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: releng/11.0/sys/fs/nfsclient/nfs_clbio.c 303909 2016-08-10 12:53:30Z kib $");
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 nfsstats newnfsstats;
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 int
82 ncl_getpages(struct vop_getpages_args *ap)
83 {
84 int i, error, nextoff, size, toff, count, npages;
85 struct uio uio;
86 struct iovec iov;
87 vm_offset_t kva;
88 struct buf *bp;
89 struct vnode *vp;
90 struct thread *td;
91 struct ucred *cred;
92 struct nfsmount *nmp;
93 vm_object_t object;
94 vm_page_t *pages;
95 struct nfsnode *np;
96
97 vp = ap->a_vp;
98 np = VTONFS(vp);
99 td = curthread; /* XXX */
100 cred = curthread->td_ucred; /* XXX */
101 nmp = VFSTONFS(vp->v_mount);
102 pages = ap->a_m;
103 npages = ap->a_count;
104
105 if ((object = vp->v_object) == NULL) {
106 printf("ncl_getpages: called with non-merged cache vnode\n");
107 return (VM_PAGER_ERROR);
108 }
109
110 if (newnfs_directio_enable && !newnfs_directio_allow_mmap) {
111 mtx_lock(&np->n_mtx);
112 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
113 mtx_unlock(&np->n_mtx);
114 printf("ncl_getpages: called on non-cacheable vnode\n");
115 return (VM_PAGER_ERROR);
116 } else
117 mtx_unlock(&np->n_mtx);
118 }
119
120 mtx_lock(&nmp->nm_mtx);
121 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
122 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
123 mtx_unlock(&nmp->nm_mtx);
124 /* We'll never get here for v4, because we always have fsinfo */
125 (void)ncl_fsinfo(nmp, vp, cred, td);
126 } else
127 mtx_unlock(&nmp->nm_mtx);
128
129 /*
130 * If the requested page is partially valid, just return it and
131 * allow the pager to zero-out the blanks. Partially valid pages
132 * can only occur at the file EOF.
133 *
134 * XXXGL: is that true for NFS, where short read can occur???
135 */
136 VM_OBJECT_WLOCK(object);
137 if (pages[npages - 1]->valid != 0 && --npages == 0)
138 goto out;
139 VM_OBJECT_WUNLOCK(object);
140
141 /*
142 * We use only the kva address for the buffer, but this is extremely
143 * convenient and fast.
144 */
145 bp = getpbuf(&ncl_pbuf_freecnt);
146
147 kva = (vm_offset_t) bp->b_data;
148 pmap_qenter(kva, pages, npages);
149 PCPU_INC(cnt.v_vnodein);
150 PCPU_ADD(cnt.v_vnodepgsin, npages);
151
152 count = npages << PAGE_SHIFT;
153 iov.iov_base = (caddr_t) kva;
154 iov.iov_len = count;
155 uio.uio_iov = &iov;
156 uio.uio_iovcnt = 1;
157 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
158 uio.uio_resid = count;
159 uio.uio_segflg = UIO_SYSSPACE;
160 uio.uio_rw = UIO_READ;
161 uio.uio_td = td;
162
163 error = ncl_readrpc(vp, &uio, cred);
164 pmap_qremove(kva, npages);
165
166 relpbuf(bp, &ncl_pbuf_freecnt);
167
168 if (error && (uio.uio_resid == count)) {
169 printf("ncl_getpages: error %d\n", error);
170 return (VM_PAGER_ERROR);
171 }
172
173 /*
174 * Calculate the number of bytes read and validate only that number
175 * of bytes. Note that due to pending writes, size may be 0. This
176 * does not mean that the remaining data is invalid!
177 */
178
179 size = count - uio.uio_resid;
180 VM_OBJECT_WLOCK(object);
181 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
182 vm_page_t m;
183 nextoff = toff + PAGE_SIZE;
184 m = pages[i];
185
186 if (nextoff <= size) {
187 /*
188 * Read operation filled an entire page
189 */
190 m->valid = VM_PAGE_BITS_ALL;
191 KASSERT(m->dirty == 0,
192 ("nfs_getpages: page %p is dirty", m));
193 } else if (size > toff) {
194 /*
195 * Read operation filled a partial page.
196 */
197 m->valid = 0;
198 vm_page_set_valid_range(m, 0, size - toff);
199 KASSERT(m->dirty == 0,
200 ("nfs_getpages: page %p is dirty", m));
201 } else {
202 /*
203 * Read operation was short. If no error
204 * occurred we may have hit a zero-fill
205 * section. We leave valid set to 0, and page
206 * is freed by vm_page_readahead_finish() if
207 * its index is not equal to requested, or
208 * page is zeroed and set valid by
209 * vm_pager_get_pages() for requested page.
210 */
211 ;
212 }
213 }
214 out:
215 VM_OBJECT_WUNLOCK(object);
216 if (ap->a_rbehind)
217 *ap->a_rbehind = 0;
218 if (ap->a_rahead)
219 *ap->a_rahead = 0;
220 return (VM_PAGER_OK);
221 }
222
223 /*
224 * Vnode op for VM putpages.
225 */
226 int
227 ncl_putpages(struct vop_putpages_args *ap)
228 {
229 struct uio uio;
230 struct iovec iov;
231 vm_offset_t kva;
232 struct buf *bp;
233 int iomode, must_commit, i, error, npages, count;
234 off_t offset;
235 int *rtvals;
236 struct vnode *vp;
237 struct thread *td;
238 struct ucred *cred;
239 struct nfsmount *nmp;
240 struct nfsnode *np;
241 vm_page_t *pages;
242
243 vp = ap->a_vp;
244 np = VTONFS(vp);
245 td = curthread; /* XXX */
246 /* Set the cred to n_writecred for the write rpcs. */
247 if (np->n_writecred != NULL)
248 cred = crhold(np->n_writecred);
249 else
250 cred = crhold(curthread->td_ucred); /* XXX */
251 nmp = VFSTONFS(vp->v_mount);
252 pages = ap->a_m;
253 count = ap->a_count;
254 rtvals = ap->a_rtvals;
255 npages = btoc(count);
256 offset = IDX_TO_OFF(pages[0]->pindex);
257
258 mtx_lock(&nmp->nm_mtx);
259 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
260 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
261 mtx_unlock(&nmp->nm_mtx);
262 (void)ncl_fsinfo(nmp, vp, cred, td);
263 } else
264 mtx_unlock(&nmp->nm_mtx);
265
266 mtx_lock(&np->n_mtx);
267 if (newnfs_directio_enable && !newnfs_directio_allow_mmap &&
268 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
269 mtx_unlock(&np->n_mtx);
270 printf("ncl_putpages: called on noncache-able vnode\n");
271 mtx_lock(&np->n_mtx);
272 }
273
274 for (i = 0; i < npages; i++)
275 rtvals[i] = VM_PAGER_ERROR;
276
277 /*
278 * When putting pages, do not extend file past EOF.
279 */
280 if (offset + count > np->n_size) {
281 count = np->n_size - offset;
282 if (count < 0)
283 count = 0;
284 }
285 mtx_unlock(&np->n_mtx);
286
287 /*
288 * We use only the kva address for the buffer, but this is extremely
289 * convenient and fast.
290 */
291 bp = getpbuf(&ncl_pbuf_freecnt);
292
293 kva = (vm_offset_t) bp->b_data;
294 pmap_qenter(kva, pages, npages);
295 PCPU_INC(cnt.v_vnodeout);
296 PCPU_ADD(cnt.v_vnodepgsout, count);
297
298 iov.iov_base = (caddr_t) kva;
299 iov.iov_len = count;
300 uio.uio_iov = &iov;
301 uio.uio_iovcnt = 1;
302 uio.uio_offset = offset;
303 uio.uio_resid = count;
304 uio.uio_segflg = UIO_SYSSPACE;
305 uio.uio_rw = UIO_WRITE;
306 uio.uio_td = td;
307
308 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0)
309 iomode = NFSWRITE_UNSTABLE;
310 else
311 iomode = NFSWRITE_FILESYNC;
312
313 error = ncl_writerpc(vp, &uio, cred, &iomode, &must_commit, 0);
314 crfree(cred);
315
316 pmap_qremove(kva, npages);
317 relpbuf(bp, &ncl_pbuf_freecnt);
318
319 if (error == 0 || !nfs_keep_dirty_on_error) {
320 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid);
321 if (must_commit)
322 ncl_clearcommit(vp->v_mount);
323 }
324 return rtvals[0];
325 }
326
327 /*
328 * For nfs, cache consistency can only be maintained approximately.
329 * Although RFC1094 does not specify the criteria, the following is
330 * believed to be compatible with the reference port.
331 * For nfs:
332 * If the file's modify time on the server has changed since the
333 * last read rpc or you have written to the file,
334 * you may have lost data cache consistency with the
335 * server, so flush all of the file's data out of the cache.
336 * Then force a getattr rpc to ensure that you have up to date
337 * attributes.
338 * NB: This implies that cache data can be read when up to
339 * NFS_ATTRTIMEO seconds out of date. If you find that you need current
340 * attributes this could be forced by setting n_attrstamp to 0 before
341 * the VOP_GETATTR() call.
342 */
343 static inline int
344 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred)
345 {
346 int error = 0;
347 struct vattr vattr;
348 struct nfsnode *np = VTONFS(vp);
349 int old_lock;
350
351 /*
352 * Grab the exclusive lock before checking whether the cache is
353 * consistent.
354 * XXX - We can make this cheaper later (by acquiring cheaper locks).
355 * But for now, this suffices.
356 */
357 old_lock = ncl_upgrade_vnlock(vp);
358 if (vp->v_iflag & VI_DOOMED) {
359 ncl_downgrade_vnlock(vp, old_lock);
360 return (EBADF);
361 }
362
363 mtx_lock(&np->n_mtx);
364 if (np->n_flag & NMODIFIED) {
365 mtx_unlock(&np->n_mtx);
366 if (vp->v_type != VREG) {
367 if (vp->v_type != VDIR)
368 panic("nfs: bioread, not dir");
369 ncl_invaldir(vp);
370 error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
371 if (error)
372 goto out;
373 }
374 np->n_attrstamp = 0;
375 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
376 error = VOP_GETATTR(vp, &vattr, cred);
377 if (error)
378 goto out;
379 mtx_lock(&np->n_mtx);
380 np->n_mtime = vattr.va_mtime;
381 mtx_unlock(&np->n_mtx);
382 } else {
383 mtx_unlock(&np->n_mtx);
384 error = VOP_GETATTR(vp, &vattr, cred);
385 if (error)
386 return (error);
387 mtx_lock(&np->n_mtx);
388 if ((np->n_flag & NSIZECHANGED)
389 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
390 mtx_unlock(&np->n_mtx);
391 if (vp->v_type == VDIR)
392 ncl_invaldir(vp);
393 error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
394 if (error)
395 goto out;
396 mtx_lock(&np->n_mtx);
397 np->n_mtime = vattr.va_mtime;
398 np->n_flag &= ~NSIZECHANGED;
399 }
400 mtx_unlock(&np->n_mtx);
401 }
402 out:
403 ncl_downgrade_vnlock(vp, old_lock);
404 return error;
405 }
406
407 /*
408 * Vnode op for read using bio
409 */
410 int
411 ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
412 {
413 struct nfsnode *np = VTONFS(vp);
414 int biosize, i;
415 struct buf *bp, *rabp;
416 struct thread *td;
417 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
418 daddr_t lbn, rabn;
419 int bcount;
420 int seqcount;
421 int nra, error = 0, n = 0, on = 0;
422 off_t tmp_off;
423
424 KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode"));
425 if (uio->uio_resid == 0)
426 return (0);
427 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */
428 return (EINVAL);
429 td = uio->uio_td;
430
431 mtx_lock(&nmp->nm_mtx);
432 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
433 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
434 mtx_unlock(&nmp->nm_mtx);
435 (void)ncl_fsinfo(nmp, vp, cred, td);
436 mtx_lock(&nmp->nm_mtx);
437 }
438 if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0)
439 (void) newnfs_iosize(nmp);
440
441 tmp_off = uio->uio_offset + uio->uio_resid;
442 if (vp->v_type != VDIR &&
443 (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) {
444 mtx_unlock(&nmp->nm_mtx);
445 return (EFBIG);
446 }
447 mtx_unlock(&nmp->nm_mtx);
448
449 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG))
450 /* No caching/ no readaheads. Just read data into the user buffer */
451 return ncl_readrpc(vp, uio, cred);
452
453 biosize = vp->v_bufobj.bo_bsize;
454 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE);
455
456 error = nfs_bioread_check_cons(vp, td, cred);
457 if (error)
458 return error;
459
460 do {
461 u_quad_t nsize;
462
463 mtx_lock(&np->n_mtx);
464 nsize = np->n_size;
465 mtx_unlock(&np->n_mtx);
466
467 switch (vp->v_type) {
468 case VREG:
469 NFSINCRGLOBAL(newnfsstats.biocache_reads);
470 lbn = uio->uio_offset / biosize;
471 on = uio->uio_offset - (lbn * biosize);
472
473 /*
474 * Start the read ahead(s), as required.
475 */
476 if (nmp->nm_readahead > 0) {
477 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
478 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) {
479 rabn = lbn + 1 + nra;
480 if (incore(&vp->v_bufobj, rabn) == NULL) {
481 rabp = nfs_getcacheblk(vp, rabn, biosize, td);
482 if (!rabp) {
483 error = newnfs_sigintr(nmp, td);
484 return (error ? error : EINTR);
485 }
486 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
487 rabp->b_flags |= B_ASYNC;
488 rabp->b_iocmd = BIO_READ;
489 vfs_busy_pages(rabp, 0);
490 if (ncl_asyncio(nmp, rabp, cred, td)) {
491 rabp->b_flags |= B_INVAL;
492 rabp->b_ioflags |= BIO_ERROR;
493 vfs_unbusy_pages(rabp);
494 brelse(rabp);
495 break;
496 }
497 } else {
498 brelse(rabp);
499 }
500 }
501 }
502 }
503
504 /* Note that bcount is *not* DEV_BSIZE aligned. */
505 bcount = biosize;
506 if ((off_t)lbn * biosize >= nsize) {
507 bcount = 0;
508 } else if ((off_t)(lbn + 1) * biosize > nsize) {
509 bcount = nsize - (off_t)lbn * biosize;
510 }
511 bp = nfs_getcacheblk(vp, lbn, bcount, td);
512
513 if (!bp) {
514 error = newnfs_sigintr(nmp, td);
515 return (error ? error : EINTR);
516 }
517
518 /*
519 * If B_CACHE is not set, we must issue the read. If this
520 * fails, we return an error.
521 */
522
523 if ((bp->b_flags & B_CACHE) == 0) {
524 bp->b_iocmd = BIO_READ;
525 vfs_busy_pages(bp, 0);
526 error = ncl_doio(vp, bp, cred, td, 0);
527 if (error) {
528 brelse(bp);
529 return (error);
530 }
531 }
532
533 /*
534 * on is the offset into the current bp. Figure out how many
535 * bytes we can copy out of the bp. Note that bcount is
536 * NOT DEV_BSIZE aligned.
537 *
538 * Then figure out how many bytes we can copy into the uio.
539 */
540
541 n = 0;
542 if (on < bcount)
543 n = MIN((unsigned)(bcount - on), uio->uio_resid);
544 break;
545 case VLNK:
546 NFSINCRGLOBAL(newnfsstats.biocache_readlinks);
547 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
548 if (!bp) {
549 error = newnfs_sigintr(nmp, td);
550 return (error ? error : EINTR);
551 }
552 if ((bp->b_flags & B_CACHE) == 0) {
553 bp->b_iocmd = BIO_READ;
554 vfs_busy_pages(bp, 0);
555 error = ncl_doio(vp, bp, cred, td, 0);
556 if (error) {
557 bp->b_ioflags |= BIO_ERROR;
558 brelse(bp);
559 return (error);
560 }
561 }
562 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
563 on = 0;
564 break;
565 case VDIR:
566 NFSINCRGLOBAL(newnfsstats.biocache_readdirs);
567 if (np->n_direofoffset
568 && uio->uio_offset >= np->n_direofoffset) {
569 return (0);
570 }
571 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
572 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
573 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
574 if (!bp) {
575 error = newnfs_sigintr(nmp, td);
576 return (error ? error : EINTR);
577 }
578 if ((bp->b_flags & B_CACHE) == 0) {
579 bp->b_iocmd = BIO_READ;
580 vfs_busy_pages(bp, 0);
581 error = ncl_doio(vp, bp, cred, td, 0);
582 if (error) {
583 brelse(bp);
584 }
585 while (error == NFSERR_BAD_COOKIE) {
586 ncl_invaldir(vp);
587 error = ncl_vinvalbuf(vp, 0, td, 1);
588 /*
589 * Yuck! The directory has been modified on the
590 * server. The only way to get the block is by
591 * reading from the beginning to get all the
592 * offset cookies.
593 *
594 * Leave the last bp intact unless there is an error.
595 * Loop back up to the while if the error is another
596 * NFSERR_BAD_COOKIE (double yuch!).
597 */
598 for (i = 0; i <= lbn && !error; i++) {
599 if (np->n_direofoffset
600 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset)
601 return (0);
602 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
603 if (!bp) {
604 error = newnfs_sigintr(nmp, td);
605 return (error ? error : EINTR);
606 }
607 if ((bp->b_flags & B_CACHE) == 0) {
608 bp->b_iocmd = BIO_READ;
609 vfs_busy_pages(bp, 0);
610 error = ncl_doio(vp, bp, cred, td, 0);
611 /*
612 * no error + B_INVAL == directory EOF,
613 * use the block.
614 */
615 if (error == 0 && (bp->b_flags & B_INVAL))
616 break;
617 }
618 /*
619 * An error will throw away the block and the
620 * for loop will break out. If no error and this
621 * is not the block we want, we throw away the
622 * block and go for the next one via the for loop.
623 */
624 if (error || i < lbn)
625 brelse(bp);
626 }
627 }
628 /*
629 * The above while is repeated if we hit another cookie
630 * error. If we hit an error and it wasn't a cookie error,
631 * we give up.
632 */
633 if (error)
634 return (error);
635 }
636
637 /*
638 * If not eof and read aheads are enabled, start one.
639 * (You need the current block first, so that you have the
640 * directory offset cookie of the next block.)
641 */
642 if (nmp->nm_readahead > 0 &&
643 (bp->b_flags & B_INVAL) == 0 &&
644 (np->n_direofoffset == 0 ||
645 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
646 incore(&vp->v_bufobj, lbn + 1) == NULL) {
647 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
648 if (rabp) {
649 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
650 rabp->b_flags |= B_ASYNC;
651 rabp->b_iocmd = BIO_READ;
652 vfs_busy_pages(rabp, 0);
653 if (ncl_asyncio(nmp, rabp, cred, td)) {
654 rabp->b_flags |= B_INVAL;
655 rabp->b_ioflags |= BIO_ERROR;
656 vfs_unbusy_pages(rabp);
657 brelse(rabp);
658 }
659 } else {
660 brelse(rabp);
661 }
662 }
663 }
664 /*
665 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is
666 * chopped for the EOF condition, we cannot tell how large
667 * NFS directories are going to be until we hit EOF. So
668 * an NFS directory buffer is *not* chopped to its EOF. Now,
669 * it just so happens that b_resid will effectively chop it
670 * to EOF. *BUT* this information is lost if the buffer goes
671 * away and is reconstituted into a B_CACHE state ( due to
672 * being VMIO ) later. So we keep track of the directory eof
673 * in np->n_direofoffset and chop it off as an extra step
674 * right here.
675 */
676 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
677 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
678 n = np->n_direofoffset - uio->uio_offset;
679 break;
680 default:
681 printf(" ncl_bioread: type %x unexpected\n", vp->v_type);
682 bp = NULL;
683 break;
684 }
685
686 if (n > 0) {
687 error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio);
688 }
689 if (vp->v_type == VLNK)
690 n = 0;
691 if (bp != NULL)
692 brelse(bp);
693 } while (error == 0 && uio->uio_resid > 0 && n > 0);
694 return (error);
695 }
696
697 /*
698 * The NFS write path cannot handle iovecs with len > 1. So we need to
699 * break up iovecs accordingly (restricting them to wsize).
700 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf).
701 * For the ASYNC case, 2 copies are needed. The first a copy from the
702 * user buffer to a staging buffer and then a second copy from the staging
703 * buffer to mbufs. This can be optimized by copying from the user buffer
704 * directly into mbufs and passing the chain down, but that requires a
705 * fair amount of re-working of the relevant codepaths (and can be done
706 * later).
707 */
708 static int
709 nfs_directio_write(vp, uiop, cred, ioflag)
710 struct vnode *vp;
711 struct uio *uiop;
712 struct ucred *cred;
713 int ioflag;
714 {
715 int error;
716 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
717 struct thread *td = uiop->uio_td;
718 int size;
719 int wsize;
720
721 mtx_lock(&nmp->nm_mtx);
722 wsize = nmp->nm_wsize;
723 mtx_unlock(&nmp->nm_mtx);
724 if (ioflag & IO_SYNC) {
725 int iomode, must_commit;
726 struct uio uio;
727 struct iovec iov;
728 do_sync:
729 while (uiop->uio_resid > 0) {
730 size = MIN(uiop->uio_resid, wsize);
731 size = MIN(uiop->uio_iov->iov_len, size);
732 iov.iov_base = uiop->uio_iov->iov_base;
733 iov.iov_len = size;
734 uio.uio_iov = &iov;
735 uio.uio_iovcnt = 1;
736 uio.uio_offset = uiop->uio_offset;
737 uio.uio_resid = size;
738 uio.uio_segflg = UIO_USERSPACE;
739 uio.uio_rw = UIO_WRITE;
740 uio.uio_td = td;
741 iomode = NFSWRITE_FILESYNC;
742 error = ncl_writerpc(vp, &uio, cred, &iomode,
743 &must_commit, 0);
744 KASSERT((must_commit == 0),
745 ("ncl_directio_write: Did not commit write"));
746 if (error)
747 return (error);
748 uiop->uio_offset += size;
749 uiop->uio_resid -= size;
750 if (uiop->uio_iov->iov_len <= size) {
751 uiop->uio_iovcnt--;
752 uiop->uio_iov++;
753 } else {
754 uiop->uio_iov->iov_base =
755 (char *)uiop->uio_iov->iov_base + size;
756 uiop->uio_iov->iov_len -= size;
757 }
758 }
759 } else {
760 struct uio *t_uio;
761 struct iovec *t_iov;
762 struct buf *bp;
763
764 /*
765 * Break up the write into blocksize chunks and hand these
766 * over to nfsiod's for write back.
767 * Unfortunately, this incurs a copy of the data. Since
768 * the user could modify the buffer before the write is
769 * initiated.
770 *
771 * The obvious optimization here is that one of the 2 copies
772 * in the async write path can be eliminated by copying the
773 * data here directly into mbufs and passing the mbuf chain
774 * down. But that will require a fair amount of re-working
775 * of the code and can be done if there's enough interest
776 * in NFS directio access.
777 */
778 while (uiop->uio_resid > 0) {
779 size = MIN(uiop->uio_resid, wsize);
780 size = MIN(uiop->uio_iov->iov_len, size);
781 bp = getpbuf(&ncl_pbuf_freecnt);
782 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
783 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
784 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK);
785 t_iov->iov_len = size;
786 t_uio->uio_iov = t_iov;
787 t_uio->uio_iovcnt = 1;
788 t_uio->uio_offset = uiop->uio_offset;
789 t_uio->uio_resid = size;
790 t_uio->uio_segflg = UIO_SYSSPACE;
791 t_uio->uio_rw = UIO_WRITE;
792 t_uio->uio_td = td;
793 KASSERT(uiop->uio_segflg == UIO_USERSPACE ||
794 uiop->uio_segflg == UIO_SYSSPACE,
795 ("nfs_directio_write: Bad uio_segflg"));
796 if (uiop->uio_segflg == UIO_USERSPACE) {
797 error = copyin(uiop->uio_iov->iov_base,
798 t_iov->iov_base, size);
799 if (error != 0)
800 goto err_free;
801 } else
802 /*
803 * UIO_SYSSPACE may never happen, but handle
804 * it just in case it does.
805 */
806 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base,
807 size);
808 bp->b_flags |= B_DIRECT;
809 bp->b_iocmd = BIO_WRITE;
810 if (cred != NOCRED) {
811 crhold(cred);
812 bp->b_wcred = cred;
813 } else
814 bp->b_wcred = NOCRED;
815 bp->b_caller1 = (void *)t_uio;
816 bp->b_vp = vp;
817 error = ncl_asyncio(nmp, bp, NOCRED, td);
818 err_free:
819 if (error) {
820 free(t_iov->iov_base, M_NFSDIRECTIO);
821 free(t_iov, M_NFSDIRECTIO);
822 free(t_uio, M_NFSDIRECTIO);
823 bp->b_vp = NULL;
824 relpbuf(bp, &ncl_pbuf_freecnt);
825 if (error == EINTR)
826 return (error);
827 goto do_sync;
828 }
829 uiop->uio_offset += size;
830 uiop->uio_resid -= size;
831 if (uiop->uio_iov->iov_len <= size) {
832 uiop->uio_iovcnt--;
833 uiop->uio_iov++;
834 } else {
835 uiop->uio_iov->iov_base =
836 (char *)uiop->uio_iov->iov_base + size;
837 uiop->uio_iov->iov_len -= size;
838 }
839 }
840 }
841 return (0);
842 }
843
844 /*
845 * Vnode op for write using bio
846 */
847 int
848 ncl_write(struct vop_write_args *ap)
849 {
850 int biosize;
851 struct uio *uio = ap->a_uio;
852 struct thread *td = uio->uio_td;
853 struct vnode *vp = ap->a_vp;
854 struct nfsnode *np = VTONFS(vp);
855 struct ucred *cred = ap->a_cred;
856 int ioflag = ap->a_ioflag;
857 struct buf *bp;
858 struct vattr vattr;
859 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
860 daddr_t lbn;
861 int bcount, noncontig_write, obcount;
862 int bp_cached, n, on, error = 0, error1, wouldcommit;
863 size_t orig_resid, local_resid;
864 off_t orig_size, tmp_off;
865
866 KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode"));
867 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
868 ("ncl_write proc"));
869 if (vp->v_type != VREG)
870 return (EIO);
871 mtx_lock(&np->n_mtx);
872 if (np->n_flag & NWRITEERR) {
873 np->n_flag &= ~NWRITEERR;
874 mtx_unlock(&np->n_mtx);
875 return (np->n_error);
876 } else
877 mtx_unlock(&np->n_mtx);
878 mtx_lock(&nmp->nm_mtx);
879 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
880 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
881 mtx_unlock(&nmp->nm_mtx);
882 (void)ncl_fsinfo(nmp, vp, cred, td);
883 mtx_lock(&nmp->nm_mtx);
884 }
885 if (nmp->nm_wsize == 0)
886 (void) newnfs_iosize(nmp);
887 mtx_unlock(&nmp->nm_mtx);
888
889 /*
890 * Synchronously flush pending buffers if we are in synchronous
891 * mode or if we are appending.
892 */
893 if (ioflag & (IO_APPEND | IO_SYNC)) {
894 mtx_lock(&np->n_mtx);
895 if (np->n_flag & NMODIFIED) {
896 mtx_unlock(&np->n_mtx);
897 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */
898 /*
899 * Require non-blocking, synchronous writes to
900 * dirty files to inform the program it needs
901 * to fsync(2) explicitly.
902 */
903 if (ioflag & IO_NDELAY)
904 return (EAGAIN);
905 #endif
906 np->n_attrstamp = 0;
907 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
908 error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
909 if (error)
910 return (error);
911 } else
912 mtx_unlock(&np->n_mtx);
913 }
914
915 orig_resid = uio->uio_resid;
916 mtx_lock(&np->n_mtx);
917 orig_size = np->n_size;
918 mtx_unlock(&np->n_mtx);
919
920 /*
921 * If IO_APPEND then load uio_offset. We restart here if we cannot
922 * get the append lock.
923 */
924 if (ioflag & IO_APPEND) {
925 np->n_attrstamp = 0;
926 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
927 error = VOP_GETATTR(vp, &vattr, cred);
928 if (error)
929 return (error);
930 mtx_lock(&np->n_mtx);
931 uio->uio_offset = np->n_size;
932 mtx_unlock(&np->n_mtx);
933 }
934
935 if (uio->uio_offset < 0)
936 return (EINVAL);
937 tmp_off = uio->uio_offset + uio->uio_resid;
938 if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)
939 return (EFBIG);
940 if (uio->uio_resid == 0)
941 return (0);
942
943 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
944 return nfs_directio_write(vp, uio, cred, ioflag);
945
946 /*
947 * Maybe this should be above the vnode op call, but so long as
948 * file servers have no limits, i don't think it matters
949 */
950 if (vn_rlimit_fsize(vp, uio, td))
951 return (EFBIG);
952
953 biosize = vp->v_bufobj.bo_bsize;
954 /*
955 * Find all of this file's B_NEEDCOMMIT buffers. If our writes
956 * would exceed the local maximum per-file write commit size when
957 * combined with those, we must decide whether to flush,
958 * go synchronous, or return error. We don't bother checking
959 * IO_UNIT -- we just make all writes atomic anyway, as there's
960 * no point optimizing for something that really won't ever happen.
961 */
962 wouldcommit = 0;
963 if (!(ioflag & IO_SYNC)) {
964 int nflag;
965
966 mtx_lock(&np->n_mtx);
967 nflag = np->n_flag;
968 mtx_unlock(&np->n_mtx);
969 if (nflag & NMODIFIED) {
970 BO_LOCK(&vp->v_bufobj);
971 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) {
972 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd,
973 b_bobufs) {
974 if (bp->b_flags & B_NEEDCOMMIT)
975 wouldcommit += bp->b_bcount;
976 }
977 }
978 BO_UNLOCK(&vp->v_bufobj);
979 }
980 }
981
982 do {
983 if (!(ioflag & IO_SYNC)) {
984 wouldcommit += biosize;
985 if (wouldcommit > nmp->nm_wcommitsize) {
986 np->n_attrstamp = 0;
987 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
988 error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
989 if (error)
990 return (error);
991 wouldcommit = biosize;
992 }
993 }
994
995 NFSINCRGLOBAL(newnfsstats.biocache_writes);
996 lbn = uio->uio_offset / biosize;
997 on = uio->uio_offset - (lbn * biosize);
998 n = MIN((unsigned)(biosize - on), uio->uio_resid);
999 again:
1000 /*
1001 * Handle direct append and file extension cases, calculate
1002 * unaligned buffer size.
1003 */
1004 mtx_lock(&np->n_mtx);
1005 if ((np->n_flag & NHASBEENLOCKED) == 0 &&
1006 (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0)
1007 noncontig_write = 1;
1008 else
1009 noncontig_write = 0;
1010 if ((uio->uio_offset == np->n_size ||
1011 (noncontig_write != 0 &&
1012 lbn == (np->n_size / biosize) &&
1013 uio->uio_offset + n > np->n_size)) && n) {
1014 mtx_unlock(&np->n_mtx);
1015 /*
1016 * Get the buffer (in its pre-append state to maintain
1017 * B_CACHE if it was previously set). Resize the
1018 * nfsnode after we have locked the buffer to prevent
1019 * readers from reading garbage.
1020 */
1021 obcount = np->n_size - (lbn * biosize);
1022 bp = nfs_getcacheblk(vp, lbn, obcount, td);
1023
1024 if (bp != NULL) {
1025 long save;
1026
1027 mtx_lock(&np->n_mtx);
1028 np->n_size = uio->uio_offset + n;
1029 np->n_flag |= NMODIFIED;
1030 vnode_pager_setsize(vp, np->n_size);
1031 mtx_unlock(&np->n_mtx);
1032
1033 save = bp->b_flags & B_CACHE;
1034 bcount = on + n;
1035 allocbuf(bp, bcount);
1036 bp->b_flags |= save;
1037 if (noncontig_write != 0 && on > obcount)
1038 vfs_bio_bzero_buf(bp, obcount, on -
1039 obcount);
1040 }
1041 } else {
1042 /*
1043 * Obtain the locked cache block first, and then
1044 * adjust the file's size as appropriate.
1045 */
1046 bcount = on + n;
1047 if ((off_t)lbn * biosize + bcount < np->n_size) {
1048 if ((off_t)(lbn + 1) * biosize < np->n_size)
1049 bcount = biosize;
1050 else
1051 bcount = np->n_size - (off_t)lbn * biosize;
1052 }
1053 mtx_unlock(&np->n_mtx);
1054 bp = nfs_getcacheblk(vp, lbn, bcount, td);
1055 mtx_lock(&np->n_mtx);
1056 if (uio->uio_offset + n > np->n_size) {
1057 np->n_size = uio->uio_offset + n;
1058 np->n_flag |= NMODIFIED;
1059 vnode_pager_setsize(vp, np->n_size);
1060 }
1061 mtx_unlock(&np->n_mtx);
1062 }
1063
1064 if (!bp) {
1065 error = newnfs_sigintr(nmp, td);
1066 if (!error)
1067 error = EINTR;
1068 break;
1069 }
1070
1071 /*
1072 * Issue a READ if B_CACHE is not set. In special-append
1073 * mode, B_CACHE is based on the buffer prior to the write
1074 * op and is typically set, avoiding the read. If a read
1075 * is required in special append mode, the server will
1076 * probably send us a short-read since we extended the file
1077 * on our end, resulting in b_resid == 0 and, thusly,
1078 * B_CACHE getting set.
1079 *
1080 * We can also avoid issuing the read if the write covers
1081 * the entire buffer. We have to make sure the buffer state
1082 * is reasonable in this case since we will not be initiating
1083 * I/O. See the comments in kern/vfs_bio.c's getblk() for
1084 * more information.
1085 *
1086 * B_CACHE may also be set due to the buffer being cached
1087 * normally.
1088 */
1089
1090 bp_cached = 1;
1091 if (on == 0 && n == bcount) {
1092 if ((bp->b_flags & B_CACHE) == 0)
1093 bp_cached = 0;
1094 bp->b_flags |= B_CACHE;
1095 bp->b_flags &= ~B_INVAL;
1096 bp->b_ioflags &= ~BIO_ERROR;
1097 }
1098
1099 if ((bp->b_flags & B_CACHE) == 0) {
1100 bp->b_iocmd = BIO_READ;
1101 vfs_busy_pages(bp, 0);
1102 error = ncl_doio(vp, bp, cred, td, 0);
1103 if (error) {
1104 brelse(bp);
1105 break;
1106 }
1107 }
1108 if (bp->b_wcred == NOCRED)
1109 bp->b_wcred = crhold(cred);
1110 mtx_lock(&np->n_mtx);
1111 np->n_flag |= NMODIFIED;
1112 mtx_unlock(&np->n_mtx);
1113
1114 /*
1115 * If dirtyend exceeds file size, chop it down. This should
1116 * not normally occur but there is an append race where it
1117 * might occur XXX, so we log it.
1118 *
1119 * If the chopping creates a reverse-indexed or degenerate
1120 * situation with dirtyoff/end, we 0 both of them.
1121 */
1122
1123 if (bp->b_dirtyend > bcount) {
1124 printf("NFS append race @%lx:%d\n",
1125 (long)bp->b_blkno * DEV_BSIZE,
1126 bp->b_dirtyend - bcount);
1127 bp->b_dirtyend = bcount;
1128 }
1129
1130 if (bp->b_dirtyoff >= bp->b_dirtyend)
1131 bp->b_dirtyoff = bp->b_dirtyend = 0;
1132
1133 /*
1134 * If the new write will leave a contiguous dirty
1135 * area, just update the b_dirtyoff and b_dirtyend,
1136 * otherwise force a write rpc of the old dirty area.
1137 *
1138 * If there has been a file lock applied to this file
1139 * or vfs.nfs.old_noncontig_writing is set, do the following:
1140 * While it is possible to merge discontiguous writes due to
1141 * our having a B_CACHE buffer ( and thus valid read data
1142 * for the hole), we don't because it could lead to
1143 * significant cache coherency problems with multiple clients,
1144 * especially if locking is implemented later on.
1145 *
1146 * If vfs.nfs.old_noncontig_writing is not set and there has
1147 * not been file locking done on this file:
1148 * Relax coherency a bit for the sake of performance and
1149 * expand the current dirty region to contain the new
1150 * write even if it means we mark some non-dirty data as
1151 * dirty.
1152 */
1153
1154 if (noncontig_write == 0 && bp->b_dirtyend > 0 &&
1155 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
1156 if (bwrite(bp) == EINTR) {
1157 error = EINTR;
1158 break;
1159 }
1160 goto again;
1161 }
1162
1163 local_resid = uio->uio_resid;
1164 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio);
1165
1166 if (error != 0 && !bp_cached) {
1167 /*
1168 * This block has no other content then what
1169 * possibly was written by the faulty uiomove.
1170 * Release it, forgetting the data pages, to
1171 * prevent the leak of uninitialized data to
1172 * usermode.
1173 */
1174 bp->b_ioflags |= BIO_ERROR;
1175 brelse(bp);
1176 uio->uio_offset -= local_resid - uio->uio_resid;
1177 uio->uio_resid = local_resid;
1178 break;
1179 }
1180
1181 /*
1182 * Since this block is being modified, it must be written
1183 * again and not just committed. Since write clustering does
1184 * not work for the stage 1 data write, only the stage 2
1185 * commit rpc, we have to clear B_CLUSTEROK as well.
1186 */
1187 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1188
1189 /*
1190 * Get the partial update on the progress made from
1191 * uiomove, if an error occurred.
1192 */
1193 if (error != 0)
1194 n = local_resid - uio->uio_resid;
1195
1196 /*
1197 * Only update dirtyoff/dirtyend if not a degenerate
1198 * condition.
1199 */
1200 if (n > 0) {
1201 if (bp->b_dirtyend > 0) {
1202 bp->b_dirtyoff = min(on, bp->b_dirtyoff);
1203 bp->b_dirtyend = max((on + n), bp->b_dirtyend);
1204 } else {
1205 bp->b_dirtyoff = on;
1206 bp->b_dirtyend = on + n;
1207 }
1208 vfs_bio_set_valid(bp, on, n);
1209 }
1210
1211 /*
1212 * If IO_SYNC do bwrite().
1213 *
1214 * IO_INVAL appears to be unused. The idea appears to be
1215 * to turn off caching in this case. Very odd. XXX
1216 */
1217 if ((ioflag & IO_SYNC)) {
1218 if (ioflag & IO_INVAL)
1219 bp->b_flags |= B_NOCACHE;
1220 error1 = bwrite(bp);
1221 if (error1 != 0) {
1222 if (error == 0)
1223 error = error1;
1224 break;
1225 }
1226 } else if ((n + on) == biosize) {
1227 bp->b_flags |= B_ASYNC;
1228 (void) ncl_writebp(bp, 0, NULL);
1229 } else {
1230 bdwrite(bp);
1231 }
1232
1233 if (error != 0)
1234 break;
1235 } while (uio->uio_resid > 0 && n > 0);
1236
1237 if (error != 0) {
1238 if (ioflag & IO_UNIT) {
1239 VATTR_NULL(&vattr);
1240 vattr.va_size = orig_size;
1241 /* IO_SYNC is handled implicitely */
1242 (void)VOP_SETATTR(vp, &vattr, cred);
1243 uio->uio_offset -= orig_resid - uio->uio_resid;
1244 uio->uio_resid = orig_resid;
1245 }
1246 }
1247
1248 return (error);
1249 }
1250
1251 /*
1252 * Get an nfs cache block.
1253 *
1254 * Allocate a new one if the block isn't currently in the cache
1255 * and return the block marked busy. If the calling process is
1256 * interrupted by a signal for an interruptible mount point, return
1257 * NULL.
1258 *
1259 * The caller must carefully deal with the possible B_INVAL state of
1260 * the buffer. ncl_doio() clears B_INVAL (and ncl_asyncio() clears it
1261 * indirectly), so synchronous reads can be issued without worrying about
1262 * the B_INVAL state. We have to be a little more careful when dealing
1263 * with writes (see comments in nfs_write()) when extending a file past
1264 * its EOF.
1265 */
1266 static struct buf *
1267 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
1268 {
1269 struct buf *bp;
1270 struct mount *mp;
1271 struct nfsmount *nmp;
1272
1273 mp = vp->v_mount;
1274 nmp = VFSTONFS(mp);
1275
1276 if (nmp->nm_flag & NFSMNT_INT) {
1277 sigset_t oldset;
1278
1279 newnfs_set_sigmask(td, &oldset);
1280 bp = getblk(vp, bn, size, PCATCH, 0, 0);
1281 newnfs_restore_sigmask(td, &oldset);
1282 while (bp == NULL) {
1283 if (newnfs_sigintr(nmp, td))
1284 return (NULL);
1285 bp = getblk(vp, bn, size, 0, 2 * hz, 0);
1286 }
1287 } else {
1288 bp = getblk(vp, bn, size, 0, 0, 0);
1289 }
1290
1291 if (vp->v_type == VREG)
1292 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE);
1293 return (bp);
1294 }
1295
1296 /*
1297 * Flush and invalidate all dirty buffers. If another process is already
1298 * doing the flush, just wait for completion.
1299 */
1300 int
1301 ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg)
1302 {
1303 struct nfsnode *np = VTONFS(vp);
1304 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
1305 int error = 0, slpflag, slptimeo;
1306 int old_lock = 0;
1307
1308 ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf");
1309
1310 if ((nmp->nm_flag & NFSMNT_INT) == 0)
1311 intrflg = 0;
1312 if ((nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF))
1313 intrflg = 1;
1314 if (intrflg) {
1315 slpflag = PCATCH;
1316 slptimeo = 2 * hz;
1317 } else {
1318 slpflag = 0;
1319 slptimeo = 0;
1320 }
1321
1322 old_lock = ncl_upgrade_vnlock(vp);
1323 if (vp->v_iflag & VI_DOOMED) {
1324 /*
1325 * Since vgonel() uses the generic vinvalbuf() to flush
1326 * dirty buffers and it does not call this function, it
1327 * is safe to just return OK when VI_DOOMED is set.
1328 */
1329 ncl_downgrade_vnlock(vp, old_lock);
1330 return (0);
1331 }
1332
1333 /*
1334 * Now, flush as required.
1335 */
1336 if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) {
1337 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object);
1338 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
1339 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object);
1340 /*
1341 * If the page clean was interrupted, fail the invalidation.
1342 * Not doing so, we run the risk of losing dirty pages in the
1343 * vinvalbuf() call below.
1344 */
1345 if (intrflg && (error = newnfs_sigintr(nmp, td)))
1346 goto out;
1347 }
1348
1349 error = vinvalbuf(vp, flags, slpflag, 0);
1350 while (error) {
1351 if (intrflg && (error = newnfs_sigintr(nmp, td)))
1352 goto out;
1353 error = vinvalbuf(vp, flags, 0, slptimeo);
1354 }
1355 if (NFSHASPNFS(nmp)) {
1356 nfscl_layoutcommit(vp, td);
1357 /*
1358 * Invalidate the attribute cache, since writes to a DS
1359 * won't update the size attribute.
1360 */
1361 mtx_lock(&np->n_mtx);
1362 np->n_attrstamp = 0;
1363 } else
1364 mtx_lock(&np->n_mtx);
1365 if (np->n_directio_asyncwr == 0)
1366 np->n_flag &= ~NMODIFIED;
1367 mtx_unlock(&np->n_mtx);
1368 out:
1369 ncl_downgrade_vnlock(vp, old_lock);
1370 return error;
1371 }
1372
1373 /*
1374 * Initiate asynchronous I/O. Return an error if no nfsiods are available.
1375 * This is mainly to avoid queueing async I/O requests when the nfsiods
1376 * are all hung on a dead server.
1377 *
1378 * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
1379 * is eventually dequeued by the async daemon, ncl_doio() *will*.
1380 */
1381 int
1382 ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
1383 {
1384 int iod;
1385 int gotiod;
1386 int slpflag = 0;
1387 int slptimeo = 0;
1388 int error, error2;
1389
1390 /*
1391 * Commits are usually short and sweet so lets save some cpu and
1392 * leave the async daemons for more important rpc's (such as reads
1393 * and writes).
1394 *
1395 * Readdirplus RPCs do vget()s to acquire the vnodes for entries
1396 * in the directory in order to update attributes. This can deadlock
1397 * with another thread that is waiting for async I/O to be done by
1398 * an nfsiod thread while holding a lock on one of these vnodes.
1399 * To avoid this deadlock, don't allow the async nfsiod threads to
1400 * perform Readdirplus RPCs.
1401 */
1402 mtx_lock(&ncl_iod_mutex);
1403 if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
1404 (nmp->nm_bufqiods > ncl_numasync / 2)) ||
1405 (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) {
1406 mtx_unlock(&ncl_iod_mutex);
1407 return(EIO);
1408 }
1409 again:
1410 if (nmp->nm_flag & NFSMNT_INT)
1411 slpflag = PCATCH;
1412 gotiod = FALSE;
1413
1414 /*
1415 * Find a free iod to process this request.
1416 */
1417 for (iod = 0; iod < ncl_numasync; iod++)
1418 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) {
1419 gotiod = TRUE;
1420 break;
1421 }
1422
1423 /*
1424 * Try to create one if none are free.
1425 */
1426 if (!gotiod)
1427 ncl_nfsiodnew();
1428 else {
1429 /*
1430 * Found one, so wake it up and tell it which
1431 * mount to process.
1432 */
1433 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n",
1434 iod, nmp));
1435 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE;
1436 ncl_iodmount[iod] = nmp;
1437 nmp->nm_bufqiods++;
1438 wakeup(&ncl_iodwant[iod]);
1439 }
1440
1441 /*
1442 * If none are free, we may already have an iod working on this mount
1443 * point. If so, it will process our request.
1444 */
1445 if (!gotiod) {
1446 if (nmp->nm_bufqiods > 0) {
1447 NFS_DPF(ASYNCIO,
1448 ("ncl_asyncio: %d iods are already processing mount %p\n",
1449 nmp->nm_bufqiods, nmp));
1450 gotiod = TRUE;
1451 }
1452 }
1453
1454 /*
1455 * If we have an iod which can process the request, then queue
1456 * the buffer.
1457 */
1458 if (gotiod) {
1459 /*
1460 * Ensure that the queue never grows too large. We still want
1461 * to asynchronize so we block rather then return EIO.
1462 */
1463 while (nmp->nm_bufqlen >= 2*ncl_numasync) {
1464 NFS_DPF(ASYNCIO,
1465 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp));
1466 nmp->nm_bufqwant = TRUE;
1467 error = newnfs_msleep(td, &nmp->nm_bufq,
1468 &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio",
1469 slptimeo);
1470 if (error) {
1471 error2 = newnfs_sigintr(nmp, td);
1472 if (error2) {
1473 mtx_unlock(&ncl_iod_mutex);
1474 return (error2);
1475 }
1476 if (slpflag == PCATCH) {
1477 slpflag = 0;
1478 slptimeo = 2 * hz;
1479 }
1480 }
1481 /*
1482 * We might have lost our iod while sleeping,
1483 * so check and loop if necessary.
1484 */
1485 goto again;
1486 }
1487
1488 /* We might have lost our nfsiod */
1489 if (nmp->nm_bufqiods == 0) {
1490 NFS_DPF(ASYNCIO,
1491 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
1492 goto again;
1493 }
1494
1495 if (bp->b_iocmd == BIO_READ) {
1496 if (bp->b_rcred == NOCRED && cred != NOCRED)
1497 bp->b_rcred = crhold(cred);
1498 } else {
1499 if (bp->b_wcred == NOCRED && cred != NOCRED)
1500 bp->b_wcred = crhold(cred);
1501 }
1502
1503 if (bp->b_flags & B_REMFREE)
1504 bremfreef(bp);
1505 BUF_KERNPROC(bp);
1506 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
1507 nmp->nm_bufqlen++;
1508 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1509 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx);
1510 VTONFS(bp->b_vp)->n_flag |= NMODIFIED;
1511 VTONFS(bp->b_vp)->n_directio_asyncwr++;
1512 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx);
1513 }
1514 mtx_unlock(&ncl_iod_mutex);
1515 return (0);
1516 }
1517
1518 mtx_unlock(&ncl_iod_mutex);
1519
1520 /*
1521 * All the iods are busy on other mounts, so return EIO to
1522 * force the caller to process the i/o synchronously.
1523 */
1524 NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n"));
1525 return (EIO);
1526 }
1527
1528 void
1529 ncl_doio_directwrite(struct buf *bp)
1530 {
1531 int iomode, must_commit;
1532 struct uio *uiop = (struct uio *)bp->b_caller1;
1533 char *iov_base = uiop->uio_iov->iov_base;
1534
1535 iomode = NFSWRITE_FILESYNC;
1536 uiop->uio_td = NULL; /* NULL since we're in nfsiod */
1537 ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0);
1538 KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write"));
1539 free(iov_base, M_NFSDIRECTIO);
1540 free(uiop->uio_iov, M_NFSDIRECTIO);
1541 free(uiop, M_NFSDIRECTIO);
1542 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1543 struct nfsnode *np = VTONFS(bp->b_vp);
1544 mtx_lock(&np->n_mtx);
1545 if (NFSHASPNFS(VFSTONFS(vnode_mount(bp->b_vp)))) {
1546 /*
1547 * Invalidate the attribute cache, since writes to a DS
1548 * won't update the size attribute.
1549 */
1550 np->n_attrstamp = 0;
1551 }
1552 np->n_directio_asyncwr--;
1553 if (np->n_directio_asyncwr == 0) {
1554 np->n_flag &= ~NMODIFIED;
1555 if ((np->n_flag & NFSYNCWAIT)) {
1556 np->n_flag &= ~NFSYNCWAIT;
1557 wakeup((caddr_t)&np->n_directio_asyncwr);
1558 }
1559 }
1560 mtx_unlock(&np->n_mtx);
1561 }
1562 bp->b_vp = NULL;
1563 relpbuf(bp, &ncl_pbuf_freecnt);
1564 }
1565
1566 /*
1567 * Do an I/O operation to/from a cache block. This may be called
1568 * synchronously or from an nfsiod.
1569 */
1570 int
1571 ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td,
1572 int called_from_strategy)
1573 {
1574 struct uio *uiop;
1575 struct nfsnode *np;
1576 struct nfsmount *nmp;
1577 int error = 0, iomode, must_commit = 0;
1578 struct uio uio;
1579 struct iovec io;
1580 struct proc *p = td ? td->td_proc : NULL;
1581 uint8_t iocmd;
1582
1583 np = VTONFS(vp);
1584 nmp = VFSTONFS(vp->v_mount);
1585 uiop = &uio;
1586 uiop->uio_iov = &io;
1587 uiop->uio_iovcnt = 1;
1588 uiop->uio_segflg = UIO_SYSSPACE;
1589 uiop->uio_td = td;
1590
1591 /*
1592 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
1593 * do this here so we do not have to do it in all the code that
1594 * calls us.
1595 */
1596 bp->b_flags &= ~B_INVAL;
1597 bp->b_ioflags &= ~BIO_ERROR;
1598
1599 KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp));
1600 iocmd = bp->b_iocmd;
1601 if (iocmd == BIO_READ) {
1602 io.iov_len = uiop->uio_resid = bp->b_bcount;
1603 io.iov_base = bp->b_data;
1604 uiop->uio_rw = UIO_READ;
1605
1606 switch (vp->v_type) {
1607 case VREG:
1608 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
1609 NFSINCRGLOBAL(newnfsstats.read_bios);
1610 error = ncl_readrpc(vp, uiop, cr);
1611
1612 if (!error) {
1613 if (uiop->uio_resid) {
1614 /*
1615 * If we had a short read with no error, we must have
1616 * hit a file hole. We should zero-fill the remainder.
1617 * This can also occur if the server hits the file EOF.
1618 *
1619 * Holes used to be able to occur due to pending
1620 * writes, but that is not possible any longer.
1621 */
1622 int nread = bp->b_bcount - uiop->uio_resid;
1623 ssize_t left = uiop->uio_resid;
1624
1625 if (left > 0)
1626 bzero((char *)bp->b_data + nread, left);
1627 uiop->uio_resid = 0;
1628 }
1629 }
1630 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */
1631 if (p && (vp->v_vflag & VV_TEXT)) {
1632 mtx_lock(&np->n_mtx);
1633 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) {
1634 mtx_unlock(&np->n_mtx);
1635 PROC_LOCK(p);
1636 killproc(p, "text file modification");
1637 PROC_UNLOCK(p);
1638 } else
1639 mtx_unlock(&np->n_mtx);
1640 }
1641 break;
1642 case VLNK:
1643 uiop->uio_offset = (off_t)0;
1644 NFSINCRGLOBAL(newnfsstats.readlink_bios);
1645 error = ncl_readlinkrpc(vp, uiop, cr);
1646 break;
1647 case VDIR:
1648 NFSINCRGLOBAL(newnfsstats.readdir_bios);
1649 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
1650 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
1651 error = ncl_readdirplusrpc(vp, uiop, cr, td);
1652 if (error == NFSERR_NOTSUPP)
1653 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
1654 }
1655 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
1656 error = ncl_readdirrpc(vp, uiop, cr, td);
1657 /*
1658 * end-of-directory sets B_INVAL but does not generate an
1659 * error.
1660 */
1661 if (error == 0 && uiop->uio_resid == bp->b_bcount)
1662 bp->b_flags |= B_INVAL;
1663 break;
1664 default:
1665 printf("ncl_doio: type %x unexpected\n", vp->v_type);
1666 break;
1667 }
1668 if (error) {
1669 bp->b_ioflags |= BIO_ERROR;
1670 bp->b_error = error;
1671 }
1672 } else {
1673 /*
1674 * If we only need to commit, try to commit
1675 */
1676 if (bp->b_flags & B_NEEDCOMMIT) {
1677 int retv;
1678 off_t off;
1679
1680 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
1681 retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff,
1682 bp->b_wcred, td);
1683 if (retv == 0) {
1684 bp->b_dirtyoff = bp->b_dirtyend = 0;
1685 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1686 bp->b_resid = 0;
1687 bufdone(bp);
1688 return (0);
1689 }
1690 if (retv == NFSERR_STALEWRITEVERF) {
1691 ncl_clearcommit(vp->v_mount);
1692 }
1693 }
1694
1695 /*
1696 * Setup for actual write
1697 */
1698 mtx_lock(&np->n_mtx);
1699 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
1700 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
1701 mtx_unlock(&np->n_mtx);
1702
1703 if (bp->b_dirtyend > bp->b_dirtyoff) {
1704 io.iov_len = uiop->uio_resid = bp->b_dirtyend
1705 - bp->b_dirtyoff;
1706 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
1707 + bp->b_dirtyoff;
1708 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
1709 uiop->uio_rw = UIO_WRITE;
1710 NFSINCRGLOBAL(newnfsstats.write_bios);
1711
1712 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
1713 iomode = NFSWRITE_UNSTABLE;
1714 else
1715 iomode = NFSWRITE_FILESYNC;
1716
1717 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit,
1718 called_from_strategy);
1719
1720 /*
1721 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
1722 * to cluster the buffers needing commit. This will allow
1723 * the system to submit a single commit rpc for the whole
1724 * cluster. We can do this even if the buffer is not 100%
1725 * dirty (relative to the NFS blocksize), so we optimize the
1726 * append-to-file-case.
1727 *
1728 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
1729 * cleared because write clustering only works for commit
1730 * rpc's, not for the data portion of the write).
1731 */
1732
1733 if (!error && iomode == NFSWRITE_UNSTABLE) {
1734 bp->b_flags |= B_NEEDCOMMIT;
1735 if (bp->b_dirtyoff == 0
1736 && bp->b_dirtyend == bp->b_bcount)
1737 bp->b_flags |= B_CLUSTEROK;
1738 } else {
1739 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1740 }
1741
1742 /*
1743 * For an interrupted write, the buffer is still valid
1744 * and the write hasn't been pushed to the server yet,
1745 * so we can't set BIO_ERROR and report the interruption
1746 * by setting B_EINTR. For the B_ASYNC case, B_EINTR
1747 * is not relevant, so the rpc attempt is essentially
1748 * a noop. For the case of a V3 write rpc not being
1749 * committed to stable storage, the block is still
1750 * dirty and requires either a commit rpc or another
1751 * write rpc with iomode == NFSV3WRITE_FILESYNC before
1752 * the block is reused. This is indicated by setting
1753 * the B_DELWRI and B_NEEDCOMMIT flags.
1754 *
1755 * EIO is returned by ncl_writerpc() to indicate a recoverable
1756 * write error and is handled as above, except that
1757 * B_EINTR isn't set. One cause of this is a stale stateid
1758 * error for the RPC that indicates recovery is required,
1759 * when called with called_from_strategy != 0.
1760 *
1761 * If the buffer is marked B_PAGING, it does not reside on
1762 * the vp's paging queues so we cannot call bdirty(). The
1763 * bp in this case is not an NFS cache block so we should
1764 * be safe. XXX
1765 *
1766 * The logic below breaks up errors into recoverable and
1767 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE
1768 * and keep the buffer around for potential write retries.
1769 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL)
1770 * and save the error in the nfsnode. This is less than ideal
1771 * but necessary. Keeping such buffers around could potentially
1772 * cause buffer exhaustion eventually (they can never be written
1773 * out, so will get constantly be re-dirtied). It also causes
1774 * all sorts of vfs panics. For non-recoverable write errors,
1775 * also invalidate the attrcache, so we'll be forced to go over
1776 * the wire for this object, returning an error to user on next
1777 * call (most of the time).
1778 */
1779 if (error == EINTR || error == EIO || error == ETIMEDOUT
1780 || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
1781 int s;
1782
1783 s = splbio();
1784 bp->b_flags &= ~(B_INVAL|B_NOCACHE);
1785 if ((bp->b_flags & B_PAGING) == 0) {
1786 bdirty(bp);
1787 bp->b_flags &= ~B_DONE;
1788 }
1789 if ((error == EINTR || error == ETIMEDOUT) &&
1790 (bp->b_flags & B_ASYNC) == 0)
1791 bp->b_flags |= B_EINTR;
1792 splx(s);
1793 } else {
1794 if (error) {
1795 bp->b_ioflags |= BIO_ERROR;
1796 bp->b_flags |= B_INVAL;
1797 bp->b_error = np->n_error = error;
1798 mtx_lock(&np->n_mtx);
1799 np->n_flag |= NWRITEERR;
1800 np->n_attrstamp = 0;
1801 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
1802 mtx_unlock(&np->n_mtx);
1803 }
1804 bp->b_dirtyoff = bp->b_dirtyend = 0;
1805 }
1806 } else {
1807 bp->b_resid = 0;
1808 bufdone(bp);
1809 return (0);
1810 }
1811 }
1812 bp->b_resid = uiop->uio_resid;
1813 if (must_commit)
1814 ncl_clearcommit(vp->v_mount);
1815 bufdone(bp);
1816 return (error);
1817 }
1818
1819 /*
1820 * Used to aid in handling ftruncate() operations on the NFS client side.
1821 * Truncation creates a number of special problems for NFS. We have to
1822 * throw away VM pages and buffer cache buffers that are beyond EOF, and
1823 * we have to properly handle VM pages or (potentially dirty) buffers
1824 * that straddle the truncation point.
1825 */
1826
1827 int
1828 ncl_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize)
1829 {
1830 struct nfsnode *np = VTONFS(vp);
1831 u_quad_t tsize;
1832 int biosize = vp->v_bufobj.bo_bsize;
1833 int error = 0;
1834
1835 mtx_lock(&np->n_mtx);
1836 tsize = np->n_size;
1837 np->n_size = nsize;
1838 mtx_unlock(&np->n_mtx);
1839
1840 if (nsize < tsize) {
1841 struct buf *bp;
1842 daddr_t lbn;
1843 int bufsize;
1844
1845 /*
1846 * vtruncbuf() doesn't get the buffer overlapping the
1847 * truncation point. We may have a B_DELWRI and/or B_CACHE
1848 * buffer that now needs to be truncated.
1849 */
1850 error = vtruncbuf(vp, cred, nsize, biosize);
1851 lbn = nsize / biosize;
1852 bufsize = nsize - (lbn * biosize);
1853 bp = nfs_getcacheblk(vp, lbn, bufsize, td);
1854 if (!bp)
1855 return EINTR;
1856 if (bp->b_dirtyoff > bp->b_bcount)
1857 bp->b_dirtyoff = bp->b_bcount;
1858 if (bp->b_dirtyend > bp->b_bcount)
1859 bp->b_dirtyend = bp->b_bcount;
1860 bp->b_flags |= B_RELBUF; /* don't leave garbage around */
1861 brelse(bp);
1862 } else {
1863 vnode_pager_setsize(vp, nsize);
1864 }
1865 return(error);
1866 }
1867
Cache object: 23bd32265f654cd4d7901e08c937ea2a
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