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/8.1/sys/nfsclient/nfs_bio.c 203756 2010-02-10 16:16:50Z rmacklem $");
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/resourcevar.h>
49 #include <sys/signalvar.h>
50 #include <sys/vmmeter.h>
51 #include <sys/vnode.h>
52
53 #include <vm/vm.h>
54 #include <vm/vm_extern.h>
55 #include <vm/vm_page.h>
56 #include <vm/vm_object.h>
57 #include <vm/vm_pager.h>
58 #include <vm/vnode_pager.h>
59
60 #include <nfs/nfsproto.h>
61 #include <nfsclient/nfs.h>
62 #include <nfsclient/nfsmount.h>
63 #include <nfsclient/nfsnode.h>
64 #include <nfsclient/nfs_kdtrace.h>
65
66 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size,
67 struct thread *td);
68 static int nfs_directio_write(struct vnode *vp, struct uio *uiop,
69 struct ucred *cred, int ioflag);
70
71 extern int nfs_directio_enable;
72 extern int nfs_directio_allow_mmap;
73
74 /*
75 * Vnode op for VM getpages.
76 */
77 int
78 nfs_getpages(struct vop_getpages_args *ap)
79 {
80 int i, error, nextoff, size, toff, count, npages;
81 struct uio uio;
82 struct iovec iov;
83 vm_offset_t kva;
84 struct buf *bp;
85 struct vnode *vp;
86 struct thread *td;
87 struct ucred *cred;
88 struct nfsmount *nmp;
89 vm_object_t object;
90 vm_page_t *pages;
91 struct nfsnode *np;
92
93 vp = ap->a_vp;
94 np = VTONFS(vp);
95 td = curthread; /* XXX */
96 cred = curthread->td_ucred; /* XXX */
97 nmp = VFSTONFS(vp->v_mount);
98 pages = ap->a_m;
99 count = ap->a_count;
100
101 if ((object = vp->v_object) == NULL) {
102 nfs_printf("nfs_getpages: called with non-merged cache vnode??\n");
103 return (VM_PAGER_ERROR);
104 }
105
106 if (nfs_directio_enable && !nfs_directio_allow_mmap) {
107 mtx_lock(&np->n_mtx);
108 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
109 mtx_unlock(&np->n_mtx);
110 nfs_printf("nfs_getpages: called on non-cacheable vnode??\n");
111 return (VM_PAGER_ERROR);
112 } else
113 mtx_unlock(&np->n_mtx);
114 }
115
116 mtx_lock(&nmp->nm_mtx);
117 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
118 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
119 mtx_unlock(&nmp->nm_mtx);
120 /* We'll never get here for v4, because we always have fsinfo */
121 (void)nfs_fsinfo(nmp, vp, cred, td);
122 } else
123 mtx_unlock(&nmp->nm_mtx);
124
125 npages = btoc(count);
126
127 /*
128 * If the requested page is partially valid, just return it and
129 * allow the pager to zero-out the blanks. Partially valid pages
130 * can only occur at the file EOF.
131 */
132 VM_OBJECT_LOCK(object);
133 if (pages[ap->a_reqpage]->valid != 0) {
134 vm_page_lock_queues();
135 for (i = 0; i < npages; ++i) {
136 if (i != ap->a_reqpage)
137 vm_page_free(pages[i]);
138 }
139 vm_page_unlock_queues();
140 VM_OBJECT_UNLOCK(object);
141 return (0);
142 }
143 VM_OBJECT_UNLOCK(object);
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 PCPU_INC(cnt.v_vnodein);
154 PCPU_ADD(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 = (nmp->nm_rpcops->nr_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 nfs_printf("nfs_getpages: error %d\n", error);
173 VM_OBJECT_LOCK(object);
174 vm_page_lock_queues();
175 for (i = 0; i < npages; ++i) {
176 if (i != ap->a_reqpage)
177 vm_page_free(pages[i]);
178 }
179 vm_page_unlock_queues();
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 vm_page_lock_queues();
193 for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
194 vm_page_t m;
195 nextoff = toff + PAGE_SIZE;
196 m = pages[i];
197
198 if (nextoff <= size) {
199 /*
200 * Read operation filled an entire page
201 */
202 m->valid = VM_PAGE_BITS_ALL;
203 KASSERT(m->dirty == 0,
204 ("nfs_getpages: page %p is dirty", m));
205 } else if (size > toff) {
206 /*
207 * Read operation filled a partial page.
208 */
209 m->valid = 0;
210 vm_page_set_valid(m, 0, size - toff);
211 KASSERT(m->dirty == 0,
212 ("nfs_getpages: page %p is dirty", m));
213 } else {
214 /*
215 * Read operation was short. If no error occured
216 * we may have hit a zero-fill section. We simply
217 * leave valid set to 0.
218 */
219 ;
220 }
221 if (i != ap->a_reqpage) {
222 /*
223 * Whether or not to leave the page activated is up in
224 * the air, but we should put the page on a page queue
225 * somewhere (it already is in the object). Result:
226 * It appears that emperical results show that
227 * deactivating pages is best.
228 */
229
230 /*
231 * Just in case someone was asking for this page we
232 * now tell them that it is ok to use.
233 */
234 if (!error) {
235 if (m->oflags & VPO_WANTED)
236 vm_page_activate(m);
237 else
238 vm_page_deactivate(m);
239 vm_page_wakeup(m);
240 } else {
241 vm_page_free(m);
242 }
243 }
244 }
245 vm_page_unlock_queues();
246 VM_OBJECT_UNLOCK(object);
247 return (0);
248 }
249
250 /*
251 * Vnode op for VM putpages.
252 */
253 int
254 nfs_putpages(struct vop_putpages_args *ap)
255 {
256 struct uio uio;
257 struct iovec iov;
258 vm_offset_t kva;
259 struct buf *bp;
260 int iomode, must_commit, i, error, npages, count;
261 off_t offset;
262 int *rtvals;
263 struct vnode *vp;
264 struct thread *td;
265 struct ucred *cred;
266 struct nfsmount *nmp;
267 struct nfsnode *np;
268 vm_page_t *pages;
269
270 vp = ap->a_vp;
271 np = VTONFS(vp);
272 td = curthread; /* XXX */
273 cred = curthread->td_ucred; /* XXX */
274 nmp = VFSTONFS(vp->v_mount);
275 pages = ap->a_m;
276 count = ap->a_count;
277 rtvals = ap->a_rtvals;
278 npages = btoc(count);
279 offset = IDX_TO_OFF(pages[0]->pindex);
280
281 mtx_lock(&nmp->nm_mtx);
282 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
283 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
284 mtx_unlock(&nmp->nm_mtx);
285 (void)nfs_fsinfo(nmp, vp, cred, td);
286 } else
287 mtx_unlock(&nmp->nm_mtx);
288
289 mtx_lock(&np->n_mtx);
290 if (nfs_directio_enable && !nfs_directio_allow_mmap &&
291 (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
292 mtx_unlock(&np->n_mtx);
293 nfs_printf("nfs_putpages: called on noncache-able vnode??\n");
294 mtx_lock(&np->n_mtx);
295 }
296
297 for (i = 0; i < npages; i++)
298 rtvals[i] = VM_PAGER_AGAIN;
299
300 /*
301 * When putting pages, do not extend file past EOF.
302 */
303 if (offset + count > np->n_size) {
304 count = np->n_size - offset;
305 if (count < 0)
306 count = 0;
307 }
308 mtx_unlock(&np->n_mtx);
309
310 /*
311 * We use only the kva address for the buffer, but this is extremely
312 * convienient and fast.
313 */
314 bp = getpbuf(&nfs_pbuf_freecnt);
315
316 kva = (vm_offset_t) bp->b_data;
317 pmap_qenter(kva, pages, npages);
318 PCPU_INC(cnt.v_vnodeout);
319 PCPU_ADD(cnt.v_vnodepgsout, count);
320
321 iov.iov_base = (caddr_t) kva;
322 iov.iov_len = count;
323 uio.uio_iov = &iov;
324 uio.uio_iovcnt = 1;
325 uio.uio_offset = offset;
326 uio.uio_resid = count;
327 uio.uio_segflg = UIO_SYSSPACE;
328 uio.uio_rw = UIO_WRITE;
329 uio.uio_td = td;
330
331 if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0)
332 iomode = NFSV3WRITE_UNSTABLE;
333 else
334 iomode = NFSV3WRITE_FILESYNC;
335
336 error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, &iomode, &must_commit);
337
338 pmap_qremove(kva, npages);
339 relpbuf(bp, &nfs_pbuf_freecnt);
340
341 if (!error) {
342 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE;
343 for (i = 0; i < nwritten; i++) {
344 rtvals[i] = VM_PAGER_OK;
345 vm_page_undirty(pages[i]);
346 }
347 if (must_commit) {
348 nfs_clearcommit(vp->v_mount);
349 }
350 }
351 return rtvals[0];
352 }
353
354 /*
355 * For nfs, cache consistency can only be maintained approximately.
356 * Although RFC1094 does not specify the criteria, the following is
357 * believed to be compatible with the reference port.
358 * For nfs:
359 * If the file's modify time on the server has changed since the
360 * last read rpc or you have written to the file,
361 * you may have lost data cache consistency with the
362 * server, so flush all of the file's data out of the cache.
363 * Then force a getattr rpc to ensure that you have up to date
364 * attributes.
365 * NB: This implies that cache data can be read when up to
366 * NFS_ATTRTIMEO seconds out of date. If you find that you need current
367 * attributes this could be forced by setting n_attrstamp to 0 before
368 * the VOP_GETATTR() call.
369 */
370 static inline int
371 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred)
372 {
373 int error = 0;
374 struct vattr vattr;
375 struct nfsnode *np = VTONFS(vp);
376 int old_lock;
377 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
378
379 /*
380 * Grab the exclusive lock before checking whether the cache is
381 * consistent.
382 * XXX - We can make this cheaper later (by acquiring cheaper locks).
383 * But for now, this suffices.
384 */
385 old_lock = nfs_upgrade_vnlock(vp);
386 if (vp->v_iflag & VI_DOOMED) {
387 nfs_downgrade_vnlock(vp, old_lock);
388 return (EBADF);
389 }
390
391 mtx_lock(&np->n_mtx);
392 if (np->n_flag & NMODIFIED) {
393 mtx_unlock(&np->n_mtx);
394 if (vp->v_type != VREG) {
395 if (vp->v_type != VDIR)
396 panic("nfs: bioread, not dir");
397 (nmp->nm_rpcops->nr_invaldir)(vp);
398 error = nfs_vinvalbuf(vp, V_SAVE, td, 1);
399 if (error)
400 goto out;
401 }
402 np->n_attrstamp = 0;
403 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
404 error = VOP_GETATTR(vp, &vattr, cred);
405 if (error)
406 goto out;
407 mtx_lock(&np->n_mtx);
408 np->n_mtime = vattr.va_mtime;
409 mtx_unlock(&np->n_mtx);
410 } else {
411 mtx_unlock(&np->n_mtx);
412 error = VOP_GETATTR(vp, &vattr, cred);
413 if (error)
414 return (error);
415 mtx_lock(&np->n_mtx);
416 if ((np->n_flag & NSIZECHANGED)
417 || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
418 mtx_unlock(&np->n_mtx);
419 if (vp->v_type == VDIR)
420 (nmp->nm_rpcops->nr_invaldir)(vp);
421 error = nfs_vinvalbuf(vp, V_SAVE, td, 1);
422 if (error)
423 goto out;
424 mtx_lock(&np->n_mtx);
425 np->n_mtime = vattr.va_mtime;
426 np->n_flag &= ~NSIZECHANGED;
427 }
428 mtx_unlock(&np->n_mtx);
429 }
430 out:
431 nfs_downgrade_vnlock(vp, old_lock);
432 return error;
433 }
434
435 /*
436 * Vnode op for read using bio
437 */
438 int
439 nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
440 {
441 struct nfsnode *np = VTONFS(vp);
442 int biosize, i;
443 struct buf *bp, *rabp;
444 struct thread *td;
445 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
446 daddr_t lbn, rabn;
447 int bcount;
448 int seqcount;
449 int nra, error = 0, n = 0, on = 0;
450
451 #ifdef DIAGNOSTIC
452 if (uio->uio_rw != UIO_READ)
453 panic("nfs_read mode");
454 #endif
455 if (uio->uio_resid == 0)
456 return (0);
457 if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */
458 return (EINVAL);
459 td = uio->uio_td;
460
461 mtx_lock(&nmp->nm_mtx);
462 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
463 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
464 mtx_unlock(&nmp->nm_mtx);
465 (void)nfs_fsinfo(nmp, vp, cred, td);
466 } else
467 mtx_unlock(&nmp->nm_mtx);
468
469 if (vp->v_type != VDIR &&
470 (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
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 int bcount;
871 int n, on, error = 0;
872 struct proc *p = td?td->td_proc:NULL;
873
874 #ifdef DIAGNOSTIC
875 if (uio->uio_rw != UIO_WRITE)
876 panic("nfs_write mode");
877 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread)
878 panic("nfs_write proc");
879 #endif
880 if (vp->v_type != VREG)
881 return (EIO);
882 mtx_lock(&np->n_mtx);
883 if (np->n_flag & NWRITEERR) {
884 np->n_flag &= ~NWRITEERR;
885 mtx_unlock(&np->n_mtx);
886 return (np->n_error);
887 } else
888 mtx_unlock(&np->n_mtx);
889 mtx_lock(&nmp->nm_mtx);
890 if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
891 (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
892 mtx_unlock(&nmp->nm_mtx);
893 (void)nfs_fsinfo(nmp, vp, cred, td);
894 } else
895 mtx_unlock(&nmp->nm_mtx);
896
897 /*
898 * Synchronously flush pending buffers if we are in synchronous
899 * mode or if we are appending.
900 */
901 if (ioflag & (IO_APPEND | IO_SYNC)) {
902 mtx_lock(&np->n_mtx);
903 if (np->n_flag & NMODIFIED) {
904 mtx_unlock(&np->n_mtx);
905 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */
906 /*
907 * Require non-blocking, synchronous writes to
908 * dirty files to inform the program it needs
909 * to fsync(2) explicitly.
910 */
911 if (ioflag & IO_NDELAY)
912 return (EAGAIN);
913 #endif
914 flush_and_restart:
915 np->n_attrstamp = 0;
916 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
917 error = nfs_vinvalbuf(vp, V_SAVE, td, 1);
918 if (error)
919 return (error);
920 } else
921 mtx_unlock(&np->n_mtx);
922 }
923
924 /*
925 * If IO_APPEND then load uio_offset. We restart here if we cannot
926 * get the append lock.
927 */
928 if (ioflag & IO_APPEND) {
929 np->n_attrstamp = 0;
930 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
931 error = VOP_GETATTR(vp, &vattr, cred);
932 if (error)
933 return (error);
934 mtx_lock(&np->n_mtx);
935 uio->uio_offset = np->n_size;
936 mtx_unlock(&np->n_mtx);
937 }
938
939 if (uio->uio_offset < 0)
940 return (EINVAL);
941 if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
942 return (EFBIG);
943 if (uio->uio_resid == 0)
944 return (0);
945
946 if (nfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
947 return nfs_directio_write(vp, uio, cred, ioflag);
948
949 /*
950 * Maybe this should be above the vnode op call, but so long as
951 * file servers have no limits, i don't think it matters
952 */
953 if (p != NULL) {
954 PROC_LOCK(p);
955 if (uio->uio_offset + uio->uio_resid >
956 lim_cur(p, RLIMIT_FSIZE)) {
957 psignal(p, SIGXFSZ);
958 PROC_UNLOCK(p);
959 return (EFBIG);
960 }
961 PROC_UNLOCK(p);
962 }
963
964 biosize = vp->v_mount->mnt_stat.f_iosize;
965 /*
966 * Find all of this file's B_NEEDCOMMIT buffers. If our writes
967 * would exceed the local maximum per-file write commit size when
968 * combined with those, we must decide whether to flush,
969 * go synchronous, or return error. We don't bother checking
970 * IO_UNIT -- we just make all writes atomic anyway, as there's
971 * no point optimizing for something that really won't ever happen.
972 */
973 if (!(ioflag & IO_SYNC)) {
974 int nflag;
975
976 mtx_lock(&np->n_mtx);
977 nflag = np->n_flag;
978 mtx_unlock(&np->n_mtx);
979 int needrestart = 0;
980 if (nmp->nm_wcommitsize < uio->uio_resid) {
981 /*
982 * If this request could not possibly be completed
983 * without exceeding the maximum outstanding write
984 * commit size, see if we can convert it into a
985 * synchronous write operation.
986 */
987 if (ioflag & IO_NDELAY)
988 return (EAGAIN);
989 ioflag |= IO_SYNC;
990 if (nflag & NMODIFIED)
991 needrestart = 1;
992 } else if (nflag & NMODIFIED) {
993 int wouldcommit = 0;
994 BO_LOCK(&vp->v_bufobj);
995 if (vp->v_bufobj.bo_dirty.bv_cnt != 0) {
996 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd,
997 b_bobufs) {
998 if (bp->b_flags & B_NEEDCOMMIT)
999 wouldcommit += bp->b_bcount;
1000 }
1001 }
1002 BO_UNLOCK(&vp->v_bufobj);
1003 /*
1004 * Since we're not operating synchronously and
1005 * bypassing the buffer cache, we are in a commit
1006 * and holding all of these buffers whether
1007 * transmitted or not. If not limited, this
1008 * will lead to the buffer cache deadlocking,
1009 * as no one else can flush our uncommitted buffers.
1010 */
1011 wouldcommit += uio->uio_resid;
1012 /*
1013 * If we would initially exceed the maximum
1014 * outstanding write commit size, flush and restart.
1015 */
1016 if (wouldcommit > nmp->nm_wcommitsize)
1017 needrestart = 1;
1018 }
1019 if (needrestart)
1020 goto flush_and_restart;
1021 }
1022
1023 do {
1024 nfsstats.biocache_writes++;
1025 lbn = uio->uio_offset / biosize;
1026 on = uio->uio_offset & (biosize-1);
1027 n = min((unsigned)(biosize - on), uio->uio_resid);
1028 again:
1029 /*
1030 * Handle direct append and file extension cases, calculate
1031 * unaligned buffer size.
1032 */
1033 mtx_lock(&np->n_mtx);
1034 if (uio->uio_offset == np->n_size && n) {
1035 mtx_unlock(&np->n_mtx);
1036 /*
1037 * Get the buffer (in its pre-append state to maintain
1038 * B_CACHE if it was previously set). Resize the
1039 * nfsnode after we have locked the buffer to prevent
1040 * readers from reading garbage.
1041 */
1042 bcount = on;
1043 bp = nfs_getcacheblk(vp, lbn, bcount, td);
1044
1045 if (bp != NULL) {
1046 long save;
1047
1048 mtx_lock(&np->n_mtx);
1049 np->n_size = uio->uio_offset + n;
1050 np->n_flag |= NMODIFIED;
1051 vnode_pager_setsize(vp, np->n_size);
1052 mtx_unlock(&np->n_mtx);
1053
1054 save = bp->b_flags & B_CACHE;
1055 bcount += n;
1056 allocbuf(bp, bcount);
1057 bp->b_flags |= save;
1058 }
1059 } else {
1060 /*
1061 * Obtain the locked cache block first, and then
1062 * adjust the file's size as appropriate.
1063 */
1064 bcount = on + n;
1065 if ((off_t)lbn * biosize + bcount < np->n_size) {
1066 if ((off_t)(lbn + 1) * biosize < np->n_size)
1067 bcount = biosize;
1068 else
1069 bcount = np->n_size - (off_t)lbn * biosize;
1070 }
1071 mtx_unlock(&np->n_mtx);
1072 bp = nfs_getcacheblk(vp, lbn, bcount, td);
1073 mtx_lock(&np->n_mtx);
1074 if (uio->uio_offset + n > np->n_size) {
1075 np->n_size = uio->uio_offset + n;
1076 np->n_flag |= NMODIFIED;
1077 vnode_pager_setsize(vp, np->n_size);
1078 }
1079 mtx_unlock(&np->n_mtx);
1080 }
1081
1082 if (!bp) {
1083 error = nfs_sigintr(nmp, td);
1084 if (!error)
1085 error = EINTR;
1086 break;
1087 }
1088
1089 /*
1090 * Issue a READ if B_CACHE is not set. In special-append
1091 * mode, B_CACHE is based on the buffer prior to the write
1092 * op and is typically set, avoiding the read. If a read
1093 * is required in special append mode, the server will
1094 * probably send us a short-read since we extended the file
1095 * on our end, resulting in b_resid == 0 and, thusly,
1096 * B_CACHE getting set.
1097 *
1098 * We can also avoid issuing the read if the write covers
1099 * the entire buffer. We have to make sure the buffer state
1100 * is reasonable in this case since we will not be initiating
1101 * I/O. See the comments in kern/vfs_bio.c's getblk() for
1102 * more information.
1103 *
1104 * B_CACHE may also be set due to the buffer being cached
1105 * normally.
1106 */
1107
1108 if (on == 0 && n == bcount) {
1109 bp->b_flags |= B_CACHE;
1110 bp->b_flags &= ~B_INVAL;
1111 bp->b_ioflags &= ~BIO_ERROR;
1112 }
1113
1114 if ((bp->b_flags & B_CACHE) == 0) {
1115 bp->b_iocmd = BIO_READ;
1116 vfs_busy_pages(bp, 0);
1117 error = nfs_doio(vp, bp, cred, td);
1118 if (error) {
1119 brelse(bp);
1120 break;
1121 }
1122 }
1123 if (bp->b_wcred == NOCRED)
1124 bp->b_wcred = crhold(cred);
1125 mtx_lock(&np->n_mtx);
1126 np->n_flag |= NMODIFIED;
1127 mtx_unlock(&np->n_mtx);
1128
1129 /*
1130 * If dirtyend exceeds file size, chop it down. This should
1131 * not normally occur but there is an append race where it
1132 * might occur XXX, so we log it.
1133 *
1134 * If the chopping creates a reverse-indexed or degenerate
1135 * situation with dirtyoff/end, we 0 both of them.
1136 */
1137
1138 if (bp->b_dirtyend > bcount) {
1139 nfs_printf("NFS append race @%lx:%d\n",
1140 (long)bp->b_blkno * DEV_BSIZE,
1141 bp->b_dirtyend - bcount);
1142 bp->b_dirtyend = bcount;
1143 }
1144
1145 if (bp->b_dirtyoff >= bp->b_dirtyend)
1146 bp->b_dirtyoff = bp->b_dirtyend = 0;
1147
1148 /*
1149 * If the new write will leave a contiguous dirty
1150 * area, just update the b_dirtyoff and b_dirtyend,
1151 * otherwise force a write rpc of the old dirty area.
1152 *
1153 * While it is possible to merge discontiguous writes due to
1154 * our having a B_CACHE buffer ( and thus valid read data
1155 * for the hole), we don't because it could lead to
1156 * significant cache coherency problems with multiple clients,
1157 * especially if locking is implemented later on.
1158 *
1159 * as an optimization we could theoretically maintain
1160 * a linked list of discontinuous areas, but we would still
1161 * have to commit them separately so there isn't much
1162 * advantage to it except perhaps a bit of asynchronization.
1163 */
1164
1165 if (bp->b_dirtyend > 0 &&
1166 (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
1167 if (bwrite(bp) == EINTR) {
1168 error = EINTR;
1169 break;
1170 }
1171 goto again;
1172 }
1173
1174 error = uiomove((char *)bp->b_data + on, n, uio);
1175
1176 /*
1177 * Since this block is being modified, it must be written
1178 * again and not just committed. Since write clustering does
1179 * not work for the stage 1 data write, only the stage 2
1180 * commit rpc, we have to clear B_CLUSTEROK as well.
1181 */
1182 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1183
1184 if (error) {
1185 bp->b_ioflags |= BIO_ERROR;
1186 brelse(bp);
1187 break;
1188 }
1189
1190 /*
1191 * Only update dirtyoff/dirtyend if not a degenerate
1192 * condition.
1193 */
1194 if (n) {
1195 if (bp->b_dirtyend > 0) {
1196 bp->b_dirtyoff = min(on, bp->b_dirtyoff);
1197 bp->b_dirtyend = max((on + n), bp->b_dirtyend);
1198 } else {
1199 bp->b_dirtyoff = on;
1200 bp->b_dirtyend = on + n;
1201 }
1202 vfs_bio_set_valid(bp, on, n);
1203 }
1204
1205 /*
1206 * If IO_SYNC do bwrite().
1207 *
1208 * IO_INVAL appears to be unused. The idea appears to be
1209 * to turn off caching in this case. Very odd. XXX
1210 */
1211 if ((ioflag & IO_SYNC)) {
1212 if (ioflag & IO_INVAL)
1213 bp->b_flags |= B_NOCACHE;
1214 error = bwrite(bp);
1215 if (error)
1216 break;
1217 } else if ((n + on) == biosize) {
1218 bp->b_flags |= B_ASYNC;
1219 (void) (nmp->nm_rpcops->nr_writebp)(bp, 0, NULL);
1220 } else {
1221 bdwrite(bp);
1222 }
1223 } while (uio->uio_resid > 0 && n > 0);
1224
1225 return (error);
1226 }
1227
1228 /*
1229 * Get an nfs cache block.
1230 *
1231 * Allocate a new one if the block isn't currently in the cache
1232 * and return the block marked busy. If the calling process is
1233 * interrupted by a signal for an interruptible mount point, return
1234 * NULL.
1235 *
1236 * The caller must carefully deal with the possible B_INVAL state of
1237 * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it
1238 * indirectly), so synchronous reads can be issued without worrying about
1239 * the B_INVAL state. We have to be a little more careful when dealing
1240 * with writes (see comments in nfs_write()) when extending a file past
1241 * its EOF.
1242 */
1243 static struct buf *
1244 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
1245 {
1246 struct buf *bp;
1247 struct mount *mp;
1248 struct nfsmount *nmp;
1249
1250 mp = vp->v_mount;
1251 nmp = VFSTONFS(mp);
1252
1253 if (nmp->nm_flag & NFSMNT_INT) {
1254 sigset_t oldset;
1255
1256 nfs_set_sigmask(td, &oldset);
1257 bp = getblk(vp, bn, size, NFS_PCATCH, 0, 0);
1258 nfs_restore_sigmask(td, &oldset);
1259 while (bp == NULL) {
1260 if (nfs_sigintr(nmp, td))
1261 return (NULL);
1262 bp = getblk(vp, bn, size, 0, 2 * hz, 0);
1263 }
1264 } else {
1265 bp = getblk(vp, bn, size, 0, 0, 0);
1266 }
1267
1268 if (vp->v_type == VREG) {
1269 int biosize;
1270
1271 biosize = mp->mnt_stat.f_iosize;
1272 bp->b_blkno = bn * (biosize / DEV_BSIZE);
1273 }
1274 return (bp);
1275 }
1276
1277 /*
1278 * Flush and invalidate all dirty buffers. If another process is already
1279 * doing the flush, just wait for completion.
1280 */
1281 int
1282 nfs_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg)
1283 {
1284 struct nfsnode *np = VTONFS(vp);
1285 struct nfsmount *nmp = VFSTONFS(vp->v_mount);
1286 int error = 0, slpflag, slptimeo;
1287 int old_lock = 0;
1288
1289 ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf");
1290
1291 if ((nmp->nm_flag & NFSMNT_INT) == 0)
1292 intrflg = 0;
1293 if (intrflg) {
1294 slpflag = NFS_PCATCH;
1295 slptimeo = 2 * hz;
1296 } else {
1297 slpflag = 0;
1298 slptimeo = 0;
1299 }
1300
1301 old_lock = nfs_upgrade_vnlock(vp);
1302 if (vp->v_iflag & VI_DOOMED) {
1303 /*
1304 * Since vgonel() uses the generic vinvalbuf() to flush
1305 * dirty buffers and it does not call this function, it
1306 * is safe to just return OK when VI_DOOMED is set.
1307 */
1308 nfs_downgrade_vnlock(vp, old_lock);
1309 return (0);
1310 }
1311
1312 /*
1313 * Now, flush as required.
1314 */
1315 if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) {
1316 VM_OBJECT_LOCK(vp->v_bufobj.bo_object);
1317 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
1318 VM_OBJECT_UNLOCK(vp->v_bufobj.bo_object);
1319 /*
1320 * If the page clean was interrupted, fail the invalidation.
1321 * Not doing so, we run the risk of losing dirty pages in the
1322 * vinvalbuf() call below.
1323 */
1324 if (intrflg && (error = nfs_sigintr(nmp, td)))
1325 goto out;
1326 }
1327
1328 error = vinvalbuf(vp, flags, slpflag, 0);
1329 while (error) {
1330 if (intrflg && (error = nfs_sigintr(nmp, td)))
1331 goto out;
1332 error = vinvalbuf(vp, flags, 0, slptimeo);
1333 }
1334 mtx_lock(&np->n_mtx);
1335 if (np->n_directio_asyncwr == 0)
1336 np->n_flag &= ~NMODIFIED;
1337 mtx_unlock(&np->n_mtx);
1338 out:
1339 nfs_downgrade_vnlock(vp, old_lock);
1340 return error;
1341 }
1342
1343 /*
1344 * Initiate asynchronous I/O. Return an error if no nfsiods are available.
1345 * This is mainly to avoid queueing async I/O requests when the nfsiods
1346 * are all hung on a dead server.
1347 *
1348 * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
1349 * is eventually dequeued by the async daemon, nfs_doio() *will*.
1350 */
1351 int
1352 nfs_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
1353 {
1354 int iod;
1355 int gotiod;
1356 int slpflag = 0;
1357 int slptimeo = 0;
1358 int error, error2;
1359
1360 /*
1361 * Commits are usually short and sweet so lets save some cpu and
1362 * leave the async daemons for more important rpc's (such as reads
1363 * and writes).
1364 */
1365 mtx_lock(&nfs_iod_mtx);
1366 if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
1367 (nmp->nm_bufqiods > nfs_numasync / 2)) {
1368 mtx_unlock(&nfs_iod_mtx);
1369 return(EIO);
1370 }
1371 again:
1372 if (nmp->nm_flag & NFSMNT_INT)
1373 slpflag = NFS_PCATCH;
1374 gotiod = FALSE;
1375
1376 /*
1377 * Find a free iod to process this request.
1378 */
1379 for (iod = 0; iod < nfs_numasync; iod++)
1380 if (nfs_iodwant[iod] == NFSIOD_AVAILABLE) {
1381 gotiod = TRUE;
1382 break;
1383 }
1384
1385 /*
1386 * Try to create one if none are free.
1387 */
1388 if (!gotiod) {
1389 iod = nfs_nfsiodnew(1);
1390 if (iod != -1)
1391 gotiod = TRUE;
1392 }
1393
1394 if (gotiod) {
1395 /*
1396 * Found one, so wake it up and tell it which
1397 * mount to process.
1398 */
1399 NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n",
1400 iod, nmp));
1401 nfs_iodwant[iod] = NFSIOD_NOT_AVAILABLE;
1402 nfs_iodmount[iod] = nmp;
1403 nmp->nm_bufqiods++;
1404 wakeup(&nfs_iodwant[iod]);
1405 }
1406
1407 /*
1408 * If none are free, we may already have an iod working on this mount
1409 * point. If so, it will process our request.
1410 */
1411 if (!gotiod) {
1412 if (nmp->nm_bufqiods > 0) {
1413 NFS_DPF(ASYNCIO,
1414 ("nfs_asyncio: %d iods are already processing mount %p\n",
1415 nmp->nm_bufqiods, nmp));
1416 gotiod = TRUE;
1417 }
1418 }
1419
1420 /*
1421 * If we have an iod which can process the request, then queue
1422 * the buffer.
1423 */
1424 if (gotiod) {
1425 /*
1426 * Ensure that the queue never grows too large. We still want
1427 * to asynchronize so we block rather then return EIO.
1428 */
1429 while (nmp->nm_bufqlen >= 2*nfs_numasync) {
1430 NFS_DPF(ASYNCIO,
1431 ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp));
1432 nmp->nm_bufqwant = TRUE;
1433 error = nfs_msleep(td, &nmp->nm_bufq, &nfs_iod_mtx,
1434 slpflag | PRIBIO,
1435 "nfsaio", slptimeo);
1436 if (error) {
1437 error2 = nfs_sigintr(nmp, td);
1438 if (error2) {
1439 mtx_unlock(&nfs_iod_mtx);
1440 return (error2);
1441 }
1442 if (slpflag == NFS_PCATCH) {
1443 slpflag = 0;
1444 slptimeo = 2 * hz;
1445 }
1446 }
1447 /*
1448 * We might have lost our iod while sleeping,
1449 * so check and loop if nescessary.
1450 */
1451 if (nmp->nm_bufqiods == 0) {
1452 NFS_DPF(ASYNCIO,
1453 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
1454 goto again;
1455 }
1456 }
1457
1458 /* We might have lost our nfsiod */
1459 if (nmp->nm_bufqiods == 0) {
1460 NFS_DPF(ASYNCIO,
1461 ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
1462 goto again;
1463 }
1464
1465 if (bp->b_iocmd == BIO_READ) {
1466 if (bp->b_rcred == NOCRED && cred != NOCRED)
1467 bp->b_rcred = crhold(cred);
1468 } else {
1469 if (bp->b_wcred == NOCRED && cred != NOCRED)
1470 bp->b_wcred = crhold(cred);
1471 }
1472
1473 if (bp->b_flags & B_REMFREE)
1474 bremfreef(bp);
1475 BUF_KERNPROC(bp);
1476 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
1477 nmp->nm_bufqlen++;
1478 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1479 mtx_lock(&(VTONFS(bp->b_vp))->n_mtx);
1480 VTONFS(bp->b_vp)->n_flag |= NMODIFIED;
1481 VTONFS(bp->b_vp)->n_directio_asyncwr++;
1482 mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx);
1483 }
1484 mtx_unlock(&nfs_iod_mtx);
1485 return (0);
1486 }
1487
1488 mtx_unlock(&nfs_iod_mtx);
1489
1490 /*
1491 * All the iods are busy on other mounts, so return EIO to
1492 * force the caller to process the i/o synchronously.
1493 */
1494 NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n"));
1495 return (EIO);
1496 }
1497
1498 void
1499 nfs_doio_directwrite(struct buf *bp)
1500 {
1501 int iomode, must_commit;
1502 struct uio *uiop = (struct uio *)bp->b_caller1;
1503 char *iov_base = uiop->uio_iov->iov_base;
1504 struct nfsmount *nmp = VFSTONFS(bp->b_vp->v_mount);
1505
1506 iomode = NFSV3WRITE_FILESYNC;
1507 uiop->uio_td = NULL; /* NULL since we're in nfsiod */
1508 (nmp->nm_rpcops->nr_writerpc)(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit);
1509 KASSERT((must_commit == 0), ("nfs_doio_directwrite: Did not commit write"));
1510 free(iov_base, M_NFSDIRECTIO);
1511 free(uiop->uio_iov, M_NFSDIRECTIO);
1512 free(uiop, M_NFSDIRECTIO);
1513 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
1514 struct nfsnode *np = VTONFS(bp->b_vp);
1515 mtx_lock(&np->n_mtx);
1516 np->n_directio_asyncwr--;
1517 if (np->n_directio_asyncwr == 0) {
1518 VTONFS(bp->b_vp)->n_flag &= ~NMODIFIED;
1519 if ((np->n_flag & NFSYNCWAIT)) {
1520 np->n_flag &= ~NFSYNCWAIT;
1521 wakeup((caddr_t)&np->n_directio_asyncwr);
1522 }
1523 }
1524 mtx_unlock(&np->n_mtx);
1525 }
1526 bp->b_vp = NULL;
1527 relpbuf(bp, &nfs_pbuf_freecnt);
1528 }
1529
1530 /*
1531 * Do an I/O operation to/from a cache block. This may be called
1532 * synchronously or from an nfsiod.
1533 */
1534 int
1535 nfs_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td)
1536 {
1537 struct uio *uiop;
1538 struct nfsnode *np;
1539 struct nfsmount *nmp;
1540 int error = 0, iomode, must_commit = 0;
1541 struct uio uio;
1542 struct iovec io;
1543 struct proc *p = td ? td->td_proc : NULL;
1544 uint8_t iocmd;
1545
1546 np = VTONFS(vp);
1547 nmp = VFSTONFS(vp->v_mount);
1548 uiop = &uio;
1549 uiop->uio_iov = &io;
1550 uiop->uio_iovcnt = 1;
1551 uiop->uio_segflg = UIO_SYSSPACE;
1552 uiop->uio_td = td;
1553
1554 /*
1555 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
1556 * do this here so we do not have to do it in all the code that
1557 * calls us.
1558 */
1559 bp->b_flags &= ~B_INVAL;
1560 bp->b_ioflags &= ~BIO_ERROR;
1561
1562 KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp));
1563 iocmd = bp->b_iocmd;
1564 if (iocmd == BIO_READ) {
1565 io.iov_len = uiop->uio_resid = bp->b_bcount;
1566 io.iov_base = bp->b_data;
1567 uiop->uio_rw = UIO_READ;
1568
1569 switch (vp->v_type) {
1570 case VREG:
1571 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
1572 nfsstats.read_bios++;
1573 error = (nmp->nm_rpcops->nr_readrpc)(vp, uiop, cr);
1574
1575 if (!error) {
1576 if (uiop->uio_resid) {
1577 /*
1578 * If we had a short read with no error, we must have
1579 * hit a file hole. We should zero-fill the remainder.
1580 * This can also occur if the server hits the file EOF.
1581 *
1582 * Holes used to be able to occur due to pending
1583 * writes, but that is not possible any longer.
1584 */
1585 int nread = bp->b_bcount - uiop->uio_resid;
1586 int left = uiop->uio_resid;
1587
1588 if (left > 0)
1589 bzero((char *)bp->b_data + nread, left);
1590 uiop->uio_resid = 0;
1591 }
1592 }
1593 /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */
1594 if (p && (vp->v_vflag & VV_TEXT)) {
1595 mtx_lock(&np->n_mtx);
1596 if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.va_mtime)) {
1597 mtx_unlock(&np->n_mtx);
1598 PROC_LOCK(p);
1599 killproc(p, "text file modification");
1600 PROC_UNLOCK(p);
1601 } else
1602 mtx_unlock(&np->n_mtx);
1603 }
1604 break;
1605 case VLNK:
1606 uiop->uio_offset = (off_t)0;
1607 nfsstats.readlink_bios++;
1608 error = (nmp->nm_rpcops->nr_readlinkrpc)(vp, uiop, cr);
1609 break;
1610 case VDIR:
1611 nfsstats.readdir_bios++;
1612 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
1613 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
1614 error = nfs_readdirplusrpc(vp, uiop, cr);
1615 if (error == NFSERR_NOTSUPP)
1616 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
1617 }
1618 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
1619 error = nfs_readdirrpc(vp, uiop, cr);
1620 /*
1621 * end-of-directory sets B_INVAL but does not generate an
1622 * error.
1623 */
1624 if (error == 0 && uiop->uio_resid == bp->b_bcount)
1625 bp->b_flags |= B_INVAL;
1626 break;
1627 default:
1628 nfs_printf("nfs_doio: type %x unexpected\n", vp->v_type);
1629 break;
1630 };
1631 if (error) {
1632 bp->b_ioflags |= BIO_ERROR;
1633 bp->b_error = error;
1634 }
1635 } else {
1636 /*
1637 * If we only need to commit, try to commit
1638 */
1639 if (bp->b_flags & B_NEEDCOMMIT) {
1640 int retv;
1641 off_t off;
1642
1643 off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
1644 retv = (nmp->nm_rpcops->nr_commit)(
1645 vp, off, bp->b_dirtyend-bp->b_dirtyoff,
1646 bp->b_wcred, td);
1647 if (retv == 0) {
1648 bp->b_dirtyoff = bp->b_dirtyend = 0;
1649 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1650 bp->b_resid = 0;
1651 bufdone(bp);
1652 return (0);
1653 }
1654 if (retv == NFSERR_STALEWRITEVERF) {
1655 nfs_clearcommit(vp->v_mount);
1656 }
1657 }
1658
1659 /*
1660 * Setup for actual write
1661 */
1662 mtx_lock(&np->n_mtx);
1663 if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
1664 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
1665 mtx_unlock(&np->n_mtx);
1666
1667 if (bp->b_dirtyend > bp->b_dirtyoff) {
1668 io.iov_len = uiop->uio_resid = bp->b_dirtyend
1669 - bp->b_dirtyoff;
1670 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
1671 + bp->b_dirtyoff;
1672 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
1673 uiop->uio_rw = UIO_WRITE;
1674 nfsstats.write_bios++;
1675
1676 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
1677 iomode = NFSV3WRITE_UNSTABLE;
1678 else
1679 iomode = NFSV3WRITE_FILESYNC;
1680
1681 error = (nmp->nm_rpcops->nr_writerpc)(vp, uiop, cr, &iomode, &must_commit);
1682
1683 /*
1684 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
1685 * to cluster the buffers needing commit. This will allow
1686 * the system to submit a single commit rpc for the whole
1687 * cluster. We can do this even if the buffer is not 100%
1688 * dirty (relative to the NFS blocksize), so we optimize the
1689 * append-to-file-case.
1690 *
1691 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
1692 * cleared because write clustering only works for commit
1693 * rpc's, not for the data portion of the write).
1694 */
1695
1696 if (!error && iomode == NFSV3WRITE_UNSTABLE) {
1697 bp->b_flags |= B_NEEDCOMMIT;
1698 if (bp->b_dirtyoff == 0
1699 && bp->b_dirtyend == bp->b_bcount)
1700 bp->b_flags |= B_CLUSTEROK;
1701 } else {
1702 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
1703 }
1704
1705 /*
1706 * For an interrupted write, the buffer is still valid
1707 * and the write hasn't been pushed to the server yet,
1708 * so we can't set BIO_ERROR and report the interruption
1709 * by setting B_EINTR. For the B_ASYNC case, B_EINTR
1710 * is not relevant, so the rpc attempt is essentially
1711 * a noop. For the case of a V3 write rpc not being
1712 * committed to stable storage, the block is still
1713 * dirty and requires either a commit rpc or another
1714 * write rpc with iomode == NFSV3WRITE_FILESYNC before
1715 * the block is reused. This is indicated by setting
1716 * the B_DELWRI and B_NEEDCOMMIT flags.
1717 *
1718 * If the buffer is marked B_PAGING, it does not reside on
1719 * the vp's paging queues so we cannot call bdirty(). The
1720 * bp in this case is not an NFS cache block so we should
1721 * be safe. XXX
1722 *
1723 * The logic below breaks up errors into recoverable and
1724 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE
1725 * and keep the buffer around for potential write retries.
1726 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL)
1727 * and save the error in the nfsnode. This is less than ideal
1728 * but necessary. Keeping such buffers around could potentially
1729 * cause buffer exhaustion eventually (they can never be written
1730 * out, so will get constantly be re-dirtied). It also causes
1731 * all sorts of vfs panics. For non-recoverable write errors,
1732 * also invalidate the attrcache, so we'll be forced to go over
1733 * the wire for this object, returning an error to user on next
1734 * call (most of the time).
1735 */
1736 if (error == EINTR || error == EIO || error == ETIMEDOUT
1737 || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
1738 int s;
1739
1740 s = splbio();
1741 bp->b_flags &= ~(B_INVAL|B_NOCACHE);
1742 if ((bp->b_flags & B_PAGING) == 0) {
1743 bdirty(bp);
1744 bp->b_flags &= ~B_DONE;
1745 }
1746 if (error && (bp->b_flags & B_ASYNC) == 0)
1747 bp->b_flags |= B_EINTR;
1748 splx(s);
1749 } else {
1750 if (error) {
1751 bp->b_ioflags |= BIO_ERROR;
1752 bp->b_flags |= B_INVAL;
1753 bp->b_error = np->n_error = error;
1754 mtx_lock(&np->n_mtx);
1755 np->n_flag |= NWRITEERR;
1756 np->n_attrstamp = 0;
1757 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
1758 mtx_unlock(&np->n_mtx);
1759 }
1760 bp->b_dirtyoff = bp->b_dirtyend = 0;
1761 }
1762 } else {
1763 bp->b_resid = 0;
1764 bufdone(bp);
1765 return (0);
1766 }
1767 }
1768 bp->b_resid = uiop->uio_resid;
1769 if (must_commit)
1770 nfs_clearcommit(vp->v_mount);
1771 bufdone(bp);
1772 return (error);
1773 }
1774
1775 /*
1776 * Used to aid in handling ftruncate() operations on the NFS client side.
1777 * Truncation creates a number of special problems for NFS. We have to
1778 * throw away VM pages and buffer cache buffers that are beyond EOF, and
1779 * we have to properly handle VM pages or (potentially dirty) buffers
1780 * that straddle the truncation point.
1781 */
1782
1783 int
1784 nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize)
1785 {
1786 struct nfsnode *np = VTONFS(vp);
1787 u_quad_t tsize;
1788 int biosize = vp->v_mount->mnt_stat.f_iosize;
1789 int error = 0;
1790
1791 mtx_lock(&np->n_mtx);
1792 tsize = np->n_size;
1793 np->n_size = nsize;
1794 mtx_unlock(&np->n_mtx);
1795
1796 if (nsize < tsize) {
1797 struct buf *bp;
1798 daddr_t lbn;
1799 int bufsize;
1800
1801 /*
1802 * vtruncbuf() doesn't get the buffer overlapping the
1803 * truncation point. We may have a B_DELWRI and/or B_CACHE
1804 * buffer that now needs to be truncated.
1805 */
1806 error = vtruncbuf(vp, cred, td, nsize, biosize);
1807 lbn = nsize / biosize;
1808 bufsize = nsize & (biosize - 1);
1809 bp = nfs_getcacheblk(vp, lbn, bufsize, td);
1810 if (!bp)
1811 return EINTR;
1812 if (bp->b_dirtyoff > bp->b_bcount)
1813 bp->b_dirtyoff = bp->b_bcount;
1814 if (bp->b_dirtyend > bp->b_bcount)
1815 bp->b_dirtyend = bp->b_bcount;
1816 bp->b_flags |= B_RELBUF; /* don't leave garbage around */
1817 brelse(bp);
1818 } else {
1819 vnode_pager_setsize(vp, nsize);
1820 }
1821 return(error);
1822 }
1823
Cache object: 0285f448c479a4694b343ef258c56005
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