1 /* $NetBSD: lfs_pages.c,v 1.9 2016/10/04 16:46:20 christos 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 /* 32 * Copyright (c) 1986, 1989, 1991, 1993, 1995 33 * The Regents of the University of California. All rights reserved. 34 * 35 * Redistribution and use in source and binary forms, with or without 36 * modification, are permitted provided that the following conditions 37 * are met: 38 * 1. Redistributions of source code must retain the above copyright 39 * notice, this list of conditions and the following disclaimer. 40 * 2. Redistributions in binary form must reproduce the above copyright 41 * notice, this list of conditions and the following disclaimer in the 42 * documentation and/or other materials provided with the distribution. 43 * 3. Neither the name of the University nor the names of its contributors 44 * may be used to endorse or promote products derived from this software 45 * without specific prior written permission. 46 * 47 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 48 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 49 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 50 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 51 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 52 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 53 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 54 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 55 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 56 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 57 * SUCH DAMAGE. 58 * 59 * @(#)lfs_vnops.c 8.13 (Berkeley) 6/10/95 60 */ 61 62 #include <sys/cdefs.h> 63 __KERNEL_RCSID(0, "$NetBSD: lfs_pages.c,v 1.9 2016/10/04 16:46:20 christos Exp $"); 64 65 #ifdef _KERNEL_OPT 66 #include "opt_compat_netbsd.h" 67 #include "opt_uvm_page_trkown.h" 68 #endif 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/namei.h> 73 #include <sys/resourcevar.h> 74 #include <sys/kernel.h> 75 #include <sys/file.h> 76 #include <sys/stat.h> 77 #include <sys/buf.h> 78 #include <sys/proc.h> 79 #include <sys/mount.h> 80 #include <sys/vnode.h> 81 #include <sys/pool.h> 82 #include <sys/signalvar.h> 83 #include <sys/kauth.h> 84 #include <sys/syslog.h> 85 #include <sys/fstrans.h> 86 87 #include <miscfs/fifofs/fifo.h> 88 #include <miscfs/genfs/genfs.h> 89 #include <miscfs/specfs/specdev.h> 90 91 #include <ufs/lfs/ulfs_inode.h> 92 #include <ufs/lfs/ulfsmount.h> 93 #include <ufs/lfs/ulfs_bswap.h> 94 #include <ufs/lfs/ulfs_extern.h> 95 96 #include <uvm/uvm.h> 97 #include <uvm/uvm_pmap.h> 98 #include <uvm/uvm_stat.h> 99 #include <uvm/uvm_pager.h> 100 101 #include <ufs/lfs/lfs.h> 102 #include <ufs/lfs/lfs_accessors.h> 103 #include <ufs/lfs/lfs_kernel.h> 104 #include <ufs/lfs/lfs_extern.h> 105 106 extern pid_t lfs_writer_daemon; 107 108 static int check_dirty(struct lfs *, struct vnode *, off_t, off_t, off_t, int, int, struct vm_page **); 109 110 int 111 lfs_getpages(void *v) 112 { 113 struct vop_getpages_args /* { 114 struct vnode *a_vp; 115 voff_t a_offset; 116 struct vm_page **a_m; 117 int *a_count; 118 int a_centeridx; 119 vm_prot_t a_access_type; 120 int a_advice; 121 int a_flags; 122 } */ *ap = v; 123 124 if (VTOI(ap->a_vp)->i_number == LFS_IFILE_INUM && 125 (ap->a_access_type & VM_PROT_WRITE) != 0) { 126 return EPERM; 127 } 128 if ((ap->a_access_type & VM_PROT_WRITE) != 0) { 129 mutex_enter(&lfs_lock); 130 LFS_SET_UINO(VTOI(ap->a_vp), IN_MODIFIED); 131 mutex_exit(&lfs_lock); 132 } 133 134 /* 135 * we're relying on the fact that genfs_getpages() always read in 136 * entire filesystem blocks. 137 */ 138 return genfs_getpages(v); 139 } 140 141 /* 142 * Wait for a page to become unbusy, possibly printing diagnostic messages 143 * as well. 144 * 145 * Called with vp->v_interlock held; return with it held. 146 */ 147 static void 148 wait_for_page(struct vnode *vp, struct vm_page *pg, const char *label) 149 { 150 KASSERT(mutex_owned(vp->v_interlock)); 151 if ((pg->flags & PG_BUSY) == 0) 152 return; /* Nothing to wait for! */ 153 154 #if defined(DEBUG) && defined(UVM_PAGE_TRKOWN) 155 static struct vm_page *lastpg; 156 157 if (label != NULL && pg != lastpg) { 158 if (pg->owner_tag) { 159 printf("lfs_putpages[%d.%d]: %s: page %p owner %d.%d [%s]\n", 160 curproc->p_pid, curlwp->l_lid, label, 161 pg, pg->owner, pg->lowner, pg->owner_tag); 162 } else { 163 printf("lfs_putpages[%d.%d]: %s: page %p unowned?!\n", 164 curproc->p_pid, curlwp->l_lid, label, pg); 165 } 166 } 167 lastpg = pg; 168 #endif 169 170 pg->flags |= PG_WANTED; 171 UVM_UNLOCK_AND_WAIT(pg, vp->v_interlock, 0, "lfsput", 0); 172 mutex_enter(vp->v_interlock); 173 } 174 175 /* 176 * This routine is called by lfs_putpages() when it can't complete the 177 * write because a page is busy. This means that either (1) someone, 178 * possibly the pagedaemon, is looking at this page, and will give it up 179 * presently; or (2) we ourselves are holding the page busy in the 180 * process of being written (either gathered or actually on its way to 181 * disk). We don't need to give up the segment lock, but we might need 182 * to call lfs_writeseg() to expedite the page's journey to disk. 183 * 184 * Called with vp->v_interlock held; return with it held. 185 */ 186 /* #define BUSYWAIT */ 187 static void 188 write_and_wait(struct lfs *fs, struct vnode *vp, struct vm_page *pg, 189 int seglocked, const char *label) 190 { 191 KASSERT(mutex_owned(vp->v_interlock)); 192 #ifndef BUSYWAIT 193 struct inode *ip = VTOI(vp); 194 struct segment *sp = fs->lfs_sp; 195 int count = 0; 196 197 if (pg == NULL) 198 return; 199 200 while (pg->flags & PG_BUSY && 201 pg->uobject == &vp->v_uobj) { 202 mutex_exit(vp->v_interlock); 203 if (sp->cbpp - sp->bpp > 1) { 204 /* Write gathered pages */ 205 lfs_updatemeta(sp); 206 lfs_release_finfo(fs); 207 (void) lfs_writeseg(fs, sp); 208 209 /* 210 * Reinitialize FIP 211 */ 212 KASSERT(sp->vp == vp); 213 lfs_acquire_finfo(fs, ip->i_number, 214 ip->i_gen); 215 } 216 ++count; 217 mutex_enter(vp->v_interlock); 218 wait_for_page(vp, pg, label); 219 } 220 if (label != NULL && count > 1) { 221 DLOG((DLOG_PAGE, "lfs_putpages[%d]: %s: %sn = %d\n", 222 curproc->p_pid, label, (count > 0 ? "looping, " : ""), 223 count)); 224 } 225 #else 226 preempt(1); 227 #endif 228 KASSERT(mutex_owned(vp->v_interlock)); 229 } 230 231 /* 232 * Make sure that for all pages in every block in the given range, 233 * either all are dirty or all are clean. If any of the pages 234 * we've seen so far are dirty, put the vnode on the paging chain, 235 * and mark it IN_PAGING. 236 * 237 * If checkfirst != 0, don't check all the pages but return at the 238 * first dirty page. 239 */ 240 static int 241 check_dirty(struct lfs *fs, struct vnode *vp, 242 off_t startoffset, off_t endoffset, off_t blkeof, 243 int flags, int checkfirst, struct vm_page **pgp) 244 { 245 int by_list; 246 struct vm_page *curpg = NULL; /* XXX: gcc */ 247 struct vm_page *pgs[MAXBSIZE / MIN_PAGE_SIZE], *pg; 248 off_t soff = 0; /* XXX: gcc */ 249 voff_t off; 250 int i; 251 int nonexistent; 252 int any_dirty; /* number of dirty pages */ 253 int dirty; /* number of dirty pages in a block */ 254 int tdirty; 255 int pages_per_block = lfs_sb_getbsize(fs) >> PAGE_SHIFT; 256 int pagedaemon = (curlwp == uvm.pagedaemon_lwp); 257 258 KASSERT(mutex_owned(vp->v_interlock)); 259 ASSERT_MAYBE_SEGLOCK(fs); 260 top: 261 by_list = (vp->v_uobj.uo_npages <= 262 ((endoffset - startoffset) >> PAGE_SHIFT) * 263 UVM_PAGE_TREE_PENALTY); 264 any_dirty = 0; 265 266 if (by_list) { 267 curpg = TAILQ_FIRST(&vp->v_uobj.memq); 268 } else { 269 soff = startoffset; 270 } 271 while (by_list || soff < MIN(blkeof, endoffset)) { 272 if (by_list) { 273 /* 274 * Find the first page in a block. Skip 275 * blocks outside our area of interest or beyond 276 * the end of file. 277 */ 278 KASSERT(curpg == NULL 279 || (curpg->flags & PG_MARKER) == 0); 280 if (pages_per_block > 1) { 281 while (curpg && 282 ((curpg->offset & lfs_sb_getbmask(fs)) || 283 curpg->offset >= vp->v_size || 284 curpg->offset >= endoffset)) { 285 curpg = TAILQ_NEXT(curpg, listq.queue); 286 KASSERT(curpg == NULL || 287 (curpg->flags & PG_MARKER) == 0); 288 } 289 } 290 if (curpg == NULL) 291 break; 292 soff = curpg->offset; 293 } 294 295 /* 296 * Mark all pages in extended range busy; find out if any 297 * of them are dirty. 298 */ 299 nonexistent = dirty = 0; 300 for (i = 0; i == 0 || i < pages_per_block; i++) { 301 KASSERT(mutex_owned(vp->v_interlock)); 302 if (by_list && pages_per_block <= 1) { 303 pgs[i] = pg = curpg; 304 } else { 305 off = soff + (i << PAGE_SHIFT); 306 pgs[i] = pg = uvm_pagelookup(&vp->v_uobj, off); 307 if (pg == NULL) { 308 ++nonexistent; 309 continue; 310 } 311 } 312 KASSERT(pg != NULL); 313 314 /* 315 * If we're holding the segment lock, we can deadlock 316 * against a process that has our page and is waiting 317 * for the cleaner, while the cleaner waits for the 318 * segment lock. Just bail in that case. 319 */ 320 if ((pg->flags & PG_BUSY) && 321 (pagedaemon || LFS_SEGLOCK_HELD(fs))) { 322 if (i > 0) 323 uvm_page_unbusy(pgs, i); 324 DLOG((DLOG_PAGE, "lfs_putpages: avoiding 3-way or pagedaemon deadlock\n")); 325 if (pgp) 326 *pgp = pg; 327 KASSERT(mutex_owned(vp->v_interlock)); 328 return -1; 329 } 330 331 while (pg->flags & PG_BUSY) { 332 wait_for_page(vp, pg, NULL); 333 KASSERT(mutex_owned(vp->v_interlock)); 334 if (i > 0) 335 uvm_page_unbusy(pgs, i); 336 KASSERT(mutex_owned(vp->v_interlock)); 337 goto top; 338 } 339 pg->flags |= PG_BUSY; 340 UVM_PAGE_OWN(pg, "lfs_putpages"); 341 342 pmap_page_protect(pg, VM_PROT_NONE); 343 tdirty = (pmap_clear_modify(pg) || 344 (pg->flags & PG_CLEAN) == 0); 345 dirty += tdirty; 346 } 347 if (pages_per_block > 0 && nonexistent >= pages_per_block) { 348 if (by_list) { 349 curpg = TAILQ_NEXT(curpg, listq.queue); 350 } else { 351 soff += lfs_sb_getbsize(fs); 352 } 353 continue; 354 } 355 356 any_dirty += dirty; 357 KASSERT(nonexistent == 0); 358 KASSERT(mutex_owned(vp->v_interlock)); 359 360 /* 361 * If any are dirty make all dirty; unbusy them, 362 * but if we were asked to clean, wire them so that 363 * the pagedaemon doesn't bother us about them while 364 * they're on their way to disk. 365 */ 366 for (i = 0; i == 0 || i < pages_per_block; i++) { 367 KASSERT(mutex_owned(vp->v_interlock)); 368 pg = pgs[i]; 369 KASSERT(!((pg->flags & PG_CLEAN) && (pg->flags & PG_DELWRI))); 370 KASSERT(pg->flags & PG_BUSY); 371 if (dirty) { 372 pg->flags &= ~PG_CLEAN; 373 if (flags & PGO_FREE) { 374 /* 375 * Wire the page so that 376 * pdaemon doesn't see it again. 377 */ 378 mutex_enter(&uvm_pageqlock); 379 uvm_pagewire(pg); 380 mutex_exit(&uvm_pageqlock); 381 382 /* Suspended write flag */ 383 pg->flags |= PG_DELWRI; 384 } 385 } 386 if (pg->flags & PG_WANTED) 387 wakeup(pg); 388 pg->flags &= ~(PG_WANTED|PG_BUSY); 389 UVM_PAGE_OWN(pg, NULL); 390 } 391 392 if (checkfirst && any_dirty) 393 break; 394 395 if (by_list) { 396 curpg = TAILQ_NEXT(curpg, listq.queue); 397 } else { 398 soff += MAX(PAGE_SIZE, lfs_sb_getbsize(fs)); 399 } 400 } 401 402 KASSERT(mutex_owned(vp->v_interlock)); 403 return any_dirty; 404 } 405 406 /* 407 * lfs_putpages functions like genfs_putpages except that 408 * 409 * (1) It needs to bounds-check the incoming requests to ensure that 410 * they are block-aligned; if they are not, expand the range and 411 * do the right thing in case, e.g., the requested range is clean 412 * but the expanded range is dirty. 413 * 414 * (2) It needs to explicitly send blocks to be written when it is done. 415 * If VOP_PUTPAGES is called without the seglock held, we simply take 416 * the seglock and let lfs_segunlock wait for us. 417 * XXX There might be a bad situation if we have to flush a vnode while 418 * XXX lfs_markv is in operation. As of this writing we panic in this 419 * XXX case. 420 * 421 * Assumptions: 422 * 423 * (1) The caller does not hold any pages in this vnode busy. If it does, 424 * there is a danger that when we expand the page range and busy the 425 * pages we will deadlock. 426 * 427 * (2) We are called with vp->v_interlock held; we must return with it 428 * released. 429 * 430 * (3) We don't absolutely have to free pages right away, provided that 431 * the request does not have PGO_SYNCIO. When the pagedaemon gives 432 * us a request with PGO_FREE, we take the pages out of the paging 433 * queue and wake up the writer, which will handle freeing them for us. 434 * 435 * We ensure that for any filesystem block, all pages for that 436 * block are either resident or not, even if those pages are higher 437 * than EOF; that means that we will be getting requests to free 438 * "unused" pages above EOF all the time, and should ignore them. 439 * 440 * (4) If we are called with PGO_LOCKED, the finfo array we are to write 441 * into has been set up for us by lfs_writefile. If not, we will 442 * have to handle allocating and/or freeing an finfo entry. 443 * 444 * XXX note that we're (ab)using PGO_LOCKED as "seglock held". 445 */ 446 447 /* How many times to loop before we should start to worry */ 448 #define TOOMANY 4 449 450 int 451 lfs_putpages(void *v) 452 { 453 int error; 454 struct vop_putpages_args /* { 455 struct vnode *a_vp; 456 voff_t a_offlo; 457 voff_t a_offhi; 458 int a_flags; 459 } */ *ap = v; 460 struct vnode *vp; 461 struct inode *ip; 462 struct lfs *fs; 463 struct segment *sp; 464 off_t origoffset, startoffset, endoffset, origendoffset, blkeof; 465 off_t off, max_endoffset; 466 bool seglocked, sync, pagedaemon, reclaim; 467 struct vm_page *pg, *busypg; 468 UVMHIST_FUNC("lfs_putpages"); UVMHIST_CALLED(ubchist); 469 int oreclaim = 0; 470 int donewriting = 0; 471 #ifdef DEBUG 472 int debug_n_again, debug_n_dirtyclean; 473 #endif 474 475 vp = ap->a_vp; 476 ip = VTOI(vp); 477 fs = ip->i_lfs; 478 sync = (ap->a_flags & PGO_SYNCIO) != 0; 479 reclaim = (ap->a_flags & PGO_RECLAIM) != 0; 480 pagedaemon = (curlwp == uvm.pagedaemon_lwp); 481 482 KASSERT(mutex_owned(vp->v_interlock)); 483 484 /* Putpages does nothing for metadata. */ 485 if (vp == fs->lfs_ivnode || vp->v_type != VREG) { 486 mutex_exit(vp->v_interlock); 487 return 0; 488 } 489 490 /* 491 * If there are no pages, don't do anything. 492 */ 493 if (vp->v_uobj.uo_npages == 0) { 494 if (TAILQ_EMPTY(&vp->v_uobj.memq) && 495 (vp->v_iflag & VI_ONWORKLST) && 496 LIST_FIRST(&vp->v_dirtyblkhd) == NULL) { 497 vp->v_iflag &= ~VI_WRMAPDIRTY; 498 vn_syncer_remove_from_worklist(vp); 499 } 500 mutex_exit(vp->v_interlock); 501 502 /* Remove us from paging queue, if we were on it */ 503 mutex_enter(&lfs_lock); 504 if (ip->i_flags & IN_PAGING) { 505 ip->i_flags &= ~IN_PAGING; 506 TAILQ_REMOVE(&fs->lfs_pchainhd, ip, i_lfs_pchain); 507 } 508 mutex_exit(&lfs_lock); 509 510 KASSERT(!mutex_owned(vp->v_interlock)); 511 return 0; 512 } 513 514 blkeof = lfs_blkroundup(fs, ip->i_size); 515 516 /* 517 * Ignore requests to free pages past EOF but in the same block 518 * as EOF, unless the vnode is being reclaimed or the request 519 * is synchronous. (If the request is sync, it comes from 520 * lfs_truncate.) 521 * 522 * To avoid being flooded with this request, make these pages 523 * look "active". 524 */ 525 if (!sync && !reclaim && 526 ap->a_offlo >= ip->i_size && ap->a_offlo < blkeof) { 527 origoffset = ap->a_offlo; 528 for (off = origoffset; off < blkeof; off += lfs_sb_getbsize(fs)) { 529 pg = uvm_pagelookup(&vp->v_uobj, off); 530 KASSERT(pg != NULL); 531 while (pg->flags & PG_BUSY) { 532 pg->flags |= PG_WANTED; 533 UVM_UNLOCK_AND_WAIT(pg, vp->v_interlock, 0, 534 "lfsput2", 0); 535 mutex_enter(vp->v_interlock); 536 } 537 mutex_enter(&uvm_pageqlock); 538 uvm_pageactivate(pg); 539 mutex_exit(&uvm_pageqlock); 540 } 541 ap->a_offlo = blkeof; 542 if (ap->a_offhi > 0 && ap->a_offhi <= ap->a_offlo) { 543 mutex_exit(vp->v_interlock); 544 return 0; 545 } 546 } 547 548 /* 549 * Extend page range to start and end at block boundaries. 550 * (For the purposes of VOP_PUTPAGES, fragments don't exist.) 551 */ 552 origoffset = ap->a_offlo; 553 origendoffset = ap->a_offhi; 554 startoffset = origoffset & ~(lfs_sb_getbmask(fs)); 555 max_endoffset = (trunc_page(LLONG_MAX) >> lfs_sb_getbshift(fs)) 556 << lfs_sb_getbshift(fs); 557 558 if (origendoffset == 0 || ap->a_flags & PGO_ALLPAGES) { 559 endoffset = max_endoffset; 560 origendoffset = endoffset; 561 } else { 562 origendoffset = round_page(ap->a_offhi); 563 endoffset = round_page(lfs_blkroundup(fs, origendoffset)); 564 } 565 566 KASSERT(startoffset > 0 || endoffset >= startoffset); 567 if (startoffset == endoffset) { 568 /* Nothing to do, why were we called? */ 569 mutex_exit(vp->v_interlock); 570 DLOG((DLOG_PAGE, "lfs_putpages: startoffset = endoffset = %" 571 PRId64 "\n", startoffset)); 572 return 0; 573 } 574 575 ap->a_offlo = startoffset; 576 ap->a_offhi = endoffset; 577 578 /* 579 * If not cleaning, just send the pages through genfs_putpages 580 * to be returned to the pool. 581 */ 582 if (!(ap->a_flags & PGO_CLEANIT)) { 583 DLOG((DLOG_PAGE, "lfs_putpages: no cleanit vn %p ino %d (flags %x)\n", 584 vp, (int)ip->i_number, ap->a_flags)); 585 int r = genfs_putpages(v); 586 KASSERT(!mutex_owned(vp->v_interlock)); 587 return r; 588 } 589 590 /* Set PGO_BUSYFAIL to avoid deadlocks */ 591 ap->a_flags |= PGO_BUSYFAIL; 592 593 /* 594 * Likewise, if we are asked to clean but the pages are not 595 * dirty, we can just free them using genfs_putpages. 596 */ 597 #ifdef DEBUG 598 debug_n_dirtyclean = 0; 599 #endif 600 do { 601 int r; 602 KASSERT(mutex_owned(vp->v_interlock)); 603 604 /* Count the number of dirty pages */ 605 r = check_dirty(fs, vp, startoffset, endoffset, blkeof, 606 ap->a_flags, 1, NULL); 607 if (r < 0) { 608 /* Pages are busy with another process */ 609 mutex_exit(vp->v_interlock); 610 return EDEADLK; 611 } 612 if (r > 0) /* Some pages are dirty */ 613 break; 614 615 /* 616 * Sometimes pages are dirtied between the time that 617 * we check and the time we try to clean them. 618 * Instruct lfs_gop_write to return EDEADLK in this case 619 * so we can write them properly. 620 */ 621 ip->i_lfs_iflags |= LFSI_NO_GOP_WRITE; 622 r = genfs_do_putpages(vp, startoffset, endoffset, 623 ap->a_flags & ~PGO_SYNCIO, &busypg); 624 ip->i_lfs_iflags &= ~LFSI_NO_GOP_WRITE; 625 if (r != EDEADLK) { 626 KASSERT(!mutex_owned(vp->v_interlock)); 627 return r; 628 } 629 630 /* One of the pages was busy. Start over. */ 631 mutex_enter(vp->v_interlock); 632 wait_for_page(vp, busypg, "dirtyclean"); 633 #ifdef DEBUG 634 ++debug_n_dirtyclean; 635 #endif 636 } while(1); 637 638 #ifdef DEBUG 639 if (debug_n_dirtyclean > TOOMANY) 640 DLOG((DLOG_PAGE, "lfs_putpages: dirtyclean: looping, n = %d\n", 641 debug_n_dirtyclean)); 642 #endif 643 644 /* 645 * Dirty and asked to clean. 646 * 647 * Pagedaemon can't actually write LFS pages; wake up 648 * the writer to take care of that. The writer will 649 * notice the pager inode queue and act on that. 650 * 651 * XXX We must drop the vp->interlock before taking the lfs_lock or we 652 * get a nasty deadlock with lfs_flush_pchain(). 653 */ 654 if (pagedaemon) { 655 mutex_exit(vp->v_interlock); 656 mutex_enter(&lfs_lock); 657 if (!(ip->i_flags & IN_PAGING)) { 658 ip->i_flags |= IN_PAGING; 659 TAILQ_INSERT_TAIL(&fs->lfs_pchainhd, ip, i_lfs_pchain); 660 } 661 wakeup(&lfs_writer_daemon); 662 mutex_exit(&lfs_lock); 663 preempt(); 664 KASSERT(!mutex_owned(vp->v_interlock)); 665 return EWOULDBLOCK; 666 } 667 668 /* 669 * If this is a file created in a recent dirop, we can't flush its 670 * inode until the dirop is complete. Drain dirops, then flush the 671 * filesystem (taking care of any other pending dirops while we're 672 * at it). 673 */ 674 if ((ap->a_flags & (PGO_CLEANIT|PGO_LOCKED)) == PGO_CLEANIT && 675 (vp->v_uflag & VU_DIROP)) { 676 DLOG((DLOG_PAGE, "lfs_putpages: flushing VU_DIROP\n")); 677 678 lfs_writer_enter(fs, "ppdirop"); 679 680 /* Note if we hold the vnode locked */ 681 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE) 682 { 683 DLOG((DLOG_PAGE, "lfs_putpages: dirop inode already locked\n")); 684 } else { 685 DLOG((DLOG_PAGE, "lfs_putpages: dirop inode not locked\n")); 686 } 687 mutex_exit(vp->v_interlock); 688 689 mutex_enter(&lfs_lock); 690 lfs_flush_fs(fs, sync ? SEGM_SYNC : 0); 691 mutex_exit(&lfs_lock); 692 693 mutex_enter(vp->v_interlock); 694 lfs_writer_leave(fs); 695 696 /* The flush will have cleaned out this vnode as well, 697 no need to do more to it. */ 698 } 699 700 /* 701 * This is it. We are going to write some pages. From here on 702 * down it's all just mechanics. 703 * 704 * Don't let genfs_putpages wait; lfs_segunlock will wait for us. 705 */ 706 ap->a_flags &= ~PGO_SYNCIO; 707 708 /* 709 * If we've already got the seglock, flush the node and return. 710 * The FIP has already been set up for us by lfs_writefile, 711 * and FIP cleanup and lfs_updatemeta will also be done there, 712 * unless genfs_putpages returns EDEADLK; then we must flush 713 * what we have, and correct FIP and segment header accounting. 714 */ 715 get_seglock: 716 /* 717 * If we are not called with the segment locked, lock it. 718 * Account for a new FIP in the segment header, and set sp->vp. 719 * (This should duplicate the setup at the top of lfs_writefile().) 720 */ 721 seglocked = (ap->a_flags & PGO_LOCKED) != 0; 722 if (!seglocked) { 723 mutex_exit(vp->v_interlock); 724 error = lfs_seglock(fs, SEGM_PROT | (sync ? SEGM_SYNC : 0)); 725 if (error != 0) { 726 KASSERT(!mutex_owned(vp->v_interlock)); 727 return error; 728 } 729 mutex_enter(vp->v_interlock); 730 lfs_acquire_finfo(fs, ip->i_number, ip->i_gen); 731 } 732 sp = fs->lfs_sp; 733 KASSERT(sp->vp == NULL); 734 sp->vp = vp; 735 736 /* Note segments written by reclaim; only for debugging */ 737 if (vdead_check(vp, VDEAD_NOWAIT) != 0) { 738 sp->seg_flags |= SEGM_RECLAIM; 739 fs->lfs_reclino = ip->i_number; 740 } 741 742 /* 743 * Ensure that the partial segment is marked SS_DIROP if this 744 * vnode is a DIROP. 745 */ 746 if (!seglocked && vp->v_uflag & VU_DIROP) { 747 SEGSUM *ssp = sp->segsum; 748 749 lfs_ss_setflags(fs, ssp, 750 lfs_ss_getflags(fs, ssp) | (SS_DIROP|SS_CONT)); 751 } 752 753 /* 754 * Loop over genfs_putpages until all pages are gathered. 755 * genfs_putpages() drops the interlock, so reacquire it if necessary. 756 * Whenever we lose the interlock we have to rerun check_dirty, as 757 * well, since more pages might have been dirtied in our absence. 758 */ 759 #ifdef DEBUG 760 debug_n_again = 0; 761 #endif 762 do { 763 busypg = NULL; 764 KASSERT(mutex_owned(vp->v_interlock)); 765 if (check_dirty(fs, vp, startoffset, endoffset, blkeof, 766 ap->a_flags, 0, &busypg) < 0) { 767 mutex_exit(vp->v_interlock); 768 /* XXX why? --ks */ 769 mutex_enter(vp->v_interlock); 770 write_and_wait(fs, vp, busypg, seglocked, NULL); 771 if (!seglocked) { 772 mutex_exit(vp->v_interlock); 773 lfs_release_finfo(fs); 774 lfs_segunlock(fs); 775 mutex_enter(vp->v_interlock); 776 } 777 sp->vp = NULL; 778 goto get_seglock; 779 } 780 781 busypg = NULL; 782 KASSERT(!mutex_owned(&uvm_pageqlock)); 783 oreclaim = (ap->a_flags & PGO_RECLAIM); 784 ap->a_flags &= ~PGO_RECLAIM; 785 error = genfs_do_putpages(vp, startoffset, endoffset, 786 ap->a_flags, &busypg); 787 ap->a_flags |= oreclaim; 788 789 if (error == EDEADLK || error == EAGAIN) { 790 DLOG((DLOG_PAGE, "lfs_putpages: genfs_putpages returned" 791 " %d ino %d off %jx (seg %d)\n", error, 792 ip->i_number, (uintmax_t)lfs_sb_getoffset(fs), 793 lfs_dtosn(fs, lfs_sb_getoffset(fs)))); 794 795 if (oreclaim) { 796 mutex_enter(vp->v_interlock); 797 write_and_wait(fs, vp, busypg, seglocked, "again"); 798 mutex_exit(vp->v_interlock); 799 } else { 800 if ((sp->seg_flags & SEGM_SINGLE) && 801 lfs_sb_getcurseg(fs) != fs->lfs_startseg) 802 donewriting = 1; 803 } 804 } else if (error) { 805 DLOG((DLOG_PAGE, "lfs_putpages: genfs_putpages returned" 806 " %d ino %d off %jx (seg %d)\n", error, 807 (int)ip->i_number, (uintmax_t)lfs_sb_getoffset(fs), 808 lfs_dtosn(fs, lfs_sb_getoffset(fs)))); 809 } 810 /* genfs_do_putpages loses the interlock */ 811 #ifdef DEBUG 812 ++debug_n_again; 813 #endif 814 if (oreclaim && error == EAGAIN) { 815 DLOG((DLOG_PAGE, "vp %p ino %d vi_flags %x a_flags %x avoiding vclean panic\n", 816 vp, (int)ip->i_number, vp->v_iflag, ap->a_flags)); 817 mutex_enter(vp->v_interlock); 818 } 819 if (error == EDEADLK) 820 mutex_enter(vp->v_interlock); 821 } while (error == EDEADLK || (oreclaim && error == EAGAIN)); 822 #ifdef DEBUG 823 if (debug_n_again > TOOMANY) 824 DLOG((DLOG_PAGE, "lfs_putpages: again: looping, n = %d\n", debug_n_again)); 825 #endif 826 827 KASSERT(sp != NULL && sp->vp == vp); 828 if (!seglocked && !donewriting) { 829 sp->vp = NULL; 830 831 /* Write indirect blocks as well */ 832 lfs_gather(fs, fs->lfs_sp, vp, lfs_match_indir); 833 lfs_gather(fs, fs->lfs_sp, vp, lfs_match_dindir); 834 lfs_gather(fs, fs->lfs_sp, vp, lfs_match_tindir); 835 836 KASSERT(sp->vp == NULL); 837 sp->vp = vp; 838 } 839 840 /* 841 * Blocks are now gathered into a segment waiting to be written. 842 * All that's left to do is update metadata, and write them. 843 */ 844 lfs_updatemeta(sp); 845 KASSERT(sp->vp == vp); 846 sp->vp = NULL; 847 848 /* 849 * If we were called from lfs_writefile, we don't need to clean up 850 * the FIP or unlock the segment lock. We're done. 851 */ 852 if (seglocked) { 853 KASSERT(!mutex_owned(vp->v_interlock)); 854 return error; 855 } 856 857 /* Clean up FIP and send it to disk. */ 858 lfs_release_finfo(fs); 859 lfs_writeseg(fs, fs->lfs_sp); 860 861 /* 862 * Remove us from paging queue if we wrote all our pages. 863 */ 864 if (origendoffset == 0 || ap->a_flags & PGO_ALLPAGES) { 865 mutex_enter(&lfs_lock); 866 if (ip->i_flags & IN_PAGING) { 867 ip->i_flags &= ~IN_PAGING; 868 TAILQ_REMOVE(&fs->lfs_pchainhd, ip, i_lfs_pchain); 869 } 870 mutex_exit(&lfs_lock); 871 } 872 873 /* 874 * XXX - with the malloc/copy writeseg, the pages are freed by now 875 * even if we don't wait (e.g. if we hold a nested lock). This 876 * will not be true if we stop using malloc/copy. 877 */ 878 KASSERT(fs->lfs_sp->seg_flags & SEGM_PROT); 879 lfs_segunlock(fs); 880 881 /* 882 * Wait for v_numoutput to drop to zero. The seglock should 883 * take care of this, but there is a slight possibility that 884 * aiodoned might not have got around to our buffers yet. 885 */ 886 if (sync) { 887 mutex_enter(vp->v_interlock); 888 while (vp->v_numoutput > 0) { 889 DLOG((DLOG_PAGE, "lfs_putpages: ino %d sleeping on" 890 " num %d\n", ip->i_number, vp->v_numoutput)); 891 cv_wait(&vp->v_cv, vp->v_interlock); 892 } 893 mutex_exit(vp->v_interlock); 894 } 895 KASSERT(!mutex_owned(vp->v_interlock)); 896 return error; 897 } 898 899