sys/vfs/hammer/hammer_object.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  * $DragonFly: src/sys/vfs/hammer/hammer_object.c,v 1.54 2008/05/04 19:57:42 dillon Exp $
  35  */
  36
  37 #include "hammer.h"
  38
  39 static int hammer_mem_add(hammer_transaction_t trans, hammer_record_t record);
  40 static int hammer_mem_lookup(hammer_cursor_t cursor, hammer_inode_t ip);
  41 static int hammer_mem_first(hammer_cursor_t cursor);
  42
  43 /*
  44  * Red-black tree support.
  45  */
  46 static int
  47 hammer_rec_rb_compare(hammer_record_t rec1, hammer_record_t rec2)
  48 {
  49         if (rec1->rec.base.base.rec_type < rec2->rec.base.base.rec_type)
  50                 return(-1);
  51         if (rec1->rec.base.base.rec_type > rec2->rec.base.base.rec_type)
  52                 return(1);
  53
  54         if (rec1->rec.base.base.key < rec2->rec.base.base.key)
  55                 return(-1);
  56         if (rec1->rec.base.base.key > rec2->rec.base.base.key)
  57                 return(1);
  58
  59         if (rec1->rec.base.base.create_tid == 0) {
  60                 if (rec2->rec.base.base.create_tid == 0)
  61                         return(0);
  62                 return(1);
  63         }
  64         if (rec2->rec.base.base.create_tid == 0)
  65                 return(-1);
  66
  67         if (rec1->rec.base.base.create_tid < rec2->rec.base.base.create_tid)
  68                 return(-1);
  69         if (rec1->rec.base.base.create_tid > rec2->rec.base.base.create_tid)
  70                 return(1);
  71
  72         /*
  73          * Never match against an item deleted by the front-end.
  74          */
  75         if (rec1->flags & HAMMER_RECF_DELETED_FE)
  76                 return(1);
  77         if (rec2->flags & HAMMER_RECF_DELETED_FE)
  78                 return(-1);
  79
  80         return(0);
  81 }
  82
  83 static int
  84 hammer_rec_compare(hammer_base_elm_t info, hammer_record_t rec)
  85 {
  86         if (info->rec_type < rec->rec.base.base.rec_type)
  87                 return(-3);
  88         if (info->rec_type > rec->rec.base.base.rec_type)
  89                 return(3);
  90
  91         if (info->key < rec->rec.base.base.key)
  92                 return(-2);
  93         if (info->key > rec->rec.base.base.key)
  94                 return(2);
  95
  96         if (info->create_tid == 0) {
  97                 if (rec->rec.base.base.create_tid == 0)
  98                         return(0);
  99                 return(1);
 100         }
 101         if (rec->rec.base.base.create_tid == 0)
 102                 return(-1);
 103         if (info->create_tid < rec->rec.base.base.create_tid)
 104                 return(-1);
 105         if (info->create_tid > rec->rec.base.base.create_tid)
 106                 return(1);
 107         return(0);
 108 }
 109
 110 /*
 111  * RB_SCAN comparison code for hammer_mem_first().  The argument order
 112  * is reversed so the comparison result has to be negated.  key_beg and
 113  * key_end are both range-inclusive.
 114  *
 115  * The creation timestamp can cause hammer_rec_compare() to return -1 or +1.
 116  * These do not stop the scan.
 117  *
 118  * Localized deletions are not cached in-memory.
 119  */
 120 static
 121 int
 122 hammer_rec_scan_cmp(hammer_record_t rec, void *data)
 123 {
 124         hammer_cursor_t cursor = data;
 125         int r;
 126
 127         r = hammer_rec_compare(&cursor->key_beg, rec);
 128         if (r > 1)
 129                 return(-1);
 130         r = hammer_rec_compare(&cursor->key_end, rec);
 131         if (r < -1)
 132                 return(1);
 133         return(0);
 134 }
 135
 136 /*
 137  * This compare function is used when simply looking up key_beg.
 138  */
 139 static
 140 int
 141 hammer_rec_find_cmp(hammer_record_t rec, void *data)
 142 {
 143         hammer_cursor_t cursor = data;
 144         int r;
 145
 146         r = hammer_rec_compare(&cursor->key_beg, rec);
 147         if (r > 1)
 148                 return(-1);
 149         if (r < -1)
 150                 return(1);
 151         return(0);
 152 }
 153
 154 RB_GENERATE(hammer_rec_rb_tree, hammer_record, rb_node, hammer_rec_rb_compare);
 155 RB_GENERATE_XLOOKUP(hammer_rec_rb_tree, INFO, hammer_record, rb_node,
 156                     hammer_rec_compare, hammer_base_elm_t);
 157
 158 /*
 159  * Allocate a record for the caller to finish filling in.  The record is
 160  * returned referenced.
 161  */
 162 hammer_record_t
 163 hammer_alloc_mem_record(hammer_inode_t ip)
 164 {
 165         hammer_record_t record;
 166
 167         ++hammer_count_records;
 168         record = kmalloc(sizeof(*record), M_HAMMER, M_WAITOK|M_ZERO);
 169         record->flush_state = HAMMER_FST_IDLE;
 170         record->ip = ip;
 171         record->rec.base.base.btype = HAMMER_BTREE_TYPE_RECORD;
 172         hammer_ref(&record->lock);
 173         return (record);
 174 }
 175
 176 void
 177 hammer_wait_mem_record(hammer_record_t record)
 178 {
 179         while (record->flush_state == HAMMER_FST_FLUSH) {
 180                 record->flags |= HAMMER_RECF_WANTED;
 181                 tsleep(record, 0, "hmrrc2", 0);
 182         }
 183 }
 184
 185 /*
 186  * Called from the backend, hammer_inode.c, after a record has been
 187  * flushed to disk.  The record has been exclusively locked by the
 188  * caller and interlocked with BE.
 189  *
 190  * We clean up the state, unlock, and release the record (the record
 191  * was referenced by the fact that it was in the HAMMER_FST_FLUSH state).
 192  */
 193 void
 194 hammer_flush_record_done(hammer_record_t record, int error)
 195 {
 196         hammer_inode_t target_ip;
 197
 198         KKASSERT(record->flush_state == HAMMER_FST_FLUSH);
 199         KKASSERT(record->flags & HAMMER_RECF_INTERLOCK_BE);
 200
 201         if (error) {
 202                 /*
 203                  * An error occured, the backend was unable to sync the
 204                  * record to its media.  Leave the record intact.
 205                  */
 206                 Debugger("flush_record_done error");
 207         }
 208
 209         if (record->flags & HAMMER_RECF_DELETED_BE) {
 210                 if ((target_ip = record->target_ip) != NULL) {
 211                         TAILQ_REMOVE(&target_ip->target_list, record,
 212                                      target_entry);
 213                         record->target_ip = NULL;
 214                         hammer_test_inode(target_ip);
 215                 }
 216                 record->flush_state = HAMMER_FST_IDLE;
 217         } else {
 218                 if (record->target_ip) {
 219                         record->flush_state = HAMMER_FST_SETUP;
 220                         hammer_test_inode(record->ip);
 221                         hammer_test_inode(record->target_ip);
 222                 } else {
 223                         record->flush_state = HAMMER_FST_IDLE;
 224                 }
 225         }
 226         record->flags &= ~HAMMER_RECF_INTERLOCK_BE;
 227         if (record->flags & HAMMER_RECF_WANTED) {
 228                 record->flags &= ~HAMMER_RECF_WANTED;
 229                 wakeup(record);
 230         }
 231         hammer_rel_mem_record(record);
 232 }
 233
 234 /*
 235  * Release a memory record.  Records marked for deletion are immediately
 236  * removed from the RB-Tree but otherwise left intact until the last ref
 237  * goes away.
 238  */
 239 void
 240 hammer_rel_mem_record(struct hammer_record *record)
 241 {
 242         hammer_inode_t ip, target_ip;
 243
 244         hammer_unref(&record->lock);
 245
 246         if (record->flags & HAMMER_RECF_DELETED_FE) {
 247                 if (record->lock.refs == 0) {
 248                         KKASSERT(record->flush_state != HAMMER_FST_FLUSH);
 249
 250                         ip = record->ip;
 251                         if ((target_ip = record->target_ip) != NULL) {
 252                                 TAILQ_REMOVE(&target_ip->target_list,
 253                                              record, target_entry);
 254                                 record->target_ip = NULL;
 255                                 hammer_test_inode(target_ip);
 256                         }
 257
 258                         if (record->flags & HAMMER_RECF_ONRBTREE) {
 259                                 RB_REMOVE(hammer_rec_rb_tree,
 260                                           &record->ip->rec_tree,
 261                                           record);
 262                                 record->flags &= ~HAMMER_RECF_ONRBTREE;
 263                                 if (RB_EMPTY(&record->ip->rec_tree)) {
 264                                         record->ip->flags &= ~HAMMER_INODE_XDIRTY;
 265                                         hammer_test_inode(record->ip);
 266                                 }
 267                         }
 268                         if (record->flags & HAMMER_RECF_ALLOCDATA) {
 269                                 --hammer_count_record_datas;
 270                                 kfree(record->data, M_HAMMER);
 271                                 record->flags &= ~HAMMER_RECF_ALLOCDATA;
 272                         }
 273                         record->data = NULL;
 274                         --hammer_count_records;
 275                         kfree(record, M_HAMMER);
 276                         return;
 277                 }
 278         }
 279 }
 280
 281 /*
 282  * Record visibility depends on whether the record is being accessed by
 283  * the backend or the frontend.
 284  *
 285  * Return non-zero if the record is visible, zero if it isn't or if it is
 286  * deleted.
 287  */
 288 static __inline
 289 int
 290 hammer_ip_iterate_mem_good(hammer_cursor_t cursor, hammer_record_t record)
 291 {
 292         if (cursor->flags & HAMMER_CURSOR_BACKEND) {
 293                 if (record->flags & HAMMER_RECF_DELETED_BE)
 294                         return(0);
 295 #if 0
 296                 if ((record->flags & HAMMER_RECF_INTERLOCK_BE) == 0)
 297                         return(0);
 298 #endif
 299         } else {
 300                 if (record->flags & HAMMER_RECF_DELETED_FE)
 301                         return(0);
 302         }
 303         return(1);
 304 }
 305
 306 /*
 307  * This callback is used as part of the RB_SCAN function for in-memory
 308  * records.  We terminate it (return -1) as soon as we get a match.
 309  *
 310  * This routine is used by frontend code.
 311  *
 312  * The primary compare code does not account for ASOF lookups.  This
 313  * code handles that case as well as a few others.
 314  */
 315 static
 316 int
 317 hammer_rec_scan_callback(hammer_record_t rec, void *data)
 318 {
 319         hammer_cursor_t cursor = data;
 320
 321         /*
 322          * We terminate on success, so this should be NULL on entry.
 323          */
 324         KKASSERT(cursor->iprec == NULL);
 325
 326         /*
 327          * Skip if the record was marked deleted.
 328          */
 329         if (hammer_ip_iterate_mem_good(cursor, rec) == 0)
 330                 return(0);
 331
 332         /*
 333          * Skip if not visible due to our as-of TID
 334          */
 335         if (cursor->flags & HAMMER_CURSOR_ASOF) {
 336                 if (cursor->asof < rec->rec.base.base.create_tid)
 337                         return(0);
 338                 if (rec->rec.base.base.delete_tid &&
 339                     cursor->asof >= rec->rec.base.base.delete_tid) {
 340                         return(0);
 341                 }
 342         }
 343
 344         /*
 345          * If the record is queued to the flusher we have to block until
 346          * it isn't.  Otherwise we may see duplication between our memory
 347          * cache and the media.
 348          */
 349         hammer_ref(&rec->lock);
 350
 351 #warning "This deadlocks"
 352 #if 0
 353         if (rec->flush_state == HAMMER_FST_FLUSH)
 354                 hammer_wait_mem_record(rec);
 355 #endif
 356
 357         /*
 358          * The record may have been deleted while we were blocked.
 359          */
 360         if (hammer_ip_iterate_mem_good(cursor, rec) == 0) {
 361                 hammer_rel_mem_record(rec);
 362                 return(0);
 363         }
 364
 365         /*
 366          * Set the matching record and stop the scan.
 367          */
 368         cursor->iprec = rec;
 369         return(-1);
 370 }
 371
 372
 373 /*
 374  * Lookup an in-memory record given the key specified in the cursor.  Works
 375  * just like hammer_btree_lookup() but operates on an inode's in-memory
 376  * record list.
 377  *
 378  * The lookup must fail if the record is marked for deferred deletion.
 379  */
 380 static
 381 int
 382 hammer_mem_lookup(hammer_cursor_t cursor, hammer_inode_t ip)
 383 {
 384         int error;
 385
 386         if (cursor->iprec) {
 387                 hammer_rel_mem_record(cursor->iprec);
 388                 cursor->iprec = NULL;
 389         }
 390         if (cursor->ip) {
 391                 KKASSERT(cursor->ip->cursor_ip_refs > 0);
 392                 --cursor->ip->cursor_ip_refs;
 393 #if 0
 394                 hammer_rec_rb_tree_scan_info_done(&cursor->scan,
 395                                                   &cursor->ip->rec_tree);
 396 #endif
 397         }
 398         cursor->ip = ip;
 399 #if 0
 400         hammer_rec_rb_tree_scan_info_link(&cursor->scan, &ip->rec_tree);
 401 #endif
 402         ++ip->cursor_ip_refs;
 403
 404 #if 0
 405         cursor->scan.node = NULL;
 406 #endif
 407         hammer_rec_rb_tree_RB_SCAN(&ip->rec_tree, hammer_rec_find_cmp,
 408                                    hammer_rec_scan_callback, cursor);
 409
 410         if (cursor->iprec == NULL)
 411                 error = ENOENT;
 412         else
 413                 error = 0;
 414         return(error);
 415 }
 416
 417 /*
 418  * hammer_mem_first() - locate the first in-memory record matching the
 419  * cursor within the bounds of the key range.
 420  */
 421 static
 422 int
 423 hammer_mem_first(hammer_cursor_t cursor)
 424 {
 425         hammer_inode_t ip;
 426
 427         ip = cursor->ip;
 428         KKASSERT(ip != NULL);
 429
 430         if (cursor->iprec) {
 431                 hammer_rel_mem_record(cursor->iprec);
 432                 cursor->iprec = NULL;
 433         }
 434
 435         hammer_rec_rb_tree_RB_SCAN(&ip->rec_tree, hammer_rec_scan_cmp,
 436                                    hammer_rec_scan_callback, cursor);
 437
 438         /*
 439          * Adjust scan.node and keep it linked into the RB-tree so we can
 440          * hold the cursor through third party modifications of the RB-tree.
 441          */
 442         if (cursor->iprec)
 443                 return(0);
 444         return(ENOENT);
 445 }
 446
 447 void
 448 hammer_mem_done(hammer_cursor_t cursor)
 449 {
 450         if (cursor->iprec) {
 451                 hammer_rel_mem_record(cursor->iprec);
 452                 cursor->iprec = NULL;
 453         }
 454 }
 455
 456 /************************************************************************
 457  *                   HAMMER IN-MEMORY RECORD FUNCTIONS                  *
 458  ************************************************************************
 459  *
 460  * These functions manipulate in-memory records.  Such records typically
 461  * exist prior to being committed to disk or indexed via the on-disk B-Tree.
 462  */
 463
 464 /*
 465  * Add a directory entry (dip,ncp) which references inode (ip).
 466  *
 467  * Note that the low 32 bits of the namekey are set temporarily to create
 468  * a unique in-memory record, and may be modified a second time when the
 469  * record is synchronized to disk.  In particular, the low 32 bits cannot be
 470  * all 0's when synching to disk, which is not handled here.
 471  */
 472 int
 473 hammer_ip_add_directory(struct hammer_transaction *trans,
 474                      struct hammer_inode *dip, struct namecache *ncp,
 475                      struct hammer_inode *ip)
 476 {
 477         hammer_record_t record;
 478         int error;
 479         int bytes;
 480
 481         record = hammer_alloc_mem_record(dip);
 482
 483         bytes = ncp->nc_nlen;   /* NOTE: terminating \0 is NOT included */
 484         if (++trans->hmp->namekey_iterator == 0)
 485                 ++trans->hmp->namekey_iterator;
 486
 487         record->type = HAMMER_MEM_RECORD_ADD;
 488         record->rec.entry.base.base.obj_id = dip->obj_id;
 489         record->rec.entry.base.base.key =
 490                 hammer_directory_namekey(ncp->nc_name, bytes);
 491         record->rec.entry.base.base.key += trans->hmp->namekey_iterator;
 492         record->rec.entry.base.base.rec_type = HAMMER_RECTYPE_DIRENTRY;
 493         record->rec.entry.base.base.obj_type = ip->ino_rec.base.base.obj_type;
 494         record->rec.entry.obj_id = ip->obj_id;
 495         record->data = (void *)ncp->nc_name;
 496         record->rec.entry.base.data_len = bytes;
 497         ++ip->ino_rec.ino_nlinks;
 498         hammer_modify_inode(trans, ip, HAMMER_INODE_RDIRTY);
 499
 500         /*
 501          * The target inode and the directory entry are bound together.
 502          */
 503         record->target_ip = ip;
 504         record->flush_state = HAMMER_FST_SETUP;
 505         TAILQ_INSERT_TAIL(&ip->target_list, record, target_entry);
 506
 507         /*
 508          * The inode now has a dependancy and must be taken out of the idle
 509          * state.  An inode not in an idle state is given an extra reference.
 510          */
 511         if (ip->flush_state == HAMMER_FST_IDLE) {
 512                 hammer_ref(&ip->lock);
 513                 ip->flush_state = HAMMER_FST_SETUP;
 514         }
 515
 516         /* NOTE: copies record->data */
 517         error = hammer_mem_add(trans, record);
 518         return(error);
 519 }
 520
 521 /*
 522  * Delete the directory entry and update the inode link count.  The
 523  * cursor must be seeked to the directory entry record being deleted.
 524  *
 525  * The related inode should be share-locked by the caller.  The caller is
 526  * on the frontend.
 527  *
 528  * This function can return EDEADLK requiring the caller to terminate
 529  * the cursor, any locks, wait on the returned record, and retry.
 530  */
 531 int
 532 hammer_ip_del_directory(struct hammer_transaction *trans,
 533                      hammer_cursor_t cursor, struct hammer_inode *dip,
 534                      struct hammer_inode *ip)
 535 {
 536         hammer_record_t record;
 537         int error;
 538
 539         if (cursor->record == &cursor->iprec->rec) {
 540                 /*
 541                  * In-memory (unsynchronized) records can simply be freed.
 542                  * Even though the HAMMER_RECF_DELETED_FE flag is ignored
 543                  * by the backend, we must still avoid races against the
 544                  * backend potentially syncing the record to the media.
 545                  *
 546                  * We cannot call hammer_ip_delete_record(), that routine may
 547                  * only be called from the backend.
 548                  */
 549                 record = cursor->iprec;
 550                 if (record->flags & HAMMER_RECF_INTERLOCK_BE) {
 551                         KKASSERT(cursor->deadlk_rec == NULL);
 552                         hammer_ref(&record->lock);
 553                         cursor->deadlk_rec = record;
 554                         error = EDEADLK;
 555                 } else {
 556                         KKASSERT(record->type == HAMMER_MEM_RECORD_ADD);
 557                         record->flags |= HAMMER_RECF_DELETED_FE;
 558                         error = 0;
 559                 }
 560         } else {
 561                 /*
 562                  * If the record is on-disk we have to queue the deletion by
 563                  * the record's key.  This also causes lookups to skip the
 564                  * record.
 565                  */
 566                 record = hammer_alloc_mem_record(dip);
 567                 record->type = HAMMER_MEM_RECORD_DEL;
 568                 record->rec.entry.base.base = cursor->record->base.base;
 569                 hammer_modify_inode(trans, ip, HAMMER_INODE_RDIRTY);
 570
 571                 record->target_ip = ip;
 572                 record->flush_state = HAMMER_FST_SETUP;
 573                 TAILQ_INSERT_TAIL(&ip->target_list, record, target_entry);
 574
 575                 /*
 576                  * The inode now has a dependancy and must be taken out of
 577                  * the idle state.  An inode not in an idle state is given
 578                  * an extra reference.
 579                  */
 580                 if (ip->flush_state == HAMMER_FST_IDLE) {
 581                         hammer_ref(&ip->lock);
 582                         ip->flush_state = HAMMER_FST_SETUP;
 583                 }
 584
 585                 error = hammer_mem_add(trans, record);
 586         }
 587
 588         /*
 589          * One less link.  The file may still be open in the OS even after
 590          * all links have gone away.
 591          *
 592          * We have to terminate the cursor before syncing the inode to
 593          * avoid deadlocking against ourselves.  XXX this may no longer
 594          * be true.
 595          *
 596          * If nlinks drops to zero and the vnode is inactive (or there is
 597          * no vnode), call hammer_inode_unloadable_check() to zonk the
 598          * inode.  If we don't do this here the inode will not be destroyed
 599          * on-media until we unmount.
 600          */
 601         if (error == 0) {
 602                 --ip->ino_rec.ino_nlinks;
 603                 hammer_modify_inode(trans, ip, HAMMER_INODE_RDIRTY);
 604                 if (ip->ino_rec.ino_nlinks == 0 &&
 605                     (ip->vp == NULL || (ip->vp->v_flag & VINACTIVE))) {
 606                         hammer_done_cursor(cursor);
 607                         hammer_inode_unloadable_check(ip, 1);
 608                         hammer_flush_inode(ip, 0);
 609                 }
 610
 611         }
 612         return(error);
 613 }
 614
 615 /*
 616  * Add a record to an inode.
 617  *
 618  * The caller must allocate the record with hammer_alloc_mem_record(ip) and
 619  * initialize the following additional fields:
 620  *
 621  * The related inode should be share-locked by the caller.  The caller is
 622  * on the frontend.
 623  *
 624  * record->rec.entry.base.base.key
 625  * record->rec.entry.base.base.rec_type
 626  * record->rec.entry.base.base.data_len
 627  * record->data         (a copy will be kmalloc'd if it cannot be embedded)
 628  */
 629 int
 630 hammer_ip_add_record(struct hammer_transaction *trans, hammer_record_t record)
 631 {
 632         hammer_inode_t ip = record->ip;
 633         int error;
 634
 635         record->rec.base.base.obj_id = ip->obj_id;
 636         record->rec.base.base.obj_type = ip->ino_rec.base.base.obj_type;
 637
 638         hammer_modify_inode(trans, ip, HAMMER_INODE_RDIRTY);
 639
 640         /* NOTE: copies record->data */
 641         error = hammer_mem_add(trans, record);
 642         return(error);
 643 }
 644
 645 /*
 646  * Sync data from a buffer cache buffer (typically) to the filesystem.  This
 647  * is called via the strategy called from a cached data source.  This code
 648  * is responsible for actually writing a data record out to the disk.
 649  *
 650  * This can only occur non-historically (i.e. 'current' data only).
 651  *
 652  * The file offset must be HAMMER_BUFSIZE aligned but the data length
 653  * can be truncated.  The record (currently) always represents a BUFSIZE
 654  * swath of space whether the data is truncated or not.
 655  */
 656 int
 657 hammer_ip_sync_data(hammer_cursor_t cursor, hammer_inode_t ip,
 658                        int64_t offset, void *data, int bytes)
 659 {
 660         hammer_transaction_t trans = cursor->trans;
 661         hammer_record_ondisk_t rec;
 662         union hammer_btree_elm elm;
 663         hammer_off_t rec_offset;
 664         void *bdata;
 665         int error;
 666
 667         KKASSERT((offset & HAMMER_BUFMASK) == 0);
 668         KKASSERT(trans->type == HAMMER_TRANS_FLS);
 669         KKASSERT(bytes != 0);
 670 retry:
 671         hammer_normalize_cursor(cursor);
 672         cursor->key_beg.obj_id = ip->obj_id;
 673         cursor->key_beg.key = offset + bytes;
 674         cursor->key_beg.create_tid = trans->tid;
 675         cursor->key_beg.delete_tid = 0;
 676         cursor->key_beg.rec_type = HAMMER_RECTYPE_DATA;
 677         cursor->asof = trans->tid;
 678         cursor->flags &= ~HAMMER_CURSOR_INITMASK;
 679         cursor->flags |= HAMMER_CURSOR_INSERT;
 680         cursor->flags |= HAMMER_CURSOR_BACKEND;
 681
 682         /*
 683          * Issue a lookup to position the cursor.
 684          */
 685         error = hammer_btree_lookup(cursor);
 686         if (error == 0) {
 687                 kprintf("hammer_ip_sync_data: duplicate data at "
 688                         "(%lld,%d) tid %016llx\n",
 689                         offset, bytes, trans->tid);
 690                 hammer_print_btree_elm(&cursor->node->ondisk->
 691                                         elms[cursor->index],
 692                                        HAMMER_BTREE_TYPE_LEAF, cursor->index);
 693                 panic("Duplicate data");
 694                 error = EIO;
 695         }
 696         if (error != ENOENT)
 697                 goto done;
 698
 699         /*
 700          * Allocate record and data space.  HAMMER_RECTYPE_DATA records
 701          * can cross buffer boundaries so we may have to split our bcopy.
 702          */
 703         rec = hammer_alloc_record(trans, &rec_offset, HAMMER_RECTYPE_DATA,
 704                                   &cursor->record_buffer,
 705                                   bytes, &bdata,
 706                                   &cursor->data_buffer, &error);
 707         if (rec == NULL)
 708                 goto done;
 709         if (hammer_debug_general & 0x1000)
 710                 kprintf("OOB RECOR2 DATA REC %016llx DATA %016llx LEN=%d\n", rec_offset, rec->base.data_off, rec->base.data_len);
 711
 712         /*
 713          * Fill everything in and insert our B-Tree node.
 714          *
 715          * NOTE: hammer_alloc_record() has already marked the related
 716          * buffers as modified.  If we do it again we will generate
 717          * unnecessary undo elements.
 718          */
 719         hammer_modify_buffer(trans, cursor->record_buffer, NULL, 0);
 720         rec->base.base.btype = HAMMER_BTREE_TYPE_RECORD;
 721         rec->base.base.obj_id = ip->obj_id;
 722         rec->base.base.key = offset + bytes;
 723         rec->base.base.create_tid = trans->tid;
 724         rec->base.base.delete_tid = 0;
 725         rec->base.base.rec_type = HAMMER_RECTYPE_DATA;
 726         rec->base.data_crc = crc32(data, bytes);
 727         hammer_modify_buffer_done(cursor->record_buffer);
 728         KKASSERT(rec->base.data_len == bytes);
 729
 730         hammer_modify_buffer(trans, cursor->data_buffer, NULL, 0);
 731         bcopy(data, bdata, bytes);
 732         hammer_modify_buffer_done(cursor->data_buffer);
 733
 734         elm.leaf.base = rec->base.base;
 735         elm.leaf.rec_offset = rec_offset;
 736         elm.leaf.data_offset = rec->base.data_off;
 737         elm.leaf.data_len = bytes;
 738         elm.leaf.data_crc = rec->base.data_crc;
 739
 740         /*
 741          * Data records can wind up on-disk before the inode itself is
 742          * on-disk.  One must assume data records may be on-disk if either
 743          * HAMMER_INODE_DONDISK or HAMMER_INODE_ONDISK is set
 744          */
 745         ip->flags |= HAMMER_INODE_DONDISK;
 746
 747         error = hammer_btree_insert(cursor, &elm);
 748         if (error == 0)
 749                 goto done;
 750
 751         hammer_blockmap_free(trans, rec_offset, HAMMER_RECORD_SIZE);
 752 done:
 753         if (error == EDEADLK) {
 754                 hammer_done_cursor(cursor);
 755                 error = hammer_init_cursor(trans, cursor, &ip->cache[0], ip);
 756                 if (error == 0)
 757                         goto retry;
 758         }
 759         return(error);
 760 }
 761
 762 #if 0
 763 /*
 764  * Sync an in-memory record to the disk.  This is called by the backend.
 765  * This code is responsible for actually writing a record out to the disk.
 766  *
 767  * This routine can only be called by the backend and the record
 768  * must have been interlocked with BE.  It will remain interlocked on
 769  * return.  If no error occurs the record will be marked deleted but
 770  * the caller is responsible for its final disposition.
 771  *
 772  * Multiple calls may be aggregated with the same cursor using
 773  * hammer_ip_sync_record_cursor().  The caller must handle EDEADLK
 774  * in that case.
 775  */
 776 int
 777 hammer_ip_sync_record(hammer_transaction_t trans, hammer_record_t record)
 778 {
 779         struct hammer_cursor cursor;
 780         int error;
 781
 782         do {
 783                 error = hammer_init_cursor(trans, &cursor,
 784                                            &record->ip->cache[0], record->ip);
 785                 if (error)
 786                         return(error);
 787                 error = hammer_ip_sync_record_cursor(&cursor, record);
 788                 hammer_done_cursor(&cursor);
 789         } while (error == EDEADLK);
 790         return (error);
 791 }
 792
 793 #endif
 794
 795 int
 796 hammer_ip_sync_record_cursor(hammer_cursor_t cursor, hammer_record_t record)
 797 {
 798         hammer_transaction_t trans = cursor->trans;
 799         hammer_record_ondisk_t rec;
 800         union hammer_btree_elm elm;
 801         hammer_off_t rec_offset;
 802         void *bdata;
 803         int error;
 804
 805         KKASSERT(record->flush_state == HAMMER_FST_FLUSH);
 806         KKASSERT(record->flags & HAMMER_RECF_INTERLOCK_BE);
 807
 808         hammer_normalize_cursor(cursor);
 809         cursor->key_beg = record->rec.base.base;
 810         cursor->flags &= ~HAMMER_CURSOR_INITMASK;
 811         cursor->flags |= HAMMER_CURSOR_BACKEND;
 812         cursor->flags &= ~HAMMER_CURSOR_INSERT;
 813
 814         /*
 815          * If we are deleting an exact match must be found on-disk.
 816          */
 817         if (record->type == HAMMER_MEM_RECORD_DEL) {
 818                 error = hammer_btree_lookup(cursor);
 819                 if (error == 0) {
 820                         error = hammer_ip_delete_record(cursor, trans->tid);
 821                         if (error == 0) {
 822                                 record->flags |= HAMMER_RECF_DELETED_FE;
 823                                 record->flags |= HAMMER_RECF_DELETED_BE;
 824                         }
 825                 }
 826                 goto done;
 827         }
 828
 829         /*
 830          * We are inserting.
 831          *
 832          * Issue a lookup to position the cursor and locate the cluster.  The
 833          * target key should not exist.  If we are creating a directory entry
 834          * we may have to iterate the low 32 bits of the key to find an unused
 835          * key.
 836          */
 837         cursor->flags |= HAMMER_CURSOR_INSERT;
 838
 839         for (;;) {
 840                 error = hammer_btree_lookup(cursor);
 841                 if (hammer_debug_inode)
 842                         kprintf("DOINSERT LOOKUP %d\n", error);
 843                 if (error)
 844                         break;
 845                 if (record->rec.base.base.rec_type != HAMMER_RECTYPE_DIRENTRY) {
 846                         kprintf("hammer_ip_sync_record: duplicate rec "
 847                                 "at (%016llx)\n", record->rec.base.base.key);
 848                         Debugger("duplicate record1");
 849                         error = EIO;
 850                         break;
 851                 }
 852                 if (++trans->hmp->namekey_iterator == 0)
 853                         ++trans->hmp->namekey_iterator;
 854                 record->rec.base.base.key &= ~(0xFFFFFFFFLL);
 855                 record->rec.base.base.key |= trans->hmp->namekey_iterator;
 856                 cursor->key_beg.key = record->rec.base.base.key;
 857         }
 858         if (error != ENOENT)
 859                 goto done;
 860
 861         /*
 862          * Allocate the record and data.  The result buffers will be
 863          * marked as being modified and further calls to
 864          * hammer_modify_buffer() will result in unneeded UNDO records.
 865          *
 866          * Support zero-fill records (data == NULL and data_len != 0)
 867          */
 868         if (record->data == NULL) {
 869                 rec = hammer_alloc_record(trans, &rec_offset,
 870                                           record->rec.base.base.rec_type,
 871                                           &cursor->record_buffer,
 872                                           0, &bdata,
 873                                           NULL, &error);
 874                 if (hammer_debug_general & 0x1000)
 875                         kprintf("NULL RECORD DATA\n");
 876         } else if (record->flags & HAMMER_RECF_INBAND) {
 877                 rec = hammer_alloc_record(trans, &rec_offset,
 878                                           record->rec.base.base.rec_type,
 879                                           &cursor->record_buffer,
 880                                           record->rec.base.data_len, &bdata,
 881                                           NULL, &error);
 882                 if (hammer_debug_general & 0x1000)
 883                         kprintf("INBAND RECORD DATA %016llx DATA %016llx LEN=%d\n", rec_offset, rec->base.data_off, record->rec.base.data_len);
 884         } else {
 885                 rec = hammer_alloc_record(trans, &rec_offset,
 886                                           record->rec.base.base.rec_type,
 887                                           &cursor->record_buffer,
 888                                           record->rec.base.data_len, &bdata,
 889                                           &cursor->data_buffer, &error);
 890                 if (hammer_debug_general & 0x1000)
 891                         kprintf("OOB RECORD DATA REC %016llx DATA %016llx LEN=%d\n", rec_offset, rec->base.data_off, record->rec.base.data_len);
 892         }
 893
 894         if (rec == NULL)
 895                 goto done;
 896
 897         /*
 898          * Fill in the remaining fields and insert our B-Tree node.
 899          */
 900         if (hammer_debug_inode)
 901                 kprintf("COPYREC %p\n", rec);
 902         hammer_modify_buffer(trans, cursor->record_buffer, NULL, 0);
 903         rec->base.base = record->rec.base.base;
 904         bcopy(&record->rec.base + 1, &rec->base + 1,
 905               HAMMER_RECORD_SIZE - sizeof(record->rec.base));
 906
 907         /*
 908          * Copy the data and deal with zero-fill support.
 909          */
 910         if (record->data && (record->flags & HAMMER_RECF_INBAND)) {
 911                 rec->base.data_crc = crc32(record->data, rec->base.data_len);
 912                 bcopy(record->data, bdata, rec->base.data_len);
 913         } else if (record->data) {
 914                 rec->base.data_crc = crc32(record->data, rec->base.data_len);
 915                 hammer_modify_buffer(trans, cursor->data_buffer, NULL, 0);
 916                 bcopy(record->data, bdata, rec->base.data_len);
 917                 hammer_modify_buffer_done(cursor->data_buffer);
 918         } else {
 919                 rec->base.data_len = record->rec.base.data_len;
 920         }
 921         hammer_modify_buffer_done(cursor->record_buffer);
 922
 923         elm.leaf.base = record->rec.base.base;
 924         elm.leaf.rec_offset = rec_offset;
 925         elm.leaf.data_offset = rec->base.data_off;
 926         elm.leaf.data_len = rec->base.data_len;
 927         elm.leaf.data_crc = rec->base.data_crc;
 928
 929         error = hammer_btree_insert(cursor, &elm);
 930         if (hammer_debug_inode)
 931                 kprintf("BTREE INSERT error %d @ %016llx:%d\n", error, cursor->node->node_offset, cursor->index);
 932
 933         /*
 934          * This occurs when the frontend creates a record and queues it to
 935          * the backend, then tries to delete the record.  The backend must
 936          * still sync the record to the media as if it were not deleted,
 937          * but must interlock with the frontend to ensure that the
 938          * synchronized record is not visible to the frontend, which means
 939          * converting it from an ADD record to a DEL record.
 940          *
 941          * The DEL record then masks the record synced to disk until another
 942          * round can delete it for real.
 943          */
 944         if (error == 0) {
 945                 if (record->flags & HAMMER_RECF_CONVERT_DELETE) {
 946                         KKASSERT(record->type == HAMMER_MEM_RECORD_ADD);
 947                         record->flags &= ~HAMMER_RECF_DELETED_FE;
 948                         record->type = HAMMER_MEM_RECORD_DEL;
 949                         KKASSERT(record->flush_state == HAMMER_FST_FLUSH);
 950                         record->flags &= ~HAMMER_RECF_CONVERT_DELETE;
 951                         /* hammer_flush_record_done takes care of the rest */
 952                 } else {
 953                         record->flags |= HAMMER_RECF_DELETED_FE;
 954                         record->flags |= HAMMER_RECF_DELETED_BE;
 955                 }
 956         } else {
 957                 hammer_blockmap_free(trans, rec_offset, HAMMER_RECORD_SIZE);
 958                 /* XXX free data buffer? */
 959         }
 960
 961 done:
 962         return(error);
 963 }
 964
 965 /*
 966  * Add the record to the inode's rec_tree.  The low 32 bits of a directory
 967  * entry's key is used to deal with hash collisions in the upper 32 bits.
 968  * A unique 64 bit key is generated in-memory and may be regenerated a
 969  * second time when the directory record is flushed to the on-disk B-Tree.
 970  *
 971  * A referenced record is passed to this function.  This function
 972  * eats the reference.  If an error occurs the record will be deleted.
 973  *
 974  * A copy of the temporary record->data pointer provided by the caller
 975  * will be made.
 976  */
 977 static
 978 int
 979 hammer_mem_add(struct hammer_transaction *trans, hammer_record_t record)
 980 {
 981         void *data;
 982         int bytes;
 983         int reclen;
 984
 985         /*
 986          * Make a private copy of record->data
 987          */
 988         if (record->data) {
 989                 /*
 990                  * Try to embed the data in extra space in the record
 991                  * union, otherwise allocate a copy.
 992                  */
 993                 bytes = record->rec.base.data_len;
 994                 switch(record->rec.base.base.rec_type) {
 995                 case HAMMER_RECTYPE_DIRENTRY:
 996                         reclen = offsetof(struct hammer_entry_record, name[0]);
 997                         break;
 998                 case HAMMER_RECTYPE_DATA:
 999                         reclen = offsetof(struct hammer_data_record, data[0]);
1000                         break;
1001                 default:
1002                         reclen = sizeof(record->rec);
1003                         break;
1004                 }
1005                 if (reclen + bytes <= HAMMER_RECORD_SIZE) {
1006                         bcopy(record->data, (char *)&record->rec + reclen,
1007                               bytes);
1008                         record->data = (void *)((char *)&record->rec + reclen);
1009                         record->flags |= HAMMER_RECF_INBAND;
1010                 } else {
1011                         ++hammer_count_record_datas;
1012                         data = kmalloc(bytes, M_HAMMER, M_WAITOK);
1013                         record->flags |= HAMMER_RECF_ALLOCDATA;
1014                         bcopy(record->data, data, bytes);
1015                         record->data = data;
1016                 }
1017         }
1018
1019         /*
1020          * Insert into the RB tree, find an unused iterator if this is
1021          * a directory entry.
1022          */
1023         while (RB_INSERT(hammer_rec_rb_tree, &record->ip->rec_tree, record)) {
1024                 if (record->rec.base.base.rec_type != HAMMER_RECTYPE_DIRENTRY){
1025                         record->flags |= HAMMER_RECF_DELETED_FE;
1026                         hammer_rel_mem_record(record);
1027                         return (EEXIST);
1028                 }
1029                 if (++trans->hmp->namekey_iterator == 0)
1030                         ++trans->hmp->namekey_iterator;
1031                 record->rec.base.base.key &= ~(0xFFFFFFFFLL);
1032                 record->rec.base.base.key |= trans->hmp->namekey_iterator;
1033         }
1034         record->flags |= HAMMER_RECF_ONRBTREE;
1035         hammer_modify_inode(trans, record->ip, HAMMER_INODE_XDIRTY);
1036         hammer_rel_mem_record(record);
1037         return(0);
1038 }
1039
1040 /************************************************************************
1041  *                   HAMMER INODE MERGED-RECORD FUNCTIONS               *
1042  ************************************************************************
1043  *
1044  * These functions augment the B-Tree scanning functions in hammer_btree.c
1045  * by merging in-memory records with on-disk records.
1046  */
1047
1048 /*
1049  * Locate a particular record either in-memory or on-disk.
1050  *
1051  * NOTE: This is basically a standalone routine, hammer_ip_next() may
1052  * NOT be called to iterate results.
1053  */
1054 int
1055 hammer_ip_lookup(hammer_cursor_t cursor, struct hammer_inode *ip)
1056 {
1057         int error;
1058
1059         /*
1060          * If the element is in-memory return it without searching the
1061          * on-disk B-Tree
1062          */
1063         error = hammer_mem_lookup(cursor, ip);
1064         if (error == 0) {
1065                 cursor->record = &cursor->iprec->rec;
1066                 return(error);
1067         }
1068         if (error != ENOENT)
1069                 return(error);
1070
1071         /*
1072          * If the inode has on-disk components search the on-disk B-Tree.
1073          */
1074         if ((ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DONDISK)) == 0)
1075                 return(error);
1076         error = hammer_btree_lookup(cursor);
1077         if (error == 0)
1078                 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_RECORD);
1079         return(error);
1080 }
1081
1082 /*
1083  * Locate the first record within the cursor's key_beg/key_end range,
1084  * restricted to a particular inode.  0 is returned on success, ENOENT
1085  * if no records matched the requested range, or some other error.
1086  *
1087  * When 0 is returned hammer_ip_next() may be used to iterate additional
1088  * records within the requested range.
1089  *
1090  * This function can return EDEADLK, requiring the caller to terminate
1091  * the cursor and try again.
1092  */
1093 int
1094 hammer_ip_first(hammer_cursor_t cursor)
1095 {
1096         hammer_inode_t ip = cursor->ip;
1097         int error;
1098
1099         KKASSERT(ip != NULL);
1100
1101         /*
1102          * Clean up fields and setup for merged scan
1103          */
1104         cursor->flags &= ~HAMMER_CURSOR_DELBTREE;
1105         cursor->flags |= HAMMER_CURSOR_ATEDISK | HAMMER_CURSOR_ATEMEM;
1106         cursor->flags |= HAMMER_CURSOR_DISKEOF | HAMMER_CURSOR_MEMEOF;
1107         if (cursor->iprec) {
1108                 hammer_rel_mem_record(cursor->iprec);
1109                 cursor->iprec = NULL;
1110         }
1111
1112         /*
1113          * Search the on-disk B-Tree.  hammer_btree_lookup() only does an
1114          * exact lookup so if we get ENOENT we have to call the iterate
1115          * function to validate the first record after the begin key.
1116          *
1117          * The ATEDISK flag is used by hammer_btree_iterate to determine
1118          * whether it must index forwards or not.  It is also used here
1119          * to select the next record from in-memory or on-disk.
1120          *
1121          * EDEADLK can only occur if the lookup hit an empty internal
1122          * element and couldn't delete it.  Since this could only occur
1123          * in-range, we can just iterate from the failure point.
1124          */
1125         if (ip->flags & (HAMMER_INODE_ONDISK|HAMMER_INODE_DONDISK)) {
1126                 error = hammer_btree_lookup(cursor);
1127                 if (error == ENOENT || error == EDEADLK) {
1128                         cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
1129                         if (hammer_debug_general & 0x2000)
1130                                 kprintf("error %d node %p %016llx index %d\n", error, cursor->node, cursor->node->node_offset, cursor->index);
1131                         error = hammer_btree_iterate(cursor);
1132                 }
1133                 if (error && error != ENOENT)
1134                         return(error);
1135                 if (error == 0) {
1136                         cursor->flags &= ~HAMMER_CURSOR_DISKEOF;
1137                         cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
1138                 } else {
1139                         cursor->flags |= HAMMER_CURSOR_ATEDISK;
1140                 }
1141         }
1142
1143         /*
1144          * Search the in-memory record list (Red-Black tree).  Unlike the
1145          * B-Tree search, mem_first checks for records in the range.
1146          */
1147         error = hammer_mem_first(cursor);
1148         if (error && error != ENOENT)
1149                 return(error);
1150         if (error == 0) {
1151                 cursor->flags &= ~HAMMER_CURSOR_MEMEOF;
1152                 cursor->flags &= ~HAMMER_CURSOR_ATEMEM;
1153                 if (hammer_ip_iterate_mem_good(cursor, cursor->iprec) == 0)
1154                         cursor->flags |= HAMMER_CURSOR_ATEMEM;
1155         }
1156
1157         /*
1158          * This will return the first matching record.
1159          */
1160         return(hammer_ip_next(cursor));
1161 }
1162
1163 /*
1164  * Retrieve the next record in a merged iteration within the bounds of the
1165  * cursor.  This call may be made multiple times after the cursor has been
1166  * initially searched with hammer_ip_first().
1167  *
1168  * 0 is returned on success, ENOENT if no further records match the
1169  * requested range, or some other error code is returned.
1170  */
1171 int
1172 hammer_ip_next(hammer_cursor_t cursor)
1173 {
1174         hammer_btree_elm_t elm;
1175         hammer_record_t rec, save;
1176         int error;
1177         int r;
1178
1179 next_btree:
1180         /*
1181          * Load the current on-disk and in-memory record.  If we ate any
1182          * records we have to get the next one.
1183          *
1184          * If we deleted the last on-disk record we had scanned ATEDISK will
1185          * be clear and DELBTREE will be set, forcing a call to iterate. The
1186          * fact that ATEDISK is clear causes iterate to re-test the 'current'
1187          * element.  If ATEDISK is set, iterate will skip the 'current'
1188          * element.
1189          *
1190          * Get the next on-disk record
1191          */
1192         if (cursor->flags & (HAMMER_CURSOR_ATEDISK|HAMMER_CURSOR_DELBTREE)) {
1193                 if ((cursor->flags & HAMMER_CURSOR_DISKEOF) == 0) {
1194                         error = hammer_btree_iterate(cursor);
1195                         cursor->flags &= ~HAMMER_CURSOR_DELBTREE;
1196                         if (error == 0)
1197                                 cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
1198                         else
1199                                 cursor->flags |= HAMMER_CURSOR_DISKEOF |
1200                                                  HAMMER_CURSOR_ATEDISK;
1201                 }
1202         }
1203
1204 next_memory:
1205         /*
1206          * Get the next in-memory record.  The record can be ripped out
1207          * of the RB tree so we maintain a scan_info structure to track
1208          * the next node.
1209          *
1210          * hammer_rec_scan_cmp:  Is the record still in our general range,
1211          *                       (non-inclusive of snapshot exclusions)?
1212          * hammer_rec_scan_callback: Is the record in our snapshot?
1213          */
1214         if (cursor->flags & HAMMER_CURSOR_ATEMEM) {
1215                 if ((cursor->flags & HAMMER_CURSOR_MEMEOF) == 0) {
1216                         save = cursor->iprec;
1217                         cursor->iprec = NULL;
1218                         rec = save ? hammer_rec_rb_tree_RB_NEXT(save) : NULL;
1219                         while (rec) {
1220                                 if (hammer_rec_scan_cmp(rec, cursor) != 0)
1221                                         break;
1222                                 if (hammer_rec_scan_callback(rec, cursor) != 0)
1223                                         break;
1224                                 rec = hammer_rec_rb_tree_RB_NEXT(rec);
1225                         }
1226                         if (save)
1227                                 hammer_rel_mem_record(save);
1228                         if (cursor->iprec) {
1229                                 KKASSERT(cursor->iprec == rec);
1230                                 cursor->flags &= ~HAMMER_CURSOR_ATEMEM;
1231                         } else {
1232                                 cursor->flags |= HAMMER_CURSOR_MEMEOF;
1233                         }
1234                 }
1235         }
1236
1237         /*
1238          * The memory record may have become stale while being held in
1239          * cursor->iprec.  We are interlocked against the backend on
1240          * with regards to B-Tree entries.
1241          */
1242         if ((cursor->flags & HAMMER_CURSOR_ATEMEM) == 0) {
1243                 if (hammer_ip_iterate_mem_good(cursor, cursor->iprec) == 0) {
1244                         cursor->flags |= HAMMER_CURSOR_ATEMEM;
1245                         goto next_memory;
1246                 }
1247         }
1248
1249         /*
1250          * Extract either the disk or memory record depending on their
1251          * relative position.
1252          */
1253         error = 0;
1254         switch(cursor->flags & (HAMMER_CURSOR_ATEDISK | HAMMER_CURSOR_ATEMEM)) {
1255         case 0:
1256                 /*
1257                  * Both entries valid.   Return the btree entry if it is
1258                  * in front of the memory entry.
1259                  */
1260                 elm = &cursor->node->ondisk->elms[cursor->index];
1261                 r = hammer_btree_cmp(&elm->base, &cursor->iprec->rec.base.base);
1262                 if (r < 0) {
1263                         error = hammer_btree_extract(cursor,
1264                                                      HAMMER_CURSOR_GET_RECORD);
1265                         cursor->flags |= HAMMER_CURSOR_ATEDISK;
1266                         break;
1267                 }
1268
1269                 /*
1270                  * If the entries match exactly the memory entry typically
1271                  * specifies an on-disk deletion and we eat both entries.
1272                  *
1273                  * If the in-memory record is not an on-disk deletion we
1274                  * probably caught the syncer while it was syncing it to
1275                  * the media.  Since we hold a shared lock on the cursor,
1276                  * the in-memory record had better be marked deleted at
1277                  * this point.
1278                  */
1279                 if (r == 0) {
1280                         if (cursor->iprec->type == HAMMER_MEM_RECORD_DEL) {
1281                                 if ((cursor->flags & HAMMER_CURSOR_DELETE_VISIBILITY) == 0) {
1282                                         cursor->flags |= HAMMER_CURSOR_ATEDISK;
1283                                         cursor->flags |= HAMMER_CURSOR_ATEMEM;
1284                                         goto next_btree;
1285                                 }
1286                         } else {
1287                                 panic("hammer_ip_next: duplicate mem/b-tree entry");
1288                                 cursor->flags |= HAMMER_CURSOR_ATEMEM;
1289                                 goto next_memory;
1290                         }
1291                 }
1292                 /* fall through to the memory entry */
1293         case HAMMER_CURSOR_ATEDISK:
1294                 /*
1295                  * Only the memory entry is valid.
1296                  */
1297                 cursor->record = &cursor->iprec->rec;
1298                 cursor->flags |= HAMMER_CURSOR_ATEMEM;
1299
1300                 /*
1301                  * If the memory entry is an on-disk deletion we should have
1302                  * also had found a B-Tree record.  If the backend beat us
1303                  * to it it would have interlocked the cursor and we should
1304                  * have seen the in-memory record marked DELETED_FE.
1305                  */
1306                 if (cursor->iprec->type == HAMMER_MEM_RECORD_DEL) {
1307                         panic("hammer_ip_next: del-on-disk with no b-tree entry");
1308                 }
1309                 break;
1310         case HAMMER_CURSOR_ATEMEM:
1311                 /*
1312                  * Only the disk entry is valid
1313                  */
1314                 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_RECORD);
1315                 cursor->flags |= HAMMER_CURSOR_ATEDISK;
1316                 break;
1317         default:
1318                 /*
1319                  * Neither entry is valid
1320                  *
1321                  * XXX error not set properly
1322                  */
1323                 cursor->record = NULL;
1324                 error = ENOENT;
1325                 break;
1326         }
1327         return(error);
1328 }
1329
1330 /*
1331  * Resolve the cursor->data pointer for the current cursor position in
1332  * a merged iteration.
1333  */
1334 int
1335 hammer_ip_resolve_data(hammer_cursor_t cursor)
1336 {
1337         int error;
1338
1339         if (cursor->iprec && cursor->record == &cursor->iprec->rec) {
1340                 cursor->data = cursor->iprec->data;
1341                 error = 0;
1342         } else {
1343                 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA);
1344         }
1345         return(error);
1346 }
1347
1348 int
1349 hammer_ip_resolve_record_and_data(hammer_cursor_t cursor)
1350 {
1351         int error;
1352
1353         if (cursor->iprec && cursor->record == &cursor->iprec->rec) {
1354                 cursor->data = cursor->iprec->data;
1355                 error = 0;
1356         } else {
1357                 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
1358                                                      HAMMER_CURSOR_GET_RECORD);
1359         }
1360         return(error);
1361 }
1362
1363 /*
1364  * Delete all records within the specified range for inode ip.
1365  *
1366  * NOTE: An unaligned range will cause new records to be added to cover
1367  * the edge cases. (XXX not implemented yet).
1368  *
1369  * NOTE: ran_end is inclusive (e.g. 0,1023 instead of 0,1024).
1370  *
1371  * NOTE: Record keys for regular file data have to be special-cased since
1372  * they indicate the end of the range (key = base + bytes).
1373  */
1374 int
1375 hammer_ip_delete_range(hammer_cursor_t cursor, hammer_inode_t ip,
1376                        int64_t ran_beg, int64_t ran_end)
1377 {
1378         hammer_transaction_t trans = cursor->trans;
1379         hammer_record_ondisk_t rec;
1380         hammer_base_elm_t base;
1381         int error;
1382         int64_t off;
1383
1384 #if 0
1385         kprintf("delete_range %p %016llx-%016llx\n", ip, ran_beg, ran_end);
1386 #endif
1387
1388         KKASSERT(trans->type == HAMMER_TRANS_FLS);
1389 retry:
1390         hammer_normalize_cursor(cursor);
1391         cursor->key_beg.obj_id = ip->obj_id;
1392         cursor->key_beg.create_tid = 0;
1393         cursor->key_beg.delete_tid = 0;
1394         cursor->key_beg.obj_type = 0;
1395         cursor->asof = ip->obj_asof;
1396         cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1397         cursor->flags |= HAMMER_CURSOR_ASOF;
1398         cursor->flags |= HAMMER_CURSOR_DELETE_VISIBILITY;
1399         cursor->flags |= HAMMER_CURSOR_BACKEND;
1400
1401         cursor->key_end = cursor->key_beg;
1402         if (ip->ino_rec.base.base.obj_type == HAMMER_OBJTYPE_DBFILE) {
1403                 cursor->key_beg.key = ran_beg;
1404                 cursor->key_beg.rec_type = HAMMER_RECTYPE_DB;
1405                 cursor->key_end.rec_type = HAMMER_RECTYPE_DB;
1406                 cursor->key_end.key = ran_end;
1407         } else {
1408                 /*
1409                  * The key in the B-Tree is (base+bytes), so the first possible
1410                  * matching key is ran_beg + 1.
1411                  */
1412                 int64_t tmp64;
1413
1414                 cursor->key_beg.key = ran_beg + 1;
1415                 cursor->key_beg.rec_type = HAMMER_RECTYPE_DATA;
1416                 cursor->key_end.rec_type = HAMMER_RECTYPE_DATA;
1417
1418                 tmp64 = ran_end + MAXPHYS + 1;  /* work around GCC-4 bug */
1419                 if (tmp64 < ran_end)
1420                         cursor->key_end.key = 0x7FFFFFFFFFFFFFFFLL;
1421                 else
1422                         cursor->key_end.key = ran_end + MAXPHYS + 1;
1423         }
1424         cursor->flags |= HAMMER_CURSOR_END_INCLUSIVE;
1425
1426         error = hammer_ip_first(cursor);
1427
1428         /*
1429          * Iterate through matching records and mark them as deleted.
1430          */
1431         while (error == 0) {
1432                 rec = cursor->record;
1433                 base = &rec->base.base;
1434
1435                 KKASSERT(base->delete_tid == 0);
1436
1437                 /*
1438                  * There may be overlap cases for regular file data.  Also
1439                  * remember the key for a regular file record is the offset
1440                  * of the last byte of the record (base + len - 1), NOT the
1441                  * base offset.
1442                  */
1443 #if 0
1444                 kprintf("delete_range rec_type %02x\n", base->rec_type);
1445 #endif
1446                 if (base->rec_type == HAMMER_RECTYPE_DATA) {
1447 #if 0
1448                         kprintf("delete_range loop key %016llx,%d\n",
1449                                 base->key - rec->base.data_len, rec->base.data_len);
1450 #endif
1451                         off = base->key - rec->base.data_len;
1452                         /*
1453                          * Check the left edge case.  We currently do not
1454                          * split existing records.
1455                          */
1456                         if (off < ran_beg) {
1457                                 panic("hammer left edge case %016llx %d\n",
1458                                         base->key, rec->base.data_len);
1459                         }
1460
1461                         /*
1462                          * Check the right edge case.  Note that the
1463                          * record can be completely out of bounds, which
1464                          * terminates the search.
1465                          *
1466                          * base->key is exclusive of the right edge while
1467                          * ran_end is inclusive of the right edge.  The
1468                          * (key - data_len) left boundary is inclusive.
1469                          *
1470                          * XXX theory-check this test at some point, are
1471                          * we missing a + 1 somewhere?  Note that ran_end
1472                          * could overflow.
1473                          */
1474                         if (base->key - 1 > ran_end) {
1475                                 if (base->key - rec->base.data_len > ran_end)
1476                                         break;
1477                                 panic("hammer right edge case\n");
1478                         }
1479                 }
1480
1481                 /*
1482                  * Mark the record and B-Tree entry as deleted.  This will
1483                  * also physically delete the B-Tree entry, record, and
1484                  * data if the retention policy dictates.  The function
1485                  * will set HAMMER_CURSOR_DELBTREE which hammer_ip_next()
1486                  * uses to perform a fixup.
1487                  */
1488                 error = hammer_ip_delete_record(cursor, trans->tid);
1489                 if (error)
1490                         break;
1491                 error = hammer_ip_next(cursor);
1492         }
1493         if (error == EDEADLK) {
1494                 hammer_done_cursor(cursor);
1495                 error = hammer_init_cursor(trans, cursor, &ip->cache[0], ip);
1496                 if (error == 0)
1497                         goto retry;
1498         }
1499         if (error == ENOENT)
1500                 error = 0;
1501         return(error);
1502 }
1503
1504 /*
1505  * Delete all user records associated with an inode except the inode record
1506  * itself.  Directory entries are not deleted (they must be properly disposed
1507  * of or nlinks would get upset).
1508  */
1509 int
1510 hammer_ip_delete_range_all(hammer_cursor_t cursor, hammer_inode_t ip,
1511                            int *countp)
1512 {
1513         hammer_transaction_t trans = cursor->trans;
1514         hammer_record_ondisk_t rec;
1515         hammer_base_elm_t base;
1516         int error;
1517
1518         KKASSERT(trans->type == HAMMER_TRANS_FLS);
1519 retry:
1520         hammer_normalize_cursor(cursor);
1521         cursor->key_beg.obj_id = ip->obj_id;
1522         cursor->key_beg.create_tid = 0;
1523         cursor->key_beg.delete_tid = 0;
1524         cursor->key_beg.obj_type = 0;
1525         cursor->key_beg.rec_type = HAMMER_RECTYPE_INODE + 1;
1526         cursor->key_beg.key = HAMMER_MIN_KEY;
1527
1528         cursor->key_end = cursor->key_beg;
1529         cursor->key_end.rec_type = 0xFFFF;
1530         cursor->key_end.key = HAMMER_MAX_KEY;
1531
1532         cursor->asof = ip->obj_asof;
1533         cursor->flags &= ~HAMMER_CURSOR_INITMASK;
1534         cursor->flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF;
1535         cursor->flags |= HAMMER_CURSOR_DELETE_VISIBILITY;
1536         cursor->flags |= HAMMER_CURSOR_BACKEND;
1537
1538         error = hammer_ip_first(cursor);
1539
1540         /*
1541          * Iterate through matching records and mark them as deleted.
1542          */
1543         while (error == 0) {
1544                 rec = cursor->record;
1545                 base = &rec->base.base;
1546
1547                 KKASSERT(base->delete_tid == 0);
1548
1549                 /*
1550                  * Mark the record and B-Tree entry as deleted.  This will
1551                  * also physically delete the B-Tree entry, record, and
1552                  * data if the retention policy dictates.  The function
1553                  * will set HAMMER_CURSOR_DELBTREE which hammer_ip_next()
1554                  * uses to perform a fixup.
1555                  *
1556                  * Directory entries (and delete-on-disk directory entries)
1557                  * must be synced and cannot be deleted.
1558                  */
1559                 if (rec->base.base.rec_type != HAMMER_RECTYPE_DIRENTRY) {
1560                         error = hammer_ip_delete_record(cursor, trans->tid);
1561                         ++*countp;
1562                 }
1563                 if (error)
1564                         break;
1565                 error = hammer_ip_next(cursor);
1566         }
1567         if (error == EDEADLK) {
1568                 hammer_done_cursor(cursor);
1569                 error = hammer_init_cursor(trans, cursor, &ip->cache[0], ip);
1570                 if (error == 0)
1571                         goto retry;
1572         }
1573         if (error == ENOENT)
1574                 error = 0;
1575         return(error);
1576 }
1577
1578 /*
1579  * Delete the record at the current cursor.  On success the cursor will
1580  * be positioned appropriately for an iteration but may no longer be at
1581  * a leaf node.
1582  *
1583  * This routine is only called from the backend.
1584  *
1585  * NOTE: This can return EDEADLK, requiring the caller to terminate the
1586  * cursor and retry.
1587  */
1588 int
1589 hammer_ip_delete_record(hammer_cursor_t cursor, hammer_tid_t tid)
1590 {
1591         hammer_btree_elm_t elm;
1592         hammer_mount_t hmp;
1593         int error;
1594         int dodelete;
1595
1596         KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND);
1597
1598         /*
1599          * In-memory (unsynchronized) records can simply be freed.  This
1600          * only occurs in range iterations since all other records are
1601          * individually synchronized.  Thus there should be no confusion with
1602          * the interlock.
1603          */
1604         if (cursor->record == &cursor->iprec->rec) {
1605                 KKASSERT((cursor->iprec->flags & HAMMER_RECF_INTERLOCK_BE) ==0);
1606                 cursor->iprec->flags |= HAMMER_RECF_DELETED_FE;
1607                 cursor->iprec->flags |= HAMMER_RECF_DELETED_BE;
1608                 return(0);
1609         }
1610
1611         /*
1612          * On-disk records are marked as deleted by updating their delete_tid.
1613          * This does not effect their position in the B-Tree (which is based
1614          * on their create_tid).
1615          */
1616         error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_RECORD);
1617         elm = NULL;
1618         hmp = cursor->node->hmp;
1619
1620         dodelete = 0;
1621         if (error == 0) {
1622                 error = hammer_cursor_upgrade(cursor);
1623                 if (error == 0) {
1624                         elm = &cursor->node->ondisk->elms[cursor->index];
1625                         hammer_modify_node(cursor->trans, cursor->node,
1626                                            &elm->leaf.base.delete_tid,
1627                                            sizeof(elm->leaf.base.delete_tid));
1628                         elm->leaf.base.delete_tid = tid;
1629                         hammer_modify_node_done(cursor->node);
1630
1631                         /*
1632                          * An on-disk record cannot have the same delete_tid
1633                          * as its create_tid.  In a chain of record updates
1634                          * this could result in a duplicate record.
1635                          */
1636                         KKASSERT(elm->leaf.base.delete_tid != elm->leaf.base.create_tid);
1637                         hammer_modify_buffer(cursor->trans, cursor->record_buffer, &cursor->record->base.base.delete_tid, sizeof(hammer_tid_t));
1638                         cursor->record->base.base.delete_tid = tid;
1639                         hammer_modify_buffer_done(cursor->record_buffer);
1640                 }
1641         }
1642
1643         /*
1644          * If we were mounted with the nohistory option, we physically
1645          * delete the record.
1646          */
1647         if (hmp->hflags & HMNT_NOHISTORY)
1648                 dodelete = 1;
1649
1650         if (error == 0 && dodelete) {
1651                 error = hammer_delete_at_cursor(cursor, NULL);
1652                 if (error) {
1653                         panic("hammer_ip_delete_record: unable to physically delete the record!\n");
1654                         error = 0;
1655                 }
1656         }
1657         return(error);
1658 }
1659
1660 int
1661 hammer_delete_at_cursor(hammer_cursor_t cursor, int64_t *stat_bytes)
1662 {
1663         hammer_btree_elm_t elm;
1664         hammer_off_t rec_offset;
1665         hammer_off_t data_offset;
1666         int32_t data_len;
1667         u_int16_t rec_type;
1668         int error;
1669
1670         elm = &cursor->node->ondisk->elms[cursor->index];
1671         KKASSERT(elm->base.btype == HAMMER_BTREE_TYPE_RECORD);
1672
1673         rec_offset = elm->leaf.rec_offset;
1674         data_offset = elm->leaf.data_offset;
1675         data_len = elm->leaf.data_len;
1676         rec_type = elm->leaf.base.rec_type;
1677
1678         error = hammer_btree_delete(cursor);
1679         if (error == 0) {
1680                 /*
1681                  * This forces a fixup for the iteration because
1682                  * the cursor is now either sitting at the 'next'
1683                  * element or sitting at the end of a leaf.
1684                  */
1685                 if ((cursor->flags & HAMMER_CURSOR_DISKEOF) == 0) {
1686                         cursor->flags |= HAMMER_CURSOR_DELBTREE;
1687                         cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
1688                 }
1689         }
1690         if (error == 0) {
1691                 hammer_blockmap_free(cursor->trans, rec_offset,
1692                                      sizeof(union hammer_record_ondisk));
1693         }
1694         if (error == 0) {
1695                 switch(data_offset & HAMMER_OFF_ZONE_MASK) {
1696                 case HAMMER_ZONE_LARGE_DATA:
1697                 case HAMMER_ZONE_SMALL_DATA:
1698                         hammer_blockmap_free(cursor->trans,
1699                                              data_offset, data_len);
1700                         break;
1701                 default:
1702                         break;
1703                 }
1704         }
1705 #if 0
1706         kprintf("hammer_delete_at_cursor: %d:%d:%08x %08x/%d "
1707                 "(%d remain in cluster)\n",
1708                 cluster->volume->vol_no, cluster->clu_no,
1709                 rec_offset, data_offset, data_len,
1710                 cluster->ondisk->stat_records);
1711 #endif
1712         return (error);
1713 }
1714
1715 /*
1716  * Determine whether we can remove a directory.  This routine checks whether
1717  * a directory is empty or not and enforces flush connectivity.
1718  *
1719  * Flush connectivity requires that we block if the target directory is
1720  * currently flushing, otherwise it may not end up in the same flush group.
1721  *
1722  * Returns 0 on success, ENOTEMPTY or EDEADLK (or other errors) on failure.
1723  */
1724 int
1725 hammer_ip_check_directory_empty(hammer_transaction_t trans,
1726                         hammer_cursor_t parent_cursor, hammer_inode_t ip)
1727 {
1728         struct hammer_cursor cursor;
1729         int error;
1730
1731         /*
1732          * Check directory empty
1733          */
1734         hammer_init_cursor(trans, &cursor, &ip->cache[0], ip);
1735
1736         cursor.key_beg.obj_id = ip->obj_id;
1737         cursor.key_beg.create_tid = 0;
1738         cursor.key_beg.delete_tid = 0;
1739         cursor.key_beg.obj_type = 0;
1740         cursor.key_beg.rec_type = HAMMER_RECTYPE_INODE + 1;
1741         cursor.key_beg.key = HAMMER_MIN_KEY;
1742
1743         cursor.key_end = cursor.key_beg;
1744         cursor.key_end.rec_type = 0xFFFF;
1745         cursor.key_end.key = HAMMER_MAX_KEY;
1746
1747         cursor.asof = ip->obj_asof;
1748         cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE | HAMMER_CURSOR_ASOF;
1749
1750         error = hammer_ip_first(&cursor);
1751         if (error == ENOENT)
1752                 error = 0;
1753         else if (error == 0)
1754                 error = ENOTEMPTY;
1755         hammer_done_cursor(&cursor);
1756         return(error);
1757 }
1758