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_interlocked(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                 /* XXX FIFO */
 397                 default:
 398                         panic("hammer2: unhandled objtype %d", ipdata->type);
 399                         break;
 400                 }
 401
 402                 if (ip == pmp->iroot)
 403                         vsetflags(vp, VROOT);
 404
 405                 vp->v_data = ip;
 406                 ip->vp = vp;
 407                 hammer2_inode_ref(ip);          /* vp association */
 408                 hammer2_inode_lock_downgrade(ip, ostate);
 409                 break;
 410         }
 411
 412         /*
 413          * Return non-NULL vp and *errorp == 0, or NULL vp and *errorp != 0.
 414          */
 415         if (hammer2_debug & 0x0002) {
 416                 kprintf("igetv vp %p refs %d aux %d\n",
 417                         vp, vp->v_sysref.refcnt, vp->v_auxrefs);
 418         }
 419         return (vp);
 420 }
 421
 422 /*
 423  * The passed-in chain must be locked and the returned inode will also be
 424  * locked.  This routine typically locates or allocates the inode, assigns
 425  * ip->chain (adding a ref to chain if necessary), and returns the inode.
 426  *
 427  * The hammer2_inode structure regulates the interface between the high level
 428  * kernel VNOPS API and the filesystem backend (the chains).
 429  *
 430  * WARNING!  This routine sucks up the chain's lock (makes it part of the
 431  *           inode lock from the point of view of the inode lock API),
 432  *           so callers need to be careful.
 433  *
 434  * WARNING!  The mount code is allowed to pass dip == NULL for iroot and
 435  *           is allowed to pass pmp == NULL and dip == NULL for sroot.
 436  */
 437 hammer2_inode_t *
 438 hammer2_inode_get(hammer2_pfsmount_t *pmp, hammer2_inode_t *dip,
 439                   hammer2_chain_t *chain)
 440 {
 441         hammer2_inode_t *nip;
 442
 443         KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
 444
 445         /*
 446          * Interlocked lookup/ref of the inode.  This code is only needed
 447          * when looking up inodes with nlinks != 0 (TODO: optimize out
 448          * otherwise and test for duplicates).
 449          */
 450 again:
 451         for (;;) {
 452                 nip = hammer2_inode_lookup(pmp, chain->data->ipdata.inum);
 453                 if (nip == NULL)
 454                         break;
 455                 ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 456                 if ((nip->flags & HAMMER2_INODE_ONRBTREE) == 0) { /* race */
 457                         ccms_thread_unlock(&nip->topo_cst);
 458                         hammer2_inode_drop(nip);
 459                         continue;
 460                 }
 461                 if (nip->chain != chain)
 462                         hammer2_inode_repoint(nip, NULL, chain);
 463
 464                 /*
 465                  * Consolidated nip/nip->chain is locked (chain locked
 466                  * by caller).
 467                  */
 468                 return nip;
 469         }
 470
 471         /*
 472          * We couldn't find the inode number, create a new inode.
 473          */
 474         if (pmp) {
 475                 nip = kmalloc(sizeof(*nip), pmp->minode, M_WAITOK | M_ZERO);
 476                 atomic_add_long(&pmp->inmem_inodes, 1);
 477                 hammer2_chain_memory_wakeup(pmp);
 478         } else {
 479                 nip = kmalloc(sizeof(*nip), M_HAMMER2, M_WAITOK | M_ZERO);
 480                 nip->flags = HAMMER2_INODE_SROOT;
 481         }
 482         nip->inum = chain->data->ipdata.inum;
 483         nip->size = chain->data->ipdata.size;
 484         nip->mtime = chain->data->ipdata.mtime;
 485         hammer2_inode_repoint(nip, NULL, chain);
 486         nip->pip = dip;                         /* can be NULL */
 487         if (dip)
 488                 hammer2_inode_ref(dip); /* ref dip for nip->pip */
 489
 490         nip->pmp = pmp;
 491
 492         /*
 493          * ref and lock on nip gives it state compatible to after a
 494          * hammer2_inode_lock_ex() call.
 495          */
 496         nip->refs = 1;
 497         ccms_cst_init(&nip->topo_cst, &nip->chain);
 498         ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 499         /* combination of thread lock and chain lock == inode lock */
 500
 501         /*
 502          * Attempt to add the inode.  If it fails we raced another inode
 503          * get.  Undo all the work and try again.
 504          */
 505         if (pmp) {
 506                 spin_lock(&pmp->inum_spin);
 507                 if (RB_INSERT(hammer2_inode_tree, &pmp->inum_tree, nip)) {
 508                         spin_unlock(&pmp->inum_spin);
 509                         ccms_thread_unlock(&nip->topo_cst);
 510                         hammer2_inode_drop(nip);
 511                         goto again;
 512                 }
 513                 atomic_set_int(&nip->flags, HAMMER2_INODE_ONRBTREE);
 514                 spin_unlock(&pmp->inum_spin);
 515         }
 516
 517         return (nip);
 518 }
 519
 520 /*
 521  * Create a new inode in the specified directory using the vattr to
 522  * figure out the type of inode.
 523  *
 524  * If no error occurs the new inode with its chain locked is returned in
 525  * *nipp, otherwise an error is returned and *nipp is set to NULL.
 526  *
 527  * If vap and/or cred are NULL the related fields are not set and the
 528  * inode type defaults to a directory.  This is used when creating PFSs
 529  * under the super-root, so the inode number is set to 1 in this case.
 530  *
 531  * dip is not locked on entry.
 532  */
 533 hammer2_inode_t *
 534 hammer2_inode_create(hammer2_trans_t *trans, hammer2_inode_t *dip,
 535                      struct vattr *vap, struct ucred *cred,
 536                      const uint8_t *name, size_t name_len,
 537                      hammer2_chain_t **chainp, int *errorp)
 538 {
 539         hammer2_inode_data_t *dipdata;
 540         hammer2_inode_data_t *nipdata;
 541         hammer2_chain_t *chain;
 542         hammer2_chain_t *parent;
 543         hammer2_inode_t *nip;
 544         hammer2_key_t key_dummy;
 545         hammer2_key_t lhc;
 546         int error;
 547         uid_t xuid;
 548         uuid_t dip_uid;
 549         uuid_t dip_gid;
 550         uint32_t dip_mode;
 551         uint8_t dip_algo;
 552         int cache_index = -1;
 553
 554         lhc = hammer2_dirhash(name, name_len);
 555         *errorp = 0;
 556
 557         /*
 558          * Locate the inode or indirect block to create the new
 559          * entry in.  At the same time check for key collisions
 560          * and iterate until we don't get one.
 561          *
 562          * NOTE: hidden inodes do not have iterators.
 563          */
 564 retry:
 565         parent = hammer2_inode_lock_ex(dip);
 566         dipdata = &dip->chain->data->ipdata;
 567         dip_uid = dipdata->uid;
 568         dip_gid = dipdata->gid;
 569         dip_mode = dipdata->mode;
 570         dip_algo = dipdata->comp_algo;
 571
 572         error = 0;
 573         while (error == 0) {
 574                 chain = hammer2_chain_lookup(&parent, &key_dummy,
 575                                              lhc, lhc, &cache_index, 0);
 576                 if (chain == NULL)
 577                         break;
 578                 if ((lhc & HAMMER2_DIRHASH_VISIBLE) == 0)
 579                         error = ENOSPC;
 580                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 581                         error = ENOSPC;
 582                 hammer2_chain_unlock(chain);
 583                 chain = NULL;
 584                 ++lhc;
 585         }
 586
 587         if (error == 0) {
 588                 error = hammer2_chain_create(trans, &parent, &chain,
 589                                              lhc, 0,
 590                                              HAMMER2_BREF_TYPE_INODE,
 591                                              HAMMER2_INODE_BYTES);
 592         }
 593
 594         /*
 595          * Cleanup and handle retries.
 596          */
 597         if (error == EAGAIN) {
 598                 hammer2_chain_ref(parent);
 599                 hammer2_inode_unlock_ex(dip, parent);
 600                 hammer2_chain_wait(parent);
 601                 hammer2_chain_drop(parent);
 602                 goto retry;
 603         }
 604         hammer2_inode_unlock_ex(dip, parent);
 605
 606         if (error) {
 607                 KKASSERT(chain == NULL);
 608                 *errorp = error;
 609                 return (NULL);
 610         }
 611
 612         /*
 613          * Set up the new inode.
 614          *
 615          * NOTE: *_get() integrates chain's lock into the inode lock.
 616          *
 617          * NOTE: Only one new inode can currently be created per
 618          *       transaction.  If the need arises we can adjust
 619          *       hammer2_trans_init() to allow more.
 620          *
 621          * NOTE: nipdata will have chain's blockset data.
 622          */
 623         chain->data->ipdata.inum = trans->sync_tid;
 624         nip = hammer2_inode_get(dip->pmp, dip, chain);
 625         nipdata = &chain->data->ipdata;
 626
 627         if (vap) {
 628                 KKASSERT(trans->inodes_created == 0);
 629                 nipdata->type = hammer2_get_obj_type(vap->va_type);
 630                 nipdata->inum = trans->sync_tid;
 631                 ++trans->inodes_created;
 632         } else {
 633                 nipdata->type = HAMMER2_OBJTYPE_DIRECTORY;
 634                 nipdata->inum = 1;
 635         }
 636
 637         /* Inherit parent's inode compression mode. */
 638         nip->comp_heuristic = 0;
 639         nipdata->comp_algo = dip_algo;
 640         nipdata->version = HAMMER2_INODE_VERSION_ONE;
 641         hammer2_update_time(&nipdata->ctime);
 642         nipdata->mtime = nipdata->ctime;
 643         if (vap)
 644                 nipdata->mode = vap->va_mode;
 645         nipdata->nlinks = 1;
 646         if (vap) {
 647                 if (dip) {
 648                         xuid = hammer2_to_unix_xid(&dip_uid);
 649                         xuid = vop_helper_create_uid(dip->pmp->mp,
 650                                                      dip_mode,
 651                                                      xuid,
 652                                                      cred,
 653                                                      &vap->va_mode);
 654                 } else {
 655                         xuid = 0;
 656                 }
 657                 if (vap->va_vaflags & VA_UID_UUID_VALID)
 658                         nipdata->uid = vap->va_uid_uuid;
 659                 else if (vap->va_uid != (uid_t)VNOVAL)
 660                         hammer2_guid_to_uuid(&nipdata->uid, vap->va_uid);
 661                 else
 662                         hammer2_guid_to_uuid(&nipdata->uid, xuid);
 663
 664                 if (vap->va_vaflags & VA_GID_UUID_VALID)
 665                         nipdata->gid = vap->va_gid_uuid;
 666                 else if (vap->va_gid != (gid_t)VNOVAL)
 667                         hammer2_guid_to_uuid(&nipdata->gid, vap->va_gid);
 668                 else if (dip)
 669                         nipdata->gid = dip_gid;
 670         }
 671
 672         /*
 673          * Regular files and softlinks allow a small amount of data to be
 674          * directly embedded in the inode.  This flag will be cleared if
 675          * the size is extended past the embedded limit.
 676          */
 677         if (nipdata->type == HAMMER2_OBJTYPE_REGFILE ||
 678             nipdata->type == HAMMER2_OBJTYPE_SOFTLINK) {
 679                 nipdata->op_flags |= HAMMER2_OPFLAG_DIRECTDATA;
 680         }
 681
 682         KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 683         bcopy(name, nipdata->filename, name_len);
 684         nipdata->name_key = lhc;
 685         nipdata->name_len = name_len;
 686         *chainp = chain;
 687
 688         return (nip);
 689 }
 690
 691 /*
 692  * chain may have been moved around by the create.
 693  */
 694 static
 695 void
 696 hammer2_chain_refactor(hammer2_chain_t **chainp)
 697 {
 698         hammer2_chain_t *chain = *chainp;
 699         hammer2_chain_core_t *core;
 700
 701         core = chain->core;
 702         while (chain->flags & HAMMER2_CHAIN_DUPLICATED) {
 703                 spin_lock(&core->cst.spin);
 704                 chain = TAILQ_NEXT(chain, core_entry);
 705                 while (chain->flags & HAMMER2_CHAIN_DUPLICATED)
 706                         chain = TAILQ_NEXT(chain, core_entry);
 707                 hammer2_chain_ref(chain);
 708                 spin_unlock(&core->cst.spin);
 709                 KKASSERT(chain->core == core);
 710
 711                 hammer2_chain_unlock(*chainp);
 712                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 713                                           HAMMER2_RESOLVE_NOREF); /* eat ref */
 714                 *chainp = chain;
 715         }
 716 }
 717
 718 /*
 719  * ochain represents the target file inode.  We need to move it to the
 720  * specified common parent directory (dip) and rename it to a special
 721  * invisible "0xINODENUMBER" filename.
 722  *
 723  * We use chain_duplicate and duplicate ochain at the new location,
 724  * renaming it appropriately.  We create a temporary chain and
 725  * then delete it to placemark where the duplicate will go.  Both of
 726  * these use the inode number for (lhc) (the key), generating the
 727  * invisible filename.
 728  */
 729 static
 730 hammer2_chain_t *
 731 hammer2_hardlink_shiftup(hammer2_trans_t *trans, hammer2_chain_t **ochainp,
 732                         hammer2_inode_t *dip, int *errorp)
 733 {
 734         hammer2_inode_data_t *nipdata;
 735         hammer2_chain_t *parent;
 736         hammer2_chain_t *ochain;
 737         hammer2_chain_t *nchain;
 738         hammer2_chain_t *tmp;
 739         hammer2_key_t key_dummy;
 740         hammer2_key_t lhc;
 741         hammer2_blockref_t bref;
 742         int cache_index = -1;
 743
 744         ochain = *ochainp;
 745         *errorp = 0;
 746         lhc = ochain->data->ipdata.inum;
 747         KKASSERT((lhc & HAMMER2_DIRHASH_VISIBLE) == 0);
 748
 749         /*
 750          * Locate the inode or indirect block to create the new
 751          * entry in.  lhc represents the inode number so there is
 752          * no collision iteration.
 753          *
 754          * There should be no key collisions with invisible inode keys.
 755          *
 756          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 757          *          dip->chain cache.
 758          */
 759 retry:
 760         parent = hammer2_inode_lock_ex(dip);
 761         /*parent = hammer2_chain_lookup_init(dip->chain, 0);*/
 762         nchain = hammer2_chain_lookup(&parent, &key_dummy,
 763                                       lhc, lhc, &cache_index, 0);
 764         if (nchain) {
 765                 kprintf("X3 chain %p parent %p dip %p dip->chain %p\n",
 766                         nchain, parent, dip, dip->chain);
 767                 hammer2_chain_unlock(nchain);
 768                 nchain = NULL;
 769                 *errorp = ENOSPC;
 770 #if 1
 771                 Debugger("X3");
 772 #endif
 773         }
 774
 775         /*
 776          * Create entry in common parent directory using the seek position
 777          * calculated above.
 778          */
 779         if (*errorp == 0) {
 780                 KKASSERT(nchain == NULL);
 781                 *errorp = hammer2_chain_create(trans, &parent, &nchain,
 782                                                lhc, 0,
 783                                                HAMMER2_BREF_TYPE_INODE,/* n/a */
 784                                                HAMMER2_INODE_BYTES);   /* n/a */
 785                 hammer2_chain_refactor(&ochain);
 786                 *ochainp = ochain;
 787         }
 788
 789         /*
 790          * Cleanup and handle retries.
 791          */
 792         if (*errorp == EAGAIN) {
 793                 hammer2_chain_ref(parent);
 794                 /* hammer2_chain_lookup_done(parent); */
 795                 hammer2_inode_unlock_ex(dip, parent);
 796                 hammer2_chain_wait(parent);
 797                 hammer2_chain_drop(parent);
 798                 goto retry;
 799         }
 800
 801         /*
 802          * Handle the error case
 803          */
 804         if (*errorp) {
 805                 KKASSERT(nchain == NULL);
 806                 hammer2_inode_unlock_ex(dip, parent);
 807                 /*hammer2_chain_lookup_done(parent);*/
 808                 return (NULL);
 809         }
 810
 811         /*
 812          * Use chain as a placeholder for (lhc), delete it and replace
 813          * it with our duplication.
 814          *
 815          * Gain a second lock on ochain for the duplication function to
 816          * unlock, maintain the caller's original lock across the call.
 817          *
 818          * This is a bit messy.
 819          */
 820         hammer2_chain_delete(trans, nchain, HAMMER2_DELETE_WILLDUP);
 821         hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
 822         tmp = ochain;
 823         bref = tmp->bref;
 824         bref.key = lhc;                 /* invisible dir entry key */
 825         bref.keybits = 0;
 826         hammer2_chain_duplicate(trans, parent, &tmp, &bref, 0);
 827         hammer2_inode_unlock_ex(dip, parent);
 828         /*hammer2_chain_lookup_done(parent);*/
 829         hammer2_chain_unlock(nchain);   /* no longer needed */
 830
 831         /*
 832          * Now set chain to our duplicate and modify it appropriately.
 833          *
 834          * Directory entries are inodes but this is a hidden hardlink
 835          * target.  The name isn't used but to ease debugging give it
 836          * a name after its inode number.
 837          */
 838         nchain = tmp;
 839         tmp = NULL;     /* safety */
 840
 841         hammer2_chain_modify(trans, &nchain, HAMMER2_MODIFY_ASSERTNOCOPY);
 842         nipdata = &nchain->data->ipdata;
 843         ksnprintf(nipdata->filename, sizeof(nipdata->filename),
 844                   "0x%016jx", (intmax_t)nipdata->inum);
 845         nipdata->name_len = strlen(nipdata->filename);
 846         nipdata->name_key = lhc;
 847
 848         return (nchain);
 849 }
 850
 851 /*
 852  * Connect the target inode represented by (*chainp) to the media topology
 853  * at (dip, name, len).
 854  *
 855  * If hlink is TRUE this function creates an OBJTYPE_HARDLINK directory
 856  * entry instead of connecting (*chainp).
 857  *
 858  * If hlink is FALSE this function uses chain_duplicate() to make a copy
 859  * if (*chainp) in the directory entry.  (*chainp) is likely to be deleted
 860  * by the caller in this case (e.g. rename).
 861  */
 862 int
 863 hammer2_inode_connect(hammer2_trans_t *trans, int hlink,
 864                       hammer2_inode_t *dip, hammer2_chain_t **chainp,
 865                       const uint8_t *name, size_t name_len)
 866 {
 867         hammer2_inode_data_t *ipdata;
 868         hammer2_chain_t *nchain;
 869         hammer2_chain_t *parent;
 870         hammer2_chain_t *ochain;
 871         hammer2_key_t key_dummy;
 872         hammer2_key_t lhc;
 873         int cache_index = -1;
 874         int error;
 875
 876         ochain = *chainp;
 877
 878         /*
 879          * Since ochain is either disconnected from the topology or represents
 880          * a hardlink terminus which is always a parent of or equal to dip,
 881          * we should be able to safely lock dip->chain for our setup.
 882          *
 883          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 884          *          dip->chain cache.
 885          */
 886         parent = hammer2_inode_lock_ex(dip);
 887         /*parent = hammer2_chain_lookup_init(dip->chain, 0);*/
 888
 889         lhc = hammer2_dirhash(name, name_len);
 890
 891         /*
 892          * Locate the inode or indirect block to create the new
 893          * entry in.  At the same time check for key collisions
 894          * and iterate until we don't get one.
 895          */
 896         error = 0;
 897         while (error == 0) {
 898                 nchain = hammer2_chain_lookup(&parent, &key_dummy,
 899                                               lhc, lhc, &cache_index, 0);
 900                 if (nchain == NULL)
 901                         break;
 902                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 903                         error = ENOSPC;
 904                 hammer2_chain_unlock(nchain);
 905                 nchain = NULL;
 906                 ++lhc;
 907         }
 908
 909         if (error == 0) {
 910                 if (hlink) {
 911                         /*
 912                          * Hardlink pointer needed, create totally fresh
 913                          * directory entry.
 914                          */
 915                         KKASSERT(nchain == NULL);
 916                         error = hammer2_chain_create(trans, &parent, &nchain,
 917                                                      lhc, 0,
 918                                                      HAMMER2_BREF_TYPE_INODE,
 919                                                      HAMMER2_INODE_BYTES);
 920                         hammer2_chain_refactor(&ochain);
 921                 } else {
 922                         /*
 923                          * Reconnect the original chain and rename.  Use
 924                          * chain_duplicate().  The caller will likely delete
 925                          * or has already deleted the original chain in
 926                          * this case.
 927                          *
 928                          * NOTE: chain_duplicate() generates a new chain
 929                          *       with CHAIN_DELETED cleared (ochain typically
 930                          *       has it set from the file unlink).
 931                          */
 932                         nchain = ochain;
 933                         ochain = NULL;
 934                         hammer2_chain_duplicate(trans, NULL, &nchain, NULL, 0);
 935                         error = hammer2_chain_create(trans, &parent, &nchain,
 936                                                      lhc, 0,
 937                                                      HAMMER2_BREF_TYPE_INODE,
 938                                                      HAMMER2_INODE_BYTES);
 939                 }
 940         }
 941
 942         /*
 943          * Unlock stuff.
 944          */
 945         KKASSERT(error != EAGAIN);
 946         hammer2_inode_unlock_ex(dip, parent);
 947         /*hammer2_chain_lookup_done(parent);*/
 948         parent = NULL;
 949
 950         /*
 951          * nchain should be NULL on error, leave ochain (== *chainp) alone.
 952          */
 953         if (error) {
 954                 KKASSERT(nchain == NULL);
 955                 return (error);
 956         }
 957
 958         /*
 959          * Directory entries are inodes so if the name has changed we have
 960          * to update the inode.
 961          *
 962          * When creating an OBJTYPE_HARDLINK entry remember to unlock the
 963          * chain, the caller will access the hardlink via the actual hardlink
 964          * target file and not the hardlink pointer entry, so we must still
 965          * return ochain.
 966          */
 967         if (hlink && hammer2_hardlink_enable >= 0) {
 968                 /*
 969                  * Create the HARDLINK pointer.  oip represents the hardlink
 970                  * target in this situation.
 971                  *
 972                  * We will return ochain (the hardlink target).
 973                  */
 974                 hammer2_chain_modify(trans, &nchain,
 975                                      HAMMER2_MODIFY_ASSERTNOCOPY);
 976                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 977                 ipdata = &nchain->data->ipdata;
 978                 bcopy(name, ipdata->filename, name_len);
 979                 ipdata->name_key = lhc;
 980                 ipdata->name_len = name_len;
 981                 ipdata->target_type = ochain->data->ipdata.type;
 982                 ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
 983                 ipdata->inum = ochain->data->ipdata.inum;
 984                 ipdata->nlinks = 1;
 985                 hammer2_chain_unlock(nchain);
 986                 nchain = ochain;
 987                 ochain = NULL;
 988         } else if (hlink && hammer2_hardlink_enable < 0) {
 989                 /*
 990                  * Create a snapshot (hardlink fake mode for debugging).
 991                  * (ochain already flushed above so we can just copy the
 992                  * bref XXX).
 993                  *
 994                  * Since this is a snapshot we return nchain in the fake
 995                  * hardlink case.
 996                  */
 997                 hammer2_chain_modify(trans, &nchain,
 998                                      HAMMER2_MODIFY_ASSERTNOCOPY);
 999                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1000                 ipdata = &nchain->data->ipdata;
1001                 *ipdata = ochain->data->ipdata;
1002                 bcopy(name, ipdata->filename, name_len);
1003                 ipdata->name_key = lhc;
1004                 ipdata->name_len = name_len;
1005                 kprintf("created fake hardlink %*.*s\n",
1006                         (int)name_len, (int)name_len, name);
1007         } else {
1008                 /*
1009                  * nchain is a duplicate of ochain at the new location.
1010                  * We must fixup the name stored in oip.  The bref key
1011                  * has already been set up.
1012                  */
1013                 hammer2_chain_modify(trans, &nchain,
1014                                      HAMMER2_MODIFY_ASSERTNOCOPY);
1015                 ipdata = &nchain->data->ipdata;
1016
1017                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1018                 bcopy(name, ipdata->filename, name_len);
1019                 ipdata->name_key = lhc;
1020                 ipdata->name_len = name_len;
1021                 ipdata->nlinks = 1;
1022         }
1023
1024         /*
1025          * We are replacing ochain with nchain, unlock ochain.  In the
1026          * case where ochain is left unchanged the code above sets
1027          * nchain to ochain and ochain to NULL, resulting in a NOP here.
1028          */
1029         if (ochain)
1030                 hammer2_chain_unlock(ochain);
1031         *chainp = nchain;
1032
1033         return (0);
1034 }
1035
1036 /*
1037  * Repoint ip->chain to nchain.  Caller must hold the inode exclusively
1038  * locked.
1039  *
1040  * ip->chain is set to nchain.  The prior chain in ip->chain is dropped
1041  * and nchain is ref'd.
1042  */
1043 void
1044 hammer2_inode_repoint(hammer2_inode_t *ip, hammer2_inode_t *pip,
1045                       hammer2_chain_t *nchain)
1046 {
1047         hammer2_chain_t *ochain;
1048         hammer2_inode_t *opip;
1049
1050         /*
1051          * Repoint ip->chain if requested.
1052          */
1053         ochain = ip->chain;
1054         ip->chain = nchain;
1055         if (nchain)
1056                 hammer2_chain_ref(nchain);
1057         if (ochain)
1058                 hammer2_chain_drop(ochain);
1059
1060         /*
1061          * Repoint ip->pip if requested (non-NULL pip).
1062          */
1063         if (pip && ip->pip != pip) {
1064                 opip = ip->pip;
1065                 hammer2_inode_ref(pip);
1066                 ip->pip = pip;
1067                 if (opip)
1068                         hammer2_inode_drop(opip);
1069         }
1070 }
1071
1072 /*
1073  * Unlink the file from the specified directory inode.  The directory inode
1074  * does not need to be locked.
1075  *
1076  * isdir determines whether a directory/non-directory check should be made.
1077  * No check is made if isdir is set to -1.
1078  *
1079  * NOTE!  The underlying file can still be active with open descriptors
1080  *        or if the chain is being manually held (e.g. for rename).
1081  *
1082  *        The caller is responsible for fixing up ip->chain if e.g. a
1083  *        rename occurs (see chain_duplicate()).
1084  */
1085 int
1086 hammer2_unlink_file(hammer2_trans_t *trans, hammer2_inode_t *dip,
1087                     const uint8_t *name, size_t name_len,
1088                     int isdir, int *hlinkp)
1089 {
1090         hammer2_inode_data_t *ipdata;
1091         hammer2_chain_t *parent;
1092         hammer2_chain_t *ochain;
1093         hammer2_chain_t *chain;
1094         hammer2_chain_t *dparent;
1095         hammer2_chain_t *dchain;
1096         hammer2_key_t key_dummy;
1097         hammer2_key_t key_next;
1098         hammer2_key_t lhc;
1099         int error;
1100         int cache_index = -1;
1101         uint8_t type;
1102
1103         error = 0;
1104         ochain = NULL;
1105         lhc = hammer2_dirhash(name, name_len);
1106
1107         /*
1108          * Search for the filename in the directory
1109          */
1110         if (hlinkp)
1111                 *hlinkp = 0;
1112         parent = hammer2_inode_lock_ex(dip);
1113         chain = hammer2_chain_lookup(&parent, &key_next,
1114                                      lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1115                                      &cache_index, 0);
1116         while (chain) {
1117                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1118                     name_len == chain->data->ipdata.name_len &&
1119                     bcmp(name, chain->data->ipdata.filename, name_len) == 0) {
1120                         break;
1121                 }
1122                 chain = hammer2_chain_next(&parent, chain, &key_next,
1123                                            key_next,
1124                                            lhc + HAMMER2_DIRHASH_LOMASK,
1125                                            &cache_index, 0);
1126         }
1127         hammer2_inode_unlock_ex(dip, NULL);     /* retain parent */
1128
1129         /*
1130          * Not found or wrong type (isdir < 0 disables the type check).
1131          * If a hardlink pointer, type checks use the hardlink target.
1132          */
1133         if (chain == NULL) {
1134                 error = ENOENT;
1135                 goto done;
1136         }
1137         if ((type = chain->data->ipdata.type) == HAMMER2_OBJTYPE_HARDLINK) {
1138                 if (hlinkp)
1139                         *hlinkp = 1;
1140                 type = chain->data->ipdata.target_type;
1141         }
1142
1143         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 0) {
1144                 error = ENOTDIR;
1145                 goto done;
1146         }
1147         if (type != HAMMER2_OBJTYPE_DIRECTORY && isdir >= 1) {
1148                 error = EISDIR;
1149                 goto done;
1150         }
1151
1152         /*
1153          * Hardlink must be resolved.  We can't hold parent locked while we
1154          * do this or we could deadlock.
1155          *
1156          * On success chain will be adjusted to point at the hardlink target
1157          * and ochain will point to the hardlink pointer in the original
1158          * directory.  Otherwise chain remains pointing to the original.
1159          */
1160         if (chain->data->ipdata.type == HAMMER2_OBJTYPE_HARDLINK) {
1161                 hammer2_chain_unlock(parent);
1162                 parent = NULL;
1163                 error = hammer2_hardlink_find(dip, &chain, &ochain);
1164         }
1165
1166         /*
1167          * If this is a directory the directory must be empty.  However, if
1168          * isdir < 0 we are doing a rename and the directory does not have
1169          * to be empty, and if isdir > 1 we are deleting a PFS/snapshot
1170          * and the directory does not have to be empty.
1171          *
1172          * NOTE: We check the full key range here which covers both visible
1173          *       and invisible entries.  Theoretically there should be no
1174          *       invisible (hardlink target) entries if there are no visible
1175          *       entries.
1176          */
1177         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 1) {
1178                 dparent = hammer2_chain_lookup_init(chain, 0);
1179                 dchain = hammer2_chain_lookup(&dparent, &key_dummy,
1180                                               0, (hammer2_key_t)-1,
1181                                               &cache_index,
1182                                               HAMMER2_LOOKUP_NODATA);
1183                 if (dchain) {
1184                         hammer2_chain_unlock(dchain);
1185                         hammer2_chain_lookup_done(dparent);
1186                         error = ENOTEMPTY;
1187                         goto done;
1188                 }
1189                 hammer2_chain_lookup_done(dparent);
1190                 dparent = NULL;
1191                 /* dchain NULL */
1192         }
1193
1194         /*
1195          * Ok, we can now unlink the chain.  We always decrement nlinks even
1196          * if the entry can be deleted in case someone has the file open and
1197          * does an fstat().
1198          *
1199          * The chain itself will no longer be in the on-media topology but
1200          * can still be flushed to the media (e.g. if an open descriptor
1201          * remains).  When the last vnode/ip ref goes away the chain will
1202          * be marked unmodified, avoiding any further (now unnecesary) I/O.
1203          *
1204          * A non-NULL ochain indicates a hardlink.
1205          */
1206         if (ochain) {
1207                 /*
1208                  * Delete the original hardlink pointer.
1209                  *
1210                  * NOTE: parent from above is NULL when ochain != NULL
1211                  *       so we can reuse it.
1212                  */
1213                 hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
1214                 hammer2_chain_delete(trans, ochain, 0);
1215                 hammer2_chain_unlock(ochain);
1216
1217                 /*
1218                  * Then decrement nlinks on hardlink target, deleting
1219                  * the target when nlinks drops to 0.
1220                  */
1221                 hammer2_chain_modify(trans, &chain, 0);
1222                 --chain->data->ipdata.nlinks;
1223                 if (chain->data->ipdata.nlinks == 0)
1224                         hammer2_chain_delete(trans, chain, 0);
1225         } else {
1226                 /*
1227                  * Otherwise this was not a hardlink and we can just
1228                  * remove the entry and decrement nlinks.
1229                  *
1230                  * NOTE: *_get() integrates chain's lock into the inode lock.
1231                  */
1232                 hammer2_chain_modify(trans, &chain, 0);
1233                 ipdata = &chain->data->ipdata;
1234                 --ipdata->nlinks;
1235                 hammer2_chain_delete(trans, chain, 0);
1236         }
1237
1238         error = 0;
1239 done:
1240         if (chain)
1241                 hammer2_chain_unlock(chain);
1242         if (parent)
1243                 hammer2_chain_lookup_done(parent);
1244         if (ochain)
1245                 hammer2_chain_drop(ochain);
1246
1247         return error;
1248 }
1249
1250 /*
1251  * Given an exclusively locked inode we consolidate its chain for hardlink
1252  * creation, adding (nlinks) to the file's link count and potentially
1253  * relocating the inode to a directory common to ip->pip and tdip.
1254  *
1255  * Replaces (*chainp) if consolidation occurred, unlocking the old chain
1256  * and returning a new locked chain.
1257  *
1258  * NOTE!  This function will also replace ip->chain.
1259  */
1260 int
1261 hammer2_hardlink_consolidate(hammer2_trans_t *trans, hammer2_inode_t *ip,
1262                              hammer2_chain_t **chainp,
1263                              hammer2_inode_t *tdip, int nlinks)
1264 {
1265         hammer2_inode_data_t *ipdata;
1266         hammer2_inode_t *fdip;
1267         hammer2_inode_t *cdip;
1268         hammer2_chain_t *chain;
1269         hammer2_chain_t *nchain;
1270         int error;
1271
1272         chain = *chainp;
1273         if (nlinks == 0 &&                      /* no hardlink needed */
1274             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE)) {
1275                 return (0);
1276         }
1277         if (hammer2_hardlink_enable < 0) {      /* fake hardlinks */
1278                 return (0);
1279         }
1280
1281         if (hammer2_hardlink_enable == 0) {     /* disallow hardlinks */
1282                 hammer2_chain_unlock(chain);
1283                 *chainp = NULL;
1284                 return (ENOTSUP);
1285         }
1286
1287         /*
1288          * cdip will be returned with a ref, but not locked.
1289          */
1290         fdip = ip->pip;
1291         cdip = hammer2_inode_common_parent(fdip, tdip);
1292
1293         /*
1294          * If no change in the hardlink's target directory is required and
1295          * this is already a hardlink target, all we need to do is adjust
1296          * the link count.
1297          *
1298          * XXX The common parent is a big wiggly due to duplication from
1299          *     renames.  Compare the core (RBTREE) pointer instead of the
1300          *     ip's.
1301          */
1302         if (cdip == fdip &&
1303             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) == 0) {
1304                 if (nlinks) {
1305                         hammer2_chain_modify(trans, &chain, 0);
1306                         chain->data->ipdata.nlinks += nlinks;
1307                 }
1308                 error = 0;
1309                 goto done;
1310         }
1311
1312         /*
1313          * We either have to move an existing hardlink target or we have
1314          * to create a fresh hardlink target.
1315          *
1316          * Hardlink targets are hidden inodes in a parent directory common
1317          * to all directory entries referencing the hardlink.
1318          */
1319         nchain = hammer2_hardlink_shiftup(trans, &chain, cdip, &error);
1320
1321         if (error == 0) {
1322                 /*
1323                  * Bump nlinks on duplicated hidden inode, repoint
1324                  * ip->chain.
1325                  */
1326                 hammer2_chain_modify(trans, &nchain, 0);
1327                 nchain->data->ipdata.nlinks += nlinks;
1328                 hammer2_inode_repoint(ip, cdip, nchain);
1329
1330                 /*
1331                  * If the old chain is not a hardlink target then replace
1332                  * it with a OBJTYPE_HARDLINK pointer.
1333                  *
1334                  * If the old chain IS a hardlink target then delete it.
1335                  */
1336                 if (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) {
1337                         /*
1338                          * Replace original non-hardlink that's been dup'd
1339                          * with a special hardlink directory entry.  We must
1340                          * set the DIRECTDATA flag to prevent sub-chains
1341                          * from trying to synchronize to the inode if the
1342                          * file is extended afterwords.
1343                          *
1344                          * DELDUP_RECORE causes the new chain to NOT inherit
1345                          * the old chain's core (sub-tree).
1346                          */
1347                         /*hammer2_chain_modify(trans, &chain, 0);*/
1348                         hammer2_chain_delete_duplicate(trans, &chain,
1349                                                        HAMMER2_DELDUP_RECORE);
1350                         hammer2_chain_modify(trans, &chain, 0);
1351                         ipdata = &chain->data->ipdata;
1352                         ipdata->target_type = ipdata->type;
1353                         ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1354                         ipdata->uflags = 0;
1355                         ipdata->rmajor = 0;
1356                         ipdata->rminor = 0;
1357                         ipdata->ctime = 0;
1358                         ipdata->mtime = 0;
1359                         ipdata->atime = 0;
1360                         ipdata->btime = 0;
1361                         bzero(&ipdata->uid, sizeof(ipdata->uid));
1362                         bzero(&ipdata->gid, sizeof(ipdata->gid));
1363                         ipdata->op_flags = HAMMER2_OPFLAG_DIRECTDATA;
1364                         ipdata->cap_flags = 0;
1365                         ipdata->mode = 0;
1366                         ipdata->size = 0;
1367                         ipdata->nlinks = 1;
1368                         ipdata->iparent = 0;    /* XXX */
1369                         ipdata->pfs_type = 0;
1370                         ipdata->pfs_inum = 0;
1371                         bzero(&ipdata->pfs_clid, sizeof(ipdata->pfs_clid));
1372                         bzero(&ipdata->pfs_fsid, sizeof(ipdata->pfs_fsid));
1373                         ipdata->data_quota = 0;
1374                         ipdata->data_count = 0;
1375                         ipdata->inode_quota = 0;
1376                         ipdata->inode_count = 0;
1377                         ipdata->attr_tid = 0;
1378                         ipdata->dirent_tid = 0;
1379                         bzero(&ipdata->u, sizeof(ipdata->u));
1380                         /* XXX transaction ids */
1381                 } else {
1382                         hammer2_chain_delete(trans, chain, 0);
1383                 }
1384
1385                 /*
1386                  * Return the new chain.
1387                  */
1388                 hammer2_chain_unlock(chain);
1389                 chain = nchain;
1390         } else {
1391                 /*
1392                  * Return an error
1393                  */
1394                 hammer2_chain_unlock(chain);
1395                 chain = NULL;
1396         }
1397
1398         /*
1399          * Cleanup, chain/nchain already dealt with.
1400          */
1401 done:
1402         *chainp = chain;
1403         hammer2_inode_drop(cdip);
1404
1405         return (error);
1406 }
1407
1408 /*
1409  * If (*ochainp) is non-NULL it points to the forward OBJTYPE_HARDLINK
1410  * inode while (*chainp) points to the resolved (hidden hardlink
1411  * target) inode.  In this situation when nlinks is 1 we wish to
1412  * deconsolidate the hardlink, moving it back to the directory that now
1413  * represents the only remaining link.
1414  */
1415 int
1416 hammer2_hardlink_deconsolidate(hammer2_trans_t *trans,
1417                                hammer2_inode_t *dip,
1418                                hammer2_chain_t **chainp,
1419                                hammer2_chain_t **ochainp)
1420 {
1421         if (*ochainp == NULL)
1422                 return (0);
1423         /* XXX */
1424         return (0);
1425 }
1426
1427 /*
1428  * The caller presents a locked *chainp pointing to a HAMMER2_BREF_TYPE_INODE
1429  * with an obj_type of HAMMER2_OBJTYPE_HARDLINK.  This routine will gobble
1430  * the *chainp and return a new locked *chainp representing the file target
1431  * (the original *chainp will be unlocked).
1432  *
1433  * When a match is found the chain representing the original HARDLINK
1434  * will be returned in *ochainp with a ref, but not locked.
1435  *
1436  * When no match is found *chainp is set to NULL and EIO is returned.
1437  * (*ochainp) will still be set to the original chain with a ref but not
1438  * locked.
1439  */
1440 int
1441 hammer2_hardlink_find(hammer2_inode_t *dip, hammer2_chain_t **chainp,
1442                       hammer2_chain_t **ochainp)
1443 {
1444         hammer2_chain_t *chain = *chainp;
1445         hammer2_chain_t *parent;
1446         hammer2_inode_t *ip;
1447         hammer2_inode_t *pip;
1448         hammer2_key_t key_dummy;
1449         hammer2_key_t lhc;
1450         int cache_index = -1;
1451
1452         pip = dip;
1453         hammer2_inode_ref(pip);         /* for loop */
1454         hammer2_chain_ref(chain);       /* for (*ochainp) */
1455         *ochainp = chain;
1456
1457         /*
1458          * Locate the hardlink.  pip is referenced and not locked,
1459          * ipp.
1460          *
1461          * chain is reused.
1462          */
1463         lhc = chain->data->ipdata.inum;
1464         hammer2_chain_unlock(chain);
1465         chain = NULL;
1466
1467         while ((ip = pip) != NULL) {
1468                 parent = hammer2_inode_lock_ex(ip);
1469                 hammer2_inode_drop(ip);                 /* loop */
1470                 KKASSERT(parent->bref.type == HAMMER2_BREF_TYPE_INODE);
1471                 chain = hammer2_chain_lookup(&parent, &key_dummy,
1472                                              lhc, lhc, &cache_index, 0);
1473                 hammer2_chain_lookup_done(parent);      /* discard parent */
1474                 if (chain)
1475                         break;
1476                 pip = ip->pip;          /* safe, ip held locked */
1477                 if (pip)
1478                         hammer2_inode_ref(pip);         /* loop */
1479                 hammer2_inode_unlock_ex(ip, NULL);
1480         }
1481
1482         /*
1483          * chain is locked, ip is locked.  Unlock ip, return the locked
1484          * chain.  *ipp is already set w/a ref count and not locked.
1485          *
1486          * (parent is already unlocked).
1487          */
1488         if (ip)
1489                 hammer2_inode_unlock_ex(ip, NULL);
1490         *chainp = chain;
1491         if (chain) {
1492                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
1493                 /* already locked */
1494                 return (0);
1495         } else {
1496                 return (EIO);
1497         }
1498 }
1499
1500 /*
1501  * Find the directory common to both fdip and tdip, hold and return
1502  * its inode.
1503  */
1504 hammer2_inode_t *
1505 hammer2_inode_common_parent(hammer2_inode_t *fdip, hammer2_inode_t *tdip)
1506 {
1507         hammer2_inode_t *scan1;
1508         hammer2_inode_t *scan2;
1509
1510         /*
1511          * We used to have a depth field but it complicated matters too
1512          * much for directory renames.  So now its ugly.  Check for
1513          * simple cases before giving up and doing it the expensive way.
1514          *
1515          * XXX need a bottom-up topology stability lock
1516          */
1517         if (fdip == tdip || fdip == tdip->pip) {
1518                 hammer2_inode_ref(fdip);
1519                 return(fdip);
1520         }
1521         if (fdip->pip == tdip) {
1522                 hammer2_inode_ref(tdip);
1523                 return(tdip);
1524         }
1525
1526         /*
1527          * XXX not MPSAFE
1528          */
1529         for (scan1 = fdip; scan1->pmp == fdip->pmp; scan1 = scan1->pip) {
1530                 scan2 = tdip;
1531                 while (scan2->pmp == tdip->pmp) {
1532                         if (scan1 == scan2) {
1533                                 hammer2_inode_ref(scan1);
1534                                 return(scan1);
1535                         }
1536                         scan2 = scan2->pip;
1537                         if (scan2 == NULL)
1538                                 break;
1539                 }
1540         }
1541         panic("hammer2_inode_common_parent: no common parent %p %p\n",
1542               fdip, tdip);
1543         /* NOT REACHED */
1544         return(NULL);
1545 }
1546
1547 /*
1548  * Synchronize the inode's frontend state with the chain state prior
1549  * to any explicit flush of the inode or any strategy write call.
1550  *
1551  * Called with a locked inode.
1552  */
1553 void
1554 hammer2_inode_fsync(hammer2_trans_t *trans, hammer2_inode_t *ip,
1555                     hammer2_chain_t **chainp)
1556 {
1557         hammer2_inode_data_t *ipdata;
1558         hammer2_chain_t *parent;
1559         hammer2_chain_t *chain;
1560         hammer2_key_t lbase;
1561         hammer2_key_t key_next;
1562         int cache_index;
1563
1564         ipdata = &ip->chain->data->ipdata;
1565
1566         if (ip->flags & HAMMER2_INODE_MTIME) {
1567                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1568                 atomic_clear_int(&ip->flags, HAMMER2_INODE_MTIME);
1569                 ipdata->mtime = ip->mtime;
1570         }
1571         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size < ipdata->size) {
1572                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1573                 ipdata->size = ip->size;
1574                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1575
1576                 /*
1577                  * We must delete any chains beyond the EOF.  The chain
1578                  * straddling the EOF will be pending in the bioq.
1579                  */
1580                 lbase = (ipdata->size + HAMMER2_PBUFMASK64) &
1581                         ~HAMMER2_PBUFMASK64;
1582                 parent = hammer2_chain_lookup_init(ip->chain, 0);
1583                 chain = hammer2_chain_lookup(&parent, &key_next,
1584                                              lbase, (hammer2_key_t)-1,
1585                                              &cache_index,
1586                                              HAMMER2_LOOKUP_NODATA);
1587                 while (chain) {
1588                         /*
1589                          * Degenerate embedded case, nothing to loop on
1590                          */
1591                         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1592                                 hammer2_chain_unlock(chain);
1593                                 break;
1594                         }
1595                         if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
1596                                 hammer2_chain_delete(trans, chain, 0);
1597                         }
1598                         chain = hammer2_chain_next(&parent, chain, &key_next,
1599                                                    key_next, (hammer2_key_t)-1,
1600                                                    &cache_index,
1601                                                    HAMMER2_LOOKUP_NODATA);
1602                 }
1603                 hammer2_chain_lookup_done(parent);
1604         } else
1605         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size > ipdata->size) {
1606                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1607                 ipdata->size = ip->size;
1608                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1609
1610                 /*
1611                  * When resizing larger we may not have any direct-data
1612                  * available.
1613                  */
1614                 if ((ipdata->op_flags & HAMMER2_OPFLAG_DIRECTDATA) &&
1615                     ip->size > HAMMER2_EMBEDDED_BYTES) {
1616                         ipdata->op_flags &= ~HAMMER2_OPFLAG_DIRECTDATA;
1617                         bzero(&ipdata->u.blockset, sizeof(ipdata->u.blockset));
1618                 }
1619         }
1620 }