1 /* $NetBSD: lfs_subr.c,v 1.60 2006/06/29 19:28:21 perseant Exp $ */ 2 3 /*- 4 * Copyright (c) 1999, 2000, 2001, 2002, 2003 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Konrad E. Schroder <perseant@hhhh.org>. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 /* 39 * Copyright (c) 1991, 1993 40 * The Regents of the University of California. All rights reserved. 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 3. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * 66 * @(#)lfs_subr.c 8.4 (Berkeley) 5/8/95 67 */ 68 69 #include <sys/cdefs.h> 70 __KERNEL_RCSID(0, "$NetBSD: lfs_subr.c,v 1.60 2006/06/29 19:28:21 perseant Exp $"); 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/namei.h> 75 #include <sys/vnode.h> 76 #include <sys/buf.h> 77 #include <sys/mount.h> 78 #include <sys/malloc.h> 79 #include <sys/proc.h> 80 81 #include <ufs/ufs/inode.h> 82 #include <ufs/lfs/lfs.h> 83 #include <ufs/lfs/lfs_extern.h> 84 85 #include <uvm/uvm.h> 86 87 #ifdef DEBUG 88 const char *lfs_res_names[LFS_NB_COUNT] = { 89 "summary", 90 "superblock", 91 "file block", 92 "cluster", 93 "clean", 94 "blkiov", 95 }; 96 #endif 97 98 int lfs_res_qty[LFS_NB_COUNT] = { 99 LFS_N_SUMMARIES, 100 LFS_N_SBLOCKS, 101 LFS_N_IBLOCKS, 102 LFS_N_CLUSTERS, 103 LFS_N_CLEAN, 104 LFS_N_BLKIOV, 105 }; 106 107 void 108 lfs_setup_resblks(struct lfs *fs) 109 { 110 int i, j; 111 int maxbpp; 112 113 ASSERT_NO_SEGLOCK(fs); 114 fs->lfs_resblk = (res_t *)malloc(LFS_N_TOTAL * sizeof(res_t), M_SEGMENT, 115 M_WAITOK); 116 for (i = 0; i < LFS_N_TOTAL; i++) { 117 fs->lfs_resblk[i].inuse = 0; 118 fs->lfs_resblk[i].p = NULL; 119 } 120 for (i = 0; i < LFS_RESHASH_WIDTH; i++) 121 LIST_INIT(fs->lfs_reshash + i); 122 123 /* 124 * These types of allocations can be larger than a page, 125 * so we can't use the pool subsystem for them. 126 */ 127 for (i = 0, j = 0; j < LFS_N_SUMMARIES; j++, i++) 128 fs->lfs_resblk[i].size = fs->lfs_sumsize; 129 for (j = 0; j < LFS_N_SBLOCKS; j++, i++) 130 fs->lfs_resblk[i].size = LFS_SBPAD; 131 for (j = 0; j < LFS_N_IBLOCKS; j++, i++) 132 fs->lfs_resblk[i].size = fs->lfs_bsize; 133 for (j = 0; j < LFS_N_CLUSTERS; j++, i++) 134 fs->lfs_resblk[i].size = MAXPHYS; 135 for (j = 0; j < LFS_N_CLEAN; j++, i++) 136 fs->lfs_resblk[i].size = MAXPHYS; 137 for (j = 0; j < LFS_N_BLKIOV; j++, i++) 138 fs->lfs_resblk[i].size = LFS_MARKV_MAXBLKCNT * sizeof(BLOCK_INFO); 139 140 for (i = 0; i < LFS_N_TOTAL; i++) { 141 fs->lfs_resblk[i].p = malloc(fs->lfs_resblk[i].size, 142 M_SEGMENT, M_WAITOK); 143 } 144 145 /* 146 * Initialize pools for small types (XXX is BPP small?) 147 */ 148 pool_init(&fs->lfs_clpool, sizeof(struct lfs_cluster), 0, 0, 0, 149 "lfsclpl", &pool_allocator_nointr); 150 pool_init(&fs->lfs_segpool, sizeof(struct segment), 0, 0, 0, 151 "lfssegpool", &pool_allocator_nointr); 152 maxbpp = ((fs->lfs_sumsize - SEGSUM_SIZE(fs)) / sizeof(int32_t) + 2); 153 maxbpp = MIN(maxbpp, segsize(fs) / fs->lfs_fsize + 2); 154 pool_init(&fs->lfs_bpppool, maxbpp * sizeof(struct buf *), 0, 0, 0, 155 "lfsbpppl", &pool_allocator_nointr); 156 } 157 158 void 159 lfs_free_resblks(struct lfs *fs) 160 { 161 int i; 162 163 pool_destroy(&fs->lfs_bpppool); 164 pool_destroy(&fs->lfs_segpool); 165 pool_destroy(&fs->lfs_clpool); 166 167 simple_lock(&fs->lfs_interlock); 168 for (i = 0; i < LFS_N_TOTAL; i++) { 169 while (fs->lfs_resblk[i].inuse) 170 ltsleep(&fs->lfs_resblk, PRIBIO + 1, "lfs_free", 0, 171 &fs->lfs_interlock); 172 if (fs->lfs_resblk[i].p != NULL) 173 free(fs->lfs_resblk[i].p, M_SEGMENT); 174 } 175 free(fs->lfs_resblk, M_SEGMENT); 176 simple_unlock(&fs->lfs_interlock); 177 } 178 179 static unsigned int 180 lfs_mhash(void *vp) 181 { 182 return (unsigned int)(((unsigned long)vp) >> 2) % LFS_RESHASH_WIDTH; 183 } 184 185 /* 186 * Return memory of the given size for the given purpose, or use one of a 187 * number of spare last-resort buffers, if malloc returns NULL. 188 */ 189 void * 190 lfs_malloc(struct lfs *fs, size_t size, int type) 191 { 192 struct lfs_res_blk *re; 193 void *r; 194 int i, s, start; 195 unsigned int h; 196 197 ASSERT_MAYBE_SEGLOCK(fs); 198 r = NULL; 199 200 /* If no mem allocated for this type, it just waits */ 201 if (lfs_res_qty[type] == 0) { 202 r = malloc(size, M_SEGMENT, M_WAITOK); 203 return r; 204 } 205 206 /* Otherwise try a quick malloc, and if it works, great */ 207 if ((r = malloc(size, M_SEGMENT, M_NOWAIT)) != NULL) { 208 return r; 209 } 210 211 /* 212 * If malloc returned NULL, we are forced to use one of our 213 * reserve blocks. We have on hand at least one summary block, 214 * at least one cluster block, at least one superblock, 215 * and several indirect blocks. 216 */ 217 218 simple_lock(&fs->lfs_interlock); 219 /* skip over blocks of other types */ 220 for (i = 0, start = 0; i < type; i++) 221 start += lfs_res_qty[i]; 222 while (r == NULL) { 223 for (i = 0; i < lfs_res_qty[type]; i++) { 224 if (fs->lfs_resblk[start + i].inuse == 0) { 225 re = fs->lfs_resblk + start + i; 226 re->inuse = 1; 227 r = re->p; 228 KASSERT(re->size >= size); 229 h = lfs_mhash(r); 230 s = splbio(); 231 LIST_INSERT_HEAD(&fs->lfs_reshash[h], re, res); 232 splx(s); 233 simple_unlock(&fs->lfs_interlock); 234 return r; 235 } 236 } 237 DLOG((DLOG_MALLOC, "sleeping on %s (%d)\n", 238 lfs_res_names[type], lfs_res_qty[type])); 239 ltsleep(&fs->lfs_resblk, PVM, "lfs_malloc", 0, 240 &fs->lfs_interlock); 241 DLOG((DLOG_MALLOC, "done sleeping on %s\n", 242 lfs_res_names[type])); 243 } 244 /* NOTREACHED */ 245 simple_unlock(&fs->lfs_interlock); 246 return r; 247 } 248 249 void 250 lfs_free(struct lfs *fs, void *p, int type) 251 { 252 int s; 253 unsigned int h; 254 res_t *re; 255 #ifdef DEBUG 256 int i; 257 #endif 258 259 ASSERT_MAYBE_SEGLOCK(fs); 260 h = lfs_mhash(p); 261 simple_lock(&fs->lfs_interlock); 262 s = splbio(); 263 LIST_FOREACH(re, &fs->lfs_reshash[h], res) { 264 if (re->p == p) { 265 KASSERT(re->inuse == 1); 266 LIST_REMOVE(re, res); 267 re->inuse = 0; 268 wakeup(&fs->lfs_resblk); 269 splx(s); 270 simple_unlock(&fs->lfs_interlock); 271 return; 272 } 273 } 274 #ifdef DEBUG 275 for (i = 0; i < LFS_N_TOTAL; i++) { 276 if (fs->lfs_resblk[i].p == p) 277 panic("lfs_free: inconsistent reserved block"); 278 } 279 #endif 280 splx(s); 281 simple_unlock(&fs->lfs_interlock); 282 283 /* 284 * If we didn't find it, free it. 285 */ 286 free(p, M_SEGMENT); 287 } 288 289 /* 290 * lfs_seglock -- 291 * Single thread the segment writer. 292 */ 293 int 294 lfs_seglock(struct lfs *fs, unsigned long flags) 295 { 296 struct segment *sp; 297 298 simple_lock(&fs->lfs_interlock); 299 if (fs->lfs_seglock) { 300 if (fs->lfs_lockpid == curproc->p_pid && 301 fs->lfs_locklwp == curlwp->l_lid) { 302 simple_unlock(&fs->lfs_interlock); 303 ++fs->lfs_seglock; 304 fs->lfs_sp->seg_flags |= flags; 305 return 0; 306 } else if (flags & SEGM_PAGEDAEMON) { 307 simple_unlock(&fs->lfs_interlock); 308 return EWOULDBLOCK; 309 } else { 310 while (fs->lfs_seglock) { 311 (void)ltsleep(&fs->lfs_seglock, PRIBIO + 1, 312 "lfs seglock", 0, &fs->lfs_interlock); 313 } 314 } 315 } 316 317 fs->lfs_seglock = 1; 318 fs->lfs_lockpid = curproc->p_pid; 319 fs->lfs_locklwp = curlwp->l_lid; 320 simple_unlock(&fs->lfs_interlock); 321 fs->lfs_cleanind = 0; 322 323 #ifdef DEBUG 324 LFS_ENTER_LOG("seglock", __FILE__, __LINE__, 0, flags, curproc->p_pid); 325 #endif 326 /* Drain fragment size changes out */ 327 lockmgr(&fs->lfs_fraglock, LK_EXCLUSIVE, 0); 328 329 sp = fs->lfs_sp = pool_get(&fs->lfs_segpool, PR_WAITOK); 330 sp->bpp = pool_get(&fs->lfs_bpppool, PR_WAITOK); 331 sp->seg_flags = flags; 332 sp->vp = NULL; 333 sp->seg_iocount = 0; 334 (void) lfs_initseg(fs); 335 336 /* 337 * Keep a cumulative count of the outstanding I/O operations. If the 338 * disk drive catches up with us it could go to zero before we finish, 339 * so we artificially increment it by one until we've scheduled all of 340 * the writes we intend to do. 341 */ 342 simple_lock(&fs->lfs_interlock); 343 ++fs->lfs_iocount; 344 simple_unlock(&fs->lfs_interlock); 345 return 0; 346 } 347 348 static void lfs_unmark_dirop(struct lfs *); 349 350 static void 351 lfs_unmark_dirop(struct lfs *fs) 352 { 353 struct inode *ip, *nip; 354 struct vnode *vp; 355 int doit; 356 357 ASSERT_NO_SEGLOCK(fs); 358 simple_lock(&fs->lfs_interlock); 359 doit = !(fs->lfs_flags & LFS_UNDIROP); 360 if (doit) 361 fs->lfs_flags |= LFS_UNDIROP; 362 if (!doit) { 363 simple_unlock(&fs->lfs_interlock); 364 return; 365 } 366 367 for (ip = TAILQ_FIRST(&fs->lfs_dchainhd); ip != NULL; ip = nip) { 368 nip = TAILQ_NEXT(ip, i_lfs_dchain); 369 simple_unlock(&fs->lfs_interlock); 370 vp = ITOV(ip); 371 372 simple_lock(&vp->v_interlock); 373 if (VOP_ISLOCKED(vp) && 374 vp->v_lock.lk_lockholder != curproc->p_pid) { 375 simple_lock(&fs->lfs_interlock); 376 simple_unlock(&vp->v_interlock); 377 continue; 378 } 379 if ((VTOI(vp)->i_flag & IN_ADIROP) == 0) { 380 simple_lock(&fs->lfs_interlock); 381 simple_lock(&lfs_subsys_lock); 382 --lfs_dirvcount; 383 simple_unlock(&lfs_subsys_lock); 384 --fs->lfs_dirvcount; 385 vp->v_flag &= ~VDIROP; 386 TAILQ_REMOVE(&fs->lfs_dchainhd, ip, i_lfs_dchain); 387 simple_unlock(&fs->lfs_interlock); 388 wakeup(&lfs_dirvcount); 389 simple_unlock(&vp->v_interlock); 390 simple_lock(&fs->lfs_interlock); 391 fs->lfs_unlockvp = vp; 392 simple_unlock(&fs->lfs_interlock); 393 vrele(vp); 394 simple_lock(&fs->lfs_interlock); 395 fs->lfs_unlockvp = NULL; 396 simple_unlock(&fs->lfs_interlock); 397 } else 398 simple_unlock(&vp->v_interlock); 399 simple_lock(&fs->lfs_interlock); 400 } 401 402 fs->lfs_flags &= ~LFS_UNDIROP; 403 simple_unlock(&fs->lfs_interlock); 404 wakeup(&fs->lfs_flags); 405 } 406 407 static void 408 lfs_auto_segclean(struct lfs *fs) 409 { 410 int i, error, s, waited; 411 412 ASSERT_SEGLOCK(fs); 413 /* 414 * Now that we've swapped lfs_activesb, but while we still 415 * hold the segment lock, run through the segment list marking 416 * the empty ones clean. 417 * XXX - do we really need to do them all at once? 418 */ 419 waited = 0; 420 for (i = 0; i < fs->lfs_nseg; i++) { 421 if ((fs->lfs_suflags[0][i] & 422 (SEGUSE_ACTIVE | SEGUSE_DIRTY | SEGUSE_EMPTY)) == 423 (SEGUSE_DIRTY | SEGUSE_EMPTY) && 424 (fs->lfs_suflags[1][i] & 425 (SEGUSE_ACTIVE | SEGUSE_DIRTY | SEGUSE_EMPTY)) == 426 (SEGUSE_DIRTY | SEGUSE_EMPTY)) { 427 428 /* Make sure the sb is written before we clean */ 429 simple_lock(&fs->lfs_interlock); 430 s = splbio(); 431 while (waited == 0 && fs->lfs_sbactive) 432 ltsleep(&fs->lfs_sbactive, PRIBIO+1, "lfs asb", 433 0, &fs->lfs_interlock); 434 splx(s); 435 simple_unlock(&fs->lfs_interlock); 436 waited = 1; 437 438 if ((error = lfs_do_segclean(fs, i)) != 0) { 439 DLOG((DLOG_CLEAN, "lfs_auto_segclean: lfs_do_segclean returned %d for seg %d\n", error, i)); 440 } 441 } 442 fs->lfs_suflags[1 - fs->lfs_activesb][i] = 443 fs->lfs_suflags[fs->lfs_activesb][i]; 444 } 445 } 446 447 /* 448 * lfs_segunlock -- 449 * Single thread the segment writer. 450 */ 451 void 452 lfs_segunlock(struct lfs *fs) 453 { 454 struct segment *sp; 455 unsigned long sync, ckp; 456 struct buf *bp; 457 int do_unmark_dirop = 0; 458 459 sp = fs->lfs_sp; 460 461 simple_lock(&fs->lfs_interlock); 462 LOCK_ASSERT(LFS_SEGLOCK_HELD(fs)); 463 if (fs->lfs_seglock == 1) { 464 if ((sp->seg_flags & (SEGM_PROT | SEGM_CLEAN)) == 0 && 465 LFS_STARVED_FOR_SEGS(fs) == 0) 466 do_unmark_dirop = 1; 467 simple_unlock(&fs->lfs_interlock); 468 sync = sp->seg_flags & SEGM_SYNC; 469 ckp = sp->seg_flags & SEGM_CKP; 470 471 /* We should have a segment summary, and nothing else */ 472 KASSERT(sp->cbpp == sp->bpp + 1); 473 474 /* Free allocated segment summary */ 475 fs->lfs_offset -= btofsb(fs, fs->lfs_sumsize); 476 bp = *sp->bpp; 477 lfs_freebuf(fs, bp); 478 479 pool_put(&fs->lfs_bpppool, sp->bpp); 480 sp->bpp = NULL; 481 482 /* 483 * If we're not sync, we're done with sp, get rid of it. 484 * Otherwise, we keep a local copy around but free 485 * fs->lfs_sp so another process can use it (we have to 486 * wait but they don't have to wait for us). 487 */ 488 if (!sync) 489 pool_put(&fs->lfs_segpool, sp); 490 fs->lfs_sp = NULL; 491 492 /* 493 * If the I/O count is non-zero, sleep until it reaches zero. 494 * At the moment, the user's process hangs around so we can 495 * sleep. 496 */ 497 simple_lock(&fs->lfs_interlock); 498 if (--fs->lfs_iocount == 0) 499 LFS_DEBUG_COUNTLOCKED("lfs_segunlock"); 500 if (fs->lfs_iocount <= 1) 501 wakeup(&fs->lfs_iocount); 502 simple_unlock(&fs->lfs_interlock); 503 /* 504 * If we're not checkpointing, we don't have to block 505 * other processes to wait for a synchronous write 506 * to complete. 507 */ 508 if (!ckp) { 509 #ifdef DEBUG 510 LFS_ENTER_LOG("segunlock_std", __FILE__, __LINE__, 0, 0, curproc->p_pid); 511 #endif 512 simple_lock(&fs->lfs_interlock); 513 --fs->lfs_seglock; 514 fs->lfs_lockpid = 0; 515 fs->lfs_locklwp = 0; 516 simple_unlock(&fs->lfs_interlock); 517 wakeup(&fs->lfs_seglock); 518 } 519 /* 520 * We let checkpoints happen asynchronously. That means 521 * that during recovery, we have to roll forward between 522 * the two segments described by the first and second 523 * superblocks to make sure that the checkpoint described 524 * by a superblock completed. 525 */ 526 simple_lock(&fs->lfs_interlock); 527 while (ckp && sync && fs->lfs_iocount) 528 (void)ltsleep(&fs->lfs_iocount, PRIBIO + 1, 529 "lfs_iocount", 0, &fs->lfs_interlock); 530 while (sync && sp->seg_iocount) { 531 (void)ltsleep(&sp->seg_iocount, PRIBIO + 1, 532 "seg_iocount", 0, &fs->lfs_interlock); 533 DLOG((DLOG_SEG, "sleeping on iocount %x == %d\n", sp, sp->seg_iocount)); 534 } 535 simple_unlock(&fs->lfs_interlock); 536 if (sync) 537 pool_put(&fs->lfs_segpool, sp); 538 539 if (ckp) { 540 fs->lfs_nactive = 0; 541 /* If we *know* everything's on disk, write both sbs */ 542 /* XXX should wait for this one */ 543 if (sync) 544 lfs_writesuper(fs, fs->lfs_sboffs[fs->lfs_activesb]); 545 lfs_writesuper(fs, fs->lfs_sboffs[1 - fs->lfs_activesb]); 546 if (!(fs->lfs_ivnode->v_mount->mnt_iflag & IMNT_UNMOUNT)) { 547 lfs_auto_segclean(fs); 548 /* If sync, we can clean the remainder too */ 549 if (sync) 550 lfs_auto_segclean(fs); 551 } 552 fs->lfs_activesb = 1 - fs->lfs_activesb; 553 #ifdef DEBUG 554 LFS_ENTER_LOG("segunlock_ckp", __FILE__, __LINE__, 0, 0, curproc->p_pid); 555 #endif 556 simple_lock(&fs->lfs_interlock); 557 --fs->lfs_seglock; 558 fs->lfs_lockpid = 0; 559 fs->lfs_locklwp = 0; 560 simple_unlock(&fs->lfs_interlock); 561 wakeup(&fs->lfs_seglock); 562 } 563 /* Reenable fragment size changes */ 564 lockmgr(&fs->lfs_fraglock, LK_RELEASE, 0); 565 if (do_unmark_dirop) 566 lfs_unmark_dirop(fs); 567 } else if (fs->lfs_seglock == 0) { 568 simple_unlock(&fs->lfs_interlock); 569 panic ("Seglock not held"); 570 } else { 571 --fs->lfs_seglock; 572 simple_unlock(&fs->lfs_interlock); 573 } 574 } 575 576 /* 577 * drain dirops and start writer. 578 */ 579 int 580 lfs_writer_enter(struct lfs *fs, const char *wmesg) 581 { 582 int error = 0; 583 584 ASSERT_MAYBE_SEGLOCK(fs); 585 simple_lock(&fs->lfs_interlock); 586 587 /* disallow dirops during flush */ 588 fs->lfs_writer++; 589 590 while (fs->lfs_dirops > 0) { 591 ++fs->lfs_diropwait; 592 error = ltsleep(&fs->lfs_writer, PRIBIO+1, wmesg, 0, 593 &fs->lfs_interlock); 594 --fs->lfs_diropwait; 595 } 596 597 if (error) 598 fs->lfs_writer--; 599 600 simple_unlock(&fs->lfs_interlock); 601 602 return error; 603 } 604 605 void 606 lfs_writer_leave(struct lfs *fs) 607 { 608 boolean_t dowakeup; 609 610 ASSERT_MAYBE_SEGLOCK(fs); 611 simple_lock(&fs->lfs_interlock); 612 dowakeup = !(--fs->lfs_writer); 613 simple_unlock(&fs->lfs_interlock); 614 if (dowakeup) 615 wakeup(&fs->lfs_dirops); 616 } 617 618 /* 619 * Unlock, wait for the cleaner, then relock to where we were before. 620 * To be used only at a fairly high level, to address a paucity of free 621 * segments propagated back from lfs_gop_write(). 622 */ 623 void 624 lfs_segunlock_relock(struct lfs *fs) 625 { 626 int n = fs->lfs_seglock; 627 u_int16_t seg_flags; 628 629 if (n == 0) 630 return; 631 632 /* Write anything we've already gathered to disk */ 633 lfs_writeseg(fs, fs->lfs_sp); 634 635 /* Save segment flags for later */ 636 seg_flags = fs->lfs_sp->seg_flags; 637 638 fs->lfs_sp->seg_flags |= SEGM_PROT; /* Don't unmark dirop nodes */ 639 while(fs->lfs_seglock) 640 lfs_segunlock(fs); 641 642 /* Wait for the cleaner */ 643 lfs_wakeup_cleaner(fs); 644 simple_lock(&fs->lfs_interlock); 645 while (LFS_STARVED_FOR_SEGS(fs)) 646 ltsleep(&fs->lfs_avail, PRIBIO, "relock", 0, 647 &fs->lfs_interlock); 648 simple_unlock(&fs->lfs_interlock); 649 650 /* Put the segment lock back the way it was. */ 651 while(n--) 652 lfs_seglock(fs, seg_flags); 653 654 return; 655 } 656 657 /* 658 * Wake up the cleaner, provided that nowrap is not set. 659 */ 660 void 661 lfs_wakeup_cleaner(struct lfs *fs) 662 { 663 if (fs->lfs_nowrap > 0) 664 return; 665 666 wakeup(&fs->lfs_nextseg); 667 wakeup(&lfs_allclean_wakeup); 668 } 669