1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 1990 University of Utah.
5 * Copyright (c) 1991 The Regents of the University of California.
6 * All rights reserved.
7 * Copyright (c) 1993, 1994 John S. Dyson
8 * Copyright (c) 1995, David Greenman
9 *
10 * This code is derived from software contributed to Berkeley by
11 * the Systems Programming Group of the University of Utah Computer
12 * Science Department.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * 3. All advertising materials mentioning features or use of this software
23 * must display the following acknowledgement:
24 * This product includes software developed by the University of
25 * California, Berkeley and its contributors.
26 * 4. Neither the name of the University nor the names of its contributors
27 * may be used to endorse or promote products derived from this software
28 * without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * SUCH DAMAGE.
41 */
42
43 /*
44 * Page to/from files (vnodes).
45 */
46
47 /*
48 * TODO:
49 * Implement VOP_GETPAGES/PUTPAGES interface for filesystems. Will
50 * greatly re-simplify the vnode_pager.
51 */
52
53 #include <sys/cdefs.h>
54 #include "opt_vm.h"
55
56 #include <sys/param.h>
57 #include <sys/kernel.h>
58 #include <sys/systm.h>
59 #include <sys/sysctl.h>
60 #include <sys/proc.h>
61 #include <sys/vnode.h>
62 #include <sys/mount.h>
63 #include <sys/bio.h>
64 #include <sys/buf.h>
65 #include <sys/vmmeter.h>
66 #include <sys/ktr.h>
67 #include <sys/limits.h>
68 #include <sys/conf.h>
69 #include <sys/refcount.h>
70 #include <sys/rwlock.h>
71 #include <sys/sf_buf.h>
72 #include <sys/domainset.h>
73 #include <sys/user.h>
74
75 #include <machine/atomic.h>
76
77 #include <vm/vm.h>
78 #include <vm/vm_param.h>
79 #include <vm/vm_object.h>
80 #include <vm/vm_page.h>
81 #include <vm/vm_pager.h>
82 #include <vm/vm_map.h>
83 #include <vm/vnode_pager.h>
84 #include <vm/vm_extern.h>
85 #include <vm/uma.h>
86
87 static int vnode_pager_addr(struct vnode *vp, vm_ooffset_t address,
88 daddr_t *rtaddress, int *run);
89 static int vnode_pager_input_smlfs(vm_object_t object, vm_page_t m);
90 static int vnode_pager_input_old(vm_object_t object, vm_page_t m);
91 static void vnode_pager_dealloc(vm_object_t);
92 static int vnode_pager_getpages(vm_object_t, vm_page_t *, int, int *, int *);
93 static int vnode_pager_getpages_async(vm_object_t, vm_page_t *, int, int *,
94 int *, vop_getpages_iodone_t, void *);
95 static void vnode_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
96 static boolean_t vnode_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
97 static vm_object_t vnode_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
98 vm_ooffset_t, struct ucred *cred);
99 static int vnode_pager_generic_getpages_done(struct buf *);
100 static void vnode_pager_generic_getpages_done_async(struct buf *);
101 static void vnode_pager_update_writecount(vm_object_t, vm_offset_t,
102 vm_offset_t);
103 static void vnode_pager_release_writecount(vm_object_t, vm_offset_t,
104 vm_offset_t);
105 static void vnode_pager_getvp(vm_object_t, struct vnode **, bool *);
106
107 const struct pagerops vnodepagerops = {
108 .pgo_kvme_type = KVME_TYPE_VNODE,
109 .pgo_alloc = vnode_pager_alloc,
110 .pgo_dealloc = vnode_pager_dealloc,
111 .pgo_getpages = vnode_pager_getpages,
112 .pgo_getpages_async = vnode_pager_getpages_async,
113 .pgo_putpages = vnode_pager_putpages,
114 .pgo_haspage = vnode_pager_haspage,
115 .pgo_update_writecount = vnode_pager_update_writecount,
116 .pgo_release_writecount = vnode_pager_release_writecount,
117 .pgo_set_writeable_dirty = vm_object_set_writeable_dirty_,
118 .pgo_mightbedirty = vm_object_mightbedirty_,
119 .pgo_getvp = vnode_pager_getvp,
120 };
121
122 static struct domainset *vnode_domainset = NULL;
123
124 SYSCTL_PROC(_debug, OID_AUTO, vnode_domainset,
125 CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_RW, &vnode_domainset, 0,
126 sysctl_handle_domainset, "A", "Default vnode NUMA policy");
127
128 static int nvnpbufs;
129 SYSCTL_INT(_vm, OID_AUTO, vnode_pbufs, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
130 &nvnpbufs, 0, "number of physical buffers allocated for vnode pager");
131
132 static uma_zone_t vnode_pbuf_zone;
133
134 static void
vnode_pager_init(void * dummy)135 vnode_pager_init(void *dummy)
136 {
137
138 #ifdef __LP64__
139 nvnpbufs = nswbuf * 2;
140 #else
141 nvnpbufs = nswbuf / 2;
142 #endif
143 TUNABLE_INT_FETCH("vm.vnode_pbufs", &nvnpbufs);
144 vnode_pbuf_zone = pbuf_zsecond_create("vnpbuf", nvnpbufs);
145 }
146 SYSINIT(vnode_pager, SI_SUB_CPU, SI_ORDER_ANY, vnode_pager_init, NULL);
147
148 /* Create the VM system backing object for this vnode */
149 int
vnode_create_vobject(struct vnode * vp,off_t isize,struct thread * td)150 vnode_create_vobject(struct vnode *vp, off_t isize, struct thread *td)
151 {
152 vm_object_t object;
153 vm_ooffset_t size = isize;
154 bool last;
155
156 if (!vn_isdisk(vp) && vn_canvmio(vp) == FALSE)
157 return (0);
158
159 object = vp->v_object;
160 if (object != NULL)
161 return (0);
162
163 if (size == 0) {
164 if (vn_isdisk(vp)) {
165 size = IDX_TO_OFF(INT_MAX);
166 } else {
167 if (vn_getsize_locked(vp, &size, td->td_ucred) != 0)
168 return (0);
169 }
170 }
171
172 object = vnode_pager_alloc(vp, size, 0, 0, td->td_ucred);
173 /*
174 * Dereference the reference we just created. This assumes
175 * that the object is associated with the vp. We still have
176 * to serialize with vnode_pager_dealloc() for the last
177 * potential reference.
178 */
179 VM_OBJECT_RLOCK(object);
180 last = refcount_release(&object->ref_count);
181 VM_OBJECT_RUNLOCK(object);
182 if (last)
183 vrele(vp);
184
185 KASSERT(vp->v_object != NULL, ("vnode_create_vobject: NULL object"));
186
187 return (0);
188 }
189
190 void
vnode_destroy_vobject(struct vnode * vp)191 vnode_destroy_vobject(struct vnode *vp)
192 {
193 struct vm_object *obj;
194
195 obj = vp->v_object;
196 if (obj == NULL || obj->handle != vp)
197 return;
198 ASSERT_VOP_ELOCKED(vp, "vnode_destroy_vobject");
199 VM_OBJECT_WLOCK(obj);
200 MPASS(obj->type == OBJT_VNODE);
201 umtx_shm_object_terminated(obj);
202 if (obj->ref_count == 0) {
203 KASSERT((obj->flags & OBJ_DEAD) == 0,
204 ("vnode_destroy_vobject: Terminating dead object"));
205 vm_object_set_flag(obj, OBJ_DEAD);
206
207 /*
208 * Clean pages and flush buffers.
209 */
210 vm_object_page_clean(obj, 0, 0, OBJPC_SYNC);
211 VM_OBJECT_WUNLOCK(obj);
212
213 vinvalbuf(vp, V_SAVE, 0, 0);
214
215 BO_LOCK(&vp->v_bufobj);
216 vp->v_bufobj.bo_flag |= BO_DEAD;
217 BO_UNLOCK(&vp->v_bufobj);
218
219 VM_OBJECT_WLOCK(obj);
220 vm_object_terminate(obj);
221 } else {
222 /*
223 * Woe to the process that tries to page now :-).
224 */
225 vm_pager_deallocate(obj);
226 VM_OBJECT_WUNLOCK(obj);
227 }
228 KASSERT(vp->v_object == NULL, ("vp %p obj %p", vp, vp->v_object));
229 }
230
231 /*
232 * Allocate (or lookup) pager for a vnode.
233 * Handle is a vnode pointer.
234 */
235 vm_object_t
vnode_pager_alloc(void * handle,vm_ooffset_t size,vm_prot_t prot,vm_ooffset_t offset,struct ucred * cred)236 vnode_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
237 vm_ooffset_t offset, struct ucred *cred)
238 {
239 vm_object_t object;
240 struct vnode *vp;
241
242 /*
243 * Pageout to vnode, no can do yet.
244 */
245 if (handle == NULL)
246 return (NULL);
247
248 vp = (struct vnode *)handle;
249 ASSERT_VOP_LOCKED(vp, "vnode_pager_alloc");
250 VNPASS(vp->v_usecount > 0, vp);
251 retry:
252 object = vp->v_object;
253
254 if (object == NULL) {
255 /*
256 * Add an object of the appropriate size
257 */
258 object = vm_object_allocate(OBJT_VNODE,
259 OFF_TO_IDX(round_page(size)));
260
261 object->un_pager.vnp.vnp_size = size;
262 object->un_pager.vnp.writemappings = 0;
263 object->domain.dr_policy = vnode_domainset;
264 object->handle = handle;
265 if ((vp->v_vflag & VV_VMSIZEVNLOCK) != 0) {
266 VM_OBJECT_WLOCK(object);
267 vm_object_set_flag(object, OBJ_SIZEVNLOCK);
268 VM_OBJECT_WUNLOCK(object);
269 }
270 VI_LOCK(vp);
271 if (vp->v_object != NULL) {
272 /*
273 * Object has been created while we were allocating.
274 */
275 VI_UNLOCK(vp);
276 VM_OBJECT_WLOCK(object);
277 KASSERT(object->ref_count == 1,
278 ("leaked ref %p %d", object, object->ref_count));
279 object->type = OBJT_DEAD;
280 refcount_init(&object->ref_count, 0);
281 VM_OBJECT_WUNLOCK(object);
282 vm_object_destroy(object);
283 goto retry;
284 }
285 vp->v_object = object;
286 VI_UNLOCK(vp);
287 vrefact(vp);
288 } else {
289 vm_object_reference(object);
290 #if VM_NRESERVLEVEL > 0
291 if ((object->flags & OBJ_COLORED) == 0) {
292 VM_OBJECT_WLOCK(object);
293 vm_object_color(object, 0);
294 VM_OBJECT_WUNLOCK(object);
295 }
296 #endif
297 }
298 return (object);
299 }
300
301 /*
302 * The object must be locked.
303 */
304 static void
vnode_pager_dealloc(vm_object_t object)305 vnode_pager_dealloc(vm_object_t object)
306 {
307 struct vnode *vp;
308 int refs;
309
310 vp = object->handle;
311 if (vp == NULL)
312 panic("vnode_pager_dealloc: pager already dealloced");
313
314 VM_OBJECT_ASSERT_WLOCKED(object);
315 vm_object_pip_wait(object, "vnpdea");
316 refs = object->ref_count;
317
318 object->handle = NULL;
319 object->type = OBJT_DEAD;
320 ASSERT_VOP_ELOCKED(vp, "vnode_pager_dealloc");
321 if (object->un_pager.vnp.writemappings > 0) {
322 object->un_pager.vnp.writemappings = 0;
323 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
324 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
325 __func__, vp, vp->v_writecount);
326 }
327 vp->v_object = NULL;
328 VI_LOCK(vp);
329
330 /*
331 * vm_map_entry_set_vnode_text() cannot reach this vnode by
332 * following object->handle. Clear all text references now.
333 * This also clears the transient references from
334 * kern_execve(), which is fine because dead_vnodeops uses nop
335 * for VOP_UNSET_TEXT().
336 */
337 if (vp->v_writecount < 0)
338 vp->v_writecount = 0;
339 VI_UNLOCK(vp);
340 VM_OBJECT_WUNLOCK(object);
341 if (refs > 0)
342 vunref(vp);
343 VM_OBJECT_WLOCK(object);
344 }
345
346 static boolean_t
vnode_pager_haspage(vm_object_t object,vm_pindex_t pindex,int * before,int * after)347 vnode_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
348 int *after)
349 {
350 struct vnode *vp = object->handle;
351 daddr_t bn;
352 uintptr_t lockstate;
353 int err;
354 daddr_t reqblock;
355 int poff;
356 int bsize;
357 int pagesperblock, blocksperpage;
358
359 VM_OBJECT_ASSERT_LOCKED(object);
360 /*
361 * If no vp or vp is doomed or marked transparent to VM, we do not
362 * have the page.
363 */
364 if (vp == NULL || VN_IS_DOOMED(vp))
365 return FALSE;
366 /*
367 * If the offset is beyond end of file we do
368 * not have the page.
369 */
370 if (IDX_TO_OFF(pindex) >= object->un_pager.vnp.vnp_size)
371 return FALSE;
372
373 bsize = vp->v_mount->mnt_stat.f_iosize;
374 pagesperblock = bsize / PAGE_SIZE;
375 blocksperpage = 0;
376 if (pagesperblock > 0) {
377 reqblock = pindex / pagesperblock;
378 } else {
379 blocksperpage = (PAGE_SIZE / bsize);
380 reqblock = pindex * blocksperpage;
381 }
382 lockstate = VM_OBJECT_DROP(object);
383 err = VOP_BMAP(vp, reqblock, NULL, &bn, after, before);
384 VM_OBJECT_PICKUP(object, lockstate);
385 if (err)
386 return TRUE;
387 if (bn == -1)
388 return FALSE;
389 if (pagesperblock > 0) {
390 poff = pindex - (reqblock * pagesperblock);
391 if (before) {
392 *before *= pagesperblock;
393 *before += poff;
394 }
395 if (after) {
396 /*
397 * The BMAP vop can report a partial block in the
398 * 'after', but must not report blocks after EOF.
399 * Assert the latter, and truncate 'after' in case
400 * of the former.
401 */
402 KASSERT((reqblock + *after) * pagesperblock <
403 roundup2(object->size, pagesperblock),
404 ("%s: reqblock %jd after %d size %ju", __func__,
405 (intmax_t )reqblock, *after,
406 (uintmax_t )object->size));
407 *after *= pagesperblock;
408 *after += pagesperblock - (poff + 1);
409 if (pindex + *after >= object->size)
410 *after = object->size - 1 - pindex;
411 }
412 } else {
413 if (before) {
414 *before /= blocksperpage;
415 }
416
417 if (after) {
418 *after /= blocksperpage;
419 }
420 }
421 return TRUE;
422 }
423
424 /*
425 * Internal routine clearing partial-page content
426 */
427 static void
vnode_pager_subpage_purge(struct vm_page * m,int base,int end)428 vnode_pager_subpage_purge(struct vm_page *m, int base, int end)
429 {
430 int size;
431
432 KASSERT(end > base && end <= PAGE_SIZE,
433 ("%s: start %d end %d", __func__, base, end));
434 size = end - base;
435
436 /*
437 * Clear out partial-page garbage in case
438 * the page has been mapped.
439 */
440 pmap_zero_page_area(m, base, size);
441
442 /*
443 * Update the valid bits to reflect the blocks
444 * that have been zeroed. Some of these valid
445 * bits may have already been set.
446 */
447 vm_page_set_valid_range(m, base, size);
448
449 /*
450 * Round up "base" to the next block boundary so
451 * that the dirty bit for a partially zeroed
452 * block is not cleared.
453 */
454 base = roundup2(base, DEV_BSIZE);
455 end = rounddown2(end, DEV_BSIZE);
456
457 if (end > base) {
458 /*
459 * Clear out partial-page dirty bits.
460 *
461 * note that we do not clear out the
462 * valid bits. This would prevent
463 * bogus_page replacement from working
464 * properly.
465 */
466 vm_page_clear_dirty(m, base, end - base);
467 }
468
469 }
470
471 /*
472 * Lets the VM system know about a change in size for a file.
473 * We adjust our own internal size and flush any cached pages in
474 * the associated object that are affected by the size change.
475 *
476 * Note: this routine may be invoked as a result of a pager put
477 * operation (possibly at object termination time), so we must be careful.
478 */
479 void
vnode_pager_setsize(struct vnode * vp,vm_ooffset_t nsize)480 vnode_pager_setsize(struct vnode *vp, vm_ooffset_t nsize)
481 {
482 vm_object_t object;
483 vm_page_t m;
484 vm_pindex_t nobjsize;
485
486 if ((object = vp->v_object) == NULL)
487 return;
488 #ifdef DEBUG_VFS_LOCKS
489 {
490 struct mount *mp;
491
492 mp = vp->v_mount;
493 if (mp != NULL && (mp->mnt_kern_flag & MNTK_VMSETSIZE_BUG) == 0)
494 assert_vop_elocked(vp,
495 "vnode_pager_setsize and not locked vnode");
496 }
497 #endif
498 VM_OBJECT_WLOCK(object);
499 if (object->type == OBJT_DEAD) {
500 VM_OBJECT_WUNLOCK(object);
501 return;
502 }
503 KASSERT(object->type == OBJT_VNODE,
504 ("not vnode-backed object %p", object));
505 if (nsize == object->un_pager.vnp.vnp_size) {
506 /*
507 * Hasn't changed size
508 */
509 VM_OBJECT_WUNLOCK(object);
510 return;
511 }
512 nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
513 if (nsize < object->un_pager.vnp.vnp_size) {
514 /*
515 * File has shrunk. Toss any cached pages beyond the new EOF.
516 */
517 if (nobjsize < object->size)
518 vm_object_page_remove(object, nobjsize, object->size,
519 0);
520 /*
521 * this gets rid of garbage at the end of a page that is now
522 * only partially backed by the vnode.
523 *
524 * XXX for some reason (I don't know yet), if we take a
525 * completely invalid page and mark it partially valid
526 * it can screw up NFS reads, so we don't allow the case.
527 */
528 if (!(nsize & PAGE_MASK))
529 goto out;
530 m = vm_page_grab(object, OFF_TO_IDX(nsize), VM_ALLOC_NOCREAT);
531 if (m == NULL)
532 goto out;
533 if (!vm_page_none_valid(m))
534 vnode_pager_subpage_purge(m, (int)nsize & PAGE_MASK,
535 PAGE_SIZE);
536 vm_page_xunbusy(m);
537 }
538 out:
539 #if defined(__powerpc__) && !defined(__powerpc64__)
540 object->un_pager.vnp.vnp_size = nsize;
541 #else
542 atomic_store_64(&object->un_pager.vnp.vnp_size, nsize);
543 #endif
544 object->size = nobjsize;
545 VM_OBJECT_WUNLOCK(object);
546 }
547
548 /*
549 * Lets the VM system know about the purged range for a file. We toss away any
550 * cached pages in the associated object that are affected by the purge
551 * operation. Partial-page area not aligned to page boundaries will be zeroed
552 * and the dirty blocks in DEV_BSIZE unit within a page will not be flushed.
553 */
554 void
vnode_pager_purge_range(struct vnode * vp,vm_ooffset_t start,vm_ooffset_t end)555 vnode_pager_purge_range(struct vnode *vp, vm_ooffset_t start, vm_ooffset_t end)
556 {
557 struct vm_page *m;
558 struct vm_object *object;
559 vm_pindex_t pi, pistart, piend;
560 bool same_page;
561 int base, pend;
562
563 ASSERT_VOP_LOCKED(vp, "vnode_pager_purge_range");
564
565 object = vp->v_object;
566 pi = start + PAGE_MASK < start ? OBJ_MAX_SIZE :
567 OFF_TO_IDX(start + PAGE_MASK);
568 pistart = OFF_TO_IDX(start);
569 piend = end == 0 ? OBJ_MAX_SIZE : OFF_TO_IDX(end);
570 same_page = pistart == piend;
571 if ((end != 0 && end <= start) || object == NULL)
572 return;
573
574 VM_OBJECT_WLOCK(object);
575
576 if (pi < piend)
577 vm_object_page_remove(object, pi, piend, 0);
578
579 if ((start & PAGE_MASK) != 0) {
580 base = (int)start & PAGE_MASK;
581 pend = same_page ? (int)end & PAGE_MASK : PAGE_SIZE;
582 m = vm_page_grab(object, pistart, VM_ALLOC_NOCREAT);
583 if (m != NULL) {
584 if (!vm_page_none_valid(m))
585 vnode_pager_subpage_purge(m, base, pend);
586 vm_page_xunbusy(m);
587 }
588 if (same_page)
589 goto out;
590 }
591 if ((end & PAGE_MASK) != 0) {
592 base = same_page ? (int)start & PAGE_MASK : 0 ;
593 pend = (int)end & PAGE_MASK;
594 m = vm_page_grab(object, piend, VM_ALLOC_NOCREAT);
595 if (m != NULL) {
596 if (!vm_page_none_valid(m))
597 vnode_pager_subpage_purge(m, base, pend);
598 vm_page_xunbusy(m);
599 }
600 }
601 out:
602 VM_OBJECT_WUNLOCK(object);
603 }
604
605 /*
606 * calculate the linear (byte) disk address of specified virtual
607 * file address
608 */
609 static int
vnode_pager_addr(struct vnode * vp,vm_ooffset_t address,daddr_t * rtaddress,int * run)610 vnode_pager_addr(struct vnode *vp, vm_ooffset_t address, daddr_t *rtaddress,
611 int *run)
612 {
613 int bsize;
614 int err;
615 daddr_t vblock;
616 daddr_t voffset;
617
618 if (VN_IS_DOOMED(vp))
619 return -1;
620
621 bsize = vp->v_mount->mnt_stat.f_iosize;
622 vblock = address / bsize;
623 voffset = address % bsize;
624
625 err = VOP_BMAP(vp, vblock, NULL, rtaddress, run, NULL);
626 if (err == 0) {
627 if (*rtaddress != -1)
628 *rtaddress += voffset / DEV_BSIZE;
629 if (run) {
630 *run += 1;
631 *run *= bsize / PAGE_SIZE;
632 *run -= voffset / PAGE_SIZE;
633 }
634 }
635
636 return (err);
637 }
638
639 static void
vnode_pager_input_bdone(struct buf * bp)640 vnode_pager_input_bdone(struct buf *bp)
641 {
642 runningbufwakeup(bp);
643 bdone(bp);
644 }
645
646 /*
647 * small block filesystem vnode pager input
648 */
649 static int
vnode_pager_input_smlfs(vm_object_t object,vm_page_t m)650 vnode_pager_input_smlfs(vm_object_t object, vm_page_t m)
651 {
652 struct vnode *vp;
653 struct bufobj *bo;
654 struct buf *bp;
655 struct sf_buf *sf;
656 daddr_t fileaddr;
657 vm_offset_t bsize;
658 vm_page_bits_t bits;
659 int error, i;
660
661 error = 0;
662 vp = object->handle;
663 if (VN_IS_DOOMED(vp))
664 return VM_PAGER_BAD;
665
666 bsize = vp->v_mount->mnt_stat.f_iosize;
667
668 VOP_BMAP(vp, 0, &bo, 0, NULL, NULL);
669
670 sf = sf_buf_alloc(m, 0);
671
672 for (i = 0; i < PAGE_SIZE / bsize; i++) {
673 vm_ooffset_t address;
674
675 bits = vm_page_bits(i * bsize, bsize);
676 if (m->valid & bits)
677 continue;
678
679 address = IDX_TO_OFF(m->pindex) + i * bsize;
680 if (address >= object->un_pager.vnp.vnp_size) {
681 fileaddr = -1;
682 } else {
683 error = vnode_pager_addr(vp, address, &fileaddr, NULL);
684 if (error)
685 break;
686 }
687 if (fileaddr != -1) {
688 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK);
689
690 /* build a minimal buffer header */
691 bp->b_iocmd = BIO_READ;
692 bp->b_iodone = vnode_pager_input_bdone;
693 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
694 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
695 bp->b_rcred = crhold(curthread->td_ucred);
696 bp->b_wcred = crhold(curthread->td_ucred);
697 bp->b_data = (caddr_t)sf_buf_kva(sf) + i * bsize;
698 bp->b_blkno = fileaddr;
699 pbgetbo(bo, bp);
700 bp->b_vp = vp;
701 bp->b_bcount = bsize;
702 bp->b_bufsize = bsize;
703 bp->b_runningbufspace = bp->b_bufsize;
704 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
705
706 /* do the input */
707 bp->b_iooffset = dbtob(bp->b_blkno);
708 bstrategy(bp);
709
710 bwait(bp, PVM, "vnsrd");
711
712 if ((bp->b_ioflags & BIO_ERROR) != 0) {
713 KASSERT(bp->b_error != 0,
714 ("%s: buf error but b_error == 0\n", __func__));
715 error = bp->b_error;
716 }
717
718 /*
719 * free the buffer header back to the swap buffer pool
720 */
721 bp->b_vp = NULL;
722 pbrelbo(bp);
723 uma_zfree(vnode_pbuf_zone, bp);
724 if (error)
725 break;
726 } else
727 bzero((caddr_t)sf_buf_kva(sf) + i * bsize, bsize);
728 KASSERT((m->dirty & bits) == 0,
729 ("vnode_pager_input_smlfs: page %p is dirty", m));
730 vm_page_bits_set(m, &m->valid, bits);
731 }
732 sf_buf_free(sf);
733 if (error) {
734 return VM_PAGER_ERROR;
735 }
736 return VM_PAGER_OK;
737 }
738
739 /*
740 * old style vnode pager input routine
741 */
742 static int
vnode_pager_input_old(vm_object_t object,vm_page_t m)743 vnode_pager_input_old(vm_object_t object, vm_page_t m)
744 {
745 struct uio auio;
746 struct iovec aiov;
747 int error;
748 int size;
749 struct sf_buf *sf;
750 struct vnode *vp;
751
752 VM_OBJECT_ASSERT_WLOCKED(object);
753 error = 0;
754
755 /*
756 * Return failure if beyond current EOF
757 */
758 if (IDX_TO_OFF(m->pindex) >= object->un_pager.vnp.vnp_size) {
759 return VM_PAGER_BAD;
760 } else {
761 size = PAGE_SIZE;
762 if (IDX_TO_OFF(m->pindex) + size > object->un_pager.vnp.vnp_size)
763 size = object->un_pager.vnp.vnp_size - IDX_TO_OFF(m->pindex);
764 vp = object->handle;
765 VM_OBJECT_WUNLOCK(object);
766
767 /*
768 * Allocate a kernel virtual address and initialize so that
769 * we can use VOP_READ/WRITE routines.
770 */
771 sf = sf_buf_alloc(m, 0);
772
773 aiov.iov_base = (caddr_t)sf_buf_kva(sf);
774 aiov.iov_len = size;
775 auio.uio_iov = &aiov;
776 auio.uio_iovcnt = 1;
777 auio.uio_offset = IDX_TO_OFF(m->pindex);
778 auio.uio_segflg = UIO_SYSSPACE;
779 auio.uio_rw = UIO_READ;
780 auio.uio_resid = size;
781 auio.uio_td = curthread;
782
783 error = VOP_READ(vp, &auio, 0, curthread->td_ucred);
784 if (!error) {
785 int count = size - auio.uio_resid;
786
787 if (count == 0)
788 error = EINVAL;
789 else if (count != PAGE_SIZE)
790 bzero((caddr_t)sf_buf_kva(sf) + count,
791 PAGE_SIZE - count);
792 }
793 sf_buf_free(sf);
794
795 VM_OBJECT_WLOCK(object);
796 }
797 KASSERT(m->dirty == 0, ("vnode_pager_input_old: page %p is dirty", m));
798 if (!error)
799 vm_page_valid(m);
800 return error ? VM_PAGER_ERROR : VM_PAGER_OK;
801 }
802
803 /*
804 * generic vnode pager input routine
805 */
806
807 /*
808 * Local media VFS's that do not implement their own VOP_GETPAGES
809 * should have their VOP_GETPAGES call to vnode_pager_generic_getpages()
810 * to implement the previous behaviour.
811 *
812 * All other FS's should use the bypass to get to the local media
813 * backing vp's VOP_GETPAGES.
814 */
815 static int
vnode_pager_getpages(vm_object_t object,vm_page_t * m,int count,int * rbehind,int * rahead)816 vnode_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
817 int *rahead)
818 {
819 struct vnode *vp;
820 int rtval;
821
822 /* Handle is stable with paging in progress. */
823 vp = object->handle;
824 rtval = VOP_GETPAGES(vp, m, count, rbehind, rahead);
825 KASSERT(rtval != EOPNOTSUPP,
826 ("vnode_pager: FS getpages not implemented\n"));
827 return rtval;
828 }
829
830 static int
vnode_pager_getpages_async(vm_object_t object,vm_page_t * m,int count,int * rbehind,int * rahead,vop_getpages_iodone_t iodone,void * arg)831 vnode_pager_getpages_async(vm_object_t object, vm_page_t *m, int count,
832 int *rbehind, int *rahead, vop_getpages_iodone_t iodone, void *arg)
833 {
834 struct vnode *vp;
835 int rtval;
836
837 vp = object->handle;
838 rtval = VOP_GETPAGES_ASYNC(vp, m, count, rbehind, rahead, iodone, arg);
839 KASSERT(rtval != EOPNOTSUPP,
840 ("vnode_pager: FS getpages_async not implemented\n"));
841 return (rtval);
842 }
843
844 /*
845 * The implementation of VOP_GETPAGES() and VOP_GETPAGES_ASYNC() for
846 * local filesystems, where partially valid pages can only occur at
847 * the end of file.
848 */
849 int
vnode_pager_local_getpages(struct vop_getpages_args * ap)850 vnode_pager_local_getpages(struct vop_getpages_args *ap)
851 {
852
853 return (vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
854 ap->a_rbehind, ap->a_rahead, NULL, NULL));
855 }
856
857 int
vnode_pager_local_getpages_async(struct vop_getpages_async_args * ap)858 vnode_pager_local_getpages_async(struct vop_getpages_async_args *ap)
859 {
860 int error;
861
862 error = vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
863 ap->a_rbehind, ap->a_rahead, ap->a_iodone, ap->a_arg);
864 if (error != 0 && ap->a_iodone != NULL)
865 ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error);
866 return (error);
867 }
868
869 /*
870 * This is now called from local media FS's to operate against their
871 * own vnodes if they fail to implement VOP_GETPAGES.
872 */
873 int
vnode_pager_generic_getpages(struct vnode * vp,vm_page_t * m,int count,int * a_rbehind,int * a_rahead,vop_getpages_iodone_t iodone,void * arg)874 vnode_pager_generic_getpages(struct vnode *vp, vm_page_t *m, int count,
875 int *a_rbehind, int *a_rahead, vop_getpages_iodone_t iodone, void *arg)
876 {
877 vm_object_t object;
878 struct bufobj *bo;
879 struct buf *bp;
880 off_t foff;
881 #ifdef INVARIANTS
882 off_t blkno0;
883 #endif
884 int bsize, pagesperblock;
885 int error, before, after, rbehind, rahead, poff, i;
886 int bytecount, secmask;
887
888 KASSERT(vp->v_type != VCHR && vp->v_type != VBLK,
889 ("%s does not support devices", __func__));
890
891 if (VN_IS_DOOMED(vp))
892 return (VM_PAGER_BAD);
893
894 object = vp->v_object;
895 foff = IDX_TO_OFF(m[0]->pindex);
896 bsize = vp->v_mount->mnt_stat.f_iosize;
897 pagesperblock = bsize / PAGE_SIZE;
898
899 KASSERT(foff < object->un_pager.vnp.vnp_size,
900 ("%s: page %p offset beyond vp %p size", __func__, m[0], vp));
901 KASSERT(count <= atop(maxphys),
902 ("%s: requested %d pages", __func__, count));
903
904 /*
905 * The last page has valid blocks. Invalid part can only
906 * exist at the end of file, and the page is made fully valid
907 * by zeroing in vm_pager_get_pages().
908 */
909 if (!vm_page_none_valid(m[count - 1]) && --count == 0) {
910 if (iodone != NULL)
911 iodone(arg, m, 1, 0);
912 return (VM_PAGER_OK);
913 }
914
915 bp = uma_zalloc(vnode_pbuf_zone, M_WAITOK);
916 MPASS((bp->b_flags & B_MAXPHYS) != 0);
917
918 /*
919 * Get the underlying device blocks for the file with VOP_BMAP().
920 * If the file system doesn't support VOP_BMAP, use old way of
921 * getting pages via VOP_READ.
922 */
923 error = VOP_BMAP(vp, foff / bsize, &bo, &bp->b_blkno, &after, &before);
924 if (error == EOPNOTSUPP) {
925 uma_zfree(vnode_pbuf_zone, bp);
926 VM_OBJECT_WLOCK(object);
927 for (i = 0; i < count; i++) {
928 VM_CNT_INC(v_vnodein);
929 VM_CNT_INC(v_vnodepgsin);
930 error = vnode_pager_input_old(object, m[i]);
931 if (error)
932 break;
933 }
934 VM_OBJECT_WUNLOCK(object);
935 return (error);
936 } else if (error != 0) {
937 uma_zfree(vnode_pbuf_zone, bp);
938 return (VM_PAGER_ERROR);
939 }
940
941 /*
942 * If the file system supports BMAP, but blocksize is smaller
943 * than a page size, then use special small filesystem code.
944 */
945 if (pagesperblock == 0) {
946 uma_zfree(vnode_pbuf_zone, bp);
947 for (i = 0; i < count; i++) {
948 VM_CNT_INC(v_vnodein);
949 VM_CNT_INC(v_vnodepgsin);
950 error = vnode_pager_input_smlfs(object, m[i]);
951 if (error)
952 break;
953 }
954 return (error);
955 }
956
957 /*
958 * A sparse file can be encountered only for a single page request,
959 * which may not be preceded by call to vm_pager_haspage().
960 */
961 if (bp->b_blkno == -1) {
962 KASSERT(count == 1,
963 ("%s: array[%d] request to a sparse file %p", __func__,
964 count, vp));
965 uma_zfree(vnode_pbuf_zone, bp);
966 pmap_zero_page(m[0]);
967 KASSERT(m[0]->dirty == 0, ("%s: page %p is dirty",
968 __func__, m[0]));
969 vm_page_valid(m[0]);
970 return (VM_PAGER_OK);
971 }
972
973 #ifdef INVARIANTS
974 blkno0 = bp->b_blkno;
975 #endif
976 bp->b_blkno += (foff % bsize) / DEV_BSIZE;
977
978 /* Recalculate blocks available after/before to pages. */
979 poff = (foff % bsize) / PAGE_SIZE;
980 before *= pagesperblock;
981 before += poff;
982 after *= pagesperblock;
983 after += pagesperblock - (poff + 1);
984 if (m[0]->pindex + after >= object->size)
985 after = object->size - 1 - m[0]->pindex;
986 KASSERT(count <= after + 1, ("%s: %d pages asked, can do only %d",
987 __func__, count, after + 1));
988 after -= count - 1;
989
990 /* Trim requested rbehind/rahead to possible values. */
991 rbehind = a_rbehind ? *a_rbehind : 0;
992 rahead = a_rahead ? *a_rahead : 0;
993 rbehind = min(rbehind, before);
994 rbehind = min(rbehind, m[0]->pindex);
995 rahead = min(rahead, after);
996 rahead = min(rahead, object->size - m[count - 1]->pindex);
997 /*
998 * Check that total amount of pages fit into buf. Trim rbehind and
999 * rahead evenly if not.
1000 */
1001 if (rbehind + rahead + count > atop(maxphys)) {
1002 int trim, sum;
1003
1004 trim = rbehind + rahead + count - atop(maxphys) + 1;
1005 sum = rbehind + rahead;
1006 if (rbehind == before) {
1007 /* Roundup rbehind trim to block size. */
1008 rbehind -= roundup(trim * rbehind / sum, pagesperblock);
1009 if (rbehind < 0)
1010 rbehind = 0;
1011 } else
1012 rbehind -= trim * rbehind / sum;
1013 rahead -= trim * rahead / sum;
1014 }
1015 KASSERT(rbehind + rahead + count <= atop(maxphys),
1016 ("%s: behind %d ahead %d count %d maxphys %lu", __func__,
1017 rbehind, rahead, count, maxphys));
1018
1019 /*
1020 * Fill in the bp->b_pages[] array with requested and optional
1021 * read behind or read ahead pages. Read behind pages are looked
1022 * up in a backward direction, down to a first cached page. Same
1023 * for read ahead pages, but there is no need to shift the array
1024 * in case of encountering a cached page.
1025 */
1026 i = bp->b_npages = 0;
1027 if (rbehind) {
1028 vm_pindex_t startpindex, tpindex;
1029 vm_page_t p;
1030
1031 VM_OBJECT_WLOCK(object);
1032 startpindex = m[0]->pindex - rbehind;
1033 if ((p = TAILQ_PREV(m[0], pglist, listq)) != NULL &&
1034 p->pindex >= startpindex)
1035 startpindex = p->pindex + 1;
1036
1037 /* tpindex is unsigned; beware of numeric underflow. */
1038 for (tpindex = m[0]->pindex - 1;
1039 tpindex >= startpindex && tpindex < m[0]->pindex;
1040 tpindex--, i++) {
1041 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL);
1042 if (p == NULL) {
1043 /* Shift the array. */
1044 for (int j = 0; j < i; j++)
1045 bp->b_pages[j] = bp->b_pages[j +
1046 tpindex + 1 - startpindex];
1047 break;
1048 }
1049 bp->b_pages[tpindex - startpindex] = p;
1050 }
1051
1052 bp->b_pgbefore = i;
1053 bp->b_npages += i;
1054 bp->b_blkno -= IDX_TO_OFF(i) / DEV_BSIZE;
1055 } else
1056 bp->b_pgbefore = 0;
1057
1058 /* Requested pages. */
1059 for (int j = 0; j < count; j++, i++)
1060 bp->b_pages[i] = m[j];
1061 bp->b_npages += count;
1062
1063 if (rahead) {
1064 vm_pindex_t endpindex, tpindex;
1065 vm_page_t p;
1066
1067 if (!VM_OBJECT_WOWNED(object))
1068 VM_OBJECT_WLOCK(object);
1069 endpindex = m[count - 1]->pindex + rahead + 1;
1070 if ((p = TAILQ_NEXT(m[count - 1], listq)) != NULL &&
1071 p->pindex < endpindex)
1072 endpindex = p->pindex;
1073 if (endpindex > object->size)
1074 endpindex = object->size;
1075
1076 for (tpindex = m[count - 1]->pindex + 1;
1077 tpindex < endpindex; i++, tpindex++) {
1078 p = vm_page_alloc(object, tpindex, VM_ALLOC_NORMAL);
1079 if (p == NULL)
1080 break;
1081 bp->b_pages[i] = p;
1082 }
1083
1084 bp->b_pgafter = i - bp->b_npages;
1085 bp->b_npages = i;
1086 } else
1087 bp->b_pgafter = 0;
1088
1089 if (VM_OBJECT_WOWNED(object))
1090 VM_OBJECT_WUNLOCK(object);
1091
1092 /* Report back actual behind/ahead read. */
1093 if (a_rbehind)
1094 *a_rbehind = bp->b_pgbefore;
1095 if (a_rahead)
1096 *a_rahead = bp->b_pgafter;
1097
1098 #ifdef INVARIANTS
1099 KASSERT(bp->b_npages <= atop(maxphys),
1100 ("%s: buf %p overflowed", __func__, bp));
1101 for (int j = 1, prev = 0; j < bp->b_npages; j++) {
1102 if (bp->b_pages[j] == bogus_page)
1103 continue;
1104 KASSERT(bp->b_pages[j]->pindex - bp->b_pages[prev]->pindex ==
1105 j - prev, ("%s: pages array not consecutive, bp %p",
1106 __func__, bp));
1107 prev = j;
1108 }
1109 #endif
1110
1111 /*
1112 * Recalculate first offset and bytecount with regards to read behind.
1113 * Truncate bytecount to vnode real size and round up physical size
1114 * for real devices.
1115 */
1116 foff = IDX_TO_OFF(bp->b_pages[0]->pindex);
1117 bytecount = bp->b_npages << PAGE_SHIFT;
1118 if ((foff + bytecount) > object->un_pager.vnp.vnp_size)
1119 bytecount = object->un_pager.vnp.vnp_size - foff;
1120 secmask = bo->bo_bsize - 1;
1121 KASSERT(secmask < PAGE_SIZE && secmask > 0,
1122 ("%s: sector size %d too large", __func__, secmask + 1));
1123 bytecount = (bytecount + secmask) & ~secmask;
1124
1125 /*
1126 * And map the pages to be read into the kva, if the filesystem
1127 * requires mapped buffers.
1128 */
1129 if ((vp->v_mount->mnt_kern_flag & MNTK_UNMAPPED_BUFS) != 0 &&
1130 unmapped_buf_allowed) {
1131 bp->b_data = unmapped_buf;
1132 bp->b_offset = 0;
1133 } else {
1134 bp->b_data = bp->b_kvabase;
1135 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages, bp->b_npages);
1136 }
1137
1138 /* Build a minimal buffer header. */
1139 bp->b_iocmd = BIO_READ;
1140 KASSERT(bp->b_rcred == NOCRED, ("leaking read ucred"));
1141 KASSERT(bp->b_wcred == NOCRED, ("leaking write ucred"));
1142 bp->b_rcred = crhold(curthread->td_ucred);
1143 bp->b_wcred = crhold(curthread->td_ucred);
1144 pbgetbo(bo, bp);
1145 bp->b_vp = vp;
1146 bp->b_bcount = bp->b_bufsize = bp->b_runningbufspace = bytecount;
1147 bp->b_iooffset = dbtob(bp->b_blkno);
1148 KASSERT(IDX_TO_OFF(m[0]->pindex - bp->b_pages[0]->pindex) ==
1149 (blkno0 - bp->b_blkno) * DEV_BSIZE +
1150 IDX_TO_OFF(m[0]->pindex) % bsize,
1151 ("wrong offsets bsize %d m[0] %ju b_pages[0] %ju "
1152 "blkno0 %ju b_blkno %ju", bsize,
1153 (uintmax_t)m[0]->pindex, (uintmax_t)bp->b_pages[0]->pindex,
1154 (uintmax_t)blkno0, (uintmax_t)bp->b_blkno));
1155
1156 atomic_add_long(&runningbufspace, bp->b_runningbufspace);
1157 VM_CNT_INC(v_vnodein);
1158 VM_CNT_ADD(v_vnodepgsin, bp->b_npages);
1159
1160 if (iodone != NULL) { /* async */
1161 bp->b_pgiodone = iodone;
1162 bp->b_caller1 = arg;
1163 bp->b_iodone = vnode_pager_generic_getpages_done_async;
1164 bp->b_flags |= B_ASYNC;
1165 BUF_KERNPROC(bp);
1166 bstrategy(bp);
1167 return (VM_PAGER_OK);
1168 } else {
1169 bp->b_iodone = bdone;
1170 bstrategy(bp);
1171 bwait(bp, PVM, "vnread");
1172 error = vnode_pager_generic_getpages_done(bp);
1173 for (i = 0; i < bp->b_npages; i++)
1174 bp->b_pages[i] = NULL;
1175 bp->b_vp = NULL;
1176 pbrelbo(bp);
1177 uma_zfree(vnode_pbuf_zone, bp);
1178 return (error != 0 ? VM_PAGER_ERROR : VM_PAGER_OK);
1179 }
1180 }
1181
1182 static void
vnode_pager_generic_getpages_done_async(struct buf * bp)1183 vnode_pager_generic_getpages_done_async(struct buf *bp)
1184 {
1185 int error;
1186
1187 error = vnode_pager_generic_getpages_done(bp);
1188 /* Run the iodone upon the requested range. */
1189 bp->b_pgiodone(bp->b_caller1, bp->b_pages + bp->b_pgbefore,
1190 bp->b_npages - bp->b_pgbefore - bp->b_pgafter, error);
1191 for (int i = 0; i < bp->b_npages; i++)
1192 bp->b_pages[i] = NULL;
1193 bp->b_vp = NULL;
1194 pbrelbo(bp);
1195 uma_zfree(vnode_pbuf_zone, bp);
1196 }
1197
1198 static int
vnode_pager_generic_getpages_done(struct buf * bp)1199 vnode_pager_generic_getpages_done(struct buf *bp)
1200 {
1201 vm_object_t object;
1202 off_t tfoff, nextoff;
1203 int i, error;
1204
1205 KASSERT((bp->b_ioflags & BIO_ERROR) == 0 || bp->b_error != 0,
1206 ("%s: buf error but b_error == 0\n", __func__));
1207 error = (bp->b_ioflags & BIO_ERROR) != 0 ? bp->b_error : 0;
1208 object = bp->b_vp->v_object;
1209
1210 runningbufwakeup(bp);
1211
1212 if (error == 0 && bp->b_bcount != bp->b_npages * PAGE_SIZE) {
1213 if (!buf_mapped(bp)) {
1214 bp->b_data = bp->b_kvabase;
1215 pmap_qenter((vm_offset_t)bp->b_data, bp->b_pages,
1216 bp->b_npages);
1217 }
1218 bzero(bp->b_data + bp->b_bcount,
1219 PAGE_SIZE * bp->b_npages - bp->b_bcount);
1220 }
1221 if (buf_mapped(bp)) {
1222 pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages);
1223 bp->b_data = unmapped_buf;
1224 }
1225
1226 /*
1227 * If the read failed, we must free any read ahead/behind pages here.
1228 * The requested pages are freed by the caller (for sync requests)
1229 * or by the bp->b_pgiodone callback (for async requests).
1230 */
1231 if (error != 0) {
1232 VM_OBJECT_WLOCK(object);
1233 for (i = 0; i < bp->b_pgbefore; i++)
1234 vm_page_free_invalid(bp->b_pages[i]);
1235 for (i = bp->b_npages - bp->b_pgafter; i < bp->b_npages; i++)
1236 vm_page_free_invalid(bp->b_pages[i]);
1237 VM_OBJECT_WUNLOCK(object);
1238 return (error);
1239 }
1240
1241 /* Read lock to protect size. */
1242 VM_OBJECT_RLOCK(object);
1243 for (i = 0, tfoff = IDX_TO_OFF(bp->b_pages[0]->pindex);
1244 i < bp->b_npages; i++, tfoff = nextoff) {
1245 vm_page_t mt;
1246
1247 nextoff = tfoff + PAGE_SIZE;
1248 mt = bp->b_pages[i];
1249 if (mt == bogus_page)
1250 continue;
1251
1252 if (nextoff <= object->un_pager.vnp.vnp_size) {
1253 /*
1254 * Read filled up entire page.
1255 */
1256 vm_page_valid(mt);
1257 KASSERT(mt->dirty == 0,
1258 ("%s: page %p is dirty", __func__, mt));
1259 KASSERT(!pmap_page_is_mapped(mt),
1260 ("%s: page %p is mapped", __func__, mt));
1261 } else {
1262 /*
1263 * Read did not fill up entire page.
1264 *
1265 * Currently we do not set the entire page valid,
1266 * we just try to clear the piece that we couldn't
1267 * read.
1268 */
1269 vm_page_set_valid_range(mt, 0,
1270 object->un_pager.vnp.vnp_size - tfoff);
1271 KASSERT((mt->dirty & vm_page_bits(0,
1272 object->un_pager.vnp.vnp_size - tfoff)) == 0,
1273 ("%s: page %p is dirty", __func__, mt));
1274 }
1275
1276 if (i < bp->b_pgbefore || i >= bp->b_npages - bp->b_pgafter)
1277 vm_page_readahead_finish(mt);
1278 }
1279 VM_OBJECT_RUNLOCK(object);
1280
1281 return (error);
1282 }
1283
1284 /*
1285 * EOPNOTSUPP is no longer legal. For local media VFS's that do not
1286 * implement their own VOP_PUTPAGES, their VOP_PUTPAGES should call to
1287 * vnode_pager_generic_putpages() to implement the previous behaviour.
1288 *
1289 * All other FS's should use the bypass to get to the local media
1290 * backing vp's VOP_PUTPAGES.
1291 */
1292 static void
vnode_pager_putpages(vm_object_t object,vm_page_t * m,int count,int flags,int * rtvals)1293 vnode_pager_putpages(vm_object_t object, vm_page_t *m, int count,
1294 int flags, int *rtvals)
1295 {
1296 int rtval __diagused;
1297 struct vnode *vp;
1298 int bytes = count * PAGE_SIZE;
1299
1300 /*
1301 * Force synchronous operation if we are extremely low on memory
1302 * to prevent a low-memory deadlock. VOP operations often need to
1303 * allocate more memory to initiate the I/O ( i.e. do a BMAP
1304 * operation ). The swapper handles the case by limiting the amount
1305 * of asynchronous I/O, but that sort of solution doesn't scale well
1306 * for the vnode pager without a lot of work.
1307 *
1308 * Also, the backing vnode's iodone routine may not wake the pageout
1309 * daemon up. This should be probably be addressed XXX.
1310 */
1311
1312 if (vm_page_count_min())
1313 flags |= VM_PAGER_PUT_SYNC;
1314
1315 /*
1316 * Call device-specific putpages function
1317 */
1318 vp = object->handle;
1319 VM_OBJECT_WUNLOCK(object);
1320 rtval = VOP_PUTPAGES(vp, m, bytes, flags, rtvals);
1321 KASSERT(rtval != EOPNOTSUPP,
1322 ("vnode_pager: stale FS putpages\n"));
1323 VM_OBJECT_WLOCK(object);
1324 }
1325
1326 static int
vn_off2bidx(vm_ooffset_t offset)1327 vn_off2bidx(vm_ooffset_t offset)
1328 {
1329
1330 return ((offset & PAGE_MASK) / DEV_BSIZE);
1331 }
1332
1333 static bool
vn_dirty_blk(vm_page_t m,vm_ooffset_t offset)1334 vn_dirty_blk(vm_page_t m, vm_ooffset_t offset)
1335 {
1336
1337 KASSERT(IDX_TO_OFF(m->pindex) <= offset &&
1338 offset < IDX_TO_OFF(m->pindex + 1),
1339 ("page %p pidx %ju offset %ju", m, (uintmax_t)m->pindex,
1340 (uintmax_t)offset));
1341 return ((m->dirty & ((vm_page_bits_t)1 << vn_off2bidx(offset))) != 0);
1342 }
1343
1344 /*
1345 * This is now called from local media FS's to operate against their
1346 * own vnodes if they fail to implement VOP_PUTPAGES.
1347 *
1348 * This is typically called indirectly via the pageout daemon and
1349 * clustering has already typically occurred, so in general we ask the
1350 * underlying filesystem to write the data out asynchronously rather
1351 * then delayed.
1352 */
1353 int
vnode_pager_generic_putpages(struct vnode * vp,vm_page_t * ma,int bytecount,int flags,int * rtvals)1354 vnode_pager_generic_putpages(struct vnode *vp, vm_page_t *ma, int bytecount,
1355 int flags, int *rtvals)
1356 {
1357 vm_object_t object;
1358 vm_page_t m;
1359 vm_ooffset_t max_offset, next_offset, poffset, prev_offset;
1360 struct uio auio;
1361 struct iovec aiov;
1362 off_t prev_resid, wrsz;
1363 int count, error, i, maxsize, ncount, pgoff, ppscheck;
1364 bool in_hole;
1365 static struct timeval lastfail;
1366 static int curfail;
1367
1368 object = vp->v_object;
1369 count = bytecount / PAGE_SIZE;
1370
1371 for (i = 0; i < count; i++)
1372 rtvals[i] = VM_PAGER_ERROR;
1373
1374 if ((int64_t)ma[0]->pindex < 0) {
1375 printf("vnode_pager_generic_putpages: "
1376 "attempt to write meta-data 0x%jx(%lx)\n",
1377 (uintmax_t)ma[0]->pindex, (u_long)ma[0]->dirty);
1378 rtvals[0] = VM_PAGER_BAD;
1379 return (VM_PAGER_BAD);
1380 }
1381
1382 maxsize = count * PAGE_SIZE;
1383 ncount = count;
1384
1385 poffset = IDX_TO_OFF(ma[0]->pindex);
1386
1387 /*
1388 * If the page-aligned write is larger then the actual file we
1389 * have to invalidate pages occurring beyond the file EOF. However,
1390 * there is an edge case where a file may not be page-aligned where
1391 * the last page is partially invalid. In this case the filesystem
1392 * may not properly clear the dirty bits for the entire page (which
1393 * could be VM_PAGE_BITS_ALL due to the page having been mmap()d).
1394 * With the page busied we are free to fix up the dirty bits here.
1395 *
1396 * We do not under any circumstances truncate the valid bits, as
1397 * this will screw up bogus page replacement.
1398 */
1399 VM_OBJECT_RLOCK(object);
1400 if (maxsize + poffset > object->un_pager.vnp.vnp_size) {
1401 if (object->un_pager.vnp.vnp_size > poffset) {
1402 maxsize = object->un_pager.vnp.vnp_size - poffset;
1403 ncount = btoc(maxsize);
1404 if ((pgoff = (int)maxsize & PAGE_MASK) != 0) {
1405 pgoff = roundup2(pgoff, DEV_BSIZE);
1406
1407 /*
1408 * If the page is busy and the following
1409 * conditions hold, then the page's dirty
1410 * field cannot be concurrently changed by a
1411 * pmap operation.
1412 */
1413 m = ma[ncount - 1];
1414 vm_page_assert_sbusied(m);
1415 KASSERT(!pmap_page_is_write_mapped(m),
1416 ("vnode_pager_generic_putpages: page %p is not read-only", m));
1417 MPASS(m->dirty != 0);
1418 vm_page_clear_dirty(m, pgoff, PAGE_SIZE -
1419 pgoff);
1420 }
1421 } else {
1422 maxsize = 0;
1423 ncount = 0;
1424 }
1425 for (i = ncount; i < count; i++)
1426 rtvals[i] = VM_PAGER_BAD;
1427 }
1428 VM_OBJECT_RUNLOCK(object);
1429
1430 auio.uio_iov = &aiov;
1431 auio.uio_segflg = UIO_NOCOPY;
1432 auio.uio_rw = UIO_WRITE;
1433 auio.uio_td = NULL;
1434 max_offset = roundup2(poffset + maxsize, DEV_BSIZE);
1435
1436 for (prev_offset = poffset; prev_offset < max_offset;) {
1437 /* Skip clean blocks. */
1438 for (in_hole = true; in_hole && prev_offset < max_offset;) {
1439 m = ma[OFF_TO_IDX(prev_offset - poffset)];
1440 for (i = vn_off2bidx(prev_offset);
1441 i < sizeof(vm_page_bits_t) * NBBY &&
1442 prev_offset < max_offset; i++) {
1443 if (vn_dirty_blk(m, prev_offset)) {
1444 in_hole = false;
1445 break;
1446 }
1447 prev_offset += DEV_BSIZE;
1448 }
1449 }
1450 if (in_hole)
1451 goto write_done;
1452
1453 /* Find longest run of dirty blocks. */
1454 for (next_offset = prev_offset; next_offset < max_offset;) {
1455 m = ma[OFF_TO_IDX(next_offset - poffset)];
1456 for (i = vn_off2bidx(next_offset);
1457 i < sizeof(vm_page_bits_t) * NBBY &&
1458 next_offset < max_offset; i++) {
1459 if (!vn_dirty_blk(m, next_offset))
1460 goto start_write;
1461 next_offset += DEV_BSIZE;
1462 }
1463 }
1464 start_write:
1465 if (next_offset > poffset + maxsize)
1466 next_offset = poffset + maxsize;
1467 if (prev_offset == next_offset)
1468 goto write_done;
1469
1470 /*
1471 * Getting here requires finding a dirty block in the
1472 * 'skip clean blocks' loop.
1473 */
1474
1475 aiov.iov_base = NULL;
1476 auio.uio_iovcnt = 1;
1477 auio.uio_offset = prev_offset;
1478 prev_resid = auio.uio_resid = aiov.iov_len = next_offset -
1479 prev_offset;
1480 error = VOP_WRITE(vp, &auio,
1481 vnode_pager_putpages_ioflags(flags), curthread->td_ucred);
1482
1483 wrsz = prev_resid - auio.uio_resid;
1484 if (wrsz == 0) {
1485 if (ppsratecheck(&lastfail, &curfail, 1) != 0) {
1486 vn_printf(vp, "vnode_pager_putpages: "
1487 "zero-length write at %ju resid %zd\n",
1488 auio.uio_offset, auio.uio_resid);
1489 }
1490 break;
1491 }
1492
1493 /* Adjust the starting offset for next iteration. */
1494 prev_offset += wrsz;
1495 MPASS(auio.uio_offset == prev_offset);
1496
1497 ppscheck = 0;
1498 if (error != 0 && (ppscheck = ppsratecheck(&lastfail,
1499 &curfail, 1)) != 0)
1500 vn_printf(vp, "vnode_pager_putpages: I/O error %d\n",
1501 error);
1502 if (auio.uio_resid != 0 && (ppscheck != 0 ||
1503 ppsratecheck(&lastfail, &curfail, 1) != 0))
1504 vn_printf(vp, "vnode_pager_putpages: residual I/O %zd "
1505 "at %ju\n", auio.uio_resid,
1506 (uintmax_t)ma[0]->pindex);
1507 if (error != 0 || auio.uio_resid != 0)
1508 break;
1509 }
1510 write_done:
1511 /* Mark completely processed pages. */
1512 for (i = 0; i < OFF_TO_IDX(prev_offset - poffset); i++)
1513 rtvals[i] = VM_PAGER_OK;
1514 /* Mark partial EOF page. */
1515 if (prev_offset == poffset + maxsize && (prev_offset & PAGE_MASK) != 0)
1516 rtvals[i++] = VM_PAGER_OK;
1517 /* Unwritten pages in range, free bonus if the page is clean. */
1518 for (; i < ncount; i++)
1519 rtvals[i] = ma[i]->dirty == 0 ? VM_PAGER_OK : VM_PAGER_ERROR;
1520 VM_CNT_ADD(v_vnodepgsout, i);
1521 VM_CNT_INC(v_vnodeout);
1522 return (rtvals[0]);
1523 }
1524
1525 int
vnode_pager_putpages_ioflags(int pager_flags)1526 vnode_pager_putpages_ioflags(int pager_flags)
1527 {
1528 int ioflags;
1529
1530 /*
1531 * Pageouts are already clustered, use IO_ASYNC to force a
1532 * bawrite() rather then a bdwrite() to prevent paging I/O
1533 * from saturating the buffer cache. Dummy-up the sequential
1534 * heuristic to cause large ranges to cluster. If neither
1535 * IO_SYNC or IO_ASYNC is set, the system decides how to
1536 * cluster.
1537 */
1538 ioflags = IO_VMIO;
1539 if ((pager_flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) != 0)
1540 ioflags |= IO_SYNC;
1541 else if ((pager_flags & VM_PAGER_CLUSTER_OK) == 0)
1542 ioflags |= IO_ASYNC;
1543 ioflags |= (pager_flags & VM_PAGER_PUT_INVAL) != 0 ? IO_INVAL: 0;
1544 ioflags |= (pager_flags & VM_PAGER_PUT_NOREUSE) != 0 ? IO_NOREUSE : 0;
1545 ioflags |= IO_SEQMAX << IO_SEQSHIFT;
1546 return (ioflags);
1547 }
1548
1549 /*
1550 * vnode_pager_undirty_pages().
1551 *
1552 * A helper to mark pages as clean after pageout that was possibly
1553 * done with a short write. The lpos argument specifies the page run
1554 * length in bytes, and the written argument specifies how many bytes
1555 * were actually written. eof is the offset past the last valid byte
1556 * in the vnode using the absolute file position of the first byte in
1557 * the run as the base from which it is computed.
1558 */
1559 void
vnode_pager_undirty_pages(vm_page_t * ma,int * rtvals,int written,off_t eof,int lpos)1560 vnode_pager_undirty_pages(vm_page_t *ma, int *rtvals, int written, off_t eof,
1561 int lpos)
1562 {
1563 int i, pos, pos_devb;
1564
1565 if (written == 0 && eof >= lpos)
1566 return;
1567 for (i = 0, pos = 0; pos < written; i++, pos += PAGE_SIZE) {
1568 if (pos < trunc_page(written)) {
1569 rtvals[i] = VM_PAGER_OK;
1570 vm_page_undirty(ma[i]);
1571 } else {
1572 /* Partially written page. */
1573 rtvals[i] = VM_PAGER_AGAIN;
1574 vm_page_clear_dirty(ma[i], 0, written & PAGE_MASK);
1575 }
1576 }
1577 if (eof >= lpos) /* avoid truncation */
1578 return;
1579 for (pos = eof, i = OFF_TO_IDX(trunc_page(pos)); pos < lpos; i++) {
1580 if (pos != trunc_page(pos)) {
1581 /*
1582 * The page contains the last valid byte in
1583 * the vnode, mark the rest of the page as
1584 * clean, potentially making the whole page
1585 * clean.
1586 */
1587 pos_devb = roundup2(pos & PAGE_MASK, DEV_BSIZE);
1588 vm_page_clear_dirty(ma[i], pos_devb, PAGE_SIZE -
1589 pos_devb);
1590
1591 /*
1592 * If the page was cleaned, report the pageout
1593 * on it as successful. msync() no longer
1594 * needs to write out the page, endlessly
1595 * creating write requests and dirty buffers.
1596 */
1597 if (ma[i]->dirty == 0)
1598 rtvals[i] = VM_PAGER_OK;
1599
1600 pos = round_page(pos);
1601 } else {
1602 /* vm_pageout_flush() clears dirty */
1603 rtvals[i] = VM_PAGER_BAD;
1604 pos += PAGE_SIZE;
1605 }
1606 }
1607 }
1608
1609 static void
vnode_pager_update_writecount(vm_object_t object,vm_offset_t start,vm_offset_t end)1610 vnode_pager_update_writecount(vm_object_t object, vm_offset_t start,
1611 vm_offset_t end)
1612 {
1613 struct vnode *vp;
1614 vm_ooffset_t old_wm;
1615
1616 VM_OBJECT_WLOCK(object);
1617 if (object->type != OBJT_VNODE) {
1618 VM_OBJECT_WUNLOCK(object);
1619 return;
1620 }
1621 old_wm = object->un_pager.vnp.writemappings;
1622 object->un_pager.vnp.writemappings += (vm_ooffset_t)end - start;
1623 vp = object->handle;
1624 if (old_wm == 0 && object->un_pager.vnp.writemappings != 0) {
1625 ASSERT_VOP_LOCKED(vp, "v_writecount inc");
1626 VOP_ADD_WRITECOUNT_CHECKED(vp, 1);
1627 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
1628 __func__, vp, vp->v_writecount);
1629 } else if (old_wm != 0 && object->un_pager.vnp.writemappings == 0) {
1630 ASSERT_VOP_LOCKED(vp, "v_writecount dec");
1631 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
1632 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
1633 __func__, vp, vp->v_writecount);
1634 }
1635 VM_OBJECT_WUNLOCK(object);
1636 }
1637
1638 static void
vnode_pager_release_writecount(vm_object_t object,vm_offset_t start,vm_offset_t end)1639 vnode_pager_release_writecount(vm_object_t object, vm_offset_t start,
1640 vm_offset_t end)
1641 {
1642 struct vnode *vp;
1643 struct mount *mp;
1644 vm_offset_t inc;
1645
1646 VM_OBJECT_WLOCK(object);
1647
1648 /*
1649 * First, recheck the object type to account for the race when
1650 * the vnode is reclaimed.
1651 */
1652 if (object->type != OBJT_VNODE) {
1653 VM_OBJECT_WUNLOCK(object);
1654 return;
1655 }
1656
1657 /*
1658 * Optimize for the case when writemappings is not going to
1659 * zero.
1660 */
1661 inc = end - start;
1662 if (object->un_pager.vnp.writemappings != inc) {
1663 object->un_pager.vnp.writemappings -= inc;
1664 VM_OBJECT_WUNLOCK(object);
1665 return;
1666 }
1667
1668 vp = object->handle;
1669 vhold(vp);
1670 VM_OBJECT_WUNLOCK(object);
1671 mp = NULL;
1672 vn_start_write(vp, &mp, V_WAIT);
1673 vn_lock(vp, LK_SHARED | LK_RETRY);
1674
1675 /*
1676 * Decrement the object's writemappings, by swapping the start
1677 * and end arguments for vnode_pager_update_writecount(). If
1678 * there was not a race with vnode reclaimation, then the
1679 * vnode's v_writecount is decremented.
1680 */
1681 vnode_pager_update_writecount(object, end, start);
1682 VOP_UNLOCK(vp);
1683 vdrop(vp);
1684 if (mp != NULL)
1685 vn_finished_write(mp);
1686 }
1687
1688 static void
vnode_pager_getvp(vm_object_t object,struct vnode ** vpp,bool * vp_heldp)1689 vnode_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp)
1690 {
1691 *vpp = object->handle;
1692 }
1693
1694 static void
vnode_pager_clean1(struct vnode * vp,int sync_flags)1695 vnode_pager_clean1(struct vnode *vp, int sync_flags)
1696 {
1697 struct vm_object *obj;
1698
1699 ASSERT_VOP_LOCKED(vp, "needs lock for writes");
1700 obj = vp->v_object;
1701 if (obj == NULL)
1702 return;
1703
1704 VM_OBJECT_WLOCK(obj);
1705 vm_object_page_clean(obj, 0, 0, sync_flags);
1706 VM_OBJECT_WUNLOCK(obj);
1707 }
1708
1709 void
vnode_pager_clean_sync(struct vnode * vp)1710 vnode_pager_clean_sync(struct vnode *vp)
1711 {
1712 vnode_pager_clean1(vp, OBJPC_SYNC);
1713 }
1714
1715 void
vnode_pager_clean_async(struct vnode * vp)1716 vnode_pager_clean_async(struct vnode *vp)
1717 {
1718 vnode_pager_clean1(vp, 0);
1719 }
1720