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 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95
37 */
38
39#include <sys/cdefs.h>
|
40__FBSDID("$FreeBSD: head/sys/nfsclient/nfs_bio.c 86089 2001-11-05 18:48:54Z dillon $");
|
| 40__FBSDID("$FreeBSD: head/sys/nfsclient/nfs_bio.c 87834 2001-12-14 01:16:57Z dillon $"); |
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/bio.h>
45#include <sys/buf.h>
46#include <sys/kernel.h>
47#include <sys/mount.h>
48#include <sys/proc.h>
49#include <sys/resourcevar.h>
50#include <sys/signalvar.h>
51#include <sys/vmmeter.h>
52#include <sys/vnode.h>
53
54#include <vm/vm.h>
55#include <vm/vm_extern.h>
56#include <vm/vm_page.h>
57#include <vm/vm_object.h>
58#include <vm/vm_pager.h>
59#include <vm/vnode_pager.h>
60
61#include <nfs/rpcv2.h>
62#include <nfs/nfsproto.h>
63#include <nfsclient/nfs.h>
64#include <nfsclient/nfsmount.h>
65#include <nfsclient/nfsnode.h>
66
67/*
68 * Just call nfs_writebp() with the force argument set to 1.
69 *
70 * NOTE: B_DONE may or may not be set in a_bp on call.
71 */
72static int
73nfs_bwrite(struct buf *bp)
74{
75
76 return (nfs_writebp(bp, 1, curthread));
77}
78
79struct buf_ops buf_ops_nfs = {
80 "buf_ops_nfs",
81 nfs_bwrite
82};
83
84static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size,
85 struct thread *td);
86
87/*
88 * Vnode op for VM getpages.
89 */
90int
91nfs_getpages(struct vop_getpages_args *ap)
92{
93 int i, error, nextoff, size, toff, count, npages;
94 struct uio uio;
95 struct iovec iov;
96 vm_offset_t kva;
97 struct buf *bp;
98 struct vnode *vp;
99 struct thread *td;
100 struct ucred *cred;
101 struct nfsmount *nmp;
102 vm_page_t *pages;
103
104 GIANT_REQUIRED;
105
106 vp = ap->a_vp;
107 td = curthread; /* XXX */
108 cred = curthread->td_proc->p_ucred; /* XXX */
109 nmp = VFSTONFS(vp->v_mount);
110 pages = ap->a_m;
111 count = ap->a_count;
112
113 if (vp->v_object == NULL) {
114 printf("nfs_getpages: called with non-merged cache vnode??\n");
115 return VM_PAGER_ERROR;
116 }
117
118 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
119 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
120 (void)nfs_fsinfo(nmp, vp, cred, td);
121 }
122
123 npages = btoc(count);
124
125 /*
126 * If the requested page is partially valid, just return it and
127 * allow the pager to zero-out the blanks. Partially valid pages
128 * can only occur at the file EOF.
129 */
130
131 {
132 vm_page_t m = pages[ap->a_reqpage];
133
134 if (m->valid != 0) {
135 /* handled by vm_fault now */
136 /* vm_page_zero_invalid(m, TRUE); */
137 for (i = 0; i < npages; ++i) {
138 if (i != ap->a_reqpage)
139 vm_page_free(pages[i]);
140 }
141 return(0);
142 }
143 }
144
145 /*
146 * We use only the kva address for the buffer, but this is extremely
147 * convienient and fast.
148 */
149 bp = getpbuf(&nfs_pbuf_freecnt);
150
151 kva = (vm_offset_t) bp->b_data;
152 pmap_qenter(kva, pages, npages);
153 cnt.v_vnodein++;
154 cnt.v_vnodepgsin += npages;
155
156 iov.iov_base = (caddr_t) kva;
157 iov.iov_len = count;
158 uio.uio_iov = &iov;
159 uio.uio_iovcnt = 1;
160 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
161 uio.uio_resid = count;
162 uio.uio_segflg = UIO_SYSSPACE;
163 uio.uio_rw = UIO_READ;
164 uio.uio_td = td;
165
166 error = nfs_readrpc(vp, &uio, cred);
167 pmap_qremove(kva, npages);
168
169 relpbuf(bp, &nfs_pbuf_freecnt);
170
171 if (error && (uio.uio_resid == count)) {
172 printf("nfs_getpages: error %d\n", error);
173 for (i = 0; i < npages; ++i) {
174 if (i != ap->a_reqpage)
175 vm_page_free(pages[i]);
176 }
177 return VM_PAGER_ERROR;
178 }
179
180 /*
181 * Calculate the number of bytes read and validate only that number
182 * of bytes. Note that due to pending writes, size may be 0. This
183 * does not mean that the remaining data is invalid!
184 */
185
186 size = count - uio.uio_resid;
187
188 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
189 vm_page_t m;
190 nextoff = toff + PAGE_SIZE;
191 m = pages[i];
192
193 m->flags &= ~PG_ZERO;
194
195 if (nextoff <= size) {
196 /*
197 * Read operation filled an entire page
198 */
199 m->valid = VM_PAGE_BITS_ALL;
200 vm_page_undirty(m);
201 } else if (size > toff) {
202 /*
203 * Read operation filled a partial page.
204 */
205 m->valid = 0;
206 vm_page_set_validclean(m, 0, size - toff);
207 /* handled by vm_fault now */
208 /* vm_page_zero_invalid(m, TRUE); */
|
209 } else {
210 /*
211 * Read operation was short. If no error occured
212 * we may have hit a zero-fill section. We simply
213 * leave valid set to 0.
214 */
215 ; |
216 }
|
210
|
217 if (i != ap->a_reqpage) {
218 /*
219 * Whether or not to leave the page activated is up in
220 * the air, but we should put the page on a page queue
221 * somewhere (it already is in the object). Result:
222 * It appears that emperical results show that
223 * deactivating pages is best.
224 */
225
226 /*
227 * Just in case someone was asking for this page we
228 * now tell them that it is ok to use.
229 */
230 if (!error) {
231 if (m->flags & PG_WANTED)
232 vm_page_activate(m);
233 else
234 vm_page_deactivate(m);
235 vm_page_wakeup(m);
236 } else {
237 vm_page_free(m);
238 }
239 }
240 }
241 return 0;
242}
243
244/*
245 * Vnode op for VM putpages.
246 */
247int
248nfs_putpages(struct vop_putpages_args *ap)
249{
250 struct uio uio;
251 struct iovec iov;
252 vm_offset_t kva;
253 struct buf *bp;
254 int iomode, must_commit, i, error, npages, count;
255 off_t offset;
256 int *rtvals;
257 struct vnode *vp;
258 struct thread *td;
259 struct ucred *cred;
260 struct nfsmount *nmp;
261 struct nfsnode *np;
262 vm_page_t *pages;
263
264 GIANT_REQUIRED;
265
266 vp = ap->a_vp;
267 np = VTONFS(vp);
268 td = curthread; /* XXX */
269 cred = curthread->td_proc->p_ucred; /* XXX */
270 nmp = VFSTONFS(vp->v_mount);
271 pages = ap->a_m;
272 count = ap->a_count;
273 rtvals = ap->a_rtvals;
274 npages = btoc(count);
275 offset = IDX_TO_OFF(pages[0]->pindex);
276
277 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
278 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
279 (void)nfs_fsinfo(nmp, vp, cred, td);
280 }
281
282 for (i = 0; i < npages; i++)
283 rtvals[i] = VM_PAGER_AGAIN;
284
285 /*
286 * When putting pages, do not extend file past EOF.
287 */
288
289 if (offset + count > np->n_size) {
290 count = np->n_size - offset;
291 if (count < 0)
292 count = 0;
293 }
294
295 /*
296 * We use only the kva address for the buffer, but this is extremely
297 * convienient and fast.
298 */
299 bp = getpbuf(&nfs_pbuf_freecnt);
300
301 kva = (vm_offset_t) bp->b_data;
302 pmap_qenter(kva, pages, npages);
303 cnt.v_vnodeout++;
304 cnt.v_vnodepgsout += count;
305
306 iov.iov_base = (caddr_t) kva;
307 iov.iov_len = count;
308 uio.uio_iov = &iov;
309 uio.uio_iovcnt = 1;
310 uio.uio_offset = offset;
311 uio.uio_resid = count;
312 uio.uio_segflg = UIO_SYSSPACE;
313 uio.uio_rw = UIO_WRITE;
314 uio.uio_td = td;
315
316 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0)
317 iomode = NFSV3WRITE_UNSTABLE;
318 else
319 iomode = NFSV3WRITE_FILESYNC;
320
321 error = nfs_writerpc(vp, &uio, cred, &iomode, &must_commit);
322
323 pmap_qremove(kva, npages);
324 relpbuf(bp, &nfs_pbuf_freecnt);
325
326 if (!error) {
327 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE;
328 for (i = 0; i < nwritten; i++) {
329 rtvals[i] = VM_PAGER_OK;
330 vm_page_undirty(pages[i]);
331 }
332 if (must_commit) {
333 nfs_clearcommit(vp->v_mount);
334 }
335 }
336 return rtvals[0];
337}
338
339/*
340 * Vnode op for read using bio
341 */
342int
343nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
344{
345 struct nfsnode *np = VTONFS(vp);
346 int biosize, i;
347 struct buf *bp = 0, *rabp;
348 struct vattr vattr;
349 struct thread *td;
350 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
351 daddr_t lbn, rabn;
352 int bcount;
353 int seqcount;
354 int nra, error = 0, n = 0, on = 0;
355
356#ifdef DIAGNOSTIC
357 if (uio->uio_rw != UIO_READ)
358 panic("nfs_read mode");
359#endif
360 if (uio->uio_resid == 0)
361 return (0);
362 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */
363 return (EINVAL);
364 td = uio->uio_td;
365
366 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
367 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
368 (void)nfs_fsinfo(nmp, vp, cred, td);
369 if (vp->v_type != VDIR &&
370 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
371 return (EFBIG);
372 biosize = vp->v_mount->mnt_stat.f_iosize;
373 seqcount = (int)((off_t)(ioflag >> 16) * biosize / BKVASIZE);
374 /*
375 * For nfs, cache consistency can only be maintained approximately.
376 * Although RFC1094 does not specify the criteria, the following is
377 * believed to be compatible with the reference port.
378 * For nfs:
379 * If the file's modify time on the server has changed since the
380 * last read rpc or you have written to the file,
381 * you may have lost data cache consistency with the
382 * server, so flush all of the file's data out of the cache.
383 * Then force a getattr rpc to ensure that you have up to date
384 * attributes.
385 * NB: This implies that cache data can be read when up to
386 * NFS_ATTRTIMEO seconds out of date. If you find that you need current
387 * attributes this could be forced by setting n_attrstamp to 0 before
388 * the VOP_GETATTR() call.
389 */
390 if (np->n_flag & NMODIFIED) {
391 if (vp->v_type != VREG) {
392 if (vp->v_type != VDIR)
393 panic("nfs: bioread, not dir");
394 nfs_invaldir(vp);
395 error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1);
396 if (error)
397 return (error);
398 }
399 np->n_attrstamp = 0;
400 error = VOP_GETATTR(vp, &vattr, cred, td);
401 if (error)
402 return (error);
403 np->n_mtime = vattr.va_mtime.tv_sec;
404 } else {
405 error = VOP_GETATTR(vp, &vattr, cred, td);
406 if (error)
407 return (error);
408 if (np->n_mtime != vattr.va_mtime.tv_sec) {
409 if (vp->v_type == VDIR)
410 nfs_invaldir(vp);
411 error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1);
412 if (error)
413 return (error);
414 np->n_mtime = vattr.va_mtime.tv_sec;
415 }
416 }
417 do {
418 switch (vp->v_type) {
419 case VREG:
420 nfsstats.biocache_reads++;
421 lbn = uio->uio_offset / biosize;
422 on = uio->uio_offset & (biosize - 1);
423
424 /*
425 * Start the read ahead(s), as required.
426 */
427 if (nfs_numasync > 0 && nmp->nm_readahead > 0) {
428 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
429 (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) {
430 rabn = lbn + 1 + nra;
431 if (!incore(vp, rabn)) {
432 rabp = nfs_getcacheblk(vp, rabn, biosize, td);
433 if (!rabp)
434 return (EINTR);
435 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
436 rabp->b_flags |= B_ASYNC;
437 rabp->b_iocmd = BIO_READ;
438 vfs_busy_pages(rabp, 0);
439 if (nfs_asyncio(rabp, cred, td)) {
440 rabp->b_flags |= B_INVAL;
441 rabp->b_ioflags |= BIO_ERROR;
442 vfs_unbusy_pages(rabp);
443 brelse(rabp);
444 break;
445 }
446 } else {
447 brelse(rabp);
448 }
449 }
450 }
451 }
452
453 /*
454 * Obtain the buffer cache block. Figure out the buffer size
455 * when we are at EOF. If we are modifying the size of the
456 * buffer based on an EOF condition we need to hold
457 * nfs_rslock() through obtaining the buffer to prevent
458 * a potential writer-appender from messing with n_size.
459 * Otherwise we may accidently truncate the buffer and
460 * lose dirty data.
461 *
462 * Note that bcount is *not* DEV_BSIZE aligned.
463 */
464
465again:
466 bcount = biosize;
467 if ((off_t)lbn * biosize >= np->n_size) {
468 bcount = 0;
469 } else if ((off_t)(lbn + 1) * biosize > np->n_size) {
470 bcount = np->n_size - (off_t)lbn * biosize;
471 }
472 if (bcount != biosize) {
473 switch(nfs_rslock(np, td)) {
474 case ENOLCK:
475 goto again;
476 /* not reached */
477 case EINTR:
478 case ERESTART:
479 return(EINTR);
480 /* not reached */
481 default:
482 break;
483 }
484 }
485
486 bp = nfs_getcacheblk(vp, lbn, bcount, td);
487
488 if (bcount != biosize)
489 nfs_rsunlock(np, td);
490 if (!bp)
491 return (EINTR);
492
493 /*
494 * If B_CACHE is not set, we must issue the read. If this
495 * fails, we return an error.
496 */
497
498 if ((bp->b_flags & B_CACHE) == 0) {
499 bp->b_iocmd = BIO_READ;
500 vfs_busy_pages(bp, 0);
501 error = nfs_doio(bp, cred, td);
502 if (error) {
503 brelse(bp);
504 return (error);
505 }
506 }
507
508 /*
509 * on is the offset into the current bp. Figure out how many
510 * bytes we can copy out of the bp. Note that bcount is
511 * NOT DEV_BSIZE aligned.
512 *
513 * Then figure out how many bytes we can copy into the uio.
514 */
515
516 n = 0;
517 if (on < bcount)
518 n = min((unsigned)(bcount - on), uio->uio_resid);
519 break;
520 case VLNK:
521 nfsstats.biocache_readlinks++;
522 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
523 if (!bp)
524 return (EINTR);
525 if ((bp->b_flags & B_CACHE) == 0) {
526 bp->b_iocmd = BIO_READ;
527 vfs_busy_pages(bp, 0);
528 error = nfs_doio(bp, cred, td);
529 if (error) {
530 bp->b_ioflags |= BIO_ERROR;
531 brelse(bp);
532 return (error);
533 }
534 }
535 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
536 on = 0;
537 break;
538 case VDIR:
539 nfsstats.biocache_readdirs++;
540 if (np->n_direofoffset
541 && uio->uio_offset >= np->n_direofoffset) {
542 return (0);
543 }
544 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
545 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
546 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
547 if (!bp)
548 return (EINTR);
549 if ((bp->b_flags & B_CACHE) == 0) {
550 bp->b_iocmd = BIO_READ;
551 vfs_busy_pages(bp, 0);
552 error = nfs_doio(bp, cred, td);
553 if (error) {
554 brelse(bp);
555 }
556 while (error == NFSERR_BAD_COOKIE) {
557 printf("got bad cookie vp %p bp %p\n", vp, bp);
558 nfs_invaldir(vp);
559 error = nfs_vinvalbuf(vp, 0, cred, td, 1);
560 /*
561 * Yuck! The directory has been modified on the
562 * server. The only way to get the block is by
563 * reading from the beginning to get all the
564 * offset cookies.
565 *
566 * Leave the last bp intact unless there is an error.
567 * Loop back up to the while if the error is another
568 * NFSERR_BAD_COOKIE (double yuch!).
569 */
570 for (i = 0; i <= lbn && !error; i++) {
571 if (np->n_direofoffset
572 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset)
573 return (0);
574 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
575 if (!bp)
576 return (EINTR);
577 if ((bp->b_flags & B_CACHE) == 0) {
578 bp->b_iocmd = BIO_READ;
579 vfs_busy_pages(bp, 0);
580 error = nfs_doio(bp, cred, td);
581 /*
582 * no error + B_INVAL == directory EOF,
583 * use the block.
584 */
585 if (error == 0 && (bp->b_flags & B_INVAL))
586 break;
587 }
588 /*
589 * An error will throw away the block and the
590 * for loop will break out. If no error and this
591 * is not the block we want, we throw away the
592 * block and go for the next one via the for loop.
593 */
594 if (error || i < lbn)
595 brelse(bp);
596 }
597 }
598 /*
599 * The above while is repeated if we hit another cookie
600 * error. If we hit an error and it wasn't a cookie error,
601 * we give up.
602 */
603 if (error)
604 return (error);
605 }
606
607 /*
608 * If not eof and read aheads are enabled, start one.
609 * (You need the current block first, so that you have the
610 * directory offset cookie of the next block.)
611 */
612 if (nfs_numasync > 0 && nmp->nm_readahead > 0 &&
613 (bp->b_flags & B_INVAL) == 0 &&
614 (np->n_direofoffset == 0 ||
615 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
616 !incore(vp, lbn + 1)) {
617 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
618 if (rabp) {
619 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
620 rabp->b_flags |= B_ASYNC;
621 rabp->b_iocmd = BIO_READ;
622 vfs_busy_pages(rabp, 0);
623 if (nfs_asyncio(rabp, cred, td)) {
624 rabp->b_flags |= B_INVAL;
625 rabp->b_ioflags |= BIO_ERROR;
626 vfs_unbusy_pages(rabp);
627 brelse(rabp);
628 }
629 } else {
630 brelse(rabp);
631 }
632 }
633 }
634 /*
635 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is
636 * chopped for the EOF condition, we cannot tell how large
637 * NFS directories are going to be until we hit EOF. So
638 * an NFS directory buffer is *not* chopped to its EOF. Now,
639 * it just so happens that b_resid will effectively chop it
640 * to EOF. *BUT* this information is lost if the buffer goes
641 * away and is reconstituted into a B_CACHE state ( due to
642 * being VMIO ) later. So we keep track of the directory eof
643 * in np->n_direofoffset and chop it off as an extra step
644 * right here.
645 */
646 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
647 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
648 n = np->n_direofoffset - uio->uio_offset;
649 break;
650 default:
651 printf(" nfs_bioread: type %x unexpected\n", vp->v_type);
652 break;
653 };
654
655 if (n > 0) {
656 error = uiomove(bp->b_data + on, (int)n, uio);
657 }
658 switch (vp->v_type) {
659 case VREG:
660 break;
661 case VLNK:
662 n = 0;
663 break;
664 case VDIR:
665 break;
666 default:
667 printf(" nfs_bioread: type %x unexpected\n", vp->v_type);
668 }
669 brelse(bp);
670 } while (error == 0 && uio->uio_resid > 0 && n > 0);
671 return (error);
672}
673
674/*
675 * Vnode op for write using bio
676 */
677int
678nfs_write(struct vop_write_args *ap)
679{
680 int biosize;
681 struct uio *uio = ap->a_uio;
682 struct thread *td = uio->uio_td;
683 struct vnode *vp = ap->a_vp;
684 struct nfsnode *np = VTONFS(vp);
685 struct ucred *cred = ap->a_cred;
686 int ioflag = ap->a_ioflag;
687 struct buf *bp;
688 struct vattr vattr;
689 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
690 daddr_t lbn;
691 int bcount;
692 int n, on, error = 0;
693 int haverslock = 0;
694 struct proc *p = td?td->td_proc:NULL;
695
696 GIANT_REQUIRED;
697
698#ifdef DIAGNOSTIC
699 if (uio->uio_rw != UIO_WRITE)
700 panic("nfs_write mode");
701 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread)
702 panic("nfs_write proc");
703#endif
704 if (vp->v_type != VREG)
705 return (EIO);
706 if (np->n_flag & NWRITEERR) {
707 np->n_flag &= ~NWRITEERR;
708 return (np->n_error);
709 }
710 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
711 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
712 (void)nfs_fsinfo(nmp, vp, cred, td);
713
714 /*
715 * Synchronously flush pending buffers if we are in synchronous
716 * mode or if we are appending.
717 */
718 if (ioflag & (IO_APPEND | IO_SYNC)) {
719 if (np->n_flag & NMODIFIED) {
720 np->n_attrstamp = 0;
721 error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1);
722 if (error)
723 return (error);
724 }
725 }
726
727 /*
728 * If IO_APPEND then load uio_offset. We restart here if we cannot
729 * get the append lock.
730 */
731restart:
732 if (ioflag & IO_APPEND) {
733 np->n_attrstamp = 0;
734 error = VOP_GETATTR(vp, &vattr, cred, td);
735 if (error)
736 return (error);
737 uio->uio_offset = np->n_size;
738 }
739
740 if (uio->uio_offset < 0)
741 return (EINVAL);
742 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
743 return (EFBIG);
744 if (uio->uio_resid == 0)
745 return (0);
746
747 /*
748 * We need to obtain the rslock if we intend to modify np->n_size
749 * in order to guarentee the append point with multiple contending
750 * writers, to guarentee that no other appenders modify n_size
751 * while we are trying to obtain a truncated buffer (i.e. to avoid
752 * accidently truncating data written by another appender due to
753 * the race), and to ensure that the buffer is populated prior to
754 * our extending of the file. We hold rslock through the entire
755 * operation.
756 *
757 * Note that we do not synchronize the case where someone truncates
758 * the file while we are appending to it because attempting to lock
759 * this case may deadlock other parts of the system unexpectedly.
760 */
761 if ((ioflag & IO_APPEND) ||
762 uio->uio_offset + uio->uio_resid > np->n_size) {
763 switch(nfs_rslock(np, td)) {
764 case ENOLCK:
765 goto restart;
766 /* not reached */
767 case EINTR:
768 case ERESTART:
769 return(EINTR);
770 /* not reached */
771 default:
772 break;
773 }
774 haverslock = 1;
775 }
776
777 /*
778 * Maybe this should be above the vnode op call, but so long as
779 * file servers have no limits, i don't think it matters
780 */
781 if (p && uio->uio_offset + uio->uio_resid >
782 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
783 PROC_LOCK(p);
784 psignal(p, SIGXFSZ);
785 PROC_UNLOCK(p);
786 if (haverslock)
787 nfs_rsunlock(np, td);
788 return (EFBIG);
789 }
790
791 biosize = vp->v_mount->mnt_stat.f_iosize;
792
793 do {
794 nfsstats.biocache_writes++;
795 lbn = uio->uio_offset / biosize;
796 on = uio->uio_offset & (biosize-1);
797 n = min((unsigned)(biosize - on), uio->uio_resid);
798again:
799 /*
800 * Handle direct append and file extension cases, calculate
801 * unaligned buffer size.
802 */
803
804 if (uio->uio_offset == np->n_size && n) {
805 /*
806 * Get the buffer (in its pre-append state to maintain
807 * B_CACHE if it was previously set). Resize the
808 * nfsnode after we have locked the buffer to prevent
809 * readers from reading garbage.
810 */
811 bcount = on;
812 bp = nfs_getcacheblk(vp, lbn, bcount, td);
813
814 if (bp != NULL) {
815 long save;
816
817 np->n_size = uio->uio_offset + n;
818 np->n_flag |= NMODIFIED;
819 vnode_pager_setsize(vp, np->n_size);
820
821 save = bp->b_flags & B_CACHE;
822 bcount += n;
823 allocbuf(bp, bcount);
824 bp->b_flags |= save;
825 bp->b_magic = B_MAGIC_NFS;
826 bp->b_op = &buf_ops_nfs;
827 }
828 } else {
829 /*
830 * Obtain the locked cache block first, and then
831 * adjust the file's size as appropriate.
832 */
833 bcount = on + n;
834 if ((off_t)lbn * biosize + bcount < np->n_size) {
835 if ((off_t)(lbn + 1) * biosize < np->n_size)
836 bcount = biosize;
837 else
838 bcount = np->n_size - (off_t)lbn * biosize;
839 }
|
834
|
840 bp = nfs_getcacheblk(vp, lbn, bcount, td);
|
836
|
841 if (uio->uio_offset + n > np->n_size) {
842 np->n_size = uio->uio_offset + n;
843 np->n_flag |= NMODIFIED;
844 vnode_pager_setsize(vp, np->n_size);
845 }
846 }
847
848 if (!bp) {
849 error = EINTR;
850 break;
851 }
852
853 /*
854 * Issue a READ if B_CACHE is not set. In special-append
855 * mode, B_CACHE is based on the buffer prior to the write
856 * op and is typically set, avoiding the read. If a read
857 * is required in special append mode, the server will
858 * probably send us a short-read since we extended the file
859 * on our end, resulting in b_resid == 0 and, thusly,
860 * B_CACHE getting set.
861 *
862 * We can also avoid issuing the read if the write covers
863 * the entire buffer. We have to make sure the buffer state
864 * is reasonable in this case since we will not be initiating
865 * I/O. See the comments in kern/vfs_bio.c's getblk() for
866 * more information.
867 *
868 * B_CACHE may also be set due to the buffer being cached
869 * normally.
870 */
871
872 if (on == 0 && n == bcount) {
873 bp->b_flags |= B_CACHE;
874 bp->b_flags &= ~B_INVAL;
875 bp->b_ioflags &= ~BIO_ERROR;
876 }
877
878 if ((bp->b_flags & B_CACHE) == 0) {
879 bp->b_iocmd = BIO_READ;
880 vfs_busy_pages(bp, 0);
881 error = nfs_doio(bp, cred, td);
882 if (error) {
883 brelse(bp);
884 break;
885 }
886 }
887 if (!bp) {
888 error = EINTR;
889 break;
890 }
891 if (bp->b_wcred == NOCRED)
892 bp->b_wcred = crhold(cred);
893 np->n_flag |= NMODIFIED;
894
895 /*
896 * If dirtyend exceeds file size, chop it down. This should
897 * not normally occur but there is an append race where it
898 * might occur XXX, so we log it.
899 *
900 * If the chopping creates a reverse-indexed or degenerate
901 * situation with dirtyoff/end, we 0 both of them.
902 */
903
904 if (bp->b_dirtyend > bcount) {
905 printf("NFS append race @%lx:%d\n",
906 (long)bp->b_blkno * DEV_BSIZE,
907 bp->b_dirtyend - bcount);
908 bp->b_dirtyend = bcount;
909 }
910
911 if (bp->b_dirtyoff >= bp->b_dirtyend)
912 bp->b_dirtyoff = bp->b_dirtyend = 0;
913
914 /*
915 * If the new write will leave a contiguous dirty
916 * area, just update the b_dirtyoff and b_dirtyend,
917 * otherwise force a write rpc of the old dirty area.
918 *
919 * While it is possible to merge discontiguous writes due to
920 * our having a B_CACHE buffer ( and thus valid read data
921 * for the hole), we don't because it could lead to
922 * significant cache coherency problems with multiple clients,
923 * especially if locking is implemented later on.
924 *
925 * as an optimization we could theoretically maintain
926 * a linked list of discontinuous areas, but we would still
927 * have to commit them separately so there isn't much
928 * advantage to it except perhaps a bit of asynchronization.
929 */
930
931 if (bp->b_dirtyend > 0 &&
932 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
933 if (BUF_WRITE(bp) == EINTR)
934 return (EINTR);
935 goto again;
936 }
937
938 error = uiomove((char *)bp->b_data + on, n, uio);
939
940 /*
941 * Since this block is being modified, it must be written
942 * again and not just committed. Since write clustering does
943 * not work for the stage 1 data write, only the stage 2
944 * commit rpc, we have to clear B_CLUSTEROK as well.
945 */
946 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
947
948 if (error) {
949 bp->b_ioflags |= BIO_ERROR;
950 brelse(bp);
951 break;
952 }
953
954 /*
955 * Only update dirtyoff/dirtyend if not a degenerate
956 * condition.
957 */
958 if (n) {
959 if (bp->b_dirtyend > 0) {
960 bp->b_dirtyoff = min(on, bp->b_dirtyoff);
961 bp->b_dirtyend = max((on + n), bp->b_dirtyend);
962 } else {
963 bp->b_dirtyoff = on;
964 bp->b_dirtyend = on + n;
965 }
966 vfs_bio_set_validclean(bp, on, n);
967 }
968 /*
969 * If IO_NOWDRAIN then set B_NOWDRAIN (nfs-backed MD
970 * filesystem)
971 */
972 if (ioflag & IO_NOWDRAIN)
973 bp->b_flags |= B_NOWDRAIN;
974
975 /*
976 * If IO_SYNC do bwrite().
977 *
978 * IO_INVAL appears to be unused. The idea appears to be
979 * to turn off caching in this case. Very odd. XXX
980 */
981 if ((ioflag & IO_SYNC)) {
982 if (ioflag & IO_INVAL)
983 bp->b_flags |= B_NOCACHE;
984 error = BUF_WRITE(bp);
985 if (error)
986 break;
987 } else if ((n + on) == biosize) {
988 bp->b_flags |= B_ASYNC;
989 (void)nfs_writebp(bp, 0, 0);
990 } else {
991 bdwrite(bp);
992 }
993 } while (uio->uio_resid > 0 && n > 0);
994
995 if (haverslock)
996 nfs_rsunlock(np, td);
997
998 return (error);
999}
1000
1001/*
1002 * Get an nfs cache block.
1003 *
1004 * Allocate a new one if the block isn't currently in the cache
1005 * and return the block marked busy. If the calling process is
1006 * interrupted by a signal for an interruptible mount point, return
1007 * NULL.
1008 *
1009 * The caller must carefully deal with the possible B_INVAL state of
1010 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it
1011 * indirectly), so synchronous reads can be issued without worrying about
1012 * the B_INVAL state. We have to be a little more careful when dealing
1013 * with writes (see comments in nfs_write()) when extending a file past
1014 * its EOF.
1015 */
1016static struct buf *
1017nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
1018{
1019 struct buf *bp;
1020 struct mount *mp;
1021 struct nfsmount *nmp;
1022
1023 mp = vp->v_mount;
1024 nmp = VFSTONFS(mp);
1025
1026 if (nmp->nm_flag & NFSMNT_INT) {
1027 bp = getblk(vp, bn, size, PCATCH, 0);
1028 while (bp == (struct buf *)0) {
1029 if (nfs_sigintr(nmp, (struct nfsreq *)0, td->td_proc))
1030 return ((struct buf *)0);
1031 bp = getblk(vp, bn, size, 0, 2 * hz);
1032 }
1033 } else {
1034 bp = getblk(vp, bn, size, 0, 0);
1035 }
1036
1037 if (vp->v_type == VREG) {
1038 int biosize;
1039
1040 biosize = mp->mnt_stat.f_iosize;
1041 bp->b_blkno = bn * (biosize / DEV_BSIZE);
1042 }
1043 return (bp);
1044}
1045
1046/*
1047 * Flush and invalidate all dirty buffers. If another process is already
1048 * doing the flush, just wait for completion.
1049 */
1050int
1051nfs_vinvalbuf(struct vnode *vp, int flags, struct ucred *cred,
1052 struct thread *td, int intrflg)
1053{
1054 struct nfsnode *np = VTONFS(vp);
1055 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
1056 int error = 0, slpflag, slptimeo;
1057
1058 if (vp->v_flag & VXLOCK) {
1059 return (0);
1060 }
1061
1062 if ((nmp->nm_flag & NFSMNT_INT) == 0)
1063 intrflg = 0;
1064 if (intrflg) {
1065 slpflag = PCATCH;
1066 slptimeo = 2 * hz;
1067 } else {
1068 slpflag = 0;
1069 slptimeo = 0;
1070 }
1071 /*
1072 * First wait for any other process doing a flush to complete.
1073 */
1074 while (np->n_flag & NFLUSHINPROG) {
1075 np->n_flag |= NFLUSHWANT;
1076 error = tsleep((caddr_t)&np->n_flag, PRIBIO + 2, "nfsvinval",
1077 slptimeo);
1078 if (error && intrflg &&
1079 nfs_sigintr(nmp, (struct nfsreq *)0, td->td_proc))
1080 return (EINTR);
1081 }
1082
1083 /*
1084 * Now, flush as required.
1085 */
1086 np->n_flag |= NFLUSHINPROG;
1087 error = vinvalbuf(vp, flags, cred, td, slpflag, 0);
1088 while (error) {
1089 if (intrflg &&
1090 nfs_sigintr(nmp, (struct nfsreq *)0, td->td_proc)) {
1091 np->n_flag &= ~NFLUSHINPROG;
1092 if (np->n_flag & NFLUSHWANT) {
1093 np->n_flag &= ~NFLUSHWANT;
1094 wakeup((caddr_t)&np->n_flag);
1095 }
1096 return (EINTR);
1097 }
1098 error = vinvalbuf(vp, flags, cred, td, 0, slptimeo);
1099 }
1100 np->n_flag &= ~(NMODIFIED | NFLUSHINPROG);
1101 if (np->n_flag & NFLUSHWANT) {
1102 np->n_flag &= ~NFLUSHWANT;
1103 wakeup((caddr_t)&np->n_flag);
1104 }
1105 return (0);
1106}
1107
1108/*
1109 * Initiate asynchronous I/O. Return an error if no nfsiods are available.
1110 * This is mainly to avoid queueing async I/O requests when the nfsiods
1111 * are all hung on a dead server.
1112 *
1113 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
1114 * is eventually dequeued by the async daemon, nfs_doio() *will*.
1115 */
1116int
1117nfs_asyncio(struct buf *bp, struct ucred *cred, struct thread *td)
1118{
1119 struct nfsmount *nmp;
1120 int i;
1121 int gotiod;
1122 int slpflag = 0;
1123 int slptimeo = 0;
1124 int error;
1125
1126 /*
1127 * If no async daemons then return EIO to force caller to run the rpc
1128 * synchronously.
1129 */
1130 if (nfs_numasync == 0)
1131 return (EIO);
1132
1133 nmp = VFSTONFS(bp->b_vp->v_mount);
1134
1135 /*
1136 * Commits are usually short and sweet so lets save some cpu and
1137 * leave the async daemons for more important rpc's (such as reads
1138 * and writes).
1139 */
1140 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
1141 (nmp->nm_bufqiods > nfs_numasync / 2)) {
1142 return(EIO);
1143 }
1144
1145again:
1146 if (nmp->nm_flag & NFSMNT_INT)
1147 slpflag = PCATCH;
1148 gotiod = FALSE;
1149
1150 /*
1151 * Find a free iod to process this request.
1152 */
1153 for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
1154 if (nfs_iodwant[i]) {
1155 /*
1156 * Found one, so wake it up and tell it which
1157 * mount to process.
1158 */
1159 NFS_DPF(ASYNCIO,
1160 ("nfs_asyncio: waking iod %d for mount %p\n",
1161 i, nmp));
1162 nfs_iodwant[i] = (struct proc *)0;
1163 nfs_iodmount[i] = nmp;
1164 nmp->nm_bufqiods++;
1165 wakeup((caddr_t)&nfs_iodwant[i]);
1166 gotiod = TRUE;
1167 break;
1168 }
1169
1170 /*
1171 * If none are free, we may already have an iod working on this mount
1172 * point. If so, it will process our request.
1173 */
1174 if (!gotiod) {
1175 if (nmp->nm_bufqiods > 0) {
1176 NFS_DPF(ASYNCIO,
1177 ("nfs_asyncio: %d iods are already processing mount %p\n",
1178 nmp->nm_bufqiods, nmp));
1179 gotiod = TRUE;
1180 }
1181 }
1182
1183 /*
1184 * If we have an iod which can process the request, then queue
1185 * the buffer.
1186 */
1187 if (gotiod) {
1188 /*
1189 * Ensure that the queue never grows too large. We still want
1190 * to asynchronize so we block rather then return EIO.
1191 */
1192 while (nmp->nm_bufqlen >= 2*nfs_numasync) {
1193 NFS_DPF(ASYNCIO,
1194 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp));
1195 nmp->nm_bufqwant = TRUE;
1196 error = tsleep(&nmp->nm_bufq, slpflag | PRIBIO,
1197 "nfsaio", slptimeo);
1198 if (error) {
1199 if (nfs_sigintr(nmp, NULL, td ? td->td_proc : NULL))
1200 return (EINTR);
1201 if (slpflag == PCATCH) {
1202 slpflag = 0;
1203 slptimeo = 2 * hz;
1204 }
1205 }
1206 /*
1207 * We might have lost our iod while sleeping,
1208 * so check and loop if nescessary.
1209 */
1210 if (nmp->nm_bufqiods == 0) {
1211 NFS_DPF(ASYNCIO,
1212 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
1213 goto again;
1214 }
1215 }
1216
1217 if (bp->b_iocmd == BIO_READ) {
1218 if (bp->b_rcred == NOCRED && cred != NOCRED)
1219 bp->b_rcred = crhold(cred);
1220 } else {
1221 bp->b_flags |= B_WRITEINPROG;
1222 if (bp->b_wcred == NOCRED && cred != NOCRED)
1223 bp->b_wcred = crhold(cred);
1224 }
1225
1226 BUF_KERNPROC(bp);
1227 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
1228 nmp->nm_bufqlen++;
1229 return (0);
1230 }
1231
1232 /*
1233 * All the iods are busy on other mounts, so return EIO to
1234 * force the caller to process the i/o synchronously.
1235 */
1236 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n"));
1237 return (EIO);
1238}
1239
1240/*
1241 * Do an I/O operation to/from a cache block. This may be called
1242 * synchronously or from an nfsiod.
1243 */
1244int
1245nfs_doio(struct buf *bp, struct ucred *cr, struct thread *td)
1246{
1247 struct uio *uiop;
1248 struct vnode *vp;
1249 struct nfsnode *np;
1250 struct nfsmount *nmp;
1251 int error = 0, iomode, must_commit = 0;
1252 struct uio uio;
1253 struct iovec io;
1254 struct proc *p = td ? td->td_proc : NULL;
1255
1256 vp = bp->b_vp;
1257 np = VTONFS(vp);
1258 nmp = VFSTONFS(vp->v_mount);
1259 uiop = &uio;
1260 uiop->uio_iov = &io;
1261 uiop->uio_iovcnt = 1;
1262 uiop->uio_segflg = UIO_SYSSPACE;
1263 uiop->uio_td = td;
1264
1265 /*
1266 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
1267 * do this here so we do not have to do it in all the code that
1268 * calls us.
1269 */
1270 bp->b_flags &= ~B_INVAL;
1271 bp->b_ioflags &= ~BIO_ERROR;
1272
1273 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp));
1274
1275 /*
1276 * Historically, paging was done with physio, but no more.
1277 */
1278 if (bp->b_flags & B_PHYS) {
1279 /*
1280 * ...though reading /dev/drum still gets us here.
1281 */
1282 io.iov_len = uiop->uio_resid = bp->b_bcount;
1283 /* mapping was done by vmapbuf() */
1284 io.iov_base = bp->b_data;
1285 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
1286 if (bp->b_iocmd == BIO_READ) {
1287 uiop->uio_rw = UIO_READ;
1288 nfsstats.read_physios++;
1289 error = nfs_readrpc(vp, uiop, cr);
1290 } else {
1291 int com;
1292
1293 iomode = NFSV3WRITE_DATASYNC;
1294 uiop->uio_rw = UIO_WRITE;
1295 nfsstats.write_physios++;
1296 error = nfs_writerpc(vp, uiop, cr, &iomode, &com);
1297 }
1298 if (error) {
1299 bp->b_ioflags |= BIO_ERROR;
1300 bp->b_error = error;
1301 }
1302 } else if (bp->b_iocmd == BIO_READ) {
1303 io.iov_len = uiop->uio_resid = bp->b_bcount;
1304 io.iov_base = bp->b_data;
1305 uiop->uio_rw = UIO_READ;
|
| 1306 |
1307 switch (vp->v_type) {
1308 case VREG:
1309 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
1310 nfsstats.read_bios++;
1311 error = nfs_readrpc(vp, uiop, cr);
|
| 1312 |
1313 if (!error) {
1314 if (uiop->uio_resid) {
1315 /*
1316 * If we had a short read with no error, we must have
1317 * hit a file hole. We should zero-fill the remainder.
1318 * This can also occur if the server hits the file EOF.
1319 *
1320 * Holes used to be able to occur due to pending
1321 * writes, but that is not possible any longer.
1322 */
1323 int nread = bp->b_bcount - uiop->uio_resid;
|
1318 int left = bp->b_bcount - nread;
|
| 1324 int left = uiop->uio_resid; |
1325
1326 if (left > 0)
1327 bzero((char *)bp->b_data + nread, left);
1328 uiop->uio_resid = 0;
1329 }
1330 }
1331 if (p && (vp->v_flag & VTEXT) &&
1332 (np->n_mtime != np->n_vattr.va_mtime.tv_sec)) {
1333 uprintf("Process killed due to text file modification\n");
1334 PROC_LOCK(p);
1335 psignal(p, SIGKILL);
1336 _PHOLD(p);
1337 PROC_UNLOCK(p);
1338 }
1339 break;
1340 case VLNK:
1341 uiop->uio_offset = (off_t)0;
1342 nfsstats.readlink_bios++;
1343 error = nfs_readlinkrpc(vp, uiop, cr);
1344 break;
1345 case VDIR:
1346 nfsstats.readdir_bios++;
1347 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
1348 if (nmp->nm_flag & NFSMNT_RDIRPLUS) {
1349 error = nfs_readdirplusrpc(vp, uiop, cr);
1350 if (error == NFSERR_NOTSUPP)
1351 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
1352 }
1353 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
1354 error = nfs_readdirrpc(vp, uiop, cr);
1355 /*
1356 * end-of-directory sets B_INVAL but does not generate an
1357 * error.
1358 */
1359 if (error == 0 && uiop->uio_resid == bp->b_bcount)
1360 bp->b_flags |= B_INVAL;
1361 break;
1362 default:
1363 printf("nfs_doio: type %x unexpected\n", vp->v_type);
1364 break;
1365 };
1366 if (error) {
1367 bp->b_ioflags |= BIO_ERROR;
1368 bp->b_error = error;
1369 }
1370 } else {
1371 /*
1372 * If we only need to commit, try to commit
1373 */
1374 if (bp->b_flags & B_NEEDCOMMIT) {
1375 int retv;
1376 off_t off;
1377
1378 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
1379 bp->b_flags |= B_WRITEINPROG;
1380 retv = nfs_commit(
1381 bp->b_vp, off, bp->b_dirtyend-bp->b_dirtyoff,
1382 bp->b_wcred, td);
1383 bp->b_flags &= ~B_WRITEINPROG;
1384 if (retv == 0) {
1385 bp->b_dirtyoff = bp->b_dirtyend = 0;
1386 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1387 bp->b_resid = 0;
1388 bufdone(bp);
1389 return (0);
1390 }
1391 if (retv == NFSERR_STALEWRITEVERF) {
1392 nfs_clearcommit(bp->b_vp->v_mount);
1393 }
1394 }
1395
1396 /*
1397 * Setup for actual write
1398 */
1399
1400 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
1401 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
1402
1403 if (bp->b_dirtyend > bp->b_dirtyoff) {
1404 io.iov_len = uiop->uio_resid = bp->b_dirtyend
1405 - bp->b_dirtyoff;
1406 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
1407 + bp->b_dirtyoff;
1408 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
1409 uiop->uio_rw = UIO_WRITE;
1410 nfsstats.write_bios++;
1411
1412 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
1413 iomode = NFSV3WRITE_UNSTABLE;
1414 else
1415 iomode = NFSV3WRITE_FILESYNC;
1416
1417 bp->b_flags |= B_WRITEINPROG;
1418 error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit);
1419
1420 /*
1421 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
1422 * to cluster the buffers needing commit. This will allow
1423 * the system to submit a single commit rpc for the whole
1424 * cluster. We can do this even if the buffer is not 100%
1425 * dirty (relative to the NFS blocksize), so we optimize the
1426 * append-to-file-case.
1427 *
1428 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
1429 * cleared because write clustering only works for commit
1430 * rpc's, not for the data portion of the write).
1431 */
1432
1433 if (!error && iomode == NFSV3WRITE_UNSTABLE) {
1434 bp->b_flags |= B_NEEDCOMMIT;
1435 if (bp->b_dirtyoff == 0
1436 && bp->b_dirtyend == bp->b_bcount)
1437 bp->b_flags |= B_CLUSTEROK;
1438 } else {
1439 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1440 }
1441 bp->b_flags &= ~B_WRITEINPROG;
1442
1443 /*
1444 * For an interrupted write, the buffer is still valid
1445 * and the write hasn't been pushed to the server yet,
1446 * so we can't set BIO_ERROR and report the interruption
1447 * by setting B_EINTR. For the B_ASYNC case, B_EINTR
1448 * is not relevant, so the rpc attempt is essentially
1449 * a noop. For the case of a V3 write rpc not being
1450 * committed to stable storage, the block is still
1451 * dirty and requires either a commit rpc or another
1452 * write rpc with iomode == NFSV3WRITE_FILESYNC before
1453 * the block is reused. This is indicated by setting
1454 * the B_DELWRI and B_NEEDCOMMIT flags.
1455 *
1456 * If the buffer is marked B_PAGING, it does not reside on
1457 * the vp's paging queues so we cannot call bdirty(). The
1458 * bp in this case is not an NFS cache block so we should
1459 * be safe. XXX
1460 */
1461 if (error == EINTR
1462 || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
1463 int s;
1464
1465 s = splbio();
1466 bp->b_flags &= ~(B_INVAL|B_NOCACHE);
1467 if ((bp->b_flags & B_PAGING) == 0) {
1468 bdirty(bp);
1469 bp->b_flags &= ~B_DONE;
1470 }
1471 if (error && (bp->b_flags & B_ASYNC) == 0)
1472 bp->b_flags |= B_EINTR;
1473 splx(s);
1474 } else {
1475 if (error) {
1476 bp->b_ioflags |= BIO_ERROR;
1477 bp->b_error = np->n_error = error;
1478 np->n_flag |= NWRITEERR;
1479 }
1480 bp->b_dirtyoff = bp->b_dirtyend = 0;
1481 }
1482 } else {
1483 bp->b_resid = 0;
1484 bufdone(bp);
1485 return (0);
1486 }
1487 }
1488 bp->b_resid = uiop->uio_resid;
1489 if (must_commit)
1490 nfs_clearcommit(vp->v_mount);
1491 bufdone(bp);
1492 return (error);
1493}
|
1494
1495/*
1496 * Used to aid in handling ftruncate() operations on the NFS client side.
1497 * Truncation creates a number of special problems for NFS. We have to
1498 * throw away VM pages and buffer cache buffers that are beyond EOF, and
1499 * we have to properly handle VM pages or (potentially dirty) buffers
1500 * that straddle the truncation point.
1501 */
1502
1503int
1504nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize)
1505{
1506 struct nfsnode *np = VTONFS(vp);
1507 u_quad_t tsize = np->n_size;
1508 int biosize = vp->v_mount->mnt_stat.f_iosize;
1509 int error = 0;
1510
1511 np->n_size = nsize;
1512
1513 if (np->n_size < tsize) {
1514 struct buf *bp;
1515 daddr_t lbn;
1516 int bufsize;
1517
1518 /*
1519 * vtruncbuf() doesn't get the buffer overlapping the
1520 * truncation point. We may have a B_DELWRI and/or B_CACHE
1521 * buffer that now needs to be truncated.
1522 */
1523 error = vtruncbuf(vp, cred, td, nsize, biosize);
1524 lbn = nsize / biosize;
1525 bufsize = nsize & (biosize - 1);
1526 bp = nfs_getcacheblk(vp, lbn, bufsize, td);
1527 if (bp->b_dirtyoff > bp->b_bcount)
1528 bp->b_dirtyoff = bp->b_bcount;
1529 if (bp->b_dirtyend > bp->b_bcount)
1530 bp->b_dirtyend = bp->b_bcount;
1531 bp->b_flags |= B_RELBUF; /* don't leave garbage around */
1532 brelse(bp);
1533 } else {
1534 vnode_pager_setsize(vp, nsize);
1535 }
1536 return(error);
1537}
1538 |
|