1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Rick Macklem at The University of Guelph.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/bio.h>
43 #include <sys/buf.h>
44 #include <sys/kernel.h>
45 #include <sys/mount.h>
46 #include <sys/rwlock.h>
47 #include <sys/vmmeter.h>
48 #include <sys/vnode.h>
49
50 #include <vm/vm.h>
51 #include <vm/vm_param.h>
52 #include <vm/vm_extern.h>
53 #include <vm/vm_page.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_pager.h>
56 #include <vm/vnode_pager.h>
57
58 #include <fs/nfs/nfsport.h>
59 #include <fs/nfsclient/nfsmount.h>
60 #include <fs/nfsclient/nfs.h>
61 #include <fs/nfsclient/nfsnode.h>
62 #include <fs/nfsclient/nfs_kdtrace.h>
63
64 extern int newnfs_directio_allow_mmap;
65 extern struct nfsstatsv1 nfsstatsv1;
66 extern struct mtx ncl_iod_mutex;
67 extern int ncl_numasync;
68 extern enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON];
69 extern struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON];
70 extern int newnfs_directio_enable;
71 extern int nfs_keep_dirty_on_error;
72
73 uma_zone_t ncl_pbuf_zone;
74
75 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size,
76 struct thread *td);
77 static int nfs_directio_write(struct vnode *vp, struct uio *uiop,
78 struct ucred *cred, int ioflag);
79
80 /*
81 * Vnode op for VM getpages.
82 */
83 SYSCTL_DECL(_vfs_nfs);
84 static int use_buf_pager = 1;
85 SYSCTL_INT(_vfs_nfs, OID_AUTO, use_buf_pager, CTLFLAG_RWTUN,
86 &use_buf_pager, 0,
87 "Use buffer pager instead of direct readrpc call");
88
89 static daddr_t
90 ncl_gbp_getblkno(struct vnode *vp, vm_ooffset_t off)
91 {
92
93 return (off / vp->v_bufobj.bo_bsize);
94 }
95
96 static int
97 ncl_gbp_getblksz(struct vnode *vp, daddr_t lbn)
98 {
99 struct nfsnode *np;
100 u_quad_t nsize;
101 int biosize, bcount;
102
103 np = VTONFS(vp);
104 NFSLOCKNODE(np);
105 nsize = np->n_size;
106 NFSUNLOCKNODE(np);
107
108 biosize = vp->v_bufobj.bo_bsize;
109 bcount = biosize;
110 if ((off_t)lbn * biosize >= nsize)
111 bcount = 0;
112 else if ((off_t)(lbn + 1) * biosize > nsize)
113 bcount = nsize - (off_t)lbn * biosize;
114 return (bcount);
115 }
116
117 int
118 ncl_getpages(struct vop_getpages_args *ap)
119 {
120 int i, error, nextoff, size, toff, count, npages;
121 struct uio uio;
122 struct iovec iov;
123 vm_offset_t kva;
124 struct buf *bp;
125 struct vnode *vp;
126 struct thread *td;
127 struct ucred *cred;
128 struct nfsmount *nmp;
129 vm_object_t object;
130 vm_page_t *pages;
131 struct nfsnode *np;
132
133 vp = ap->a_vp;
134 np = VTONFS(vp);
135 td = curthread;
136 cred = curthread->td_ucred;
137 nmp = VFSTONFS(vp->v_mount);
138 pages = ap->a_m;
139 npages = ap->a_count;
140
141 if ((object = vp->v_object) == NULL) {
142 printf("ncl_getpages: called with non-merged cache vnode\n");
143 return (VM_PAGER_ERROR);
144 }
145
146 if (newnfs_directio_enable && !newnfs_directio_allow_mmap) {
147 NFSLOCKNODE(np);
148 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
149 NFSUNLOCKNODE(np);
150 printf("ncl_getpages: called on non-cacheable vnode\n");
151 return (VM_PAGER_ERROR);
152 } else
153 NFSUNLOCKNODE(np);
154 }
155
156 mtx_lock(&nmp->nm_mtx);
157 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
158 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
159 mtx_unlock(&nmp->nm_mtx);
160 /* We'll never get here for v4, because we always have fsinfo */
161 (void)ncl_fsinfo(nmp, vp, cred, td);
162 } else
163 mtx_unlock(&nmp->nm_mtx);
164
165 if (use_buf_pager)
166 return (vfs_bio_getpages(vp, pages, npages, ap->a_rbehind,
167 ap->a_rahead, ncl_gbp_getblkno, ncl_gbp_getblksz));
168
169 /*
170 * If the requested page is partially valid, just return it and
171 * allow the pager to zero-out the blanks. Partially valid pages
172 * can only occur at the file EOF.
173 *
174 * XXXGL: is that true for NFS, where short read can occur???
175 */
176 VM_OBJECT_WLOCK(object);
177 if (!vm_page_none_valid(pages[npages - 1]) && --npages == 0)
178 goto out;
179 VM_OBJECT_WUNLOCK(object);
180
181 /*
182 * We use only the kva address for the buffer, but this is extremely
183 * convenient and fast.
184 */
185 bp = uma_zalloc(ncl_pbuf_zone, M_WAITOK);
186
187 kva = (vm_offset_t) bp->b_data;
188 pmap_qenter(kva, pages, npages);
189 VM_CNT_INC(v_vnodein);
190 VM_CNT_ADD(v_vnodepgsin, npages);
191
192 count = npages << PAGE_SHIFT;
193 iov.iov_base = (caddr_t) kva;
194 iov.iov_len = count;
195 uio.uio_iov = &iov;
196 uio.uio_iovcnt = 1;
197 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
198 uio.uio_resid = count;
199 uio.uio_segflg = UIO_SYSSPACE;
200 uio.uio_rw = UIO_READ;
201 uio.uio_td = td;
202
203 error = ncl_readrpc(vp, &uio, cred);
204 pmap_qremove(kva, npages);
205
206 uma_zfree(ncl_pbuf_zone, bp);
207
208 if (error && (uio.uio_resid == count)) {
209 printf("ncl_getpages: error %d\n", error);
210 return (VM_PAGER_ERROR);
211 }
212
213 /*
214 * Calculate the number of bytes read and validate only that number
215 * of bytes. Note that due to pending writes, size may be 0. This
216 * does not mean that the remaining data is invalid!
217 */
218
219 size = count - uio.uio_resid;
220 VM_OBJECT_WLOCK(object);
221 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
222 vm_page_t m;
223 nextoff = toff + PAGE_SIZE;
224 m = pages[i];
225
226 if (nextoff <= size) {
227 /*
228 * Read operation filled an entire page
229 */
230 vm_page_valid(m);
231 KASSERT(m->dirty == 0,
232 ("nfs_getpages: page %p is dirty", m));
233 } else if (size > toff) {
234 /*
235 * Read operation filled a partial page.
236 */
237 vm_page_invalid(m);
238 vm_page_set_valid_range(m, 0, size - toff);
239 KASSERT(m->dirty == 0,
240 ("nfs_getpages: page %p is dirty", m));
241 } else {
242 /*
243 * Read operation was short. If no error
244 * occurred we may have hit a zero-fill
245 * section. We leave valid set to 0, and page
246 * is freed by vm_page_readahead_finish() if
247 * its index is not equal to requested, or
248 * page is zeroed and set valid by
249 * vm_pager_get_pages() for requested page.
250 */
251 ;
252 }
253 }
254 out:
255 VM_OBJECT_WUNLOCK(object);
256 if (ap->a_rbehind)
257 *ap->a_rbehind = 0;
258 if (ap->a_rahead)
259 *ap->a_rahead = 0;
260 return (VM_PAGER_OK);
261 }
262
263 /*
264 * Vnode op for VM putpages.
265 */
266 int
267 ncl_putpages(struct vop_putpages_args *ap)
268 {
269 struct uio uio;
270 struct iovec iov;
271 int i, error, npages, count;
272 off_t offset;
273 int *rtvals;
274 struct vnode *vp;
275 struct thread *td;
276 struct ucred *cred;
277 struct nfsmount *nmp;
278 struct nfsnode *np;
279 vm_page_t *pages;
280
281 vp = ap->a_vp;
282 np = VTONFS(vp);
283 td = curthread; /* XXX */
284 /* Set the cred to n_writecred for the write rpcs. */
285 if (np->n_writecred != NULL)
286 cred = crhold(np->n_writecred);
287 else
288 cred = crhold(curthread->td_ucred); /* XXX */
289 nmp = VFSTONFS(vp->v_mount);
290 pages = ap->a_m;
291 count = ap->a_count;
292 rtvals = ap->a_rtvals;
293 npages = btoc(count);
294 offset = IDX_TO_OFF(pages[0]->pindex);
295
296 mtx_lock(&nmp->nm_mtx);
297 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
298 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
299 mtx_unlock(&nmp->nm_mtx);
300 (void)ncl_fsinfo(nmp, vp, cred, td);
301 } else
302 mtx_unlock(&nmp->nm_mtx);
303
304 NFSLOCKNODE(np);
305 if (newnfs_directio_enable && !newnfs_directio_allow_mmap &&
306 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
307 NFSUNLOCKNODE(np);
308 printf("ncl_putpages: called on noncache-able vnode\n");
309 NFSLOCKNODE(np);
310 }
311 /*
312 * When putting pages, do not extend file past EOF.
313 */
314 if (offset + count > np->n_size) {
315 count = np->n_size - offset;
316 if (count < 0)
317 count = 0;
318 }
319 NFSUNLOCKNODE(np);
320
321 for (i = 0; i < npages; i++)
322 rtvals[i] = VM_PAGER_ERROR;
323
324 VM_CNT_INC(v_vnodeout);
325 VM_CNT_ADD(v_vnodepgsout, count);
326
327 iov.iov_base = unmapped_buf;
328 iov.iov_len = count;
329 uio.uio_iov = &iov;
330 uio.uio_iovcnt = 1;
331 uio.uio_offset = offset;
332 uio.uio_resid = count;
333 uio.uio_segflg = UIO_NOCOPY;
334 uio.uio_rw = UIO_WRITE;
335 uio.uio_td = td;
336
337 error = VOP_WRITE(vp, &uio, vnode_pager_putpages_ioflags(ap->a_sync),
338 cred);
339 crfree(cred);
340
341 if (error == 0 || !nfs_keep_dirty_on_error) {
342 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid,
343 np->n_size - offset, npages * PAGE_SIZE);
344 }
345 return (rtvals[0]);
346 }
347
348 /*
349 * For nfs, cache consistency can only be maintained approximately.
350 * Although RFC1094 does not specify the criteria, the following is
351 * believed to be compatible with the reference port.
352 * For nfs:
353 * If the file's modify time on the server has changed since the
354 * last read rpc or you have written to the file,
355 * you may have lost data cache consistency with the
356 * server, so flush all of the file's data out of the cache.
357 * Then force a getattr rpc to ensure that you have up to date
358 * attributes.
359 * NB: This implies that cache data can be read when up to
360 * NFS_ATTRTIMEO seconds out of date. If you find that you need current
361 * attributes this could be forced by setting n_attrstamp to 0 before
362 * the VOP_GETATTR() call.
363 */
364 static inline int
365 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred)
366 {
367 int error = 0;
368 struct vattr vattr;
369 struct nfsnode *np = VTONFS(vp);
370 bool old_lock;
371
372 /*
373 * Ensure the exclusove access to the node before checking
374 * whether the cache is consistent.
375 */
376 old_lock = ncl_excl_start(vp);
377 NFSLOCKNODE(np);
378 if (np->n_flag & NMODIFIED) {
379 NFSUNLOCKNODE(np);
380 if (vp->v_type != VREG) {
381 if (vp->v_type != VDIR)
382 panic("nfs: bioread, not dir");
383 ncl_invaldir(vp);
384 error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1);
385 if (error != 0)
386 goto out;
387 }
388 np->n_attrstamp = 0;
389 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
390 error = VOP_GETATTR(vp, &vattr, cred);
391 if (error)
392 goto out;
393 NFSLOCKNODE(np);
394 np->n_mtime = vattr.va_mtime;
395 NFSUNLOCKNODE(np);
396 } else {
397 NFSUNLOCKNODE(np);
398 error = VOP_GETATTR(vp, &vattr, cred);
399 if (error)
400 goto out;
401 NFSLOCKNODE(np);
402 if ((np->n_flag & NSIZECHANGED)
403 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
404 NFSUNLOCKNODE(np);
405 if (vp->v_type == VDIR)
406 ncl_invaldir(vp);
407 error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1);
408 if (error != 0)
409 goto out;
410 NFSLOCKNODE(np);
411 np->n_mtime = vattr.va_mtime;
412 np->n_flag &= ~NSIZECHANGED;
413 }
414 NFSUNLOCKNODE(np);
415 }
416 out:
417 ncl_excl_finish(vp, old_lock);
418 return (error);
419 }
420
421 /*
422 * Vnode op for read using bio
423 */
424 int
425 ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
426 {
427 struct nfsnode *np = VTONFS(vp);
428 struct buf *bp, *rabp;
429 struct thread *td;
430 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
431 daddr_t lbn, rabn;
432 int biosize, bcount, error, i, n, nra, on, save2, seqcount;
433 off_t tmp_off;
434
435 KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode"));
436 if (uio->uio_resid == 0)
437 return (0);
438 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */
439 return (EINVAL);
440 td = uio->uio_td;
441
442 mtx_lock(&nmp->nm_mtx);
443 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
444 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
445 mtx_unlock(&nmp->nm_mtx);
446 (void)ncl_fsinfo(nmp, vp, cred, td);
447 mtx_lock(&nmp->nm_mtx);
448 }
449 if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0)
450 (void) newnfs_iosize(nmp);
451
452 tmp_off = uio->uio_offset + uio->uio_resid;
453 if (vp->v_type != VDIR &&
454 (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) {
455 mtx_unlock(&nmp->nm_mtx);
456 return (EFBIG);
457 }
458 mtx_unlock(&nmp->nm_mtx);
459
460 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG))
461 /* No caching/ no readaheads. Just read data into the user buffer */
462 return ncl_readrpc(vp, uio, cred);
463
464 n = 0;
465 on = 0;
466 biosize = vp->v_bufobj.bo_bsize;
467 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE);
468
469 error = nfs_bioread_check_cons(vp, td, cred);
470 if (error)
471 return error;
472
473 save2 = curthread_pflags2_set(TDP2_SBPAGES);
474 do {
475 u_quad_t nsize;
476
477 NFSLOCKNODE(np);
478 nsize = np->n_size;
479 NFSUNLOCKNODE(np);
480
481 switch (vp->v_type) {
482 case VREG:
483 NFSINCRGLOBAL(nfsstatsv1.biocache_reads);
484 lbn = uio->uio_offset / biosize;
485 on = uio->uio_offset - (lbn * biosize);
486
487 /*
488 * Start the read ahead(s), as required.
489 */
490 if (nmp->nm_readahead > 0) {
491 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
492 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) {
493 rabn = lbn + 1 + nra;
494 if (incore(&vp->v_bufobj, rabn) == NULL) {
495 rabp = nfs_getcacheblk(vp, rabn, biosize, td);
496 if (!rabp) {
497 error = newnfs_sigintr(nmp, td);
498 if (error == 0)
499 error = EINTR;
500 goto out;
501 }
502 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
503 rabp->b_flags |= B_ASYNC;
504 rabp->b_iocmd = BIO_READ;
505 vfs_busy_pages(rabp, 0);
506 if (ncl_asyncio(nmp, rabp, cred, td)) {
507 rabp->b_flags |= B_INVAL;
508 rabp->b_ioflags |= BIO_ERROR;
509 vfs_unbusy_pages(rabp);
510 brelse(rabp);
511 break;
512 }
513 } else {
514 brelse(rabp);
515 }
516 }
517 }
518 }
519
520 /* Note that bcount is *not* DEV_BSIZE aligned. */
521 bcount = biosize;
522 if ((off_t)lbn * biosize >= nsize) {
523 bcount = 0;
524 } else if ((off_t)(lbn + 1) * biosize > nsize) {
525 bcount = nsize - (off_t)lbn * biosize;
526 }
527 bp = nfs_getcacheblk(vp, lbn, bcount, td);
528
529 if (!bp) {
530 error = newnfs_sigintr(nmp, td);
531 if (error == 0)
532 error = EINTR;
533 goto out;
534 }
535
536 /*
537 * If B_CACHE is not set, we must issue the read. If this
538 * fails, we return an error.
539 */
540
541 if ((bp->b_flags & B_CACHE) == 0) {
542 bp->b_iocmd = BIO_READ;
543 vfs_busy_pages(bp, 0);
544 error = ncl_doio(vp, bp, cred, td, 0);
545 if (error) {
546 brelse(bp);
547 goto out;
548 }
549 }
550
551 /*
552 * on is the offset into the current bp. Figure out how many
553 * bytes we can copy out of the bp. Note that bcount is
554 * NOT DEV_BSIZE aligned.
555 *
556 * Then figure out how many bytes we can copy into the uio.
557 */
558
559 n = 0;
560 if (on < bcount)
561 n = MIN((unsigned)(bcount - on), uio->uio_resid);
562 break;
563 case VLNK:
564 NFSINCRGLOBAL(nfsstatsv1.biocache_readlinks);
565 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
566 if (!bp) {
567 error = newnfs_sigintr(nmp, td);
568 if (error == 0)
569 error = EINTR;
570 goto out;
571 }
572 if ((bp->b_flags & B_CACHE) == 0) {
573 bp->b_iocmd = BIO_READ;
574 vfs_busy_pages(bp, 0);
575 error = ncl_doio(vp, bp, cred, td, 0);
576 if (error) {
577 bp->b_ioflags |= BIO_ERROR;
578 brelse(bp);
579 goto out;
580 }
581 }
582 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
583 on = 0;
584 break;
585 case VDIR:
586 NFSINCRGLOBAL(nfsstatsv1.biocache_readdirs);
587 if (np->n_direofoffset
588 && uio->uio_offset >= np->n_direofoffset) {
589 error = 0;
590 goto out;
591 }
592 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
593 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
594 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
595 if (!bp) {
596 error = newnfs_sigintr(nmp, td);
597 if (error == 0)
598 error = EINTR;
599 goto out;
600 }
601 if ((bp->b_flags & B_CACHE) == 0) {
602 bp->b_iocmd = BIO_READ;
603 vfs_busy_pages(bp, 0);
604 error = ncl_doio(vp, bp, cred, td, 0);
605 if (error) {
606 brelse(bp);
607 }
608 while (error == NFSERR_BAD_COOKIE) {
609 ncl_invaldir(vp);
610 error = ncl_vinvalbuf(vp, 0, td, 1);
611
612 /*
613 * Yuck! The directory has been modified on the
614 * server. The only way to get the block is by
615 * reading from the beginning to get all the
616 * offset cookies.
617 *
618 * Leave the last bp intact unless there is an error.
619 * Loop back up to the while if the error is another
620 * NFSERR_BAD_COOKIE (double yuch!).
621 */
622 for (i = 0; i <= lbn && !error; i++) {
623 if (np->n_direofoffset
624 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) {
625 error = 0;
626 goto out;
627 }
628 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
629 if (!bp) {
630 error = newnfs_sigintr(nmp, td);
631 if (error == 0)
632 error = EINTR;
633 goto out;
634 }
635 if ((bp->b_flags & B_CACHE) == 0) {
636 bp->b_iocmd = BIO_READ;
637 vfs_busy_pages(bp, 0);
638 error = ncl_doio(vp, bp, cred, td, 0);
639 /*
640 * no error + B_INVAL == directory EOF,
641 * use the block.
642 */
643 if (error == 0 && (bp->b_flags & B_INVAL))
644 break;
645 }
646 /*
647 * An error will throw away the block and the
648 * for loop will break out. If no error and this
649 * is not the block we want, we throw away the
650 * block and go for the next one via the for loop.
651 */
652 if (error || i < lbn)
653 brelse(bp);
654 }
655 }
656 /*
657 * The above while is repeated if we hit another cookie
658 * error. If we hit an error and it wasn't a cookie error,
659 * we give up.
660 */
661 if (error)
662 goto out;
663 }
664
665 /*
666 * If not eof and read aheads are enabled, start one.
667 * (You need the current block first, so that you have the
668 * directory offset cookie of the next block.)
669 */
670 if (nmp->nm_readahead > 0 &&
671 (bp->b_flags & B_INVAL) == 0 &&
672 (np->n_direofoffset == 0 ||
673 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
674 incore(&vp->v_bufobj, lbn + 1) == NULL) {
675 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
676 if (rabp) {
677 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
678 rabp->b_flags |= B_ASYNC;
679 rabp->b_iocmd = BIO_READ;
680 vfs_busy_pages(rabp, 0);
681 if (ncl_asyncio(nmp, rabp, cred, td)) {
682 rabp->b_flags |= B_INVAL;
683 rabp->b_ioflags |= BIO_ERROR;
684 vfs_unbusy_pages(rabp);
685 brelse(rabp);
686 }
687 } else {
688 brelse(rabp);
689 }
690 }
691 }
692 /*
693 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is
694 * chopped for the EOF condition, we cannot tell how large
695 * NFS directories are going to be until we hit EOF. So
696 * an NFS directory buffer is *not* chopped to its EOF. Now,
697 * it just so happens that b_resid will effectively chop it
698 * to EOF. *BUT* this information is lost if the buffer goes
699 * away and is reconstituted into a B_CACHE state ( due to
700 * being VMIO ) later. So we keep track of the directory eof
701 * in np->n_direofoffset and chop it off as an extra step
702 * right here.
703 */
704 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
705 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
706 n = np->n_direofoffset - uio->uio_offset;
707 break;
708 default:
709 printf(" ncl_bioread: type %x unexpected\n", vp->v_type);
710 bp = NULL;
711 break;
712 }
713
714 if (n > 0) {
715 error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio);
716 }
717 if (vp->v_type == VLNK)
718 n = 0;
719 if (bp != NULL)
720 brelse(bp);
721 } while (error == 0 && uio->uio_resid > 0 && n > 0);
722 out:
723 curthread_pflags2_restore(save2);
724 if ((curthread->td_pflags2 & TDP2_SBPAGES) == 0) {
725 NFSLOCKNODE(np);
726 ncl_pager_setsize(vp, NULL);
727 }
728 return (error);
729 }
730
731 /*
732 * The NFS write path cannot handle iovecs with len > 1. So we need to
733 * break up iovecs accordingly (restricting them to wsize).
734 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf).
735 * For the ASYNC case, 2 copies are needed. The first a copy from the
736 * user buffer to a staging buffer and then a second copy from the staging
737 * buffer to mbufs. This can be optimized by copying from the user buffer
738 * directly into mbufs and passing the chain down, but that requires a
739 * fair amount of re-working of the relevant codepaths (and can be done
740 * later).
741 */
742 static int
743 nfs_directio_write(vp, uiop, cred, ioflag)
744 struct vnode *vp;
745 struct uio *uiop;
746 struct ucred *cred;
747 int ioflag;
748 {
749 int error;
750 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
751 struct thread *td = uiop->uio_td;
752 int size;
753 int wsize;
754
755 mtx_lock(&nmp->nm_mtx);
756 wsize = nmp->nm_wsize;
757 mtx_unlock(&nmp->nm_mtx);
758 if (ioflag & IO_SYNC) {
759 int iomode, must_commit;
760 struct uio uio;
761 struct iovec iov;
762 do_sync:
763 while (uiop->uio_resid > 0) {
764 size = MIN(uiop->uio_resid, wsize);
765 size = MIN(uiop->uio_iov->iov_len, size);
766 iov.iov_base = uiop->uio_iov->iov_base;
767 iov.iov_len = size;
768 uio.uio_iov = &iov;
769 uio.uio_iovcnt = 1;
770 uio.uio_offset = uiop->uio_offset;
771 uio.uio_resid = size;
772 uio.uio_segflg = UIO_USERSPACE;
773 uio.uio_rw = UIO_WRITE;
774 uio.uio_td = td;
775 iomode = NFSWRITE_FILESYNC;
776 error = ncl_writerpc(vp, &uio, cred, &iomode,
777 &must_commit, 0);
778 KASSERT((must_commit == 0),
779 ("ncl_directio_write: Did not commit write"));
780 if (error)
781 return (error);
782 uiop->uio_offset += size;
783 uiop->uio_resid -= size;
784 if (uiop->uio_iov->iov_len <= size) {
785 uiop->uio_iovcnt--;
786 uiop->uio_iov++;
787 } else {
788 uiop->uio_iov->iov_base =
789 (char *)uiop->uio_iov->iov_base + size;
790 uiop->uio_iov->iov_len -= size;
791 }
792 }
793 } else {
794 struct uio *t_uio;
795 struct iovec *t_iov;
796 struct buf *bp;
797
798 /*
799 * Break up the write into blocksize chunks and hand these
800 * over to nfsiod's for write back.
801 * Unfortunately, this incurs a copy of the data. Since
802 * the user could modify the buffer before the write is
803 * initiated.
804 *
805 * The obvious optimization here is that one of the 2 copies
806 * in the async write path can be eliminated by copying the
807 * data here directly into mbufs and passing the mbuf chain
808 * down. But that will require a fair amount of re-working
809 * of the code and can be done if there's enough interest
810 * in NFS directio access.
811 */
812 while (uiop->uio_resid > 0) {
813 size = MIN(uiop->uio_resid, wsize);
814 size = MIN(uiop->uio_iov->iov_len, size);
815 bp = uma_zalloc(ncl_pbuf_zone, M_WAITOK);
816 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
817 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
818 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK);
819 t_iov->iov_len = size;
820 t_uio->uio_iov = t_iov;
821 t_uio->uio_iovcnt = 1;
822 t_uio->uio_offset = uiop->uio_offset;
823 t_uio->uio_resid = size;
824 t_uio->uio_segflg = UIO_SYSSPACE;
825 t_uio->uio_rw = UIO_WRITE;
826 t_uio->uio_td = td;
827 KASSERT(uiop->uio_segflg == UIO_USERSPACE ||
828 uiop->uio_segflg == UIO_SYSSPACE,
829 ("nfs_directio_write: Bad uio_segflg"));
830 if (uiop->uio_segflg == UIO_USERSPACE) {
831 error = copyin(uiop->uio_iov->iov_base,
832 t_iov->iov_base, size);
833 if (error != 0)
834 goto err_free;
835 } else
836 /*
837 * UIO_SYSSPACE may never happen, but handle
838 * it just in case it does.
839 */
840 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base,
841 size);
842 bp->b_flags |= B_DIRECT;
843 bp->b_iocmd = BIO_WRITE;
844 if (cred != NOCRED) {
845 crhold(cred);
846 bp->b_wcred = cred;
847 } else
848 bp->b_wcred = NOCRED;
849 bp->b_caller1 = (void *)t_uio;
850 bp->b_vp = vp;
851 error = ncl_asyncio(nmp, bp, NOCRED, td);
852 err_free:
853 if (error) {
854 free(t_iov->iov_base, M_NFSDIRECTIO);
855 free(t_iov, M_NFSDIRECTIO);
856 free(t_uio, M_NFSDIRECTIO);
857 bp->b_vp = NULL;
858 uma_zfree(ncl_pbuf_zone, bp);
859 if (error == EINTR)
860 return (error);
861 goto do_sync;
862 }
863 uiop->uio_offset += size;
864 uiop->uio_resid -= size;
865 if (uiop->uio_iov->iov_len <= size) {
866 uiop->uio_iovcnt--;
867 uiop->uio_iov++;
868 } else {
869 uiop->uio_iov->iov_base =
870 (char *)uiop->uio_iov->iov_base + size;
871 uiop->uio_iov->iov_len -= size;
872 }
873 }
874 }
875 return (0);
876 }
877
878 /*
879 * Vnode op for write using bio
880 */
881 int
882 ncl_write(struct vop_write_args *ap)
883 {
884 int biosize;
885 struct uio *uio = ap->a_uio;
886 struct thread *td = uio->uio_td;
887 struct vnode *vp = ap->a_vp;
888 struct nfsnode *np = VTONFS(vp);
889 struct ucred *cred = ap->a_cred;
890 int ioflag = ap->a_ioflag;
891 struct buf *bp;
892 struct vattr vattr;
893 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
894 daddr_t lbn;
895 int bcount, noncontig_write, obcount;
896 int bp_cached, n, on, error = 0, error1, wouldcommit;
897 size_t orig_resid, local_resid;
898 off_t orig_size, tmp_off;
899
900 KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode"));
901 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
902 ("ncl_write proc"));
903 if (vp->v_type != VREG)
904 return (EIO);
905 NFSLOCKNODE(np);
906 if (np->n_flag & NWRITEERR) {
907 np->n_flag &= ~NWRITEERR;
908 NFSUNLOCKNODE(np);
909 return (np->n_error);
910 } else
911 NFSUNLOCKNODE(np);
912 mtx_lock(&nmp->nm_mtx);
913 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
914 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
915 mtx_unlock(&nmp->nm_mtx);
916 (void)ncl_fsinfo(nmp, vp, cred, td);
917 mtx_lock(&nmp->nm_mtx);
918 }
919 if (nmp->nm_wsize == 0)
920 (void) newnfs_iosize(nmp);
921 mtx_unlock(&nmp->nm_mtx);
922
923 /*
924 * Synchronously flush pending buffers if we are in synchronous
925 * mode or if we are appending.
926 */
927 if (ioflag & (IO_APPEND | IO_SYNC)) {
928 NFSLOCKNODE(np);
929 if (np->n_flag & NMODIFIED) {
930 NFSUNLOCKNODE(np);
931 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */
932 /*
933 * Require non-blocking, synchronous writes to
934 * dirty files to inform the program it needs
935 * to fsync(2) explicitly.
936 */
937 if (ioflag & IO_NDELAY)
938 return (EAGAIN);
939 #endif
940 np->n_attrstamp = 0;
941 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
942 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
943 IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
944 if (error != 0)
945 return (error);
946 } else
947 NFSUNLOCKNODE(np);
948 }
949
950 orig_resid = uio->uio_resid;
951 NFSLOCKNODE(np);
952 orig_size = np->n_size;
953 NFSUNLOCKNODE(np);
954
955 /*
956 * If IO_APPEND then load uio_offset. We restart here if we cannot
957 * get the append lock.
958 */
959 if (ioflag & IO_APPEND) {
960 np->n_attrstamp = 0;
961 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
962 error = VOP_GETATTR(vp, &vattr, cred);
963 if (error)
964 return (error);
965 NFSLOCKNODE(np);
966 uio->uio_offset = np->n_size;
967 NFSUNLOCKNODE(np);
968 }
969
970 if (uio->uio_offset < 0)
971 return (EINVAL);
972 tmp_off = uio->uio_offset + uio->uio_resid;
973 if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)
974 return (EFBIG);
975 if (uio->uio_resid == 0)
976 return (0);
977
978 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
979 return nfs_directio_write(vp, uio, cred, ioflag);
980
981 /*
982 * Maybe this should be above the vnode op call, but so long as
983 * file servers have no limits, i don't think it matters
984 */
985 if (vn_rlimit_fsize(vp, uio, td))
986 return (EFBIG);
987
988 biosize = vp->v_bufobj.bo_bsize;
989 /*
990 * Find all of this file's B_NEEDCOMMIT buffers. If our writes
991 * would exceed the local maximum per-file write commit size when
992 * combined with those, we must decide whether to flush,
993 * go synchronous, or return error. We don't bother checking
994 * IO_UNIT -- we just make all writes atomic anyway, as there's
995 * no point optimizing for something that really won't ever happen.
996 */
997 wouldcommit = 0;
998 if (!(ioflag & IO_SYNC)) {
999 int nflag;
1000
1001 NFSLOCKNODE(np);
1002 nflag = np->n_flag;
1003 NFSUNLOCKNODE(np);
1004 if (nflag & NMODIFIED) {
1005 BO_LOCK(&vp->v_bufobj);
1006 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) {
1007 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd,
1008 b_bobufs) {
1009 if (bp->b_flags & B_NEEDCOMMIT)
1010 wouldcommit += bp->b_bcount;
1011 }
1012 }
1013 BO_UNLOCK(&vp->v_bufobj);
1014 }
1015 }
1016
1017 do {
1018 if (!(ioflag & IO_SYNC)) {
1019 wouldcommit += biosize;
1020 if (wouldcommit > nmp->nm_wcommitsize) {
1021 np->n_attrstamp = 0;
1022 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
1023 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
1024 IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
1025 if (error != 0)
1026 return (error);
1027 wouldcommit = biosize;
1028 }
1029 }
1030
1031 NFSINCRGLOBAL(nfsstatsv1.biocache_writes);
1032 lbn = uio->uio_offset / biosize;
1033 on = uio->uio_offset - (lbn * biosize);
1034 n = MIN((unsigned)(biosize - on), uio->uio_resid);
1035 again:
1036 /*
1037 * Handle direct append and file extension cases, calculate
1038 * unaligned buffer size.
1039 */
1040 NFSLOCKNODE(np);
1041 if ((np->n_flag & NHASBEENLOCKED) == 0 &&
1042 (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0)
1043 noncontig_write = 1;
1044 else
1045 noncontig_write = 0;
1046 if ((uio->uio_offset == np->n_size ||
1047 (noncontig_write != 0 &&
1048 lbn == (np->n_size / biosize) &&
1049 uio->uio_offset + n > np->n_size)) && n) {
1050 NFSUNLOCKNODE(np);
1051 /*
1052 * Get the buffer (in its pre-append state to maintain
1053 * B_CACHE if it was previously set). Resize the
1054 * nfsnode after we have locked the buffer to prevent
1055 * readers from reading garbage.
1056 */
1057 obcount = np->n_size - (lbn * biosize);
1058 bp = nfs_getcacheblk(vp, lbn, obcount, td);
1059
1060 if (bp != NULL) {
1061 long save;
1062
1063 NFSLOCKNODE(np);
1064 np->n_size = uio->uio_offset + n;
1065 np->n_flag |= NMODIFIED;
1066 vnode_pager_setsize(vp, np->n_size);
1067 NFSUNLOCKNODE(np);
1068
1069 save = bp->b_flags & B_CACHE;
1070 bcount = on + n;
1071 allocbuf(bp, bcount);
1072 bp->b_flags |= save;
1073 if (noncontig_write != 0 && on > obcount)
1074 vfs_bio_bzero_buf(bp, obcount, on -
1075 obcount);
1076 }
1077 } else {
1078 /*
1079 * Obtain the locked cache block first, and then
1080 * adjust the file's size as appropriate.
1081 */
1082 bcount = on + n;
1083 if ((off_t)lbn * biosize + bcount < np->n_size) {
1084 if ((off_t)(lbn + 1) * biosize < np->n_size)
1085 bcount = biosize;
1086 else
1087 bcount = np->n_size - (off_t)lbn * biosize;
1088 }
1089 NFSUNLOCKNODE(np);
1090 bp = nfs_getcacheblk(vp, lbn, bcount, td);
1091 NFSLOCKNODE(np);
1092 if (uio->uio_offset + n > np->n_size) {
1093 np->n_size = uio->uio_offset + n;
1094 np->n_flag |= NMODIFIED;
1095 vnode_pager_setsize(vp, np->n_size);
1096 }
1097 NFSUNLOCKNODE(np);
1098 }
1099
1100 if (!bp) {
1101 error = newnfs_sigintr(nmp, td);
1102 if (!error)
1103 error = EINTR;
1104 break;
1105 }
1106
1107 /*
1108 * Issue a READ if B_CACHE is not set. In special-append
1109 * mode, B_CACHE is based on the buffer prior to the write
1110 * op and is typically set, avoiding the read. If a read
1111 * is required in special append mode, the server will
1112 * probably send us a short-read since we extended the file
1113 * on our end, resulting in b_resid == 0 and, thusly,
1114 * B_CACHE getting set.
1115 *
1116 * We can also avoid issuing the read if the write covers
1117 * the entire buffer. We have to make sure the buffer state
1118 * is reasonable in this case since we will not be initiating
1119 * I/O. See the comments in kern/vfs_bio.c's getblk() for
1120 * more information.
1121 *
1122 * B_CACHE may also be set due to the buffer being cached
1123 * normally.
1124 */
1125
1126 bp_cached = 1;
1127 if (on == 0 && n == bcount) {
1128 if ((bp->b_flags & B_CACHE) == 0)
1129 bp_cached = 0;
1130 bp->b_flags |= B_CACHE;
1131 bp->b_flags &= ~B_INVAL;
1132 bp->b_ioflags &= ~BIO_ERROR;
1133 }
1134
1135 if ((bp->b_flags & B_CACHE) == 0) {
1136 bp->b_iocmd = BIO_READ;
1137 vfs_busy_pages(bp, 0);
1138 error = ncl_doio(vp, bp, cred, td, 0);
1139 if (error) {
1140 brelse(bp);
1141 break;
1142 }
1143 }
1144 if (bp->b_wcred == NOCRED)
1145 bp->b_wcred = crhold(cred);
1146 NFSLOCKNODE(np);
1147 np->n_flag |= NMODIFIED;
1148 NFSUNLOCKNODE(np);
1149
1150 /*
1151 * If dirtyend exceeds file size, chop it down. This should
1152 * not normally occur but there is an append race where it
1153 * might occur XXX, so we log it.
1154 *
1155 * If the chopping creates a reverse-indexed or degenerate
1156 * situation with dirtyoff/end, we 0 both of them.
1157 */
1158
1159 if (bp->b_dirtyend > bcount) {
1160 printf("NFS append race @%lx:%d\n",
1161 (long)bp->b_blkno * DEV_BSIZE,
1162 bp->b_dirtyend - bcount);
1163 bp->b_dirtyend = bcount;
1164 }
1165
1166 if (bp->b_dirtyoff >= bp->b_dirtyend)
1167 bp->b_dirtyoff = bp->b_dirtyend = 0;
1168
1169 /*
1170 * If the new write will leave a contiguous dirty
1171 * area, just update the b_dirtyoff and b_dirtyend,
1172 * otherwise force a write rpc of the old dirty area.
1173 *
1174 * If there has been a file lock applied to this file
1175 * or vfs.nfs.old_noncontig_writing is set, do the following:
1176 * While it is possible to merge discontiguous writes due to
1177 * our having a B_CACHE buffer ( and thus valid read data
1178 * for the hole), we don't because it could lead to
1179 * significant cache coherency problems with multiple clients,
1180 * especially if locking is implemented later on.
1181 *
1182 * If vfs.nfs.old_noncontig_writing is not set and there has
1183 * not been file locking done on this file:
1184 * Relax coherency a bit for the sake of performance and
1185 * expand the current dirty region to contain the new
1186 * write even if it means we mark some non-dirty data as
1187 * dirty.
1188 */
1189
1190 if (noncontig_write == 0 && bp->b_dirtyend > 0 &&
1191 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
1192 if (bwrite(bp) == EINTR) {
1193 error = EINTR;
1194 break;
1195 }
1196 goto again;
1197 }
1198
1199 local_resid = uio->uio_resid;
1200 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio);
1201
1202 if (error != 0 && !bp_cached) {
1203 /*
1204 * This block has no other content then what
1205 * possibly was written by the faulty uiomove.
1206 * Release it, forgetting the data pages, to
1207 * prevent the leak of uninitialized data to
1208 * usermode.
1209 */
1210 bp->b_ioflags |= BIO_ERROR;
1211 brelse(bp);
1212 uio->uio_offset -= local_resid - uio->uio_resid;
1213 uio->uio_resid = local_resid;
1214 break;
1215 }
1216
1217 /*
1218 * Since this block is being modified, it must be written
1219 * again and not just committed. Since write clustering does
1220 * not work for the stage 1 data write, only the stage 2
1221 * commit rpc, we have to clear B_CLUSTEROK as well.
1222 */
1223 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1224
1225 /*
1226 * Get the partial update on the progress made from
1227 * uiomove, if an error occurred.
1228 */
1229 if (error != 0)
1230 n = local_resid - uio->uio_resid;
1231
1232 /*
1233 * Only update dirtyoff/dirtyend if not a degenerate
1234 * condition.
1235 */
1236 if (n > 0) {
1237 if (bp->b_dirtyend > 0) {
1238 bp->b_dirtyoff = min(on, bp->b_dirtyoff);
1239 bp->b_dirtyend = max((on + n), bp->b_dirtyend);
1240 } else {
1241 bp->b_dirtyoff = on;
1242 bp->b_dirtyend = on + n;
1243 }
1244 vfs_bio_set_valid(bp, on, n);
1245 }
1246
1247 /*
1248 * If IO_SYNC do bwrite().
1249 *
1250 * IO_INVAL appears to be unused. The idea appears to be
1251 * to turn off caching in this case. Very odd. XXX
1252 */
1253 if ((ioflag & IO_SYNC)) {
1254 if (ioflag & IO_INVAL)
1255 bp->b_flags |= B_NOCACHE;
1256 error1 = bwrite(bp);
1257 if (error1 != 0) {
1258 if (error == 0)
1259 error = error1;
1260 break;
1261 }
1262 } else if ((n + on) == biosize || (ioflag & IO_ASYNC) != 0) {
1263 bp->b_flags |= B_ASYNC;
1264 (void) ncl_writebp(bp, 0, NULL);
1265 } else {
1266 bdwrite(bp);
1267 }
1268
1269 if (error != 0)
1270 break;
1271 } while (uio->uio_resid > 0 && n > 0);
1272
1273 if (error != 0) {
1274 if (ioflag & IO_UNIT) {
1275 VATTR_NULL(&vattr);
1276 vattr.va_size = orig_size;
1277 /* IO_SYNC is handled implicitely */
1278 (void)VOP_SETATTR(vp, &vattr, cred);
1279 uio->uio_offset -= orig_resid - uio->uio_resid;
1280 uio->uio_resid = orig_resid;
1281 }
1282 }
1283
1284 return (error);
1285 }
1286
1287 /*
1288 * Get an nfs cache block.
1289 *
1290 * Allocate a new one if the block isn't currently in the cache
1291 * and return the block marked busy. If the calling process is
1292 * interrupted by a signal for an interruptible mount point, return
1293 * NULL.
1294 *
1295 * The caller must carefully deal with the possible B_INVAL state of
1296 * the buffer. ncl_doio() clears B_INVAL (and ncl_asyncio() clears it
1297 * indirectly), so synchronous reads can be issued without worrying about
1298 * the B_INVAL state. We have to be a little more careful when dealing
1299 * with writes (see comments in nfs_write()) when extending a file past
1300 * its EOF.
1301 */
1302 static struct buf *
1303 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
1304 {
1305 struct buf *bp;
1306 struct mount *mp;
1307 struct nfsmount *nmp;
1308
1309 mp = vp->v_mount;
1310 nmp = VFSTONFS(mp);
1311
1312 if (nmp->nm_flag & NFSMNT_INT) {
1313 sigset_t oldset;
1314
1315 newnfs_set_sigmask(td, &oldset);
1316 bp = getblk(vp, bn, size, PCATCH, 0, 0);
1317 newnfs_restore_sigmask(td, &oldset);
1318 while (bp == NULL) {
1319 if (newnfs_sigintr(nmp, td))
1320 return (NULL);
1321 bp = getblk(vp, bn, size, 0, 2 * hz, 0);
1322 }
1323 } else {
1324 bp = getblk(vp, bn, size, 0, 0, 0);
1325 }
1326
1327 if (vp->v_type == VREG)
1328 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE);
1329 return (bp);
1330 }
1331
1332 /*
1333 * Flush and invalidate all dirty buffers. If another process is already
1334 * doing the flush, just wait for completion.
1335 */
1336 int
1337 ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg)
1338 {
1339 struct nfsnode *np = VTONFS(vp);
1340 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
1341 int error = 0, slpflag, slptimeo;
1342 bool old_lock;
1343
1344 ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf");
1345
1346 if ((nmp->nm_flag & NFSMNT_INT) == 0)
1347 intrflg = 0;
1348 if (NFSCL_FORCEDISM(nmp->nm_mountp))
1349 intrflg = 1;
1350 if (intrflg) {
1351 slpflag = PCATCH;
1352 slptimeo = 2 * hz;
1353 } else {
1354 slpflag = 0;
1355 slptimeo = 0;
1356 }
1357
1358 old_lock = ncl_excl_start(vp);
1359 if (old_lock)
1360 flags |= V_ALLOWCLEAN;
1361
1362 /*
1363 * Now, flush as required.
1364 */
1365 if ((flags & (V_SAVE | V_VMIO)) == V_SAVE &&
1366 vp->v_bufobj.bo_object != NULL) {
1367 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object);
1368 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
1369 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object);
1370 /*
1371 * If the page clean was interrupted, fail the invalidation.
1372 * Not doing so, we run the risk of losing dirty pages in the
1373 * vinvalbuf() call below.
1374 */
1375 if (intrflg && (error = newnfs_sigintr(nmp, td)))
1376 goto out;
1377 }
1378
1379 error = vinvalbuf(vp, flags, slpflag, 0);
1380 while (error) {
1381 if (intrflg && (error = newnfs_sigintr(nmp, td)))
1382 goto out;
1383 error = vinvalbuf(vp, flags, 0, slptimeo);
1384 }
1385 if (NFSHASPNFS(nmp)) {
1386 nfscl_layoutcommit(vp, td);
1387 /*
1388 * Invalidate the attribute cache, since writes to a DS
1389 * won't update the size attribute.
1390 */
1391 NFSLOCKNODE(np);
1392 np->n_attrstamp = 0;
1393 } else
1394 NFSLOCKNODE(np);
1395 if (np->n_directio_asyncwr == 0)
1396 np->n_flag &= ~NMODIFIED;
1397 NFSUNLOCKNODE(np);
1398 out:
1399 ncl_excl_finish(vp, old_lock);
1400 return error;
1401 }
1402
1403 /*
1404 * Initiate asynchronous I/O. Return an error if no nfsiods are available.
1405 * This is mainly to avoid queueing async I/O requests when the nfsiods
1406 * are all hung on a dead server.
1407 *
1408 * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
1409 * is eventually dequeued by the async daemon, ncl_doio() *will*.
1410 */
1411 int
1412 ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
1413 {
1414 int iod;
1415 int gotiod;
1416 int slpflag = 0;
1417 int slptimeo = 0;
1418 int error, error2;
1419
1420 /*
1421 * Commits are usually short and sweet so lets save some cpu and
1422 * leave the async daemons for more important rpc's (such as reads
1423 * and writes).
1424 *
1425 * Readdirplus RPCs do vget()s to acquire the vnodes for entries
1426 * in the directory in order to update attributes. This can deadlock
1427 * with another thread that is waiting for async I/O to be done by
1428 * an nfsiod thread while holding a lock on one of these vnodes.
1429 * To avoid this deadlock, don't allow the async nfsiod threads to
1430 * perform Readdirplus RPCs.
1431 */
1432 NFSLOCKIOD();
1433 if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
1434 (nmp->nm_bufqiods > ncl_numasync / 2)) ||
1435 (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) {
1436 NFSUNLOCKIOD();
1437 return(EIO);
1438 }
1439 again:
1440 if (nmp->nm_flag & NFSMNT_INT)
1441 slpflag = PCATCH;
1442 gotiod = FALSE;
1443
1444 /*
1445 * Find a free iod to process this request.
1446 */
1447 for (iod = 0; iod < ncl_numasync; iod++)
1448 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) {
1449 gotiod = TRUE;
1450 break;
1451 }
1452
1453 /*
1454 * Try to create one if none are free.
1455 */
1456 if (!gotiod)
1457 ncl_nfsiodnew();
1458 else {
1459 /*
1460 * Found one, so wake it up and tell it which
1461 * mount to process.
1462 */
1463 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n",
1464 iod, nmp));
1465 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE;
1466 ncl_iodmount[iod] = nmp;
1467 nmp->nm_bufqiods++;
1468 wakeup(&ncl_iodwant[iod]);
1469 }
1470
1471 /*
1472 * If none are free, we may already have an iod working on this mount
1473 * point. If so, it will process our request.
1474 */
1475 if (!gotiod) {
1476 if (nmp->nm_bufqiods > 0) {
1477 NFS_DPF(ASYNCIO,
1478 ("ncl_asyncio: %d iods are already processing mount %p\n",
1479 nmp->nm_bufqiods, nmp));
1480 gotiod = TRUE;
1481 }
1482 }
1483
1484 /*
1485 * If we have an iod which can process the request, then queue
1486 * the buffer.
1487 */
1488 if (gotiod) {
1489 /*
1490 * Ensure that the queue never grows too large. We still want
1491 * to asynchronize so we block rather then return EIO.
1492 */
1493 while (nmp->nm_bufqlen >= 2*ncl_numasync) {
1494 NFS_DPF(ASYNCIO,
1495 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp));
1496 nmp->nm_bufqwant = TRUE;
1497 error = newnfs_msleep(td, &nmp->nm_bufq,
1498 &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio",
1499 slptimeo);
1500 if (error) {
1501 error2 = newnfs_sigintr(nmp, td);
1502 if (error2) {
1503 NFSUNLOCKIOD();
1504 return (error2);
1505 }
1506 if (slpflag == PCATCH) {
1507 slpflag = 0;
1508 slptimeo = 2 * hz;
1509 }
1510 }
1511 /*
1512 * We might have lost our iod while sleeping,
1513 * so check and loop if necessary.
1514 */
1515 goto again;
1516 }
1517
1518 /* We might have lost our nfsiod */
1519 if (nmp->nm_bufqiods == 0) {
1520 NFS_DPF(ASYNCIO,
1521 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
1522 goto again;
1523 }
1524
1525 if (bp->b_iocmd == BIO_READ) {
1526 if (bp->b_rcred == NOCRED && cred != NOCRED)
1527 bp->b_rcred = crhold(cred);
1528 } else {
1529 if (bp->b_wcred == NOCRED && cred != NOCRED)
1530 bp->b_wcred = crhold(cred);
1531 }
1532
1533 if (bp->b_flags & B_REMFREE)
1534 bremfreef(bp);
1535 BUF_KERNPROC(bp);
1536 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
1537 nmp->nm_bufqlen++;
1538 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1539 NFSLOCKNODE(VTONFS(bp->b_vp));
1540 VTONFS(bp->b_vp)->n_flag |= NMODIFIED;
1541 VTONFS(bp->b_vp)->n_directio_asyncwr++;
1542 NFSUNLOCKNODE(VTONFS(bp->b_vp));
1543 }
1544 NFSUNLOCKIOD();
1545 return (0);
1546 }
1547
1548 NFSUNLOCKIOD();
1549
1550 /*
1551 * All the iods are busy on other mounts, so return EIO to
1552 * force the caller to process the i/o synchronously.
1553 */
1554 NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n"));
1555 return (EIO);
1556 }
1557
1558 void
1559 ncl_doio_directwrite(struct buf *bp)
1560 {
1561 int iomode, must_commit;
1562 struct uio *uiop = (struct uio *)bp->b_caller1;
1563 char *iov_base = uiop->uio_iov->iov_base;
1564
1565 iomode = NFSWRITE_FILESYNC;
1566 uiop->uio_td = NULL; /* NULL since we're in nfsiod */
1567 ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0);
1568 KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write"));
1569 free(iov_base, M_NFSDIRECTIO);
1570 free(uiop->uio_iov, M_NFSDIRECTIO);
1571 free(uiop, M_NFSDIRECTIO);
1572 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1573 struct nfsnode *np = VTONFS(bp->b_vp);
1574 NFSLOCKNODE(np);
1575 if (NFSHASPNFS(VFSTONFS(bp->b_vp->v_mount))) {
1576 /*
1577 * Invalidate the attribute cache, since writes to a DS
1578 * won't update the size attribute.
1579 */
1580 np->n_attrstamp = 0;
1581 }
1582 np->n_directio_asyncwr--;
1583 if (np->n_directio_asyncwr == 0) {
1584 np->n_flag &= ~NMODIFIED;
1585 if ((np->n_flag & NFSYNCWAIT)) {
1586 np->n_flag &= ~NFSYNCWAIT;
1587 wakeup((caddr_t)&np->n_directio_asyncwr);
1588 }
1589 }
1590 NFSUNLOCKNODE(np);
1591 }
1592 bp->b_vp = NULL;
1593 uma_zfree(ncl_pbuf_zone, bp);
1594 }
1595
1596 /*
1597 * Do an I/O operation to/from a cache block. This may be called
1598 * synchronously or from an nfsiod.
1599 */
1600 int
1601 ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td,
1602 int called_from_strategy)
1603 {
1604 struct uio *uiop;
1605 struct nfsnode *np;
1606 struct nfsmount *nmp;
1607 int error = 0, iomode, must_commit = 0;
1608 struct uio uio;
1609 struct iovec io;
1610 struct proc *p = td ? td->td_proc : NULL;
1611 uint8_t iocmd;
1612
1613 np = VTONFS(vp);
1614 nmp = VFSTONFS(vp->v_mount);
1615 uiop = &uio;
1616 uiop->uio_iov = &io;
1617 uiop->uio_iovcnt = 1;
1618 uiop->uio_segflg = UIO_SYSSPACE;
1619 uiop->uio_td = td;
1620
1621 /*
1622 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
1623 * do this here so we do not have to do it in all the code that
1624 * calls us.
1625 */
1626 bp->b_flags &= ~B_INVAL;
1627 bp->b_ioflags &= ~BIO_ERROR;
1628
1629 KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp));
1630 iocmd = bp->b_iocmd;
1631 if (iocmd == BIO_READ) {
1632 io.iov_len = uiop->uio_resid = bp->b_bcount;
1633 io.iov_base = bp->b_data;
1634 uiop->uio_rw = UIO_READ;
1635
1636 switch (vp->v_type) {
1637 case VREG:
1638 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
1639 NFSINCRGLOBAL(nfsstatsv1.read_bios);
1640 error = ncl_readrpc(vp, uiop, cr);
1641
1642 if (!error) {
1643 if (uiop->uio_resid) {
1644 /*
1645 * If we had a short read with no error, we must have
1646 * hit a file hole. We should zero-fill the remainder.
1647 * This can also occur if the server hits the file EOF.
1648 *
1649 * Holes used to be able to occur due to pending
1650 * writes, but that is not possible any longer.
1651 */
1652 int nread = bp->b_bcount - uiop->uio_resid;
1653 ssize_t left = uiop->uio_resid;
1654
1655 if (left > 0)
1656 bzero((char *)bp->b_data + nread, left);
1657 uiop->uio_resid = 0;
1658 }
1659 }
1660 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */
1661 if (p && vp->v_writecount <= -1) {
1662 NFSLOCKNODE(np);
1663 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) {
1664 NFSUNLOCKNODE(np);
1665 PROC_LOCK(p);
1666 killproc(p, "text file modification");
1667 PROC_UNLOCK(p);
1668 } else
1669 NFSUNLOCKNODE(np);
1670 }
1671 break;
1672 case VLNK:
1673 uiop->uio_offset = (off_t)0;
1674 NFSINCRGLOBAL(nfsstatsv1.readlink_bios);
1675 error = ncl_readlinkrpc(vp, uiop, cr);
1676 break;
1677 case VDIR:
1678 NFSINCRGLOBAL(nfsstatsv1.readdir_bios);
1679 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
1680 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
1681 error = ncl_readdirplusrpc(vp, uiop, cr, td);
1682 if (error == NFSERR_NOTSUPP)
1683 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
1684 }
1685 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
1686 error = ncl_readdirrpc(vp, uiop, cr, td);
1687 /*
1688 * end-of-directory sets B_INVAL but does not generate an
1689 * error.
1690 */
1691 if (error == 0 && uiop->uio_resid == bp->b_bcount)
1692 bp->b_flags |= B_INVAL;
1693 break;
1694 default:
1695 printf("ncl_doio: type %x unexpected\n", vp->v_type);
1696 break;
1697 }
1698 if (error) {
1699 bp->b_ioflags |= BIO_ERROR;
1700 bp->b_error = error;
1701 }
1702 } else {
1703 /*
1704 * If we only need to commit, try to commit
1705 */
1706 if (bp->b_flags & B_NEEDCOMMIT) {
1707 int retv;
1708 off_t off;
1709
1710 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
1711 retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff,
1712 bp->b_wcred, td);
1713 if (retv == 0) {
1714 bp->b_dirtyoff = bp->b_dirtyend = 0;
1715 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1716 bp->b_resid = 0;
1717 bufdone(bp);
1718 return (0);
1719 }
1720 if (retv == NFSERR_STALEWRITEVERF) {
1721 ncl_clearcommit(vp->v_mount);
1722 }
1723 }
1724
1725 /*
1726 * Setup for actual write
1727 */
1728 NFSLOCKNODE(np);
1729 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
1730 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
1731 NFSUNLOCKNODE(np);
1732
1733 if (bp->b_dirtyend > bp->b_dirtyoff) {
1734 io.iov_len = uiop->uio_resid = bp->b_dirtyend
1735 - bp->b_dirtyoff;
1736 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
1737 + bp->b_dirtyoff;
1738 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
1739 uiop->uio_rw = UIO_WRITE;
1740 NFSINCRGLOBAL(nfsstatsv1.write_bios);
1741
1742 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
1743 iomode = NFSWRITE_UNSTABLE;
1744 else
1745 iomode = NFSWRITE_FILESYNC;
1746
1747 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit,
1748 called_from_strategy);
1749
1750 /*
1751 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
1752 * to cluster the buffers needing commit. This will allow
1753 * the system to submit a single commit rpc for the whole
1754 * cluster. We can do this even if the buffer is not 100%
1755 * dirty (relative to the NFS blocksize), so we optimize the
1756 * append-to-file-case.
1757 *
1758 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
1759 * cleared because write clustering only works for commit
1760 * rpc's, not for the data portion of the write).
1761 */
1762
1763 if (!error && iomode == NFSWRITE_UNSTABLE) {
1764 bp->b_flags |= B_NEEDCOMMIT;
1765 if (bp->b_dirtyoff == 0
1766 && bp->b_dirtyend == bp->b_bcount)
1767 bp->b_flags |= B_CLUSTEROK;
1768 } else {
1769 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1770 }
1771
1772 /*
1773 * For an interrupted write, the buffer is still valid
1774 * and the write hasn't been pushed to the server yet,
1775 * so we can't set BIO_ERROR and report the interruption
1776 * by setting B_EINTR. For the B_ASYNC case, B_EINTR
1777 * is not relevant, so the rpc attempt is essentially
1778 * a noop. For the case of a V3 write rpc not being
1779 * committed to stable storage, the block is still
1780 * dirty and requires either a commit rpc or another
1781 * write rpc with iomode == NFSV3WRITE_FILESYNC before
1782 * the block is reused. This is indicated by setting
1783 * the B_DELWRI and B_NEEDCOMMIT flags.
1784 *
1785 * EIO is returned by ncl_writerpc() to indicate a recoverable
1786 * write error and is handled as above, except that
1787 * B_EINTR isn't set. One cause of this is a stale stateid
1788 * error for the RPC that indicates recovery is required,
1789 * when called with called_from_strategy != 0.
1790 *
1791 * If the buffer is marked B_PAGING, it does not reside on
1792 * the vp's paging queues so we cannot call bdirty(). The
1793 * bp in this case is not an NFS cache block so we should
1794 * be safe. XXX
1795 *
1796 * The logic below breaks up errors into recoverable and
1797 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE
1798 * and keep the buffer around for potential write retries.
1799 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL)
1800 * and save the error in the nfsnode. This is less than ideal
1801 * but necessary. Keeping such buffers around could potentially
1802 * cause buffer exhaustion eventually (they can never be written
1803 * out, so will get constantly be re-dirtied). It also causes
1804 * all sorts of vfs panics. For non-recoverable write errors,
1805 * also invalidate the attrcache, so we'll be forced to go over
1806 * the wire for this object, returning an error to user on next
1807 * call (most of the time).
1808 */
1809 if (error == EINTR || error == EIO || error == ETIMEDOUT
1810 || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
1811 bp->b_flags &= ~(B_INVAL|B_NOCACHE);
1812 if ((bp->b_flags & B_PAGING) == 0) {
1813 bdirty(bp);
1814 bp->b_flags &= ~B_DONE;
1815 }
1816 if ((error == EINTR || error == ETIMEDOUT) &&
1817 (bp->b_flags & B_ASYNC) == 0)
1818 bp->b_flags |= B_EINTR;
1819 } else {
1820 if (error) {
1821 bp->b_ioflags |= BIO_ERROR;
1822 bp->b_flags |= B_INVAL;
1823 bp->b_error = np->n_error = error;
1824 NFSLOCKNODE(np);
1825 np->n_flag |= NWRITEERR;
1826 np->n_attrstamp = 0;
1827 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
1828 NFSUNLOCKNODE(np);
1829 }
1830 bp->b_dirtyoff = bp->b_dirtyend = 0;
1831 }
1832 } else {
1833 bp->b_resid = 0;
1834 bufdone(bp);
1835 return (0);
1836 }
1837 }
1838 bp->b_resid = uiop->uio_resid;
1839 if (must_commit)
1840 ncl_clearcommit(vp->v_mount);
1841 bufdone(bp);
1842 return (error);
1843 }
1844
1845 /*
1846 * Used to aid in handling ftruncate() operations on the NFS client side.
1847 * Truncation creates a number of special problems for NFS. We have to
1848 * throw away VM pages and buffer cache buffers that are beyond EOF, and
1849 * we have to properly handle VM pages or (potentially dirty) buffers
1850 * that straddle the truncation point.
1851 */
1852
1853 int
1854 ncl_meta_setsize(struct vnode *vp, struct thread *td, u_quad_t nsize)
1855 {
1856 struct nfsnode *np = VTONFS(vp);
1857 u_quad_t tsize;
1858 int biosize = vp->v_bufobj.bo_bsize;
1859 int error = 0;
1860
1861 NFSLOCKNODE(np);
1862 tsize = np->n_size;
1863 np->n_size = nsize;
1864 NFSUNLOCKNODE(np);
1865
1866 if (nsize < tsize) {
1867 struct buf *bp;
1868 daddr_t lbn;
1869 int bufsize;
1870
1871 /*
1872 * vtruncbuf() doesn't get the buffer overlapping the
1873 * truncation point. We may have a B_DELWRI and/or B_CACHE
1874 * buffer that now needs to be truncated.
1875 */
1876 error = vtruncbuf(vp, nsize, biosize);
1877 lbn = nsize / biosize;
1878 bufsize = nsize - (lbn * biosize);
1879 bp = nfs_getcacheblk(vp, lbn, bufsize, td);
1880 if (!bp)
1881 return EINTR;
1882 if (bp->b_dirtyoff > bp->b_bcount)
1883 bp->b_dirtyoff = bp->b_bcount;
1884 if (bp->b_dirtyend > bp->b_bcount)
1885 bp->b_dirtyend = bp->b_bcount;
1886 bp->b_flags |= B_RELBUF; /* don't leave garbage around */
1887 brelse(bp);
1888 } else {
1889 vnode_pager_setsize(vp, nsize);
1890 }
1891 return(error);
1892 }
Cache object: dcac711c8786e81738a54c9d2a710ffb
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