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_ondisk.c,v 1.76 2008/08/29 20:19:08 dillon Exp $ 35 */ 36 /* 37 * Manage HAMMER's on-disk structures. These routines are primarily 38 * responsible for interfacing with the kernel's I/O subsystem and for 39 * managing in-memory structures. 40 */ 41 42 #include "hammer.h" 43 #include <sys/fcntl.h> 44 #include <sys/nlookup.h> 45 #include <sys/buf.h> 46 47 #include <sys/buf2.h> 48 49 static void hammer_free_volume(hammer_volume_t volume); 50 static int hammer_load_volume(hammer_volume_t volume); 51 static int hammer_load_buffer(hammer_buffer_t buffer, int isnew); 52 static int hammer_load_node(hammer_transaction_t trans, 53 hammer_node_t node, int isnew); 54 static void _hammer_rel_node(hammer_node_t node, int locked); 55 56 static int 57 hammer_vol_rb_compare(hammer_volume_t vol1, hammer_volume_t vol2) 58 { 59 if (vol1->vol_no < vol2->vol_no) 60 return(-1); 61 if (vol1->vol_no > vol2->vol_no) 62 return(1); 63 return(0); 64 } 65 66 /* 67 * hammer_buffer structures are indexed via their zoneX_offset, not 68 * their zone2_offset. 69 */ 70 static int 71 hammer_buf_rb_compare(hammer_buffer_t buf1, hammer_buffer_t buf2) 72 { 73 if (buf1->zoneX_offset < buf2->zoneX_offset) 74 return(-1); 75 if (buf1->zoneX_offset > buf2->zoneX_offset) 76 return(1); 77 return(0); 78 } 79 80 static int 81 hammer_nod_rb_compare(hammer_node_t node1, hammer_node_t node2) 82 { 83 if (node1->node_offset < node2->node_offset) 84 return(-1); 85 if (node1->node_offset > node2->node_offset) 86 return(1); 87 return(0); 88 } 89 90 RB_GENERATE2(hammer_vol_rb_tree, hammer_volume, rb_node, 91 hammer_vol_rb_compare, int32_t, vol_no); 92 RB_GENERATE2(hammer_buf_rb_tree, hammer_buffer, rb_node, 93 hammer_buf_rb_compare, hammer_off_t, zoneX_offset); 94 RB_GENERATE2(hammer_nod_rb_tree, hammer_node, rb_node, 95 hammer_nod_rb_compare, hammer_off_t, node_offset); 96 97 /************************************************************************ 98 * VOLUMES * 99 ************************************************************************ 100 * 101 * Load a HAMMER volume by name. Returns 0 on success or a positive error 102 * code on failure. Volumes must be loaded at mount time, get_volume() will 103 * not load a new volume. 104 * 105 * The passed devvp is vref()'d but not locked. This function consumes the 106 * ref (typically by associating it with the volume structure). 107 * 108 * Calls made to hammer_load_volume() or single-threaded 109 */ 110 int 111 hammer_install_volume(struct hammer_mount *hmp, const char *volname, 112 struct vnode *devvp) 113 { 114 struct mount *mp; 115 hammer_volume_t volume; 116 struct hammer_volume_ondisk *ondisk; 117 struct nlookupdata nd; 118 struct buf *bp = NULL; 119 int error; 120 int ronly; 121 int setmp = 0; 122 123 mp = hmp->mp; 124 ronly = ((mp->mnt_flag & MNT_RDONLY) ? 1 : 0); 125 126 /* 127 * Allocate a volume structure 128 */ 129 ++hammer_count_volumes; 130 volume = kmalloc(sizeof(*volume), hmp->m_misc, M_WAITOK|M_ZERO); 131 volume->vol_name = kstrdup(volname, hmp->m_misc); 132 volume->io.hmp = hmp; /* bootstrap */ 133 hammer_io_init(&volume->io, volume, HAMMER_STRUCTURE_VOLUME); 134 volume->io.offset = 0LL; 135 volume->io.bytes = HAMMER_BUFSIZE; 136 137 /* 138 * Get the device vnode 139 */ 140 if (devvp == NULL) { 141 error = nlookup_init(&nd, volume->vol_name, UIO_SYSSPACE, NLC_FOLLOW); 142 if (error == 0) 143 error = nlookup(&nd); 144 if (error == 0) 145 error = cache_vref(&nd.nl_nch, nd.nl_cred, &volume->devvp); 146 nlookup_done(&nd); 147 } else { 148 error = 0; 149 volume->devvp = devvp; 150 } 151 152 if (error == 0) { 153 if (vn_isdisk(volume->devvp, &error)) { 154 error = vfs_mountedon(volume->devvp); 155 } 156 } 157 if (error == 0 && vcount(volume->devvp) > 0) 158 error = EBUSY; 159 if (error == 0) { 160 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY); 161 error = vinvalbuf(volume->devvp, V_SAVE, 0, 0); 162 if (error == 0) { 163 error = VOP_OPEN(volume->devvp, 164 (ronly ? FREAD : FREAD|FWRITE), 165 FSCRED, NULL); 166 } 167 vn_unlock(volume->devvp); 168 } 169 if (error) { 170 hammer_free_volume(volume); 171 return(error); 172 } 173 volume->devvp->v_rdev->si_mountpoint = mp; 174 setmp = 1; 175 176 /* 177 * Extract the volume number from the volume header and do various 178 * sanity checks. 179 */ 180 error = bread(volume->devvp, 0LL, HAMMER_BUFSIZE, &bp); 181 if (error) 182 goto late_failure; 183 ondisk = (void *)bp->b_data; 184 if (ondisk->vol_signature != HAMMER_FSBUF_VOLUME) { 185 kprintf("hammer_mount: volume %s has an invalid header\n", 186 volume->vol_name); 187 error = EFTYPE; 188 goto late_failure; 189 } 190 volume->vol_no = ondisk->vol_no; 191 volume->buffer_base = ondisk->vol_buf_beg; 192 volume->vol_flags = ondisk->vol_flags; 193 volume->nblocks = ondisk->vol_nblocks; 194 volume->maxbuf_off = HAMMER_ENCODE_RAW_BUFFER(volume->vol_no, 195 ondisk->vol_buf_end - ondisk->vol_buf_beg); 196 volume->maxraw_off = ondisk->vol_buf_end; 197 198 if (RB_EMPTY(&hmp->rb_vols_root)) { 199 hmp->fsid = ondisk->vol_fsid; 200 } else if (bcmp(&hmp->fsid, &ondisk->vol_fsid, sizeof(uuid_t))) { 201 kprintf("hammer_mount: volume %s's fsid does not match " 202 "other volumes\n", volume->vol_name); 203 error = EFTYPE; 204 goto late_failure; 205 } 206 207 /* 208 * Insert the volume structure into the red-black tree. 209 */ 210 if (RB_INSERT(hammer_vol_rb_tree, &hmp->rb_vols_root, volume)) { 211 kprintf("hammer_mount: volume %s has a duplicate vol_no %d\n", 212 volume->vol_name, volume->vol_no); 213 error = EEXIST; 214 } 215 216 /* 217 * Set the root volume . HAMMER special cases rootvol the structure. 218 * We do not hold a ref because this would prevent related I/O 219 * from being flushed. 220 */ 221 if (error == 0 && ondisk->vol_rootvol == ondisk->vol_no) { 222 hmp->rootvol = volume; 223 hmp->nvolumes = ondisk->vol_count; 224 if (bp) { 225 brelse(bp); 226 bp = NULL; 227 } 228 hmp->mp->mnt_stat.f_blocks += ondisk->vol0_stat_bigblocks * 229 (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE); 230 hmp->mp->mnt_vstat.f_blocks += ondisk->vol0_stat_bigblocks * 231 (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE); 232 } 233 late_failure: 234 if (bp) 235 brelse(bp); 236 if (error) { 237 /*vinvalbuf(volume->devvp, V_SAVE, 0, 0);*/ 238 if (setmp) 239 volume->devvp->v_rdev->si_mountpoint = NULL; 240 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY); 241 VOP_CLOSE(volume->devvp, ronly ? FREAD : FREAD|FWRITE, NULL); 242 vn_unlock(volume->devvp); 243 hammer_free_volume(volume); 244 } 245 return (error); 246 } 247 248 /* 249 * This is called for each volume when updating the mount point from 250 * read-write to read-only or vise-versa. 251 */ 252 int 253 hammer_adjust_volume_mode(hammer_volume_t volume, void *data __unused) 254 { 255 if (volume->devvp) { 256 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY); 257 if (volume->io.hmp->ronly) { 258 /* do not call vinvalbuf */ 259 VOP_OPEN(volume->devvp, FREAD, FSCRED, NULL); 260 VOP_CLOSE(volume->devvp, FREAD|FWRITE, NULL); 261 } else { 262 /* do not call vinvalbuf */ 263 VOP_OPEN(volume->devvp, FREAD|FWRITE, FSCRED, NULL); 264 VOP_CLOSE(volume->devvp, FREAD, NULL); 265 } 266 vn_unlock(volume->devvp); 267 } 268 return(0); 269 } 270 271 /* 272 * Unload and free a HAMMER volume. Must return >= 0 to continue scan 273 * so returns -1 on failure. 274 */ 275 int 276 hammer_unload_volume(hammer_volume_t volume, void *data __unused) 277 { 278 hammer_mount_t hmp = volume->io.hmp; 279 int ronly = ((hmp->mp->mnt_flag & MNT_RDONLY) ? 1 : 0); 280 281 /* 282 * Clean up the root volume pointer, which is held unlocked in hmp. 283 */ 284 if (hmp->rootvol == volume) 285 hmp->rootvol = NULL; 286 287 /* 288 * We must not flush a dirty buffer to disk on umount. It should 289 * have already been dealt with by the flusher, or we may be in 290 * catastrophic failure. 291 */ 292 hammer_io_clear_modify(&volume->io, 1); 293 volume->io.waitdep = 1; 294 295 /* 296 * Clean up the persistent ref ioerror might have on the volume 297 */ 298 if (volume->io.ioerror) 299 hammer_io_clear_error_noassert(&volume->io); 300 301 /* 302 * This should release the bp. Releasing the volume with flush set 303 * implies the interlock is set. 304 */ 305 hammer_ref_interlock_true(&volume->io.lock); 306 hammer_rel_volume(volume, 1); 307 KKASSERT(volume->io.bp == NULL); 308 309 /* 310 * There should be no references on the volume, no clusters, and 311 * no super-clusters. 312 */ 313 KKASSERT(hammer_norefs(&volume->io.lock)); 314 315 volume->ondisk = NULL; 316 if (volume->devvp) { 317 if (volume->devvp->v_rdev && 318 volume->devvp->v_rdev->si_mountpoint == hmp->mp 319 ) { 320 volume->devvp->v_rdev->si_mountpoint = NULL; 321 } 322 if (ronly) { 323 /* 324 * Make sure we don't sync anything to disk if we 325 * are in read-only mode (1) or critically-errored 326 * (2). Note that there may be dirty buffers in 327 * normal read-only mode from crash recovery. 328 */ 329 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY); 330 vinvalbuf(volume->devvp, 0, 0, 0); 331 VOP_CLOSE(volume->devvp, FREAD, NULL); 332 vn_unlock(volume->devvp); 333 } else { 334 /* 335 * Normal termination, save any dirty buffers 336 * (XXX there really shouldn't be any). 337 */ 338 vn_lock(volume->devvp, LK_EXCLUSIVE | LK_RETRY); 339 vinvalbuf(volume->devvp, V_SAVE, 0, 0); 340 VOP_CLOSE(volume->devvp, FREAD|FWRITE, NULL); 341 vn_unlock(volume->devvp); 342 } 343 } 344 345 /* 346 * Destroy the structure 347 */ 348 RB_REMOVE(hammer_vol_rb_tree, &hmp->rb_vols_root, volume); 349 hammer_free_volume(volume); 350 return(0); 351 } 352 353 static 354 void 355 hammer_free_volume(hammer_volume_t volume) 356 { 357 hammer_mount_t hmp = volume->io.hmp; 358 359 if (volume->vol_name) { 360 kfree(volume->vol_name, hmp->m_misc); 361 volume->vol_name = NULL; 362 } 363 if (volume->devvp) { 364 vrele(volume->devvp); 365 volume->devvp = NULL; 366 } 367 --hammer_count_volumes; 368 kfree(volume, hmp->m_misc); 369 } 370 371 /* 372 * Get a HAMMER volume. The volume must already exist. 373 */ 374 hammer_volume_t 375 hammer_get_volume(struct hammer_mount *hmp, int32_t vol_no, int *errorp) 376 { 377 struct hammer_volume *volume; 378 379 /* 380 * Locate the volume structure 381 */ 382 volume = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, vol_no); 383 if (volume == NULL) { 384 *errorp = ENOENT; 385 return(NULL); 386 } 387 388 /* 389 * Reference the volume, load/check the data on the 0->1 transition. 390 * hammer_load_volume() will dispose of the interlock on return, 391 * and also clean up the ref count on error. 392 */ 393 if (hammer_ref_interlock(&volume->io.lock)) { 394 *errorp = hammer_load_volume(volume); 395 if (*errorp) 396 volume = NULL; 397 } else { 398 KKASSERT(volume->ondisk); 399 *errorp = 0; 400 } 401 return(volume); 402 } 403 404 int 405 hammer_ref_volume(hammer_volume_t volume) 406 { 407 int error; 408 409 /* 410 * Reference the volume and deal with the check condition used to 411 * load its ondisk info. 412 */ 413 if (hammer_ref_interlock(&volume->io.lock)) { 414 error = hammer_load_volume(volume); 415 } else { 416 KKASSERT(volume->ondisk); 417 error = 0; 418 } 419 return (error); 420 } 421 422 /* 423 * May be called without fs_token 424 */ 425 hammer_volume_t 426 hammer_get_root_volume(struct hammer_mount *hmp, int *errorp) 427 { 428 hammer_volume_t volume; 429 430 volume = hmp->rootvol; 431 KKASSERT(volume != NULL); 432 433 /* 434 * Reference the volume and deal with the check condition used to 435 * load its ondisk info. 436 */ 437 if (hammer_ref_interlock(&volume->io.lock)) { 438 lwkt_gettoken(&volume->io.hmp->fs_token); 439 *errorp = hammer_load_volume(volume); 440 lwkt_reltoken(&volume->io.hmp->fs_token); 441 if (*errorp) 442 volume = NULL; 443 } else { 444 KKASSERT(volume->ondisk); 445 *errorp = 0; 446 } 447 return (volume); 448 } 449 450 /* 451 * Load a volume's on-disk information. The volume must be referenced and 452 * the interlock is held on call. The interlock will be released on return. 453 * The reference will also be released on return if an error occurs. 454 */ 455 static int 456 hammer_load_volume(hammer_volume_t volume) 457 { 458 int error; 459 460 if (volume->ondisk == NULL) { 461 error = hammer_io_read(volume->devvp, &volume->io, 462 HAMMER_BUFSIZE); 463 if (error == 0) { 464 volume->ondisk = (void *)volume->io.bp->b_data; 465 hammer_ref_interlock_done(&volume->io.lock); 466 } else { 467 hammer_rel_volume(volume, 1); 468 } 469 } else { 470 error = 0; 471 } 472 return(error); 473 } 474 475 /* 476 * Release a previously acquired reference on the volume. 477 * 478 * Volumes are not unloaded from memory during normal operation. 479 * 480 * May be called without fs_token 481 */ 482 void 483 hammer_rel_volume(hammer_volume_t volume, int locked) 484 { 485 struct buf *bp; 486 487 if (hammer_rel_interlock(&volume->io.lock, locked)) { 488 lwkt_gettoken(&volume->io.hmp->fs_token); 489 volume->ondisk = NULL; 490 bp = hammer_io_release(&volume->io, locked); 491 lwkt_reltoken(&volume->io.hmp->fs_token); 492 hammer_rel_interlock_done(&volume->io.lock, locked); 493 if (bp) 494 brelse(bp); 495 } 496 } 497 498 int 499 hammer_mountcheck_volumes(struct hammer_mount *hmp) 500 { 501 hammer_volume_t vol; 502 int i; 503 504 for (i = 0; i < hmp->nvolumes; ++i) { 505 vol = RB_LOOKUP(hammer_vol_rb_tree, &hmp->rb_vols_root, i); 506 if (vol == NULL) 507 return(EINVAL); 508 } 509 return(0); 510 } 511 512 /************************************************************************ 513 * BUFFERS * 514 ************************************************************************ 515 * 516 * Manage buffers. Currently most blockmap-backed zones are direct-mapped 517 * to zone-2 buffer offsets, without a translation stage. However, the 518 * hammer_buffer structure is indexed by its zoneX_offset, not its 519 * zone2_offset. 520 * 521 * The proper zone must be maintained throughout the code-base all the way 522 * through to the big-block allocator, or routines like hammer_del_buffers() 523 * will not be able to locate all potentially conflicting buffers. 524 */ 525 526 /* 527 * Helper function returns whether a zone offset can be directly translated 528 * to a raw buffer index or not. Really only the volume and undo zones 529 * can't be directly translated. Volumes are special-cased and undo zones 530 * shouldn't be aliased accessed in read-only mode. 531 * 532 * This function is ONLY used to detect aliased zones during a read-only 533 * mount. 534 */ 535 static __inline int 536 hammer_direct_zone(hammer_off_t buf_offset) 537 { 538 switch(HAMMER_ZONE_DECODE(buf_offset)) { 539 case HAMMER_ZONE_RAW_BUFFER_INDEX: 540 case HAMMER_ZONE_FREEMAP_INDEX: 541 case HAMMER_ZONE_BTREE_INDEX: 542 case HAMMER_ZONE_META_INDEX: 543 case HAMMER_ZONE_LARGE_DATA_INDEX: 544 case HAMMER_ZONE_SMALL_DATA_INDEX: 545 return(1); 546 default: 547 return(0); 548 } 549 /* NOT REACHED */ 550 } 551 552 hammer_buffer_t 553 hammer_get_buffer(hammer_mount_t hmp, hammer_off_t buf_offset, 554 int bytes, int isnew, int *errorp) 555 { 556 hammer_buffer_t buffer; 557 hammer_volume_t volume; 558 hammer_off_t zone2_offset; 559 hammer_io_type_t iotype; 560 int vol_no; 561 int zone; 562 563 buf_offset &= ~HAMMER_BUFMASK64; 564 again: 565 /* 566 * Shortcut if the buffer is already cached 567 */ 568 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, buf_offset); 569 if (buffer) { 570 /* 571 * Once refed the ondisk field will not be cleared by 572 * any other action. Shortcut the operation if the 573 * ondisk structure is valid. 574 */ 575 found_aliased: 576 if (hammer_ref_interlock(&buffer->io.lock) == 0) { 577 hammer_io_advance(&buffer->io); 578 KKASSERT(buffer->ondisk); 579 *errorp = 0; 580 return(buffer); 581 } 582 583 /* 584 * 0->1 transition or defered 0->1 transition (CHECK), 585 * interlock now held. Shortcut if ondisk is already 586 * assigned. 587 */ 588 atomic_add_int(&hammer_count_refedbufs, 1); 589 if (buffer->ondisk) { 590 hammer_io_advance(&buffer->io); 591 hammer_ref_interlock_done(&buffer->io.lock); 592 *errorp = 0; 593 return(buffer); 594 } 595 596 /* 597 * The buffer is no longer loose if it has a ref, and 598 * cannot become loose once it gains a ref. Loose 599 * buffers will never be in a modified state. This should 600 * only occur on the 0->1 transition of refs. 601 * 602 * lose_list can be modified via a biodone() interrupt 603 * so the io_token must be held. 604 */ 605 if (buffer->io.mod_root == &hmp->lose_root) { 606 lwkt_gettoken(&hmp->io_token); 607 if (buffer->io.mod_root == &hmp->lose_root) { 608 RB_REMOVE(hammer_mod_rb_tree, 609 buffer->io.mod_root, &buffer->io); 610 buffer->io.mod_root = NULL; 611 KKASSERT(buffer->io.modified == 0); 612 } 613 lwkt_reltoken(&hmp->io_token); 614 } 615 goto found; 616 } else if (hmp->ronly && hammer_direct_zone(buf_offset)) { 617 /* 618 * If this is a read-only mount there could be an alias 619 * in the raw-zone. If there is we use that buffer instead. 620 * 621 * rw mounts will not have aliases. Also note when going 622 * from ro -> rw the recovered raw buffers are flushed and 623 * reclaimed, so again there will not be any aliases once 624 * the mount is rw. 625 */ 626 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, 627 (buf_offset & ~HAMMER_OFF_ZONE_MASK) | 628 HAMMER_ZONE_RAW_BUFFER); 629 if (buffer) { 630 kprintf("HAMMER: recovered aliased %016jx\n", 631 (intmax_t)buf_offset); 632 goto found_aliased; 633 } 634 } 635 636 /* 637 * What is the buffer class? 638 */ 639 zone = HAMMER_ZONE_DECODE(buf_offset); 640 641 switch(zone) { 642 case HAMMER_ZONE_LARGE_DATA_INDEX: 643 case HAMMER_ZONE_SMALL_DATA_INDEX: 644 iotype = HAMMER_STRUCTURE_DATA_BUFFER; 645 break; 646 case HAMMER_ZONE_UNDO_INDEX: 647 iotype = HAMMER_STRUCTURE_UNDO_BUFFER; 648 break; 649 case HAMMER_ZONE_META_INDEX: 650 default: 651 /* 652 * NOTE: inode data and directory entries are placed in this 653 * zone. inode atime/mtime is updated in-place and thus 654 * buffers containing inodes must be synchronized as 655 * meta-buffers, same as buffers containing B-Tree info. 656 */ 657 iotype = HAMMER_STRUCTURE_META_BUFFER; 658 break; 659 } 660 661 /* 662 * Handle blockmap offset translations 663 */ 664 if (zone >= HAMMER_ZONE_BTREE_INDEX) { 665 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, errorp); 666 } else if (zone == HAMMER_ZONE_UNDO_INDEX) { 667 zone2_offset = hammer_undo_lookup(hmp, buf_offset, errorp); 668 } else { 669 KKASSERT(zone == HAMMER_ZONE_RAW_BUFFER_INDEX); 670 zone2_offset = buf_offset; 671 *errorp = 0; 672 } 673 if (*errorp) 674 return(NULL); 675 676 /* 677 * NOTE: zone2_offset and maxbuf_off are both full zone-2 offset 678 * specifications. 679 */ 680 KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) == 681 HAMMER_ZONE_RAW_BUFFER); 682 vol_no = HAMMER_VOL_DECODE(zone2_offset); 683 volume = hammer_get_volume(hmp, vol_no, errorp); 684 if (volume == NULL) 685 return(NULL); 686 687 KKASSERT(zone2_offset < volume->maxbuf_off); 688 689 /* 690 * Allocate a new buffer structure. We will check for races later. 691 */ 692 ++hammer_count_buffers; 693 buffer = kmalloc(sizeof(*buffer), hmp->m_misc, 694 M_WAITOK|M_ZERO|M_USE_RESERVE); 695 buffer->zone2_offset = zone2_offset; 696 buffer->zoneX_offset = buf_offset; 697 698 hammer_io_init(&buffer->io, volume, iotype); 699 buffer->io.offset = volume->ondisk->vol_buf_beg + 700 (zone2_offset & HAMMER_OFF_SHORT_MASK); 701 buffer->io.bytes = bytes; 702 TAILQ_INIT(&buffer->clist); 703 hammer_ref_interlock_true(&buffer->io.lock); 704 705 /* 706 * Insert the buffer into the RB tree and handle late collisions. 707 */ 708 if (RB_INSERT(hammer_buf_rb_tree, &hmp->rb_bufs_root, buffer)) { 709 hammer_rel_volume(volume, 0); 710 buffer->io.volume = NULL; /* safety */ 711 if (hammer_rel_interlock(&buffer->io.lock, 1)) /* safety */ 712 hammer_rel_interlock_done(&buffer->io.lock, 1); 713 --hammer_count_buffers; 714 kfree(buffer, hmp->m_misc); 715 goto again; 716 } 717 atomic_add_int(&hammer_count_refedbufs, 1); 718 found: 719 720 /* 721 * The buffer is referenced and interlocked. Load the buffer 722 * if necessary. hammer_load_buffer() deals with the interlock 723 * and, if an error is returned, also deals with the ref. 724 */ 725 if (buffer->ondisk == NULL) { 726 *errorp = hammer_load_buffer(buffer, isnew); 727 if (*errorp) 728 buffer = NULL; 729 } else { 730 hammer_io_advance(&buffer->io); 731 hammer_ref_interlock_done(&buffer->io.lock); 732 *errorp = 0; 733 } 734 return(buffer); 735 } 736 737 /* 738 * This is used by the direct-read code to deal with large-data buffers 739 * created by the reblocker and mirror-write code. The direct-read code 740 * bypasses the HAMMER buffer subsystem and so any aliased dirty or write- 741 * running hammer buffers must be fully synced to disk before we can issue 742 * the direct-read. 743 * 744 * This code path is not considered critical as only the rebocker and 745 * mirror-write code will create large-data buffers via the HAMMER buffer 746 * subsystem. They do that because they operate at the B-Tree level and 747 * do not access the vnode/inode structures. 748 */ 749 void 750 hammer_sync_buffers(hammer_mount_t hmp, hammer_off_t base_offset, int bytes) 751 { 752 hammer_buffer_t buffer; 753 int error; 754 755 KKASSERT((base_offset & HAMMER_OFF_ZONE_MASK) == 756 HAMMER_ZONE_LARGE_DATA); 757 758 while (bytes > 0) { 759 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, 760 base_offset); 761 if (buffer && (buffer->io.modified || buffer->io.running)) { 762 error = hammer_ref_buffer(buffer); 763 if (error == 0) { 764 hammer_io_wait(&buffer->io); 765 if (buffer->io.modified) { 766 hammer_io_write_interlock(&buffer->io); 767 hammer_io_flush(&buffer->io, 0); 768 hammer_io_done_interlock(&buffer->io); 769 hammer_io_wait(&buffer->io); 770 } 771 hammer_rel_buffer(buffer, 0); 772 } 773 } 774 base_offset += HAMMER_BUFSIZE; 775 bytes -= HAMMER_BUFSIZE; 776 } 777 } 778 779 /* 780 * Destroy all buffers covering the specified zoneX offset range. This 781 * is called when the related blockmap layer2 entry is freed or when 782 * a direct write bypasses our buffer/buffer-cache subsystem. 783 * 784 * The buffers may be referenced by the caller itself. Setting reclaim 785 * will cause the buffer to be destroyed when it's ref count reaches zero. 786 * 787 * Return 0 on success, EAGAIN if some buffers could not be destroyed due 788 * to additional references held by other threads, or some other (typically 789 * fatal) error. 790 */ 791 int 792 hammer_del_buffers(hammer_mount_t hmp, hammer_off_t base_offset, 793 hammer_off_t zone2_offset, int bytes, 794 int report_conflicts) 795 { 796 hammer_buffer_t buffer; 797 hammer_volume_t volume; 798 int vol_no; 799 int error; 800 int ret_error; 801 802 vol_no = HAMMER_VOL_DECODE(zone2_offset); 803 volume = hammer_get_volume(hmp, vol_no, &ret_error); 804 KKASSERT(ret_error == 0); 805 806 while (bytes > 0) { 807 buffer = RB_LOOKUP(hammer_buf_rb_tree, &hmp->rb_bufs_root, 808 base_offset); 809 if (buffer) { 810 error = hammer_ref_buffer(buffer); 811 if (hammer_debug_general & 0x20000) { 812 kprintf("hammer: delbufr %016jx " 813 "rerr=%d 1ref=%d\n", 814 (intmax_t)buffer->zoneX_offset, 815 error, 816 hammer_oneref(&buffer->io.lock)); 817 } 818 if (error == 0 && !hammer_oneref(&buffer->io.lock)) { 819 error = EAGAIN; 820 hammer_rel_buffer(buffer, 0); 821 } 822 if (error == 0) { 823 KKASSERT(buffer->zone2_offset == zone2_offset); 824 hammer_io_clear_modify(&buffer->io, 1); 825 buffer->io.reclaim = 1; 826 buffer->io.waitdep = 1; 827 KKASSERT(buffer->io.volume == volume); 828 hammer_rel_buffer(buffer, 0); 829 } 830 } else { 831 error = hammer_io_inval(volume, zone2_offset); 832 } 833 if (error) { 834 ret_error = error; 835 if (report_conflicts || 836 (hammer_debug_general & 0x8000)) { 837 kprintf("hammer_del_buffers: unable to " 838 "invalidate %016llx buffer=%p rep=%d\n", 839 (long long)base_offset, 840 buffer, report_conflicts); 841 } 842 } 843 base_offset += HAMMER_BUFSIZE; 844 zone2_offset += HAMMER_BUFSIZE; 845 bytes -= HAMMER_BUFSIZE; 846 } 847 hammer_rel_volume(volume, 0); 848 return (ret_error); 849 } 850 851 /* 852 * Given a referenced and interlocked buffer load/validate the data. 853 * 854 * The buffer interlock will be released on return. If an error is 855 * returned the buffer reference will also be released (and the buffer 856 * pointer will thus be stale). 857 */ 858 static int 859 hammer_load_buffer(hammer_buffer_t buffer, int isnew) 860 { 861 hammer_volume_t volume; 862 int error; 863 864 /* 865 * Load the buffer's on-disk info 866 */ 867 volume = buffer->io.volume; 868 869 if (hammer_debug_io & 0x0004) { 870 kprintf("load_buffer %016llx %016llx isnew=%d od=%p\n", 871 (long long)buffer->zoneX_offset, 872 (long long)buffer->zone2_offset, 873 isnew, buffer->ondisk); 874 } 875 876 if (buffer->ondisk == NULL) { 877 /* 878 * Issue the read or generate a new buffer. When reading 879 * the limit argument controls any read-ahead clustering 880 * hammer_io_read() is allowed to do. 881 * 882 * We cannot read-ahead in the large-data zone and we cannot 883 * cross a largeblock boundary as the next largeblock might 884 * use a different buffer size. 885 */ 886 if (isnew) { 887 error = hammer_io_new(volume->devvp, &buffer->io); 888 } else if ((buffer->zoneX_offset & HAMMER_OFF_ZONE_MASK) == 889 HAMMER_ZONE_LARGE_DATA) { 890 error = hammer_io_read(volume->devvp, &buffer->io, 891 buffer->io.bytes); 892 } else { 893 hammer_off_t limit; 894 895 limit = (buffer->zone2_offset + 896 HAMMER_LARGEBLOCK_MASK64) & 897 ~HAMMER_LARGEBLOCK_MASK64; 898 limit -= buffer->zone2_offset; 899 error = hammer_io_read(volume->devvp, &buffer->io, 900 limit); 901 } 902 if (error == 0) 903 buffer->ondisk = (void *)buffer->io.bp->b_data; 904 } else if (isnew) { 905 error = hammer_io_new(volume->devvp, &buffer->io); 906 } else { 907 error = 0; 908 } 909 if (error == 0) { 910 hammer_io_advance(&buffer->io); 911 hammer_ref_interlock_done(&buffer->io.lock); 912 } else { 913 hammer_rel_buffer(buffer, 1); 914 } 915 return (error); 916 } 917 918 /* 919 * NOTE: Called from RB_SCAN, must return >= 0 for scan to continue. 920 * This routine is only called during unmount or when a volume is 921 * removed. 922 * 923 * If data != NULL, it specifies a volume whoose buffers should 924 * be unloaded. 925 */ 926 int 927 hammer_unload_buffer(hammer_buffer_t buffer, void *data) 928 { 929 struct hammer_volume *volume = (struct hammer_volume *) data; 930 931 /* 932 * If volume != NULL we are only interested in unloading buffers 933 * associated with a particular volume. 934 */ 935 if (volume != NULL && volume != buffer->io.volume) 936 return 0; 937 938 /* 939 * Clean up the persistent ref ioerror might have on the buffer 940 * and acquire a ref. Expect a 0->1 transition. 941 */ 942 if (buffer->io.ioerror) { 943 hammer_io_clear_error_noassert(&buffer->io); 944 atomic_add_int(&hammer_count_refedbufs, -1); 945 } 946 hammer_ref_interlock_true(&buffer->io.lock); 947 atomic_add_int(&hammer_count_refedbufs, 1); 948 949 /* 950 * We must not flush a dirty buffer to disk on umount. It should 951 * have already been dealt with by the flusher, or we may be in 952 * catastrophic failure. 953 * 954 * We must set waitdep to ensure that a running buffer is waited 955 * on and released prior to us trying to unload the volume. 956 */ 957 hammer_io_clear_modify(&buffer->io, 1); 958 hammer_flush_buffer_nodes(buffer); 959 buffer->io.waitdep = 1; 960 hammer_rel_buffer(buffer, 1); 961 return(0); 962 } 963 964 /* 965 * Reference a buffer that is either already referenced or via a specially 966 * handled pointer (aka cursor->buffer). 967 */ 968 int 969 hammer_ref_buffer(hammer_buffer_t buffer) 970 { 971 hammer_mount_t hmp; 972 int error; 973 int locked; 974 975 /* 976 * Acquire a ref, plus the buffer will be interlocked on the 977 * 0->1 transition. 978 */ 979 locked = hammer_ref_interlock(&buffer->io.lock); 980 hmp = buffer->io.hmp; 981 982 /* 983 * At this point a biodone() will not touch the buffer other then 984 * incidental bits. However, lose_list can be modified via 985 * a biodone() interrupt. 986 * 987 * No longer loose. lose_list requires the io_token. 988 */ 989 if (buffer->io.mod_root == &hmp->lose_root) { 990 lwkt_gettoken(&hmp->io_token); 991 if (buffer->io.mod_root == &hmp->lose_root) { 992 RB_REMOVE(hammer_mod_rb_tree, 993 buffer->io.mod_root, &buffer->io); 994 buffer->io.mod_root = NULL; 995 } 996 lwkt_reltoken(&hmp->io_token); 997 } 998 999 if (locked) { 1000 atomic_add_int(&hammer_count_refedbufs, 1); 1001 error = hammer_load_buffer(buffer, 0); 1002 /* NOTE: on error the buffer pointer is stale */ 1003 } else { 1004 error = 0; 1005 } 1006 return(error); 1007 } 1008 1009 /* 1010 * Release a reference on the buffer. On the 1->0 transition the 1011 * underlying IO will be released but the data reference is left 1012 * cached. 1013 * 1014 * Only destroy the structure itself if the related buffer cache buffer 1015 * was disassociated from it. This ties the management of the structure 1016 * to the buffer cache subsystem. buffer->ondisk determines whether the 1017 * embedded io is referenced or not. 1018 */ 1019 void 1020 hammer_rel_buffer(hammer_buffer_t buffer, int locked) 1021 { 1022 hammer_volume_t volume; 1023 hammer_mount_t hmp; 1024 struct buf *bp = NULL; 1025 int freeme = 0; 1026 1027 hmp = buffer->io.hmp; 1028 1029 if (hammer_rel_interlock(&buffer->io.lock, locked) == 0) 1030 return; 1031 1032 /* 1033 * hammer_count_refedbufs accounting. Decrement if we are in 1034 * the error path or if CHECK is clear. 1035 * 1036 * If we are not in the error path and CHECK is set the caller 1037 * probably just did a hammer_ref() and didn't account for it, 1038 * so we don't account for the loss here. 1039 */ 1040 if (locked || (buffer->io.lock.refs & HAMMER_REFS_CHECK) == 0) 1041 atomic_add_int(&hammer_count_refedbufs, -1); 1042 1043 /* 1044 * If the caller locked us or the normal released transitions 1045 * from 1->0 (and acquired the lock) attempt to release the 1046 * io. If the called locked us we tell hammer_io_release() 1047 * to flush (which would be the unload or failure path). 1048 */ 1049 bp = hammer_io_release(&buffer->io, locked); 1050 1051 /* 1052 * If the buffer has no bp association and no refs we can destroy 1053 * it. 1054 * 1055 * NOTE: It is impossible for any associated B-Tree nodes to have 1056 * refs if the buffer has no additional refs. 1057 */ 1058 if (buffer->io.bp == NULL && hammer_norefs(&buffer->io.lock)) { 1059 RB_REMOVE(hammer_buf_rb_tree, 1060 &buffer->io.hmp->rb_bufs_root, 1061 buffer); 1062 volume = buffer->io.volume; 1063 buffer->io.volume = NULL; /* sanity */ 1064 hammer_rel_volume(volume, 0); 1065 hammer_io_clear_modlist(&buffer->io); 1066 hammer_flush_buffer_nodes(buffer); 1067 KKASSERT(TAILQ_EMPTY(&buffer->clist)); 1068 freeme = 1; 1069 } 1070 1071 /* 1072 * Cleanup 1073 */ 1074 hammer_rel_interlock_done(&buffer->io.lock, locked); 1075 if (bp) 1076 brelse(bp); 1077 if (freeme) { 1078 --hammer_count_buffers; 1079 kfree(buffer, hmp->m_misc); 1080 } 1081 } 1082 1083 /* 1084 * Access the filesystem buffer containing the specified hammer offset. 1085 * buf_offset is a conglomeration of the volume number and vol_buf_beg 1086 * relative buffer offset. It must also have bit 55 set to be valid. 1087 * (see hammer_off_t in hammer_disk.h). 1088 * 1089 * Any prior buffer in *bufferp will be released and replaced by the 1090 * requested buffer. 1091 * 1092 * NOTE: The buffer is indexed via its zoneX_offset but we allow the 1093 * passed cached *bufferp to match against either zoneX or zone2. 1094 */ 1095 static __inline 1096 void * 1097 _hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes, 1098 int *errorp, struct hammer_buffer **bufferp) 1099 { 1100 hammer_buffer_t buffer; 1101 int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK; 1102 1103 buf_offset &= ~HAMMER_BUFMASK64; 1104 KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) != 0); 1105 1106 buffer = *bufferp; 1107 if (buffer == NULL || (buffer->zone2_offset != buf_offset && 1108 buffer->zoneX_offset != buf_offset)) { 1109 if (buffer) 1110 hammer_rel_buffer(buffer, 0); 1111 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 0, errorp); 1112 *bufferp = buffer; 1113 } else { 1114 *errorp = 0; 1115 } 1116 1117 /* 1118 * Return a pointer to the buffer data. 1119 */ 1120 if (buffer == NULL) 1121 return(NULL); 1122 else 1123 return((char *)buffer->ondisk + xoff); 1124 } 1125 1126 void * 1127 hammer_bread(hammer_mount_t hmp, hammer_off_t buf_offset, 1128 int *errorp, struct hammer_buffer **bufferp) 1129 { 1130 return(_hammer_bread(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp)); 1131 } 1132 1133 void * 1134 hammer_bread_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes, 1135 int *errorp, struct hammer_buffer **bufferp) 1136 { 1137 bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK; 1138 return(_hammer_bread(hmp, buf_offset, bytes, errorp, bufferp)); 1139 } 1140 1141 /* 1142 * Access the filesystem buffer containing the specified hammer offset. 1143 * No disk read operation occurs. The result buffer may contain garbage. 1144 * 1145 * Any prior buffer in *bufferp will be released and replaced by the 1146 * requested buffer. 1147 * 1148 * This function marks the buffer dirty but does not increment its 1149 * modify_refs count. 1150 */ 1151 static __inline 1152 void * 1153 _hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes, 1154 int *errorp, struct hammer_buffer **bufferp) 1155 { 1156 hammer_buffer_t buffer; 1157 int32_t xoff = (int32_t)buf_offset & HAMMER_BUFMASK; 1158 1159 buf_offset &= ~HAMMER_BUFMASK64; 1160 1161 buffer = *bufferp; 1162 if (buffer == NULL || (buffer->zone2_offset != buf_offset && 1163 buffer->zoneX_offset != buf_offset)) { 1164 if (buffer) 1165 hammer_rel_buffer(buffer, 0); 1166 buffer = hammer_get_buffer(hmp, buf_offset, bytes, 1, errorp); 1167 *bufferp = buffer; 1168 } else { 1169 *errorp = 0; 1170 } 1171 1172 /* 1173 * Return a pointer to the buffer data. 1174 */ 1175 if (buffer == NULL) 1176 return(NULL); 1177 else 1178 return((char *)buffer->ondisk + xoff); 1179 } 1180 1181 void * 1182 hammer_bnew(hammer_mount_t hmp, hammer_off_t buf_offset, 1183 int *errorp, struct hammer_buffer **bufferp) 1184 { 1185 return(_hammer_bnew(hmp, buf_offset, HAMMER_BUFSIZE, errorp, bufferp)); 1186 } 1187 1188 void * 1189 hammer_bnew_ext(hammer_mount_t hmp, hammer_off_t buf_offset, int bytes, 1190 int *errorp, struct hammer_buffer **bufferp) 1191 { 1192 bytes = (bytes + HAMMER_BUFMASK) & ~HAMMER_BUFMASK; 1193 return(_hammer_bnew(hmp, buf_offset, bytes, errorp, bufferp)); 1194 } 1195 1196 /************************************************************************ 1197 * NODES * 1198 ************************************************************************ 1199 * 1200 * Manage B-Tree nodes. B-Tree nodes represent the primary indexing 1201 * method used by the HAMMER filesystem. 1202 * 1203 * Unlike other HAMMER structures, a hammer_node can be PASSIVELY 1204 * associated with its buffer, and will only referenced the buffer while 1205 * the node itself is referenced. 1206 * 1207 * A hammer_node can also be passively associated with other HAMMER 1208 * structures, such as inodes, while retaining 0 references. These 1209 * associations can be cleared backwards using a pointer-to-pointer in 1210 * the hammer_node. 1211 * 1212 * This allows the HAMMER implementation to cache hammer_nodes long-term 1213 * and short-cut a great deal of the infrastructure's complexity. In 1214 * most cases a cached node can be reacquired without having to dip into 1215 * either the buffer or cluster management code. 1216 * 1217 * The caller must pass a referenced cluster on call and will retain 1218 * ownership of the reference on return. The node will acquire its own 1219 * additional references, if necessary. 1220 */ 1221 hammer_node_t 1222 hammer_get_node(hammer_transaction_t trans, hammer_off_t node_offset, 1223 int isnew, int *errorp) 1224 { 1225 hammer_mount_t hmp = trans->hmp; 1226 hammer_node_t node; 1227 int doload; 1228 1229 KKASSERT((node_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_BTREE); 1230 1231 /* 1232 * Locate the structure, allocating one if necessary. 1233 */ 1234 again: 1235 node = RB_LOOKUP(hammer_nod_rb_tree, &hmp->rb_nods_root, node_offset); 1236 if (node == NULL) { 1237 ++hammer_count_nodes; 1238 node = kmalloc(sizeof(*node), hmp->m_misc, M_WAITOK|M_ZERO|M_USE_RESERVE); 1239 node->node_offset = node_offset; 1240 node->hmp = hmp; 1241 TAILQ_INIT(&node->cursor_list); 1242 TAILQ_INIT(&node->cache_list); 1243 if (RB_INSERT(hammer_nod_rb_tree, &hmp->rb_nods_root, node)) { 1244 --hammer_count_nodes; 1245 kfree(node, hmp->m_misc); 1246 goto again; 1247 } 1248 doload = hammer_ref_interlock_true(&node->lock); 1249 } else { 1250 doload = hammer_ref_interlock(&node->lock); 1251 } 1252 if (doload) { 1253 *errorp = hammer_load_node(trans, node, isnew); 1254 trans->flags |= HAMMER_TRANSF_DIDIO; 1255 if (*errorp) 1256 node = NULL; 1257 } else { 1258 KKASSERT(node->ondisk); 1259 *errorp = 0; 1260 hammer_io_advance(&node->buffer->io); 1261 } 1262 return(node); 1263 } 1264 1265 /* 1266 * Reference an already-referenced node. 0->1 transitions should assert 1267 * so we do not have to deal with hammer_ref() setting CHECK. 1268 */ 1269 void 1270 hammer_ref_node(hammer_node_t node) 1271 { 1272 KKASSERT(hammer_isactive(&node->lock) && node->ondisk != NULL); 1273 hammer_ref(&node->lock); 1274 } 1275 1276 /* 1277 * Load a node's on-disk data reference. Called with the node referenced 1278 * and interlocked. 1279 * 1280 * On return the node interlock will be unlocked. If a non-zero error code 1281 * is returned the node will also be dereferenced (and the caller's pointer 1282 * will be stale). 1283 */ 1284 static int 1285 hammer_load_node(hammer_transaction_t trans, hammer_node_t node, int isnew) 1286 { 1287 hammer_buffer_t buffer; 1288 hammer_off_t buf_offset; 1289 int error; 1290 1291 error = 0; 1292 if (node->ondisk == NULL) { 1293 /* 1294 * This is a little confusing but the jist is that 1295 * node->buffer determines whether the node is on 1296 * the buffer's clist and node->ondisk determines 1297 * whether the buffer is referenced. 1298 * 1299 * We could be racing a buffer release, in which case 1300 * node->buffer may become NULL while we are blocked 1301 * referencing the buffer. 1302 */ 1303 if ((buffer = node->buffer) != NULL) { 1304 error = hammer_ref_buffer(buffer); 1305 if (error == 0 && node->buffer == NULL) { 1306 TAILQ_INSERT_TAIL(&buffer->clist, 1307 node, entry); 1308 node->buffer = buffer; 1309 } 1310 } else { 1311 buf_offset = node->node_offset & ~HAMMER_BUFMASK64; 1312 buffer = hammer_get_buffer(node->hmp, buf_offset, 1313 HAMMER_BUFSIZE, 0, &error); 1314 if (buffer) { 1315 KKASSERT(error == 0); 1316 TAILQ_INSERT_TAIL(&buffer->clist, 1317 node, entry); 1318 node->buffer = buffer; 1319 } 1320 } 1321 if (error) 1322 goto failed; 1323 node->ondisk = (void *)((char *)buffer->ondisk + 1324 (node->node_offset & HAMMER_BUFMASK)); 1325 1326 /* 1327 * Check CRC. NOTE: Neither flag is set and the CRC is not 1328 * generated on new B-Tree nodes. 1329 */ 1330 if (isnew == 0 && 1331 (node->flags & HAMMER_NODE_CRCANY) == 0) { 1332 if (hammer_crc_test_btree(node->ondisk) == 0) { 1333 if (hammer_debug_critical) 1334 Debugger("CRC FAILED: B-TREE NODE"); 1335 node->flags |= HAMMER_NODE_CRCBAD; 1336 } else { 1337 node->flags |= HAMMER_NODE_CRCGOOD; 1338 } 1339 } 1340 } 1341 if (node->flags & HAMMER_NODE_CRCBAD) { 1342 if (trans->flags & HAMMER_TRANSF_CRCDOM) 1343 error = EDOM; 1344 else 1345 error = EIO; 1346 } 1347 failed: 1348 if (error) { 1349 _hammer_rel_node(node, 1); 1350 } else { 1351 hammer_ref_interlock_done(&node->lock); 1352 } 1353 return (error); 1354 } 1355 1356 /* 1357 * Safely reference a node, interlock against flushes via the IO subsystem. 1358 */ 1359 hammer_node_t 1360 hammer_ref_node_safe(hammer_transaction_t trans, hammer_node_cache_t cache, 1361 int *errorp) 1362 { 1363 hammer_node_t node; 1364 int doload; 1365 1366 node = cache->node; 1367 if (node != NULL) { 1368 doload = hammer_ref_interlock(&node->lock); 1369 if (doload) { 1370 *errorp = hammer_load_node(trans, node, 0); 1371 if (*errorp) 1372 node = NULL; 1373 } else { 1374 KKASSERT(node->ondisk); 1375 if (node->flags & HAMMER_NODE_CRCBAD) { 1376 if (trans->flags & HAMMER_TRANSF_CRCDOM) 1377 *errorp = EDOM; 1378 else 1379 *errorp = EIO; 1380 _hammer_rel_node(node, 0); 1381 node = NULL; 1382 } else { 1383 *errorp = 0; 1384 } 1385 } 1386 } else { 1387 *errorp = ENOENT; 1388 } 1389 return(node); 1390 } 1391 1392 /* 1393 * Release a hammer_node. On the last release the node dereferences 1394 * its underlying buffer and may or may not be destroyed. 1395 * 1396 * If locked is non-zero the passed node has been interlocked by the 1397 * caller and we are in the failure/unload path, otherwise it has not and 1398 * we are doing a normal release. 1399 * 1400 * This function will dispose of the interlock and the reference. 1401 * On return the node pointer is stale. 1402 */ 1403 void 1404 _hammer_rel_node(hammer_node_t node, int locked) 1405 { 1406 hammer_buffer_t buffer; 1407 1408 /* 1409 * Deref the node. If this isn't the 1->0 transition we're basically 1410 * done. If locked is non-zero this function will just deref the 1411 * locked node and return TRUE, otherwise it will deref the locked 1412 * node and either lock and return TRUE on the 1->0 transition or 1413 * not lock and return FALSE. 1414 */ 1415 if (hammer_rel_interlock(&node->lock, locked) == 0) 1416 return; 1417 1418 /* 1419 * Either locked was non-zero and we are interlocked, or the 1420 * hammer_rel_interlock() call returned non-zero and we are 1421 * interlocked. 1422 * 1423 * The ref-count must still be decremented if locked != 0 so 1424 * the cleanup required still varies a bit. 1425 * 1426 * hammer_flush_node() when called with 1 or 2 will dispose of 1427 * the lock and possible ref-count. 1428 */ 1429 if (node->ondisk == NULL) { 1430 hammer_flush_node(node, locked + 1); 1431 /* node is stale now */ 1432 return; 1433 } 1434 1435 /* 1436 * Do not disassociate the node from the buffer if it represents 1437 * a modified B-Tree node that still needs its crc to be generated. 1438 */ 1439 if (node->flags & HAMMER_NODE_NEEDSCRC) { 1440 hammer_rel_interlock_done(&node->lock, locked); 1441 return; 1442 } 1443 1444 /* 1445 * Do final cleanups and then either destroy the node and leave it 1446 * passively cached. The buffer reference is removed regardless. 1447 */ 1448 buffer = node->buffer; 1449 node->ondisk = NULL; 1450 1451 if ((node->flags & HAMMER_NODE_FLUSH) == 0) { 1452 /* 1453 * Normal release. 1454 */ 1455 hammer_rel_interlock_done(&node->lock, locked); 1456 } else { 1457 /* 1458 * Destroy the node. 1459 */ 1460 hammer_flush_node(node, locked + 1); 1461 /* node is stale */ 1462 1463 } 1464 hammer_rel_buffer(buffer, 0); 1465 } 1466 1467 void 1468 hammer_rel_node(hammer_node_t node) 1469 { 1470 _hammer_rel_node(node, 0); 1471 } 1472 1473 /* 1474 * Free space on-media associated with a B-Tree node. 1475 */ 1476 void 1477 hammer_delete_node(hammer_transaction_t trans, hammer_node_t node) 1478 { 1479 KKASSERT((node->flags & HAMMER_NODE_DELETED) == 0); 1480 node->flags |= HAMMER_NODE_DELETED; 1481 hammer_blockmap_free(trans, node->node_offset, sizeof(*node->ondisk)); 1482 } 1483 1484 /* 1485 * Passively cache a referenced hammer_node. The caller may release 1486 * the node on return. 1487 */ 1488 void 1489 hammer_cache_node(hammer_node_cache_t cache, hammer_node_t node) 1490 { 1491 /* 1492 * If the node doesn't exist, or is being deleted, don't cache it! 1493 * 1494 * The node can only ever be NULL in the I/O failure path. 1495 */ 1496 if (node == NULL || (node->flags & HAMMER_NODE_DELETED)) 1497 return; 1498 if (cache->node == node) 1499 return; 1500 while (cache->node) 1501 hammer_uncache_node(cache); 1502 if (node->flags & HAMMER_NODE_DELETED) 1503 return; 1504 cache->node = node; 1505 TAILQ_INSERT_TAIL(&node->cache_list, cache, entry); 1506 } 1507 1508 void 1509 hammer_uncache_node(hammer_node_cache_t cache) 1510 { 1511 hammer_node_t node; 1512 1513 if ((node = cache->node) != NULL) { 1514 TAILQ_REMOVE(&node->cache_list, cache, entry); 1515 cache->node = NULL; 1516 if (TAILQ_EMPTY(&node->cache_list)) 1517 hammer_flush_node(node, 0); 1518 } 1519 } 1520 1521 /* 1522 * Remove a node's cache references and destroy the node if it has no 1523 * other references or backing store. 1524 * 1525 * locked == 0 Normal unlocked operation 1526 * locked == 1 Call hammer_rel_interlock_done(..., 0); 1527 * locked == 2 Call hammer_rel_interlock_done(..., 1); 1528 * 1529 * XXX for now this isn't even close to being MPSAFE so the refs check 1530 * is sufficient. 1531 */ 1532 void 1533 hammer_flush_node(hammer_node_t node, int locked) 1534 { 1535 hammer_node_cache_t cache; 1536 hammer_buffer_t buffer; 1537 hammer_mount_t hmp = node->hmp; 1538 int dofree; 1539 1540 while ((cache = TAILQ_FIRST(&node->cache_list)) != NULL) { 1541 TAILQ_REMOVE(&node->cache_list, cache, entry); 1542 cache->node = NULL; 1543 } 1544 1545 /* 1546 * NOTE: refs is predisposed if another thread is blocking and 1547 * will be larger than 0 in that case. We aren't MPSAFE 1548 * here. 1549 */ 1550 if (node->ondisk == NULL && hammer_norefs(&node->lock)) { 1551 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0); 1552 RB_REMOVE(hammer_nod_rb_tree, &node->hmp->rb_nods_root, node); 1553 if ((buffer = node->buffer) != NULL) { 1554 node->buffer = NULL; 1555 TAILQ_REMOVE(&buffer->clist, node, entry); 1556 /* buffer is unreferenced because ondisk is NULL */ 1557 } 1558 dofree = 1; 1559 } else { 1560 dofree = 0; 1561 } 1562 1563 /* 1564 * Deal with the interlock if locked == 1 or locked == 2. 1565 */ 1566 if (locked) 1567 hammer_rel_interlock_done(&node->lock, locked - 1); 1568 1569 /* 1570 * Destroy if requested 1571 */ 1572 if (dofree) { 1573 --hammer_count_nodes; 1574 kfree(node, hmp->m_misc); 1575 } 1576 } 1577 1578 /* 1579 * Flush passively cached B-Tree nodes associated with this buffer. 1580 * This is only called when the buffer is about to be destroyed, so 1581 * none of the nodes should have any references. The buffer is locked. 1582 * 1583 * We may be interlocked with the buffer. 1584 */ 1585 void 1586 hammer_flush_buffer_nodes(hammer_buffer_t buffer) 1587 { 1588 hammer_node_t node; 1589 1590 while ((node = TAILQ_FIRST(&buffer->clist)) != NULL) { 1591 KKASSERT(node->ondisk == NULL); 1592 KKASSERT((node->flags & HAMMER_NODE_NEEDSCRC) == 0); 1593 1594 if (hammer_try_interlock_norefs(&node->lock)) { 1595 hammer_ref(&node->lock); 1596 node->flags |= HAMMER_NODE_FLUSH; 1597 _hammer_rel_node(node, 1); 1598 } else { 1599 KKASSERT(node->buffer != NULL); 1600 buffer = node->buffer; 1601 node->buffer = NULL; 1602 TAILQ_REMOVE(&buffer->clist, node, entry); 1603 /* buffer is unreferenced because ondisk is NULL */ 1604 } 1605 } 1606 } 1607 1608 1609 /************************************************************************ 1610 * ALLOCATORS * 1611 ************************************************************************/ 1612 1613 /* 1614 * Allocate a B-Tree node. 1615 */ 1616 hammer_node_t 1617 hammer_alloc_btree(hammer_transaction_t trans, hammer_off_t hint, int *errorp) 1618 { 1619 hammer_buffer_t buffer = NULL; 1620 hammer_node_t node = NULL; 1621 hammer_off_t node_offset; 1622 1623 node_offset = hammer_blockmap_alloc(trans, HAMMER_ZONE_BTREE_INDEX, 1624 sizeof(struct hammer_node_ondisk), 1625 hint, errorp); 1626 if (*errorp == 0) { 1627 node = hammer_get_node(trans, node_offset, 1, errorp); 1628 hammer_modify_node_noundo(trans, node); 1629 bzero(node->ondisk, sizeof(*node->ondisk)); 1630 hammer_modify_node_done(node); 1631 } 1632 if (buffer) 1633 hammer_rel_buffer(buffer, 0); 1634 return(node); 1635 } 1636 1637 /* 1638 * Allocate data. If the address of a data buffer is supplied then 1639 * any prior non-NULL *data_bufferp will be released and *data_bufferp 1640 * will be set to the related buffer. The caller must release it when 1641 * finally done. The initial *data_bufferp should be set to NULL by 1642 * the caller. 1643 * 1644 * The caller is responsible for making hammer_modify*() calls on the 1645 * *data_bufferp. 1646 */ 1647 void * 1648 hammer_alloc_data(hammer_transaction_t trans, int32_t data_len, 1649 u_int16_t rec_type, hammer_off_t *data_offsetp, 1650 struct hammer_buffer **data_bufferp, 1651 hammer_off_t hint, int *errorp) 1652 { 1653 void *data; 1654 int zone; 1655 1656 /* 1657 * Allocate data 1658 */ 1659 if (data_len) { 1660 switch(rec_type) { 1661 case HAMMER_RECTYPE_INODE: 1662 case HAMMER_RECTYPE_DIRENTRY: 1663 case HAMMER_RECTYPE_EXT: 1664 case HAMMER_RECTYPE_FIX: 1665 case HAMMER_RECTYPE_PFS: 1666 case HAMMER_RECTYPE_SNAPSHOT: 1667 case HAMMER_RECTYPE_CONFIG: 1668 zone = HAMMER_ZONE_META_INDEX; 1669 break; 1670 case HAMMER_RECTYPE_DATA: 1671 case HAMMER_RECTYPE_DB: 1672 if (data_len <= HAMMER_BUFSIZE / 2) { 1673 zone = HAMMER_ZONE_SMALL_DATA_INDEX; 1674 } else { 1675 data_len = (data_len + HAMMER_BUFMASK) & 1676 ~HAMMER_BUFMASK; 1677 zone = HAMMER_ZONE_LARGE_DATA_INDEX; 1678 } 1679 break; 1680 default: 1681 panic("hammer_alloc_data: rec_type %04x unknown", 1682 rec_type); 1683 zone = 0; /* NOT REACHED */ 1684 break; 1685 } 1686 *data_offsetp = hammer_blockmap_alloc(trans, zone, data_len, 1687 hint, errorp); 1688 } else { 1689 *data_offsetp = 0; 1690 } 1691 if (*errorp == 0 && data_bufferp) { 1692 if (data_len) { 1693 data = hammer_bread_ext(trans->hmp, *data_offsetp, 1694 data_len, errorp, data_bufferp); 1695 } else { 1696 data = NULL; 1697 } 1698 } else { 1699 data = NULL; 1700 } 1701 return(data); 1702 } 1703 1704 /* 1705 * Sync dirty buffers to the media and clean-up any loose ends. 1706 * 1707 * These functions do not start the flusher going, they simply 1708 * queue everything up to the flusher. 1709 */ 1710 static int hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data); 1711 1712 int 1713 hammer_queue_inodes_flusher(hammer_mount_t hmp, int waitfor) 1714 { 1715 struct hammer_sync_info info; 1716 1717 info.error = 0; 1718 info.waitfor = waitfor; 1719 if (waitfor == MNT_WAIT) { 1720 vsyncscan(hmp->mp, VMSC_GETVP | VMSC_ONEPASS, 1721 hammer_sync_scan2, &info); 1722 } else { 1723 vsyncscan(hmp->mp, VMSC_GETVP | VMSC_ONEPASS | VMSC_NOWAIT, 1724 hammer_sync_scan2, &info); 1725 } 1726 return(info.error); 1727 } 1728 1729 /* 1730 * Filesystem sync. If doing a synchronous sync make a second pass on 1731 * the vnodes in case any were already flushing during the first pass, 1732 * and activate the flusher twice (the second time brings the UNDO FIFO's 1733 * start position up to the end position after the first call). 1734 * 1735 * If doing a lazy sync make just one pass on the vnode list, ignoring 1736 * any new vnodes added to the list while the sync is in progress. 1737 */ 1738 int 1739 hammer_sync_hmp(hammer_mount_t hmp, int waitfor) 1740 { 1741 struct hammer_sync_info info; 1742 int flags; 1743 1744 flags = VMSC_GETVP; 1745 if (waitfor & MNT_LAZY) 1746 flags |= VMSC_ONEPASS; 1747 1748 info.error = 0; 1749 info.waitfor = MNT_NOWAIT; 1750 vsyncscan(hmp->mp, flags | VMSC_NOWAIT, hammer_sync_scan2, &info); 1751 1752 if (info.error == 0 && (waitfor & MNT_WAIT)) { 1753 info.waitfor = waitfor; 1754 vsyncscan(hmp->mp, flags, hammer_sync_scan2, &info); 1755 } 1756 if (waitfor == MNT_WAIT) { 1757 hammer_flusher_sync(hmp); 1758 hammer_flusher_sync(hmp); 1759 } else { 1760 hammer_flusher_async(hmp, NULL); 1761 hammer_flusher_async(hmp, NULL); 1762 } 1763 return(info.error); 1764 } 1765 1766 static int 1767 hammer_sync_scan2(struct mount *mp, struct vnode *vp, void *data) 1768 { 1769 struct hammer_sync_info *info = data; 1770 struct hammer_inode *ip; 1771 int error; 1772 1773 ip = VTOI(vp); 1774 if (ip == NULL) 1775 return(0); 1776 if (vp->v_type == VNON || vp->v_type == VBAD) { 1777 vclrisdirty(vp); 1778 return(0); 1779 } 1780 if ((ip->flags & HAMMER_INODE_MODMASK) == 0 && 1781 RB_EMPTY(&vp->v_rbdirty_tree)) { 1782 vclrisdirty(vp); 1783 return(0); 1784 } 1785 error = VOP_FSYNC(vp, MNT_NOWAIT, 0); 1786 if (error) 1787 info->error = error; 1788 return(0); 1789 } 1790