int left = sizeof(*cmd->data_pdu) - cmd->offset + hdgst;
498 	int ret;
499 
500 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->data_pdu),
501 			offset_in_page(cmd->data_pdu) + cmd->offset,
502 			left, MSG_DONTWAIT | MSG_MORE);
503 	if (ret <= 0)
504 		return ret;
505 
506 	cmd->offset += ret;
507 	left -= ret;
508 
509 	if (left)
510 		return -EAGAIN;
511 
512 	cmd->state = NVMET_TCP_SEND_DATA;
513 	cmd->offset  = 0;
514 	return 1;
515 }
516 
517 static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd)
518 {
519 	struct nvmet_tcp_queue *queue = cmd->queue;
520 	int ret;
521 
522 	while (cmd->cur_sg) {
523 		struct page *page = sg_page(cmd->cur_sg);
524 		u32 left = cmd->cur_sg->length - cmd->offset;
525 
526 		ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
527 					left, MSG_DONTWAIT | MSG_MORE);
528 		if (ret <= 0)
529 			return ret;
530 
531 		cmd->offset += ret;
532 		cmd->wbytes_done += ret;
533 
534 		/* Done with sg?*/
535 		if (cmd->offset == cmd->cur_sg->length) {
536 			cmd->cur_sg = sg_next(cmd->cur_sg);
537 			cmd->offset = 0;
538 		}
539 	}
540 
541 	if (queue->data_digest) {
542 		cmd->state = NVMET_TCP_SEND_DDGST;
543 		cmd->offset = 0;
544 	} else {
545 		nvmet_setup_response_pdu(cmd);
546 	}
547 	return 1;
548 
549 }
550 
551 static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
552 		bool last_in_batch)
553 {
554 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
555 	int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
556 	int flags = MSG_DONTWAIT;
557 	int ret;
558 
559 	if (!last_in_batch && cmd->queue->send_list_len)
560 		flags |= MSG_MORE;
561 	else
562 		flags |= MSG_EOR;
563 
564 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
565 		offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
566 	if (ret <= 0)
567 		return ret;
568 	cmd->offset += ret;
569 	left -= ret;
570 
571 	if (left)
572 		return -EAGAIN;
573 
574 	kfree(cmd->iov);
575 	sgl_free(cmd->req.sg);
576 	cmd->queue->snd_cmd = NULL;
577 	nvmet_tcp_put_cmd(cmd);
578 	return 1;
579 }
580 
581 static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
582 {
583 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
584 	int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
585 	int flags = MSG_DONTWAIT;
586 	int ret;
587 
588 	if (!last_in_batch && cmd->queue->send_list_len)
589 		flags |= MSG_MORE;
590 	else
591 		flags |= MSG_EOR;
592 
593 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
594 		offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
595 	if (ret <= 0)
596 		return ret;
597 	cmd->offset += ret;
598 	left -= ret;
599 
600 	if (left)
601 		return -EAGAIN;
602 
603 	cmd->queue->snd_cmd = NULL;
604 	return 1;
605 }
606 
607 static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd)
608 {
609 	struct nvmet_tcp_queue *queue = cmd->queue;
610 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
611 	struct kvec iov = {
612 		.iov_base = &cmd->exp_ddgst + cmd->offset,
613 		.iov_len = NVME_TCP_DIGEST_LENGTH - cmd->offset
614 	};
615 	int ret;
616 
617 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
618 	if (unlikely(ret <= 0))
619 		return ret;
620 
621 	cmd->offset += ret;
622 	nvmet_setup_response_pdu(cmd);
623 	return 1;
624 }
625 
626 static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
627 		bool last_in_batch)
628 {
629 	struct nvmet_tcp_cmd *cmd = queue->snd_cmd;
630 	int ret = 0;
631 
632 	if (!cmd || queue->state == NVMET_TCP_Q_DISCONNECTING) {
633 		cmd = nvmet_tcp_fetch_cmd(queue);
634 		if (unlikely(!cmd))
635 			return 0;
636 	}
637 
638 	if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
639 		ret = nvmet_try_send_data_pdu(cmd);
640 		if (ret <= 0)
641 			goto done_send;
642 	}
643 
644 	if (cmd->state == NVMET_TCP_SEND_DATA) {
645 		ret = nvmet_try_send_data(cmd);
646 		if (ret <= 0)
647 			goto done_send;
648 	}
649 
650 	if (cmd->state == NVMET_TCP_SEND_DDGST) {
651 		ret = nvmet_try_send_ddgst(cmd);
652 		if (ret <= 0)
653 			goto done_send;
654 	}
655 
656 	if (cmd->state == NVMET_TCP_SEND_R2T) {
657 		ret = nvmet_try_send_r2t(cmd, last_in_batch);
658 		if (ret <= 0)
659 			goto done_send;
660 	}
661 
662 	if (cmd->state == NVMET_TCP_SEND_RESPONSE)
663 		ret = nvmet_try_send_response(cmd, last_in_batch);
664 
665 done_send:
666 	if (ret < 0) {
667 		if (ret == -EAGAIN)
668 			return 0;
669 		return ret;
670 	}
671 
672 	return 1;
673 }
674 
675 static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
676 		int budget, int *sends)
677 {
678 	int i, ret = 0;
679 
680 	for (i = 0; i < budget; i++) {
681 		ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
682 		if (ret <= 0)
683 			break;
684 		(*sends)++;
685 	}
686 
687 	return ret;
688 }
689 
690 static void nvmet_prepare_receive_pdu(struct nvmet_tcp_queue *queue)
691 {
692 	queue->offset = 0;
693 	queue->left = sizeof(struct nvme_tcp_hdr);
694 	queue->cmd = NULL;
695 	queue->rcv_state = NVMET_TCP_RECV_PDU;
696 }
697 
698 static void nvmet_tcp_free_crypto(struct nvmet_tcp_queue *queue)
699 {
700 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(queue->rcv_hash);
701 
702 	ahash_request_free(queue->rcv_hash);
703 	ahash_request_free(queue->snd_hash);
704 	crypto_free_ahash(tfm);
705 }
706 
707 static int nvmet_tcp_alloc_crypto(struct nvmet_tcp_queue *queue)
708 {
709 	struct crypto_ahash *tfm;
710 
711 	tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
712 	if (IS_ERR(tfm))
713 		return PTR_ERR(tfm);
714 
715 	queue->snd_hash = ahash_request_alloc(tfm, GFP_KERNEL);
716 	if (!queue->snd_hash)
717 		goto free_tfm;
718 	ahash_request_set_callback(queue->snd_hash, 0, NULL, NULL);
719 
720 	queue->rcv_hash = ahash_request_alloc(tfm, GFP_KERNEL);
721 	if (!queue->rcv_hash)
722 		goto free_snd_hash;
723 	ahash_request_set_callback(queue->rcv_hash, 0, NULL, NULL);
724 
725 	return 0;
726 free_snd_hash:
727 	ahash_request_free(queue->snd_hash);
728 free_tfm:
729 	crypto_free_ahash(tfm);
730 	return -ENOMEM;
731 }
732 
733 
734 static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
735 {
736 	struct nvme_tcp_icreq_pdu *icreq = &queue->pdu.icreq;
737 	struct nvme_tcp_icresp_pdu *icresp = &queue->pdu.icresp;
738 	struct msghdr msg = {};
739 	struct kvec iov;
740 	int ret;
741 
742 	if (le32_to_cpu(icreq->hdr.plen) != sizeof(struct nvme_tcp_icreq_pdu)) {
743 		pr_err("bad nvme-tcp pdu length (%d)\n",
744 			le32_to_cpu(icreq->hdr.plen));
745 		nvmet_tcp_fatal_error(queue);
746 	}
747 
748 	if (icreq->pfv != NVME_TCP_PFV_1_0) {
749 		pr_err("queue %d: bad pfv %d\n", queue->idx, icreq->pfv);
750 		return -EPROTO;
751 	}
752 
753 	if (icreq->hpda != 0) {
754 		pr_err("queue %d: unsupported hpda %d\n", queue->idx,
755 			icreq->hpda);
756 		return -EPROTO;
757 	}
758 
759 	if (icreq->maxr2t != 0) {
760 		pr_err("queue %d: unsupported maxr2t %d\n", queue->idx,
761 			le32_to_cpu(icreq->maxr2t) + 1);
762 		return -EPROTO;
763 	}
764 
765 	queue->hdr_digest = !!(icreq->digest & NVME_TCP_HDR_DIGEST_ENABLE);
766 	queue->data_digest = !!(icreq->digest & NVME_TCP_DATA_DIGEST_ENABLE);
767 	if (queue->hdr_digest || queue->data_digest) {
768 		ret = nvmet_tcp_alloc_crypto(queue);
769 		if (ret)
770 			return ret;
771 	}
772 
773 	memset(icresp, 0, sizeof(*icresp));
774 	icresp->hdr.type = nvme_tcp_icresp;
775 	icresp->hdr.hlen = sizeof(*icresp);
776 	icresp->hdr.pdo = 0;
777 	icresp->hdr.plen = cpu_to_le32(icresp->hdr.hlen);
778 	icresp->pfv = cpu_to_le16(NVME_TCP_PFV_1_0);
779 	icresp->maxdata = cpu_to_le32(0xffff); /* FIXME: support r2t */
780 	icresp->cpda = 0;
781 	if (queue->hdr_digest)
782 		icresp->digest |= NVME_TCP_HDR_DIGEST_ENABLE;
783 	if (queue->data_digest)
784 		icresp->digest |= NVME_TCP_DATA_DIGEST_ENABLE;
785 
786 	iov.iov_base = icresp;
787 	iov.iov_len = sizeof(*icresp);
788 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
789 	if (ret < 0)
790 		goto free_crypto;
791 
792 	queue->state = NVMET_TCP_Q_LIVE;
793 	nvmet_prepare_receive_pdu(queue);
794 	return 0;
795 free_crypto:
796 	if (queue->hdr_digest || queue->data_digest)
797 		nvmet_tcp_free_crypto(queue);
798 	return ret;
799 }
800 
801 static void nvmet_tcp_handle_req_failure(struct nvmet_tcp_queue *queue,
802 		struct nvmet_tcp_cmd *cmd, struct nvmet_req *req)
803 {
804 	int ret;
805 
806 	/* recover the expected data transfer length */
807 	req->data_len = le32_to_cpu(req->cmd->common.dptr.sgl.length);
808 
809 	if (!nvme_is_write(cmd->req.cmd) ||
810 	    req->data_len > cmd->req.port->inline_data_size) {
811 		nvmet_prepare_receive_pdu(queue);
812 		return;
813 	}
814 
815 	ret = nvmet_tcp_map_data(cmd);
816 	if (unlikely(ret)) {
817 		pr_err("queue %d: failed to map data\n", queue->idx);
818 		nvmet_tcp_fatal_error(queue);
819 		return;
820 	}
821 
822 	queue->rcv_state = NVMET_TCP_RECV_DATA;
823 	nvmet_tcp_map_pdu_iovec(cmd);
824 	cmd->flags |= NVMET_TCP_F_INIT_FAILED;
825 }
826 
827 static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
828 {
829 	struct nvme_tcp_data_pdu *data = &queue->pdu.data;
830 	struct nvmet_tcp_cmd *cmd;
831 
832 	cmd = &queue->cmds[data->ttag];
833 
834 	if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
835 		pr_err("ttag %u unexpected data offset %u (expected %u)\n",
836 			data->ttag, le32_to_cpu(data->data_offset),
837 			cmd->rbytes_done);
838 		/* FIXME: use path and transport errors */
839 		nvmet_req_complete(&cmd->req,
840 			NVME_SC_INVALID_FIELD | NVME_SC_DNR);
841 		return -EPROTO;
842 	}
843 
844 	cmd->pdu_len = le32_to_cpu(data->data_length);
845 	cmd->pdu_recv = 0;
846 	nvmet_tcp_map_pdu_iovec(cmd);
847 	queue->cmd = cmd;
848 	queue->rcv_state = NVMET_TCP_RECV_DATA;
849 
850 	return 0;
851 }
852 
853 static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
854 {
855 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
856 	struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
857 	struct nvmet_req *req;
858 	int ret;
859 
860 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
861 		if (hdr->type != nvme_tcp_icreq) {
862 			pr_err("unexpected pdu type (%d) before icreq\n",
863 				hdr->type);
864 			nvmet_tcp_fatal_error(queue);
865 			return -EPROTO;
866 		}
867 		return nvmet_tcp_handle_icreq(queue);
868 	}
869 
870 	if (hdr->type == nvme_tcp_h2c_data) {
871 		ret = nvmet_tcp_handle_h2c_data_pdu(queue);
872 		if (unlikely(ret))
873 			return ret;
874 		return 0;
875 	}
876 
877 	queue->cmd = nvmet_tcp_get_cmd(queue);
878 	if (unlikely(!queue->cmd)) {
879 		/* This should never happen */
880 		pr_err("queue %d: out of commands (%d) send_list_len: %d, opcode: %d",
881 			queue->idx, queue->nr_cmds, queue->send_list_len,
882 			nvme_cmd->common.opcode);
883 		nvmet_tcp_fatal_error(queue);
884 		return -ENOMEM;
885 	}
886 
887 	req = &queue->cmd->req;
888 	memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
889 
890 	if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
891 			&queue->nvme_sq, &nvmet_tcp_ops))) {
892 		pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
893 			req->cmd, req->cmd->common.command_id,
894 			req->cmd->common.opcode,
895 			le32_to_cpu(req->cmd->common.dptr.sgl.length));
896 
897 		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
898 		return -EAGAIN;
899 	}
900 
901 	ret = nvmet_tcp_map_data(queue->cmd);
902 	if (unlikely(ret)) {
903 		pr_err("queue %d: failed to map data\n", queue->idx);
904 		if (nvmet_tcp_has_inline_data(queue->cmd))
905 			nvmet_tcp_fatal_error(queue);
906 		else
907 			nvmet_req_complete(req, ret);
908 		ret = -EAGAIN;
909 		goto out;
910 	}
911 
912 	if (nvmet_tcp_need_data_in(queue->cmd)) {
913 		if (nvmet_tcp_has_inline_data(queue->cmd)) {
914 			queue->rcv_state = NVMET_TCP_RECV_DATA;
915 			nvmet_tcp_map_pdu_iovec(queue->cmd);
916 			return 0;
917 		}
918 		/* send back R2T */
919 		nvmet_tcp_queue_response(&queue->cmd->req);
920 		goto out;
921 	}
922 
923 	nvmet_req_execute(&queue->cmd->req);
924 out:
925 	nvmet_prepare_receive_pdu(queue);
926 	return ret;
927 }
928 
929 static const u8 nvme_tcp_pdu_sizes[] = {
930 	[nvme_tcp_icreq]	= sizeof(struct nvme_tcp_icreq_pdu),
931 	[nvme_tcp_cmd]		= sizeof(struct nvme_tcp_cmd_pdu),
932 	[nvme_tcp_h2c_data]	= sizeof(struct nvme_tcp_data_pdu),
933 };
934 
935 static inline u8 nvmet_tcp_pdu_size(u8 type)
936 {
937 	size_t idx = type;
938 
939 	return (idx < ARRAY_SIZE(nvme_tcp_pdu_sizes) &&
940 		nvme_tcp_pdu_sizes[idx]) ?
941 			nvme_tcp_pdu_sizes[idx] : 0;
942 }
943 
944 static inline bool nvmet_tcp_pdu_valid(u8 type)
945 {
946 	switch (type) {
947 	case nvme_tcp_icreq:
948 	case nvme_tcp_cmd:
949 	case nvme_tcp_h2c_data:
950 		/* fallthru */
951 		return true;
952 	}
953 
954 	return false;
955 }
956 
957 static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
958 {
959 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
960 	int len;
961 	struct kvec iov;
962 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
963 
964 recv:
965 	iov.iov_base = (void *)&queue->pdu + queue->offset;
966 	iov.iov_len = queue->left;
967 	len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
968 			iov.iov_len, msg.msg_flags);
969 	if (unlikely(len < 0))
970 		return len;
971 
972 	queue->offset += len;
973 	queue->left -= len;
974 	if (queue->left)
975 		return -EAGAIN;
976 
977 	if (queue->offset == sizeof(struct nvme_tcp_hdr)) {
978 		u8 hdgst = nvmet_tcp_hdgst_len(queue);
979 
980 		if (unlikely(!nvmet_tcp_pdu_valid(hdr->type))) {
981 			pr_err("unexpected pdu type %d\n", hdr->type);
982 			nvmet_tcp_fatal_error(queue);
983 			return -EIO;
984 		}
985 
986 		if (unlikely(hdr->hlen != nvmet_tcp_pdu_size(hdr->type))) {
987 			pr_err("pdu %d bad hlen %d\n", hdr->type, hdr->hlen);
988 			return -EIO;
989 		}
990 
991 		queue->left = hdr->hlen - queue->offset + hdgst;
992 		goto recv;
993 	}
994 
995 	if (queue->hdr_digest &&
996 	    nvmet_tcp_verify_hdgst(queue, &queue->pdu, queue->offset)) {
997 		nvmet_tcp_fatal_error(queue); /* fatal */
998 		return -EPROTO;
999 	}
1000 
1001 	if (queue->data_digest &&
1002 	    nvmet_tcp_check_ddgst(queue, &queue->pdu)) {
1003 		nvmet_tcp_fatal_error(queue); /* fatal */
1004 		return -EPROTO;
1005 	}
1006 
1007 	return nvmet_tcp_done_recv_pdu(queue);
1008 }
1009 
1010 static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
1011 {
1012 	struct nvmet_tcp_queue *queue = cmd->queue;
1013 
1014 	nvmet_tcp_ddgst(queue->rcv_hash, cmd);
1015 	queue->offset = 0;
1016 	queue->left = NVME_TCP_DIGEST_LENGTH;
1017 	queue->rcv_state = NVMET_TCP_RECV_DDGST;
1018 }
1019 
1020 static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
1021 {
1022 	struct nvmet_tcp_cmd  *cmd = queue->cmd;
1023 	int ret;
1024 
1025 	while (msg_data_left(&cmd->recv_msg)) {
1026 		ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
1027 			cmd->recv_msg.msg_flags);
1028 		if (ret <= 0)
1029 			return ret;
1030 
1031 		cmd->pdu_recv += ret;
1032 		cmd->rbytes_done += ret;
1033 	}
1034 
1035 	nvmet_tcp_unmap_pdu_iovec(cmd);
1036 
1037 	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1038 	    cmd->rbytes_done == cmd->req.transfer_len) {
1039 		if (queue->data_digest) {
1040 			nvmet_tcp_prep_recv_ddgst(cmd);
1041 			return 0;
1042 		}
1043 		nvmet_req_execute(&cmd->req);
1044 	}
1045 
1046 	nvmet_prepare_receive_pdu(queue);
1047 	return 0;
1048 }
1049 
1050 static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
1051 {
1052 	struct nvmet_tcp_cmd *cmd = queue->cmd;
1053 	int ret;
1054 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1055 	struct kvec iov = {
1056 		.iov_base = (void *)&cmd->recv_ddgst + queue->offset,
1057 		.iov_len = queue->left
1058 	};
1059 
1060 	ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1061 			iov.iov_len, msg.msg_flags);
1062 	if (unlikely(ret < 0))
1063 		return ret;
1064 
1065 	queue->offset += ret;
1066 	queue->left -= ret;
1067 	if (queue->left)
1068 		return -EAGAIN;
1069 
1070 	if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) {
1071 		pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n",
1072 			queue->idx, cmd->req.cmd->common.command_id,
1073 			queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
1074 			le32_to_cpu(cmd->exp_ddgst));
1075 		nvmet_tcp_finish_cmd(cmd);
1076 		nvmet_tcp_fatal_error(queue);
1077 		ret = -EPROTO;
1078 		goto out;
1079 	}
1080 
1081 	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1082 	    cmd->rbytes_done == cmd->req.transfer_len)
1083 		nvmet_req_execute(&cmd->req);
1084 	ret = 0;
1085 out:
1086 	nvmet_prepare_receive_pdu(queue);
1087 	return ret;
1088 }
1089 
1090 static int nvmet_tcp_try_recv_one(struct nvmet_tcp_queue *queue)
1091 {
1092 	int result = 0;
1093 
1094 	if (unlikely(queue->rcv_state == NVMET_TCP_RECV_ERR))
1095 		return 0;
1096 
1097 	if (queue->rcv_state == NVMET_TCP_RECV_PDU) {
1098 		result = nvmet_tcp_try_recv_pdu(queue);
1099 		if (result != 0)
1100 			goto done_recv;
1101 	}
1102 
1103 	if (queue->rcv_state == NVMET_TCP_RECV_DATA) {
1104 		result = nvmet_tcp_try_recv_data(queue);
1105 		if (result != 0)
1106 			goto done_recv;
1107 	}
1108 
1109 	if (queue->rcv_state == NVMET_TCP_RECV_DDGST) {
1110 		result = nvmet_tcp_try_recv_ddgst(queue);
1111 		if (result != 0)
1112 			goto done_recv;
1113 	}
1114 
1115 done_recv:
1116 	if (result < 0) {
1117 		if (result == -EAGAIN)
1118 			return 0;
1119 		return result;
1120 	}
1121 	return 1;
1122 }
1123 
1124 static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
1125 		int budget, int *recvs)
1126 {
1127 	int i, ret = 0;
1128 
1129 	for (i = 0; i < budget; i++) {
1130 		ret = nvmet_tcp_try_recv_one(queue);
1131 		if (ret <= 0)
1132 			break;
1133 		(*recvs)++;
1134 	}
1135 
1136 	return ret;
1137 }
1138 
1139 static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
1140 {
1141 	spin_lock(&queue->state_lock);
1142 	if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
1143 		queue->state = NVMET_TCP_Q_DISCONNECTING;
1144 		schedule_work(&queue->release_work);
1145 	}
1146 	spin_unlock(&queue->state_lock);
1147 }
1148 
1149 static void nvmet_tcp_io_work(struct work_struct *w)
1150 {
1151 	struct nvmet_tcp_queue *queue =
1152 		container_of(w, struct nvmet_tcp_queue, io_work);
1153 	bool pending;
1154 	int ret, ops = 0;
1155 
1156 	do {
1157 		pending = false;
1158 
1159 		ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
1160 		if (ret > 0) {
1161 			pending = true;
1162 		} else if (ret < 0) {
1163 			if (ret == -EPIPE || ret == -ECONNRESET)
1164 				kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1165 			else
1166 				nvmet_tcp_fatal_error(queue);
1167 			return;
1168 		}
1169 
1170 		ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
1171 		if (ret > 0) {
1172 			/* transmitted message/data */
1173 			pending = true;
1174 		} else if (ret < 0) {
1175 			if (ret == -EPIPE || ret == -ECONNRESET)
1176 				kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1177 			else
1178 				nvmet_tcp_fatal_error(queue);
1179 			return;
1180 		}
1181 
1182 	} while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
1183 
1184 	/*
1185 	 * We exahusted our budget, requeue our selves
1186 	 */
1187 	if (pending)
1188 		queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1189 }
1190 
1191 static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
1192 		struct nvmet_tcp_cmd *c)
1193 {
1194 	u8 hdgst = nvmet_tcp_hdgst_len(queue);
1195 
1196 	c->queue = queue;
1197 	c->req.port = queue->port->nport;
1198 
1199 	c->cmd_pdu = page_frag_alloc(&queue->pf_cache,
1200 			sizeof(*c->cmd_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1201 	if (!c->cmd_pdu)
1202 		return -ENOMEM;
1203 	c->req.cmd = &c->cmd_pdu->cmd;
1204 
1205 	c->rsp_pdu = page_frag_alloc(&queue->pf_cache,
1206 			sizeof(*c->rsp_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1207 	if (!c->rsp_pdu)
1208 		goto out_free_cmd;
1209 	c->req.rsp = &c->rsp_pdu->cqe;
1210 
1211 	c->data_pdu = page_frag_alloc(&queue->pf_cache,
1212 			sizeof(*c->data_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1213 	if (!c->data_pdu)
1214 		goto out_free_rsp;
1215 
1216 	c->r2t_pdu = page_frag_alloc(&queue->pf_cache,
1217 			sizeof(*c->r2t_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1218 	if (!c->r2t_pdu)
1219 		goto out_free_data;
1220 
1221 	c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1222 
1223 	list_add_tail(&c->entry, &queue->free_list);
1224 
1225 	return 0;
1226 out_free_data:
1227 	page_frag_free(c->data_pdu);
1228 out_free_rsp:
1229 	page_frag_free(c->rsp_pdu);
1230 out_free_cmd:
1231 	page_frag_free(c->cmd_pdu);
1232 	return -ENOMEM;
1233 }
1234 
1235 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c)
1236 {
1237 	page_frag_free(c->r2t_pdu);
1238 	page_frag_free(c->data_pdu);
1239 	page_frag_free(c->rsp_pdu);
1240 	page_frag_free(c->cmd_pdu);
1241 }
1242 
1243 static int nvmet_tcp_alloc_cmds(struct nvmet_tcp_queue *queue)
1244 {
1245 	struct nvmet_tcp_cmd *cmds;
1246 	int i, ret = -EINVAL, nr_cmds = queue->nr_cmds;
1247 
1248 	cmds = kcalloc(nr_cmds, sizeof(struct nvmet_tcp_cmd), GFP_KERNEL);
1249 	if (!cmds)
1250 		goto out;
1251 
1252 	for (i = 0; i < nr_cmds; i++) {
1253 		ret = nvmet_tcp_alloc_cmd(queue, cmds + i);
1254 		if (ret)
1255 			goto out_free;
1256 	}
1257 
1258 	queue->cmds = cmds;
1259 
1260 	return 0;
1261 out_free:
1262 	while (--i >= 0)
1263 		nvmet_tcp_free_cmd(cmds + i);
1264 	kfree(cmds);
1265 out:
1266 	return ret;
1267 }
1268 
1269 static void nvmet_tcp_free_cmds(struct nvmet_tcp_queue *queue)
1270 {
1271 	struct nvmet_tcp_cmd *cmds = queue->cmds;
1272 	int i;
1273 
1274 	for (i = 0; i < queue->nr_cmds; i++)
1275 		nvmet_tcp_free_cmd(cmds + i);
1276 
1277 	nvmet_tcp_free_cmd(&queue->connect);
1278 	kfree(cmds);
1279 }
1280 
1281 static void nvmet_tcp_restore_socket_callbacks(struct nvmet_tcp_queue *queue)
1282 {
1283 	struct socket *sock = queue->sock;
1284 
1285 	write_lock_bh(&sock->sk->sk_callback_lock);
1286 	sock->sk->sk_data_ready =  queue->data_ready;
1287 	sock->sk->sk_state_change = queue->state_change;
1288 	sock->sk->sk_write_space = queue->write_space;
1289 	sock->sk->sk_user_data = NULL;
1290 	write_unlock_bh(&sock->sk->sk_callback_lock);
1291 }
1292 
1293 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
1294 {
1295 	nvmet_req_uninit(&cmd->req);
1296 	nvmet_tcp_unmap_pdu_iovec(cmd);
1297 	sgl_free(cmd->req.sg);
1298 }
1299 
1300 static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
1301 {
1302 	struct nvmet_tcp_cmd *cmd = queue->cmds;
1303 	int i;
1304 
1305 	for (i = 0; i < queue->nr_cmds; i++, cmd++) {
1306 		if (nvmet_tcp_need_data_in(cmd))
1307 			nvmet_tcp_finish_cmd(cmd);
1308 	}
1309 
1310 	if (!queue->nr_cmds && nvmet_tcp_need_data_in(&queue->connect)) {
1311 		/* failed in connect */
1312 		nvmet_tcp_finish_cmd(&queue->connect);
1313 	}
1314 }
1315 
1316 static void nvmet_tcp_release_queue_work(struct work_struct *w)
1317 {
1318 	struct nvmet_tcp_queue *queue =
1319 		container_of(w, struct nvmet_tcp_queue, release_work);
1320 
1321 	mutex_lock(&nvmet_tcp_queue_mutex);
1322 	list_del_init(&queue->queue_list);
1323 	mutex_unlock(&nvmet_tcp_queue_mutex);
1324 
1325 	nvmet_tcp_restore_socket_callbacks(queue);
1326 	flush_work(&queue->io_work);
1327 
1328 	nvmet_tcp_uninit_data_in_cmds(queue);
1329 	nvmet_sq_destroy(&queue->nvme_sq);
1330 	cancel_work_sync(&queue->io_work);
1331 	sock_release(queue->sock);
1332 	nvmet_tcp_free_cmds(queue);
1333 	if (queue->hdr_digest || queue->data_digest)
1334 		nvmet_tcp_free_crypto(queue);
1335 	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1336 
1337 	kfree(queue);
1338 }
1339 
1340 static void nvmet_tcp_data_ready(struct sock *sk)
1341 {
1342 	struct nvmet_tcp_queue *queue;
1343 
1344 	read_lock_bh(&sk->sk_callback_lock);
1345 	queue = sk->sk_user_data;
1346 	if (likely(queue))
1347 		queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1348 	read_unlock_bh(&sk->sk_callback_lock);
1349 }
1350 
1351 static void nvmet_tcp_write_space(struct sock *sk)
1352 {
1353 	struct nvmet_tcp_queue *queue;
1354 
1355 	read_lock_bh(&sk->sk_callback_lock);
1356 	queue = sk->sk_user_data;
1357 	if (unlikely(!queue))
1358 		goto out;
1359 
1360 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
1361 		queue->write_space(sk);
1362 		goto out;
1363 	}
1364 
1365 	if (sk_stream_is_writeable(sk)) {
1366 		clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1367 		queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1368 	}
1369 out:
1370 	read_unlock_bh(&sk->sk_callback_lock);
1371 }
1372 
1373 static void nvmet_tcp_state_change(struct sock *sk)
1374 {
1375 	struct nvmet_tcp_queue *queue;
1376 
1377 	write_lock_bh(&sk->sk_callback_lock);
1378 	queue = sk->sk_user_data;
1379 	if (!queue)
1380 		goto done;
1381 
1382 	switch (sk->sk_state) {
1383 	case TCP_FIN_WAIT1:
1384 	case TCP_CLOSE_WAIT:
1385 	case TCP_CLOSE:
1386 		/* FALLTHRU */
1387 		sk->sk_user_data = NULL;
1388 		nvmet_tcp_schedule_release_queue(queue);
1389 		break;
1390 	default:
1391 		pr_warn("queue %d unhandled state %d\n",
1392 			queue->idx, sk->sk_state);
1393 	}
1394 done:
1395 	write_unlock_bh(&sk->sk_callback_lock);
1396 }
1397 
1398 static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
1399 {
1400 	struct socket *sock = queue->sock;
1401 	struct linger sol = { .l_onoff = 1, .l_linger = 0 };
1402 	int ret;
1403 
1404 	ret = kernel_getsockname(sock,
1405 		(struct sockaddr *)&queue->sockaddr);
1406 	if (ret < 0)
1407 		return ret;
1408 
1409 	ret = kernel_getpeername(sock,
1410 		(struct sockaddr *)&queue->sockaddr_peer);
1411 	if (ret < 0)
1412 		return ret;
1413 
1414 	/*
1415 	 * Cleanup whatever is sitting in the TCP transmit queue on socket
1416 	 * close. This is done to prevent stale data from being sent should
1417 	 * the network connection be restored before TCP times out.
1418 	 */
1419 	ret = kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER,
1420 			(char *)&sol, sizeof(sol));
1421 	if (ret)
1422 		return ret;
1423 
1424 	write_lock_bh(&sock->sk->sk_callback_lock);
1425 	sock->sk->sk_user_data = queue;
1426 	queue->data_ready = sock->sk->sk_data_ready;
1427 	sock->sk->sk_data_ready = nvmet_tcp_data_ready;
1428 	queue->state_change = sock->sk->sk_state_change;
1429 	sock->sk->sk_state_change = nvmet_tcp_state_change;
1430 	queue->write_space = sock->sk->sk_write_space;
1431 	sock->sk->sk_write_space = nvmet_tcp_write_space;
1432 	write_unlock_bh(&sock->sk->sk_callback_lock);
1433 
1434 	return 0;
1435 }
1436 
1437 static int nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
1438 		struct socket *newsock)
1439 {
1440 	struct nvmet_tcp_queue *queue;
1441 	int ret;
1442 
1443 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1444 	if (!queue)
1445 		return -ENOMEM;
1446 
1447 	INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
1448 	INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
1449 	queue->sock = newsock;
1450 	queue->port = port;
1451 	queue->nr_cmds = 0;
1452 	spin_lock_init(&queue->state_lock);
1453 	queue->state = NVMET_TCP_Q_CONNECTING;
1454 	INIT_LIST_HEAD(&queue->free_list);
1455 	init_llist_head(&queue->resp_list);
1456 	INIT_LIST_HEAD(&queue->resp_send_list);
1457 
1458 	queue->idx = ida_simple_get(&nvmet_tcp_queue_ida, 0, 0, GFP_KERNEL);
1459 	if (queue->idx < 0) {
1460 		ret = queue->idx;
1461 		goto out_free_queue;
1462 	}
1463 
1464 	ret = nvmet_tcp_alloc_cmd(queue, &queue->connect);
1465 	if (ret)
1466 		goto out_ida_remove;
1467 
1468 	ret = nvmet_sq_init(&queue->nvme_sq);
1469 	if (ret)
1470 		goto out_free_connect;
1471 
1472 	port->last_cpu = cpumask_next_wrap(port->last_cpu,
1473 				cpu_online_mask, -1, false);
1474 	queue->cpu = port->last_cpu;
1475 	nvmet_prepare_receive_pdu(queue);
1476 
1477 	mutex_lock(&nvmet_tcp_queue_mutex);
1478 	list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
1479 	mutex_unlock(&nvmet_tcp_queue_mutex);
1480 
1481 	ret = nvmet_tcp_set_queue_sock(queue);
1482 	if (ret)
1483 		goto out_destroy_sq;
1484 
1485 	queue_work_on(queue->cpu, nvmet_tcp_wq, &queue->io_work);
1486 
1487 	return 0;
1488 out_destroy_sq:
1489 	mutex_lock(&nvmet_tcp_queue_mutex);
1490 	list_del_init(&queue->queue_list);
1491 	mutex_unlock(&nvmet_tcp_queue_mutex);
1492 	nvmet_sq_destroy(&queue->nvme_sq);
1493 out_free_connect:
1494 	nvmet_tcp_free_cmd(&queue->connect);
1495 out_ida_remove:
1496 	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1497 out_free_queue:
1498 	kfree(queue);
1499 	return ret;
1500 }
1501 
1502 static void nvmet_tcp_accept_work(struct work_struct *w)
1503 {
1504 	struct nvmet_tcp_port *port =
1505 		container_of(w, struct nvmet_tcp_port, accept_work);
1506 	struct socket *newsock;
1507 	int ret;
1508 
1509 	while (true) {
1510 		ret = kernel_accept(port->sock, &newsock, O_NONBLOCK);
1511 		if (ret < 0) {
1512 			if (ret != -EAGAIN)
1513 				pr_warn("failed to accept err=%d\n", ret);
1514 			return;
1515 		}
1516 		ret = nvmet_tcp_alloc_queue(port, newsock);
1517 		if (ret) {
1518 			pr_err("failed to allocate queue\n");
1519 			sock_release(newsock);
1520 		}
1521 	}
1522 }
1523 
1524 static void nvmet_tcp_listen_data_ready(struct sock *sk)
1525 {
1526 	struct nvmet_tcp_port *port;
1527 
1528 	read_lock_bh(&sk->sk_callback_lock);
1529 	port = sk->sk_user_data;
1530 	if (!port)
1531 		goto out;
1532 
1533 	if (sk->sk_state == TCP_LISTEN)
1534 		schedule_work(&port->accept_work);
1535 out:
1536 	read_unlock_bh(&sk->sk_callback_lock);
1537 }
1538 
1539 static int nvmet_tcp_add_port(struct nvmet_port *nport)
1540 {
1541 	struct nvmet_tcp_port *port;
1542 	__kernel_sa_family_t af;
1543 	int opt, ret;
1544 
1545 	port = kzalloc(sizeof(*port), GFP_KERNEL);
1546 	if (!port)
1547 		return -ENOMEM;
1548 
1549 	switch (nport->disc_addr.adrfam) {
1550 	case NVMF_ADDR_FAMILY_IP4:
1551 		af = AF_INET;
1552 		break;
1553 	case NVMF_ADDR_FAMILY_IP6:
1554 		af = AF_INET6;
1555 		break;
1556 	default:
1557 		pr_err("address family %d not supported\n",
1558 				nport->disc_addr.adrfam);
1559 		ret = -EINVAL;
1560 		goto err_port;
1561 	}
1562 
1563 	ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
1564 			nport->disc_addr.trsvcid, &port->addr);
1565 	if (ret) {
1566 		pr_err("malformed ip/port passed: %s:%s\n",
1567 			nport->disc_addr.traddr, nport->disc_addr.trsvcid);
1568 		goto err_port;
1569 	}
1570 
1571 	port->nport = nport;
1572 	port->last_cpu = -1;
1573 	INIT_WORK(&port->accept_work, nvmet_tcp_accept_work);
1574 	if (port->nport->inline_data_size < 0)
1575 		port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
1576 
1577 	ret = sock_create(port->addr.ss_family, SOCK_STREAM,
1578 				IPPROTO_TCP, &port->sock);
1579 	if (ret) {
1580 		pr_err("failed to create a socket\n");
1581 		goto err_port;
1582 	}
1583 
1584 	port->sock->sk->sk_user_data = port;
1585 	port->data_ready = port->sock->sk->sk_data_ready;
1586 	port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
1587 
1588 	opt = 1;
1589 	ret = kernel_setsockopt(port->sock, IPPROTO_TCP,
1590 			TCP_NODELAY, (char *)&opt, sizeof(opt));
1591 	if (ret) {
1592 		pr_err("failed to set TCP_NODELAY sock opt %d\n", ret);
1593 		goto err_sock;
1594 	}
1595 
1596 	ret = kernel_setsockopt(port->sock, SOL_SOCKET, SO_REUSEADDR,
1597 			(char *)&opt, sizeof(opt));
1598 	if (ret) {
1599 		pr_err("failed to set SO_REUSEADDR sock opt %d\n", ret);
1600 		goto err_sock;
1601 	}
1602 
1603 	ret = kernel_bind(port->sock, (struct sockaddr *)&port->addr,
1604 			sizeof(port->addr));
1605 	if (ret) {
1606 		pr_err("failed to bind port socket %d\n", ret);
1607 		goto err_sock;
1608 	}
1609 
1610 	ret = kernel_listen(port->sock, 128);
1611 	if (ret) {
1612 		pr_err("failed to listen %d on port sock\n", ret);
1613 		goto err_sock;
1614 	}
1615 
1616 	nport->priv = port;
1617 	pr_info("enabling port %d (%pISpc)\n",
1618 		le16_to_cpu(nport->disc_addr.portid), &port->addr);
1619 
1620 	return 0;
1621 
1622 err_sock:
1623 	sock_release(port->sock);
1624 err_port:
1625 	kfree(port);
1626 	return ret;
1627 }
1628 
1629 static void nvmet_tcp_remove_port(struct nvmet_port *nport)
1630 {
1631 	struct nvmet_tcp_port *port = nport->priv;
1632 
1633 	write_lock_bh(&port->sock->sk->sk_callback_lock);
1634 	port->sock->sk->sk_data_ready = port->data_ready;
1635 	port->sock->sk->sk_user_data = NULL;
1636 	write_unlock_bh(&port->sock->sk->sk_callback_lock);
1637 	cancel_work_sync(&port->accept_work);
1638 
1639 	sock_release(port->sock);
1640 	kfree(port);
1641 }
1642 
1643 static void nvmet_tcp_delete_ctrl(struct nvmet_ctrl *ctrl)
1644 {
1645 	struct nvmet_tcp_queue *queue;
1646 
1647 	mutex_lock(&nvmet_tcp_queue_mutex);
1648 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1649 		if (queue->nvme_sq.ctrl == ctrl)
1650 			kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1651 	mutex_unlock(&nvmet_tcp_queue_mutex);
1652 }
1653 
1654 static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
1655 {
1656 	struct nvmet_tcp_queue *queue =
1657 		container_of(sq, struct nvmet_tcp_queue, nvme_sq);
1658 
1659 	if (sq->qid == 0) {
1660 		/* Let inflight controller teardown complete */
1661 		flush_scheduled_work();
1662 	}
1663 
1664 	queue->nr_cmds = sq->size * 2;
1665 	if (nvmet_tcp_alloc_cmds(queue))
1666 		return NVME_SC_INTERNAL;
1667 	return 0;
1668 }
1669 
1670 static void nvmet_tcp_disc_port_addr(struct nvmet_req *req,
1671 		struct nvmet_port *nport, char *traddr)
1672 {
1673 	struct nvmet_tcp_port *port = nport->priv;
1674 
1675 	if (inet_addr_is_any((struct sockaddr *)&port->addr)) {
1676 		struct nvmet_tcp_cmd *cmd =
1677 			container_of(req, struct nvmet_tcp_cmd, req);
1678 		struct nvmet_tcp_queue *queue = cmd->queue;
1679 
1680 		sprintf(traddr, "%pISc", (struct sockaddr *)&queue->sockaddr);
1681 	} else {
1682 		memcpy(traddr, nport->disc_addr.traddr, NVMF_TRADDR_SIZE);
1683 	}
1684 }
1685 
1686 static struct nvmet_fabrics_ops nvmet_tcp_ops = {
1687 	.owner			= THIS_MODULE,
1688 	.type			= NVMF_TRTYPE_TCP,
1689 	.msdbd			= 1,
1690 	.has_keyed_sgls		= 0,
1691 	.add_port		= nvmet_tcp_add_port,
1692 	.remove_port		= nvmet_tcp_remove_port,
1693 	.queue_response		= nvmet_tcp_queue_response,
1694 	.delete_ctrl		= nvmet_tcp_delete_ctrl,
1695 	.install_queue		= nvmet_tcp_install_queue,
1696 	.disc_traddr		= nvmet_tcp_disc_port_addr,
1697 };
1698 
1699 static int __init nvmet_tcp_init(void)
1700 {
1701 	int ret;
1702 
1703 	nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq", WQ_HIGHPRI, 0);
1704 	if (!nvmet_tcp_wq)
1705 		return -ENOMEM;
1706 
1707 	ret = nvmet_register_transport(&nvmet_tcp_ops);
1708 	if (ret)
1709 		goto err;
1710 
1711 	return 0;
1712 err:
1713 	destroy_workqueue(nvmet_tcp_wq);
1714 	return ret;
1715 }
1716 
1717 static void __exit nvmet_tcp_exit(void)
1718 {
1719 	struct nvmet_tcp_queue *queue;
1720 
1721 	nvmet_unregister_transport(&nvmet_tcp_ops);
1722 
1723 	flush_scheduled_work();
1724 	mutex_lock(&nvmet_tcp_queue_mutex);
1725 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1726 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1727 	mutex_unlock(&nvmet_tcp_queue_mutex);
1728 	flush_scheduled_work();
1729 
1730 	destroy_workqueue(nvmet_tcp_wq);
1731 }
1732 
1733 module_init(nvmet_tcp_init);
1734 module_exit(nvmet_tcp_exit);
1735 
1736 MODULE_LICENSE("GPL v2");
1737 MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */
1738