xref: /titanic_51/usr/src/uts/common/syscall/sendfile.c (revision b8201470142151ac3303d2d0b875fc282299de45)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/t_lock.h>
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/buf.h>
32 #include <sys/conf.h>
33 #include <sys/cred.h>
34 #include <sys/kmem.h>
35 #include <sys/sysmacros.h>
36 #include <sys/vfs.h>
37 #include <sys/vnode.h>
38 #include <sys/debug.h>
39 #include <sys/errno.h>
40 #include <sys/time.h>
41 #include <sys/file.h>
42 #include <sys/open.h>
43 #include <sys/user.h>
44 #include <sys/termios.h>
45 #include <sys/stream.h>
46 #include <sys/strsubr.h>
47 #include <sys/sunddi.h>
48 #include <sys/esunddi.h>
49 #include <sys/flock.h>
50 #include <sys/modctl.h>
51 #include <sys/cmn_err.h>
52 #include <sys/vmsystm.h>
53 
54 #include <sys/socket.h>
55 #include <sys/socketvar.h>
56 #include <fs/sockfs/sockcommon.h>
57 #include <fs/sockfs/socktpi.h>
58 
59 #include <netinet/in.h>
60 #include <sys/sendfile.h>
61 #include <sys/un.h>
62 #include <sys/tihdr.h>
63 #include <sys/atomic.h>
64 
65 #include <inet/common.h>
66 #include <inet/ip.h>
67 #include <inet/ip6.h>
68 #include <inet/tcp.h>
69 
70 extern int sosendfile64(file_t *, file_t *, const struct ksendfilevec64 *,
71 		ssize32_t *);
72 extern int nl7c_sendfilev(struct sonode *, u_offset_t *, struct sendfilevec *,
73 		int, ssize_t *);
74 extern int snf_segmap(file_t *, vnode_t *, u_offset_t, u_offset_t, ssize_t *,
75 		boolean_t);
76 extern sotpi_info_t *sotpi_sototpi(struct sonode *);
77 
78 #define	SEND_MAX_CHUNK	16
79 
80 #if defined(_SYSCALL32_IMPL) || defined(_ILP32)
81 /*
82  * 64 bit offsets for 32 bit applications only running either on
83  * 64 bit kernel or 32 bit kernel. For 32 bit apps, we can't transfer
84  * more than 2GB of data.
85  */
86 int
87 sendvec_chunk64(file_t *fp, u_offset_t *fileoff, struct ksendfilevec64 *sfv,
88     int copy_cnt, ssize32_t *count)
89 {
90 	struct vnode *vp;
91 	ushort_t fflag;
92 	int ioflag;
93 	size32_t cnt;
94 	ssize32_t sfv_len;
95 	ssize32_t tmpcount;
96 	u_offset_t sfv_off;
97 	struct uio auio;
98 	struct iovec aiov;
99 	int i, error;
100 
101 	fflag = fp->f_flag;
102 	vp = fp->f_vnode;
103 	for (i = 0; i < copy_cnt; i++) {
104 
105 		if (ISSIG(curthread, JUSTLOOKING))
106 			return (EINTR);
107 
108 		/*
109 		 * Do similar checks as "write" as we are writing
110 		 * sfv_len bytes into "vp".
111 		 */
112 		sfv_len = (ssize32_t)sfv->sfv_len;
113 
114 		if (sfv_len == 0) {
115 			sfv++;
116 			continue;
117 		}
118 
119 		if (sfv_len < 0)
120 			return (EINVAL);
121 
122 		if (vp->v_type == VREG) {
123 			if (*fileoff >= curproc->p_fsz_ctl) {
124 				mutex_enter(&curproc->p_lock);
125 				(void) rctl_action(
126 				    rctlproc_legacy[RLIMIT_FSIZE],
127 				    curproc->p_rctls, curproc, RCA_SAFE);
128 				mutex_exit(&curproc->p_lock);
129 				return (EFBIG);
130 			}
131 
132 			if (*fileoff >= OFFSET_MAX(fp))
133 				return (EFBIG);
134 
135 			if (*fileoff + sfv_len > OFFSET_MAX(fp))
136 				return (EINVAL);
137 		}
138 
139 		tmpcount = *count + sfv_len;
140 		if (tmpcount < 0)
141 			return (EINVAL);
142 
143 		sfv_off = sfv->sfv_off;
144 
145 		auio.uio_extflg = UIO_COPY_DEFAULT;
146 		if (sfv->sfv_fd == SFV_FD_SELF) {
147 			aiov.iov_len = sfv_len;
148 			aiov.iov_base = (caddr_t)(uintptr_t)sfv_off;
149 			auio.uio_loffset = *fileoff;
150 			auio.uio_iovcnt = 1;
151 			auio.uio_resid = sfv_len;
152 			auio.uio_iov = &aiov;
153 			auio.uio_segflg = UIO_USERSPACE;
154 			auio.uio_llimit = curproc->p_fsz_ctl;
155 			auio.uio_fmode = fflag;
156 			ioflag = auio.uio_fmode & (FAPPEND|FSYNC|FDSYNC|FRSYNC);
157 			while (sfv_len > 0) {
158 				error = VOP_WRITE(vp, &auio, ioflag,
159 				    fp->f_cred, NULL);
160 				cnt = sfv_len - auio.uio_resid;
161 				sfv_len -= cnt;
162 				ttolwp(curthread)->lwp_ru.ioch += (ulong_t)cnt;
163 				if (vp->v_type == VREG)
164 					*fileoff += cnt;
165 				*count += cnt;
166 				if (error != 0)
167 					return (error);
168 			}
169 		} else {
170 			file_t	*ffp;
171 			vnode_t	*readvp;
172 			size_t	size;
173 			caddr_t	ptr;
174 
175 			if ((ffp = getf(sfv->sfv_fd)) == NULL)
176 				return (EBADF);
177 
178 			if ((ffp->f_flag & FREAD) == 0) {
179 				releasef(sfv->sfv_fd);
180 				return (EBADF);
181 			}
182 
183 			readvp = ffp->f_vnode;
184 			if (readvp->v_type != VREG) {
185 				releasef(sfv->sfv_fd);
186 				return (EINVAL);
187 			}
188 
189 			/*
190 			 * No point reading and writing to same vp,
191 			 * as long as both are regular files. readvp is not
192 			 * locked; but since we got it from an open file the
193 			 * contents will be valid during the time of access.
194 			 */
195 			if (vn_compare(vp, readvp)) {
196 				releasef(sfv->sfv_fd);
197 				return (EINVAL);
198 			}
199 
200 			/*
201 			 * Optimize the regular file over
202 			 * the socket case.
203 			 */
204 			if (vp->v_type == VSOCK) {
205 				error = sosendfile64(fp, ffp, sfv,
206 				    (ssize32_t *)&cnt);
207 				*count += cnt;
208 				if (error)
209 					return (error);
210 				sfv++;
211 				continue;
212 			}
213 
214 			/*
215 			 * Note: we assume readvp != vp. "vp" is already
216 			 * locked, and "readvp" must not be.
217 			 */
218 			if (readvp < vp) {
219 				VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
220 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
221 				    NULL);
222 				(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
223 			} else {
224 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
225 				    NULL);
226 			}
227 
228 			/*
229 			 * Same checks as in pread64.
230 			 */
231 			if (sfv_off > MAXOFFSET_T) {
232 				VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
233 				releasef(sfv->sfv_fd);
234 				return (EINVAL);
235 			}
236 
237 			if (sfv_off + sfv_len > MAXOFFSET_T)
238 				sfv_len = (ssize32_t)(MAXOFFSET_T - sfv_off);
239 
240 			/* Find the native blocksize to transfer data */
241 			size = MIN(vp->v_vfsp->vfs_bsize,
242 			    readvp->v_vfsp->vfs_bsize);
243 			size = sfv_len < size ? sfv_len : size;
244 			ptr = kmem_alloc(size, KM_NOSLEEP);
245 			if (ptr == NULL) {
246 				VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
247 				releasef(sfv->sfv_fd);
248 				return (ENOMEM);
249 			}
250 
251 			while (sfv_len > 0) {
252 				size_t	iov_len;
253 
254 				iov_len = MIN(size, sfv_len);
255 				aiov.iov_base = ptr;
256 				aiov.iov_len = iov_len;
257 				auio.uio_loffset = sfv_off;
258 				auio.uio_iov = &aiov;
259 				auio.uio_iovcnt = 1;
260 				auio.uio_resid = iov_len;
261 				auio.uio_segflg = UIO_SYSSPACE;
262 				auio.uio_llimit = MAXOFFSET_T;
263 				auio.uio_fmode = ffp->f_flag;
264 				ioflag = auio.uio_fmode &
265 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
266 
267 				/*
268 				 * If read sync is not asked for,
269 				 * filter sync flags
270 				 */
271 				if ((ioflag & FRSYNC) == 0)
272 					ioflag &= ~(FSYNC|FDSYNC);
273 				error = VOP_READ(readvp, &auio, ioflag,
274 				    fp->f_cred, NULL);
275 				if (error) {
276 					kmem_free(ptr, size);
277 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
278 					    NULL);
279 					releasef(sfv->sfv_fd);
280 					return (error);
281 				}
282 
283 				/*
284 				 * Check how must data was really read.
285 				 * Decrement the 'len' and increment the
286 				 * 'off' appropriately.
287 				 */
288 				cnt = iov_len - auio.uio_resid;
289 				if (cnt == 0) {
290 					/*
291 					 * If we were reading a pipe (currently
292 					 * not implemented), we may now lose
293 					 * data.
294 					 */
295 					kmem_free(ptr, size);
296 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
297 					    NULL);
298 					releasef(sfv->sfv_fd);
299 					return (EINVAL);
300 				}
301 				sfv_len -= cnt;
302 				sfv_off += cnt;
303 
304 				aiov.iov_base = ptr;
305 				aiov.iov_len = cnt;
306 				auio.uio_loffset = *fileoff;
307 				auio.uio_iov = &aiov;
308 				auio.uio_iovcnt = 1;
309 				auio.uio_resid = cnt;
310 				auio.uio_segflg = UIO_SYSSPACE;
311 				auio.uio_llimit = curproc->p_fsz_ctl;
312 				auio.uio_fmode = fflag;
313 				ioflag = auio.uio_fmode &
314 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
315 				error = VOP_WRITE(vp, &auio, ioflag,
316 				    fp->f_cred, NULL);
317 
318 				/*
319 				 * Check how much data was written. Increment
320 				 * the 'len' and decrement the 'off' if all
321 				 * the data was not written.
322 				 */
323 				cnt -= auio.uio_resid;
324 				sfv_len += auio.uio_resid;
325 				sfv_off -= auio.uio_resid;
326 				ttolwp(curthread)->lwp_ru.ioch += (ulong_t)cnt;
327 				if (vp->v_type == VREG)
328 					*fileoff += cnt;
329 				*count += cnt;
330 				if (error != 0) {
331 					kmem_free(ptr, size);
332 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
333 					    NULL);
334 					releasef(sfv->sfv_fd);
335 					return (error);
336 				}
337 			}
338 			VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
339 			releasef(sfv->sfv_fd);
340 			kmem_free(ptr, size);
341 		}
342 		sfv++;
343 	}
344 	return (0);
345 }
346 
347 ssize32_t
348 sendvec64(file_t *fp, const struct ksendfilevec64 *vec, int sfvcnt,
349 	size32_t *xferred, int fildes)
350 {
351 	u_offset_t		fileoff;
352 	int			copy_cnt;
353 	const struct ksendfilevec64 *copy_vec;
354 	struct ksendfilevec64 sfv[SEND_MAX_CHUNK];
355 	struct vnode *vp;
356 	int error;
357 	ssize32_t count = 0;
358 
359 	vp = fp->f_vnode;
360 	(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
361 
362 	copy_vec = vec;
363 	fileoff = fp->f_offset;
364 
365 	do {
366 		copy_cnt = MIN(sfvcnt, SEND_MAX_CHUNK);
367 		if (copyin(copy_vec, sfv, copy_cnt *
368 		    sizeof (struct ksendfilevec64))) {
369 			error = EFAULT;
370 			break;
371 		}
372 
373 		error = sendvec_chunk64(fp, &fileoff, sfv, copy_cnt, &count);
374 		if (error != 0)
375 			break;
376 
377 		copy_vec += copy_cnt;
378 		sfvcnt -= copy_cnt;
379 	} while (sfvcnt > 0);
380 
381 	if (vp->v_type == VREG)
382 		fp->f_offset += count;
383 
384 	VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
385 	if (copyout(&count, xferred, sizeof (count)))
386 		error = EFAULT;
387 	releasef(fildes);
388 	if (error != 0)
389 		return (set_errno(error));
390 	return (count);
391 }
392 #endif
393 
394 int
395 sendvec_small_chunk(file_t *fp, u_offset_t *fileoff, struct sendfilevec *sfv,
396     int copy_cnt, ssize_t total_size, int maxblk, ssize_t *count)
397 {
398 	struct vnode *vp;
399 	struct uio auio;
400 	struct iovec aiov;
401 	ushort_t fflag;
402 	int ioflag;
403 	int i, error;
404 	size_t cnt;
405 	ssize_t sfv_len;
406 	u_offset_t sfv_off;
407 #ifdef _SYSCALL32_IMPL
408 	model_t model = get_udatamodel();
409 	u_offset_t maxoff = (model == DATAMODEL_ILP32) ?
410 	    MAXOFF32_T : MAXOFFSET_T;
411 #else
412 	const u_offset_t maxoff = MAXOFF32_T;
413 #endif
414 	mblk_t *dmp = NULL;
415 	int wroff;
416 	int buf_left = 0;
417 	size_t	iov_len;
418 	mblk_t  *head, *tmp;
419 	size_t  size = total_size;
420 	size_t  extra;
421 	int tail_len;
422 	struct nmsghdr msg;
423 
424 	fflag = fp->f_flag;
425 	vp = fp->f_vnode;
426 
427 	ASSERT(vp->v_type == VSOCK);
428 	ASSERT(maxblk > 0);
429 
430 	/* If nothing to send, return */
431 	if (total_size == 0)
432 		return (0);
433 
434 	if (vp->v_stream != NULL) {
435 		wroff = (int)vp->v_stream->sd_wroff;
436 		tail_len = (int)vp->v_stream->sd_tail;
437 	} else {
438 		struct sonode *so;
439 
440 		so = VTOSO(vp);
441 		wroff = so->so_proto_props.sopp_wroff;
442 		tail_len = so->so_proto_props.sopp_tail;
443 	}
444 
445 	extra = wroff + tail_len;
446 
447 	buf_left = MIN(total_size, maxblk);
448 	head = dmp = allocb(buf_left + extra, BPRI_HI);
449 	if (head == NULL)
450 		return (ENOMEM);
451 	head->b_wptr = head->b_rptr = head->b_rptr + wroff;
452 	bzero(&msg, sizeof (msg));
453 
454 	auio.uio_extflg = UIO_COPY_DEFAULT;
455 	for (i = 0; i < copy_cnt; i++) {
456 		if (ISSIG(curthread, JUSTLOOKING)) {
457 			freemsg(head);
458 			return (EINTR);
459 		}
460 
461 		/*
462 		 * Do similar checks as "write" as we are writing
463 		 * sfv_len bytes into "vp".
464 		 */
465 		sfv_len = (ssize_t)sfv->sfv_len;
466 
467 		if (sfv_len == 0) {
468 			sfv++;
469 			continue;
470 		}
471 
472 		/* Check for overflow */
473 #ifdef _SYSCALL32_IMPL
474 		if (model == DATAMODEL_ILP32) {
475 			if (((ssize32_t)(*count + sfv_len)) < 0) {
476 				freemsg(head);
477 				return (EINVAL);
478 			}
479 		} else
480 #endif
481 		if ((*count + sfv_len) < 0) {
482 			freemsg(head);
483 			return (EINVAL);
484 		}
485 
486 		sfv_off = (u_offset_t)(ulong_t)sfv->sfv_off;
487 
488 		if (sfv->sfv_fd == SFV_FD_SELF) {
489 			while (sfv_len > 0) {
490 				if (buf_left == 0) {
491 					tmp = dmp;
492 					buf_left = MIN(total_size, maxblk);
493 					iov_len = MIN(buf_left, sfv_len);
494 					dmp = allocb(buf_left + extra, BPRI_HI);
495 					if (dmp == NULL) {
496 						freemsg(head);
497 						return (ENOMEM);
498 					}
499 					dmp->b_wptr = dmp->b_rptr =
500 					    dmp->b_rptr + wroff;
501 					tmp->b_cont = dmp;
502 				} else {
503 					iov_len = MIN(buf_left, sfv_len);
504 				}
505 
506 				aiov.iov_len = iov_len;
507 				aiov.iov_base = (caddr_t)(uintptr_t)sfv_off;
508 				auio.uio_loffset = *fileoff;
509 				auio.uio_iovcnt = 1;
510 				auio.uio_resid = iov_len;
511 				auio.uio_iov = &aiov;
512 				auio.uio_segflg = UIO_USERSPACE;
513 				auio.uio_llimit = curproc->p_fsz_ctl;
514 				auio.uio_fmode = fflag;
515 
516 				buf_left -= iov_len;
517 				total_size -= iov_len;
518 				sfv_len -= iov_len;
519 				sfv_off += iov_len;
520 
521 				error = uiomove((caddr_t)dmp->b_wptr,
522 				    iov_len, UIO_WRITE, &auio);
523 				if (error != 0) {
524 					freemsg(head);
525 					return (error);
526 				}
527 				dmp->b_wptr += iov_len;
528 			}
529 		} else {
530 			file_t	*ffp;
531 			vnode_t	*readvp;
532 
533 			if ((ffp = getf(sfv->sfv_fd)) == NULL) {
534 				freemsg(head);
535 				return (EBADF);
536 			}
537 
538 			if ((ffp->f_flag & FREAD) == 0) {
539 				releasef(sfv->sfv_fd);
540 				freemsg(head);
541 				return (EACCES);
542 			}
543 
544 			readvp = ffp->f_vnode;
545 			if (readvp->v_type != VREG) {
546 				releasef(sfv->sfv_fd);
547 				freemsg(head);
548 				return (EINVAL);
549 			}
550 
551 			/*
552 			 * No point reading and writing to same vp,
553 			 * as long as both are regular files. readvp is not
554 			 * locked; but since we got it from an open file the
555 			 * contents will be valid during the time of access.
556 			 */
557 
558 			if (vn_compare(vp, readvp)) {
559 				releasef(sfv->sfv_fd);
560 				freemsg(head);
561 				return (EINVAL);
562 			}
563 
564 			/*
565 			 * Note: we assume readvp != vp. "vp" is already
566 			 * locked, and "readvp" must not be.
567 			 */
568 
569 			if (readvp < vp) {
570 				VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
571 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
572 				    NULL);
573 				(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
574 			} else {
575 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
576 				    NULL);
577 			}
578 
579 			/* Same checks as in pread */
580 			if (sfv_off > maxoff) {
581 				VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
582 				releasef(sfv->sfv_fd);
583 				freemsg(head);
584 				return (EINVAL);
585 			}
586 			if (sfv_off + sfv_len > maxoff) {
587 				total_size -= (sfv_off + sfv_len - maxoff);
588 				sfv_len = (ssize_t)((offset_t)maxoff -
589 				    sfv_off);
590 			}
591 
592 			while (sfv_len > 0) {
593 				if (buf_left == 0) {
594 					tmp = dmp;
595 					buf_left = MIN(total_size, maxblk);
596 					iov_len = MIN(buf_left, sfv_len);
597 					dmp = allocb(buf_left + extra, BPRI_HI);
598 					if (dmp == NULL) {
599 						VOP_RWUNLOCK(readvp,
600 						    V_WRITELOCK_FALSE, NULL);
601 						releasef(sfv->sfv_fd);
602 						freemsg(head);
603 						return (ENOMEM);
604 					}
605 					dmp->b_wptr = dmp->b_rptr =
606 					    dmp->b_rptr + wroff;
607 					tmp->b_cont = dmp;
608 				} else {
609 					iov_len = MIN(buf_left, sfv_len);
610 				}
611 				aiov.iov_base = (caddr_t)dmp->b_wptr;
612 				aiov.iov_len = iov_len;
613 				auio.uio_loffset = sfv_off;
614 				auio.uio_iov = &aiov;
615 				auio.uio_iovcnt = 1;
616 				auio.uio_resid = iov_len;
617 				auio.uio_segflg = UIO_SYSSPACE;
618 				auio.uio_llimit = MAXOFFSET_T;
619 				auio.uio_fmode = ffp->f_flag;
620 				ioflag = auio.uio_fmode &
621 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
622 
623 				/*
624 				 * If read sync is not asked for,
625 				 * filter sync flags
626 				 */
627 				if ((ioflag & FRSYNC) == 0)
628 					ioflag &= ~(FSYNC|FDSYNC);
629 				error = VOP_READ(readvp, &auio, ioflag,
630 				    fp->f_cred, NULL);
631 				if (error != 0) {
632 					/*
633 					 * If we were reading a pipe (currently
634 					 * not implemented), we may now loose
635 					 * data.
636 					 */
637 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
638 					    NULL);
639 					releasef(sfv->sfv_fd);
640 					freemsg(head);
641 					return (error);
642 				}
643 
644 				/*
645 				 * Check how much data was really read.
646 				 * Decrement the 'len' and increment the
647 				 * 'off' appropriately.
648 				 */
649 				cnt = iov_len - auio.uio_resid;
650 				if (cnt == 0) {
651 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
652 					    NULL);
653 					releasef(sfv->sfv_fd);
654 					freemsg(head);
655 					return (EINVAL);
656 				}
657 				sfv_len -= cnt;
658 				sfv_off += cnt;
659 				total_size -= cnt;
660 				buf_left -= cnt;
661 
662 				dmp->b_wptr += cnt;
663 			}
664 			VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
665 			releasef(sfv->sfv_fd);
666 		}
667 		sfv++;
668 	}
669 
670 	ASSERT(total_size == 0);
671 	error = socket_sendmblk(VTOSO(vp), &msg, fflag, CRED(), &head);
672 	if (error != 0) {
673 		if (head != NULL)
674 			freemsg(head);
675 		return (error);
676 	}
677 	ttolwp(curthread)->lwp_ru.ioch += (ulong_t)size;
678 	*count += size;
679 
680 	return (0);
681 }
682 
683 
684 int
685 sendvec_chunk(file_t *fp, u_offset_t *fileoff, struct sendfilevec *sfv,
686     int copy_cnt, ssize_t *count)
687 {
688 	struct vnode *vp;
689 	struct uio auio;
690 	struct iovec aiov;
691 	ushort_t fflag;
692 	int ioflag;
693 	int i, error;
694 	size_t cnt;
695 	ssize_t sfv_len;
696 	u_offset_t sfv_off;
697 #ifdef _SYSCALL32_IMPL
698 	model_t model = get_udatamodel();
699 	u_offset_t maxoff = (model == DATAMODEL_ILP32) ?
700 	    MAXOFF32_T : MAXOFFSET_T;
701 #else
702 	const u_offset_t maxoff = MAXOFF32_T;
703 #endif
704 	mblk_t	*dmp = NULL;
705 	char	*buf = NULL;
706 	size_t  extra;
707 	int maxblk, wroff, tail_len;
708 	struct sonode *so;
709 	stdata_t *stp;
710 	struct nmsghdr msg;
711 
712 	fflag = fp->f_flag;
713 	vp = fp->f_vnode;
714 
715 	if (vp->v_type == VSOCK) {
716 		so = VTOSO(vp);
717 		if (vp->v_stream != NULL) {
718 			stp = vp->v_stream;
719 			wroff = (int)stp->sd_wroff;
720 			tail_len = (int)stp->sd_tail;
721 			maxblk = (int)stp->sd_maxblk;
722 		} else {
723 			stp = NULL;
724 			wroff = so->so_proto_props.sopp_wroff;
725 			tail_len = so->so_proto_props.sopp_tail;
726 			maxblk = so->so_proto_props.sopp_maxblk;
727 		}
728 		extra = wroff + tail_len;
729 	}
730 
731 	bzero(&msg, sizeof (msg));
732 	auio.uio_extflg = UIO_COPY_DEFAULT;
733 	for (i = 0; i < copy_cnt; i++) {
734 		if (ISSIG(curthread, JUSTLOOKING))
735 			return (EINTR);
736 
737 		/*
738 		 * Do similar checks as "write" as we are writing
739 		 * sfv_len bytes into "vp".
740 		 */
741 		sfv_len = (ssize_t)sfv->sfv_len;
742 
743 		if (sfv_len == 0) {
744 			sfv++;
745 			continue;
746 		}
747 
748 		if (vp->v_type == VREG) {
749 			if (*fileoff >= curproc->p_fsz_ctl) {
750 				mutex_enter(&curproc->p_lock);
751 				(void) rctl_action(
752 				    rctlproc_legacy[RLIMIT_FSIZE],
753 				    curproc->p_rctls, curproc, RCA_SAFE);
754 				mutex_exit(&curproc->p_lock);
755 
756 				return (EFBIG);
757 			}
758 
759 			if (*fileoff >= maxoff)
760 				return (EFBIG);
761 
762 			if (*fileoff + sfv_len > maxoff)
763 				return (EINVAL);
764 		}
765 
766 		/* Check for overflow */
767 #ifdef _SYSCALL32_IMPL
768 		if (model == DATAMODEL_ILP32) {
769 			if (((ssize32_t)(*count + sfv_len)) < 0)
770 				return (EINVAL);
771 		} else
772 #endif
773 		if ((*count + sfv_len) < 0)
774 			return (EINVAL);
775 
776 		sfv_off = (u_offset_t)(ulong_t)sfv->sfv_off;
777 
778 		if (sfv->sfv_fd == SFV_FD_SELF) {
779 			if (vp->v_type == VSOCK) {
780 				while (sfv_len > 0) {
781 					size_t iov_len;
782 
783 					iov_len = sfv_len;
784 					if (!SOCK_IS_NONSTR(so) &&
785 					    SOTOTPI(so)->sti_kssl_ctx != NULL)
786 						iov_len = MIN(iov_len, maxblk);
787 
788 					aiov.iov_len = iov_len;
789 					aiov.iov_base =
790 					    (caddr_t)(uintptr_t)sfv_off;
791 
792 					auio.uio_iov = &aiov;
793 					auio.uio_iovcnt = 1;
794 					auio.uio_loffset = *fileoff;
795 					auio.uio_segflg = UIO_USERSPACE;
796 					auio.uio_fmode = fflag;
797 					auio.uio_llimit = curproc->p_fsz_ctl;
798 					auio.uio_resid = iov_len;
799 
800 					dmp = allocb(iov_len + extra, BPRI_HI);
801 					if (dmp == NULL)
802 						return (ENOMEM);
803 					dmp->b_wptr = dmp->b_rptr =
804 					    dmp->b_rptr + wroff;
805 					error = uiomove((caddr_t)dmp->b_wptr,
806 					    iov_len, UIO_WRITE, &auio);
807 					if (error != 0) {
808 						freeb(dmp);
809 						return (error);
810 					}
811 					dmp->b_wptr += iov_len;
812 					error = socket_sendmblk(VTOSO(vp),
813 					    &msg, fflag, CRED(), &dmp);
814 
815 					if (error != 0) {
816 						if (dmp != NULL)
817 							freeb(dmp);
818 						return (error);
819 					}
820 					ttolwp(curthread)->lwp_ru.ioch +=
821 					    (ulong_t)iov_len;
822 					*count += iov_len;
823 					sfv_len -= iov_len;
824 					sfv_off += iov_len;
825 				}
826 			} else {
827 				aiov.iov_len = sfv_len;
828 				aiov.iov_base = (caddr_t)(uintptr_t)sfv_off;
829 
830 				auio.uio_iov = &aiov;
831 				auio.uio_iovcnt = 1;
832 				auio.uio_loffset = *fileoff;
833 				auio.uio_segflg = UIO_USERSPACE;
834 				auio.uio_fmode = fflag;
835 				auio.uio_llimit = curproc->p_fsz_ctl;
836 				auio.uio_resid = sfv_len;
837 
838 				ioflag = auio.uio_fmode &
839 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
840 				while (sfv_len > 0) {
841 					error = VOP_WRITE(vp, &auio, ioflag,
842 					    fp->f_cred, NULL);
843 					cnt = sfv_len - auio.uio_resid;
844 					sfv_len -= cnt;
845 					ttolwp(curthread)->lwp_ru.ioch +=
846 					    (ulong_t)cnt;
847 					*fileoff += cnt;
848 					*count += cnt;
849 					if (error != 0)
850 						return (error);
851 				}
852 			}
853 		} else {
854 			int segmapit = 0;
855 			file_t	*ffp;
856 			vnode_t	*readvp;
857 			struct vnode *realvp;
858 			size_t	size;
859 			caddr_t	ptr;
860 
861 			if ((ffp = getf(sfv->sfv_fd)) == NULL)
862 				return (EBADF);
863 
864 			if ((ffp->f_flag & FREAD) == 0) {
865 				releasef(sfv->sfv_fd);
866 				return (EBADF);
867 			}
868 
869 			readvp = ffp->f_vnode;
870 			if (VOP_REALVP(readvp, &realvp, NULL) == 0)
871 				readvp = realvp;
872 			if (readvp->v_type != VREG) {
873 				releasef(sfv->sfv_fd);
874 				return (EINVAL);
875 			}
876 
877 			/*
878 			 * No point reading and writing to same vp,
879 			 * as long as both are regular files. readvp is not
880 			 * locked; but since we got it from an open file the
881 			 * contents will be valid during the time of access.
882 			 */
883 			if (vn_compare(vp, readvp)) {
884 				releasef(sfv->sfv_fd);
885 				return (EINVAL);
886 			}
887 
888 			/*
889 			 * Note: we assume readvp != vp. "vp" is already
890 			 * locked, and "readvp" must not be.
891 			 */
892 			if (readvp < vp) {
893 				VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
894 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
895 				    NULL);
896 				(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
897 			} else {
898 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
899 				    NULL);
900 			}
901 
902 			/* Same checks as in pread */
903 			if (sfv_off > maxoff) {
904 				VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
905 				releasef(sfv->sfv_fd);
906 				return (EINVAL);
907 			}
908 			if (sfv_off + sfv_len > maxoff) {
909 				sfv_len = (ssize_t)((offset_t)maxoff -
910 				    sfv_off);
911 			}
912 			/* Find the native blocksize to transfer data */
913 			size = MIN(vp->v_vfsp->vfs_bsize,
914 			    readvp->v_vfsp->vfs_bsize);
915 			size = sfv_len < size ? sfv_len : size;
916 
917 			if (vp->v_type != VSOCK) {
918 				segmapit = 0;
919 				buf = kmem_alloc(size, KM_NOSLEEP);
920 				if (buf == NULL) {
921 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
922 					    NULL);
923 					releasef(sfv->sfv_fd);
924 					return (ENOMEM);
925 				}
926 			} else {
927 				uint_t	copyflag;
928 
929 				copyflag = stp != NULL ? stp->sd_copyflag :
930 				    so->so_proto_props.sopp_zcopyflag;
931 				/*
932 				 * For sockets acting as an SSL proxy, we
933 				 * need to adjust the size to the maximum
934 				 * SSL record size set in the stream head.
935 				 */
936 				if (!SOCK_IS_NONSTR(so) &&
937 				    _SOTOTPI(so)->sti_kssl_ctx != NULL)
938 					size = MIN(size, maxblk);
939 
940 				if (vn_has_flocks(readvp) ||
941 				    readvp->v_flag & VNOMAP ||
942 				    copyflag & STZCVMUNSAFE) {
943 					segmapit = 0;
944 				} else if (copyflag & STZCVMSAFE) {
945 					segmapit = 1;
946 				} else {
947 					int on = 1;
948 					if (socket_setsockopt(VTOSO(vp),
949 					    SOL_SOCKET, SO_SND_COPYAVOID,
950 					    &on, sizeof (on), CRED()) == 0)
951 					segmapit = 1;
952 				}
953 			}
954 
955 			if (segmapit) {
956 				boolean_t nowait;
957 
958 				nowait = (sfv->sfv_flag & SFV_NOWAIT) != 0;
959 				error = snf_segmap(fp, readvp, sfv_off,
960 				    (u_offset_t)sfv_len, (ssize_t *)&cnt,
961 				    nowait);
962 				releasef(sfv->sfv_fd);
963 				*count += cnt;
964 				if (error)
965 					return (error);
966 				sfv++;
967 				continue;
968 			}
969 
970 			while (sfv_len > 0) {
971 				size_t	iov_len;
972 
973 				iov_len = MIN(size, sfv_len);
974 
975 				if (vp->v_type == VSOCK) {
976 					dmp = allocb(iov_len + extra, BPRI_HI);
977 					if (dmp == NULL) {
978 						VOP_RWUNLOCK(readvp,
979 						    V_WRITELOCK_FALSE, NULL);
980 						releasef(sfv->sfv_fd);
981 						return (ENOMEM);
982 					}
983 					dmp->b_wptr = dmp->b_rptr =
984 					    dmp->b_rptr + wroff;
985 					ptr = (caddr_t)dmp->b_rptr;
986 				} else {
987 					ptr = buf;
988 				}
989 
990 				aiov.iov_base = ptr;
991 				aiov.iov_len = iov_len;
992 				auio.uio_loffset = sfv_off;
993 				auio.uio_iov = &aiov;
994 				auio.uio_iovcnt = 1;
995 				auio.uio_resid = iov_len;
996 				auio.uio_segflg = UIO_SYSSPACE;
997 				auio.uio_llimit = MAXOFFSET_T;
998 				auio.uio_fmode = ffp->f_flag;
999 				ioflag = auio.uio_fmode &
1000 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
1001 
1002 				/*
1003 				 * If read sync is not asked for,
1004 				 * filter sync flags
1005 				 */
1006 				if ((ioflag & FRSYNC) == 0)
1007 					ioflag &= ~(FSYNC|FDSYNC);
1008 				error = VOP_READ(readvp, &auio, ioflag,
1009 				    fp->f_cred, NULL);
1010 				if (error != 0) {
1011 					/*
1012 					 * If we were reading a pipe (currently
1013 					 * not implemented), we may now lose
1014 					 * data.
1015 					 */
1016 					if (vp->v_type == VSOCK)
1017 						freeb(dmp);
1018 					else
1019 						kmem_free(buf, size);
1020 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
1021 					    NULL);
1022 					releasef(sfv->sfv_fd);
1023 					return (error);
1024 				}
1025 
1026 				/*
1027 				 * Check how much data was really read.
1028 				 * Decrement the 'len' and increment the
1029 				 * 'off' appropriately.
1030 				 */
1031 				cnt = iov_len - auio.uio_resid;
1032 				if (cnt == 0) {
1033 					if (vp->v_type == VSOCK)
1034 						freeb(dmp);
1035 					else
1036 						kmem_free(buf, size);
1037 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
1038 					    NULL);
1039 					releasef(sfv->sfv_fd);
1040 					return (EINVAL);
1041 				}
1042 				sfv_len -= cnt;
1043 				sfv_off += cnt;
1044 
1045 				if (vp->v_type == VSOCK) {
1046 					dmp->b_wptr = dmp->b_rptr + cnt;
1047 
1048 					error = socket_sendmblk(VTOSO(vp),
1049 					    &msg, fflag, CRED(), &dmp);
1050 
1051 					if (error != 0) {
1052 						if (dmp != NULL)
1053 							freeb(dmp);
1054 						VOP_RWUNLOCK(readvp,
1055 						    V_WRITELOCK_FALSE, NULL);
1056 						releasef(sfv->sfv_fd);
1057 						return (error);
1058 					}
1059 
1060 					ttolwp(curthread)->lwp_ru.ioch +=
1061 					    (ulong_t)cnt;
1062 					*count += cnt;
1063 				} else {
1064 
1065 					aiov.iov_base = ptr;
1066 					aiov.iov_len = cnt;
1067 					auio.uio_loffset = *fileoff;
1068 					auio.uio_resid = cnt;
1069 					auio.uio_iov = &aiov;
1070 					auio.uio_iovcnt = 1;
1071 					auio.uio_segflg = UIO_SYSSPACE;
1072 					auio.uio_llimit = curproc->p_fsz_ctl;
1073 					auio.uio_fmode = fflag;
1074 					ioflag = auio.uio_fmode &
1075 					    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
1076 					error = VOP_WRITE(vp, &auio, ioflag,
1077 					    fp->f_cred, NULL);
1078 
1079 					/*
1080 					 * Check how much data was written.
1081 					 * Increment the 'len' and decrement the
1082 					 * 'off' if all the data was not
1083 					 * written.
1084 					 */
1085 					cnt -= auio.uio_resid;
1086 					sfv_len += auio.uio_resid;
1087 					sfv_off -= auio.uio_resid;
1088 					ttolwp(curthread)->lwp_ru.ioch +=
1089 					    (ulong_t)cnt;
1090 					*fileoff += cnt;
1091 					*count += cnt;
1092 					if (error != 0) {
1093 						kmem_free(buf, size);
1094 						VOP_RWUNLOCK(readvp,
1095 						    V_WRITELOCK_FALSE, NULL);
1096 						releasef(sfv->sfv_fd);
1097 						return (error);
1098 					}
1099 				}
1100 			}
1101 			if (buf) {
1102 				kmem_free(buf, size);
1103 				buf = NULL;
1104 			}
1105 			VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
1106 			releasef(sfv->sfv_fd);
1107 		}
1108 		sfv++;
1109 	}
1110 	return (0);
1111 }
1112 
1113 ssize_t
1114 sendfilev(int opcode, int fildes, const struct sendfilevec *vec, int sfvcnt,
1115     size_t *xferred)
1116 {
1117 	int error = 0;
1118 	int first_vector_error = 0;
1119 	file_t *fp;
1120 	struct vnode *vp;
1121 	struct sonode *so;
1122 	u_offset_t fileoff;
1123 	int copy_cnt;
1124 	const struct sendfilevec *copy_vec;
1125 	struct sendfilevec sfv[SEND_MAX_CHUNK];
1126 	ssize_t count = 0;
1127 #ifdef _SYSCALL32_IMPL
1128 	struct ksendfilevec32 sfv32[SEND_MAX_CHUNK];
1129 #endif
1130 	ssize_t total_size;
1131 	int i;
1132 	boolean_t is_sock = B_FALSE;
1133 	int maxblk = 0;
1134 
1135 	if (sfvcnt <= 0)
1136 		return (set_errno(EINVAL));
1137 
1138 	if ((fp = getf(fildes)) == NULL)
1139 		return (set_errno(EBADF));
1140 
1141 	if (((fp->f_flag) & FWRITE) == 0) {
1142 		error = EBADF;
1143 		goto err;
1144 	}
1145 
1146 	fileoff = fp->f_offset;
1147 	vp = fp->f_vnode;
1148 
1149 	switch (vp->v_type) {
1150 	case VSOCK:
1151 		so = VTOSO(vp);
1152 		is_sock = B_TRUE;
1153 		if (SOCK_IS_NONSTR(so)) {
1154 			maxblk = so->so_proto_props.sopp_maxblk;
1155 		} else {
1156 			maxblk = (int)vp->v_stream->sd_maxblk;
1157 		}
1158 		break;
1159 	case VREG:
1160 		break;
1161 	default:
1162 		error = EINVAL;
1163 		goto err;
1164 	}
1165 
1166 	switch (opcode) {
1167 	case SENDFILEV :
1168 		break;
1169 #if defined(_SYSCALL32_IMPL) || defined(_ILP32)
1170 	case SENDFILEV64 :
1171 		return (sendvec64(fp, (struct ksendfilevec64 *)vec, sfvcnt,
1172 		    (size32_t *)xferred, fildes));
1173 #endif
1174 	default :
1175 		error = ENOSYS;
1176 		break;
1177 	}
1178 
1179 	(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
1180 	copy_vec = vec;
1181 
1182 	do {
1183 		total_size = 0;
1184 		copy_cnt = MIN(sfvcnt, SEND_MAX_CHUNK);
1185 #ifdef _SYSCALL32_IMPL
1186 		/* 32-bit callers need to have their iovec expanded. */
1187 		if (get_udatamodel() == DATAMODEL_ILP32) {
1188 			if (copyin(copy_vec, sfv32,
1189 			    copy_cnt * sizeof (ksendfilevec32_t))) {
1190 				error = EFAULT;
1191 				break;
1192 			}
1193 
1194 			for (i = 0; i < copy_cnt; i++) {
1195 				sfv[i].sfv_fd = sfv32[i].sfv_fd;
1196 				sfv[i].sfv_off =
1197 				    (off_t)(uint32_t)sfv32[i].sfv_off;
1198 				sfv[i].sfv_len = (size_t)sfv32[i].sfv_len;
1199 				total_size += sfv[i].sfv_len;
1200 				sfv[i].sfv_flag = sfv32[i].sfv_flag;
1201 				/*
1202 				 * Individual elements of the vector must not
1203 				 * wrap or overflow, as later math is signed.
1204 				 * Equally total_size needs to be checked after
1205 				 * each vector is added in, to be sure that
1206 				 * rogue values haven't overflowed the counter.
1207 				 */
1208 				if (((ssize32_t)sfv[i].sfv_len < 0) ||
1209 				    ((ssize32_t)total_size < 0)) {
1210 					/*
1211 					 * Truncate the vector to send data
1212 					 * described by elements before the
1213 					 * error.
1214 					 */
1215 					copy_cnt = i;
1216 					first_vector_error = EINVAL;
1217 					/* total_size can't be trusted */
1218 					if ((ssize32_t)total_size < 0)
1219 						error = EINVAL;
1220 					break;
1221 				}
1222 			}
1223 			/* Nothing to do, process errors */
1224 			if (copy_cnt == 0)
1225 				break;
1226 
1227 		} else {
1228 #endif
1229 			if (copyin(copy_vec, sfv,
1230 			    copy_cnt * sizeof (sendfilevec_t))) {
1231 				error = EFAULT;
1232 				break;
1233 			}
1234 
1235 			for (i = 0; i < copy_cnt; i++) {
1236 				total_size += sfv[i].sfv_len;
1237 				/*
1238 				 * Individual elements of the vector must not
1239 				 * wrap or overflow, as later math is signed.
1240 				 * Equally total_size needs to be checked after
1241 				 * each vector is added in, to be sure that
1242 				 * rogue values haven't overflowed the counter.
1243 				 */
1244 				if (((ssize_t)sfv[i].sfv_len < 0) ||
1245 				    (total_size < 0)) {
1246 					/*
1247 					 * Truncate the vector to send data
1248 					 * described by elements before the
1249 					 * error.
1250 					 */
1251 					copy_cnt = i;
1252 					first_vector_error = EINVAL;
1253 					/* total_size can't be trusted */
1254 					if (total_size < 0)
1255 						error = EINVAL;
1256 					break;
1257 				}
1258 			}
1259 			/* Nothing to do, process errors */
1260 			if (copy_cnt == 0)
1261 				break;
1262 #ifdef _SYSCALL32_IMPL
1263 		}
1264 #endif
1265 
1266 		/*
1267 		 * The task between deciding to use sendvec_small_chunk
1268 		 * and sendvec_chunk is dependant on multiple things:
1269 		 *
1270 		 * i) latency is important for smaller files. So if the
1271 		 * data is smaller than 'tcp_slow_start_initial' times
1272 		 * maxblk, then use sendvec_small_chunk which creates
1273 		 * maxblk size mblks and chains them together and sends
1274 		 * them to TCP in one shot. It also leaves 'wroff' size
1275 		 * space for the headers in each mblk.
1276 		 *
1277 		 * ii) for total size bigger than 'tcp_slow_start_initial'
1278 		 * time maxblk, its probably real file data which is
1279 		 * dominating. So its better to use sendvec_chunk because
1280 		 * performance goes to dog if we don't do pagesize reads.
1281 		 * sendvec_chunk will do pagesize reads and write them
1282 		 * in pagesize mblks to TCP.
1283 		 *
1284 		 * Side Notes: A write to file has not been optimized.
1285 		 * Future zero copy code will plugin into sendvec_chunk
1286 		 * only because doing zero copy for files smaller then
1287 		 * pagesize is useless.
1288 		 *
1289 		 * Note, if socket has NL7C enabled then call NL7C's
1290 		 * senfilev() function to consume the sfv[].
1291 		 */
1292 		if (is_sock) {
1293 			if (!SOCK_IS_NONSTR(so) &&
1294 			    _SOTOTPI(so)->sti_nl7c_flags != 0) {
1295 				error = nl7c_sendfilev(so, &fileoff,
1296 				    sfv, copy_cnt, &count);
1297 			} else if ((total_size <= (4 * maxblk)) &&
1298 			    error == 0) {
1299 				error = sendvec_small_chunk(fp,
1300 				    &fileoff, sfv, copy_cnt,
1301 				    total_size, maxblk, &count);
1302 			} else {
1303 				error = sendvec_chunk(fp, &fileoff,
1304 				    sfv, copy_cnt, &count);
1305 			}
1306 		} else {
1307 			ASSERT(vp->v_type == VREG);
1308 			error = sendvec_chunk(fp, &fileoff, sfv, copy_cnt,
1309 			    &count);
1310 		}
1311 
1312 
1313 #ifdef _SYSCALL32_IMPL
1314 	if (get_udatamodel() == DATAMODEL_ILP32)
1315 		copy_vec = (const struct sendfilevec *)((char *)copy_vec +
1316 		    (copy_cnt * sizeof (ksendfilevec32_t)));
1317 	else
1318 #endif
1319 		copy_vec += copy_cnt;
1320 		sfvcnt -= copy_cnt;
1321 
1322 	/* Process all vector members up to first error */
1323 	} while ((sfvcnt > 0) && first_vector_error == 0 && error == 0);
1324 
1325 	if (vp->v_type == VREG)
1326 		fp->f_offset += count;
1327 
1328 	VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
1329 
1330 #ifdef _SYSCALL32_IMPL
1331 	if (get_udatamodel() == DATAMODEL_ILP32) {
1332 		ssize32_t count32 = (ssize32_t)count;
1333 		if (copyout(&count32, xferred, sizeof (count32)))
1334 			error = EFAULT;
1335 		releasef(fildes);
1336 		if (error != 0)
1337 			return (set_errno(error));
1338 		if (first_vector_error != 0)
1339 			return (set_errno(first_vector_error));
1340 		return (count32);
1341 	}
1342 #endif
1343 	if (copyout(&count, xferred, sizeof (count)))
1344 		error = EFAULT;
1345 	releasef(fildes);
1346 	if (error != 0)
1347 		return (set_errno(error));
1348 	if (first_vector_error != 0)
1349 		return (set_errno(first_vector_error));
1350 	return (count);
1351 err:
1352 	ASSERT(error != 0);
1353 	releasef(fildes);
1354 	return (set_errno(error));
1355 }
1356