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/11.1/sys/fs/nfsclient/nfs_clbio.c 317134 2017-04-19 11:13:32Z 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 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 for (i = 0; i < npages; i++)
311 rtvals[i] = VM_PAGER_ERROR;
312
313 /*
314 * When putting pages, do not extend file past EOF.
315 */
316 if (offset + count > np->n_size) {
317 count = np->n_size - offset;
318 if (count < 0)
319 count = 0;
320 }
321 mtx_unlock(&np->n_mtx);
322
323 PCPU_INC(cnt.v_vnodeout);
324 PCPU_ADD(cnt.v_vnodepgsout, count);
325
326 iov.iov_base = unmapped_buf;
327 iov.iov_len = count;
328 uio.uio_iov = &iov;
329 uio.uio_iovcnt = 1;
330 uio.uio_offset = offset;
331 uio.uio_resid = count;
332 uio.uio_segflg = UIO_NOCOPY;
333 uio.uio_rw = UIO_WRITE;
334 uio.uio_td = td;
335
336 error = VOP_WRITE(vp, &uio, vnode_pager_putpages_ioflags(ap->a_sync),
337 cred);
338 crfree(cred);
339
340 if (error == 0 || !nfs_keep_dirty_on_error)
341 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid);
342 return (rtvals[0]);
343 }
344
345 /*
346 * For nfs, cache consistency can only be maintained approximately.
347 * Although RFC1094 does not specify the criteria, the following is
348 * believed to be compatible with the reference port.
349 * For nfs:
350 * If the file's modify time on the server has changed since the
351 * last read rpc or you have written to the file,
352 * you may have lost data cache consistency with the
353 * server, so flush all of the file's data out of the cache.
354 * Then force a getattr rpc to ensure that you have up to date
355 * attributes.
356 * NB: This implies that cache data can be read when up to
357 * NFS_ATTRTIMEO seconds out of date. If you find that you need current
358 * attributes this could be forced by setting n_attrstamp to 0 before
359 * the VOP_GETATTR() call.
360 */
361 static inline int
362 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred)
363 {
364 int error = 0;
365 struct vattr vattr;
366 struct nfsnode *np = VTONFS(vp);
367 int old_lock;
368
369 /*
370 * Grab the exclusive lock before checking whether the cache is
371 * consistent.
372 * XXX - We can make this cheaper later (by acquiring cheaper locks).
373 * But for now, this suffices.
374 */
375 old_lock = ncl_upgrade_vnlock(vp);
376 if (vp->v_iflag & VI_DOOMED) {
377 error = EBADF;
378 goto out;
379 }
380
381 mtx_lock(&np->n_mtx);
382 if (np->n_flag & NMODIFIED) {
383 mtx_unlock(&np->n_mtx);
384 if (vp->v_type != VREG) {
385 if (vp->v_type != VDIR)
386 panic("nfs: bioread, not dir");
387 ncl_invaldir(vp);
388 error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
389 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
390 error = EBADF;
391 if (error != 0)
392 goto out;
393 }
394 np->n_attrstamp = 0;
395 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
396 error = VOP_GETATTR(vp, &vattr, cred);
397 if (error)
398 goto out;
399 mtx_lock(&np->n_mtx);
400 np->n_mtime = vattr.va_mtime;
401 mtx_unlock(&np->n_mtx);
402 } else {
403 mtx_unlock(&np->n_mtx);
404 error = VOP_GETATTR(vp, &vattr, cred);
405 if (error)
406 return (error);
407 mtx_lock(&np->n_mtx);
408 if ((np->n_flag & NSIZECHANGED)
409 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
410 mtx_unlock(&np->n_mtx);
411 if (vp->v_type == VDIR)
412 ncl_invaldir(vp);
413 error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
414 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
415 error = EBADF;
416 if (error != 0)
417 goto out;
418 mtx_lock(&np->n_mtx);
419 np->n_mtime = vattr.va_mtime;
420 np->n_flag &= ~NSIZECHANGED;
421 }
422 mtx_unlock(&np->n_mtx);
423 }
424 out:
425 ncl_downgrade_vnlock(vp, old_lock);
426 return (error);
427 }
428
429 /*
430 * Vnode op for read using bio
431 */
432 int
433 ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
434 {
435 struct nfsnode *np = VTONFS(vp);
436 int biosize, i;
437 struct buf *bp, *rabp;
438 struct thread *td;
439 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
440 daddr_t lbn, rabn;
441 int bcount;
442 int seqcount;
443 int nra, error = 0, n = 0, on = 0;
444 off_t tmp_off;
445
446 KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode"));
447 if (uio->uio_resid == 0)
448 return (0);
449 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */
450 return (EINVAL);
451 td = uio->uio_td;
452
453 mtx_lock(&nmp->nm_mtx);
454 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
455 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
456 mtx_unlock(&nmp->nm_mtx);
457 (void)ncl_fsinfo(nmp, vp, cred, td);
458 mtx_lock(&nmp->nm_mtx);
459 }
460 if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0)
461 (void) newnfs_iosize(nmp);
462
463 tmp_off = uio->uio_offset + uio->uio_resid;
464 if (vp->v_type != VDIR &&
465 (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) {
466 mtx_unlock(&nmp->nm_mtx);
467 return (EFBIG);
468 }
469 mtx_unlock(&nmp->nm_mtx);
470
471 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG))
472 /* No caching/ no readaheads. Just read data into the user buffer */
473 return ncl_readrpc(vp, uio, cred);
474
475 biosize = vp->v_bufobj.bo_bsize;
476 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE);
477
478 error = nfs_bioread_check_cons(vp, td, cred);
479 if (error)
480 return error;
481
482 do {
483 u_quad_t nsize;
484
485 mtx_lock(&np->n_mtx);
486 nsize = np->n_size;
487 mtx_unlock(&np->n_mtx);
488
489 switch (vp->v_type) {
490 case VREG:
491 NFSINCRGLOBAL(nfsstatsv1.biocache_reads);
492 lbn = uio->uio_offset / biosize;
493 on = uio->uio_offset - (lbn * biosize);
494
495 /*
496 * Start the read ahead(s), as required.
497 */
498 if (nmp->nm_readahead > 0) {
499 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
500 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) {
501 rabn = lbn + 1 + nra;
502 if (incore(&vp->v_bufobj, rabn) == NULL) {
503 rabp = nfs_getcacheblk(vp, rabn, biosize, td);
504 if (!rabp) {
505 error = newnfs_sigintr(nmp, td);
506 return (error ? error : EINTR);
507 }
508 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
509 rabp->b_flags |= B_ASYNC;
510 rabp->b_iocmd = BIO_READ;
511 vfs_busy_pages(rabp, 0);
512 if (ncl_asyncio(nmp, rabp, cred, td)) {
513 rabp->b_flags |= B_INVAL;
514 rabp->b_ioflags |= BIO_ERROR;
515 vfs_unbusy_pages(rabp);
516 brelse(rabp);
517 break;
518 }
519 } else {
520 brelse(rabp);
521 }
522 }
523 }
524 }
525
526 /* Note that bcount is *not* DEV_BSIZE aligned. */
527 bcount = biosize;
528 if ((off_t)lbn * biosize >= nsize) {
529 bcount = 0;
530 } else if ((off_t)(lbn + 1) * biosize > nsize) {
531 bcount = nsize - (off_t)lbn * biosize;
532 }
533 bp = nfs_getcacheblk(vp, lbn, bcount, td);
534
535 if (!bp) {
536 error = newnfs_sigintr(nmp, td);
537 return (error ? error : EINTR);
538 }
539
540 /*
541 * If B_CACHE is not set, we must issue the read. If this
542 * fails, we return an error.
543 */
544
545 if ((bp->b_flags & B_CACHE) == 0) {
546 bp->b_iocmd = BIO_READ;
547 vfs_busy_pages(bp, 0);
548 error = ncl_doio(vp, bp, cred, td, 0);
549 if (error) {
550 brelse(bp);
551 return (error);
552 }
553 }
554
555 /*
556 * on is the offset into the current bp. Figure out how many
557 * bytes we can copy out of the bp. Note that bcount is
558 * NOT DEV_BSIZE aligned.
559 *
560 * Then figure out how many bytes we can copy into the uio.
561 */
562
563 n = 0;
564 if (on < bcount)
565 n = MIN((unsigned)(bcount - on), uio->uio_resid);
566 break;
567 case VLNK:
568 NFSINCRGLOBAL(nfsstatsv1.biocache_readlinks);
569 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
570 if (!bp) {
571 error = newnfs_sigintr(nmp, td);
572 return (error ? error : EINTR);
573 }
574 if ((bp->b_flags & B_CACHE) == 0) {
575 bp->b_iocmd = BIO_READ;
576 vfs_busy_pages(bp, 0);
577 error = ncl_doio(vp, bp, cred, td, 0);
578 if (error) {
579 bp->b_ioflags |= BIO_ERROR;
580 brelse(bp);
581 return (error);
582 }
583 }
584 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
585 on = 0;
586 break;
587 case VDIR:
588 NFSINCRGLOBAL(nfsstatsv1.biocache_readdirs);
589 if (np->n_direofoffset
590 && uio->uio_offset >= np->n_direofoffset) {
591 return (0);
592 }
593 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
594 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
595 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
596 if (!bp) {
597 error = newnfs_sigintr(nmp, td);
598 return (error ? error : EINTR);
599 }
600 if ((bp->b_flags & B_CACHE) == 0) {
601 bp->b_iocmd = BIO_READ;
602 vfs_busy_pages(bp, 0);
603 error = ncl_doio(vp, bp, cred, td, 0);
604 if (error) {
605 brelse(bp);
606 }
607 while (error == NFSERR_BAD_COOKIE) {
608 ncl_invaldir(vp);
609 error = ncl_vinvalbuf(vp, 0, td, 1);
610 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
611 return (EBADF);
612
613 /*
614 * Yuck! The directory has been modified on the
615 * server. The only way to get the block is by
616 * reading from the beginning to get all the
617 * offset cookies.
618 *
619 * Leave the last bp intact unless there is an error.
620 * Loop back up to the while if the error is another
621 * NFSERR_BAD_COOKIE (double yuch!).
622 */
623 for (i = 0; i <= lbn && !error; i++) {
624 if (np->n_direofoffset
625 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset)
626 return (0);
627 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
628 if (!bp) {
629 error = newnfs_sigintr(nmp, td);
630 return (error ? error : EINTR);
631 }
632 if ((bp->b_flags & B_CACHE) == 0) {
633 bp->b_iocmd = BIO_READ;
634 vfs_busy_pages(bp, 0);
635 error = ncl_doio(vp, bp, cred, td, 0);
636 /*
637 * no error + B_INVAL == directory EOF,
638 * use the block.
639 */
640 if (error == 0 && (bp->b_flags & B_INVAL))
641 break;
642 }
643 /*
644 * An error will throw away the block and the
645 * for loop will break out. If no error and this
646 * is not the block we want, we throw away the
647 * block and go for the next one via the for loop.
648 */
649 if (error || i < lbn)
650 brelse(bp);
651 }
652 }
653 /*
654 * The above while is repeated if we hit another cookie
655 * error. If we hit an error and it wasn't a cookie error,
656 * we give up.
657 */
658 if (error)
659 return (error);
660 }
661
662 /*
663 * If not eof and read aheads are enabled, start one.
664 * (You need the current block first, so that you have the
665 * directory offset cookie of the next block.)
666 */
667 if (nmp->nm_readahead > 0 &&
668 (bp->b_flags & B_INVAL) == 0 &&
669 (np->n_direofoffset == 0 ||
670 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
671 incore(&vp->v_bufobj, lbn + 1) == NULL) {
672 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
673 if (rabp) {
674 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
675 rabp->b_flags |= B_ASYNC;
676 rabp->b_iocmd = BIO_READ;
677 vfs_busy_pages(rabp, 0);
678 if (ncl_asyncio(nmp, rabp, cred, td)) {
679 rabp->b_flags |= B_INVAL;
680 rabp->b_ioflags |= BIO_ERROR;
681 vfs_unbusy_pages(rabp);
682 brelse(rabp);
683 }
684 } else {
685 brelse(rabp);
686 }
687 }
688 }
689 /*
690 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is
691 * chopped for the EOF condition, we cannot tell how large
692 * NFS directories are going to be until we hit EOF. So
693 * an NFS directory buffer is *not* chopped to its EOF. Now,
694 * it just so happens that b_resid will effectively chop it
695 * to EOF. *BUT* this information is lost if the buffer goes
696 * away and is reconstituted into a B_CACHE state ( due to
697 * being VMIO ) later. So we keep track of the directory eof
698 * in np->n_direofoffset and chop it off as an extra step
699 * right here.
700 */
701 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
702 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
703 n = np->n_direofoffset - uio->uio_offset;
704 break;
705 default:
706 printf(" ncl_bioread: type %x unexpected\n", vp->v_type);
707 bp = NULL;
708 break;
709 }
710
711 if (n > 0) {
712 error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio);
713 }
714 if (vp->v_type == VLNK)
715 n = 0;
716 if (bp != NULL)
717 brelse(bp);
718 } while (error == 0 && uio->uio_resid > 0 && n > 0);
719 return (error);
720 }
721
722 /*
723 * The NFS write path cannot handle iovecs with len > 1. So we need to
724 * break up iovecs accordingly (restricting them to wsize).
725 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf).
726 * For the ASYNC case, 2 copies are needed. The first a copy from the
727 * user buffer to a staging buffer and then a second copy from the staging
728 * buffer to mbufs. This can be optimized by copying from the user buffer
729 * directly into mbufs and passing the chain down, but that requires a
730 * fair amount of re-working of the relevant codepaths (and can be done
731 * later).
732 */
733 static int
734 nfs_directio_write(vp, uiop, cred, ioflag)
735 struct vnode *vp;
736 struct uio *uiop;
737 struct ucred *cred;
738 int ioflag;
739 {
740 int error;
741 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
742 struct thread *td = uiop->uio_td;
743 int size;
744 int wsize;
745
746 mtx_lock(&nmp->nm_mtx);
747 wsize = nmp->nm_wsize;
748 mtx_unlock(&nmp->nm_mtx);
749 if (ioflag & IO_SYNC) {
750 int iomode, must_commit;
751 struct uio uio;
752 struct iovec iov;
753 do_sync:
754 while (uiop->uio_resid > 0) {
755 size = MIN(uiop->uio_resid, wsize);
756 size = MIN(uiop->uio_iov->iov_len, size);
757 iov.iov_base = uiop->uio_iov->iov_base;
758 iov.iov_len = size;
759 uio.uio_iov = &iov;
760 uio.uio_iovcnt = 1;
761 uio.uio_offset = uiop->uio_offset;
762 uio.uio_resid = size;
763 uio.uio_segflg = UIO_USERSPACE;
764 uio.uio_rw = UIO_WRITE;
765 uio.uio_td = td;
766 iomode = NFSWRITE_FILESYNC;
767 error = ncl_writerpc(vp, &uio, cred, &iomode,
768 &must_commit, 0);
769 KASSERT((must_commit == 0),
770 ("ncl_directio_write: Did not commit write"));
771 if (error)
772 return (error);
773 uiop->uio_offset += size;
774 uiop->uio_resid -= size;
775 if (uiop->uio_iov->iov_len <= size) {
776 uiop->uio_iovcnt--;
777 uiop->uio_iov++;
778 } else {
779 uiop->uio_iov->iov_base =
780 (char *)uiop->uio_iov->iov_base + size;
781 uiop->uio_iov->iov_len -= size;
782 }
783 }
784 } else {
785 struct uio *t_uio;
786 struct iovec *t_iov;
787 struct buf *bp;
788
789 /*
790 * Break up the write into blocksize chunks and hand these
791 * over to nfsiod's for write back.
792 * Unfortunately, this incurs a copy of the data. Since
793 * the user could modify the buffer before the write is
794 * initiated.
795 *
796 * The obvious optimization here is that one of the 2 copies
797 * in the async write path can be eliminated by copying the
798 * data here directly into mbufs and passing the mbuf chain
799 * down. But that will require a fair amount of re-working
800 * of the code and can be done if there's enough interest
801 * in NFS directio access.
802 */
803 while (uiop->uio_resid > 0) {
804 size = MIN(uiop->uio_resid, wsize);
805 size = MIN(uiop->uio_iov->iov_len, size);
806 bp = getpbuf(&ncl_pbuf_freecnt);
807 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
808 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
809 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK);
810 t_iov->iov_len = size;
811 t_uio->uio_iov = t_iov;
812 t_uio->uio_iovcnt = 1;
813 t_uio->uio_offset = uiop->uio_offset;
814 t_uio->uio_resid = size;
815 t_uio->uio_segflg = UIO_SYSSPACE;
816 t_uio->uio_rw = UIO_WRITE;
817 t_uio->uio_td = td;
818 KASSERT(uiop->uio_segflg == UIO_USERSPACE ||
819 uiop->uio_segflg == UIO_SYSSPACE,
820 ("nfs_directio_write: Bad uio_segflg"));
821 if (uiop->uio_segflg == UIO_USERSPACE) {
822 error = copyin(uiop->uio_iov->iov_base,
823 t_iov->iov_base, size);
824 if (error != 0)
825 goto err_free;
826 } else
827 /*
828 * UIO_SYSSPACE may never happen, but handle
829 * it just in case it does.
830 */
831 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base,
832 size);
833 bp->b_flags |= B_DIRECT;
834 bp->b_iocmd = BIO_WRITE;
835 if (cred != NOCRED) {
836 crhold(cred);
837 bp->b_wcred = cred;
838 } else
839 bp->b_wcred = NOCRED;
840 bp->b_caller1 = (void *)t_uio;
841 bp->b_vp = vp;
842 error = ncl_asyncio(nmp, bp, NOCRED, td);
843 err_free:
844 if (error) {
845 free(t_iov->iov_base, M_NFSDIRECTIO);
846 free(t_iov, M_NFSDIRECTIO);
847 free(t_uio, M_NFSDIRECTIO);
848 bp->b_vp = NULL;
849 relpbuf(bp, &ncl_pbuf_freecnt);
850 if (error == EINTR)
851 return (error);
852 goto do_sync;
853 }
854 uiop->uio_offset += size;
855 uiop->uio_resid -= size;
856 if (uiop->uio_iov->iov_len <= size) {
857 uiop->uio_iovcnt--;
858 uiop->uio_iov++;
859 } else {
860 uiop->uio_iov->iov_base =
861 (char *)uiop->uio_iov->iov_base + size;
862 uiop->uio_iov->iov_len -= size;
863 }
864 }
865 }
866 return (0);
867 }
868
869 /*
870 * Vnode op for write using bio
871 */
872 int
873 ncl_write(struct vop_write_args *ap)
874 {
875 int biosize;
876 struct uio *uio = ap->a_uio;
877 struct thread *td = uio->uio_td;
878 struct vnode *vp = ap->a_vp;
879 struct nfsnode *np = VTONFS(vp);
880 struct ucred *cred = ap->a_cred;
881 int ioflag = ap->a_ioflag;
882 struct buf *bp;
883 struct vattr vattr;
884 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
885 daddr_t lbn;
886 int bcount, noncontig_write, obcount;
887 int bp_cached, n, on, error = 0, error1, wouldcommit;
888 size_t orig_resid, local_resid;
889 off_t orig_size, tmp_off;
890
891 KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode"));
892 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
893 ("ncl_write proc"));
894 if (vp->v_type != VREG)
895 return (EIO);
896 mtx_lock(&np->n_mtx);
897 if (np->n_flag & NWRITEERR) {
898 np->n_flag &= ~NWRITEERR;
899 mtx_unlock(&np->n_mtx);
900 return (np->n_error);
901 } else
902 mtx_unlock(&np->n_mtx);
903 mtx_lock(&nmp->nm_mtx);
904 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
905 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
906 mtx_unlock(&nmp->nm_mtx);
907 (void)ncl_fsinfo(nmp, vp, cred, td);
908 mtx_lock(&nmp->nm_mtx);
909 }
910 if (nmp->nm_wsize == 0)
911 (void) newnfs_iosize(nmp);
912 mtx_unlock(&nmp->nm_mtx);
913
914 /*
915 * Synchronously flush pending buffers if we are in synchronous
916 * mode or if we are appending.
917 */
918 if (ioflag & (IO_APPEND | IO_SYNC)) {
919 mtx_lock(&np->n_mtx);
920 if (np->n_flag & NMODIFIED) {
921 mtx_unlock(&np->n_mtx);
922 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */
923 /*
924 * Require non-blocking, synchronous writes to
925 * dirty files to inform the program it needs
926 * to fsync(2) explicitly.
927 */
928 if (ioflag & IO_NDELAY)
929 return (EAGAIN);
930 #endif
931 np->n_attrstamp = 0;
932 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
933 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
934 IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
935 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
936 error = EBADF;
937 if (error != 0)
938 return (error);
939 } else
940 mtx_unlock(&np->n_mtx);
941 }
942
943 orig_resid = uio->uio_resid;
944 mtx_lock(&np->n_mtx);
945 orig_size = np->n_size;
946 mtx_unlock(&np->n_mtx);
947
948 /*
949 * If IO_APPEND then load uio_offset. We restart here if we cannot
950 * get the append lock.
951 */
952 if (ioflag & IO_APPEND) {
953 np->n_attrstamp = 0;
954 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
955 error = VOP_GETATTR(vp, &vattr, cred);
956 if (error)
957 return (error);
958 mtx_lock(&np->n_mtx);
959 uio->uio_offset = np->n_size;
960 mtx_unlock(&np->n_mtx);
961 }
962
963 if (uio->uio_offset < 0)
964 return (EINVAL);
965 tmp_off = uio->uio_offset + uio->uio_resid;
966 if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)
967 return (EFBIG);
968 if (uio->uio_resid == 0)
969 return (0);
970
971 if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
972 return nfs_directio_write(vp, uio, cred, ioflag);
973
974 /*
975 * Maybe this should be above the vnode op call, but so long as
976 * file servers have no limits, i don't think it matters
977 */
978 if (vn_rlimit_fsize(vp, uio, td))
979 return (EFBIG);
980
981 biosize = vp->v_bufobj.bo_bsize;
982 /*
983 * Find all of this file's B_NEEDCOMMIT buffers. If our writes
984 * would exceed the local maximum per-file write commit size when
985 * combined with those, we must decide whether to flush,
986 * go synchronous, or return error. We don't bother checking
987 * IO_UNIT -- we just make all writes atomic anyway, as there's
988 * no point optimizing for something that really won't ever happen.
989 */
990 wouldcommit = 0;
991 if (!(ioflag & IO_SYNC)) {
992 int nflag;
993
994 mtx_lock(&np->n_mtx);
995 nflag = np->n_flag;
996 mtx_unlock(&np->n_mtx);
997 if (nflag & NMODIFIED) {
998 BO_LOCK(&vp->v_bufobj);
999 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) {
1000 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd,
1001 b_bobufs) {
1002 if (bp->b_flags & B_NEEDCOMMIT)
1003 wouldcommit += bp->b_bcount;
1004 }
1005 }
1006 BO_UNLOCK(&vp->v_bufobj);
1007 }
1008 }
1009
1010 do {
1011 if (!(ioflag & IO_SYNC)) {
1012 wouldcommit += biosize;
1013 if (wouldcommit > nmp->nm_wcommitsize) {
1014 np->n_attrstamp = 0;
1015 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
1016 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
1017 IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
1018 if (error == 0 &&
1019 (vp->v_iflag & VI_DOOMED) != 0)
1020 error = EBADF;
1021 if (error != 0)
1022 return (error);
1023 wouldcommit = biosize;
1024 }
1025 }
1026
1027 NFSINCRGLOBAL(nfsstatsv1.biocache_writes);
1028 lbn = uio->uio_offset / biosize;
1029 on = uio->uio_offset - (lbn * biosize);
1030 n = MIN((unsigned)(biosize - on), uio->uio_resid);
1031 again:
1032 /*
1033 * Handle direct append and file extension cases, calculate
1034 * unaligned buffer size.
1035 */
1036 mtx_lock(&np->n_mtx);
1037 if ((np->n_flag & NHASBEENLOCKED) == 0 &&
1038 (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0)
1039 noncontig_write = 1;
1040 else
1041 noncontig_write = 0;
1042 if ((uio->uio_offset == np->n_size ||
1043 (noncontig_write != 0 &&
1044 lbn == (np->n_size / biosize) &&
1045 uio->uio_offset + n > np->n_size)) && n) {
1046 mtx_unlock(&np->n_mtx);
1047 /*
1048 * Get the buffer (in its pre-append state to maintain
1049 * B_CACHE if it was previously set). Resize the
1050 * nfsnode after we have locked the buffer to prevent
1051 * readers from reading garbage.
1052 */
1053 obcount = np->n_size - (lbn * biosize);
1054 bp = nfs_getcacheblk(vp, lbn, obcount, td);
1055
1056 if (bp != NULL) {
1057 long save;
1058
1059 mtx_lock(&np->n_mtx);
1060 np->n_size = uio->uio_offset + n;
1061 np->n_flag |= NMODIFIED;
1062 vnode_pager_setsize(vp, np->n_size);
1063 mtx_unlock(&np->n_mtx);
1064
1065 save = bp->b_flags & B_CACHE;
1066 bcount = on + n;
1067 allocbuf(bp, bcount);
1068 bp->b_flags |= save;
1069 if (noncontig_write != 0 && on > obcount)
1070 vfs_bio_bzero_buf(bp, obcount, on -
1071 obcount);
1072 }
1073 } else {
1074 /*
1075 * Obtain the locked cache block first, and then
1076 * adjust the file's size as appropriate.
1077 */
1078 bcount = on + n;
1079 if ((off_t)lbn * biosize + bcount < np->n_size) {
1080 if ((off_t)(lbn + 1) * biosize < np->n_size)
1081 bcount = biosize;
1082 else
1083 bcount = np->n_size - (off_t)lbn * biosize;
1084 }
1085 mtx_unlock(&np->n_mtx);
1086 bp = nfs_getcacheblk(vp, lbn, bcount, td);
1087 mtx_lock(&np->n_mtx);
1088 if (uio->uio_offset + n > np->n_size) {
1089 np->n_size = uio->uio_offset + n;
1090 np->n_flag |= NMODIFIED;
1091 vnode_pager_setsize(vp, np->n_size);
1092 }
1093 mtx_unlock(&np->n_mtx);
1094 }
1095
1096 if (!bp) {
1097 error = newnfs_sigintr(nmp, td);
1098 if (!error)
1099 error = EINTR;
1100 break;
1101 }
1102
1103 /*
1104 * Issue a READ if B_CACHE is not set. In special-append
1105 * mode, B_CACHE is based on the buffer prior to the write
1106 * op and is typically set, avoiding the read. If a read
1107 * is required in special append mode, the server will
1108 * probably send us a short-read since we extended the file
1109 * on our end, resulting in b_resid == 0 and, thusly,
1110 * B_CACHE getting set.
1111 *
1112 * We can also avoid issuing the read if the write covers
1113 * the entire buffer. We have to make sure the buffer state
1114 * is reasonable in this case since we will not be initiating
1115 * I/O. See the comments in kern/vfs_bio.c's getblk() for
1116 * more information.
1117 *
1118 * B_CACHE may also be set due to the buffer being cached
1119 * normally.
1120 */
1121
1122 bp_cached = 1;
1123 if (on == 0 && n == bcount) {
1124 if ((bp->b_flags & B_CACHE) == 0)
1125 bp_cached = 0;
1126 bp->b_flags |= B_CACHE;
1127 bp->b_flags &= ~B_INVAL;
1128 bp->b_ioflags &= ~BIO_ERROR;
1129 }
1130
1131 if ((bp->b_flags & B_CACHE) == 0) {
1132 bp->b_iocmd = BIO_READ;
1133 vfs_busy_pages(bp, 0);
1134 error = ncl_doio(vp, bp, cred, td, 0);
1135 if (error) {
1136 brelse(bp);
1137 break;
1138 }
1139 }
1140 if (bp->b_wcred == NOCRED)
1141 bp->b_wcred = crhold(cred);
1142 mtx_lock(&np->n_mtx);
1143 np->n_flag |= NMODIFIED;
1144 mtx_unlock(&np->n_mtx);
1145
1146 /*
1147 * If dirtyend exceeds file size, chop it down. This should
1148 * not normally occur but there is an append race where it
1149 * might occur XXX, so we log it.
1150 *
1151 * If the chopping creates a reverse-indexed or degenerate
1152 * situation with dirtyoff/end, we 0 both of them.
1153 */
1154
1155 if (bp->b_dirtyend > bcount) {
1156 printf("NFS append race @%lx:%d\n",
1157 (long)bp->b_blkno * DEV_BSIZE,
1158 bp->b_dirtyend - bcount);
1159 bp->b_dirtyend = bcount;
1160 }
1161
1162 if (bp->b_dirtyoff >= bp->b_dirtyend)
1163 bp->b_dirtyoff = bp->b_dirtyend = 0;
1164
1165 /*
1166 * If the new write will leave a contiguous dirty
1167 * area, just update the b_dirtyoff and b_dirtyend,
1168 * otherwise force a write rpc of the old dirty area.
1169 *
1170 * If there has been a file lock applied to this file
1171 * or vfs.nfs.old_noncontig_writing is set, do the following:
1172 * While it is possible to merge discontiguous writes due to
1173 * our having a B_CACHE buffer ( and thus valid read data
1174 * for the hole), we don't because it could lead to
1175 * significant cache coherency problems with multiple clients,
1176 * especially if locking is implemented later on.
1177 *
1178 * If vfs.nfs.old_noncontig_writing is not set and there has
1179 * not been file locking done on this file:
1180 * Relax coherency a bit for the sake of performance and
1181 * expand the current dirty region to contain the new
1182 * write even if it means we mark some non-dirty data as
1183 * dirty.
1184 */
1185
1186 if (noncontig_write == 0 && bp->b_dirtyend > 0 &&
1187 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
1188 if (bwrite(bp) == EINTR) {
1189 error = EINTR;
1190 break;
1191 }
1192 goto again;
1193 }
1194
1195 local_resid = uio->uio_resid;
1196 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio);
1197
1198 if (error != 0 && !bp_cached) {
1199 /*
1200 * This block has no other content then what
1201 * possibly was written by the faulty uiomove.
1202 * Release it, forgetting the data pages, to
1203 * prevent the leak of uninitialized data to
1204 * usermode.
1205 */
1206 bp->b_ioflags |= BIO_ERROR;
1207 brelse(bp);
1208 uio->uio_offset -= local_resid - uio->uio_resid;
1209 uio->uio_resid = local_resid;
1210 break;
1211 }
1212
1213 /*
1214 * Since this block is being modified, it must be written
1215 * again and not just committed. Since write clustering does
1216 * not work for the stage 1 data write, only the stage 2
1217 * commit rpc, we have to clear B_CLUSTEROK as well.
1218 */
1219 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1220
1221 /*
1222 * Get the partial update on the progress made from
1223 * uiomove, if an error occurred.
1224 */
1225 if (error != 0)
1226 n = local_resid - uio->uio_resid;
1227
1228 /*
1229 * Only update dirtyoff/dirtyend if not a degenerate
1230 * condition.
1231 */
1232 if (n > 0) {
1233 if (bp->b_dirtyend > 0) {
1234 bp->b_dirtyoff = min(on, bp->b_dirtyoff);
1235 bp->b_dirtyend = max((on + n), bp->b_dirtyend);
1236 } else {
1237 bp->b_dirtyoff = on;
1238 bp->b_dirtyend = on + n;
1239 }
1240 vfs_bio_set_valid(bp, on, n);
1241 }
1242
1243 /*
1244 * If IO_SYNC do bwrite().
1245 *
1246 * IO_INVAL appears to be unused. The idea appears to be
1247 * to turn off caching in this case. Very odd. XXX
1248 */
1249 if ((ioflag & IO_SYNC)) {
1250 if (ioflag & IO_INVAL)
1251 bp->b_flags |= B_NOCACHE;
1252 error1 = bwrite(bp);
1253 if (error1 != 0) {
1254 if (error == 0)
1255 error = error1;
1256 break;
1257 }
1258 } else if ((n + on) == biosize || (ioflag & IO_ASYNC) != 0) {
1259 bp->b_flags |= B_ASYNC;
1260 (void) ncl_writebp(bp, 0, NULL);
1261 } else {
1262 bdwrite(bp);
1263 }
1264
1265 if (error != 0)
1266 break;
1267 } while (uio->uio_resid > 0 && n > 0);
1268
1269 if (error != 0) {
1270 if (ioflag & IO_UNIT) {
1271 VATTR_NULL(&vattr);
1272 vattr.va_size = orig_size;
1273 /* IO_SYNC is handled implicitely */
1274 (void)VOP_SETATTR(vp, &vattr, cred);
1275 uio->uio_offset -= orig_resid - uio->uio_resid;
1276 uio->uio_resid = orig_resid;
1277 }
1278 }
1279
1280 return (error);
1281 }
1282
1283 /*
1284 * Get an nfs cache block.
1285 *
1286 * Allocate a new one if the block isn't currently in the cache
1287 * and return the block marked busy. If the calling process is
1288 * interrupted by a signal for an interruptible mount point, return
1289 * NULL.
1290 *
1291 * The caller must carefully deal with the possible B_INVAL state of
1292 * the buffer. ncl_doio() clears B_INVAL (and ncl_asyncio() clears it
1293 * indirectly), so synchronous reads can be issued without worrying about
1294 * the B_INVAL state. We have to be a little more careful when dealing
1295 * with writes (see comments in nfs_write()) when extending a file past
1296 * its EOF.
1297 */
1298 static struct buf *
1299 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
1300 {
1301 struct buf *bp;
1302 struct mount *mp;
1303 struct nfsmount *nmp;
1304
1305 mp = vp->v_mount;
1306 nmp = VFSTONFS(mp);
1307
1308 if (nmp->nm_flag & NFSMNT_INT) {
1309 sigset_t oldset;
1310
1311 newnfs_set_sigmask(td, &oldset);
1312 bp = getblk(vp, bn, size, PCATCH, 0, 0);
1313 newnfs_restore_sigmask(td, &oldset);
1314 while (bp == NULL) {
1315 if (newnfs_sigintr(nmp, td))
1316 return (NULL);
1317 bp = getblk(vp, bn, size, 0, 2 * hz, 0);
1318 }
1319 } else {
1320 bp = getblk(vp, bn, size, 0, 0, 0);
1321 }
1322
1323 if (vp->v_type == VREG)
1324 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE);
1325 return (bp);
1326 }
1327
1328 /*
1329 * Flush and invalidate all dirty buffers. If another process is already
1330 * doing the flush, just wait for completion.
1331 */
1332 int
1333 ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg)
1334 {
1335 struct nfsnode *np = VTONFS(vp);
1336 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
1337 int error = 0, slpflag, slptimeo;
1338 int old_lock = 0;
1339
1340 ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf");
1341
1342 if ((nmp->nm_flag & NFSMNT_INT) == 0)
1343 intrflg = 0;
1344 if ((nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF))
1345 intrflg = 1;
1346 if (intrflg) {
1347 slpflag = PCATCH;
1348 slptimeo = 2 * hz;
1349 } else {
1350 slpflag = 0;
1351 slptimeo = 0;
1352 }
1353
1354 old_lock = ncl_upgrade_vnlock(vp);
1355 if (vp->v_iflag & VI_DOOMED) {
1356 /*
1357 * Since vgonel() uses the generic vinvalbuf() to flush
1358 * dirty buffers and it does not call this function, it
1359 * is safe to just return OK when VI_DOOMED is set.
1360 */
1361 ncl_downgrade_vnlock(vp, old_lock);
1362 return (0);
1363 }
1364
1365 /*
1366 * Now, flush as required.
1367 */
1368 if ((flags & (V_SAVE | V_VMIO)) == V_SAVE &&
1369 vp->v_bufobj.bo_object != NULL) {
1370 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object);
1371 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
1372 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object);
1373 /*
1374 * If the page clean was interrupted, fail the invalidation.
1375 * Not doing so, we run the risk of losing dirty pages in the
1376 * vinvalbuf() call below.
1377 */
1378 if (intrflg && (error = newnfs_sigintr(nmp, td)))
1379 goto out;
1380 }
1381
1382 error = vinvalbuf(vp, flags, slpflag, 0);
1383 while (error) {
1384 if (intrflg && (error = newnfs_sigintr(nmp, td)))
1385 goto out;
1386 error = vinvalbuf(vp, flags, 0, slptimeo);
1387 }
1388 if (NFSHASPNFS(nmp)) {
1389 nfscl_layoutcommit(vp, td);
1390 /*
1391 * Invalidate the attribute cache, since writes to a DS
1392 * won't update the size attribute.
1393 */
1394 mtx_lock(&np->n_mtx);
1395 np->n_attrstamp = 0;
1396 } else
1397 mtx_lock(&np->n_mtx);
1398 if (np->n_directio_asyncwr == 0)
1399 np->n_flag &= ~NMODIFIED;
1400 mtx_unlock(&np->n_mtx);
1401 out:
1402 ncl_downgrade_vnlock(vp, old_lock);
1403 return error;
1404 }
1405
1406 /*
1407 * Initiate asynchronous I/O. Return an error if no nfsiods are available.
1408 * This is mainly to avoid queueing async I/O requests when the nfsiods
1409 * are all hung on a dead server.
1410 *
1411 * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
1412 * is eventually dequeued by the async daemon, ncl_doio() *will*.
1413 */
1414 int
1415 ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
1416 {
1417 int iod;
1418 int gotiod;
1419 int slpflag = 0;
1420 int slptimeo = 0;
1421 int error, error2;
1422
1423 /*
1424 * Commits are usually short and sweet so lets save some cpu and
1425 * leave the async daemons for more important rpc's (such as reads
1426 * and writes).
1427 *
1428 * Readdirplus RPCs do vget()s to acquire the vnodes for entries
1429 * in the directory in order to update attributes. This can deadlock
1430 * with another thread that is waiting for async I/O to be done by
1431 * an nfsiod thread while holding a lock on one of these vnodes.
1432 * To avoid this deadlock, don't allow the async nfsiod threads to
1433 * perform Readdirplus RPCs.
1434 */
1435 mtx_lock(&ncl_iod_mutex);
1436 if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
1437 (nmp->nm_bufqiods > ncl_numasync / 2)) ||
1438 (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) {
1439 mtx_unlock(&ncl_iod_mutex);
1440 return(EIO);
1441 }
1442 again:
1443 if (nmp->nm_flag & NFSMNT_INT)
1444 slpflag = PCATCH;
1445 gotiod = FALSE;
1446
1447 /*
1448 * Find a free iod to process this request.
1449 */
1450 for (iod = 0; iod < ncl_numasync; iod++)
1451 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) {
1452 gotiod = TRUE;
1453 break;
1454 }
1455
1456 /*
1457 * Try to create one if none are free.
1458 */
1459 if (!gotiod)
1460 ncl_nfsiodnew();
1461 else {
1462 /*
1463 * Found one, so wake it up and tell it which
1464 * mount to process.
1465 */
1466 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n",
1467 iod, nmp));
1468 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE;
1469 ncl_iodmount[iod] = nmp;
1470 nmp->nm_bufqiods++;
1471 wakeup(&ncl_iodwant[iod]);
1472 }
1473
1474 /*
1475 * If none are free, we may already have an iod working on this mount
1476 * point. If so, it will process our request.
1477 */
1478 if (!gotiod) {
1479 if (nmp->nm_bufqiods > 0) {
1480 NFS_DPF(ASYNCIO,
1481 ("ncl_asyncio: %d iods are already processing mount %p\n",
1482 nmp->nm_bufqiods, nmp));
1483 gotiod = TRUE;
1484 }
1485 }
1486
1487 /*
1488 * If we have an iod which can process the request, then queue
1489 * the buffer.
1490 */
1491 if (gotiod) {
1492 /*
1493 * Ensure that the queue never grows too large. We still want
1494 * to asynchronize so we block rather then return EIO.
1495 */
1496 while (nmp->nm_bufqlen >= 2*ncl_numasync) {
1497 NFS_DPF(ASYNCIO,
1498 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp));
1499 nmp->nm_bufqwant = TRUE;
1500 error = newnfs_msleep(td, &nmp->nm_bufq,
1501 &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio",
1502 slptimeo);
1503 if (error) {
1504 error2 = newnfs_sigintr(nmp, td);
1505 if (error2) {
1506 mtx_unlock(&ncl_iod_mutex);
1507 return (error2);
1508 }
1509 if (slpflag == PCATCH) {
1510 slpflag = 0;
1511 slptimeo = 2 * hz;
1512 }
1513 }
1514 /*
1515 * We might have lost our iod while sleeping,
1516 * so check and loop if necessary.
1517 */
1518 goto again;
1519 }
1520
1521 /* We might have lost our nfsiod */
1522 if (nmp->nm_bufqiods == 0) {
1523 NFS_DPF(ASYNCIO,
1524 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
1525 goto again;
1526 }
1527
1528 if (bp->b_iocmd == BIO_READ) {
1529 if (bp->b_rcred == NOCRED && cred != NOCRED)
1530 bp->b_rcred = crhold(cred);
1531 } else {
1532 if (bp->b_wcred == NOCRED && cred != NOCRED)
1533 bp->b_wcred = crhold(cred);
1534 }
1535
1536 if (bp->b_flags & B_REMFREE)
1537 bremfreef(bp);
1538 BUF_KERNPROC(bp);
1539 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
1540 nmp->nm_bufqlen++;
1541 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1542 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx);
1543 VTONFS(bp->b_vp)->n_flag |= NMODIFIED;
1544 VTONFS(bp->b_vp)->n_directio_asyncwr++;
1545 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx);
1546 }
1547 mtx_unlock(&ncl_iod_mutex);
1548 return (0);
1549 }
1550
1551 mtx_unlock(&ncl_iod_mutex);
1552
1553 /*
1554 * All the iods are busy on other mounts, so return EIO to
1555 * force the caller to process the i/o synchronously.
1556 */
1557 NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n"));
1558 return (EIO);
1559 }
1560
1561 void
1562 ncl_doio_directwrite(struct buf *bp)
1563 {
1564 int iomode, must_commit;
1565 struct uio *uiop = (struct uio *)bp->b_caller1;
1566 char *iov_base = uiop->uio_iov->iov_base;
1567
1568 iomode = NFSWRITE_FILESYNC;
1569 uiop->uio_td = NULL; /* NULL since we're in nfsiod */
1570 ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0);
1571 KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write"));
1572 free(iov_base, M_NFSDIRECTIO);
1573 free(uiop->uio_iov, M_NFSDIRECTIO);
1574 free(uiop, M_NFSDIRECTIO);
1575 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1576 struct nfsnode *np = VTONFS(bp->b_vp);
1577 mtx_lock(&np->n_mtx);
1578 if (NFSHASPNFS(VFSTONFS(vnode_mount(bp->b_vp)))) {
1579 /*
1580 * Invalidate the attribute cache, since writes to a DS
1581 * won't update the size attribute.
1582 */
1583 np->n_attrstamp = 0;
1584 }
1585 np->n_directio_asyncwr--;
1586 if (np->n_directio_asyncwr == 0) {
1587 np->n_flag &= ~NMODIFIED;
1588 if ((np->n_flag & NFSYNCWAIT)) {
1589 np->n_flag &= ~NFSYNCWAIT;
1590 wakeup((caddr_t)&np->n_directio_asyncwr);
1591 }
1592 }
1593 mtx_unlock(&np->n_mtx);
1594 }
1595 bp->b_vp = NULL;
1596 relpbuf(bp, &ncl_pbuf_freecnt);
1597 }
1598
1599 /*
1600 * Do an I/O operation to/from a cache block. This may be called
1601 * synchronously or from an nfsiod.
1602 */
1603 int
1604 ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td,
1605 int called_from_strategy)
1606 {
1607 struct uio *uiop;
1608 struct nfsnode *np;
1609 struct nfsmount *nmp;
1610 int error = 0, iomode, must_commit = 0;
1611 struct uio uio;
1612 struct iovec io;
1613 struct proc *p = td ? td->td_proc : NULL;
1614 uint8_t iocmd;
1615
1616 np = VTONFS(vp);
1617 nmp = VFSTONFS(vp->v_mount);
1618 uiop = &uio;
1619 uiop->uio_iov = &io;
1620 uiop->uio_iovcnt = 1;
1621 uiop->uio_segflg = UIO_SYSSPACE;
1622 uiop->uio_td = td;
1623
1624 /*
1625 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
1626 * do this here so we do not have to do it in all the code that
1627 * calls us.
1628 */
1629 bp->b_flags &= ~B_INVAL;
1630 bp->b_ioflags &= ~BIO_ERROR;
1631
1632 KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp));
1633 iocmd = bp->b_iocmd;
1634 if (iocmd == BIO_READ) {
1635 io.iov_len = uiop->uio_resid = bp->b_bcount;
1636 io.iov_base = bp->b_data;
1637 uiop->uio_rw = UIO_READ;
1638
1639 switch (vp->v_type) {
1640 case VREG:
1641 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
1642 NFSINCRGLOBAL(nfsstatsv1.read_bios);
1643 error = ncl_readrpc(vp, uiop, cr);
1644
1645 if (!error) {
1646 if (uiop->uio_resid) {
1647 /*
1648 * If we had a short read with no error, we must have
1649 * hit a file hole. We should zero-fill the remainder.
1650 * This can also occur if the server hits the file EOF.
1651 *
1652 * Holes used to be able to occur due to pending
1653 * writes, but that is not possible any longer.
1654 */
1655 int nread = bp->b_bcount - uiop->uio_resid;
1656 ssize_t left = uiop->uio_resid;
1657
1658 if (left > 0)
1659 bzero((char *)bp->b_data + nread, left);
1660 uiop->uio_resid = 0;
1661 }
1662 }
1663 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */
1664 if (p && (vp->v_vflag & VV_TEXT)) {
1665 mtx_lock(&np->n_mtx);
1666 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) {
1667 mtx_unlock(&np->n_mtx);
1668 PROC_LOCK(p);
1669 killproc(p, "text file modification");
1670 PROC_UNLOCK(p);
1671 } else
1672 mtx_unlock(&np->n_mtx);
1673 }
1674 break;
1675 case VLNK:
1676 uiop->uio_offset = (off_t)0;
1677 NFSINCRGLOBAL(nfsstatsv1.readlink_bios);
1678 error = ncl_readlinkrpc(vp, uiop, cr);
1679 break;
1680 case VDIR:
1681 NFSINCRGLOBAL(nfsstatsv1.readdir_bios);
1682 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
1683 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
1684 error = ncl_readdirplusrpc(vp, uiop, cr, td);
1685 if (error == NFSERR_NOTSUPP)
1686 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
1687 }
1688 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
1689 error = ncl_readdirrpc(vp, uiop, cr, td);
1690 /*
1691 * end-of-directory sets B_INVAL but does not generate an
1692 * error.
1693 */
1694 if (error == 0 && uiop->uio_resid == bp->b_bcount)
1695 bp->b_flags |= B_INVAL;
1696 break;
1697 default:
1698 printf("ncl_doio: type %x unexpected\n", vp->v_type);
1699 break;
1700 }
1701 if (error) {
1702 bp->b_ioflags |= BIO_ERROR;
1703 bp->b_error = error;
1704 }
1705 } else {
1706 /*
1707 * If we only need to commit, try to commit
1708 */
1709 if (bp->b_flags & B_NEEDCOMMIT) {
1710 int retv;
1711 off_t off;
1712
1713 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
1714 retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff,
1715 bp->b_wcred, td);
1716 if (retv == 0) {
1717 bp->b_dirtyoff = bp->b_dirtyend = 0;
1718 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1719 bp->b_resid = 0;
1720 bufdone(bp);
1721 return (0);
1722 }
1723 if (retv == NFSERR_STALEWRITEVERF) {
1724 ncl_clearcommit(vp->v_mount);
1725 }
1726 }
1727
1728 /*
1729 * Setup for actual write
1730 */
1731 mtx_lock(&np->n_mtx);
1732 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
1733 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
1734 mtx_unlock(&np->n_mtx);
1735
1736 if (bp->b_dirtyend > bp->b_dirtyoff) {
1737 io.iov_len = uiop->uio_resid = bp->b_dirtyend
1738 - bp->b_dirtyoff;
1739 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
1740 + bp->b_dirtyoff;
1741 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
1742 uiop->uio_rw = UIO_WRITE;
1743 NFSINCRGLOBAL(nfsstatsv1.write_bios);
1744
1745 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
1746 iomode = NFSWRITE_UNSTABLE;
1747 else
1748 iomode = NFSWRITE_FILESYNC;
1749
1750 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit,
1751 called_from_strategy);
1752
1753 /*
1754 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
1755 * to cluster the buffers needing commit. This will allow
1756 * the system to submit a single commit rpc for the whole
1757 * cluster. We can do this even if the buffer is not 100%
1758 * dirty (relative to the NFS blocksize), so we optimize the
1759 * append-to-file-case.
1760 *
1761 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
1762 * cleared because write clustering only works for commit
1763 * rpc's, not for the data portion of the write).
1764 */
1765
1766 if (!error && iomode == NFSWRITE_UNSTABLE) {
1767 bp->b_flags |= B_NEEDCOMMIT;
1768 if (bp->b_dirtyoff == 0
1769 && bp->b_dirtyend == bp->b_bcount)
1770 bp->b_flags |= B_CLUSTEROK;
1771 } else {
1772 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1773 }
1774
1775 /*
1776 * For an interrupted write, the buffer is still valid
1777 * and the write hasn't been pushed to the server yet,
1778 * so we can't set BIO_ERROR and report the interruption
1779 * by setting B_EINTR. For the B_ASYNC case, B_EINTR
1780 * is not relevant, so the rpc attempt is essentially
1781 * a noop. For the case of a V3 write rpc not being
1782 * committed to stable storage, the block is still
1783 * dirty and requires either a commit rpc or another
1784 * write rpc with iomode == NFSV3WRITE_FILESYNC before
1785 * the block is reused. This is indicated by setting
1786 * the B_DELWRI and B_NEEDCOMMIT flags.
1787 *
1788 * EIO is returned by ncl_writerpc() to indicate a recoverable
1789 * write error and is handled as above, except that
1790 * B_EINTR isn't set. One cause of this is a stale stateid
1791 * error for the RPC that indicates recovery is required,
1792 * when called with called_from_strategy != 0.
1793 *
1794 * If the buffer is marked B_PAGING, it does not reside on
1795 * the vp's paging queues so we cannot call bdirty(). The
1796 * bp in this case is not an NFS cache block so we should
1797 * be safe. XXX
1798 *
1799 * The logic below breaks up errors into recoverable and
1800 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE
1801 * and keep the buffer around for potential write retries.
1802 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL)
1803 * and save the error in the nfsnode. This is less than ideal
1804 * but necessary. Keeping such buffers around could potentially
1805 * cause buffer exhaustion eventually (they can never be written
1806 * out, so will get constantly be re-dirtied). It also causes
1807 * all sorts of vfs panics. For non-recoverable write errors,
1808 * also invalidate the attrcache, so we'll be forced to go over
1809 * the wire for this object, returning an error to user on next
1810 * call (most of the time).
1811 */
1812 if (error == EINTR || error == EIO || error == ETIMEDOUT
1813 || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
1814 bp->b_flags &= ~(B_INVAL|B_NOCACHE);
1815 if ((bp->b_flags & B_PAGING) == 0) {
1816 bdirty(bp);
1817 bp->b_flags &= ~B_DONE;
1818 }
1819 if ((error == EINTR || error == ETIMEDOUT) &&
1820 (bp->b_flags & B_ASYNC) == 0)
1821 bp->b_flags |= B_EINTR;
1822 } else {
1823 if (error) {
1824 bp->b_ioflags |= BIO_ERROR;
1825 bp->b_flags |= B_INVAL;
1826 bp->b_error = np->n_error = error;
1827 mtx_lock(&np->n_mtx);
1828 np->n_flag |= NWRITEERR;
1829 np->n_attrstamp = 0;
1830 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
1831 mtx_unlock(&np->n_mtx);
1832 }
1833 bp->b_dirtyoff = bp->b_dirtyend = 0;
1834 }
1835 } else {
1836 bp->b_resid = 0;
1837 bufdone(bp);
1838 return (0);
1839 }
1840 }
1841 bp->b_resid = uiop->uio_resid;
1842 if (must_commit)
1843 ncl_clearcommit(vp->v_mount);
1844 bufdone(bp);
1845 return (error);
1846 }
1847
1848 /*
1849 * Used to aid in handling ftruncate() operations on the NFS client side.
1850 * Truncation creates a number of special problems for NFS. We have to
1851 * throw away VM pages and buffer cache buffers that are beyond EOF, and
1852 * we have to properly handle VM pages or (potentially dirty) buffers
1853 * that straddle the truncation point.
1854 */
1855
1856 int
1857 ncl_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize)
1858 {
1859 struct nfsnode *np = VTONFS(vp);
1860 u_quad_t tsize;
1861 int biosize = vp->v_bufobj.bo_bsize;
1862 int error = 0;
1863
1864 mtx_lock(&np->n_mtx);
1865 tsize = np->n_size;
1866 np->n_size = nsize;
1867 mtx_unlock(&np->n_mtx);
1868
1869 if (nsize < tsize) {
1870 struct buf *bp;
1871 daddr_t lbn;
1872 int bufsize;
1873
1874 /*
1875 * vtruncbuf() doesn't get the buffer overlapping the
1876 * truncation point. We may have a B_DELWRI and/or B_CACHE
1877 * buffer that now needs to be truncated.
1878 */
1879 error = vtruncbuf(vp, cred, nsize, biosize);
1880 lbn = nsize / biosize;
1881 bufsize = nsize - (lbn * biosize);
1882 bp = nfs_getcacheblk(vp, lbn, bufsize, td);
1883 if (!bp)
1884 return EINTR;
1885 if (bp->b_dirtyoff > bp->b_bcount)
1886 bp->b_dirtyoff = bp->b_bcount;
1887 if (bp->b_dirtyend > bp->b_bcount)
1888 bp->b_dirtyend = bp->b_bcount;
1889 bp->b_flags |= B_RELBUF; /* don't leave garbage around */
1890 brelse(bp);
1891 } else {
1892 vnode_pager_setsize(vp, nsize);
1893 }
1894 return(error);
1895 }
1896
Cache object: 122b14eabfc3f0b894f0c9442066a076
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