xref: /dragonfly/sys/vfs/smbfs/smbfs_io.c (revision f02303f9)
1 /*
2  * Copyright (c) 2000-2001, Boris Popov
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *    This product includes software developed by Boris Popov.
16  * 4. Neither the name of the author nor the names of any co-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 AUTHOR 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 AUTHOR 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  * $FreeBSD: src/sys/fs/smbfs/smbfs_io.c,v 1.3.2.3 2003/01/17 08:20:26 tjr Exp $
33  * $DragonFly: src/sys/vfs/smbfs/smbfs_io.c,v 1.28 2007/02/22 15:50:50 corecode Exp $
34  *
35  */
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/resourcevar.h>	/* defines plimit structure in proc struct */
39 #include <sys/kernel.h>
40 #include <sys/proc.h>
41 #include <sys/fcntl.h>
42 #include <sys/mount.h>
43 #include <sys/namei.h>
44 #include <sys/vnode.h>
45 #include <sys/dirent.h>
46 #include <sys/signalvar.h>
47 #include <sys/sysctl.h>
48 
49 #include  <machine/limits.h>
50 
51 #include <vm/vm.h>
52 #include <vm/vm_page.h>
53 #include <vm/vm_extern.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_pager.h>
56 #include <vm/vnode_pager.h>
57 /*
58 #include <sys/ioccom.h>
59 */
60 #include <netproto/smb/smb.h>
61 #include <netproto/smb/smb_conn.h>
62 #include <netproto/smb/smb_subr.h>
63 
64 #include "smbfs.h"
65 #include "smbfs_node.h"
66 #include "smbfs_subr.h"
67 
68 #include <sys/buf.h>
69 
70 #include <sys/thread2.h>
71 
72 /*#define SMBFS_RWGENERIC*/
73 
74 extern int smbfs_pbuf_freecnt;
75 
76 static int smbfs_fastlookup = 1;
77 
78 SYSCTL_DECL(_vfs_smbfs);
79 SYSCTL_INT(_vfs_smbfs, OID_AUTO, fastlookup, CTLFLAG_RW, &smbfs_fastlookup, 0, "");
80 
81 static int
82 smbfs_readvdir(struct vnode *vp, struct uio *uio, struct ucred *cred)
83 {
84 	struct smb_cred scred;
85 	struct smbfs_fctx *ctx;
86 	struct vnode *newvp;
87 	struct smbnode *np = VTOSMB(vp);
88 	int error, offset, retval/*, *eofflag = ap->a_eofflag*/;
89 
90 	np = VTOSMB(vp);
91 	SMBVDEBUG("dirname='%s'\n", np->n_name);
92 	smb_makescred(&scred, uio->uio_td, cred);
93 
94 	if (uio->uio_resid < 0 || uio->uio_offset < 0 ||
95 	    uio->uio_offset > INT_MAX)
96 		return(EINVAL);
97 
98 	error = 0;
99 	offset = uio->uio_offset;
100 
101 	if (uio->uio_resid > 0 && offset < 1) {
102 		if (vop_write_dirent(&error, uio, np->n_ino, DT_DIR, 1, "."))
103 			goto done;
104 		if (error)
105 			goto done;
106 		++offset;
107 	}
108 
109 	if (uio->uio_resid > 0 && offset < 2) {
110 		if (vop_write_dirent(&error, uio,
111 		    np->n_parent ? VTOSMB(np->n_parent)->n_ino : 2,
112 		    DT_DIR, 2, ".."))
113 			goto done;
114 		if (error)
115 			goto done;
116 		++offset;
117 	}
118 
119 	if (uio->uio_resid == 0)
120 		goto done;
121 
122 	if (offset != np->n_dirofs || np->n_dirseq == NULL) {
123 		SMBVDEBUG("Reopening search %ld:%ld\n", offset, np->n_dirofs);
124 		if (np->n_dirseq) {
125 			smbfs_findclose(np->n_dirseq, &scred);
126 			np->n_dirseq = NULL;
127 		}
128 		np->n_dirofs = 2;
129 		error = smbfs_findopen(np, "*", 1,
130 		    SMB_FA_SYSTEM | SMB_FA_HIDDEN | SMB_FA_DIR,
131 		    &scred, &ctx);
132 		if (error) {
133 			SMBVDEBUG("can not open search, error = %d", error);
134 			return error;
135 		}
136 		np->n_dirseq = ctx;
137 	} else {
138 		ctx = np->n_dirseq;
139 	}
140 	while (np->n_dirofs < offset) {
141 		error = smbfs_findnext(ctx, offset - np->n_dirofs, &scred);
142 		++np->n_dirofs;
143 		if (error) {
144 			smbfs_findclose(np->n_dirseq, &scred);
145 			np->n_dirseq = NULL;
146 			return error == ENOENT ? 0 : error;
147 		}
148 	}
149 	error = 0;
150 	while (uio->uio_resid > 0 && !error) {
151 		/*
152 		 * Overestimate the size of a record a bit, doesn't really
153 		 * hurt to be wrong here.
154 		 */
155 		error = smbfs_findnext(ctx, uio->uio_resid / _DIRENT_RECLEN(255) + 1, &scred);
156 		if (error)
157 			break;
158 		np->n_dirofs++;
159 		++offset;
160 
161 		retval = vop_write_dirent(&error, uio, ctx->f_attr.fa_ino,
162 		    (ctx->f_attr.fa_attr & SMB_FA_DIR) ? DT_DIR : DT_REG,
163 		    ctx->f_nmlen, ctx->f_name);
164 		if (retval)
165 			break;
166 		if (smbfs_fastlookup && !error) {
167 			error = smbfs_nget(vp->v_mount, vp, ctx->f_name,
168 			    ctx->f_nmlen, &ctx->f_attr, &newvp);
169 			if (!error)
170 				vput(newvp);
171 		}
172 	}
173 	if (error == ENOENT)
174 		error = 0;
175 done:
176 	uio->uio_offset = offset;
177 	return error;
178 }
179 
180 int
181 smbfs_readvnode(struct vnode *vp, struct uio *uiop, struct ucred *cred)
182 {
183 	struct thread *td;
184 	struct smbmount *smp = VFSTOSMBFS(vp->v_mount);
185 	struct smbnode *np = VTOSMB(vp);
186 	struct vattr vattr;
187 	struct smb_cred scred;
188 	int error, lks;
189 
190 	/*
191 	 * Protect against method which is not supported for now
192 	 */
193 	if (uiop->uio_segflg == UIO_NOCOPY)
194 		return EOPNOTSUPP;
195 
196 	if (vp->v_type != VREG && vp->v_type != VDIR) {
197 		SMBFSERR("vn types other than VREG or VDIR are unsupported !\n");
198 		return EIO;
199 	}
200 	if (uiop->uio_resid == 0)
201 		return 0;
202 	if (uiop->uio_offset < 0)
203 		return EINVAL;
204 /*	if (uiop->uio_offset + uiop->uio_resid > smp->nm_maxfilesize)
205 		return EFBIG;*/
206 	td = uiop->uio_td;
207 	if (vp->v_type == VDIR) {
208 		lks = LK_EXCLUSIVE;/*lockstatus(&vp->v_lock, td);*/
209 		if (lks == LK_SHARED)
210 			vn_lock(vp, LK_UPGRADE | LK_RETRY);
211 		error = smbfs_readvdir(vp, uiop, cred);
212 		if (lks == LK_SHARED)
213 			vn_lock(vp, LK_DOWNGRADE | LK_RETRY);
214 		return error;
215 	}
216 
217 /*	biosize = SSTOCN(smp->sm_share)->sc_txmax;*/
218 	if (np->n_flag & NMODIFIED) {
219 		smbfs_attr_cacheremove(vp);
220 		error = VOP_GETATTR(vp, &vattr);
221 		if (error)
222 			return error;
223 		np->n_mtime.tv_sec = vattr.va_mtime.tv_sec;
224 	} else {
225 		error = VOP_GETATTR(vp, &vattr);
226 		if (error)
227 			return error;
228 		if (np->n_mtime.tv_sec != vattr.va_mtime.tv_sec) {
229 			error = smbfs_vinvalbuf(vp, V_SAVE, 1);
230 			if (error)
231 				return error;
232 			np->n_mtime.tv_sec = vattr.va_mtime.tv_sec;
233 		}
234 	}
235 	smb_makescred(&scred, td, cred);
236 	return smb_read(smp->sm_share, np->n_fid, uiop, &scred);
237 }
238 
239 int
240 smbfs_writevnode(struct vnode *vp, struct uio *uiop,
241 		 struct ucred *cred, int ioflag)
242 {
243 	struct thread *td;
244 	struct smbmount *smp = VTOSMBFS(vp);
245 	struct smbnode *np = VTOSMB(vp);
246 	struct smb_cred scred;
247 	int error = 0;
248 
249 	if (vp->v_type != VREG) {
250 		SMBERROR("vn types other than VREG unsupported !\n");
251 		return EIO;
252 	}
253 	SMBVDEBUG("ofs=%d,resid=%d\n",(int)uiop->uio_offset, uiop->uio_resid);
254 	if (uiop->uio_offset < 0)
255 		return EINVAL;
256 /*	if (uiop->uio_offset + uiop->uio_resid > smp->nm_maxfilesize)
257 		return (EFBIG);*/
258 	td = uiop->uio_td;
259 	if (ioflag & (IO_APPEND | IO_SYNC)) {
260 		if (np->n_flag & NMODIFIED) {
261 			smbfs_attr_cacheremove(vp);
262 			error = smbfs_vinvalbuf(vp, V_SAVE, 1);
263 			if (error)
264 				return error;
265 		}
266 		if (ioflag & IO_APPEND) {
267 #if notyet
268 			/*
269 			 * File size can be changed by another client
270 			 */
271 			smbfs_attr_cacheremove(vp);
272 			error = VOP_GETATTR(vp, &vattr);
273 			if (error) return (error);
274 #endif
275 			uiop->uio_offset = np->n_size;
276 		}
277 	}
278 	if (uiop->uio_resid == 0)
279 		return 0;
280 	if (td->td_proc &&
281 	    uiop->uio_offset + uiop->uio_resid >
282 	    td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
283 		lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ);
284 		return EFBIG;
285 	}
286 	smb_makescred(&scred, td, cred);
287 	error = smb_write(smp->sm_share, np->n_fid, uiop, &scred);
288 	SMBVDEBUG("after: ofs=%d,resid=%d\n",(int)uiop->uio_offset, uiop->uio_resid);
289 	if (!error) {
290 		if (uiop->uio_offset > np->n_size) {
291 			np->n_size = uiop->uio_offset;
292 			vnode_pager_setsize(vp, np->n_size);
293 		}
294 	}
295 	return error;
296 }
297 
298 /*
299  * Do an I/O operation to/from a cache block.
300  */
301 int
302 smbfs_doio(struct vnode *vp, struct bio *bio, struct ucred *cr, struct thread *td)
303 {
304 	struct buf *bp = bio->bio_buf;
305 	struct smbmount *smp = VFSTOSMBFS(vp->v_mount);
306 	struct smbnode *np = VTOSMB(vp);
307 	struct uio uio, *uiop = &uio;
308 	struct iovec io;
309 	struct smb_cred scred;
310 	int error = 0;
311 
312 	uiop->uio_iov = &io;
313 	uiop->uio_iovcnt = 1;
314 	uiop->uio_segflg = UIO_SYSSPACE;
315 	uiop->uio_td = td;
316 
317 	smb_makescred(&scred, td, cr);
318 
319 	if (bp->b_cmd == BUF_CMD_READ) {
320 	    io.iov_len = uiop->uio_resid = bp->b_bcount;
321 	    io.iov_base = bp->b_data;
322 	    uiop->uio_rw = UIO_READ;
323 	    switch (vp->v_type) {
324 	      case VREG:
325 		uiop->uio_offset = bio->bio_offset;
326 		error = smb_read(smp->sm_share, np->n_fid, uiop, &scred);
327 		if (error)
328 			break;
329 		if (uiop->uio_resid) {
330 			int left = uiop->uio_resid;
331 			int nread = bp->b_bcount - left;
332 			if (left > 0)
333 			    bzero((char *)bp->b_data + nread, left);
334 		}
335 		break;
336 	    default:
337 		kprintf("smbfs_doio:  type %x unexpected\n",vp->v_type);
338 		break;
339 	    };
340 	    if (error) {
341 		bp->b_error = error;
342 		bp->b_flags |= B_ERROR;
343 	    }
344 	} else { /* write */
345 	    KKASSERT(bp->b_cmd == BUF_CMD_WRITE);
346 	    if (bio->bio_offset + bp->b_dirtyend > np->n_size)
347 		bp->b_dirtyend = np->n_size - bio->bio_offset;
348 
349 	    if (bp->b_dirtyend > bp->b_dirtyoff) {
350 		io.iov_len = uiop->uio_resid = bp->b_dirtyend - bp->b_dirtyoff;
351 		uiop->uio_offset = bio->bio_offset + bp->b_dirtyoff;
352 		io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
353 		uiop->uio_rw = UIO_WRITE;
354 		error = smb_write(smp->sm_share, np->n_fid, uiop, &scred);
355 
356 		/*
357 		 * For an interrupted write, the buffer is still valid
358 		 * and the write hasn't been pushed to the server yet,
359 		 * so we can't set BIO_ERROR and report the interruption
360 		 * by setting B_EINTR. For the B_ASYNC case, B_EINTR
361 		 * is not relevant, so the rpc attempt is essentially
362 		 * a noop.  For the case of a V3 write rpc not being
363 		 * committed to stable storage, the block is still
364 		 * dirty and requires either a commit rpc or another
365 		 * write rpc with iomode == NFSV3WRITE_FILESYNC before
366 		 * the block is reused. This is indicated by setting
367 		 * the B_DELWRI and B_NEEDCOMMIT flags.
368 		 */
369     		if (error == EINTR
370 		    || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
371 
372 			crit_enter();
373 			bp->b_flags &= ~(B_INVAL|B_NOCACHE);
374 			if ((bp->b_flags & B_ASYNC) == 0)
375 			    bp->b_flags |= B_EINTR;
376 			if ((bp->b_flags & B_PAGING) == 0)
377 			    bdirty(bp);
378 			if ((bp->b_flags & B_ASYNC) == 0)
379 			    bp->b_flags |= B_EINTR;
380 			crit_exit();
381 	    	} else {
382 			if (error) {
383 				bp->b_flags |= B_ERROR;
384 				bp->b_error = error;
385 			}
386 			bp->b_dirtyoff = bp->b_dirtyend = 0;
387 		}
388 	    } else {
389 		bp->b_resid = 0;
390 		biodone(bio);
391 		return 0;
392 	    }
393 	}
394 	bp->b_resid = uiop->uio_resid;
395 	biodone(bio);
396 	return error;
397 }
398 
399 /*
400  * Vnode op for VM getpages.
401  * Wish wish .... get rid from multiple IO routines
402  *
403  * smbfs_getpages(struct vnode *a_vp, vm_page_t *a_m, int a_count,
404  *		  int a_reqpage, vm_ooffset_t a_offset)
405  */
406 int
407 smbfs_getpages(struct vop_getpages_args *ap)
408 {
409 #ifdef SMBFS_RWGENERIC
410 	return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
411 		ap->a_reqpage);
412 #else
413 	int i, error, nextoff, size, toff, npages, count;
414 	int doclose;
415 	struct uio uio;
416 	struct iovec iov;
417 	vm_offset_t kva;
418 	struct buf *bp;
419 	struct vnode *vp;
420 	struct thread *td = curthread;	/* XXX */
421 	struct ucred *cred;
422 	struct smbmount *smp;
423 	struct smbnode *np;
424 	struct smb_cred scred;
425 	vm_page_t *pages;
426 
427 	KKASSERT(td->td_proc);
428 
429 	vp = ap->a_vp;
430 	cred = td->td_proc->p_ucred;
431 	np = VTOSMB(vp);
432 	smp = VFSTOSMBFS(vp->v_mount);
433 	pages = ap->a_m;
434 	count = ap->a_count;
435 
436 	if (vp->v_object == NULL) {
437 		kprintf("smbfs_getpages: called with non-merged cache vnode??\n");
438 		return VM_PAGER_ERROR;
439 	}
440 	smb_makescred(&scred, td, cred);
441 
442 	bp = getpbuf(&smbfs_pbuf_freecnt);
443 	npages = btoc(count);
444 	kva = (vm_offset_t) bp->b_data;
445 	pmap_qenter(kva, pages, npages);
446 
447 	iov.iov_base = (caddr_t) kva;
448 	iov.iov_len = count;
449 	uio.uio_iov = &iov;
450 	uio.uio_iovcnt = 1;
451 	uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
452 	uio.uio_resid = count;
453 	uio.uio_segflg = UIO_SYSSPACE;
454 	uio.uio_rw = UIO_READ;
455 	uio.uio_td = td;
456 
457 	/*
458 	 * This is kinda nasty.  Since smbfs is physically closing the
459 	 * fid on close(), we have to reopen it if necessary.  There are
460 	 * other races here too, such as if another process opens the same
461 	 * file while we are blocked in read. XXX
462 	 */
463 	error = 0;
464 	doclose = 0;
465 	if (np->n_opencount == 0) {
466 		error = smbfs_smb_open(np, SMB_AM_OPENREAD, &scred);
467 		if (error == 0)
468 			doclose = 1;
469 	}
470 	if (error == 0)
471 		error = smb_read(smp->sm_share, np->n_fid, &uio, &scred);
472 	if (doclose)
473 		smbfs_smb_close(smp->sm_share, np->n_fid, NULL, &scred);
474 	pmap_qremove(kva, npages);
475 
476 	relpbuf(bp, &smbfs_pbuf_freecnt);
477 
478 	if (error && (uio.uio_resid == count)) {
479 		kprintf("smbfs_getpages: error %d\n",error);
480 		for (i = 0; i < npages; i++) {
481 			if (ap->a_reqpage != i)
482 				vnode_pager_freepage(pages[i]);
483 		}
484 		return VM_PAGER_ERROR;
485 	}
486 
487 	size = count - uio.uio_resid;
488 
489 	for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
490 		vm_page_t m;
491 		nextoff = toff + PAGE_SIZE;
492 		m = pages[i];
493 
494 		m->flags &= ~PG_ZERO;
495 
496 		if (nextoff <= size) {
497 			m->valid = VM_PAGE_BITS_ALL;
498 			m->dirty = 0;
499 		} else {
500 			int nvalid = ((size + DEV_BSIZE - 1) - toff) & ~(DEV_BSIZE - 1);
501 			vm_page_set_validclean(m, 0, nvalid);
502 		}
503 
504 		if (i != ap->a_reqpage) {
505 			/*
506 			 * Whether or not to leave the page activated is up in
507 			 * the air, but we should put the page on a page queue
508 			 * somewhere (it already is in the object).  Result:
509 			 * It appears that emperical results show that
510 			 * deactivating pages is best.
511 			 */
512 
513 			/*
514 			 * Just in case someone was asking for this page we
515 			 * now tell them that it is ok to use.
516 			 */
517 			if (!error) {
518 				if (m->flags & PG_WANTED)
519 					vm_page_activate(m);
520 				else
521 					vm_page_deactivate(m);
522 				vm_page_wakeup(m);
523 			} else {
524 				vnode_pager_freepage(m);
525 			}
526 		}
527 	}
528 	return 0;
529 #endif /* SMBFS_RWGENERIC */
530 }
531 
532 /*
533  * Vnode op for VM putpages.
534  * possible bug: all IO done in sync mode
535  * Note that vop_close always invalidate pages before close, so it's
536  * not necessary to open vnode.
537  *
538  * smbfs_putpages(struct vnode *a_vp, vm_page_t *a_m, int a_count, int a_sync,
539  *		  int *a_rtvals, vm_ooffset_t a_offset)
540  */
541 int
542 smbfs_putpages(struct vop_putpages_args *ap)
543 {
544 	int error;
545 	struct vnode *vp = ap->a_vp;
546 	struct thread *td = curthread;	/* XXX */
547 	struct ucred *cred;
548 
549 #ifdef SMBFS_RWGENERIC
550 	KKASSERT(td->td_proc);
551 	cred = td->td_proc->p_ucred;
552 	VOP_OPEN(vp, FWRITE, cred, NULL);
553 	error = vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count,
554 		ap->a_sync, ap->a_rtvals);
555 	VOP_CLOSE(vp, FWRITE, cred);
556 	return error;
557 #else
558 	struct uio uio;
559 	struct iovec iov;
560 	vm_offset_t kva;
561 	struct buf *bp;
562 	int i, npages, count;
563 	int doclose;
564 	int *rtvals;
565 	struct smbmount *smp;
566 	struct smbnode *np;
567 	struct smb_cred scred;
568 	vm_page_t *pages;
569 
570 	KKASSERT(td->td_proc);
571 	cred = td->td_proc->p_ucred;
572 /*	VOP_OPEN(vp, FWRITE, cred, NULL);*/
573 	np = VTOSMB(vp);
574 	smp = VFSTOSMBFS(vp->v_mount);
575 	pages = ap->a_m;
576 	count = ap->a_count;
577 	rtvals = ap->a_rtvals;
578 	npages = btoc(count);
579 
580 	for (i = 0; i < npages; i++) {
581 		rtvals[i] = VM_PAGER_AGAIN;
582 	}
583 
584 	bp = getpbuf(&smbfs_pbuf_freecnt);
585 	kva = (vm_offset_t) bp->b_data;
586 	pmap_qenter(kva, pages, npages);
587 
588 	iov.iov_base = (caddr_t) kva;
589 	iov.iov_len = count;
590 	uio.uio_iov = &iov;
591 	uio.uio_iovcnt = 1;
592 	uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
593 	uio.uio_resid = count;
594 	uio.uio_segflg = UIO_SYSSPACE;
595 	uio.uio_rw = UIO_WRITE;
596 	uio.uio_td = td;
597 	SMBVDEBUG("ofs=%d,resid=%d\n",(int)uio.uio_offset, uio.uio_resid);
598 
599 	smb_makescred(&scred, td, cred);
600 
601 	/*
602 	 * This is kinda nasty.  Since smbfs is physically closing the
603 	 * fid on close(), we have to reopen it if necessary.  There are
604 	 * other races here too, such as if another process opens the same
605 	 * file while we are blocked in read, or the file is open read-only
606 	 * XXX
607 	 */
608 	error = 0;
609 	doclose = 0;
610 	if (np->n_opencount == 0) {
611 		error = smbfs_smb_open(np, SMB_AM_OPENRW, &scred);
612 		if (error == 0)
613 			doclose = 1;
614 	}
615 	if (error == 0)
616 		error = smb_write(smp->sm_share, np->n_fid, &uio, &scred);
617 	if (doclose)
618 		smbfs_smb_close(smp->sm_share, np->n_fid, NULL, &scred);
619 /*	VOP_CLOSE(vp, FWRITE, cred);*/
620 	SMBVDEBUG("paged write done: %d\n", error);
621 
622 	pmap_qremove(kva, npages);
623 	relpbuf(bp, &smbfs_pbuf_freecnt);
624 
625 	if (!error) {
626 		int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE;
627 		for (i = 0; i < nwritten; i++) {
628 			rtvals[i] = VM_PAGER_OK;
629 			pages[i]->dirty = 0;
630 		}
631 	}
632 	return rtvals[0];
633 #endif /* SMBFS_RWGENERIC */
634 }
635 
636 /*
637  * Flush and invalidate all dirty buffers. If another process is already
638  * doing the flush, just wait for completion.
639  */
640 int
641 smbfs_vinvalbuf(struct vnode *vp, int flags, int intrflg)
642 {
643 	struct smbnode *np = VTOSMB(vp);
644 	int error = 0, slpflag, slptimeo;
645 
646 	if (vp->v_flag & VRECLAIMED)
647 		return 0;
648 	if (intrflg) {
649 		slpflag = PCATCH;
650 		slptimeo = 2 * hz;
651 	} else {
652 		slpflag = 0;
653 		slptimeo = 0;
654 	}
655 	while (np->n_flag & NFLUSHINPROG) {
656 		np->n_flag |= NFLUSHWANT;
657 		error = tsleep((caddr_t)&np->n_flag, 0, "smfsvinv", slptimeo);
658 		error = smb_proc_intr(curthread);
659 		if (error == EINTR && intrflg)
660 			return EINTR;
661 	}
662 	np->n_flag |= NFLUSHINPROG;
663 	error = vinvalbuf(vp, flags, slpflag, 0);
664 	while (error) {
665 		if (intrflg && (error == ERESTART || error == EINTR)) {
666 			np->n_flag &= ~NFLUSHINPROG;
667 			if (np->n_flag & NFLUSHWANT) {
668 				np->n_flag &= ~NFLUSHWANT;
669 				wakeup((caddr_t)&np->n_flag);
670 			}
671 			return EINTR;
672 		}
673 		error = vinvalbuf(vp, flags, slpflag, 0);
674 	}
675 	np->n_flag &= ~(NMODIFIED | NFLUSHINPROG);
676 	if (np->n_flag & NFLUSHWANT) {
677 		np->n_flag &= ~NFLUSHWANT;
678 		wakeup((caddr_t)&np->n_flag);
679 	}
680 	return (error);
681 }
682