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->sync_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->sync_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 static
 752 hammer2_chain_t *
 753 hammer2_hardlink_shiftup(hammer2_trans_t *trans, hammer2_chain_t **ochainp,
 754                         hammer2_inode_t *dip, int *errorp)
 755 {
 756         hammer2_inode_data_t *nipdata;
 757         hammer2_chain_t *parent;
 758         hammer2_chain_t *ochain;
 759         hammer2_chain_t *nchain;
 760         hammer2_chain_t *tmp;
 761         hammer2_key_t key_dummy;
 762         hammer2_key_t lhc;
 763         hammer2_blockref_t bref;
 764         int cache_index = -1;
 765
 766         ochain = *ochainp;
 767         *errorp = 0;
 768         lhc = ochain->data->ipdata.inum;
 769         KKASSERT((lhc & HAMMER2_DIRHASH_VISIBLE) == 0);
 770
 771         /*
 772          * Locate the inode or indirect block to create the new
 773          * entry in.  lhc represents the inode number so there is
 774          * no collision iteration.
 775          *
 776          * There should be no key collisions with invisible inode keys.
 777          *
 778          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 779          *          dip->chain cache.
 780          */
 781 retry:
 782         parent = hammer2_inode_lock_ex(dip);
 783         /*parent = hammer2_chain_lookup_init(dip->chain, 0);*/
 784         nchain = hammer2_chain_lookup(&parent, &key_dummy,
 785                                       lhc, lhc, &cache_index, 0);
 786         if (nchain) {
 787                 kprintf("X3 chain %p parent %p dip %p dip->chain %p\n",
 788                         nchain, parent, dip, dip->chain);
 789                 hammer2_chain_unlock(nchain);
 790                 nchain = NULL;
 791                 *errorp = ENOSPC;
 792 #if 1
 793                 Debugger("X3");
 794 #endif
 795         }
 796
 797         /*
 798          * Create entry in common parent directory using the seek position
 799          * calculated above.
 800          */
 801         if (*errorp == 0) {
 802                 KKASSERT(nchain == NULL);
 803                 *errorp = hammer2_chain_create(trans, &parent, &nchain,
 804                                                lhc, 0,
 805                                                HAMMER2_BREF_TYPE_INODE,/* n/a */
 806                                                HAMMER2_INODE_BYTES);   /* n/a */
 807                 hammer2_chain_refactor(&ochain);
 808                 *ochainp = ochain;
 809         }
 810
 811         /*
 812          * Cleanup and handle retries.
 813          */
 814         if (*errorp == EAGAIN) {
 815                 hammer2_chain_ref(parent);
 816                 /* hammer2_chain_lookup_done(parent); */
 817                 hammer2_inode_unlock_ex(dip, parent);
 818                 hammer2_chain_wait(parent);
 819                 hammer2_chain_drop(parent);
 820                 goto retry;
 821         }
 822
 823         /*
 824          * Handle the error case
 825          */
 826         if (*errorp) {
 827                 KKASSERT(nchain == NULL);
 828                 hammer2_inode_unlock_ex(dip, parent);
 829                 /*hammer2_chain_lookup_done(parent);*/
 830                 return (NULL);
 831         }
 832
 833         /*
 834          * Use chain as a placeholder for (lhc), delete it and replace
 835          * it with our duplication.
 836          *
 837          * Gain a second lock on ochain for the duplication function to
 838          * unlock, maintain the caller's original lock across the call.
 839          *
 840          * This is a bit messy.
 841          */
 842         hammer2_chain_delete(trans, nchain, HAMMER2_DELETE_WILLDUP);
 843         hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
 844         tmp = ochain;
 845         bref = tmp->bref;
 846         bref.key = lhc;                 /* invisible dir entry key */
 847         bref.keybits = 0;
 848         hammer2_chain_duplicate(trans, &parent, &tmp, &bref, 0);
 849         hammer2_inode_unlock_ex(dip, parent);
 850         /*hammer2_chain_lookup_done(parent);*/
 851         hammer2_chain_unlock(nchain);   /* no longer needed */
 852
 853         /*
 854          * Now set chain to our duplicate and modify it appropriately.
 855          *
 856          * Directory entries are inodes but this is a hidden hardlink
 857          * target.  The name isn't used but to ease debugging give it
 858          * a name after its inode number.
 859          */
 860         nchain = tmp;
 861         tmp = NULL;     /* safety */
 862
 863         hammer2_chain_modify(trans, &nchain, HAMMER2_MODIFY_ASSERTNOCOPY);
 864         nipdata = &nchain->data->ipdata;
 865         ksnprintf(nipdata->filename, sizeof(nipdata->filename),
 866                   "0x%016jx", (intmax_t)nipdata->inum);
 867         nipdata->name_len = strlen(nipdata->filename);
 868         nipdata->name_key = lhc;
 869
 870         return (nchain);
 871 }
 872
 873 /*
 874  * Connect the target inode represented by (*chainp) to the media topology
 875  * at (dip, name, len).
 876  *
 877  * If hlink is TRUE this function creates an OBJTYPE_HARDLINK directory
 878  * entry instead of connecting (*chainp).
 879  *
 880  * If hlink is FALSE this function uses chain_duplicate() to make a copy
 881  * if (*chainp) in the directory entry.  (*chainp) is likely to be deleted
 882  * by the caller in this case (e.g. rename).
 883  */
 884 int
 885 hammer2_inode_connect(hammer2_trans_t *trans, int hlink,
 886                       hammer2_inode_t *dip, hammer2_chain_t **chainp,
 887                       const uint8_t *name, size_t name_len)
 888 {
 889         hammer2_inode_data_t *ipdata;
 890         hammer2_chain_t *nchain;
 891         hammer2_chain_t *parent;
 892         hammer2_chain_t *ochain;
 893         hammer2_key_t key_dummy;
 894         hammer2_key_t lhc;
 895         int cache_index = -1;
 896         int error;
 897
 898         ochain = *chainp;
 899
 900         /*
 901          * Since ochain is either disconnected from the topology or represents
 902          * a hardlink terminus which is always a parent of or equal to dip,
 903          * we should be able to safely lock dip->chain for our setup.
 904          *
 905          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 906          *          dip->chain cache.
 907          */
 908         parent = hammer2_inode_lock_ex(dip);
 909         /*parent = hammer2_chain_lookup_init(dip->chain, 0);*/
 910
 911         lhc = hammer2_dirhash(name, name_len);
 912
 913         /*
 914          * Locate the inode or indirect block to create the new
 915          * entry in.  At the same time check for key collisions
 916          * and iterate until we don't get one.
 917          */
 918         error = 0;
 919         while (error == 0) {
 920                 nchain = hammer2_chain_lookup(&parent, &key_dummy,
 921                                               lhc, lhc, &cache_index, 0);
 922                 if (nchain == NULL)
 923                         break;
 924                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 925                         error = ENOSPC;
 926                 hammer2_chain_unlock(nchain);
 927                 nchain = NULL;
 928                 ++lhc;
 929         }
 930
 931         if (error == 0) {
 932                 if (hlink) {
 933                         /*
 934                          * Hardlink pointer needed, create totally fresh
 935                          * directory entry.
 936                          */
 937                         KKASSERT(nchain == NULL);
 938                         error = hammer2_chain_create(trans, &parent, &nchain,
 939                                                      lhc, 0,
 940                                                      HAMMER2_BREF_TYPE_INODE,
 941                                                      HAMMER2_INODE_BYTES);
 942                         hammer2_chain_refactor(&ochain);
 943                 } else {
 944                         /*
 945                          * Reconnect the original chain and rename.  Use
 946                          * chain_duplicate().  The caller will likely delete
 947                          * or has already deleted the original chain in
 948                          * this case.
 949                          *
 950                          * NOTE: chain_duplicate() generates a new chain
 951                          *       with CHAIN_DELETED cleared (ochain typically
 952                          *       has it set from the file unlink).
 953                          */
 954                         nchain = ochain;
 955                         ochain = NULL;
 956                         hammer2_chain_duplicate(trans, NULL, &nchain, NULL, 0);
 957                         error = hammer2_chain_create(trans, &parent, &nchain,
 958                                                      lhc, 0,
 959                                                      HAMMER2_BREF_TYPE_INODE,
 960                                                      HAMMER2_INODE_BYTES);
 961                 }
 962         }
 963
 964         /*
 965          * Unlock stuff.
 966          */
 967         KKASSERT(error != EAGAIN);
 968         hammer2_inode_unlock_ex(dip, parent);
 969         /*hammer2_chain_lookup_done(parent);*/
 970         parent = NULL;
 971
 972         /*
 973          * nchain should be NULL on error, leave ochain (== *chainp) alone.
 974          */
 975         if (error) {
 976                 KKASSERT(nchain == NULL);
 977                 return (error);
 978         }
 979
 980         /*
 981          * Directory entries are inodes so if the name has changed we have
 982          * to update the inode.
 983          *
 984          * When creating an OBJTYPE_HARDLINK entry remember to unlock the
 985          * chain, the caller will access the hardlink via the actual hardlink
 986          * target file and not the hardlink pointer entry, so we must still
 987          * return ochain.
 988          */
 989         if (hlink && hammer2_hardlink_enable >= 0) {
 990                 /*
 991                  * Create the HARDLINK pointer.  oip represents the hardlink
 992                  * target in this situation.
 993                  *
 994                  * We will return ochain (the hardlink target).
 995                  */
 996                 hammer2_chain_modify(trans, &nchain,
 997                                      HAMMER2_MODIFY_ASSERTNOCOPY);
 998                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 999                 ipdata = &nchain->data->ipdata;
1000                 bcopy(name, ipdata->filename, name_len);
1001                 ipdata->name_key = lhc;
1002                 ipdata->name_len = name_len;
1003                 ipdata->target_type = ochain->data->ipdata.type;
1004                 ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1005                 ipdata->inum = ochain->data->ipdata.inum;
1006                 ipdata->nlinks = 1;
1007                 hammer2_chain_unlock(nchain);
1008                 nchain = ochain;
1009                 ochain = NULL;
1010         } else if (hlink && hammer2_hardlink_enable < 0) {
1011                 /*
1012                  * Create a snapshot (hardlink fake mode for debugging).
1013                  * (ochain already flushed above so we can just copy the
1014                  * bref XXX).
1015                  *
1016                  * Since this is a snapshot we return nchain in the fake
1017                  * hardlink case.
1018                  */
1019                 hammer2_chain_modify(trans, &nchain,
1020                                      HAMMER2_MODIFY_ASSERTNOCOPY);
1021                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1022                 ipdata = &nchain->data->ipdata;
1023                 *ipdata = ochain->data->ipdata;
1024                 bcopy(name, ipdata->filename, name_len);
1025                 ipdata->name_key = lhc;
1026                 ipdata->name_len = name_len;
1027                 atomic_clear_int(&nchain->core->flags,
1028                                  HAMMER2_CORE_COUNTEDBREFS);
1029                 kprintf("created fake hardlink %*.*s\n",
1030                         (int)name_len, (int)name_len, name);
1031         } else {
1032                 /*
1033                  * nchain is a duplicate of ochain at the new location.
1034                  * We must fixup the name stored in oip.  The bref key
1035                  * has already been set up.
1036                  */
1037                 hammer2_chain_modify(trans, &nchain,
1038                                      HAMMER2_MODIFY_ASSERTNOCOPY);
1039                 ipdata = &nchain->data->ipdata;
1040
1041                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1042                 bcopy(name, ipdata->filename, name_len);
1043                 ipdata->name_key = lhc;
1044                 ipdata->name_len = name_len;
1045                 ipdata->nlinks = 1;
1046         }
1047
1048         /*
1049          * We are replacing ochain with nchain, unlock ochain.  In the
1050          * case where ochain is left unchanged the code above sets
1051          * nchain to ochain and ochain to NULL, resulting in a NOP here.
1052          */
1053         if (ochain)
1054                 hammer2_chain_unlock(ochain);
1055         *chainp = nchain;
1056
1057         return (0);
1058 }
1059
1060 /*
1061  * Repoint ip->chain to nchain.  Caller must hold the inode exclusively
1062  * locked.
1063  *
1064  * ip->chain is set to nchain.  The prior chain in ip->chain is dropped
1065  * and nchain is ref'd.
1066  */
1067 void
1068 hammer2_inode_repoint(hammer2_inode_t *ip, hammer2_inode_t *pip,
1069                       hammer2_chain_t *nchain)
1070 {
1071         hammer2_chain_t *ochain;
1072         hammer2_inode_t *opip;
1073
1074         /*
1075          * Repoint ip->chain if requested.
1076          */
1077         ochain = ip->chain;
1078         ip->chain = nchain;
1079         if (nchain)
1080                 hammer2_chain_ref(nchain);
1081         if (ochain)
1082                 hammer2_chain_drop(ochain);
1083
1084         /*
1085          * Repoint ip->pip if requested (non-NULL pip).
1086          */
1087         if (pip && ip->pip != pip) {
1088                 opip = ip->pip;
1089                 hammer2_inode_ref(pip);
1090                 ip->pip = pip;
1091                 if (opip)
1092                         hammer2_inode_drop(opip);
1093         }
1094 }
1095
1096 /*
1097  * Unlink the file from the specified directory inode.  The directory inode
1098  * does not need to be locked.
1099  *
1100  * isdir determines whether a directory/non-directory check should be made.
1101  * No check is made if isdir is set to -1.
1102  *
1103  * NOTE!  The underlying file can still be active with open descriptors
1104  *        or if the chain is being manually held (e.g. for rename).
1105  *
1106  *        The caller is responsible for fixing up ip->chain if e.g. a
1107  *        rename occurs (see chain_duplicate()).
1108  */
1109 int
1110 hammer2_unlink_file(hammer2_trans_t *trans, hammer2_inode_t *dip,
1111                     const uint8_t *name, size_t name_len,
1112                     int isdir, int *hlinkp)
1113 {
1114         hammer2_inode_data_t *ipdata;
1115         hammer2_chain_t *parent;
1116         hammer2_chain_t *ochain;
1117         hammer2_chain_t *chain;
1118         hammer2_chain_t *dparent;
1119         hammer2_chain_t *dchain;
1120         hammer2_key_t key_dummy;
1121         hammer2_key_t key_next;
1122         hammer2_key_t lhc;
1123         int error;
1124         int cache_index = -1;
1125         uint8_t type;
1126
1127         error = 0;
1128         ochain = NULL;
1129         lhc = hammer2_dirhash(name, name_len);
1130
1131         /*
1132          * Search for the filename in the directory
1133          */
1134         if (hlinkp)
1135                 *hlinkp = 0;
1136         parent = hammer2_inode_lock_ex(dip);
1137         chain = hammer2_chain_lookup(&parent, &key_next,
1138                                      lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1139                                      &cache_index, 0);
1140         while (chain) {
1141                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1142                     name_len == chain->data->ipdata.name_len &&
1143                     bcmp(name, chain->data->ipdata.filename, name_len) == 0) {
1144                         break;
1145                 }
1146                 chain = hammer2_chain_next(&parent, chain, &key_next,
1147                                            key_next,
1148                                            lhc + HAMMER2_DIRHASH_LOMASK,
1149                                            &cache_index, 0);
1150         }
1151         hammer2_inode_unlock_ex(dip, NULL);     /* retain parent */
1152
1153         /*
1154          * Not found or wrong type (isdir < 0 disables the type check).
1155          * If a hardlink pointer, type checks use the hardlink target.
1156          */
1157         if (chain == NULL) {
1158                 error = ENOENT;
1159                 goto done;
1160         }
1161         if ((type = chain->data->ipdata.type) == HAMMER2_OBJTYPE_HARDLINK) {
1162                 if (hlinkp)
1163                         *hlinkp = 1;
1164                 type = chain->data->ipdata.target_type;
1165         }
1166
1167         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 0) {
1168                 error = ENOTDIR;
1169                 goto done;
1170         }
1171         if (type != HAMMER2_OBJTYPE_DIRECTORY && isdir >= 1) {
1172                 error = EISDIR;
1173                 goto done;
1174         }
1175
1176         /*
1177          * Hardlink must be resolved.  We can't hold parent locked while we
1178          * do this or we could deadlock.
1179          *
1180          * On success chain will be adjusted to point at the hardlink target
1181          * and ochain will point to the hardlink pointer in the original
1182          * directory.  Otherwise chain remains pointing to the original.
1183          */
1184         if (chain->data->ipdata.type == HAMMER2_OBJTYPE_HARDLINK) {
1185                 hammer2_chain_unlock(parent);
1186                 parent = NULL;
1187                 error = hammer2_hardlink_find(dip, &chain, &ochain);
1188         }
1189
1190         /*
1191          * If this is a directory the directory must be empty.  However, if
1192          * isdir < 0 we are doing a rename and the directory does not have
1193          * to be empty, and if isdir > 1 we are deleting a PFS/snapshot
1194          * and the directory does not have to be empty.
1195          *
1196          * NOTE: We check the full key range here which covers both visible
1197          *       and invisible entries.  Theoretically there should be no
1198          *       invisible (hardlink target) entries if there are no visible
1199          *       entries.
1200          */
1201         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 1) {
1202                 dparent = hammer2_chain_lookup_init(chain, 0);
1203                 dchain = hammer2_chain_lookup(&dparent, &key_dummy,
1204                                               0, (hammer2_key_t)-1,
1205                                               &cache_index,
1206                                               HAMMER2_LOOKUP_NODATA);
1207                 if (dchain) {
1208                         hammer2_chain_unlock(dchain);
1209                         hammer2_chain_lookup_done(dparent);
1210                         error = ENOTEMPTY;
1211                         goto done;
1212                 }
1213                 hammer2_chain_lookup_done(dparent);
1214                 dparent = NULL;
1215                 /* dchain NULL */
1216         }
1217
1218         /*
1219          * Ok, we can now unlink the chain.  We always decrement nlinks even
1220          * if the entry can be deleted in case someone has the file open and
1221          * does an fstat().
1222          *
1223          * The chain itself will no longer be in the on-media topology but
1224          * can still be flushed to the media (e.g. if an open descriptor
1225          * remains).  When the last vnode/ip ref goes away the chain will
1226          * be marked unmodified, avoiding any further (now unnecesary) I/O.
1227          *
1228          * A non-NULL ochain indicates a hardlink.
1229          */
1230         if (ochain) {
1231                 /*
1232                  * Delete the original hardlink pointer.
1233                  *
1234                  * NOTE: parent from above is NULL when ochain != NULL
1235                  *       so we can reuse it.
1236                  */
1237                 hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
1238                 hammer2_chain_delete(trans, ochain, 0);
1239                 hammer2_chain_unlock(ochain);
1240
1241                 /*
1242                  * Then decrement nlinks on hardlink target, deleting
1243                  * the target when nlinks drops to 0.
1244                  */
1245                 hammer2_chain_modify(trans, &chain, 0);
1246                 --chain->data->ipdata.nlinks;
1247                 if (chain->data->ipdata.nlinks == 0)
1248                         hammer2_chain_delete(trans, chain, 0);
1249         } else {
1250                 /*
1251                  * Otherwise this was not a hardlink and we can just
1252                  * remove the entry and decrement nlinks.
1253                  *
1254                  * NOTE: *_get() integrates chain's lock into the inode lock.
1255                  */
1256                 hammer2_chain_modify(trans, &chain, 0);
1257                 ipdata = &chain->data->ipdata;
1258                 --ipdata->nlinks;
1259                 hammer2_chain_delete(trans, chain, 0);
1260         }
1261
1262         error = 0;
1263 done:
1264         if (chain)
1265                 hammer2_chain_unlock(chain);
1266         if (parent)
1267                 hammer2_chain_lookup_done(parent);
1268         if (ochain)
1269                 hammer2_chain_drop(ochain);
1270
1271         return error;
1272 }
1273
1274 /*
1275  * Given an exclusively locked inode we consolidate its chain for hardlink
1276  * creation, adding (nlinks) to the file's link count and potentially
1277  * relocating the inode to a directory common to ip->pip and tdip.
1278  *
1279  * Replaces (*chainp) if consolidation occurred, unlocking the old chain
1280  * and returning a new locked chain.
1281  *
1282  * NOTE!  This function will also replace ip->chain.
1283  */
1284 int
1285 hammer2_hardlink_consolidate(hammer2_trans_t *trans, hammer2_inode_t *ip,
1286                              hammer2_chain_t **chainp,
1287                              hammer2_inode_t *tdip, int nlinks)
1288 {
1289         hammer2_inode_data_t *ipdata;
1290         hammer2_inode_t *fdip;
1291         hammer2_inode_t *cdip;
1292         hammer2_chain_t *chain;
1293         hammer2_chain_t *nchain;
1294         int error;
1295
1296         chain = *chainp;
1297         if (nlinks == 0 &&                      /* no hardlink needed */
1298             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE)) {
1299                 return (0);
1300         }
1301         if (hammer2_hardlink_enable < 0) {      /* fake hardlinks */
1302                 return (0);
1303         }
1304
1305         if (hammer2_hardlink_enable == 0) {     /* disallow hardlinks */
1306                 hammer2_chain_unlock(chain);
1307                 *chainp = NULL;
1308                 return (ENOTSUP);
1309         }
1310
1311         /*
1312          * cdip will be returned with a ref, but not locked.
1313          */
1314         fdip = ip->pip;
1315         cdip = hammer2_inode_common_parent(fdip, tdip);
1316
1317         /*
1318          * If no change in the hardlink's target directory is required and
1319          * this is already a hardlink target, all we need to do is adjust
1320          * the link count.
1321          *
1322          * XXX The common parent is a big wiggly due to duplication from
1323          *     renames.  Compare the core (RBTREE) pointer instead of the
1324          *     ip's.
1325          */
1326         if (cdip == fdip &&
1327             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) == 0) {
1328                 if (nlinks) {
1329                         hammer2_chain_modify(trans, &chain, 0);
1330                         chain->data->ipdata.nlinks += nlinks;
1331                 }
1332                 error = 0;
1333                 goto done;
1334         }
1335
1336         /*
1337          * We either have to move an existing hardlink target or we have
1338          * to create a fresh hardlink target.
1339          *
1340          * Hardlink targets are hidden inodes in a parent directory common
1341          * to all directory entries referencing the hardlink.
1342          */
1343         nchain = hammer2_hardlink_shiftup(trans, &chain, cdip, &error);
1344
1345         if (error == 0) {
1346                 /*
1347                  * Bump nlinks on duplicated hidden inode, repoint
1348                  * ip->chain.
1349                  */
1350                 hammer2_chain_modify(trans, &nchain, 0);
1351                 nchain->data->ipdata.nlinks += nlinks;
1352                 hammer2_inode_repoint(ip, cdip, nchain);
1353
1354                 /*
1355                  * If the old chain is not a hardlink target then replace
1356                  * it with a OBJTYPE_HARDLINK pointer.
1357                  *
1358                  * If the old chain IS a hardlink target then delete it.
1359                  */
1360                 if (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) {
1361                         /*
1362                          * Replace original non-hardlink that's been dup'd
1363                          * with a special hardlink directory entry.  We must
1364                          * set the DIRECTDATA flag to prevent sub-chains
1365                          * from trying to synchronize to the inode if the
1366                          * file is extended afterwords.
1367                          *
1368                          * DELDUP_RECORE causes the new chain to NOT inherit
1369                          * the old chain's core (sub-tree).  The new chain
1370                          * will already be marked modified.
1371                          */
1372                         /*hammer2_chain_modify(trans, &chain, 0);*/
1373                         hammer2_chain_delete_duplicate(trans, &chain,
1374                                                        HAMMER2_DELDUP_RECORE);
1375                         ipdata = &chain->data->ipdata;
1376                         ipdata->target_type = ipdata->type;
1377                         ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1378                         ipdata->uflags = 0;
1379                         ipdata->rmajor = 0;
1380                         ipdata->rminor = 0;
1381                         ipdata->ctime = 0;
1382                         ipdata->mtime = 0;
1383                         ipdata->atime = 0;
1384                         ipdata->btime = 0;
1385                         bzero(&ipdata->uid, sizeof(ipdata->uid));
1386                         bzero(&ipdata->gid, sizeof(ipdata->gid));
1387                         ipdata->op_flags = HAMMER2_OPFLAG_DIRECTDATA;
1388                         ipdata->cap_flags = 0;
1389                         ipdata->mode = 0;
1390                         ipdata->size = 0;
1391                         ipdata->nlinks = 1;
1392                         ipdata->iparent = 0;    /* XXX */
1393                         ipdata->pfs_type = 0;
1394                         ipdata->pfs_inum = 0;
1395                         bzero(&ipdata->pfs_clid, sizeof(ipdata->pfs_clid));
1396                         bzero(&ipdata->pfs_fsid, sizeof(ipdata->pfs_fsid));
1397                         ipdata->data_quota = 0;
1398                         ipdata->data_count = 0;
1399                         ipdata->inode_quota = 0;
1400                         ipdata->inode_count = 0;
1401                         ipdata->attr_tid = 0;
1402                         ipdata->dirent_tid = 0;
1403                         bzero(&ipdata->u, sizeof(ipdata->u));
1404                         /* XXX transaction ids */
1405                 } else {
1406                         hammer2_chain_delete(trans, chain, 0);
1407                 }
1408
1409                 /*
1410                  * Return the new chain.
1411                  */
1412                 hammer2_chain_unlock(chain);
1413                 chain = nchain;
1414         } else {
1415                 /*
1416                  * Return an error
1417                  */
1418                 hammer2_chain_unlock(chain);
1419                 chain = NULL;
1420         }
1421
1422         /*
1423          * Cleanup, chain/nchain already dealt with.
1424          */
1425 done:
1426         *chainp = chain;
1427         hammer2_inode_drop(cdip);
1428
1429         return (error);
1430 }
1431
1432 /*
1433  * If (*ochainp) is non-NULL it points to the forward OBJTYPE_HARDLINK
1434  * inode while (*chainp) points to the resolved (hidden hardlink
1435  * target) inode.  In this situation when nlinks is 1 we wish to
1436  * deconsolidate the hardlink, moving it back to the directory that now
1437  * represents the only remaining link.
1438  */
1439 int
1440 hammer2_hardlink_deconsolidate(hammer2_trans_t *trans,
1441                                hammer2_inode_t *dip,
1442                                hammer2_chain_t **chainp,
1443                                hammer2_chain_t **ochainp)
1444 {
1445         if (*ochainp == NULL)
1446                 return (0);
1447         /* XXX */
1448         return (0);
1449 }
1450
1451 /*
1452  * The caller presents a locked *chainp pointing to a HAMMER2_BREF_TYPE_INODE
1453  * with an obj_type of HAMMER2_OBJTYPE_HARDLINK.  This routine will gobble
1454  * the *chainp and return a new locked *chainp representing the file target
1455  * (the original *chainp will be unlocked).
1456  *
1457  * When a match is found the chain representing the original HARDLINK
1458  * will be returned in *ochainp with a ref, but not locked.
1459  *
1460  * When no match is found *chainp is set to NULL and EIO is returned.
1461  * (*ochainp) will still be set to the original chain with a ref but not
1462  * locked.
1463  */
1464 int
1465 hammer2_hardlink_find(hammer2_inode_t *dip, hammer2_chain_t **chainp,
1466                       hammer2_chain_t **ochainp)
1467 {
1468         hammer2_chain_t *chain = *chainp;
1469         hammer2_chain_t *parent;
1470         hammer2_inode_t *ip;
1471         hammer2_inode_t *pip;
1472         hammer2_key_t key_dummy;
1473         hammer2_key_t lhc;
1474         int cache_index = -1;
1475
1476         pip = dip;
1477         hammer2_inode_ref(pip);         /* for loop */
1478         hammer2_chain_ref(chain);       /* for (*ochainp) */
1479         *ochainp = chain;
1480
1481         /*
1482          * Locate the hardlink.  pip is referenced and not locked,
1483          * ipp.
1484          *
1485          * chain is reused.
1486          */
1487         lhc = chain->data->ipdata.inum;
1488         hammer2_chain_unlock(chain);
1489         chain = NULL;
1490
1491         while ((ip = pip) != NULL) {
1492                 parent = hammer2_inode_lock_ex(ip);
1493                 hammer2_inode_drop(ip);                 /* loop */
1494                 KKASSERT(parent->bref.type == HAMMER2_BREF_TYPE_INODE);
1495                 chain = hammer2_chain_lookup(&parent, &key_dummy,
1496                                              lhc, lhc, &cache_index, 0);
1497                 hammer2_chain_lookup_done(parent);      /* discard parent */
1498                 if (chain)
1499                         break;
1500                 pip = ip->pip;          /* safe, ip held locked */
1501                 if (pip)
1502                         hammer2_inode_ref(pip);         /* loop */
1503                 hammer2_inode_unlock_ex(ip, NULL);
1504         }
1505
1506         /*
1507          * chain is locked, ip is locked.  Unlock ip, return the locked
1508          * chain.  *ipp is already set w/a ref count and not locked.
1509          *
1510          * (parent is already unlocked).
1511          */
1512         if (ip)
1513                 hammer2_inode_unlock_ex(ip, NULL);
1514         *chainp = chain;
1515         if (chain) {
1516                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
1517                 /* already locked */
1518                 return (0);
1519         } else {
1520                 return (EIO);
1521         }
1522 }
1523
1524 /*
1525  * Find the directory common to both fdip and tdip, hold and return
1526  * its inode.
1527  */
1528 hammer2_inode_t *
1529 hammer2_inode_common_parent(hammer2_inode_t *fdip, hammer2_inode_t *tdip)
1530 {
1531         hammer2_inode_t *scan1;
1532         hammer2_inode_t *scan2;
1533
1534         /*
1535          * We used to have a depth field but it complicated matters too
1536          * much for directory renames.  So now its ugly.  Check for
1537          * simple cases before giving up and doing it the expensive way.
1538          *
1539          * XXX need a bottom-up topology stability lock
1540          */
1541         if (fdip == tdip || fdip == tdip->pip) {
1542                 hammer2_inode_ref(fdip);
1543                 return(fdip);
1544         }
1545         if (fdip->pip == tdip) {
1546                 hammer2_inode_ref(tdip);
1547                 return(tdip);
1548         }
1549
1550         /*
1551          * XXX not MPSAFE
1552          */
1553         for (scan1 = fdip; scan1->pmp == fdip->pmp; scan1 = scan1->pip) {
1554                 scan2 = tdip;
1555                 while (scan2->pmp == tdip->pmp) {
1556                         if (scan1 == scan2) {
1557                                 hammer2_inode_ref(scan1);
1558                                 return(scan1);
1559                         }
1560                         scan2 = scan2->pip;
1561                         if (scan2 == NULL)
1562                                 break;
1563                 }
1564         }
1565         panic("hammer2_inode_common_parent: no common parent %p %p\n",
1566               fdip, tdip);
1567         /* NOT REACHED */
1568         return(NULL);
1569 }
1570
1571 /*
1572  * Synchronize the inode's frontend state with the chain state prior
1573  * to any explicit flush of the inode or any strategy write call.
1574  *
1575  * Called with a locked inode.
1576  */
1577 void
1578 hammer2_inode_fsync(hammer2_trans_t *trans, hammer2_inode_t *ip,
1579                     hammer2_chain_t **chainp)
1580 {
1581         hammer2_inode_data_t *ipdata;
1582         hammer2_chain_t *parent;
1583         hammer2_chain_t *chain;
1584         hammer2_key_t lbase;
1585         hammer2_key_t key_next;
1586         int cache_index;
1587
1588         ipdata = &ip->chain->data->ipdata;
1589
1590         if (ip->flags & HAMMER2_INODE_MTIME) {
1591                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1592                 atomic_clear_int(&ip->flags, HAMMER2_INODE_MTIME);
1593                 ipdata->mtime = ip->mtime;
1594         }
1595         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size < ipdata->size) {
1596                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1597                 ipdata->size = ip->size;
1598                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1599
1600                 /*
1601                  * We must delete any chains beyond the EOF.  The chain
1602                  * straddling the EOF will be pending in the bioq.
1603                  */
1604                 lbase = (ipdata->size + HAMMER2_PBUFMASK64) &
1605                         ~HAMMER2_PBUFMASK64;
1606                 parent = hammer2_chain_lookup_init(ip->chain, 0);
1607                 chain = hammer2_chain_lookup(&parent, &key_next,
1608                                              lbase, (hammer2_key_t)-1,
1609                                              &cache_index,
1610                                              HAMMER2_LOOKUP_NODATA);
1611                 while (chain) {
1612                         /*
1613                          * Degenerate embedded case, nothing to loop on
1614                          */
1615                         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1616                                 hammer2_chain_unlock(chain);
1617                                 break;
1618                         }
1619                         if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
1620                                 hammer2_chain_delete(trans, chain, 0);
1621                         }
1622                         chain = hammer2_chain_next(&parent, chain, &key_next,
1623                                                    key_next, (hammer2_key_t)-1,
1624                                                    &cache_index,
1625                                                    HAMMER2_LOOKUP_NODATA);
1626                 }
1627                 hammer2_chain_lookup_done(parent);
1628         } else
1629         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size > ipdata->size) {
1630                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1631                 ipdata->size = ip->size;
1632                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1633
1634                 /*
1635                  * When resizing larger we may not have any direct-data
1636                  * available.
1637                  */
1638                 if ((ipdata->op_flags & HAMMER2_OPFLAG_DIRECTDATA) &&
1639                     ip->size > HAMMER2_EMBEDDED_BYTES) {
1640                         ipdata->op_flags &= ~HAMMER2_OPFLAG_DIRECTDATA;
1641                         bzero(&ipdata->u.blockset, sizeof(ipdata->u.blockset));
1642                 }
1643         }
1644 }