xref: /openbmc/linux/drivers/nvme/target/tcp.c (revision b4e18b29)
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 NVMET_TCP_RECV_BUDGET		8
33 #define NVMET_TCP_SEND_BUDGET		8
34 #define NVMET_TCP_IO_WORK_BUDGET	64
35 
36 enum nvmet_tcp_send_state {
37 	NVMET_TCP_SEND_DATA_PDU,
38 	NVMET_TCP_SEND_DATA,
39 	NVMET_TCP_SEND_R2T,
40 	NVMET_TCP_SEND_DDGST,
41 	NVMET_TCP_SEND_RESPONSE
42 };
43 
44 enum nvmet_tcp_recv_state {
45 	NVMET_TCP_RECV_PDU,
46 	NVMET_TCP_RECV_DATA,
47 	NVMET_TCP_RECV_DDGST,
48 	NVMET_TCP_RECV_ERR,
49 };
50 
51 enum {
52 	NVMET_TCP_F_INIT_FAILED = (1 << 0),
53 };
54 
55 struct nvmet_tcp_cmd {
56 	struct nvmet_tcp_queue		*queue;
57 	struct nvmet_req		req;
58 
59 	struct nvme_tcp_cmd_pdu		*cmd_pdu;
60 	struct nvme_tcp_rsp_pdu		*rsp_pdu;
61 	struct nvme_tcp_data_pdu	*data_pdu;
62 	struct nvme_tcp_r2t_pdu		*r2t_pdu;
63 
64 	u32				rbytes_done;
65 	u32				wbytes_done;
66 
67 	u32				pdu_len;
68 	u32				pdu_recv;
69 	int				sg_idx;
70 	int				nr_mapped;
71 	struct msghdr			recv_msg;
72 	struct kvec			*iov;
73 	u32				flags;
74 
75 	struct list_head		entry;
76 	struct llist_node		lentry;
77 
78 	/* send state */
79 	u32				offset;
80 	struct scatterlist		*cur_sg;
81 	enum nvmet_tcp_send_state	state;
82 
83 	__le32				exp_ddgst;
84 	__le32				recv_ddgst;
85 };
86 
87 enum nvmet_tcp_queue_state {
88 	NVMET_TCP_Q_CONNECTING,
89 	NVMET_TCP_Q_LIVE,
90 	NVMET_TCP_Q_DISCONNECTING,
91 };
92 
93 struct nvmet_tcp_queue {
94 	struct socket		*sock;
95 	struct nvmet_tcp_port	*port;
96 	struct work_struct	io_work;
97 	struct nvmet_cq		nvme_cq;
98 	struct nvmet_sq		nvme_sq;
99 
100 	/* send state */
101 	struct nvmet_tcp_cmd	*cmds;
102 	unsigned int		nr_cmds;
103 	struct list_head	free_list;
104 	struct llist_head	resp_list;
105 	struct list_head	resp_send_list;
106 	int			send_list_len;
107 	struct nvmet_tcp_cmd	*snd_cmd;
108 
109 	/* recv state */
110 	int			offset;
111 	int			left;
112 	enum nvmet_tcp_recv_state rcv_state;
113 	struct nvmet_tcp_cmd	*cmd;
114 	union nvme_tcp_pdu	pdu;
115 
116 	/* digest state */
117 	bool			hdr_digest;
118 	bool			data_digest;
119 	struct ahash_request	*snd_hash;
120 	struct ahash_request	*rcv_hash;
121 
122 	spinlock_t		state_lock;
123 	enum nvmet_tcp_queue_state state;
124 
125 	struct sockaddr_storage	sockaddr;
126 	struct sockaddr_storage	sockaddr_peer;
127 	struct work_struct	release_work;
128 
129 	int			idx;
130 	struct list_head	queue_list;
131 
132 	struct nvmet_tcp_cmd	connect;
133 
134 	struct page_frag_cache	pf_cache;
135 
136 	void (*data_ready)(struct sock *);
137 	void (*state_change)(struct sock *);
138 	void (*write_space)(struct sock *);
139 };
140 
141 struct nvmet_tcp_port {
142 	struct socket		*sock;
143 	struct work_struct	accept_work;
144 	struct nvmet_port	*nport;
145 	struct sockaddr_storage addr;
146 	void (*data_ready)(struct sock *);
147 };
148 
149 static DEFINE_IDA(nvmet_tcp_queue_ida);
150 static LIST_HEAD(nvmet_tcp_queue_list);
151 static DEFINE_MUTEX(nvmet_tcp_queue_mutex);
152 
153 static struct workqueue_struct *nvmet_tcp_wq;
154 static const struct nvmet_fabrics_ops nvmet_tcp_ops;
155 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c);
156 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd);
157 
158 static inline u16 nvmet_tcp_cmd_tag(struct nvmet_tcp_queue *queue,
159 		struct nvmet_tcp_cmd *cmd)
160 {
161 	if (unlikely(!queue->nr_cmds)) {
162 		/* We didn't allocate cmds yet, send 0xffff */
163 		return USHRT_MAX;
164 	}
165 
166 	return cmd - queue->cmds;
167 }
168 
169 static inline bool nvmet_tcp_has_data_in(struct nvmet_tcp_cmd *cmd)
170 {
171 	return nvme_is_write(cmd->req.cmd) &&
172 		cmd->rbytes_done < cmd->req.transfer_len;
173 }
174 
175 static inline bool nvmet_tcp_need_data_in(struct nvmet_tcp_cmd *cmd)
176 {
177 	return nvmet_tcp_has_data_in(cmd) && !cmd->req.cqe->status;
178 }
179 
180 static inline bool nvmet_tcp_need_data_out(struct nvmet_tcp_cmd *cmd)
181 {
182 	return !nvme_is_write(cmd->req.cmd) &&
183 		cmd->req.transfer_len > 0 &&
184 		!cmd->req.cqe->status;
185 }
186 
187 static inline bool nvmet_tcp_has_inline_data(struct nvmet_tcp_cmd *cmd)
188 {
189 	return nvme_is_write(cmd->req.cmd) && cmd->pdu_len &&
190 		!cmd->rbytes_done;
191 }
192 
193 static inline struct nvmet_tcp_cmd *
194 nvmet_tcp_get_cmd(struct nvmet_tcp_queue *queue)
195 {
196 	struct nvmet_tcp_cmd *cmd;
197 
198 	cmd = list_first_entry_or_null(&queue->free_list,
199 				struct nvmet_tcp_cmd, entry);
200 	if (!cmd)
201 		return NULL;
202 	list_del_init(&cmd->entry);
203 
204 	cmd->rbytes_done = cmd->wbytes_done = 0;
205 	cmd->pdu_len = 0;
206 	cmd->pdu_recv = 0;
207 	cmd->iov = NULL;
208 	cmd->flags = 0;
209 	return cmd;
210 }
211 
212 static inline void nvmet_tcp_put_cmd(struct nvmet_tcp_cmd *cmd)
213 {
214 	if (unlikely(cmd == &cmd->queue->connect))
215 		return;
216 
217 	list_add_tail(&cmd->entry, &cmd->queue->free_list);
218 }
219 
220 static inline int queue_cpu(struct nvmet_tcp_queue *queue)
221 {
222 	return queue->sock->sk->sk_incoming_cpu;
223 }
224 
225 static inline u8 nvmet_tcp_hdgst_len(struct nvmet_tcp_queue *queue)
226 {
227 	return queue->hdr_digest ? NVME_TCP_DIGEST_LENGTH : 0;
228 }
229 
230 static inline u8 nvmet_tcp_ddgst_len(struct nvmet_tcp_queue *queue)
231 {
232 	return queue->data_digest ? NVME_TCP_DIGEST_LENGTH : 0;
233 }
234 
235 static inline void nvmet_tcp_hdgst(struct ahash_request *hash,
236 		void *pdu, size_t len)
237 {
238 	struct scatterlist sg;
239 
240 	sg_init_one(&sg, pdu, len);
241 	ahash_request_set_crypt(hash, &sg, pdu + len, len);
242 	crypto_ahash_digest(hash);
243 }
244 
245 static int nvmet_tcp_verify_hdgst(struct nvmet_tcp_queue *queue,
246 	void *pdu, size_t len)
247 {
248 	struct nvme_tcp_hdr *hdr = pdu;
249 	__le32 recv_digest;
250 	__le32 exp_digest;
251 
252 	if (unlikely(!(hdr->flags & NVME_TCP_F_HDGST))) {
253 		pr_err("queue %d: header digest enabled but no header digest\n",
254 			queue->idx);
255 		return -EPROTO;
256 	}
257 
258 	recv_digest = *(__le32 *)(pdu + hdr->hlen);
259 	nvmet_tcp_hdgst(queue->rcv_hash, pdu, len);
260 	exp_digest = *(__le32 *)(pdu + hdr->hlen);
261 	if (recv_digest != exp_digest) {
262 		pr_err("queue %d: header digest error: recv %#x expected %#x\n",
263 			queue->idx, le32_to_cpu(recv_digest),
264 			le32_to_cpu(exp_digest));
265 		return -EPROTO;
266 	}
267 
268 	return 0;
269 }
270 
271 static int nvmet_tcp_check_ddgst(struct nvmet_tcp_queue *queue, void *pdu)
272 {
273 	struct nvme_tcp_hdr *hdr = pdu;
274 	u8 digest_len = nvmet_tcp_hdgst_len(queue);
275 	u32 len;
276 
277 	len = le32_to_cpu(hdr->plen) - hdr->hlen -
278 		(hdr->flags & NVME_TCP_F_HDGST ? digest_len : 0);
279 
280 	if (unlikely(len && !(hdr->flags & NVME_TCP_F_DDGST))) {
281 		pr_err("queue %d: data digest flag is cleared\n", queue->idx);
282 		return -EPROTO;
283 	}
284 
285 	return 0;
286 }
287 
288 static void nvmet_tcp_unmap_pdu_iovec(struct nvmet_tcp_cmd *cmd)
289 {
290 	struct scatterlist *sg;
291 	int i;
292 
293 	sg = &cmd->req.sg[cmd->sg_idx];
294 
295 	for (i = 0; i < cmd->nr_mapped; i++)
296 		kunmap(sg_page(&sg[i]));
297 }
298 
299 static void nvmet_tcp_map_pdu_iovec(struct nvmet_tcp_cmd *cmd)
300 {
301 	struct kvec *iov = cmd->iov;
302 	struct scatterlist *sg;
303 	u32 length, offset, sg_offset;
304 
305 	length = cmd->pdu_len;
306 	cmd->nr_mapped = DIV_ROUND_UP(length, PAGE_SIZE);
307 	offset = cmd->rbytes_done;
308 	cmd->sg_idx = offset / PAGE_SIZE;
309 	sg_offset = offset % PAGE_SIZE;
310 	sg = &cmd->req.sg[cmd->sg_idx];
311 
312 	while (length) {
313 		u32 iov_len = min_t(u32, length, sg->length - sg_offset);
314 
315 		iov->iov_base = kmap(sg_page(sg)) + sg->offset + sg_offset;
316 		iov->iov_len = iov_len;
317 
318 		length -= iov_len;
319 		sg = sg_next(sg);
320 		iov++;
321 		sg_offset = 0;
322 	}
323 
324 	iov_iter_kvec(&cmd->recv_msg.msg_iter, READ, cmd->iov,
325 		cmd->nr_mapped, cmd->pdu_len);
326 }
327 
328 static void nvmet_tcp_fatal_error(struct nvmet_tcp_queue *queue)
329 {
330 	queue->rcv_state = NVMET_TCP_RECV_ERR;
331 	if (queue->nvme_sq.ctrl)
332 		nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
333 	else
334 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
335 }
336 
337 static void nvmet_tcp_socket_error(struct nvmet_tcp_queue *queue, int status)
338 {
339 	if (status == -EPIPE || status == -ECONNRESET)
340 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
341 	else
342 		nvmet_tcp_fatal_error(queue);
343 }
344 
345 static int nvmet_tcp_map_data(struct nvmet_tcp_cmd *cmd)
346 {
347 	struct nvme_sgl_desc *sgl = &cmd->req.cmd->common.dptr.sgl;
348 	u32 len = le32_to_cpu(sgl->length);
349 
350 	if (!len)
351 		return 0;
352 
353 	if (sgl->type == ((NVME_SGL_FMT_DATA_DESC << 4) |
354 			  NVME_SGL_FMT_OFFSET)) {
355 		if (!nvme_is_write(cmd->req.cmd))
356 			return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
357 
358 		if (len > cmd->req.port->inline_data_size)
359 			return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
360 		cmd->pdu_len = len;
361 	}
362 	cmd->req.transfer_len += len;
363 
364 	cmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt);
365 	if (!cmd->req.sg)
366 		return NVME_SC_INTERNAL;
367 	cmd->cur_sg = cmd->req.sg;
368 
369 	if (nvmet_tcp_has_data_in(cmd)) {
370 		cmd->iov = kmalloc_array(cmd->req.sg_cnt,
371 				sizeof(*cmd->iov), GFP_KERNEL);
372 		if (!cmd->iov)
373 			goto err;
374 	}
375 
376 	return 0;
377 err:
378 	sgl_free(cmd->req.sg);
379 	return NVME_SC_INTERNAL;
380 }
381 
382 static void nvmet_tcp_ddgst(struct ahash_request *hash,
383 		struct nvmet_tcp_cmd *cmd)
384 {
385 	ahash_request_set_crypt(hash, cmd->req.sg,
386 		(void *)&cmd->exp_ddgst, cmd->req.transfer_len);
387 	crypto_ahash_digest(hash);
388 }
389 
390 static void nvmet_setup_c2h_data_pdu(struct nvmet_tcp_cmd *cmd)
391 {
392 	struct nvme_tcp_data_pdu *pdu = cmd->data_pdu;
393 	struct nvmet_tcp_queue *queue = cmd->queue;
394 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
395 	u8 ddgst = nvmet_tcp_ddgst_len(cmd->queue);
396 
397 	cmd->offset = 0;
398 	cmd->state = NVMET_TCP_SEND_DATA_PDU;
399 
400 	pdu->hdr.type = nvme_tcp_c2h_data;
401 	pdu->hdr.flags = NVME_TCP_F_DATA_LAST | (queue->nvme_sq.sqhd_disabled ?
402 						NVME_TCP_F_DATA_SUCCESS : 0);
403 	pdu->hdr.hlen = sizeof(*pdu);
404 	pdu->hdr.pdo = pdu->hdr.hlen + hdgst;
405 	pdu->hdr.plen =
406 		cpu_to_le32(pdu->hdr.hlen + hdgst +
407 				cmd->req.transfer_len + ddgst);
408 	pdu->command_id = cmd->req.cqe->command_id;
409 	pdu->data_length = cpu_to_le32(cmd->req.transfer_len);
410 	pdu->data_offset = cpu_to_le32(cmd->wbytes_done);
411 
412 	if (queue->data_digest) {
413 		pdu->hdr.flags |= NVME_TCP_F_DDGST;
414 		nvmet_tcp_ddgst(queue->snd_hash, cmd);
415 	}
416 
417 	if (cmd->queue->hdr_digest) {
418 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
419 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
420 	}
421 }
422 
423 static void nvmet_setup_r2t_pdu(struct nvmet_tcp_cmd *cmd)
424 {
425 	struct nvme_tcp_r2t_pdu *pdu = cmd->r2t_pdu;
426 	struct nvmet_tcp_queue *queue = cmd->queue;
427 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
428 
429 	cmd->offset = 0;
430 	cmd->state = NVMET_TCP_SEND_R2T;
431 
432 	pdu->hdr.type = nvme_tcp_r2t;
433 	pdu->hdr.flags = 0;
434 	pdu->hdr.hlen = sizeof(*pdu);
435 	pdu->hdr.pdo = 0;
436 	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
437 
438 	pdu->command_id = cmd->req.cmd->common.command_id;
439 	pdu->ttag = nvmet_tcp_cmd_tag(cmd->queue, cmd);
440 	pdu->r2t_length = cpu_to_le32(cmd->req.transfer_len - cmd->rbytes_done);
441 	pdu->r2t_offset = cpu_to_le32(cmd->rbytes_done);
442 	if (cmd->queue->hdr_digest) {
443 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
444 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
445 	}
446 }
447 
448 static void nvmet_setup_response_pdu(struct nvmet_tcp_cmd *cmd)
449 {
450 	struct nvme_tcp_rsp_pdu *pdu = cmd->rsp_pdu;
451 	struct nvmet_tcp_queue *queue = cmd->queue;
452 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
453 
454 	cmd->offset = 0;
455 	cmd->state = NVMET_TCP_SEND_RESPONSE;
456 
457 	pdu->hdr.type = nvme_tcp_rsp;
458 	pdu->hdr.flags = 0;
459 	pdu->hdr.hlen = sizeof(*pdu);
460 	pdu->hdr.pdo = 0;
461 	pdu->hdr.plen = cpu_to_le32(pdu->hdr.hlen + hdgst);
462 	if (cmd->queue->hdr_digest) {
463 		pdu->hdr.flags |= NVME_TCP_F_HDGST;
464 		nvmet_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
465 	}
466 }
467 
468 static void nvmet_tcp_process_resp_list(struct nvmet_tcp_queue *queue)
469 {
470 	struct llist_node *node;
471 	struct nvmet_tcp_cmd *cmd;
472 
473 	for (node = llist_del_all(&queue->resp_list); node; node = node->next) {
474 		cmd = llist_entry(node, struct nvmet_tcp_cmd, lentry);
475 		list_add(&cmd->entry, &queue->resp_send_list);
476 		queue->send_list_len++;
477 	}
478 }
479 
480 static struct nvmet_tcp_cmd *nvmet_tcp_fetch_cmd(struct nvmet_tcp_queue *queue)
481 {
482 	queue->snd_cmd = list_first_entry_or_null(&queue->resp_send_list,
483 				struct nvmet_tcp_cmd, entry);
484 	if (!queue->snd_cmd) {
485 		nvmet_tcp_process_resp_list(queue);
486 		queue->snd_cmd =
487 			list_first_entry_or_null(&queue->resp_send_list,
488 					struct nvmet_tcp_cmd, entry);
489 		if (unlikely(!queue->snd_cmd))
490 			return NULL;
491 	}
492 
493 	list_del_init(&queue->snd_cmd->entry);
494 	queue->send_list_len--;
495 
496 	if (nvmet_tcp_need_data_out(queue->snd_cmd))
497 		nvmet_setup_c2h_data_pdu(queue->snd_cmd);
498 	else if (nvmet_tcp_need_data_in(queue->snd_cmd))
499 		nvmet_setup_r2t_pdu(queue->snd_cmd);
500 	else
501 		nvmet_setup_response_pdu(queue->snd_cmd);
502 
503 	return queue->snd_cmd;
504 }
505 
506 static void nvmet_tcp_queue_response(struct nvmet_req *req)
507 {
508 	struct nvmet_tcp_cmd *cmd =
509 		container_of(req, struct nvmet_tcp_cmd, req);
510 	struct nvmet_tcp_queue	*queue = cmd->queue;
511 
512 	llist_add(&cmd->lentry, &queue->resp_list);
513 	queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &cmd->queue->io_work);
514 }
515 
516 static int nvmet_try_send_data_pdu(struct nvmet_tcp_cmd *cmd)
517 {
518 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
519 	int left = sizeof(*cmd->data_pdu) - cmd->offset + hdgst;
520 	int ret;
521 
522 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->data_pdu),
523 			offset_in_page(cmd->data_pdu) + cmd->offset,
524 			left, MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST);
525 	if (ret <= 0)
526 		return ret;
527 
528 	cmd->offset += ret;
529 	left -= ret;
530 
531 	if (left)
532 		return -EAGAIN;
533 
534 	cmd->state = NVMET_TCP_SEND_DATA;
535 	cmd->offset  = 0;
536 	return 1;
537 }
538 
539 static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
540 {
541 	struct nvmet_tcp_queue *queue = cmd->queue;
542 	int ret;
543 
544 	while (cmd->cur_sg) {
545 		struct page *page = sg_page(cmd->cur_sg);
546 		u32 left = cmd->cur_sg->length - cmd->offset;
547 		int flags = MSG_DONTWAIT;
548 
549 		if ((!last_in_batch && cmd->queue->send_list_len) ||
550 		    cmd->wbytes_done + left < cmd->req.transfer_len ||
551 		    queue->data_digest || !queue->nvme_sq.sqhd_disabled)
552 			flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
553 
554 		ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset,
555 					left, flags);
556 		if (ret <= 0)
557 			return ret;
558 
559 		cmd->offset += ret;
560 		cmd->wbytes_done += ret;
561 
562 		/* Done with sg?*/
563 		if (cmd->offset == cmd->cur_sg->length) {
564 			cmd->cur_sg = sg_next(cmd->cur_sg);
565 			cmd->offset = 0;
566 		}
567 	}
568 
569 	if (queue->data_digest) {
570 		cmd->state = NVMET_TCP_SEND_DDGST;
571 		cmd->offset = 0;
572 	} else {
573 		if (queue->nvme_sq.sqhd_disabled) {
574 			cmd->queue->snd_cmd = NULL;
575 			nvmet_tcp_put_cmd(cmd);
576 		} else {
577 			nvmet_setup_response_pdu(cmd);
578 		}
579 	}
580 
581 	if (queue->nvme_sq.sqhd_disabled) {
582 		kfree(cmd->iov);
583 		sgl_free(cmd->req.sg);
584 	}
585 
586 	return 1;
587 
588 }
589 
590 static int nvmet_try_send_response(struct nvmet_tcp_cmd *cmd,
591 		bool last_in_batch)
592 {
593 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
594 	int left = sizeof(*cmd->rsp_pdu) - cmd->offset + hdgst;
595 	int flags = MSG_DONTWAIT;
596 	int ret;
597 
598 	if (!last_in_batch && cmd->queue->send_list_len)
599 		flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
600 	else
601 		flags |= MSG_EOR;
602 
603 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->rsp_pdu),
604 		offset_in_page(cmd->rsp_pdu) + cmd->offset, left, flags);
605 	if (ret <= 0)
606 		return ret;
607 	cmd->offset += ret;
608 	left -= ret;
609 
610 	if (left)
611 		return -EAGAIN;
612 
613 	kfree(cmd->iov);
614 	sgl_free(cmd->req.sg);
615 	cmd->queue->snd_cmd = NULL;
616 	nvmet_tcp_put_cmd(cmd);
617 	return 1;
618 }
619 
620 static int nvmet_try_send_r2t(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
621 {
622 	u8 hdgst = nvmet_tcp_hdgst_len(cmd->queue);
623 	int left = sizeof(*cmd->r2t_pdu) - cmd->offset + hdgst;
624 	int flags = MSG_DONTWAIT;
625 	int ret;
626 
627 	if (!last_in_batch && cmd->queue->send_list_len)
628 		flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
629 	else
630 		flags |= MSG_EOR;
631 
632 	ret = kernel_sendpage(cmd->queue->sock, virt_to_page(cmd->r2t_pdu),
633 		offset_in_page(cmd->r2t_pdu) + cmd->offset, left, flags);
634 	if (ret <= 0)
635 		return ret;
636 	cmd->offset += ret;
637 	left -= ret;
638 
639 	if (left)
640 		return -EAGAIN;
641 
642 	cmd->queue->snd_cmd = NULL;
643 	return 1;
644 }
645 
646 static int nvmet_try_send_ddgst(struct nvmet_tcp_cmd *cmd, bool last_in_batch)
647 {
648 	struct nvmet_tcp_queue *queue = cmd->queue;
649 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
650 	struct kvec iov = {
651 		.iov_base = &cmd->exp_ddgst + cmd->offset,
652 		.iov_len = NVME_TCP_DIGEST_LENGTH - cmd->offset
653 	};
654 	int ret;
655 
656 	if (!last_in_batch && cmd->queue->send_list_len)
657 		msg.msg_flags |= MSG_MORE;
658 	else
659 		msg.msg_flags |= MSG_EOR;
660 
661 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
662 	if (unlikely(ret <= 0))
663 		return ret;
664 
665 	cmd->offset += ret;
666 
667 	if (queue->nvme_sq.sqhd_disabled) {
668 		cmd->queue->snd_cmd = NULL;
669 		nvmet_tcp_put_cmd(cmd);
670 	} else {
671 		nvmet_setup_response_pdu(cmd);
672 	}
673 	return 1;
674 }
675 
676 static int nvmet_tcp_try_send_one(struct nvmet_tcp_queue *queue,
677 		bool last_in_batch)
678 {
679 	struct nvmet_tcp_cmd *cmd = queue->snd_cmd;
680 	int ret = 0;
681 
682 	if (!cmd || queue->state == NVMET_TCP_Q_DISCONNECTING) {
683 		cmd = nvmet_tcp_fetch_cmd(queue);
684 		if (unlikely(!cmd))
685 			return 0;
686 	}
687 
688 	if (cmd->state == NVMET_TCP_SEND_DATA_PDU) {
689 		ret = nvmet_try_send_data_pdu(cmd);
690 		if (ret <= 0)
691 			goto done_send;
692 	}
693 
694 	if (cmd->state == NVMET_TCP_SEND_DATA) {
695 		ret = nvmet_try_send_data(cmd, last_in_batch);
696 		if (ret <= 0)
697 			goto done_send;
698 	}
699 
700 	if (cmd->state == NVMET_TCP_SEND_DDGST) {
701 		ret = nvmet_try_send_ddgst(cmd, last_in_batch);
702 		if (ret <= 0)
703 			goto done_send;
704 	}
705 
706 	if (cmd->state == NVMET_TCP_SEND_R2T) {
707 		ret = nvmet_try_send_r2t(cmd, last_in_batch);
708 		if (ret <= 0)
709 			goto done_send;
710 	}
711 
712 	if (cmd->state == NVMET_TCP_SEND_RESPONSE)
713 		ret = nvmet_try_send_response(cmd, last_in_batch);
714 
715 done_send:
716 	if (ret < 0) {
717 		if (ret == -EAGAIN)
718 			return 0;
719 		return ret;
720 	}
721 
722 	return 1;
723 }
724 
725 static int nvmet_tcp_try_send(struct nvmet_tcp_queue *queue,
726 		int budget, int *sends)
727 {
728 	int i, ret = 0;
729 
730 	for (i = 0; i < budget; i++) {
731 		ret = nvmet_tcp_try_send_one(queue, i == budget - 1);
732 		if (unlikely(ret < 0)) {
733 			nvmet_tcp_socket_error(queue, ret);
734 			goto done;
735 		} else if (ret == 0) {
736 			break;
737 		}
738 		(*sends)++;
739 	}
740 done:
741 	return ret;
742 }
743 
744 static void nvmet_prepare_receive_pdu(struct nvmet_tcp_queue *queue)
745 {
746 	queue->offset = 0;
747 	queue->left = sizeof(struct nvme_tcp_hdr);
748 	queue->cmd = NULL;
749 	queue->rcv_state = NVMET_TCP_RECV_PDU;
750 }
751 
752 static void nvmet_tcp_free_crypto(struct nvmet_tcp_queue *queue)
753 {
754 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(queue->rcv_hash);
755 
756 	ahash_request_free(queue->rcv_hash);
757 	ahash_request_free(queue->snd_hash);
758 	crypto_free_ahash(tfm);
759 }
760 
761 static int nvmet_tcp_alloc_crypto(struct nvmet_tcp_queue *queue)
762 {
763 	struct crypto_ahash *tfm;
764 
765 	tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
766 	if (IS_ERR(tfm))
767 		return PTR_ERR(tfm);
768 
769 	queue->snd_hash = ahash_request_alloc(tfm, GFP_KERNEL);
770 	if (!queue->snd_hash)
771 		goto free_tfm;
772 	ahash_request_set_callback(queue->snd_hash, 0, NULL, NULL);
773 
774 	queue->rcv_hash = ahash_request_alloc(tfm, GFP_KERNEL);
775 	if (!queue->rcv_hash)
776 		goto free_snd_hash;
777 	ahash_request_set_callback(queue->rcv_hash, 0, NULL, NULL);
778 
779 	return 0;
780 free_snd_hash:
781 	ahash_request_free(queue->snd_hash);
782 free_tfm:
783 	crypto_free_ahash(tfm);
784 	return -ENOMEM;
785 }
786 
787 
788 static int nvmet_tcp_handle_icreq(struct nvmet_tcp_queue *queue)
789 {
790 	struct nvme_tcp_icreq_pdu *icreq = &queue->pdu.icreq;
791 	struct nvme_tcp_icresp_pdu *icresp = &queue->pdu.icresp;
792 	struct msghdr msg = {};
793 	struct kvec iov;
794 	int ret;
795 
796 	if (le32_to_cpu(icreq->hdr.plen) != sizeof(struct nvme_tcp_icreq_pdu)) {
797 		pr_err("bad nvme-tcp pdu length (%d)\n",
798 			le32_to_cpu(icreq->hdr.plen));
799 		nvmet_tcp_fatal_error(queue);
800 	}
801 
802 	if (icreq->pfv != NVME_TCP_PFV_1_0) {
803 		pr_err("queue %d: bad pfv %d\n", queue->idx, icreq->pfv);
804 		return -EPROTO;
805 	}
806 
807 	if (icreq->hpda != 0) {
808 		pr_err("queue %d: unsupported hpda %d\n", queue->idx,
809 			icreq->hpda);
810 		return -EPROTO;
811 	}
812 
813 	queue->hdr_digest = !!(icreq->digest & NVME_TCP_HDR_DIGEST_ENABLE);
814 	queue->data_digest = !!(icreq->digest & NVME_TCP_DATA_DIGEST_ENABLE);
815 	if (queue->hdr_digest || queue->data_digest) {
816 		ret = nvmet_tcp_alloc_crypto(queue);
817 		if (ret)
818 			return ret;
819 	}
820 
821 	memset(icresp, 0, sizeof(*icresp));
822 	icresp->hdr.type = nvme_tcp_icresp;
823 	icresp->hdr.hlen = sizeof(*icresp);
824 	icresp->hdr.pdo = 0;
825 	icresp->hdr.plen = cpu_to_le32(icresp->hdr.hlen);
826 	icresp->pfv = cpu_to_le16(NVME_TCP_PFV_1_0);
827 	icresp->maxdata = cpu_to_le32(0x400000); /* 16M arbitrary limit */
828 	icresp->cpda = 0;
829 	if (queue->hdr_digest)
830 		icresp->digest |= NVME_TCP_HDR_DIGEST_ENABLE;
831 	if (queue->data_digest)
832 		icresp->digest |= NVME_TCP_DATA_DIGEST_ENABLE;
833 
834 	iov.iov_base = icresp;
835 	iov.iov_len = sizeof(*icresp);
836 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
837 	if (ret < 0)
838 		goto free_crypto;
839 
840 	queue->state = NVMET_TCP_Q_LIVE;
841 	nvmet_prepare_receive_pdu(queue);
842 	return 0;
843 free_crypto:
844 	if (queue->hdr_digest || queue->data_digest)
845 		nvmet_tcp_free_crypto(queue);
846 	return ret;
847 }
848 
849 static void nvmet_tcp_handle_req_failure(struct nvmet_tcp_queue *queue,
850 		struct nvmet_tcp_cmd *cmd, struct nvmet_req *req)
851 {
852 	size_t data_len = le32_to_cpu(req->cmd->common.dptr.sgl.length);
853 	int ret;
854 
855 	if (!nvme_is_write(cmd->req.cmd) ||
856 	    data_len > cmd->req.port->inline_data_size) {
857 		nvmet_prepare_receive_pdu(queue);
858 		return;
859 	}
860 
861 	ret = nvmet_tcp_map_data(cmd);
862 	if (unlikely(ret)) {
863 		pr_err("queue %d: failed to map data\n", queue->idx);
864 		nvmet_tcp_fatal_error(queue);
865 		return;
866 	}
867 
868 	queue->rcv_state = NVMET_TCP_RECV_DATA;
869 	nvmet_tcp_map_pdu_iovec(cmd);
870 	cmd->flags |= NVMET_TCP_F_INIT_FAILED;
871 }
872 
873 static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue)
874 {
875 	struct nvme_tcp_data_pdu *data = &queue->pdu.data;
876 	struct nvmet_tcp_cmd *cmd;
877 
878 	if (likely(queue->nr_cmds))
879 		cmd = &queue->cmds[data->ttag];
880 	else
881 		cmd = &queue->connect;
882 
883 	if (le32_to_cpu(data->data_offset) != cmd->rbytes_done) {
884 		pr_err("ttag %u unexpected data offset %u (expected %u)\n",
885 			data->ttag, le32_to_cpu(data->data_offset),
886 			cmd->rbytes_done);
887 		/* FIXME: use path and transport errors */
888 		nvmet_req_complete(&cmd->req,
889 			NVME_SC_INVALID_FIELD | NVME_SC_DNR);
890 		return -EPROTO;
891 	}
892 
893 	cmd->pdu_len = le32_to_cpu(data->data_length);
894 	cmd->pdu_recv = 0;
895 	nvmet_tcp_map_pdu_iovec(cmd);
896 	queue->cmd = cmd;
897 	queue->rcv_state = NVMET_TCP_RECV_DATA;
898 
899 	return 0;
900 }
901 
902 static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)
903 {
904 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
905 	struct nvme_command *nvme_cmd = &queue->pdu.cmd.cmd;
906 	struct nvmet_req *req;
907 	int ret;
908 
909 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
910 		if (hdr->type != nvme_tcp_icreq) {
911 			pr_err("unexpected pdu type (%d) before icreq\n",
912 				hdr->type);
913 			nvmet_tcp_fatal_error(queue);
914 			return -EPROTO;
915 		}
916 		return nvmet_tcp_handle_icreq(queue);
917 	}
918 
919 	if (hdr->type == nvme_tcp_h2c_data) {
920 		ret = nvmet_tcp_handle_h2c_data_pdu(queue);
921 		if (unlikely(ret))
922 			return ret;
923 		return 0;
924 	}
925 
926 	queue->cmd = nvmet_tcp_get_cmd(queue);
927 	if (unlikely(!queue->cmd)) {
928 		/* This should never happen */
929 		pr_err("queue %d: out of commands (%d) send_list_len: %d, opcode: %d",
930 			queue->idx, queue->nr_cmds, queue->send_list_len,
931 			nvme_cmd->common.opcode);
932 		nvmet_tcp_fatal_error(queue);
933 		return -ENOMEM;
934 	}
935 
936 	req = &queue->cmd->req;
937 	memcpy(req->cmd, nvme_cmd, sizeof(*nvme_cmd));
938 
939 	if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
940 			&queue->nvme_sq, &nvmet_tcp_ops))) {
941 		pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
942 			req->cmd, req->cmd->common.command_id,
943 			req->cmd->common.opcode,
944 			le32_to_cpu(req->cmd->common.dptr.sgl.length));
945 
946 		nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
947 		return -EAGAIN;
948 	}
949 
950 	ret = nvmet_tcp_map_data(queue->cmd);
951 	if (unlikely(ret)) {
952 		pr_err("queue %d: failed to map data\n", queue->idx);
953 		if (nvmet_tcp_has_inline_data(queue->cmd))
954 			nvmet_tcp_fatal_error(queue);
955 		else
956 			nvmet_req_complete(req, ret);
957 		ret = -EAGAIN;
958 		goto out;
959 	}
960 
961 	if (nvmet_tcp_need_data_in(queue->cmd)) {
962 		if (nvmet_tcp_has_inline_data(queue->cmd)) {
963 			queue->rcv_state = NVMET_TCP_RECV_DATA;
964 			nvmet_tcp_map_pdu_iovec(queue->cmd);
965 			return 0;
966 		}
967 		/* send back R2T */
968 		nvmet_tcp_queue_response(&queue->cmd->req);
969 		goto out;
970 	}
971 
972 	queue->cmd->req.execute(&queue->cmd->req);
973 out:
974 	nvmet_prepare_receive_pdu(queue);
975 	return ret;
976 }
977 
978 static const u8 nvme_tcp_pdu_sizes[] = {
979 	[nvme_tcp_icreq]	= sizeof(struct nvme_tcp_icreq_pdu),
980 	[nvme_tcp_cmd]		= sizeof(struct nvme_tcp_cmd_pdu),
981 	[nvme_tcp_h2c_data]	= sizeof(struct nvme_tcp_data_pdu),
982 };
983 
984 static inline u8 nvmet_tcp_pdu_size(u8 type)
985 {
986 	size_t idx = type;
987 
988 	return (idx < ARRAY_SIZE(nvme_tcp_pdu_sizes) &&
989 		nvme_tcp_pdu_sizes[idx]) ?
990 			nvme_tcp_pdu_sizes[idx] : 0;
991 }
992 
993 static inline bool nvmet_tcp_pdu_valid(u8 type)
994 {
995 	switch (type) {
996 	case nvme_tcp_icreq:
997 	case nvme_tcp_cmd:
998 	case nvme_tcp_h2c_data:
999 		/* fallthru */
1000 		return true;
1001 	}
1002 
1003 	return false;
1004 }
1005 
1006 static int nvmet_tcp_try_recv_pdu(struct nvmet_tcp_queue *queue)
1007 {
1008 	struct nvme_tcp_hdr *hdr = &queue->pdu.cmd.hdr;
1009 	int len;
1010 	struct kvec iov;
1011 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1012 
1013 recv:
1014 	iov.iov_base = (void *)&queue->pdu + queue->offset;
1015 	iov.iov_len = queue->left;
1016 	len = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1017 			iov.iov_len, msg.msg_flags);
1018 	if (unlikely(len < 0))
1019 		return len;
1020 
1021 	queue->offset += len;
1022 	queue->left -= len;
1023 	if (queue->left)
1024 		return -EAGAIN;
1025 
1026 	if (queue->offset == sizeof(struct nvme_tcp_hdr)) {
1027 		u8 hdgst = nvmet_tcp_hdgst_len(queue);
1028 
1029 		if (unlikely(!nvmet_tcp_pdu_valid(hdr->type))) {
1030 			pr_err("unexpected pdu type %d\n", hdr->type);
1031 			nvmet_tcp_fatal_error(queue);
1032 			return -EIO;
1033 		}
1034 
1035 		if (unlikely(hdr->hlen != nvmet_tcp_pdu_size(hdr->type))) {
1036 			pr_err("pdu %d bad hlen %d\n", hdr->type, hdr->hlen);
1037 			return -EIO;
1038 		}
1039 
1040 		queue->left = hdr->hlen - queue->offset + hdgst;
1041 		goto recv;
1042 	}
1043 
1044 	if (queue->hdr_digest &&
1045 	    nvmet_tcp_verify_hdgst(queue, &queue->pdu, queue->offset)) {
1046 		nvmet_tcp_fatal_error(queue); /* fatal */
1047 		return -EPROTO;
1048 	}
1049 
1050 	if (queue->data_digest &&
1051 	    nvmet_tcp_check_ddgst(queue, &queue->pdu)) {
1052 		nvmet_tcp_fatal_error(queue); /* fatal */
1053 		return -EPROTO;
1054 	}
1055 
1056 	return nvmet_tcp_done_recv_pdu(queue);
1057 }
1058 
1059 static void nvmet_tcp_prep_recv_ddgst(struct nvmet_tcp_cmd *cmd)
1060 {
1061 	struct nvmet_tcp_queue *queue = cmd->queue;
1062 
1063 	nvmet_tcp_ddgst(queue->rcv_hash, cmd);
1064 	queue->offset = 0;
1065 	queue->left = NVME_TCP_DIGEST_LENGTH;
1066 	queue->rcv_state = NVMET_TCP_RECV_DDGST;
1067 }
1068 
1069 static int nvmet_tcp_try_recv_data(struct nvmet_tcp_queue *queue)
1070 {
1071 	struct nvmet_tcp_cmd  *cmd = queue->cmd;
1072 	int ret;
1073 
1074 	while (msg_data_left(&cmd->recv_msg)) {
1075 		ret = sock_recvmsg(cmd->queue->sock, &cmd->recv_msg,
1076 			cmd->recv_msg.msg_flags);
1077 		if (ret <= 0)
1078 			return ret;
1079 
1080 		cmd->pdu_recv += ret;
1081 		cmd->rbytes_done += ret;
1082 	}
1083 
1084 	nvmet_tcp_unmap_pdu_iovec(cmd);
1085 
1086 	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1087 	    cmd->rbytes_done == cmd->req.transfer_len) {
1088 		if (queue->data_digest) {
1089 			nvmet_tcp_prep_recv_ddgst(cmd);
1090 			return 0;
1091 		}
1092 		cmd->req.execute(&cmd->req);
1093 	}
1094 
1095 	nvmet_prepare_receive_pdu(queue);
1096 	return 0;
1097 }
1098 
1099 static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
1100 {
1101 	struct nvmet_tcp_cmd *cmd = queue->cmd;
1102 	int ret;
1103 	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
1104 	struct kvec iov = {
1105 		.iov_base = (void *)&cmd->recv_ddgst + queue->offset,
1106 		.iov_len = queue->left
1107 	};
1108 
1109 	ret = kernel_recvmsg(queue->sock, &msg, &iov, 1,
1110 			iov.iov_len, msg.msg_flags);
1111 	if (unlikely(ret < 0))
1112 		return ret;
1113 
1114 	queue->offset += ret;
1115 	queue->left -= ret;
1116 	if (queue->left)
1117 		return -EAGAIN;
1118 
1119 	if (queue->data_digest && cmd->exp_ddgst != cmd->recv_ddgst) {
1120 		pr_err("queue %d: cmd %d pdu (%d) data digest error: recv %#x expected %#x\n",
1121 			queue->idx, cmd->req.cmd->common.command_id,
1122 			queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
1123 			le32_to_cpu(cmd->exp_ddgst));
1124 		nvmet_tcp_finish_cmd(cmd);
1125 		nvmet_tcp_fatal_error(queue);
1126 		ret = -EPROTO;
1127 		goto out;
1128 	}
1129 
1130 	if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED) &&
1131 	    cmd->rbytes_done == cmd->req.transfer_len)
1132 		cmd->req.execute(&cmd->req);
1133 	ret = 0;
1134 out:
1135 	nvmet_prepare_receive_pdu(queue);
1136 	return ret;
1137 }
1138 
1139 static int nvmet_tcp_try_recv_one(struct nvmet_tcp_queue *queue)
1140 {
1141 	int result = 0;
1142 
1143 	if (unlikely(queue->rcv_state == NVMET_TCP_RECV_ERR))
1144 		return 0;
1145 
1146 	if (queue->rcv_state == NVMET_TCP_RECV_PDU) {
1147 		result = nvmet_tcp_try_recv_pdu(queue);
1148 		if (result != 0)
1149 			goto done_recv;
1150 	}
1151 
1152 	if (queue->rcv_state == NVMET_TCP_RECV_DATA) {
1153 		result = nvmet_tcp_try_recv_data(queue);
1154 		if (result != 0)
1155 			goto done_recv;
1156 	}
1157 
1158 	if (queue->rcv_state == NVMET_TCP_RECV_DDGST) {
1159 		result = nvmet_tcp_try_recv_ddgst(queue);
1160 		if (result != 0)
1161 			goto done_recv;
1162 	}
1163 
1164 done_recv:
1165 	if (result < 0) {
1166 		if (result == -EAGAIN)
1167 			return 0;
1168 		return result;
1169 	}
1170 	return 1;
1171 }
1172 
1173 static int nvmet_tcp_try_recv(struct nvmet_tcp_queue *queue,
1174 		int budget, int *recvs)
1175 {
1176 	int i, ret = 0;
1177 
1178 	for (i = 0; i < budget; i++) {
1179 		ret = nvmet_tcp_try_recv_one(queue);
1180 		if (unlikely(ret < 0)) {
1181 			nvmet_tcp_socket_error(queue, ret);
1182 			goto done;
1183 		} else if (ret == 0) {
1184 			break;
1185 		}
1186 		(*recvs)++;
1187 	}
1188 done:
1189 	return ret;
1190 }
1191 
1192 static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue *queue)
1193 {
1194 	spin_lock(&queue->state_lock);
1195 	if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
1196 		queue->state = NVMET_TCP_Q_DISCONNECTING;
1197 		schedule_work(&queue->release_work);
1198 	}
1199 	spin_unlock(&queue->state_lock);
1200 }
1201 
1202 static void nvmet_tcp_io_work(struct work_struct *w)
1203 {
1204 	struct nvmet_tcp_queue *queue =
1205 		container_of(w, struct nvmet_tcp_queue, io_work);
1206 	bool pending;
1207 	int ret, ops = 0;
1208 
1209 	do {
1210 		pending = false;
1211 
1212 		ret = nvmet_tcp_try_recv(queue, NVMET_TCP_RECV_BUDGET, &ops);
1213 		if (ret > 0)
1214 			pending = true;
1215 		else if (ret < 0)
1216 			return;
1217 
1218 		ret = nvmet_tcp_try_send(queue, NVMET_TCP_SEND_BUDGET, &ops);
1219 		if (ret > 0)
1220 			pending = true;
1221 		else if (ret < 0)
1222 			return;
1223 
1224 	} while (pending && ops < NVMET_TCP_IO_WORK_BUDGET);
1225 
1226 	/*
1227 	 * We exahusted our budget, requeue our selves
1228 	 */
1229 	if (pending)
1230 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1231 }
1232 
1233 static int nvmet_tcp_alloc_cmd(struct nvmet_tcp_queue *queue,
1234 		struct nvmet_tcp_cmd *c)
1235 {
1236 	u8 hdgst = nvmet_tcp_hdgst_len(queue);
1237 
1238 	c->queue = queue;
1239 	c->req.port = queue->port->nport;
1240 
1241 	c->cmd_pdu = page_frag_alloc(&queue->pf_cache,
1242 			sizeof(*c->cmd_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1243 	if (!c->cmd_pdu)
1244 		return -ENOMEM;
1245 	c->req.cmd = &c->cmd_pdu->cmd;
1246 
1247 	c->rsp_pdu = page_frag_alloc(&queue->pf_cache,
1248 			sizeof(*c->rsp_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1249 	if (!c->rsp_pdu)
1250 		goto out_free_cmd;
1251 	c->req.cqe = &c->rsp_pdu->cqe;
1252 
1253 	c->data_pdu = page_frag_alloc(&queue->pf_cache,
1254 			sizeof(*c->data_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1255 	if (!c->data_pdu)
1256 		goto out_free_rsp;
1257 
1258 	c->r2t_pdu = page_frag_alloc(&queue->pf_cache,
1259 			sizeof(*c->r2t_pdu) + hdgst, GFP_KERNEL | __GFP_ZERO);
1260 	if (!c->r2t_pdu)
1261 		goto out_free_data;
1262 
1263 	c->recv_msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1264 
1265 	list_add_tail(&c->entry, &queue->free_list);
1266 
1267 	return 0;
1268 out_free_data:
1269 	page_frag_free(c->data_pdu);
1270 out_free_rsp:
1271 	page_frag_free(c->rsp_pdu);
1272 out_free_cmd:
1273 	page_frag_free(c->cmd_pdu);
1274 	return -ENOMEM;
1275 }
1276 
1277 static void nvmet_tcp_free_cmd(struct nvmet_tcp_cmd *c)
1278 {
1279 	page_frag_free(c->r2t_pdu);
1280 	page_frag_free(c->data_pdu);
1281 	page_frag_free(c->rsp_pdu);
1282 	page_frag_free(c->cmd_pdu);
1283 }
1284 
1285 static int nvmet_tcp_alloc_cmds(struct nvmet_tcp_queue *queue)
1286 {
1287 	struct nvmet_tcp_cmd *cmds;
1288 	int i, ret = -EINVAL, nr_cmds = queue->nr_cmds;
1289 
1290 	cmds = kcalloc(nr_cmds, sizeof(struct nvmet_tcp_cmd), GFP_KERNEL);
1291 	if (!cmds)
1292 		goto out;
1293 
1294 	for (i = 0; i < nr_cmds; i++) {
1295 		ret = nvmet_tcp_alloc_cmd(queue, cmds + i);
1296 		if (ret)
1297 			goto out_free;
1298 	}
1299 
1300 	queue->cmds = cmds;
1301 
1302 	return 0;
1303 out_free:
1304 	while (--i >= 0)
1305 		nvmet_tcp_free_cmd(cmds + i);
1306 	kfree(cmds);
1307 out:
1308 	return ret;
1309 }
1310 
1311 static void nvmet_tcp_free_cmds(struct nvmet_tcp_queue *queue)
1312 {
1313 	struct nvmet_tcp_cmd *cmds = queue->cmds;
1314 	int i;
1315 
1316 	for (i = 0; i < queue->nr_cmds; i++)
1317 		nvmet_tcp_free_cmd(cmds + i);
1318 
1319 	nvmet_tcp_free_cmd(&queue->connect);
1320 	kfree(cmds);
1321 }
1322 
1323 static void nvmet_tcp_restore_socket_callbacks(struct nvmet_tcp_queue *queue)
1324 {
1325 	struct socket *sock = queue->sock;
1326 
1327 	write_lock_bh(&sock->sk->sk_callback_lock);
1328 	sock->sk->sk_data_ready =  queue->data_ready;
1329 	sock->sk->sk_state_change = queue->state_change;
1330 	sock->sk->sk_write_space = queue->write_space;
1331 	sock->sk->sk_user_data = NULL;
1332 	write_unlock_bh(&sock->sk->sk_callback_lock);
1333 }
1334 
1335 static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
1336 {
1337 	nvmet_req_uninit(&cmd->req);
1338 	nvmet_tcp_unmap_pdu_iovec(cmd);
1339 	kfree(cmd->iov);
1340 	sgl_free(cmd->req.sg);
1341 }
1342 
1343 static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
1344 {
1345 	struct nvmet_tcp_cmd *cmd = queue->cmds;
1346 	int i;
1347 
1348 	for (i = 0; i < queue->nr_cmds; i++, cmd++) {
1349 		if (nvmet_tcp_need_data_in(cmd))
1350 			nvmet_tcp_finish_cmd(cmd);
1351 	}
1352 
1353 	if (!queue->nr_cmds && nvmet_tcp_need_data_in(&queue->connect)) {
1354 		/* failed in connect */
1355 		nvmet_tcp_finish_cmd(&queue->connect);
1356 	}
1357 }
1358 
1359 static void nvmet_tcp_release_queue_work(struct work_struct *w)
1360 {
1361 	struct nvmet_tcp_queue *queue =
1362 		container_of(w, struct nvmet_tcp_queue, release_work);
1363 
1364 	mutex_lock(&nvmet_tcp_queue_mutex);
1365 	list_del_init(&queue->queue_list);
1366 	mutex_unlock(&nvmet_tcp_queue_mutex);
1367 
1368 	nvmet_tcp_restore_socket_callbacks(queue);
1369 	flush_work(&queue->io_work);
1370 
1371 	nvmet_tcp_uninit_data_in_cmds(queue);
1372 	nvmet_sq_destroy(&queue->nvme_sq);
1373 	cancel_work_sync(&queue->io_work);
1374 	sock_release(queue->sock);
1375 	nvmet_tcp_free_cmds(queue);
1376 	if (queue->hdr_digest || queue->data_digest)
1377 		nvmet_tcp_free_crypto(queue);
1378 	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1379 
1380 	kfree(queue);
1381 }
1382 
1383 static void nvmet_tcp_data_ready(struct sock *sk)
1384 {
1385 	struct nvmet_tcp_queue *queue;
1386 
1387 	read_lock_bh(&sk->sk_callback_lock);
1388 	queue = sk->sk_user_data;
1389 	if (likely(queue))
1390 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1391 	read_unlock_bh(&sk->sk_callback_lock);
1392 }
1393 
1394 static void nvmet_tcp_write_space(struct sock *sk)
1395 {
1396 	struct nvmet_tcp_queue *queue;
1397 
1398 	read_lock_bh(&sk->sk_callback_lock);
1399 	queue = sk->sk_user_data;
1400 	if (unlikely(!queue))
1401 		goto out;
1402 
1403 	if (unlikely(queue->state == NVMET_TCP_Q_CONNECTING)) {
1404 		queue->write_space(sk);
1405 		goto out;
1406 	}
1407 
1408 	if (sk_stream_is_writeable(sk)) {
1409 		clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1410 		queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1411 	}
1412 out:
1413 	read_unlock_bh(&sk->sk_callback_lock);
1414 }
1415 
1416 static void nvmet_tcp_state_change(struct sock *sk)
1417 {
1418 	struct nvmet_tcp_queue *queue;
1419 
1420 	write_lock_bh(&sk->sk_callback_lock);
1421 	queue = sk->sk_user_data;
1422 	if (!queue)
1423 		goto done;
1424 
1425 	switch (sk->sk_state) {
1426 	case TCP_FIN_WAIT1:
1427 	case TCP_CLOSE_WAIT:
1428 	case TCP_CLOSE:
1429 		/* FALLTHRU */
1430 		sk->sk_user_data = NULL;
1431 		nvmet_tcp_schedule_release_queue(queue);
1432 		break;
1433 	default:
1434 		pr_warn("queue %d unhandled state %d\n",
1435 			queue->idx, sk->sk_state);
1436 	}
1437 done:
1438 	write_unlock_bh(&sk->sk_callback_lock);
1439 }
1440 
1441 static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
1442 {
1443 	struct socket *sock = queue->sock;
1444 	struct inet_sock *inet = inet_sk(sock->sk);
1445 	int ret;
1446 
1447 	ret = kernel_getsockname(sock,
1448 		(struct sockaddr *)&queue->sockaddr);
1449 	if (ret < 0)
1450 		return ret;
1451 
1452 	ret = kernel_getpeername(sock,
1453 		(struct sockaddr *)&queue->sockaddr_peer);
1454 	if (ret < 0)
1455 		return ret;
1456 
1457 	/*
1458 	 * Cleanup whatever is sitting in the TCP transmit queue on socket
1459 	 * close. This is done to prevent stale data from being sent should
1460 	 * the network connection be restored before TCP times out.
1461 	 */
1462 	sock_no_linger(sock->sk);
1463 
1464 	if (so_priority > 0)
1465 		sock_set_priority(sock->sk, so_priority);
1466 
1467 	/* Set socket type of service */
1468 	if (inet->rcv_tos > 0)
1469 		ip_sock_set_tos(sock->sk, inet->rcv_tos);
1470 
1471 	write_lock_bh(&sock->sk->sk_callback_lock);
1472 	sock->sk->sk_user_data = queue;
1473 	queue->data_ready = sock->sk->sk_data_ready;
1474 	sock->sk->sk_data_ready = nvmet_tcp_data_ready;
1475 	queue->state_change = sock->sk->sk_state_change;
1476 	sock->sk->sk_state_change = nvmet_tcp_state_change;
1477 	queue->write_space = sock->sk->sk_write_space;
1478 	sock->sk->sk_write_space = nvmet_tcp_write_space;
1479 	write_unlock_bh(&sock->sk->sk_callback_lock);
1480 
1481 	return 0;
1482 }
1483 
1484 static int nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
1485 		struct socket *newsock)
1486 {
1487 	struct nvmet_tcp_queue *queue;
1488 	int ret;
1489 
1490 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1491 	if (!queue)
1492 		return -ENOMEM;
1493 
1494 	INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
1495 	INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
1496 	queue->sock = newsock;
1497 	queue->port = port;
1498 	queue->nr_cmds = 0;
1499 	spin_lock_init(&queue->state_lock);
1500 	queue->state = NVMET_TCP_Q_CONNECTING;
1501 	INIT_LIST_HEAD(&queue->free_list);
1502 	init_llist_head(&queue->resp_list);
1503 	INIT_LIST_HEAD(&queue->resp_send_list);
1504 
1505 	queue->idx = ida_simple_get(&nvmet_tcp_queue_ida, 0, 0, GFP_KERNEL);
1506 	if (queue->idx < 0) {
1507 		ret = queue->idx;
1508 		goto out_free_queue;
1509 	}
1510 
1511 	ret = nvmet_tcp_alloc_cmd(queue, &queue->connect);
1512 	if (ret)
1513 		goto out_ida_remove;
1514 
1515 	ret = nvmet_sq_init(&queue->nvme_sq);
1516 	if (ret)
1517 		goto out_free_connect;
1518 
1519 	nvmet_prepare_receive_pdu(queue);
1520 
1521 	mutex_lock(&nvmet_tcp_queue_mutex);
1522 	list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
1523 	mutex_unlock(&nvmet_tcp_queue_mutex);
1524 
1525 	ret = nvmet_tcp_set_queue_sock(queue);
1526 	if (ret)
1527 		goto out_destroy_sq;
1528 
1529 	queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
1530 
1531 	return 0;
1532 out_destroy_sq:
1533 	mutex_lock(&nvmet_tcp_queue_mutex);
1534 	list_del_init(&queue->queue_list);
1535 	mutex_unlock(&nvmet_tcp_queue_mutex);
1536 	nvmet_sq_destroy(&queue->nvme_sq);
1537 out_free_connect:
1538 	nvmet_tcp_free_cmd(&queue->connect);
1539 out_ida_remove:
1540 	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
1541 out_free_queue:
1542 	kfree(queue);
1543 	return ret;
1544 }
1545 
1546 static void nvmet_tcp_accept_work(struct work_struct *w)
1547 {
1548 	struct nvmet_tcp_port *port =
1549 		container_of(w, struct nvmet_tcp_port, accept_work);
1550 	struct socket *newsock;
1551 	int ret;
1552 
1553 	while (true) {
1554 		ret = kernel_accept(port->sock, &newsock, O_NONBLOCK);
1555 		if (ret < 0) {
1556 			if (ret != -EAGAIN)
1557 				pr_warn("failed to accept err=%d\n", ret);
1558 			return;
1559 		}
1560 		ret = nvmet_tcp_alloc_queue(port, newsock);
1561 		if (ret) {
1562 			pr_err("failed to allocate queue\n");
1563 			sock_release(newsock);
1564 		}
1565 	}
1566 }
1567 
1568 static void nvmet_tcp_listen_data_ready(struct sock *sk)
1569 {
1570 	struct nvmet_tcp_port *port;
1571 
1572 	read_lock_bh(&sk->sk_callback_lock);
1573 	port = sk->sk_user_data;
1574 	if (!port)
1575 		goto out;
1576 
1577 	if (sk->sk_state == TCP_LISTEN)
1578 		schedule_work(&port->accept_work);
1579 out:
1580 	read_unlock_bh(&sk->sk_callback_lock);
1581 }
1582 
1583 static int nvmet_tcp_add_port(struct nvmet_port *nport)
1584 {
1585 	struct nvmet_tcp_port *port;
1586 	__kernel_sa_family_t af;
1587 	int ret;
1588 
1589 	port = kzalloc(sizeof(*port), GFP_KERNEL);
1590 	if (!port)
1591 		return -ENOMEM;
1592 
1593 	switch (nport->disc_addr.adrfam) {
1594 	case NVMF_ADDR_FAMILY_IP4:
1595 		af = AF_INET;
1596 		break;
1597 	case NVMF_ADDR_FAMILY_IP6:
1598 		af = AF_INET6;
1599 		break;
1600 	default:
1601 		pr_err("address family %d not supported\n",
1602 				nport->disc_addr.adrfam);
1603 		ret = -EINVAL;
1604 		goto err_port;
1605 	}
1606 
1607 	ret = inet_pton_with_scope(&init_net, af, nport->disc_addr.traddr,
1608 			nport->disc_addr.trsvcid, &port->addr);
1609 	if (ret) {
1610 		pr_err("malformed ip/port passed: %s:%s\n",
1611 			nport->disc_addr.traddr, nport->disc_addr.trsvcid);
1612 		goto err_port;
1613 	}
1614 
1615 	port->nport = nport;
1616 	INIT_WORK(&port->accept_work, nvmet_tcp_accept_work);
1617 	if (port->nport->inline_data_size < 0)
1618 		port->nport->inline_data_size = NVMET_TCP_DEF_INLINE_DATA_SIZE;
1619 
1620 	ret = sock_create(port->addr.ss_family, SOCK_STREAM,
1621 				IPPROTO_TCP, &port->sock);
1622 	if (ret) {
1623 		pr_err("failed to create a socket\n");
1624 		goto err_port;
1625 	}
1626 
1627 	port->sock->sk->sk_user_data = port;
1628 	port->data_ready = port->sock->sk->sk_data_ready;
1629 	port->sock->sk->sk_data_ready = nvmet_tcp_listen_data_ready;
1630 	sock_set_reuseaddr(port->sock->sk);
1631 	tcp_sock_set_nodelay(port->sock->sk);
1632 	if (so_priority > 0)
1633 		sock_set_priority(port->sock->sk, so_priority);
1634 
1635 	ret = kernel_bind(port->sock, (struct sockaddr *)&port->addr,
1636 			sizeof(port->addr));
1637 	if (ret) {
1638 		pr_err("failed to bind port socket %d\n", ret);
1639 		goto err_sock;
1640 	}
1641 
1642 	ret = kernel_listen(port->sock, 128);
1643 	if (ret) {
1644 		pr_err("failed to listen %d on port sock\n", ret);
1645 		goto err_sock;
1646 	}
1647 
1648 	nport->priv = port;
1649 	pr_info("enabling port %d (%pISpc)\n",
1650 		le16_to_cpu(nport->disc_addr.portid), &port->addr);
1651 
1652 	return 0;
1653 
1654 err_sock:
1655 	sock_release(port->sock);
1656 err_port:
1657 	kfree(port);
1658 	return ret;
1659 }
1660 
1661 static void nvmet_tcp_remove_port(struct nvmet_port *nport)
1662 {
1663 	struct nvmet_tcp_port *port = nport->priv;
1664 
1665 	write_lock_bh(&port->sock->sk->sk_callback_lock);
1666 	port->sock->sk->sk_data_ready = port->data_ready;
1667 	port->sock->sk->sk_user_data = NULL;
1668 	write_unlock_bh(&port->sock->sk->sk_callback_lock);
1669 	cancel_work_sync(&port->accept_work);
1670 
1671 	sock_release(port->sock);
1672 	kfree(port);
1673 }
1674 
1675 static void nvmet_tcp_delete_ctrl(struct nvmet_ctrl *ctrl)
1676 {
1677 	struct nvmet_tcp_queue *queue;
1678 
1679 	mutex_lock(&nvmet_tcp_queue_mutex);
1680 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1681 		if (queue->nvme_sq.ctrl == ctrl)
1682 			kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1683 	mutex_unlock(&nvmet_tcp_queue_mutex);
1684 }
1685 
1686 static u16 nvmet_tcp_install_queue(struct nvmet_sq *sq)
1687 {
1688 	struct nvmet_tcp_queue *queue =
1689 		container_of(sq, struct nvmet_tcp_queue, nvme_sq);
1690 
1691 	if (sq->qid == 0) {
1692 		/* Let inflight controller teardown complete */
1693 		flush_scheduled_work();
1694 	}
1695 
1696 	queue->nr_cmds = sq->size * 2;
1697 	if (nvmet_tcp_alloc_cmds(queue))
1698 		return NVME_SC_INTERNAL;
1699 	return 0;
1700 }
1701 
1702 static void nvmet_tcp_disc_port_addr(struct nvmet_req *req,
1703 		struct nvmet_port *nport, char *traddr)
1704 {
1705 	struct nvmet_tcp_port *port = nport->priv;
1706 
1707 	if (inet_addr_is_any((struct sockaddr *)&port->addr)) {
1708 		struct nvmet_tcp_cmd *cmd =
1709 			container_of(req, struct nvmet_tcp_cmd, req);
1710 		struct nvmet_tcp_queue *queue = cmd->queue;
1711 
1712 		sprintf(traddr, "%pISc", (struct sockaddr *)&queue->sockaddr);
1713 	} else {
1714 		memcpy(traddr, nport->disc_addr.traddr, NVMF_TRADDR_SIZE);
1715 	}
1716 }
1717 
1718 static const struct nvmet_fabrics_ops nvmet_tcp_ops = {
1719 	.owner			= THIS_MODULE,
1720 	.type			= NVMF_TRTYPE_TCP,
1721 	.msdbd			= 1,
1722 	.add_port		= nvmet_tcp_add_port,
1723 	.remove_port		= nvmet_tcp_remove_port,
1724 	.queue_response		= nvmet_tcp_queue_response,
1725 	.delete_ctrl		= nvmet_tcp_delete_ctrl,
1726 	.install_queue		= nvmet_tcp_install_queue,
1727 	.disc_traddr		= nvmet_tcp_disc_port_addr,
1728 };
1729 
1730 static int __init nvmet_tcp_init(void)
1731 {
1732 	int ret;
1733 
1734 	nvmet_tcp_wq = alloc_workqueue("nvmet_tcp_wq", WQ_HIGHPRI, 0);
1735 	if (!nvmet_tcp_wq)
1736 		return -ENOMEM;
1737 
1738 	ret = nvmet_register_transport(&nvmet_tcp_ops);
1739 	if (ret)
1740 		goto err;
1741 
1742 	return 0;
1743 err:
1744 	destroy_workqueue(nvmet_tcp_wq);
1745 	return ret;
1746 }
1747 
1748 static void __exit nvmet_tcp_exit(void)
1749 {
1750 	struct nvmet_tcp_queue *queue;
1751 
1752 	nvmet_unregister_transport(&nvmet_tcp_ops);
1753 
1754 	flush_scheduled_work();
1755 	mutex_lock(&nvmet_tcp_queue_mutex);
1756 	list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
1757 		kernel_sock_shutdown(queue->sock, SHUT_RDWR);
1758 	mutex_unlock(&nvmet_tcp_queue_mutex);
1759 	flush_scheduled_work();
1760 
1761 	destroy_workqueue(nvmet_tcp_wq);
1762 }
1763 
1764 module_init(nvmet_tcp_init);
1765 module_exit(nvmet_tcp_exit);
1766 
1767 MODULE_LICENSE("GPL v2");
1768 MODULE_ALIAS("nvmet-transport-3"); /* 3 == NVMF_TRTYPE_TCP */
1769