1 /*-
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Rick Macklem at The University of Guelph.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95
33 */
34
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/bio.h>
41 #include <sys/buf.h>
42 #include <sys/kernel.h>
43 #include <sys/mount.h>
44 #include <sys/rwlock.h>
45 #include <sys/vmmeter.h>
46 #include <sys/vnode.h>
47
48 #include <vm/vm.h>
49 #include <vm/vm_param.h>
50 #include <vm/vm_extern.h>
51 #include <vm/vm_page.h>
52 #include <vm/vm_object.h>
53 #include <vm/vm_pager.h>
54 #include <vm/vnode_pager.h>
55
56 #include <fs/nfs/nfsport.h>
57 #include <fs/nfsclient/nfsmount.h>
58 #include <fs/nfsclient/nfs.h>
59 #include <fs/nfsclient/nfsnode.h>
60 #include <fs/nfsclient/nfs_kdtrace.h>
61
62 extern int newnfs_directio_allow_mmap;
63 extern struct nfsstatsv1 nfsstatsv1;
64 extern struct mtx ncl_iod_mutex;
65 extern int ncl_numasync;
66 extern enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON];
67 extern struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON];
68 extern int newnfs_directio_enable;
69 extern int nfs_keep_dirty_on_error;
70
71 int ncl_pbuf_freecnt = -1; /* start out unlimited */
72
73 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size,
74 struct thread *td);
75 static int nfs_directio_write(struct vnode *vp, struct uio *uiop,
76 struct ucred *cred, int ioflag);
77
78 /*
79 * Vnode op for VM getpages.
80 */
81 SYSCTL_DECL(_vfs_nfs);
82 static int use_buf_pager = 0;
83 SYSCTL_INT(_vfs_nfs, OID_AUTO, use_buf_pager, CTLFLAG_RWTUN,
84 &use_buf_pager, 0,
85 "Use buffer pager instead of direct readrpc call");
86
87 static daddr_t
88 ncl_gbp_getblkno(struct vnode *vp, vm_ooffset_t off)
89 {
90
91 return (off / vp->v_bufobj.bo_bsize);
92 }
93
94 static int
95 ncl_gbp_getblksz(struct vnode *vp, daddr_t lbn)
96 {
97 struct nfsnode *np;
98 u_quad_t nsize;
99 int biosize, bcount;
100
101 np = VTONFS(vp);
102 mtx_lock(&np->n_mtx);
103 nsize = np->n_size;
104 mtx_unlock(&np->n_mtx);
105
106 biosize = vp->v_bufobj.bo_bsize;
107 bcount = biosize;
108 if ((off_t)lbn * biosize >= nsize)
109 bcount = 0;
110 else if ((off_t)(lbn + 1) * biosize > nsize)
111 bcount = nsize - (off_t)lbn * biosize;
112 return (bcount);
113 }
114
115 int
116 ncl_getpages(struct vop_getpages_args *ap)
117 {
118 int i, error, nextoff, size, toff, count, npages;
119 struct uio uio;
120 struct iovec iov;
121 vm_offset_t kva;
122 struct buf *bp;
123 struct vnode *vp;
124 struct thread *td;
125 struct ucred *cred;
126 struct nfsmount *nmp;
127 vm_object_t object;
128 vm_page_t *pages;
129 struct nfsnode *np;
130
131 vp = ap->a_vp;
132 np = VTONFS(vp);
133 td = curthread;
134 cred = curthread->td_ucred;
135 nmp = VFSTONFS(vp->v_mount);
136 pages = ap->a_m;
137 npages = ap->a_count;
138
139 if ((object = vp->v_object) == NULL) {
140 printf("ncl_getpages: called with non-merged cache vnode\n");
141 return (VM_PAGER_ERROR);
142 }
143
144 if (newnfs_directio_enable && !newnfs_directio_allow_mmap) {
145 mtx_lock(&np->n_mtx);
146 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
147 mtx_unlock(&np->n_mtx);
148 printf("ncl_getpages: called on non-cacheable vnode\n");
149 return (VM_PAGER_ERROR);
150 } else
151 mtx_unlock(&np->n_mtx);
152 }
153
154 mtx_lock(&nmp->nm_mtx);
155 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
156 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
157 mtx_unlock(&nmp->nm_mtx);
158 /* We'll never get here for v4, because we always have fsinfo */
159 (void)ncl_fsinfo(nmp, vp, cred, td);
160 } else
161 mtx_unlock(&nmp->nm_mtx);
162
163 if (use_buf_pager)
164 return (vfs_bio_getpages(vp, pages, npages, ap->a_rbehind,
165 ap->a_rahead, ncl_gbp_getblkno, ncl_gbp_getblksz));
166
167 /*
168 * If the requested page is partially valid, just return it and
169 * allow the pager to zero-out the blanks. Partially valid pages
170 * can only occur at the file EOF.
171 *
172 * XXXGL: is that true for NFS, where short read can occur???
173 */
174 VM_OBJECT_WLOCK(object);
175 if (pages[npages - 1]->valid != 0 && --npages == 0)
176 goto out;
177 VM_OBJECT_WUNLOCK(object);
178
179 /*
180 * We use only the kva address for the buffer, but this is extremely
181 * convenient and fast.
182 */
183 bp = getpbuf(&ncl_pbuf_freecnt);
184
185 kva = (vm_offset_t) bp->b_data;
186 pmap_qenter(kva, pages, npages);
187 PCPU_INC(cnt.v_vnodein);
188 PCPU_ADD(cnt.v_vnodepgsin, npages);
189
190 count = npages << PAGE_SHIFT;
191 iov.iov_base = (caddr_t) kva;
192 iov.iov_len = count;
193 uio.uio_iov = &iov;
194 uio.uio_iovcnt = 1;
195 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
196 uio.uio_resid = count;
197 uio.uio_segflg = UIO_SYSSPACE;
198 uio.uio_rw = UIO_READ;
199 uio.uio_td = td;
200
201 error = ncl_readrpc(vp, &uio, cred);
202 pmap_qremove(kva, npages);
203
204 relpbuf(bp, &ncl_pbuf_freecnt);
205
206 if (error && (uio.uio_resid == count)) {
207 printf("ncl_getpages: error %d\n", error);
208 return (VM_PAGER_ERROR);
209 }
210
211 /*
212 * Calculate the number of bytes read and validate only that number
213 * of bytes. Note that due to pending writes, size may be 0. This
214 * does not mean that the remaining data is invalid!
215 */
216
217 size = count - uio.uio_resid;
218 VM_OBJECT_WLOCK(object);
219 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
220 vm_page_t m;
221 nextoff = toff + PAGE_SIZE;
222 m = pages[i];
223
224 if (nextoff <= size) {
225 /*
226 * Read operation filled an entire page
227 */
228 m->valid = VM_PAGE_BITS_ALL;
229 KASSERT(m->dirty == 0,
230 ("nfs_getpages: page %p is dirty", m));
231 } else if (size > toff) {
232 /*
233 * Read operation filled a partial page.
234 */
235 m->valid = 0;
236 vm_page_set_valid_range(m, 0, size - toff);
237 KASSERT(m->dirty == 0,
238 ("nfs_getpages: page %p is dirty", m));
239 } else {
240 /*
241 * Read operation was short. If no error
242 * occurred we may have hit a zero-fill
243 * section. We leave valid set to 0, and page
244 * is freed by vm_page_readahead_finish() if
245 * its index is not equal to requested, or
246 * page is zeroed and set valid by
247 * vm_pager_get_pages() for requested page.
248 */
249 ;
250 }
251 }
252 out:
253 VM_OBJECT_WUNLOCK(object);
254 if (ap->a_rbehind)
255 *ap->a_rbehind = 0;
256 if (ap->a_rahead)
257 *ap->a_rahead = 0;
258 return (VM_PAGER_OK);
259 }
260
261 /*
262 * Vnode op for VM putpages.
263 */
264 int
265 ncl_putpages(struct vop_putpages_args *ap)
266 {
267 struct uio uio;
268 struct iovec iov;
269 int i, error, npages, count;
270 off_t offset;
271 int *rtvals;
272 struct vnode *vp;
273 struct thread *td;
274 struct ucred *cred;
275 struct nfsmount *nmp;
276 struct nfsnode *np;
277 vm_page_t *pages;
278
279 vp = ap->a_vp;
280 np = VTONFS(vp);
281 td = curthread; /* XXX */
282 /* Set the cred to n_writecred for the write rpcs. */
283 if (np->n_writecred != NULL)
284 cred = crhold(np->n_writecred);
285 else
286 cred = crhold(curthread->td_ucred); /* XXX */
287 nmp = VFSTONFS(vp->v_mount);
288 pages = ap->a_m;
289 count = ap->a_count;
290 rtvals = ap->a_rtvals;
291 npages = btoc(count);
292 offset = IDX_TO_OFF(pages[0]->pindex);
293
294 mtx_lock(&nmp->nm_mtx);
295 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
296 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
297 mtx_unlock(&nmp->nm_mtx);
298 (void)ncl_fsinfo(nmp, vp, cred, td);
299 } else
300 mtx_unlock(&nmp->nm_mtx);
301
302 mtx_lock(&np->n_mtx);
303 if (newnfs_directio_enable && !newnfs_directio_allow_mmap &&
304 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
305 mtx_unlock(&np->n_mtx);
306 printf("ncl_putpages: called on noncache-able vnode\n");
307 mtx_lock(&np->n_mtx);
308 }
309 /*
310 * When putting pages, do not extend file past EOF.
311 */
312 if (offset + count > np->n_size) {
313 count = np->n_size - offset;
314 if (count < 0)
315 count = 0;
316 }
317 mtx_unlock(&np->n_mtx);
318
319 for (i = 0; i < npages; i++)
320 rtvals[i] = VM_PAGER_ERROR;
321
322 PCPU_INC(cnt.v_vnodeout);
323 PCPU_ADD(cnt.v_vnodepgsout, count);
324
325 iov.iov_base = unmapped_buf;
326 iov.iov_len = count;
327 uio.uio_iov = &iov;
328 uio.uio_iovcnt = 1;
329 uio.uio_offset = offset;
330 uio.uio_resid = count;
331 uio.uio_segflg = UIO_NOCOPY;
332 uio.uio_rw = UIO_WRITE;
333 uio.uio_td = td;
334
335 error = VOP_WRITE(vp, &uio, vnode_pager_putpages_ioflags(ap->a_sync),
336 cred);
337 crfree(cred);
338
339 if (error == 0 || !nfs_keep_dirty_on_error) {
340 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid,
341 np->n_size - offset, npages * PAGE_SIZE);
342 }
343 return (rtvals[0]);
344 }
345
346 /*
347 * For nfs, cache consistency can only be maintained approximately.
348 * Although RFC1094 does not specify the criteria, the following is
349 * believed to be compatible with the reference port.
350 * For nfs:
351 * If the file's modify time on the server has changed since the
352 * last read rpc or you have written to the file,
353 * you may have lost data cache consistency with the
354 * server, so flush all of the file's data out of the cache.
355 * Then force a getattr rpc to ensure that you have up to date
356 * attributes.
357 * NB: This implies that cache data can be read when up to
358 * NFS_ATTRTIMEO seconds out of date. If you find that you need current
359 * attributes this could be forced by setting n_attrstamp to 0 before
360 * the VOP_GETATTR() call.
361 */
362 static inline int
363 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred)
364 {
365 int error = 0;
366 struct vattr vattr;
367 struct nfsnode *np = VTONFS(vp);
368 bool old_lock;
369
370 /*
371 * Ensure the exclusove access to the node before checking
372 * whether the cache is consistent.
373 */
374 old_lock = ncl_excl_start(vp);
375 mtx_lock(&np->n_mtx);
376 if (np->n_flag & NMODIFIED) {
377 mtx_unlock(&np->n_mtx);
378 if (vp->v_type != VREG) {
379 if (vp->v_type != VDIR)
380 panic("nfs: bioread, not dir");
381 ncl_invaldir(vp);
382 error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1);
383 if (error != 0)
384 goto out;
385 }
386 np->n_attrstamp = 0;
387 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
388 error = VOP_GETATTR(vp, &vattr, cred);
389 if (error)
390 goto out;
391 mtx_lock(&np->n_mtx);
392 np->n_mtime = vattr.va_mtime;
393 mtx_unlock(&np->n_mtx);
394 } else {
395 mtx_unlock(&np->n_mtx);
396 error = VOP_GETATTR(vp, &vattr, cred);
397 if (error)
398 goto out;
399 mtx_lock(&np->n_mtx);
400 if ((np->n_flag & NSIZECHANGED)
401 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
402 mtx_unlock(&np->n_mtx);
403 if (vp->v_type == VDIR)
404 ncl_invaldir(vp);
405 error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1);
406 if (error != 0)
407 goto out;
408 mtx_lock(&np->n_mtx);
409 np->n_mtime = vattr.va_mtime;
410 np->n_flag &= ~NSIZECHANGED;
411 }
412 mtx_unlock(&np->n_mtx);
413 }
414 out:
415 ncl_excl_finish(vp, old_lock);
416 return (error);
417 }
418
419 /*
420 * Vnode op for read using bio
421 */
422 int
423 ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
424 {
425 struct nfsnode *np = VTONFS(vp);
426 int biosize, i;
427 struct buf *bp, *rabp;
428 struct thread *td;
429 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
430 daddr_t lbn, rabn;
431 int bcount;
432 int seqcount;
433 int nra, error = 0, n = 0, on = 0;
434 off_t tmp_off;
435
436 KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode"));
437 if (uio->uio_resid == 0)
438 return (0);
439 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */
440 return (EINVAL);
441 td = uio->uio_td;
442
443 mtx_lock(&nmp->nm_mtx);
444 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
445 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
446 mtx_unlock(&nmp->nm_mtx);
447 (void)ncl_fsinfo(nmp, vp, cred, td);
448 mtx_lock(&nmp->nm_mtx);
449 }
450 if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0)
451 (void) newnfs_iosize(nmp);
452
453 tmp_off = uio->uio_offset + uio->uio_resid;
454 if (vp->v_type != VDIR &&
455 (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) {
456 mtx_unlock(&nmp->nm_mtx);
457 return (EFBIG);
458 }
459 mtx_unlock(&nmp->nm_mtx);
460
461 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG))
462 /* No caching/ no readaheads. Just read data into the user buffer */
463 return ncl_readrpc(vp, uio, cred);
464
465 biosize = vp->v_bufobj.bo_bsize;
466 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE);
467
468 error = nfs_bioread_check_cons(vp, td, cred);
469 if (error)
470 return error;
471
472 do {
473 u_quad_t nsize;
474
475 mtx_lock(&np->n_mtx);
476 nsize = np->n_size;
477 mtx_unlock(&np->n_mtx);
478
479 switch (vp->v_type) {
480 case VREG:
481 NFSINCRGLOBAL(nfsstatsv1.biocache_reads);
482 lbn = uio->uio_offset / biosize;
483 on = uio->uio_offset - (lbn * biosize);
484
485 /*
486 * Start the read ahead(s), as required.
487 */
488 if (nmp->nm_readahead > 0) {
489 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
490 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) {
491 rabn = lbn + 1 + nra;
492 if (incore(&vp->v_bufobj, rabn) == NULL) {
493 rabp = nfs_getcacheblk(vp, rabn, biosize, td);
494 if (!rabp) {
495 error = newnfs_sigintr(nmp, td);
496 return (error ? error : EINTR);
497 }
498 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
499 rabp->b_flags |= B_ASYNC;
500 rabp->b_iocmd = BIO_READ;
501 vfs_busy_pages(rabp, 0);
502 if (ncl_asyncio(nmp, rabp, cred, td)) {
503 rabp->b_flags |= B_INVAL;
504 rabp->b_ioflags |= BIO_ERROR;
505 vfs_unbusy_pages(rabp);
506 brelse(rabp);
507 break;
508 }
509 } else {
510 brelse(rabp);
511 }
512 }
513 }
514 }
515
516 /* Note that bcount is *not* DEV_BSIZE aligned. */
517 bcount = biosize;
518 if ((off_t)lbn * biosize >= nsize) {
519 bcount = 0;
520 } else if ((off_t)(lbn + 1) * biosize > nsize) {
521 bcount = nsize - (off_t)lbn * biosize;
522 }
523 bp = nfs_getcacheblk(vp, lbn, bcount, td);
524
525 if (!bp) {
526 error = newnfs_sigintr(nmp, td);
527 return (error ? error : EINTR);
528 }
529
530 /*
531 * If B_CACHE is not set, we must issue the read. If this
532 * fails, we return an error.
533 */
534
535 if ((bp->b_flags & B_CACHE) == 0) {
536 bp->b_iocmd = BIO_READ;
537 vfs_busy_pages(bp, 0);
538 error = ncl_doio(vp, bp, cred, td, 0);
539 if (error) {
540 brelse(bp);
541 return (error);
542 }
543 }
544
545 /*
546 * on is the offset into the current bp. Figure out how many
547 * bytes we can copy out of the bp. Note that bcount is
548 * NOT DEV_BSIZE aligned.
549 *
550 * Then figure out how many bytes we can copy into the uio.
551 */
552
553 n = 0;
554 if (on < bcount)
555 n = MIN((unsigned)(bcount - on), uio->uio_resid);
556 break;
557 case VLNK:
558 NFSINCRGLOBAL(nfsstatsv1.biocache_readlinks);
559 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
560 if (!bp) {
561 error = newnfs_sigintr(nmp, td);
562 return (error ? error : EINTR);
563 }
564 if ((bp->b_flags & B_CACHE) == 0) {
565 bp->b_iocmd = BIO_READ;
566 vfs_busy_pages(bp, 0);
567 error = ncl_doio(vp, bp, cred, td, 0);
568 if (error) {
569 bp->b_ioflags |= BIO_ERROR;
570 brelse(bp);
571 return (error);
572 }
573 }
574 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
575 on = 0;
576 break;
577 case VDIR:
578 NFSINCRGLOBAL(nfsstatsv1.biocache_readdirs);
579 if (np->n_direofoffset
580 && uio->uio_offset >= np->n_direofoffset) {
581 return (0);
582 }
583 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
584 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
585 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
586 if (!bp) {
587 error = newnfs_sigintr(nmp, td);
588 return (error ? error : EINTR);
589 }
590 if ((bp->b_flags & B_CACHE) == 0) {
591 bp->b_iocmd = BIO_READ;
592 vfs_busy_pages(bp, 0);
593 error = ncl_doio(vp, bp, cred, td, 0);
594 if (error) {
595 brelse(bp);
596 }
597 while (error == NFSERR_BAD_COOKIE) {
598 ncl_invaldir(vp);
599 error = ncl_vinvalbuf(vp, 0, td, 1);
600
601 /*
602 * Yuck! The directory has been modified on the
603 * server. The only way to get the block is by
604 * reading from the beginning to get all the
605 * offset cookies.
606 *
607 * Leave the last bp intact unless there is an error.
608 * Loop back up to the while if the error is another
609 * NFSERR_BAD_COOKIE (double yuch!).
610 */
611 for (i = 0; i <= lbn && !error; i++) {
612 if (np->n_direofoffset
613 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset)
614 return (0);
615 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
616 if (!bp) {
617 error = newnfs_sigintr(nmp, td);
618 return (error ? error : EINTR);
619 }
620 if ((bp->b_flags & B_CACHE) == 0) {
621 bp->b_iocmd = BIO_READ;
622 vfs_busy_pages(bp, 0);
623 error = ncl_doio(vp, bp, cred, td, 0);
624 /*
625 * no error + B_INVAL == directory EOF,
626 * use the block.
627 */
628 if (error == 0 && (bp->b_flags & B_INVAL))
629 break;
630 }
631 /*
632 * An error will throw away the block and the
633 * for loop will break out. If no error and this
634 * is not the block we want, we throw away the
635 * block and go for the next one via the for loop.
636 */
637 if (error || i < lbn)
638 brelse(bp);
639 }
640 }
641 /*
642 * The above while is repeated if we hit another cookie
643 * error. If we hit an error and it wasn't a cookie error,
644 * we give up.
645 */
646 if (error)
647 return (error);
648 }
649
650 /*
651 * If not eof and read aheads are enabled, start one.
652 * (You need the current block first, so that you have the
653 * directory offset cookie of the next block.)
654 */
655 if (nmp->nm_readahead > 0 &&
656 (bp->b_flags & B_INVAL) == 0 &&
657 (np->n_direofoffset == 0 ||
658 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
659 incore(&vp->v_bufobj, lbn + 1) == NULL) {
660 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
661 if (rabp) {
662 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
663 rabp->b_flags |= B_ASYNC;
664 rabp->b_iocmd = BIO_READ;
665 vfs_busy_pages(rabp, 0);
666 if (ncl_asyncio(nmp, rabp, cred, td)) {
667 rabp->b_flags |= B_INVAL;
668 rabp->b_ioflags |= BIO_ERROR;
669 vfs_unbusy_pages(rabp);
670 brelse(rabp);
671 }
672 } else {
673 brelse(rabp);
674 }
675 }
676 }
677 /*
678 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is
679 * chopped for the EOF condition, we cannot tell how large
680 * NFS directories are going to be until we hit EOF. So
681 * an NFS directory buffer is *not* chopped to its EOF. Now,
682 * it just so happens that b_resid will effectively chop it
683 * to EOF. *BUT* this information is lost if the buffer goes
684 * away and is reconstituted into a B_CACHE state ( due to
685 * being VMIO ) later. So we keep track of the directory eof
686 * in np->n_direofoffset and chop it off as an extra step
687 * right here.
688 */
689 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
690 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
691 n = np->n_direofoffset - uio->uio_offset;
692 break;
693 default:
694 printf(" ncl_bioread: type %x unexpected\n", vp->v_type);
695 bp = NULL;
696 break;
697 }
698
699 if (n > 0) {
700 error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio);
701 }
702 if (vp->v_type == VLNK)
703 n = 0;
704 if (bp != NULL)
705 brelse(bp);
706 } while (error == 0 && uio->uio_resid > 0 && n > 0);
707 return (error);
708 }
709
710 /*
711 * The NFS write path cannot handle iovecs with len > 1. So we need to
712 * break up iovecs accordingly (restricting them to wsize).
713 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf).
714 * For the ASYNC case, 2 copies are needed. The first a copy from the
715 * user buffer to a staging buffer and then a second copy from the staging
716 * buffer to mbufs. This can be optimized by copying from the user buffer
717 * directly into mbufs and passing the chain down, but that requires a
718 * fair amount of re-working of the relevant codepaths (and can be done
719 * later).
720 */
721 static int
722 nfs_directio_write(vp, uiop, cred, ioflag)
723 struct vnode *vp;
724 struct uio *uiop;
725 struct ucred *cred;
726 int ioflag;
727 {
728 int error;
729 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
730 struct thread *td = uiop->uio_td;
731 int size;
732 int wsize;
733
734 mtx_lock(&nmp->nm_mtx);
735 wsize = nmp->nm_wsize;
736 mtx_unlock(&nmp->nm_mtx);
737 if (ioflag & IO_SYNC) {
738 int iomode, must_commit;
739 struct uio uio;
740 struct iovec iov;
741 do_sync:
742 while (uiop->uio_resid > 0) {
743 size = MIN(uiop->uio_resid, wsize);
744 size = MIN(uiop->uio_iov->iov_len, size);
745 iov.iov_base = uiop->uio_iov->iov_base;
746 iov.iov_len = size;
747 uio.uio_iov = &iov;
748 uio.uio_iovcnt = 1;
749 uio.uio_offset = uiop->uio_offset;
750 uio.uio_resid = size;
751 uio.uio_segflg = UIO_USERSPACE;
752 uio.uio_rw = UIO_WRITE;
753 uio.uio_td = td;
754 iomode = NFSWRITE_FILESYNC;
755 error = ncl_writerpc(vp, &uio, cred, &iomode,
756 &must_commit, 0);
757 KASSERT((must_commit == 0),
758 ("ncl_directio_write: Did not commit write"));
759 if (error)
760 return (error);
761 uiop->uio_offset += size;
762 uiop->uio_resid -= size;
763 if (uiop->uio_iov->iov_len <= size) {
764 uiop->uio_iovcnt--;
765 uiop->uio_iov++;
766 } else {
767 uiop->uio_iov->iov_base =
768 (char *)uiop->uio_iov->iov_base + size;
769 uiop->uio_iov->iov_len -= size;
770 }
771 }
772 } else {
773 struct uio *t_uio;
774 struct iovec *t_iov;
775 struct buf *bp;
776
777 /*
778 * Break up the write into blocksize chunks and hand these
779 * over to nfsiod's for write back.
780 * Unfortunately, this incurs a copy of the data. Since
781 * the user could modify the buffer before the write is
782 * initiated.
783 *
784 * The obvious optimization here is that one of the 2 copies
785 * in the async write path can be eliminated by copying the
786 * data here directly into mbufs and passing the mbuf chain
787 * down. But that will require a fair amount of re-working
788 * of the code and can be done if there's enough interest
789 * in NFS directio access.
790 */
791 while (uiop->uio_resid > 0) {
792 size = MIN(uiop->uio_resid, wsize);
793 size = MIN(uiop->uio_iov->iov_len, size);
794 bp = getpbuf(&ncl_pbuf_freecnt);
795 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
796 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
797 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK);
798 t_iov->iov_len = size;
799 t_uio->uio_iov = t_iov;
800 t_uio->uio_iovcnt = 1;
801 t_uio->uio_offset = uiop->uio_offset;
802 t_uio->uio_resid = size;
803 t_uio->uio_segflg = UIO_SYSSPACE;
804 t_uio->uio_rw = UIO_WRITE;
805 t_uio->uio_td = td;
806 KASSERT(uiop->uio_segflg == UIO_USERSPACE ||
807 uiop->uio_segflg == UIO_SYSSPACE,
808 ("nfs_directio_write: Bad uio_segflg"));
809 if (uiop->uio_segflg == UIO_USERSPACE) {
810 error = copyin(uiop->uio_iov->iov_base,
811 t_iov->iov_base, size);
812 if (error != 0)
813 goto err_free;
814 } else
815 /*
816 * UIO_SYSSPACE may never happen, but handle
817 * it just in case it does.
818 */
819 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base,
820 size);
821 bp->b_flags |= B_DIRECT;
822 bp->b_iocmd = BIO_WRITE;
823 if (cred != NOCRED) {
824 crhold(cred);
825 bp->b_wcred = cred;
826 } else
827 bp->b_wcred = NOCRED;
828 bp->b_caller1 = (void *)t_uio;
829 bp->b_vp = vp;
830 error = ncl_asyncio(nmp, bp, NOCRED, td);
831 err_free:
832 if (error) {
833 free(t_iov->iov_base, M_NFSDIRECTIO);
834 free(t_iov, M_NFSDIRECTIO);
835 free(t_uio, M_NFSDIRECTIO);
836 bp->b_vp = NULL;
837 relpbuf(bp, &ncl_pbuf_freecnt);
838 if (error == EINTR)
839 return (error);
840 goto do_sync;
841 }
842 uiop->uio_offset += size;
843 uiop->uio_resid -= size;
844 if (uiop->uio_iov->iov_len <= size) {
845 uiop->uio_iovcnt--;
846 uiop->uio_iov++;
847 } else {
848 uiop->uio_iov->iov_base =
849 (char *)uiop->uio_iov->iov_base + size;
850 uiop->uio_iov->iov_len -= size;
851 }
852 }
853 }
854 return (0);
855 }
856
857 /*
858 * Vnode op for write using bio
859 */
860 int
861 ncl_write(struct vop_write_args *ap)
862 {
863 int biosize;
864 struct uio *uio = ap->a_uio;
865 struct thread *td = uio->uio_td;
866 struct vnode *vp = ap->a_vp;
867 struct nfsnode *np = VTONFS(vp);
868 struct ucred *cred = ap->a_cred;
869 int ioflag = ap->a_ioflag;
870 struct buf *bp;
871 struct vattr vattr;
872 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
873 daddr_t lbn;
874 int bcount, noncontig_write, obcount;
875 int bp_cached, n, on, error = 0, error1, wouldcommit;
876 size_t orig_resid, local_resid;
877 off_t orig_size, tmp_off;
878
879 KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode"));
880 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
881 ("ncl_write proc"));
882 if (vp->v_type != VREG)
883 return (EIO);
884 mtx_lock(&np->n_mtx);
885 if (np->n_flag & NWRITEERR) {
886 np->n_flag &= ~NWRITEERR;
887 mtx_unlock(&np->n_mtx);
888 return (np->n_error);
889 } else
890 mtx_unlock(&np->n_mtx);
891 mtx_lock(&nmp->nm_mtx);
892 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
893 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
894 mtx_unlock(&nmp->nm_mtx);
895 (void)ncl_fsinfo(nmp, vp, cred, td);
896 mtx_lock(&nmp->nm_mtx);
897 }
898 if (nmp->nm_wsize == 0)
899 (void) newnfs_iosize(nmp);
900 mtx_unlock(&nmp->nm_mtx);
901
902 /*
903 * Synchronously flush pending buffers if we are in synchronous
904 * mode or if we are appending.
905 */
906 if (ioflag & (IO_APPEND | IO_SYNC)) {
907 mtx_lock(&np->n_mtx);
908 if (np->n_flag & NMODIFIED) {
909 mtx_unlock(&np->n_mtx);
910 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */
911 /*
912 * Require non-blocking, synchronous writes to
913 * dirty files to inform the program it needs
914 * to fsync(2) explicitly.
915 */
916 if (ioflag & IO_NDELAY)
917 return (EAGAIN);
918 #endif
919 np->n_attrstamp = 0;
920 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
921 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
922 IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
923 if (error != 0)
924 return (error);
925 } else
926 mtx_unlock(&np->n_mtx);
927 }
928
929 orig_resid = uio->uio_resid;
930 mtx_lock(&np->n_mtx);
931 orig_size = np->n_size;
932 mtx_unlock(&np->n_mtx);
933
934 /*
935 * If IO_APPEND then load uio_offset. We restart here if we cannot
936 * get the append lock.
937 */
938 if (ioflag & IO_APPEND) {
939 np->n_attrstamp = 0;
940 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
941 error = VOP_GETATTR(vp, &vattr, cred);
942 if (error)
943 return (error);
944 mtx_lock(&np->n_mtx);
945 uio->uio_offset = np->n_size;
946 mtx_unlock(&np->n_mtx);
947 }
948
949 if (uio->uio_offset < 0)
950 return (EINVAL);
951 tmp_off = uio->uio_offset + uio->uio_resid;
952 if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)
953 return (EFBIG);
954 if (uio->uio_resid == 0)
955 return (0);
956
957 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
958 return nfs_directio_write(vp, uio, cred, ioflag);
959
960 /*
961 * Maybe this should be above the vnode op call, but so long as
962 * file servers have no limits, i don't think it matters
963 */
964 if (vn_rlimit_fsize(vp, uio, td))
965 return (EFBIG);
966
967 biosize = vp->v_bufobj.bo_bsize;
968 /*
969 * Find all of this file's B_NEEDCOMMIT buffers. If our writes
970 * would exceed the local maximum per-file write commit size when
971 * combined with those, we must decide whether to flush,
972 * go synchronous, or return error. We don't bother checking
973 * IO_UNIT -- we just make all writes atomic anyway, as there's
974 * no point optimizing for something that really won't ever happen.
975 */
976 wouldcommit = 0;
977 if (!(ioflag & IO_SYNC)) {
978 int nflag;
979
980 mtx_lock(&np->n_mtx);
981 nflag = np->n_flag;
982 mtx_unlock(&np->n_mtx);
983 if (nflag & NMODIFIED) {
984 BO_LOCK(&vp->v_bufobj);
985 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) {
986 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd,
987 b_bobufs) {
988 if (bp->b_flags & B_NEEDCOMMIT)
989 wouldcommit += bp->b_bcount;
990 }
991 }
992 BO_UNLOCK(&vp->v_bufobj);
993 }
994 }
995
996 do {
997 if (!(ioflag & IO_SYNC)) {
998 wouldcommit += biosize;
999 if (wouldcommit > nmp->nm_wcommitsize) {
1000 np->n_attrstamp = 0;
1001 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
1002 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
1003 IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
1004 if (error != 0)
1005 return (error);
1006 wouldcommit = biosize;
1007 }
1008 }
1009
1010 NFSINCRGLOBAL(nfsstatsv1.biocache_writes);
1011 lbn = uio->uio_offset / biosize;
1012 on = uio->uio_offset - (lbn * biosize);
1013 n = MIN((unsigned)(biosize - on), uio->uio_resid);
1014 again:
1015 /*
1016 * Handle direct append and file extension cases, calculate
1017 * unaligned buffer size.
1018 */
1019 mtx_lock(&np->n_mtx);
1020 if ((np->n_flag & NHASBEENLOCKED) == 0 &&
1021 (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0)
1022 noncontig_write = 1;
1023 else
1024 noncontig_write = 0;
1025 if ((uio->uio_offset == np->n_size ||
1026 (noncontig_write != 0 &&
1027 lbn == (np->n_size / biosize) &&
1028 uio->uio_offset + n > np->n_size)) && n) {
1029 mtx_unlock(&np->n_mtx);
1030 /*
1031 * Get the buffer (in its pre-append state to maintain
1032 * B_CACHE if it was previously set). Resize the
1033 * nfsnode after we have locked the buffer to prevent
1034 * readers from reading garbage.
1035 */
1036 obcount = np->n_size - (lbn * biosize);
1037 bp = nfs_getcacheblk(vp, lbn, obcount, td);
1038
1039 if (bp != NULL) {
1040 long save;
1041
1042 mtx_lock(&np->n_mtx);
1043 np->n_size = uio->uio_offset + n;
1044 np->n_flag |= NMODIFIED;
1045 vnode_pager_setsize(vp, np->n_size);
1046 mtx_unlock(&np->n_mtx);
1047
1048 save = bp->b_flags & B_CACHE;
1049 bcount = on + n;
1050 allocbuf(bp, bcount);
1051 bp->b_flags |= save;
1052 if (noncontig_write != 0 && on > obcount)
1053 vfs_bio_bzero_buf(bp, obcount, on -
1054 obcount);
1055 }
1056 } else {
1057 /*
1058 * Obtain the locked cache block first, and then
1059 * adjust the file's size as appropriate.
1060 */
1061 bcount = on + n;
1062 if ((off_t)lbn * biosize + bcount < np->n_size) {
1063 if ((off_t)(lbn + 1) * biosize < np->n_size)
1064 bcount = biosize;
1065 else
1066 bcount = np->n_size - (off_t)lbn * biosize;
1067 }
1068 mtx_unlock(&np->n_mtx);
1069 bp = nfs_getcacheblk(vp, lbn, bcount, td);
1070 mtx_lock(&np->n_mtx);
1071 if (uio->uio_offset + n > np->n_size) {
1072 np->n_size = uio->uio_offset + n;
1073 np->n_flag |= NMODIFIED;
1074 vnode_pager_setsize(vp, np->n_size);
1075 }
1076 mtx_unlock(&np->n_mtx);
1077 }
1078
1079 if (!bp) {
1080 error = newnfs_sigintr(nmp, td);
1081 if (!error)
1082 error = EINTR;
1083 break;
1084 }
1085
1086 /*
1087 * Issue a READ if B_CACHE is not set. In special-append
1088 * mode, B_CACHE is based on the buffer prior to the write
1089 * op and is typically set, avoiding the read. If a read
1090 * is required in special append mode, the server will
1091 * probably send us a short-read since we extended the file
1092 * on our end, resulting in b_resid == 0 and, thusly,
1093 * B_CACHE getting set.
1094 *
1095 * We can also avoid issuing the read if the write covers
1096 * the entire buffer. We have to make sure the buffer state
1097 * is reasonable in this case since we will not be initiating
1098 * I/O. See the comments in kern/vfs_bio.c's getblk() for
1099 * more information.
1100 *
1101 * B_CACHE may also be set due to the buffer being cached
1102 * normally.
1103 */
1104
1105 bp_cached = 1;
1106 if (on == 0 && n == bcount) {
1107 if ((bp->b_flags & B_CACHE) == 0)
1108 bp_cached = 0;
1109 bp->b_flags |= B_CACHE;
1110 bp->b_flags &= ~B_INVAL;
1111 bp->b_ioflags &= ~BIO_ERROR;
1112 }
1113
1114 if ((bp->b_flags & B_CACHE) == 0) {
1115 bp->b_iocmd = BIO_READ;
1116 vfs_busy_pages(bp, 0);
1117 error = ncl_doio(vp, bp, cred, td, 0);
1118 if (error) {
1119 brelse(bp);
1120 break;
1121 }
1122 }
1123 if (bp->b_wcred == NOCRED)
1124 bp->b_wcred = crhold(cred);
1125 mtx_lock(&np->n_mtx);
1126 np->n_flag |= NMODIFIED;
1127 mtx_unlock(&np->n_mtx);
1128
1129 /*
1130 * If dirtyend exceeds file size, chop it down. This should
1131 * not normally occur but there is an append race where it
1132 * might occur XXX, so we log it.
1133 *
1134 * If the chopping creates a reverse-indexed or degenerate
1135 * situation with dirtyoff/end, we 0 both of them.
1136 */
1137
1138 if (bp->b_dirtyend > bcount) {
1139 printf("NFS append race @%lx:%d\n",
1140 (long)bp->b_blkno * DEV_BSIZE,
1141 bp->b_dirtyend - bcount);
1142 bp->b_dirtyend = bcount;
1143 }
1144
1145 if (bp->b_dirtyoff >= bp->b_dirtyend)
1146 bp->b_dirtyoff = bp->b_dirtyend = 0;
1147
1148 /*
1149 * If the new write will leave a contiguous dirty
1150 * area, just update the b_dirtyoff and b_dirtyend,
1151 * otherwise force a write rpc of the old dirty area.
1152 *
1153 * If there has been a file lock applied to this file
1154 * or vfs.nfs.old_noncontig_writing is set, do the following:
1155 * While it is possible to merge discontiguous writes due to
1156 * our having a B_CACHE buffer ( and thus valid read data
1157 * for the hole), we don't because it could lead to
1158 * significant cache coherency problems with multiple clients,
1159 * especially if locking is implemented later on.
1160 *
1161 * If vfs.nfs.old_noncontig_writing is not set and there has
1162 * not been file locking done on this file:
1163 * Relax coherency a bit for the sake of performance and
1164 * expand the current dirty region to contain the new
1165 * write even if it means we mark some non-dirty data as
1166 * dirty.
1167 */
1168
1169 if (noncontig_write == 0 && bp->b_dirtyend > 0 &&
1170 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
1171 if (bwrite(bp) == EINTR) {
1172 error = EINTR;
1173 break;
1174 }
1175 goto again;
1176 }
1177
1178 local_resid = uio->uio_resid;
1179 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio);
1180
1181 if (error != 0 && !bp_cached) {
1182 /*
1183 * This block has no other content then what
1184 * possibly was written by the faulty uiomove.
1185 * Release it, forgetting the data pages, to
1186 * prevent the leak of uninitialized data to
1187 * usermode.
1188 */
1189 bp->b_ioflags |= BIO_ERROR;
1190 brelse(bp);
1191 uio->uio_offset -= local_resid - uio->uio_resid;
1192 uio->uio_resid = local_resid;
1193 break;
1194 }
1195
1196 /*
1197 * Since this block is being modified, it must be written
1198 * again and not just committed. Since write clustering does
1199 * not work for the stage 1 data write, only the stage 2
1200 * commit rpc, we have to clear B_CLUSTEROK as well.
1201 */
1202 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1203
1204 /*
1205 * Get the partial update on the progress made from
1206 * uiomove, if an error occurred.
1207 */
1208 if (error != 0)
1209 n = local_resid - uio->uio_resid;
1210
1211 /*
1212 * Only update dirtyoff/dirtyend if not a degenerate
1213 * condition.
1214 */
1215 if (n > 0) {
1216 if (bp->b_dirtyend > 0) {
1217 bp->b_dirtyoff = min(on, bp->b_dirtyoff);
1218 bp->b_dirtyend = max((on + n), bp->b_dirtyend);
1219 } else {
1220 bp->b_dirtyoff = on;
1221 bp->b_dirtyend = on + n;
1222 }
1223 vfs_bio_set_valid(bp, on, n);
1224 }
1225
1226 /*
1227 * If IO_SYNC do bwrite().
1228 *
1229 * IO_INVAL appears to be unused. The idea appears to be
1230 * to turn off caching in this case. Very odd. XXX
1231 */
1232 if ((ioflag & IO_SYNC)) {
1233 if (ioflag & IO_INVAL)
1234 bp->b_flags |= B_NOCACHE;
1235 error1 = bwrite(bp);
1236 if (error1 != 0) {
1237 if (error == 0)
1238 error = error1;
1239 break;
1240 }
1241 } else if ((n + on) == biosize || (ioflag & IO_ASYNC) != 0) {
1242 bp->b_flags |= B_ASYNC;
1243 (void) ncl_writebp(bp, 0, NULL);
1244 } else {
1245 bdwrite(bp);
1246 }
1247
1248 if (error != 0)
1249 break;
1250 } while (uio->uio_resid > 0 && n > 0);
1251
1252 if (error != 0) {
1253 if (ioflag & IO_UNIT) {
1254 VATTR_NULL(&vattr);
1255 vattr.va_size = orig_size;
1256 /* IO_SYNC is handled implicitely */
1257 (void)VOP_SETATTR(vp, &vattr, cred);
1258 uio->uio_offset -= orig_resid - uio->uio_resid;
1259 uio->uio_resid = orig_resid;
1260 }
1261 }
1262
1263 return (error);
1264 }
1265
1266 /*
1267 * Get an nfs cache block.
1268 *
1269 * Allocate a new one if the block isn't currently in the cache
1270 * and return the block marked busy. If the calling process is
1271 * interrupted by a signal for an interruptible mount point, return
1272 * NULL.
1273 *
1274 * The caller must carefully deal with the possible B_INVAL state of
1275 * the buffer. ncl_doio() clears B_INVAL (and ncl_asyncio() clears it
1276 * indirectly), so synchronous reads can be issued without worrying about
1277 * the B_INVAL state. We have to be a little more careful when dealing
1278 * with writes (see comments in nfs_write()) when extending a file past
1279 * its EOF.
1280 */
1281 static struct buf *
1282 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
1283 {
1284 struct buf *bp;
1285 struct mount *mp;
1286 struct nfsmount *nmp;
1287
1288 mp = vp->v_mount;
1289 nmp = VFSTONFS(mp);
1290
1291 if (nmp->nm_flag & NFSMNT_INT) {
1292 sigset_t oldset;
1293
1294 newnfs_set_sigmask(td, &oldset);
1295 bp = getblk(vp, bn, size, PCATCH, 0, 0);
1296 newnfs_restore_sigmask(td, &oldset);
1297 while (bp == NULL) {
1298 if (newnfs_sigintr(nmp, td))
1299 return (NULL);
1300 bp = getblk(vp, bn, size, 0, 2 * hz, 0);
1301 }
1302 } else {
1303 bp = getblk(vp, bn, size, 0, 0, 0);
1304 }
1305
1306 if (vp->v_type == VREG)
1307 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE);
1308 return (bp);
1309 }
1310
1311 /*
1312 * Flush and invalidate all dirty buffers. If another process is already
1313 * doing the flush, just wait for completion.
1314 */
1315 int
1316 ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg)
1317 {
1318 struct nfsnode *np = VTONFS(vp);
1319 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
1320 int error = 0, slpflag, slptimeo;
1321 bool old_lock;
1322
1323 ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf");
1324
1325 if ((nmp->nm_flag & NFSMNT_INT) == 0)
1326 intrflg = 0;
1327 if (NFSCL_FORCEDISM(nmp->nm_mountp))
1328 intrflg = 1;
1329 if (intrflg) {
1330 slpflag = PCATCH;
1331 slptimeo = 2 * hz;
1332 } else {
1333 slpflag = 0;
1334 slptimeo = 0;
1335 }
1336
1337 old_lock = ncl_excl_start(vp);
1338 if (old_lock)
1339 flags |= V_ALLOWCLEAN;
1340
1341 /*
1342 * Now, flush as required.
1343 */
1344 if ((flags & (V_SAVE | V_VMIO)) == V_SAVE &&
1345 vp->v_bufobj.bo_object != NULL) {
1346 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object);
1347 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
1348 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object);
1349 /*
1350 * If the page clean was interrupted, fail the invalidation.
1351 * Not doing so, we run the risk of losing dirty pages in the
1352 * vinvalbuf() call below.
1353 */
1354 if (intrflg && (error = newnfs_sigintr(nmp, td)))
1355 goto out;
1356 }
1357
1358 error = vinvalbuf(vp, flags, slpflag, 0);
1359 while (error) {
1360 if (intrflg && (error = newnfs_sigintr(nmp, td)))
1361 goto out;
1362 error = vinvalbuf(vp, flags, 0, slptimeo);
1363 }
1364 if (NFSHASPNFS(nmp)) {
1365 nfscl_layoutcommit(vp, td);
1366 /*
1367 * Invalidate the attribute cache, since writes to a DS
1368 * won't update the size attribute.
1369 */
1370 mtx_lock(&np->n_mtx);
1371 np->n_attrstamp = 0;
1372 } else
1373 mtx_lock(&np->n_mtx);
1374 if (np->n_directio_asyncwr == 0)
1375 np->n_flag &= ~NMODIFIED;
1376 mtx_unlock(&np->n_mtx);
1377 out:
1378 ncl_excl_finish(vp, old_lock);
1379 return error;
1380 }
1381
1382 /*
1383 * Initiate asynchronous I/O. Return an error if no nfsiods are available.
1384 * This is mainly to avoid queueing async I/O requests when the nfsiods
1385 * are all hung on a dead server.
1386 *
1387 * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
1388 * is eventually dequeued by the async daemon, ncl_doio() *will*.
1389 */
1390 int
1391 ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
1392 {
1393 int iod;
1394 int gotiod;
1395 int slpflag = 0;
1396 int slptimeo = 0;
1397 int error, error2;
1398
1399 /*
1400 * Commits are usually short and sweet so lets save some cpu and
1401 * leave the async daemons for more important rpc's (such as reads
1402 * and writes).
1403 *
1404 * Readdirplus RPCs do vget()s to acquire the vnodes for entries
1405 * in the directory in order to update attributes. This can deadlock
1406 * with another thread that is waiting for async I/O to be done by
1407 * an nfsiod thread while holding a lock on one of these vnodes.
1408 * To avoid this deadlock, don't allow the async nfsiod threads to
1409 * perform Readdirplus RPCs.
1410 */
1411 mtx_lock(&ncl_iod_mutex);
1412 if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
1413 (nmp->nm_bufqiods > ncl_numasync / 2)) ||
1414 (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) {
1415 mtx_unlock(&ncl_iod_mutex);
1416 return(EIO);
1417 }
1418 again:
1419 if (nmp->nm_flag & NFSMNT_INT)
1420 slpflag = PCATCH;
1421 gotiod = FALSE;
1422
1423 /*
1424 * Find a free iod to process this request.
1425 */
1426 for (iod = 0; iod < ncl_numasync; iod++)
1427 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) {
1428 gotiod = TRUE;
1429 break;
1430 }
1431
1432 /*
1433 * Try to create one if none are free.
1434 */
1435 if (!gotiod)
1436 ncl_nfsiodnew();
1437 else {
1438 /*
1439 * Found one, so wake it up and tell it which
1440 * mount to process.
1441 */
1442 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n",
1443 iod, nmp));
1444 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE;
1445 ncl_iodmount[iod] = nmp;
1446 nmp->nm_bufqiods++;
1447 wakeup(&ncl_iodwant[iod]);
1448 }
1449
1450 /*
1451 * If none are free, we may already have an iod working on this mount
1452 * point. If so, it will process our request.
1453 */
1454 if (!gotiod) {
1455 if (nmp->nm_bufqiods > 0) {
1456 NFS_DPF(ASYNCIO,
1457 ("ncl_asyncio: %d iods are already processing mount %p\n",
1458 nmp->nm_bufqiods, nmp));
1459 gotiod = TRUE;
1460 }
1461 }
1462
1463 /*
1464 * If we have an iod which can process the request, then queue
1465 * the buffer.
1466 */
1467 if (gotiod) {
1468 /*
1469 * Ensure that the queue never grows too large. We still want
1470 * to asynchronize so we block rather then return EIO.
1471 */
1472 while (nmp->nm_bufqlen >= 2*ncl_numasync) {
1473 NFS_DPF(ASYNCIO,
1474 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp));
1475 nmp->nm_bufqwant = TRUE;
1476 error = newnfs_msleep(td, &nmp->nm_bufq,
1477 &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio",
1478 slptimeo);
1479 if (error) {
1480 error2 = newnfs_sigintr(nmp, td);
1481 if (error2) {
1482 mtx_unlock(&ncl_iod_mutex);
1483 return (error2);
1484 }
1485 if (slpflag == PCATCH) {
1486 slpflag = 0;
1487 slptimeo = 2 * hz;
1488 }
1489 }
1490 /*
1491 * We might have lost our iod while sleeping,
1492 * so check and loop if necessary.
1493 */
1494 goto again;
1495 }
1496
1497 /* We might have lost our nfsiod */
1498 if (nmp->nm_bufqiods == 0) {
1499 NFS_DPF(ASYNCIO,
1500 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
1501 goto again;
1502 }
1503
1504 if (bp->b_iocmd == BIO_READ) {
1505 if (bp->b_rcred == NOCRED && cred != NOCRED)
1506 bp->b_rcred = crhold(cred);
1507 } else {
1508 if (bp->b_wcred == NOCRED && cred != NOCRED)
1509 bp->b_wcred = crhold(cred);
1510 }
1511
1512 if (bp->b_flags & B_REMFREE)
1513 bremfreef(bp);
1514 BUF_KERNPROC(bp);
1515 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
1516 nmp->nm_bufqlen++;
1517 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1518 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx);
1519 VTONFS(bp->b_vp)->n_flag |= NMODIFIED;
1520 VTONFS(bp->b_vp)->n_directio_asyncwr++;
1521 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx);
1522 }
1523 mtx_unlock(&ncl_iod_mutex);
1524 return (0);
1525 }
1526
1527 mtx_unlock(&ncl_iod_mutex);
1528
1529 /*
1530 * All the iods are busy on other mounts, so return EIO to
1531 * force the caller to process the i/o synchronously.
1532 */
1533 NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n"));
1534 return (EIO);
1535 }
1536
1537 void
1538 ncl_doio_directwrite(struct buf *bp)
1539 {
1540 int iomode, must_commit;
1541 struct uio *uiop = (struct uio *)bp->b_caller1;
1542 char *iov_base = uiop->uio_iov->iov_base;
1543
1544 iomode = NFSWRITE_FILESYNC;
1545 uiop->uio_td = NULL; /* NULL since we're in nfsiod */
1546 ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0);
1547 KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write"));
1548 free(iov_base, M_NFSDIRECTIO);
1549 free(uiop->uio_iov, M_NFSDIRECTIO);
1550 free(uiop, M_NFSDIRECTIO);
1551 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1552 struct nfsnode *np = VTONFS(bp->b_vp);
1553 mtx_lock(&np->n_mtx);
1554 if (NFSHASPNFS(VFSTONFS(vnode_mount(bp->b_vp)))) {
1555 /*
1556 * Invalidate the attribute cache, since writes to a DS
1557 * won't update the size attribute.
1558 */
1559 np->n_attrstamp = 0;
1560 }
1561 np->n_directio_asyncwr--;
1562 if (np->n_directio_asyncwr == 0) {
1563 np->n_flag &= ~NMODIFIED;
1564 if ((np->n_flag & NFSYNCWAIT)) {
1565 np->n_flag &= ~NFSYNCWAIT;
1566 wakeup((caddr_t)&np->n_directio_asyncwr);
1567 }
1568 }
1569 mtx_unlock(&np->n_mtx);
1570 }
1571 bp->b_vp = NULL;
1572 relpbuf(bp, &ncl_pbuf_freecnt);
1573 }
1574
1575 /*
1576 * Do an I/O operation to/from a cache block. This may be called
1577 * synchronously or from an nfsiod.
1578 */
1579 int
1580 ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td,
1581 int called_from_strategy)
1582 {
1583 struct uio *uiop;
1584 struct nfsnode *np;
1585 struct nfsmount *nmp;
1586 int error = 0, iomode, must_commit = 0;
1587 struct uio uio;
1588 struct iovec io;
1589 struct proc *p = td ? td->td_proc : NULL;
1590 uint8_t iocmd;
1591
1592 np = VTONFS(vp);
1593 nmp = VFSTONFS(vp->v_mount);
1594 uiop = &uio;
1595 uiop->uio_iov = &io;
1596 uiop->uio_iovcnt = 1;
1597 uiop->uio_segflg = UIO_SYSSPACE;
1598 uiop->uio_td = td;
1599
1600 /*
1601 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
1602 * do this here so we do not have to do it in all the code that
1603 * calls us.
1604 */
1605 bp->b_flags &= ~B_INVAL;
1606 bp->b_ioflags &= ~BIO_ERROR;
1607
1608 KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp));
1609 iocmd = bp->b_iocmd;
1610 if (iocmd == BIO_READ) {
1611 io.iov_len = uiop->uio_resid = bp->b_bcount;
1612 io.iov_base = bp->b_data;
1613 uiop->uio_rw = UIO_READ;
1614
1615 switch (vp->v_type) {
1616 case VREG:
1617 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
1618 NFSINCRGLOBAL(nfsstatsv1.read_bios);
1619 error = ncl_readrpc(vp, uiop, cr);
1620
1621 if (!error) {
1622 if (uiop->uio_resid) {
1623 /*
1624 * If we had a short read with no error, we must have
1625 * hit a file hole. We should zero-fill the remainder.
1626 * This can also occur if the server hits the file EOF.
1627 *
1628 * Holes used to be able to occur due to pending
1629 * writes, but that is not possible any longer.
1630 */
1631 int nread = bp->b_bcount - uiop->uio_resid;
1632 ssize_t left = uiop->uio_resid;
1633
1634 if (left > 0)
1635 bzero((char *)bp->b_data + nread, left);
1636 uiop->uio_resid = 0;
1637 }
1638 }
1639 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */
1640 if (p && (vp->v_vflag & VV_TEXT)) {
1641 mtx_lock(&np->n_mtx);
1642 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) {
1643 mtx_unlock(&np->n_mtx);
1644 PROC_LOCK(p);
1645 killproc(p, "text file modification");
1646 PROC_UNLOCK(p);
1647 } else
1648 mtx_unlock(&np->n_mtx);
1649 }
1650 break;
1651 case VLNK:
1652 uiop->uio_offset = (off_t)0;
1653 NFSINCRGLOBAL(nfsstatsv1.readlink_bios);
1654 error = ncl_readlinkrpc(vp, uiop, cr);
1655 break;
1656 case VDIR:
1657 NFSINCRGLOBAL(nfsstatsv1.readdir_bios);
1658 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
1659 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
1660 error = ncl_readdirplusrpc(vp, uiop, cr, td);
1661 if (error == NFSERR_NOTSUPP)
1662 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
1663 }
1664 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
1665 error = ncl_readdirrpc(vp, uiop, cr, td);
1666 /*
1667 * end-of-directory sets B_INVAL but does not generate an
1668 * error.
1669 */
1670 if (error == 0 && uiop->uio_resid == bp->b_bcount)
1671 bp->b_flags |= B_INVAL;
1672 break;
1673 default:
1674 printf("ncl_doio: type %x unexpected\n", vp->v_type);
1675 break;
1676 }
1677 if (error) {
1678 bp->b_ioflags |= BIO_ERROR;
1679 bp->b_error = error;
1680 }
1681 } else {
1682 /*
1683 * If we only need to commit, try to commit
1684 */
1685 if (bp->b_flags & B_NEEDCOMMIT) {
1686 int retv;
1687 off_t off;
1688
1689 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
1690 retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff,
1691 bp->b_wcred, td);
1692 if (retv == 0) {
1693 bp->b_dirtyoff = bp->b_dirtyend = 0;
1694 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1695 bp->b_resid = 0;
1696 bufdone(bp);
1697 return (0);
1698 }
1699 if (retv == NFSERR_STALEWRITEVERF) {
1700 ncl_clearcommit(vp->v_mount);
1701 }
1702 }
1703
1704 /*
1705 * Setup for actual write
1706 */
1707 mtx_lock(&np->n_mtx);
1708 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
1709 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
1710 mtx_unlock(&np->n_mtx);
1711
1712 if (bp->b_dirtyend > bp->b_dirtyoff) {
1713 io.iov_len = uiop->uio_resid = bp->b_dirtyend
1714 - bp->b_dirtyoff;
1715 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
1716 + bp->b_dirtyoff;
1717 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
1718 uiop->uio_rw = UIO_WRITE;
1719 NFSINCRGLOBAL(nfsstatsv1.write_bios);
1720
1721 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
1722 iomode = NFSWRITE_UNSTABLE;
1723 else
1724 iomode = NFSWRITE_FILESYNC;
1725
1726 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit,
1727 called_from_strategy);
1728
1729 /*
1730 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
1731 * to cluster the buffers needing commit. This will allow
1732 * the system to submit a single commit rpc for the whole
1733 * cluster. We can do this even if the buffer is not 100%
1734 * dirty (relative to the NFS blocksize), so we optimize the
1735 * append-to-file-case.
1736 *
1737 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
1738 * cleared because write clustering only works for commit
1739 * rpc's, not for the data portion of the write).
1740 */
1741
1742 if (!error && iomode == NFSWRITE_UNSTABLE) {
1743 bp->b_flags |= B_NEEDCOMMIT;
1744 if (bp->b_dirtyoff == 0
1745 && bp->b_dirtyend == bp->b_bcount)
1746 bp->b_flags |= B_CLUSTEROK;
1747 } else {
1748 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1749 }
1750
1751 /*
1752 * For an interrupted write, the buffer is still valid
1753 * and the write hasn't been pushed to the server yet,
1754 * so we can't set BIO_ERROR and report the interruption
1755 * by setting B_EINTR. For the B_ASYNC case, B_EINTR
1756 * is not relevant, so the rpc attempt is essentially
1757 * a noop. For the case of a V3 write rpc not being
1758 * committed to stable storage, the block is still
1759 * dirty and requires either a commit rpc or another
1760 * write rpc with iomode == NFSV3WRITE_FILESYNC before
1761 * the block is reused. This is indicated by setting
1762 * the B_DELWRI and B_NEEDCOMMIT flags.
1763 *
1764 * EIO is returned by ncl_writerpc() to indicate a recoverable
1765 * write error and is handled as above, except that
1766 * B_EINTR isn't set. One cause of this is a stale stateid
1767 * error for the RPC that indicates recovery is required,
1768 * when called with called_from_strategy != 0.
1769 *
1770 * If the buffer is marked B_PAGING, it does not reside on
1771 * the vp's paging queues so we cannot call bdirty(). The
1772 * bp in this case is not an NFS cache block so we should
1773 * be safe. XXX
1774 *
1775 * The logic below breaks up errors into recoverable and
1776 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE
1777 * and keep the buffer around for potential write retries.
1778 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL)
1779 * and save the error in the nfsnode. This is less than ideal
1780 * but necessary. Keeping such buffers around could potentially
1781 * cause buffer exhaustion eventually (they can never be written
1782 * out, so will get constantly be re-dirtied). It also causes
1783 * all sorts of vfs panics. For non-recoverable write errors,
1784 * also invalidate the attrcache, so we'll be forced to go over
1785 * the wire for this object, returning an error to user on next
1786 * call (most of the time).
1787 */
1788 if (error == EINTR || error == EIO || error == ETIMEDOUT
1789 || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
1790 bp->b_flags &= ~(B_INVAL|B_NOCACHE);
1791 if ((bp->b_flags & B_PAGING) == 0) {
1792 bdirty(bp);
1793 bp->b_flags &= ~B_DONE;
1794 }
1795 if ((error == EINTR || error == ETIMEDOUT) &&
1796 (bp->b_flags & B_ASYNC) == 0)
1797 bp->b_flags |= B_EINTR;
1798 } else {
1799 if (error) {
1800 bp->b_ioflags |= BIO_ERROR;
1801 bp->b_flags |= B_INVAL;
1802 bp->b_error = np->n_error = error;
1803 mtx_lock(&np->n_mtx);
1804 np->n_flag |= NWRITEERR;
1805 np->n_attrstamp = 0;
1806 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
1807 mtx_unlock(&np->n_mtx);
1808 }
1809 bp->b_dirtyoff = bp->b_dirtyend = 0;
1810 }
1811 } else {
1812 bp->b_resid = 0;
1813 bufdone(bp);
1814 return (0);
1815 }
1816 }
1817 bp->b_resid = uiop->uio_resid;
1818 if (must_commit)
1819 ncl_clearcommit(vp->v_mount);
1820 bufdone(bp);
1821 return (error);
1822 }
1823
1824 /*
1825 * Used to aid in handling ftruncate() operations on the NFS client side.
1826 * Truncation creates a number of special problems for NFS. We have to
1827 * throw away VM pages and buffer cache buffers that are beyond EOF, and
1828 * we have to properly handle VM pages or (potentially dirty) buffers
1829 * that straddle the truncation point.
1830 */
1831
1832 int
1833 ncl_meta_setsize(struct vnode *vp, struct thread *td, u_quad_t nsize)
1834 {
1835 struct nfsnode *np = VTONFS(vp);
1836 u_quad_t tsize;
1837 int biosize = vp->v_bufobj.bo_bsize;
1838 int error = 0;
1839
1840 mtx_lock(&np->n_mtx);
1841 tsize = np->n_size;
1842 np->n_size = nsize;
1843 mtx_unlock(&np->n_mtx);
1844
1845 if (nsize < tsize) {
1846 struct buf *bp;
1847 daddr_t lbn;
1848 int bufsize;
1849
1850 /*
1851 * vtruncbuf() doesn't get the buffer overlapping the
1852 * truncation point. We may have a B_DELWRI and/or B_CACHE
1853 * buffer that now needs to be truncated.
1854 */
1855 error = vtruncbuf(vp, nsize, biosize);
1856 lbn = nsize / biosize;
1857 bufsize = nsize - (lbn * biosize);
1858 bp = nfs_getcacheblk(vp, lbn, bufsize, td);
1859 if (!bp)
1860 return EINTR;
1861 if (bp->b_dirtyoff > bp->b_bcount)
1862 bp->b_dirtyoff = bp->b_bcount;
1863 if (bp->b_dirtyend > bp->b_bcount)
1864 bp->b_dirtyend = bp->b_bcount;
1865 bp->b_flags |= B_RELBUF; /* don't leave garbage around */
1866 brelse(bp);
1867 } else {
1868 vnode_pager_setsize(vp, nsize);
1869 }
1870 return(error);
1871 }
1872
Cache object: 33080f36241dfc025732acd4f3d7f026
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