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 which can cause ip's cached
  67  * 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_core_t *core;
  79
  80         hammer2_inode_ref(ip);
  81         ccms_thread_lock(&ip->topo_cst, CCMS_STATE_EXCLUSIVE);
  82
  83         chain = ip->chain;
  84         core = chain->core;
  85         for (;;) {
  86                 if (chain->flags & HAMMER2_CHAIN_DUPLICATED) {
  87                         spin_lock(&core->cst.spin);
  88                         while (chain->flags & HAMMER2_CHAIN_DUPLICATED)
  89                                 chain = TAILQ_NEXT(chain, core_entry);
  90                         hammer2_chain_ref(chain);
  91                         spin_unlock(&core->cst.spin);
  92                         hammer2_inode_repoint(ip, NULL, chain);
  93                         hammer2_chain_drop(chain);
  94                 }
  95                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS);
  96                 if ((chain->flags & HAMMER2_CHAIN_DUPLICATED) == 0)
  97                         break;
  98                 hammer2_chain_unlock(chain);
  99         }
 100         return (chain);
 101 }
 102
 103 void
 104 hammer2_inode_unlock_ex(hammer2_inode_t *ip, hammer2_chain_t *chain)
 105 {
 106         /*
 107          * XXX this will catch parent directories too which we don't
 108          *     really want.
 109          */
 110         if (chain)
 111                 hammer2_chain_unlock(chain);
 112         ccms_thread_unlock(&ip->topo_cst);
 113         hammer2_inode_drop(ip);
 114 }
 115
 116 /*
 117  * NOTE: We don't combine the inode/chain lock because putting away an
 118  *       inode would otherwise confuse multiple lock holders of the inode.
 119  *
 120  *       Shared locks are especially sensitive to having too many shared
 121  *       lock counts (from the same thread) on certain paths which might
 122  *       need to upgrade them.  Only one count of a shared lock can be
 123  *       upgraded.
 124  */
 125 hammer2_chain_t *
 126 hammer2_inode_lock_sh(hammer2_inode_t *ip)
 127 {
 128         hammer2_chain_t *chain;
 129
 130         hammer2_inode_ref(ip);
 131         for (;;) {
 132                 ccms_thread_lock(&ip->topo_cst, CCMS_STATE_SHARED);
 133
 134                 chain = ip->chain;
 135                 KKASSERT(chain != NULL);        /* for now */
 136                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 137                                           HAMMER2_RESOLVE_SHARED);
 138
 139                 /*
 140                  * Resolve duplication races
 141                  */
 142                 if ((chain->flags & HAMMER2_CHAIN_DUPLICATED) == 0)
 143                         break;
 144                 hammer2_chain_unlock(chain);
 145                 ccms_thread_unlock(&ip->topo_cst);
 146                 chain = hammer2_inode_lock_ex(ip);
 147                 hammer2_inode_unlock_ex(ip, chain);
 148         }
 149         return (chain);
 150 }
 151
 152 void
 153 hammer2_inode_unlock_sh(hammer2_inode_t *ip, hammer2_chain_t *chain)
 154 {
 155         if (chain)
 156                 hammer2_chain_unlock(chain);
 157         ccms_thread_unlock(&ip->topo_cst);
 158         hammer2_inode_drop(ip);
 159 }
 160
 161 ccms_state_t
 162 hammer2_inode_lock_temp_release(hammer2_inode_t *ip)
 163 {
 164         return(ccms_thread_lock_temp_release(&ip->topo_cst));
 165 }
 166
 167 void
 168 hammer2_inode_lock_temp_restore(hammer2_inode_t *ip, ccms_state_t ostate)
 169 {
 170         ccms_thread_lock_temp_restore(&ip->topo_cst, ostate);
 171 }
 172
 173 ccms_state_t
 174 hammer2_inode_lock_upgrade(hammer2_inode_t *ip)
 175 {
 176         return(ccms_thread_lock_upgrade(&ip->topo_cst));
 177 }
 178
 179 void
 180 hammer2_inode_lock_downgrade(hammer2_inode_t *ip, ccms_state_t ostate)
 181 {
 182         ccms_thread_lock_downgrade(&ip->topo_cst, ostate);
 183 }
 184
 185 /*
 186  * Lookup an inode by inode number
 187  */
 188 hammer2_inode_t *
 189 hammer2_inode_lookup(hammer2_pfsmount_t *pmp, hammer2_tid_t inum)
 190 {
 191         hammer2_inode_t *ip;
 192
 193         if (pmp) {
 194                 spin_lock(&pmp->inum_spin);
 195                 ip = RB_LOOKUP(hammer2_inode_tree, &pmp->inum_tree, inum);
 196                 if (ip)
 197                         hammer2_inode_ref(ip);
 198                 spin_unlock(&pmp->inum_spin);
 199         } else {
 200                 ip = NULL;
 201         }
 202         return(ip);
 203 }
 204
 205 /*
 206  * Adding a ref to an inode is only legal if the inode already has at least
 207  * one ref.
 208  */
 209 void
 210 hammer2_inode_ref(hammer2_inode_t *ip)
 211 {
 212         atomic_add_int(&ip->refs, 1);
 213 }
 214
 215 /*
 216  * Drop an inode reference, freeing the inode when the last reference goes
 217  * away.
 218  */
 219 void
 220 hammer2_inode_drop(hammer2_inode_t *ip)
 221 {
 222         hammer2_pfsmount_t *pmp;
 223         hammer2_inode_t *pip;
 224         u_int refs;
 225
 226         while (ip) {
 227                 refs = ip->refs;
 228                 cpu_ccfence();
 229                 if (refs == 1) {
 230                         /*
 231                          * Transition to zero, must interlock with
 232                          * the inode inumber lookup tree (if applicable).
 233                          *
 234                          * NOTE: The super-root inode has no pmp.
 235                          */
 236                         pmp = ip->pmp;
 237                         if (pmp)
 238                                 spin_lock(&pmp->inum_spin);
 239
 240                         if (atomic_cmpset_int(&ip->refs, 1, 0)) {
 241                                 KKASSERT(ip->topo_cst.count == 0);
 242                                 if (ip->flags & HAMMER2_INODE_ONRBTREE) {
 243                                         atomic_clear_int(&ip->flags,
 244                                                      HAMMER2_INODE_ONRBTREE);
 245                                         RB_REMOVE(hammer2_inode_tree,
 246                                                   &pmp->inum_tree, ip);
 247                                 }
 248                                 if (pmp)
 249                                         spin_unlock(&pmp->inum_spin);
 250
 251                                 pip = ip->pip;
 252                                 ip->pip = NULL;
 253                                 ip->pmp = NULL;
 254
 255                                 /*
 256                                  * Cleaning out ip->chain isn't entirely
 257                                  * trivial.
 258                                  */
 259                                 hammer2_inode_repoint(ip, NULL, NULL);
 260
 261                                 /*
 262                                  * We have to drop pip (if non-NULL) to
 263                                  * dispose of our implied reference from
 264                                  * ip->pip.  We can simply loop on it.
 265                                  */
 266                                 if (pmp) {
 267                                         KKASSERT((ip->flags &
 268                                                   HAMMER2_INODE_SROOT) == 0);
 269                                         kfree(ip, pmp->minode);
 270                                         atomic_add_long(&pmp->inmem_inodes, -1);
 271                                 } else {
 272                                         KKASSERT(ip->flags &
 273                                                  HAMMER2_INODE_SROOT);
 274                                         kfree(ip, M_HAMMER2);
 275                                 }
 276                                 ip = pip;
 277                                 /* continue with pip (can be NULL) */
 278                         } else {
 279                                 if (pmp)
 280                                         spin_unlock(&ip->pmp->inum_spin);
 281                         }
 282                 } else {
 283                         /*
 284                          * Non zero transition
 285                          */
 286                         if (atomic_cmpset_int(&ip->refs, refs, refs - 1))
 287                                 break;
 288                 }
 289         }
 290 }
 291
 292 /*
 293  * Get the vnode associated with the given inode, allocating the vnode if
 294  * necessary.  The vnode will be returned exclusively locked.
 295  *
 296  * The caller must lock the inode (shared or exclusive).
 297  *
 298  * Great care must be taken to avoid deadlocks and vnode acquisition/reclaim
 299  * races.
 300  */
 301 struct vnode *
 302 hammer2_igetv(hammer2_inode_t *ip, int *errorp)
 303 {
 304         hammer2_inode_data_t *ipdata;
 305         hammer2_pfsmount_t *pmp;
 306         struct vnode *vp;
 307         ccms_state_t ostate;
 308
 309         pmp = ip->pmp;
 310         KKASSERT(pmp != NULL);
 311         *errorp = 0;
 312         ipdata = &ip->chain->data->ipdata;
 313
 314         for (;;) {
 315                 /*
 316                  * Attempt to reuse an existing vnode assignment.  It is
 317                  * possible to race a reclaim so the vget() may fail.  The
 318                  * inode must be unlocked during the vget() to avoid a
 319                  * deadlock against a reclaim.
 320                  */
 321                 vp = ip->vp;
 322                 if (vp) {
 323                         /*
 324                          * Inode must be unlocked during the vget() to avoid
 325                          * possible deadlocks, but leave the ip ref intact.
 326                          *
 327                          * vnode is held to prevent destruction during the
 328                          * vget().  The vget() can still fail if we lost
 329                          * a reclaim race on the vnode.
 330                          */
 331                         vhold(vp);
 332                         ostate = hammer2_inode_lock_temp_release(ip);
 333                         if (vget(vp, LK_EXCLUSIVE)) {
 334                                 vdrop(vp);
 335                                 hammer2_inode_lock_temp_restore(ip, ostate);
 336                                 continue;
 337                         }
 338                         hammer2_inode_lock_temp_restore(ip, ostate);
 339                         vdrop(vp);
 340                         /* vp still locked and ref from vget */
 341                         if (ip->vp != vp) {
 342                                 kprintf("hammer2: igetv race %p/%p\n",
 343                                         ip->vp, vp);
 344                                 vput(vp);
 345                                 continue;
 346                         }
 347                         *errorp = 0;
 348                         break;
 349                 }
 350
 351                 /*
 352                  * No vnode exists, allocate a new vnode.  Beware of
 353                  * allocation races.  This function will return an
 354                  * exclusively locked and referenced vnode.
 355                  */
 356                 *errorp = getnewvnode(VT_HAMMER2, pmp->mp, &vp, 0, 0);
 357                 if (*errorp) {
 358                         kprintf("hammer2: igetv getnewvnode failed %d\n",
 359                                 *errorp);
 360                         vp = NULL;
 361                         break;
 362                 }
 363
 364                 /*
 365                  * Lock the inode and check for an allocation race.
 366                  */
 367                 ostate = hammer2_inode_lock_upgrade(ip);
 368                 if (ip->vp != NULL) {
 369                         vp->v_type = VBAD;
 370                         vx_put(vp);
 371                         hammer2_inode_lock_downgrade(ip, ostate);
 372                         continue;
 373                 }
 374
 375                 switch (ipdata->type) {
 376                 case HAMMER2_OBJTYPE_DIRECTORY:
 377                         vp->v_type = VDIR;
 378                         break;
 379                 case HAMMER2_OBJTYPE_REGFILE:
 380                         vp->v_type = VREG;
 381                         vinitvmio(vp, ipdata->size,
 382                                   HAMMER2_LBUFSIZE,
 383                                   (int)ipdata->size & HAMMER2_LBUFMASK);
 384                         break;
 385                 case HAMMER2_OBJTYPE_SOFTLINK:
 386                         /*
 387                          * XXX for now we are using the generic file_read
 388                          * and file_write code so we need a buffer cache
 389                          * association.
 390                          */
 391                         vp->v_type = VLNK;
 392                         vinitvmio(vp, ipdata->size,
 393                                   HAMMER2_LBUFSIZE,
 394                                   (int)ipdata->size & HAMMER2_LBUFMASK);
 395                         break;
 396                 case HAMMER2_OBJTYPE_CDEV:
 397                         vp->v_type = VCHR;
 398                         /* fall through */
 399                 case HAMMER2_OBJTYPE_BDEV:
 400                         vp->v_ops = &pmp->mp->mnt_vn_spec_ops;
 401                         if (ipdata->type != HAMMER2_OBJTYPE_CDEV)
 402                                 vp->v_type = VBLK;
 403                         addaliasu(vp, ipdata->rmajor, ipdata->rminor);
 404                         break;
 405                 case HAMMER2_OBJTYPE_FIFO:
 406                         vp->v_type = VFIFO;
 407                         vp->v_ops = &pmp->mp->mnt_vn_fifo_ops;
 408                         break;
 409                 default:
 410                         panic("hammer2: unhandled objtype %d", ipdata->type);
 411                         break;
 412                 }
 413
 414                 if (ip == pmp->iroot)
 415                         vsetflags(vp, VROOT);
 416
 417                 vp->v_data = ip;
 418                 ip->vp = vp;
 419                 hammer2_inode_ref(ip);          /* vp association */
 420                 hammer2_inode_lock_downgrade(ip, ostate);
 421                 break;
 422         }
 423
 424         /*
 425          * Return non-NULL vp and *errorp == 0, or NULL vp and *errorp != 0.
 426          */
 427         if (hammer2_debug & 0x0002) {
 428                 kprintf("igetv vp %p refs 0x%08x aux 0x%08x\n",
 429                         vp, vp->v_refcnt, vp->v_auxrefs);
 430         }
 431         return (vp);
 432 }
 433
 434 /*
 435  * The passed-in chain must be locked and the returned inode will also be
 436  * locked.  This routine typically locates or allocates the inode, assigns
 437  * ip->chain (adding a ref to chain if necessary), and returns the inode.
 438  *
 439  * The hammer2_inode structure regulates the interface between the high level
 440  * kernel VNOPS API and the filesystem backend (the chains).
 441  *
 442  * WARNING!  This routine sucks up the chain's lock (makes it part of the
 443  *           inode lock from the point of view of the inode lock API),
 444  *           so callers need to be careful.
 445  *
 446  * WARNING!  The mount code is allowed to pass dip == NULL for iroot and
 447  *           is allowed to pass pmp == NULL and dip == NULL for sroot.
 448  */
 449 hammer2_inode_t *
 450 hammer2_inode_get(hammer2_pfsmount_t *pmp, hammer2_inode_t *dip,
 451                   hammer2_chain_t *chain)
 452 {
 453         hammer2_inode_t *nip;
 454
 455         KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
 456
 457         /*
 458          * Interlocked lookup/ref of the inode.  This code is only needed
 459          * when looking up inodes with nlinks != 0 (TODO: optimize out
 460          * otherwise and test for duplicates).
 461          */
 462 again:
 463         for (;;) {
 464                 nip = hammer2_inode_lookup(pmp, chain->data->ipdata.inum);
 465                 if (nip == NULL)
 466                         break;
 467                 ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 468                 if ((nip->flags & HAMMER2_INODE_ONRBTREE) == 0) { /* race */
 469                         ccms_thread_unlock(&nip->topo_cst);
 470                         hammer2_inode_drop(nip);
 471                         continue;
 472                 }
 473                 if (nip->chain != chain)
 474                         hammer2_inode_repoint(nip, NULL, chain);
 475
 476                 /*
 477                  * Consolidated nip/nip->chain is locked (chain locked
 478                  * by caller).
 479                  */
 480                 return nip;
 481         }
 482
 483         /*
 484          * We couldn't find the inode number, create a new inode.
 485          */
 486         if (pmp) {
 487                 nip = kmalloc(sizeof(*nip), pmp->minode, M_WAITOK | M_ZERO);
 488                 atomic_add_long(&pmp->inmem_inodes, 1);
 489                 hammer2_chain_memory_wakeup(pmp);
 490         } else {
 491                 nip = kmalloc(sizeof(*nip), M_HAMMER2, M_WAITOK | M_ZERO);
 492                 nip->flags = HAMMER2_INODE_SROOT;
 493         }
 494         nip->inum = chain->data->ipdata.inum;
 495         nip->size = chain->data->ipdata.size;
 496         nip->mtime = chain->data->ipdata.mtime;
 497         hammer2_inode_repoint(nip, NULL, chain);
 498         nip->pip = dip;                         /* can be NULL */
 499         if (dip)
 500                 hammer2_inode_ref(dip); /* ref dip for nip->pip */
 501
 502         nip->pmp = pmp;
 503
 504         /*
 505          * ref and lock on nip gives it state compatible to after a
 506          * hammer2_inode_lock_ex() call.
 507          */
 508         nip->refs = 1;
 509         ccms_cst_init(&nip->topo_cst, &nip->chain);
 510         ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 511         /* combination of thread lock and chain lock == inode lock */
 512
 513         /*
 514          * Attempt to add the inode.  If it fails we raced another inode
 515          * get.  Undo all the work and try again.
 516          */
 517         if (pmp) {
 518                 spin_lock(&pmp->inum_spin);
 519                 if (RB_INSERT(hammer2_inode_tree, &pmp->inum_tree, nip)) {
 520                         spin_unlock(&pmp->inum_spin);
 521                         ccms_thread_unlock(&nip->topo_cst);
 522                         hammer2_inode_drop(nip);
 523                         goto again;
 524                 }
 525                 atomic_set_int(&nip->flags, HAMMER2_INODE_ONRBTREE);
 526                 spin_unlock(&pmp->inum_spin);
 527         }
 528
 529         return (nip);
 530 }
 531
 532 /*
 533  * Create a new inode in the specified directory using the vattr to
 534  * figure out the type of inode.
 535  *
 536  * If no error occurs the new inode with its chain locked is returned in
 537  * *nipp, otherwise an error is returned and *nipp is set to NULL.
 538  *
 539  * If vap and/or cred are NULL the related fields are not set and the
 540  * inode type defaults to a directory.  This is used when creating PFSs
 541  * under the super-root, so the inode number is set to 1 in this case.
 542  *
 543  * dip is not locked on entry.
 544  */
 545 hammer2_inode_t *
 546 hammer2_inode_create(hammer2_trans_t *trans, hammer2_inode_t *dip,
 547                      struct vattr *vap, struct ucred *cred,
 548                      const uint8_t *name, size_t name_len,
 549                      hammer2_chain_t **chainp, int *errorp)
 550 {
 551         hammer2_inode_data_t *dipdata;
 552         hammer2_inode_data_t *nipdata;
 553         hammer2_chain_t *chain;
 554         hammer2_chain_t *parent;
 555         hammer2_inode_t *nip;
 556         hammer2_key_t key_dummy;
 557         hammer2_key_t lhc;
 558         int error;
 559         uid_t xuid;
 560         uuid_t dip_uid;
 561         uuid_t dip_gid;
 562         uint32_t dip_mode;
 563         uint8_t dip_algo;
 564         int cache_index = -1;
 565
 566         lhc = hammer2_dirhash(name, name_len);
 567         *errorp = 0;
 568
 569         /*
 570          * Locate the inode or indirect block to create the new
 571          * entry in.  At the same time check for key collisions
 572          * and iterate until we don't get one.
 573          *
 574          * NOTE: hidden inodes do not have iterators.
 575          */
 576 retry:
 577         parent = hammer2_inode_lock_ex(dip);
 578         dipdata = &dip->chain->data->ipdata;
 579         dip_uid = dipdata->uid;
 580         dip_gid = dipdata->gid;
 581         dip_mode = dipdata->mode;
 582         dip_algo = dipdata->comp_algo;
 583
 584         error = 0;
 585         while (error == 0) {
 586                 chain = hammer2_chain_lookup(&parent, &key_dummy,
 587                                              lhc, lhc, &cache_index, 0);
 588                 if (chain == NULL)
 589                         break;
 590                 if ((lhc & HAMMER2_DIRHASH_VISIBLE) == 0)
 591                         error = ENOSPC;
 592                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 593                         error = ENOSPC;
 594                 hammer2_chain_unlock(chain);
 595                 chain = NULL;
 596                 ++lhc;
 597         }
 598
 599         if (error == 0) {
 600                 error = hammer2_chain_create(trans, &parent, &chain,
 601                                              lhc, 0,
 602                                              HAMMER2_BREF_TYPE_INODE,
 603                                              HAMMER2_INODE_BYTES);
 604         }
 605
 606         /*
 607          * Cleanup and handle retries.
 608          */
 609         if (error == EAGAIN) {
 610                 hammer2_chain_ref(parent);
 611                 hammer2_inode_unlock_ex(dip, parent);
 612                 hammer2_chain_wait(parent);
 613                 hammer2_chain_drop(parent);
 614                 goto retry;
 615         }
 616         hammer2_inode_unlock_ex(dip, parent);
 617
 618         if (error) {
 619                 KKASSERT(chain == NULL);
 620                 *errorp = error;
 621                 return (NULL);
 622         }
 623
 624         /*
 625          * Set up the new inode.
 626          *
 627          * NOTE: *_get() integrates chain's lock into the inode lock.
 628          *
 629          * NOTE: Only one new inode can currently be created per
 630          *       transaction.  If the need arises we can adjust
 631          *       hammer2_trans_init() to allow more.
 632          *
 633          * NOTE: nipdata will have chain's blockset data.
 634          */
 635         chain->data->ipdata.inum = trans->inode_tid;
 636         nip = hammer2_inode_get(dip->pmp, dip, chain);
 637         nipdata = &chain->data->ipdata;
 638
 639         if (vap) {
 640                 KKASSERT(trans->inodes_created == 0);
 641                 nipdata->type = hammer2_get_obj_type(vap->va_type);
 642                 nipdata->inum = trans->inode_tid;
 643                 ++trans->inodes_created;
 644
 645                 switch (nipdata->type) {
 646                 case HAMMER2_OBJTYPE_CDEV:
 647                 case HAMMER2_OBJTYPE_BDEV:
 648                         nipdata->rmajor = vap->va_rmajor;
 649                         nipdata->rminor = vap->va_rminor;
 650                         break;
 651                 default:
 652                         break;
 653                 }
 654         } else {
 655                 nipdata->type = HAMMER2_OBJTYPE_DIRECTORY;
 656                 nipdata->inum = 1;
 657         }
 658
 659         /* Inherit parent's inode compression mode. */
 660         nip->comp_heuristic = 0;
 661         nipdata->comp_algo = dip_algo;
 662         nipdata->version = HAMMER2_INODE_VERSION_ONE;
 663         hammer2_update_time(&nipdata->ctime);
 664         nipdata->mtime = nipdata->ctime;
 665         if (vap)
 666                 nipdata->mode = vap->va_mode;
 667         nipdata->nlinks = 1;
 668         if (vap) {
 669                 if (dip && dip->pmp) {
 670                         xuid = hammer2_to_unix_xid(&dip_uid);
 671                         xuid = vop_helper_create_uid(dip->pmp->mp,
 672                                                      dip_mode,
 673                                                      xuid,
 674                                                      cred,
 675                                                      &vap->va_mode);
 676                 } else {
 677                         /* super-root has no dip and/or pmp */
 678                         xuid = 0;
 679                 }
 680                 if (vap->va_vaflags & VA_UID_UUID_VALID)
 681                         nipdata->uid = vap->va_uid_uuid;
 682                 else if (vap->va_uid != (uid_t)VNOVAL)
 683                         hammer2_guid_to_uuid(&nipdata->uid, vap->va_uid);
 684                 else
 685                         hammer2_guid_to_uuid(&nipdata->uid, xuid);
 686
 687                 if (vap->va_vaflags & VA_GID_UUID_VALID)
 688                         nipdata->gid = vap->va_gid_uuid;
 689                 else if (vap->va_gid != (gid_t)VNOVAL)
 690                         hammer2_guid_to_uuid(&nipdata->gid, vap->va_gid);
 691                 else if (dip)
 692                         nipdata->gid = dip_gid;
 693         }
 694
 695         /*
 696          * Regular files and softlinks allow a small amount of data to be
 697          * directly embedded in the inode.  This flag will be cleared if
 698          * the size is extended past the embedded limit.
 699          */
 700         if (nipdata->type == HAMMER2_OBJTYPE_REGFILE ||
 701             nipdata->type == HAMMER2_OBJTYPE_SOFTLINK) {
 702                 nipdata->op_flags |= HAMMER2_OPFLAG_DIRECTDATA;
 703         }
 704
 705         KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 706         bcopy(name, nipdata->filename, name_len);
 707         nipdata->name_key = lhc;
 708         nipdata->name_len = name_len;
 709         *chainp = chain;
 710
 711         return (nip);
 712 }
 713
 714 /*
 715  * chain may have been moved around by the create.
 716  */
 717 void
 718 hammer2_chain_refactor(hammer2_chain_t **chainp)
 719 {
 720         hammer2_chain_t *chain = *chainp;
 721         hammer2_chain_core_t *core;
 722
 723         core = chain->core;
 724         while (chain->flags & HAMMER2_CHAIN_DUPLICATED) {
 725                 spin_lock(&core->cst.spin);
 726                 chain = TAILQ_NEXT(chain, core_entry);
 727                 while (chain->flags & HAMMER2_CHAIN_DUPLICATED)
 728                         chain = TAILQ_NEXT(chain, core_entry);
 729                 hammer2_chain_ref(chain);
 730                 spin_unlock(&core->cst.spin);
 731                 KKASSERT(chain->core == core);
 732
 733                 hammer2_chain_unlock(*chainp);
 734                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 735                                           HAMMER2_RESOLVE_NOREF); /* eat ref */
 736                 *chainp = chain;
 737         }
 738 }
 739
 740 /*
 741  * ochain represents the target file inode.  We need to move it to the
 742  * specified common parent directory (dip) and rename it to a special
 743  * invisible "0xINODENUMBER" filename.
 744  *
 745  * We use chain_duplicate and duplicate ochain at the new location,
 746  * renaming it appropriately.  We create a temporary chain and
 747  * then delete it to placemark where the duplicate will go.  Both of
 748  * these use the inode number for (lhc) (the key), generating the
 749  * invisible filename.
 750  *
 751  * The original ochain is deleted.
 752  */
 753 static
 754 hammer2_chain_t *
 755 hammer2_hardlink_shiftup(hammer2_trans_t *trans, hammer2_chain_t **ochainp,
 756                         hammer2_inode_t *dip, int *errorp)
 757 {
 758         hammer2_inode_data_t *nipdata;
 759         hammer2_chain_t *parent;
 760         hammer2_chain_t *ochain;
 761         hammer2_chain_t *nchain;
 762         hammer2_chain_t *tmp;
 763         hammer2_key_t key_dummy;
 764         hammer2_key_t lhc;
 765         hammer2_blockref_t bref;
 766         int cache_index = -1;
 767
 768         ochain = *ochainp;
 769         *errorp = 0;
 770         lhc = ochain->data->ipdata.inum;
 771         KKASSERT((lhc & HAMMER2_DIRHASH_VISIBLE) == 0);
 772
 773         /*
 774          * Locate the inode or indirect block to create the new
 775          * entry in.  lhc represents the inode number so there is
 776          * no collision iteration.
 777          *
 778          * There should be no key collisions with invisible inode keys.
 779          *
 780          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 781          *          dip->chain cache.
 782          */
 783 retry:
 784         parent = hammer2_inode_lock_ex(dip);
 785         /*parent = hammer2_chain_lookup_init(dip->chain, 0);*/
 786         nchain = hammer2_chain_lookup(&parent, &key_dummy,
 787                                       lhc, lhc, &cache_index, 0);
 788         if (nchain) {
 789                 kprintf("X3 chain %p parent %p dip %p dip->chain %p\n",
 790                         nchain, parent, dip, dip->chain);
 791                 hammer2_chain_unlock(nchain);
 792                 nchain = NULL;
 793                 *errorp = ENOSPC;
 794 #if 0
 795                 Debugger("X3");
 796 #endif
 797         }
 798
 799         /*
 800          * Create entry in common parent directory using the seek position
 801          * calculated above.
 802          */
 803         if (*errorp == 0) {
 804                 KKASSERT(nchain == NULL);
 805                 *errorp = hammer2_chain_create(trans, &parent, &nchain,
 806                                                lhc, 0,
 807                                                HAMMER2_BREF_TYPE_INODE,/* n/a */
 808                                                HAMMER2_INODE_BYTES);   /* n/a */
 809                 hammer2_chain_refactor(&ochain);
 810                 *ochainp = ochain;
 811         }
 812
 813         /*
 814          * Cleanup and handle retries.
 815          */
 816         if (*errorp == EAGAIN) {
 817                 hammer2_chain_ref(parent);
 818                 /* hammer2_chain_lookup_done(parent); */
 819                 hammer2_inode_unlock_ex(dip, parent);
 820                 hammer2_chain_wait(parent);
 821                 hammer2_chain_drop(parent);
 822                 goto retry;
 823         }
 824
 825         /*
 826          * Handle the error case
 827          */
 828         if (*errorp) {
 829                 KKASSERT(nchain == NULL);
 830                 hammer2_inode_unlock_ex(dip, parent);
 831                 /*hammer2_chain_lookup_done(parent);*/
 832                 return (NULL);
 833         }
 834
 835         /*
 836          * Use nchain as a placeholder for (lhc), delete it and replace
 837          * it with our duplication.
 838          *
 839          * Gain a second lock on ochain for the duplication function to
 840          * unlock, maintain the caller's original lock across the call.
 841          *
 842          * This is a bit messy.
 843          */
 844         hammer2_chain_delete(trans, nchain, 0);
 845         hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
 846         tmp = ochain;
 847         bref = tmp->bref;
 848         bref.key = lhc;                 /* invisible dir entry key */
 849         bref.keybits = 0;
 850         hammer2_chain_duplicate(trans, &parent, &tmp, &bref, 0);
 851         hammer2_inode_unlock_ex(dip, parent);
 852         /*hammer2_chain_lookup_done(parent);*/
 853         hammer2_chain_unlock(nchain);   /* no longer needed */
 854
 855         /*
 856          * Now set nchain to our duplicate and modify it appropriately.
 857          * Note that this may result in a delete-duplicate.
 858          *
 859          * Directory entries are inodes but this is a hidden hardlink
 860          * target.  The name isn't used but to ease debugging give it
 861          * a name after its inode number.
 862          */
 863         nchain = tmp;
 864         tmp = NULL;     /* safety */
 865
 866         hammer2_chain_modify(trans, &nchain, 0);
 867         nipdata = &nchain->data->ipdata;
 868         ksnprintf(nipdata->filename, sizeof(nipdata->filename),
 869                   "0x%016jx", (intmax_t)nipdata->inum);
 870         nipdata->name_len = strlen(nipdata->filename);
 871         nipdata->name_key = lhc;
 872
 873         return (nchain);
 874 }
 875
 876 /*
 877  * Connect the target inode represented by (*chainp) to the media topology
 878  * at (dip, name, len).
 879  *
 880  * If hlink is TRUE this function creates an OBJTYPE_HARDLINK directory
 881  * entry instead of connecting (*chainp).
 882  *
 883  * If hlink is FALSE this function uses chain_duplicate() to make a copy
 884  * if (*chainp) in the directory entry.  (*chainp) is likely to be deleted
 885  * by the caller in this case (e.g. rename).
 886  */
 887 int
 888 hammer2_inode_connect(hammer2_trans_t *trans, int hlink,
 889                       hammer2_inode_t *dip, hammer2_chain_t **chainp,
 890                       const uint8_t *name, size_t name_len)
 891 {
 892         hammer2_inode_data_t *ipdata;
 893         hammer2_chain_t *nchain;
 894         hammer2_chain_t *parent;
 895         hammer2_chain_t *ochain;
 896         hammer2_key_t key_dummy;
 897         hammer2_key_t lhc;
 898         int cache_index = -1;
 899         int error;
 900
 901         ochain = *chainp;
 902
 903         /*
 904          * Since ochain is either disconnected from the topology or represents
 905          * a hardlink terminus which is always a parent of or equal to dip,
 906          * we should be able to safely lock dip->chain for our setup.
 907          *
 908          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 909          *          dip->chain cache.
 910          */
 911         parent = hammer2_inode_lock_ex(dip);
 912         /*parent = hammer2_chain_lookup_init(dip->chain, 0);*/
 913
 914         lhc = hammer2_dirhash(name, name_len);
 915
 916         /*
 917          * Locate the inode or indirect block to create the new
 918          * entry in.  At the same time check for key collisions
 919          * and iterate until we don't get one.
 920          */
 921         error = 0;
 922         while (error == 0) {
 923                 nchain = hammer2_chain_lookup(&parent, &key_dummy,
 924                                               lhc, lhc, &cache_index, 0);
 925                 if (nchain == NULL)
 926                         break;
 927                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 928                         error = ENOSPC;
 929                 hammer2_chain_unlock(nchain);
 930                 nchain = NULL;
 931                 ++lhc;
 932         }
 933
 934         if (error == 0) {
 935                 if (hlink) {
 936                         /*
 937                          * Hardlink pointer needed, create totally fresh
 938                          * directory entry.
 939                          */
 940                         KKASSERT(nchain == NULL);
 941                         error = hammer2_chain_create(trans, &parent, &nchain,
 942                                                      lhc, 0,
 943                                                      HAMMER2_BREF_TYPE_INODE,
 944                                                      HAMMER2_INODE_BYTES);
 945                         hammer2_chain_refactor(&ochain);
 946                 } else {
 947                         /*
 948                          * Reconnect the original chain and rename.  Use
 949                          * chain_duplicate().  The caller will likely delete
 950                          * or has already deleted the original chain in
 951                          * this case.
 952                          *
 953                          * NOTE: chain_duplicate() generates a new chain
 954                          *       with CHAIN_DELETED cleared (ochain typically
 955                          *       has it set from the file unlink).
 956                          */
 957                         nchain = ochain;
 958                         ochain = NULL;
 959                         hammer2_chain_duplicate(trans, NULL, &nchain, NULL, 0);
 960                         error = hammer2_chain_create(trans, &parent, &nchain,
 961                                                      lhc, 0,
 962                                                      HAMMER2_BREF_TYPE_INODE,
 963                                                      HAMMER2_INODE_BYTES);
 964                 }
 965         }
 966
 967         /*
 968          * Unlock stuff.
 969          */
 970         KKASSERT(error != EAGAIN);
 971         hammer2_inode_unlock_ex(dip, parent);
 972         /*hammer2_chain_lookup_done(parent);*/
 973         parent = NULL;
 974
 975         /*
 976          * nchain should be NULL on error, leave ochain (== *chainp) alone.
 977          */
 978         if (error) {
 979                 KKASSERT(nchain == NULL);
 980                 return (error);
 981         }
 982
 983         /*
 984          * Directory entries are inodes so if the name has changed we have
 985          * to update the inode.
 986          *
 987          * When creating an OBJTYPE_HARDLINK entry remember to unlock the
 988          * chain, the caller will access the hardlink via the actual hardlink
 989          * target file and not the hardlink pointer entry, so we must still
 990          * return ochain.
 991          */
 992         if (hlink && hammer2_hardlink_enable >= 0) {
 993                 /*
 994                  * Create the HARDLINK pointer.  oip represents the hardlink
 995                  * target in this situation.
 996                  *
 997                  * We will return ochain (the hardlink target).
 998                  */
 999                 hammer2_chain_modify(trans, &nchain,
1000                                      HAMMER2_MODIFY_ASSERTNOCOPY);
1001                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1002                 ipdata = &nchain->data->ipdata;
1003                 bcopy(name, ipdata->filename, name_len);
1004                 ipdata->name_key = lhc;
1005                 ipdata->name_len = name_len;
1006                 ipdata->target_type = ochain->data->ipdata.type;
1007                 ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1008                 ipdata->inum = ochain->data->ipdata.inum;
1009                 ipdata->nlinks = 1;
1010                 hammer2_chain_unlock(nchain);
1011                 nchain = ochain;
1012                 ochain = NULL;
1013         } else if (hlink && hammer2_hardlink_enable < 0) {
1014                 /*
1015                  * Create a snapshot (hardlink fake mode for debugging).
1016                  * (ochain already flushed above so we can just copy the
1017                  * bref XXX).
1018                  *
1019                  * Since this is a snapshot we return nchain in the fake
1020                  * hardlink case.
1021                  */
1022                 hammer2_chain_modify(trans, &nchain,
1023                                      HAMMER2_MODIFY_ASSERTNOCOPY);
1024                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1025                 ipdata = &nchain->data->ipdata;
1026                 *ipdata = ochain->data->ipdata;
1027                 bcopy(name, ipdata->filename, name_len);
1028                 ipdata->name_key = lhc;
1029                 ipdata->name_len = name_len;
1030                 atomic_clear_int(&nchain->core->flags,
1031                                  HAMMER2_CORE_COUNTEDBREFS);
1032                 kprintf("created fake hardlink %*.*s\n",
1033                         (int)name_len, (int)name_len, name);
1034         } else {
1035                 /*
1036                  * nchain is a duplicate of ochain at the new location.
1037                  * We must fixup the name stored in oip.  The bref key
1038                  * has already been set up.
1039                  */
1040                 hammer2_chain_modify(trans, &nchain,
1041                                      HAMMER2_MODIFY_ASSERTNOCOPY);
1042                 ipdata = &nchain->data->ipdata;
1043
1044                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1045                 bcopy(name, ipdata->filename, name_len);
1046                 ipdata->name_key = lhc;
1047                 ipdata->name_len = name_len;
1048                 ipdata->nlinks = 1;
1049         }
1050
1051         /*
1052          * We are replacing ochain with nchain, unlock ochain.  In the
1053          * case where ochain is left unchanged the code above sets
1054          * nchain to ochain and ochain to NULL, resulting in a NOP here.
1055          */
1056         if (ochain)
1057                 hammer2_chain_unlock(ochain);
1058         *chainp = nchain;
1059
1060         return (0);
1061 }
1062
1063 /*
1064  * Repoint ip->chain to nchain.  Caller must hold the inode exclusively
1065  * locked.
1066  *
1067  * ip->chain is set to nchain.  The prior chain in ip->chain is dropped
1068  * and nchain is ref'd.
1069  */
1070 void
1071 hammer2_inode_repoint(hammer2_inode_t *ip, hammer2_inode_t *pip,
1072                       hammer2_chain_t *nchain)
1073 {
1074         hammer2_chain_t *ochain;
1075         hammer2_inode_t *opip;
1076
1077         /*
1078          * Repoint ip->chain if requested.
1079          */
1080         ochain = ip->chain;
1081         ip->chain = nchain;
1082         if (nchain)
1083                 hammer2_chain_ref(nchain);
1084         if (ochain)
1085                 hammer2_chain_drop(ochain);
1086
1087         /*
1088          * Repoint ip->pip if requested (non-NULL pip).
1089          */
1090         if (pip && ip->pip != pip) {
1091                 opip = ip->pip;
1092                 hammer2_inode_ref(pip);
1093                 ip->pip = pip;
1094                 if (opip)
1095                         hammer2_inode_drop(opip);
1096         }
1097 }
1098
1099 /*
1100  * Unlink the file from the specified directory inode.  The directory inode
1101  * does not need to be locked.
1102  *
1103  * isdir determines whether a directory/non-directory check should be made.
1104  * No check is made if isdir is set to -1.
1105  *
1106  * NOTE!  The underlying file can still be active with open descriptors
1107  *        or if the chain is being manually held (e.g. for rename).
1108  *
1109  *        The caller is responsible for fixing up ip->chain if e.g. a
1110  *        rename occurs (see chain_duplicate()).
1111  */
1112 int
1113 hammer2_unlink_file(hammer2_trans_t *trans, hammer2_inode_t *dip,
1114                     const uint8_t *name, size_t name_len,
1115                     int isdir, int *hlinkp)
1116 {
1117         hammer2_inode_data_t *ipdata;
1118         hammer2_chain_t *parent;
1119         hammer2_chain_t *ochain;
1120         hammer2_chain_t *chain;
1121         hammer2_chain_t *dparent;
1122         hammer2_chain_t *dchain;
1123         hammer2_key_t key_dummy;
1124         hammer2_key_t key_next;
1125         hammer2_key_t lhc;
1126         int error;
1127         int cache_index = -1;
1128         uint8_t type;
1129
1130         error = 0;
1131         ochain = NULL;
1132         lhc = hammer2_dirhash(name, name_len);
1133
1134         /*
1135          * Search for the filename in the directory
1136          */
1137         if (hlinkp)
1138                 *hlinkp = 0;
1139         parent = hammer2_inode_lock_ex(dip);
1140         chain = hammer2_chain_lookup(&parent, &key_next,
1141                                      lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1142                                      &cache_index, 0);
1143         while (chain) {
1144                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1145                     name_len == chain->data->ipdata.name_len &&
1146                     bcmp(name, chain->data->ipdata.filename, name_len) == 0) {
1147                         break;
1148                 }
1149                 chain = hammer2_chain_next(&parent, chain, &key_next,
1150                                            key_next,
1151                                            lhc + HAMMER2_DIRHASH_LOMASK,
1152                                            &cache_index, 0);
1153         }
1154         hammer2_inode_unlock_ex(dip, NULL);     /* retain parent */
1155
1156         /*
1157          * Not found or wrong type (isdir < 0 disables the type check).
1158          * If a hardlink pointer, type checks use the hardlink target.
1159          */
1160         if (chain == NULL) {
1161                 error = ENOENT;
1162                 goto done;
1163         }
1164         if ((type = chain->data->ipdata.type) == HAMMER2_OBJTYPE_HARDLINK) {
1165                 if (hlinkp)
1166                         *hlinkp = 1;
1167                 type = chain->data->ipdata.target_type;
1168         }
1169
1170         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 0) {
1171                 error = ENOTDIR;
1172                 goto done;
1173         }
1174         if (type != HAMMER2_OBJTYPE_DIRECTORY && isdir >= 1) {
1175                 error = EISDIR;
1176                 goto done;
1177         }
1178
1179         /*
1180          * Hardlink must be resolved.  We can't hold parent locked while we
1181          * do this or we could deadlock.
1182          *
1183          * On success chain will be adjusted to point at the hardlink target
1184          * and ochain will point to the hardlink pointer in the original
1185          * directory.  Otherwise chain remains pointing to the original.
1186          */
1187         if (chain->data->ipdata.type == HAMMER2_OBJTYPE_HARDLINK) {
1188                 hammer2_chain_unlock(parent);
1189                 parent = NULL;
1190                 error = hammer2_hardlink_find(dip, &chain, &ochain);
1191         }
1192
1193         /*
1194          * If this is a directory the directory must be empty.  However, if
1195          * isdir < 0 we are doing a rename and the directory does not have
1196          * to be empty, and if isdir > 1 we are deleting a PFS/snapshot
1197          * and the directory does not have to be empty.
1198          *
1199          * NOTE: We check the full key range here which covers both visible
1200          *       and invisible entries.  Theoretically there should be no
1201          *       invisible (hardlink target) entries if there are no visible
1202          *       entries.
1203          */
1204         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 1) {
1205                 dparent = hammer2_chain_lookup_init(chain, 0);
1206                 dchain = hammer2_chain_lookup(&dparent, &key_dummy,
1207                                               0, (hammer2_key_t)-1,
1208                                               &cache_index,
1209                                               HAMMER2_LOOKUP_NODATA);
1210                 if (dchain) {
1211                         hammer2_chain_unlock(dchain);
1212                         hammer2_chain_lookup_done(dparent);
1213                         error = ENOTEMPTY;
1214                         goto done;
1215                 }
1216                 hammer2_chain_lookup_done(dparent);
1217                 dparent = NULL;
1218                 /* dchain NULL */
1219         }
1220
1221         /*
1222          * Ok, we can now unlink the chain.  We always decrement nlinks even
1223          * if the entry can be deleted in case someone has the file open and
1224          * does an fstat().
1225          *
1226          * The chain itself will no longer be in the on-media topology but
1227          * can still be flushed to the media (e.g. if an open descriptor
1228          * remains).  When the last vnode/ip ref goes away the chain will
1229          * be marked unmodified, avoiding any further (now unnecesary) I/O.
1230          *
1231          * A non-NULL ochain indicates a hardlink.
1232          */
1233         if (ochain) {
1234                 /*
1235                  * Delete the original hardlink pointer.
1236                  *
1237                  * NOTE: parent from above is NULL when ochain != NULL
1238                  *       so we can reuse it.
1239                  */
1240                 hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
1241                 hammer2_chain_delete(trans, ochain, 0);
1242                 hammer2_chain_unlock(ochain);
1243
1244                 /*
1245                  * Then decrement nlinks on hardlink target, deleting
1246                  * the target when nlinks drops to 0.
1247                  */
1248                 hammer2_chain_modify(trans, &chain, 0);
1249                 --chain->data->ipdata.nlinks;
1250                 if (chain->data->ipdata.nlinks == 0)
1251                         hammer2_chain_delete(trans, chain, 0);
1252         } else {
1253                 /*
1254                  * Otherwise this was not a hardlink and we can just
1255                  * remove the entry and decrement nlinks.
1256                  *
1257                  * NOTE: *_get() integrates chain's lock into the inode lock.
1258                  */
1259                 hammer2_chain_modify(trans, &chain, 0);
1260                 ipdata = &chain->data->ipdata;
1261                 --ipdata->nlinks;
1262                 hammer2_chain_delete(trans, chain, 0);
1263         }
1264
1265         error = 0;
1266 done:
1267         if (chain)
1268                 hammer2_chain_unlock(chain);
1269         if (parent)
1270                 hammer2_chain_lookup_done(parent);
1271         if (ochain)
1272                 hammer2_chain_drop(ochain);
1273
1274         return error;
1275 }
1276
1277 /*
1278  * Given an exclusively locked inode we consolidate its chain for hardlink
1279  * creation, adding (nlinks) to the file's link count and potentially
1280  * relocating the inode to a directory common to ip->pip and tdip.
1281  *
1282  * Replaces (*chainp) if consolidation occurred, unlocking the old chain
1283  * and returning a new locked chain.
1284  *
1285  * NOTE!  This function will also replace ip->chain.
1286  */
1287 int
1288 hammer2_hardlink_consolidate(hammer2_trans_t *trans, hammer2_inode_t *ip,
1289                              hammer2_chain_t **chainp,
1290                              hammer2_inode_t *tdip, int nlinks)
1291 {
1292         hammer2_inode_data_t *ipdata;
1293         hammer2_inode_t *fdip;
1294         hammer2_inode_t *cdip;
1295         hammer2_chain_t *chain;
1296         hammer2_chain_t *nchain;
1297         int error;
1298
1299         chain = *chainp;
1300         if (nlinks == 0 &&                      /* no hardlink needed */
1301             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE)) {
1302                 return (0);
1303         }
1304         if (hammer2_hardlink_enable < 0) {      /* fake hardlinks */
1305                 return (0);
1306         }
1307
1308         if (hammer2_hardlink_enable == 0) {     /* disallow hardlinks */
1309                 hammer2_chain_unlock(chain);
1310                 *chainp = NULL;
1311                 return (ENOTSUP);
1312         }
1313
1314         /*
1315          * cdip will be returned with a ref, but not locked.
1316          */
1317         fdip = ip->pip;
1318         cdip = hammer2_inode_common_parent(fdip, tdip);
1319
1320         /*
1321          * If no change in the hardlink's target directory is required and
1322          * this is already a hardlink target, all we need to do is adjust
1323          * the link count.
1324          *
1325          * XXX The common parent is a big wiggly due to duplication from
1326          *     renames.  Compare the core (RBTREE) pointer instead of the
1327          *     ip's.
1328          */
1329         if (cdip == fdip &&
1330             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) == 0) {
1331                 if (nlinks) {
1332                         hammer2_chain_modify(trans, &chain, 0);
1333                         chain->data->ipdata.nlinks += nlinks;
1334                 }
1335                 error = 0;
1336                 goto done;
1337         }
1338
1339         /*
1340          * We either have to move an existing hardlink target or we have
1341          * to create a fresh hardlink target.
1342          *
1343          * Hardlink targets are hidden inodes in a parent directory common
1344          * to all directory entries referencing the hardlink.
1345          */
1346         nchain = hammer2_hardlink_shiftup(trans, &chain, cdip, &error);
1347
1348         if (error == 0) {
1349                 /*
1350                  * Bump nlinks on duplicated hidden inode, repoint
1351                  * ip->chain.
1352                  */
1353                 hammer2_chain_modify(trans, &nchain, 0);
1354                 nchain->data->ipdata.nlinks += nlinks;
1355                 hammer2_inode_repoint(ip, cdip, nchain);
1356
1357                 /*
1358                  * If the old chain is not a hardlink target then replace
1359                  * it with a OBJTYPE_HARDLINK pointer.
1360                  *
1361                  * If the old chain IS a hardlink target then delete it.
1362                  */
1363                 if (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) {
1364                         /*
1365                          * Replace original non-hardlink that's been dup'd
1366                          * with a special hardlink directory entry.  We must
1367                          * set the DIRECTDATA flag to prevent sub-chains
1368                          * from trying to synchronize to the inode if the
1369                          * file is extended afterwords.
1370                          *
1371                          * DELDUP_RECORE causes the new chain to NOT inherit
1372                          * the old chain's core (sub-tree).  The new chain
1373                          * will already be marked modified.
1374                          */
1375                         /*hammer2_chain_modify(trans, &chain, 0);*/
1376                         hammer2_chain_delete_duplicate(trans, &chain,
1377                                                        HAMMER2_DELDUP_RECORE);
1378                         ipdata = &chain->data->ipdata;
1379                         ipdata->target_type = ipdata->type;
1380                         ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1381                         ipdata->uflags = 0;
1382                         ipdata->rmajor = 0;
1383                         ipdata->rminor = 0;
1384                         ipdata->ctime = 0;
1385                         ipdata->mtime = 0;
1386                         ipdata->atime = 0;
1387                         ipdata->btime = 0;
1388                         bzero(&ipdata->uid, sizeof(ipdata->uid));
1389                         bzero(&ipdata->gid, sizeof(ipdata->gid));
1390                         ipdata->op_flags = HAMMER2_OPFLAG_DIRECTDATA;
1391                         ipdata->cap_flags = 0;
1392                         ipdata->mode = 0;
1393                         ipdata->size = 0;
1394                         ipdata->nlinks = 1;
1395                         ipdata->iparent = 0;    /* XXX */
1396                         ipdata->pfs_type = 0;
1397                         ipdata->pfs_inum = 0;
1398                         bzero(&ipdata->pfs_clid, sizeof(ipdata->pfs_clid));
1399                         bzero(&ipdata->pfs_fsid, sizeof(ipdata->pfs_fsid));
1400                         ipdata->data_quota = 0;
1401                         ipdata->data_count = 0;
1402                         ipdata->inode_quota = 0;
1403                         ipdata->inode_count = 0;
1404                         ipdata->attr_tid = 0;
1405                         ipdata->dirent_tid = 0;
1406                         bzero(&ipdata->u, sizeof(ipdata->u));
1407                         /* XXX transaction ids */
1408                 } else {
1409                         hammer2_chain_delete(trans, chain, 0);
1410                 }
1411
1412                 /*
1413                  * Return the new chain.
1414                  */
1415                 hammer2_chain_unlock(chain);
1416                 chain = nchain;
1417         } else {
1418                 /*
1419                  * Return an error
1420                  */
1421                 hammer2_chain_unlock(chain);
1422                 chain = NULL;
1423         }
1424
1425         /*
1426          * Cleanup, chain/nchain already dealt with.
1427          */
1428 done:
1429         *chainp = chain;
1430         hammer2_inode_drop(cdip);
1431
1432         return (error);
1433 }
1434
1435 /*
1436  * If (*ochainp) is non-NULL it points to the forward OBJTYPE_HARDLINK
1437  * inode while (*chainp) points to the resolved (hidden hardlink
1438  * target) inode.  In this situation when nlinks is 1 we wish to
1439  * deconsolidate the hardlink, moving it back to the directory that now
1440  * represents the only remaining link.
1441  */
1442 int
1443 hammer2_hardlink_deconsolidate(hammer2_trans_t *trans,
1444                                hammer2_inode_t *dip,
1445                                hammer2_chain_t **chainp,
1446                                hammer2_chain_t **ochainp)
1447 {
1448         if (*ochainp == NULL)
1449                 return (0);
1450         /* XXX */
1451         return (0);
1452 }
1453
1454 /*
1455  * The caller presents a locked *chainp pointing to a HAMMER2_BREF_TYPE_INODE
1456  * with an obj_type of HAMMER2_OBJTYPE_HARDLINK.  This routine will gobble
1457  * the *chainp and return a new locked *chainp representing the file target
1458  * (the original *chainp will be unlocked).
1459  *
1460  * When a match is found the chain representing the original HARDLINK
1461  * will be returned in *ochainp with a ref, but not locked.
1462  *
1463  * When no match is found *chainp is set to NULL and EIO is returned.
1464  * (*ochainp) will still be set to the original chain with a ref but not
1465  * locked.
1466  */
1467 int
1468 hammer2_hardlink_find(hammer2_inode_t *dip, hammer2_chain_t **chainp,
1469                       hammer2_chain_t **ochainp)
1470 {
1471         hammer2_chain_t *chain = *chainp;
1472         hammer2_chain_t *parent;
1473         hammer2_inode_t *ip;
1474         hammer2_inode_t *pip;
1475         hammer2_key_t key_dummy;
1476         hammer2_key_t lhc;
1477         int cache_index = -1;
1478
1479         pip = dip;
1480         hammer2_inode_ref(pip);         /* for loop */
1481         hammer2_chain_ref(chain);       /* for (*ochainp) */
1482         *ochainp = chain;
1483
1484         /*
1485          * Locate the hardlink.  pip is referenced and not locked,
1486          * ipp.
1487          *
1488          * chain is reused.
1489          */
1490         lhc = chain->data->ipdata.inum;
1491         hammer2_chain_unlock(chain);
1492         chain = NULL;
1493
1494         while ((ip = pip) != NULL) {
1495                 parent = hammer2_inode_lock_ex(ip);
1496                 hammer2_inode_drop(ip);                 /* loop */
1497                 KKASSERT(parent->bref.type == HAMMER2_BREF_TYPE_INODE);
1498                 chain = hammer2_chain_lookup(&parent, &key_dummy,
1499                                              lhc, lhc, &cache_index, 0);
1500                 hammer2_chain_lookup_done(parent);      /* discard parent */
1501                 if (chain)
1502                         break;
1503                 pip = ip->pip;          /* safe, ip held locked */
1504                 if (pip)
1505                         hammer2_inode_ref(pip);         /* loop */
1506                 hammer2_inode_unlock_ex(ip, NULL);
1507         }
1508
1509         /*
1510          * chain is locked, ip is locked.  Unlock ip, return the locked
1511          * chain.  *ipp is already set w/a ref count and not locked.
1512          *
1513          * (parent is already unlocked).
1514          */
1515         if (ip)
1516                 hammer2_inode_unlock_ex(ip, NULL);
1517         *chainp = chain;
1518         if (chain) {
1519                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
1520                 /* already locked */
1521                 return (0);
1522         } else {
1523                 return (EIO);
1524         }
1525 }
1526
1527 /*
1528  * Find the directory common to both fdip and tdip, hold and return
1529  * its inode.
1530  */
1531 hammer2_inode_t *
1532 hammer2_inode_common_parent(hammer2_inode_t *fdip, hammer2_inode_t *tdip)
1533 {
1534         hammer2_inode_t *scan1;
1535         hammer2_inode_t *scan2;
1536
1537         /*
1538          * We used to have a depth field but it complicated matters too
1539          * much for directory renames.  So now its ugly.  Check for
1540          * simple cases before giving up and doing it the expensive way.
1541          *
1542          * XXX need a bottom-up topology stability lock
1543          */
1544         if (fdip == tdip || fdip == tdip->pip) {
1545                 hammer2_inode_ref(fdip);
1546                 return(fdip);
1547         }
1548         if (fdip->pip == tdip) {
1549                 hammer2_inode_ref(tdip);
1550                 return(tdip);
1551         }
1552
1553         /*
1554          * XXX not MPSAFE
1555          */
1556         for (scan1 = fdip; scan1->pmp == fdip->pmp; scan1 = scan1->pip) {
1557                 scan2 = tdip;
1558                 while (scan2->pmp == tdip->pmp) {
1559                         if (scan1 == scan2) {
1560                                 hammer2_inode_ref(scan1);
1561                                 return(scan1);
1562                         }
1563                         scan2 = scan2->pip;
1564                         if (scan2 == NULL)
1565                                 break;
1566                 }
1567         }
1568         panic("hammer2_inode_common_parent: no common parent %p %p\n",
1569               fdip, tdip);
1570         /* NOT REACHED */
1571         return(NULL);
1572 }
1573
1574 /*
1575  * Synchronize the inode's frontend state with the chain state prior
1576  * to any explicit flush of the inode or any strategy write call.
1577  *
1578  * Called with a locked inode.
1579  */
1580 void
1581 hammer2_inode_fsync(hammer2_trans_t *trans, hammer2_inode_t *ip,
1582                     hammer2_chain_t **chainp)
1583 {
1584         hammer2_inode_data_t *ipdata;
1585         hammer2_chain_t *parent;
1586         hammer2_chain_t *chain;
1587         hammer2_key_t lbase;
1588         hammer2_key_t key_next;
1589         int cache_index;
1590
1591         ipdata = &ip->chain->data->ipdata;
1592
1593         if (ip->flags & HAMMER2_INODE_MTIME) {
1594                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1595                 atomic_clear_int(&ip->flags, HAMMER2_INODE_MTIME);
1596                 ipdata->mtime = ip->mtime;
1597         }
1598         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size < ipdata->size) {
1599                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1600                 ipdata->size = ip->size;
1601                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1602
1603                 /*
1604                  * We must delete any chains beyond the EOF.  The chain
1605                  * straddling the EOF will be pending in the bioq.
1606                  */
1607                 lbase = (ipdata->size + HAMMER2_PBUFMASK64) &
1608                         ~HAMMER2_PBUFMASK64;
1609                 parent = hammer2_chain_lookup_init(ip->chain, 0);
1610                 chain = hammer2_chain_lookup(&parent, &key_next,
1611                                              lbase, (hammer2_key_t)-1,
1612                                              &cache_index,
1613                                              HAMMER2_LOOKUP_NODATA);
1614                 while (chain) {
1615                         /*
1616                          * Degenerate embedded case, nothing to loop on
1617                          */
1618                         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1619                                 hammer2_chain_unlock(chain);
1620                                 break;
1621                         }
1622                         if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
1623                                 hammer2_chain_delete(trans, chain, 0);
1624                         }
1625                         chain = hammer2_chain_next(&parent, chain, &key_next,
1626                                                    key_next, (hammer2_key_t)-1,
1627                                                    &cache_index,
1628                                                    HAMMER2_LOOKUP_NODATA);
1629                 }
1630                 hammer2_chain_lookup_done(parent);
1631         } else
1632         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size > ipdata->size) {
1633                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1634                 ipdata->size = ip->size;
1635                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1636
1637                 /*
1638                  * When resizing larger we may not have any direct-data
1639                  * available.
1640                  */
1641                 if ((ipdata->op_flags & HAMMER2_OPFLAG_DIRECTDATA) &&
1642                     ip->size > HAMMER2_EMBEDDED_BYTES) {
1643                         ipdata->op_flags &= ~HAMMER2_OPFLAG_DIRECTDATA;
1644                         bzero(&ipdata->u.blockset, sizeof(ipdata->u.blockset));
1645                 }
1646         }
1647 }