sys/vfs/hammer2/hammer2_inode.c

   1 /*
   2  * Copyright (c) 2011-2013 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@dragonflybsd.org>
   6  * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35 #include <sys/cdefs.h>
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/types.h>
  39 #include <sys/lock.h>
  40 #include <sys/uuid.h>
  41
  42 #include "hammer2.h"
  43
  44 RB_GENERATE2(hammer2_inode_tree, hammer2_inode, rbnode, hammer2_inode_cmp,
  45              hammer2_tid_t, inum);
  46
  47 int
  48 hammer2_inode_cmp(hammer2_inode_t *ip1, hammer2_inode_t *ip2)
  49 {
  50         if (ip1->inum < ip2->inum)
  51                 return(-1);
  52         if (ip1->inum > ip2->inum)
  53                 return(1);
  54         return(0);
  55 }
  56
  57 /*
  58  * HAMMER2 inode locks
  59  *
  60  * HAMMER2 offers shared locks and exclusive locks on inodes.
  61  *
  62  * An inode's ip->chain pointer is resolved and stable while an inode is
  63  * locked, and can be cleaned out at any time (become NULL) when an inode
  64  * is not locked.
  65  *
  66  * This function handles duplication races and hardlink replacement races
  67  * which can cause ip's cached chain to become stale.
  68  *
  69  * The underlying chain is also locked and returned.
  70  *
  71  * NOTE: We don't combine the inode/chain lock because putting away an
  72  *       inode would otherwise confuse multiple lock holders of the inode.
  73  */
  74 hammer2_chain_t *
  75 hammer2_inode_lock_ex(hammer2_inode_t *ip)
  76 {
  77         hammer2_chain_t *chain;
  78         hammer2_chain_t *ochain;
  79         hammer2_chain_core_t *core;
  80         int error;
  81
  82         hammer2_inode_ref(ip);
  83         ccms_thread_lock(&ip->topo_cst, CCMS_STATE_EXCLUSIVE);
  84
  85         chain = ip->chain;
  86         core = chain->core;
  87         for (;;) {
  88                 if (chain->flags & HAMMER2_CHAIN_DUPLICATED) {
  89                         spin_lock(&core->cst.spin);
  90                         while (chain->flags & HAMMER2_CHAIN_DUPLICATED)
  91                                 chain = TAILQ_NEXT(chain, core_entry);
  92                         hammer2_chain_ref(chain);
  93                         spin_unlock(&core->cst.spin);
  94                         hammer2_inode_repoint(ip, NULL, chain);
  95                         hammer2_chain_drop(chain);
  96                 }
  97                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS);
  98                 if ((chain->flags & HAMMER2_CHAIN_DUPLICATED) == 0)
  99                         break;
 100                 hammer2_chain_unlock(chain);
 101         }
 102         if (chain->data->ipdata.type == HAMMER2_OBJTYPE_HARDLINK) {
 103                 error = hammer2_hardlink_find(ip->pip, &chain, &ochain);
 104                 hammer2_chain_drop(ochain);
 105                 KKASSERT(error == 0);
 106                 /* XXX error handling */
 107         }
 108         return (chain);
 109 }
 110
 111 void
 112 hammer2_inode_unlock_ex(hammer2_inode_t *ip, hammer2_chain_t *chain)
 113 {
 114         /*
 115          * XXX this will catch parent directories too which we don't
 116          *     really want.
 117          */
 118         if (chain)
 119                 hammer2_chain_unlock(chain);
 120         ccms_thread_unlock(&ip->topo_cst);
 121         hammer2_inode_drop(ip);
 122 }
 123
 124 /*
 125  * NOTE: We don't combine the inode/chain lock because putting away an
 126  *       inode would otherwise confuse multiple lock holders of the inode.
 127  *
 128  *       Shared locks are especially sensitive to having too many shared
 129  *       lock counts (from the same thread) on certain paths which might
 130  *       need to upgrade them.  Only one count of a shared lock can be
 131  *       upgraded.
 132  */
 133 hammer2_chain_t *
 134 hammer2_inode_lock_sh(hammer2_inode_t *ip)
 135 {
 136         hammer2_chain_t *chain;
 137
 138         hammer2_inode_ref(ip);
 139         for (;;) {
 140                 ccms_thread_lock(&ip->topo_cst, CCMS_STATE_SHARED);
 141
 142                 chain = ip->chain;
 143                 KKASSERT(chain != NULL);        /* for now */
 144                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 145                                           HAMMER2_RESOLVE_SHARED);
 146
 147                 /*
 148                  * Resolve duplication races, resolve hardlinks by giving
 149                  * up and cycling an exclusive lock.
 150                  */
 151                 if ((chain->flags & HAMMER2_CHAIN_DUPLICATED) == 0 &&
 152                     chain->data->ipdata.type != HAMMER2_OBJTYPE_HARDLINK) {
 153                         break;
 154                 }
 155                 hammer2_chain_unlock(chain);
 156                 ccms_thread_unlock(&ip->topo_cst);
 157                 chain = hammer2_inode_lock_ex(ip);
 158                 hammer2_inode_unlock_ex(ip, chain);
 159         }
 160         return (chain);
 161 }
 162
 163 void
 164 hammer2_inode_unlock_sh(hammer2_inode_t *ip, hammer2_chain_t *chain)
 165 {
 166         if (chain)
 167                 hammer2_chain_unlock(chain);
 168         ccms_thread_unlock(&ip->topo_cst);
 169         hammer2_inode_drop(ip);
 170 }
 171
 172 ccms_state_t
 173 hammer2_inode_lock_temp_release(hammer2_inode_t *ip)
 174 {
 175         return(ccms_thread_lock_temp_release(&ip->topo_cst));
 176 }
 177
 178 void
 179 hammer2_inode_lock_temp_restore(hammer2_inode_t *ip, ccms_state_t ostate)
 180 {
 181         ccms_thread_lock_temp_restore(&ip->topo_cst, ostate);
 182 }
 183
 184 ccms_state_t
 185 hammer2_inode_lock_upgrade(hammer2_inode_t *ip)
 186 {
 187         return(ccms_thread_lock_upgrade(&ip->topo_cst));
 188 }
 189
 190 void
 191 hammer2_inode_lock_downgrade(hammer2_inode_t *ip, ccms_state_t ostate)
 192 {
 193         ccms_thread_lock_downgrade(&ip->topo_cst, ostate);
 194 }
 195
 196 /*
 197  * Lookup an inode by inode number
 198  */
 199 hammer2_inode_t *
 200 hammer2_inode_lookup(hammer2_pfsmount_t *pmp, hammer2_tid_t inum)
 201 {
 202         hammer2_inode_t *ip;
 203
 204         if (pmp) {
 205                 spin_lock(&pmp->inum_spin);
 206                 ip = RB_LOOKUP(hammer2_inode_tree, &pmp->inum_tree, inum);
 207                 if (ip)
 208                         hammer2_inode_ref(ip);
 209                 spin_unlock(&pmp->inum_spin);
 210         } else {
 211                 ip = NULL;
 212         }
 213         return(ip);
 214 }
 215
 216 /*
 217  * Adding a ref to an inode is only legal if the inode already has at least
 218  * one ref.
 219  */
 220 void
 221 hammer2_inode_ref(hammer2_inode_t *ip)
 222 {
 223         atomic_add_int(&ip->refs, 1);
 224 }
 225
 226 /*
 227  * Drop an inode reference, freeing the inode when the last reference goes
 228  * away.
 229  */
 230 void
 231 hammer2_inode_drop(hammer2_inode_t *ip)
 232 {
 233         hammer2_pfsmount_t *pmp;
 234         hammer2_inode_t *pip;
 235         u_int refs;
 236
 237         while (ip) {
 238                 refs = ip->refs;
 239                 cpu_ccfence();
 240                 if (refs == 1) {
 241                         /*
 242                          * Transition to zero, must interlock with
 243                          * the inode inumber lookup tree (if applicable).
 244                          *
 245                          * NOTE: The super-root inode has no pmp.
 246                          */
 247                         pmp = ip->pmp;
 248                         if (pmp)
 249                                 spin_lock(&pmp->inum_spin);
 250
 251                         if (atomic_cmpset_int(&ip->refs, 1, 0)) {
 252                                 KKASSERT(ip->topo_cst.count == 0);
 253                                 if (ip->flags & HAMMER2_INODE_ONRBTREE) {
 254                                         atomic_clear_int(&ip->flags,
 255                                                      HAMMER2_INODE_ONRBTREE);
 256                                         RB_REMOVE(hammer2_inode_tree,
 257                                                   &pmp->inum_tree, ip);
 258                                 }
 259                                 if (pmp)
 260                                         spin_unlock(&pmp->inum_spin);
 261
 262                                 pip = ip->pip;
 263                                 ip->pip = NULL;
 264                                 ip->pmp = NULL;
 265
 266                                 /*
 267                                  * Cleaning out ip->chain isn't entirely
 268                                  * trivial.
 269                                  */
 270                                 hammer2_inode_repoint(ip, NULL, NULL);
 271
 272                                 /*
 273                                  * We have to drop pip (if non-NULL) to
 274                                  * dispose of our implied reference from
 275                                  * ip->pip.  We can simply loop on it.
 276                                  */
 277                                 if (pmp) {
 278                                         KKASSERT((ip->flags &
 279                                                   HAMMER2_INODE_SROOT) == 0);
 280                                         kfree(ip, pmp->minode);
 281                                         atomic_add_long(&pmp->inmem_inodes, -1);
 282                                 } else {
 283                                         KKASSERT(ip->flags &
 284                                                  HAMMER2_INODE_SROOT);
 285                                         kfree(ip, M_HAMMER2);
 286                                 }
 287                                 ip = pip;
 288                                 /* continue with pip (can be NULL) */
 289                         } else {
 290                                 if (pmp)
 291                                         spin_unlock(&ip->pmp->inum_spin);
 292                         }
 293                 } else {
 294                         /*
 295                          * Non zero transition
 296                          */
 297                         if (atomic_cmpset_int(&ip->refs, refs, refs - 1))
 298                                 break;
 299                 }
 300         }
 301 }
 302
 303 /*
 304  * Get the vnode associated with the given inode, allocating the vnode if
 305  * necessary.  The vnode will be returned exclusively locked.
 306  *
 307  * The caller must lock the inode (shared or exclusive).
 308  *
 309  * Great care must be taken to avoid deadlocks and vnode acquisition/reclaim
 310  * races.
 311  */
 312 struct vnode *
 313 hammer2_igetv(hammer2_inode_t *ip, int *errorp)
 314 {
 315         hammer2_inode_data_t *ipdata;
 316         hammer2_pfsmount_t *pmp;
 317         struct vnode *vp;
 318         ccms_state_t ostate;
 319
 320         pmp = ip->pmp;
 321         KKASSERT(pmp != NULL);
 322         *errorp = 0;
 323         ipdata = &ip->chain->data->ipdata;
 324
 325         for (;;) {
 326                 /*
 327                  * Attempt to reuse an existing vnode assignment.  It is
 328                  * possible to race a reclaim so the vget() may fail.  The
 329                  * inode must be unlocked during the vget() to avoid a
 330                  * deadlock against a reclaim.
 331                  */
 332                 vp = ip->vp;
 333                 if (vp) {
 334                         /*
 335                          * Inode must be unlocked during the vget() to avoid
 336                          * possible deadlocks, but leave the ip ref intact.
 337                          *
 338                          * vnode is held to prevent destruction during the
 339                          * vget().  The vget() can still fail if we lost
 340                          * a reclaim race on the vnode.
 341                          */
 342                         vhold(vp);
 343                         ostate = hammer2_inode_lock_temp_release(ip);
 344                         if (vget(vp, LK_EXCLUSIVE)) {
 345                                 vdrop(vp);
 346                                 hammer2_inode_lock_temp_restore(ip, ostate);
 347                                 continue;
 348                         }
 349                         hammer2_inode_lock_temp_restore(ip, ostate);
 350                         vdrop(vp);
 351                         /* vp still locked and ref from vget */
 352                         if (ip->vp != vp) {
 353                                 kprintf("hammer2: igetv race %p/%p\n",
 354                                         ip->vp, vp);
 355                                 vput(vp);
 356                                 continue;
 357                         }
 358                         *errorp = 0;
 359                         break;
 360                 }
 361
 362                 /*
 363                  * No vnode exists, allocate a new vnode.  Beware of
 364                  * allocation races.  This function will return an
 365                  * exclusively locked and referenced vnode.
 366                  */
 367                 *errorp = getnewvnode(VT_HAMMER2, pmp->mp, &vp, 0, 0);
 368                 if (*errorp) {
 369                         kprintf("hammer2: igetv getnewvnode failed %d\n",
 370                                 *errorp);
 371                         vp = NULL;
 372                         break;
 373                 }
 374
 375                 /*
 376                  * Lock the inode and check for an allocation race.
 377                  */
 378                 ostate = hammer2_inode_lock_upgrade(ip);
 379                 if (ip->vp != NULL) {
 380                         vp->v_type = VBAD;
 381                         vx_put(vp);
 382                         hammer2_inode_lock_downgrade(ip, ostate);
 383                         continue;
 384                 }
 385
 386                 switch (ipdata->type) {
 387                 case HAMMER2_OBJTYPE_DIRECTORY:
 388                         vp->v_type = VDIR;
 389                         break;
 390                 case HAMMER2_OBJTYPE_REGFILE:
 391                         vp->v_type = VREG;
 392                         vinitvmio(vp, ipdata->size,
 393                                   HAMMER2_LBUFSIZE,
 394                                   (int)ipdata->size & HAMMER2_LBUFMASK);
 395                         break;
 396                 case HAMMER2_OBJTYPE_SOFTLINK:
 397                         /*
 398                          * XXX for now we are using the generic file_read
 399                          * and file_write code so we need a buffer cache
 400                          * association.
 401                          */
 402                         vp->v_type = VLNK;
 403                         vinitvmio(vp, ipdata->size,
 404                                   HAMMER2_LBUFSIZE,
 405                                   (int)ipdata->size & HAMMER2_LBUFMASK);
 406                         break;
 407                 case HAMMER2_OBJTYPE_CDEV:
 408                         vp->v_type = VCHR;
 409                         /* fall through */
 410                 case HAMMER2_OBJTYPE_BDEV:
 411                         vp->v_ops = &pmp->mp->mnt_vn_spec_ops;
 412                         if (ipdata->type != HAMMER2_OBJTYPE_CDEV)
 413                                 vp->v_type = VBLK;
 414                         addaliasu(vp, ipdata->rmajor, ipdata->rminor);
 415                         break;
 416                 case HAMMER2_OBJTYPE_FIFO:
 417                         vp->v_type = VFIFO;
 418                         vp->v_ops = &pmp->mp->mnt_vn_fifo_ops;
 419                         break;
 420                 default:
 421                         panic("hammer2: unhandled objtype %d", ipdata->type);
 422                         break;
 423                 }
 424
 425                 if (ip == pmp->iroot)
 426                         vsetflags(vp, VROOT);
 427
 428                 vp->v_data = ip;
 429                 ip->vp = vp;
 430                 hammer2_inode_ref(ip);          /* vp association */
 431                 hammer2_inode_lock_downgrade(ip, ostate);
 432                 break;
 433         }
 434
 435         /*
 436          * Return non-NULL vp and *errorp == 0, or NULL vp and *errorp != 0.
 437          */
 438         if (hammer2_debug & 0x0002) {
 439                 kprintf("igetv vp %p refs 0x%08x aux 0x%08x\n",
 440                         vp, vp->v_refcnt, vp->v_auxrefs);
 441         }
 442         return (vp);
 443 }
 444
 445 /*
 446  * The passed-in chain must be locked and the returned inode will also be
 447  * locked.  This routine typically locates or allocates the inode, assigns
 448  * ip->chain (adding a ref to chain if necessary), and returns the inode.
 449  *
 450  * The hammer2_inode structure regulates the interface between the high level
 451  * kernel VNOPS API and the filesystem backend (the chains).
 452  *
 453  * WARNING!  This routine sucks up the chain's lock (makes it part of the
 454  *           inode lock from the point of view of the inode lock API),
 455  *           so callers need to be careful.
 456  *
 457  * WARNING!  The mount code is allowed to pass dip == NULL for iroot and
 458  *           is allowed to pass pmp == NULL and dip == NULL for sroot.
 459  */
 460 hammer2_inode_t *
 461 hammer2_inode_get(hammer2_pfsmount_t *pmp, hammer2_inode_t *dip,
 462                   hammer2_chain_t *chain)
 463 {
 464         hammer2_inode_t *nip;
 465
 466         KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
 467
 468         /*
 469          * Interlocked lookup/ref of the inode.  This code is only needed
 470          * when looking up inodes with nlinks != 0 (TODO: optimize out
 471          * otherwise and test for duplicates).
 472          */
 473 again:
 474         for (;;) {
 475                 nip = hammer2_inode_lookup(pmp, chain->data->ipdata.inum);
 476                 if (nip == NULL)
 477                         break;
 478                 ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 479                 if ((nip->flags & HAMMER2_INODE_ONRBTREE) == 0) { /* race */
 480                         ccms_thread_unlock(&nip->topo_cst);
 481                         hammer2_inode_drop(nip);
 482                         continue;
 483                 }
 484                 if (nip->chain != chain)
 485                         hammer2_inode_repoint(nip, NULL, chain);
 486
 487                 /*
 488                  * Consolidated nip/nip->chain is locked (chain locked
 489                  * by caller).
 490                  */
 491                 return nip;
 492         }
 493
 494         /*
 495          * We couldn't find the inode number, create a new inode.
 496          */
 497         if (pmp) {
 498                 nip = kmalloc(sizeof(*nip), pmp->minode, M_WAITOK | M_ZERO);
 499                 atomic_add_long(&pmp->inmem_inodes, 1);
 500                 hammer2_chain_memory_inc(pmp);
 501                 hammer2_chain_memory_wakeup(pmp);
 502         } else {
 503                 nip = kmalloc(sizeof(*nip), M_HAMMER2, M_WAITOK | M_ZERO);
 504                 nip->flags = HAMMER2_INODE_SROOT;
 505         }
 506         nip->inum = chain->data->ipdata.inum;
 507         nip->size = chain->data->ipdata.size;
 508         nip->mtime = chain->data->ipdata.mtime;
 509         hammer2_inode_repoint(nip, NULL, chain);
 510         nip->pip = dip;                         /* can be NULL */
 511         if (dip)
 512                 hammer2_inode_ref(dip); /* ref dip for nip->pip */
 513
 514         nip->pmp = pmp;
 515
 516         /*
 517          * ref and lock on nip gives it state compatible to after a
 518          * hammer2_inode_lock_ex() call.
 519          */
 520         nip->refs = 1;
 521         ccms_cst_init(&nip->topo_cst, &nip->chain);
 522         ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 523         /* combination of thread lock and chain lock == inode lock */
 524
 525         /*
 526          * Attempt to add the inode.  If it fails we raced another inode
 527          * get.  Undo all the work and try again.
 528          */
 529         if (pmp) {
 530                 spin_lock(&pmp->inum_spin);
 531                 if (RB_INSERT(hammer2_inode_tree, &pmp->inum_tree, nip)) {
 532                         spin_unlock(&pmp->inum_spin);
 533                         ccms_thread_unlock(&nip->topo_cst);
 534                         hammer2_inode_drop(nip);
 535                         goto again;
 536                 }
 537                 atomic_set_int(&nip->flags, HAMMER2_INODE_ONRBTREE);
 538                 spin_unlock(&pmp->inum_spin);
 539         }
 540
 541         return (nip);
 542 }
 543
 544 /*
 545  * Create a new inode in the specified directory using the vattr to
 546  * figure out the type of inode.
 547  *
 548  * If no error occurs the new inode with its chain locked is returned in
 549  * *nipp, otherwise an error is returned and *nipp is set to NULL.
 550  *
 551  * If vap and/or cred are NULL the related fields are not set and the
 552  * inode type defaults to a directory.  This is used when creating PFSs
 553  * under the super-root, so the inode number is set to 1 in this case.
 554  *
 555  * dip is not locked on entry.
 556  */
 557 hammer2_inode_t *
 558 hammer2_inode_create(hammer2_trans_t *trans, hammer2_inode_t *dip,
 559                      struct vattr *vap, struct ucred *cred,
 560                      const uint8_t *name, size_t name_len,
 561                      hammer2_chain_t **chainp, int *errorp)
 562 {
 563         hammer2_inode_data_t *dipdata;
 564         hammer2_inode_data_t *nipdata;
 565         hammer2_chain_t *chain;
 566         hammer2_chain_t *parent;
 567         hammer2_inode_t *nip;
 568         hammer2_key_t key_dummy;
 569         hammer2_key_t lhc;
 570         int error;
 571         uid_t xuid;
 572         uuid_t dip_uid;
 573         uuid_t dip_gid;
 574         uint32_t dip_mode;
 575         uint8_t dip_algo;
 576         int cache_index = -1;
 577
 578         lhc = hammer2_dirhash(name, name_len);
 579         *errorp = 0;
 580
 581         /*
 582          * Locate the inode or indirect block to create the new
 583          * entry in.  At the same time check for key collisions
 584          * and iterate until we don't get one.
 585          *
 586          * NOTE: hidden inodes do not have iterators.
 587          */
 588 retry:
 589         parent = hammer2_inode_lock_ex(dip);
 590         dipdata = &dip->chain->data->ipdata;
 591         dip_uid = dipdata->uid;
 592         dip_gid = dipdata->gid;
 593         dip_mode = dipdata->mode;
 594         dip_algo = dipdata->comp_algo;
 595
 596         error = 0;
 597         while (error == 0) {
 598                 chain = hammer2_chain_lookup(&parent, &key_dummy,
 599                                              lhc, lhc, &cache_index, 0);
 600                 if (chain == NULL)
 601                         break;
 602                 if ((lhc & HAMMER2_DIRHASH_VISIBLE) == 0)
 603                         error = ENOSPC;
 604                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 605                         error = ENOSPC;
 606                 hammer2_chain_unlock(chain);
 607                 chain = NULL;
 608                 ++lhc;
 609         }
 610
 611         if (error == 0) {
 612                 error = hammer2_chain_create(trans, &parent, &chain,
 613                                              lhc, 0,
 614                                              HAMMER2_BREF_TYPE_INODE,
 615                                              HAMMER2_INODE_BYTES);
 616         }
 617
 618         /*
 619          * Cleanup and handle retries.
 620          */
 621         if (error == EAGAIN) {
 622                 hammer2_chain_ref(parent);
 623                 hammer2_inode_unlock_ex(dip, parent);
 624                 hammer2_chain_wait(parent);
 625                 hammer2_chain_drop(parent);
 626                 goto retry;
 627         }
 628         hammer2_inode_unlock_ex(dip, parent);
 629
 630         if (error) {
 631                 KKASSERT(chain == NULL);
 632                 *errorp = error;
 633                 return (NULL);
 634         }
 635
 636         /*
 637          * Set up the new inode.
 638          *
 639          * NOTE: *_get() integrates chain's lock into the inode lock.
 640          *
 641          * NOTE: Only one new inode can currently be created per
 642          *       transaction.  If the need arises we can adjust
 643          *       hammer2_trans_init() to allow more.
 644          *
 645          * NOTE: nipdata will have chain's blockset data.
 646          */
 647         chain->data->ipdata.inum = trans->inode_tid;
 648         nip = hammer2_inode_get(dip->pmp, dip, chain);
 649         nipdata = &chain->data->ipdata;
 650
 651         if (vap) {
 652                 KKASSERT(trans->inodes_created == 0);
 653                 nipdata->type = hammer2_get_obj_type(vap->va_type);
 654                 nipdata->inum = trans->inode_tid;
 655                 ++trans->inodes_created;
 656
 657                 switch (nipdata->type) {
 658                 case HAMMER2_OBJTYPE_CDEV:
 659                 case HAMMER2_OBJTYPE_BDEV:
 660                         nipdata->rmajor = vap->va_rmajor;
 661                         nipdata->rminor = vap->va_rminor;
 662                         break;
 663                 default:
 664                         break;
 665                 }
 666         } else {
 667                 nipdata->type = HAMMER2_OBJTYPE_DIRECTORY;
 668                 nipdata->inum = 1;
 669         }
 670
 671         /* Inherit parent's inode compression mode. */
 672         nip->comp_heuristic = 0;
 673         nipdata->comp_algo = dip_algo;
 674         nipdata->version = HAMMER2_INODE_VERSION_ONE;
 675         hammer2_update_time(&nipdata->ctime);
 676         nipdata->mtime = nipdata->ctime;
 677         if (vap)
 678                 nipdata->mode = vap->va_mode;
 679         nipdata->nlinks = 1;
 680         if (vap) {
 681                 if (dip && dip->pmp) {
 682                         xuid = hammer2_to_unix_xid(&dip_uid);
 683                         xuid = vop_helper_create_uid(dip->pmp->mp,
 684                                                      dip_mode,
 685                                                      xuid,
 686                                                      cred,
 687                                                      &vap->va_mode);
 688                 } else {
 689                         /* super-root has no dip and/or pmp */
 690                         xuid = 0;
 691                 }
 692                 if (vap->va_vaflags & VA_UID_UUID_VALID)
 693                         nipdata->uid = vap->va_uid_uuid;
 694                 else if (vap->va_uid != (uid_t)VNOVAL)
 695                         hammer2_guid_to_uuid(&nipdata->uid, vap->va_uid);
 696                 else
 697                         hammer2_guid_to_uuid(&nipdata->uid, xuid);
 698
 699                 if (vap->va_vaflags & VA_GID_UUID_VALID)
 700                         nipdata->gid = vap->va_gid_uuid;
 701                 else if (vap->va_gid != (gid_t)VNOVAL)
 702                         hammer2_guid_to_uuid(&nipdata->gid, vap->va_gid);
 703                 else if (dip)
 704                         nipdata->gid = dip_gid;
 705         }
 706
 707         /*
 708          * Regular files and softlinks allow a small amount of data to be
 709          * directly embedded in the inode.  This flag will be cleared if
 710          * the size is extended past the embedded limit.
 711          */
 712         if (nipdata->type == HAMMER2_OBJTYPE_REGFILE ||
 713             nipdata->type == HAMMER2_OBJTYPE_SOFTLINK) {
 714                 nipdata->op_flags |= HAMMER2_OPFLAG_DIRECTDATA;
 715         }
 716
 717         KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 718         bcopy(name, nipdata->filename, name_len);
 719         nipdata->name_key = lhc;
 720         nipdata->name_len = name_len;
 721         *chainp = chain;
 722
 723         return (nip);
 724 }
 725
 726 /*
 727  * chain may have been moved around by the create.
 728  */
 729 void
 730 hammer2_chain_refactor(hammer2_chain_t **chainp)
 731 {
 732         hammer2_chain_t *chain = *chainp;
 733         hammer2_chain_core_t *core;
 734
 735         core = chain->core;
 736         while (chain->flags & HAMMER2_CHAIN_DUPLICATED) {
 737                 spin_lock(&core->cst.spin);
 738                 chain = TAILQ_NEXT(chain, core_entry);
 739                 while (chain->flags & HAMMER2_CHAIN_DUPLICATED)
 740                         chain = TAILQ_NEXT(chain, core_entry);
 741                 hammer2_chain_ref(chain);
 742                 spin_unlock(&core->cst.spin);
 743                 KKASSERT(chain->core == core);
 744
 745                 hammer2_chain_unlock(*chainp);
 746                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 747                                           HAMMER2_RESOLVE_NOREF); /* eat ref */
 748                 *chainp = chain;
 749         }
 750 }
 751
 752 /*
 753  * Shift *chainp up to the specified directory, change the filename
 754  * to "0xINODENUMBER", and adjust the key.  The chain becomes the
 755  * invisible hardlink target.
 756  *
 757  * The original *chainp has already been marked deleted.
 758  */
 759 static
 760 void
 761 hammer2_hardlink_shiftup(hammer2_trans_t *trans, hammer2_chain_t **chainp,
 762                         hammer2_inode_t *dip, int nlinks, int *errorp)
 763 {
 764         hammer2_inode_data_t *nipdata;
 765         hammer2_chain_t *parent;
 766         hammer2_chain_t *chain;
 767         hammer2_chain_t *xchain;
 768         hammer2_key_t key_dummy;
 769         hammer2_key_t lhc;
 770         hammer2_blockref_t bref;
 771         int cache_index = -1;
 772
 773         chain = *chainp;
 774         lhc = chain->data->ipdata.inum;
 775         KKASSERT((lhc & HAMMER2_DIRHASH_VISIBLE) == 0);
 776
 777         /*
 778          * Locate the inode or indirect block to create the new
 779          * entry in.  lhc represents the inode number so there is
 780          * no collision iteration.
 781          *
 782          * There should be no key collisions with invisible inode keys.
 783          *
 784          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 785          *          dip->chain cache.
 786          */
 787 retry:
 788         *errorp = 0;
 789         parent = hammer2_inode_lock_ex(dip);
 790         /*parent = hammer2_chain_lookup_init(dip->chain, 0);*/
 791         xchain = hammer2_chain_lookup(&parent, &key_dummy,
 792                                       lhc, lhc, &cache_index, 0);
 793         if (xchain) {
 794                 kprintf("X3 chain %p parent %p dip %p dip->chain %p\n",
 795                         xchain, parent, dip, dip->chain);
 796                 hammer2_chain_unlock(xchain);
 797                 xchain = NULL;
 798                 *errorp = ENOSPC;
 799 #if 0
 800                 Debugger("X3");
 801 #endif
 802         }
 803
 804         /*
 805          * Create entry in common parent directory using the seek position
 806          * calculated above.
 807          *
 808          * We must refactor chain because it might have been shifted into
 809          * an indirect chain by the create.
 810          */
 811         if (*errorp == 0) {
 812                 KKASSERT(xchain == NULL);
 813 #if 0
 814                 *errorp = hammer2_chain_create(trans, &parent, &xchain,
 815                                                lhc, 0,
 816                                                HAMMER2_BREF_TYPE_INODE,/* n/a */
 817                                                HAMMER2_INODE_BYTES);   /* n/a */
 818 #endif
 819                 /*XXX this somehow isn't working on chain XXX*/
 820                 /*KKASSERT(xxx)*/
 821         }
 822
 823         /*
 824          * Cleanup and handle retries.
 825          */
 826         if (*errorp == EAGAIN) {
 827                 hammer2_chain_ref(parent);
 828                 /* hammer2_chain_lookup_done(parent); */
 829                 hammer2_inode_unlock_ex(dip, parent);
 830                 hammer2_chain_wait(parent);
 831                 hammer2_chain_drop(parent);
 832                 goto retry;
 833         }
 834
 835         /*
 836          * Handle the error case
 837          */
 838         if (*errorp) {
 839                 panic("error2");
 840                 KKASSERT(xchain == NULL);
 841                 hammer2_inode_unlock_ex(dip, parent);
 842                 /*hammer2_chain_lookup_done(parent);*/
 843                 return;
 844         }
 845
 846         /*
 847          * Use xchain as a placeholder for (lhc).  Duplicate chain to the
 848          * same target bref as xchain and then delete xchain.  The duplication
 849          * occurs after xchain in flush order even though xchain is deleted
 850          * after the duplication. XXX
 851          *
 852          * WARNING! Duplications (to a different parent) can cause indirect
 853          *          blocks to be inserted, refactor xchain.
 854          */
 855         bref = chain->bref;
 856         bref.key = lhc;                 /* invisible dir entry key */
 857         bref.keybits = 0;
 858 #if 0
 859         hammer2_chain_delete(trans, xchain, 0);
 860 #endif
 861         hammer2_chain_duplicate(trans, &parent, &chain, &bref, 0, 2);
 862 #if 0
 863         hammer2_chain_refactor(&xchain);
 864         /*hammer2_chain_delete(trans, xchain, 0);*/
 865 #endif
 866
 867         hammer2_inode_unlock_ex(dip, parent);
 868         /*hammer2_chain_lookup_done(parent);*/
 869 #if 0
 870         hammer2_chain_unlock(xchain);   /* no longer needed */
 871 #endif
 872
 873         /*
 874          * chain is now 'live' again.. adjust the filename.
 875          *
 876          * Directory entries are inodes but this is a hidden hardlink
 877          * target.  The name isn't used but to ease debugging give it
 878          * a name after its inode number.
 879          */
 880         hammer2_chain_modify(trans, &chain, 0);
 881         nipdata = &chain->data->ipdata;
 882         ksnprintf(nipdata->filename, sizeof(nipdata->filename),
 883                   "0x%016jx", (intmax_t)nipdata->inum);
 884         nipdata->name_len = strlen(nipdata->filename);
 885         nipdata->name_key = lhc;
 886         nipdata->nlinks += nlinks;
 887
 888         *chainp = chain;
 889 }
 890
 891 /*
 892  * Connect the target inode represented by (*chainp) to the media topology
 893  * at (dip, name, len).
 894  *
 895  * If hlink is TRUE this function creates an OBJTYPE_HARDLINK directory
 896  * entry instead of connecting (*chainp).
 897  *
 898  * If hlink is FALSE this function uses chain_duplicate() to make a copy
 899  * if (*chainp) in the directory entry.  (*chainp) is likely to be deleted
 900  * by the caller in this case (e.g. rename).
 901  */
 902 int
 903 hammer2_inode_connect(hammer2_trans_t *trans, int hlink,
 904                       hammer2_inode_t *dip, hammer2_chain_t **chainp,
 905                       const uint8_t *name, size_t name_len)
 906 {
 907         hammer2_inode_data_t *ipdata;
 908         hammer2_chain_t *nchain;
 909         hammer2_chain_t *parent;
 910         hammer2_chain_t *ochain;
 911         hammer2_key_t key_dummy;
 912         hammer2_key_t lhc;
 913         int cache_index = -1;
 914         int error;
 915
 916         ochain = *chainp;
 917
 918         /*
 919          * Since ochain is either disconnected from the topology or represents
 920          * a hardlink terminus which is always a parent of or equal to dip,
 921          * we should be able to safely lock dip->chain for our setup.
 922          *
 923          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 924          *          dip->chain cache.
 925          */
 926         parent = hammer2_inode_lock_ex(dip);
 927         /*parent = hammer2_chain_lookup_init(dip->chain, 0);*/
 928
 929         lhc = hammer2_dirhash(name, name_len);
 930
 931         /*
 932          * Locate the inode or indirect block to create the new
 933          * entry in.  At the same time check for key collisions
 934          * and iterate until we don't get one.
 935          */
 936         error = 0;
 937         while (error == 0) {
 938                 nchain = hammer2_chain_lookup(&parent, &key_dummy,
 939                                               lhc, lhc, &cache_index, 0);
 940                 if (nchain == NULL)
 941                         break;
 942                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 943                         error = ENOSPC;
 944                 hammer2_chain_unlock(nchain);
 945                 nchain = NULL;
 946                 ++lhc;
 947         }
 948
 949         if (error == 0) {
 950                 if (hlink) {
 951                         /*
 952                          * Hardlink pointer needed, create totally fresh
 953                          * directory entry.
 954                          *
 955                          * We must refactor ochain because it might have
 956                          * been shifted into an indirect chain by the
 957                          * create.
 958                          */
 959                         KKASSERT(nchain == NULL);
 960                         error = hammer2_chain_create(trans, &parent, &nchain,
 961                                                      lhc, 0,
 962                                                      HAMMER2_BREF_TYPE_INODE,
 963                                                      HAMMER2_INODE_BYTES);
 964                         hammer2_chain_refactor(&ochain);
 965                 } else {
 966                         /*
 967                          * Reconnect the original chain and rename.  Use
 968                          * chain_duplicate().  The caller will likely delete
 969                          * or has already deleted the original chain in
 970                          * this case.
 971                          *
 972                          * NOTE: chain_duplicate() generates a new chain
 973                          *       with CHAIN_DELETED cleared (ochain typically
 974                          *       has it set from the file unlink).
 975                          *
 976                          * WARNING! Can cause held-over chains to require a
 977                          *          refactor.  Fortunately we have none (our
 978                          *          locked chains are passed into and
 979                          *          modified by the call).
 980                          */
 981                         nchain = ochain;
 982                         ochain = NULL;
 983                         hammer2_chain_duplicate(trans, NULL, &nchain, NULL,
 984                                                 0, 3);
 985                         error = hammer2_chain_create(trans, &parent, &nchain,
 986                                                      lhc, 0,
 987                                                      HAMMER2_BREF_TYPE_INODE,
 988                                                      HAMMER2_INODE_BYTES);
 989                 }
 990         }
 991
 992         /*
 993          * Unlock stuff.
 994          */
 995         KKASSERT(error != EAGAIN);
 996         hammer2_inode_unlock_ex(dip, parent);
 997         /*hammer2_chain_lookup_done(parent);*/
 998         parent = NULL;
 999
1000         /*
1001          * nchain should be NULL on error, leave ochain (== *chainp) alone.
1002          */
1003         if (error) {
1004                 KKASSERT(nchain == NULL);
1005                 return (error);
1006         }
1007
1008         /*
1009          * Directory entries are inodes so if the name has changed we have
1010          * to update the inode.
1011          *
1012          * When creating an OBJTYPE_HARDLINK entry remember to unlock the
1013          * chain, the caller will access the hardlink via the actual hardlink
1014          * target file and not the hardlink pointer entry, so we must still
1015          * return ochain.
1016          */
1017         if (hlink && hammer2_hardlink_enable >= 0) {
1018                 /*
1019                  * Create the HARDLINK pointer.  oip represents the hardlink
1020                  * target in this situation.
1021                  *
1022                  * We will return ochain (the hardlink target).
1023                  */
1024                 hammer2_chain_modify(trans, &nchain, 0);
1025                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1026                 ipdata = &nchain->data->ipdata;
1027                 bcopy(name, ipdata->filename, name_len);
1028                 ipdata->name_key = lhc;
1029                 ipdata->name_len = name_len;
1030                 ipdata->target_type = ochain->data->ipdata.type;
1031                 ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1032                 ipdata->inum = ochain->data->ipdata.inum;
1033                 ipdata->nlinks = 1;
1034                 hammer2_chain_unlock(nchain);
1035                 nchain = ochain;
1036                 ochain = NULL;
1037         } else if (hlink && hammer2_hardlink_enable < 0) {
1038                 /*
1039                  * Create a snapshot (hardlink fake mode for debugging).
1040                  * (ochain already flushed above so we can just copy the
1041                  * bref XXX).
1042                  *
1043                  * Since this is a snapshot we return nchain in the fake
1044                  * hardlink case.
1045                  */
1046                 hammer2_chain_modify(trans, &nchain, 0);
1047                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1048                 ipdata = &nchain->data->ipdata;
1049                 *ipdata = ochain->data->ipdata;
1050                 bcopy(name, ipdata->filename, name_len);
1051                 ipdata->name_key = lhc;
1052                 ipdata->name_len = name_len;
1053                 atomic_clear_int(&nchain->core->flags,
1054                                  HAMMER2_CORE_COUNTEDBREFS);
1055                 kprintf("created fake hardlink %*.*s\n",
1056                         (int)name_len, (int)name_len, name);
1057         } else {
1058                 /*
1059                  * nchain is a duplicate of ochain at the new location.
1060                  * We must fixup the name stored in oip.  The bref key
1061                  * has already been set up.
1062                  */
1063                 hammer2_chain_modify(trans, &nchain, 0);
1064                 ipdata = &nchain->data->ipdata;
1065
1066                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1067                 bcopy(name, ipdata->filename, name_len);
1068                 ipdata->name_key = lhc;
1069                 ipdata->name_len = name_len;
1070                 ipdata->nlinks = 1;
1071         }
1072
1073         /*
1074          * We are replacing ochain with nchain, unlock ochain.  In the
1075          * case where ochain is left unchanged the code above sets
1076          * nchain to ochain and ochain to NULL, resulting in a NOP here.
1077          */
1078         if (ochain)
1079                 hammer2_chain_unlock(ochain);
1080         *chainp = nchain;
1081
1082         return (0);
1083 }
1084
1085 /*
1086  * Repoint ip->chain to nchain.  Caller must hold the inode exclusively
1087  * locked.
1088  *
1089  * ip->chain is set to nchain.  The prior chain in ip->chain is dropped
1090  * and nchain is ref'd.
1091  */
1092 void
1093 hammer2_inode_repoint(hammer2_inode_t *ip, hammer2_inode_t *pip,
1094                       hammer2_chain_t *nchain)
1095 {
1096         hammer2_chain_t *ochain;
1097         hammer2_inode_t *opip;
1098
1099         /*
1100          * Repoint ip->chain if requested.
1101          */
1102         ochain = ip->chain;
1103         ip->chain = nchain;
1104         if (nchain)
1105                 hammer2_chain_ref(nchain);
1106         if (ochain)
1107                 hammer2_chain_drop(ochain);
1108
1109         /*
1110          * Repoint ip->pip if requested (non-NULL pip).
1111          */
1112         if (pip && ip->pip != pip) {
1113                 opip = ip->pip;
1114                 hammer2_inode_ref(pip);
1115                 ip->pip = pip;
1116                 if (opip)
1117                         hammer2_inode_drop(opip);
1118         }
1119 }
1120
1121 /*
1122  * Unlink the file from the specified directory inode.  The directory inode
1123  * does not need to be locked.
1124  *
1125  * isdir determines whether a directory/non-directory check should be made.
1126  * No check is made if isdir is set to -1.
1127  *
1128  * NOTE!  The underlying file can still be active with open descriptors
1129  *        or if the chain is being manually held (e.g. for rename).
1130  *
1131  *        The caller is responsible for fixing up ip->chain if e.g. a
1132  *        rename occurs (see chain_duplicate()).
1133  */
1134 int
1135 hammer2_unlink_file(hammer2_trans_t *trans, hammer2_inode_t *dip,
1136                     const uint8_t *name, size_t name_len,
1137                     int isdir, int *hlinkp)
1138 {
1139         hammer2_inode_data_t *ipdata;
1140         hammer2_chain_t *parent;
1141         hammer2_chain_t *ochain;
1142         hammer2_chain_t *chain;
1143         hammer2_chain_t *dparent;
1144         hammer2_chain_t *dchain;
1145         hammer2_key_t key_dummy;
1146         hammer2_key_t key_next;
1147         hammer2_key_t lhc;
1148         int error;
1149         int cache_index = -1;
1150         uint8_t type;
1151
1152         error = 0;
1153         ochain = NULL;
1154         lhc = hammer2_dirhash(name, name_len);
1155
1156         /*
1157          * Search for the filename in the directory
1158          */
1159         if (hlinkp)
1160                 *hlinkp = 0;
1161         parent = hammer2_inode_lock_ex(dip);
1162         chain = hammer2_chain_lookup(&parent, &key_next,
1163                                      lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1164                                      &cache_index, 0);
1165         while (chain) {
1166                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1167                     name_len == chain->data->ipdata.name_len &&
1168                     bcmp(name, chain->data->ipdata.filename, name_len) == 0) {
1169                         break;
1170                 }
1171                 chain = hammer2_chain_next(&parent, chain, &key_next,
1172                                            key_next,
1173                                            lhc + HAMMER2_DIRHASH_LOMASK,
1174                                            &cache_index, 0);
1175         }
1176         hammer2_inode_unlock_ex(dip, NULL);     /* retain parent */
1177
1178         /*
1179          * Not found or wrong type (isdir < 0 disables the type check).
1180          * If a hardlink pointer, type checks use the hardlink target.
1181          */
1182         if (chain == NULL) {
1183                 error = ENOENT;
1184                 goto done;
1185         }
1186         if ((type = chain->data->ipdata.type) == HAMMER2_OBJTYPE_HARDLINK) {
1187                 if (hlinkp)
1188                         *hlinkp = 1;
1189                 type = chain->data->ipdata.target_type;
1190         }
1191
1192         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 0) {
1193                 error = ENOTDIR;
1194                 goto done;
1195         }
1196         if (type != HAMMER2_OBJTYPE_DIRECTORY && isdir >= 1) {
1197                 error = EISDIR;
1198                 goto done;
1199         }
1200
1201         /*
1202          * Hardlink must be resolved.  We can't hold parent locked while we
1203          * do this or we could deadlock.
1204          *
1205          * On success chain will be adjusted to point at the hardlink target
1206          * and ochain will point to the hardlink pointer in the original
1207          * directory.  Otherwise chain remains pointing to the original.
1208          */
1209         if (chain->data->ipdata.type == HAMMER2_OBJTYPE_HARDLINK) {
1210                 hammer2_chain_unlock(parent);
1211                 parent = NULL;
1212                 error = hammer2_hardlink_find(dip, &chain, &ochain);
1213         }
1214
1215         /*
1216          * If this is a directory the directory must be empty.  However, if
1217          * isdir < 0 we are doing a rename and the directory does not have
1218          * to be empty, and if isdir > 1 we are deleting a PFS/snapshot
1219          * and the directory does not have to be empty.
1220          *
1221          * NOTE: We check the full key range here which covers both visible
1222          *       and invisible entries.  Theoretically there should be no
1223          *       invisible (hardlink target) entries if there are no visible
1224          *       entries.
1225          */
1226         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 1) {
1227                 dparent = hammer2_chain_lookup_init(chain, 0);
1228                 dchain = hammer2_chain_lookup(&dparent, &key_dummy,
1229                                               0, (hammer2_key_t)-1,
1230                                               &cache_index,
1231                                               HAMMER2_LOOKUP_NODATA);
1232                 if (dchain) {
1233                         hammer2_chain_unlock(dchain);
1234                         hammer2_chain_lookup_done(dparent);
1235                         error = ENOTEMPTY;
1236                         goto done;
1237                 }
1238                 hammer2_chain_lookup_done(dparent);
1239                 dparent = NULL;
1240                 /* dchain NULL */
1241         }
1242
1243         /*
1244          * Ok, we can now unlink the chain.  We always decrement nlinks even
1245          * if the entry can be deleted in case someone has the file open and
1246          * does an fstat().
1247          *
1248          * The chain itself will no longer be in the on-media topology but
1249          * can still be flushed to the media (e.g. if an open descriptor
1250          * remains).  When the last vnode/ip ref goes away the chain will
1251          * be marked unmodified, avoiding any further (now unnecesary) I/O.
1252          *
1253          * A non-NULL ochain indicates a hardlink.
1254          */
1255         if (ochain) {
1256                 /*
1257                  * Delete the original hardlink pointer.
1258                  *
1259                  * NOTE: parent from above is NULL when ochain != NULL
1260                  *       so we can reuse it.
1261                  */
1262                 hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
1263                 hammer2_chain_delete(trans, ochain, 0);
1264                 hammer2_chain_unlock(ochain);
1265
1266                 /*
1267                  * Then decrement nlinks on hardlink target, deleting
1268                  * the target when nlinks drops to 0.
1269                  */
1270                 hammer2_chain_modify(trans, &chain, 0);
1271                 --chain->data->ipdata.nlinks;
1272                 if (chain->data->ipdata.nlinks == 0)
1273                         hammer2_chain_delete(trans, chain, 0);
1274         } else {
1275                 /*
1276                  * Otherwise this was not a hardlink and we can just
1277                  * remove the entry and decrement nlinks.
1278                  *
1279                  * NOTE: *_get() integrates chain's lock into the inode lock.
1280                  */
1281                 hammer2_chain_modify(trans, &chain, 0);
1282                 ipdata = &chain->data->ipdata;
1283                 --ipdata->nlinks;
1284                 hammer2_chain_delete(trans, chain, 0);
1285         }
1286
1287         error = 0;
1288 done:
1289         if (chain)
1290                 hammer2_chain_unlock(chain);
1291         if (parent)
1292                 hammer2_chain_lookup_done(parent);
1293         if (ochain)
1294                 hammer2_chain_drop(ochain);
1295
1296         return error;
1297 }
1298
1299 /*
1300  * Given an exclusively locked inode and chain we consolidate its chain
1301  * for hardlink creation, adding (nlinks) to the file's link count and
1302  * potentially relocating the inode to a directory common to ip->pip and tdip.
1303  *
1304  * Replaces (*chainp) if consolidation occurred, unlocking the old chain
1305  * and returning a new locked chain.
1306  *
1307  * NOTE!  This function will also replace ip->chain.
1308  */
1309 int
1310 hammer2_hardlink_consolidate(hammer2_trans_t *trans, hammer2_inode_t *ip,
1311                              hammer2_chain_t **chainp,
1312                              hammer2_inode_t *tdip, int nlinks)
1313 {
1314         hammer2_inode_data_t *ipdata;
1315         hammer2_inode_t *fdip;
1316         hammer2_inode_t *cdip;
1317         hammer2_chain_t *chain;
1318         hammer2_chain_t *nchain;
1319         int error;
1320
1321         chain = *chainp;
1322         if (nlinks == 0 &&                      /* no hardlink needed */
1323             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE)) {
1324                 return (0);
1325         }
1326         if (hammer2_hardlink_enable < 0) {      /* fake hardlinks */
1327                 return (0);
1328         }
1329
1330         if (hammer2_hardlink_enable == 0) {     /* disallow hardlinks */
1331                 hammer2_chain_unlock(chain);
1332                 *chainp = NULL;
1333                 return (ENOTSUP);
1334         }
1335
1336         /*
1337          * cdip will be returned with a ref, but not locked.
1338          */
1339         fdip = ip->pip;
1340         cdip = hammer2_inode_common_parent(fdip, tdip);
1341
1342         /*
1343          * If no change in the hardlink's target directory is required and
1344          * this is already a hardlink target, all we need to do is adjust
1345          * the link count.
1346          *
1347          * XXX The common parent is a big wiggly due to duplication from
1348          *     renames.  Compare the core (RBTREE) pointer instead of the
1349          *     ip's.
1350          */
1351         if (cdip == fdip &&
1352             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) == 0) {
1353                 if (nlinks) {
1354                         hammer2_chain_modify(trans, &chain, 0);
1355                         chain->data->ipdata.nlinks += nlinks;
1356                 }
1357                 error = 0;
1358                 goto done;
1359         }
1360
1361
1362         /*
1363          * chain is the real inode.  If it's visible we have to convert it
1364          * to a hardlink pointer.  If it is not visible then it is already
1365          * a hardlink target and only needs to be deleted.
1366          */
1367         KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0);
1368         KKASSERT(chain->data->ipdata.type != HAMMER2_OBJTYPE_HARDLINK);
1369         if (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) {
1370                 /*
1371                  * We are going to duplicate chain later, causing its
1372                  * media block to be shifted to the duplicate.  Even though
1373                  * we are delete-duplicating nchain here it might decide not
1374                  * to reallocate the block.  Set FORCECOW to force it to.
1375                  */
1376                 nchain = chain;
1377                 hammer2_chain_lock(nchain, HAMMER2_RESOLVE_ALWAYS);
1378                 atomic_set_int(&nchain->flags, HAMMER2_CHAIN_FORCECOW);
1379                 hammer2_chain_delete_duplicate(trans, &nchain,
1380                                                HAMMER2_DELDUP_RECORE);
1381                 KKASSERT((chain->flags & HAMMER2_CHAIN_DUPLICATED) == 0);
1382
1383                 ipdata = &nchain->data->ipdata;
1384                 ipdata->target_type = ipdata->type;
1385                 ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1386                 ipdata->uflags = 0;
1387                 ipdata->rmajor = 0;
1388                 ipdata->rminor = 0;
1389                 ipdata->ctime = 0;
1390                 ipdata->mtime = 0;
1391                 ipdata->atime = 0;
1392                 ipdata->btime = 0;
1393                 bzero(&ipdata->uid, sizeof(ipdata->uid));
1394                 bzero(&ipdata->gid, sizeof(ipdata->gid));
1395                 ipdata->op_flags = HAMMER2_OPFLAG_DIRECTDATA;
1396                 ipdata->cap_flags = 0;
1397                 ipdata->mode = 0;
1398                 ipdata->size = 0;
1399                 ipdata->nlinks = 1;
1400                 ipdata->iparent = 0;    /* XXX */
1401                 ipdata->pfs_type = 0;
1402                 ipdata->pfs_inum = 0;
1403                 bzero(&ipdata->pfs_clid, sizeof(ipdata->pfs_clid));
1404                 bzero(&ipdata->pfs_fsid, sizeof(ipdata->pfs_fsid));
1405                 ipdata->data_quota = 0;
1406                 ipdata->data_count = 0;
1407                 ipdata->inode_quota = 0;
1408                 ipdata->inode_count = 0;
1409                 ipdata->attr_tid = 0;
1410                 ipdata->dirent_tid = 0;
1411                 bzero(&ipdata->u, sizeof(ipdata->u));
1412                 /* XXX transaction ids */
1413         } else {
1414                 hammer2_chain_delete(trans, chain, 0);
1415                 nchain = NULL;
1416         }
1417
1418         /*
1419          * chain represents the hardlink target and is now flagged deleted.
1420          * duplicate it to the parent directory and adjust nlinks.
1421          *
1422          * WARNING! The shiftup() call can cause nchain to be moved into
1423          *          an indirect block, and our nchain will wind up pointing
1424          *          to the older/original version.
1425          */
1426         KKASSERT(chain->flags & HAMMER2_CHAIN_DELETED);
1427         hammer2_hardlink_shiftup(trans, &chain, cdip, nlinks, &error);
1428
1429         if (error == 0)
1430                 hammer2_inode_repoint(ip, cdip, chain);
1431
1432         /*
1433          * Unlock the original chain last as the lock blocked races against
1434          * the creation of the new hardlink target.
1435          */
1436         if (nchain)
1437                 hammer2_chain_unlock(nchain);
1438
1439 done:
1440         /*
1441          * Cleanup, chain/nchain already dealt with.
1442          */
1443         *chainp = chain;
1444         hammer2_inode_drop(cdip);
1445
1446         return (error);
1447 }
1448
1449 /*
1450  * If (*ochainp) is non-NULL it points to the forward OBJTYPE_HARDLINK
1451  * inode while (*chainp) points to the resolved (hidden hardlink
1452  * target) inode.  In this situation when nlinks is 1 we wish to
1453  * deconsolidate the hardlink, moving it back to the directory that now
1454  * represents the only remaining link.
1455  */
1456 int
1457 hammer2_hardlink_deconsolidate(hammer2_trans_t *trans,
1458                                hammer2_inode_t *dip,
1459                                hammer2_chain_t **chainp,
1460                                hammer2_chain_t **ochainp)
1461 {
1462         if (*ochainp == NULL)
1463                 return (0);
1464         /* XXX */
1465         return (0);
1466 }
1467
1468 /*
1469  * The caller presents a locked *chainp pointing to a HAMMER2_BREF_TYPE_INODE
1470  * with an obj_type of HAMMER2_OBJTYPE_HARDLINK.  This routine will gobble
1471  * the *chainp and return a new locked *chainp representing the file target
1472  * (the original *chainp will be unlocked).
1473  *
1474  * When a match is found the chain representing the original HARDLINK
1475  * will be returned in *ochainp with a ref, but not locked.
1476  *
1477  * When no match is found *chainp is set to NULL and EIO is returned.
1478  * (*ochainp) will still be set to the original chain with a ref but not
1479  * locked.
1480  */
1481 int
1482 hammer2_hardlink_find(hammer2_inode_t *dip, hammer2_chain_t **chainp,
1483                       hammer2_chain_t **ochainp)
1484 {
1485         hammer2_chain_t *chain = *chainp;
1486         hammer2_chain_t *parent;
1487         hammer2_inode_t *ip;
1488         hammer2_inode_t *pip;
1489         hammer2_key_t key_dummy;
1490         hammer2_key_t lhc;
1491         int cache_index = -1;
1492
1493         pip = dip;
1494         hammer2_inode_ref(pip);         /* for loop */
1495         hammer2_chain_ref(chain);       /* for (*ochainp) */
1496         *ochainp = chain;
1497
1498         /*
1499          * Locate the hardlink.  pip is referenced and not locked,
1500          * ipp.
1501          *
1502          * chain is reused.
1503          */
1504         lhc = chain->data->ipdata.inum;
1505         hammer2_chain_unlock(chain);
1506         chain = NULL;
1507
1508         while ((ip = pip) != NULL) {
1509                 parent = hammer2_inode_lock_ex(ip);
1510                 hammer2_inode_drop(ip);                 /* loop */
1511                 KKASSERT(parent->bref.type == HAMMER2_BREF_TYPE_INODE);
1512                 chain = hammer2_chain_lookup(&parent, &key_dummy,
1513                                              lhc, lhc, &cache_index, 0);
1514                 hammer2_chain_lookup_done(parent);      /* discard parent */
1515                 if (chain)
1516                         break;
1517                 pip = ip->pip;          /* safe, ip held locked */
1518                 if (pip)
1519                         hammer2_inode_ref(pip);         /* loop */
1520                 hammer2_inode_unlock_ex(ip, NULL);
1521         }
1522
1523         /*
1524          * chain is locked, ip is locked.  Unlock ip, return the locked
1525          * chain.  *ipp is already set w/a ref count and not locked.
1526          *
1527          * (parent is already unlocked).
1528          */
1529         if (ip)
1530                 hammer2_inode_unlock_ex(ip, NULL);
1531         *chainp = chain;
1532         if (chain) {
1533                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
1534                 /* already locked */
1535                 return (0);
1536         } else {
1537                 return (EIO);
1538         }
1539 }
1540
1541 /*
1542  * Find the directory common to both fdip and tdip, hold and return
1543  * its inode.
1544  */
1545 hammer2_inode_t *
1546 hammer2_inode_common_parent(hammer2_inode_t *fdip, hammer2_inode_t *tdip)
1547 {
1548         hammer2_inode_t *scan1;
1549         hammer2_inode_t *scan2;
1550
1551         /*
1552          * We used to have a depth field but it complicated matters too
1553          * much for directory renames.  So now its ugly.  Check for
1554          * simple cases before giving up and doing it the expensive way.
1555          *
1556          * XXX need a bottom-up topology stability lock
1557          */
1558         if (fdip == tdip || fdip == tdip->pip) {
1559                 hammer2_inode_ref(fdip);
1560                 return(fdip);
1561         }
1562         if (fdip->pip == tdip) {
1563                 hammer2_inode_ref(tdip);
1564                 return(tdip);
1565         }
1566
1567         /*
1568          * XXX not MPSAFE
1569          */
1570         for (scan1 = fdip; scan1->pmp == fdip->pmp; scan1 = scan1->pip) {
1571                 scan2 = tdip;
1572                 while (scan2->pmp == tdip->pmp) {
1573                         if (scan1 == scan2) {
1574                                 hammer2_inode_ref(scan1);
1575                                 return(scan1);
1576                         }
1577                         scan2 = scan2->pip;
1578                         if (scan2 == NULL)
1579                                 break;
1580                 }
1581         }
1582         panic("hammer2_inode_common_parent: no common parent %p %p\n",
1583               fdip, tdip);
1584         /* NOT REACHED */
1585         return(NULL);
1586 }
1587
1588 /*
1589  * Synchronize the inode's frontend state with the chain state prior
1590  * to any explicit flush of the inode or any strategy write call.
1591  *
1592  * Called with a locked inode.
1593  */
1594 void
1595 hammer2_inode_fsync(hammer2_trans_t *trans, hammer2_inode_t *ip,
1596                     hammer2_chain_t **chainp)
1597 {
1598         hammer2_inode_data_t *ipdata;
1599         hammer2_chain_t *parent;
1600         hammer2_chain_t *chain;
1601         hammer2_key_t lbase;
1602         hammer2_key_t key_next;
1603         int cache_index;
1604
1605         ipdata = &ip->chain->data->ipdata;
1606
1607         if (ip->flags & HAMMER2_INODE_MTIME) {
1608                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1609                 atomic_clear_int(&ip->flags, HAMMER2_INODE_MTIME);
1610                 ipdata->mtime = ip->mtime;
1611         }
1612         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size < ipdata->size) {
1613                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1614                 ipdata->size = ip->size;
1615                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1616
1617                 /*
1618                  * We must delete any chains beyond the EOF.  The chain
1619                  * straddling the EOF will be pending in the bioq.
1620                  */
1621                 lbase = (ipdata->size + HAMMER2_PBUFMASK64) &
1622                         ~HAMMER2_PBUFMASK64;
1623                 parent = hammer2_chain_lookup_init(ip->chain, 0);
1624                 chain = hammer2_chain_lookup(&parent, &key_next,
1625                                              lbase, (hammer2_key_t)-1,
1626                                              &cache_index,
1627                                              HAMMER2_LOOKUP_NODATA);
1628                 while (chain) {
1629                         /*
1630                          * Degenerate embedded case, nothing to loop on
1631                          */
1632                         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1633                                 hammer2_chain_unlock(chain);
1634                                 break;
1635                         }
1636                         if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
1637                                 hammer2_chain_delete(trans, chain, 0);
1638                         }
1639                         chain = hammer2_chain_next(&parent, chain, &key_next,
1640                                                    key_next, (hammer2_key_t)-1,
1641                                                    &cache_index,
1642                                                    HAMMER2_LOOKUP_NODATA);
1643                 }
1644                 hammer2_chain_lookup_done(parent);
1645         } else
1646         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size > ipdata->size) {
1647                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1648                 ipdata->size = ip->size;
1649                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1650
1651                 /*
1652                  * When resizing larger we may not have any direct-data
1653                  * available.
1654                  */
1655                 if ((ipdata->op_flags & HAMMER2_OPFLAG_DIRECTDATA) &&
1656                     ip->size > HAMMER2_EMBEDDED_BYTES) {
1657                         ipdata->op_flags &= ~HAMMER2_OPFLAG_DIRECTDATA;
1658                         bzero(&ipdata->u.blockset, sizeof(ipdata->u.blockset));
1659                 }
1660         }
1661 }