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  * The underlying chain is also locked and returned.
  67  *
  68  * NOTE: We don't combine the inode/chain lock because putting away an
  69  *       inode would otherwise confuse multiple lock holders of the inode.
  70  */
  71 hammer2_chain_t *
  72 hammer2_inode_lock_ex(hammer2_inode_t *ip)
  73 {
  74         hammer2_chain_t *chain;
  75
  76         hammer2_inode_ref(ip);
  77         ccms_thread_lock(&ip->topo_cst, CCMS_STATE_EXCLUSIVE);
  78
  79         /*
  80          * ip->chain fixup.  Certain duplications used to move inodes
  81          * into indirect blocks (for example) can cause ip->chain to
  82          * become stale.
  83          */
  84 again:
  85         chain = ip->chain;
  86         if (hammer2_chain_refactor_test(chain, 1)) {
  87                 spin_lock(&chain->core->cst.spin);
  88                 while (hammer2_chain_refactor_test(chain, 1))
  89                         chain = chain->next_parent;
  90                 if (ip->chain != chain) {
  91                         hammer2_chain_ref(chain);
  92                         spin_unlock(&chain->core->cst.spin);
  93                         hammer2_inode_repoint(ip, NULL, chain);
  94                         hammer2_chain_drop(chain);
  95                 } else {
  96                         spin_unlock(&chain->core->cst.spin);
  97                 }
  98         }
  99
 100         KKASSERT(chain != NULL);        /* for now */
 101         hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS);
 102
 103         /*
 104          * Resolve duplication races
 105          */
 106         if (hammer2_chain_refactor_test(chain, 1)) {
 107                 hammer2_chain_unlock(chain);
 108                 goto again;
 109         }
 110         return (chain);
 111 }
 112
 113 void
 114 hammer2_inode_unlock_ex(hammer2_inode_t *ip, hammer2_chain_t *chain)
 115 {
 116         /*
 117          * XXX this will catch parent directories too which we don't
 118          *     really want.
 119          */
 120         if (chain)
 121                 hammer2_chain_unlock(chain);
 122         ccms_thread_unlock(&ip->topo_cst);
 123         hammer2_inode_drop(ip);
 124 }
 125
 126 /*
 127  * NOTE: We don't combine the inode/chain lock because putting away an
 128  *       inode would otherwise confuse multiple lock holders of the inode.
 129  *
 130  *       Shared locks are especially sensitive to having too many shared
 131  *       lock counts (from the same thread) on certain paths which might
 132  *       need to upgrade them.  Only one count of a shared lock can be
 133  *       upgraded.
 134  */
 135 hammer2_chain_t *
 136 hammer2_inode_lock_sh(hammer2_inode_t *ip)
 137 {
 138         hammer2_chain_t *chain;
 139
 140         hammer2_inode_ref(ip);
 141 again:
 142         ccms_thread_lock(&ip->topo_cst, CCMS_STATE_SHARED);
 143
 144         chain = ip->chain;
 145         KKASSERT(chain != NULL);        /* for now */
 146         hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 147                                   HAMMER2_RESOLVE_SHARED);
 148
 149         /*
 150          * Resolve duplication races
 151          */
 152         if (hammer2_chain_refactor_test(chain, 1)) {
 153                 hammer2_chain_unlock(chain);
 154                 ccms_thread_unlock(&ip->topo_cst);
 155                 chain = hammer2_inode_lock_ex(ip);
 156                 hammer2_inode_unlock_ex(ip, chain);
 157                 goto again;
 158         }
 159         return (chain);
 160 }
 161
 162 void
 163 hammer2_inode_unlock_sh(hammer2_inode_t *ip, hammer2_chain_t *chain)
 164 {
 165         if (chain)
 166                 hammer2_chain_unlock(chain);
 167         ccms_thread_unlock(&ip->topo_cst);
 168         hammer2_inode_drop(ip);
 169 }
 170
 171 ccms_state_t
 172 hammer2_inode_lock_temp_release(hammer2_inode_t *ip)
 173 {
 174         return(ccms_thread_lock_temp_release(&ip->topo_cst));
 175 }
 176
 177 void
 178 hammer2_inode_lock_temp_restore(hammer2_inode_t *ip, ccms_state_t ostate)
 179 {
 180         ccms_thread_lock_temp_restore(&ip->topo_cst, ostate);
 181 }
 182
 183 ccms_state_t
 184 hammer2_inode_lock_upgrade(hammer2_inode_t *ip)
 185 {
 186         return(ccms_thread_lock_upgrade(&ip->topo_cst));
 187 }
 188
 189 void
 190 hammer2_inode_lock_downgrade(hammer2_inode_t *ip, ccms_state_t ostate)
 191 {
 192         ccms_thread_lock_downgrade(&ip->topo_cst, ostate);
 193 }
 194
 195 /*
 196  * Lookup an inode by inode number
 197  */
 198 hammer2_inode_t *
 199 hammer2_inode_lookup(hammer2_pfsmount_t *pmp, hammer2_tid_t inum)
 200 {
 201         hammer2_inode_t *ip;
 202
 203         if (pmp) {
 204                 spin_lock(&pmp->inum_spin);
 205                 ip = RB_LOOKUP(hammer2_inode_tree, &pmp->inum_tree, inum);
 206                 if (ip)
 207                         hammer2_inode_ref(ip);
 208                 spin_unlock(&pmp->inum_spin);
 209         } else {
 210                 ip = NULL;
 211         }
 212         return(ip);
 213 }
 214
 215 /*
 216  * Adding a ref to an inode is only legal if the inode already has at least
 217  * one ref.
 218  */
 219 void
 220 hammer2_inode_ref(hammer2_inode_t *ip)
 221 {
 222         atomic_add_int(&ip->refs, 1);
 223 }
 224
 225 /*
 226  * Drop an inode reference, freeing the inode when the last reference goes
 227  * away.
 228  */
 229 void
 230 hammer2_inode_drop(hammer2_inode_t *ip)
 231 {
 232         hammer2_pfsmount_t *pmp;
 233         hammer2_inode_t *pip;
 234         u_int refs;
 235
 236         while (ip) {
 237                 refs = ip->refs;
 238                 cpu_ccfence();
 239                 if (refs == 1) {
 240                         /*
 241                          * Transition to zero, must interlock with
 242                          * the inode inumber lookup tree (if applicable).
 243                          *
 244                          * NOTE: The super-root inode has no pmp.
 245                          */
 246                         pmp = ip->pmp;
 247                         if (pmp)
 248                                 spin_lock(&pmp->inum_spin);
 249
 250                         if (atomic_cmpset_int(&ip->refs, 1, 0)) {
 251                                 KKASSERT(ip->topo_cst.count == 0);
 252                                 if (ip->flags & HAMMER2_INODE_ONRBTREE) {
 253                                         atomic_clear_int(&ip->flags,
 254                                                      HAMMER2_INODE_ONRBTREE);
 255                                         RB_REMOVE(hammer2_inode_tree,
 256                                                   &pmp->inum_tree, ip);
 257                                 }
 258                                 if (pmp)
 259                                         spin_unlock(&pmp->inum_spin);
 260
 261                                 pip = ip->pip;
 262                                 ip->pip = NULL;
 263                                 ip->pmp = NULL;
 264
 265                                 /*
 266                                  * Cleaning out ip->chain isn't entirely
 267                                  * trivial.
 268                                  */
 269                                 hammer2_inode_repoint(ip, NULL, NULL);
 270
 271                                 /*
 272                                  * We have to drop pip (if non-NULL) to
 273                                  * dispose of our implied reference from
 274                                  * ip->pip.  We can simply loop on it.
 275                                  */
 276                                 if (pmp) {
 277                                         KKASSERT((ip->flags &
 278                                                   HAMMER2_INODE_SROOT) == 0);
 279                                         kfree(ip, pmp->minode);
 280                                 } else {
 281                                         KKASSERT(ip->flags &
 282                                                  HAMMER2_INODE_SROOT);
 283                                         kfree(ip, M_HAMMER2);
 284                                 }
 285                                 ip = pip;
 286                                 /* continue with pip (can be NULL) */
 287                         } else {
 288                                 if (pmp)
 289                                         spin_unlock(&ip->pmp->inum_spin);
 290                         }
 291                 } else {
 292                         /*
 293                          * Non zero transition
 294                          */
 295                         if (atomic_cmpset_int(&ip->refs, refs, refs - 1))
 296                                 break;
 297                 }
 298         }
 299 }
 300
 301 /*
 302  * Get the vnode associated with the given inode, allocating the vnode if
 303  * necessary.  The vnode will be returned exclusively locked.
 304  *
 305  * The caller must lock the inode (shared or exclusive).
 306  *
 307  * Great care must be taken to avoid deadlocks and vnode acquisition/reclaim
 308  * races.
 309  */
 310 struct vnode *
 311 hammer2_igetv(hammer2_inode_t *ip, int *errorp)
 312 {
 313         hammer2_inode_data_t *ipdata;
 314         hammer2_pfsmount_t *pmp;
 315         struct vnode *vp;
 316         ccms_state_t ostate;
 317
 318         pmp = ip->pmp;
 319         KKASSERT(pmp != NULL);
 320         *errorp = 0;
 321         ipdata = &ip->chain->data->ipdata;
 322
 323         for (;;) {
 324                 /*
 325                  * Attempt to reuse an existing vnode assignment.  It is
 326                  * possible to race a reclaim so the vget() may fail.  The
 327                  * inode must be unlocked during the vget() to avoid a
 328                  * deadlock against a reclaim.
 329                  */
 330                 vp = ip->vp;
 331                 if (vp) {
 332                         /*
 333                          * Inode must be unlocked during the vget() to avoid
 334                          * possible deadlocks, but leave the ip ref intact.
 335                          *
 336                          * vnode is held to prevent destruction during the
 337                          * vget().  The vget() can still fail if we lost
 338                          * a reclaim race on the vnode.
 339                          */
 340                         vhold_interlocked(vp);
 341                         ostate = hammer2_inode_lock_temp_release(ip);
 342                         if (vget(vp, LK_EXCLUSIVE)) {
 343                                 vdrop(vp);
 344                                 hammer2_inode_lock_temp_restore(ip, ostate);
 345                                 continue;
 346                         }
 347                         hammer2_inode_lock_temp_restore(ip, ostate);
 348                         vdrop(vp);
 349                         /* vp still locked and ref from vget */
 350                         if (ip->vp != vp) {
 351                                 kprintf("hammer2: igetv race %p/%p\n",
 352                                         ip->vp, vp);
 353                                 vput(vp);
 354                                 continue;
 355                         }
 356                         *errorp = 0;
 357                         break;
 358                 }
 359
 360                 /*
 361                  * No vnode exists, allocate a new vnode.  Beware of
 362                  * allocation races.  This function will return an
 363                  * exclusively locked and referenced vnode.
 364                  */
 365                 *errorp = getnewvnode(VT_HAMMER2, pmp->mp, &vp, 0, 0);
 366                 if (*errorp) {
 367                         kprintf("hammer2: igetv getnewvnode failed %d\n",
 368                                 *errorp);
 369                         vp = NULL;
 370                         break;
 371                 }
 372
 373                 /*
 374                  * Lock the inode and check for an allocation race.
 375                  */
 376                 ostate = hammer2_inode_lock_upgrade(ip);
 377                 if (ip->vp != NULL) {
 378                         vp->v_type = VBAD;
 379                         vx_put(vp);
 380                         hammer2_inode_lock_downgrade(ip, ostate);
 381                         continue;
 382                 }
 383
 384                 switch (ipdata->type) {
 385                 case HAMMER2_OBJTYPE_DIRECTORY:
 386                         vp->v_type = VDIR;
 387                         break;
 388                 case HAMMER2_OBJTYPE_REGFILE:
 389                         vp->v_type = VREG;
 390                         vinitvmio(vp, ipdata->size,
 391                                   HAMMER2_LBUFSIZE,
 392                                   (int)ipdata->size & HAMMER2_LBUFMASK);
 393                         break;
 394                 case HAMMER2_OBJTYPE_SOFTLINK:
 395                         /*
 396                          * XXX for now we are using the generic file_read
 397                          * and file_write code so we need a buffer cache
 398                          * association.
 399                          */
 400                         vp->v_type = VLNK;
 401                         vinitvmio(vp, ipdata->size,
 402                                   HAMMER2_LBUFSIZE,
 403                                   (int)ipdata->size & HAMMER2_LBUFMASK);
 404                         break;
 405                 /* XXX FIFO */
 406                 default:
 407                         panic("hammer2: unhandled objtype %d", ipdata->type);
 408                         break;
 409                 }
 410
 411                 if (ip == pmp->iroot)
 412                         vsetflags(vp, VROOT);
 413
 414                 vp->v_data = ip;
 415                 ip->vp = vp;
 416                 hammer2_inode_ref(ip);          /* vp association */
 417                 hammer2_inode_lock_downgrade(ip, ostate);
 418                 break;
 419         }
 420
 421         /*
 422          * Return non-NULL vp and *errorp == 0, or NULL vp and *errorp != 0.
 423          */
 424         if (hammer2_debug & 0x0002) {
 425                 kprintf("igetv vp %p refs %d aux %d\n",
 426                         vp, vp->v_sysref.refcnt, vp->v_auxrefs);
 427         }
 428         return (vp);
 429 }
 430
 431 /*
 432  * The passed-in chain must be locked and the returned inode will also be
 433  * locked.  This routine typically locates or allocates the inode, assigns
 434  * ip->chain (adding a ref to chain if necessary), and returns the inode.
 435  *
 436  * The hammer2_inode structure regulates the interface between the high level
 437  * kernel VNOPS API and the filesystem backend (the chains).
 438  *
 439  * WARNING!  This routine sucks up the chain's lock (makes it part of the
 440  *           inode lock from the point of view of the inode lock API),
 441  *           so callers need to be careful.
 442  *
 443  * WARNING!  The mount code is allowed to pass dip == NULL for iroot and
 444  *           is allowed to pass pmp == NULL and dip == NULL for sroot.
 445  */
 446 hammer2_inode_t *
 447 hammer2_inode_get(hammer2_pfsmount_t *pmp, hammer2_inode_t *dip,
 448                   hammer2_chain_t *chain)
 449 {
 450         hammer2_inode_t *nip;
 451
 452         KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
 453
 454         /*
 455          * Interlocked lookup/ref of the inode.  This code is only needed
 456          * when looking up inodes with nlinks != 0 (TODO: optimize out
 457          * otherwise and test for duplicates).
 458          */
 459 again:
 460         for (;;) {
 461                 nip = hammer2_inode_lookup(pmp, chain->data->ipdata.inum);
 462                 if (nip == NULL)
 463                         break;
 464                 ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 465                 if ((nip->flags & HAMMER2_INODE_ONRBTREE) == 0) { /* race */
 466                         ccms_thread_unlock(&nip->topo_cst);
 467                         hammer2_inode_drop(nip);
 468                         continue;
 469                 }
 470                 if (nip->chain != chain)
 471                         hammer2_inode_repoint(nip, NULL, chain);
 472
 473                 /*
 474                  * Consolidated nip/nip->chain is locked (chain locked
 475                  * by caller).
 476                  */
 477                 return nip;
 478         }
 479
 480         /*
 481          * We couldn't find the inode number, create a new inode.
 482          */
 483         if (pmp) {
 484                 nip = kmalloc(sizeof(*nip), pmp->minode, M_WAITOK | M_ZERO);
 485         } else {
 486                 nip = kmalloc(sizeof(*nip), M_HAMMER2, M_WAITOK | M_ZERO);
 487                 nip->flags = HAMMER2_INODE_SROOT;
 488         }
 489         nip->inum = chain->data->ipdata.inum;
 490         hammer2_inode_repoint(nip, NULL, chain);
 491         nip->pip = dip;                         /* can be NULL */
 492         if (dip)
 493                 hammer2_inode_ref(dip); /* ref dip for nip->pip */
 494
 495         nip->pmp = pmp;
 496
 497         /*
 498          * ref and lock on nip gives it state compatible to after a
 499          * hammer2_inode_lock_ex() call.
 500          */
 501         nip->refs = 1;
 502         ccms_cst_init(&nip->topo_cst, &nip->chain);
 503         ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 504         /* combination of thread lock and chain lock == inode lock */
 505
 506         /*
 507          * Attempt to add the inode.  If it fails we raced another inode
 508          * get.  Undo all the work and try again.
 509          */
 510         if (pmp) {
 511                 spin_lock(&pmp->inum_spin);
 512                 if (RB_INSERT(hammer2_inode_tree, &pmp->inum_tree, nip)) {
 513                         spin_unlock(&pmp->inum_spin);
 514                         ccms_thread_unlock(&nip->topo_cst);
 515                         hammer2_inode_drop(nip);
 516                         goto again;
 517                 }
 518                 atomic_set_int(&nip->flags, HAMMER2_INODE_ONRBTREE);
 519                 spin_unlock(&pmp->inum_spin);
 520         }
 521
 522         return (nip);
 523 }
 524
 525 /*
 526  * Create a new inode in the specified directory using the vattr to
 527  * figure out the type of inode.
 528  *
 529  * If no error occurs the new inode with its chain locked is returned in
 530  * *nipp, otherwise an error is returned and *nipp is set to NULL.
 531  *
 532  * If vap and/or cred are NULL the related fields are not set and the
 533  * inode type defaults to a directory.  This is used when creating PFSs
 534  * under the super-root, so the inode number is set to 1 in this case.
 535  *
 536  * dip is not locked on entry.
 537  */
 538 hammer2_inode_t *
 539 hammer2_inode_create(hammer2_trans_t *trans, hammer2_inode_t *dip,
 540                      struct vattr *vap, struct ucred *cred,
 541                      const uint8_t *name, size_t name_len,
 542                      hammer2_chain_t **chainp, int *errorp)
 543 {
 544         hammer2_inode_data_t *dipdata;
 545         hammer2_inode_data_t *nipdata;
 546         hammer2_chain_t *chain;
 547         hammer2_chain_t *parent;
 548         hammer2_inode_t *nip;
 549         hammer2_key_t lhc;
 550         int error;
 551         uid_t xuid;
 552         uuid_t dip_uid;
 553         uuid_t dip_gid;
 554         uint32_t dip_mode;
 555
 556         lhc = hammer2_dirhash(name, name_len);
 557         *errorp = 0;
 558
 559         /*
 560          * Locate the inode or indirect block to create the new
 561          * entry in.  At the same time check for key collisions
 562          * and iterate until we don't get one.
 563          *
 564          * NOTE: hidden inodes do not have iterators.
 565          */
 566 retry:
 567         parent = hammer2_inode_lock_ex(dip);
 568         dipdata = &dip->chain->data->ipdata;
 569         dip_uid = dipdata->uid;
 570         dip_gid = dipdata->gid;
 571         dip_mode = dipdata->mode;
 572
 573         error = 0;
 574         while (error == 0) {
 575                 chain = hammer2_chain_lookup(&parent, lhc, lhc, 0);
 576                 if (chain == NULL)
 577                         break;
 578                 if ((lhc & HAMMER2_DIRHASH_VISIBLE) == 0)
 579                         error = ENOSPC;
 580                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 581                         error = ENOSPC;
 582                 hammer2_chain_unlock(chain);
 583                 chain = NULL;
 584                 ++lhc;
 585         }
 586         if (error == 0) {
 587                 error = hammer2_chain_create(trans, &parent, &chain,
 588                                              lhc, 0,
 589                                              HAMMER2_BREF_TYPE_INODE,
 590                                              HAMMER2_INODE_BYTES);
 591         }
 592
 593         /*
 594          * Cleanup and handle retries.
 595          */
 596         if (error == EAGAIN) {
 597                 hammer2_chain_ref(parent);
 598                 hammer2_inode_unlock_ex(dip, parent);
 599                 hammer2_chain_wait(parent);
 600                 hammer2_chain_drop(parent);
 601                 goto retry;
 602         }
 603         hammer2_inode_unlock_ex(dip, parent);
 604
 605         if (error) {
 606                 KKASSERT(chain == NULL);
 607                 *errorp = error;
 608                 return (NULL);
 609         }
 610
 611         /*
 612          * Set up the new inode.
 613          *
 614          * NOTE: *_get() integrates chain's lock into the inode lock.
 615          *
 616          * NOTE: Only one new inode can currently be created per
 617          *       transaction.  If the need arises we can adjust
 618          *       hammer2_trans_init() to allow more.
 619          */
 620         chain->data->ipdata.inum = trans->sync_tid;
 621         nip = hammer2_inode_get(dip->pmp, dip, chain);
 622         nipdata = &chain->data->ipdata;
 623
 624         if (vap) {
 625                 KKASSERT(trans->inodes_created == 0);
 626                 nipdata->type = hammer2_get_obj_type(vap->va_type);
 627                 nipdata->inum = trans->sync_tid;
 628                 ++trans->inodes_created;
 629         } else {
 630                 nipdata->type = HAMMER2_OBJTYPE_DIRECTORY;
 631                 nipdata->inum = 1;
 632         }
 633         nipdata->version = HAMMER2_INODE_VERSION_ONE;
 634         hammer2_update_time(&nipdata->ctime);
 635         nipdata->mtime = nipdata->ctime;
 636         if (vap)
 637                 nipdata->mode = vap->va_mode;
 638         nipdata->nlinks = 1;
 639         if (vap) {
 640                 if (dip) {
 641                         xuid = hammer2_to_unix_xid(&dip_uid);
 642                         xuid = vop_helper_create_uid(dip->pmp->mp,
 643                                                      dip_mode,
 644                                                      xuid,
 645                                                      cred,
 646                                                      &vap->va_mode);
 647                 } else {
 648                         xuid = 0;
 649                 }
 650                 if (vap->va_vaflags & VA_UID_UUID_VALID)
 651                         nipdata->uid = vap->va_uid_uuid;
 652                 else if (vap->va_uid != (uid_t)VNOVAL)
 653                         hammer2_guid_to_uuid(&nipdata->uid, vap->va_uid);
 654                 else
 655                         hammer2_guid_to_uuid(&nipdata->uid, xuid);
 656
 657                 if (vap->va_vaflags & VA_GID_UUID_VALID)
 658                         nipdata->gid = vap->va_gid_uuid;
 659                 else if (vap->va_gid != (gid_t)VNOVAL)
 660                         hammer2_guid_to_uuid(&nipdata->gid, vap->va_gid);
 661                 else if (dip)
 662                         nipdata->gid = dip_gid;
 663         }
 664
 665         /*
 666          * Regular files and softlinks allow a small amount of data to be
 667          * directly embedded in the inode.  This flag will be cleared if
 668          * the size is extended past the embedded limit.
 669          */
 670         if (nipdata->type == HAMMER2_OBJTYPE_REGFILE ||
 671             nipdata->type == HAMMER2_OBJTYPE_SOFTLINK) {
 672                 nipdata->op_flags |= HAMMER2_OPFLAG_DIRECTDATA;
 673         }
 674
 675         KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 676         bcopy(name, nipdata->filename, name_len);
 677         nipdata->name_key = lhc;
 678         nipdata->name_len = name_len;
 679         *chainp = chain;
 680
 681         return (nip);
 682 }
 683
 684 /*
 685  * chain may have been moved around by the create.
 686  */
 687 static
 688 void
 689 hammer2_chain_refactor(hammer2_chain_t **chainp)
 690 {
 691         hammer2_chain_t *chain = *chainp;
 692         hammer2_chain_core_t *core;
 693
 694         core = chain->core;
 695         spin_lock(&core->cst.spin);
 696         while (hammer2_chain_refactor_test(chain, 1)) {
 697                 chain = chain->next_parent;
 698                 while (hammer2_chain_refactor_test(chain, 1))
 699                         chain = chain->next_parent;
 700                 hammer2_chain_ref(chain);
 701                 spin_unlock(&core->cst.spin);
 702
 703                 hammer2_chain_unlock(*chainp);
 704                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 705                                           HAMMER2_RESOLVE_NOREF); /* eat ref */
 706                 *chainp = chain;
 707                 spin_lock(&core->cst.spin);
 708         }
 709         spin_unlock(&core->cst.spin);
 710 }
 711
 712 /*
 713  * ochain represents the target file inode.  We need to move it to the
 714  * specified common parent directory (dip) and rename it to a special
 715  * invisible "0xINODENUMBER" filename.
 716  *
 717  * We use chain_duplicate and duplicate ochain at the new location,
 718  * renaming it appropriately.  We create a temporary chain and
 719  * then delete it to placemark where the duplicate will go.  Both of
 720  * these use the inode number for (lhc) (the key), generating the
 721  * invisible filename.
 722  */
 723 static
 724 hammer2_chain_t *
 725 hammer2_hardlink_shiftup(hammer2_trans_t *trans, hammer2_chain_t **ochainp,
 726                         hammer2_inode_t *dip, int *errorp)
 727 {
 728         hammer2_inode_data_t *nipdata;
 729         hammer2_chain_t *parent;
 730         hammer2_chain_t *ochain;
 731         hammer2_chain_t *nchain;
 732         hammer2_chain_t *tmp;
 733         hammer2_key_t lhc;
 734         hammer2_blockref_t bref;
 735
 736         ochain = *ochainp;
 737         *errorp = 0;
 738         lhc = ochain->data->ipdata.inum;
 739         KKASSERT((lhc & HAMMER2_DIRHASH_VISIBLE) == 0);
 740
 741         /*
 742          * Locate the inode or indirect block to create the new
 743          * entry in.  lhc represents the inode number so there is
 744          * no collision iteration.
 745          *
 746          * There should be no key collisions with invisible inode keys.
 747          */
 748 retry:
 749         parent = hammer2_chain_lookup_init(dip->chain, 0);
 750         nchain = hammer2_chain_lookup(&parent, lhc, lhc, 0);
 751         if (nchain) {
 752                 kprintf("X3 chain %p parent %p dip %p dip->chain %p\n",
 753                         nchain, parent, dip, dip->chain);
 754                 hammer2_chain_unlock(nchain);
 755                 nchain = NULL;
 756                 *errorp = ENOSPC;
 757 #if 1
 758                 Debugger("X3");
 759 #endif
 760         }
 761
 762         /*
 763          * Create entry in common parent directory using the seek position
 764          * calculated above.
 765          */
 766         if (*errorp == 0) {
 767                 KKASSERT(nchain == NULL);
 768                 *errorp = hammer2_chain_create(trans, &parent, &nchain,
 769                                                lhc, 0,
 770                                                HAMMER2_BREF_TYPE_INODE,/* n/a */
 771                                                HAMMER2_INODE_BYTES);   /* n/a */
 772                 hammer2_chain_refactor(&ochain);
 773                 *ochainp = ochain;
 774         }
 775
 776         /*
 777          * Cleanup and handle retries.
 778          */
 779         if (*errorp == EAGAIN) {
 780                 hammer2_chain_ref(parent);
 781                 hammer2_chain_lookup_done(parent);
 782                 hammer2_chain_wait(parent);
 783                 hammer2_chain_drop(parent);
 784                 goto retry;
 785         }
 786
 787         /*
 788          * Handle the error case
 789          */
 790         if (*errorp) {
 791                 KKASSERT(nchain == NULL);
 792                 hammer2_chain_lookup_done(parent);
 793                 return (NULL);
 794         }
 795
 796         /*
 797          * Use chain as a placeholder for (lhc), delete it and replace
 798          * it with our duplication.
 799          *
 800          * Gain a second lock on ochain for the duplication function to
 801          * unlock, maintain the caller's original lock across the call.
 802          *
 803          * This is a bit messy.
 804          */
 805         hammer2_chain_delete(trans, nchain);
 806         hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
 807         tmp = ochain;
 808         bref = tmp->bref;
 809         bref.key = lhc;                 /* invisible dir entry key */
 810         bref.keybits = 0;
 811         hammer2_chain_duplicate(trans, parent, nchain->index, &tmp, &bref);
 812         hammer2_chain_lookup_done(parent);
 813         hammer2_chain_unlock(nchain);   /* no longer needed */
 814
 815         /*
 816          * Now set chain to our duplicate and modify it appropriately.
 817          *
 818          * Directory entries are inodes but this is a hidden hardlink
 819          * target.  The name isn't used but to ease debugging give it
 820          * a name after its inode number.
 821          */
 822         nchain = tmp;
 823         tmp = NULL;     /* safety */
 824
 825         hammer2_chain_modify(trans, &nchain, HAMMER2_MODIFY_ASSERTNOCOPY);
 826         nipdata = &nchain->data->ipdata;
 827         ksnprintf(nipdata->filename, sizeof(nipdata->filename),
 828                   "0x%016jx", (intmax_t)nipdata->inum);
 829         nipdata->name_len = strlen(nipdata->filename);
 830         nipdata->name_key = lhc;
 831
 832         return (nchain);
 833 }
 834
 835 /*
 836  * Connect the target inode represented by (*chainp) to the media topology
 837  * at (dip, name, len).
 838  *
 839  * If hlink is TRUE this function creates an OBJTYPE_HARDLINK directory
 840  * entry instead of connecting (*chainp).
 841  *
 842  * If hlink is FALSE this function uses chain_duplicate() to make a copy
 843  * if (*chainp) in the directory entry.  (*chainp) is likely to be deleted
 844  * by the caller in this case (e.g. rename).
 845  */
 846 int
 847 hammer2_inode_connect(hammer2_trans_t *trans, int hlink,
 848                       hammer2_inode_t *dip, hammer2_chain_t **chainp,
 849                       const uint8_t *name, size_t name_len)
 850 {
 851         hammer2_inode_data_t *ipdata;
 852         hammer2_chain_t *nchain;
 853         hammer2_chain_t *parent;
 854         hammer2_chain_t *ochain;
 855         hammer2_key_t lhc;
 856         int error;
 857
 858         ochain = *chainp;
 859
 860         /*
 861          * Since ochain is either disconnected from the topology or represents
 862          * a hardlink terminus which is always a parent of or equal to dip,
 863          * we should be able to safely lock dip->chain for our setup.
 864          */
 865         parent = hammer2_chain_lookup_init(dip->chain, 0);
 866
 867         lhc = hammer2_dirhash(name, name_len);
 868
 869         /*
 870          * Locate the inode or indirect block to create the new
 871          * entry in.  At the same time check for key collisions
 872          * and iterate until we don't get one.
 873          */
 874         error = 0;
 875         while (error == 0) {
 876                 nchain = hammer2_chain_lookup(&parent, lhc, lhc, 0);
 877                 if (nchain == NULL)
 878                         break;
 879                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 880                         error = ENOSPC;
 881                 hammer2_chain_unlock(nchain);
 882                 nchain = NULL;
 883                 ++lhc;
 884         }
 885
 886         if (error == 0) {
 887                 if (hlink) {
 888                         /*
 889                          * Hardlink pointer needed, create totally fresh
 890                          * directory entry.
 891                          */
 892                         KKASSERT(nchain == NULL);
 893                         error = hammer2_chain_create(trans, &parent, &nchain,
 894                                                      lhc, 0,
 895                                                      HAMMER2_BREF_TYPE_INODE,
 896                                                      HAMMER2_INODE_BYTES);
 897                         hammer2_chain_refactor(&ochain);
 898                 } else {
 899                         /*
 900                          * Reconnect the original chain and rename.  Use
 901                          * chain_duplicate().  The caller will likely delete
 902                          * or has already deleted the original chain in
 903                          * this case.
 904                          *
 905                          * NOTE: chain_duplicate() generates a new chain
 906                          *       with CHAIN_DELETED cleared (ochain typically
 907                          *       has it set from the file unlink).
 908                          */
 909                         nchain = ochain;
 910                         ochain = NULL;
 911                         hammer2_chain_duplicate(trans, NULL, -1, &nchain, NULL);
 912                         error = hammer2_chain_create(trans, &parent, &nchain,
 913                                                      lhc, 0,
 914                                                      HAMMER2_BREF_TYPE_INODE,
 915                                                      HAMMER2_INODE_BYTES);
 916                 }
 917         }
 918
 919         /*
 920          * Unlock stuff.
 921          */
 922         KKASSERT(error != EAGAIN);
 923         hammer2_chain_lookup_done(parent);
 924         parent = NULL;
 925
 926         /*
 927          * nchain should be NULL on error, leave ochain (== *chainp) alone.
 928          */
 929         if (error) {
 930                 KKASSERT(nchain == NULL);
 931                 return (error);
 932         }
 933
 934         /*
 935          * Directory entries are inodes so if the name has changed we have
 936          * to update the inode.
 937          *
 938          * When creating an OBJTYPE_HARDLINK entry remember to unlock the
 939          * chain, the caller will access the hardlink via the actual hardlink
 940          * target file and not the hardlink pointer entry, so we must still
 941          * return ochain.
 942          */
 943         if (hlink && hammer2_hardlink_enable >= 0) {
 944                 /*
 945                  * Create the HARDLINK pointer.  oip represents the hardlink
 946                  * target in this situation.
 947                  *
 948                  * We will return ochain (the hardlink target).
 949                  */
 950                 hammer2_chain_modify(trans, &nchain,
 951                                      HAMMER2_MODIFY_ASSERTNOCOPY);
 952                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 953                 ipdata = &nchain->data->ipdata;
 954                 bcopy(name, ipdata->filename, name_len);
 955                 ipdata->name_key = lhc;
 956                 ipdata->name_len = name_len;
 957                 ipdata->target_type = ochain->data->ipdata.type;
 958                 ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
 959                 ipdata->inum = ochain->data->ipdata.inum;
 960                 ipdata->nlinks = 1;
 961                 hammer2_chain_unlock(nchain);
 962                 nchain = ochain;
 963                 ochain = NULL;
 964         } else if (hlink && hammer2_hardlink_enable < 0) {
 965                 /*
 966                  * Create a snapshot (hardlink fake mode for debugging).
 967                  * (ochain already flushed above so we can just copy the
 968                  * bref XXX).
 969                  *
 970                  * Since this is a snapshot we return nchain in the fake
 971                  * hardlink case.
 972                  */
 973                 hammer2_chain_modify(trans, &nchain,
 974                                      HAMMER2_MODIFY_ASSERTNOCOPY);
 975                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 976                 ipdata = &nchain->data->ipdata;
 977                 *ipdata = ochain->data->ipdata;
 978                 bcopy(name, ipdata->filename, name_len);
 979                 ipdata->name_key = lhc;
 980                 ipdata->name_len = name_len;
 981                 kprintf("created fake hardlink %*.*s\n",
 982                         (int)name_len, (int)name_len, name);
 983         } else {
 984                 /*
 985                  * nchain is a duplicate of ochain at the new location.
 986                  * We must fixup the name stored in oip.  The bref key
 987                  * has already been set up.
 988                  */
 989                 hammer2_chain_modify(trans, &nchain,
 990                                      HAMMER2_MODIFY_ASSERTNOCOPY);
 991                 ipdata = &nchain->data->ipdata;
 992
 993                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 994                 bcopy(name, ipdata->filename, name_len);
 995                 ipdata->name_key = lhc;
 996                 ipdata->name_len = name_len;
 997                 ipdata->nlinks = 1;
 998         }
 999
1000         /*
1001          * We are replacing ochain with nchain, unlock ochain.  In the
1002          * case where ochain is left unchanged the code above sets
1003          * nchain to ochain and ochain to NULL, resulting in a NOP here.
1004          */
1005         if (ochain)
1006                 hammer2_chain_unlock(ochain);
1007         *chainp = nchain;
1008
1009         return (0);
1010 }
1011
1012 /*
1013  * Repoint ip->chain to nchain.  Caller must hold the inode exclusively
1014  * locked.
1015  *
1016  * ip->chain is set to nchain.  The prior chain in ip->chain is dropped
1017  * and nchain is ref'd.
1018  */
1019 void
1020 hammer2_inode_repoint(hammer2_inode_t *ip, hammer2_inode_t *pip,
1021                       hammer2_chain_t *nchain)
1022 {
1023         hammer2_chain_t *ochain;
1024         hammer2_inode_t *opip;
1025
1026         /*
1027          * Repoint ip->chain if requested.
1028          */
1029         ochain = ip->chain;
1030         ip->chain = nchain;
1031         if (nchain)
1032                 hammer2_chain_ref(nchain);
1033         if (ochain)
1034                 hammer2_chain_drop(ochain);
1035
1036         /*
1037          * Repoint ip->pip if requested (non-NULL pip).
1038          */
1039         if (pip && ip->pip != pip) {
1040                 opip = ip->pip;
1041                 hammer2_inode_ref(pip);
1042                 ip->pip = pip;
1043                 if (opip)
1044                         hammer2_inode_drop(opip);
1045         }
1046 }
1047
1048 /*
1049  * Unlink the file from the specified directory inode.  The directory inode
1050  * does not need to be locked.
1051  *
1052  * isdir determines whether a directory/non-directory check should be made.
1053  * No check is made if isdir is set to -1.
1054  *
1055  * NOTE!  This function does not prevent the underlying file from still
1056  *        being used if it has other refs (such as from an inode, or if it's
1057  *        chain is manually held).  However, the caller is responsible for
1058  *        fixing up ip->chain if e.g. a rename occurs (see chain_duplicate()).
1059  */
1060 int
1061 hammer2_unlink_file(hammer2_trans_t *trans, hammer2_inode_t *dip,
1062                     const uint8_t *name, size_t name_len,
1063                     int isdir, int *hlinkp)
1064 {
1065         hammer2_inode_data_t *ipdata;
1066         hammer2_chain_t *parent;
1067         hammer2_chain_t *ochain;
1068         hammer2_chain_t *chain;
1069         hammer2_chain_t *dparent;
1070         hammer2_chain_t *dchain;
1071         hammer2_key_t lhc;
1072         int error;
1073         uint8_t type;
1074
1075         error = 0;
1076         ochain = NULL;
1077         lhc = hammer2_dirhash(name, name_len);
1078
1079         /*
1080          * Search for the filename in the directory
1081          */
1082         if (hlinkp)
1083                 *hlinkp = 0;
1084         parent = hammer2_inode_lock_ex(dip);
1085         chain = hammer2_chain_lookup(&parent,
1086                                      lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1087                                      0);
1088         while (chain) {
1089                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1090                     name_len == chain->data->ipdata.name_len &&
1091                     bcmp(name, chain->data->ipdata.filename, name_len) == 0) {
1092                         break;
1093                 }
1094                 chain = hammer2_chain_next(&parent, chain,
1095                                            lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1096                                            0);
1097         }
1098         hammer2_inode_unlock_ex(dip, NULL);     /* retain parent */
1099
1100         /*
1101          * Not found or wrong type (isdir < 0 disables the type check).
1102          * If a hardlink pointer, type checks use the hardlink target.
1103          */
1104         if (chain == NULL) {
1105                 error = ENOENT;
1106                 goto done;
1107         }
1108         if ((type = chain->data->ipdata.type) == HAMMER2_OBJTYPE_HARDLINK) {
1109                 if (hlinkp)
1110                         *hlinkp = 1;
1111                 type = chain->data->ipdata.target_type;
1112         }
1113
1114         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 0) {
1115                 error = ENOTDIR;
1116                 goto done;
1117         }
1118         if (type != HAMMER2_OBJTYPE_DIRECTORY && isdir >= 1) {
1119                 error = EISDIR;
1120                 goto done;
1121         }
1122
1123         /*
1124          * Hardlink must be resolved.  We can't hold parent locked while we
1125          * do this or we could deadlock.
1126          *
1127          * On success chain will be adjusted to point at the hardlink target
1128          * and ochain will point to the hardlink pointer in the original
1129          * directory.  Otherwise chain remains pointing to the original.
1130          */
1131         if (chain->data->ipdata.type == HAMMER2_OBJTYPE_HARDLINK) {
1132                 hammer2_chain_unlock(parent);
1133                 parent = NULL;
1134                 error = hammer2_hardlink_find(dip, &chain, &ochain);
1135         }
1136
1137         /*
1138          * If this is a directory the directory must be empty.  However, if
1139          * isdir < 0 we are doing a rename and the directory does not have
1140          * to be empty, and if isdir > 1 we are deleting a PFS/snapshot
1141          * and the directory does not have to be empty.
1142          *
1143          * NOTE: We check the full key range here which covers both visible
1144          *       and invisible entries.  Theoretically there should be no
1145          *       invisible (hardlink target) entries if there are no visible
1146          *       entries.
1147          */
1148         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 1) {
1149                 dparent = hammer2_chain_lookup_init(chain, 0);
1150                 dchain = hammer2_chain_lookup(&dparent,
1151                                               0, (hammer2_key_t)-1,
1152                                               HAMMER2_LOOKUP_NODATA);
1153                 if (dchain) {
1154                         hammer2_chain_unlock(dchain);
1155                         hammer2_chain_lookup_done(dparent);
1156                         error = ENOTEMPTY;
1157                         goto done;
1158                 }
1159                 hammer2_chain_lookup_done(dparent);
1160                 dparent = NULL;
1161                 /* dchain NULL */
1162         }
1163
1164         /*
1165          * Ok, we can now unlink the chain.  We always decrement nlinks even
1166          * if the entry can be deleted in case someone has the file open and
1167          * does an fstat().
1168          *
1169          * The chain itself will no longer be in the on-media topology but
1170          * can still be flushed to the media (e.g. if an open descriptor
1171          * remains).  When the last vnode/ip ref goes away the chain will
1172          * be marked unmodified, avoiding any further (now unnecesary) I/O.
1173          *
1174          * A non-NULL ochain indicates a hardlink.
1175          */
1176         if (ochain) {
1177                 /*
1178                  * Delete the original hardlink pointer.
1179                  *
1180                  * NOTE: parent from above is NULL when ochain != NULL
1181                  *       so we can reuse it.
1182                  */
1183                 hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
1184                 hammer2_chain_delete(trans, ochain);
1185                 hammer2_chain_unlock(ochain);
1186
1187                 /*
1188                  * Then decrement nlinks on hardlink target, deleting
1189                  * the target when nlinks drops to 0.
1190                  */
1191                 hammer2_chain_modify(trans, &chain, 0);
1192                 --chain->data->ipdata.nlinks;
1193                 if (chain->data->ipdata.nlinks == 0)
1194                         hammer2_chain_delete(trans, chain);
1195         } else {
1196                 /*
1197                  * Otherwise this was not a hardlink and we can just
1198                  * remove the entry and decrement nlinks.
1199                  *
1200                  * NOTE: *_get() integrates chain's lock into the inode lock.
1201                  */
1202                 hammer2_chain_modify(trans, &chain, 0);
1203                 ipdata = &chain->data->ipdata;
1204                 --ipdata->nlinks;
1205                 hammer2_chain_delete(trans, chain);
1206         }
1207
1208         error = 0;
1209 done:
1210         if (chain)
1211                 hammer2_chain_unlock(chain);
1212         if (parent)
1213                 hammer2_chain_lookup_done(parent);
1214         if (ochain)
1215                 hammer2_chain_drop(ochain);
1216
1217         return error;
1218 }
1219
1220 /*
1221  * Given an exclusively locked inode we consolidate its chain for hardlink
1222  * creation, adding (nlinks) to the file's link count and potentially
1223  * relocating the inode to a directory common to ip->pip and tdip.
1224  *
1225  * Replaces (*chainp) if consolidation occurred, unlocking the old chain
1226  * and returning a new locked chain.
1227  *
1228  * NOTE!  This function will also replace ip->chain.
1229  */
1230 int
1231 hammer2_hardlink_consolidate(hammer2_trans_t *trans, hammer2_inode_t *ip,
1232                              hammer2_chain_t **chainp,
1233                              hammer2_inode_t *tdip, int nlinks)
1234 {
1235         hammer2_inode_data_t *ipdata;
1236         hammer2_inode_t *fdip;
1237         hammer2_inode_t *cdip;
1238         hammer2_chain_t *chain;
1239         hammer2_chain_t *nchain;
1240         int error;
1241
1242         chain = *chainp;
1243         if (nlinks == 0 &&                      /* no hardlink needed */
1244             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE)) {
1245                 return (0);
1246         }
1247         if (hammer2_hardlink_enable < 0) {      /* fake hardlinks */
1248                 return (0);
1249         }
1250
1251         if (hammer2_hardlink_enable == 0) {     /* disallow hardlinks */
1252                 hammer2_chain_unlock(chain);
1253                 *chainp = NULL;
1254                 return (ENOTSUP);
1255         }
1256
1257         /*
1258          * cdip will be returned with a ref, but not locked.
1259          */
1260         fdip = ip->pip;
1261         cdip = hammer2_inode_common_parent(fdip, tdip);
1262
1263         /*
1264          * If no change in the hardlink's target directory is required and
1265          * this is already a hardlink target, all we need to do is adjust
1266          * the link count.
1267          *
1268          * XXX The common parent is a big wiggly due to duplication from
1269          *     renames.  Compare the core (RBTREE) pointer instead of the
1270          *     ip's.
1271          */
1272         if (cdip == fdip &&
1273             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) == 0) {
1274                 if (nlinks) {
1275                         hammer2_chain_modify(trans, &chain, 0);
1276                         chain->data->ipdata.nlinks += nlinks;
1277                 }
1278                 error = 0;
1279                 goto done;
1280         }
1281
1282         /*
1283          * We either have to move an existing hardlink target or we have
1284          * to create a fresh hardlink target.
1285          *
1286          * Hardlink targets are hidden inodes in a parent directory common
1287          * to all directory entries referencing the hardlink.
1288          */
1289         nchain = hammer2_hardlink_shiftup(trans, &chain, cdip, &error);
1290
1291         if (error == 0) {
1292                 /*
1293                  * Bump nlinks on duplicated hidden inode, repoint
1294                  * ip->chain.
1295                  */
1296                 hammer2_chain_modify(trans, &nchain, 0);
1297                 nchain->data->ipdata.nlinks += nlinks;
1298                 hammer2_inode_repoint(ip, cdip, nchain);
1299
1300                 /*
1301                  * If the old chain is not a hardlink target then replace
1302                  * it with a OBJTYPE_HARDLINK pointer.
1303                  *
1304                  * If the old chain IS a hardlink target then delete it.
1305                  */
1306                 if (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) {
1307                         /*
1308                          * Replace original non-hardlink that's been dup'd
1309                          * with a special hardlink directory entry.  We must
1310                          * set the DIRECTDATA flag to prevent sub-chains
1311                          * from trying to synchronize to the inode if the
1312                          * file is extended afterwords.
1313                          */
1314                         hammer2_chain_modify(trans, &chain, 0);
1315                         hammer2_chain_delete_duplicate(trans, &chain,
1316                                                        HAMMER2_DELDUP_RECORE);
1317                         ipdata = &chain->data->ipdata;
1318                         ipdata->target_type = ipdata->type;
1319                         ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1320                         ipdata->uflags = 0;
1321                         ipdata->rmajor = 0;
1322                         ipdata->rminor = 0;
1323                         ipdata->ctime = 0;
1324                         ipdata->mtime = 0;
1325                         ipdata->atime = 0;
1326                         ipdata->btime = 0;
1327                         bzero(&ipdata->uid, sizeof(ipdata->uid));
1328                         bzero(&ipdata->gid, sizeof(ipdata->gid));
1329                         ipdata->op_flags = HAMMER2_OPFLAG_DIRECTDATA;
1330                         ipdata->cap_flags = 0;
1331                         ipdata->mode = 0;
1332                         ipdata->size = 0;
1333                         ipdata->nlinks = 1;
1334                         ipdata->iparent = 0;    /* XXX */
1335                         ipdata->pfs_type = 0;
1336                         ipdata->pfs_inum = 0;
1337                         bzero(&ipdata->pfs_clid, sizeof(ipdata->pfs_clid));
1338                         bzero(&ipdata->pfs_fsid, sizeof(ipdata->pfs_fsid));
1339                         ipdata->data_quota = 0;
1340                         ipdata->data_count = 0;
1341                         ipdata->inode_quota = 0;
1342                         ipdata->inode_count = 0;
1343                         ipdata->attr_tid = 0;
1344                         ipdata->dirent_tid = 0;
1345                         bzero(&ipdata->u, sizeof(ipdata->u));
1346                         /* XXX transaction ids */
1347                 } else {
1348                         hammer2_chain_delete(trans, chain);
1349                 }
1350
1351                 /*
1352                  * Return the new chain.
1353                  */
1354                 hammer2_chain_unlock(chain);
1355                 chain = nchain;
1356         } else {
1357                 /*
1358                  * Return an error
1359                  */
1360                 hammer2_chain_unlock(chain);
1361                 chain = NULL;
1362         }
1363
1364         /*
1365          * Cleanup, chain/nchain already dealt with.
1366          */
1367 done:
1368         *chainp = chain;
1369         hammer2_inode_drop(cdip);
1370
1371         return (error);
1372 }
1373
1374 /*
1375  * If (*ochainp) is non-NULL it points to the forward OBJTYPE_HARDLINK
1376  * inode while (*chainp) points to the resolved (hidden hardlink
1377  * target) inode.  In this situation when nlinks is 1 we wish to
1378  * deconsolidate the hardlink, moving it back to the directory that now
1379  * represents the only remaining link.
1380  */
1381 int
1382 hammer2_hardlink_deconsolidate(hammer2_trans_t *trans,
1383                                hammer2_inode_t *dip,
1384                                hammer2_chain_t **chainp,
1385                                hammer2_chain_t **ochainp)
1386 {
1387         if (*ochainp == NULL)
1388                 return (0);
1389         /* XXX */
1390         return (0);
1391 }
1392
1393 /*
1394  * The caller presents a locked *chainp pointing to a HAMMER2_BREF_TYPE_INODE
1395  * with an obj_type of HAMMER2_OBJTYPE_HARDLINK.  This routine will gobble
1396  * the *chainp and return a new locked *chainp representing the file target
1397  * (the original *chainp will be unlocked).
1398  *
1399  * When a match is found the chain representing the original HARDLINK
1400  * will be returned in *ochainp with a ref, but not locked.
1401  *
1402  * When no match is found *chainp is set to NULL and EIO is returned.
1403  * (*ochainp) will still be set to the original chain with a ref but not
1404  * locked.
1405  */
1406 int
1407 hammer2_hardlink_find(hammer2_inode_t *dip, hammer2_chain_t **chainp,
1408                       hammer2_chain_t **ochainp)
1409 {
1410         hammer2_chain_t *chain = *chainp;
1411         hammer2_chain_t *parent;
1412         hammer2_inode_t *ip;
1413         hammer2_inode_t *pip;
1414         hammer2_key_t lhc;
1415
1416         pip = dip;
1417         hammer2_inode_ref(pip);         /* for loop */
1418         hammer2_chain_ref(chain);       /* for (*ochainp) */
1419         *ochainp = chain;
1420
1421         /*
1422          * Locate the hardlink.  pip is referenced and not locked,
1423          * ipp.
1424          *
1425          * chain is reused.
1426          */
1427         lhc = chain->data->ipdata.inum;
1428         hammer2_chain_unlock(chain);
1429         chain = NULL;
1430
1431         while ((ip = pip) != NULL) {
1432                 parent = hammer2_inode_lock_ex(ip);
1433                 hammer2_inode_drop(ip);                 /* loop */
1434                 KKASSERT(parent->bref.type == HAMMER2_BREF_TYPE_INODE);
1435                 chain = hammer2_chain_lookup(&parent, lhc, lhc, 0);
1436                 hammer2_chain_lookup_done(parent);      /* discard parent */
1437                 if (chain)
1438                         break;
1439                 pip = ip->pip;          /* safe, ip held locked */
1440                 if (pip)
1441                         hammer2_inode_ref(pip);         /* loop */
1442                 hammer2_inode_unlock_ex(ip, NULL);
1443         }
1444
1445         /*
1446          * chain is locked, ip is locked.  Unlock ip, return the locked
1447          * chain.  *ipp is already set w/a ref count and not locked.
1448          *
1449          * (parent is already unlocked).
1450          */
1451         if (ip)
1452                 hammer2_inode_unlock_ex(ip, NULL);
1453         *chainp = chain;
1454         if (chain) {
1455                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
1456                 /* already locked */
1457                 return (0);
1458         } else {
1459                 return (EIO);
1460         }
1461 }
1462
1463 /*
1464  * Find the directory common to both fdip and tdip, hold and return
1465  * its inode.
1466  */
1467 hammer2_inode_t *
1468 hammer2_inode_common_parent(hammer2_inode_t *fdip, hammer2_inode_t *tdip)
1469 {
1470         hammer2_inode_t *scan1;
1471         hammer2_inode_t *scan2;
1472
1473         /*
1474          * We used to have a depth field but it complicated matters too
1475          * much for directory renames.  So now its ugly.  Check for
1476          * simple cases before giving up and doing it the expensive way.
1477          *
1478          * XXX need a bottom-up topology stability lock
1479          */
1480         if (fdip == tdip || fdip == tdip->pip) {
1481                 hammer2_inode_ref(fdip);
1482                 return(fdip);
1483         }
1484         if (fdip->pip == tdip) {
1485                 hammer2_inode_ref(tdip);
1486                 return(tdip);
1487         }
1488
1489         /*
1490          * XXX not MPSAFE
1491          */
1492         for (scan1 = fdip; scan1->pmp == fdip->pmp; scan1 = scan1->pip) {
1493                 scan2 = tdip;
1494                 while (scan2->pmp == tdip->pmp) {
1495                         if (scan1 == scan2) {
1496                                 hammer2_inode_ref(scan1);
1497                                 return(scan1);
1498                         }
1499                         scan2 = scan2->pip;
1500                         if (scan2 == NULL)
1501                                 break;
1502                 }
1503         }
1504         panic("hammer2_inode_common_parent: no common parent %p %p\n",
1505               fdip, tdip);
1506         /* NOT REACHED */
1507         return(NULL);
1508 }