1 /* $NetBSD: lfs_bio.c,v 1.149 2020/09/05 16:30:13 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 1999, 2000, 2001, 2002, 2003, 2008 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) 1991, 1993
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_bio.c 8.10 (Berkeley) 6/10/95
60 */
61
62 #include <sys/cdefs.h>
63 __KERNEL_RCSID(0, "$NetBSD: lfs_bio.c,v 1.149 2020/09/05 16:30:13 riastradh Exp $");
64
65 #include <sys/param.h>
66 #include <sys/systm.h>
67 #include <sys/proc.h>
68 #include <sys/buf.h>
69 #include <sys/vnode.h>
70 #include <sys/resourcevar.h>
71 #include <sys/mount.h>
72 #include <sys/kernel.h>
73 #include <sys/kauth.h>
74
75 #include <ufs/lfs/ulfs_inode.h>
76 #include <ufs/lfs/ulfsmount.h>
77 #include <ufs/lfs/ulfs_extern.h>
78
79 #include <ufs/lfs/lfs.h>
80 #include <ufs/lfs/lfs_accessors.h>
81 #include <ufs/lfs/lfs_extern.h>
82 #include <ufs/lfs/lfs_kernel.h>
83
84 #include <uvm/uvm_extern.h>
85
86 /*
87 * LFS block write function.
88 *
89 * XXX
90 * No write cost accounting is done.
91 * This is almost certainly wrong for synchronous operations and NFS.
92 *
93 * protected by lfs_lock.
94 */
95 int locked_queue_count = 0; /* Count of locked-down buffers. */
96 long locked_queue_bytes = 0L; /* Total size of locked buffers. */
97 int lfs_subsys_pages = 0L; /* Total number LFS-written pages */
98 int lfs_fs_pagetrip = 0; /* # of pages to trip per-fs write */
99 int lfs_writing = 0; /* Set if already kicked off a writer
100 because of buffer space */
101 int locked_queue_waiters = 0; /* Number of processes waiting on lq */
102
103 /* Lock and condition variables for above. */
104 kcondvar_t locked_queue_cv;
105 kcondvar_t lfs_writing_cv;
106 kmutex_t lfs_lock;
107
108 extern int lfs_dostats;
109
110 /*
111 * reserved number/bytes of locked buffers
112 */
113 int locked_queue_rcount = 0;
114 long locked_queue_rbytes = 0L;
115
116 static int lfs_fits_buf(struct lfs *, int, int);
117 static int lfs_reservebuf(struct lfs *, struct vnode *vp, struct vnode *vp2,
118 int, int);
119 static int lfs_reserveavail(struct lfs *, struct vnode *vp, struct vnode *vp2,
120 int);
121
122 static int
lfs_fits_buf(struct lfs * fs,int n,int bytes)123 lfs_fits_buf(struct lfs *fs, int n, int bytes)
124 {
125 int count_fit, bytes_fit;
126
127 ASSERT_NO_SEGLOCK(fs);
128 KASSERT(mutex_owned(&lfs_lock));
129
130 count_fit =
131 (locked_queue_count + locked_queue_rcount + n <= LFS_WAIT_BUFS);
132 bytes_fit =
133 (locked_queue_bytes + locked_queue_rbytes + bytes <= LFS_WAIT_BYTES);
134
135 #ifdef DEBUG
136 if (!count_fit) {
137 DLOG((DLOG_AVAIL, "lfs_fits_buf: no fit count: %d + %d + %d >= %d\n",
138 locked_queue_count, locked_queue_rcount,
139 n, LFS_WAIT_BUFS));
140 }
141 if (!bytes_fit) {
142 DLOG((DLOG_AVAIL, "lfs_fits_buf: no fit bytes: %ld + %ld + %d >= %ld\n",
143 locked_queue_bytes, locked_queue_rbytes,
144 bytes, LFS_WAIT_BYTES));
145 }
146 #endif /* DEBUG */
147
148 return (count_fit && bytes_fit);
149 }
150
151 /* ARGSUSED */
152 static int
lfs_reservebuf(struct lfs * fs,struct vnode * vp,struct vnode * vp2,int n,int bytes)153 lfs_reservebuf(struct lfs *fs, struct vnode *vp,
154 struct vnode *vp2, int n, int bytes)
155 {
156 int cantwait;
157
158 ASSERT_MAYBE_SEGLOCK(fs);
159 KASSERT(locked_queue_rcount >= 0);
160 KASSERT(locked_queue_rbytes >= 0);
161
162 cantwait = (VTOI(vp)->i_state & IN_ADIROP) || fs->lfs_unlockvp == vp;
163 mutex_enter(&lfs_lock);
164 while (!cantwait && n > 0 && !lfs_fits_buf(fs, n, bytes)) {
165 int error;
166
167 lfs_flush(fs, 0, 0);
168
169 DLOG((DLOG_AVAIL, "lfs_reservebuf: waiting: count=%d, bytes=%ld\n",
170 locked_queue_count, locked_queue_bytes));
171 ++locked_queue_waiters;
172 error = cv_timedwait_sig(&locked_queue_cv, &lfs_lock,
173 hz * LFS_BUFWAIT);
174 --locked_queue_waiters;
175 if (error && error != EWOULDBLOCK) {
176 mutex_exit(&lfs_lock);
177 return error;
178 }
179 }
180
181 locked_queue_rcount += n;
182 locked_queue_rbytes += bytes;
183
184 if (n < 0 && locked_queue_waiters > 0) {
185 DLOG((DLOG_AVAIL, "lfs_reservebuf: broadcast: count=%d, bytes=%ld\n",
186 locked_queue_count, locked_queue_bytes));
187 cv_broadcast(&locked_queue_cv);
188 }
189
190 mutex_exit(&lfs_lock);
191
192 KASSERT(locked_queue_rcount >= 0);
193 KASSERT(locked_queue_rbytes >= 0);
194
195 return 0;
196 }
197
198 /*
199 * Try to reserve some blocks, prior to performing a sensitive operation that
200 * requires the vnode lock to be honored. If there is not enough space, wait
201 * for the space to become available.
202 *
203 * Called with vp locked. (Note nowever that if fsb < 0, vp is ignored.)
204 */
205 static int
lfs_reserveavail(struct lfs * fs,struct vnode * vp,struct vnode * vp2,int fsb)206 lfs_reserveavail(struct lfs *fs, struct vnode *vp,
207 struct vnode *vp2, int fsb)
208 {
209 CLEANERINFO *cip;
210 struct buf *bp;
211 int error, slept;
212 int cantwait;
213
214 ASSERT_MAYBE_SEGLOCK(fs);
215 slept = 0;
216 mutex_enter(&lfs_lock);
217 cantwait = (VTOI(vp)->i_state & IN_ADIROP) || fs->lfs_unlockvp == vp;
218 while (!cantwait && fsb > 0 &&
219 !lfs_fits(fs, fsb + fs->lfs_ravail + fs->lfs_favail)) {
220 mutex_exit(&lfs_lock);
221
222 if (!slept) {
223 DLOG((DLOG_AVAIL, "lfs_reserve: waiting for %ld (bfree = %jd,"
224 " est_bfree = %jd)\n",
225 fsb + fs->lfs_ravail + fs->lfs_favail,
226 (intmax_t)lfs_sb_getbfree(fs),
227 (intmax_t)LFS_EST_BFREE(fs)));
228 }
229 ++slept;
230
231 /* Wake up the cleaner */
232 LFS_CLEANERINFO(cip, fs, bp);
233 LFS_SYNC_CLEANERINFO(cip, fs, bp, 0);
234 lfs_wakeup_cleaner(fs);
235
236 mutex_enter(&lfs_lock);
237 /* Cleaner might have run while we were reading, check again */
238 if (lfs_fits(fs, fsb + fs->lfs_ravail + fs->lfs_favail))
239 break;
240
241 error = mtsleep(&fs->lfs_availsleep, PCATCH | PUSER,
242 "lfs_reserve", 0, &lfs_lock);
243 if (error) {
244 mutex_exit(&lfs_lock);
245 return error;
246 }
247 }
248 #ifdef DEBUG
249 if (slept) {
250 DLOG((DLOG_AVAIL, "lfs_reserve: woke up\n"));
251 }
252 #endif
253 fs->lfs_ravail += fsb;
254 mutex_exit(&lfs_lock);
255
256 return 0;
257 }
258
259 #ifdef DIAGNOSTIC
260 int lfs_rescount;
261 int lfs_rescountdirop;
262 #endif
263
264 int
lfs_reserve(struct lfs * fs,struct vnode * vp,struct vnode * vp2,int fsb)265 lfs_reserve(struct lfs *fs, struct vnode *vp, struct vnode *vp2, int fsb)
266 {
267 int error;
268
269 ASSERT_MAYBE_SEGLOCK(fs);
270 if (vp2) {
271 /* Make sure we're not in the process of reclaiming vp2 */
272 mutex_enter(&lfs_lock);
273 while(fs->lfs_flags & LFS_UNDIROP) {
274 mtsleep(&fs->lfs_flags, PRIBIO + 1, "lfsrundirop", 0,
275 &lfs_lock);
276 }
277 mutex_exit(&lfs_lock);
278 }
279
280 KASSERT(fsb < 0 || VOP_ISLOCKED(vp));
281 KASSERT(vp2 == NULL || fsb < 0 || VOP_ISLOCKED(vp2));
282 KASSERT(vp2 == NULL || vp2 != fs->lfs_unlockvp);
283
284 #ifdef DIAGNOSTIC
285 mutex_enter(&lfs_lock);
286 if (fsb > 0)
287 lfs_rescount++;
288 else if (fsb < 0)
289 lfs_rescount--;
290 if (lfs_rescount < 0)
291 panic("lfs_rescount");
292 mutex_exit(&lfs_lock);
293 #endif
294
295 error = lfs_reserveavail(fs, vp, vp2, fsb);
296 if (error)
297 return error;
298
299 /*
300 * XXX just a guess. should be more precise.
301 */
302 error = lfs_reservebuf(fs, vp, vp2, fsb, lfs_fsbtob(fs, fsb));
303 if (error)
304 lfs_reserveavail(fs, vp, vp2, -fsb);
305
306 return error;
307 }
308
309 int
lfs_max_bufs(void)310 lfs_max_bufs(void)
311 {
312
313 return LFS_MAX_RESOURCE(buf_nbuf(), 1);
314 }
315
316 int
lfs_wait_bufs(void)317 lfs_wait_bufs(void)
318 {
319
320 return LFS_WAIT_RESOURCE(buf_nbuf(), 1);
321 }
322
323 int
lfs_bwrite(void * v)324 lfs_bwrite(void *v)
325 {
326 struct vop_bwrite_args /* {
327 struct vnode *a_vp;
328 struct buf *a_bp;
329 } */ *ap = v;
330 struct buf *bp = ap->a_bp;
331
332 KASSERTMSG((VTOI(bp->b_vp)->i_lfs->lfs_ronly ||
333 !(bp->b_flags & B_ASYNC)),
334 "bawrite LFS buffer");
335 return lfs_bwrite_ext(bp, 0);
336 }
337
338 /*
339 * Determine if there is enough room currently available to write fsb
340 * blocks. We need enough blocks for the new blocks, the current
341 * inode blocks (including potentially the ifile inode), a summary block,
342 * and the segment usage table, plus an ifile block.
343 */
344 int
lfs_fits(struct lfs * fs,int fsb)345 lfs_fits(struct lfs *fs, int fsb)
346 {
347 int64_t needed;
348
349 ASSERT_NO_SEGLOCK(fs);
350 needed = fsb + lfs_btofsb(fs, lfs_sb_getsumsize(fs)) +
351 ((howmany(lfs_sb_getuinodes(fs) + 1, LFS_INOPB(fs)) +
352 lfs_sb_getsegtabsz(fs) +
353 1) << (lfs_sb_getbshift(fs) - lfs_sb_getffshift(fs)));
354
355 if (needed >= lfs_sb_getavail(fs)) {
356 #ifdef DEBUG
357 DLOG((DLOG_AVAIL, "lfs_fits: no fit: fsb = %ld, uinodes = %ld, "
358 "needed = %jd, avail = %jd\n",
359 (long)fsb, (long)lfs_sb_getuinodes(fs), (intmax_t)needed,
360 (intmax_t)lfs_sb_getavail(fs)));
361 #endif
362 return 0;
363 }
364 return 1;
365 }
366
367 int
lfs_availwait(struct lfs * fs,int fsb)368 lfs_availwait(struct lfs *fs, int fsb)
369 {
370 int error;
371 CLEANERINFO *cip;
372 struct buf *cbp;
373
374 ASSERT_NO_SEGLOCK(fs);
375 /* Push cleaner blocks through regardless */
376 mutex_enter(&lfs_lock);
377 if (LFS_SEGLOCK_HELD(fs) &&
378 fs->lfs_sp->seg_flags & (SEGM_CLEAN | SEGM_FORCE_CKP)) {
379 mutex_exit(&lfs_lock);
380 return 0;
381 }
382 mutex_exit(&lfs_lock);
383
384 while (!lfs_fits(fs, fsb)) {
385 /*
386 * Out of space, need cleaner to run.
387 * Update the cleaner info, then wake it up.
388 * Note the cleanerinfo block is on the ifile
389 * so it CANT_WAIT.
390 */
391 LFS_CLEANERINFO(cip, fs, cbp);
392 LFS_SYNC_CLEANERINFO(cip, fs, cbp, 0);
393
394 #ifdef DEBUG
395 DLOG((DLOG_AVAIL, "lfs_availwait: out of available space, "
396 "waiting on cleaner\n"));
397 #endif
398
399 lfs_wakeup_cleaner(fs);
400 KASSERTMSG(!LFS_SEGLOCK_HELD(fs), "lfs_availwait: deadlock");
401 error = tsleep(&fs->lfs_availsleep, PCATCH | PUSER,
402 "cleaner", 0);
403 if (error)
404 return (error);
405 }
406 return 0;
407 }
408
409 int
lfs_bwrite_ext(struct buf * bp,int flags)410 lfs_bwrite_ext(struct buf *bp, int flags)
411 {
412 struct lfs *fs;
413 struct inode *ip;
414 struct vnode *vp;
415 int fsb;
416
417 vp = bp->b_vp;
418 fs = VFSTOULFS(vp->v_mount)->um_lfs;
419
420 ASSERT_MAYBE_SEGLOCK(fs);
421 KASSERT(bp->b_cflags & BC_BUSY);
422 KASSERT(flags & BW_CLEAN || !LFS_IS_MALLOC_BUF(bp));
423 KASSERT((bp->b_flags & B_LOCKED) || !(bp->b_oflags & BO_DELWRI));
424
425 /*
426 * Don't write *any* blocks if we're mounted read-only, or
427 * if we are "already unmounted".
428 *
429 * In particular the cleaner can't write blocks either.
430 */
431 if (fs->lfs_ronly || (lfs_sb_getpflags(fs) & LFS_PF_CLEAN)) {
432 bp->b_oflags &= ~BO_DELWRI;
433 bp->b_flags |= B_READ; /* XXX is this right? --ks */
434 bp->b_error = 0;
435 mutex_enter(&bufcache_lock);
436 LFS_UNLOCK_BUF(bp);
437 if (LFS_IS_MALLOC_BUF(bp))
438 bp->b_cflags &= ~BC_BUSY;
439 else
440 brelsel(bp, 0);
441 mutex_exit(&bufcache_lock);
442 return (fs->lfs_ronly ? EROFS : 0);
443 }
444
445 /*
446 * Set the delayed write flag and use reassignbuf to move the buffer
447 * from the clean list to the dirty one.
448 *
449 * Set the B_LOCKED flag and unlock the buffer, causing brelse to move
450 * the buffer onto the LOCKED free list. This is necessary, otherwise
451 * getnewbuf() would try to reclaim the buffers using bawrite, which
452 * isn't going to work.
453 *
454 * XXX we don't let meta-data writes run out of space because they can
455 * come from the segment writer. We need to make sure that there is
456 * enough space reserved so that there's room to write meta-data
457 * blocks.
458 */
459 if ((bp->b_flags & B_LOCKED) == 0) {
460 fsb = lfs_numfrags(fs, bp->b_bcount);
461
462 ip = VTOI(vp);
463 mutex_enter(&lfs_lock);
464 if (flags & BW_CLEAN) {
465 LFS_SET_UINO(ip, IN_CLEANING);
466 } else {
467 LFS_SET_UINO(ip, IN_MODIFIED);
468 }
469 mutex_exit(&lfs_lock);
470 lfs_sb_subavail(fs, fsb);
471
472 mutex_enter(&bufcache_lock);
473 mutex_enter(vp->v_interlock);
474 bp->b_oflags = (bp->b_oflags | BO_DELWRI) & ~BO_DONE;
475 LFS_LOCK_BUF(bp);
476 bp->b_flags &= ~B_READ;
477 bp->b_error = 0;
478 reassignbuf(bp, bp->b_vp);
479 mutex_exit(vp->v_interlock);
480 } else {
481 mutex_enter(&bufcache_lock);
482 }
483
484 if (bp->b_iodone != NULL)
485 bp->b_cflags &= ~BC_BUSY;
486 else
487 brelsel(bp, 0);
488 mutex_exit(&bufcache_lock);
489
490 return (0);
491 }
492
493 /*
494 * Called and return with the lfs_lock held.
495 */
496 void
lfs_flush_fs(struct lfs * fs,int flags)497 lfs_flush_fs(struct lfs *fs, int flags)
498 {
499 ASSERT_NO_SEGLOCK(fs);
500 KASSERT(mutex_owned(&lfs_lock));
501 if (fs->lfs_ronly)
502 return;
503
504 if (lfs_dostats)
505 ++lfs_stats.flush_invoked;
506
507 fs->lfs_pdflush = 0;
508 mutex_exit(&lfs_lock);
509 lfs_writer_enter(fs, "fldirop");
510 lfs_segwrite(fs->lfs_ivnode->v_mount, flags);
511 lfs_writer_leave(fs);
512 mutex_enter(&lfs_lock);
513 fs->lfs_favail = 0; /* XXX */
514 }
515
516 /*
517 * This routine initiates segment writes when LFS is consuming too many
518 * resources. Ideally the pageout daemon would be able to direct LFS
519 * more subtly.
520 * XXX We have one static count of locked buffers;
521 * XXX need to think more about the multiple filesystem case.
522 *
523 * Called and return with lfs_lock held.
524 * If fs != NULL, we hold the segment lock for fs.
525 */
526 void
lfs_flush(struct lfs * fs,int flags,int only_onefs)527 lfs_flush(struct lfs *fs, int flags, int only_onefs)
528 {
529 extern u_int64_t locked_fakequeue_count;
530 mount_iterator_t *iter;
531 struct mount *mp;
532 struct lfs *tfs;
533
534 KASSERT(mutex_owned(&lfs_lock));
535 KDASSERT(fs == NULL || !LFS_SEGLOCK_HELD(fs));
536
537 if (lfs_dostats)
538 ++lfs_stats.write_exceeded;
539 /* XXX should we include SEGM_CKP here? */
540 if (lfs_writing && !(flags & SEGM_SYNC)) {
541 DLOG((DLOG_FLUSH, "lfs_flush: not flushing because another flush is active\n"));
542 return;
543 }
544 while (lfs_writing)
545 cv_wait(&lfs_writing_cv, &lfs_lock);
546 lfs_writing = 1;
547
548 mutex_exit(&lfs_lock);
549
550 if (only_onefs) {
551 KASSERT(fs != NULL);
552 if (vfs_busy(fs->lfs_ivnode->v_mount))
553 goto errout;
554 mutex_enter(&lfs_lock);
555 lfs_flush_fs(fs, flags);
556 mutex_exit(&lfs_lock);
557 vfs_unbusy(fs->lfs_ivnode->v_mount);
558 } else {
559 locked_fakequeue_count = 0;
560 mountlist_iterator_init(&iter);
561 while ((mp = mountlist_iterator_next(iter)) != NULL) {
562 if (strncmp(&mp->mnt_stat.f_fstypename[0], MOUNT_LFS,
563 sizeof(mp->mnt_stat.f_fstypename)) == 0) {
564 tfs = VFSTOULFS(mp)->um_lfs;
565 mutex_enter(&lfs_lock);
566 lfs_flush_fs(tfs, flags);
567 mutex_exit(&lfs_lock);
568 }
569 }
570 mountlist_iterator_destroy(iter);
571 }
572 wakeup(&lfs_subsys_pages);
573
574 errout:
575 mutex_enter(&lfs_lock);
576 KASSERT(lfs_writing);
577 lfs_writing = 0;
578 wakeup(&lfs_writing);
579 }
580
581 #define INOCOUNT(fs) howmany(lfs_sb_getuinodes(fs), LFS_INOPB(fs))
582 #define INOBYTES(fs) (lfs_sb_getuinodes(fs) * DINOSIZE(fs))
583
584 /*
585 * make sure that we don't have too many locked buffers.
586 * flush buffers if needed.
587 */
588 int
lfs_check(struct vnode * vp,daddr_t blkno,int flags)589 lfs_check(struct vnode *vp, daddr_t blkno, int flags)
590 {
591 int error;
592 struct lfs *fs;
593 struct inode *ip;
594 extern kcondvar_t lfs_writerd_cv;
595
596 error = 0;
597 ip = VTOI(vp);
598
599 /* If out of buffers, wait on writer */
600 /* XXX KS - if it's the Ifile, we're probably the cleaner! */
601 if (ip->i_number == LFS_IFILE_INUM)
602 return 0;
603 /* If we're being called from inside a dirop, don't sleep */
604 if (ip->i_state & IN_ADIROP)
605 return 0;
606
607 fs = ip->i_lfs;
608
609 ASSERT_NO_SEGLOCK(fs);
610
611 /*
612 * If we would flush below, but dirops are active, sleep.
613 * Note that a dirop cannot ever reach this code!
614 */
615 mutex_enter(&lfs_lock);
616 while (fs->lfs_dirops > 0 &&
617 (locked_queue_count + INOCOUNT(fs) > LFS_MAX_BUFS ||
618 locked_queue_bytes + INOBYTES(fs) > LFS_MAX_BYTES ||
619 lfs_subsys_pages > LFS_MAX_PAGES ||
620 fs->lfs_dirvcount > LFS_MAX_FSDIROP(fs) ||
621 lfs_dirvcount > LFS_MAX_DIROP || fs->lfs_diropwait > 0))
622 {
623 ++fs->lfs_diropwait;
624 mtsleep(&fs->lfs_writer, PRIBIO+1, "bufdirop", 0,
625 &lfs_lock);
626 --fs->lfs_diropwait;
627 }
628
629 #ifdef DEBUG
630 if (locked_queue_count + INOCOUNT(fs) > LFS_MAX_BUFS)
631 DLOG((DLOG_FLUSH, "lfs_check: lqc = %d, max %d\n",
632 locked_queue_count + INOCOUNT(fs), LFS_MAX_BUFS));
633 if (locked_queue_bytes + INOBYTES(fs) > LFS_MAX_BYTES)
634 DLOG((DLOG_FLUSH, "lfs_check: lqb = %ld, max %ld\n",
635 locked_queue_bytes + INOBYTES(fs), LFS_MAX_BYTES));
636 if (lfs_subsys_pages > LFS_MAX_PAGES)
637 DLOG((DLOG_FLUSH, "lfs_check: lssp = %d, max %d\n",
638 lfs_subsys_pages, LFS_MAX_PAGES));
639 if (lfs_fs_pagetrip && fs->lfs_pages > lfs_fs_pagetrip)
640 DLOG((DLOG_FLUSH, "lfs_check: fssp = %d, trip at %d\n",
641 fs->lfs_pages, lfs_fs_pagetrip));
642 if (lfs_dirvcount > LFS_MAX_DIROP)
643 DLOG((DLOG_FLUSH, "lfs_check: ldvc = %d, max %d\n",
644 lfs_dirvcount, LFS_MAX_DIROP));
645 if (fs->lfs_dirvcount > LFS_MAX_FSDIROP(fs))
646 DLOG((DLOG_FLUSH, "lfs_check: lfdvc = %d, max %d\n",
647 fs->lfs_dirvcount, LFS_MAX_FSDIROP(fs)));
648 if (fs->lfs_diropwait > 0)
649 DLOG((DLOG_FLUSH, "lfs_check: ldvw = %d\n",
650 fs->lfs_diropwait));
651 #endif
652
653 /* If there are too many pending dirops, we have to flush them. */
654 if (fs->lfs_dirvcount > LFS_MAX_FSDIROP(fs) ||
655 lfs_dirvcount > LFS_MAX_DIROP || fs->lfs_diropwait > 0) {
656 KASSERT(fs->lfs_dirops == 0);
657 fs->lfs_writer++;
658 mutex_exit(&lfs_lock);
659 lfs_flush_dirops(fs);
660 mutex_enter(&lfs_lock);
661 if (--fs->lfs_writer == 0)
662 cv_broadcast(&fs->lfs_diropscv);
663 KASSERT(fs->lfs_dirops == 0);
664 } else if (locked_queue_count + INOCOUNT(fs) > LFS_MAX_BUFS ||
665 locked_queue_bytes + INOBYTES(fs) > LFS_MAX_BYTES ||
666 lfs_subsys_pages > LFS_MAX_PAGES ||
667 fs->lfs_dirvcount > LFS_MAX_FSDIROP(fs) ||
668 lfs_dirvcount > LFS_MAX_DIROP || fs->lfs_diropwait > 0) {
669 lfs_flush(fs, flags, 0);
670 } else if (lfs_fs_pagetrip && fs->lfs_pages > lfs_fs_pagetrip) {
671 /*
672 * If we didn't flush the whole thing, some filesystems
673 * still might want to be flushed.
674 */
675 ++fs->lfs_pdflush;
676 cv_broadcast(&lfs_writerd_cv);
677 }
678
679 while (locked_queue_count + INOCOUNT(fs) >= LFS_WAIT_BUFS ||
680 locked_queue_bytes + INOBYTES(fs) >= LFS_WAIT_BYTES ||
681 lfs_subsys_pages > LFS_WAIT_PAGES ||
682 fs->lfs_dirvcount > LFS_MAX_FSDIROP(fs) ||
683 lfs_dirvcount > LFS_MAX_DIROP) {
684
685 if (lfs_dostats)
686 ++lfs_stats.wait_exceeded;
687 DLOG((DLOG_AVAIL, "lfs_check: waiting: count=%d, bytes=%ld\n",
688 locked_queue_count, locked_queue_bytes));
689 ++locked_queue_waiters;
690 error = cv_timedwait_sig(&locked_queue_cv, &lfs_lock,
691 hz * LFS_BUFWAIT);
692 --locked_queue_waiters;
693 if (error != EWOULDBLOCK)
694 break;
695
696 /*
697 * lfs_flush might not flush all the buffers, if some of the
698 * inodes were locked or if most of them were Ifile blocks
699 * and we weren't asked to checkpoint. Try flushing again
700 * to keep us from blocking indefinitely.
701 */
702 if (locked_queue_count + INOCOUNT(fs) >= LFS_MAX_BUFS ||
703 locked_queue_bytes + INOBYTES(fs) >= LFS_MAX_BYTES) {
704 lfs_flush(fs, flags | SEGM_CKP, 0);
705 }
706 }
707 mutex_exit(&lfs_lock);
708 return (error);
709 }
710
711 /*
712 * Allocate a new buffer header.
713 */
714 struct buf *
lfs_newbuf(struct lfs * fs,struct vnode * vp,daddr_t daddr,size_t size,int type)715 lfs_newbuf(struct lfs *fs, struct vnode *vp, daddr_t daddr, size_t size, int type)
716 {
717 struct buf *bp;
718 size_t nbytes;
719
720 ASSERT_MAYBE_SEGLOCK(fs);
721 nbytes = roundup(size, lfs_fsbtob(fs, 1));
722
723 bp = getiobuf(NULL, true);
724 if (nbytes) {
725 bp->b_data = lfs_malloc(fs, nbytes, type);
726 /* memset(bp->b_data, 0, nbytes); */
727 }
728 KASSERT(vp != NULL);
729 KASSERT(bp != NULL);
730
731 bp->b_bufsize = size;
732 bp->b_bcount = size;
733 bp->b_lblkno = daddr;
734 bp->b_blkno = daddr;
735 bp->b_error = 0;
736 bp->b_resid = 0;
737 bp->b_iodone = lfs_free_aiodone;
738 bp->b_cflags |= BC_BUSY | BC_NOCACHE;
739 bp->b_private = fs;
740
741 mutex_enter(&bufcache_lock);
742 mutex_enter(vp->v_interlock);
743 bgetvp(vp, bp);
744 mutex_exit(vp->v_interlock);
745 mutex_exit(&bufcache_lock);
746
747 return (bp);
748 }
749
750 void
lfs_freebuf(struct lfs * fs,struct buf * bp)751 lfs_freebuf(struct lfs *fs, struct buf *bp)
752 {
753 struct vnode *vp;
754
755 if ((vp = bp->b_vp) != NULL) {
756 mutex_enter(&bufcache_lock);
757 mutex_enter(vp->v_interlock);
758 brelvp(bp);
759 mutex_exit(vp->v_interlock);
760 mutex_exit(&bufcache_lock);
761 }
762 if (!(bp->b_cflags & BC_INVAL)) { /* BC_INVAL indicates a "fake" buffer */
763 lfs_free(fs, bp->b_data, LFS_NB_UNKNOWN);
764 bp->b_data = NULL;
765 }
766 putiobuf(bp);
767 }
768
769 int
lfs_wait_pages(void)770 lfs_wait_pages(void)
771 {
772 int active, inactive;
773
774 uvm_estimatepageable(&active, &inactive);
775 return LFS_WAIT_RESOURCE(active + inactive + uvm_availmem(false), 1);
776 }
777
778 int
lfs_max_pages(void)779 lfs_max_pages(void)
780 {
781 int active, inactive;
782
783 uvm_estimatepageable(&active, &inactive);
784 return LFS_MAX_RESOURCE(active + inactive + uvm_availmem(false), 1);
785 }
786