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 static void
 105 tunable_mbinit(void *dummy)
 106 {
 107
 108         /* This has to be done before VM init. */
 109         nmbclusters = 1024 + maxusers * 64;
 110         nmbjumbop = nmbclusters / 2;
 111         nmbjumbo9 = nmbjumbop / 2;
 112         nmbjumbo16 = nmbjumbo9 / 2;
 113         TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters);
 114 }
 115 SYSINIT(tunable_mbinit, SI_SUB_TUNABLES, SI_ORDER_ANY, tunable_mbinit, NULL);
 116
 117 /* XXX: These should be tuneables. Can't change UMA limits on the fly. */
 118 static int
 119 sysctl_nmbclusters(SYSCTL_HANDLER_ARGS)
 120 {
 121         int error, newnmbclusters;
 122
 123         newnmbclusters = nmbclusters;
 124         error = sysctl_handle_int(oidp, &newnmbclusters, 0, req);
 125         if (error == 0 && req->newptr) {
 126                 if (newnmbclusters > nmbclusters) {
 127                         nmbclusters = newnmbclusters;
 128                         uma_zone_set_max(zone_clust, nmbclusters);
 129                         EVENTHANDLER_INVOKE(nmbclusters_change);
 130                 } else
 131                         error = EINVAL;
 132         }
 133         return (error);
 134 }
 135 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbclusters, CTLTYPE_INT|CTLFLAG_RW,
 136 &nmbclusters, 0, sysctl_nmbclusters, "IU",
 137     "Maximum number of mbuf clusters allowed");
 138
 139 static int
 140 sysctl_nmbjumbop(SYSCTL_HANDLER_ARGS)
 141 {
 142         int error, newnmbjumbop;
 143
 144         newnmbjumbop = nmbjumbop;
 145         error = sysctl_handle_int(oidp, &newnmbjumbop, 0, req);
 146         if (error == 0 && req->newptr) {
 147                 if (newnmbjumbop> nmbjumbop) {
 148                         nmbjumbop = newnmbjumbop;
 149                         uma_zone_set_max(zone_jumbop, nmbjumbop);
 150                 } else
 151                         error = EINVAL;
 152         }
 153         return (error);
 154 }
 155 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbop, CTLTYPE_INT|CTLFLAG_RW,
 156 &nmbjumbop, 0, sysctl_nmbjumbop, "IU",
 157          "Maximum number of mbuf page size jumbo clusters allowed");
 158
 159
 160 static int
 161 sysctl_nmbjumbo9(SYSCTL_HANDLER_ARGS)
 162 {
 163         int error, newnmbjumbo9;
 164
 165         newnmbjumbo9 = nmbjumbo9;
 166         error = sysctl_handle_int(oidp, &newnmbjumbo9, 0, req);
 167         if (error == 0 && req->newptr) {
 168                 if (newnmbjumbo9> nmbjumbo9) {
 169                         nmbjumbo9 = newnmbjumbo9;
 170                         uma_zone_set_max(zone_jumbo9, nmbjumbo9);
 171                 } else
 172                         error = EINVAL;
 173         }
 174         return (error);
 175 }
 176 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo9, CTLTYPE_INT|CTLFLAG_RW,
 177 &nmbjumbo9, 0, sysctl_nmbjumbo9, "IU",
 178         "Maximum number of mbuf 9k jumbo clusters allowed");
 179
 180 static int
 181 sysctl_nmbjumbo16(SYSCTL_HANDLER_ARGS)
 182 {
 183         int error, newnmbjumbo16;
 184
 185         newnmbjumbo16 = nmbjumbo16;
 186         error = sysctl_handle_int(oidp, &newnmbjumbo16, 0, req);
 187         if (error == 0 && req->newptr) {
 188                 if (newnmbjumbo16> nmbjumbo16) {
 189                         nmbjumbo16 = newnmbjumbo16;
 190                         uma_zone_set_max(zone_jumbo16, nmbjumbo16);
 191                 } else
 192                         error = EINVAL;
 193         }
 194         return (error);
 195 }
 196 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo16, CTLTYPE_INT|CTLFLAG_RW,
 197 &nmbjumbo16, 0, sysctl_nmbjumbo16, "IU",
 198     "Maximum number of mbuf 16k jumbo clusters allowed");
 199
 200
 201
 202 SYSCTL_STRUCT(_kern_ipc, OID_AUTO, mbstat, CTLFLAG_RD, &mbstat, mbstat,
 203     "Mbuf general information and statistics");
 204
 205 /*
 206  * Zones from which we allocate.
 207  */
 208 uma_zone_t      zone_mbuf;
 209 uma_zone_t      zone_clust;
 210 uma_zone_t      zone_pack;
 211 uma_zone_t      zone_jumbop;
 212 uma_zone_t      zone_jumbo9;
 213 uma_zone_t      zone_jumbo16;
 214 uma_zone_t      zone_ext_refcnt;
 215
 216 /*
 217  * Local prototypes.
 218  */
 219 static int      mb_ctor_mbuf(void *, int, void *, int);
 220 static int      mb_ctor_clust(void *, int, void *, int);
 221 static int      mb_ctor_pack(void *, int, void *, int);
 222 static void     mb_dtor_mbuf(void *, int, void *);
 223 static void     mb_dtor_clust(void *, int, void *);
 224 static void     mb_dtor_pack(void *, int, void *);
 225 static int      mb_zinit_pack(void *, int, int);
 226 static void     mb_zfini_pack(void *, int);
 227
 228 static void     mb_reclaim(void *);
 229 static void     mbuf_init(void *);
 230 static void    *mbuf_jumbo_alloc(uma_zone_t, int, u_int8_t *, int);
 231 static void     mbuf_jumbo_free(void *, int, u_int8_t);
 232
 233 static MALLOC_DEFINE(M_JUMBOFRAME, "jumboframes", "mbuf jumbo frame buffers");
 234
 235 /* Ensure that MSIZE doesn't break dtom() - it must be a power of 2 */
 236 CTASSERT((((MSIZE - 1) ^ MSIZE) + 1) >> 1 == MSIZE);
 237
 238 /*
 239  * Initialize FreeBSD Network buffer allocation.
 240  */
 241 SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbuf_init, NULL);
 242 static void
 243 mbuf_init(void *dummy)
 244 {
 245
 246         /*
 247          * Configure UMA zones for Mbufs, Clusters, and Packets.
 248          */
 249         zone_mbuf = uma_zcreate(MBUF_MEM_NAME, MSIZE,
 250             mb_ctor_mbuf, mb_dtor_mbuf,
 251 #ifdef INVARIANTS
 252             trash_init, trash_fini,
 253 #else
 254             NULL, NULL,
 255 #endif
 256             MSIZE - 1, UMA_ZONE_MAXBUCKET);
 257
 258         zone_clust = uma_zcreate(MBUF_CLUSTER_MEM_NAME, MCLBYTES,
 259             mb_ctor_clust, mb_dtor_clust,
 260 #ifdef INVARIANTS
 261             trash_init, trash_fini,
 262 #else
 263             NULL, NULL,
 264 #endif
 265             UMA_ALIGN_PTR, UMA_ZONE_REFCNT);
 266         if (nmbclusters > 0)
 267                 uma_zone_set_max(zone_clust, nmbclusters);
 268
 269         zone_pack = uma_zsecond_create(MBUF_PACKET_MEM_NAME, mb_ctor_pack,
 270             mb_dtor_pack, mb_zinit_pack, mb_zfini_pack, zone_mbuf);
 271
 272         /* Make jumbo frame zone too. Page size, 9k and 16k. */
 273         zone_jumbop = uma_zcreate(MBUF_JUMBOP_MEM_NAME, MJUMPAGESIZE,
 274             mb_ctor_clust, mb_dtor_clust,
 275 #ifdef INVARIANTS
 276             trash_init, trash_fini,
 277 #else
 278             NULL, NULL,
 279 #endif
 280             UMA_ALIGN_PTR, UMA_ZONE_REFCNT);
 281         if (nmbjumbop > 0)
 282                 uma_zone_set_max(zone_jumbop, nmbjumbop);
 283
 284         zone_jumbo9 = uma_zcreate(MBUF_JUMBO9_MEM_NAME, MJUM9BYTES,
 285             mb_ctor_clust, mb_dtor_clust,
 286 #ifdef INVARIANTS
 287             trash_init, trash_fini,
 288 #else
 289             NULL, NULL,
 290 #endif
 291             UMA_ALIGN_PTR, UMA_ZONE_REFCNT);
 292         if (nmbjumbo9 > 0)
 293                 uma_zone_set_max(zone_jumbo9, nmbjumbo9);
 294         uma_zone_set_allocf(zone_jumbo9, mbuf_jumbo_alloc);
 295         uma_zone_set_freef(zone_jumbo9, mbuf_jumbo_free);
 296
 297         zone_jumbo16 = uma_zcreate(MBUF_JUMBO16_MEM_NAME, MJUM16BYTES,
 298             mb_ctor_clust, mb_dtor_clust,
 299 #ifdef INVARIANTS
 300             trash_init, trash_fini,
 301 #else
 302             NULL, NULL,
 303 #endif
 304             UMA_ALIGN_PTR, UMA_ZONE_REFCNT);
 305         if (nmbjumbo16 > 0)
 306                 uma_zone_set_max(zone_jumbo16, nmbjumbo16);
 307         uma_zone_set_allocf(zone_jumbo16, mbuf_jumbo_alloc);
 308         uma_zone_set_freef(zone_jumbo16, mbuf_jumbo_free);
 309
 310         zone_ext_refcnt = uma_zcreate(MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int),
 311             NULL, NULL,
 312             NULL, NULL,
 313             UMA_ALIGN_PTR, UMA_ZONE_ZINIT);
 314
 315         /* uma_prealloc() goes here... */
 316
 317         /*
 318          * Hook event handler for low-memory situation, used to
 319          * drain protocols and push data back to the caches (UMA
 320          * later pushes it back to VM).
 321          */
 322         EVENTHANDLER_REGISTER(vm_lowmem, mb_reclaim, NULL,
 323             EVENTHANDLER_PRI_FIRST);
 324
 325         /*
 326          * [Re]set counters and local statistics knobs.
 327          * XXX Some of these should go and be replaced, but UMA stat
 328          * gathering needs to be revised.
 329          */
 330         mbstat.m_mbufs = 0;
 331         mbstat.m_mclusts = 0;
 332         mbstat.m_drain = 0;
 333         mbstat.m_msize = MSIZE;
 334         mbstat.m_mclbytes = MCLBYTES;
 335         mbstat.m_minclsize = MINCLSIZE;
 336         mbstat.m_mlen = MLEN;
 337         mbstat.m_mhlen = MHLEN;
 338         mbstat.m_numtypes = MT_NTYPES;
 339
 340         mbstat.m_mcfail = mbstat.m_mpfail = 0;
 341         mbstat.sf_iocnt = 0;
 342         mbstat.sf_allocwait = mbstat.sf_allocfail = 0;
 343 }
 344
 345 /*
 346  * UMA backend page allocator for the jumbo frame zones.
 347  *
 348  * Allocates kernel virtual memory that is backed by contiguous physical
 349  * pages.
 350  */
 351 static void *
 352 mbuf_jumbo_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
 353 {
 354
 355         /* Inform UMA that this allocator uses kernel_map/object. */
 356         *flags = UMA_SLAB_KERNEL;
 357         return (contigmalloc(bytes, M_JUMBOFRAME, wait, (vm_paddr_t)0,
 358             ~(vm_paddr_t)0, 1, 0));
 359 }
 360
 361 /*
 362  * UMA backend page deallocator for the jumbo frame zones.
 363  */
 364 static void
 365 mbuf_jumbo_free(void *mem, int size, u_int8_t flags)
 366 {
 367
 368         contigfree(mem, size, M_JUMBOFRAME);
 369 }
 370
 371 /*
 372  * Constructor for Mbuf master zone.
 373  *
 374  * The 'arg' pointer points to a mb_args structure which
 375  * contains call-specific information required to support the
 376  * mbuf allocation API.  See mbuf.h.
 377  */
 378 static int
 379 mb_ctor_mbuf(void *mem, int size, void *arg, int how)
 380 {
 381         struct mbuf *m;
 382         struct mb_args *args;
 383 #ifdef MAC
 384         int error;
 385 #endif
 386         int flags;
 387         short type;
 388
 389 #ifdef INVARIANTS
 390         trash_ctor(mem, size, arg, how);
 391 #endif
 392         m = (struct mbuf *)mem;
 393         args = (struct mb_args *)arg;
 394         flags = args->flags;
 395         type = args->type;
 396
 397         /*
 398          * The mbuf is initialized later.  The caller has the
 399          * responsibility to set up any MAC labels too.
 400          */
 401         if (type == MT_NOINIT)
 402                 return (0);
 403
 404         m->m_next = NULL;
 405         m->m_nextpkt = NULL;
 406         m->m_len = 0;
 407         m->m_flags = flags;
 408         m->m_type = type;
 409         if (flags & M_PKTHDR) {
 410                 m->m_data = m->m_pktdat;
 411                 m->m_pkthdr.rcvif = NULL;
 412                 m->m_pkthdr.len = 0;
 413                 m->m_pkthdr.header = NULL;
 414                 m->m_pkthdr.csum_flags = 0;
 415                 m->m_pkthdr.csum_data = 0;
 416                 m->m_pkthdr.tso_segsz = 0;
 417                 m->m_pkthdr.ether_vtag = 0;
 418                 SLIST_INIT(&m->m_pkthdr.tags);
 419 #ifdef MAC
 420                 /* If the label init fails, fail the alloc */
 421                 error = mac_mbuf_init(m, how);
 422                 if (error)
 423                         return (error);
 424 #endif
 425         } else
 426                 m->m_data = m->m_dat;
 427         return (0);
 428 }
 429
 430 /*
 431  * The Mbuf master zone destructor.
 432  */
 433 static void
 434 mb_dtor_mbuf(void *mem, int size, void *arg)
 435 {
 436         struct mbuf *m;
 437         unsigned long flags;
 438
 439         m = (struct mbuf *)mem;
 440         flags = (unsigned long)arg;
 441
 442         if ((flags & MB_NOTAGS) == 0 && (m->m_flags & M_PKTHDR) != 0)
 443                 m_tag_delete_chain(m, NULL);
 444         KASSERT((m->m_flags & M_EXT) == 0, ("%s: M_EXT set", __func__));
 445         KASSERT((m->m_flags & M_NOFREE) == 0, ("%s: M_NOFREE set", __func__));
 446 #ifdef INVARIANTS
 447         trash_dtor(mem, size, arg);
 448 #endif
 449 }
 450
 451 /*
 452  * The Mbuf Packet zone destructor.
 453  */
 454 static void
 455 mb_dtor_pack(void *mem, int size, void *arg)
 456 {
 457         struct mbuf *m;
 458
 459         m = (struct mbuf *)mem;
 460         if ((m->m_flags & M_PKTHDR) != 0)
 461                 m_tag_delete_chain(m, NULL);
 462
 463         /* Make sure we've got a clean cluster back. */
 464         KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
 465         KASSERT(m->m_ext.ext_buf != NULL, ("%s: ext_buf == NULL", __func__));
 466         KASSERT(m->m_ext.ext_free == NULL, ("%s: ext_free != NULL", __func__));
 467         KASSERT(m->m_ext.ext_arg1 == NULL, ("%s: ext_arg1 != NULL", __func__));
 468         KASSERT(m->m_ext.ext_arg2 == NULL, ("%s: ext_arg2 != NULL", __func__));
 469         KASSERT(m->m_ext.ext_size == MCLBYTES, ("%s: ext_size != MCLBYTES", __func__));
 470         KASSERT(m->m_ext.ext_type == EXT_PACKET, ("%s: ext_type != EXT_PACKET", __func__));
 471         KASSERT(*m->m_ext.ref_cnt == 1, ("%s: ref_cnt != 1", __func__));
 472 #ifdef INVARIANTS
 473         trash_dtor(m->m_ext.ext_buf, MCLBYTES, arg);
 474 #endif
 475         /*
 476          * If there are processes blocked on zone_clust, waiting for pages
 477          * to be freed up, * cause them to be woken up by draining the
 478          * packet zone.  We are exposed to a race here * (in the check for
 479          * the UMA_ZFLAG_FULL) where we might miss the flag set, but that
 480          * is deliberate. We don't want to acquire the zone lock for every
 481          * mbuf free.
 482          */
 483         if (uma_zone_exhausted_nolock(zone_clust))
 484                 zone_drain(zone_pack);
 485 }
 486
 487 /*
 488  * The Cluster and Jumbo[PAGESIZE|9|16] zone constructor.
 489  *
 490  * Here the 'arg' pointer points to the Mbuf which we
 491  * are configuring cluster storage for.  If 'arg' is
 492  * empty we allocate just the cluster without setting
 493  * the mbuf to it.  See mbuf.h.
 494  */
 495 static int
 496 mb_ctor_clust(void *mem, int size, void *arg, int how)
 497 {
 498         struct mbuf *m;
 499         u_int *refcnt;
 500         int type;
 501         uma_zone_t zone;
 502
 503 #ifdef INVARIANTS
 504         trash_ctor(mem, size, arg, how);
 505 #endif
 506         switch (size) {
 507         case MCLBYTES:
 508                 type = EXT_CLUSTER;
 509                 zone = zone_clust;
 510                 break;
 511 #if MJUMPAGESIZE != MCLBYTES
 512         case MJUMPAGESIZE:
 513                 type = EXT_JUMBOP;
 514                 zone = zone_jumbop;
 515                 break;
 516 #endif
 517         case MJUM9BYTES:
 518                 type = EXT_JUMBO9;
 519                 zone = zone_jumbo9;
 520                 break;
 521         case MJUM16BYTES:
 522                 type = EXT_JUMBO16;
 523                 zone = zone_jumbo16;
 524                 break;
 525         default:
 526                 panic("unknown cluster size");
 527                 break;
 528         }
 529
 530         m = (struct mbuf *)arg;
 531         refcnt = uma_find_refcnt(zone, mem);
 532         *refcnt = 1;
 533         if (m != NULL) {
 534                 m->m_ext.ext_buf = (caddr_t)mem;
 535                 m->m_data = m->m_ext.ext_buf;
 536                 m->m_flags |= M_EXT;
 537                 m->m_ext.ext_free = NULL;
 538                 m->m_ext.ext_arg1 = NULL;
 539                 m->m_ext.ext_arg2 = NULL;
 540                 m->m_ext.ext_size = size;
 541                 m->m_ext.ext_type = type;
 542                 m->m_ext.ref_cnt = refcnt;
 543         }
 544
 545         return (0);
 546 }
 547
 548 /*
 549  * The Mbuf Cluster zone destructor.
 550  */
 551 static void
 552 mb_dtor_clust(void *mem, int size, void *arg)
 553 {
 554 #ifdef INVARIANTS
 555         uma_zone_t zone;
 556
 557         zone = m_getzone(size);
 558         KASSERT(*(uma_find_refcnt(zone, mem)) <= 1,
 559                 ("%s: refcnt incorrect %u", __func__,
 560                  *(uma_find_refcnt(zone, mem))) );
 561
 562         trash_dtor(mem, size, arg);
 563 #endif
 564 }
 565
 566 /*
 567  * The Packet secondary zone's init routine, executed on the
 568  * object's transition from mbuf keg slab to zone cache.
 569  */
 570 static int
 571 mb_zinit_pack(void *mem, int size, int how)
 572 {
 573         struct mbuf *m;
 574
 575         m = (struct mbuf *)mem;         /* m is virgin. */
 576         if (uma_zalloc_arg(zone_clust, m, how) == NULL ||
 577             m->m_ext.ext_buf == NULL)
 578                 return (ENOMEM);
 579         m->m_ext.ext_type = EXT_PACKET; /* Override. */
 580 #ifdef INVARIANTS
 581         trash_init(m->m_ext.ext_buf, MCLBYTES, how);
 582 #endif
 583         return (0);
 584 }
 585
 586 /*
 587  * The Packet secondary zone's fini routine, executed on the
 588  * object's transition from zone cache to keg slab.
 589  */
 590 static void
 591 mb_zfini_pack(void *mem, int size)
 592 {
 593         struct mbuf *m;
 594
 595         m = (struct mbuf *)mem;
 596 #ifdef INVARIANTS
 597         trash_fini(m->m_ext.ext_buf, MCLBYTES);
 598 #endif
 599         uma_zfree_arg(zone_clust, m->m_ext.ext_buf, NULL);
 600 #ifdef INVARIANTS
 601         trash_dtor(mem, size, NULL);
 602 #endif
 603 }
 604
 605 /*
 606  * The "packet" keg constructor.
 607  */
 608 static int
 609 mb_ctor_pack(void *mem, int size, void *arg, int how)
 610 {
 611         struct mbuf *m;
 612         struct mb_args *args;
 613 #ifdef MAC
 614         int error;
 615 #endif
 616         int flags;
 617         short type;
 618
 619         m = (struct mbuf *)mem;
 620         args = (struct mb_args *)arg;
 621         flags = args->flags;
 622         type = args->type;
 623
 624 #ifdef INVARIANTS
 625         trash_ctor(m->m_ext.ext_buf, MCLBYTES, arg, how);
 626 #endif
 627         m->m_next = NULL;
 628         m->m_nextpkt = NULL;
 629         m->m_data = m->m_ext.ext_buf;
 630         m->m_len = 0;
 631         m->m_flags = (flags | M_EXT);
 632         m->m_type = type;
 633
 634         if (flags & M_PKTHDR) {
 635                 m->m_pkthdr.rcvif = NULL;
 636                 m->m_pkthdr.len = 0;
 637                 m->m_pkthdr.header = NULL;
 638                 m->m_pkthdr.csum_flags = 0;
 639                 m->m_pkthdr.csum_data = 0;
 640                 m->m_pkthdr.tso_segsz = 0;
 641                 m->m_pkthdr.ether_vtag = 0;
 642                 SLIST_INIT(&m->m_pkthdr.tags);
 643 #ifdef MAC
 644                 /* If the label init fails, fail the alloc */
 645                 error = mac_mbuf_init(m, how);
 646                 if (error)
 647                         return (error);
 648 #endif
 649         }
 650         /* m_ext is already initialized. */
 651
 652         return (0);
 653 }
 654
 655 /*
 656  * This is the protocol drain routine.
 657  *
 658  * No locks should be held when this is called.  The drain routines have to
 659  * presently acquire some locks which raises the possibility of lock order
 660  * reversal.
 661  */
 662 static void
 663 mb_reclaim(void *junk)
 664 {
 665         struct domain *dp;
 666         struct protosw *pr;
 667
 668         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK | WARN_PANIC, NULL,
 669             "mb_reclaim()");
 670
 671         for (dp = domains; dp != NULL; dp = dp->dom_next)
 672                 for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
 673                         if (pr->pr_drain != NULL)
 674                                 (*pr->pr_drain)();
 675 }