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/9.0/sys/nfsclient/nfs_bio.c 224733 2011-08-09 15:29:58Z jhb $");
37
38 #include "opt_kdtrace.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/bio.h>
43 #include <sys/buf.h>
44 #include <sys/kernel.h>
45 #include <sys/mbuf.h>
46 #include <sys/mount.h>
47 #include <sys/proc.h>
48 #include <sys/vmmeter.h>
49 #include <sys/vnode.h>
50
51 #include <vm/vm.h>
52 #include <vm/vm_extern.h>
53 #include <vm/vm_page.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_pager.h>
56 #include <vm/vnode_pager.h>
57
58 #include <nfs/nfsproto.h>
59 #include <nfsclient/nfs.h>
60 #include <nfsclient/nfsmount.h>
61 #include <nfsclient/nfsnode.h>
62 #include <nfs/nfs_kdtrace.h>
63
64 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size,
65 struct thread *td);
66 static int nfs_directio_write(struct vnode *vp, struct uio *uiop,
67 struct ucred *cred, int ioflag);
68
69 extern int nfs_directio_enable;
70 extern int nfs_directio_allow_mmap;
71
72 /*
73 * Vnode op for VM getpages.
74 */
75 int
76 nfs_getpages(struct vop_getpages_args *ap)
77 {
78 int i, error, nextoff, size, toff, count, npages;
79 struct uio uio;
80 struct iovec iov;
81 vm_offset_t kva;
82 struct buf *bp;
83 struct vnode *vp;
84 struct thread *td;
85 struct ucred *cred;
86 struct nfsmount *nmp;
87 vm_object_t object;
88 vm_page_t *pages;
89 struct nfsnode *np;
90
91 vp = ap->a_vp;
92 np = VTONFS(vp);
93 td = curthread; /* XXX */
94 cred = curthread->td_ucred; /* XXX */
95 nmp = VFSTONFS(vp->v_mount);
96 pages = ap->a_m;
97 count = ap->a_count;
98
99 if ((object = vp->v_object) == NULL) {
100 nfs_printf("nfs_getpages: called with non-merged cache vnode??\n");
101 return (VM_PAGER_ERROR);
102 }
103
104 if (nfs_directio_enable && !nfs_directio_allow_mmap) {
105 mtx_lock(&np->n_mtx);
106 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
107 mtx_unlock(&np->n_mtx);
108 nfs_printf("nfs_getpages: called on non-cacheable vnode??\n");
109 return (VM_PAGER_ERROR);
110 } else
111 mtx_unlock(&np->n_mtx);
112 }
113
114 mtx_lock(&nmp->nm_mtx);
115 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
116 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
117 mtx_unlock(&nmp->nm_mtx);
118 /* We'll never get here for v4, because we always have fsinfo */
119 (void)nfs_fsinfo(nmp, vp, cred, td);
120 } else
121 mtx_unlock(&nmp->nm_mtx);
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 VM_OBJECT_LOCK(object);
131 if (pages[ap->a_reqpage]->valid != 0) {
132 for (i = 0; i < npages; ++i) {
133 if (i != ap->a_reqpage) {
134 vm_page_lock(pages[i]);
135 vm_page_free(pages[i]);
136 vm_page_unlock(pages[i]);
137 }
138 }
139 VM_OBJECT_UNLOCK(object);
140 return (0);
141 }
142 VM_OBJECT_UNLOCK(object);
143
144 /*
145 * We use only the kva address for the buffer, but this is extremely
146 * convienient and fast.
147 */
148 bp = getpbuf(&nfs_pbuf_freecnt);
149
150 kva = (vm_offset_t) bp->b_data;
151 pmap_qenter(kva, pages, npages);
152 PCPU_INC(cnt.v_vnodein);
153 PCPU_ADD(cnt.v_vnodepgsin, npages);
154
155 iov.iov_base = (caddr_t) kva;
156 iov.iov_len = count;
157 uio.uio_iov = &iov;
158 uio.uio_iovcnt = 1;
159 uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
160 uio.uio_resid = count;
161 uio.uio_segflg = UIO_SYSSPACE;
162 uio.uio_rw = UIO_READ;
163 uio.uio_td = td;
164
165 error = (nmp->nm_rpcops->nr_readrpc)(vp, &uio, cred);
166 pmap_qremove(kva, npages);
167
168 relpbuf(bp, &nfs_pbuf_freecnt);
169
170 if (error && (uio.uio_resid == count)) {
171 nfs_printf("nfs_getpages: error %d\n", error);
172 VM_OBJECT_LOCK(object);
173 for (i = 0; i < npages; ++i) {
174 if (i != ap->a_reqpage) {
175 vm_page_lock(pages[i]);
176 vm_page_free(pages[i]);
177 vm_page_unlock(pages[i]);
178 }
179 }
180 VM_OBJECT_UNLOCK(object);
181 return (VM_PAGER_ERROR);
182 }
183
184 /*
185 * Calculate the number of bytes read and validate only that number
186 * of bytes. Note that due to pending writes, size may be 0. This
187 * does not mean that the remaining data is invalid!
188 */
189
190 size = count - uio.uio_resid;
191 VM_OBJECT_LOCK(object);
192 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
193 vm_page_t m;
194 nextoff = toff + PAGE_SIZE;
195 m = pages[i];
196
197 if (nextoff <= size) {
198 /*
199 * Read operation filled an entire page
200 */
201 m->valid = VM_PAGE_BITS_ALL;
202 KASSERT(m->dirty == 0,
203 ("nfs_getpages: page %p is dirty", m));
204 } else if (size > toff) {
205 /*
206 * Read operation filled a partial page.
207 */
208 m->valid = 0;
209 vm_page_set_valid(m, 0, size - toff);
210 KASSERT(m->dirty == 0,
211 ("nfs_getpages: page %p is dirty", m));
212 } else {
213 /*
214 * Read operation was short. If no error occured
215 * we may have hit a zero-fill section. We simply
216 * leave valid set to 0.
217 */
218 ;
219 }
220 if (i != ap->a_reqpage) {
221 /*
222 * Whether or not to leave the page activated is up in
223 * the air, but we should put the page on a page queue
224 * somewhere (it already is in the object). Result:
225 * It appears that emperical results show that
226 * deactivating pages is best.
227 */
228
229 /*
230 * Just in case someone was asking for this page we
231 * now tell them that it is ok to use.
232 */
233 if (!error) {
234 if (m->oflags & VPO_WANTED) {
235 vm_page_lock(m);
236 vm_page_activate(m);
237 vm_page_unlock(m);
238 } else {
239 vm_page_lock(m);
240 vm_page_deactivate(m);
241 vm_page_unlock(m);
242 }
243 vm_page_wakeup(m);
244 } else {
245 vm_page_lock(m);
246 vm_page_free(m);
247 vm_page_unlock(m);
248 }
249 }
250 }
251 VM_OBJECT_UNLOCK(object);
252 return (0);
253 }
254
255 /*
256 * Vnode op for VM putpages.
257 */
258 int
259 nfs_putpages(struct vop_putpages_args *ap)
260 {
261 struct uio uio;
262 struct iovec iov;
263 vm_offset_t kva;
264 struct buf *bp;
265 int iomode, must_commit, i, error, npages, count;
266 off_t offset;
267 int *rtvals;
268 struct vnode *vp;
269 struct thread *td;
270 struct ucred *cred;
271 struct nfsmount *nmp;
272 struct nfsnode *np;
273 vm_page_t *pages;
274
275 vp = ap->a_vp;
276 np = VTONFS(vp);
277 td = curthread; /* XXX */
278 cred = curthread->td_ucred; /* XXX */
279 nmp = VFSTONFS(vp->v_mount);
280 pages = ap->a_m;
281 count = ap->a_count;
282 rtvals = ap->a_rtvals;
283 npages = btoc(count);
284 offset = IDX_TO_OFF(pages[0]->pindex);
285
286 mtx_lock(&nmp->nm_mtx);
287 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
288 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
289 mtx_unlock(&nmp->nm_mtx);
290 (void)nfs_fsinfo(nmp, vp, cred, td);
291 } else
292 mtx_unlock(&nmp->nm_mtx);
293
294 mtx_lock(&np->n_mtx);
295 if (nfs_directio_enable && !nfs_directio_allow_mmap &&
296 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
297 mtx_unlock(&np->n_mtx);
298 nfs_printf("nfs_putpages: called on noncache-able vnode??\n");
299 mtx_lock(&np->n_mtx);
300 }
301
302 for (i = 0; i < npages; i++)
303 rtvals[i] = VM_PAGER_ERROR;
304
305 /*
306 * When putting pages, do not extend file past EOF.
307 */
308 if (offset + count > np->n_size) {
309 count = np->n_size - offset;
310 if (count < 0)
311 count = 0;
312 }
313 mtx_unlock(&np->n_mtx);
314
315 /*
316 * We use only the kva address for the buffer, but this is extremely
317 * convienient and fast.
318 */
319 bp = getpbuf(&nfs_pbuf_freecnt);
320
321 kva = (vm_offset_t) bp->b_data;
322 pmap_qenter(kva, pages, npages);
323 PCPU_INC(cnt.v_vnodeout);
324 PCPU_ADD(cnt.v_vnodepgsout, count);
325
326 iov.iov_base = (caddr_t) kva;
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_SYSSPACE;
333 uio.uio_rw = UIO_WRITE;
334 uio.uio_td = td;
335
336 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0)
337 iomode = NFSV3WRITE_UNSTABLE;
338 else
339 iomode = NFSV3WRITE_FILESYNC;
340
341 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, &iomode, &must_commit);
342
343 pmap_qremove(kva, npages);
344 relpbuf(bp, &nfs_pbuf_freecnt);
345
346 if (!error) {
347 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid);
348 if (must_commit) {
349 nfs_clearcommit(vp->v_mount);
350 }
351 }
352 return rtvals[0];
353 }
354
355 /*
356 * For nfs, cache consistency can only be maintained approximately.
357 * Although RFC1094 does not specify the criteria, the following is
358 * believed to be compatible with the reference port.
359 * For nfs:
360 * If the file's modify time on the server has changed since the
361 * last read rpc or you have written to the file,
362 * you may have lost data cache consistency with the
363 * server, so flush all of the file's data out of the cache.
364 * Then force a getattr rpc to ensure that you have up to date
365 * attributes.
366 * NB: This implies that cache data can be read when up to
367 * NFS_ATTRTIMEO seconds out of date. If you find that you need current
368 * attributes this could be forced by setting n_attrstamp to 0 before
369 * the VOP_GETATTR() call.
370 */
371 static inline int
372 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred)
373 {
374 int error = 0;
375 struct vattr vattr;
376 struct nfsnode *np = VTONFS(vp);
377 int old_lock;
378 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
379
380 /*
381 * Grab the exclusive lock before checking whether the cache is
382 * consistent.
383 * XXX - We can make this cheaper later (by acquiring cheaper locks).
384 * But for now, this suffices.
385 */
386 old_lock = nfs_upgrade_vnlock(vp);
387 if (vp->v_iflag & VI_DOOMED) {
388 nfs_downgrade_vnlock(vp, old_lock);
389 return (EBADF);
390 }
391
392 mtx_lock(&np->n_mtx);
393 if (np->n_flag & NMODIFIED) {
394 mtx_unlock(&np->n_mtx);
395 if (vp->v_type != VREG) {
396 if (vp->v_type != VDIR)
397 panic("nfs: bioread, not dir");
398 (nmp->nm_rpcops->nr_invaldir)(vp);
399 error = nfs_vinvalbuf(vp, V_SAVE, td, 1);
400 if (error)
401 goto out;
402 }
403 np->n_attrstamp = 0;
404 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
405 error = VOP_GETATTR(vp, &vattr, cred);
406 if (error)
407 goto out;
408 mtx_lock(&np->n_mtx);
409 np->n_mtime = vattr.va_mtime;
410 mtx_unlock(&np->n_mtx);
411 } else {
412 mtx_unlock(&np->n_mtx);
413 error = VOP_GETATTR(vp, &vattr, cred);
414 if (error)
415 return (error);
416 mtx_lock(&np->n_mtx);
417 if ((np->n_flag & NSIZECHANGED)
418 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
419 mtx_unlock(&np->n_mtx);
420 if (vp->v_type == VDIR)
421 (nmp->nm_rpcops->nr_invaldir)(vp);
422 error = nfs_vinvalbuf(vp, V_SAVE, td, 1);
423 if (error)
424 goto out;
425 mtx_lock(&np->n_mtx);
426 np->n_mtime = vattr.va_mtime;
427 np->n_flag &= ~NSIZECHANGED;
428 }
429 mtx_unlock(&np->n_mtx);
430 }
431 out:
432 nfs_downgrade_vnlock(vp, old_lock);
433 return error;
434 }
435
436 /*
437 * Vnode op for read using bio
438 */
439 int
440 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
441 {
442 struct nfsnode *np = VTONFS(vp);
443 int biosize, i;
444 struct buf *bp, *rabp;
445 struct thread *td;
446 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
447 daddr_t lbn, rabn;
448 off_t end;
449 int bcount;
450 int seqcount;
451 int nra, error = 0, n = 0, on = 0;
452
453 KASSERT(uio->uio_rw == UIO_READ, ("nfs_read mode"));
454 if (uio->uio_resid == 0)
455 return (0);
456 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */
457 return (EINVAL);
458 td = uio->uio_td;
459
460 mtx_lock(&nmp->nm_mtx);
461 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
462 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
463 mtx_unlock(&nmp->nm_mtx);
464 (void)nfs_fsinfo(nmp, vp, cred, td);
465 } else
466 mtx_unlock(&nmp->nm_mtx);
467
468 end = uio->uio_offset + uio->uio_resid;
469 if (vp->v_type != VDIR &&
470 (end > nmp->nm_maxfilesize || end < uio->uio_offset))
471 return (EFBIG);
472
473 if (nfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG))
474 /* No caching/ no readaheads. Just read data into the user buffer */
475 return nfs_readrpc(vp, uio, cred);
476
477 biosize = vp->v_mount->mnt_stat.f_iosize;
478 seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE);
479
480 error = nfs_bioread_check_cons(vp, td, cred);
481 if (error)
482 return error;
483
484 do {
485 u_quad_t nsize;
486
487 mtx_lock(&np->n_mtx);
488 nsize = np->n_size;
489 mtx_unlock(&np->n_mtx);
490
491 switch (vp->v_type) {
492 case VREG:
493 nfsstats.biocache_reads++;
494 lbn = uio->uio_offset / biosize;
495 on = uio->uio_offset & (biosize - 1);
496
497 /*
498 * Start the read ahead(s), as required.
499 */
500 if (nmp->nm_readahead > 0) {
501 for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
502 (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) {
503 rabn = lbn + 1 + nra;
504 if (incore(&vp->v_bufobj, rabn) == NULL) {
505 rabp = nfs_getcacheblk(vp, rabn, biosize, td);
506 if (!rabp) {
507 error = nfs_sigintr(nmp, td);
508 return (error ? error : EINTR);
509 }
510 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
511 rabp->b_flags |= B_ASYNC;
512 rabp->b_iocmd = BIO_READ;
513 vfs_busy_pages(rabp, 0);
514 if (nfs_asyncio(nmp, rabp, cred, td)) {
515 rabp->b_flags |= B_INVAL;
516 rabp->b_ioflags |= BIO_ERROR;
517 vfs_unbusy_pages(rabp);
518 brelse(rabp);
519 break;
520 }
521 } else {
522 brelse(rabp);
523 }
524 }
525 }
526 }
527
528 /* Note that bcount is *not* DEV_BSIZE aligned. */
529 bcount = biosize;
530 if ((off_t)lbn * biosize >= nsize) {
531 bcount = 0;
532 } else if ((off_t)(lbn + 1) * biosize > nsize) {
533 bcount = nsize - (off_t)lbn * biosize;
534 }
535 bp = nfs_getcacheblk(vp, lbn, bcount, td);
536
537 if (!bp) {
538 error = nfs_sigintr(nmp, td);
539 return (error ? error : EINTR);
540 }
541
542 /*
543 * If B_CACHE is not set, we must issue the read. If this
544 * fails, we return an error.
545 */
546
547 if ((bp->b_flags & B_CACHE) == 0) {
548 bp->b_iocmd = BIO_READ;
549 vfs_busy_pages(bp, 0);
550 error = nfs_doio(vp, bp, cred, td);
551 if (error) {
552 brelse(bp);
553 return (error);
554 }
555 }
556
557 /*
558 * on is the offset into the current bp. Figure out how many
559 * bytes we can copy out of the bp. Note that bcount is
560 * NOT DEV_BSIZE aligned.
561 *
562 * Then figure out how many bytes we can copy into the uio.
563 */
564
565 n = 0;
566 if (on < bcount)
567 n = min((unsigned)(bcount - on), uio->uio_resid);
568 break;
569 case VLNK:
570 nfsstats.biocache_readlinks++;
571 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
572 if (!bp) {
573 error = nfs_sigintr(nmp, td);
574 return (error ? error : EINTR);
575 }
576 if ((bp->b_flags & B_CACHE) == 0) {
577 bp->b_iocmd = BIO_READ;
578 vfs_busy_pages(bp, 0);
579 error = nfs_doio(vp, bp, cred, td);
580 if (error) {
581 bp->b_ioflags |= BIO_ERROR;
582 brelse(bp);
583 return (error);
584 }
585 }
586 n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
587 on = 0;
588 break;
589 case VDIR:
590 nfsstats.biocache_readdirs++;
591 if (np->n_direofoffset
592 && uio->uio_offset >= np->n_direofoffset) {
593 return (0);
594 }
595 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
596 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
597 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
598 if (!bp) {
599 error = nfs_sigintr(nmp, td);
600 return (error ? error : EINTR);
601 }
602 if ((bp->b_flags & B_CACHE) == 0) {
603 bp->b_iocmd = BIO_READ;
604 vfs_busy_pages(bp, 0);
605 error = nfs_doio(vp, bp, cred, td);
606 if (error) {
607 brelse(bp);
608 }
609 while (error == NFSERR_BAD_COOKIE) {
610 (nmp->nm_rpcops->nr_invaldir)(vp);
611 error = nfs_vinvalbuf(vp, 0, td, 1);
612 /*
613 * Yuck! The directory has been modified on the
614 * server. The only way to get the block is by
615 * reading from the beginning to get all the
616 * offset cookies.
617 *
618 * Leave the last bp intact unless there is an error.
619 * Loop back up to the while if the error is another
620 * NFSERR_BAD_COOKIE (double yuch!).
621 */
622 for (i = 0; i <= lbn && !error; i++) {
623 if (np->n_direofoffset
624 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset)
625 return (0);
626 bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
627 if (!bp) {
628 error = nfs_sigintr(nmp, td);
629 return (error ? error : EINTR);
630 }
631 if ((bp->b_flags & B_CACHE) == 0) {
632 bp->b_iocmd = BIO_READ;
633 vfs_busy_pages(bp, 0);
634 error = nfs_doio(vp, bp, cred, td);
635 /*
636 * no error + B_INVAL == directory EOF,
637 * use the block.
638 */
639 if (error == 0 && (bp->b_flags & B_INVAL))
640 break;
641 }
642 /*
643 * An error will throw away the block and the
644 * for loop will break out. If no error and this
645 * is not the block we want, we throw away the
646 * block and go for the next one via the for loop.
647 */
648 if (error || i < lbn)
649 brelse(bp);
650 }
651 }
652 /*
653 * The above while is repeated if we hit another cookie
654 * error. If we hit an error and it wasn't a cookie error,
655 * we give up.
656 */
657 if (error)
658 return (error);
659 }
660
661 /*
662 * If not eof and read aheads are enabled, start one.
663 * (You need the current block first, so that you have the
664 * directory offset cookie of the next block.)
665 */
666 if (nmp->nm_readahead > 0 &&
667 (bp->b_flags & B_INVAL) == 0 &&
668 (np->n_direofoffset == 0 ||
669 (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
670 incore(&vp->v_bufobj, lbn + 1) == NULL) {
671 rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
672 if (rabp) {
673 if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
674 rabp->b_flags |= B_ASYNC;
675 rabp->b_iocmd = BIO_READ;
676 vfs_busy_pages(rabp, 0);
677 if (nfs_asyncio(nmp, rabp, cred, td)) {
678 rabp->b_flags |= B_INVAL;
679 rabp->b_ioflags |= BIO_ERROR;
680 vfs_unbusy_pages(rabp);
681 brelse(rabp);
682 }
683 } else {
684 brelse(rabp);
685 }
686 }
687 }
688 /*
689 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is
690 * chopped for the EOF condition, we cannot tell how large
691 * NFS directories are going to be until we hit EOF. So
692 * an NFS directory buffer is *not* chopped to its EOF. Now,
693 * it just so happens that b_resid will effectively chop it
694 * to EOF. *BUT* this information is lost if the buffer goes
695 * away and is reconstituted into a B_CACHE state ( due to
696 * being VMIO ) later. So we keep track of the directory eof
697 * in np->n_direofoffset and chop it off as an extra step
698 * right here.
699 */
700 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
701 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
702 n = np->n_direofoffset - uio->uio_offset;
703 break;
704 default:
705 nfs_printf(" nfs_bioread: type %x unexpected\n", vp->v_type);
706 bp = NULL;
707 break;
708 };
709
710 if (n > 0) {
711 error = uiomove(bp->b_data + on, (int)n, uio);
712 }
713 if (vp->v_type == VLNK)
714 n = 0;
715 if (bp != NULL)
716 brelse(bp);
717 } while (error == 0 && uio->uio_resid > 0 && n > 0);
718 return (error);
719 }
720
721 /*
722 * The NFS write path cannot handle iovecs with len > 1. So we need to
723 * break up iovecs accordingly (restricting them to wsize).
724 * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf).
725 * For the ASYNC case, 2 copies are needed. The first a copy from the
726 * user buffer to a staging buffer and then a second copy from the staging
727 * buffer to mbufs. This can be optimized by copying from the user buffer
728 * directly into mbufs and passing the chain down, but that requires a
729 * fair amount of re-working of the relevant codepaths (and can be done
730 * later).
731 */
732 static int
733 nfs_directio_write(vp, uiop, cred, ioflag)
734 struct vnode *vp;
735 struct uio *uiop;
736 struct ucred *cred;
737 int ioflag;
738 {
739 int error;
740 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
741 struct thread *td = uiop->uio_td;
742 int size;
743 int wsize;
744
745 mtx_lock(&nmp->nm_mtx);
746 wsize = nmp->nm_wsize;
747 mtx_unlock(&nmp->nm_mtx);
748 if (ioflag & IO_SYNC) {
749 int iomode, must_commit;
750 struct uio uio;
751 struct iovec iov;
752 do_sync:
753 while (uiop->uio_resid > 0) {
754 size = min(uiop->uio_resid, wsize);
755 size = min(uiop->uio_iov->iov_len, size);
756 iov.iov_base = uiop->uio_iov->iov_base;
757 iov.iov_len = size;
758 uio.uio_iov = &iov;
759 uio.uio_iovcnt = 1;
760 uio.uio_offset = uiop->uio_offset;
761 uio.uio_resid = size;
762 uio.uio_segflg = UIO_USERSPACE;
763 uio.uio_rw = UIO_WRITE;
764 uio.uio_td = td;
765 iomode = NFSV3WRITE_FILESYNC;
766 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred,
767 &iomode, &must_commit);
768 KASSERT((must_commit == 0),
769 ("nfs_directio_write: Did not commit write"));
770 if (error)
771 return (error);
772 uiop->uio_offset += size;
773 uiop->uio_resid -= size;
774 if (uiop->uio_iov->iov_len <= size) {
775 uiop->uio_iovcnt--;
776 uiop->uio_iov++;
777 } else {
778 uiop->uio_iov->iov_base =
779 (char *)uiop->uio_iov->iov_base + size;
780 uiop->uio_iov->iov_len -= size;
781 }
782 }
783 } else {
784 struct uio *t_uio;
785 struct iovec *t_iov;
786 struct buf *bp;
787
788 /*
789 * Break up the write into blocksize chunks and hand these
790 * over to nfsiod's for write back.
791 * Unfortunately, this incurs a copy of the data. Since
792 * the user could modify the buffer before the write is
793 * initiated.
794 *
795 * The obvious optimization here is that one of the 2 copies
796 * in the async write path can be eliminated by copying the
797 * data here directly into mbufs and passing the mbuf chain
798 * down. But that will require a fair amount of re-working
799 * of the code and can be done if there's enough interest
800 * in NFS directio access.
801 */
802 while (uiop->uio_resid > 0) {
803 size = min(uiop->uio_resid, wsize);
804 size = min(uiop->uio_iov->iov_len, size);
805 bp = getpbuf(&nfs_pbuf_freecnt);
806 t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
807 t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
808 t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK);
809 t_iov->iov_len = size;
810 t_uio->uio_iov = t_iov;
811 t_uio->uio_iovcnt = 1;
812 t_uio->uio_offset = uiop->uio_offset;
813 t_uio->uio_resid = size;
814 t_uio->uio_segflg = UIO_SYSSPACE;
815 t_uio->uio_rw = UIO_WRITE;
816 t_uio->uio_td = td;
817 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, size);
818 bp->b_flags |= B_DIRECT;
819 bp->b_iocmd = BIO_WRITE;
820 if (cred != NOCRED) {
821 crhold(cred);
822 bp->b_wcred = cred;
823 } else
824 bp->b_wcred = NOCRED;
825 bp->b_caller1 = (void *)t_uio;
826 bp->b_vp = vp;
827 error = nfs_asyncio(nmp, bp, NOCRED, td);
828 if (error) {
829 free(t_iov->iov_base, M_NFSDIRECTIO);
830 free(t_iov, M_NFSDIRECTIO);
831 free(t_uio, M_NFSDIRECTIO);
832 bp->b_vp = NULL;
833 relpbuf(bp, &nfs_pbuf_freecnt);
834 if (error == EINTR)
835 return (error);
836 goto do_sync;
837 }
838 uiop->uio_offset += size;
839 uiop->uio_resid -= size;
840 if (uiop->uio_iov->iov_len <= size) {
841 uiop->uio_iovcnt--;
842 uiop->uio_iov++;
843 } else {
844 uiop->uio_iov->iov_base =
845 (char *)uiop->uio_iov->iov_base + size;
846 uiop->uio_iov->iov_len -= size;
847 }
848 }
849 }
850 return (0);
851 }
852
853 /*
854 * Vnode op for write using bio
855 */
856 int
857 nfs_write(struct vop_write_args *ap)
858 {
859 int biosize;
860 struct uio *uio = ap->a_uio;
861 struct thread *td = uio->uio_td;
862 struct vnode *vp = ap->a_vp;
863 struct nfsnode *np = VTONFS(vp);
864 struct ucred *cred = ap->a_cred;
865 int ioflag = ap->a_ioflag;
866 struct buf *bp;
867 struct vattr vattr;
868 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
869 daddr_t lbn;
870 off_t end;
871 int bcount;
872 int n, on, error = 0;
873
874 KASSERT(uio->uio_rw == UIO_WRITE, ("nfs_write mode"));
875 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
876 ("nfs_write proc"));
877 if (vp->v_type != VREG)
878 return (EIO);
879 mtx_lock(&np->n_mtx);
880 if (np->n_flag & NWRITEERR) {
881 np->n_flag &= ~NWRITEERR;
882 mtx_unlock(&np->n_mtx);
883 return (np->n_error);
884 } else
885 mtx_unlock(&np->n_mtx);
886 mtx_lock(&nmp->nm_mtx);
887 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
888 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
889 mtx_unlock(&nmp->nm_mtx);
890 (void)nfs_fsinfo(nmp, vp, cred, td);
891 } else
892 mtx_unlock(&nmp->nm_mtx);
893
894 /*
895 * Synchronously flush pending buffers if we are in synchronous
896 * mode or if we are appending.
897 */
898 if (ioflag & (IO_APPEND | IO_SYNC)) {
899 mtx_lock(&np->n_mtx);
900 if (np->n_flag & NMODIFIED) {
901 mtx_unlock(&np->n_mtx);
902 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */
903 /*
904 * Require non-blocking, synchronous writes to
905 * dirty files to inform the program it needs
906 * to fsync(2) explicitly.
907 */
908 if (ioflag & IO_NDELAY)
909 return (EAGAIN);
910 #endif
911 flush_and_restart:
912 np->n_attrstamp = 0;
913 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
914 error = nfs_vinvalbuf(vp, V_SAVE, td, 1);
915 if (error)
916 return (error);
917 } else
918 mtx_unlock(&np->n_mtx);
919 }
920
921 /*
922 * If IO_APPEND then load uio_offset. We restart here if we cannot
923 * get the append lock.
924 */
925 if (ioflag & IO_APPEND) {
926 np->n_attrstamp = 0;
927 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
928 error = VOP_GETATTR(vp, &vattr, cred);
929 if (error)
930 return (error);
931 mtx_lock(&np->n_mtx);
932 uio->uio_offset = np->n_size;
933 mtx_unlock(&np->n_mtx);
934 }
935
936 if (uio->uio_offset < 0)
937 return (EINVAL);
938 end = uio->uio_offset + uio->uio_resid;
939 if (end > nmp->nm_maxfilesize || end < uio->uio_offset)
940 return (EFBIG);
941 if (uio->uio_resid == 0)
942 return (0);
943
944 if (nfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
945 return nfs_directio_write(vp, uio, cred, ioflag);
946
947 /*
948 * Maybe this should be above the vnode op call, but so long as
949 * file servers have no limits, i don't think it matters
950 */
951 if (vn_rlimit_fsize(vp, uio, td))
952 return (EFBIG);
953
954 biosize = vp->v_mount->mnt_stat.f_iosize;
955 /*
956 * Find all of this file's B_NEEDCOMMIT buffers. If our writes
957 * would exceed the local maximum per-file write commit size when
958 * combined with those, we must decide whether to flush,
959 * go synchronous, or return error. We don't bother checking
960 * IO_UNIT -- we just make all writes atomic anyway, as there's
961 * no point optimizing for something that really won't ever happen.
962 */
963 if (!(ioflag & IO_SYNC)) {
964 int nflag;
965
966 mtx_lock(&np->n_mtx);
967 nflag = np->n_flag;
968 mtx_unlock(&np->n_mtx);
969 int needrestart = 0;
970 if (nmp->nm_wcommitsize < uio->uio_resid) {
971 /*
972 * If this request could not possibly be completed
973 * without exceeding the maximum outstanding write
974 * commit size, see if we can convert it into a
975 * synchronous write operation.
976 */
977 if (ioflag & IO_NDELAY)
978 return (EAGAIN);
979 ioflag |= IO_SYNC;
980 if (nflag & NMODIFIED)
981 needrestart = 1;
982 } else if (nflag & NMODIFIED) {
983 int wouldcommit = 0;
984 BO_LOCK(&vp->v_bufobj);
985 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) {
986 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd,
987 b_bobufs) {
988 if (bp->b_flags & B_NEEDCOMMIT)
989 wouldcommit += bp->b_bcount;
990 }
991 }
992 BO_UNLOCK(&vp->v_bufobj);
993 /*
994 * Since we're not operating synchronously and
995 * bypassing the buffer cache, we are in a commit
996 * and holding all of these buffers whether
997 * transmitted or not. If not limited, this
998 * will lead to the buffer cache deadlocking,
999 * as no one else can flush our uncommitted buffers.
1000 */
1001 wouldcommit += uio->uio_resid;
1002 /*
1003 * If we would initially exceed the maximum
1004 * outstanding write commit size, flush and restart.
1005 */
1006 if (wouldcommit > nmp->nm_wcommitsize)
1007 needrestart = 1;
1008 }
1009 if (needrestart)
1010 goto flush_and_restart;
1011 }
1012
1013 do {
1014 nfsstats.biocache_writes++;
1015 lbn = uio->uio_offset / biosize;
1016 on = uio->uio_offset & (biosize-1);
1017 n = min((unsigned)(biosize - on), uio->uio_resid);
1018 again:
1019 /*
1020 * Handle direct append and file extension cases, calculate
1021 * unaligned buffer size.
1022 */
1023 mtx_lock(&np->n_mtx);
1024 if (uio->uio_offset == np->n_size && n) {
1025 mtx_unlock(&np->n_mtx);
1026 /*
1027 * Get the buffer (in its pre-append state to maintain
1028 * B_CACHE if it was previously set). Resize the
1029 * nfsnode after we have locked the buffer to prevent
1030 * readers from reading garbage.
1031 */
1032 bcount = on;
1033 bp = nfs_getcacheblk(vp, lbn, bcount, td);
1034
1035 if (bp != NULL) {
1036 long save;
1037
1038 mtx_lock(&np->n_mtx);
1039 np->n_size = uio->uio_offset + n;
1040 np->n_flag |= NMODIFIED;
1041 vnode_pager_setsize(vp, np->n_size);
1042 mtx_unlock(&np->n_mtx);
1043
1044 save = bp->b_flags & B_CACHE;
1045 bcount += n;
1046 allocbuf(bp, bcount);
1047 bp->b_flags |= save;
1048 }
1049 } else {
1050 /*
1051 * Obtain the locked cache block first, and then
1052 * adjust the file's size as appropriate.
1053 */
1054 bcount = on + n;
1055 if ((off_t)lbn * biosize + bcount < np->n_size) {
1056 if ((off_t)(lbn + 1) * biosize < np->n_size)
1057 bcount = biosize;
1058 else
1059 bcount = np->n_size - (off_t)lbn * biosize;
1060 }
1061 mtx_unlock(&np->n_mtx);
1062 bp = nfs_getcacheblk(vp, lbn, bcount, td);
1063 mtx_lock(&np->n_mtx);
1064 if (uio->uio_offset + n > np->n_size) {
1065 np->n_size = uio->uio_offset + n;
1066 np->n_flag |= NMODIFIED;
1067 vnode_pager_setsize(vp, np->n_size);
1068 }
1069 mtx_unlock(&np->n_mtx);
1070 }
1071
1072 if (!bp) {
1073 error = nfs_sigintr(nmp, td);
1074 if (!error)
1075 error = EINTR;
1076 break;
1077 }
1078
1079 /*
1080 * Issue a READ if B_CACHE is not set. In special-append
1081 * mode, B_CACHE is based on the buffer prior to the write
1082 * op and is typically set, avoiding the read. If a read
1083 * is required in special append mode, the server will
1084 * probably send us a short-read since we extended the file
1085 * on our end, resulting in b_resid == 0 and, thusly,
1086 * B_CACHE getting set.
1087 *
1088 * We can also avoid issuing the read if the write covers
1089 * the entire buffer. We have to make sure the buffer state
1090 * is reasonable in this case since we will not be initiating
1091 * I/O. See the comments in kern/vfs_bio.c's getblk() for
1092 * more information.
1093 *
1094 * B_CACHE may also be set due to the buffer being cached
1095 * normally.
1096 */
1097
1098 if (on == 0 && n == bcount) {
1099 bp->b_flags |= B_CACHE;
1100 bp->b_flags &= ~B_INVAL;
1101 bp->b_ioflags &= ~BIO_ERROR;
1102 }
1103
1104 if ((bp->b_flags & B_CACHE) == 0) {
1105 bp->b_iocmd = BIO_READ;
1106 vfs_busy_pages(bp, 0);
1107 error = nfs_doio(vp, bp, cred, td);
1108 if (error) {
1109 brelse(bp);
1110 break;
1111 }
1112 }
1113 if (bp->b_wcred == NOCRED)
1114 bp->b_wcred = crhold(cred);
1115 mtx_lock(&np->n_mtx);
1116 np->n_flag |= NMODIFIED;
1117 mtx_unlock(&np->n_mtx);
1118
1119 /*
1120 * If dirtyend exceeds file size, chop it down. This should
1121 * not normally occur but there is an append race where it
1122 * might occur XXX, so we log it.
1123 *
1124 * If the chopping creates a reverse-indexed or degenerate
1125 * situation with dirtyoff/end, we 0 both of them.
1126 */
1127
1128 if (bp->b_dirtyend > bcount) {
1129 nfs_printf("NFS append race @%lx:%d\n",
1130 (long)bp->b_blkno * DEV_BSIZE,
1131 bp->b_dirtyend - bcount);
1132 bp->b_dirtyend = bcount;
1133 }
1134
1135 if (bp->b_dirtyoff >= bp->b_dirtyend)
1136 bp->b_dirtyoff = bp->b_dirtyend = 0;
1137
1138 /*
1139 * If the new write will leave a contiguous dirty
1140 * area, just update the b_dirtyoff and b_dirtyend,
1141 * otherwise force a write rpc of the old dirty area.
1142 *
1143 * While it is possible to merge discontiguous writes due to
1144 * our having a B_CACHE buffer ( and thus valid read data
1145 * for the hole), we don't because it could lead to
1146 * significant cache coherency problems with multiple clients,
1147 * especially if locking is implemented later on.
1148 *
1149 * as an optimization we could theoretically maintain
1150 * a linked list of discontinuous areas, but we would still
1151 * have to commit them separately so there isn't much
1152 * advantage to it except perhaps a bit of asynchronization.
1153 */
1154
1155 if (bp->b_dirtyend > 0 &&
1156 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
1157 if (bwrite(bp) == EINTR) {
1158 error = EINTR;
1159 break;
1160 }
1161 goto again;
1162 }
1163
1164 error = uiomove((char *)bp->b_data + on, n, uio);
1165
1166 /*
1167 * Since this block is being modified, it must be written
1168 * again and not just committed. Since write clustering does
1169 * not work for the stage 1 data write, only the stage 2
1170 * commit rpc, we have to clear B_CLUSTEROK as well.
1171 */
1172 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1173
1174 if (error) {
1175 bp->b_ioflags |= BIO_ERROR;
1176 brelse(bp);
1177 break;
1178 }
1179
1180 /*
1181 * Only update dirtyoff/dirtyend if not a degenerate
1182 * condition.
1183 */
1184 if (n) {
1185 if (bp->b_dirtyend > 0) {
1186 bp->b_dirtyoff = min(on, bp->b_dirtyoff);
1187 bp->b_dirtyend = max((on + n), bp->b_dirtyend);
1188 } else {
1189 bp->b_dirtyoff = on;
1190 bp->b_dirtyend = on + n;
1191 }
1192 vfs_bio_set_valid(bp, on, n);
1193 }
1194
1195 /*
1196 * If IO_SYNC do bwrite().
1197 *
1198 * IO_INVAL appears to be unused. The idea appears to be
1199 * to turn off caching in this case. Very odd. XXX
1200 */
1201 if ((ioflag & IO_SYNC)) {
1202 if (ioflag & IO_INVAL)
1203 bp->b_flags |= B_NOCACHE;
1204 error = bwrite(bp);
1205 if (error)
1206 break;
1207 } else if ((n + on) == biosize) {
1208 bp->b_flags |= B_ASYNC;
1209 (void) (nmp->nm_rpcops->nr_writebp)(bp, 0, NULL);
1210 } else {
1211 bdwrite(bp);
1212 }
1213 } while (uio->uio_resid > 0 && n > 0);
1214
1215 return (error);
1216 }
1217
1218 /*
1219 * Get an nfs cache block.
1220 *
1221 * Allocate a new one if the block isn't currently in the cache
1222 * and return the block marked busy. If the calling process is
1223 * interrupted by a signal for an interruptible mount point, return
1224 * NULL.
1225 *
1226 * The caller must carefully deal with the possible B_INVAL state of
1227 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it
1228 * indirectly), so synchronous reads can be issued without worrying about
1229 * the B_INVAL state. We have to be a little more careful when dealing
1230 * with writes (see comments in nfs_write()) when extending a file past
1231 * its EOF.
1232 */
1233 static struct buf *
1234 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
1235 {
1236 struct buf *bp;
1237 struct mount *mp;
1238 struct nfsmount *nmp;
1239
1240 mp = vp->v_mount;
1241 nmp = VFSTONFS(mp);
1242
1243 if (nmp->nm_flag & NFSMNT_INT) {
1244 sigset_t oldset;
1245
1246 nfs_set_sigmask(td, &oldset);
1247 bp = getblk(vp, bn, size, NFS_PCATCH, 0, 0);
1248 nfs_restore_sigmask(td, &oldset);
1249 while (bp == NULL) {
1250 if (nfs_sigintr(nmp, td))
1251 return (NULL);
1252 bp = getblk(vp, bn, size, 0, 2 * hz, 0);
1253 }
1254 } else {
1255 bp = getblk(vp, bn, size, 0, 0, 0);
1256 }
1257
1258 if (vp->v_type == VREG) {
1259 int biosize;
1260
1261 biosize = mp->mnt_stat.f_iosize;
1262 bp->b_blkno = bn * (biosize / DEV_BSIZE);
1263 }
1264 return (bp);
1265 }
1266
1267 /*
1268 * Flush and invalidate all dirty buffers. If another process is already
1269 * doing the flush, just wait for completion.
1270 */
1271 int
1272 nfs_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg)
1273 {
1274 struct nfsnode *np = VTONFS(vp);
1275 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
1276 int error = 0, slpflag, slptimeo;
1277 int old_lock = 0;
1278
1279 ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf");
1280
1281 if ((nmp->nm_flag & NFSMNT_INT) == 0)
1282 intrflg = 0;
1283 if (intrflg) {
1284 slpflag = NFS_PCATCH;
1285 slptimeo = 2 * hz;
1286 } else {
1287 slpflag = 0;
1288 slptimeo = 0;
1289 }
1290
1291 old_lock = nfs_upgrade_vnlock(vp);
1292 if (vp->v_iflag & VI_DOOMED) {
1293 /*
1294 * Since vgonel() uses the generic vinvalbuf() to flush
1295 * dirty buffers and it does not call this function, it
1296 * is safe to just return OK when VI_DOOMED is set.
1297 */
1298 nfs_downgrade_vnlock(vp, old_lock);
1299 return (0);
1300 }
1301
1302 /*
1303 * Now, flush as required.
1304 */
1305 if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) {
1306 VM_OBJECT_LOCK(vp->v_bufobj.bo_object);
1307 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
1308 VM_OBJECT_UNLOCK(vp->v_bufobj.bo_object);
1309 /*
1310 * If the page clean was interrupted, fail the invalidation.
1311 * Not doing so, we run the risk of losing dirty pages in the
1312 * vinvalbuf() call below.
1313 */
1314 if (intrflg && (error = nfs_sigintr(nmp, td)))
1315 goto out;
1316 }
1317
1318 error = vinvalbuf(vp, flags, slpflag, 0);
1319 while (error) {
1320 if (intrflg && (error = nfs_sigintr(nmp, td)))
1321 goto out;
1322 error = vinvalbuf(vp, flags, 0, slptimeo);
1323 }
1324 mtx_lock(&np->n_mtx);
1325 if (np->n_directio_asyncwr == 0)
1326 np->n_flag &= ~NMODIFIED;
1327 mtx_unlock(&np->n_mtx);
1328 out:
1329 nfs_downgrade_vnlock(vp, old_lock);
1330 return error;
1331 }
1332
1333 /*
1334 * Initiate asynchronous I/O. Return an error if no nfsiods are available.
1335 * This is mainly to avoid queueing async I/O requests when the nfsiods
1336 * are all hung on a dead server.
1337 *
1338 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
1339 * is eventually dequeued by the async daemon, nfs_doio() *will*.
1340 */
1341 int
1342 nfs_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
1343 {
1344 int iod;
1345 int gotiod;
1346 int slpflag = 0;
1347 int slptimeo = 0;
1348 int error, error2;
1349
1350 /*
1351 * Commits are usually short and sweet so lets save some cpu and
1352 * leave the async daemons for more important rpc's (such as reads
1353 * and writes).
1354 */
1355 mtx_lock(&nfs_iod_mtx);
1356 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
1357 (nmp->nm_bufqiods > nfs_numasync / 2)) {
1358 mtx_unlock(&nfs_iod_mtx);
1359 return(EIO);
1360 }
1361 again:
1362 if (nmp->nm_flag & NFSMNT_INT)
1363 slpflag = NFS_PCATCH;
1364 gotiod = FALSE;
1365
1366 /*
1367 * Find a free iod to process this request.
1368 */
1369 for (iod = 0; iod < nfs_numasync; iod++)
1370 if (nfs_iodwant[iod] == NFSIOD_AVAILABLE) {
1371 gotiod = TRUE;
1372 break;
1373 }
1374
1375 /*
1376 * Try to create one if none are free.
1377 */
1378 if (!gotiod)
1379 nfs_nfsiodnew();
1380 else {
1381 /*
1382 * Found one, so wake it up and tell it which
1383 * mount to process.
1384 */
1385 NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n",
1386 iod, nmp));
1387 nfs_iodwant[iod] = NFSIOD_NOT_AVAILABLE;
1388 nfs_iodmount[iod] = nmp;
1389 nmp->nm_bufqiods++;
1390 wakeup(&nfs_iodwant[iod]);
1391 }
1392
1393 /*
1394 * If none are free, we may already have an iod working on this mount
1395 * point. If so, it will process our request.
1396 */
1397 if (!gotiod) {
1398 if (nmp->nm_bufqiods > 0) {
1399 NFS_DPF(ASYNCIO,
1400 ("nfs_asyncio: %d iods are already processing mount %p\n",
1401 nmp->nm_bufqiods, nmp));
1402 gotiod = TRUE;
1403 }
1404 }
1405
1406 /*
1407 * If we have an iod which can process the request, then queue
1408 * the buffer.
1409 */
1410 if (gotiod) {
1411 /*
1412 * Ensure that the queue never grows too large. We still want
1413 * to asynchronize so we block rather then return EIO.
1414 */
1415 while (nmp->nm_bufqlen >= 2 * nfs_numasync) {
1416 NFS_DPF(ASYNCIO,
1417 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp));
1418 nmp->nm_bufqwant = TRUE;
1419 error = nfs_msleep(td, &nmp->nm_bufq, &nfs_iod_mtx,
1420 slpflag | PRIBIO,
1421 "nfsaio", slptimeo);
1422 if (error) {
1423 error2 = nfs_sigintr(nmp, td);
1424 if (error2) {
1425 mtx_unlock(&nfs_iod_mtx);
1426 return (error2);
1427 }
1428 if (slpflag == NFS_PCATCH) {
1429 slpflag = 0;
1430 slptimeo = 2 * hz;
1431 }
1432 }
1433 /*
1434 * We might have lost our iod while sleeping,
1435 * so check and loop if nescessary.
1436 */
1437 goto again;
1438 }
1439
1440 /* We might have lost our nfsiod */
1441 if (nmp->nm_bufqiods == 0) {
1442 NFS_DPF(ASYNCIO,
1443 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
1444 goto again;
1445 }
1446
1447 if (bp->b_iocmd == BIO_READ) {
1448 if (bp->b_rcred == NOCRED && cred != NOCRED)
1449 bp->b_rcred = crhold(cred);
1450 } else {
1451 if (bp->b_wcred == NOCRED && cred != NOCRED)
1452 bp->b_wcred = crhold(cred);
1453 }
1454
1455 if (bp->b_flags & B_REMFREE)
1456 bremfreef(bp);
1457 BUF_KERNPROC(bp);
1458 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
1459 nmp->nm_bufqlen++;
1460 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1461 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx);
1462 VTONFS(bp->b_vp)->n_flag |= NMODIFIED;
1463 VTONFS(bp->b_vp)->n_directio_asyncwr++;
1464 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx);
1465 }
1466 mtx_unlock(&nfs_iod_mtx);
1467 return (0);
1468 }
1469
1470 mtx_unlock(&nfs_iod_mtx);
1471
1472 /*
1473 * All the iods are busy on other mounts, so return EIO to
1474 * force the caller to process the i/o synchronously.
1475 */
1476 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n"));
1477 return (EIO);
1478 }
1479
1480 void
1481 nfs_doio_directwrite(struct buf *bp)
1482 {
1483 int iomode, must_commit;
1484 struct uio *uiop = (struct uio *)bp->b_caller1;
1485 char *iov_base = uiop->uio_iov->iov_base;
1486 struct nfsmount *nmp = VFSTONFS(bp->b_vp->v_mount);
1487
1488 iomode = NFSV3WRITE_FILESYNC;
1489 uiop->uio_td = NULL; /* NULL since we're in nfsiod */
1490 (nmp->nm_rpcops->nr_writerpc)(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit);
1491 KASSERT((must_commit == 0), ("nfs_doio_directwrite: Did not commit write"));
1492 free(iov_base, M_NFSDIRECTIO);
1493 free(uiop->uio_iov, M_NFSDIRECTIO);
1494 free(uiop, M_NFSDIRECTIO);
1495 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1496 struct nfsnode *np = VTONFS(bp->b_vp);
1497 mtx_lock(&np->n_mtx);
1498 np->n_directio_asyncwr--;
1499 if (np->n_directio_asyncwr == 0) {
1500 VTONFS(bp->b_vp)->n_flag &= ~NMODIFIED;
1501 if ((np->n_flag & NFSYNCWAIT)) {
1502 np->n_flag &= ~NFSYNCWAIT;
1503 wakeup((caddr_t)&np->n_directio_asyncwr);
1504 }
1505 }
1506 mtx_unlock(&np->n_mtx);
1507 }
1508 bp->b_vp = NULL;
1509 relpbuf(bp, &nfs_pbuf_freecnt);
1510 }
1511
1512 /*
1513 * Do an I/O operation to/from a cache block. This may be called
1514 * synchronously or from an nfsiod.
1515 */
1516 int
1517 nfs_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td)
1518 {
1519 struct uio *uiop;
1520 struct nfsnode *np;
1521 struct nfsmount *nmp;
1522 int error = 0, iomode, must_commit = 0;
1523 struct uio uio;
1524 struct iovec io;
1525 struct proc *p = td ? td->td_proc : NULL;
1526 uint8_t iocmd;
1527
1528 np = VTONFS(vp);
1529 nmp = VFSTONFS(vp->v_mount);
1530 uiop = &uio;
1531 uiop->uio_iov = &io;
1532 uiop->uio_iovcnt = 1;
1533 uiop->uio_segflg = UIO_SYSSPACE;
1534 uiop->uio_td = td;
1535
1536 /*
1537 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
1538 * do this here so we do not have to do it in all the code that
1539 * calls us.
1540 */
1541 bp->b_flags &= ~B_INVAL;
1542 bp->b_ioflags &= ~BIO_ERROR;
1543
1544 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp));
1545 iocmd = bp->b_iocmd;
1546 if (iocmd == BIO_READ) {
1547 io.iov_len = uiop->uio_resid = bp->b_bcount;
1548 io.iov_base = bp->b_data;
1549 uiop->uio_rw = UIO_READ;
1550
1551 switch (vp->v_type) {
1552 case VREG:
1553 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
1554 nfsstats.read_bios++;
1555 error = (nmp->nm_rpcops->nr_readrpc)(vp, uiop, cr);
1556
1557 if (!error) {
1558 if (uiop->uio_resid) {
1559 /*
1560 * If we had a short read with no error, we must have
1561 * hit a file hole. We should zero-fill the remainder.
1562 * This can also occur if the server hits the file EOF.
1563 *
1564 * Holes used to be able to occur due to pending
1565 * writes, but that is not possible any longer.
1566 */
1567 int nread = bp->b_bcount - uiop->uio_resid;
1568 int left = uiop->uio_resid;
1569
1570 if (left > 0)
1571 bzero((char *)bp->b_data + nread, left);
1572 uiop->uio_resid = 0;
1573 }
1574 }
1575 /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */
1576 if (p && (vp->v_vflag & VV_TEXT)) {
1577 mtx_lock(&np->n_mtx);
1578 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.va_mtime)) {
1579 mtx_unlock(&np->n_mtx);
1580 PROC_LOCK(p);
1581 killproc(p, "text file modification");
1582 PROC_UNLOCK(p);
1583 } else
1584 mtx_unlock(&np->n_mtx);
1585 }
1586 break;
1587 case VLNK:
1588 uiop->uio_offset = (off_t)0;
1589 nfsstats.readlink_bios++;
1590 error = (nmp->nm_rpcops->nr_readlinkrpc)(vp, uiop, cr);
1591 break;
1592 case VDIR:
1593 nfsstats.readdir_bios++;
1594 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
1595 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
1596 error = nfs_readdirplusrpc(vp, uiop, cr);
1597 if (error == NFSERR_NOTSUPP)
1598 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
1599 }
1600 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
1601 error = nfs_readdirrpc(vp, uiop, cr);
1602 /*
1603 * end-of-directory sets B_INVAL but does not generate an
1604 * error.
1605 */
1606 if (error == 0 && uiop->uio_resid == bp->b_bcount)
1607 bp->b_flags |= B_INVAL;
1608 break;
1609 default:
1610 nfs_printf("nfs_doio: type %x unexpected\n", vp->v_type);
1611 break;
1612 };
1613 if (error) {
1614 bp->b_ioflags |= BIO_ERROR;
1615 bp->b_error = error;
1616 }
1617 } else {
1618 /*
1619 * If we only need to commit, try to commit
1620 */
1621 if (bp->b_flags & B_NEEDCOMMIT) {
1622 int retv;
1623 off_t off;
1624
1625 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
1626 retv = (nmp->nm_rpcops->nr_commit)(
1627 vp, off, bp->b_dirtyend-bp->b_dirtyoff,
1628 bp->b_wcred, td);
1629 if (retv == 0) {
1630 bp->b_dirtyoff = bp->b_dirtyend = 0;
1631 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1632 bp->b_resid = 0;
1633 bufdone(bp);
1634 return (0);
1635 }
1636 if (retv == NFSERR_STALEWRITEVERF) {
1637 nfs_clearcommit(vp->v_mount);
1638 }
1639 }
1640
1641 /*
1642 * Setup for actual write
1643 */
1644 mtx_lock(&np->n_mtx);
1645 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
1646 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
1647 mtx_unlock(&np->n_mtx);
1648
1649 if (bp->b_dirtyend > bp->b_dirtyoff) {
1650 io.iov_len = uiop->uio_resid = bp->b_dirtyend
1651 - bp->b_dirtyoff;
1652 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
1653 + bp->b_dirtyoff;
1654 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
1655 uiop->uio_rw = UIO_WRITE;
1656 nfsstats.write_bios++;
1657
1658 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
1659 iomode = NFSV3WRITE_UNSTABLE;
1660 else
1661 iomode = NFSV3WRITE_FILESYNC;
1662
1663 error = (nmp->nm_rpcops->nr_writerpc)(vp, uiop, cr, &iomode, &must_commit);
1664
1665 /*
1666 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
1667 * to cluster the buffers needing commit. This will allow
1668 * the system to submit a single commit rpc for the whole
1669 * cluster. We can do this even if the buffer is not 100%
1670 * dirty (relative to the NFS blocksize), so we optimize the
1671 * append-to-file-case.
1672 *
1673 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
1674 * cleared because write clustering only works for commit
1675 * rpc's, not for the data portion of the write).
1676 */
1677
1678 if (!error && iomode == NFSV3WRITE_UNSTABLE) {
1679 bp->b_flags |= B_NEEDCOMMIT;
1680 if (bp->b_dirtyoff == 0
1681 && bp->b_dirtyend == bp->b_bcount)
1682 bp->b_flags |= B_CLUSTEROK;
1683 } else {
1684 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1685 }
1686
1687 /*
1688 * For an interrupted write, the buffer is still valid
1689 * and the write hasn't been pushed to the server yet,
1690 * so we can't set BIO_ERROR and report the interruption
1691 * by setting B_EINTR. For the B_ASYNC case, B_EINTR
1692 * is not relevant, so the rpc attempt is essentially
1693 * a noop. For the case of a V3 write rpc not being
1694 * committed to stable storage, the block is still
1695 * dirty and requires either a commit rpc or another
1696 * write rpc with iomode == NFSV3WRITE_FILESYNC before
1697 * the block is reused. This is indicated by setting
1698 * the B_DELWRI and B_NEEDCOMMIT flags.
1699 *
1700 * If the buffer is marked B_PAGING, it does not reside on
1701 * the vp's paging queues so we cannot call bdirty(). The
1702 * bp in this case is not an NFS cache block so we should
1703 * be safe. XXX
1704 *
1705 * The logic below breaks up errors into recoverable and
1706 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE
1707 * and keep the buffer around for potential write retries.
1708 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL)
1709 * and save the error in the nfsnode. This is less than ideal
1710 * but necessary. Keeping such buffers around could potentially
1711 * cause buffer exhaustion eventually (they can never be written
1712 * out, so will get constantly be re-dirtied). It also causes
1713 * all sorts of vfs panics. For non-recoverable write errors,
1714 * also invalidate the attrcache, so we'll be forced to go over
1715 * the wire for this object, returning an error to user on next
1716 * call (most of the time).
1717 */
1718 if (error == EINTR || error == EIO || error == ETIMEDOUT
1719 || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
1720 int s;
1721
1722 s = splbio();
1723 bp->b_flags &= ~(B_INVAL|B_NOCACHE);
1724 if ((bp->b_flags & B_PAGING) == 0) {
1725 bdirty(bp);
1726 bp->b_flags &= ~B_DONE;
1727 }
1728 if (error && (bp->b_flags & B_ASYNC) == 0)
1729 bp->b_flags |= B_EINTR;
1730 splx(s);
1731 } else {
1732 if (error) {
1733 bp->b_ioflags |= BIO_ERROR;
1734 bp->b_flags |= B_INVAL;
1735 bp->b_error = np->n_error = error;
1736 mtx_lock(&np->n_mtx);
1737 np->n_flag |= NWRITEERR;
1738 np->n_attrstamp = 0;
1739 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
1740 mtx_unlock(&np->n_mtx);
1741 }
1742 bp->b_dirtyoff = bp->b_dirtyend = 0;
1743 }
1744 } else {
1745 bp->b_resid = 0;
1746 bufdone(bp);
1747 return (0);
1748 }
1749 }
1750 bp->b_resid = uiop->uio_resid;
1751 if (must_commit)
1752 nfs_clearcommit(vp->v_mount);
1753 bufdone(bp);
1754 return (error);
1755 }
1756
1757 /*
1758 * Used to aid in handling ftruncate() operations on the NFS client side.
1759 * Truncation creates a number of special problems for NFS. We have to
1760 * throw away VM pages and buffer cache buffers that are beyond EOF, and
1761 * we have to properly handle VM pages or (potentially dirty) buffers
1762 * that straddle the truncation point.
1763 */
1764
1765 int
1766 nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize)
1767 {
1768 struct nfsnode *np = VTONFS(vp);
1769 u_quad_t tsize;
1770 int biosize = vp->v_mount->mnt_stat.f_iosize;
1771 int error = 0;
1772
1773 mtx_lock(&np->n_mtx);
1774 tsize = np->n_size;
1775 np->n_size = nsize;
1776 mtx_unlock(&np->n_mtx);
1777
1778 if (nsize < tsize) {
1779 struct buf *bp;
1780 daddr_t lbn;
1781 int bufsize;
1782
1783 /*
1784 * vtruncbuf() doesn't get the buffer overlapping the
1785 * truncation point. We may have a B_DELWRI and/or B_CACHE
1786 * buffer that now needs to be truncated.
1787 */
1788 error = vtruncbuf(vp, cred, td, nsize, biosize);
1789 lbn = nsize / biosize;
1790 bufsize = nsize & (biosize - 1);
1791 bp = nfs_getcacheblk(vp, lbn, bufsize, td);
1792 if (!bp)
1793 return EINTR;
1794 if (bp->b_dirtyoff > bp->b_bcount)
1795 bp->b_dirtyoff = bp->b_bcount;
1796 if (bp->b_dirtyend > bp->b_bcount)
1797 bp->b_dirtyend = bp->b_bcount;
1798 bp->b_flags |= B_RELBUF; /* don't leave garbage around */
1799 brelse(bp);
1800 } else {
1801 vnode_pager_setsize(vp, nsize);
1802 }
1803 return(error);
1804 }
1805
Cache object: ba6d4acd72ee21f9f7cdcb297782b760
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