1 /*
2  * GPL HEADER START
3  *
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 only,
8  * as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License version 2 for more details (a copy is included
14  * in the LICENSE file that accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License
17  * version 2 along with this program; If not, see
18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19  *
20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21  * CA 95054 USA or visit www.sun.com if you need additional information or
22  * have any questions.
23  *
24  * GPL HEADER END
25  */
26 /*
27  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
28  * Use is subject to license terms.
29  *
30  * Copyright (c) 2011, 2012, Intel Corporation.
31  */
32 /*
33  * This file is part of Lustre, http://www.lustre.org/
34  * Lustre is a trademark of Sun Microsystems, Inc.
35  *
36  * lnet/lnet/lib-move.c
37  *
38  * Data movement routines
39  */
40 
41 #define DEBUG_SUBSYSTEM S_LNET
42 
43 #include "../../include/linux/lnet/lib-lnet.h"
44 
45 static int local_nid_dist_zero = 1;
46 module_param(local_nid_dist_zero, int, 0444);
47 MODULE_PARM_DESC(local_nid_dist_zero, "Reserved");
48 
49 int
lnet_fail_nid(lnet_nid_t nid,unsigned int threshold)50 lnet_fail_nid(lnet_nid_t nid, unsigned int threshold)
51 {
52 	lnet_test_peer_t *tp;
53 	struct list_head *el;
54 	struct list_head *next;
55 	struct list_head cull;
56 
57 	LASSERT(the_lnet.ln_init);
58 
59 	/* NB: use lnet_net_lock(0) to serialize operations on test peers */
60 	if (threshold != 0) {
61 		/* Adding a new entry */
62 		LIBCFS_ALLOC(tp, sizeof(*tp));
63 		if (tp == NULL)
64 			return -ENOMEM;
65 
66 		tp->tp_nid = nid;
67 		tp->tp_threshold = threshold;
68 
69 		lnet_net_lock(0);
70 		list_add_tail(&tp->tp_list, &the_lnet.ln_test_peers);
71 		lnet_net_unlock(0);
72 		return 0;
73 	}
74 
75 	/* removing entries */
76 	INIT_LIST_HEAD(&cull);
77 
78 	lnet_net_lock(0);
79 
80 	list_for_each_safe(el, next, &the_lnet.ln_test_peers) {
81 		tp = list_entry(el, lnet_test_peer_t, tp_list);
82 
83 		if (tp->tp_threshold == 0 ||    /* needs culling anyway */
84 		    nid == LNET_NID_ANY ||       /* removing all entries */
85 		    tp->tp_nid == nid) {	  /* matched this one */
86 			list_del(&tp->tp_list);
87 			list_add(&tp->tp_list, &cull);
88 		}
89 	}
90 
91 	lnet_net_unlock(0);
92 
93 	while (!list_empty(&cull)) {
94 		tp = list_entry(cull.next, lnet_test_peer_t, tp_list);
95 
96 		list_del(&tp->tp_list);
97 		LIBCFS_FREE(tp, sizeof(*tp));
98 	}
99 	return 0;
100 }
101 
102 static int
fail_peer(lnet_nid_t nid,int outgoing)103 fail_peer(lnet_nid_t nid, int outgoing)
104 {
105 	lnet_test_peer_t *tp;
106 	struct list_head *el;
107 	struct list_head *next;
108 	struct list_head cull;
109 	int fail = 0;
110 
111 	INIT_LIST_HEAD(&cull);
112 
113 	/* NB: use lnet_net_lock(0) to serialize operations on test peers */
114 	lnet_net_lock(0);
115 
116 	list_for_each_safe(el, next, &the_lnet.ln_test_peers) {
117 		tp = list_entry(el, lnet_test_peer_t, tp_list);
118 
119 		if (tp->tp_threshold == 0) {
120 			/* zombie entry */
121 			if (outgoing) {
122 				/* only cull zombies on outgoing tests,
123 				 * since we may be at interrupt priority on
124 				 * incoming messages. */
125 				list_del(&tp->tp_list);
126 				list_add(&tp->tp_list, &cull);
127 			}
128 			continue;
129 		}
130 
131 		if (tp->tp_nid == LNET_NID_ANY || /* fail every peer */
132 		    nid == tp->tp_nid) {	/* fail this peer */
133 			fail = 1;
134 
135 			if (tp->tp_threshold != LNET_MD_THRESH_INF) {
136 				tp->tp_threshold--;
137 				if (outgoing &&
138 				    tp->tp_threshold == 0) {
139 					/* see above */
140 					list_del(&tp->tp_list);
141 					list_add(&tp->tp_list, &cull);
142 				}
143 			}
144 			break;
145 		}
146 	}
147 
148 	lnet_net_unlock(0);
149 
150 	while (!list_empty(&cull)) {
151 		tp = list_entry(cull.next, lnet_test_peer_t, tp_list);
152 		list_del(&tp->tp_list);
153 
154 		LIBCFS_FREE(tp, sizeof(*tp));
155 	}
156 
157 	return fail;
158 }
159 
160 unsigned int
lnet_iov_nob(unsigned int niov,struct kvec * iov)161 lnet_iov_nob(unsigned int niov, struct kvec *iov)
162 {
163 	unsigned int nob = 0;
164 
165 	while (niov-- > 0)
166 		nob += (iov++)->iov_len;
167 
168 	return nob;
169 }
170 EXPORT_SYMBOL(lnet_iov_nob);
171 
172 void
lnet_copy_iov2iov(unsigned int ndiov,struct kvec * diov,unsigned int doffset,unsigned int nsiov,struct kvec * siov,unsigned int soffset,unsigned int nob)173 lnet_copy_iov2iov(unsigned int ndiov, struct kvec *diov, unsigned int doffset,
174 		   unsigned int nsiov, struct kvec *siov, unsigned int soffset,
175 		   unsigned int nob)
176 {
177 	/* NB diov, siov are READ-ONLY */
178 	unsigned int this_nob;
179 
180 	if (nob == 0)
181 		return;
182 
183 	/* skip complete frags before 'doffset' */
184 	LASSERT(ndiov > 0);
185 	while (doffset >= diov->iov_len) {
186 		doffset -= diov->iov_len;
187 		diov++;
188 		ndiov--;
189 		LASSERT(ndiov > 0);
190 	}
191 
192 	/* skip complete frags before 'soffset' */
193 	LASSERT(nsiov > 0);
194 	while (soffset >= siov->iov_len) {
195 		soffset -= siov->iov_len;
196 		siov++;
197 		nsiov--;
198 		LASSERT(nsiov > 0);
199 	}
200 
201 	do {
202 		LASSERT(ndiov > 0);
203 		LASSERT(nsiov > 0);
204 		this_nob = min(diov->iov_len - doffset,
205 			       siov->iov_len - soffset);
206 		this_nob = min(this_nob, nob);
207 
208 		memcpy((char *)diov->iov_base + doffset,
209 			(char *)siov->iov_base + soffset, this_nob);
210 		nob -= this_nob;
211 
212 		if (diov->iov_len > doffset + this_nob) {
213 			doffset += this_nob;
214 		} else {
215 			diov++;
216 			ndiov--;
217 			doffset = 0;
218 		}
219 
220 		if (siov->iov_len > soffset + this_nob) {
221 			soffset += this_nob;
222 		} else {
223 			siov++;
224 			nsiov--;
225 			soffset = 0;
226 		}
227 	} while (nob > 0);
228 }
229 EXPORT_SYMBOL(lnet_copy_iov2iov);
230 
231 int
lnet_extract_iov(int dst_niov,struct kvec * dst,int src_niov,struct kvec * src,unsigned int offset,unsigned int len)232 lnet_extract_iov(int dst_niov, struct kvec *dst,
233 		  int src_niov, struct kvec *src,
234 		  unsigned int offset, unsigned int len)
235 {
236 	/* Initialise 'dst' to the subset of 'src' starting at 'offset',
237 	 * for exactly 'len' bytes, and return the number of entries.
238 	 * NB not destructive to 'src' */
239 	unsigned int frag_len;
240 	unsigned int niov;
241 
242 	if (len == 0)			   /* no data => */
243 		return 0;		     /* no frags */
244 
245 	LASSERT(src_niov > 0);
246 	while (offset >= src->iov_len) {      /* skip initial frags */
247 		offset -= src->iov_len;
248 		src_niov--;
249 		src++;
250 		LASSERT(src_niov > 0);
251 	}
252 
253 	niov = 1;
254 	for (;;) {
255 		LASSERT(src_niov > 0);
256 		LASSERT((int)niov <= dst_niov);
257 
258 		frag_len = src->iov_len - offset;
259 		dst->iov_base = ((char *)src->iov_base) + offset;
260 
261 		if (len <= frag_len) {
262 			dst->iov_len = len;
263 			return niov;
264 		}
265 
266 		dst->iov_len = frag_len;
267 
268 		len -= frag_len;
269 		dst++;
270 		src++;
271 		niov++;
272 		src_niov--;
273 		offset = 0;
274 	}
275 }
276 EXPORT_SYMBOL(lnet_extract_iov);
277 
278 unsigned int
lnet_kiov_nob(unsigned int niov,lnet_kiov_t * kiov)279 lnet_kiov_nob(unsigned int niov, lnet_kiov_t *kiov)
280 {
281 	unsigned int nob = 0;
282 
283 	while (niov-- > 0)
284 		nob += (kiov++)->kiov_len;
285 
286 	return nob;
287 }
288 EXPORT_SYMBOL(lnet_kiov_nob);
289 
290 void
lnet_copy_kiov2kiov(unsigned int ndiov,lnet_kiov_t * diov,unsigned int doffset,unsigned int nsiov,lnet_kiov_t * siov,unsigned int soffset,unsigned int nob)291 lnet_copy_kiov2kiov(unsigned int ndiov, lnet_kiov_t *diov, unsigned int doffset,
292 		    unsigned int nsiov, lnet_kiov_t *siov, unsigned int soffset,
293 		    unsigned int nob)
294 {
295 	/* NB diov, siov are READ-ONLY */
296 	unsigned int this_nob;
297 	char *daddr = NULL;
298 	char *saddr = NULL;
299 
300 	if (nob == 0)
301 		return;
302 
303 	LASSERT(!in_interrupt());
304 
305 	LASSERT(ndiov > 0);
306 	while (doffset >= diov->kiov_len) {
307 		doffset -= diov->kiov_len;
308 		diov++;
309 		ndiov--;
310 		LASSERT(ndiov > 0);
311 	}
312 
313 	LASSERT(nsiov > 0);
314 	while (soffset >= siov->kiov_len) {
315 		soffset -= siov->kiov_len;
316 		siov++;
317 		nsiov--;
318 		LASSERT(nsiov > 0);
319 	}
320 
321 	do {
322 		LASSERT(ndiov > 0);
323 		LASSERT(nsiov > 0);
324 		this_nob = min(diov->kiov_len - doffset,
325 			       siov->kiov_len - soffset);
326 		this_nob = min(this_nob, nob);
327 
328 		if (daddr == NULL)
329 			daddr = ((char *)kmap(diov->kiov_page)) +
330 				diov->kiov_offset + doffset;
331 		if (saddr == NULL)
332 			saddr = ((char *)kmap(siov->kiov_page)) +
333 				siov->kiov_offset + soffset;
334 
335 		/* Vanishing risk of kmap deadlock when mapping 2 pages.
336 		 * However in practice at least one of the kiovs will be mapped
337 		 * kernel pages and the map/unmap will be NOOPs */
338 
339 		memcpy(daddr, saddr, this_nob);
340 		nob -= this_nob;
341 
342 		if (diov->kiov_len > doffset + this_nob) {
343 			daddr += this_nob;
344 			doffset += this_nob;
345 		} else {
346 			kunmap(diov->kiov_page);
347 			daddr = NULL;
348 			diov++;
349 			ndiov--;
350 			doffset = 0;
351 		}
352 
353 		if (siov->kiov_len > soffset + this_nob) {
354 			saddr += this_nob;
355 			soffset += this_nob;
356 		} else {
357 			kunmap(siov->kiov_page);
358 			saddr = NULL;
359 			siov++;
360 			nsiov--;
361 			soffset = 0;
362 		}
363 	} while (nob > 0);
364 
365 	if (daddr != NULL)
366 		kunmap(diov->kiov_page);
367 	if (saddr != NULL)
368 		kunmap(siov->kiov_page);
369 }
370 EXPORT_SYMBOL(lnet_copy_kiov2kiov);
371 
372 void
lnet_copy_kiov2iov(unsigned int niov,struct kvec * iov,unsigned int iovoffset,unsigned int nkiov,lnet_kiov_t * kiov,unsigned int kiovoffset,unsigned int nob)373 lnet_copy_kiov2iov(unsigned int niov, struct kvec *iov, unsigned int iovoffset,
374 		   unsigned int nkiov, lnet_kiov_t *kiov,
375 		   unsigned int kiovoffset, unsigned int nob)
376 {
377 	/* NB iov, kiov are READ-ONLY */
378 	unsigned int this_nob;
379 	char *addr = NULL;
380 
381 	if (nob == 0)
382 		return;
383 
384 	LASSERT(!in_interrupt());
385 
386 	LASSERT(niov > 0);
387 	while (iovoffset >= iov->iov_len) {
388 		iovoffset -= iov->iov_len;
389 		iov++;
390 		niov--;
391 		LASSERT(niov > 0);
392 	}
393 
394 	LASSERT(nkiov > 0);
395 	while (kiovoffset >= kiov->kiov_len) {
396 		kiovoffset -= kiov->kiov_len;
397 		kiov++;
398 		nkiov--;
399 		LASSERT(nkiov > 0);
400 	}
401 
402 	do {
403 		LASSERT(niov > 0);
404 		LASSERT(nkiov > 0);
405 		this_nob = min(iov->iov_len - iovoffset,
406 			       (__kernel_size_t) kiov->kiov_len - kiovoffset);
407 		this_nob = min(this_nob, nob);
408 
409 		if (addr == NULL)
410 			addr = ((char *)kmap(kiov->kiov_page)) +
411 				kiov->kiov_offset + kiovoffset;
412 
413 		memcpy((char *)iov->iov_base + iovoffset, addr, this_nob);
414 		nob -= this_nob;
415 
416 		if (iov->iov_len > iovoffset + this_nob) {
417 			iovoffset += this_nob;
418 		} else {
419 			iov++;
420 			niov--;
421 			iovoffset = 0;
422 		}
423 
424 		if (kiov->kiov_len > kiovoffset + this_nob) {
425 			addr += this_nob;
426 			kiovoffset += this_nob;
427 		} else {
428 			kunmap(kiov->kiov_page);
429 			addr = NULL;
430 			kiov++;
431 			nkiov--;
432 			kiovoffset = 0;
433 		}
434 
435 	} while (nob > 0);
436 
437 	if (addr != NULL)
438 		kunmap(kiov->kiov_page);
439 }
440 EXPORT_SYMBOL(lnet_copy_kiov2iov);
441 
442 void
lnet_copy_iov2kiov(unsigned int nkiov,lnet_kiov_t * kiov,unsigned int kiovoffset,unsigned int niov,struct kvec * iov,unsigned int iovoffset,unsigned int nob)443 lnet_copy_iov2kiov(unsigned int nkiov, lnet_kiov_t *kiov,
444 		   unsigned int kiovoffset, unsigned int niov,
445 		   struct kvec *iov, unsigned int iovoffset,
446 		   unsigned int nob)
447 {
448 	/* NB kiov, iov are READ-ONLY */
449 	unsigned int this_nob;
450 	char *addr = NULL;
451 
452 	if (nob == 0)
453 		return;
454 
455 	LASSERT(!in_interrupt());
456 
457 	LASSERT(nkiov > 0);
458 	while (kiovoffset >= kiov->kiov_len) {
459 		kiovoffset -= kiov->kiov_len;
460 		kiov++;
461 		nkiov--;
462 		LASSERT(nkiov > 0);
463 	}
464 
465 	LASSERT(niov > 0);
466 	while (iovoffset >= iov->iov_len) {
467 		iovoffset -= iov->iov_len;
468 		iov++;
469 		niov--;
470 		LASSERT(niov > 0);
471 	}
472 
473 	do {
474 		LASSERT(nkiov > 0);
475 		LASSERT(niov > 0);
476 		this_nob = min((__kernel_size_t) kiov->kiov_len - kiovoffset,
477 			       iov->iov_len - iovoffset);
478 		this_nob = min(this_nob, nob);
479 
480 		if (addr == NULL)
481 			addr = ((char *)kmap(kiov->kiov_page)) +
482 				kiov->kiov_offset + kiovoffset;
483 
484 		memcpy(addr, (char *)iov->iov_base + iovoffset, this_nob);
485 		nob -= this_nob;
486 
487 		if (kiov->kiov_len > kiovoffset + this_nob) {
488 			addr += this_nob;
489 			kiovoffset += this_nob;
490 		} else {
491 			kunmap(kiov->kiov_page);
492 			addr = NULL;
493 			kiov++;
494 			nkiov--;
495 			kiovoffset = 0;
496 		}
497 
498 		if (iov->iov_len > iovoffset + this_nob) {
499 			iovoffset += this_nob;
500 		} else {
501 			iov++;
502 			niov--;
503 			iovoffset = 0;
504 		}
505 	} while (nob > 0);
506 
507 	if (addr != NULL)
508 		kunmap(kiov->kiov_page);
509 }
510 EXPORT_SYMBOL(lnet_copy_iov2kiov);
511 
512 int
lnet_extract_kiov(int dst_niov,lnet_kiov_t * dst,int src_niov,lnet_kiov_t * src,unsigned int offset,unsigned int len)513 lnet_extract_kiov(int dst_niov, lnet_kiov_t *dst,
514 		   int src_niov, lnet_kiov_t *src,
515 		   unsigned int offset, unsigned int len)
516 {
517 	/* Initialise 'dst' to the subset of 'src' starting at 'offset',
518 	 * for exactly 'len' bytes, and return the number of entries.
519 	 * NB not destructive to 'src' */
520 	unsigned int frag_len;
521 	unsigned int niov;
522 
523 	if (len == 0)			   /* no data => */
524 		return 0;		     /* no frags */
525 
526 	LASSERT(src_niov > 0);
527 	while (offset >= src->kiov_len) {      /* skip initial frags */
528 		offset -= src->kiov_len;
529 		src_niov--;
530 		src++;
531 		LASSERT(src_niov > 0);
532 	}
533 
534 	niov = 1;
535 	for (;;) {
536 		LASSERT(src_niov > 0);
537 		LASSERT((int)niov <= dst_niov);
538 
539 		frag_len = src->kiov_len - offset;
540 		dst->kiov_page = src->kiov_page;
541 		dst->kiov_offset = src->kiov_offset + offset;
542 
543 		if (len <= frag_len) {
544 			dst->kiov_len = len;
545 			LASSERT(dst->kiov_offset + dst->kiov_len
546 					     <= PAGE_CACHE_SIZE);
547 			return niov;
548 		}
549 
550 		dst->kiov_len = frag_len;
551 		LASSERT(dst->kiov_offset + dst->kiov_len <= PAGE_CACHE_SIZE);
552 
553 		len -= frag_len;
554 		dst++;
555 		src++;
556 		niov++;
557 		src_niov--;
558 		offset = 0;
559 	}
560 }
561 EXPORT_SYMBOL(lnet_extract_kiov);
562 
563 static void
lnet_ni_recv(lnet_ni_t * ni,void * private,lnet_msg_t * msg,int delayed,unsigned int offset,unsigned int mlen,unsigned int rlen)564 lnet_ni_recv(lnet_ni_t *ni, void *private, lnet_msg_t *msg, int delayed,
565 	     unsigned int offset, unsigned int mlen, unsigned int rlen)
566 {
567 	unsigned int niov = 0;
568 	struct kvec *iov = NULL;
569 	lnet_kiov_t *kiov = NULL;
570 	int rc;
571 
572 	LASSERT(!in_interrupt());
573 	LASSERT(mlen == 0 || msg != NULL);
574 
575 	if (msg != NULL) {
576 		LASSERT(msg->msg_receiving);
577 		LASSERT(!msg->msg_sending);
578 		LASSERT(rlen == msg->msg_len);
579 		LASSERT(mlen <= msg->msg_len);
580 		LASSERT(msg->msg_offset == offset);
581 		LASSERT(msg->msg_wanted == mlen);
582 
583 		msg->msg_receiving = 0;
584 
585 		if (mlen != 0) {
586 			niov = msg->msg_niov;
587 			iov  = msg->msg_iov;
588 			kiov = msg->msg_kiov;
589 
590 			LASSERT(niov > 0);
591 			LASSERT((iov == NULL) != (kiov == NULL));
592 		}
593 	}
594 
595 	rc = (ni->ni_lnd->lnd_recv)(ni, private, msg, delayed,
596 				    niov, iov, kiov, offset, mlen, rlen);
597 	if (rc < 0)
598 		lnet_finalize(ni, msg, rc);
599 }
600 
601 static void
lnet_setpayloadbuffer(lnet_msg_t * msg)602 lnet_setpayloadbuffer(lnet_msg_t *msg)
603 {
604 	lnet_libmd_t *md = msg->msg_md;
605 
606 	LASSERT(msg->msg_len > 0);
607 	LASSERT(!msg->msg_routing);
608 	LASSERT(md != NULL);
609 	LASSERT(msg->msg_niov == 0);
610 	LASSERT(msg->msg_iov == NULL);
611 	LASSERT(msg->msg_kiov == NULL);
612 
613 	msg->msg_niov = md->md_niov;
614 	if ((md->md_options & LNET_MD_KIOV) != 0)
615 		msg->msg_kiov = md->md_iov.kiov;
616 	else
617 		msg->msg_iov = md->md_iov.iov;
618 }
619 
620 void
lnet_prep_send(lnet_msg_t * msg,int type,lnet_process_id_t target,unsigned int offset,unsigned int len)621 lnet_prep_send(lnet_msg_t *msg, int type, lnet_process_id_t target,
622 	       unsigned int offset, unsigned int len)
623 {
624 	msg->msg_type = type;
625 	msg->msg_target = target;
626 	msg->msg_len = len;
627 	msg->msg_offset = offset;
628 
629 	if (len != 0)
630 		lnet_setpayloadbuffer(msg);
631 
632 	memset(&msg->msg_hdr, 0, sizeof(msg->msg_hdr));
633 	msg->msg_hdr.type	   = cpu_to_le32(type);
634 	msg->msg_hdr.dest_nid       = cpu_to_le64(target.nid);
635 	msg->msg_hdr.dest_pid       = cpu_to_le32(target.pid);
636 	/* src_nid will be set later */
637 	msg->msg_hdr.src_pid	= cpu_to_le32(the_lnet.ln_pid);
638 	msg->msg_hdr.payload_length = cpu_to_le32(len);
639 }
640 
641 static void
lnet_ni_send(lnet_ni_t * ni,lnet_msg_t * msg)642 lnet_ni_send(lnet_ni_t *ni, lnet_msg_t *msg)
643 {
644 	void *priv = msg->msg_private;
645 	int rc;
646 
647 	LASSERT(!in_interrupt());
648 	LASSERT(LNET_NETTYP(LNET_NIDNET(ni->ni_nid)) == LOLND ||
649 		 (msg->msg_txcredit && msg->msg_peertxcredit));
650 
651 	rc = (ni->ni_lnd->lnd_send)(ni, priv, msg);
652 	if (rc < 0)
653 		lnet_finalize(ni, msg, rc);
654 }
655 
656 static int
lnet_ni_eager_recv(lnet_ni_t * ni,lnet_msg_t * msg)657 lnet_ni_eager_recv(lnet_ni_t *ni, lnet_msg_t *msg)
658 {
659 	int rc;
660 
661 	LASSERT(!msg->msg_sending);
662 	LASSERT(msg->msg_receiving);
663 	LASSERT(!msg->msg_rx_ready_delay);
664 	LASSERT(ni->ni_lnd->lnd_eager_recv != NULL);
665 
666 	msg->msg_rx_ready_delay = 1;
667 	rc = (ni->ni_lnd->lnd_eager_recv)(ni, msg->msg_private, msg,
668 					  &msg->msg_private);
669 	if (rc != 0) {
670 		CERROR("recv from %s / send to %s aborted: eager_recv failed %d\n",
671 		       libcfs_nid2str(msg->msg_rxpeer->lp_nid),
672 		       libcfs_id2str(msg->msg_target), rc);
673 		LASSERT(rc < 0); /* required by my callers */
674 	}
675 
676 	return rc;
677 }
678 
679 /* NB: caller shall hold a ref on 'lp' as I'd drop lnet_net_lock */
680 static void
lnet_ni_query_locked(lnet_ni_t * ni,lnet_peer_t * lp)681 lnet_ni_query_locked(lnet_ni_t *ni, lnet_peer_t *lp)
682 {
683 	unsigned long last_alive = 0;
684 
685 	LASSERT(lnet_peer_aliveness_enabled(lp));
686 	LASSERT(ni->ni_lnd->lnd_query != NULL);
687 
688 	lnet_net_unlock(lp->lp_cpt);
689 	(ni->ni_lnd->lnd_query)(ni, lp->lp_nid, &last_alive);
690 	lnet_net_lock(lp->lp_cpt);
691 
692 	lp->lp_last_query = cfs_time_current();
693 
694 	if (last_alive != 0) /* NI has updated timestamp */
695 		lp->lp_last_alive = last_alive;
696 }
697 
698 /* NB: always called with lnet_net_lock held */
699 static inline int
lnet_peer_is_alive(lnet_peer_t * lp,unsigned long now)700 lnet_peer_is_alive(lnet_peer_t *lp, unsigned long now)
701 {
702 	int alive;
703 	unsigned long deadline;
704 
705 	LASSERT(lnet_peer_aliveness_enabled(lp));
706 
707 	/* Trust lnet_notify() if it has more recent aliveness news, but
708 	 * ignore the initial assumed death (see lnet_peers_start_down()).
709 	 */
710 	if (!lp->lp_alive && lp->lp_alive_count > 0 &&
711 	    cfs_time_aftereq(lp->lp_timestamp, lp->lp_last_alive))
712 		return 0;
713 
714 	deadline = cfs_time_add(lp->lp_last_alive,
715 				cfs_time_seconds(lp->lp_ni->ni_peertimeout));
716 	alive = cfs_time_after(deadline, now);
717 
718 	/* Update obsolete lp_alive except for routers assumed to be dead
719 	 * initially, because router checker would update aliveness in this
720 	 * case, and moreover lp_last_alive at peer creation is assumed.
721 	 */
722 	if (alive && !lp->lp_alive &&
723 	    !(lnet_isrouter(lp) && lp->lp_alive_count == 0))
724 		lnet_notify_locked(lp, 0, 1, lp->lp_last_alive);
725 
726 	return alive;
727 }
728 
729 /* NB: returns 1 when alive, 0 when dead, negative when error;
730  *     may drop the lnet_net_lock */
731 static int
lnet_peer_alive_locked(lnet_peer_t * lp)732 lnet_peer_alive_locked(lnet_peer_t *lp)
733 {
734 	unsigned long now = cfs_time_current();
735 
736 	if (!lnet_peer_aliveness_enabled(lp))
737 		return -ENODEV;
738 
739 	if (lnet_peer_is_alive(lp, now))
740 		return 1;
741 
742 	/* Peer appears dead, but we should avoid frequent NI queries (at
743 	 * most once per lnet_queryinterval seconds). */
744 	if (lp->lp_last_query != 0) {
745 		static const int lnet_queryinterval = 1;
746 
747 		unsigned long next_query =
748 			   cfs_time_add(lp->lp_last_query,
749 					cfs_time_seconds(lnet_queryinterval));
750 
751 		if (time_before(now, next_query)) {
752 			if (lp->lp_alive)
753 				CWARN("Unexpected aliveness of peer %s: %d < %d (%d/%d)\n",
754 				      libcfs_nid2str(lp->lp_nid),
755 				      (int)now, (int)next_query,
756 				      lnet_queryinterval,
757 				      lp->lp_ni->ni_peertimeout);
758 			return 0;
759 		}
760 	}
761 
762 	/* query NI for latest aliveness news */
763 	lnet_ni_query_locked(lp->lp_ni, lp);
764 
765 	if (lnet_peer_is_alive(lp, now))
766 		return 1;
767 
768 	lnet_notify_locked(lp, 0, 0, lp->lp_last_alive);
769 	return 0;
770 }
771 
772 /**
773  * \param msg The message to be sent.
774  * \param do_send True if lnet_ni_send() should be called in this function.
775  *	  lnet_send() is going to lnet_net_unlock immediately after this, so
776  *	  it sets do_send FALSE and I don't do the unlock/send/lock bit.
777  *
778  * \retval 0 If \a msg sent or OK to send.
779  * \retval EAGAIN If \a msg blocked for credit.
780  * \retval EHOSTUNREACH If the next hop of the message appears dead.
781  * \retval ECANCELED If the MD of the message has been unlinked.
782  */
783 static int
lnet_post_send_locked(lnet_msg_t * msg,int do_send)784 lnet_post_send_locked(lnet_msg_t *msg, int do_send)
785 {
786 	lnet_peer_t *lp = msg->msg_txpeer;
787 	lnet_ni_t *ni = lp->lp_ni;
788 	int cpt = msg->msg_tx_cpt;
789 	struct lnet_tx_queue *tq = ni->ni_tx_queues[cpt];
790 
791 	/* non-lnet_send() callers have checked before */
792 	LASSERT(!do_send || msg->msg_tx_delayed);
793 	LASSERT(!msg->msg_receiving);
794 	LASSERT(msg->msg_tx_committed);
795 
796 	/* NB 'lp' is always the next hop */
797 	if ((msg->msg_target.pid & LNET_PID_USERFLAG) == 0 &&
798 	    lnet_peer_alive_locked(lp) == 0) {
799 		the_lnet.ln_counters[cpt]->drop_count++;
800 		the_lnet.ln_counters[cpt]->drop_length += msg->msg_len;
801 		lnet_net_unlock(cpt);
802 
803 		CNETERR("Dropping message for %s: peer not alive\n",
804 			libcfs_id2str(msg->msg_target));
805 		if (do_send)
806 			lnet_finalize(ni, msg, -EHOSTUNREACH);
807 
808 		lnet_net_lock(cpt);
809 		return EHOSTUNREACH;
810 	}
811 
812 	if (msg->msg_md != NULL &&
813 	    (msg->msg_md->md_flags & LNET_MD_FLAG_ABORTED) != 0) {
814 		lnet_net_unlock(cpt);
815 
816 		CNETERR("Aborting message for %s: LNetM[DE]Unlink() already called on the MD/ME.\n",
817 			libcfs_id2str(msg->msg_target));
818 		if (do_send)
819 			lnet_finalize(ni, msg, -ECANCELED);
820 
821 		lnet_net_lock(cpt);
822 		return ECANCELED;
823 	}
824 
825 	if (!msg->msg_peertxcredit) {
826 		LASSERT((lp->lp_txcredits < 0) ==
827 			 !list_empty(&lp->lp_txq));
828 
829 		msg->msg_peertxcredit = 1;
830 		lp->lp_txqnob += msg->msg_len + sizeof(lnet_hdr_t);
831 		lp->lp_txcredits--;
832 
833 		if (lp->lp_txcredits < lp->lp_mintxcredits)
834 			lp->lp_mintxcredits = lp->lp_txcredits;
835 
836 		if (lp->lp_txcredits < 0) {
837 			msg->msg_tx_delayed = 1;
838 			list_add_tail(&msg->msg_list, &lp->lp_txq);
839 			return EAGAIN;
840 		}
841 	}
842 
843 	if (!msg->msg_txcredit) {
844 		LASSERT((tq->tq_credits < 0) ==
845 			!list_empty(&tq->tq_delayed));
846 
847 		msg->msg_txcredit = 1;
848 		tq->tq_credits--;
849 
850 		if (tq->tq_credits < tq->tq_credits_min)
851 			tq->tq_credits_min = tq->tq_credits;
852 
853 		if (tq->tq_credits < 0) {
854 			msg->msg_tx_delayed = 1;
855 			list_add_tail(&msg->msg_list, &tq->tq_delayed);
856 			return EAGAIN;
857 		}
858 	}
859 
860 	if (do_send) {
861 		lnet_net_unlock(cpt);
862 		lnet_ni_send(ni, msg);
863 		lnet_net_lock(cpt);
864 	}
865 	return 0;
866 }
867 
868 static lnet_rtrbufpool_t *
lnet_msg2bufpool(lnet_msg_t * msg)869 lnet_msg2bufpool(lnet_msg_t *msg)
870 {
871 	lnet_rtrbufpool_t *rbp;
872 	int cpt;
873 
874 	LASSERT(msg->msg_rx_committed);
875 
876 	cpt = msg->msg_rx_cpt;
877 	rbp = &the_lnet.ln_rtrpools[cpt][0];
878 
879 	LASSERT(msg->msg_len <= LNET_MTU);
880 	while (msg->msg_len > (unsigned int)rbp->rbp_npages * PAGE_CACHE_SIZE) {
881 		rbp++;
882 		LASSERT(rbp < &the_lnet.ln_rtrpools[cpt][LNET_NRBPOOLS]);
883 	}
884 
885 	return rbp;
886 }
887 
888 static int
lnet_post_routed_recv_locked(lnet_msg_t * msg,int do_recv)889 lnet_post_routed_recv_locked(lnet_msg_t *msg, int do_recv)
890 {
891 	/* lnet_parse is going to lnet_net_unlock immediately after this, so it
892 	 * sets do_recv FALSE and I don't do the unlock/send/lock bit.  I
893 	 * return EAGAIN if msg blocked and 0 if received or OK to receive */
894 	lnet_peer_t *lp = msg->msg_rxpeer;
895 	lnet_rtrbufpool_t *rbp;
896 	lnet_rtrbuf_t *rb;
897 
898 	LASSERT(msg->msg_iov == NULL);
899 	LASSERT(msg->msg_kiov == NULL);
900 	LASSERT(msg->msg_niov == 0);
901 	LASSERT(msg->msg_routing);
902 	LASSERT(msg->msg_receiving);
903 	LASSERT(!msg->msg_sending);
904 
905 	/* non-lnet_parse callers only receive delayed messages */
906 	LASSERT(!do_recv || msg->msg_rx_delayed);
907 
908 	if (!msg->msg_peerrtrcredit) {
909 		LASSERT((lp->lp_rtrcredits < 0) ==
910 			 !list_empty(&lp->lp_rtrq));
911 
912 		msg->msg_peerrtrcredit = 1;
913 		lp->lp_rtrcredits--;
914 		if (lp->lp_rtrcredits < lp->lp_minrtrcredits)
915 			lp->lp_minrtrcredits = lp->lp_rtrcredits;
916 
917 		if (lp->lp_rtrcredits < 0) {
918 			/* must have checked eager_recv before here */
919 			LASSERT(msg->msg_rx_ready_delay);
920 			msg->msg_rx_delayed = 1;
921 			list_add_tail(&msg->msg_list, &lp->lp_rtrq);
922 			return EAGAIN;
923 		}
924 	}
925 
926 	rbp = lnet_msg2bufpool(msg);
927 
928 	if (!msg->msg_rtrcredit) {
929 		LASSERT((rbp->rbp_credits < 0) ==
930 			 !list_empty(&rbp->rbp_msgs));
931 
932 		msg->msg_rtrcredit = 1;
933 		rbp->rbp_credits--;
934 		if (rbp->rbp_credits < rbp->rbp_mincredits)
935 			rbp->rbp_mincredits = rbp->rbp_credits;
936 
937 		if (rbp->rbp_credits < 0) {
938 			/* must have checked eager_recv before here */
939 			LASSERT(msg->msg_rx_ready_delay);
940 			msg->msg_rx_delayed = 1;
941 			list_add_tail(&msg->msg_list, &rbp->rbp_msgs);
942 			return EAGAIN;
943 		}
944 	}
945 
946 	LASSERT(!list_empty(&rbp->rbp_bufs));
947 	rb = list_entry(rbp->rbp_bufs.next, lnet_rtrbuf_t, rb_list);
948 	list_del(&rb->rb_list);
949 
950 	msg->msg_niov = rbp->rbp_npages;
951 	msg->msg_kiov = &rb->rb_kiov[0];
952 
953 	if (do_recv) {
954 		int cpt = msg->msg_rx_cpt;
955 
956 		lnet_net_unlock(cpt);
957 		lnet_ni_recv(lp->lp_ni, msg->msg_private, msg, 1,
958 			     0, msg->msg_len, msg->msg_len);
959 		lnet_net_lock(cpt);
960 	}
961 	return 0;
962 }
963 
964 void
lnet_return_tx_credits_locked(lnet_msg_t * msg)965 lnet_return_tx_credits_locked(lnet_msg_t *msg)
966 {
967 	lnet_peer_t *txpeer = msg->msg_txpeer;
968 	lnet_msg_t *msg2;
969 
970 	if (msg->msg_txcredit) {
971 		struct lnet_ni *ni = txpeer->lp_ni;
972 		struct lnet_tx_queue *tq = ni->ni_tx_queues[msg->msg_tx_cpt];
973 
974 		/* give back NI txcredits */
975 		msg->msg_txcredit = 0;
976 
977 		LASSERT((tq->tq_credits < 0) ==
978 			!list_empty(&tq->tq_delayed));
979 
980 		tq->tq_credits++;
981 		if (tq->tq_credits <= 0) {
982 			msg2 = list_entry(tq->tq_delayed.next,
983 					      lnet_msg_t, msg_list);
984 			list_del(&msg2->msg_list);
985 
986 			LASSERT(msg2->msg_txpeer->lp_ni == ni);
987 			LASSERT(msg2->msg_tx_delayed);
988 
989 			(void) lnet_post_send_locked(msg2, 1);
990 		}
991 	}
992 
993 	if (msg->msg_peertxcredit) {
994 		/* give back peer txcredits */
995 		msg->msg_peertxcredit = 0;
996 
997 		LASSERT((txpeer->lp_txcredits < 0) ==
998 			!list_empty(&txpeer->lp_txq));
999 
1000 		txpeer->lp_txqnob -= msg->msg_len + sizeof(lnet_hdr_t);
1001 		LASSERT(txpeer->lp_txqnob >= 0);
1002 
1003 		txpeer->lp_txcredits++;
1004 		if (txpeer->lp_txcredits <= 0) {
1005 			msg2 = list_entry(txpeer->lp_txq.next,
1006 					      lnet_msg_t, msg_list);
1007 			list_del(&msg2->msg_list);
1008 
1009 			LASSERT(msg2->msg_txpeer == txpeer);
1010 			LASSERT(msg2->msg_tx_delayed);
1011 
1012 			(void) lnet_post_send_locked(msg2, 1);
1013 		}
1014 	}
1015 
1016 	if (txpeer != NULL) {
1017 		msg->msg_txpeer = NULL;
1018 		lnet_peer_decref_locked(txpeer);
1019 	}
1020 }
1021 
1022 void
lnet_return_rx_credits_locked(lnet_msg_t * msg)1023 lnet_return_rx_credits_locked(lnet_msg_t *msg)
1024 {
1025 	lnet_peer_t *rxpeer = msg->msg_rxpeer;
1026 	lnet_msg_t *msg2;
1027 
1028 	if (msg->msg_rtrcredit) {
1029 		/* give back global router credits */
1030 		lnet_rtrbuf_t *rb;
1031 		lnet_rtrbufpool_t *rbp;
1032 
1033 		/* NB If a msg ever blocks for a buffer in rbp_msgs, it stays
1034 		 * there until it gets one allocated, or aborts the wait
1035 		 * itself */
1036 		LASSERT(msg->msg_kiov != NULL);
1037 
1038 		rb = list_entry(msg->msg_kiov, lnet_rtrbuf_t, rb_kiov[0]);
1039 		rbp = rb->rb_pool;
1040 		LASSERT(rbp == lnet_msg2bufpool(msg));
1041 
1042 		msg->msg_kiov = NULL;
1043 		msg->msg_rtrcredit = 0;
1044 
1045 		LASSERT((rbp->rbp_credits < 0) ==
1046 			!list_empty(&rbp->rbp_msgs));
1047 		LASSERT((rbp->rbp_credits > 0) ==
1048 			!list_empty(&rbp->rbp_bufs));
1049 
1050 		list_add(&rb->rb_list, &rbp->rbp_bufs);
1051 		rbp->rbp_credits++;
1052 		if (rbp->rbp_credits <= 0) {
1053 			msg2 = list_entry(rbp->rbp_msgs.next,
1054 					      lnet_msg_t, msg_list);
1055 			list_del(&msg2->msg_list);
1056 
1057 			(void) lnet_post_routed_recv_locked(msg2, 1);
1058 		}
1059 	}
1060 
1061 	if (msg->msg_peerrtrcredit) {
1062 		/* give back peer router credits */
1063 		msg->msg_peerrtrcredit = 0;
1064 
1065 		LASSERT((rxpeer->lp_rtrcredits < 0) ==
1066 			!list_empty(&rxpeer->lp_rtrq));
1067 
1068 		rxpeer->lp_rtrcredits++;
1069 		if (rxpeer->lp_rtrcredits <= 0) {
1070 			msg2 = list_entry(rxpeer->lp_rtrq.next,
1071 					      lnet_msg_t, msg_list);
1072 			list_del(&msg2->msg_list);
1073 
1074 			(void) lnet_post_routed_recv_locked(msg2, 1);
1075 		}
1076 	}
1077 	if (rxpeer != NULL) {
1078 		msg->msg_rxpeer = NULL;
1079 		lnet_peer_decref_locked(rxpeer);
1080 	}
1081 }
1082 
1083 static int
lnet_compare_routes(lnet_route_t * r1,lnet_route_t * r2)1084 lnet_compare_routes(lnet_route_t *r1, lnet_route_t *r2)
1085 {
1086 	lnet_peer_t *p1 = r1->lr_gateway;
1087 	lnet_peer_t *p2 = r2->lr_gateway;
1088 
1089 	if (r1->lr_priority < r2->lr_priority)
1090 		return 1;
1091 
1092 	if (r1->lr_priority > r2->lr_priority)
1093 		return -1;
1094 
1095 	if (r1->lr_hops < r2->lr_hops)
1096 		return 1;
1097 
1098 	if (r1->lr_hops > r2->lr_hops)
1099 		return -1;
1100 
1101 	if (p1->lp_txqnob < p2->lp_txqnob)
1102 		return 1;
1103 
1104 	if (p1->lp_txqnob > p2->lp_txqnob)
1105 		return -1;
1106 
1107 	if (p1->lp_txcredits > p2->lp_txcredits)
1108 		return 1;
1109 
1110 	if (p1->lp_txcredits < p2->lp_txcredits)
1111 		return -1;
1112 
1113 	if (r1->lr_seq - r2->lr_seq <= 0)
1114 		return 1;
1115 
1116 	return -1;
1117 }
1118 
1119 static lnet_peer_t *
lnet_find_route_locked(lnet_ni_t * ni,lnet_nid_t target,lnet_nid_t rtr_nid)1120 lnet_find_route_locked(lnet_ni_t *ni, lnet_nid_t target, lnet_nid_t rtr_nid)
1121 {
1122 	lnet_remotenet_t *rnet;
1123 	lnet_route_t *rtr;
1124 	lnet_route_t *rtr_best;
1125 	lnet_route_t *rtr_last;
1126 	struct lnet_peer *lp_best;
1127 	struct lnet_peer *lp;
1128 	int rc;
1129 
1130 	/* If @rtr_nid is not LNET_NID_ANY, return the gateway with
1131 	 * rtr_nid nid, otherwise find the best gateway I can use */
1132 
1133 	rnet = lnet_find_net_locked(LNET_NIDNET(target));
1134 	if (rnet == NULL)
1135 		return NULL;
1136 
1137 	lp_best = NULL;
1138 	rtr_best = rtr_last = NULL;
1139 	list_for_each_entry(rtr, &rnet->lrn_routes, lr_list) {
1140 		lp = rtr->lr_gateway;
1141 
1142 		if (!lp->lp_alive || /* gateway is down */
1143 		    ((lp->lp_ping_feats & LNET_PING_FEAT_NI_STATUS) != 0 &&
1144 		     rtr->lr_downis != 0)) /* NI to target is down */
1145 			continue;
1146 
1147 		if (ni != NULL && lp->lp_ni != ni)
1148 			continue;
1149 
1150 		if (lp->lp_nid == rtr_nid) /* it's pre-determined router */
1151 			return lp;
1152 
1153 		if (lp_best == NULL) {
1154 			rtr_best = rtr_last = rtr;
1155 			lp_best = lp;
1156 			continue;
1157 		}
1158 
1159 		/* no protection on below fields, but it's harmless */
1160 		if (rtr_last->lr_seq - rtr->lr_seq < 0)
1161 			rtr_last = rtr;
1162 
1163 		rc = lnet_compare_routes(rtr, rtr_best);
1164 		if (rc < 0)
1165 			continue;
1166 
1167 		rtr_best = rtr;
1168 		lp_best = lp;
1169 	}
1170 
1171 	/* set sequence number on the best router to the latest sequence + 1
1172 	 * so we can round-robin all routers, it's race and inaccurate but
1173 	 * harmless and functional  */
1174 	if (rtr_best != NULL)
1175 		rtr_best->lr_seq = rtr_last->lr_seq + 1;
1176 	return lp_best;
1177 }
1178 
1179 int
lnet_send(lnet_nid_t src_nid,lnet_msg_t * msg,lnet_nid_t rtr_nid)1180 lnet_send(lnet_nid_t src_nid, lnet_msg_t *msg, lnet_nid_t rtr_nid)
1181 {
1182 	lnet_nid_t dst_nid = msg->msg_target.nid;
1183 	struct lnet_ni *src_ni;
1184 	struct lnet_ni *local_ni;
1185 	struct lnet_peer *lp;
1186 	int cpt;
1187 	int cpt2;
1188 	int rc;
1189 
1190 	/* NB: rtr_nid is set to LNET_NID_ANY for all current use-cases,
1191 	 * but we might want to use pre-determined router for ACK/REPLY
1192 	 * in the future */
1193 	/* NB: ni != NULL == interface pre-determined (ACK/REPLY) */
1194 	LASSERT(msg->msg_txpeer == NULL);
1195 	LASSERT(!msg->msg_sending);
1196 	LASSERT(!msg->msg_target_is_router);
1197 	LASSERT(!msg->msg_receiving);
1198 
1199 	msg->msg_sending = 1;
1200 
1201 	LASSERT(!msg->msg_tx_committed);
1202 	cpt = lnet_cpt_of_nid(rtr_nid == LNET_NID_ANY ? dst_nid : rtr_nid);
1203  again:
1204 	lnet_net_lock(cpt);
1205 
1206 	if (the_lnet.ln_shutdown) {
1207 		lnet_net_unlock(cpt);
1208 		return -ESHUTDOWN;
1209 	}
1210 
1211 	if (src_nid == LNET_NID_ANY) {
1212 		src_ni = NULL;
1213 	} else {
1214 		src_ni = lnet_nid2ni_locked(src_nid, cpt);
1215 		if (src_ni == NULL) {
1216 			lnet_net_unlock(cpt);
1217 			LCONSOLE_WARN("Can't send to %s: src %s is not a local nid\n",
1218 				      libcfs_nid2str(dst_nid),
1219 				      libcfs_nid2str(src_nid));
1220 			return -EINVAL;
1221 		}
1222 		LASSERT(!msg->msg_routing);
1223 	}
1224 
1225 	/* Is this for someone on a local network? */
1226 	local_ni = lnet_net2ni_locked(LNET_NIDNET(dst_nid), cpt);
1227 
1228 	if (local_ni != NULL) {
1229 		if (src_ni == NULL) {
1230 			src_ni = local_ni;
1231 			src_nid = src_ni->ni_nid;
1232 		} else if (src_ni == local_ni) {
1233 			lnet_ni_decref_locked(local_ni, cpt);
1234 		} else {
1235 			lnet_ni_decref_locked(local_ni, cpt);
1236 			lnet_ni_decref_locked(src_ni, cpt);
1237 			lnet_net_unlock(cpt);
1238 			LCONSOLE_WARN("No route to %s via from %s\n",
1239 				      libcfs_nid2str(dst_nid),
1240 				      libcfs_nid2str(src_nid));
1241 			return -EINVAL;
1242 		}
1243 
1244 		LASSERT(src_nid != LNET_NID_ANY);
1245 		lnet_msg_commit(msg, cpt);
1246 
1247 		if (!msg->msg_routing)
1248 			msg->msg_hdr.src_nid = cpu_to_le64(src_nid);
1249 
1250 		if (src_ni == the_lnet.ln_loni) {
1251 			/* No send credit hassles with LOLND */
1252 			lnet_net_unlock(cpt);
1253 			lnet_ni_send(src_ni, msg);
1254 
1255 			lnet_net_lock(cpt);
1256 			lnet_ni_decref_locked(src_ni, cpt);
1257 			lnet_net_unlock(cpt);
1258 			return 0;
1259 		}
1260 
1261 		rc = lnet_nid2peer_locked(&lp, dst_nid, cpt);
1262 		/* lp has ref on src_ni; lose mine */
1263 		lnet_ni_decref_locked(src_ni, cpt);
1264 		if (rc != 0) {
1265 			lnet_net_unlock(cpt);
1266 			LCONSOLE_WARN("Error %d finding peer %s\n", rc,
1267 				      libcfs_nid2str(dst_nid));
1268 			/* ENOMEM or shutting down */
1269 			return rc;
1270 		}
1271 		LASSERT(lp->lp_ni == src_ni);
1272 	} else {
1273 		/* sending to a remote network */
1274 		lp = lnet_find_route_locked(src_ni, dst_nid, rtr_nid);
1275 		if (lp == NULL) {
1276 			if (src_ni != NULL)
1277 				lnet_ni_decref_locked(src_ni, cpt);
1278 			lnet_net_unlock(cpt);
1279 
1280 			LCONSOLE_WARN("No route to %s via %s (all routers down)\n",
1281 				      libcfs_id2str(msg->msg_target),
1282 				      libcfs_nid2str(src_nid));
1283 			return -EHOSTUNREACH;
1284 		}
1285 
1286 		/* rtr_nid is LNET_NID_ANY or NID of pre-determined router,
1287 		 * it's possible that rtr_nid isn't LNET_NID_ANY and lp isn't
1288 		 * pre-determined router, this can happen if router table
1289 		 * was changed when we release the lock */
1290 		if (rtr_nid != lp->lp_nid) {
1291 			cpt2 = lnet_cpt_of_nid_locked(lp->lp_nid);
1292 			if (cpt2 != cpt) {
1293 				if (src_ni != NULL)
1294 					lnet_ni_decref_locked(src_ni, cpt);
1295 				lnet_net_unlock(cpt);
1296 
1297 				rtr_nid = lp->lp_nid;
1298 				cpt = cpt2;
1299 				goto again;
1300 			}
1301 		}
1302 
1303 		CDEBUG(D_NET, "Best route to %s via %s for %s %d\n",
1304 		       libcfs_nid2str(dst_nid), libcfs_nid2str(lp->lp_nid),
1305 		       lnet_msgtyp2str(msg->msg_type), msg->msg_len);
1306 
1307 		if (src_ni == NULL) {
1308 			src_ni = lp->lp_ni;
1309 			src_nid = src_ni->ni_nid;
1310 		} else {
1311 			LASSERT(src_ni == lp->lp_ni);
1312 			lnet_ni_decref_locked(src_ni, cpt);
1313 		}
1314 
1315 		lnet_peer_addref_locked(lp);
1316 
1317 		LASSERT(src_nid != LNET_NID_ANY);
1318 		lnet_msg_commit(msg, cpt);
1319 
1320 		if (!msg->msg_routing) {
1321 			/* I'm the source and now I know which NI to send on */
1322 			msg->msg_hdr.src_nid = cpu_to_le64(src_nid);
1323 		}
1324 
1325 		msg->msg_target_is_router = 1;
1326 		msg->msg_target.nid = lp->lp_nid;
1327 		msg->msg_target.pid = LUSTRE_SRV_LNET_PID;
1328 	}
1329 
1330 	/* 'lp' is our best choice of peer */
1331 
1332 	LASSERT(!msg->msg_peertxcredit);
1333 	LASSERT(!msg->msg_txcredit);
1334 	LASSERT(msg->msg_txpeer == NULL);
1335 
1336 	msg->msg_txpeer = lp;		   /* msg takes my ref on lp */
1337 
1338 	rc = lnet_post_send_locked(msg, 0);
1339 	lnet_net_unlock(cpt);
1340 
1341 	if (rc == EHOSTUNREACH || rc == ECANCELED)
1342 		return -rc;
1343 
1344 	if (rc == 0)
1345 		lnet_ni_send(src_ni, msg);
1346 
1347 	return 0; /* rc == 0 or EAGAIN */
1348 }
1349 
1350 static void
lnet_drop_message(lnet_ni_t * ni,int cpt,void * private,unsigned int nob)1351 lnet_drop_message(lnet_ni_t *ni, int cpt, void *private, unsigned int nob)
1352 {
1353 	lnet_net_lock(cpt);
1354 	the_lnet.ln_counters[cpt]->drop_count++;
1355 	the_lnet.ln_counters[cpt]->drop_length += nob;
1356 	lnet_net_unlock(cpt);
1357 
1358 	lnet_ni_recv(ni, private, NULL, 0, 0, 0, nob);
1359 }
1360 
1361 static void
lnet_recv_put(lnet_ni_t * ni,lnet_msg_t * msg)1362 lnet_recv_put(lnet_ni_t *ni, lnet_msg_t *msg)
1363 {
1364 	lnet_hdr_t *hdr = &msg->msg_hdr;
1365 
1366 	if (msg->msg_wanted != 0)
1367 		lnet_setpayloadbuffer(msg);
1368 
1369 	lnet_build_msg_event(msg, LNET_EVENT_PUT);
1370 
1371 	/* Must I ACK?  If so I'll grab the ack_wmd out of the header and put
1372 	 * it back into the ACK during lnet_finalize() */
1373 	msg->msg_ack = (!lnet_is_wire_handle_none(&hdr->msg.put.ack_wmd) &&
1374 			(msg->msg_md->md_options & LNET_MD_ACK_DISABLE) == 0);
1375 
1376 	lnet_ni_recv(ni, msg->msg_private, msg, msg->msg_rx_delayed,
1377 		     msg->msg_offset, msg->msg_wanted, hdr->payload_length);
1378 }
1379 
1380 static int
lnet_parse_put(lnet_ni_t * ni,lnet_msg_t * msg)1381 lnet_parse_put(lnet_ni_t *ni, lnet_msg_t *msg)
1382 {
1383 	lnet_hdr_t *hdr = &msg->msg_hdr;
1384 	struct lnet_match_info info;
1385 	int rc;
1386 
1387 	/* Convert put fields to host byte order */
1388 	hdr->msg.put.match_bits	= le64_to_cpu(hdr->msg.put.match_bits);
1389 	hdr->msg.put.ptl_index	= le32_to_cpu(hdr->msg.put.ptl_index);
1390 	hdr->msg.put.offset	= le32_to_cpu(hdr->msg.put.offset);
1391 
1392 	info.mi_id.nid	= hdr->src_nid;
1393 	info.mi_id.pid	= hdr->src_pid;
1394 	info.mi_opc	= LNET_MD_OP_PUT;
1395 	info.mi_portal	= hdr->msg.put.ptl_index;
1396 	info.mi_rlength	= hdr->payload_length;
1397 	info.mi_roffset	= hdr->msg.put.offset;
1398 	info.mi_mbits	= hdr->msg.put.match_bits;
1399 
1400 	msg->msg_rx_ready_delay = ni->ni_lnd->lnd_eager_recv == NULL;
1401 
1402  again:
1403 	rc = lnet_ptl_match_md(&info, msg);
1404 	switch (rc) {
1405 	default:
1406 		LBUG();
1407 
1408 	case LNET_MATCHMD_OK:
1409 		lnet_recv_put(ni, msg);
1410 		return 0;
1411 
1412 	case LNET_MATCHMD_NONE:
1413 		if (msg->msg_rx_delayed) /* attached on delayed list */
1414 			return 0;
1415 
1416 		rc = lnet_ni_eager_recv(ni, msg);
1417 		if (rc == 0)
1418 			goto again;
1419 		/* fall through */
1420 
1421 	case LNET_MATCHMD_DROP:
1422 		CNETERR("Dropping PUT from %s portal %d match %llu offset %d length %d: %d\n",
1423 			libcfs_id2str(info.mi_id), info.mi_portal,
1424 			info.mi_mbits, info.mi_roffset, info.mi_rlength, rc);
1425 
1426 		return ENOENT;	/* +ve: OK but no match */
1427 	}
1428 }
1429 
1430 static int
lnet_parse_get(lnet_ni_t * ni,lnet_msg_t * msg,int rdma_get)1431 lnet_parse_get(lnet_ni_t *ni, lnet_msg_t *msg, int rdma_get)
1432 {
1433 	struct lnet_match_info info;
1434 	lnet_hdr_t *hdr = &msg->msg_hdr;
1435 	lnet_handle_wire_t reply_wmd;
1436 	int rc;
1437 
1438 	/* Convert get fields to host byte order */
1439 	hdr->msg.get.match_bits  = le64_to_cpu(hdr->msg.get.match_bits);
1440 	hdr->msg.get.ptl_index   = le32_to_cpu(hdr->msg.get.ptl_index);
1441 	hdr->msg.get.sink_length = le32_to_cpu(hdr->msg.get.sink_length);
1442 	hdr->msg.get.src_offset  = le32_to_cpu(hdr->msg.get.src_offset);
1443 
1444 	info.mi_id.nid  = hdr->src_nid;
1445 	info.mi_id.pid  = hdr->src_pid;
1446 	info.mi_opc     = LNET_MD_OP_GET;
1447 	info.mi_portal  = hdr->msg.get.ptl_index;
1448 	info.mi_rlength = hdr->msg.get.sink_length;
1449 	info.mi_roffset = hdr->msg.get.src_offset;
1450 	info.mi_mbits   = hdr->msg.get.match_bits;
1451 
1452 	rc = lnet_ptl_match_md(&info, msg);
1453 	if (rc == LNET_MATCHMD_DROP) {
1454 		CNETERR("Dropping GET from %s portal %d match %llu offset %d length %d\n",
1455 			libcfs_id2str(info.mi_id), info.mi_portal,
1456 			info.mi_mbits, info.mi_roffset, info.mi_rlength);
1457 		return ENOENT;	/* +ve: OK but no match */
1458 	}
1459 
1460 	LASSERT(rc == LNET_MATCHMD_OK);
1461 
1462 	lnet_build_msg_event(msg, LNET_EVENT_GET);
1463 
1464 	reply_wmd = hdr->msg.get.return_wmd;
1465 
1466 	lnet_prep_send(msg, LNET_MSG_REPLY, info.mi_id,
1467 		       msg->msg_offset, msg->msg_wanted);
1468 
1469 	msg->msg_hdr.msg.reply.dst_wmd = reply_wmd;
1470 
1471 	if (rdma_get) {
1472 		/* The LND completes the REPLY from her recv procedure */
1473 		lnet_ni_recv(ni, msg->msg_private, msg, 0,
1474 			     msg->msg_offset, msg->msg_len, msg->msg_len);
1475 		return 0;
1476 	}
1477 
1478 	lnet_ni_recv(ni, msg->msg_private, NULL, 0, 0, 0, 0);
1479 	msg->msg_receiving = 0;
1480 
1481 	rc = lnet_send(ni->ni_nid, msg, LNET_NID_ANY);
1482 	if (rc < 0) {
1483 		/* didn't get as far as lnet_ni_send() */
1484 		CERROR("%s: Unable to send REPLY for GET from %s: %d\n",
1485 		       libcfs_nid2str(ni->ni_nid),
1486 		       libcfs_id2str(info.mi_id), rc);
1487 
1488 		lnet_finalize(ni, msg, rc);
1489 	}
1490 
1491 	return 0;
1492 }
1493 
1494 static int
lnet_parse_reply(lnet_ni_t * ni,lnet_msg_t * msg)1495 lnet_parse_reply(lnet_ni_t *ni, lnet_msg_t *msg)
1496 {
1497 	void *private = msg->msg_private;
1498 	lnet_hdr_t *hdr = &msg->msg_hdr;
1499 	lnet_process_id_t src = {0};
1500 	lnet_libmd_t *md;
1501 	int rlength;
1502 	int mlength;
1503 	int cpt;
1504 
1505 	cpt = lnet_cpt_of_cookie(hdr->msg.reply.dst_wmd.wh_object_cookie);
1506 	lnet_res_lock(cpt);
1507 
1508 	src.nid = hdr->src_nid;
1509 	src.pid = hdr->src_pid;
1510 
1511 	/* NB handles only looked up by creator (no flips) */
1512 	md = lnet_wire_handle2md(&hdr->msg.reply.dst_wmd);
1513 	if (md == NULL || md->md_threshold == 0 || md->md_me != NULL) {
1514 		CNETERR("%s: Dropping REPLY from %s for %s MD %#llx.%#llx\n",
1515 			libcfs_nid2str(ni->ni_nid), libcfs_id2str(src),
1516 			(md == NULL) ? "invalid" : "inactive",
1517 			hdr->msg.reply.dst_wmd.wh_interface_cookie,
1518 			hdr->msg.reply.dst_wmd.wh_object_cookie);
1519 		if (md != NULL && md->md_me != NULL)
1520 			CERROR("REPLY MD also attached to portal %d\n",
1521 			       md->md_me->me_portal);
1522 
1523 		lnet_res_unlock(cpt);
1524 		return ENOENT;		  /* +ve: OK but no match */
1525 	}
1526 
1527 	LASSERT(md->md_offset == 0);
1528 
1529 	rlength = hdr->payload_length;
1530 	mlength = min_t(uint, rlength, md->md_length);
1531 
1532 	if (mlength < rlength &&
1533 	    (md->md_options & LNET_MD_TRUNCATE) == 0) {
1534 		CNETERR("%s: Dropping REPLY from %s length %d for MD %#llx would overflow (%d)\n",
1535 			libcfs_nid2str(ni->ni_nid), libcfs_id2str(src),
1536 			rlength, hdr->msg.reply.dst_wmd.wh_object_cookie,
1537 			mlength);
1538 		lnet_res_unlock(cpt);
1539 		return ENOENT;	  /* +ve: OK but no match */
1540 	}
1541 
1542 	CDEBUG(D_NET, "%s: Reply from %s of length %d/%d into md %#llx\n",
1543 	       libcfs_nid2str(ni->ni_nid), libcfs_id2str(src),
1544 	       mlength, rlength, hdr->msg.reply.dst_wmd.wh_object_cookie);
1545 
1546 	lnet_msg_attach_md(msg, md, 0, mlength);
1547 
1548 	if (mlength != 0)
1549 		lnet_setpayloadbuffer(msg);
1550 
1551 	lnet_res_unlock(cpt);
1552 
1553 	lnet_build_msg_event(msg, LNET_EVENT_REPLY);
1554 
1555 	lnet_ni_recv(ni, private, msg, 0, 0, mlength, rlength);
1556 	return 0;
1557 }
1558 
1559 static int
lnet_parse_ack(lnet_ni_t * ni,lnet_msg_t * msg)1560 lnet_parse_ack(lnet_ni_t *ni, lnet_msg_t *msg)
1561 {
1562 	lnet_hdr_t *hdr = &msg->msg_hdr;
1563 	lnet_process_id_t src = {0};
1564 	lnet_libmd_t *md;
1565 	int cpt;
1566 
1567 	src.nid = hdr->src_nid;
1568 	src.pid = hdr->src_pid;
1569 
1570 	/* Convert ack fields to host byte order */
1571 	hdr->msg.ack.match_bits = le64_to_cpu(hdr->msg.ack.match_bits);
1572 	hdr->msg.ack.mlength = le32_to_cpu(hdr->msg.ack.mlength);
1573 
1574 	cpt = lnet_cpt_of_cookie(hdr->msg.ack.dst_wmd.wh_object_cookie);
1575 	lnet_res_lock(cpt);
1576 
1577 	/* NB handles only looked up by creator (no flips) */
1578 	md = lnet_wire_handle2md(&hdr->msg.ack.dst_wmd);
1579 	if (md == NULL || md->md_threshold == 0 || md->md_me != NULL) {
1580 		/* Don't moan; this is expected */
1581 		CDEBUG(D_NET,
1582 		       "%s: Dropping ACK from %s to %s MD %#llx.%#llx\n",
1583 		       libcfs_nid2str(ni->ni_nid), libcfs_id2str(src),
1584 		       (md == NULL) ? "invalid" : "inactive",
1585 		       hdr->msg.ack.dst_wmd.wh_interface_cookie,
1586 		       hdr->msg.ack.dst_wmd.wh_object_cookie);
1587 		if (md != NULL && md->md_me != NULL)
1588 			CERROR("Source MD also attached to portal %d\n",
1589 			       md->md_me->me_portal);
1590 
1591 		lnet_res_unlock(cpt);
1592 		return ENOENT;		  /* +ve! */
1593 	}
1594 
1595 	CDEBUG(D_NET, "%s: ACK from %s into md %#llx\n",
1596 	       libcfs_nid2str(ni->ni_nid), libcfs_id2str(src),
1597 	       hdr->msg.ack.dst_wmd.wh_object_cookie);
1598 
1599 	lnet_msg_attach_md(msg, md, 0, 0);
1600 
1601 	lnet_res_unlock(cpt);
1602 
1603 	lnet_build_msg_event(msg, LNET_EVENT_ACK);
1604 
1605 	lnet_ni_recv(ni, msg->msg_private, msg, 0, 0, 0, msg->msg_len);
1606 	return 0;
1607 }
1608 
1609 static int
lnet_parse_forward_locked(lnet_ni_t * ni,lnet_msg_t * msg)1610 lnet_parse_forward_locked(lnet_ni_t *ni, lnet_msg_t *msg)
1611 {
1612 	int rc = 0;
1613 
1614 	if (msg->msg_rxpeer->lp_rtrcredits <= 0 ||
1615 	    lnet_msg2bufpool(msg)->rbp_credits <= 0) {
1616 		if (ni->ni_lnd->lnd_eager_recv == NULL) {
1617 			msg->msg_rx_ready_delay = 1;
1618 		} else {
1619 			lnet_net_unlock(msg->msg_rx_cpt);
1620 			rc = lnet_ni_eager_recv(ni, msg);
1621 			lnet_net_lock(msg->msg_rx_cpt);
1622 		}
1623 	}
1624 
1625 	if (rc == 0)
1626 		rc = lnet_post_routed_recv_locked(msg, 0);
1627 	return rc;
1628 }
1629 
1630 char *
lnet_msgtyp2str(int type)1631 lnet_msgtyp2str(int type)
1632 {
1633 	switch (type) {
1634 	case LNET_MSG_ACK:
1635 		return "ACK";
1636 	case LNET_MSG_PUT:
1637 		return "PUT";
1638 	case LNET_MSG_GET:
1639 		return "GET";
1640 	case LNET_MSG_REPLY:
1641 		return "REPLY";
1642 	case LNET_MSG_HELLO:
1643 		return "HELLO";
1644 	default:
1645 		return "<UNKNOWN>";
1646 	}
1647 }
1648 EXPORT_SYMBOL(lnet_msgtyp2str);
1649 
1650 void
lnet_print_hdr(lnet_hdr_t * hdr)1651 lnet_print_hdr(lnet_hdr_t *hdr)
1652 {
1653 	lnet_process_id_t src = {0};
1654 	lnet_process_id_t dst = {0};
1655 	char *type_str = lnet_msgtyp2str(hdr->type);
1656 
1657 	src.nid = hdr->src_nid;
1658 	src.pid = hdr->src_pid;
1659 
1660 	dst.nid = hdr->dest_nid;
1661 	dst.pid = hdr->dest_pid;
1662 
1663 	CWARN("P3 Header at %p of type %s\n", hdr, type_str);
1664 	CWARN("    From %s\n", libcfs_id2str(src));
1665 	CWARN("    To   %s\n", libcfs_id2str(dst));
1666 
1667 	switch (hdr->type) {
1668 	default:
1669 		break;
1670 
1671 	case LNET_MSG_PUT:
1672 		CWARN("    Ptl index %d, ack md %#llx.%#llx, match bits %llu\n",
1673 		      hdr->msg.put.ptl_index,
1674 		      hdr->msg.put.ack_wmd.wh_interface_cookie,
1675 		      hdr->msg.put.ack_wmd.wh_object_cookie,
1676 		      hdr->msg.put.match_bits);
1677 		CWARN("    Length %d, offset %d, hdr data %#llx\n",
1678 		      hdr->payload_length, hdr->msg.put.offset,
1679 		      hdr->msg.put.hdr_data);
1680 		break;
1681 
1682 	case LNET_MSG_GET:
1683 		CWARN("    Ptl index %d, return md %#llx.%#llx, match bits %llu\n",
1684 		      hdr->msg.get.ptl_index,
1685 		      hdr->msg.get.return_wmd.wh_interface_cookie,
1686 		      hdr->msg.get.return_wmd.wh_object_cookie,
1687 		      hdr->msg.get.match_bits);
1688 		CWARN("    Length %d, src offset %d\n",
1689 		      hdr->msg.get.sink_length,
1690 		      hdr->msg.get.src_offset);
1691 		break;
1692 
1693 	case LNET_MSG_ACK:
1694 		CWARN("    dst md %#llx.%#llx, manipulated length %d\n",
1695 		      hdr->msg.ack.dst_wmd.wh_interface_cookie,
1696 		      hdr->msg.ack.dst_wmd.wh_object_cookie,
1697 		      hdr->msg.ack.mlength);
1698 		break;
1699 
1700 	case LNET_MSG_REPLY:
1701 		CWARN("    dst md %#llx.%#llx, length %d\n",
1702 		      hdr->msg.reply.dst_wmd.wh_interface_cookie,
1703 		      hdr->msg.reply.dst_wmd.wh_object_cookie,
1704 		      hdr->payload_length);
1705 	}
1706 
1707 }
1708 
1709 int
lnet_parse(lnet_ni_t * ni,lnet_hdr_t * hdr,lnet_nid_t from_nid,void * private,int rdma_req)1710 lnet_parse(lnet_ni_t *ni, lnet_hdr_t *hdr, lnet_nid_t from_nid,
1711 	   void *private, int rdma_req)
1712 {
1713 	int rc = 0;
1714 	int cpt;
1715 	int for_me;
1716 	struct lnet_msg *msg;
1717 	lnet_pid_t dest_pid;
1718 	lnet_nid_t dest_nid;
1719 	lnet_nid_t src_nid;
1720 	__u32 payload_length;
1721 	__u32 type;
1722 
1723 	LASSERT(!in_interrupt());
1724 
1725 	type = le32_to_cpu(hdr->type);
1726 	src_nid = le64_to_cpu(hdr->src_nid);
1727 	dest_nid = le64_to_cpu(hdr->dest_nid);
1728 	dest_pid = le32_to_cpu(hdr->dest_pid);
1729 	payload_length = le32_to_cpu(hdr->payload_length);
1730 
1731 	for_me = (ni->ni_nid == dest_nid);
1732 	cpt = lnet_cpt_of_nid(from_nid);
1733 
1734 	switch (type) {
1735 	case LNET_MSG_ACK:
1736 	case LNET_MSG_GET:
1737 		if (payload_length > 0) {
1738 			CERROR("%s, src %s: bad %s payload %d (0 expected)\n",
1739 			       libcfs_nid2str(from_nid),
1740 			       libcfs_nid2str(src_nid),
1741 			       lnet_msgtyp2str(type), payload_length);
1742 			return -EPROTO;
1743 		}
1744 		break;
1745 
1746 	case LNET_MSG_PUT:
1747 	case LNET_MSG_REPLY:
1748 		if (payload_length >
1749 		   (__u32)(for_me ? LNET_MAX_PAYLOAD : LNET_MTU)) {
1750 			CERROR("%s, src %s: bad %s payload %d (%d max expected)\n",
1751 			       libcfs_nid2str(from_nid),
1752 			       libcfs_nid2str(src_nid),
1753 			       lnet_msgtyp2str(type),
1754 			       payload_length,
1755 			       for_me ? LNET_MAX_PAYLOAD : LNET_MTU);
1756 			return -EPROTO;
1757 		}
1758 		break;
1759 
1760 	default:
1761 		CERROR("%s, src %s: Bad message type 0x%x\n",
1762 		       libcfs_nid2str(from_nid),
1763 		       libcfs_nid2str(src_nid), type);
1764 		return -EPROTO;
1765 	}
1766 
1767 	if (the_lnet.ln_routing &&
1768 	    ni->ni_last_alive != ktime_get_real_seconds()) {
1769 		lnet_ni_lock(ni);
1770 
1771 		/* NB: so far here is the only place to set NI status to "up */
1772 		ni->ni_last_alive = ktime_get_real_seconds();
1773 		if (ni->ni_status != NULL &&
1774 		    ni->ni_status->ns_status == LNET_NI_STATUS_DOWN)
1775 			ni->ni_status->ns_status = LNET_NI_STATUS_UP;
1776 		lnet_ni_unlock(ni);
1777 	}
1778 
1779 	/* Regard a bad destination NID as a protocol error.  Senders should
1780 	 * know what they're doing; if they don't they're misconfigured, buggy
1781 	 * or malicious so we chop them off at the knees :) */
1782 
1783 	if (!for_me) {
1784 		if (LNET_NIDNET(dest_nid) == LNET_NIDNET(ni->ni_nid)) {
1785 			/* should have gone direct */
1786 			CERROR("%s, src %s: Bad dest nid %s (should have been sent direct)\n",
1787 			       libcfs_nid2str(from_nid),
1788 			       libcfs_nid2str(src_nid),
1789 			       libcfs_nid2str(dest_nid));
1790 			return -EPROTO;
1791 		}
1792 
1793 		if (lnet_islocalnid(dest_nid)) {
1794 			/* dest is another local NI; sender should have used
1795 			 * this node's NID on its own network */
1796 			CERROR("%s, src %s: Bad dest nid %s (it's my nid but on a different network)\n",
1797 			       libcfs_nid2str(from_nid),
1798 			       libcfs_nid2str(src_nid),
1799 			       libcfs_nid2str(dest_nid));
1800 			return -EPROTO;
1801 		}
1802 
1803 		if (rdma_req && type == LNET_MSG_GET) {
1804 			CERROR("%s, src %s: Bad optimized GET for %s (final destination must be me)\n",
1805 			       libcfs_nid2str(from_nid),
1806 			       libcfs_nid2str(src_nid),
1807 			       libcfs_nid2str(dest_nid));
1808 			return -EPROTO;
1809 		}
1810 
1811 		if (!the_lnet.ln_routing) {
1812 			CERROR("%s, src %s: Dropping message for %s (routing not enabled)\n",
1813 			       libcfs_nid2str(from_nid),
1814 			       libcfs_nid2str(src_nid),
1815 			       libcfs_nid2str(dest_nid));
1816 			goto drop;
1817 		}
1818 	}
1819 
1820 	/* Message looks OK; we're not going to return an error, so we MUST
1821 	 * call back lnd_recv() come what may... */
1822 
1823 	if (!list_empty(&the_lnet.ln_test_peers) && /* normally we don't */
1824 	    fail_peer(src_nid, 0)) {	     /* shall we now? */
1825 		CERROR("%s, src %s: Dropping %s to simulate failure\n",
1826 		       libcfs_nid2str(from_nid), libcfs_nid2str(src_nid),
1827 		       lnet_msgtyp2str(type));
1828 		goto drop;
1829 	}
1830 
1831 	msg = lnet_msg_alloc();
1832 	if (msg == NULL) {
1833 		CERROR("%s, src %s: Dropping %s (out of memory)\n",
1834 		       libcfs_nid2str(from_nid), libcfs_nid2str(src_nid),
1835 		       lnet_msgtyp2str(type));
1836 		goto drop;
1837 	}
1838 
1839 	/* msg zeroed in lnet_msg_alloc;
1840 	 * i.e. flags all clear, pointers NULL etc
1841 	 */
1842 
1843 	msg->msg_type = type;
1844 	msg->msg_private = private;
1845 	msg->msg_receiving = 1;
1846 	msg->msg_len = msg->msg_wanted = payload_length;
1847 	msg->msg_offset = 0;
1848 	msg->msg_hdr = *hdr;
1849 	/* for building message event */
1850 	msg->msg_from = from_nid;
1851 	if (!for_me) {
1852 		msg->msg_target.pid	= dest_pid;
1853 		msg->msg_target.nid	= dest_nid;
1854 		msg->msg_routing	= 1;
1855 
1856 	} else {
1857 		/* convert common msg->hdr fields to host byteorder */
1858 		msg->msg_hdr.type	= type;
1859 		msg->msg_hdr.src_nid	= src_nid;
1860 		msg->msg_hdr.src_pid	= le32_to_cpu(msg->msg_hdr.src_pid);
1861 		msg->msg_hdr.dest_nid	= dest_nid;
1862 		msg->msg_hdr.dest_pid	= dest_pid;
1863 		msg->msg_hdr.payload_length = payload_length;
1864 	}
1865 
1866 	lnet_net_lock(cpt);
1867 	rc = lnet_nid2peer_locked(&msg->msg_rxpeer, from_nid, cpt);
1868 	if (rc != 0) {
1869 		lnet_net_unlock(cpt);
1870 		CERROR("%s, src %s: Dropping %s (error %d looking up sender)\n",
1871 		       libcfs_nid2str(from_nid), libcfs_nid2str(src_nid),
1872 		       lnet_msgtyp2str(type), rc);
1873 		lnet_msg_free(msg);
1874 		goto drop;
1875 	}
1876 
1877 	if (lnet_isrouter(msg->msg_rxpeer)) {
1878 		lnet_peer_set_alive(msg->msg_rxpeer);
1879 		if (avoid_asym_router_failure &&
1880 		    LNET_NIDNET(src_nid) != LNET_NIDNET(from_nid)) {
1881 			/* received a remote message from router, update
1882 			 * remote NI status on this router.
1883 			 * NB: multi-hop routed message will be ignored.
1884 			 */
1885 			lnet_router_ni_update_locked(msg->msg_rxpeer,
1886 						     LNET_NIDNET(src_nid));
1887 		}
1888 	}
1889 
1890 	lnet_msg_commit(msg, cpt);
1891 
1892 	if (!for_me) {
1893 		rc = lnet_parse_forward_locked(ni, msg);
1894 		lnet_net_unlock(cpt);
1895 
1896 		if (rc < 0)
1897 			goto free_drop;
1898 		if (rc == 0) {
1899 			lnet_ni_recv(ni, msg->msg_private, msg, 0,
1900 				     0, payload_length, payload_length);
1901 		}
1902 		return 0;
1903 	}
1904 
1905 	lnet_net_unlock(cpt);
1906 
1907 	switch (type) {
1908 	case LNET_MSG_ACK:
1909 		rc = lnet_parse_ack(ni, msg);
1910 		break;
1911 	case LNET_MSG_PUT:
1912 		rc = lnet_parse_put(ni, msg);
1913 		break;
1914 	case LNET_MSG_GET:
1915 		rc = lnet_parse_get(ni, msg, rdma_req);
1916 		break;
1917 	case LNET_MSG_REPLY:
1918 		rc = lnet_parse_reply(ni, msg);
1919 		break;
1920 	default:
1921 		LASSERT(0);
1922 		rc = -EPROTO;
1923 		goto free_drop;  /* prevent an unused label if !kernel */
1924 	}
1925 
1926 	if (rc == 0)
1927 		return 0;
1928 
1929 	LASSERT(rc == ENOENT);
1930 
1931  free_drop:
1932 	LASSERT(msg->msg_md == NULL);
1933 	lnet_finalize(ni, msg, rc);
1934 
1935  drop:
1936 	lnet_drop_message(ni, cpt, private, payload_length);
1937 	return 0;
1938 }
1939 EXPORT_SYMBOL(lnet_parse);
1940 
1941 void
lnet_drop_delayed_msg_list(struct list_head * head,char * reason)1942 lnet_drop_delayed_msg_list(struct list_head *head, char *reason)
1943 {
1944 	while (!list_empty(head)) {
1945 		lnet_process_id_t id = {0};
1946 		lnet_msg_t *msg;
1947 
1948 		msg = list_entry(head->next, lnet_msg_t, msg_list);
1949 		list_del(&msg->msg_list);
1950 
1951 		id.nid = msg->msg_hdr.src_nid;
1952 		id.pid = msg->msg_hdr.src_pid;
1953 
1954 		LASSERT(msg->msg_md == NULL);
1955 		LASSERT(msg->msg_rx_delayed);
1956 		LASSERT(msg->msg_rxpeer != NULL);
1957 		LASSERT(msg->msg_hdr.type == LNET_MSG_PUT);
1958 
1959 		CWARN("Dropping delayed PUT from %s portal %d match %llu offset %d length %d: %s\n",
1960 		      libcfs_id2str(id),
1961 		      msg->msg_hdr.msg.put.ptl_index,
1962 		      msg->msg_hdr.msg.put.match_bits,
1963 		      msg->msg_hdr.msg.put.offset,
1964 		      msg->msg_hdr.payload_length, reason);
1965 
1966 		/* NB I can't drop msg's ref on msg_rxpeer until after I've
1967 		 * called lnet_drop_message(), so I just hang onto msg as well
1968 		 * until that's done */
1969 
1970 		lnet_drop_message(msg->msg_rxpeer->lp_ni,
1971 				  msg->msg_rxpeer->lp_cpt,
1972 				  msg->msg_private, msg->msg_len);
1973 		/*
1974 		 * NB: message will not generate event because w/o attached MD,
1975 		 * but we still should give error code so lnet_msg_decommit()
1976 		 * can skip counters operations and other checks.
1977 		 */
1978 		lnet_finalize(msg->msg_rxpeer->lp_ni, msg, -ENOENT);
1979 	}
1980 }
1981 
1982 void
lnet_recv_delayed_msg_list(struct list_head * head)1983 lnet_recv_delayed_msg_list(struct list_head *head)
1984 {
1985 	while (!list_empty(head)) {
1986 		lnet_msg_t *msg;
1987 		lnet_process_id_t id;
1988 
1989 		msg = list_entry(head->next, lnet_msg_t, msg_list);
1990 		list_del(&msg->msg_list);
1991 
1992 		/* md won't disappear under me, since each msg
1993 		 * holds a ref on it */
1994 
1995 		id.nid = msg->msg_hdr.src_nid;
1996 		id.pid = msg->msg_hdr.src_pid;
1997 
1998 		LASSERT(msg->msg_rx_delayed);
1999 		LASSERT(msg->msg_md != NULL);
2000 		LASSERT(msg->msg_rxpeer != NULL);
2001 		LASSERT(msg->msg_hdr.type == LNET_MSG_PUT);
2002 
2003 		CDEBUG(D_NET, "Resuming delayed PUT from %s portal %d match %llu offset %d length %d.\n",
2004 		       libcfs_id2str(id), msg->msg_hdr.msg.put.ptl_index,
2005 		       msg->msg_hdr.msg.put.match_bits,
2006 		       msg->msg_hdr.msg.put.offset,
2007 		       msg->msg_hdr.payload_length);
2008 
2009 		lnet_recv_put(msg->msg_rxpeer->lp_ni, msg);
2010 	}
2011 }
2012 
2013 /**
2014  * Initiate an asynchronous PUT operation.
2015  *
2016  * There are several events associated with a PUT: completion of the send on
2017  * the initiator node (LNET_EVENT_SEND), and when the send completes
2018  * successfully, the receipt of an acknowledgment (LNET_EVENT_ACK) indicating
2019  * that the operation was accepted by the target. The event LNET_EVENT_PUT is
2020  * used at the target node to indicate the completion of incoming data
2021  * delivery.
2022  *
2023  * The local events will be logged in the EQ associated with the MD pointed to
2024  * by \a mdh handle. Using a MD without an associated EQ results in these
2025  * events being discarded. In this case, the caller must have another
2026  * mechanism (e.g., a higher level protocol) for determining when it is safe
2027  * to modify the memory region associated with the MD.
2028  *
2029  * Note that LNet does not guarantee the order of LNET_EVENT_SEND and
2030  * LNET_EVENT_ACK, though intuitively ACK should happen after SEND.
2031  *
2032  * \param self Indicates the NID of a local interface through which to send
2033  * the PUT request. Use LNET_NID_ANY to let LNet choose one by itself.
2034  * \param mdh A handle for the MD that describes the memory to be sent. The MD
2035  * must be "free floating" (See LNetMDBind()).
2036  * \param ack Controls whether an acknowledgment is requested.
2037  * Acknowledgments are only sent when they are requested by the initiating
2038  * process and the target MD enables them.
2039  * \param target A process identifier for the target process.
2040  * \param portal The index in the \a target's portal table.
2041  * \param match_bits The match bits to use for MD selection at the target
2042  * process.
2043  * \param offset The offset into the target MD (only used when the target
2044  * MD has the LNET_MD_MANAGE_REMOTE option set).
2045  * \param hdr_data 64 bits of user data that can be included in the message
2046  * header. This data is written to an event queue entry at the target if an
2047  * EQ is present on the matching MD.
2048  *
2049  * \retval  0      Success, and only in this case events will be generated
2050  * and logged to EQ (if it exists).
2051  * \retval -EIO    Simulated failure.
2052  * \retval -ENOMEM Memory allocation failure.
2053  * \retval -ENOENT Invalid MD object.
2054  *
2055  * \see lnet_event_t::hdr_data and lnet_event_kind_t.
2056  */
2057 int
LNetPut(lnet_nid_t self,lnet_handle_md_t mdh,lnet_ack_req_t ack,lnet_process_id_t target,unsigned int portal,__u64 match_bits,unsigned int offset,__u64 hdr_data)2058 LNetPut(lnet_nid_t self, lnet_handle_md_t mdh, lnet_ack_req_t ack,
2059 	lnet_process_id_t target, unsigned int portal,
2060 	__u64 match_bits, unsigned int offset,
2061 	__u64 hdr_data)
2062 {
2063 	struct lnet_msg *msg;
2064 	struct lnet_libmd *md;
2065 	int cpt;
2066 	int rc;
2067 
2068 	LASSERT(the_lnet.ln_init);
2069 	LASSERT(the_lnet.ln_refcount > 0);
2070 
2071 	if (!list_empty(&the_lnet.ln_test_peers) && /* normally we don't */
2072 	    fail_peer(target.nid, 1)) { /* shall we now? */
2073 		CERROR("Dropping PUT to %s: simulated failure\n",
2074 		       libcfs_id2str(target));
2075 		return -EIO;
2076 	}
2077 
2078 	msg = lnet_msg_alloc();
2079 	if (msg == NULL) {
2080 		CERROR("Dropping PUT to %s: ENOMEM on lnet_msg_t\n",
2081 		       libcfs_id2str(target));
2082 		return -ENOMEM;
2083 	}
2084 	msg->msg_vmflush = !!memory_pressure_get();
2085 
2086 	cpt = lnet_cpt_of_cookie(mdh.cookie);
2087 	lnet_res_lock(cpt);
2088 
2089 	md = lnet_handle2md(&mdh);
2090 	if (md == NULL || md->md_threshold == 0 || md->md_me != NULL) {
2091 		CERROR("Dropping PUT (%llu:%d:%s): MD (%d) invalid\n",
2092 		       match_bits, portal, libcfs_id2str(target),
2093 		       md == NULL ? -1 : md->md_threshold);
2094 		if (md != NULL && md->md_me != NULL)
2095 			CERROR("Source MD also attached to portal %d\n",
2096 			       md->md_me->me_portal);
2097 		lnet_res_unlock(cpt);
2098 
2099 		lnet_msg_free(msg);
2100 		return -ENOENT;
2101 	}
2102 
2103 	CDEBUG(D_NET, "LNetPut -> %s\n", libcfs_id2str(target));
2104 
2105 	lnet_msg_attach_md(msg, md, 0, 0);
2106 
2107 	lnet_prep_send(msg, LNET_MSG_PUT, target, 0, md->md_length);
2108 
2109 	msg->msg_hdr.msg.put.match_bits = cpu_to_le64(match_bits);
2110 	msg->msg_hdr.msg.put.ptl_index = cpu_to_le32(portal);
2111 	msg->msg_hdr.msg.put.offset = cpu_to_le32(offset);
2112 	msg->msg_hdr.msg.put.hdr_data = hdr_data;
2113 
2114 	/* NB handles only looked up by creator (no flips) */
2115 	if (ack == LNET_ACK_REQ) {
2116 		msg->msg_hdr.msg.put.ack_wmd.wh_interface_cookie =
2117 			the_lnet.ln_interface_cookie;
2118 		msg->msg_hdr.msg.put.ack_wmd.wh_object_cookie =
2119 			md->md_lh.lh_cookie;
2120 	} else {
2121 		msg->msg_hdr.msg.put.ack_wmd.wh_interface_cookie =
2122 			LNET_WIRE_HANDLE_COOKIE_NONE;
2123 		msg->msg_hdr.msg.put.ack_wmd.wh_object_cookie =
2124 			LNET_WIRE_HANDLE_COOKIE_NONE;
2125 	}
2126 
2127 	lnet_res_unlock(cpt);
2128 
2129 	lnet_build_msg_event(msg, LNET_EVENT_SEND);
2130 
2131 	rc = lnet_send(self, msg, LNET_NID_ANY);
2132 	if (rc != 0) {
2133 		CNETERR("Error sending PUT to %s: %d\n",
2134 		       libcfs_id2str(target), rc);
2135 		lnet_finalize(NULL, msg, rc);
2136 	}
2137 
2138 	/* completion will be signalled by an event */
2139 	return 0;
2140 }
2141 EXPORT_SYMBOL(LNetPut);
2142 
2143 lnet_msg_t *
lnet_create_reply_msg(lnet_ni_t * ni,lnet_msg_t * getmsg)2144 lnet_create_reply_msg(lnet_ni_t *ni, lnet_msg_t *getmsg)
2145 {
2146 	/* The LND can DMA direct to the GET md (i.e. no REPLY msg).  This
2147 	 * returns a msg for the LND to pass to lnet_finalize() when the sink
2148 	 * data has been received.
2149 	 *
2150 	 * CAVEAT EMPTOR: 'getmsg' is the original GET, which is freed when
2151 	 * lnet_finalize() is called on it, so the LND must call this first */
2152 
2153 	struct lnet_msg *msg = lnet_msg_alloc();
2154 	struct lnet_libmd *getmd = getmsg->msg_md;
2155 	lnet_process_id_t peer_id = getmsg->msg_target;
2156 	int cpt;
2157 
2158 	LASSERT(!getmsg->msg_target_is_router);
2159 	LASSERT(!getmsg->msg_routing);
2160 
2161 	cpt = lnet_cpt_of_cookie(getmd->md_lh.lh_cookie);
2162 	lnet_res_lock(cpt);
2163 
2164 	LASSERT(getmd->md_refcount > 0);
2165 
2166 	if (msg == NULL) {
2167 		CERROR("%s: Dropping REPLY from %s: can't allocate msg\n",
2168 			libcfs_nid2str(ni->ni_nid), libcfs_id2str(peer_id));
2169 		goto drop;
2170 	}
2171 
2172 	if (getmd->md_threshold == 0) {
2173 		CERROR("%s: Dropping REPLY from %s for inactive MD %p\n",
2174 			libcfs_nid2str(ni->ni_nid), libcfs_id2str(peer_id),
2175 			getmd);
2176 		lnet_res_unlock(cpt);
2177 		goto drop;
2178 	}
2179 
2180 	LASSERT(getmd->md_offset == 0);
2181 
2182 	CDEBUG(D_NET, "%s: Reply from %s md %p\n",
2183 	       libcfs_nid2str(ni->ni_nid), libcfs_id2str(peer_id), getmd);
2184 
2185 	/* setup information for lnet_build_msg_event */
2186 	msg->msg_from = peer_id.nid;
2187 	msg->msg_type = LNET_MSG_GET; /* flag this msg as an "optimized" GET */
2188 	msg->msg_hdr.src_nid = peer_id.nid;
2189 	msg->msg_hdr.payload_length = getmd->md_length;
2190 	msg->msg_receiving = 1; /* required by lnet_msg_attach_md */
2191 
2192 	lnet_msg_attach_md(msg, getmd, getmd->md_offset, getmd->md_length);
2193 	lnet_res_unlock(cpt);
2194 
2195 	cpt = lnet_cpt_of_nid(peer_id.nid);
2196 
2197 	lnet_net_lock(cpt);
2198 	lnet_msg_commit(msg, cpt);
2199 	lnet_net_unlock(cpt);
2200 
2201 	lnet_build_msg_event(msg, LNET_EVENT_REPLY);
2202 
2203 	return msg;
2204 
2205  drop:
2206 	cpt = lnet_cpt_of_nid(peer_id.nid);
2207 
2208 	lnet_net_lock(cpt);
2209 	the_lnet.ln_counters[cpt]->drop_count++;
2210 	the_lnet.ln_counters[cpt]->drop_length += getmd->md_length;
2211 	lnet_net_unlock(cpt);
2212 
2213 	if (msg != NULL)
2214 		lnet_msg_free(msg);
2215 
2216 	return NULL;
2217 }
2218 EXPORT_SYMBOL(lnet_create_reply_msg);
2219 
2220 void
lnet_set_reply_msg_len(lnet_ni_t * ni,lnet_msg_t * reply,unsigned int len)2221 lnet_set_reply_msg_len(lnet_ni_t *ni, lnet_msg_t *reply, unsigned int len)
2222 {
2223 	/* Set the REPLY length, now the RDMA that elides the REPLY message has
2224 	 * completed and I know it. */
2225 	LASSERT(reply != NULL);
2226 	LASSERT(reply->msg_type == LNET_MSG_GET);
2227 	LASSERT(reply->msg_ev.type == LNET_EVENT_REPLY);
2228 
2229 	/* NB I trusted my peer to RDMA.  If she tells me she's written beyond
2230 	 * the end of my buffer, I might as well be dead. */
2231 	LASSERT(len <= reply->msg_ev.mlength);
2232 
2233 	reply->msg_ev.mlength = len;
2234 }
2235 EXPORT_SYMBOL(lnet_set_reply_msg_len);
2236 
2237 /**
2238  * Initiate an asynchronous GET operation.
2239  *
2240  * On the initiator node, an LNET_EVENT_SEND is logged when the GET request
2241  * is sent, and an LNET_EVENT_REPLY is logged when the data returned from
2242  * the target node in the REPLY has been written to local MD.
2243  *
2244  * On the target node, an LNET_EVENT_GET is logged when the GET request
2245  * arrives and is accepted into a MD.
2246  *
2247  * \param self,target,portal,match_bits,offset See the discussion in LNetPut().
2248  * \param mdh A handle for the MD that describes the memory into which the
2249  * requested data will be received. The MD must be "free floating"
2250  * (See LNetMDBind()).
2251  *
2252  * \retval  0      Success, and only in this case events will be generated
2253  * and logged to EQ (if it exists) of the MD.
2254  * \retval -EIO    Simulated failure.
2255  * \retval -ENOMEM Memory allocation failure.
2256  * \retval -ENOENT Invalid MD object.
2257  */
2258 int
LNetGet(lnet_nid_t self,lnet_handle_md_t mdh,lnet_process_id_t target,unsigned int portal,__u64 match_bits,unsigned int offset)2259 LNetGet(lnet_nid_t self, lnet_handle_md_t mdh,
2260 	lnet_process_id_t target, unsigned int portal,
2261 	__u64 match_bits, unsigned int offset)
2262 {
2263 	struct lnet_msg *msg;
2264 	struct lnet_libmd *md;
2265 	int cpt;
2266 	int rc;
2267 
2268 	LASSERT(the_lnet.ln_init);
2269 	LASSERT(the_lnet.ln_refcount > 0);
2270 
2271 	if (!list_empty(&the_lnet.ln_test_peers) && /* normally we don't */
2272 	    fail_peer(target.nid, 1)) {	  /* shall we now? */
2273 		CERROR("Dropping GET to %s: simulated failure\n",
2274 		       libcfs_id2str(target));
2275 		return -EIO;
2276 	}
2277 
2278 	msg = lnet_msg_alloc();
2279 	if (msg == NULL) {
2280 		CERROR("Dropping GET to %s: ENOMEM on lnet_msg_t\n",
2281 		       libcfs_id2str(target));
2282 		return -ENOMEM;
2283 	}
2284 
2285 	cpt = lnet_cpt_of_cookie(mdh.cookie);
2286 	lnet_res_lock(cpt);
2287 
2288 	md = lnet_handle2md(&mdh);
2289 	if (md == NULL || md->md_threshold == 0 || md->md_me != NULL) {
2290 		CERROR("Dropping GET (%llu:%d:%s): MD (%d) invalid\n",
2291 		       match_bits, portal, libcfs_id2str(target),
2292 		       md == NULL ? -1 : md->md_threshold);
2293 		if (md != NULL && md->md_me != NULL)
2294 			CERROR("REPLY MD also attached to portal %d\n",
2295 			       md->md_me->me_portal);
2296 
2297 		lnet_res_unlock(cpt);
2298 
2299 		lnet_msg_free(msg);
2300 		return -ENOENT;
2301 	}
2302 
2303 	CDEBUG(D_NET, "LNetGet -> %s\n", libcfs_id2str(target));
2304 
2305 	lnet_msg_attach_md(msg, md, 0, 0);
2306 
2307 	lnet_prep_send(msg, LNET_MSG_GET, target, 0, 0);
2308 
2309 	msg->msg_hdr.msg.get.match_bits = cpu_to_le64(match_bits);
2310 	msg->msg_hdr.msg.get.ptl_index = cpu_to_le32(portal);
2311 	msg->msg_hdr.msg.get.src_offset = cpu_to_le32(offset);
2312 	msg->msg_hdr.msg.get.sink_length = cpu_to_le32(md->md_length);
2313 
2314 	/* NB handles only looked up by creator (no flips) */
2315 	msg->msg_hdr.msg.get.return_wmd.wh_interface_cookie =
2316 		the_lnet.ln_interface_cookie;
2317 	msg->msg_hdr.msg.get.return_wmd.wh_object_cookie =
2318 		md->md_lh.lh_cookie;
2319 
2320 	lnet_res_unlock(cpt);
2321 
2322 	lnet_build_msg_event(msg, LNET_EVENT_SEND);
2323 
2324 	rc = lnet_send(self, msg, LNET_NID_ANY);
2325 	if (rc < 0) {
2326 		CNETERR("Error sending GET to %s: %d\n",
2327 		       libcfs_id2str(target), rc);
2328 		lnet_finalize(NULL, msg, rc);
2329 	}
2330 
2331 	/* completion will be signalled by an event */
2332 	return 0;
2333 }
2334 EXPORT_SYMBOL(LNetGet);
2335 
2336 /**
2337  * Calculate distance to node at \a dstnid.
2338  *
2339  * \param dstnid Target NID.
2340  * \param srcnidp If not NULL, NID of the local interface to reach \a dstnid
2341  * is saved here.
2342  * \param orderp If not NULL, order of the route to reach \a dstnid is saved
2343  * here.
2344  *
2345  * \retval 0 If \a dstnid belongs to a local interface, and reserved option
2346  * local_nid_dist_zero is set, which is the default.
2347  * \retval positives Distance to target NID, i.e. number of hops plus one.
2348  * \retval -EHOSTUNREACH If \a dstnid is not reachable.
2349  */
2350 int
LNetDist(lnet_nid_t dstnid,lnet_nid_t * srcnidp,__u32 * orderp)2351 LNetDist(lnet_nid_t dstnid, lnet_nid_t *srcnidp, __u32 *orderp)
2352 {
2353 	struct list_head *e;
2354 	struct lnet_ni *ni;
2355 	lnet_remotenet_t *rnet;
2356 	__u32 dstnet = LNET_NIDNET(dstnid);
2357 	int hops;
2358 	int cpt;
2359 	__u32 order = 2;
2360 	struct list_head *rn_list;
2361 
2362 	/* if !local_nid_dist_zero, I don't return a distance of 0 ever
2363 	 * (when lustre sees a distance of 0, it substitutes 0@lo), so I
2364 	 * keep order 0 free for 0@lo and order 1 free for a local NID
2365 	 * match */
2366 
2367 	LASSERT(the_lnet.ln_init);
2368 	LASSERT(the_lnet.ln_refcount > 0);
2369 
2370 	cpt = lnet_net_lock_current();
2371 
2372 	list_for_each(e, &the_lnet.ln_nis) {
2373 		ni = list_entry(e, lnet_ni_t, ni_list);
2374 
2375 		if (ni->ni_nid == dstnid) {
2376 			if (srcnidp != NULL)
2377 				*srcnidp = dstnid;
2378 			if (orderp != NULL) {
2379 				if (LNET_NETTYP(LNET_NIDNET(dstnid)) == LOLND)
2380 					*orderp = 0;
2381 				else
2382 					*orderp = 1;
2383 			}
2384 			lnet_net_unlock(cpt);
2385 
2386 			return local_nid_dist_zero ? 0 : 1;
2387 		}
2388 
2389 		if (LNET_NIDNET(ni->ni_nid) == dstnet) {
2390 			if (srcnidp != NULL)
2391 				*srcnidp = ni->ni_nid;
2392 			if (orderp != NULL)
2393 				*orderp = order;
2394 			lnet_net_unlock(cpt);
2395 			return 1;
2396 		}
2397 
2398 		order++;
2399 	}
2400 
2401 	rn_list = lnet_net2rnethash(dstnet);
2402 	list_for_each(e, rn_list) {
2403 		rnet = list_entry(e, lnet_remotenet_t, lrn_list);
2404 
2405 		if (rnet->lrn_net == dstnet) {
2406 			lnet_route_t *route;
2407 			lnet_route_t *shortest = NULL;
2408 
2409 			LASSERT(!list_empty(&rnet->lrn_routes));
2410 
2411 			list_for_each_entry(route, &rnet->lrn_routes,
2412 						lr_list) {
2413 				if (shortest == NULL ||
2414 				    route->lr_hops < shortest->lr_hops)
2415 					shortest = route;
2416 			}
2417 
2418 			LASSERT(shortest != NULL);
2419 			hops = shortest->lr_hops;
2420 			if (srcnidp != NULL)
2421 				*srcnidp = shortest->lr_gateway->lp_ni->ni_nid;
2422 			if (orderp != NULL)
2423 				*orderp = order;
2424 			lnet_net_unlock(cpt);
2425 			return hops + 1;
2426 		}
2427 		order++;
2428 	}
2429 
2430 	lnet_net_unlock(cpt);
2431 	return -EHOSTUNREACH;
2432 }
2433 EXPORT_SYMBOL(LNetDist);
2434