xref: /netbsd-src/sys/miscfs/genfs/genfs_vnops.c (revision bcc8ec9959e7b01e313d813067bfb43a3ad70551)
1 /*	$NetBSD: genfs_vnops.c,v 1.24 2000/12/27 04:47:43 chs Exp $	*/
2 
3 /*
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
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  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  */
36 
37 #include "opt_nfsserver.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/proc.h>
42 #include <sys/kernel.h>
43 #include <sys/mount.h>
44 #include <sys/namei.h>
45 #include <sys/vnode.h>
46 #include <sys/fcntl.h>
47 #include <sys/malloc.h>
48 #include <sys/poll.h>
49 
50 #include <miscfs/genfs/genfs.h>
51 #include <miscfs/specfs/specdev.h>
52 
53 #include <uvm/uvm.h>
54 #include <uvm/uvm_pager.h>
55 
56 #ifdef NFSSERVER
57 #include <nfs/rpcv2.h>
58 #include <nfs/nfsproto.h>
59 #include <nfs/nfs.h>
60 #include <nfs/nqnfs.h>
61 #include <nfs/nfs_var.h>
62 #endif
63 
64 int
65 genfs_poll(v)
66 	void *v;
67 {
68 	struct vop_poll_args /* {
69 		struct vnode *a_vp;
70 		int a_events;
71 		struct proc *a_p;
72 	} */ *ap = v;
73 
74 	return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
75 }
76 
77 int
78 genfs_fsync(v)
79 	void *v;
80 {
81 	struct vop_fsync_args /* {
82 		struct vnode *a_vp;
83 		struct ucred *a_cred;
84 		int a_flags;
85 		off_t offlo;
86 		off_t offhi;
87 		struct proc *a_p;
88 	} */ *ap = v;
89 	struct vnode *vp = ap->a_vp;
90 	int wait;
91 
92 	wait = (ap->a_flags & FSYNC_WAIT) != 0;
93 	vflushbuf(vp, wait);
94 	if ((ap->a_flags & FSYNC_DATAONLY) != 0)
95 		return (0);
96 	else
97 		return (VOP_UPDATE(vp, NULL, NULL, wait ? UPDATE_WAIT : 0));
98 }
99 
100 int
101 genfs_seek(v)
102 	void *v;
103 {
104 	struct vop_seek_args /* {
105 		struct vnode *a_vp;
106 		off_t a_oldoff;
107 		off_t a_newoff;
108 		struct ucred *a_ucred;
109 	} */ *ap = v;
110 
111 	if (ap->a_newoff < 0)
112 		return (EINVAL);
113 
114 	return (0);
115 }
116 
117 int
118 genfs_abortop(v)
119 	void *v;
120 {
121 	struct vop_abortop_args /* {
122 		struct vnode *a_dvp;
123 		struct componentname *a_cnp;
124 	} */ *ap = v;
125 
126 	if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
127 		PNBUF_PUT(ap->a_cnp->cn_pnbuf);
128 	return (0);
129 }
130 
131 int
132 genfs_fcntl(v)
133 	void *v;
134 {
135 	struct vop_fcntl_args /* {
136 		struct vnode *a_vp;
137 		u_int a_command;
138 		caddr_t a_data;
139 		int a_fflag;
140 		struct ucred *a_cred;
141 		struct proc *a_p;
142 	} */ *ap = v;
143 
144 	if (ap->a_command == F_SETFL)
145 		return (0);
146 	else
147 		return (EOPNOTSUPP);
148 }
149 
150 /*ARGSUSED*/
151 int
152 genfs_badop(v)
153 	void *v;
154 {
155 
156 	panic("genfs: bad op");
157 }
158 
159 /*ARGSUSED*/
160 int
161 genfs_nullop(v)
162 	void *v;
163 {
164 
165 	return (0);
166 }
167 
168 /*ARGSUSED*/
169 int
170 genfs_einval(v)
171 	void *v;
172 {
173 
174 	return (EINVAL);
175 }
176 
177 /*ARGSUSED*/
178 int
179 genfs_eopnotsupp(v)
180 	void *v;
181 {
182 
183 	return (EOPNOTSUPP);
184 }
185 
186 /*
187  * Called when an fs doesn't support a particular vop but the vop needs to
188  * vrele, vput, or vunlock passed in vnodes.
189  */
190 int
191 genfs_eopnotsupp_rele(v)
192 	void *v;
193 {
194 	struct vop_generic_args /*
195 		struct vnodeop_desc *a_desc;
196 		/ * other random data follows, presumably * /
197 	} */ *ap = v;
198 	struct vnodeop_desc *desc = ap->a_desc;
199 	struct vnode *vp;
200 	int flags, i, j, offset;
201 
202 	flags = desc->vdesc_flags;
203 	for (i = 0; i < VDESC_MAX_VPS; flags >>=1, i++) {
204 		if ((offset = desc->vdesc_vp_offsets[i]) == VDESC_NO_OFFSET)
205 			break;	/* stop at end of list */
206 		if ((j = flags & VDESC_VP0_WILLPUT)) {
207 			vp = *VOPARG_OFFSETTO(struct vnode**,offset,ap);
208 			switch (j) {
209 			case VDESC_VP0_WILLPUT:
210 				vput(vp);
211 				break;
212 			case VDESC_VP0_WILLUNLOCK:
213 				VOP_UNLOCK(vp, 0);
214 				break;
215 			case VDESC_VP0_WILLRELE:
216 				vrele(vp);
217 				break;
218 			}
219 		}
220 	}
221 
222 	return (EOPNOTSUPP);
223 }
224 
225 /*ARGSUSED*/
226 int
227 genfs_ebadf(v)
228 	void *v;
229 {
230 
231 	return (EBADF);
232 }
233 
234 /* ARGSUSED */
235 int
236 genfs_enoioctl(v)
237 	void *v;
238 {
239 
240 	return (ENOTTY);
241 }
242 
243 
244 /*
245  * Eliminate all activity associated with the requested vnode
246  * and with all vnodes aliased to the requested vnode.
247  */
248 int
249 genfs_revoke(v)
250 	void *v;
251 {
252 	struct vop_revoke_args /* {
253 		struct vnode *a_vp;
254 		int a_flags;
255 	} */ *ap = v;
256 	struct vnode *vp, *vq;
257 	struct proc *p = curproc;	/* XXX */
258 
259 #ifdef DIAGNOSTIC
260 	if ((ap->a_flags & REVOKEALL) == 0)
261 		panic("genfs_revoke: not revokeall");
262 #endif
263 
264 	vp = ap->a_vp;
265 	simple_lock(&vp->v_interlock);
266 
267 	if (vp->v_flag & VALIASED) {
268 		/*
269 		 * If a vgone (or vclean) is already in progress,
270 		 * wait until it is done and return.
271 		 */
272 		if (vp->v_flag & VXLOCK) {
273 			vp->v_flag |= VXWANT;
274 			simple_unlock(&vp->v_interlock);
275 			tsleep((caddr_t)vp, PINOD, "vop_revokeall", 0);
276 			return (0);
277 		}
278 		/*
279 		 * Ensure that vp will not be vgone'd while we
280 		 * are eliminating its aliases.
281 		 */
282 		vp->v_flag |= VXLOCK;
283 		simple_unlock(&vp->v_interlock);
284 		while (vp->v_flag & VALIASED) {
285 			simple_lock(&spechash_slock);
286 			for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
287 				if (vq->v_rdev != vp->v_rdev ||
288 				    vq->v_type != vp->v_type || vp == vq)
289 					continue;
290 				simple_unlock(&spechash_slock);
291 				vgone(vq);
292 				break;
293 			}
294 			if (vq == NULLVP)
295 				simple_unlock(&spechash_slock);
296 		}
297 		/*
298 		 * Remove the lock so that vgone below will
299 		 * really eliminate the vnode after which time
300 		 * vgone will awaken any sleepers.
301 		 */
302 		simple_lock(&vp->v_interlock);
303 		vp->v_flag &= ~VXLOCK;
304 	}
305 	vgonel(vp, p);
306 	return (0);
307 }
308 
309 /*
310  * Lock the node.
311  */
312 int
313 genfs_lock(v)
314 	void *v;
315 {
316 	struct vop_lock_args /* {
317 		struct vnode *a_vp;
318 		int a_flags;
319 	} */ *ap = v;
320 	struct vnode *vp = ap->a_vp;
321 
322 	return (lockmgr(&vp->v_lock, ap->a_flags, &vp->v_interlock));
323 }
324 
325 /*
326  * Unlock the node.
327  */
328 int
329 genfs_unlock(v)
330 	void *v;
331 {
332 	struct vop_unlock_args /* {
333 		struct vnode *a_vp;
334 		int a_flags;
335 	} */ *ap = v;
336 	struct vnode *vp = ap->a_vp;
337 
338 	return (lockmgr(&vp->v_lock, ap->a_flags | LK_RELEASE,
339 		&vp->v_interlock));
340 }
341 
342 /*
343  * Return whether or not the node is locked.
344  */
345 int
346 genfs_islocked(v)
347 	void *v;
348 {
349 	struct vop_islocked_args /* {
350 		struct vnode *a_vp;
351 	} */ *ap = v;
352 	struct vnode *vp = ap->a_vp;
353 
354 	return (lockstatus(&vp->v_lock));
355 }
356 
357 /*
358  * Stubs to use when there is no locking to be done on the underlying object.
359  */
360 int
361 genfs_nolock(v)
362 	void *v;
363 {
364 	struct vop_lock_args /* {
365 		struct vnode *a_vp;
366 		int a_flags;
367 		struct proc *a_p;
368 	} */ *ap = v;
369 
370 	/*
371 	 * Since we are not using the lock manager, we must clear
372 	 * the interlock here.
373 	 */
374 	if (ap->a_flags & LK_INTERLOCK)
375 		simple_unlock(&ap->a_vp->v_interlock);
376 	return (0);
377 }
378 
379 int
380 genfs_nounlock(v)
381 	void *v;
382 {
383 	return (0);
384 }
385 
386 int
387 genfs_noislocked(v)
388 	void *v;
389 {
390 	return (0);
391 }
392 
393 /*
394  * Local lease check for NFS servers.  Just set up args and let
395  * nqsrv_getlease() do the rest.  If NFSSERVER is not in the kernel,
396  * this is a null operation.
397  */
398 int
399 genfs_lease_check(v)
400 	void *v;
401 {
402 #ifdef NFSSERVER
403 	struct vop_lease_args /* {
404 		struct vnode *a_vp;
405 		struct proc *a_p;
406 		struct ucred *a_cred;
407 		int a_flag;
408 	} */ *ap = v;
409 	u_int32_t duration = 0;
410 	int cache;
411 	u_quad_t frev;
412 
413 	(void) nqsrv_getlease(ap->a_vp, &duration, ND_CHECK | ap->a_flag,
414 	    NQLOCALSLP, ap->a_p, (struct mbuf *)0, &cache, &frev, ap->a_cred);
415 	return (0);
416 #else
417 	return (0);
418 #endif /* NFSSERVER */
419 }
420 
421 /*
422  * generic VM getpages routine.
423  * Return PG_BUSY pages for the given range,
424  * reading from backing store if necessary.
425  */
426 
427 int
428 genfs_getpages(v)
429 	void *v;
430 {
431 	struct vop_getpages_args /* {
432 		struct vnode *a_vp;
433 		voff_t a_offset;
434 		vm_page_t *a_m;
435 		int *a_count;
436 		int a_centeridx;
437 		vm_prot_t a_access_type;
438 		int a_advice;
439 		int a_flags;
440 	} */ *ap = v;
441 
442 	off_t eof, offset, origoffset, startoffset, endoffset, raoffset;
443 	daddr_t lbn, blkno;
444 	int s, i, error, npages, orignpages, npgs, run, ridx, pidx, pcount;
445 	int fs_bshift, fs_bsize, dev_bshift, dev_bsize;
446 	int flags = ap->a_flags;
447 	size_t bytes, iobytes, tailbytes, totalbytes, skipbytes;
448 	vaddr_t kva;
449 	struct buf *bp, *mbp;
450 	struct vnode *vp = ap->a_vp;
451 	struct uvm_object *uobj = &vp->v_uvm.u_obj;
452 	struct vm_page *pgs[16];			/* XXXUBC 16 */
453 	struct ucred *cred = curproc->p_ucred;		/* XXXUBC curproc */
454 	boolean_t async = (flags & PGO_SYNCIO) == 0;
455 	boolean_t write = (ap->a_access_type & VM_PROT_WRITE) != 0;
456 	boolean_t sawhole = FALSE;
457 	UVMHIST_FUNC("genfs_getpages"); UVMHIST_CALLED(ubchist);
458 
459 	/* XXXUBC temp limit */
460 	if (*ap->a_count > 16) {
461 		return EINVAL;
462 	}
463 
464 	error = VOP_SIZE(vp, vp->v_uvm.u_size, &eof);
465 	if (error) {
466 		return error;
467 	}
468 
469 #ifdef DIAGNOSTIC
470 	if (ap->a_centeridx < 0 || ap->a_centeridx > *ap->a_count) {
471 		panic("genfs_getpages: centeridx %d out of range",
472 		      ap->a_centeridx);
473 	}
474 	if (ap->a_offset & (PAGE_SIZE - 1) || ap->a_offset < 0) {
475 		panic("genfs_getpages: offset 0x%x", (int)ap->a_offset);
476 	}
477 	if (*ap->a_count < 0) {
478 		panic("genfs_getpages: count %d < 0", *ap->a_count);
479 	}
480 #endif
481 
482 	/*
483 	 * Bounds-check the request.
484 	 */
485 
486 	error = 0;
487 	origoffset = ap->a_offset;
488 
489 	if (origoffset + (ap->a_centeridx << PAGE_SHIFT) >= eof &&
490 	    (flags & PGO_PASTEOF) == 0) {
491 		if ((flags & PGO_LOCKED) == 0) {
492 			simple_unlock(&uobj->vmobjlock);
493 		}
494 		UVMHIST_LOG(ubchist, "off 0x%x count %d goes past EOF 0x%x",
495 			    origoffset, *ap->a_count, eof,0);
496 		return EINVAL;
497 	}
498 
499 	/*
500 	 * For PGO_LOCKED requests, just return whatever's in memory.
501 	 */
502 
503 	if (flags & PGO_LOCKED) {
504 		uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m,
505 			      UFP_NOWAIT|UFP_NOALLOC|UFP_NORDONLY);
506 
507 		return ap->a_m[ap->a_centeridx] == NULL ? EBUSY : 0;
508 	}
509 
510 	/* vnode is VOP_LOCKed, uobj is locked */
511 
512 	if (write && (vp->v_flag & VONWORKLST) == 0) {
513 		vn_syncer_add_to_worklist(vp, filedelay);
514 	}
515 
516 	/*
517 	 * find the requested pages and make some simple checks.
518 	 * leave space in the page array for a whole block.
519 	 */
520 
521 	fs_bshift = vp->v_mount->mnt_fs_bshift;
522 	fs_bsize = 1 << fs_bshift;
523 	dev_bshift = vp->v_mount->mnt_dev_bshift;
524 	dev_bsize = 1 << dev_bshift;
525 	KASSERT((eof & (dev_bsize - 1)) == 0);
526 
527 	orignpages = min(*ap->a_count,
528 	    round_page(eof - origoffset) >> PAGE_SHIFT);
529 	if (flags & PGO_PASTEOF) {
530 		orignpages = *ap->a_count;
531 	}
532 	npages = orignpages;
533 	startoffset = origoffset & ~(fs_bsize - 1);
534 	endoffset = round_page((origoffset + (npages << PAGE_SHIFT)
535 				+ fs_bsize - 1) & ~(fs_bsize - 1));
536 	endoffset = min(endoffset, round_page(eof));
537 	ridx = (origoffset - startoffset) >> PAGE_SHIFT;
538 
539 	memset(pgs, 0, sizeof(pgs));
540 	uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], UFP_ALL);
541 
542 	/*
543 	 * if PGO_OVERWRITE is set, don't bother reading the pages.
544 	 * PGO_OVERWRITE also means that the caller guarantees
545 	 * that the pages already have backing store allocated.
546 	 */
547 
548 	if (flags & PGO_OVERWRITE) {
549 		UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0);
550 
551 		for (i = 0; i < npages; i++) {
552 			struct vm_page *pg = pgs[ridx + i];
553 
554 			if (pg->flags & PG_FAKE) {
555 				uvm_pagezero(pg);
556 				pg->flags &= ~(PG_FAKE);
557 			}
558 			pg->flags &= ~(PG_RDONLY);
559 		}
560 		goto out;
561 	}
562 
563 	/*
564 	 * if the pages are already resident, just return them.
565 	 */
566 
567 	for (i = 0; i < npages; i++) {
568 		struct vm_page *pg = pgs[ridx + i];
569 
570 		if ((pg->flags & PG_FAKE) ||
571 		    (write && (pg->flags & PG_RDONLY))) {
572 			break;
573 		}
574 	}
575 	if (i == npages) {
576 		UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0);
577 		raoffset = origoffset + (orignpages << PAGE_SHIFT);
578 		goto raout;
579 	}
580 
581 	/*
582 	 * the page wasn't resident and we're not overwriting,
583 	 * so we're going to have to do some i/o.
584 	 * find any additional pages needed to cover the expanded range.
585 	 */
586 
587 	if (startoffset != origoffset) {
588 
589 		/*
590 		 * XXXUBC we need to avoid deadlocks caused by locking
591 		 * additional pages at lower offsets than pages we
592 		 * already have locked.  for now, unlock them all and
593 		 * start over.
594 		 */
595 
596 		for (i = 0; i < npages; i++) {
597 			struct vm_page *pg = pgs[ridx + i];
598 
599 			if (pg->flags & PG_FAKE) {
600 				pg->flags |= PG_RELEASED;
601 			}
602 		}
603 		uvm_page_unbusy(&pgs[ridx], npages);
604 		memset(pgs, 0, sizeof(pgs));
605 
606 		UVMHIST_LOG(ubchist, "reset npages start 0x%x end 0x%x",
607 			    startoffset, endoffset, 0,0);
608 		npages = (endoffset - startoffset) >> PAGE_SHIFT;
609 		npgs = npages;
610 		uvn_findpages(uobj, startoffset, &npgs, pgs, UFP_ALL);
611 	}
612 	simple_unlock(&uobj->vmobjlock);
613 
614 	/*
615 	 * read the desired page(s).
616 	 */
617 
618 	totalbytes = npages << PAGE_SHIFT;
619 	bytes = min(totalbytes, eof - startoffset);
620 	tailbytes = totalbytes - bytes;
621 	skipbytes = 0;
622 
623 	kva = uvm_pagermapin(pgs, npages, UVMPAGER_MAPIN_WAITOK |
624 			     UVMPAGER_MAPIN_READ);
625 
626 	s = splbio();
627 	mbp = pool_get(&bufpool, PR_WAITOK);
628 	splx(s);
629 	mbp->b_bufsize = totalbytes;
630 	mbp->b_data = (void *)kva;
631 	mbp->b_resid = mbp->b_bcount = bytes;
632 	mbp->b_flags = B_BUSY|B_READ| (async ? B_CALL : 0);
633 	mbp->b_iodone = uvm_aio_biodone;
634 	mbp->b_vp = vp;
635 	LIST_INIT(&mbp->b_dep);
636 
637 	/*
638 	 * if EOF is in the middle of the last page, zero the part past EOF.
639 	 */
640 
641 	if (tailbytes > 0 && (pgs[bytes >> PAGE_SHIFT]->flags & PG_FAKE)) {
642 		memset((void *)(kva + bytes), 0, tailbytes);
643 	}
644 
645 	/*
646 	 * now loop over the pages, reading as needed.
647 	 */
648 
649 	if (write) {
650 		lockmgr(&vp->v_glock, LK_EXCLUSIVE, NULL);
651 	} else {
652 		lockmgr(&vp->v_glock, LK_SHARED, NULL);
653 	}
654 
655 	bp = NULL;
656 	for (offset = startoffset;
657 	     bytes > 0;
658 	     offset += iobytes, bytes -= iobytes) {
659 
660 		/*
661 		 * skip pages which don't need to be read.
662 		 */
663 
664 		pidx = (offset - startoffset) >> PAGE_SHIFT;
665 		while ((pgs[pidx]->flags & PG_FAKE) == 0) {
666 			size_t b;
667 
668 			KASSERT((offset & (PAGE_SIZE - 1)) == 0);
669 			b = min(PAGE_SIZE, bytes);
670 			offset += b;
671 			bytes -= b;
672 			skipbytes += b;
673 			pidx++;
674 			UVMHIST_LOG(ubchist, "skipping, new offset 0x%x",
675 				    offset, 0,0,0);
676 			if (bytes == 0) {
677 				goto loopdone;
678 			}
679 		}
680 
681 		/*
682 		 * bmap the file to find out the blkno to read from and
683 		 * how much we can read in one i/o.  if bmap returns an error,
684 		 * skip the rest of the top-level i/o.
685 		 */
686 
687 		lbn = offset >> fs_bshift;
688 		error = VOP_BMAP(vp, lbn, NULL, &blkno, &run);
689 		if (error) {
690 			UVMHIST_LOG(ubchist, "VOP_BMAP lbn 0x%x -> %d\n",
691 				    lbn, error,0,0);
692 			skipbytes += bytes;
693 			goto loopdone;
694 		}
695 
696 		/*
697 		 * see how many pages can be read with this i/o.
698 		 * reduce the i/o size if necessary to avoid
699 		 * overwriting pages with valid data.
700 		 */
701 
702 		iobytes = min(((lbn + 1 + run) << fs_bshift) - offset, bytes);
703 		if (offset + iobytes > round_page(offset)) {
704 			pcount = 1;
705 			while (pidx + pcount < npages &&
706 			       pgs[pidx + pcount]->flags & PG_FAKE) {
707 				pcount++;
708 			}
709 			iobytes = min(iobytes, (pcount << PAGE_SHIFT) -
710 				      (offset - trunc_page(offset)));
711 		}
712 
713 		/*
714 		 * if this block isn't allocated, zero it instead of reading it.
715 		 * if this is a read access, mark the pages we zeroed PG_RDONLY.
716 		 */
717 
718 		if (blkno < 0) {
719 			UVMHIST_LOG(ubchist, "lbn 0x%x -> HOLE", lbn,0,0,0);
720 
721 			sawhole = TRUE;
722 			memset((char *)kva + (offset - startoffset), 0,
723 			       iobytes);
724 			skipbytes += iobytes;
725 
726 			if (!write) {
727 				int holepages =
728 					(round_page(offset + iobytes) -
729 					 trunc_page(offset)) >> PAGE_SHIFT;
730 				for (i = 0; i < holepages; i++) {
731 					pgs[pidx + i]->flags |= PG_RDONLY;
732 				}
733 			}
734 			continue;
735 		}
736 
737 		/*
738 		 * allocate a sub-buf for this piece of the i/o
739 		 * (or just use mbp if there's only 1 piece),
740 		 * and start it going.
741 		 */
742 
743 		if (offset == startoffset && iobytes == bytes) {
744 			bp = mbp;
745 		} else {
746 			s = splbio();
747 			bp = pool_get(&bufpool, PR_WAITOK);
748 			splx(s);
749 			bp->b_data = (char *)kva + offset - startoffset;
750 			bp->b_resid = bp->b_bcount = iobytes;
751 			bp->b_flags = B_BUSY|B_READ|B_CALL;
752 			bp->b_iodone = uvm_aio_biodone1;
753 			bp->b_vp = vp;
754 			LIST_INIT(&bp->b_dep);
755 		}
756 		bp->b_lblkno = 0;
757 		bp->b_private = mbp;
758 
759 		/* adjust physical blkno for partial blocks */
760 		bp->b_blkno = blkno + ((offset - (lbn << fs_bshift)) >>
761 				       dev_bshift);
762 
763 		UVMHIST_LOG(ubchist, "bp %p offset 0x%x bcount 0x%x blkno 0x%x",
764 			    bp, offset, iobytes, bp->b_blkno);
765 
766 		VOP_STRATEGY(bp);
767 	}
768 
769 loopdone:
770 	if (skipbytes) {
771 		s = splbio();
772 		if (error) {
773 			mbp->b_flags |= B_ERROR;
774 			mbp->b_error = error;
775 		}
776 		mbp->b_resid -= skipbytes;
777 		if (mbp->b_resid == 0) {
778 			biodone(mbp);
779 		}
780 		splx(s);
781 	}
782 
783 	if (async) {
784 		UVMHIST_LOG(ubchist, "returning PEND",0,0,0,0);
785 		lockmgr(&vp->v_glock, LK_RELEASE, NULL);
786 		return EINPROGRESS;
787 	}
788 	if (bp != NULL) {
789 		error = biowait(mbp);
790 	}
791 	s = splbio();
792 	pool_put(&bufpool, mbp);
793 	splx(s);
794 	uvm_pagermapout(kva, npages);
795 	raoffset = startoffset + totalbytes;
796 
797 	/*
798 	 * if this we encountered a hole then we have to do a little more work.
799 	 * for read faults, we marked the page PG_RDONLY so that future
800 	 * write accesses to the page will fault again.
801 	 * for write faults, we must make sure that the backing store for
802 	 * the page is completely allocated while the pages are locked.
803 	 */
804 
805 	if (error == 0 && sawhole && write) {
806 		error = VOP_BALLOCN(vp, startoffset, npages << PAGE_SHIFT,
807 				   cred, 0);
808 		if (error) {
809 			UVMHIST_LOG(ubchist, "balloc lbn 0x%x -> %d",
810 				    lbn, error,0,0);
811 			lockmgr(&vp->v_glock, LK_RELEASE, NULL);
812 			simple_lock(&uobj->vmobjlock);
813 			goto out;
814 		}
815 	}
816 	lockmgr(&vp->v_glock, LK_RELEASE, NULL);
817 	simple_lock(&uobj->vmobjlock);
818 
819 	/*
820 	 * see if we want to start any readahead.
821 	 * XXXUBC for now, just read the next 128k on 64k boundaries.
822 	 * this is pretty nonsensical, but it is 50% faster than reading
823 	 * just the next 64k.
824 	 */
825 
826 raout:
827 	if (!error && !async && !write && ((int)raoffset & 0xffff) == 0 &&
828 	    PAGE_SHIFT <= 16) {
829 		int racount;
830 
831 		racount = 1 << (16 - PAGE_SHIFT);
832 		(void) VOP_GETPAGES(vp, raoffset, NULL, &racount, 0,
833 				    VM_PROT_READ, 0, 0);
834 		simple_lock(&uobj->vmobjlock);
835 
836 		racount = 1 << (16 - PAGE_SHIFT);
837 		(void) VOP_GETPAGES(vp, raoffset + 0x10000, NULL, &racount, 0,
838 				    VM_PROT_READ, 0, 0);
839 		simple_lock(&uobj->vmobjlock);
840 	}
841 
842 	/*
843 	 * we're almost done!  release the pages...
844 	 * for errors, we free the pages.
845 	 * otherwise we activate them and mark them as valid and clean.
846 	 * also, unbusy pages that were not actually requested.
847 	 */
848 
849 out:
850 	if (error) {
851 		uvm_lock_pageq();
852 		for (i = 0; i < npages; i++) {
853 			if (pgs[i] == NULL) {
854 				continue;
855 			}
856 			UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x",
857 				    pgs[i], pgs[i]->flags, 0,0);
858 			if ((pgs[i]->flags & PG_FAKE) == 0) {
859 				continue;
860 			}
861 			if (pgs[i]->flags & PG_WANTED) {
862 				wakeup(pgs[i]);
863 			}
864 			uvm_pagefree(pgs[i]);
865 		}
866 		uvm_unlock_pageq();
867 		simple_unlock(&uobj->vmobjlock);
868 		UVMHIST_LOG(ubchist, "returning error %d", error,0,0,0);
869 		return error;
870 	}
871 
872 	UVMHIST_LOG(ubchist, "succeeding, npages %d", npages,0,0,0);
873 	for (i = 0; i < npages; i++) {
874 		if (pgs[i] == NULL) {
875 			continue;
876 		}
877 		UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x",
878 			    pgs[i], pgs[i]->flags, 0,0);
879 		if (pgs[i]->flags & PG_FAKE) {
880 			UVMHIST_LOG(ubchist, "unfaking pg %p offset 0x%x",
881 				    pgs[i], pgs[i]->offset,0,0);
882 			pgs[i]->flags &= ~(PG_FAKE);
883 			pmap_clear_modify(pgs[i]);
884 			pmap_clear_reference(pgs[i]);
885 		}
886 		if (write) {
887 			pgs[i]->flags &= ~(PG_RDONLY);
888 		}
889 		if (i < ridx || i >= ridx + orignpages || async) {
890 			UVMHIST_LOG(ubchist, "unbusy pg %p offset 0x%x",
891 				    pgs[i], pgs[i]->offset,0,0);
892 			if (pgs[i]->flags & PG_WANTED) {
893 				wakeup(pgs[i]);
894 			}
895 			if (pgs[i]->wire_count == 0) {
896 				uvm_pageactivate(pgs[i]);
897 			}
898 			pgs[i]->flags &= ~(PG_WANTED|PG_BUSY);
899 			UVM_PAGE_OWN(pgs[i], NULL);
900 		}
901 	}
902 	simple_unlock(&uobj->vmobjlock);
903 	if (ap->a_m != NULL) {
904 		memcpy(ap->a_m, &pgs[ridx],
905 		       orignpages * sizeof(struct vm_page *));
906 	}
907 	return 0;
908 }
909 
910 /*
911  * generic VM putpages routine.
912  * Write the given range of pages to backing store.
913  */
914 
915 int
916 genfs_putpages(v)
917 	void *v;
918 {
919 	struct vop_putpages_args /* {
920 		struct vnode *a_vp;
921 		struct vm_page **a_m;
922 		int a_count;
923 		int a_flags;
924 		int *a_rtvals;
925 	} */ *ap = v;
926 
927 	int s, error, error2, npages, run;
928 	int fs_bshift, dev_bshift, dev_bsize;
929 	vaddr_t kva;
930 	off_t eof, offset, startoffset;
931 	size_t bytes, iobytes, skipbytes;
932 	daddr_t lbn, blkno;
933 	struct vm_page *pg;
934 	struct buf *mbp, *bp;
935 	struct vnode *vp = ap->a_vp;
936 	boolean_t async = (ap->a_flags & PGO_SYNCIO) == 0;
937 	UVMHIST_FUNC("genfs_putpages"); UVMHIST_CALLED(ubchist);
938 
939 	simple_unlock(&vp->v_uvm.u_obj.vmobjlock);
940 
941 	error = VOP_SIZE(vp, vp->v_uvm.u_size, &eof);
942 	if (error) {
943 		return error;
944 	}
945 
946 	error = error2 = 0;
947 	npages = ap->a_count;
948 	fs_bshift = vp->v_mount->mnt_fs_bshift;
949 	dev_bshift = vp->v_mount->mnt_dev_bshift;
950 	dev_bsize = 1 << dev_bshift;
951 	KASSERT((eof & (dev_bsize - 1)) == 0);
952 
953 	pg = ap->a_m[0];
954 	startoffset = pg->offset;
955 	bytes = min(npages << PAGE_SHIFT, eof - startoffset);
956 	skipbytes = 0;
957 	KASSERT(bytes != 0);
958 
959 	kva = uvm_pagermapin(ap->a_m, npages, UVMPAGER_MAPIN_WAITOK);
960 
961 	s = splbio();
962 	vp->v_numoutput += 2;
963 	mbp = pool_get(&bufpool, PR_WAITOK);
964 	UVMHIST_LOG(ubchist, "vp %p mbp %p num now %d bytes 0x%x",
965 		    vp, mbp, vp->v_numoutput, bytes);
966 	splx(s);
967 	mbp->b_bufsize = npages << PAGE_SHIFT;
968 	mbp->b_data = (void *)kva;
969 	mbp->b_resid = mbp->b_bcount = bytes;
970 	mbp->b_flags = B_BUSY|B_WRITE|B_AGE |
971 		(async ? B_CALL : 0) |
972 		(curproc == uvm.pagedaemon_proc ? B_PDAEMON : 0);
973 	mbp->b_iodone = uvm_aio_biodone;
974 	mbp->b_vp = vp;
975 	LIST_INIT(&mbp->b_dep);
976 
977 	bp = NULL;
978 	for (offset = startoffset;
979 	     bytes > 0;
980 	     offset += iobytes, bytes -= iobytes) {
981 		lbn = offset >> fs_bshift;
982 		error = VOP_BMAP(vp, lbn, NULL, &blkno, &run);
983 		if (error) {
984 			UVMHIST_LOG(ubchist, "VOP_BMAP() -> %d", error,0,0,0);
985 			skipbytes += bytes;
986 			bytes = 0;
987 			break;
988 		}
989 
990 		iobytes = min(((lbn + 1 + run) << fs_bshift) - offset, bytes);
991 		if (blkno == (daddr_t)-1) {
992 			skipbytes += iobytes;
993 			continue;
994 		}
995 
996 		/* if it's really one i/o, don't make a second buf */
997 		if (offset == startoffset && iobytes == bytes) {
998 			bp = mbp;
999 		} else {
1000 			s = splbio();
1001 			vp->v_numoutput++;
1002 			bp = pool_get(&bufpool, PR_WAITOK);
1003 			UVMHIST_LOG(ubchist, "vp %p bp %p num now %d",
1004 				    vp, bp, vp->v_numoutput, 0);
1005 			splx(s);
1006 			bp->b_data = (char *)kva +
1007 				(vaddr_t)(offset - pg->offset);
1008 			bp->b_resid = bp->b_bcount = iobytes;
1009 			bp->b_flags = B_BUSY|B_WRITE|B_CALL|B_ASYNC;
1010 			bp->b_iodone = uvm_aio_biodone1;
1011 			bp->b_vp = vp;
1012 			LIST_INIT(&bp->b_dep);
1013 		}
1014 		bp->b_lblkno = 0;
1015 		bp->b_private = mbp;
1016 
1017 		/* adjust physical blkno for partial blocks */
1018 		bp->b_blkno = blkno + ((offset - (lbn << fs_bshift)) >>
1019 				       dev_bshift);
1020 		UVMHIST_LOG(ubchist, "vp %p offset 0x%x bcount 0x%x blkno 0x%x",
1021 			    vp, offset, bp->b_bcount, bp->b_blkno);
1022 		VOP_STRATEGY(bp);
1023 	}
1024 	if (skipbytes) {
1025 		UVMHIST_LOG(ubchist, "skipbytes %d", bytes, 0,0,0);
1026 		s = splbio();
1027 		mbp->b_resid -= skipbytes;
1028 		if (mbp->b_resid == 0) {
1029 			biodone(mbp);
1030 		}
1031 		splx(s);
1032 	}
1033 	if (async) {
1034 		UVMHIST_LOG(ubchist, "returning PEND", 0,0,0,0);
1035 		return EINPROGRESS;
1036 	}
1037 	if (bp != NULL) {
1038 		UVMHIST_LOG(ubchist, "waiting for mbp %p", mbp,0,0,0);
1039 		error2 = biowait(mbp);
1040 	}
1041 	if (bioops.io_pageiodone) {
1042 		(*bioops.io_pageiodone)(mbp);
1043 	}
1044 	s = splbio();
1045 	vwakeup(mbp);
1046 	pool_put(&bufpool, mbp);
1047 	splx(s);
1048 	uvm_pagermapout(kva, npages);
1049 	UVMHIST_LOG(ubchist, "returning, error %d", error,0,0,0);
1050 	return error ? error : error2;
1051 }
1052 
1053 int
1054 genfs_size(v)
1055 	void *v;
1056 {
1057 	struct vop_size_args /* {
1058 		struct vnode *a_vp;
1059 		off_t a_size;
1060 		off_t *a_eobp;
1061 	} */ *ap = v;
1062 	int bsize;
1063 
1064 	bsize = 1 << ap->a_vp->v_mount->mnt_fs_bshift;
1065 	*ap->a_eobp = (ap->a_size + bsize - 1) & ~(bsize - 1);
1066 	return 0;
1067 }
1068