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_io.c,v 1.53 2008/08/06 15:38:58 dillon Exp $ 35 */ 36 /* 37 * IO Primitives and buffer cache management 38 * 39 * All major data-tracking structures in HAMMER contain a struct hammer_io 40 * which is used to manage their backing store. We use filesystem buffers 41 * for backing store and we leave them passively associated with their 42 * HAMMER structures. 43 * 44 * If the kernel tries to destroy a passively associated buf which we cannot 45 * yet let go we set B_LOCKED in the buffer and then actively released it 46 * later when we can. 47 */ 48 49 #include "hammer.h" 50 #include <sys/fcntl.h> 51 #include <sys/nlookup.h> 52 #include <sys/buf.h> 53 #include <sys/buf2.h> 54 55 static void hammer_io_modify(hammer_io_t io, int count); 56 static void hammer_io_deallocate(struct buf *bp); 57 #if 0 58 static void hammer_io_direct_read_complete(struct bio *nbio); 59 #endif 60 static void hammer_io_direct_write_complete(struct bio *nbio); 61 static int hammer_io_direct_uncache_callback(hammer_inode_t ip, void *data); 62 static void hammer_io_set_modlist(struct hammer_io *io); 63 64 /* 65 * Initialize a new, already-zero'd hammer_io structure, or reinitialize 66 * an existing hammer_io structure which may have switched to another type. 67 */ 68 void 69 hammer_io_init(hammer_io_t io, hammer_mount_t hmp, enum hammer_io_type type) 70 { 71 io->hmp = hmp; 72 io->type = type; 73 } 74 75 /* 76 * Helper routine to disassociate a buffer cache buffer from an I/O 77 * structure. The buffer is unlocked and marked appropriate for reclamation. 78 * 79 * The io may have 0 or 1 references depending on who called us. The 80 * caller is responsible for dealing with the refs. 81 * 82 * This call can only be made when no action is required on the buffer. 83 * 84 * The caller must own the buffer and the IO must indicate that the 85 * structure no longer owns it (io.released != 0). 86 */ 87 static void 88 hammer_io_disassociate(hammer_io_structure_t iou) 89 { 90 struct buf *bp = iou->io.bp; 91 92 KKASSERT(iou->io.released); 93 KKASSERT(iou->io.modified == 0); 94 KKASSERT(LIST_FIRST(&bp->b_dep) == (void *)iou); 95 buf_dep_init(bp); 96 iou->io.bp = NULL; 97 98 /* 99 * If the buffer was locked someone wanted to get rid of it. 100 */ 101 if (bp->b_flags & B_LOCKED) { 102 --hammer_count_io_locked; 103 bp->b_flags &= ~B_LOCKED; 104 } 105 if (iou->io.reclaim) { 106 bp->b_flags |= B_NOCACHE|B_RELBUF; 107 iou->io.reclaim = 0; 108 } 109 110 switch(iou->io.type) { 111 case HAMMER_STRUCTURE_VOLUME: 112 iou->volume.ondisk = NULL; 113 break; 114 case HAMMER_STRUCTURE_DATA_BUFFER: 115 case HAMMER_STRUCTURE_META_BUFFER: 116 case HAMMER_STRUCTURE_UNDO_BUFFER: 117 iou->buffer.ondisk = NULL; 118 break; 119 } 120 } 121 122 /* 123 * Wait for any physical IO to complete 124 */ 125 void 126 hammer_io_wait(hammer_io_t io) 127 { 128 if (io->running) { 129 crit_enter(); 130 tsleep_interlock(io); 131 io->waiting = 1; 132 for (;;) { 133 tsleep(io, 0, "hmrflw", 0); 134 if (io->running == 0) 135 break; 136 tsleep_interlock(io); 137 io->waiting = 1; 138 if (io->running == 0) 139 break; 140 } 141 crit_exit(); 142 } 143 } 144 145 /* 146 * Wait for all hammer_io-initated write I/O's to complete. This is not 147 * supposed to count direct I/O's but some can leak through (for 148 * non-full-sized direct I/Os). 149 */ 150 void 151 hammer_io_wait_all(hammer_mount_t hmp, const char *ident) 152 { 153 crit_enter(); 154 while (hmp->io_running_space) 155 tsleep(&hmp->io_running_space, 0, ident, 0); 156 crit_exit(); 157 } 158 159 #define HAMMER_MAXRA 4 160 161 /* 162 * Load bp for a HAMMER structure. The io must be exclusively locked by 163 * the caller. 164 * 165 * This routine is mostly used on meta-data and small-data blocks. Generally 166 * speaking HAMMER assumes some locality of reference and will cluster 167 * a 64K read. 168 * 169 * Note that clustering occurs at the device layer, not the logical layer. 170 * If the buffers do not apply to the current operation they may apply to 171 * some other. 172 */ 173 int 174 hammer_io_read(struct vnode *devvp, struct hammer_io *io, hammer_off_t limit) 175 { 176 struct buf *bp; 177 int error; 178 179 if ((bp = io->bp) == NULL) { 180 hammer_count_io_running_read += io->bytes; 181 if (hammer_cluster_enable) { 182 error = cluster_read(devvp, limit, 183 io->offset, io->bytes, 184 HAMMER_CLUSTER_SIZE, 185 HAMMER_CLUSTER_BUFS, &io->bp); 186 } else { 187 error = bread(devvp, io->offset, io->bytes, &io->bp); 188 } 189 hammer_stats_disk_read += io->bytes; 190 hammer_count_io_running_read -= io->bytes; 191 192 /* 193 * The code generally assumes b_ops/b_dep has been set-up, 194 * even if we error out here. 195 */ 196 bp = io->bp; 197 bp->b_ops = &hammer_bioops; 198 KKASSERT(LIST_FIRST(&bp->b_dep) == NULL); 199 LIST_INSERT_HEAD(&bp->b_dep, &io->worklist, node); 200 BUF_KERNPROC(bp); 201 KKASSERT(io->modified == 0); 202 KKASSERT(io->running == 0); 203 KKASSERT(io->waiting == 0); 204 io->released = 0; /* we hold an active lock on bp */ 205 } else { 206 error = 0; 207 } 208 return(error); 209 } 210 211 /* 212 * Similar to hammer_io_read() but returns a zero'd out buffer instead. 213 * Must be called with the IO exclusively locked. 214 * 215 * vfs_bio_clrbuf() is kinda nasty, enforce serialization against background 216 * I/O by forcing the buffer to not be in a released state before calling 217 * it. 218 * 219 * This function will also mark the IO as modified but it will not 220 * increment the modify_refs count. 221 */ 222 int 223 hammer_io_new(struct vnode *devvp, struct hammer_io *io) 224 { 225 struct buf *bp; 226 227 if ((bp = io->bp) == NULL) { 228 io->bp = getblk(devvp, io->offset, io->bytes, 0, 0); 229 bp = io->bp; 230 bp->b_ops = &hammer_bioops; 231 KKASSERT(LIST_FIRST(&bp->b_dep) == NULL); 232 LIST_INSERT_HEAD(&bp->b_dep, &io->worklist, node); 233 io->released = 0; 234 KKASSERT(io->running == 0); 235 io->waiting = 0; 236 BUF_KERNPROC(bp); 237 } else { 238 if (io->released) { 239 regetblk(bp); 240 BUF_KERNPROC(bp); 241 io->released = 0; 242 } 243 } 244 hammer_io_modify(io, 0); 245 vfs_bio_clrbuf(bp); 246 return(0); 247 } 248 249 /* 250 * Remove potential device level aliases against buffers managed by high level 251 * vnodes. Aliases can also be created due to mixed buffer sizes. 252 * 253 * This is nasty because the buffers are also VMIO-backed. Even if a buffer 254 * does not exist its backing VM pages might, and we have to invalidate 255 * those as well or a getblk() will reinstate them. 256 */ 257 void 258 hammer_io_inval(hammer_volume_t volume, hammer_off_t zone2_offset) 259 { 260 hammer_io_structure_t iou; 261 hammer_off_t phys_offset; 262 struct buf *bp; 263 264 phys_offset = volume->ondisk->vol_buf_beg + 265 (zone2_offset & HAMMER_OFF_SHORT_MASK); 266 crit_enter(); 267 if ((bp = findblk(volume->devvp, phys_offset)) != NULL) 268 bp = getblk(volume->devvp, phys_offset, bp->b_bufsize, 0, 0); 269 else 270 bp = getblk(volume->devvp, phys_offset, HAMMER_BUFSIZE, 0, 0); 271 if ((iou = (void *)LIST_FIRST(&bp->b_dep)) != NULL) { 272 hammer_ref(&iou->io.lock); 273 hammer_io_clear_modify(&iou->io, 1); 274 bundirty(bp); 275 iou->io.reclaim = 1; 276 iou->io.waitdep = 1; 277 KKASSERT(iou->io.lock.refs == 0); 278 hammer_rel_buffer(&iou->buffer, 0); 279 /*hammer_io_deallocate(bp);*/ 280 } else { 281 KKASSERT((bp->b_flags & B_LOCKED) == 0); 282 bundirty(bp); 283 bp->b_flags |= B_NOCACHE|B_RELBUF; 284 } 285 brelse(bp); 286 crit_exit(); 287 } 288 289 /* 290 * This routine is called on the last reference to a hammer structure. 291 * The io is usually interlocked with io.loading and io.refs must be 1. 292 * 293 * This routine may return a non-NULL bp to the caller for dispoal. Disposal 294 * simply means the caller finishes decrementing the ref-count on the 295 * IO structure then brelse()'s the bp. The bp may or may not still be 296 * passively associated with the IO. 297 * 298 * The only requirement here is that modified meta-data and volume-header 299 * buffer may NOT be disassociated from the IO structure, and consequently 300 * we also leave such buffers actively associated with the IO if they already 301 * are (since the kernel can't do anything with them anyway). Only the 302 * flusher is allowed to write such buffers out. Modified pure-data and 303 * undo buffers are returned to the kernel but left passively associated 304 * so we can track when the kernel writes the bp out. 305 */ 306 struct buf * 307 hammer_io_release(struct hammer_io *io, int flush) 308 { 309 union hammer_io_structure *iou = (void *)io; 310 struct buf *bp; 311 312 if ((bp = io->bp) == NULL) 313 return(NULL); 314 315 /* 316 * Try to flush a dirty IO to disk if asked to by the 317 * caller or if the kernel tried to flush the buffer in the past. 318 * 319 * Kernel-initiated flushes are only allowed for pure-data buffers. 320 * meta-data and volume buffers can only be flushed explicitly 321 * by HAMMER. 322 */ 323 if (io->modified) { 324 if (flush) { 325 hammer_io_flush(io); 326 } else if (bp->b_flags & B_LOCKED) { 327 switch(io->type) { 328 case HAMMER_STRUCTURE_DATA_BUFFER: 329 case HAMMER_STRUCTURE_UNDO_BUFFER: 330 hammer_io_flush(io); 331 break; 332 default: 333 break; 334 } 335 } /* else no explicit request to flush the buffer */ 336 } 337 338 /* 339 * Wait for the IO to complete if asked to. This occurs when 340 * the buffer must be disposed of definitively during an umount 341 * or buffer invalidation. 342 */ 343 if (io->waitdep && io->running) { 344 hammer_io_wait(io); 345 } 346 347 /* 348 * Return control of the buffer to the kernel (with the provisio 349 * that our bioops can override kernel decisions with regards to 350 * the buffer). 351 */ 352 if ((flush || io->reclaim) && io->modified == 0 && io->running == 0) { 353 /* 354 * Always disassociate the bp if an explicit flush 355 * was requested and the IO completed with no error 356 * (so unmount can really clean up the structure). 357 */ 358 if (io->released) { 359 regetblk(bp); 360 BUF_KERNPROC(bp); 361 } else { 362 io->released = 1; 363 } 364 hammer_io_disassociate((hammer_io_structure_t)io); 365 /* return the bp */ 366 } else if (io->modified) { 367 /* 368 * Only certain IO types can be released to the kernel if 369 * the buffer has been modified. 370 * 371 * volume and meta-data IO types may only be explicitly 372 * flushed by HAMMER. 373 */ 374 switch(io->type) { 375 case HAMMER_STRUCTURE_DATA_BUFFER: 376 case HAMMER_STRUCTURE_UNDO_BUFFER: 377 if (io->released == 0) { 378 io->released = 1; 379 bdwrite(bp); 380 } 381 break; 382 default: 383 break; 384 } 385 bp = NULL; /* bp left associated */ 386 } else if (io->released == 0) { 387 /* 388 * Clean buffers can be generally released to the kernel. 389 * We leave the bp passively associated with the HAMMER 390 * structure and use bioops to disconnect it later on 391 * if the kernel wants to discard the buffer. 392 * 393 * We can steal the structure's ownership of the bp. 394 */ 395 io->released = 1; 396 if (bp->b_flags & B_LOCKED) { 397 hammer_io_disassociate(iou); 398 /* return the bp */ 399 } else { 400 if (io->reclaim) { 401 hammer_io_disassociate(iou); 402 /* return the bp */ 403 } else { 404 /* return the bp (bp passively associated) */ 405 } 406 } 407 } else { 408 /* 409 * A released buffer is passively associate with our 410 * hammer_io structure. The kernel cannot destroy it 411 * without making a bioops call. If the kernel (B_LOCKED) 412 * or we (reclaim) requested that the buffer be destroyed 413 * we destroy it, otherwise we do a quick get/release to 414 * reset its position in the kernel's LRU list. 415 * 416 * Leaving the buffer passively associated allows us to 417 * use the kernel's LRU buffer flushing mechanisms rather 418 * then rolling our own. 419 * 420 * XXX there are two ways of doing this. We can re-acquire 421 * and passively release to reset the LRU, or not. 422 */ 423 if (io->running == 0) { 424 regetblk(bp); 425 if ((bp->b_flags & B_LOCKED) || io->reclaim) { 426 hammer_io_disassociate(iou); 427 /* return the bp */ 428 } else { 429 /* return the bp (bp passively associated) */ 430 } 431 } else { 432 /* 433 * bp is left passively associated but we do not 434 * try to reacquire it. Interactions with the io 435 * structure will occur on completion of the bp's 436 * I/O. 437 */ 438 bp = NULL; 439 } 440 } 441 return(bp); 442 } 443 444 /* 445 * This routine is called with a locked IO when a flush is desired and 446 * no other references to the structure exists other then ours. This 447 * routine is ONLY called when HAMMER believes it is safe to flush a 448 * potentially modified buffer out. 449 */ 450 void 451 hammer_io_flush(struct hammer_io *io) 452 { 453 struct buf *bp; 454 455 /* 456 * Degenerate case - nothing to flush if nothing is dirty. 457 */ 458 if (io->modified == 0) { 459 return; 460 } 461 462 KKASSERT(io->bp); 463 KKASSERT(io->modify_refs <= 0); 464 465 /* 466 * Acquire ownership of the bp, particularly before we clear our 467 * modified flag. 468 * 469 * We are going to bawrite() this bp. Don't leave a window where 470 * io->released is set, we actually own the bp rather then our 471 * buffer. 472 */ 473 bp = io->bp; 474 if (io->released) { 475 regetblk(bp); 476 /* BUF_KERNPROC(io->bp); */ 477 /* io->released = 0; */ 478 KKASSERT(io->released); 479 KKASSERT(io->bp == bp); 480 } 481 io->released = 1; 482 483 /* 484 * Acquire exclusive access to the bp and then clear the modified 485 * state of the buffer prior to issuing I/O to interlock any 486 * modifications made while the I/O is in progress. This shouldn't 487 * happen anyway but losing data would be worse. The modified bit 488 * will be rechecked after the IO completes. 489 * 490 * NOTE: This call also finalizes the buffer's content (inval == 0). 491 * 492 * This is only legal when lock.refs == 1 (otherwise we might clear 493 * the modified bit while there are still users of the cluster 494 * modifying the data). 495 * 496 * Do this before potentially blocking so any attempt to modify the 497 * ondisk while we are blocked blocks waiting for us. 498 */ 499 hammer_ref(&io->lock); 500 hammer_io_clear_modify(io, 0); 501 hammer_unref(&io->lock); 502 503 /* 504 * Transfer ownership to the kernel and initiate I/O. 505 */ 506 io->running = 1; 507 io->hmp->io_running_space += io->bytes; 508 hammer_count_io_running_write += io->bytes; 509 bawrite(bp); 510 } 511 512 /************************************************************************ 513 * BUFFER DIRTYING * 514 ************************************************************************ 515 * 516 * These routines deal with dependancies created when IO buffers get 517 * modified. The caller must call hammer_modify_*() on a referenced 518 * HAMMER structure prior to modifying its on-disk data. 519 * 520 * Any intent to modify an IO buffer acquires the related bp and imposes 521 * various write ordering dependancies. 522 */ 523 524 /* 525 * Mark a HAMMER structure as undergoing modification. Meta-data buffers 526 * are locked until the flusher can deal with them, pure data buffers 527 * can be written out. 528 */ 529 static 530 void 531 hammer_io_modify(hammer_io_t io, int count) 532 { 533 /* 534 * io->modify_refs must be >= 0 535 */ 536 while (io->modify_refs < 0) { 537 io->waitmod = 1; 538 tsleep(io, 0, "hmrmod", 0); 539 } 540 541 /* 542 * Shortcut if nothing to do. 543 */ 544 KKASSERT(io->lock.refs != 0 && io->bp != NULL); 545 io->modify_refs += count; 546 if (io->modified && io->released == 0) 547 return; 548 549 hammer_lock_ex(&io->lock); 550 if (io->modified == 0) { 551 hammer_io_set_modlist(io); 552 io->modified = 1; 553 } 554 if (io->released) { 555 regetblk(io->bp); 556 BUF_KERNPROC(io->bp); 557 io->released = 0; 558 KKASSERT(io->modified != 0); 559 } 560 hammer_unlock(&io->lock); 561 } 562 563 static __inline 564 void 565 hammer_io_modify_done(hammer_io_t io) 566 { 567 KKASSERT(io->modify_refs > 0); 568 --io->modify_refs; 569 if (io->modify_refs == 0 && io->waitmod) { 570 io->waitmod = 0; 571 wakeup(io); 572 } 573 } 574 575 void 576 hammer_io_write_interlock(hammer_io_t io) 577 { 578 while (io->modify_refs != 0) { 579 io->waitmod = 1; 580 tsleep(io, 0, "hmrmod", 0); 581 } 582 io->modify_refs = -1; 583 } 584 585 void 586 hammer_io_done_interlock(hammer_io_t io) 587 { 588 KKASSERT(io->modify_refs == -1); 589 io->modify_refs = 0; 590 if (io->waitmod) { 591 io->waitmod = 0; 592 wakeup(io); 593 } 594 } 595 596 /* 597 * Caller intends to modify a volume's ondisk structure. 598 * 599 * This is only allowed if we are the flusher or we have a ref on the 600 * sync_lock. 601 */ 602 void 603 hammer_modify_volume(hammer_transaction_t trans, hammer_volume_t volume, 604 void *base, int len) 605 { 606 KKASSERT (trans == NULL || trans->sync_lock_refs > 0); 607 608 hammer_io_modify(&volume->io, 1); 609 if (len) { 610 intptr_t rel_offset = (intptr_t)base - (intptr_t)volume->ondisk; 611 KKASSERT((rel_offset & ~(intptr_t)HAMMER_BUFMASK) == 0); 612 hammer_generate_undo(trans, &volume->io, 613 HAMMER_ENCODE_RAW_VOLUME(volume->vol_no, rel_offset), 614 base, len); 615 } 616 } 617 618 /* 619 * Caller intends to modify a buffer's ondisk structure. 620 * 621 * This is only allowed if we are the flusher or we have a ref on the 622 * sync_lock. 623 */ 624 void 625 hammer_modify_buffer(hammer_transaction_t trans, hammer_buffer_t buffer, 626 void *base, int len) 627 { 628 KKASSERT (trans == NULL || trans->sync_lock_refs > 0); 629 630 hammer_io_modify(&buffer->io, 1); 631 if (len) { 632 intptr_t rel_offset = (intptr_t)base - (intptr_t)buffer->ondisk; 633 KKASSERT((rel_offset & ~(intptr_t)HAMMER_BUFMASK) == 0); 634 hammer_generate_undo(trans, &buffer->io, 635 buffer->zone2_offset + rel_offset, 636 base, len); 637 } 638 } 639 640 void 641 hammer_modify_volume_done(hammer_volume_t volume) 642 { 643 hammer_io_modify_done(&volume->io); 644 } 645 646 void 647 hammer_modify_buffer_done(hammer_buffer_t buffer) 648 { 649 hammer_io_modify_done(&buffer->io); 650 } 651 652 /* 653 * Mark an entity as not being dirty any more and finalize any 654 * delayed adjustments to the buffer. 655 * 656 * Delayed adjustments are an important performance enhancement, allowing 657 * us to avoid recalculating B-Tree node CRCs over and over again when 658 * making bulk-modifications to the B-Tree. 659 * 660 * If inval is non-zero delayed adjustments are ignored. 661 * 662 * This routine may dereference related btree nodes and cause the 663 * buffer to be dereferenced. The caller must own a reference on io. 664 */ 665 void 666 hammer_io_clear_modify(struct hammer_io *io, int inval) 667 { 668 if (io->modified == 0) 669 return; 670 671 /* 672 * Take us off the mod-list and clear the modified bit. 673 */ 674 KKASSERT(io->mod_list != NULL); 675 if (io->mod_list == &io->hmp->volu_list || 676 io->mod_list == &io->hmp->meta_list) { 677 io->hmp->locked_dirty_space -= io->bytes; 678 hammer_count_dirtybufspace -= io->bytes; 679 } 680 TAILQ_REMOVE(io->mod_list, io, mod_entry); 681 io->mod_list = NULL; 682 io->modified = 0; 683 684 /* 685 * If this bit is not set there are no delayed adjustments. 686 */ 687 if (io->gencrc == 0) 688 return; 689 io->gencrc = 0; 690 691 /* 692 * Finalize requested CRCs. The NEEDSCRC flag also holds a reference 693 * on the node (& underlying buffer). Release the node after clearing 694 * the flag. 695 */ 696 if (io->type == HAMMER_STRUCTURE_META_BUFFER) { 697 hammer_buffer_t buffer = (void *)io; 698 hammer_node_t node; 699 700 restart: 701 TAILQ_FOREACH(node, &buffer->clist, entry) { 702 if ((node->flags & HAMMER_NODE_NEEDSCRC) == 0) 703 continue; 704 node->flags &= ~HAMMER_NODE_NEEDSCRC; 705 KKASSERT(node->ondisk); 706 if (inval == 0) 707 node->ondisk->crc = crc32(&node->ondisk->crc + 1, HAMMER_BTREE_CRCSIZE); 708 hammer_rel_node(node); 709 goto restart; 710 } 711 } 712 /* caller must still have ref on io */ 713 KKASSERT(io->lock.refs > 0); 714 } 715 716 /* 717 * Clear the IO's modify list. Even though the IO is no longer modified 718 * it may still be on the lose_list. This routine is called just before 719 * the governing hammer_buffer is destroyed. 720 */ 721 void 722 hammer_io_clear_modlist(struct hammer_io *io) 723 { 724 KKASSERT(io->modified == 0); 725 if (io->mod_list) { 726 crit_enter(); /* biodone race against list */ 727 KKASSERT(io->mod_list == &io->hmp->lose_list); 728 TAILQ_REMOVE(io->mod_list, io, mod_entry); 729 io->mod_list = NULL; 730 crit_exit(); 731 } 732 } 733 734 static void 735 hammer_io_set_modlist(struct hammer_io *io) 736 { 737 struct hammer_mount *hmp = io->hmp; 738 739 KKASSERT(io->mod_list == NULL); 740 741 switch(io->type) { 742 case HAMMER_STRUCTURE_VOLUME: 743 io->mod_list = &hmp->volu_list; 744 hmp->locked_dirty_space += io->bytes; 745 hammer_count_dirtybufspace += io->bytes; 746 break; 747 case HAMMER_STRUCTURE_META_BUFFER: 748 io->mod_list = &hmp->meta_list; 749 hmp->locked_dirty_space += io->bytes; 750 hammer_count_dirtybufspace += io->bytes; 751 break; 752 case HAMMER_STRUCTURE_UNDO_BUFFER: 753 io->mod_list = &hmp->undo_list; 754 break; 755 case HAMMER_STRUCTURE_DATA_BUFFER: 756 io->mod_list = &hmp->data_list; 757 break; 758 } 759 TAILQ_INSERT_TAIL(io->mod_list, io, mod_entry); 760 } 761 762 /************************************************************************ 763 * HAMMER_BIOOPS * 764 ************************************************************************ 765 * 766 */ 767 768 /* 769 * Pre-IO initiation kernel callback - cluster build only 770 */ 771 static void 772 hammer_io_start(struct buf *bp) 773 { 774 } 775 776 /* 777 * Post-IO completion kernel callback - MAY BE CALLED FROM INTERRUPT! 778 * 779 * NOTE: HAMMER may modify a buffer after initiating I/O. The modified bit 780 * may also be set if we were marking a cluster header open. Only remove 781 * our dependancy if the modified bit is clear. 782 */ 783 static void 784 hammer_io_complete(struct buf *bp) 785 { 786 union hammer_io_structure *iou = (void *)LIST_FIRST(&bp->b_dep); 787 788 KKASSERT(iou->io.released == 1); 789 790 /* 791 * Deal with people waiting for I/O to drain 792 */ 793 if (iou->io.running) { 794 /* 795 * Deal with critical write errors. Once a critical error 796 * has been flagged in hmp the UNDO FIFO will not be updated. 797 * That way crash recover will give us a consistent 798 * filesystem. 799 * 800 * Because of this we can throw away failed UNDO buffers. If 801 * we throw away META or DATA buffers we risk corrupting 802 * the now read-only version of the filesystem visible to 803 * the user. Clear B_ERROR so the buffer is not re-dirtied 804 * by the kernel and ref the io so it doesn't get thrown 805 * away. 806 */ 807 if (bp->b_flags & B_ERROR) { 808 hammer_critical_error(iou->io.hmp, NULL, bp->b_error, 809 "while flushing meta-data"); 810 switch(iou->io.type) { 811 case HAMMER_STRUCTURE_UNDO_BUFFER: 812 break; 813 default: 814 if (iou->io.ioerror == 0) { 815 iou->io.ioerror = 1; 816 if (iou->io.lock.refs == 0) 817 ++hammer_count_refedbufs; 818 hammer_ref(&iou->io.lock); 819 } 820 break; 821 } 822 bp->b_flags &= ~B_ERROR; 823 bundirty(bp); 824 #if 0 825 hammer_io_set_modlist(&iou->io); 826 iou->io.modified = 1; 827 #endif 828 } 829 hammer_stats_disk_write += iou->io.bytes; 830 hammer_count_io_running_write -= iou->io.bytes; 831 iou->io.hmp->io_running_space -= iou->io.bytes; 832 if (iou->io.hmp->io_running_space == 0) 833 wakeup(&iou->io.hmp->io_running_space); 834 KKASSERT(iou->io.hmp->io_running_space >= 0); 835 iou->io.running = 0; 836 } else { 837 hammer_stats_disk_read += iou->io.bytes; 838 } 839 840 if (iou->io.waiting) { 841 iou->io.waiting = 0; 842 wakeup(iou); 843 } 844 845 /* 846 * If B_LOCKED is set someone wanted to deallocate the bp at some 847 * point, do it now if refs has become zero. 848 */ 849 if ((bp->b_flags & B_LOCKED) && iou->io.lock.refs == 0) { 850 KKASSERT(iou->io.modified == 0); 851 --hammer_count_io_locked; 852 bp->b_flags &= ~B_LOCKED; 853 hammer_io_deallocate(bp); 854 /* structure may be dead now */ 855 } 856 } 857 858 /* 859 * Callback from kernel when it wishes to deallocate a passively 860 * associated structure. This mostly occurs with clean buffers 861 * but it may be possible for a holding structure to be marked dirty 862 * while its buffer is passively associated. The caller owns the bp. 863 * 864 * If we cannot disassociate we set B_LOCKED to prevent the buffer 865 * from getting reused. 866 * 867 * WARNING: Because this can be called directly by getnewbuf we cannot 868 * recurse into the tree. If a bp cannot be immediately disassociated 869 * our only recourse is to set B_LOCKED. 870 * 871 * WARNING: This may be called from an interrupt via hammer_io_complete() 872 */ 873 static void 874 hammer_io_deallocate(struct buf *bp) 875 { 876 hammer_io_structure_t iou = (void *)LIST_FIRST(&bp->b_dep); 877 878 KKASSERT((bp->b_flags & B_LOCKED) == 0 && iou->io.running == 0); 879 if (iou->io.lock.refs > 0 || iou->io.modified) { 880 /* 881 * It is not legal to disassociate a modified buffer. This 882 * case really shouldn't ever occur. 883 */ 884 bp->b_flags |= B_LOCKED; 885 ++hammer_count_io_locked; 886 } else { 887 /* 888 * Disassociate the BP. If the io has no refs left we 889 * have to add it to the loose list. 890 */ 891 hammer_io_disassociate(iou); 892 if (iou->io.type != HAMMER_STRUCTURE_VOLUME) { 893 KKASSERT(iou->io.bp == NULL); 894 KKASSERT(iou->io.mod_list == NULL); 895 crit_enter(); /* biodone race against list */ 896 iou->io.mod_list = &iou->io.hmp->lose_list; 897 TAILQ_INSERT_TAIL(iou->io.mod_list, &iou->io, mod_entry); 898 crit_exit(); 899 } 900 } 901 } 902 903 static int 904 hammer_io_fsync(struct vnode *vp) 905 { 906 return(0); 907 } 908 909 /* 910 * NOTE: will not be called unless we tell the kernel about the 911 * bioops. Unused... we use the mount's VFS_SYNC instead. 912 */ 913 static int 914 hammer_io_sync(struct mount *mp) 915 { 916 return(0); 917 } 918 919 static void 920 hammer_io_movedeps(struct buf *bp1, struct buf *bp2) 921 { 922 } 923 924 /* 925 * I/O pre-check for reading and writing. HAMMER only uses this for 926 * B_CACHE buffers so checkread just shouldn't happen, but if it does 927 * allow it. 928 * 929 * Writing is a different case. We don't want the kernel to try to write 930 * out a buffer that HAMMER may be modifying passively or which has a 931 * dependancy. In addition, kernel-demanded writes can only proceed for 932 * certain types of buffers (i.e. UNDO and DATA types). Other dirty 933 * buffer types can only be explicitly written by the flusher. 934 * 935 * checkwrite will only be called for bdwrite()n buffers. If we return 936 * success the kernel is guaranteed to initiate the buffer write. 937 */ 938 static int 939 hammer_io_checkread(struct buf *bp) 940 { 941 return(0); 942 } 943 944 static int 945 hammer_io_checkwrite(struct buf *bp) 946 { 947 hammer_io_t io = (void *)LIST_FIRST(&bp->b_dep); 948 949 /* 950 * This shouldn't happen under normal operation. 951 */ 952 if (io->type == HAMMER_STRUCTURE_VOLUME || 953 io->type == HAMMER_STRUCTURE_META_BUFFER) { 954 if (!panicstr) 955 panic("hammer_io_checkwrite: illegal buffer"); 956 if ((bp->b_flags & B_LOCKED) == 0) { 957 bp->b_flags |= B_LOCKED; 958 ++hammer_count_io_locked; 959 } 960 return(1); 961 } 962 963 /* 964 * We can only clear the modified bit if the IO is not currently 965 * undergoing modification. Otherwise we may miss changes. 966 * 967 * Only data and undo buffers can reach here. These buffers do 968 * not have terminal crc functions but we temporarily reference 969 * the IO anyway, just in case. 970 */ 971 if (io->modify_refs == 0 && io->modified) { 972 hammer_ref(&io->lock); 973 hammer_io_clear_modify(io, 0); 974 hammer_unref(&io->lock); 975 } else if (io->modified) { 976 KKASSERT(io->type == HAMMER_STRUCTURE_DATA_BUFFER); 977 } 978 979 /* 980 * The kernel is going to start the IO, set io->running. 981 */ 982 KKASSERT(io->running == 0); 983 io->running = 1; 984 io->hmp->io_running_space += io->bytes; 985 hammer_count_io_running_write += io->bytes; 986 return(0); 987 } 988 989 /* 990 * Return non-zero if we wish to delay the kernel's attempt to flush 991 * this buffer to disk. 992 */ 993 static int 994 hammer_io_countdeps(struct buf *bp, int n) 995 { 996 return(0); 997 } 998 999 struct bio_ops hammer_bioops = { 1000 .io_start = hammer_io_start, 1001 .io_complete = hammer_io_complete, 1002 .io_deallocate = hammer_io_deallocate, 1003 .io_fsync = hammer_io_fsync, 1004 .io_sync = hammer_io_sync, 1005 .io_movedeps = hammer_io_movedeps, 1006 .io_countdeps = hammer_io_countdeps, 1007 .io_checkread = hammer_io_checkread, 1008 .io_checkwrite = hammer_io_checkwrite, 1009 }; 1010 1011 /************************************************************************ 1012 * DIRECT IO OPS * 1013 ************************************************************************ 1014 * 1015 * These functions operate directly on the buffer cache buffer associated 1016 * with a front-end vnode rather then a back-end device vnode. 1017 */ 1018 1019 /* 1020 * Read a buffer associated with a front-end vnode directly from the 1021 * disk media. The bio may be issued asynchronously. If leaf is non-NULL 1022 * we validate the CRC. 1023 * 1024 * We must check for the presence of a HAMMER buffer to handle the case 1025 * where the reblocker has rewritten the data (which it does via the HAMMER 1026 * buffer system, not via the high-level vnode buffer cache), but not yet 1027 * committed the buffer to the media. 1028 */ 1029 int 1030 hammer_io_direct_read(hammer_mount_t hmp, struct bio *bio, 1031 hammer_btree_leaf_elm_t leaf) 1032 { 1033 hammer_off_t buf_offset; 1034 hammer_off_t zone2_offset; 1035 hammer_volume_t volume; 1036 struct buf *bp; 1037 struct bio *nbio; 1038 int vol_no; 1039 int error; 1040 1041 buf_offset = bio->bio_offset; 1042 KKASSERT((buf_offset & HAMMER_OFF_ZONE_MASK) == 1043 HAMMER_ZONE_LARGE_DATA); 1044 1045 /* 1046 * The buffer cache may have an aliased buffer (the reblocker can 1047 * write them). If it does we have to sync any dirty data before 1048 * we can build our direct-read. This is a non-critical code path. 1049 */ 1050 bp = bio->bio_buf; 1051 hammer_sync_buffers(hmp, buf_offset, bp->b_bufsize); 1052 1053 /* 1054 * Resolve to a zone-2 offset. The conversion just requires 1055 * munging the top 4 bits but we want to abstract it anyway 1056 * so the blockmap code can verify the zone assignment. 1057 */ 1058 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, &error); 1059 if (error) 1060 goto done; 1061 KKASSERT((zone2_offset & HAMMER_OFF_ZONE_MASK) == 1062 HAMMER_ZONE_RAW_BUFFER); 1063 1064 /* 1065 * Resolve volume and raw-offset for 3rd level bio. The 1066 * offset will be specific to the volume. 1067 */ 1068 vol_no = HAMMER_VOL_DECODE(zone2_offset); 1069 volume = hammer_get_volume(hmp, vol_no, &error); 1070 if (error == 0 && zone2_offset >= volume->maxbuf_off) 1071 error = EIO; 1072 1073 if (error == 0) { 1074 /* 1075 * 3rd level bio 1076 */ 1077 nbio = push_bio(bio); 1078 nbio->bio_offset = volume->ondisk->vol_buf_beg + 1079 (zone2_offset & HAMMER_OFF_SHORT_MASK); 1080 #if 0 1081 /* 1082 * XXX disabled - our CRC check doesn't work if the OS 1083 * does bogus_page replacement on the direct-read. 1084 */ 1085 if (leaf && hammer_verify_data) { 1086 nbio->bio_done = hammer_io_direct_read_complete; 1087 nbio->bio_caller_info1.uvalue32 = leaf->data_crc; 1088 } 1089 #endif 1090 hammer_stats_disk_read += bp->b_bufsize; 1091 vn_strategy(volume->devvp, nbio); 1092 } 1093 hammer_rel_volume(volume, 0); 1094 done: 1095 if (error) { 1096 kprintf("hammer_direct_read: failed @ %016llx\n", 1097 zone2_offset); 1098 bp->b_error = error; 1099 bp->b_flags |= B_ERROR; 1100 biodone(bio); 1101 } 1102 return(error); 1103 } 1104 1105 #if 0 1106 /* 1107 * On completion of the BIO this callback must check the data CRC 1108 * and chain to the previous bio. 1109 */ 1110 static 1111 void 1112 hammer_io_direct_read_complete(struct bio *nbio) 1113 { 1114 struct bio *obio; 1115 struct buf *bp; 1116 u_int32_t rec_crc = nbio->bio_caller_info1.uvalue32; 1117 1118 bp = nbio->bio_buf; 1119 if (crc32(bp->b_data, bp->b_bufsize) != rec_crc) { 1120 kprintf("HAMMER: data_crc error @%016llx/%d\n", 1121 nbio->bio_offset, bp->b_bufsize); 1122 if (hammer_debug_debug) 1123 Debugger(""); 1124 bp->b_flags |= B_ERROR; 1125 bp->b_error = EIO; 1126 } 1127 obio = pop_bio(nbio); 1128 biodone(obio); 1129 } 1130 #endif 1131 1132 /* 1133 * Write a buffer associated with a front-end vnode directly to the 1134 * disk media. The bio may be issued asynchronously. 1135 * 1136 * The BIO is associated with the specified record and RECF_DIRECT_IO 1137 * is set. The recorded is added to its object. 1138 */ 1139 int 1140 hammer_io_direct_write(hammer_mount_t hmp, hammer_record_t record, 1141 struct bio *bio) 1142 { 1143 hammer_btree_leaf_elm_t leaf = &record->leaf; 1144 hammer_off_t buf_offset; 1145 hammer_off_t zone2_offset; 1146 hammer_volume_t volume; 1147 hammer_buffer_t buffer; 1148 struct buf *bp; 1149 struct bio *nbio; 1150 char *ptr; 1151 int vol_no; 1152 int error; 1153 1154 buf_offset = leaf->data_offset; 1155 1156 KKASSERT(buf_offset > HAMMER_ZONE_BTREE); 1157 KKASSERT(bio->bio_buf->b_cmd == BUF_CMD_WRITE); 1158 1159 if ((buf_offset & HAMMER_BUFMASK) == 0 && 1160 leaf->data_len >= HAMMER_BUFSIZE) { 1161 /* 1162 * We are using the vnode's bio to write directly to the 1163 * media, any hammer_buffer at the same zone-X offset will 1164 * now have stale data. 1165 */ 1166 zone2_offset = hammer_blockmap_lookup(hmp, buf_offset, &error); 1167 vol_no = HAMMER_VOL_DECODE(zone2_offset); 1168 volume = hammer_get_volume(hmp, vol_no, &error); 1169 1170 if (error == 0 && zone2_offset >= volume->maxbuf_off) 1171 error = EIO; 1172 if (error == 0) { 1173 bp = bio->bio_buf; 1174 KKASSERT((bp->b_bufsize & HAMMER_BUFMASK) == 0); 1175 /* 1176 hammer_del_buffers(hmp, buf_offset, 1177 zone2_offset, bp->b_bufsize); 1178 */ 1179 1180 /* 1181 * Second level bio - cached zone2 offset. 1182 * 1183 * (We can put our bio_done function in either the 1184 * 2nd or 3rd level). 1185 */ 1186 nbio = push_bio(bio); 1187 nbio->bio_offset = zone2_offset; 1188 nbio->bio_done = hammer_io_direct_write_complete; 1189 nbio->bio_caller_info1.ptr = record; 1190 record->zone2_offset = zone2_offset; 1191 record->flags |= HAMMER_RECF_DIRECT_IO | 1192 HAMMER_RECF_DIRECT_INVAL; 1193 1194 /* 1195 * Third level bio - raw offset specific to the 1196 * correct volume. 1197 */ 1198 zone2_offset &= HAMMER_OFF_SHORT_MASK; 1199 nbio = push_bio(nbio); 1200 nbio->bio_offset = volume->ondisk->vol_buf_beg + 1201 zone2_offset; 1202 hammer_stats_disk_write += bp->b_bufsize; 1203 vn_strategy(volume->devvp, nbio); 1204 } 1205 hammer_rel_volume(volume, 0); 1206 } else { 1207 /* 1208 * Must fit in a standard HAMMER buffer. In this case all 1209 * consumers use the HAMMER buffer system and RECF_DIRECT_IO 1210 * does not need to be set-up. 1211 */ 1212 KKASSERT(((buf_offset ^ (buf_offset + leaf->data_len - 1)) & ~HAMMER_BUFMASK64) == 0); 1213 buffer = NULL; 1214 ptr = hammer_bread(hmp, buf_offset, &error, &buffer); 1215 if (error == 0) { 1216 bp = bio->bio_buf; 1217 bp->b_flags |= B_AGE; 1218 hammer_io_modify(&buffer->io, 1); 1219 bcopy(bp->b_data, ptr, leaf->data_len); 1220 hammer_io_modify_done(&buffer->io); 1221 hammer_rel_buffer(buffer, 0); 1222 bp->b_resid = 0; 1223 biodone(bio); 1224 } 1225 } 1226 if (error == 0) { 1227 /* 1228 * The record is all setup now, add it. Potential conflics 1229 * have already been dealt with. 1230 */ 1231 error = hammer_mem_add(record); 1232 KKASSERT(error == 0); 1233 } else { 1234 /* 1235 * Major suckage occured. 1236 */ 1237 kprintf("hammer_direct_write: failed @ %016llx\n", 1238 leaf->data_offset); 1239 bp = bio->bio_buf; 1240 bp->b_resid = 0; 1241 bp->b_error = EIO; 1242 bp->b_flags |= B_ERROR; 1243 biodone(bio); 1244 record->flags |= HAMMER_RECF_DELETED_FE; 1245 hammer_rel_mem_record(record); 1246 } 1247 return(error); 1248 } 1249 1250 /* 1251 * On completion of the BIO this callback must disconnect 1252 * it from the hammer_record and chain to the previous bio. 1253 * 1254 * An I/O error forces the mount to read-only. Data buffers 1255 * are not B_LOCKED like meta-data buffers are, so we have to 1256 * throw the buffer away to prevent the kernel from retrying. 1257 */ 1258 static 1259 void 1260 hammer_io_direct_write_complete(struct bio *nbio) 1261 { 1262 struct bio *obio; 1263 struct buf *bp; 1264 hammer_record_t record = nbio->bio_caller_info1.ptr; 1265 1266 bp = nbio->bio_buf; 1267 obio = pop_bio(nbio); 1268 if (bp->b_flags & B_ERROR) { 1269 hammer_critical_error(record->ip->hmp, record->ip, 1270 bp->b_error, 1271 "while writing bulk data"); 1272 bp->b_flags |= B_INVAL; 1273 } 1274 biodone(obio); 1275 1276 KKASSERT(record != NULL); 1277 KKASSERT(record->flags & HAMMER_RECF_DIRECT_IO); 1278 record->flags &= ~HAMMER_RECF_DIRECT_IO; 1279 if (record->flags & HAMMER_RECF_DIRECT_WAIT) { 1280 record->flags &= ~HAMMER_RECF_DIRECT_WAIT; 1281 wakeup(&record->flags); 1282 } 1283 } 1284 1285 1286 /* 1287 * This is called before a record is either committed to the B-Tree 1288 * or destroyed, to resolve any associated direct-IO. 1289 * 1290 * (1) We must wait for any direct-IO related to the record to complete. 1291 * 1292 * (2) We must remove any buffer cache aliases for data accessed via 1293 * leaf->data_offset or zone2_offset so non-direct-IO consumers 1294 * (the mirroring and reblocking code) do not see stale data. 1295 */ 1296 void 1297 hammer_io_direct_wait(hammer_record_t record) 1298 { 1299 /* 1300 * Wait for I/O to complete 1301 */ 1302 if (record->flags & HAMMER_RECF_DIRECT_IO) { 1303 crit_enter(); 1304 while (record->flags & HAMMER_RECF_DIRECT_IO) { 1305 record->flags |= HAMMER_RECF_DIRECT_WAIT; 1306 tsleep(&record->flags, 0, "hmdiow", 0); 1307 } 1308 crit_exit(); 1309 } 1310 1311 /* 1312 * Invalidate any related buffer cache aliases. 1313 */ 1314 if (record->flags & HAMMER_RECF_DIRECT_INVAL) { 1315 KKASSERT(record->leaf.data_offset); 1316 hammer_del_buffers(record->ip->hmp, 1317 record->leaf.data_offset, 1318 record->zone2_offset, 1319 record->leaf.data_len); 1320 record->flags &= ~HAMMER_RECF_DIRECT_INVAL; 1321 } 1322 } 1323 1324 /* 1325 * This is called to remove the second-level cached zone-2 offset from 1326 * frontend buffer cache buffers, now stale due to a data relocation. 1327 * These offsets are generated by cluster_read() via VOP_BMAP, or directly 1328 * by hammer_vop_strategy_read(). 1329 * 1330 * This is rather nasty because here we have something like the reblocker 1331 * scanning the raw B-Tree with no held references on anything, really, 1332 * other then a shared lock on the B-Tree node, and we have to access the 1333 * frontend's buffer cache to check for and clean out the association. 1334 * Specifically, if the reblocker is moving data on the disk, these cached 1335 * offsets will become invalid. 1336 * 1337 * Only data record types associated with the large-data zone are subject 1338 * to direct-io and need to be checked. 1339 * 1340 */ 1341 void 1342 hammer_io_direct_uncache(hammer_mount_t hmp, hammer_btree_leaf_elm_t leaf) 1343 { 1344 struct hammer_inode_info iinfo; 1345 int zone; 1346 1347 if (leaf->base.rec_type != HAMMER_RECTYPE_DATA) 1348 return; 1349 zone = HAMMER_ZONE_DECODE(leaf->data_offset); 1350 if (zone != HAMMER_ZONE_LARGE_DATA_INDEX) 1351 return; 1352 iinfo.obj_id = leaf->base.obj_id; 1353 iinfo.obj_asof = 0; /* unused */ 1354 iinfo.obj_localization = leaf->base.localization & 1355 HAMMER_LOCALIZE_PSEUDOFS_MASK; 1356 iinfo.u.leaf = leaf; 1357 hammer_scan_inode_snapshots(hmp, &iinfo, 1358 hammer_io_direct_uncache_callback, 1359 leaf); 1360 } 1361 1362 static int 1363 hammer_io_direct_uncache_callback(hammer_inode_t ip, void *data) 1364 { 1365 hammer_inode_info_t iinfo = data; 1366 hammer_off_t data_offset; 1367 hammer_off_t file_offset; 1368 struct vnode *vp; 1369 struct buf *bp; 1370 int blksize; 1371 1372 if (ip->vp == NULL) 1373 return(0); 1374 data_offset = iinfo->u.leaf->data_offset; 1375 file_offset = iinfo->u.leaf->base.key - iinfo->u.leaf->data_len; 1376 blksize = iinfo->u.leaf->data_len; 1377 KKASSERT((blksize & HAMMER_BUFMASK) == 0); 1378 1379 hammer_ref(&ip->lock); 1380 if (hammer_get_vnode(ip, &vp) == 0) { 1381 if ((bp = findblk(ip->vp, file_offset)) != NULL && 1382 bp->b_bio2.bio_offset != NOOFFSET) { 1383 bp = getblk(ip->vp, file_offset, blksize, 0, 0); 1384 bp->b_bio2.bio_offset = NOOFFSET; 1385 brelse(bp); 1386 } 1387 vput(vp); 1388 } 1389 hammer_rel_inode(ip, 0); 1390 return(0); 1391 } 1392 1393