sys/vfs/hammer/hammer_inode.c

   1 /*
   2  * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include "hammer.h"
  36 #include <vm/vm_extern.h>
  37
  38 static int      hammer_unload_inode(struct hammer_inode *ip);
  39 static void     hammer_free_inode(hammer_inode_t ip);
  40 static void     hammer_flush_inode_core(hammer_inode_t ip,
  41                                         hammer_flush_group_t flg, int flags);
  42 static int      hammer_setup_child_callback(hammer_record_t rec, void *data);
  43 #if 0
  44 static int      hammer_syncgrp_child_callback(hammer_record_t rec, void *data);
  45 #endif
  46 static int      hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
  47                                         hammer_flush_group_t flg);
  48 static int      hammer_setup_parent_inodes_helper(hammer_record_t record,
  49                                         int depth, hammer_flush_group_t flg);
  50 static void     hammer_inode_wakereclaims(hammer_inode_t ip);
  51 static struct hammer_inostats *hammer_inode_inostats(hammer_mount_t hmp,
  52                                         pid_t pid);
  53
  54 #ifdef DEBUG_TRUNCATE
  55 extern struct hammer_inode *HammerTruncIp;
  56 #endif
  57
  58 struct krate hammer_gen_krate = { 1 };
  59
  60 /*
  61  * RB-Tree support for inode structures
  62  */
  63 int
  64 hammer_ino_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2)
  65 {
  66         if (ip1->obj_localization < ip2->obj_localization)
  67                 return(-1);
  68         if (ip1->obj_localization > ip2->obj_localization)
  69                 return(1);
  70         if (ip1->obj_id < ip2->obj_id)
  71                 return(-1);
  72         if (ip1->obj_id > ip2->obj_id)
  73                 return(1);
  74         if (ip1->obj_asof < ip2->obj_asof)
  75                 return(-1);
  76         if (ip1->obj_asof > ip2->obj_asof)
  77                 return(1);
  78         return(0);
  79 }
  80
  81 int
  82 hammer_redo_rb_compare(hammer_inode_t ip1, hammer_inode_t ip2)
  83 {
  84         if (ip1->redo_fifo_start < ip2->redo_fifo_start)
  85                 return(-1);
  86         if (ip1->redo_fifo_start > ip2->redo_fifo_start)
  87                 return(1);
  88         return(0);
  89 }
  90
  91 /*
  92  * RB-Tree support for inode structures / special LOOKUP_INFO
  93  */
  94 static int
  95 hammer_inode_info_cmp(hammer_inode_info_t info, hammer_inode_t ip)
  96 {
  97         if (info->obj_localization < ip->obj_localization)
  98                 return(-1);
  99         if (info->obj_localization > ip->obj_localization)
 100                 return(1);
 101         if (info->obj_id < ip->obj_id)
 102                 return(-1);
 103         if (info->obj_id > ip->obj_id)
 104                 return(1);
 105         if (info->obj_asof < ip->obj_asof)
 106                 return(-1);
 107         if (info->obj_asof > ip->obj_asof)
 108                 return(1);
 109         return(0);
 110 }
 111
 112 /*
 113  * Used by hammer_scan_inode_snapshots() to locate all of an object's
 114  * snapshots.  Note that the asof field is not tested, which we can get
 115  * away with because it is the lowest-priority field.
 116  */
 117 static int
 118 hammer_inode_info_cmp_all_history(hammer_inode_t ip, void *data)
 119 {
 120         hammer_inode_info_t info = data;
 121
 122         if (ip->obj_localization > info->obj_localization)
 123                 return(1);
 124         if (ip->obj_localization < info->obj_localization)
 125                 return(-1);
 126         if (ip->obj_id > info->obj_id)
 127                 return(1);
 128         if (ip->obj_id < info->obj_id)
 129                 return(-1);
 130         return(0);
 131 }
 132
 133 /*
 134  * Used by hammer_unload_pseudofs() to locate all inodes associated with
 135  * a particular PFS.
 136  */
 137 static int
 138 hammer_inode_pfs_cmp(hammer_inode_t ip, void *data)
 139 {
 140         u_int32_t localization = *(u_int32_t *)data;
 141         if (ip->obj_localization > localization)
 142                 return(1);
 143         if (ip->obj_localization < localization)
 144                 return(-1);
 145         return(0);
 146 }
 147
 148 /*
 149  * RB-Tree support for pseudofs structures
 150  */
 151 static int
 152 hammer_pfs_rb_compare(hammer_pseudofs_inmem_t p1, hammer_pseudofs_inmem_t p2)
 153 {
 154         if (p1->localization < p2->localization)
 155                 return(-1);
 156         if (p1->localization > p2->localization)
 157                 return(1);
 158         return(0);
 159 }
 160
 161
 162 RB_GENERATE(hammer_ino_rb_tree, hammer_inode, rb_node, hammer_ino_rb_compare);
 163 RB_GENERATE_XLOOKUP(hammer_ino_rb_tree, INFO, hammer_inode, rb_node,
 164                 hammer_inode_info_cmp, hammer_inode_info_t);
 165 RB_GENERATE2(hammer_pfs_rb_tree, hammer_pseudofs_inmem, rb_node,
 166              hammer_pfs_rb_compare, u_int32_t, localization);
 167
 168 /*
 169  * The kernel is not actively referencing this vnode but is still holding
 170  * it cached.
 171  *
 172  * This is called from the frontend.
 173  *
 174  * MPALMOSTSAFE
 175  */
 176 int
 177 hammer_vop_inactive(struct vop_inactive_args *ap)
 178 {
 179         struct hammer_inode *ip = VTOI(ap->a_vp);
 180         hammer_mount_t hmp;
 181
 182         /*
 183          * Degenerate case
 184          */
 185         if (ip == NULL) {
 186                 vrecycle(ap->a_vp);
 187                 return(0);
 188         }
 189
 190         /*
 191          * If the inode no longer has visibility in the filesystem try to
 192          * recycle it immediately, even if the inode is dirty.  Recycling
 193          * it quickly allows the system to reclaim buffer cache and VM
 194          * resources which can matter a lot in a heavily loaded system.
 195          *
 196          * This can deadlock in vfsync() if we aren't careful.
 197          *
 198          * Do not queue the inode to the flusher if we still have visibility,
 199          * otherwise namespace calls such as chmod will unnecessarily generate
 200          * multiple inode updates.
 201          */
 202         if (ip->ino_data.nlinks == 0) {
 203                 hmp = ip->hmp;
 204                 lwkt_gettoken(&hmp->fs_token);
 205                 hammer_inode_unloadable_check(ip, 0);
 206                 if (ip->flags & HAMMER_INODE_MODMASK)
 207                         hammer_flush_inode(ip, 0);
 208                 lwkt_reltoken(&hmp->fs_token);
 209                 vrecycle(ap->a_vp);
 210         }
 211         return(0);
 212 }
 213
 214 /*
 215  * Release the vnode association.  This is typically (but not always)
 216  * the last reference on the inode.
 217  *
 218  * Once the association is lost we are on our own with regards to
 219  * flushing the inode.
 220  *
 221  * We must interlock ip->vp so hammer_get_vnode() can avoid races.
 222  */
 223 int
 224 hammer_vop_reclaim(struct vop_reclaim_args *ap)
 225 {
 226         struct hammer_inode *ip;
 227         hammer_mount_t hmp;
 228         struct vnode *vp;
 229
 230         vp = ap->a_vp;
 231
 232         if ((ip = vp->v_data) != NULL) {
 233                 hmp = ip->hmp;
 234                 lwkt_gettoken(&hmp->fs_token);
 235                 hammer_lock_ex(&ip->lock);
 236                 vp->v_data = NULL;
 237                 ip->vp = NULL;
 238
 239                 if ((ip->flags & HAMMER_INODE_RECLAIM) == 0) {
 240                         ++hammer_count_reclaims;
 241                         ++hmp->count_reclaims;
 242                         ip->flags |= HAMMER_INODE_RECLAIM;
 243                 }
 244                 hammer_unlock(&ip->lock);
 245                 vclrisdirty(vp);
 246                 hammer_rel_inode(ip, 1);
 247                 lwkt_reltoken(&hmp->fs_token);
 248         }
 249         return(0);
 250 }
 251
 252 /*
 253  * Inform the kernel that the inode is dirty.  This will be checked
 254  * by vn_unlock().
 255  *
 256  * Theoretically in order to reclaim a vnode the hammer_vop_reclaim()
 257  * must be called which will interlock against our inode lock, so
 258  * if VRECLAIMED is not set vp->v_mount (as used by vsetisdirty())
 259  * should be stable without having to acquire any new locks.
 260  */
 261 void
 262 hammer_inode_dirty(struct hammer_inode *ip)
 263 {
 264         struct vnode *vp;
 265
 266         if ((ip->flags & HAMMER_INODE_MODMASK) &&
 267             (vp = ip->vp) != NULL &&
 268             (vp->v_flag & (VRECLAIMED | VISDIRTY)) == 0) {
 269                 vsetisdirty(vp);
 270         }
 271 }
 272
 273 /*
 274  * Return a locked vnode for the specified inode.  The inode must be
 275  * referenced but NOT LOCKED on entry and will remain referenced on
 276  * return.
 277  *
 278  * Called from the frontend.
 279  */
 280 int
 281 hammer_get_vnode(struct hammer_inode *ip, struct vnode **vpp)
 282 {
 283         hammer_mount_t hmp;
 284         struct vnode *vp;
 285         int error = 0;
 286         u_int8_t obj_type;
 287
 288         hmp = ip->hmp;
 289
 290         for (;;) {
 291                 if ((vp = ip->vp) == NULL) {
 292                         error = getnewvnode(VT_HAMMER, hmp->mp, vpp, 0, 0);
 293                         if (error)
 294                                 break;
 295                         hammer_lock_ex(&ip->lock);
 296                         if (ip->vp != NULL) {
 297                                 hammer_unlock(&ip->lock);
 298                                 vp = *vpp;
 299                                 vp->v_type = VBAD;
 300                                 vx_put(vp);
 301                                 continue;
 302                         }
 303                         hammer_ref(&ip->lock);
 304                         vp = *vpp;
 305                         ip->vp = vp;
 306
 307                         obj_type = ip->ino_data.obj_type;
 308                         vp->v_type = hammer_get_vnode_type(obj_type);
 309
 310                         hammer_inode_wakereclaims(ip);
 311
 312                         switch(ip->ino_data.obj_type) {
 313                         case HAMMER_OBJTYPE_CDEV:
 314                         case HAMMER_OBJTYPE_BDEV:
 315                                 vp->v_ops = &hmp->mp->mnt_vn_spec_ops;
 316                                 addaliasu(vp, ip->ino_data.rmajor,
 317                                           ip->ino_data.rminor);
 318                                 break;
 319                         case HAMMER_OBJTYPE_FIFO:
 320                                 vp->v_ops = &hmp->mp->mnt_vn_fifo_ops;
 321                                 break;
 322                         case HAMMER_OBJTYPE_REGFILE:
 323                                 break;
 324                         default:
 325                                 break;
 326                         }
 327
 328                         /*
 329                          * Only mark as the root vnode if the ip is not
 330                          * historical, otherwise the VFS cache will get
 331                          * confused.  The other half of the special handling
 332                          * is in hammer_vop_nlookupdotdot().
 333                          *
 334                          * Pseudo-filesystem roots can be accessed via
 335                          * non-root filesystem paths and setting VROOT may
 336                          * confuse the namecache.  Set VPFSROOT instead.
 337                          */
 338                         if (ip->obj_id == HAMMER_OBJID_ROOT) {
 339                                 if (ip->obj_asof == hmp->asof) {
 340                                         if (ip->obj_localization == 0)
 341                                                 vsetflags(vp, VROOT);
 342                                         else
 343                                                 vsetflags(vp, VPFSROOT);
 344                                 } else {
 345                                         vsetflags(vp, VPFSROOT);
 346                                 }
 347                         }
 348
 349                         vp->v_data = (void *)ip;
 350                         /* vnode locked by getnewvnode() */
 351                         /* make related vnode dirty if inode dirty? */
 352                         hammer_unlock(&ip->lock);
 353                         if (vp->v_type == VREG) {
 354                                 vinitvmio(vp, ip->ino_data.size,
 355                                           hammer_blocksize(ip->ino_data.size),
 356                                           hammer_blockoff(ip->ino_data.size));
 357                         }
 358                         break;
 359                 }
 360
 361                 /*
 362                  * Interlock vnode clearing.  This does not prevent the
 363                  * vnode from going into a reclaimed state but it does
 364                  * prevent it from being destroyed or reused so the vget()
 365                  * will properly fail.
 366                  */
 367                 hammer_lock_ex(&ip->lock);
 368                 if ((vp = ip->vp) == NULL) {
 369                         hammer_unlock(&ip->lock);
 370                         continue;
 371                 }
 372                 vhold(vp);
 373                 hammer_unlock(&ip->lock);
 374
 375                 /*
 376                  * loop if the vget fails (aka races), or if the vp
 377                  * no longer matches ip->vp.
 378                  */
 379                 if (vget(vp, LK_EXCLUSIVE) == 0) {
 380                         if (vp == ip->vp) {
 381                                 vdrop(vp);
 382                                 break;
 383                         }
 384                         vput(vp);
 385                 }
 386                 vdrop(vp);
 387         }
 388         *vpp = vp;
 389         return(error);
 390 }
 391
 392 /*
 393  * Locate all copies of the inode for obj_id compatible with the specified
 394  * asof, reference, and issue the related call-back.  This routine is used
 395  * for direct-io invalidation and does not create any new inodes.
 396  */
 397 void
 398 hammer_scan_inode_snapshots(hammer_mount_t hmp, hammer_inode_info_t iinfo,
 399                             int (*callback)(hammer_inode_t ip, void *data),
 400                             void *data)
 401 {
 402         hammer_ino_rb_tree_RB_SCAN(&hmp->rb_inos_root,
 403                                    hammer_inode_info_cmp_all_history,
 404                                    callback, iinfo);
 405 }
 406
 407 /*
 408  * Acquire a HAMMER inode.  The returned inode is not locked.  These functions
 409  * do not attach or detach the related vnode (use hammer_get_vnode() for
 410  * that).
 411  *
 412  * The flags argument is only applied for newly created inodes, and only
 413  * certain flags are inherited.
 414  *
 415  * Called from the frontend.
 416  */
 417 struct hammer_inode *
 418 hammer_get_inode(hammer_transaction_t trans, hammer_inode_t dip,
 419                  int64_t obj_id, hammer_tid_t asof, u_int32_t localization,
 420                  int flags, int *errorp)
 421 {
 422         hammer_mount_t hmp = trans->hmp;
 423         struct hammer_node_cache *cachep;
 424         struct hammer_inode_info iinfo;
 425         struct hammer_cursor cursor;
 426         struct hammer_inode *ip;
 427
 428
 429         /*
 430          * Determine if we already have an inode cached.  If we do then
 431          * we are golden.
 432          *
 433          * If we find an inode with no vnode we have to mark the
 434          * transaction such that hammer_inode_waitreclaims() is
 435          * called later on to avoid building up an infinite number
 436          * of inodes.  Otherwise we can continue to * add new inodes
 437          * faster then they can be disposed of, even with the tsleep
 438          * delay.
 439          *
 440          * If we find a dummy inode we return a failure so dounlink
 441          * (which does another lookup) doesn't try to mess with the
 442          * link count.  hammer_vop_nresolve() uses hammer_get_dummy_inode()
 443          * to ref dummy inodes.
 444          */
 445         iinfo.obj_id = obj_id;
 446         iinfo.obj_asof = asof;
 447         iinfo.obj_localization = localization;
 448 loop:
 449         ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
 450         if (ip) {
 451                 if (ip->flags & HAMMER_INODE_DUMMY) {
 452                         *errorp = ENOENT;
 453                         return(NULL);
 454                 }
 455                 hammer_ref(&ip->lock);
 456                 *errorp = 0;
 457                 return(ip);
 458         }
 459
 460         /*
 461          * Allocate a new inode structure and deal with races later.
 462          */
 463         ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
 464         ++hammer_count_inodes;
 465         ++hmp->count_inodes;
 466         ip->obj_id = obj_id;
 467         ip->obj_asof = iinfo.obj_asof;
 468         ip->obj_localization = localization;
 469         ip->hmp = hmp;
 470         ip->flags = flags & HAMMER_INODE_RO;
 471         ip->cache[0].ip = ip;
 472         ip->cache[1].ip = ip;
 473         ip->cache[2].ip = ip;
 474         ip->cache[3].ip = ip;
 475         if (hmp->ronly)
 476                 ip->flags |= HAMMER_INODE_RO;
 477         ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
 478                 0x7FFFFFFFFFFFFFFFLL;
 479         RB_INIT(&ip->rec_tree);
 480         TAILQ_INIT(&ip->target_list);
 481         hammer_ref(&ip->lock);
 482
 483         /*
 484          * Locate the on-disk inode.  If this is a PFS root we always
 485          * access the current version of the root inode and (if it is not
 486          * a master) always access information under it with a snapshot
 487          * TID.
 488          *
 489          * We cache recent inode lookups in this directory in dip->cache[2].
 490          * If we can't find it we assume the inode we are looking for is
 491          * close to the directory inode.
 492          */
 493 retry:
 494         cachep = NULL;
 495         if (dip) {
 496                 if (dip->cache[2].node)
 497                         cachep = &dip->cache[2];
 498                 else
 499                         cachep = &dip->cache[0];
 500         }
 501         hammer_init_cursor(trans, &cursor, cachep, NULL);
 502         cursor.key_beg.localization = localization + HAMMER_LOCALIZE_INODE;
 503         cursor.key_beg.obj_id = ip->obj_id;
 504         cursor.key_beg.key = 0;
 505         cursor.key_beg.create_tid = 0;
 506         cursor.key_beg.delete_tid = 0;
 507         cursor.key_beg.rec_type = HAMMER_RECTYPE_INODE;
 508         cursor.key_beg.obj_type = 0;
 509
 510         cursor.asof = iinfo.obj_asof;
 511         cursor.flags = HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_GET_DATA |
 512                        HAMMER_CURSOR_ASOF;
 513
 514         *errorp = hammer_btree_lookup(&cursor);
 515         if (*errorp == EDEADLK) {
 516                 hammer_done_cursor(&cursor);
 517                 goto retry;
 518         }
 519
 520         /*
 521          * On success the B-Tree lookup will hold the appropriate
 522          * buffer cache buffers and provide a pointer to the requested
 523          * information.  Copy the information to the in-memory inode
 524          * and cache the B-Tree node to improve future operations.
 525          */
 526         if (*errorp == 0) {
 527                 ip->ino_leaf = cursor.node->ondisk->elms[cursor.index].leaf;
 528                 ip->ino_data = cursor.data->inode;
 529
 530                 /*
 531                  * cache[0] tries to cache the location of the object inode.
 532                  * The assumption is that it is near the directory inode.
 533                  *
 534                  * cache[1] tries to cache the location of the object data.
 535                  * We might have something in the governing directory from
 536                  * scan optimizations (see the strategy code in
 537                  * hammer_vnops.c).
 538                  *
 539                  * We update dip->cache[2], if possible, with the location
 540                  * of the object inode for future directory shortcuts.
 541                  */
 542                 hammer_cache_node(&ip->cache[0], cursor.node);
 543                 if (dip) {
 544                         if (dip->cache[3].node) {
 545                                 hammer_cache_node(&ip->cache[1],
 546                                                   dip->cache[3].node);
 547                         }
 548                         hammer_cache_node(&dip->cache[2], cursor.node);
 549                 }
 550
 551                 /*
 552                  * The file should not contain any data past the file size
 553                  * stored in the inode.  Setting save_trunc_off to the
 554                  * file size instead of max reduces B-Tree lookup overheads
 555                  * on append by allowing the flusher to avoid checking for
 556                  * record overwrites.
 557                  */
 558                 ip->save_trunc_off = ip->ino_data.size;
 559
 560                 /*
 561                  * Locate and assign the pseudofs management structure to
 562                  * the inode.
 563                  */
 564                 if (dip && dip->obj_localization == ip->obj_localization) {
 565                         ip->pfsm = dip->pfsm;
 566                         hammer_ref(&ip->pfsm->lock);
 567                 } else {
 568                         ip->pfsm = hammer_load_pseudofs(trans,
 569                                                         ip->obj_localization,
 570                                                         errorp);
 571                         *errorp = 0;    /* ignore ENOENT */
 572                 }
 573         }
 574
 575         /*
 576          * The inode is placed on the red-black tree and will be synced to
 577          * the media when flushed or by the filesystem sync.  If this races
 578          * another instantiation/lookup the insertion will fail.
 579          */
 580         if (*errorp == 0) {
 581                 if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
 582                         hammer_free_inode(ip);
 583                         hammer_done_cursor(&cursor);
 584                         goto loop;
 585                 }
 586                 ip->flags |= HAMMER_INODE_ONDISK;
 587         } else {
 588                 if (ip->flags & HAMMER_INODE_RSV_INODES) {
 589                         ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
 590                         --hmp->rsv_inodes;
 591                 }
 592
 593                 hammer_free_inode(ip);
 594                 ip = NULL;
 595         }
 596         hammer_done_cursor(&cursor);
 597
 598         /*
 599          * NEWINODE is only set if the inode becomes dirty later,
 600          * setting it here just leads to unnecessary stalls.
 601          *
 602          * trans->flags |= HAMMER_TRANSF_NEWINODE;
 603          */
 604         return (ip);
 605 }
 606
 607 /*
 608  * Get a dummy inode to placemark a broken directory entry.
 609  */
 610 struct hammer_inode *
 611 hammer_get_dummy_inode(hammer_transaction_t trans, hammer_inode_t dip,
 612                  int64_t obj_id, hammer_tid_t asof, u_int32_t localization,
 613                  int flags, int *errorp)
 614 {
 615         hammer_mount_t hmp = trans->hmp;
 616         struct hammer_inode_info iinfo;
 617         struct hammer_inode *ip;
 618
 619         /*
 620          * Determine if we already have an inode cached.  If we do then
 621          * we are golden.
 622          *
 623          * If we find an inode with no vnode we have to mark the
 624          * transaction such that hammer_inode_waitreclaims() is
 625          * called later on to avoid building up an infinite number
 626          * of inodes.  Otherwise we can continue to * add new inodes
 627          * faster then they can be disposed of, even with the tsleep
 628          * delay.
 629          *
 630          * If we find a non-fake inode we return an error.  Only fake
 631          * inodes can be returned by this routine.
 632          */
 633         iinfo.obj_id = obj_id;
 634         iinfo.obj_asof = asof;
 635         iinfo.obj_localization = localization;
 636 loop:
 637         *errorp = 0;
 638         ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
 639         if (ip) {
 640                 if ((ip->flags & HAMMER_INODE_DUMMY) == 0) {
 641                         *errorp = ENOENT;
 642                         return(NULL);
 643                 }
 644                 hammer_ref(&ip->lock);
 645                 return(ip);
 646         }
 647
 648         /*
 649          * Allocate a new inode structure and deal with races later.
 650          */
 651         ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
 652         ++hammer_count_inodes;
 653         ++hmp->count_inodes;
 654         ip->obj_id = obj_id;
 655         ip->obj_asof = iinfo.obj_asof;
 656         ip->obj_localization = localization;
 657         ip->hmp = hmp;
 658         ip->flags = flags | HAMMER_INODE_RO | HAMMER_INODE_DUMMY;
 659         ip->cache[0].ip = ip;
 660         ip->cache[1].ip = ip;
 661         ip->cache[2].ip = ip;
 662         ip->cache[3].ip = ip;
 663         ip->sync_trunc_off = ip->trunc_off = ip->save_trunc_off =
 664                 0x7FFFFFFFFFFFFFFFLL;
 665         RB_INIT(&ip->rec_tree);
 666         TAILQ_INIT(&ip->target_list);
 667         hammer_ref(&ip->lock);
 668
 669         /*
 670          * Populate the dummy inode.  Leave everything zero'd out.
 671          *
 672          * (ip->ino_leaf and ip->ino_data)
 673          *
 674          * Make the dummy inode a FIFO object which most copy programs
 675          * will properly ignore.
 676          */
 677         ip->save_trunc_off = ip->ino_data.size;
 678         ip->ino_data.obj_type = HAMMER_OBJTYPE_FIFO;
 679
 680         /*
 681          * Locate and assign the pseudofs management structure to
 682          * the inode.
 683          */
 684         if (dip && dip->obj_localization == ip->obj_localization) {
 685                 ip->pfsm = dip->pfsm;
 686                 hammer_ref(&ip->pfsm->lock);
 687         } else {
 688                 ip->pfsm = hammer_load_pseudofs(trans, ip->obj_localization,
 689                                                 errorp);
 690                 *errorp = 0;    /* ignore ENOENT */
 691         }
 692
 693         /*
 694          * The inode is placed on the red-black tree and will be synced to
 695          * the media when flushed or by the filesystem sync.  If this races
 696          * another instantiation/lookup the insertion will fail.
 697          *
 698          * NOTE: Do not set HAMMER_INODE_ONDISK.  The inode is a fake.
 699          */
 700         if (*errorp == 0) {
 701                 if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
 702                         hammer_free_inode(ip);
 703                         goto loop;
 704                 }
 705         } else {
 706                 if (ip->flags & HAMMER_INODE_RSV_INODES) {
 707                         ip->flags &= ~HAMMER_INODE_RSV_INODES; /* sanity */
 708                         --hmp->rsv_inodes;
 709                 }
 710                 hammer_free_inode(ip);
 711                 ip = NULL;
 712         }
 713         trans->flags |= HAMMER_TRANSF_NEWINODE;
 714         return (ip);
 715 }
 716
 717 /*
 718  * Return a referenced inode only if it is in our inode cache.
 719  *
 720  * Dummy inodes do not count.
 721  */
 722 struct hammer_inode *
 723 hammer_find_inode(hammer_transaction_t trans, int64_t obj_id,
 724                   hammer_tid_t asof, u_int32_t localization)
 725 {
 726         hammer_mount_t hmp = trans->hmp;
 727         struct hammer_inode_info iinfo;
 728         struct hammer_inode *ip;
 729
 730         iinfo.obj_id = obj_id;
 731         iinfo.obj_asof = asof;
 732         iinfo.obj_localization = localization;
 733
 734         ip = hammer_ino_rb_tree_RB_LOOKUP_INFO(&hmp->rb_inos_root, &iinfo);
 735         if (ip) {
 736                 if (ip->flags & HAMMER_INODE_DUMMY)
 737                         ip = NULL;
 738                 else
 739                         hammer_ref(&ip->lock);
 740         }
 741         return(ip);
 742 }
 743
 744 /*
 745  * Create a new filesystem object, returning the inode in *ipp.  The
 746  * returned inode will be referenced.  The inode is created in-memory.
 747  *
 748  * If pfsm is non-NULL the caller wishes to create the root inode for
 749  * a master PFS.
 750  */
 751 int
 752 hammer_create_inode(hammer_transaction_t trans, struct vattr *vap,
 753                     struct ucred *cred,
 754                     hammer_inode_t dip, const char *name, int namelen,
 755                     hammer_pseudofs_inmem_t pfsm, struct hammer_inode **ipp)
 756 {
 757         hammer_mount_t hmp;
 758         hammer_inode_t ip;
 759         uid_t xuid;
 760         int error;
 761         int64_t namekey;
 762         u_int32_t dummy;
 763
 764         hmp = trans->hmp;
 765
 766         /*
 767          * Disallow the creation of new inodes in directories which
 768          * have been deleted.  In HAMMER, this will cause a record
 769          * syncing assertion later on in the flush code.
 770          */
 771         if (dip && dip->ino_data.nlinks == 0) {
 772                 *ipp = NULL;
 773                 return (EINVAL);
 774         }
 775
 776         /*
 777          * Allocate inode
 778          */
 779         ip = kmalloc(sizeof(*ip), hmp->m_inodes, M_WAITOK|M_ZERO);
 780         ++hammer_count_inodes;
 781         ++hmp->count_inodes;
 782         trans->flags |= HAMMER_TRANSF_NEWINODE;
 783
 784         if (pfsm) {
 785                 KKASSERT(pfsm->localization != 0);
 786                 ip->obj_id = HAMMER_OBJID_ROOT;
 787                 ip->obj_localization = pfsm->localization;
 788         } else {
 789                 KKASSERT(dip != NULL);
 790                 namekey = hammer_directory_namekey(dip, name, namelen, &dummy);
 791                 ip->obj_id = hammer_alloc_objid(hmp, dip, namekey);
 792                 ip->obj_localization = dip->obj_localization;
 793         }
 794
 795         KKASSERT(ip->obj_id != 0);
 796         ip->obj_asof = hmp->asof;
 797         ip->hmp = hmp;
 798         ip->flush_state = HAMMER_FST_IDLE;
 799         ip->flags = HAMMER_INODE_DDIRTY |
 800                     HAMMER_INODE_ATIME | HAMMER_INODE_MTIME;
 801         ip->cache[0].ip = ip;
 802         ip->cache[1].ip = ip;
 803         ip->cache[2].ip = ip;
 804         ip->cache[3].ip = ip;
 805
 806         ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
 807         /* ip->save_trunc_off = 0; (already zero) */
 808         RB_INIT(&ip->rec_tree);
 809         TAILQ_INIT(&ip->target_list);
 810
 811         ip->ino_data.atime = trans->time;
 812         ip->ino_data.mtime = trans->time;
 813         ip->ino_data.size = 0;
 814         ip->ino_data.nlinks = 0;
 815
 816         /*
 817          * A nohistory designator on the parent directory is inherited by
 818          * the child.  We will do this even for pseudo-fs creation... the
 819          * sysad can turn it off.
 820          */
 821         if (dip) {
 822                 ip->ino_data.uflags = dip->ino_data.uflags &
 823                                       (SF_NOHISTORY|UF_NOHISTORY|UF_NODUMP);
 824         }
 825
 826         ip->ino_leaf.base.btype = HAMMER_BTREE_TYPE_RECORD;
 827         ip->ino_leaf.base.localization = ip->obj_localization +
 828                                          HAMMER_LOCALIZE_INODE;
 829         ip->ino_leaf.base.obj_id = ip->obj_id;
 830         ip->ino_leaf.base.key = 0;
 831         ip->ino_leaf.base.create_tid = 0;
 832         ip->ino_leaf.base.delete_tid = 0;
 833         ip->ino_leaf.base.rec_type = HAMMER_RECTYPE_INODE;
 834         ip->ino_leaf.base.obj_type = hammer_get_obj_type(vap->va_type);
 835
 836         ip->ino_data.obj_type = ip->ino_leaf.base.obj_type;
 837         ip->ino_data.version = HAMMER_INODE_DATA_VERSION;
 838         ip->ino_data.mode = vap->va_mode;
 839         ip->ino_data.ctime = trans->time;
 840
 841         /*
 842          * If we are running version 2 or greater directory entries are
 843          * inode-localized instead of data-localized.
 844          */
 845         if (trans->hmp->version >= HAMMER_VOL_VERSION_TWO) {
 846                 if (ip->ino_leaf.base.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
 847                         ip->ino_data.cap_flags |=
 848                                 HAMMER_INODE_CAP_DIR_LOCAL_INO;
 849                 }
 850         }
 851         if (trans->hmp->version >= HAMMER_VOL_VERSION_SIX) {
 852                 if (ip->ino_leaf.base.obj_type == HAMMER_OBJTYPE_DIRECTORY) {
 853                         ip->ino_data.cap_flags |=
 854                                 HAMMER_INODE_CAP_DIRHASH_ALG1;
 855                 }
 856         }
 857
 858         /*
 859          * Setup the ".." pointer.  This only needs to be done for directories
 860          * but we do it for all objects as a recovery aid if dip exists.
 861          * The inode is probably a PFS root if dip is NULL.
 862          */
 863         if (dip)
 864                 ip->ino_data.parent_obj_id = dip->ino_leaf.base.obj_id;
 865 #if 0
 866         /*
 867          * The parent_obj_localization field only applies to pseudo-fs roots.
 868          * XXX this is no longer applicable, PFSs are no longer directly
 869          * tied into the parent's directory structure.
 870          */
 871         if (ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY &&
 872             ip->obj_id == HAMMER_OBJID_ROOT) {
 873                 ip->ino_data.ext.obj.parent_obj_localization =
 874                                                 dip->obj_localization;
 875         }
 876 #endif
 877
 878         switch(ip->ino_leaf.base.obj_type) {
 879         case HAMMER_OBJTYPE_CDEV:
 880         case HAMMER_OBJTYPE_BDEV:
 881                 ip->ino_data.rmajor = vap->va_rmajor;
 882                 ip->ino_data.rminor = vap->va_rminor;
 883                 break;
 884         default:
 885                 break;
 886         }
 887
 888         /*
 889          * Calculate default uid/gid and overwrite with information from
 890          * the vap.
 891          */
 892         if (dip) {
 893                 xuid = hammer_to_unix_xid(&dip->ino_data.uid);
 894                 xuid = vop_helper_create_uid(hmp->mp, dip->ino_data.mode,
 895                                              xuid, cred, &vap->va_mode);
 896         } else {
 897                 xuid = 0;
 898         }
 899         ip->ino_data.mode = vap->va_mode;
 900
 901         if (vap->va_vaflags & VA_UID_UUID_VALID)
 902                 ip->ino_data.uid = vap->va_uid_uuid;
 903         else if (vap->va_uid != (uid_t)VNOVAL)
 904                 hammer_guid_to_uuid(&ip->ino_data.uid, vap->va_uid);
 905         else
 906                 hammer_guid_to_uuid(&ip->ino_data.uid, xuid);
 907
 908         if (vap->va_vaflags & VA_GID_UUID_VALID)
 909                 ip->ino_data.gid = vap->va_gid_uuid;
 910         else if (vap->va_gid != (gid_t)VNOVAL)
 911                 hammer_guid_to_uuid(&ip->ino_data.gid, vap->va_gid);
 912         else if (dip)
 913                 ip->ino_data.gid = dip->ino_data.gid;
 914
 915         hammer_ref(&ip->lock);
 916
 917         if (pfsm) {
 918                 ip->pfsm = pfsm;
 919                 hammer_ref(&pfsm->lock);
 920                 error = 0;
 921         } else if (dip->obj_localization == ip->obj_localization) {
 922                 ip->pfsm = dip->pfsm;
 923                 hammer_ref(&ip->pfsm->lock);
 924                 error = 0;
 925         } else {
 926                 ip->pfsm = hammer_load_pseudofs(trans,
 927                                                 ip->obj_localization,
 928                                                 &error);
 929                 error = 0;      /* ignore ENOENT */
 930         }
 931
 932         if (error) {
 933                 hammer_free_inode(ip);
 934                 ip = NULL;
 935         } else if (RB_INSERT(hammer_ino_rb_tree, &hmp->rb_inos_root, ip)) {
 936                 panic("hammer_create_inode: duplicate obj_id %llx",
 937                       (long long)ip->obj_id);
 938                 /* not reached */
 939                 hammer_free_inode(ip);
 940         }
 941         *ipp = ip;
 942         return(error);
 943 }
 944
 945 /*
 946  * Final cleanup / freeing of an inode structure
 947  */
 948 static void
 949 hammer_free_inode(hammer_inode_t ip)
 950 {
 951         struct hammer_mount *hmp;
 952
 953         hmp = ip->hmp;
 954         KKASSERT(hammer_oneref(&ip->lock));
 955         hammer_uncache_node(&ip->cache[0]);
 956         hammer_uncache_node(&ip->cache[1]);
 957         hammer_uncache_node(&ip->cache[2]);
 958         hammer_uncache_node(&ip->cache[3]);
 959         hammer_inode_wakereclaims(ip);
 960         if (ip->objid_cache)
 961                 hammer_clear_objid(ip);
 962         --hammer_count_inodes;
 963         --hmp->count_inodes;
 964         if (ip->pfsm) {
 965                 hammer_rel_pseudofs(hmp, ip->pfsm);
 966                 ip->pfsm = NULL;
 967         }
 968         kfree(ip, hmp->m_inodes);
 969         ip = NULL;
 970 }
 971
 972 /*
 973  * Retrieve pseudo-fs data.  NULL will never be returned.
 974  *
 975  * If an error occurs *errorp will be set and a default template is returned,
 976  * otherwise *errorp is set to 0.  Typically when an error occurs it will
 977  * be ENOENT.
 978  */
 979 hammer_pseudofs_inmem_t
 980 hammer_load_pseudofs(hammer_transaction_t trans,
 981                      u_int32_t localization, int *errorp)
 982 {
 983         hammer_mount_t hmp = trans->hmp;
 984         hammer_inode_t ip;
 985         hammer_pseudofs_inmem_t pfsm;
 986         struct hammer_cursor cursor;
 987         int bytes;
 988
 989 retry:
 990         pfsm = RB_LOOKUP(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, localization);
 991         if (pfsm) {
 992                 hammer_ref(&pfsm->lock);
 993                 *errorp = 0;
 994                 return(pfsm);
 995         }
 996
 997         /*
 998          * PFS records are associated with the root inode (not the PFS root
 999          * inode, but the real root).  Avoid an infinite recursion if loading
1000          * the PFS for the real root.
1001          */
1002         if (localization) {
1003                 ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT,
1004                                       HAMMER_MAX_TID,
1005                                       HAMMER_DEF_LOCALIZATION, 0, errorp);
1006         } else {
1007                 ip = NULL;
1008         }
1009
1010         pfsm = kmalloc(sizeof(*pfsm), hmp->m_misc, M_WAITOK | M_ZERO);
1011         pfsm->localization = localization;
1012         pfsm->pfsd.unique_uuid = trans->rootvol->ondisk->vol_fsid;
1013         pfsm->pfsd.shared_uuid = pfsm->pfsd.unique_uuid;
1014
1015         hammer_init_cursor(trans, &cursor, (ip ? &ip->cache[1] : NULL), ip);
1016         cursor.key_beg.localization = HAMMER_DEF_LOCALIZATION +
1017                                       HAMMER_LOCALIZE_MISC;
1018         cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
1019         cursor.key_beg.create_tid = 0;
1020         cursor.key_beg.delete_tid = 0;
1021         cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
1022         cursor.key_beg.obj_type = 0;
1023         cursor.key_beg.key = localization;
1024         cursor.asof = HAMMER_MAX_TID;
1025         cursor.flags |= HAMMER_CURSOR_ASOF;
1026
1027         if (ip)
1028                 *errorp = hammer_ip_lookup(&cursor);
1029         else
1030                 *errorp = hammer_btree_lookup(&cursor);
1031         if (*errorp == 0) {
1032                 *errorp = hammer_ip_resolve_data(&cursor);
1033                 if (*errorp == 0) {
1034                         if (cursor.data->pfsd.mirror_flags &
1035                             HAMMER_PFSD_DELETED) {
1036                                 *errorp = ENOENT;
1037                         } else {
1038                                 bytes = cursor.leaf->data_len;
1039                                 if (bytes > sizeof(pfsm->pfsd))
1040                                         bytes = sizeof(pfsm->pfsd);
1041                                 bcopy(cursor.data, &pfsm->pfsd, bytes);
1042                         }
1043                 }
1044         }
1045         hammer_done_cursor(&cursor);
1046
1047         pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1048         hammer_ref(&pfsm->lock);
1049         if (ip)
1050                 hammer_rel_inode(ip, 0);
1051         if (RB_INSERT(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm)) {
1052                 kfree(pfsm, hmp->m_misc);
1053                 goto retry;
1054         }
1055         return(pfsm);
1056 }
1057
1058 /*
1059  * Store pseudo-fs data.  The backend will automatically delete any prior
1060  * on-disk pseudo-fs data but we have to delete in-memory versions.
1061  */
1062 int
1063 hammer_save_pseudofs(hammer_transaction_t trans, hammer_pseudofs_inmem_t pfsm)
1064 {
1065         struct hammer_cursor cursor;
1066         hammer_record_t record;
1067         hammer_inode_t ip;
1068         int error;
1069
1070         /*
1071          * PFS records are associated with the root inode (not the PFS root
1072          * inode, but the real root).
1073          */
1074         ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1075                               HAMMER_DEF_LOCALIZATION, 0, &error);
1076 retry:
1077         pfsm->fsid_udev = hammer_fsid_to_udev(&pfsm->pfsd.shared_uuid);
1078         hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
1079         cursor.key_beg.localization = ip->obj_localization +
1080                                       HAMMER_LOCALIZE_MISC;
1081         cursor.key_beg.obj_id = HAMMER_OBJID_ROOT;
1082         cursor.key_beg.create_tid = 0;
1083         cursor.key_beg.delete_tid = 0;
1084         cursor.key_beg.rec_type = HAMMER_RECTYPE_PFS;
1085         cursor.key_beg.obj_type = 0;
1086         cursor.key_beg.key = pfsm->localization;
1087         cursor.asof = HAMMER_MAX_TID;
1088         cursor.flags |= HAMMER_CURSOR_ASOF;
1089
1090         /*
1091          * Replace any in-memory version of the record.
1092          */
1093         error = hammer_ip_lookup(&cursor);
1094         if (error == 0 && hammer_cursor_inmem(&cursor)) {
1095                 record = cursor.iprec;
1096                 if (record->flags & HAMMER_RECF_INTERLOCK_BE) {
1097                         KKASSERT(cursor.deadlk_rec == NULL);
1098                         hammer_ref(&record->lock);
1099                         cursor.deadlk_rec = record;
1100                         error = EDEADLK;
1101                 } else {
1102                         record->flags |= HAMMER_RECF_DELETED_FE;
1103                         error = 0;
1104                 }
1105         }
1106
1107         /*
1108          * Allocate replacement general record.  The backend flush will
1109          * delete any on-disk version of the record.
1110          */
1111         if (error == 0 || error == ENOENT) {
1112                 record = hammer_alloc_mem_record(ip, sizeof(pfsm->pfsd));
1113                 record->type = HAMMER_MEM_RECORD_GENERAL;
1114
1115                 record->leaf.base.localization = ip->obj_localization +
1116                                                  HAMMER_LOCALIZE_MISC;
1117                 record->leaf.base.rec_type = HAMMER_RECTYPE_PFS;
1118                 record->leaf.base.key = pfsm->localization;
1119                 record->leaf.data_len = sizeof(pfsm->pfsd);
1120                 bcopy(&pfsm->pfsd, record->data, sizeof(pfsm->pfsd));
1121                 error = hammer_ip_add_record(trans, record);
1122         }
1123         hammer_done_cursor(&cursor);
1124         if (error == EDEADLK)
1125                 goto retry;
1126         hammer_rel_inode(ip, 0);
1127         return(error);
1128 }
1129
1130 /*
1131  * Create a root directory for a PFS if one does not alredy exist.
1132  *
1133  * The PFS root stands alone so we must also bump the nlinks count
1134  * to prevent it from being destroyed on release.
1135  */
1136 int
1137 hammer_mkroot_pseudofs(hammer_transaction_t trans, struct ucred *cred,
1138                        hammer_pseudofs_inmem_t pfsm)
1139 {
1140         hammer_inode_t ip;
1141         struct vattr vap;
1142         int error;
1143
1144         ip = hammer_get_inode(trans, NULL, HAMMER_OBJID_ROOT, HAMMER_MAX_TID,
1145                               pfsm->localization, 0, &error);
1146         if (ip == NULL) {
1147                 vattr_null(&vap);
1148                 vap.va_mode = 0755;
1149                 vap.va_type = VDIR;
1150                 error = hammer_create_inode(trans, &vap, cred,
1151                                             NULL, NULL, 0,
1152                                             pfsm, &ip);
1153                 if (error == 0) {
1154                         ++ip->ino_data.nlinks;
1155                         hammer_modify_inode(trans, ip, HAMMER_INODE_DDIRTY);
1156                 }
1157         }
1158         if (ip)
1159                 hammer_rel_inode(ip, 0);
1160         return(error);
1161 }
1162
1163 /*
1164  * Unload any vnodes & inodes associated with a PFS, return ENOTEMPTY
1165  * if we are unable to disassociate all the inodes.
1166  */
1167 static
1168 int
1169 hammer_unload_pseudofs_callback(hammer_inode_t ip, void *data)
1170 {
1171         int res;
1172
1173         hammer_ref(&ip->lock);
1174         if (hammer_isactive(&ip->lock) == 2 && ip->vp)
1175                 vclean_unlocked(ip->vp);
1176         if (hammer_isactive(&ip->lock) == 1 && ip->vp == NULL)
1177                 res = 0;
1178         else
1179                 res = -1;       /* stop, someone is using the inode */
1180         hammer_rel_inode(ip, 0);
1181         return(res);
1182 }
1183
1184 int
1185 hammer_unload_pseudofs(hammer_transaction_t trans, u_int32_t localization)
1186 {
1187         int res;
1188         int try;
1189
1190         for (try = res = 0; try < 4; ++try) {
1191                 res = hammer_ino_rb_tree_RB_SCAN(&trans->hmp->rb_inos_root,
1192                                            hammer_inode_pfs_cmp,
1193                                            hammer_unload_pseudofs_callback,
1194                                            &localization);
1195                 if (res == 0 && try > 1)
1196                         break;
1197                 hammer_flusher_sync(trans->hmp);
1198         }
1199         if (res != 0)
1200                 res = ENOTEMPTY;
1201         return(res);
1202 }
1203
1204
1205 /*
1206  * Release a reference on a PFS
1207  */
1208 void
1209 hammer_rel_pseudofs(hammer_mount_t hmp, hammer_pseudofs_inmem_t pfsm)
1210 {
1211         hammer_rel(&pfsm->lock);
1212         if (hammer_norefs(&pfsm->lock)) {
1213                 RB_REMOVE(hammer_pfs_rb_tree, &hmp->rb_pfsm_root, pfsm);
1214                 kfree(pfsm, hmp->m_misc);
1215         }
1216 }
1217
1218 /*
1219  * Called by hammer_sync_inode().
1220  */
1221 static int
1222 hammer_update_inode(hammer_cursor_t cursor, hammer_inode_t ip)
1223 {
1224         hammer_transaction_t trans = cursor->trans;
1225         hammer_record_t record;
1226         int error;
1227         int redirty;
1228
1229 retry:
1230         error = 0;
1231
1232         /*
1233          * If the inode has a presence on-disk then locate it and mark
1234          * it deleted, setting DELONDISK.
1235          *
1236          * The record may or may not be physically deleted, depending on
1237          * the retention policy.
1238          */
1239         if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) ==
1240             HAMMER_INODE_ONDISK) {
1241                 hammer_normalize_cursor(cursor);
1242                 cursor->key_beg.localization = ip->obj_localization +
1243                                                HAMMER_LOCALIZE_INODE;
1244                 cursor->key_beg.obj_id = ip->obj_id;
1245                 cursor->key_beg.key = 0;
1246                 cursor->key_beg.create_tid = 0;
1247                 cursor->key_beg.delete_tid = 0;
1248                 cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1249                 cursor->key_beg.obj_type = 0;
1250                 cursor->asof = ip->obj_asof;
1251                 cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1252                 cursor->flags |= HAMMER_CURSOR_GET_LEAF | HAMMER_CURSOR_ASOF;
1253                 cursor->flags |= HAMMER_CURSOR_BACKEND;
1254
1255                 error = hammer_btree_lookup(cursor);
1256                 if (hammer_debug_inode)
1257                         kprintf("IPDEL %p %08x %d", ip, ip->flags, error);
1258
1259                 if (error == 0) {
1260                         error = hammer_ip_delete_record(cursor, ip, trans->tid);
1261                         if (hammer_debug_inode)
1262                                 kprintf(" error %d\n", error);
1263                         if (error == 0) {
1264                                 ip->flags |= HAMMER_INODE_DELONDISK;
1265                         }
1266                         if (cursor->node)
1267                                 hammer_cache_node(&ip->cache[0], cursor->node);
1268                 }
1269                 if (error == EDEADLK) {
1270                         hammer_done_cursor(cursor);
1271                         error = hammer_init_cursor(trans, cursor,
1272                                                    &ip->cache[0], ip);
1273                         if (hammer_debug_inode)
1274                                 kprintf("IPDED %p %d\n", ip, error);
1275                         if (error == 0)
1276                                 goto retry;
1277                 }
1278         }
1279
1280         /*
1281          * Ok, write out the initial record or a new record (after deleting
1282          * the old one), unless the DELETED flag is set.  This routine will
1283          * clear DELONDISK if it writes out a record.
1284          *
1285          * Update our inode statistics if this is the first application of
1286          * the inode on-disk.
1287          */
1288         if (error == 0 && (ip->flags & HAMMER_INODE_DELETED) == 0) {
1289                 /*
1290                  * Generate a record and write it to the media.  We clean-up
1291                  * the state before releasing so we do not have to set-up
1292                  * a flush_group.
1293                  */
1294                 record = hammer_alloc_mem_record(ip, 0);
1295                 record->type = HAMMER_MEM_RECORD_INODE;
1296                 record->flush_state = HAMMER_FST_FLUSH;
1297                 record->leaf = ip->sync_ino_leaf;
1298                 record->leaf.base.create_tid = trans->tid;
1299                 record->leaf.data_len = sizeof(ip->sync_ino_data);
1300                 record->leaf.create_ts = trans->time32;
1301                 record->data = (void *)&ip->sync_ino_data;
1302                 record->flags |= HAMMER_RECF_INTERLOCK_BE;
1303
1304                 /*
1305                  * If this flag is set we cannot sync the new file size
1306                  * because we haven't finished related truncations.  The
1307                  * inode will be flushed in another flush group to finish
1308                  * the job.
1309                  */
1310                 if ((ip->flags & HAMMER_INODE_WOULDBLOCK) &&
1311                     ip->sync_ino_data.size != ip->ino_data.size) {
1312                         redirty = 1;
1313                         ip->sync_ino_data.size = ip->ino_data.size;
1314                 } else {
1315                         redirty = 0;
1316                 }
1317
1318                 for (;;) {
1319                         error = hammer_ip_sync_record_cursor(cursor, record);
1320                         if (hammer_debug_inode)
1321                                 kprintf("GENREC %p rec %08x %d\n",
1322                                         ip, record->flags, error);
1323                         if (error != EDEADLK)
1324                                 break;
1325                         hammer_done_cursor(cursor);
1326                         error = hammer_init_cursor(trans, cursor,
1327                                                    &ip->cache[0], ip);
1328                         if (hammer_debug_inode)
1329                                 kprintf("GENREC reinit %d\n", error);
1330                         if (error)
1331                                 break;
1332                 }
1333
1334                 /*
1335                  * Note:  The record was never on the inode's record tree
1336                  * so just wave our hands importantly and destroy it.
1337                  */
1338                 record->flags |= HAMMER_RECF_COMMITTED;
1339                 record->flags &= ~HAMMER_RECF_INTERLOCK_BE;
1340                 record->flush_state = HAMMER_FST_IDLE;
1341                 ++ip->rec_generation;
1342                 hammer_rel_mem_record(record);
1343
1344                 /*
1345                  * Finish up.
1346                  */
1347                 if (error == 0) {
1348                         if (hammer_debug_inode)
1349                                 kprintf("CLEANDELOND %p %08x\n", ip, ip->flags);
1350                         ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1351                                             HAMMER_INODE_SDIRTY |
1352                                             HAMMER_INODE_ATIME |
1353                                             HAMMER_INODE_MTIME);
1354                         ip->flags &= ~HAMMER_INODE_DELONDISK;
1355                         if (redirty)
1356                                 ip->sync_flags |= HAMMER_INODE_DDIRTY;
1357
1358                         /*
1359                          * Root volume count of inodes
1360                          */
1361                         hammer_sync_lock_sh(trans);
1362                         if ((ip->flags & HAMMER_INODE_ONDISK) == 0) {
1363                                 hammer_modify_volume_field(trans,
1364                                                            trans->rootvol,
1365                                                            vol0_stat_inodes);
1366                                 ++ip->hmp->rootvol->ondisk->vol0_stat_inodes;
1367                                 hammer_modify_volume_done(trans->rootvol);
1368                                 ip->flags |= HAMMER_INODE_ONDISK;
1369                                 if (hammer_debug_inode)
1370                                         kprintf("NOWONDISK %p\n", ip);
1371                         }
1372                         hammer_sync_unlock(trans);
1373                 }
1374         }
1375
1376         /*
1377          * If the inode has been destroyed, clean out any left-over flags
1378          * that may have been set by the frontend.
1379          */
1380         if (error == 0 && (ip->flags & HAMMER_INODE_DELETED)) {
1381                 ip->sync_flags &= ~(HAMMER_INODE_DDIRTY |
1382                                     HAMMER_INODE_SDIRTY |
1383                                     HAMMER_INODE_ATIME |
1384                                     HAMMER_INODE_MTIME);
1385         }
1386         return(error);
1387 }
1388
1389 /*
1390  * Update only the itimes fields.
1391  *
1392  * ATIME can be updated without generating any UNDO.  MTIME is updated
1393  * with UNDO so it is guaranteed to be synchronized properly in case of
1394  * a crash.
1395  *
1396  * Neither field is included in the B-Tree leaf element's CRC, which is how
1397  * we can get away with updating ATIME the way we do.
1398  */
1399 static int
1400 hammer_update_itimes(hammer_cursor_t cursor, hammer_inode_t ip)
1401 {
1402         hammer_transaction_t trans = cursor->trans;
1403         int error;
1404
1405 retry:
1406         if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DELONDISK)) !=
1407             HAMMER_INODE_ONDISK) {
1408                 return(0);
1409         }
1410
1411         hammer_normalize_cursor(cursor);
1412         cursor->key_beg.localization = ip->obj_localization +
1413                                        HAMMER_LOCALIZE_INODE;
1414         cursor->key_beg.obj_id = ip->obj_id;
1415         cursor->key_beg.key = 0;
1416         cursor->key_beg.create_tid = 0;
1417         cursor->key_beg.delete_tid = 0;
1418         cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE;
1419         cursor->key_beg.obj_type = 0;
1420         cursor->asof = ip->obj_asof;
1421         cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1422         cursor->flags |= HAMMER_CURSOR_ASOF;
1423         cursor->flags |= HAMMER_CURSOR_GET_LEAF;
1424         cursor->flags |= HAMMER_CURSOR_GET_DATA;
1425         cursor->flags |= HAMMER_CURSOR_BACKEND;
1426
1427         error = hammer_btree_lookup(cursor);
1428         if (error == 0) {
1429                 hammer_cache_node(&ip->cache[0], cursor->node);
1430                 if (ip->sync_flags & HAMMER_INODE_MTIME) {
1431                         /*
1432                          * Updating MTIME requires an UNDO.  Just cover
1433                          * both atime and mtime.
1434                          */
1435                         hammer_sync_lock_sh(trans);
1436                         hammer_modify_buffer(trans, cursor->data_buffer,
1437                                      HAMMER_ITIMES_BASE(&cursor->data->inode),
1438                                      HAMMER_ITIMES_BYTES);
1439                         cursor->data->inode.atime = ip->sync_ino_data.atime;
1440                         cursor->data->inode.mtime = ip->sync_ino_data.mtime;
1441                         hammer_modify_buffer_done(cursor->data_buffer);
1442                         hammer_sync_unlock(trans);
1443                 } else if (ip->sync_flags & HAMMER_INODE_ATIME) {
1444                         /*
1445                          * Updating atime only can be done in-place with
1446                          * no UNDO.
1447                          */
1448                         hammer_sync_lock_sh(trans);
1449                         hammer_modify_buffer(trans, cursor->data_buffer,
1450                                              NULL, 0);
1451                         cursor->data->inode.atime = ip->sync_ino_data.atime;
1452                         hammer_modify_buffer_done(cursor->data_buffer);
1453                         hammer_sync_unlock(trans);
1454                 }
1455                 ip->sync_flags &= ~(HAMMER_INODE_ATIME | HAMMER_INODE_MTIME);
1456         }
1457         if (error == EDEADLK) {
1458                 hammer_done_cursor(cursor);
1459                 error = hammer_init_cursor(trans, cursor,
1460                                            &ip->cache[0], ip);
1461                 if (error == 0)
1462                         goto retry;
1463         }
1464         return(error);
1465 }
1466
1467 /*
1468  * Release a reference on an inode, flush as requested.
1469  *
1470  * On the last reference we queue the inode to the flusher for its final
1471  * disposition.
1472  */
1473 void
1474 hammer_rel_inode(struct hammer_inode *ip, int flush)
1475 {
1476         /*
1477          * Handle disposition when dropping the last ref.
1478          */
1479         for (;;) {
1480                 if (hammer_oneref(&ip->lock)) {
1481                         /*
1482                          * Determine whether on-disk action is needed for
1483                          * the inode's final disposition.
1484                          */
1485                         KKASSERT(ip->vp == NULL);
1486                         hammer_inode_unloadable_check(ip, 0);
1487                         if (ip->flags & HAMMER_INODE_MODMASK) {
1488                                 hammer_flush_inode(ip, 0);
1489                         } else if (hammer_oneref(&ip->lock)) {
1490                                 hammer_unload_inode(ip);
1491                                 break;
1492                         }
1493                 } else {
1494                         if (flush)
1495                                 hammer_flush_inode(ip, 0);
1496
1497                         /*
1498                          * The inode still has multiple refs, try to drop
1499                          * one ref.
1500                          */
1501                         KKASSERT(hammer_isactive(&ip->lock) >= 1);
1502                         if (hammer_isactive(&ip->lock) > 1) {
1503                                 hammer_rel(&ip->lock);
1504                                 break;
1505                         }
1506                 }
1507         }
1508 }
1509
1510 /*
1511  * Unload and destroy the specified inode.  Must be called with one remaining
1512  * reference.  The reference is disposed of.
1513  *
1514  * The inode must be completely clean.
1515  */
1516 static int
1517 hammer_unload_inode(struct hammer_inode *ip)
1518 {
1519         hammer_mount_t hmp = ip->hmp;
1520
1521         KASSERT(hammer_oneref(&ip->lock),
1522                 ("hammer_unload_inode: %d refs", hammer_isactive(&ip->lock)));
1523         KKASSERT(ip->vp == NULL);
1524         KKASSERT(ip->flush_state == HAMMER_FST_IDLE);
1525         KKASSERT(ip->cursor_ip_refs == 0);
1526         KKASSERT(hammer_notlocked(&ip->lock));
1527         KKASSERT((ip->flags & HAMMER_INODE_MODMASK) == 0);
1528
1529         KKASSERT(RB_EMPTY(&ip->rec_tree));
1530         KKASSERT(TAILQ_EMPTY(&ip->target_list));
1531
1532         if (ip->flags & HAMMER_INODE_RDIRTY) {
1533                 RB_REMOVE(hammer_redo_rb_tree, &hmp->rb_redo_root, ip);
1534                 ip->flags &= ~HAMMER_INODE_RDIRTY;
1535         }
1536         RB_REMOVE(hammer_ino_rb_tree, &hmp->rb_inos_root, ip);
1537
1538         hammer_free_inode(ip);
1539         return(0);
1540 }
1541
1542 /*
1543  * Called during unmounting if a critical error occured.  The in-memory
1544  * inode and all related structures are destroyed.
1545  *
1546  * If a critical error did not occur the unmount code calls the standard
1547  * release and asserts that the inode is gone.
1548  */
1549 int
1550 hammer_destroy_inode_callback(struct hammer_inode *ip, void *data __unused)
1551 {
1552         hammer_record_t rec;
1553
1554         /*
1555          * Get rid of the inodes in-memory records, regardless of their
1556          * state, and clear the mod-mask.
1557          */
1558         while ((rec = TAILQ_FIRST(&ip->target_list)) != NULL) {
1559                 TAILQ_REMOVE(&ip->target_list, rec, target_entry);
1560                 rec->target_ip = NULL;
1561                 if (rec->flush_state == HAMMER_FST_SETUP)
1562                         rec->flush_state = HAMMER_FST_IDLE;
1563         }
1564         while ((rec = RB_ROOT(&ip->rec_tree)) != NULL) {
1565                 if (rec->flush_state == HAMMER_FST_FLUSH)
1566                         --rec->flush_group->refs;
1567                 else
1568                         hammer_ref(&rec->lock);
1569                 KKASSERT(hammer_oneref(&rec->lock));
1570                 rec->flush_state = HAMMER_FST_IDLE;
1571                 rec->flush_group = NULL;
1572                 rec->flags |= HAMMER_RECF_DELETED_FE; /* wave hands */
1573                 rec->flags |= HAMMER_RECF_DELETED_BE; /* wave hands */
1574                 ++ip->rec_generation;
1575                 hammer_rel_mem_record(rec);
1576         }
1577         ip->flags &= ~HAMMER_INODE_MODMASK;
1578         ip->sync_flags &= ~HAMMER_INODE_MODMASK;
1579         KKASSERT(ip->vp == NULL);
1580
1581         /*
1582          * Remove the inode from any flush group, force it idle.  FLUSH
1583          * and SETUP states have an inode ref.
1584          */
1585         switch(ip->flush_state) {
1586         case HAMMER_FST_FLUSH:
1587                 RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
1588                 --ip->flush_group->refs;
1589                 ip->flush_group = NULL;
1590                 /* fall through */
1591         case HAMMER_FST_SETUP:
1592                 hammer_rel(&ip->lock);
1593                 ip->flush_state = HAMMER_FST_IDLE;
1594                 /* fall through */
1595         case HAMMER_FST_IDLE:
1596                 break;
1597         }
1598
1599         /*
1600          * There shouldn't be any associated vnode.  The unload needs at
1601          * least one ref, if we do have a vp steal its ip ref.
1602          */
1603         if (ip->vp) {
1604                 kprintf("hammer_destroy_inode_callback: Unexpected "
1605                         "vnode association ip %p vp %p\n", ip, ip->vp);
1606                 ip->vp->v_data = NULL;
1607                 ip->vp = NULL;
1608         } else {
1609                 hammer_ref(&ip->lock);
1610         }
1611         hammer_unload_inode(ip);
1612         return(0);
1613 }
1614
1615 /*
1616  * Called on mount -u when switching from RW to RO or vise-versa.  Adjust
1617  * the read-only flag for cached inodes.
1618  *
1619  * This routine is called from a RB_SCAN().
1620  */
1621 int
1622 hammer_reload_inode(hammer_inode_t ip, void *arg __unused)
1623 {
1624         hammer_mount_t hmp = ip->hmp;
1625
1626         if (hmp->ronly || hmp->asof != HAMMER_MAX_TID)
1627                 ip->flags |= HAMMER_INODE_RO;
1628         else
1629                 ip->flags &= ~HAMMER_INODE_RO;
1630         return(0);
1631 }
1632
1633 /*
1634  * A transaction has modified an inode, requiring updates as specified by
1635  * the passed flags.
1636  *
1637  * HAMMER_INODE_DDIRTY: Inode data has been updated, not incl mtime/atime,
1638  *                      and not including size changes due to write-append
1639  *                      (but other size changes are included).
1640  * HAMMER_INODE_SDIRTY: Inode data has been updated, size changes due to
1641  *                      write-append.
1642  * HAMMER_INODE_XDIRTY: Dirty in-memory records
1643  * HAMMER_INODE_BUFS:   Dirty buffer cache buffers
1644  * HAMMER_INODE_DELETED: Inode record/data must be deleted
1645  * HAMMER_INODE_ATIME/MTIME: mtime/atime has been updated
1646  */
1647 void
1648 hammer_modify_inode(hammer_transaction_t trans, hammer_inode_t ip, int flags)
1649 {
1650         /*
1651          * ronly of 0 or 2 does not trigger assertion.
1652          * 2 is a special error state
1653          */
1654         KKASSERT(ip->hmp->ronly != 1 ||
1655                   (flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
1656                             HAMMER_INODE_SDIRTY |
1657                             HAMMER_INODE_BUFS | HAMMER_INODE_DELETED |
1658                             HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) == 0);
1659         if ((ip->flags & HAMMER_INODE_RSV_INODES) == 0) {
1660                 ip->flags |= HAMMER_INODE_RSV_INODES;
1661                 ++ip->hmp->rsv_inodes;
1662         }
1663
1664         /*
1665          * Set the NEWINODE flag in the transaction if the inode
1666          * transitions to a dirty state.  This is used to track
1667          * the load on the inode cache.
1668          */
1669         if (trans &&
1670             (ip->flags & HAMMER_INODE_MODMASK) == 0 &&
1671             (flags & HAMMER_INODE_MODMASK)) {
1672                 trans->flags |= HAMMER_TRANSF_NEWINODE;
1673         }
1674         if (flags & HAMMER_INODE_MODMASK)
1675                 hammer_inode_dirty(ip);
1676         ip->flags |= flags;
1677 }
1678
1679 /*
1680  * Attempt to quickly update the atime for a hammer inode.  Return 0 on
1681  * success, -1 on failure.
1682  *
1683  * We attempt to update the atime with only the ip lock and not the
1684  * whole filesystem lock in order to improve concurrency.  We can only
1685  * do this safely if the ATIME flag is already pending on the inode.
1686  *
1687  * This function is called via a vnops path (ip pointer is stable) without
1688  * fs_token held.
1689  */
1690 int
1691 hammer_update_atime_quick(hammer_inode_t ip)
1692 {
1693         struct timeval tv;
1694         int res = -1;
1695
1696         if ((ip->flags & HAMMER_INODE_RO) ||
1697             (ip->hmp->mp->mnt_flag & MNT_NOATIME)) {
1698                 /*
1699                  * Silently indicate success on read-only mount/snap
1700                  */
1701                 res = 0;
1702         } else if (ip->flags & HAMMER_INODE_ATIME) {
1703                 /*
1704                  * Double check with inode lock held against backend.  This
1705                  * is only safe if all we need to do is update
1706                  * ino_data.atime.
1707                  */
1708                 getmicrotime(&tv);
1709                 hammer_lock_ex(&ip->lock);
1710                 if (ip->flags & HAMMER_INODE_ATIME) {
1711                         ip->ino_data.atime =
1712                             (unsigned long)tv.tv_sec * 1000000ULL + tv.tv_usec;
1713                         res = 0;
1714                 }
1715                 hammer_unlock(&ip->lock);
1716         }
1717         return res;
1718 }
1719
1720 /*
1721  * Request that an inode be flushed.  This whole mess cannot block and may
1722  * recurse (if not synchronous).  Once requested HAMMER will attempt to
1723  * actively flush the inode until the flush can be done.
1724  *
1725  * The inode may already be flushing, or may be in a setup state.  We can
1726  * place the inode in a flushing state if it is currently idle and flag it
1727  * to reflush if it is currently flushing.
1728  *
1729  * Upon return if the inode could not be flushed due to a setup
1730  * dependancy, then it will be automatically flushed when the dependancy
1731  * is satisfied.
1732  */
1733 void
1734 hammer_flush_inode(hammer_inode_t ip, int flags)
1735 {
1736         hammer_mount_t hmp;
1737         hammer_flush_group_t flg;
1738         int good;
1739
1740         /*
1741          * fill_flush_group is the first flush group we may be able to
1742          * continue filling, it may be open or closed but it will always
1743          * be past the currently flushing (running) flg.
1744          *
1745          * next_flush_group is the next open flush group.
1746          */
1747         hmp = ip->hmp;
1748         while ((flg = hmp->fill_flush_group) != NULL) {
1749                 KKASSERT(flg->running == 0);
1750                 if (flg->total_count + flg->refs <= ip->hmp->undo_rec_limit &&
1751                     flg->total_count <= hammer_autoflush) {
1752                         break;
1753                 }
1754                 hmp->fill_flush_group = TAILQ_NEXT(flg, flush_entry);
1755                 hammer_flusher_async(ip->hmp, flg);
1756         }
1757         if (flg == NULL) {
1758                 flg = kmalloc(sizeof(*flg), hmp->m_misc, M_WAITOK|M_ZERO);
1759                 flg->seq = hmp->flusher.next++;
1760                 if (hmp->next_flush_group == NULL)
1761                         hmp->next_flush_group = flg;
1762                 if (hmp->fill_flush_group == NULL)
1763                         hmp->fill_flush_group = flg;
1764                 RB_INIT(&flg->flush_tree);
1765                 TAILQ_INSERT_TAIL(&hmp->flush_group_list, flg, flush_entry);
1766         }
1767
1768         /*
1769          * Trivial 'nothing to flush' case.  If the inode is in a SETUP
1770          * state we have to put it back into an IDLE state so we can
1771          * drop the extra ref.
1772          *
1773          * If we have a parent dependancy we must still fall through
1774          * so we can run it.
1775          */
1776         if ((ip->flags & HAMMER_INODE_MODMASK) == 0) {
1777                 if (ip->flush_state == HAMMER_FST_SETUP &&
1778                     TAILQ_EMPTY(&ip->target_list)) {
1779                         ip->flush_state = HAMMER_FST_IDLE;
1780                         hammer_rel_inode(ip, 0);
1781                 }
1782                 if (ip->flush_state == HAMMER_FST_IDLE)
1783                         return;
1784         }
1785
1786         /*
1787          * Our flush action will depend on the current state.
1788          */
1789         switch(ip->flush_state) {
1790         case HAMMER_FST_IDLE:
1791                 /*
1792                  * We have no dependancies and can flush immediately.  Some
1793                  * our children may not be flushable so we have to re-test
1794                  * with that additional knowledge.
1795                  */
1796                 hammer_flush_inode_core(ip, flg, flags);
1797                 break;
1798         case HAMMER_FST_SETUP:
1799                 /*
1800                  * Recurse upwards through dependancies via target_list
1801                  * and start their flusher actions going if possible.
1802                  *
1803                  * 'good' is our connectivity.  -1 means we have none and
1804                  * can't flush, 0 means there weren't any dependancies, and
1805                  * 1 means we have good connectivity.
1806                  */
1807                 good = hammer_setup_parent_inodes(ip, 0, flg);
1808
1809                 if (good >= 0) {
1810                         /*
1811                          * We can continue if good >= 0.  Determine how
1812                          * many records under our inode can be flushed (and
1813                          * mark them).
1814                          */
1815                         hammer_flush_inode_core(ip, flg, flags);
1816                 } else {
1817                         /*
1818                          * Parent has no connectivity, tell it to flush
1819                          * us as soon as it does.
1820                          *
1821                          * The REFLUSH flag is also needed to trigger
1822                          * dependancy wakeups.
1823                          */
1824                         ip->flags |= HAMMER_INODE_CONN_DOWN |
1825                                      HAMMER_INODE_REFLUSH;
1826                         if (flags & HAMMER_FLUSH_SIGNAL) {
1827                                 ip->flags |= HAMMER_INODE_RESIGNAL;
1828                                 hammer_flusher_async(ip->hmp, flg);
1829                         }
1830                 }
1831                 break;
1832         case HAMMER_FST_FLUSH:
1833                 /*
1834                  * We are already flushing, flag the inode to reflush
1835                  * if needed after it completes its current flush.
1836                  *
1837                  * The REFLUSH flag is also needed to trigger
1838                  * dependancy wakeups.
1839                  */
1840                 if ((ip->flags & HAMMER_INODE_REFLUSH) == 0)
1841                         ip->flags |= HAMMER_INODE_REFLUSH;
1842                 if (flags & HAMMER_FLUSH_SIGNAL) {
1843                         ip->flags |= HAMMER_INODE_RESIGNAL;
1844                         hammer_flusher_async(ip->hmp, flg);
1845                 }
1846                 break;
1847         }
1848 }
1849
1850 /*
1851  * Scan ip->target_list, which is a list of records owned by PARENTS to our
1852  * ip which reference our ip.
1853  *
1854  * XXX This is a huge mess of recursive code, but not one bit of it blocks
1855  *     so for now do not ref/deref the structures.  Note that if we use the
1856  *     ref/rel code later, the rel CAN block.
1857  */
1858 static int
1859 hammer_setup_parent_inodes(hammer_inode_t ip, int depth,
1860                            hammer_flush_group_t flg)
1861 {
1862         hammer_record_t depend;
1863         int good;
1864         int r;
1865
1866         /*
1867          * If we hit our recursion limit and we have parent dependencies
1868          * We cannot continue.  Returning < 0 will cause us to be flagged
1869          * for reflush.  Returning -2 cuts off additional dependency checks
1870          * because they are likely to also hit the depth limit.
1871          *
1872          * We cannot return < 0 if there are no dependencies or there might
1873          * not be anything to wakeup (ip).
1874          */
1875         if (depth == 20 && TAILQ_FIRST(&ip->target_list)) {
1876                 if (hammer_debug_general & 0x10000)
1877                         krateprintf(&hammer_gen_krate,
1878                             "HAMMER Warning: depth limit reached on "
1879                             "setup recursion, inode %p %016llx\n",
1880                             ip, (long long)ip->obj_id);
1881                 return(-2);
1882         }
1883
1884         /*
1885          * Scan dependencies
1886          */
1887         good = 0;
1888         TAILQ_FOREACH(depend, &ip->target_list, target_entry) {
1889                 r = hammer_setup_parent_inodes_helper(depend, depth, flg);
1890                 KKASSERT(depend->target_ip == ip);
1891                 if (r < 0 && good == 0)
1892                         good = -1;
1893                 if (r > 0)
1894                         good = 1;
1895
1896                 /*
1897                  * If we failed due to the recursion depth limit then stop
1898                  * now.
1899                  */
1900                 if (r == -2)
1901                         break;
1902         }
1903         return(good);
1904 }
1905
1906 /*
1907  * This helper function takes a record representing the dependancy between
1908  * the parent inode and child inode.
1909  *
1910  * record               = record in question (*rec in below)
1911  * record->ip           = parent inode (*pip in below)
1912  * record->target_ip    = child inode (*ip in below)
1913  *
1914  * *pip--------------\
1915  *    ^               \rec_tree
1916  *     \               \
1917  *      \ip            /\\\\\ rbtree of recs from parent inode's view
1918  *       \            //\\\\\\
1919  *        \          / ........
1920  *         \        /
1921  *          \------*rec------target_ip------>*ip
1922  *               ...target_entry<----...----->target_list<---...
1923  *                                            list of recs from inode's view
1924  *
1925  * We are asked to recurse upwards and convert the record from SETUP
1926  * to FLUSH if possible.
1927  *
1928  * Return 1 if the record gives us connectivity
1929  *
1930  * Return 0 if the record is not relevant
1931  *
1932  * Return -1 if we can't resolve the dependancy and there is no connectivity.
1933  */
1934 static int
1935 hammer_setup_parent_inodes_helper(hammer_record_t record, int depth,
1936                                   hammer_flush_group_t flg)
1937 {
1938         hammer_inode_t pip;
1939         int good;
1940
1941         KKASSERT(record->flush_state != HAMMER_FST_IDLE);
1942         pip = record->ip;
1943
1944         /*
1945          * If the record is already flushing, is it in our flush group?
1946          *
1947          * If it is in our flush group but it is a general record or a
1948          * delete-on-disk, it does not improve our connectivity (return 0),
1949          * and if the target inode is not trying to destroy itself we can't
1950          * allow the operation yet anyway (the second return -1).
1951          */
1952         if (record->flush_state == HAMMER_FST_FLUSH) {
1953                 /*
1954                  * If not in our flush group ask the parent to reflush
1955                  * us as soon as possible.
1956                  */
1957                 if (record->flush_group != flg) {
1958                         pip->flags |= HAMMER_INODE_REFLUSH;
1959                         record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1960                         return(-1);
1961                 }
1962
1963                 /*
1964                  * If in our flush group everything is already set up,
1965                  * just return whether the record will improve our
1966                  * visibility or not.
1967                  */
1968                 if (record->type == HAMMER_MEM_RECORD_ADD)
1969                         return(1);
1970                 return(0);
1971         }
1972
1973         /*
1974          * It must be a setup record.  Try to resolve the setup dependancies
1975          * by recursing upwards so we can place ip on the flush list.
1976          *
1977          * Limit ourselves to 20 levels of recursion to avoid blowing out
1978          * the kernel stack.  If we hit the recursion limit we can't flush
1979          * until the parent flushes.  The parent will flush independantly
1980          * on its own and ultimately a deep recursion will be resolved.
1981          */
1982         KKASSERT(record->flush_state == HAMMER_FST_SETUP);
1983
1984         good = hammer_setup_parent_inodes(pip, depth + 1, flg);
1985
1986         /*
1987          * If good < 0 the parent has no connectivity and we cannot safely
1988          * flush the directory entry, which also means we can't flush our
1989          * ip.  Flag us for downward recursion once the parent's
1990          * connectivity is resolved.  Flag the parent for [re]flush or it
1991          * may not check for downward recursions.
1992          */
1993         if (good < 0) {
1994                 pip->flags |= HAMMER_INODE_REFLUSH;
1995                 record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
1996                 return(good);
1997         }
1998
1999         /*
2000          * We are go, place the parent inode in a flushing state so we can
2001          * place its record in a flushing state.  Note that the parent
2002          * may already be flushing.  The record must be in the same flush
2003          * group as the parent.
2004          */
2005         if (pip->flush_state != HAMMER_FST_FLUSH)
2006                 hammer_flush_inode_core(pip, flg, HAMMER_FLUSH_RECURSION);
2007         KKASSERT(pip->flush_state == HAMMER_FST_FLUSH);
2008
2009         /*
2010          * It is possible for a rename to create a loop in the recursion
2011          * and revisit a record.  This will result in the record being
2012          * placed in a flush state unexpectedly.  This check deals with
2013          * the case.
2014          */
2015         if (record->flush_state == HAMMER_FST_FLUSH) {
2016                 if (record->type == HAMMER_MEM_RECORD_ADD)
2017                         return(1);
2018                 return(0);
2019         }
2020
2021         KKASSERT(record->flush_state == HAMMER_FST_SETUP);
2022
2023 #if 0
2024         if (record->type == HAMMER_MEM_RECORD_DEL &&
2025             (record->target_ip->flags & (HAMMER_INODE_DELETED|HAMMER_INODE_DELONDISK)) == 0) {
2026                 /*
2027                  * Regardless of flushing state we cannot sync this path if the
2028                  * record represents a delete-on-disk but the target inode
2029                  * is not ready to sync its own deletion.
2030                  *
2031                  * XXX need to count effective nlinks to determine whether
2032                  * the flush is ok, otherwise removing a hardlink will
2033                  * just leave the DEL record to rot.
2034                  */
2035                 record->target_ip->flags |= HAMMER_INODE_REFLUSH;
2036                 return(-1);
2037         } else
2038 #endif
2039         if (pip->flush_group == flg) {
2040                 /*
2041                  * Because we have not calculated nlinks yet we can just
2042                  * set records to the flush state if the parent is in
2043                  * the same flush group as we are.
2044                  */
2045                 record->flush_state = HAMMER_FST_FLUSH;
2046                 record->flush_group = flg;
2047                 ++record->flush_group->refs;
2048                 hammer_ref(&record->lock);
2049
2050                 /*
2051                  * A general directory-add contributes to our visibility.
2052                  *
2053                  * Otherwise it is probably a directory-delete or
2054                  * delete-on-disk record and does not contribute to our
2055                  * visbility (but we can still flush it).
2056                  */
2057                 if (record->type == HAMMER_MEM_RECORD_ADD)
2058                         return(1);
2059                 return(0);
2060         } else {
2061                 /*
2062                  * If the parent is not in our flush group we cannot
2063                  * flush this record yet, there is no visibility.
2064                  * We tell the parent to reflush and mark ourselves
2065                  * so the parent knows it should flush us too.
2066                  */
2067                 pip->flags |= HAMMER_INODE_REFLUSH;
2068                 record->target_ip->flags |= HAMMER_INODE_CONN_DOWN;
2069                 return(-1);
2070         }
2071 }
2072
2073 /*
2074  * This is the core routine placing an inode into the FST_FLUSH state.
2075  */
2076 static void
2077 hammer_flush_inode_core(hammer_inode_t ip, hammer_flush_group_t flg, int flags)
2078 {
2079         hammer_mount_t hmp = ip->hmp;
2080         int go_count;
2081
2082         /*
2083          * Set flush state and prevent the flusher from cycling into
2084          * the next flush group.  Do not place the ip on the list yet.
2085          * Inodes not in the idle state get an extra reference.
2086          */
2087         KKASSERT(ip->flush_state != HAMMER_FST_FLUSH);
2088         if (ip->flush_state == HAMMER_FST_IDLE)
2089                 hammer_ref(&ip->lock);
2090         ip->flush_state = HAMMER_FST_FLUSH;
2091         ip->flush_group = flg;
2092         ++hmp->flusher.group_lock;
2093         ++hmp->count_iqueued;
2094         ++hammer_count_iqueued;
2095         ++flg->total_count;
2096         hammer_redo_fifo_start_flush(ip);
2097
2098 #if 0
2099         /*
2100          * We need to be able to vfsync/truncate from the backend.
2101          *
2102          * XXX Any truncation from the backend will acquire the vnode
2103          *     independently.
2104          */
2105         KKASSERT((ip->flags & HAMMER_INODE_VHELD) == 0);
2106         if (ip->vp && (ip->vp->v_flag & VINACTIVE) == 0) {
2107                 ip->flags |= HAMMER_INODE_VHELD;
2108                 vref(ip->vp);
2109         }
2110 #endif
2111
2112         /*
2113          * Figure out how many in-memory records we can actually flush
2114          * (not including inode meta-data, buffers, etc).
2115          */
2116         KKASSERT((ip->flags & HAMMER_INODE_WOULDBLOCK) == 0);
2117         if (flags & HAMMER_FLUSH_RECURSION) {
2118                 /*
2119                  * If this is a upwards recursion we do not want to
2120                  * recurse down again!
2121                  */
2122                 go_count = 1;
2123 #if 0
2124         } else if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2125                 /*
2126                  * No new records are added if we must complete a flush
2127                  * from a previous cycle, but we do have to move the records
2128                  * from the previous cycle to the current one.
2129                  */
2130 #if 0
2131                 go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2132                                    hammer_syncgrp_child_callback, NULL);
2133 #endif
2134                 go_count = 1;
2135 #endif
2136         } else {
2137                 /*
2138                  * Normal flush, scan records and bring them into the flush.
2139                  * Directory adds and deletes are usually skipped (they are
2140                  * grouped with the related inode rather then with the
2141                  * directory).
2142                  *
2143                  * go_count can be negative, which means the scan aborted
2144                  * due to the flush group being over-full and we should
2145                  * flush what we have.
2146                  */
2147                 go_count = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
2148                                    hammer_setup_child_callback, NULL);
2149         }
2150
2151         /*
2152          * This is a more involved test that includes go_count.  If we
2153          * can't flush, flag the inode and return.  If go_count is 0 we
2154          * were are unable to flush any records in our rec_tree and
2155          * must ignore the XDIRTY flag.
2156          */
2157         if (go_count == 0) {
2158                 if ((ip->flags & HAMMER_INODE_MODMASK_NOXDIRTY) == 0) {
2159                         --hmp->count_iqueued;
2160                         --hammer_count_iqueued;
2161
2162                         --flg->total_count;
2163                         ip->flush_state = HAMMER_FST_SETUP;
2164                         ip->flush_group = NULL;
2165                         if (flags & HAMMER_FLUSH_SIGNAL) {
2166                                 ip->flags |= HAMMER_INODE_REFLUSH |
2167                                              HAMMER_INODE_RESIGNAL;
2168                         } else {
2169                                 ip->flags |= HAMMER_INODE_REFLUSH;
2170                         }
2171 #if 0
2172                         if (ip->flags & HAMMER_INODE_VHELD) {
2173                                 ip->flags &= ~HAMMER_INODE_VHELD;
2174                                 vrele(ip->vp);
2175                         }
2176 #endif
2177
2178                         /*
2179                          * REFLUSH is needed to trigger dependancy wakeups
2180                          * when an inode is in SETUP.
2181                          */
2182                         ip->flags |= HAMMER_INODE_REFLUSH;
2183                         if (--hmp->flusher.group_lock == 0)
2184                                 wakeup(&hmp->flusher.group_lock);
2185                         return;
2186                 }
2187         }
2188
2189         /*
2190          * Snapshot the state of the inode for the backend flusher.
2191          *
2192          * We continue to retain save_trunc_off even when all truncations
2193          * have been resolved as an optimization to determine if we can
2194          * skip the B-Tree lookup for overwrite deletions.
2195          *
2196          * NOTE: The DELETING flag is a mod flag, but it is also sticky,
2197          * and stays in ip->flags.  Once set, it stays set until the
2198          * inode is destroyed.
2199          */
2200         if (ip->flags & HAMMER_INODE_TRUNCATED) {
2201                 KKASSERT((ip->sync_flags & HAMMER_INODE_TRUNCATED) == 0);
2202                 ip->sync_trunc_off = ip->trunc_off;
2203                 ip->trunc_off = 0x7FFFFFFFFFFFFFFFLL;
2204                 ip->flags &= ~HAMMER_INODE_TRUNCATED;
2205                 ip->sync_flags |= HAMMER_INODE_TRUNCATED;
2206
2207                 /*
2208                  * The save_trunc_off used to cache whether the B-Tree
2209                  * holds any records past that point is not used until
2210                  * after the truncation has succeeded, so we can safely
2211                  * set it now.
2212                  */
2213                 if (ip->save_trunc_off > ip->sync_trunc_off)
2214                         ip->save_trunc_off = ip->sync_trunc_off;
2215         }
2216         ip->sync_flags |= (ip->flags & HAMMER_INODE_MODMASK &
2217                            ~HAMMER_INODE_TRUNCATED);
2218         ip->sync_ino_leaf = ip->ino_leaf;
2219         ip->sync_ino_data = ip->ino_data;
2220         ip->flags &= ~HAMMER_INODE_MODMASK | HAMMER_INODE_TRUNCATED;
2221 #ifdef DEBUG_TRUNCATE
2222         if ((ip->sync_flags & HAMMER_INODE_TRUNCATED) && ip == HammerTruncIp)
2223                 kprintf("truncateS %016llx\n", ip->sync_trunc_off);
2224 #endif
2225
2226         /*
2227          * The flusher list inherits our inode and reference.
2228          */
2229         KKASSERT(flg->running == 0);
2230         RB_INSERT(hammer_fls_rb_tree, &flg->flush_tree, ip);
2231         if (--hmp->flusher.group_lock == 0)
2232                 wakeup(&hmp->flusher.group_lock);
2233
2234         /*
2235          * Auto-flush the group if it grows too large.  Make sure the
2236          * inode reclaim wait pipeline continues to work.
2237          */
2238         if (flg->total_count >= hammer_autoflush ||
2239             flg->total_count >= hammer_limit_reclaims / 4) {
2240                 if (hmp->fill_flush_group == flg)
2241                         hmp->fill_flush_group = TAILQ_NEXT(flg, flush_entry);
2242                 hammer_flusher_async(hmp, flg);
2243         }
2244 }
2245
2246 /*
2247  * Callback for scan of ip->rec_tree.  Try to include each record in our
2248  * flush.  ip->flush_group has been set but the inode has not yet been
2249  * moved into a flushing state.
2250  *
2251  * If we get stuck on a record we have to set HAMMER_INODE_REFLUSH on
2252  * both inodes.
2253  *
2254  * We return 1 for any record placed or found in FST_FLUSH, which prevents
2255  * the caller from shortcutting the flush.
2256  */
2257 static int
2258 hammer_setup_child_callback(hammer_record_t rec, void *data)
2259 {
2260         hammer_flush_group_t flg;
2261         hammer_inode_t target_ip;
2262         hammer_inode_t ip;
2263         int r;
2264
2265         /*
2266          * Records deleted or committed by the backend are ignored.
2267          * Note that the flush detects deleted frontend records at
2268          * multiple points to deal with races.  This is just the first
2269          * line of defense.  The only time HAMMER_RECF_DELETED_FE cannot
2270          * be set is when HAMMER_RECF_INTERLOCK_BE is set, because it
2271          * messes up link-count calculations.
2272          *
2273          * NOTE: Don't get confused between record deletion and, say,
2274          * directory entry deletion.  The deletion of a directory entry
2275          * which is on-media has nothing to do with the record deletion
2276          * flags.
2277          */
2278         if (rec->flags & (HAMMER_RECF_DELETED_FE | HAMMER_RECF_DELETED_BE |
2279                           HAMMER_RECF_COMMITTED)) {
2280                 if (rec->flush_state == HAMMER_FST_FLUSH) {
2281                         KKASSERT(rec->flush_group == rec->ip->flush_group);
2282                         r = 1;
2283                 } else {
2284                         r = 0;
2285                 }
2286                 return(r);
2287         }
2288
2289         /*
2290          * If the record is in an idle state it has no dependancies and
2291          * can be flushed.
2292          */
2293         ip = rec->ip;
2294         flg = ip->flush_group;
2295         r = 0;
2296
2297         switch(rec->flush_state) {
2298         case HAMMER_FST_IDLE:
2299                 /*
2300                  * The record has no setup dependancy, we can flush it.
2301                  */
2302                 KKASSERT(rec->target_ip == NULL);
2303                 rec->flush_state = HAMMER_FST_FLUSH;
2304                 rec->flush_group = flg;
2305                 ++flg->refs;
2306                 hammer_ref(&rec->lock);
2307                 r = 1;
2308                 break;
2309         case HAMMER_FST_SETUP:
2310                 /*
2311                  * The record has a setup dependancy.  These are typically
2312                  * directory entry adds and deletes.  Such entries will be
2313                  * flushed when their inodes are flushed so we do not
2314                  * usually have to add them to the flush here.  However,
2315                  * if the target_ip has set HAMMER_INODE_CONN_DOWN then
2316                  * it is asking us to flush this record (and it).
2317                  */
2318                 target_ip = rec->target_ip;
2319                 KKASSERT(target_ip != NULL);
2320                 KKASSERT(target_ip->flush_state != HAMMER_FST_IDLE);
2321
2322                 /*
2323                  * If the target IP is already flushing in our group
2324                  * we could associate the record, but target_ip has
2325                  * already synced ino_data to sync_ino_data and we
2326                  * would also have to adjust nlinks.   Plus there are
2327                  * ordering issues for adds and deletes.
2328                  *
2329                  * Reflush downward if this is an ADD, and upward if
2330                  * this is a DEL.
2331                  */
2332                 if (target_ip->flush_state == HAMMER_FST_FLUSH) {
2333                         if (rec->type == HAMMER_MEM_RECORD_ADD)
2334                                 ip->flags |= HAMMER_INODE_REFLUSH;
2335                         else
2336                                 target_ip->flags |= HAMMER_INODE_REFLUSH;
2337                         break;
2338                 }
2339
2340                 /*
2341                  * Target IP is not yet flushing.  This can get complex
2342                  * because we have to be careful about the recursion.
2343                  *
2344                  * Directories create an issue for us in that if a flush
2345                  * of a directory is requested the expectation is to flush
2346                  * any pending directory entries, but this will cause the
2347                  * related inodes to recursively flush as well.  We can't
2348                  * really defer the operation so just get as many as we
2349                  * can and
2350                  */
2351 #if 0
2352                 if ((target_ip->flags & HAMMER_INODE_RECLAIM) == 0 &&
2353                     (target_ip->flags & HAMMER_INODE_CONN_DOWN) == 0) {
2354                         /*
2355                          * We aren't reclaiming and the target ip was not
2356                          * previously prevented from flushing due to this
2357                          * record dependancy.  Do not flush this record.
2358                          */
2359                         /*r = 0;*/
2360                 } else
2361 #endif
2362                 if (flg->total_count + flg->refs >
2363                            ip->hmp->undo_rec_limit) {
2364                         /*
2365                          * Our flush group is over-full and we risk blowing
2366                          * out the UNDO FIFO.  Stop the scan, flush what we
2367                          * have, then reflush the directory.
2368                          *
2369                          * The directory may be forced through multiple
2370                          * flush groups before it can be completely
2371                          * flushed.
2372                          */
2373                         ip->flags |= HAMMER_INODE_RESIGNAL |
2374                                      HAMMER_INODE_REFLUSH;
2375                         r = -1;
2376                 } else if (rec->type == HAMMER_MEM_RECORD_ADD) {
2377                         /*
2378                          * If the target IP is not flushing we can force
2379                          * it to flush, even if it is unable to write out
2380                          * any of its own records we have at least one in
2381                          * hand that we CAN deal with.
2382                          */
2383                         rec->flush_state = HAMMER_FST_FLUSH;
2384                         rec->flush_group = flg;
2385                         ++flg->refs;
2386                         hammer_ref(&rec->lock);
2387                         hammer_flush_inode_core(target_ip, flg,
2388                                                 HAMMER_FLUSH_RECURSION);
2389                         r = 1;
2390                 } else {
2391                         /*
2392                          * General or delete-on-disk record.
2393                          *
2394                          * XXX this needs help.  If a delete-on-disk we could
2395                          * disconnect the target.  If the target has its own
2396                          * dependancies they really need to be flushed.
2397                          *
2398                          * XXX
2399                          */
2400                         rec->flush_state = HAMMER_FST_FLUSH;
2401                         rec->flush_group = flg;
2402                         ++flg->refs;
2403                         hammer_ref(&rec->lock);
2404                         hammer_flush_inode_core(target_ip, flg,
2405                                                 HAMMER_FLUSH_RECURSION);
2406                         r = 1;
2407                 }
2408                 break;
2409         case HAMMER_FST_FLUSH:
2410                 /*
2411                  * The record could be part of a previous flush group if the
2412                  * inode is a directory (the record being a directory entry).
2413                  * Once the flush group was closed a hammer_test_inode()
2414                  * function can cause a new flush group to be setup, placing
2415                  * the directory inode itself in a new flush group.
2416                  *
2417                  * When associated with a previous flush group we count it
2418                  * as if it were in our current flush group, since it will
2419                  * effectively be flushed by the time we flush our current
2420                  * flush group.
2421                  */
2422                 KKASSERT(
2423                     rec->ip->ino_data.obj_type == HAMMER_OBJTYPE_DIRECTORY ||
2424                     rec->flush_group == flg);
2425                 r = 1;
2426                 break;
2427         }
2428         return(r);
2429 }
2430
2431 #if 0
2432 /*
2433  * This version just moves records already in a flush state to the new
2434  * flush group and that is it.
2435  */
2436 static int
2437 hammer_syncgrp_child_callback(hammer_record_t rec, void *data)
2438 {
2439         hammer_inode_t ip = rec->ip;
2440
2441         switch(rec->flush_state) {
2442         case HAMMER_FST_FLUSH:
2443                 KKASSERT(rec->flush_group == ip->flush_group);
2444                 break;
2445         default:
2446                 break;
2447         }
2448         return(0);
2449 }
2450 #endif
2451
2452 /*
2453  * Wait for a previously queued flush to complete.
2454  *
2455  * If a critical error occured we don't try to wait.
2456  */
2457 void
2458 hammer_wait_inode(hammer_inode_t ip)
2459 {
2460         /*
2461          * The inode can be in a SETUP state in which case RESIGNAL
2462          * should be set.  If RESIGNAL is not set then the previous
2463          * flush completed and a later operation placed the inode
2464          * in a passive setup state again, so we're done.
2465          *
2466          * The inode can be in a FLUSH state in which case we
2467          * can just wait for completion.
2468          */
2469         while (ip->flush_state == HAMMER_FST_FLUSH ||
2470             (ip->flush_state == HAMMER_FST_SETUP &&
2471              (ip->flags & HAMMER_INODE_RESIGNAL))) {
2472                 /*
2473                  * Don't try to flush on a critical error
2474                  */
2475                 if (ip->hmp->flags & HAMMER_MOUNT_CRITICAL_ERROR)
2476                         break;
2477
2478                 /*
2479                  * If the inode was already being flushed its flg
2480                  * may not have been queued to the backend.  We
2481                  * have to make sure it gets queued or we can wind
2482                  * up blocked or deadlocked (particularly if we are
2483                  * the vnlru thread).
2484                  */
2485                 if (ip->flush_state == HAMMER_FST_FLUSH) {
2486                         KKASSERT(ip->flush_group);
2487                         if (ip->flush_group->closed == 0) {
2488                                 if (hammer_debug_inode) {
2489                                         kprintf("hammer: debug: forcing "
2490                                                 "async flush ip %016jx\n",
2491                                                 (intmax_t)ip->obj_id);
2492                                 }
2493                                 hammer_flusher_async(ip->hmp,
2494                                                      ip->flush_group);
2495                                 continue; /* retest */
2496                         }
2497                 }
2498
2499                 /*
2500                  * In a flush state with the flg queued to the backend
2501                  * or in a setup state with RESIGNAL set, we can safely
2502                  * wait.
2503                  */
2504                 ip->flags |= HAMMER_INODE_FLUSHW;
2505                 tsleep(&ip->flags, 0, "hmrwin", 0);
2506         }
2507
2508 #if 0
2509         /*
2510          * The inode may have been in a passive setup state,
2511          * call flush to make sure we get signaled.
2512          */
2513         if (ip->flush_state == HAMMER_FST_SETUP)
2514                 hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2515 #endif
2516
2517 }
2518
2519 /*
2520  * Called by the backend code when a flush has been completed.
2521  * The inode has already been removed from the flush list.
2522  *
2523  * A pipelined flush can occur, in which case we must re-enter the
2524  * inode on the list and re-copy its fields.
2525  */
2526 void
2527 hammer_flush_inode_done(hammer_inode_t ip, int error)
2528 {
2529         hammer_mount_t hmp;
2530         int dorel;
2531
2532         KKASSERT(ip->flush_state == HAMMER_FST_FLUSH);
2533
2534         hmp = ip->hmp;
2535
2536         /*
2537          * Auto-reflush if the backend could not completely flush
2538          * the inode.  This fixes a case where a deferred buffer flush
2539          * could cause fsync to return early.
2540          */
2541         if (ip->sync_flags & HAMMER_INODE_MODMASK)
2542                 ip->flags |= HAMMER_INODE_REFLUSH;
2543
2544         /*
2545          * Merge left-over flags back into the frontend and fix the state.
2546          * Incomplete truncations are retained by the backend.
2547          */
2548         ip->error = error;
2549         ip->flags |= ip->sync_flags & ~HAMMER_INODE_TRUNCATED;
2550         ip->sync_flags &= HAMMER_INODE_TRUNCATED;
2551
2552         /*
2553          * The backend may have adjusted nlinks, so if the adjusted nlinks
2554          * does not match the fronttend set the frontend's DDIRTY flag again.
2555          */
2556         if (ip->ino_data.nlinks != ip->sync_ino_data.nlinks)
2557                 ip->flags |= HAMMER_INODE_DDIRTY;
2558
2559         /*
2560          * Fix up the dirty buffer status.
2561          */
2562         if (ip->vp && RB_ROOT(&ip->vp->v_rbdirty_tree)) {
2563                 ip->flags |= HAMMER_INODE_BUFS;
2564         }
2565         hammer_redo_fifo_end_flush(ip);
2566
2567         /*
2568          * Re-set the XDIRTY flag if some of the inode's in-memory records
2569          * could not be flushed.
2570          */
2571         KKASSERT((RB_EMPTY(&ip->rec_tree) &&
2572                   (ip->flags & HAMMER_INODE_XDIRTY) == 0) ||
2573                  (!RB_EMPTY(&ip->rec_tree) &&
2574                   (ip->flags & HAMMER_INODE_XDIRTY) != 0));
2575
2576         /*
2577          * Do not lose track of inodes which no longer have vnode
2578          * assocations, otherwise they may never get flushed again.
2579          *
2580          * The reflush flag can be set superfluously, causing extra pain
2581          * for no reason.  If the inode is no longer modified it no longer
2582          * needs to be flushed.
2583          */
2584         if (ip->flags & HAMMER_INODE_MODMASK) {
2585                 if (ip->vp == NULL)
2586                         ip->flags |= HAMMER_INODE_REFLUSH;
2587         } else {
2588                 ip->flags &= ~HAMMER_INODE_REFLUSH;
2589         }
2590
2591         /*
2592          * The fs token is held but the inode lock is not held.  Because this
2593          * is a backend flush it is possible that the vnode has no references
2594          * and cause a reclaim race inside vsetisdirty() if/when it blocks.
2595          *
2596          * Therefore, we must lock the inode around this particular dirtying
2597          * operation.  We don't have to around other dirtying operations
2598          * where the vnode is implicitly or explicitly held.
2599          */
2600         if (ip->flags & HAMMER_INODE_MODMASK) {
2601                 hammer_lock_ex(&ip->lock);
2602                 hammer_inode_dirty(ip);
2603                 hammer_unlock(&ip->lock);
2604         }
2605
2606         /*
2607          * Adjust the flush state.
2608          */
2609         if (ip->flags & HAMMER_INODE_WOULDBLOCK) {
2610                 /*
2611                  * We were unable to flush out all our records, leave the
2612                  * inode in a flush state and in the current flush group.
2613                  * The flush group will be re-run.
2614                  *
2615                  * This occurs if the UNDO block gets too full or there is
2616                  * too much dirty meta-data and allows the flusher to
2617                  * finalize the UNDO block and then re-flush.
2618                  */
2619                 ip->flags &= ~HAMMER_INODE_WOULDBLOCK;
2620                 dorel = 0;
2621         } else {
2622                 /*
2623                  * Remove from the flush_group
2624                  */
2625                 RB_REMOVE(hammer_fls_rb_tree, &ip->flush_group->flush_tree, ip);
2626                 ip->flush_group = NULL;
2627
2628 #if 0
2629                 /*
2630                  * Clean up the vnode ref and tracking counts.
2631                  */
2632                 if (ip->flags & HAMMER_INODE_VHELD) {
2633                         ip->flags &= ~HAMMER_INODE_VHELD;
2634                         vrele(ip->vp);
2635                 }
2636 #endif
2637                 --hmp->count_iqueued;
2638                 --hammer_count_iqueued;
2639
2640                 /*
2641                  * And adjust the state.
2642                  */
2643                 if (TAILQ_EMPTY(&ip->target_list) && RB_EMPTY(&ip->rec_tree)) {
2644                         ip->flush_state = HAMMER_FST_IDLE;
2645                         dorel = 1;
2646                 } else {
2647                         ip->flush_state = HAMMER_FST_SETUP;
2648                         dorel = 0;
2649                 }
2650
2651                 /*
2652                  * If the frontend is waiting for a flush to complete,
2653                  * wake it up.
2654                  */
2655                 if (ip->flags & HAMMER_INODE_FLUSHW) {
2656                         ip->flags &= ~HAMMER_INODE_FLUSHW;
2657                         wakeup(&ip->flags);
2658                 }
2659
2660                 /*
2661                  * If the frontend made more changes and requested another
2662                  * flush, then try to get it running.
2663                  *
2664                  * Reflushes are aborted when the inode is errored out.
2665                  */
2666                 if (ip->flags & HAMMER_INODE_REFLUSH) {
2667                         ip->flags &= ~HAMMER_INODE_REFLUSH;
2668                         if (ip->flags & HAMMER_INODE_RESIGNAL) {
2669                                 ip->flags &= ~HAMMER_INODE_RESIGNAL;
2670                                 hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
2671                         } else {
2672                                 hammer_flush_inode(ip, 0);
2673                         }
2674                 }
2675         }
2676
2677         /*
2678          * If we have no parent dependancies we can clear CONN_DOWN
2679          */
2680         if (TAILQ_EMPTY(&ip->target_list))
2681                 ip->flags &= ~HAMMER_INODE_CONN_DOWN;
2682
2683         /*
2684          * If the inode is now clean drop the space reservation.
2685          */
2686         if ((ip->flags & HAMMER_INODE_MODMASK) == 0 &&
2687             (ip->flags & HAMMER_INODE_RSV_INODES)) {
2688                 ip->flags &= ~HAMMER_INODE_RSV_INODES;
2689                 --hmp->rsv_inodes;
2690         }
2691
2692         ip->flags &= ~HAMMER_INODE_SLAVEFLUSH;
2693
2694         if (dorel)
2695                 hammer_rel_inode(ip, 0);
2696 }
2697
2698 /*
2699  * Called from hammer_sync_inode() to synchronize in-memory records
2700  * to the media.
2701  */
2702 static int
2703 hammer_sync_record_callback(hammer_record_t record, void *data)
2704 {
2705         hammer_cursor_t cursor = data;
2706         hammer_transaction_t trans = cursor->trans;
2707         hammer_mount_t hmp = trans->hmp;
2708         int error;
2709
2710         /*
2711          * Skip records that do not belong to the current flush.
2712          */
2713         ++hammer_stats_record_iterations;
2714         if (record->flush_state != HAMMER_FST_FLUSH)
2715                 return(0);
2716
2717 #if 1
2718         if (record->flush_group != record->ip->flush_group) {
2719                 kprintf("sync_record %p ip %p bad flush group %p %p\n", record, record->ip, record->flush_group ,record->ip->flush_group);
2720                 if (hammer_debug_critical)
2721                         Debugger("blah2");
2722                 return(0);
2723         }
2724 #endif
2725         KKASSERT(record->flush_group == record->ip->flush_group);
2726
2727         /*
2728          * Interlock the record using the BE flag.  Once BE is set the
2729          * frontend cannot change the state of FE.
2730          *
2731          * NOTE: If FE is set prior to us setting BE we still sync the
2732          * record out, but the flush completion code converts it to
2733          * a delete-on-disk record instead of destroying it.
2734          */
2735         KKASSERT((record->flags & HAMMER_RECF_INTERLOCK_BE) == 0);
2736         record->flags |= HAMMER_RECF_INTERLOCK_BE;
2737
2738         /*
2739          * The backend has already disposed of the record.
2740          */
2741         if (record->flags & (HAMMER_RECF_DELETED_BE | HAMMER_RECF_COMMITTED)) {
2742                 error = 0;
2743                 goto done;
2744         }
2745
2746         /*
2747          * If the whole inode is being deleted and all on-disk records will
2748          * be deleted very soon, we can't sync any new records to disk
2749          * because they will be deleted in the same transaction they were
2750          * created in (delete_tid == create_tid), which will assert.
2751          *
2752          * XXX There may be a case with RECORD_ADD with DELETED_FE set
2753          * that we currently panic on.
2754          */
2755         if (record->ip->sync_flags & HAMMER_INODE_DELETING) {
2756                 switch(record->type) {
2757                 case HAMMER_MEM_RECORD_DATA:
2758                         /*
2759                          * We don't have to do anything, if the record was
2760                          * committed the space will have been accounted for
2761                          * in the blockmap.
2762                          */
2763                         /* fall through */
2764                 case HAMMER_MEM_RECORD_GENERAL:
2765                         /*
2766                          * Set deleted-by-backend flag.  Do not set the
2767                          * backend committed flag, because we are throwing
2768                          * the record away.
2769                          */
2770                         record->flags |= HAMMER_RECF_DELETED_BE;
2771                         ++record->ip->rec_generation;
2772                         error = 0;
2773                         goto done;
2774                 case HAMMER_MEM_RECORD_ADD:
2775                         panic("hammer_sync_record_callback: illegal add "
2776                               "during inode deletion record %p", record);
2777                         break; /* NOT REACHED */
2778                 case HAMMER_MEM_RECORD_INODE:
2779                         panic("hammer_sync_record_callback: attempt to "
2780                               "sync inode record %p?", record);
2781                         break; /* NOT REACHED */
2782                 case HAMMER_MEM_RECORD_DEL:
2783                         /*
2784                          * Follow through and issue the on-disk deletion
2785                          */
2786                         break;
2787                 }
2788         }
2789
2790         /*
2791          * If DELETED_FE is set special handling is needed for directory
2792          * entries.  Dependant pieces related to the directory entry may
2793          * have already been synced to disk.  If this occurs we have to
2794          * sync the directory entry and then change the in-memory record
2795          * from an ADD to a DELETE to cover the fact that it's been
2796          * deleted by the frontend.
2797          *
2798          * A directory delete covering record (MEM_RECORD_DEL) can never
2799          * be deleted by the frontend.
2800          *
2801          * Any other record type (aka DATA) can be deleted by the frontend.
2802          * XXX At the moment the flusher must skip it because there may
2803          * be another data record in the flush group for the same block,
2804          * meaning that some frontend data changes can leak into the backend's
2805          * synchronization point.
2806          */
2807         if (record->flags & HAMMER_RECF_DELETED_FE) {
2808                 if (record->type == HAMMER_MEM_RECORD_ADD) {
2809                         /*
2810                          * Convert a front-end deleted directory-add to
2811                          * a directory-delete entry later.
2812                          */
2813                         record->flags |= HAMMER_RECF_CONVERT_DELETE;
2814                 } else {
2815                         /*
2816                          * Dispose of the record (race case).  Mark as
2817                          * deleted by backend (and not committed).
2818                          */
2819                         KKASSERT(record->type != HAMMER_MEM_RECORD_DEL);
2820                         record->flags |= HAMMER_RECF_DELETED_BE;
2821                         ++record->ip->rec_generation;
2822                         error = 0;
2823                         goto done;
2824                 }
2825         }
2826
2827         /*
2828          * Assign the create_tid for new records.  Deletions already
2829          * have the record's entire key properly set up.
2830          */
2831         if (record->type != HAMMER_MEM_RECORD_DEL) {
2832                 record->leaf.base.create_tid = trans->tid;
2833                 record->leaf.create_ts = trans->time32;
2834         }
2835
2836         /*
2837          * This actually moves the record to the on-media B-Tree.  We
2838          * must also generate REDO_TERM entries in the UNDO/REDO FIFO
2839          * indicating that the related REDO_WRITE(s) have been committed.
2840          *
2841          * During recovery any REDO_TERM's within the nominal recovery span
2842          * are ignored since the related meta-data is being undone, causing
2843          * any matching REDO_WRITEs to execute.  The REDO_TERMs outside
2844          * the nominal recovery span will match against REDO_WRITEs and
2845          * prevent them from being executed (because the meta-data has
2846          * already been synchronized).
2847          */
2848         if (record->flags & HAMMER_RECF_REDO) {
2849                 KKASSERT(record->type == HAMMER_MEM_RECORD_DATA);
2850                 hammer_generate_redo(trans, record->ip,
2851                                      record->leaf.base.key -
2852                                          record->leaf.data_len,
2853                                      HAMMER_REDO_TERM_WRITE,
2854                                      NULL,
2855                                      record->leaf.data_len);
2856         }
2857
2858         for (;;) {
2859                 error = hammer_ip_sync_record_cursor(cursor, record);
2860                 if (error != EDEADLK)
2861                         break;
2862                 hammer_done_cursor(cursor);
2863                 error = hammer_init_cursor(trans, cursor, &record->ip->cache[0],
2864                                            record->ip);
2865                 if (error)
2866                         break;
2867         }
2868         record->flags &= ~HAMMER_RECF_CONVERT_DELETE;
2869
2870         if (error)
2871                 error = -error;
2872 done:
2873         hammer_flush_record_done(record, error);
2874
2875         /*
2876          * Do partial finalization if we have built up too many dirty
2877          * buffers.  Otherwise a buffer cache deadlock can occur when
2878          * doing things like creating tens of thousands of tiny files.
2879          *
2880          * We must release our cursor lock to avoid a 3-way deadlock
2881          * due to the exclusive sync lock the finalizer must get.
2882          *
2883          * WARNING: See warnings in hammer_unlock_cursor() function.
2884          */
2885         if (hammer_flusher_meta_limit(hmp) ||
2886             vm_page_count_severe()) {
2887                 hammer_unlock_cursor(cursor);
2888                 hammer_flusher_finalize(trans, 0);
2889                 hammer_lock_cursor(cursor);
2890         }
2891         return(error);
2892 }
2893
2894 /*
2895  * Backend function called by the flusher to sync an inode to media.
2896  */
2897 int
2898 hammer_sync_inode(hammer_transaction_t trans, hammer_inode_t ip)
2899 {
2900         struct hammer_cursor cursor;
2901         hammer_node_t tmp_node;
2902         hammer_record_t depend;
2903         hammer_record_t next;
2904         int error, tmp_error;
2905         u_int64_t nlinks;
2906
2907         if ((ip->sync_flags & HAMMER_INODE_MODMASK) == 0)
2908                 return(0);
2909
2910         error = hammer_init_cursor(trans, &cursor, &ip->cache[1], ip);
2911         if (error)
2912                 goto done;
2913
2914         /*
2915          * Any directory records referencing this inode which are not in
2916          * our current flush group must adjust our nlink count for the
2917          * purposes of synchronizating to disk.
2918          *
2919          * Records which are in our flush group can be unlinked from our
2920          * inode now, potentially allowing the inode to be physically
2921          * deleted.
2922          *
2923          * This cannot block.
2924          */
2925         nlinks = ip->ino_data.nlinks;
2926         next = TAILQ_FIRST(&ip->target_list);
2927         while ((depend = next) != NULL) {
2928                 next = TAILQ_NEXT(depend, target_entry);
2929                 if (depend->flush_state == HAMMER_FST_FLUSH &&
2930                     depend->flush_group == ip->flush_group) {
2931                         /*
2932                          * If this is an ADD that was deleted by the frontend
2933                          * the frontend nlinks count will have already been
2934                          * decremented, but the backend is going to sync its
2935                          * directory entry and must account for it.  The
2936                          * record will be converted to a delete-on-disk when
2937                          * it gets synced.
2938                          *
2939                          * If the ADD was not deleted by the frontend we
2940                          * can remove the dependancy from our target_list.
2941                          */
2942                         if (depend->flags & HAMMER_RECF_DELETED_FE) {
2943                                 ++nlinks;
2944                         } else {
2945                                 TAILQ_REMOVE(&ip->target_list, depend,
2946                                              target_entry);
2947                                 depend->target_ip = NULL;
2948                         }
2949                 } else if ((depend->flags & HAMMER_RECF_DELETED_FE) == 0) {
2950                         /*
2951                          * Not part of our flush group and not deleted by
2952                          * the front-end, adjust the link count synced to
2953                          * the media (undo what the frontend did when it
2954                          * queued the record).
2955                          */
2956                         KKASSERT((depend->flags & HAMMER_RECF_DELETED_BE) == 0);
2957                         switch(depend->type) {
2958                         case HAMMER_MEM_RECORD_ADD:
2959                                 --nlinks;
2960                                 break;
2961                         case HAMMER_MEM_RECORD_DEL:
2962                                 ++nlinks;
2963                                 break;
2964                         default:
2965                                 break;
2966                         }
2967                 }
2968         }
2969
2970         /*
2971          * Set dirty if we had to modify the link count.
2972          */
2973         if (ip->sync_ino_data.nlinks != nlinks) {
2974                 KKASSERT((int64_t)nlinks >= 0);
2975                 ip->sync_ino_data.nlinks = nlinks;
2976                 ip->sync_flags |= HAMMER_INODE_DDIRTY;
2977         }
2978
2979         /*
2980          * If there is a trunction queued destroy any data past the (aligned)
2981          * truncation point.  Userland will have dealt with the buffer
2982          * containing the truncation point for us.
2983          *
2984          * We don't flush pending frontend data buffers until after we've
2985          * dealt with the truncation.
2986          */
2987         if (ip->sync_flags & HAMMER_INODE_TRUNCATED) {
2988                 /*
2989                  * Interlock trunc_off.  The VOP front-end may continue to
2990                  * make adjustments to it while we are blocked.
2991                  */
2992                 off_t trunc_off;
2993                 off_t aligned_trunc_off;
2994                 int blkmask;
2995
2996                 trunc_off = ip->sync_trunc_off;
2997                 blkmask = hammer_blocksize(trunc_off) - 1;
2998                 aligned_trunc_off = (trunc_off + blkmask) & ~(int64_t)blkmask;
2999
3000                 /*
3001                  * Delete any whole blocks on-media.  The front-end has
3002                  * already cleaned out any partial block and made it
3003                  * pending.  The front-end may have updated trunc_off
3004                  * while we were blocked so we only use sync_trunc_off.
3005                  *
3006                  * This operation can blow out the buffer cache, EWOULDBLOCK
3007                  * means we were unable to complete the deletion.  The
3008                  * deletion will update sync_trunc_off in that case.
3009                  */
3010                 error = hammer_ip_delete_range(&cursor, ip,
3011                                                 aligned_trunc_off,
3012                                                 0x7FFFFFFFFFFFFFFFLL, 2);
3013                 if (error == EWOULDBLOCK) {
3014                         ip->flags |= HAMMER_INODE_WOULDBLOCK;
3015                         error = 0;
3016                         goto defer_buffer_flush;
3017                 }
3018
3019                 if (error)
3020                         goto done;
3021
3022                 /*
3023                  * Generate a REDO_TERM_TRUNC entry in the UNDO/REDO FIFO.
3024                  *
3025                  * XXX we do this even if we did not previously generate
3026                  * a REDO_TRUNC record.  This operation may enclosed the
3027                  * range for multiple prior truncation entries in the REDO
3028                  * log.
3029                  */
3030                 if (trans->hmp->version >= HAMMER_VOL_VERSION_FOUR &&
3031                     (ip->flags & HAMMER_INODE_RDIRTY)) {
3032                         hammer_generate_redo(trans, ip, aligned_trunc_off,
3033                                              HAMMER_REDO_TERM_TRUNC,
3034                                              NULL, 0);
3035                 }
3036
3037                 /*
3038                  * Clear the truncation flag on the backend after we have
3039                  * completed the deletions.  Backend data is now good again
3040                  * (including new records we are about to sync, below).
3041                  *
3042                  * Leave sync_trunc_off intact.  As we write additional
3043                  * records the backend will update sync_trunc_off.  This
3044                  * tells the backend whether it can skip the overwrite
3045                  * test.  This should work properly even when the backend
3046                  * writes full blocks where the truncation point straddles
3047                  * the block because the comparison is against the base
3048                  * offset of the record.
3049                  */
3050                 ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
3051                 /* ip->sync_trunc_off = 0x7FFFFFFFFFFFFFFFLL; */
3052         } else {
3053                 error = 0;
3054         }
3055
3056         /*
3057          * Now sync related records.  These will typically be directory
3058          * entries, records tracking direct-writes, or delete-on-disk records.
3059          */
3060         if (error == 0) {
3061                 tmp_error = RB_SCAN(hammer_rec_rb_tree, &ip->rec_tree, NULL,
3062                                     hammer_sync_record_callback, &cursor);
3063                 if (tmp_error < 0)
3064                         tmp_error = -error;
3065                 if (tmp_error)
3066                         error = tmp_error;
3067         }
3068         hammer_cache_node(&ip->cache[1], cursor.node);
3069
3070         /*
3071          * Re-seek for inode update, assuming our cache hasn't been ripped
3072          * out from under us.
3073          */
3074         if (error == 0) {
3075                 tmp_node = hammer_ref_node_safe(trans, &ip->cache[0], &error);
3076                 if (tmp_node) {
3077                         hammer_cursor_downgrade(&cursor);
3078                         hammer_lock_sh(&tmp_node->lock);
3079                         if ((tmp_node->flags & HAMMER_NODE_DELETED) == 0)
3080                                 hammer_cursor_seek(&cursor, tmp_node, 0);
3081                         hammer_unlock(&tmp_node->lock);
3082                         hammer_rel_node(tmp_node);
3083                 }
3084                 error = 0;
3085         }
3086
3087         /*
3088          * If we are deleting the inode the frontend had better not have
3089          * any active references on elements making up the inode.
3090          *
3091          * The call to hammer_ip_delete_clean() cleans up auxillary records
3092          * but not DB or DATA records.  Those must have already been deleted
3093          * by the normal truncation mechanic.
3094          */
3095         if (error == 0 && ip->sync_ino_data.nlinks == 0 &&
3096                 RB_EMPTY(&ip->rec_tree)  &&
3097             (ip->sync_flags & HAMMER_INODE_DELETING) &&
3098             (ip->flags & HAMMER_INODE_DELETED) == 0) {
3099                 int count1 = 0;
3100
3101                 error = hammer_ip_delete_clean(&cursor, ip, &count1);
3102                 if (error == 0) {
3103                         ip->flags |= HAMMER_INODE_DELETED;
3104                         ip->sync_flags &= ~HAMMER_INODE_DELETING;
3105                         ip->sync_flags &= ~HAMMER_INODE_TRUNCATED;
3106                         KKASSERT(RB_EMPTY(&ip->rec_tree));
3107
3108                         /*
3109                          * Set delete_tid in both the frontend and backend
3110                          * copy of the inode record.  The DELETED flag handles
3111                          * this, do not set DDIRTY.
3112                          */
3113                         ip->ino_leaf.base.delete_tid = trans->tid;
3114                         ip->sync_ino_leaf.base.delete_tid = trans->tid;
3115                         ip->ino_leaf.delete_ts = trans->time32;
3116                         ip->sync_ino_leaf.delete_ts = trans->time32;
3117
3118
3119                         /*
3120                          * Adjust the inode count in the volume header
3121                          */
3122                         hammer_sync_lock_sh(trans);
3123                         if (ip->flags & HAMMER_INODE_ONDISK) {
3124                                 hammer_modify_volume_field(trans,
3125                                                            trans->rootvol,
3126                                                            vol0_stat_inodes);
3127                                 --ip->hmp->rootvol->ondisk->vol0_stat_inodes;
3128                                 hammer_modify_volume_done(trans->rootvol);
3129                         }
3130                         hammer_sync_unlock(trans);
3131                 }
3132         }
3133
3134         if (error)
3135                 goto done;
3136         ip->sync_flags &= ~HAMMER_INODE_BUFS;
3137
3138 defer_buffer_flush:
3139         /*
3140          * Now update the inode's on-disk inode-data and/or on-disk record.
3141          * DELETED and ONDISK are managed only in ip->flags.
3142          *
3143          * In the case of a defered buffer flush we still update the on-disk
3144          * inode to satisfy visibility requirements if there happen to be
3145          * directory dependancies.
3146          */
3147         switch(ip->flags & (HAMMER_INODE_DELETED | HAMMER_INODE_ONDISK)) {
3148         case HAMMER_INODE_DELETED|HAMMER_INODE_ONDISK:
3149                 /*
3150                  * If deleted and on-disk, don't set any additional flags.
3151                  * the delete flag takes care of things.
3152                  *
3153                  * Clear flags which may have been set by the frontend.
3154                  */
3155                 ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
3156                                     HAMMER_INODE_SDIRTY |
3157                                     HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
3158                                     HAMMER_INODE_DELETING);
3159                 break;
3160         case HAMMER_INODE_DELETED:
3161                 /*
3162                  * Take care of the case where a deleted inode was never
3163                  * flushed to the disk in the first place.
3164                  *
3165                  * Clear flags which may have been set by the frontend.
3166                  */
3167                 ip->sync_flags &= ~(HAMMER_INODE_DDIRTY | HAMMER_INODE_XDIRTY |
3168                                     HAMMER_INODE_SDIRTY |
3169                                     HAMMER_INODE_ATIME | HAMMER_INODE_MTIME |
3170                                     HAMMER_INODE_DELETING);
3171                 while (RB_ROOT(&ip->rec_tree)) {
3172                         hammer_record_t record = RB_ROOT(&ip->rec_tree);
3173                         hammer_ref(&record->lock);
3174                         KKASSERT(hammer_oneref(&record->lock));
3175                         record->flags |= HAMMER_RECF_DELETED_BE;
3176                         ++record->ip->rec_generation;
3177                         hammer_rel_mem_record(record);
3178                 }
3179                 break;
3180         case HAMMER_INODE_ONDISK:
3181                 /*
3182                  * If already on-disk, do not set any additional flags.
3183                  */
3184                 break;
3185         default:
3186                 /*
3187                  * If not on-disk and not deleted, set DDIRTY to force
3188                  * an initial record to be written.
3189                  *
3190                  * Also set the create_tid in both the frontend and backend
3191                  * copy of the inode record.
3192                  */
3193                 ip->ino_leaf.base.create_tid = trans->tid;
3194                 ip->ino_leaf.create_ts = trans->time32;
3195                 ip->sync_ino_leaf.base.create_tid = trans->tid;
3196                 ip->sync_ino_leaf.create_ts = trans->time32;
3197                 ip->sync_flags |= HAMMER_INODE_DDIRTY;
3198                 break;
3199         }
3200
3201         /*
3202          * If DDIRTY or SDIRTY is set, write out a new record.
3203          * If the inode is already on-disk the old record is marked as
3204          * deleted.
3205          *
3206          * If DELETED is set hammer_update_inode() will delete the existing
3207          * record without writing out a new one.
3208          *
3209          * If *ONLY* the ITIMES flag is set we can update the record in-place.
3210          */
3211         if (ip->flags & HAMMER_INODE_DELETED) {
3212                 error = hammer_update_inode(&cursor, ip);
3213         } else
3214         if (!(ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY)) &&
3215             (ip->sync_flags & (HAMMER_INODE_ATIME | HAMMER_INODE_MTIME))) {
3216                 error = hammer_update_itimes(&cursor, ip);
3217         } else
3218         if (ip->sync_flags & (HAMMER_INODE_DDIRTY | HAMMER_INODE_SDIRTY |
3219                               HAMMER_INODE_ATIME | HAMMER_INODE_MTIME)) {
3220                 error = hammer_update_inode(&cursor, ip);
3221         }
3222 done:
3223         if (ip->flags & HAMMER_INODE_MODMASK)
3224                 hammer_inode_dirty(ip);
3225         if (error) {
3226                 hammer_critical_error(ip->hmp, ip, error,
3227                                       "while syncing inode");
3228         }
3229         hammer_done_cursor(&cursor);
3230         return(error);
3231 }
3232
3233 /*
3234  * This routine is called when the OS is no longer actively referencing
3235  * the inode (but might still be keeping it cached), or when releasing
3236  * the last reference to an inode.
3237  *
3238  * At this point if the inode's nlinks count is zero we want to destroy
3239  * it, which may mean destroying it on-media too.
3240  */
3241 void
3242 hammer_inode_unloadable_check(hammer_inode_t ip, int getvp)
3243 {
3244         struct vnode *vp;
3245
3246         /*
3247          * Set the DELETING flag when the link count drops to 0 and the
3248          * OS no longer has any opens on the inode.
3249          *
3250          * The backend will clear DELETING (a mod flag) and set DELETED
3251          * (a state flag) when it is actually able to perform the
3252          * operation.
3253          *
3254          * Don't reflag the deletion if the flusher is currently syncing
3255          * one that was already flagged.  A previously set DELETING flag
3256          * may bounce around flags and sync_flags until the operation is
3257          * completely done.
3258          *
3259          * Do not attempt to modify a snapshot inode (one set to read-only).
3260          */
3261         if (ip->ino_data.nlinks == 0 &&
3262             ((ip->flags | ip->sync_flags) & (HAMMER_INODE_RO|HAMMER_INODE_DELETING|HAMMER_INODE_DELETED)) == 0) {
3263                 ip->flags |= HAMMER_INODE_DELETING;
3264                 ip->flags |= HAMMER_INODE_TRUNCATED;
3265                 ip->trunc_off = 0;
3266                 vp = NULL;
3267                 if (getvp) {
3268                         if (hammer_get_vnode(ip, &vp) != 0)
3269                                 return;
3270                 }
3271
3272                 /*
3273                  * Final cleanup
3274                  */
3275                 if (ip->vp)
3276                         nvtruncbuf(ip->vp, 0, HAMMER_BUFSIZE, 0, 0);
3277                 if (ip->flags & HAMMER_INODE_MODMASK)
3278                         hammer_inode_dirty(ip);
3279                 if (getvp)
3280                         vput(vp);
3281         }
3282 }
3283
3284 /*
3285  * After potentially resolving a dependancy the inode is tested
3286  * to determine whether it needs to be reflushed.
3287  */
3288 void
3289 hammer_test_inode(hammer_inode_t ip)
3290 {
3291         if (ip->flags & HAMMER_INODE_REFLUSH) {
3292                 ip->flags &= ~HAMMER_INODE_REFLUSH;
3293                 hammer_ref(&ip->lock);
3294                 if (ip->flags & HAMMER_INODE_RESIGNAL) {
3295                         ip->flags &= ~HAMMER_INODE_RESIGNAL;
3296                         hammer_flush_inode(ip, HAMMER_FLUSH_SIGNAL);
3297                 } else {
3298                         hammer_flush_inode(ip, 0);
3299                 }
3300                 hammer_rel_inode(ip, 0);
3301         }
3302 }
3303
3304 /*
3305  * Clear the RECLAIM flag on an inode.  This occurs when the inode is
3306  * reassociated with a vp or just before it gets freed.
3307  *
3308  * Pipeline wakeups to threads blocked due to an excessive number of
3309  * detached inodes.  This typically occurs when atime updates accumulate
3310  * while scanning a directory tree.
3311  */
3312 static void
3313 hammer_inode_wakereclaims(hammer_inode_t ip)
3314 {
3315         struct hammer_reclaim *reclaim;
3316         hammer_mount_t hmp = ip->hmp;
3317
3318         if ((ip->flags & HAMMER_INODE_RECLAIM) == 0)
3319                 return;
3320
3321         --hammer_count_reclaims;
3322         --hmp->count_reclaims;
3323         ip->flags &= ~HAMMER_INODE_RECLAIM;
3324
3325         if ((reclaim = TAILQ_FIRST(&hmp->reclaim_list)) != NULL) {
3326                 KKASSERT(reclaim->count > 0);
3327                 if (--reclaim->count == 0) {
3328                         TAILQ_REMOVE(&hmp->reclaim_list, reclaim, entry);
3329                         wakeup(reclaim);
3330                 }
3331         }
3332 }
3333
3334 /*
3335  * Setup our reclaim pipeline.  We only let so many detached (and dirty)
3336  * inodes build up before we start blocking.  This routine is called
3337  * if a new inode is created or an inode is loaded from media.
3338  *
3339  * When we block we don't care *which* inode has finished reclaiming,
3340  * as long as one does.
3341  *
3342  * The reclaim pipeline is primarily governed by the auto-flush which is
3343  * 1/4 hammer_limit_reclaims.  We don't want to block if the count is
3344  * less than 1/2 hammer_limit_reclaims.  From 1/2 to full count is
3345  * dynamically governed.
3346  */
3347 void
3348 hammer_inode_waitreclaims(hammer_transaction_t trans)
3349 {
3350         hammer_mount_t hmp = trans->hmp;
3351         struct hammer_reclaim reclaim;
3352         int lower_limit;
3353
3354         /*
3355          * Track inode load, delay if the number of reclaiming inodes is
3356          * between 2/4 and 4/4 hammer_limit_reclaims, depending.
3357          */
3358         if (curthread->td_proc) {
3359                 struct hammer_inostats *stats;
3360
3361                 stats = hammer_inode_inostats(hmp, curthread->td_proc->p_pid);
3362                 ++stats->count;
3363
3364                 if (stats->count > hammer_limit_reclaims / 2)
3365                         stats->count = hammer_limit_reclaims / 2;
3366                 lower_limit = hammer_limit_reclaims - stats->count;
3367                 if (hammer_debug_general & 0x10000) {
3368                         kprintf("pid %5d limit %d\n",
3369                                 (int)curthread->td_proc->p_pid, lower_limit);
3370                 }
3371         } else {
3372                 lower_limit = hammer_limit_reclaims * 3 / 4;
3373         }
3374         if (hmp->count_reclaims >= lower_limit) {
3375                 reclaim.count = 1;
3376                 TAILQ_INSERT_TAIL(&hmp->reclaim_list, &reclaim, entry);
3377                 tsleep(&reclaim, 0, "hmrrcm", hz);
3378                 if (reclaim.count > 0)
3379                         TAILQ_REMOVE(&hmp->reclaim_list, &reclaim, entry);
3380         }
3381 }
3382
3383 /*
3384  * Keep track of reclaim statistics on a per-pid basis using a loose
3385  * 4-way set associative hash table.  Collisions inherit the count of
3386  * the previous entry.
3387  *
3388  * NOTE: We want to be careful here to limit the chain size.  If the chain
3389  *       size is too large a pid will spread its stats out over too many
3390  *       entries under certain types of heavy filesystem activity and
3391  *       wind up not delaying long enough.
3392  */
3393 static
3394 struct hammer_inostats *
3395 hammer_inode_inostats(hammer_mount_t hmp, pid_t pid)
3396 {
3397         struct hammer_inostats *stats;
3398         int delta;
3399         int chain;
3400         static volatile int iterator;   /* we don't care about MP races */
3401
3402         /*
3403          * Chain up to 4 times to find our entry.
3404          */
3405         for (chain = 0; chain < 4; ++chain) {
3406                 stats = &hmp->inostats[(pid + chain) & HAMMER_INOSTATS_HMASK];
3407                 if (stats->pid == pid)
3408                         break;
3409         }
3410
3411         /*
3412          * Replace one of the four chaining entries with our new entry.
3413          */
3414         if (chain == 4) {
3415                 stats = &hmp->inostats[(pid + (iterator++ & 3)) &
3416                                        HAMMER_INOSTATS_HMASK];
3417                 stats->pid = pid;
3418         }
3419
3420         /*
3421          * Decay the entry
3422          */
3423         if (stats->count && stats->ltick != ticks) {
3424                 delta = ticks - stats->ltick;
3425                 stats->ltick = ticks;
3426                 if (delta <= 0 || delta > hz * 60)
3427                         stats->count = 0;
3428                 else
3429                         stats->count = stats->count * hz / (hz + delta);
3430         }
3431         if (hammer_debug_general & 0x10000)
3432                 kprintf("pid %5d stats %d\n", (int)pid, stats->count);
3433         return (stats);
3434 }
3435
3436 #if 0
3437
3438 /*
3439  * XXX not used, doesn't work very well due to the large batching nature
3440  * of flushes.
3441  *
3442  * A larger then normal backlog of inodes is sitting in the flusher,
3443  * enforce a general slowdown to let it catch up.  This routine is only
3444  * called on completion of a non-flusher-related transaction which
3445  * performed B-Tree node I/O.
3446  *
3447  * It is possible for the flusher to stall in a continuous load.
3448  * blogbench -i1000 -o seems to do a good job generating this sort of load.
3449  * If the flusher is unable to catch up the inode count can bloat until
3450  * we run out of kvm.
3451  *
3452  * This is a bit of a hack.
3453  */
3454 void
3455 hammer_inode_waithard(hammer_mount_t hmp)
3456 {
3457         /*
3458          * Hysteresis.
3459          */
3460         if (hmp->flags & HAMMER_MOUNT_FLUSH_RECOVERY) {
3461                 if (hmp->count_reclaims < hammer_limit_reclaims / 2 &&
3462                     hmp->count_iqueued < hmp->count_inodes / 20) {
3463                         hmp->flags &= ~HAMMER_MOUNT_FLUSH_RECOVERY;
3464                         return;
3465                 }
3466         } else {
3467                 if (hmp->count_reclaims < hammer_limit_reclaims ||
3468                     hmp->count_iqueued < hmp->count_inodes / 10) {
3469                         return;
3470                 }
3471                 hmp->flags |= HAMMER_MOUNT_FLUSH_RECOVERY;
3472         }
3473
3474         /*
3475          * Block for one flush cycle.
3476          */
3477         hammer_flusher_wait_next(hmp);
3478 }
3479
3480 #endif