FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_mbuf.c
1 /*-
2 * Copyright (c) 2004, 2005,
3 * Bosko Milekic <bmilekic@FreeBSD.org>. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 #include "opt_mac.h"
32 #include "opt_param.h"
33
34 #include <sys/param.h>
35 #include <sys/malloc.h>
36 #include <sys/systm.h>
37 #include <sys/mbuf.h>
38 #include <sys/domain.h>
39 #include <sys/eventhandler.h>
40 #include <sys/kernel.h>
41 #include <sys/protosw.h>
42 #include <sys/smp.h>
43 #include <sys/sysctl.h>
44
45 #include <security/mac/mac_framework.h>
46
47 #include <vm/vm.h>
48 #include <vm/vm_page.h>
49 #include <vm/uma.h>
50 #include <vm/uma_int.h>
51 #include <vm/uma_dbg.h>
52
53 /*
54 * In FreeBSD, Mbufs and Mbuf Clusters are allocated from UMA
55 * Zones.
56 *
57 * Mbuf Clusters (2K, contiguous) are allocated from the Cluster
58 * Zone. The Zone can be capped at kern.ipc.nmbclusters, if the
59 * administrator so desires.
60 *
61 * Mbufs are allocated from a UMA Master Zone called the Mbuf
62 * Zone.
63 *
64 * Additionally, FreeBSD provides a Packet Zone, which it
65 * configures as a Secondary Zone to the Mbuf Master Zone,
66 * thus sharing backend Slab kegs with the Mbuf Master Zone.
67 *
68 * Thus common-case allocations and locking are simplified:
69 *
70 * m_clget() m_getcl()
71 * | |
72 * | .------------>[(Packet Cache)] m_get(), m_gethdr()
73 * | | [ Packet ] |
74 * [(Cluster Cache)] [ Secondary ] [ (Mbuf Cache) ]
75 * [ Cluster Zone ] [ Zone ] [ Mbuf Master Zone ]
76 * | \________ |
77 * [ Cluster Keg ] \ /
78 * | [ Mbuf Keg ]
79 * [ Cluster Slabs ] |
80 * | [ Mbuf Slabs ]
81 * \____________(VM)_________________/
82 *
83 *
84 * Whenever an object is allocated with uma_zalloc() out of
85 * one of the Zones its _ctor_ function is executed. The same
86 * for any deallocation through uma_zfree() the _dtor_ function
87 * is executed.
88 *
89 * Caches are per-CPU and are filled from the Master Zone.
90 *
91 * Whenever an object is allocated from the underlying global
92 * memory pool it gets pre-initialized with the _zinit_ functions.
93 * When the Keg's are overfull objects get decomissioned with
94 * _zfini_ functions and free'd back to the global memory pool.
95 *
96 */
97
98 int nmbclusters; /* limits number of mbuf clusters */
99 int nmbjumbop; /* limits number of page size jumbo clusters */
100 int nmbjumbo9; /* limits number of 9k jumbo clusters */
101 int nmbjumbo16; /* limits number of 16k jumbo clusters */
102 struct mbstat mbstat;
103
104 /*
105 * tunable_mbinit() has to be run before init_maxsockets() thus
106 * the SYSINIT order below is SI_ORDER_MIDDLE while init_maxsockets()
107 * runs at SI_ORDER_ANY.
108 */
109 static void
110 tunable_mbinit(void *dummy)
111 {
112
113 /* This has to be done before VM init. */
114 nmbclusters = 1024 + maxusers * 64;
115 nmbjumbop = nmbclusters / 2;
116 nmbjumbo9 = nmbjumbop / 2;
117 nmbjumbo16 = nmbjumbo9 / 2;
118 TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters);
119 }
120 SYSINIT(tunable_mbinit, SI_SUB_TUNABLES, SI_ORDER_MIDDLE, tunable_mbinit, NULL);
121
122 /* XXX: These should be tuneables. Can't change UMA limits on the fly. */
123 static int
124 sysctl_nmbclusters(SYSCTL_HANDLER_ARGS)
125 {
126 int error, newnmbclusters;
127
128 newnmbclusters = nmbclusters;
129 error = sysctl_handle_int(oidp, &newnmbclusters, 0, req);
130 if (error == 0 && req->newptr) {
131 if (newnmbclusters > nmbclusters) {
132 nmbclusters = newnmbclusters;
133 uma_zone_set_max(zone_clust, nmbclusters);
134 EVENTHANDLER_INVOKE(nmbclusters_change);
135 } else
136 error = EINVAL;
137 }
138 return (error);
139 }
140 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbclusters, CTLTYPE_INT|CTLFLAG_RW,
141 &nmbclusters, 0, sysctl_nmbclusters, "IU",
142 "Maximum number of mbuf clusters allowed");
143
144 static int
145 sysctl_nmbjumbop(SYSCTL_HANDLER_ARGS)
146 {
147 int error, newnmbjumbop;
148
149 newnmbjumbop = nmbjumbop;
150 error = sysctl_handle_int(oidp, &newnmbjumbop, 0, req);
151 if (error == 0 && req->newptr) {
152 if (newnmbjumbop> nmbjumbop) {
153 nmbjumbop = newnmbjumbop;
154 uma_zone_set_max(zone_jumbop, nmbjumbop);
155 } else
156 error = EINVAL;
157 }
158 return (error);
159 }
160 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbop, CTLTYPE_INT|CTLFLAG_RW,
161 &nmbjumbop, 0, sysctl_nmbjumbop, "IU",
162 "Maximum number of mbuf page size jumbo clusters allowed");
163
164
165 static int
166 sysctl_nmbjumbo9(SYSCTL_HANDLER_ARGS)
167 {
168 int error, newnmbjumbo9;
169
170 newnmbjumbo9 = nmbjumbo9;
171 error = sysctl_handle_int(oidp, &newnmbjumbo9, 0, req);
172 if (error == 0 && req->newptr) {
173 if (newnmbjumbo9> nmbjumbo9) {
174 nmbjumbo9 = newnmbjumbo9;
175 uma_zone_set_max(zone_jumbo9, nmbjumbo9);
176 } else
177 error = EINVAL;
178 }
179 return (error);
180 }
181 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo9, CTLTYPE_INT|CTLFLAG_RW,
182 &nmbjumbo9, 0, sysctl_nmbjumbo9, "IU",
183 "Maximum number of mbuf 9k jumbo clusters allowed");
184
185 static int
186 sysctl_nmbjumbo16(SYSCTL_HANDLER_ARGS)
187 {
188 int error, newnmbjumbo16;
189
190 newnmbjumbo16 = nmbjumbo16;
191 error = sysctl_handle_int(oidp, &newnmbjumbo16, 0, req);
192 if (error == 0 && req->newptr) {
193 if (newnmbjumbo16> nmbjumbo16) {
194 nmbjumbo16 = newnmbjumbo16;
195 uma_zone_set_max(zone_jumbo16, nmbjumbo16);
196 } else
197 error = EINVAL;
198 }
199 return (error);
200 }
201 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo16, CTLTYPE_INT|CTLFLAG_RW,
202 &nmbjumbo16, 0, sysctl_nmbjumbo16, "IU",
203 "Maximum number of mbuf 16k jumbo clusters allowed");
204
205
206
207 SYSCTL_STRUCT(_kern_ipc, OID_AUTO, mbstat, CTLFLAG_RD, &mbstat, mbstat,
208 "Mbuf general information and statistics");
209
210 /*
211 * Zones from which we allocate.
212 */
213 uma_zone_t zone_mbuf;
214 uma_zone_t zone_clust;
215 uma_zone_t zone_pack;
216 uma_zone_t zone_jumbop;
217 uma_zone_t zone_jumbo9;
218 uma_zone_t zone_jumbo16;
219 uma_zone_t zone_ext_refcnt;
220
221 /*
222 * Local prototypes.
223 */
224 static int mb_ctor_mbuf(void *, int, void *, int);
225 static int mb_ctor_clust(void *, int, void *, int);
226 static int mb_ctor_pack(void *, int, void *, int);
227 static void mb_dtor_mbuf(void *, int, void *);
228 static void mb_dtor_clust(void *, int, void *);
229 static void mb_dtor_pack(void *, int, void *);
230 static int mb_zinit_pack(void *, int, int);
231 static void mb_zfini_pack(void *, int);
232
233 static void mb_reclaim(void *);
234 static void mbuf_init(void *);
235 static void *mbuf_jumbo_alloc(uma_zone_t, int, u_int8_t *, int);
236 static void mbuf_jumbo_free(void *, int, u_int8_t);
237
238 static MALLOC_DEFINE(M_JUMBOFRAME, "jumboframes", "mbuf jumbo frame buffers");
239
240 /* Ensure that MSIZE doesn't break dtom() - it must be a power of 2 */
241 CTASSERT((((MSIZE - 1) ^ MSIZE) + 1) >> 1 == MSIZE);
242
243 /*
244 * Initialize FreeBSD Network buffer allocation.
245 */
246 SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbuf_init, NULL);
247 static void
248 mbuf_init(void *dummy)
249 {
250
251 /*
252 * Configure UMA zones for Mbufs, Clusters, and Packets.
253 */
254 zone_mbuf = uma_zcreate(MBUF_MEM_NAME, MSIZE,
255 mb_ctor_mbuf, mb_dtor_mbuf,
256 #ifdef INVARIANTS
257 trash_init, trash_fini,
258 #else
259 NULL, NULL,
260 #endif
261 MSIZE - 1, UMA_ZONE_MAXBUCKET);
262
263 zone_clust = uma_zcreate(MBUF_CLUSTER_MEM_NAME, MCLBYTES,
264 mb_ctor_clust, mb_dtor_clust,
265 #ifdef INVARIANTS
266 trash_init, trash_fini,
267 #else
268 NULL, NULL,
269 #endif
270 UMA_ALIGN_PTR, UMA_ZONE_REFCNT);
271 if (nmbclusters > 0)
272 uma_zone_set_max(zone_clust, nmbclusters);
273
274 zone_pack = uma_zsecond_create(MBUF_PACKET_MEM_NAME, mb_ctor_pack,
275 mb_dtor_pack, mb_zinit_pack, mb_zfini_pack, zone_mbuf);
276
277 /* Make jumbo frame zone too. Page size, 9k and 16k. */
278 zone_jumbop = uma_zcreate(MBUF_JUMBOP_MEM_NAME, MJUMPAGESIZE,
279 mb_ctor_clust, mb_dtor_clust,
280 #ifdef INVARIANTS
281 trash_init, trash_fini,
282 #else
283 NULL, NULL,
284 #endif
285 UMA_ALIGN_PTR, UMA_ZONE_REFCNT);
286 if (nmbjumbop > 0)
287 uma_zone_set_max(zone_jumbop, nmbjumbop);
288
289 zone_jumbo9 = uma_zcreate(MBUF_JUMBO9_MEM_NAME, MJUM9BYTES,
290 mb_ctor_clust, mb_dtor_clust,
291 #ifdef INVARIANTS
292 trash_init, trash_fini,
293 #else
294 NULL, NULL,
295 #endif
296 UMA_ALIGN_PTR, UMA_ZONE_REFCNT);
297 if (nmbjumbo9 > 0)
298 uma_zone_set_max(zone_jumbo9, nmbjumbo9);
299 uma_zone_set_allocf(zone_jumbo9, mbuf_jumbo_alloc);
300 uma_zone_set_freef(zone_jumbo9, mbuf_jumbo_free);
301
302 zone_jumbo16 = uma_zcreate(MBUF_JUMBO16_MEM_NAME, MJUM16BYTES,
303 mb_ctor_clust, mb_dtor_clust,
304 #ifdef INVARIANTS
305 trash_init, trash_fini,
306 #else
307 NULL, NULL,
308 #endif
309 UMA_ALIGN_PTR, UMA_ZONE_REFCNT);
310 if (nmbjumbo16 > 0)
311 uma_zone_set_max(zone_jumbo16, nmbjumbo16);
312 uma_zone_set_allocf(zone_jumbo16, mbuf_jumbo_alloc);
313 uma_zone_set_freef(zone_jumbo16, mbuf_jumbo_free);
314
315 zone_ext_refcnt = uma_zcreate(MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int),
316 NULL, NULL,
317 NULL, NULL,
318 UMA_ALIGN_PTR, UMA_ZONE_ZINIT);
319
320 /* uma_prealloc() goes here... */
321
322 /*
323 * Hook event handler for low-memory situation, used to
324 * drain protocols and push data back to the caches (UMA
325 * later pushes it back to VM).
326 */
327 EVENTHANDLER_REGISTER(vm_lowmem, mb_reclaim, NULL,
328 EVENTHANDLER_PRI_FIRST);
329
330 /*
331 * [Re]set counters and local statistics knobs.
332 * XXX Some of these should go and be replaced, but UMA stat
333 * gathering needs to be revised.
334 */
335 mbstat.m_mbufs = 0;
336 mbstat.m_mclusts = 0;
337 mbstat.m_drain = 0;
338 mbstat.m_msize = MSIZE;
339 mbstat.m_mclbytes = MCLBYTES;
340 mbstat.m_minclsize = MINCLSIZE;
341 mbstat.m_mlen = MLEN;
342 mbstat.m_mhlen = MHLEN;
343 mbstat.m_numtypes = MT_NTYPES;
344
345 mbstat.m_mcfail = mbstat.m_mpfail = 0;
346 mbstat.sf_iocnt = 0;
347 mbstat.sf_allocwait = mbstat.sf_allocfail = 0;
348 }
349
350 /*
351 * UMA backend page allocator for the jumbo frame zones.
352 *
353 * Allocates kernel virtual memory that is backed by contiguous physical
354 * pages.
355 */
356 static void *
357 mbuf_jumbo_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
358 {
359
360 /* Inform UMA that this allocator uses kernel_map/object. */
361 *flags = UMA_SLAB_KERNEL;
362 return (contigmalloc(bytes, M_JUMBOFRAME, wait, (vm_paddr_t)0,
363 ~(vm_paddr_t)0, 1, 0));
364 }
365
366 /*
367 * UMA backend page deallocator for the jumbo frame zones.
368 */
369 static void
370 mbuf_jumbo_free(void *mem, int size, u_int8_t flags)
371 {
372
373 contigfree(mem, size, M_JUMBOFRAME);
374 }
375
376 /*
377 * Constructor for Mbuf master zone.
378 *
379 * The 'arg' pointer points to a mb_args structure which
380 * contains call-specific information required to support the
381 * mbuf allocation API. See mbuf.h.
382 */
383 static int
384 mb_ctor_mbuf(void *mem, int size, void *arg, int how)
385 {
386 struct mbuf *m;
387 struct mb_args *args;
388 #ifdef MAC
389 int error;
390 #endif
391 int flags;
392 short type;
393
394 #ifdef INVARIANTS
395 trash_ctor(mem, size, arg, how);
396 #endif
397 m = (struct mbuf *)mem;
398 args = (struct mb_args *)arg;
399 flags = args->flags;
400 type = args->type;
401
402 /*
403 * The mbuf is initialized later. The caller has the
404 * responsibility to set up any MAC labels too.
405 */
406 if (type == MT_NOINIT)
407 return (0);
408
409 m->m_next = NULL;
410 m->m_nextpkt = NULL;
411 m->m_len = 0;
412 m->m_flags = flags;
413 m->m_type = type;
414 if (flags & M_PKTHDR) {
415 m->m_data = m->m_pktdat;
416 m->m_pkthdr.rcvif = NULL;
417 m->m_pkthdr.len = 0;
418 m->m_pkthdr.header = NULL;
419 m->m_pkthdr.csum_flags = 0;
420 m->m_pkthdr.csum_data = 0;
421 m->m_pkthdr.tso_segsz = 0;
422 m->m_pkthdr.ether_vtag = 0;
423 SLIST_INIT(&m->m_pkthdr.tags);
424 #ifdef MAC
425 /* If the label init fails, fail the alloc */
426 error = mac_init_mbuf(m, how);
427 if (error)
428 return (error);
429 #endif
430 } else
431 m->m_data = m->m_dat;
432 return (0);
433 }
434
435 /*
436 * The Mbuf master zone destructor.
437 */
438 static void
439 mb_dtor_mbuf(void *mem, int size, void *arg)
440 {
441 struct mbuf *m;
442 unsigned long flags;
443
444 m = (struct mbuf *)mem;
445 flags = (unsigned long)arg;
446
447 if ((flags & MB_NOTAGS) == 0 && (m->m_flags & M_PKTHDR) != 0)
448 m_tag_delete_chain(m, NULL);
449 KASSERT((m->m_flags & M_EXT) == 0, ("%s: M_EXT set", __func__));
450 KASSERT((m->m_flags & M_NOFREE) == 0, ("%s: M_NOFREE set", __func__));
451 #ifdef INVARIANTS
452 trash_dtor(mem, size, arg);
453 #endif
454 }
455
456 /*
457 * The Mbuf Packet zone destructor.
458 */
459 static void
460 mb_dtor_pack(void *mem, int size, void *arg)
461 {
462 struct mbuf *m;
463
464 m = (struct mbuf *)mem;
465 if ((m->m_flags & M_PKTHDR) != 0)
466 m_tag_delete_chain(m, NULL);
467
468 /* Make sure we've got a clean cluster back. */
469 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
470 KASSERT(m->m_ext.ext_buf != NULL, ("%s: ext_buf == NULL", __func__));
471 KASSERT(m->m_ext.ext_free == NULL, ("%s: ext_free != NULL", __func__));
472 KASSERT(m->m_ext.ext_args == NULL, ("%s: ext_args != NULL", __func__));
473 KASSERT(m->m_ext.ext_size == MCLBYTES, ("%s: ext_size != MCLBYTES", __func__));
474 KASSERT(m->m_ext.ext_type == EXT_PACKET, ("%s: ext_type != EXT_PACKET", __func__));
475 KASSERT(*m->m_ext.ref_cnt == 1, ("%s: ref_cnt != 1", __func__));
476 #ifdef INVARIANTS
477 trash_dtor(m->m_ext.ext_buf, MCLBYTES, arg);
478 #endif
479 /*
480 * If there are processes blocked on zone_clust, waiting for pages to be freed up,
481 * cause them to be woken up by draining the packet zone. We are exposed to a race here
482 * (in the check for the UMA_ZFLAG_FULL) where we might miss the flag set, but that is
483 * deliberate. We don't want to acquire the zone lock for every mbuf free.
484 */
485 if (uma_zone_exhausted_nolock(zone_clust))
486 zone_drain(zone_pack);
487 }
488
489 /*
490 * The Cluster and Jumbo[PAGESIZE|9|16] zone constructor.
491 *
492 * Here the 'arg' pointer points to the Mbuf which we
493 * are configuring cluster storage for. If 'arg' is
494 * empty we allocate just the cluster without setting
495 * the mbuf to it. See mbuf.h.
496 */
497 static int
498 mb_ctor_clust(void *mem, int size, void *arg, int how)
499 {
500 struct mbuf *m;
501 u_int *refcnt;
502 int type;
503 uma_zone_t zone;
504
505 #ifdef INVARIANTS
506 trash_ctor(mem, size, arg, how);
507 #endif
508 switch (size) {
509 case MCLBYTES:
510 type = EXT_CLUSTER;
511 zone = zone_clust;
512 break;
513 #if MJUMPAGESIZE != MCLBYTES
514 case MJUMPAGESIZE:
515 type = EXT_JUMBOP;
516 zone = zone_jumbop;
517 break;
518 #endif
519 case MJUM9BYTES:
520 type = EXT_JUMBO9;
521 zone = zone_jumbo9;
522 break;
523 case MJUM16BYTES:
524 type = EXT_JUMBO16;
525 zone = zone_jumbo16;
526 break;
527 default:
528 panic("unknown cluster size");
529 break;
530 }
531
532 m = (struct mbuf *)arg;
533 refcnt = uma_find_refcnt(zone, mem);
534 *refcnt = 1;
535 if (m != NULL) {
536 m->m_ext.ext_buf = (caddr_t)mem;
537 m->m_data = m->m_ext.ext_buf;
538 m->m_flags |= M_EXT;
539 m->m_ext.ext_free = NULL;
540 m->m_ext.ext_args = NULL;
541 m->m_ext.ext_size = size;
542 m->m_ext.ext_type = type;
543 m->m_ext.ref_cnt = refcnt;
544 }
545
546 return (0);
547 }
548
549 /*
550 * The Mbuf Cluster zone destructor.
551 */
552 static void
553 mb_dtor_clust(void *mem, int size, void *arg)
554 {
555 #ifdef INVARIANTS
556 uma_zone_t zone;
557
558 zone = m_getzone(size);
559 KASSERT(*(uma_find_refcnt(zone, mem)) <= 1,
560 ("%s: refcnt incorrect %u", __func__,
561 *(uma_find_refcnt(zone, mem))) );
562
563 trash_dtor(mem, size, arg);
564 #endif
565 }
566
567 /*
568 * The Packet secondary zone's init routine, executed on the
569 * object's transition from mbuf keg slab to zone cache.
570 */
571 static int
572 mb_zinit_pack(void *mem, int size, int how)
573 {
574 struct mbuf *m;
575
576 m = (struct mbuf *)mem; /* m is virgin. */
577 if (uma_zalloc_arg(zone_clust, m, how) == NULL ||
578 m->m_ext.ext_buf == NULL)
579 return (ENOMEM);
580 m->m_ext.ext_type = EXT_PACKET; /* Override. */
581 #ifdef INVARIANTS
582 trash_init(m->m_ext.ext_buf, MCLBYTES, how);
583 #endif
584 return (0);
585 }
586
587 /*
588 * The Packet secondary zone's fini routine, executed on the
589 * object's transition from zone cache to keg slab.
590 */
591 static void
592 mb_zfini_pack(void *mem, int size)
593 {
594 struct mbuf *m;
595
596 m = (struct mbuf *)mem;
597 #ifdef INVARIANTS
598 trash_fini(m->m_ext.ext_buf, MCLBYTES);
599 #endif
600 uma_zfree_arg(zone_clust, m->m_ext.ext_buf, NULL);
601 #ifdef INVARIANTS
602 trash_dtor(mem, size, NULL);
603 #endif
604 }
605
606 /*
607 * The "packet" keg constructor.
608 */
609 static int
610 mb_ctor_pack(void *mem, int size, void *arg, int how)
611 {
612 struct mbuf *m;
613 struct mb_args *args;
614 #ifdef MAC
615 int error;
616 #endif
617 int flags;
618 short type;
619
620 m = (struct mbuf *)mem;
621 args = (struct mb_args *)arg;
622 flags = args->flags;
623 type = args->type;
624
625 #ifdef INVARIANTS
626 trash_ctor(m->m_ext.ext_buf, MCLBYTES, arg, how);
627 #endif
628 m->m_next = NULL;
629 m->m_nextpkt = NULL;
630 m->m_data = m->m_ext.ext_buf;
631 m->m_len = 0;
632 m->m_flags = (flags | M_EXT);
633 m->m_type = type;
634
635 if (flags & M_PKTHDR) {
636 m->m_pkthdr.rcvif = NULL;
637 m->m_pkthdr.len = 0;
638 m->m_pkthdr.header = NULL;
639 m->m_pkthdr.csum_flags = 0;
640 m->m_pkthdr.csum_data = 0;
641 m->m_pkthdr.tso_segsz = 0;
642 m->m_pkthdr.ether_vtag = 0;
643 SLIST_INIT(&m->m_pkthdr.tags);
644 #ifdef MAC
645 /* If the label init fails, fail the alloc */
646 error = mac_init_mbuf(m, how);
647 if (error)
648 return (error);
649 #endif
650 }
651 /* m_ext is already initialized. */
652
653 return (0);
654 }
655
656 /*
657 * This is the protocol drain routine.
658 *
659 * No locks should be held when this is called. The drain routines have to
660 * presently acquire some locks which raises the possibility of lock order
661 * reversal.
662 */
663 static void
664 mb_reclaim(void *junk)
665 {
666 struct domain *dp;
667 struct protosw *pr;
668
669 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK | WARN_PANIC, NULL,
670 "mb_reclaim()");
671
672 for (dp = domains; dp != NULL; dp = dp->dom_next)
673 for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
674 if (pr->pr_drain != NULL)
675 (*pr->pr_drain)();
676 }
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