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 static void hammer2_inode_move_to_hidden(hammer2_trans_t *trans,
  45                                          hammer2_chain_t **chainp,
  46                                          hammer2_tid_t inum);
  47
  48 RB_GENERATE2(hammer2_inode_tree, hammer2_inode, rbnode, hammer2_inode_cmp,
  49              hammer2_tid_t, inum);
  50
  51 int
  52 hammer2_inode_cmp(hammer2_inode_t *ip1, hammer2_inode_t *ip2)
  53 {
  54         if (ip1->inum < ip2->inum)
  55                 return(-1);
  56         if (ip1->inum > ip2->inum)
  57                 return(1);
  58         return(0);
  59 }
  60
  61 /*
  62  * HAMMER2 inode locks
  63  *
  64  * HAMMER2 offers shared locks and exclusive locks on inodes.
  65  *
  66  * An inode's ip->chain pointer is resolved and stable while an inode is
  67  * locked, and can be cleaned out at any time (become NULL) when an inode
  68  * is not locked.
  69  *
  70  * This function handles duplication races and hardlink replacement races
  71  * which can cause ip's cached chain to become stale.
  72  *
  73  * The underlying chain is also locked and returned.
  74  *
  75  * NOTE: We don't combine the inode/chain lock because putting away an
  76  *       inode would otherwise confuse multiple lock holders of the inode.
  77  */
  78 hammer2_chain_t *
  79 hammer2_inode_lock_ex(hammer2_inode_t *ip)
  80 {
  81         hammer2_chain_t *chain;
  82         hammer2_chain_t *ochain;
  83         hammer2_chain_core_t *core;
  84         int error;
  85
  86         hammer2_inode_ref(ip);
  87         ccms_thread_lock(&ip->topo_cst, CCMS_STATE_EXCLUSIVE);
  88
  89         chain = ip->chain;
  90         core = chain->core;
  91         for (;;) {
  92                 if (chain->flags & HAMMER2_CHAIN_DUPLICATED) {
  93                         spin_lock(&core->cst.spin);
  94                         while (chain->flags & HAMMER2_CHAIN_DUPLICATED)
  95                                 chain = TAILQ_NEXT(chain, core_entry);
  96                         hammer2_chain_ref(chain);
  97                         spin_unlock(&core->cst.spin);
  98                         hammer2_inode_repoint(ip, NULL, chain);
  99                         hammer2_chain_drop(chain);
 100                 }
 101                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS);
 102                 if ((chain->flags & HAMMER2_CHAIN_DUPLICATED) == 0)
 103                         break;
 104                 hammer2_chain_unlock(chain);
 105         }
 106         if (chain->data->ipdata.type == HAMMER2_OBJTYPE_HARDLINK &&
 107             (chain->flags & HAMMER2_CHAIN_DELETED) == 0) {
 108                 error = hammer2_hardlink_find(ip->pip, &chain, &ochain);
 109                 hammer2_chain_drop(ochain);
 110                 KKASSERT(error == 0);
 111                 /* XXX error handling */
 112         }
 113         return (chain);
 114 }
 115
 116 void
 117 hammer2_inode_unlock_ex(hammer2_inode_t *ip, hammer2_chain_t *chain)
 118 {
 119         /*
 120          * XXX this will catch parent directories too which we don't
 121          *     really want.
 122          */
 123         if (chain)
 124                 hammer2_chain_unlock(chain);
 125         ccms_thread_unlock(&ip->topo_cst);
 126         hammer2_inode_drop(ip);
 127 }
 128
 129 /*
 130  * NOTE: We don't combine the inode/chain lock because putting away an
 131  *       inode would otherwise confuse multiple lock holders of the inode.
 132  *
 133  *       Shared locks are especially sensitive to having too many shared
 134  *       lock counts (from the same thread) on certain paths which might
 135  *       need to upgrade them.  Only one count of a shared lock can be
 136  *       upgraded.
 137  */
 138 hammer2_chain_t *
 139 hammer2_inode_lock_sh(hammer2_inode_t *ip)
 140 {
 141         hammer2_chain_t *chain;
 142
 143         hammer2_inode_ref(ip);
 144         for (;;) {
 145                 ccms_thread_lock(&ip->topo_cst, CCMS_STATE_SHARED);
 146
 147                 chain = ip->chain;
 148                 KKASSERT(chain != NULL);        /* for now */
 149                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 150                                           HAMMER2_RESOLVE_SHARED);
 151
 152                 /*
 153                  * Resolve duplication races, resolve hardlinks by giving
 154                  * up and cycling an exclusive lock.
 155                  */
 156                 if ((chain->flags & HAMMER2_CHAIN_DUPLICATED) == 0 &&
 157                     chain->data->ipdata.type != HAMMER2_OBJTYPE_HARDLINK) {
 158                         break;
 159                 }
 160                 hammer2_chain_unlock(chain);
 161                 ccms_thread_unlock(&ip->topo_cst);
 162                 chain = hammer2_inode_lock_ex(ip);
 163                 hammer2_inode_unlock_ex(ip, chain);
 164         }
 165         return (chain);
 166 }
 167
 168 void
 169 hammer2_inode_unlock_sh(hammer2_inode_t *ip, hammer2_chain_t *chain)
 170 {
 171         if (chain)
 172                 hammer2_chain_unlock(chain);
 173         ccms_thread_unlock(&ip->topo_cst);
 174         hammer2_inode_drop(ip);
 175 }
 176
 177 ccms_state_t
 178 hammer2_inode_lock_temp_release(hammer2_inode_t *ip)
 179 {
 180         return(ccms_thread_lock_temp_release(&ip->topo_cst));
 181 }
 182
 183 void
 184 hammer2_inode_lock_temp_restore(hammer2_inode_t *ip, ccms_state_t ostate)
 185 {
 186         ccms_thread_lock_temp_restore(&ip->topo_cst, ostate);
 187 }
 188
 189 ccms_state_t
 190 hammer2_inode_lock_upgrade(hammer2_inode_t *ip)
 191 {
 192         return(ccms_thread_lock_upgrade(&ip->topo_cst));
 193 }
 194
 195 void
 196 hammer2_inode_lock_downgrade(hammer2_inode_t *ip, ccms_state_t ostate)
 197 {
 198         ccms_thread_lock_downgrade(&ip->topo_cst, ostate);
 199 }
 200
 201 /*
 202  * Lookup an inode by inode number
 203  */
 204 hammer2_inode_t *
 205 hammer2_inode_lookup(hammer2_pfsmount_t *pmp, hammer2_tid_t inum)
 206 {
 207         hammer2_inode_t *ip;
 208
 209         if (pmp) {
 210                 spin_lock(&pmp->inum_spin);
 211                 ip = RB_LOOKUP(hammer2_inode_tree, &pmp->inum_tree, inum);
 212                 if (ip)
 213                         hammer2_inode_ref(ip);
 214                 spin_unlock(&pmp->inum_spin);
 215         } else {
 216                 ip = NULL;
 217         }
 218         return(ip);
 219 }
 220
 221 /*
 222  * Adding a ref to an inode is only legal if the inode already has at least
 223  * one ref.
 224  */
 225 void
 226 hammer2_inode_ref(hammer2_inode_t *ip)
 227 {
 228         atomic_add_int(&ip->refs, 1);
 229 }
 230
 231 /*
 232  * Drop an inode reference, freeing the inode when the last reference goes
 233  * away.
 234  */
 235 void
 236 hammer2_inode_drop(hammer2_inode_t *ip)
 237 {
 238         hammer2_pfsmount_t *pmp;
 239         hammer2_inode_t *pip;
 240         u_int refs;
 241
 242         while (ip) {
 243                 refs = ip->refs;
 244                 cpu_ccfence();
 245                 if (refs == 1) {
 246                         /*
 247                          * Transition to zero, must interlock with
 248                          * the inode inumber lookup tree (if applicable).
 249                          *
 250                          * NOTE: The super-root inode has no pmp.
 251                          */
 252                         pmp = ip->pmp;
 253                         if (pmp)
 254                                 spin_lock(&pmp->inum_spin);
 255
 256                         if (atomic_cmpset_int(&ip->refs, 1, 0)) {
 257                                 KKASSERT(ip->topo_cst.count == 0);
 258                                 if (ip->flags & HAMMER2_INODE_ONRBTREE) {
 259                                         atomic_clear_int(&ip->flags,
 260                                                      HAMMER2_INODE_ONRBTREE);
 261                                         RB_REMOVE(hammer2_inode_tree,
 262                                                   &pmp->inum_tree, ip);
 263                                 }
 264                                 if (pmp)
 265                                         spin_unlock(&pmp->inum_spin);
 266
 267                                 pip = ip->pip;
 268                                 ip->pip = NULL;
 269                                 ip->pmp = NULL;
 270
 271                                 /*
 272                                  * Cleaning out ip->chain isn't entirely
 273                                  * trivial.
 274                                  */
 275                                 hammer2_inode_repoint(ip, NULL, NULL);
 276
 277                                 /*
 278                                  * We have to drop pip (if non-NULL) to
 279                                  * dispose of our implied reference from
 280                                  * ip->pip.  We can simply loop on it.
 281                                  */
 282                                 if (pmp) {
 283                                         KKASSERT((ip->flags &
 284                                                   HAMMER2_INODE_SROOT) == 0);
 285                                         kfree(ip, pmp->minode);
 286                                         atomic_add_long(&pmp->inmem_inodes, -1);
 287                                 } else {
 288                                         KKASSERT(ip->flags &
 289                                                  HAMMER2_INODE_SROOT);
 290                                         kfree(ip, M_HAMMER2);
 291                                 }
 292                                 ip = pip;
 293                                 /* continue with pip (can be NULL) */
 294                         } else {
 295                                 if (pmp)
 296                                         spin_unlock(&ip->pmp->inum_spin);
 297                         }
 298                 } else {
 299                         /*
 300                          * Non zero transition
 301                          */
 302                         if (atomic_cmpset_int(&ip->refs, refs, refs - 1))
 303                                 break;
 304                 }
 305         }
 306 }
 307
 308 /*
 309  * Get the vnode associated with the given inode, allocating the vnode if
 310  * necessary.  The vnode will be returned exclusively locked.
 311  *
 312  * The caller must lock the inode (shared or exclusive).
 313  *
 314  * Great care must be taken to avoid deadlocks and vnode acquisition/reclaim
 315  * races.
 316  */
 317 struct vnode *
 318 hammer2_igetv(hammer2_inode_t *ip, int *errorp)
 319 {
 320         hammer2_inode_data_t *ipdata;
 321         hammer2_pfsmount_t *pmp;
 322         struct vnode *vp;
 323         ccms_state_t ostate;
 324
 325         pmp = ip->pmp;
 326         KKASSERT(pmp != NULL);
 327         *errorp = 0;
 328         ipdata = &ip->chain->data->ipdata;
 329
 330         for (;;) {
 331                 /*
 332                  * Attempt to reuse an existing vnode assignment.  It is
 333                  * possible to race a reclaim so the vget() may fail.  The
 334                  * inode must be unlocked during the vget() to avoid a
 335                  * deadlock against a reclaim.
 336                  */
 337                 vp = ip->vp;
 338                 if (vp) {
 339                         /*
 340                          * Inode must be unlocked during the vget() to avoid
 341                          * possible deadlocks, but leave the ip ref intact.
 342                          *
 343                          * vnode is held to prevent destruction during the
 344                          * vget().  The vget() can still fail if we lost
 345                          * a reclaim race on the vnode.
 346                          */
 347                         vhold(vp);
 348                         ostate = hammer2_inode_lock_temp_release(ip);
 349                         if (vget(vp, LK_EXCLUSIVE)) {
 350                                 vdrop(vp);
 351                                 hammer2_inode_lock_temp_restore(ip, ostate);
 352                                 continue;
 353                         }
 354                         hammer2_inode_lock_temp_restore(ip, ostate);
 355                         vdrop(vp);
 356                         /* vp still locked and ref from vget */
 357                         if (ip->vp != vp) {
 358                                 kprintf("hammer2: igetv race %p/%p\n",
 359                                         ip->vp, vp);
 360                                 vput(vp);
 361                                 continue;
 362                         }
 363                         *errorp = 0;
 364                         break;
 365                 }
 366
 367                 /*
 368                  * No vnode exists, allocate a new vnode.  Beware of
 369                  * allocation races.  This function will return an
 370                  * exclusively locked and referenced vnode.
 371                  */
 372                 *errorp = getnewvnode(VT_HAMMER2, pmp->mp, &vp, 0, 0);
 373                 if (*errorp) {
 374                         kprintf("hammer2: igetv getnewvnode failed %d\n",
 375                                 *errorp);
 376                         vp = NULL;
 377                         break;
 378                 }
 379
 380                 /*
 381                  * Lock the inode and check for an allocation race.
 382                  */
 383                 ostate = hammer2_inode_lock_upgrade(ip);
 384                 if (ip->vp != NULL) {
 385                         vp->v_type = VBAD;
 386                         vx_put(vp);
 387                         hammer2_inode_lock_downgrade(ip, ostate);
 388                         continue;
 389                 }
 390
 391                 switch (ipdata->type) {
 392                 case HAMMER2_OBJTYPE_DIRECTORY:
 393                         vp->v_type = VDIR;
 394                         break;
 395                 case HAMMER2_OBJTYPE_REGFILE:
 396                         vp->v_type = VREG;
 397                         vinitvmio(vp, ipdata->size,
 398                                   HAMMER2_LBUFSIZE,
 399                                   (int)ipdata->size & HAMMER2_LBUFMASK);
 400                         break;
 401                 case HAMMER2_OBJTYPE_SOFTLINK:
 402                         /*
 403                          * XXX for now we are using the generic file_read
 404                          * and file_write code so we need a buffer cache
 405                          * association.
 406                          */
 407                         vp->v_type = VLNK;
 408                         vinitvmio(vp, ipdata->size,
 409                                   HAMMER2_LBUFSIZE,
 410                                   (int)ipdata->size & HAMMER2_LBUFMASK);
 411                         break;
 412                 case HAMMER2_OBJTYPE_CDEV:
 413                         vp->v_type = VCHR;
 414                         /* fall through */
 415                 case HAMMER2_OBJTYPE_BDEV:
 416                         vp->v_ops = &pmp->mp->mnt_vn_spec_ops;
 417                         if (ipdata->type != HAMMER2_OBJTYPE_CDEV)
 418                                 vp->v_type = VBLK;
 419                         addaliasu(vp, ipdata->rmajor, ipdata->rminor);
 420                         break;
 421                 case HAMMER2_OBJTYPE_FIFO:
 422                         vp->v_type = VFIFO;
 423                         vp->v_ops = &pmp->mp->mnt_vn_fifo_ops;
 424                         break;
 425                 default:
 426                         panic("hammer2: unhandled objtype %d", ipdata->type);
 427                         break;
 428                 }
 429
 430                 if (ip == pmp->iroot)
 431                         vsetflags(vp, VROOT);
 432
 433                 vp->v_data = ip;
 434                 ip->vp = vp;
 435                 hammer2_inode_ref(ip);          /* vp association */
 436                 hammer2_inode_lock_downgrade(ip, ostate);
 437                 break;
 438         }
 439
 440         /*
 441          * Return non-NULL vp and *errorp == 0, or NULL vp and *errorp != 0.
 442          */
 443         if (hammer2_debug & 0x0002) {
 444                 kprintf("igetv vp %p refs 0x%08x aux 0x%08x\n",
 445                         vp, vp->v_refcnt, vp->v_auxrefs);
 446         }
 447         return (vp);
 448 }
 449
 450 /*
 451  * The passed-in chain must be locked and the returned inode will also be
 452  * locked.  This routine typically locates or allocates the inode, assigns
 453  * ip->chain (adding a ref to chain if necessary), and returns the inode.
 454  *
 455  * The hammer2_inode structure regulates the interface between the high level
 456  * kernel VNOPS API and the filesystem backend (the chains).
 457  *
 458  * WARNING!  This routine sucks up the chain's lock (makes it part of the
 459  *           inode lock from the point of view of the inode lock API),
 460  *           so callers need to be careful.
 461  *
 462  * WARNING!  The mount code is allowed to pass dip == NULL for iroot and
 463  *           is allowed to pass pmp == NULL and dip == NULL for sroot.
 464  */
 465 hammer2_inode_t *
 466 hammer2_inode_get(hammer2_pfsmount_t *pmp, hammer2_inode_t *dip,
 467                   hammer2_chain_t *chain)
 468 {
 469         hammer2_inode_t *nip;
 470
 471         KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
 472
 473         /*
 474          * Interlocked lookup/ref of the inode.  This code is only needed
 475          * when looking up inodes with nlinks != 0 (TODO: optimize out
 476          * otherwise and test for duplicates).
 477          */
 478 again:
 479         for (;;) {
 480                 nip = hammer2_inode_lookup(pmp, chain->data->ipdata.inum);
 481                 if (nip == NULL)
 482                         break;
 483                 ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 484                 if ((nip->flags & HAMMER2_INODE_ONRBTREE) == 0) { /* race */
 485                         ccms_thread_unlock(&nip->topo_cst);
 486                         hammer2_inode_drop(nip);
 487                         continue;
 488                 }
 489                 if (nip->chain != chain)
 490                         hammer2_inode_repoint(nip, NULL, chain);
 491
 492                 /*
 493                  * Consolidated nip/nip->chain is locked (chain locked
 494                  * by caller).
 495                  */
 496                 return nip;
 497         }
 498
 499         /*
 500          * We couldn't find the inode number, create a new inode.
 501          */
 502         if (pmp) {
 503                 nip = kmalloc(sizeof(*nip), pmp->minode, M_WAITOK | M_ZERO);
 504                 atomic_add_long(&pmp->inmem_inodes, 1);
 505                 hammer2_chain_memory_inc(pmp);
 506                 hammer2_chain_memory_wakeup(pmp);
 507         } else {
 508                 nip = kmalloc(sizeof(*nip), M_HAMMER2, M_WAITOK | M_ZERO);
 509                 nip->flags = HAMMER2_INODE_SROOT;
 510         }
 511         nip->inum = chain->data->ipdata.inum;
 512         nip->size = chain->data->ipdata.size;
 513         nip->mtime = chain->data->ipdata.mtime;
 514         hammer2_inode_repoint(nip, NULL, chain);
 515         nip->pip = dip;                         /* can be NULL */
 516         if (dip)
 517                 hammer2_inode_ref(dip); /* ref dip for nip->pip */
 518
 519         nip->pmp = pmp;
 520
 521         /*
 522          * ref and lock on nip gives it state compatible to after a
 523          * hammer2_inode_lock_ex() call.
 524          */
 525         nip->refs = 1;
 526         ccms_cst_init(&nip->topo_cst, &nip->chain);
 527         ccms_thread_lock(&nip->topo_cst, CCMS_STATE_EXCLUSIVE);
 528         /* combination of thread lock and chain lock == inode lock */
 529
 530         /*
 531          * Attempt to add the inode.  If it fails we raced another inode
 532          * get.  Undo all the work and try again.
 533          */
 534         if (pmp) {
 535                 spin_lock(&pmp->inum_spin);
 536                 if (RB_INSERT(hammer2_inode_tree, &pmp->inum_tree, nip)) {
 537                         spin_unlock(&pmp->inum_spin);
 538                         ccms_thread_unlock(&nip->topo_cst);
 539                         hammer2_inode_drop(nip);
 540                         goto again;
 541                 }
 542                 atomic_set_int(&nip->flags, HAMMER2_INODE_ONRBTREE);
 543                 spin_unlock(&pmp->inum_spin);
 544         }
 545
 546         return (nip);
 547 }
 548
 549 /*
 550  * Create a new inode in the specified directory using the vattr to
 551  * figure out the type of inode.
 552  *
 553  * If no error occurs the new inode with its chain locked is returned in
 554  * *nipp, otherwise an error is returned and *nipp is set to NULL.
 555  *
 556  * If vap and/or cred are NULL the related fields are not set and the
 557  * inode type defaults to a directory.  This is used when creating PFSs
 558  * under the super-root, so the inode number is set to 1 in this case.
 559  *
 560  * dip is not locked on entry.
 561  */
 562 hammer2_inode_t *
 563 hammer2_inode_create(hammer2_trans_t *trans, hammer2_inode_t *dip,
 564                      struct vattr *vap, struct ucred *cred,
 565                      const uint8_t *name, size_t name_len,
 566                      hammer2_chain_t **chainp, int *errorp)
 567 {
 568         hammer2_inode_data_t *dipdata;
 569         hammer2_inode_data_t *nipdata;
 570         hammer2_chain_t *chain;
 571         hammer2_chain_t *parent;
 572         hammer2_inode_t *nip;
 573         hammer2_key_t key_dummy;
 574         hammer2_key_t lhc;
 575         int error;
 576         uid_t xuid;
 577         uuid_t dip_uid;
 578         uuid_t dip_gid;
 579         uint32_t dip_mode;
 580         uint8_t dip_algo;
 581         int cache_index = -1;
 582
 583         lhc = hammer2_dirhash(name, name_len);
 584         *errorp = 0;
 585
 586         /*
 587          * Locate the inode or indirect block to create the new
 588          * entry in.  At the same time check for key collisions
 589          * and iterate until we don't get one.
 590          *
 591          * NOTE: hidden inodes do not have iterators.
 592          */
 593 retry:
 594         parent = hammer2_inode_lock_ex(dip);
 595         dipdata = &dip->chain->data->ipdata;
 596         dip_uid = dipdata->uid;
 597         dip_gid = dipdata->gid;
 598         dip_mode = dipdata->mode;
 599         dip_algo = dipdata->comp_algo;
 600
 601         error = 0;
 602         while (error == 0) {
 603                 chain = hammer2_chain_lookup(&parent, &key_dummy,
 604                                              lhc, lhc, &cache_index, 0);
 605                 if (chain == NULL)
 606                         break;
 607                 if ((lhc & HAMMER2_DIRHASH_VISIBLE) == 0)
 608                         error = ENOSPC;
 609                 if ((lhc & HAMMER2_DIRHASH_LOMASK) == HAMMER2_DIRHASH_LOMASK)
 610                         error = ENOSPC;
 611                 hammer2_chain_unlock(chain);
 612                 chain = NULL;
 613                 ++lhc;
 614         }
 615
 616         if (error == 0) {
 617                 error = hammer2_chain_create(trans, &parent, &chain,
 618                                              lhc, 0,
 619                                              HAMMER2_BREF_TYPE_INODE,
 620                                              HAMMER2_INODE_BYTES);
 621         }
 622
 623         /*
 624          * Cleanup and handle retries.
 625          */
 626         if (error == EAGAIN) {
 627                 hammer2_chain_ref(parent);
 628                 hammer2_inode_unlock_ex(dip, parent);
 629                 hammer2_chain_wait(parent);
 630                 hammer2_chain_drop(parent);
 631                 goto retry;
 632         }
 633         hammer2_inode_unlock_ex(dip, parent);
 634
 635         if (error) {
 636                 KKASSERT(chain == NULL);
 637                 *errorp = error;
 638                 return (NULL);
 639         }
 640
 641         /*
 642          * Set up the new inode.
 643          *
 644          * NOTE: *_get() integrates chain's lock into the inode lock.
 645          *
 646          * NOTE: Only one new inode can currently be created per
 647          *       transaction.  If the need arises we can adjust
 648          *       hammer2_trans_init() to allow more.
 649          *
 650          * NOTE: nipdata will have chain's blockset data.
 651          */
 652         chain->data->ipdata.inum = trans->inode_tid;
 653         nip = hammer2_inode_get(dip->pmp, dip, chain);
 654         nipdata = &chain->data->ipdata;
 655
 656         if (vap) {
 657                 KKASSERT(trans->inodes_created == 0);
 658                 nipdata->type = hammer2_get_obj_type(vap->va_type);
 659                 nipdata->inum = trans->inode_tid;
 660                 ++trans->inodes_created;
 661
 662                 switch (nipdata->type) {
 663                 case HAMMER2_OBJTYPE_CDEV:
 664                 case HAMMER2_OBJTYPE_BDEV:
 665                         nipdata->rmajor = vap->va_rmajor;
 666                         nipdata->rminor = vap->va_rminor;
 667                         break;
 668                 default:
 669                         break;
 670                 }
 671         } else {
 672                 nipdata->type = HAMMER2_OBJTYPE_DIRECTORY;
 673                 nipdata->inum = 1;
 674         }
 675
 676         /* Inherit parent's inode compression mode. */
 677         nip->comp_heuristic = 0;
 678         nipdata->comp_algo = dip_algo;
 679         nipdata->version = HAMMER2_INODE_VERSION_ONE;
 680         hammer2_update_time(&nipdata->ctime);
 681         nipdata->mtime = nipdata->ctime;
 682         if (vap)
 683                 nipdata->mode = vap->va_mode;
 684         nipdata->nlinks = 1;
 685         if (vap) {
 686                 if (dip && dip->pmp) {
 687                         xuid = hammer2_to_unix_xid(&dip_uid);
 688                         xuid = vop_helper_create_uid(dip->pmp->mp,
 689                                                      dip_mode,
 690                                                      xuid,
 691                                                      cred,
 692                                                      &vap->va_mode);
 693                 } else {
 694                         /* super-root has no dip and/or pmp */
 695                         xuid = 0;
 696                 }
 697                 if (vap->va_vaflags & VA_UID_UUID_VALID)
 698                         nipdata->uid = vap->va_uid_uuid;
 699                 else if (vap->va_uid != (uid_t)VNOVAL)
 700                         hammer2_guid_to_uuid(&nipdata->uid, vap->va_uid);
 701                 else
 702                         hammer2_guid_to_uuid(&nipdata->uid, xuid);
 703
 704                 if (vap->va_vaflags & VA_GID_UUID_VALID)
 705                         nipdata->gid = vap->va_gid_uuid;
 706                 else if (vap->va_gid != (gid_t)VNOVAL)
 707                         hammer2_guid_to_uuid(&nipdata->gid, vap->va_gid);
 708                 else if (dip)
 709                         nipdata->gid = dip_gid;
 710         }
 711
 712         /*
 713          * Regular files and softlinks allow a small amount of data to be
 714          * directly embedded in the inode.  This flag will be cleared if
 715          * the size is extended past the embedded limit.
 716          */
 717         if (nipdata->type == HAMMER2_OBJTYPE_REGFILE ||
 718             nipdata->type == HAMMER2_OBJTYPE_SOFTLINK) {
 719                 nipdata->op_flags |= HAMMER2_OPFLAG_DIRECTDATA;
 720         }
 721
 722         KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
 723         bcopy(name, nipdata->filename, name_len);
 724         nipdata->name_key = lhc;
 725         nipdata->name_len = name_len;
 726         *chainp = chain;
 727
 728         return (nip);
 729 }
 730
 731 /*
 732  * chain may have been moved around by the create.
 733  */
 734 void
 735 hammer2_chain_refactor(hammer2_chain_t **chainp)
 736 {
 737         hammer2_chain_t *chain = *chainp;
 738         hammer2_chain_core_t *core;
 739
 740         core = chain->core;
 741         while (chain->flags & HAMMER2_CHAIN_DUPLICATED) {
 742                 spin_lock(&core->cst.spin);
 743                 chain = TAILQ_NEXT(chain, core_entry);
 744                 while (chain->flags & HAMMER2_CHAIN_DUPLICATED)
 745                         chain = TAILQ_NEXT(chain, core_entry);
 746                 hammer2_chain_ref(chain);
 747                 spin_unlock(&core->cst.spin);
 748                 KKASSERT(chain->core == core);
 749
 750                 hammer2_chain_unlock(*chainp);
 751                 hammer2_chain_lock(chain, HAMMER2_RESOLVE_ALWAYS |
 752                                           HAMMER2_RESOLVE_NOREF); /* eat ref */
 753                 *chainp = chain;
 754         }
 755 }
 756
 757 /*
 758  * Shift *chainp up to the specified directory, change the filename
 759  * to "0xINODENUMBER", and adjust the key.  The chain becomes the
 760  * invisible hardlink target.
 761  *
 762  * The original *chainp has already been marked deleted.
 763  */
 764 static
 765 void
 766 hammer2_hardlink_shiftup(hammer2_trans_t *trans, hammer2_chain_t **chainp,
 767                         hammer2_inode_t *dip, hammer2_chain_t **dchainp,
 768                         int nlinks, int *errorp)
 769 {
 770         hammer2_inode_data_t *nipdata;
 771         hammer2_chain_t *chain;
 772         hammer2_chain_t *xchain;
 773         hammer2_key_t key_dummy;
 774         hammer2_key_t lhc;
 775         hammer2_blockref_t bref;
 776         int cache_index = -1;
 777
 778         chain = *chainp;
 779         lhc = chain->data->ipdata.inum;
 780         KKASSERT((lhc & HAMMER2_DIRHASH_VISIBLE) == 0);
 781
 782         /*
 783          * Locate the inode or indirect block to create the new
 784          * entry in.  lhc represents the inode number so there is
 785          * no collision iteration.
 786          *
 787          * There should be no key collisions with invisible inode keys.
 788          *
 789          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 790          *          dip->chain cache.
 791          */
 792 retry:
 793         *errorp = 0;
 794         xchain = hammer2_chain_lookup(dchainp, &key_dummy,
 795                                       lhc, lhc, &cache_index, 0);
 796         if (xchain) {
 797                 kprintf("X3 chain %p dip %p dchain %p dip->chain %p\n",
 798                         xchain, dip, *dchainp, dip->chain);
 799                 hammer2_chain_unlock(xchain);
 800                 xchain = NULL;
 801                 *errorp = ENOSPC;
 802 #if 0
 803                 Debugger("X3");
 804 #endif
 805         }
 806
 807         /*
 808          * Create entry in common parent directory using the seek position
 809          * calculated above.
 810          *
 811          * We must refactor chain because it might have been shifted into
 812          * an indirect chain by the create.
 813          */
 814         if (*errorp == 0) {
 815                 KKASSERT(xchain == NULL);
 816 #if 0
 817                 *errorp = hammer2_chain_create(trans, dchainp, &xchain,
 818                                                lhc, 0,
 819                                                HAMMER2_BREF_TYPE_INODE,/* n/a */
 820                                                HAMMER2_INODE_BYTES);   /* n/a */
 821 #endif
 822                 /*XXX this somehow isn't working on chain XXX*/
 823                 /*KKASSERT(xxx)*/
 824         }
 825
 826         /*
 827          * Cleanup and handle retries.
 828          */
 829         if (*errorp == EAGAIN) {
 830                 kprintf("R");
 831                 hammer2_chain_wait(*dchainp);
 832                 hammer2_chain_drop(*dchainp);
 833                 goto retry;
 834         }
 835
 836         /*
 837          * Handle the error case
 838          */
 839         if (*errorp) {
 840                 panic("error2");
 841                 KKASSERT(xchain == NULL);
 842                 return;
 843         }
 844
 845         /*
 846          * Use xchain as a placeholder for (lhc).  Duplicate chain to the
 847          * same target bref as xchain and then delete xchain.  The duplication
 848          * occurs after xchain in flush order even though xchain is deleted
 849          * after the duplication. XXX
 850          *
 851          * WARNING! Duplications (to a different parent) can cause indirect
 852          *          blocks to be inserted, refactor xchain.
 853          */
 854         bref = chain->bref;
 855         bref.key = lhc;                 /* invisible dir entry key */
 856         bref.keybits = 0;
 857         hammer2_chain_duplicate(trans, dchainp, &chain, &bref, 0, 2);
 858
 859         /*
 860          * chain is now 'live' again.. adjust the filename.
 861          *
 862          * Directory entries are inodes but this is a hidden hardlink
 863          * target.  The name isn't used but to ease debugging give it
 864          * a name after its inode number.
 865          */
 866         hammer2_chain_modify(trans, &chain, 0);
 867         nipdata = &chain->data->ipdata;
 868         ksnprintf(nipdata->filename, sizeof(nipdata->filename),
 869                   "0x%016jx", (intmax_t)nipdata->inum);
 870         nipdata->name_len = strlen(nipdata->filename);
 871         nipdata->name_key = lhc;
 872         nipdata->nlinks += nlinks;
 873
 874         *chainp = chain;
 875 }
 876
 877 /*
 878  * Connect the target inode represented by (*chainp) to the media topology
 879  * at (dip, name, len).
 880  *
 881  * If hlink is TRUE this function creates an OBJTYPE_HARDLINK directory
 882  * entry instead of connecting (*chainp).
 883  *
 884  * If hlink is FALSE this function uses chain_duplicate() to make a copy
 885  * if (*chainp) in the directory entry.  (*chainp) is likely to be deleted
 886  * by the caller in this case (e.g. rename).
 887  */
 888 int
 889 hammer2_inode_connect(hammer2_trans_t *trans,
 890                       hammer2_chain_t **chainp, int hlink,
 891                       hammer2_inode_t *dip, hammer2_chain_t **dchainp,
 892                       const uint8_t *name, size_t name_len,
 893                       hammer2_key_t lhc)
 894 {
 895         hammer2_inode_data_t *ipdata;
 896         hammer2_chain_t *nchain;
 897         hammer2_chain_t *ochain;
 898         hammer2_key_t key_dummy;
 899         int cache_index = -1;
 900         int error;
 901
 902         /*
 903          * Since ochain is either disconnected from the topology or represents
 904          * a hardlink terminus which is always a parent of or equal to dip,
 905          * we should be able to safely lock dip->chain for our setup.
 906          *
 907          * WARNING! Must use inode_lock_ex() on dip to handle a stale
 908          *          dip->chain cache.
 909          */
 910         ochain = *chainp;
 911
 912         /*
 913          * If name is non-NULL we calculate lhc, else we use the passed-in
 914          * lhc.
 915          */
 916         if (name) {
 917                 lhc = hammer2_dirhash(name, name_len);
 918
 919                 /*
 920                  * Locate the inode or indirect block to create the new
 921                  * entry in.  At the same time check for key collisions
 922                  * and iterate until we don't get one.
 923                  */
 924                 error = 0;
 925                 while (error == 0) {
 926                         nchain = hammer2_chain_lookup(dchainp, &key_dummy,
 927                                                       lhc, lhc,
 928                                                       &cache_index, 0);
 929                         if (nchain == NULL)
 930                                 break;
 931                         if ((lhc & HAMMER2_DIRHASH_LOMASK) ==
 932                             HAMMER2_DIRHASH_LOMASK) {
 933                                 error = ENOSPC;
 934                         }
 935                         hammer2_chain_unlock(nchain);
 936                         nchain = NULL;
 937                         ++lhc;
 938                 }
 939         }
 940
 941         if (error == 0) {
 942                 if (hlink) {
 943                         /*
 944                          * Hardlink pointer needed, create totally fresh
 945                          * directory entry.
 946                          *
 947                          * We must refactor ochain because it might have
 948                          * been shifted into an indirect chain by the
 949                          * create.
 950                          */
 951                         KKASSERT(nchain == NULL);
 952                         error = hammer2_chain_create(trans, dchainp, &nchain,
 953                                                      lhc, 0,
 954                                                      HAMMER2_BREF_TYPE_INODE,
 955                                                      HAMMER2_INODE_BYTES);
 956                         hammer2_chain_refactor(&ochain);
 957                 } else {
 958                         /*
 959                          * Reconnect the original chain and rename.  Use
 960                          * chain_duplicate().  The caller will likely delete
 961                          * or has already deleted the original chain in
 962                          * this case.
 963                          *
 964                          * NOTE: chain_duplicate() generates a new chain
 965                          *       with CHAIN_DELETED cleared (ochain typically
 966                          *       has it set from the file unlink).
 967                          *
 968                          * WARNING! Can cause held-over chains to require a
 969                          *          refactor.  Fortunately we have none (our
 970                          *          locked chains are passed into and
 971                          *          modified by the call).
 972                          */
 973                         nchain = ochain;
 974                         ochain = NULL;
 975                         hammer2_chain_duplicate(trans, NULL, &nchain, NULL,
 976                                                 0, 3);
 977                         error = hammer2_chain_create(trans, dchainp, &nchain,
 978                                                      lhc, 0,
 979                                                      HAMMER2_BREF_TYPE_INODE,
 980                                                      HAMMER2_INODE_BYTES);
 981                 }
 982         }
 983
 984         /*
 985          * Unlock stuff.
 986          */
 987         KKASSERT(error != EAGAIN);
 988
 989         /*
 990          * nchain should be NULL on error, leave ochain (== *chainp) alone.
 991          */
 992         if (error) {
 993                 KKASSERT(nchain == NULL);
 994                 return (error);
 995         }
 996
 997         /*
 998          * Directory entries are inodes so if the name has changed we have
 999          * to update the inode.
1000          *
1001          * When creating an OBJTYPE_HARDLINK entry remember to unlock the
1002          * chain, the caller will access the hardlink via the actual hardlink
1003          * target file and not the hardlink pointer entry, so we must still
1004          * return ochain.
1005          */
1006         if (hlink && hammer2_hardlink_enable >= 0) {
1007                 /*
1008                  * Create the HARDLINK pointer.  oip represents the hardlink
1009                  * target in this situation.
1010                  *
1011                  * We will return ochain (the hardlink target).
1012                  */
1013                 hammer2_chain_modify(trans, &nchain, 0);
1014                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1015                 ipdata = &nchain->data->ipdata;
1016                 bcopy(name, ipdata->filename, name_len);
1017                 ipdata->name_key = lhc;
1018                 ipdata->name_len = name_len;
1019                 ipdata->target_type = ochain->data->ipdata.type;
1020                 ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1021                 ipdata->inum = ochain->data->ipdata.inum;
1022                 ipdata->nlinks = 1;
1023                 hammer2_chain_unlock(nchain);
1024                 nchain = ochain;
1025                 ochain = NULL;
1026         } else if (hlink && hammer2_hardlink_enable < 0) {
1027                 /*
1028                  * Create a snapshot (hardlink fake mode for debugging).
1029                  * (ochain already flushed above so we can just copy the
1030                  * bref XXX).
1031                  *
1032                  * Since this is a snapshot we return nchain in the fake
1033                  * hardlink case.
1034                  */
1035                 hammer2_chain_modify(trans, &nchain, 0);
1036                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1037                 ipdata = &nchain->data->ipdata;
1038                 *ipdata = ochain->data->ipdata;
1039                 bcopy(name, ipdata->filename, name_len);
1040                 ipdata->name_key = lhc;
1041                 ipdata->name_len = name_len;
1042                 atomic_clear_int(&nchain->core->flags,
1043                                  HAMMER2_CORE_COUNTEDBREFS);
1044                 kprintf("created fake hardlink %*.*s\n",
1045                         (int)name_len, (int)name_len, name);
1046         } else {
1047                 /*
1048                  * nchain is a duplicate of ochain at the new location.
1049                  * We must fixup the name stored in oip.  The bref key
1050                  * has already been set up.
1051                  */
1052                 hammer2_chain_modify(trans, &nchain, 0);
1053                 ipdata = &nchain->data->ipdata;
1054
1055                 KKASSERT(name_len < HAMMER2_INODE_MAXNAME);
1056                 bcopy(name, ipdata->filename, name_len);
1057                 ipdata->name_key = lhc;
1058                 ipdata->name_len = name_len;
1059                 ipdata->nlinks = 1;
1060         }
1061
1062         /*
1063          * We are replacing ochain with nchain, unlock ochain.  In the
1064          * case where ochain is left unchanged the code above sets
1065          * nchain to ochain and ochain to NULL, resulting in a NOP here.
1066          */
1067         if (ochain)
1068                 hammer2_chain_unlock(ochain);
1069         *chainp = nchain;
1070
1071         return (0);
1072 }
1073
1074 /*
1075  * Repoint ip->chain to nchain.  Caller must hold the inode exclusively
1076  * locked.
1077  *
1078  * ip->chain is set to nchain.  The prior chain in ip->chain is dropped
1079  * and nchain is ref'd.
1080  */
1081 void
1082 hammer2_inode_repoint(hammer2_inode_t *ip, hammer2_inode_t *pip,
1083                       hammer2_chain_t *nchain)
1084 {
1085         hammer2_chain_t *ochain;
1086         hammer2_inode_t *opip;
1087
1088         /*
1089          * Repoint ip->chain if requested.
1090          */
1091         ochain = ip->chain;
1092         ip->chain = nchain;
1093         if (nchain)
1094                 hammer2_chain_ref(nchain);
1095         if (ochain)
1096                 hammer2_chain_drop(ochain);
1097
1098         /*
1099          * Repoint ip->pip if requested (non-NULL pip).
1100          */
1101         if (pip && ip->pip != pip) {
1102                 opip = ip->pip;
1103                 hammer2_inode_ref(pip);
1104                 ip->pip = pip;
1105                 if (opip)
1106                         hammer2_inode_drop(opip);
1107         }
1108 }
1109
1110 /*
1111  * Unlink the file from the specified directory inode.  The directory inode
1112  * does not need to be locked.
1113  *
1114  * isdir determines whether a directory/non-directory check should be made.
1115  * No check is made if isdir is set to -1.
1116  *
1117  * isopen specifies whether special unlink-with-open-descriptor handling
1118  * must be performed.  If set to -1 the caller is deleting a PFS and we
1119  * check whether the chain is mounted or not (chain->pmp != NULL).  1 is
1120  * implied if it is mounted.
1121  *
1122  * If isopen is 1 and nlinks drops to 0 this function must move the chain
1123  * to a special hidden directory until last-close occurs on the file.
1124  *
1125  * NOTE!  The underlying file can still be active with open descriptors
1126  *        or if the chain is being manually held (e.g. for rename).
1127  *
1128  *        The caller is responsible for fixing up ip->chain if e.g. a
1129  *        rename occurs (see chain_duplicate()).
1130  */
1131 int
1132 hammer2_unlink_file(hammer2_trans_t *trans, hammer2_inode_t *dip,
1133                     const uint8_t *name, size_t name_len,
1134                     int isdir, int *hlinkp, struct nchandle *nch)
1135 {
1136         hammer2_inode_data_t *ipdata;
1137         hammer2_chain_t *parent;
1138         hammer2_chain_t *ochain;
1139         hammer2_chain_t *chain;
1140         hammer2_chain_t *dparent;
1141         hammer2_chain_t *dchain;
1142         hammer2_key_t key_dummy;
1143         hammer2_key_t key_next;
1144         hammer2_key_t lhc;
1145         int error;
1146         int cache_index = -1;
1147         uint8_t type;
1148
1149         error = 0;
1150         ochain = NULL;
1151         lhc = hammer2_dirhash(name, name_len);
1152
1153         /*
1154          * Search for the filename in the directory
1155          */
1156         if (hlinkp)
1157                 *hlinkp = 0;
1158         parent = hammer2_inode_lock_ex(dip);
1159         chain = hammer2_chain_lookup(&parent, &key_next,
1160                                      lhc, lhc + HAMMER2_DIRHASH_LOMASK,
1161                                      &cache_index, 0);
1162         while (chain) {
1163                 if (chain->bref.type == HAMMER2_BREF_TYPE_INODE &&
1164                     name_len == chain->data->ipdata.name_len &&
1165                     bcmp(name, chain->data->ipdata.filename, name_len) == 0) {
1166                         break;
1167                 }
1168                 chain = hammer2_chain_next(&parent, chain, &key_next,
1169                                            key_next,
1170                                            lhc + HAMMER2_DIRHASH_LOMASK,
1171                                            &cache_index, 0);
1172         }
1173         hammer2_inode_unlock_ex(dip, NULL);     /* retain parent */
1174
1175         /*
1176          * Not found or wrong type (isdir < 0 disables the type check).
1177          * If a hardlink pointer, type checks use the hardlink target.
1178          */
1179         if (chain == NULL) {
1180                 error = ENOENT;
1181                 goto done;
1182         }
1183         if ((type = chain->data->ipdata.type) == HAMMER2_OBJTYPE_HARDLINK) {
1184                 if (hlinkp)
1185                         *hlinkp = 1;
1186                 type = chain->data->ipdata.target_type;
1187         }
1188
1189         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 0) {
1190                 error = ENOTDIR;
1191                 goto done;
1192         }
1193         if (type != HAMMER2_OBJTYPE_DIRECTORY && isdir >= 1) {
1194                 error = EISDIR;
1195                 goto done;
1196         }
1197
1198         /*
1199          * Hardlink must be resolved.  We can't hold the parent locked
1200          * while we do this or we could deadlock.
1201          *
1202          * On success chain will be adjusted to point at the hardlink target
1203          * and ochain will point to the hardlink pointer in the original
1204          * directory.  Otherwise chain remains pointing to the original.
1205          */
1206         if (chain->data->ipdata.type == HAMMER2_OBJTYPE_HARDLINK) {
1207                 hammer2_chain_unlock(parent);
1208                 parent = NULL;
1209                 error = hammer2_hardlink_find(dip, &chain, &ochain);
1210         }
1211
1212         /*
1213          * If this is a directory the directory must be empty.  However, if
1214          * isdir < 0 we are doing a rename and the directory does not have
1215          * to be empty, and if isdir > 1 we are deleting a PFS/snapshot
1216          * and the directory does not have to be empty.
1217          *
1218          * NOTE: We check the full key range here which covers both visible
1219          *       and invisible entries.  Theoretically there should be no
1220          *       invisible (hardlink target) entries if there are no visible
1221          *       entries.
1222          */
1223         if (type == HAMMER2_OBJTYPE_DIRECTORY && isdir == 1) {
1224                 dparent = hammer2_chain_lookup_init(chain, 0);
1225                 dchain = hammer2_chain_lookup(&dparent, &key_dummy,
1226                                               0, (hammer2_key_t)-1,
1227                                               &cache_index,
1228                                               HAMMER2_LOOKUP_NODATA);
1229                 if (dchain) {
1230                         hammer2_chain_unlock(dchain);
1231                         hammer2_chain_lookup_done(dparent);
1232                         error = ENOTEMPTY;
1233                         goto done;
1234                 }
1235                 hammer2_chain_lookup_done(dparent);
1236                 dparent = NULL;
1237                 /* dchain NULL */
1238         }
1239
1240         /*
1241          * Ok, we can now unlink the chain.  We always decrement nlinks even
1242          * if the entry can be deleted in case someone has the file open and
1243          * does an fstat().
1244          *
1245          * The chain itself will no longer be in the on-media topology but
1246          * can still be flushed to the media (e.g. if an open descriptor
1247          * remains).  When the last vnode/ip ref goes away the chain will
1248          * be marked unmodified, avoiding any further (now unnecesary) I/O.
1249          *
1250          * A non-NULL ochain indicates a hardlink.
1251          */
1252         if (ochain) {
1253                 /*
1254                  * Delete the original hardlink pointer unconditionally.
1255                  * (any open descriptors will migrate to the hardlink
1256                  * target and have no affect on this operation).
1257                  *
1258                  * NOTE: parent from above is NULL when ochain != NULL
1259                  *       so we can reuse it.
1260                  */
1261                 hammer2_chain_lock(ochain, HAMMER2_RESOLVE_ALWAYS);
1262                 hammer2_chain_delete(trans, ochain, 0);
1263                 hammer2_chain_unlock(ochain);
1264         }
1265
1266         /*
1267          * Decrement nlinks on the hardlink target (or original file if
1268          * there it was not hardlinked).  Delete the target when nlinks
1269          * reaches 0 with special handling if (isopen) is set.
1270          *
1271          * NOTE! In DragonFly the vnops function calls cache_unlink() after
1272          *       calling us here to clean out the namecache association,
1273          *       (which does not represent a ref for the open-test), and to
1274          *       force finalization of the vnode if/when the last ref gets
1275          *       dropped.
1276          *
1277          * NOTE! Files are unlinked by rename and then relinked.  nch will be
1278          *       passed as NULL in this situation.  hammer2_inode_connect()
1279          *       will bump nlinks.
1280          */
1281         KKASSERT(chain != NULL);
1282         hammer2_chain_modify(trans, &chain, 0);
1283         ipdata = &chain->data->ipdata;
1284         --ipdata->nlinks;
1285         if ((int64_t)ipdata->nlinks < 0)        /* XXX debugging */
1286                 ipdata->nlinks = 0;
1287         if (ipdata->nlinks == 0) {
1288                 if ((chain->flags & HAMMER2_CHAIN_PFSROOT) && chain->pmp) {
1289                         error = EINVAL;
1290                         kprintf("hammer2: PFS \"%s\" cannot be deleted "
1291                                 "while still mounted\n",
1292                                 ipdata->filename);
1293                         goto done;
1294                 }
1295                 if (nch && cache_isopen(nch)) {
1296                         kprintf("WARNING: unlinking open file\n");
1297                         atomic_set_int(&chain->flags, HAMMER2_CHAIN_UNLINKED);
1298                         hammer2_inode_move_to_hidden(trans, &chain,
1299                                                      ipdata->inum);
1300                 } else {
1301                         hammer2_chain_delete(trans, chain, 0);
1302                 }
1303         }
1304         error = 0;
1305 done:
1306         if (chain)
1307                 hammer2_chain_unlock(chain);
1308         if (parent)
1309                 hammer2_chain_lookup_done(parent);
1310         if (ochain)
1311                 hammer2_chain_drop(ochain);
1312
1313         return error;
1314 }
1315
1316 /*
1317  * This is called from the mount code to initialize pmp->ihidden
1318  */
1319 void
1320 hammer2_inode_install_hidden(hammer2_pfsmount_t *pmp)
1321 {
1322         hammer2_trans_t trans;
1323         hammer2_chain_t *parent;
1324         hammer2_chain_t *chain;
1325         hammer2_chain_t *scan;
1326         hammer2_inode_data_t *ipdata;
1327         hammer2_key_t key_dummy;
1328         hammer2_key_t key_next;
1329         int cache_index;
1330         int error;
1331         int count;
1332
1333         if (pmp->ihidden)
1334                 return;
1335
1336         /*
1337          * Find the hidden directory
1338          */
1339         bzero(&key_dummy, sizeof(key_dummy));
1340         hammer2_trans_init(&trans, pmp, NULL, 0);
1341
1342         parent = hammer2_inode_lock_ex(pmp->iroot);
1343         chain = hammer2_chain_lookup(&parent, &key_dummy,
1344                                      HAMMER2_INODE_HIDDENDIR,
1345                                      HAMMER2_INODE_HIDDENDIR,
1346                                      &cache_index, 0);
1347         if (chain) {
1348                 pmp->ihidden = hammer2_inode_get(pmp, pmp->iroot, chain);
1349                 hammer2_inode_ref(pmp->ihidden);
1350
1351                 /*
1352                  * Remove any unlinked files which were left open as-of
1353                  * any system crash.
1354                  */
1355                 count = 0;
1356                 scan = hammer2_chain_lookup(&chain, &key_next,
1357                                             0, HAMMER2_MAX_TID,
1358                                             &cache_index,
1359                                             HAMMER2_LOOKUP_NODATA);
1360                 while (scan) {
1361                         if (scan->bref.type == HAMMER2_BREF_TYPE_INODE) {
1362                                 hammer2_chain_delete(&trans, scan, 0);
1363                                 ++count;
1364                         }
1365                         scan = hammer2_chain_next(&chain, scan, &key_next,
1366                                                    0, HAMMER2_MAX_TID,
1367                                                    &cache_index,
1368                                                    HAMMER2_LOOKUP_NODATA);
1369                 }
1370
1371                 hammer2_inode_unlock_ex(pmp->ihidden, chain);
1372                 hammer2_inode_unlock_ex(pmp->iroot, parent);
1373                 hammer2_trans_done(&trans);
1374                 kprintf("hammer2: PFS loaded hidden dir, "
1375                         "removed %d dead entries\n", count);
1376                 return;
1377         }
1378
1379         /*
1380          * Create the hidden directory
1381          */
1382         error = hammer2_chain_create(&trans, &parent, &chain,
1383                                      HAMMER2_INODE_HIDDENDIR, 0,
1384                                      HAMMER2_BREF_TYPE_INODE,
1385                                      HAMMER2_INODE_BYTES);
1386         hammer2_inode_unlock_ex(pmp->iroot, parent);
1387         hammer2_chain_modify(&trans, &chain, 0);
1388         ipdata = &chain->data->ipdata;
1389         ipdata->type = HAMMER2_OBJTYPE_DIRECTORY;
1390         ipdata->inum = HAMMER2_INODE_HIDDENDIR;
1391         ipdata->nlinks = 1;
1392         kprintf("hammer2: PFS root missing hidden directory, creating\n");
1393
1394         pmp->ihidden = hammer2_inode_get(pmp, pmp->iroot, chain);
1395         hammer2_inode_ref(pmp->ihidden);
1396         hammer2_inode_unlock_ex(pmp->ihidden, chain);
1397         hammer2_trans_done(&trans);
1398 }
1399
1400 /*
1401  * If an open file is unlinked H2 needs to retain the file in the topology
1402  * to ensure that its backing store is not recovered by the bulk free scan.
1403  * This also allows us to avoid having to special-case the CHAIN_DELETED flag.
1404  *
1405  * To do this the file is moved to a hidden directory in the PFS root and
1406  * renamed.  The hidden directory must be created if it does not exist.
1407  */
1408 static
1409 void
1410 hammer2_inode_move_to_hidden(hammer2_trans_t *trans, hammer2_chain_t **chainp,
1411                              hammer2_tid_t inum)
1412 {
1413         hammer2_chain_t *chain;
1414         hammer2_chain_t *dchain;
1415         hammer2_pfsmount_t *pmp;
1416         int error;
1417
1418         chain = *chainp;
1419         pmp = chain->pmp;
1420         KKASSERT(pmp != NULL);
1421         KKASSERT(pmp->ihidden != NULL);
1422
1423         hammer2_chain_delete(trans, chain, 0);
1424         dchain = hammer2_inode_lock_ex(pmp->ihidden);
1425         error = hammer2_inode_connect(trans, chainp, 0,
1426                                       pmp->ihidden, &dchain,
1427                                       NULL, 0, inum);
1428         hammer2_inode_unlock_ex(pmp->ihidden, dchain);
1429         KKASSERT(error == 0);
1430 }
1431
1432 /*
1433  * Given an exclusively locked inode and chain we consolidate its chain
1434  * for hardlink creation, adding (nlinks) to the file's link count and
1435  * potentially relocating the inode to a directory common to ip->pip and tdip.
1436  *
1437  * Replaces (*chainp) if consolidation occurred, unlocking the old chain
1438  * and returning a new locked chain.
1439  *
1440  * NOTE!  This function will also replace ip->chain.
1441  */
1442 int
1443 hammer2_hardlink_consolidate(hammer2_trans_t *trans,
1444                              hammer2_inode_t *ip, hammer2_chain_t **chainp,
1445                              hammer2_inode_t *cdip, hammer2_chain_t **cdchainp,
1446                              int nlinks)
1447 {
1448         hammer2_inode_data_t *ipdata;
1449         hammer2_chain_t *chain;
1450         hammer2_chain_t *nchain;
1451         int error;
1452
1453         chain = *chainp;
1454         if (nlinks == 0 &&                      /* no hardlink needed */
1455             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE)) {
1456                 return (0);
1457         }
1458         if (hammer2_hardlink_enable < 0) {      /* fake hardlinks */
1459                 return (0);
1460         }
1461
1462         if (hammer2_hardlink_enable == 0) {     /* disallow hardlinks */
1463                 hammer2_chain_unlock(chain);
1464                 *chainp = NULL;
1465                 return (ENOTSUP);
1466         }
1467
1468         /*
1469          * If no change in the hardlink's target directory is required and
1470          * this is already a hardlink target, all we need to do is adjust
1471          * the link count.
1472          */
1473         if (cdip == ip->pip &&
1474             (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) == 0) {
1475                 if (nlinks) {
1476                         hammer2_chain_modify(trans, &chain, 0);
1477                         chain->data->ipdata.nlinks += nlinks;
1478                 }
1479                 error = 0;
1480                 goto done;
1481         }
1482
1483
1484         /*
1485          * chain is the real inode.  If it's visible we have to convert it
1486          * to a hardlink pointer.  If it is not visible then it is already
1487          * a hardlink target and only needs to be deleted.
1488          */
1489         KKASSERT((chain->flags & HAMMER2_CHAIN_DELETED) == 0);
1490         KKASSERT(chain->data->ipdata.type != HAMMER2_OBJTYPE_HARDLINK);
1491         if (chain->data->ipdata.name_key & HAMMER2_DIRHASH_VISIBLE) {
1492                 /*
1493                  * We are going to duplicate chain later, causing its
1494                  * media block to be shifted to the duplicate.  Even though
1495                  * we are delete-duplicating nchain here it might decide not
1496                  * to reallocate the block.  Set FORCECOW to force it to.
1497                  */
1498                 nchain = chain;
1499                 hammer2_chain_lock(nchain, HAMMER2_RESOLVE_ALWAYS);
1500                 atomic_set_int(&nchain->flags, HAMMER2_CHAIN_FORCECOW);
1501                 hammer2_chain_delete_duplicate(trans, &nchain,
1502                                                HAMMER2_DELDUP_RECORE);
1503                 KKASSERT((chain->flags & HAMMER2_CHAIN_DUPLICATED) == 0);
1504
1505                 ipdata = &nchain->data->ipdata;
1506                 ipdata->target_type = ipdata->type;
1507                 ipdata->type = HAMMER2_OBJTYPE_HARDLINK;
1508                 ipdata->uflags = 0;
1509                 ipdata->rmajor = 0;
1510                 ipdata->rminor = 0;
1511                 ipdata->ctime = 0;
1512                 ipdata->mtime = 0;
1513                 ipdata->atime = 0;
1514                 ipdata->btime = 0;
1515                 bzero(&ipdata->uid, sizeof(ipdata->uid));
1516                 bzero(&ipdata->gid, sizeof(ipdata->gid));
1517                 ipdata->op_flags = HAMMER2_OPFLAG_DIRECTDATA;
1518                 ipdata->cap_flags = 0;
1519                 ipdata->mode = 0;
1520                 ipdata->size = 0;
1521                 ipdata->nlinks = 1;
1522                 ipdata->iparent = 0;    /* XXX */
1523                 ipdata->pfs_type = 0;
1524                 ipdata->pfs_inum = 0;
1525                 bzero(&ipdata->pfs_clid, sizeof(ipdata->pfs_clid));
1526                 bzero(&ipdata->pfs_fsid, sizeof(ipdata->pfs_fsid));
1527                 ipdata->data_quota = 0;
1528                 ipdata->data_count = 0;
1529                 ipdata->inode_quota = 0;
1530                 ipdata->inode_count = 0;
1531                 ipdata->attr_tid = 0;
1532                 ipdata->dirent_tid = 0;
1533                 bzero(&ipdata->u, sizeof(ipdata->u));
1534                 /* XXX transaction ids */
1535         } else {
1536                 hammer2_chain_delete(trans, chain, 0);
1537                 nchain = NULL;
1538         }
1539
1540         /*
1541          * chain represents the hardlink target and is now flagged deleted.
1542          * duplicate it to the parent directory and adjust nlinks.
1543          *
1544          * WARNING! The shiftup() call can cause nchain to be moved into
1545          *          an indirect block, and our nchain will wind up pointing
1546          *          to the older/original version.
1547          */
1548         KKASSERT(chain->flags & HAMMER2_CHAIN_DELETED);
1549         hammer2_hardlink_shiftup(trans, &chain, cdip, cdchainp, nlinks, &error);
1550
1551         if (error == 0)
1552                 hammer2_inode_repoint(ip, cdip, chain);
1553
1554         /*
1555          * Unlock the original chain last as the lock blocked races against
1556          * the creation of the new hardlink target.
1557          */
1558         if (nchain)
1559                 hammer2_chain_unlock(nchain);
1560
1561 done:
1562         /*
1563          * Cleanup, chain/nchain already dealt with.
1564          */
1565         *chainp = chain;
1566         hammer2_inode_drop(cdip);
1567
1568         return (error);
1569 }
1570
1571 /*
1572  * If (*ochainp) is non-NULL it points to the forward OBJTYPE_HARDLINK
1573  * inode while (*chainp) points to the resolved (hidden hardlink
1574  * target) inode.  In this situation when nlinks is 1 we wish to
1575  * deconsolidate the hardlink, moving it back to the directory that now
1576  * represents the only remaining link.
1577  */
1578 int
1579 hammer2_hardlink_deconsolidate(hammer2_trans_t *trans,
1580                                hammer2_inode_t *dip,
1581                                hammer2_chain_t **chainp,
1582                                hammer2_chain_t **ochainp)
1583 {
1584         if (*ochainp == NULL)
1585                 return (0);
1586         /* XXX */
1587         return (0);
1588 }
1589
1590 /*
1591  * The caller presents a locked *chainp pointing to a HAMMER2_BREF_TYPE_INODE
1592  * with an obj_type of HAMMER2_OBJTYPE_HARDLINK.  This routine will gobble
1593  * the *chainp and return a new locked *chainp representing the file target
1594  * (the original *chainp will be unlocked).
1595  *
1596  * When a match is found the chain representing the original HARDLINK
1597  * will be returned in *ochainp with a ref, but not locked.
1598  *
1599  * When no match is found *chainp is set to NULL and EIO is returned.
1600  * (*ochainp) will still be set to the original chain with a ref but not
1601  * locked.
1602  */
1603 int
1604 hammer2_hardlink_find(hammer2_inode_t *dip, hammer2_chain_t **chainp,
1605                       hammer2_chain_t **ochainp)
1606 {
1607         hammer2_chain_t *chain = *chainp;
1608         hammer2_chain_t *parent;
1609         hammer2_inode_t *ip;
1610         hammer2_inode_t *pip;
1611         hammer2_key_t key_dummy;
1612         hammer2_key_t lhc;
1613         int cache_index = -1;
1614
1615         pip = dip;
1616         hammer2_inode_ref(pip);         /* for loop */
1617         hammer2_chain_ref(chain);       /* for (*ochainp) */
1618         *ochainp = chain;
1619
1620         /*
1621          * Locate the hardlink.  pip is referenced and not locked,
1622          * ipp.
1623          *
1624          * chain is reused.
1625          */
1626         lhc = chain->data->ipdata.inum;
1627         hammer2_chain_unlock(chain);
1628         chain = NULL;
1629
1630         while ((ip = pip) != NULL) {
1631                 parent = hammer2_inode_lock_ex(ip);
1632                 hammer2_inode_drop(ip);                 /* loop */
1633                 KKASSERT(parent->bref.type == HAMMER2_BREF_TYPE_INODE);
1634                 chain = hammer2_chain_lookup(&parent, &key_dummy,
1635                                              lhc, lhc, &cache_index, 0);
1636                 hammer2_chain_lookup_done(parent);      /* discard parent */
1637                 if (chain)
1638                         break;
1639                 pip = ip->pip;          /* safe, ip held locked */
1640                 if (pip)
1641                         hammer2_inode_ref(pip);         /* loop */
1642                 hammer2_inode_unlock_ex(ip, NULL);
1643         }
1644
1645         /*
1646          * chain is locked, ip is locked.  Unlock ip, return the locked
1647          * chain.  *ipp is already set w/a ref count and not locked.
1648          *
1649          * (parent is already unlocked).
1650          */
1651         if (ip)
1652                 hammer2_inode_unlock_ex(ip, NULL);
1653         *chainp = chain;
1654         if (chain) {
1655                 KKASSERT(chain->bref.type == HAMMER2_BREF_TYPE_INODE);
1656                 /* already locked */
1657                 return (0);
1658         } else {
1659                 return (EIO);
1660         }
1661 }
1662
1663 /*
1664  * Find the directory common to both fdip and tdip, hold and return
1665  * its inode.
1666  */
1667 hammer2_inode_t *
1668 hammer2_inode_common_parent(hammer2_inode_t *fdip, hammer2_inode_t *tdip)
1669 {
1670         hammer2_inode_t *scan1;
1671         hammer2_inode_t *scan2;
1672
1673         /*
1674          * We used to have a depth field but it complicated matters too
1675          * much for directory renames.  So now its ugly.  Check for
1676          * simple cases before giving up and doing it the expensive way.
1677          *
1678          * XXX need a bottom-up topology stability lock
1679          */
1680         if (fdip == tdip || fdip == tdip->pip) {
1681                 hammer2_inode_ref(fdip);
1682                 return(fdip);
1683         }
1684         if (fdip->pip == tdip) {
1685                 hammer2_inode_ref(tdip);
1686                 return(tdip);
1687         }
1688
1689         /*
1690          * XXX not MPSAFE
1691          */
1692         for (scan1 = fdip; scan1->pmp == fdip->pmp; scan1 = scan1->pip) {
1693                 scan2 = tdip;
1694                 while (scan2->pmp == tdip->pmp) {
1695                         if (scan1 == scan2) {
1696                                 hammer2_inode_ref(scan1);
1697                                 return(scan1);
1698                         }
1699                         scan2 = scan2->pip;
1700                         if (scan2 == NULL)
1701                                 break;
1702                 }
1703         }
1704         panic("hammer2_inode_common_parent: no common parent %p %p\n",
1705               fdip, tdip);
1706         /* NOT REACHED */
1707         return(NULL);
1708 }
1709
1710 /*
1711  * Synchronize the inode's frontend state with the chain state prior
1712  * to any explicit flush of the inode or any strategy write call.
1713  *
1714  * Called with a locked inode.
1715  */
1716 void
1717 hammer2_inode_fsync(hammer2_trans_t *trans, hammer2_inode_t *ip,
1718                     hammer2_chain_t **chainp)
1719 {
1720         hammer2_inode_data_t *ipdata;
1721         hammer2_chain_t *parent;
1722         hammer2_chain_t *chain;
1723         hammer2_key_t lbase;
1724         hammer2_key_t key_next;
1725         int cache_index;
1726
1727         ipdata = &ip->chain->data->ipdata;
1728
1729         if (ip->flags & HAMMER2_INODE_MTIME) {
1730                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1731                 atomic_clear_int(&ip->flags, HAMMER2_INODE_MTIME);
1732                 ipdata->mtime = ip->mtime;
1733         }
1734         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size < ipdata->size) {
1735                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1736                 ipdata->size = ip->size;
1737                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1738
1739                 /*
1740                  * We must delete any chains beyond the EOF.  The chain
1741                  * straddling the EOF will be pending in the bioq.
1742                  */
1743                 lbase = (ipdata->size + HAMMER2_PBUFMASK64) &
1744                         ~HAMMER2_PBUFMASK64;
1745                 parent = hammer2_chain_lookup_init(ip->chain, 0);
1746                 chain = hammer2_chain_lookup(&parent, &key_next,
1747                                              lbase, (hammer2_key_t)-1,
1748                                              &cache_index,
1749                                              HAMMER2_LOOKUP_NODATA);
1750                 while (chain) {
1751                         /*
1752                          * Degenerate embedded case, nothing to loop on
1753                          */
1754                         if (chain->bref.type == HAMMER2_BREF_TYPE_INODE) {
1755                                 hammer2_chain_unlock(chain);
1756                                 break;
1757                         }
1758                         if (chain->bref.type == HAMMER2_BREF_TYPE_DATA) {
1759                                 hammer2_chain_delete(trans, chain, 0);
1760                         }
1761                         chain = hammer2_chain_next(&parent, chain, &key_next,
1762                                                    key_next, (hammer2_key_t)-1,
1763                                                    &cache_index,
1764                                                    HAMMER2_LOOKUP_NODATA);
1765                 }
1766                 hammer2_chain_lookup_done(parent);
1767         } else
1768         if ((ip->flags & HAMMER2_INODE_RESIZED) && ip->size > ipdata->size) {
1769                 ipdata = hammer2_chain_modify_ip(trans, ip, chainp, 0);
1770                 ipdata->size = ip->size;
1771                 atomic_clear_int(&ip->flags, HAMMER2_INODE_RESIZED);
1772
1773                 /*
1774                  * When resizing larger we may not have any direct-data
1775                  * available.
1776                  */
1777                 if ((ipdata->op_flags & HAMMER2_OPFLAG_DIRECTDATA) &&
1778                     ip->size > HAMMER2_EMBEDDED_BYTES) {
1779                         ipdata->op_flags &= ~HAMMER2_OPFLAG_DIRECTDATA;
1780                         bzero(&ipdata->u.blockset, sizeof(ipdata->u.blockset));
1781                 }
1782         }
1783 }