xref: /titanic_50/usr/src/uts/common/syscall/sendfile.c (revision a307732568c3d861c38b0342ae32434226d10e94)
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 (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/t_lock.h>
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/buf.h>
31 #include <sys/conf.h>
32 #include <sys/cred.h>
33 #include <sys/kmem.h>
34 #include <sys/sysmacros.h>
35 #include <sys/vfs.h>
36 #include <sys/vnode.h>
37 #include <sys/debug.h>
38 #include <sys/errno.h>
39 #include <sys/time.h>
40 #include <sys/file.h>
41 #include <sys/open.h>
42 #include <sys/user.h>
43 #include <sys/termios.h>
44 #include <sys/stream.h>
45 #include <sys/strsubr.h>
46 #include <sys/sunddi.h>
47 #include <sys/esunddi.h>
48 #include <sys/flock.h>
49 #include <sys/modctl.h>
50 #include <sys/cmn_err.h>
51 #include <sys/vmsystm.h>
52 
53 #include <sys/socket.h>
54 #include <sys/socketvar.h>
55 #include <fs/sockfs/sockcommon.h>
56 #include <fs/sockfs/socktpi.h>
57 
58 #include <netinet/in.h>
59 #include <sys/sendfile.h>
60 #include <sys/un.h>
61 #include <sys/tihdr.h>
62 #include <sys/atomic.h>
63 
64 #include <inet/common.h>
65 #include <inet/ip.h>
66 #include <inet/ip6.h>
67 #include <inet/tcp.h>
68 
69 extern int sosendfile64(file_t *, file_t *, const struct ksendfilevec64 *,
70 		ssize32_t *);
71 extern int nl7c_sendfilev(struct sonode *, u_offset_t *, struct sendfilevec *,
72 		int, ssize_t *);
73 extern int snf_segmap(file_t *, vnode_t *, u_offset_t, u_offset_t, ssize_t *,
74 		boolean_t);
75 extern sotpi_info_t *sotpi_sototpi(struct sonode *);
76 
77 #define	SEND_MAX_CHUNK	16
78 
79 #if defined(_SYSCALL32_IMPL) || defined(_ILP32)
80 /*
81  * 64 bit offsets for 32 bit applications only running either on
82  * 64 bit kernel or 32 bit kernel. For 32 bit apps, we can't transfer
83  * more than 2GB of data.
84  */
85 int
86 sendvec_chunk64(file_t *fp, u_offset_t *fileoff, struct ksendfilevec64 *sfv,
87     int copy_cnt, ssize32_t *count)
88 {
89 	struct vnode *vp;
90 	ushort_t fflag;
91 	int ioflag;
92 	size32_t cnt;
93 	ssize32_t sfv_len;
94 	ssize32_t tmpcount;
95 	u_offset_t sfv_off;
96 	struct uio auio;
97 	struct iovec aiov;
98 	int i, error;
99 
100 	fflag = fp->f_flag;
101 	vp = fp->f_vnode;
102 	for (i = 0; i < copy_cnt; i++) {
103 
104 		if (ISSIG(curthread, JUSTLOOKING))
105 			return (EINTR);
106 
107 		/*
108 		 * Do similar checks as "write" as we are writing
109 		 * sfv_len bytes into "vp".
110 		 */
111 		sfv_len = (ssize32_t)sfv->sfv_len;
112 
113 		if (sfv_len == 0) {
114 			sfv++;
115 			continue;
116 		}
117 
118 		if (sfv_len < 0)
119 			return (EINVAL);
120 
121 		if (vp->v_type == VREG) {
122 			if (*fileoff >= curproc->p_fsz_ctl) {
123 				mutex_enter(&curproc->p_lock);
124 				(void) rctl_action(
125 				    rctlproc_legacy[RLIMIT_FSIZE],
126 				    curproc->p_rctls, curproc, RCA_SAFE);
127 				mutex_exit(&curproc->p_lock);
128 				return (EFBIG);
129 			}
130 
131 			if (*fileoff >= OFFSET_MAX(fp))
132 				return (EFBIG);
133 
134 			if (*fileoff + sfv_len > OFFSET_MAX(fp))
135 				return (EINVAL);
136 		}
137 
138 		tmpcount = *count + sfv_len;
139 		if (tmpcount < 0)
140 			return (EINVAL);
141 
142 		sfv_off = sfv->sfv_off;
143 
144 		auio.uio_extflg = UIO_COPY_DEFAULT;
145 		if (sfv->sfv_fd == SFV_FD_SELF) {
146 			aiov.iov_len = sfv_len;
147 			aiov.iov_base = (caddr_t)(uintptr_t)sfv_off;
148 			auio.uio_loffset = *fileoff;
149 			auio.uio_iovcnt = 1;
150 			auio.uio_resid = sfv_len;
151 			auio.uio_iov = &aiov;
152 			auio.uio_segflg = UIO_USERSPACE;
153 			auio.uio_llimit = curproc->p_fsz_ctl;
154 			auio.uio_fmode = fflag;
155 			ioflag = auio.uio_fmode & (FAPPEND|FSYNC|FDSYNC|FRSYNC);
156 			while (sfv_len > 0) {
157 				error = VOP_WRITE(vp, &auio, ioflag,
158 				    fp->f_cred, NULL);
159 				cnt = sfv_len - auio.uio_resid;
160 				sfv_len -= cnt;
161 				ttolwp(curthread)->lwp_ru.ioch += (ulong_t)cnt;
162 				if (vp->v_type == VREG)
163 					*fileoff += cnt;
164 				*count += cnt;
165 				if (error != 0)
166 					return (error);
167 			}
168 		} else {
169 			file_t	*ffp;
170 			vnode_t	*readvp;
171 			size_t	size;
172 			caddr_t	ptr;
173 
174 			if ((ffp = getf(sfv->sfv_fd)) == NULL)
175 				return (EBADF);
176 
177 			if ((ffp->f_flag & FREAD) == 0) {
178 				releasef(sfv->sfv_fd);
179 				return (EBADF);
180 			}
181 
182 			readvp = ffp->f_vnode;
183 			if (readvp->v_type != VREG) {
184 				releasef(sfv->sfv_fd);
185 				return (EINVAL);
186 			}
187 
188 			/*
189 			 * No point reading and writing to same vp,
190 			 * as long as both are regular files. readvp is not
191 			 * locked; but since we got it from an open file the
192 			 * contents will be valid during the time of access.
193 			 */
194 			if (vn_compare(vp, readvp)) {
195 				releasef(sfv->sfv_fd);
196 				return (EINVAL);
197 			}
198 
199 			/*
200 			 * Optimize the regular file over
201 			 * the socket case.
202 			 */
203 			if (vp->v_type == VSOCK) {
204 				error = sosendfile64(fp, ffp, sfv,
205 				    (ssize32_t *)&cnt);
206 				*count += cnt;
207 				if (error)
208 					return (error);
209 				sfv++;
210 				continue;
211 			}
212 
213 			/*
214 			 * Note: we assume readvp != vp. "vp" is already
215 			 * locked, and "readvp" must not be.
216 			 */
217 			if (readvp < vp) {
218 				VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
219 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
220 				    NULL);
221 				(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
222 			} else {
223 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
224 				    NULL);
225 			}
226 
227 			/*
228 			 * Same checks as in pread64.
229 			 */
230 			if (sfv_off > MAXOFFSET_T) {
231 				VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
232 				releasef(sfv->sfv_fd);
233 				return (EINVAL);
234 			}
235 
236 			if (sfv_off + sfv_len > MAXOFFSET_T)
237 				sfv_len = (ssize32_t)(MAXOFFSET_T - sfv_off);
238 
239 			/* Find the native blocksize to transfer data */
240 			size = MIN(vp->v_vfsp->vfs_bsize,
241 			    readvp->v_vfsp->vfs_bsize);
242 			size = sfv_len < size ? sfv_len : size;
243 			ptr = kmem_alloc(size, KM_NOSLEEP);
244 			if (ptr == NULL) {
245 				VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
246 				releasef(sfv->sfv_fd);
247 				return (ENOMEM);
248 			}
249 
250 			while (sfv_len > 0) {
251 				size_t	iov_len;
252 
253 				iov_len = MIN(size, sfv_len);
254 				aiov.iov_base = ptr;
255 				aiov.iov_len = iov_len;
256 				auio.uio_loffset = sfv_off;
257 				auio.uio_iov = &aiov;
258 				auio.uio_iovcnt = 1;
259 				auio.uio_resid = iov_len;
260 				auio.uio_segflg = UIO_SYSSPACE;
261 				auio.uio_llimit = MAXOFFSET_T;
262 				auio.uio_fmode = ffp->f_flag;
263 				ioflag = auio.uio_fmode &
264 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
265 
266 				/*
267 				 * If read sync is not asked for,
268 				 * filter sync flags
269 				 */
270 				if ((ioflag & FRSYNC) == 0)
271 					ioflag &= ~(FSYNC|FDSYNC);
272 				error = VOP_READ(readvp, &auio, ioflag,
273 				    fp->f_cred, NULL);
274 				if (error) {
275 					kmem_free(ptr, size);
276 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
277 					    NULL);
278 					releasef(sfv->sfv_fd);
279 					return (error);
280 				}
281 
282 				/*
283 				 * Check how must data was really read.
284 				 * Decrement the 'len' and increment the
285 				 * 'off' appropriately.
286 				 */
287 				cnt = iov_len - auio.uio_resid;
288 				if (cnt == 0) {
289 					/*
290 					 * If we were reading a pipe (currently
291 					 * not implemented), we may now lose
292 					 * data.
293 					 */
294 					kmem_free(ptr, size);
295 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
296 					    NULL);
297 					releasef(sfv->sfv_fd);
298 					return (EINVAL);
299 				}
300 				sfv_len -= cnt;
301 				sfv_off += cnt;
302 
303 				aiov.iov_base = ptr;
304 				aiov.iov_len = cnt;
305 				auio.uio_loffset = *fileoff;
306 				auio.uio_iov = &aiov;
307 				auio.uio_iovcnt = 1;
308 				auio.uio_resid = cnt;
309 				auio.uio_segflg = UIO_SYSSPACE;
310 				auio.uio_llimit = curproc->p_fsz_ctl;
311 				auio.uio_fmode = fflag;
312 				ioflag = auio.uio_fmode &
313 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
314 				error = VOP_WRITE(vp, &auio, ioflag,
315 				    fp->f_cred, NULL);
316 
317 				/*
318 				 * Check how much data was written. Increment
319 				 * the 'len' and decrement the 'off' if all
320 				 * the data was not written.
321 				 */
322 				cnt -= auio.uio_resid;
323 				sfv_len += auio.uio_resid;
324 				sfv_off -= auio.uio_resid;
325 				ttolwp(curthread)->lwp_ru.ioch += (ulong_t)cnt;
326 				if (vp->v_type == VREG)
327 					*fileoff += cnt;
328 				*count += cnt;
329 				if (error != 0) {
330 					kmem_free(ptr, size);
331 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
332 					    NULL);
333 					releasef(sfv->sfv_fd);
334 					return (error);
335 				}
336 			}
337 			VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
338 			releasef(sfv->sfv_fd);
339 			kmem_free(ptr, size);
340 		}
341 		sfv++;
342 	}
343 	return (0);
344 }
345 
346 ssize32_t
347 sendvec64(file_t *fp, const struct ksendfilevec64 *vec, int sfvcnt,
348 	size32_t *xferred, int fildes)
349 {
350 	u_offset_t		fileoff;
351 	int			copy_cnt;
352 	const struct ksendfilevec64 *copy_vec;
353 	struct ksendfilevec64 sfv[SEND_MAX_CHUNK];
354 	struct vnode *vp;
355 	int error;
356 	ssize32_t count = 0;
357 
358 	vp = fp->f_vnode;
359 	(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
360 
361 	copy_vec = vec;
362 	fileoff = fp->f_offset;
363 
364 	do {
365 		copy_cnt = MIN(sfvcnt, SEND_MAX_CHUNK);
366 		if (copyin(copy_vec, sfv, copy_cnt *
367 		    sizeof (struct ksendfilevec64))) {
368 			error = EFAULT;
369 			break;
370 		}
371 
372 		error = sendvec_chunk64(fp, &fileoff, sfv, copy_cnt, &count);
373 		if (error != 0)
374 			break;
375 
376 		copy_vec += copy_cnt;
377 		sfvcnt -= copy_cnt;
378 	} while (sfvcnt > 0);
379 
380 	if (vp->v_type == VREG)
381 		fp->f_offset += count;
382 
383 	VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
384 	if (copyout(&count, xferred, sizeof (count)))
385 		error = EFAULT;
386 	releasef(fildes);
387 	if (error != 0)
388 		return (set_errno(error));
389 	return (count);
390 }
391 #endif
392 
393 int
394 sendvec_small_chunk(file_t *fp, u_offset_t *fileoff, struct sendfilevec *sfv,
395     int copy_cnt, ssize_t total_size, int maxblk, ssize_t *count)
396 {
397 	struct vnode *vp;
398 	struct uio auio;
399 	struct iovec aiov;
400 	ushort_t fflag;
401 	int ioflag;
402 	int i, error;
403 	size_t cnt;
404 	ssize_t sfv_len;
405 	u_offset_t sfv_off;
406 #ifdef _SYSCALL32_IMPL
407 	model_t model = get_udatamodel();
408 	u_offset_t maxoff = (model == DATAMODEL_ILP32) ?
409 	    MAXOFF32_T : MAXOFFSET_T;
410 #else
411 	const u_offset_t maxoff = MAXOFF32_T;
412 #endif
413 	mblk_t *dmp = NULL;
414 	int wroff;
415 	int buf_left = 0;
416 	size_t	iov_len;
417 	mblk_t  *head, *tmp;
418 	size_t  size = total_size;
419 	size_t  extra;
420 	int tail_len;
421 	struct nmsghdr msg;
422 
423 	fflag = fp->f_flag;
424 	vp = fp->f_vnode;
425 
426 	ASSERT(vp->v_type == VSOCK);
427 	ASSERT(maxblk > 0);
428 
429 	/* If nothing to send, return */
430 	if (total_size == 0)
431 		return (0);
432 
433 	if (vp->v_stream != NULL) {
434 		wroff = (int)vp->v_stream->sd_wroff;
435 		tail_len = (int)vp->v_stream->sd_tail;
436 	} else {
437 		struct sonode *so;
438 
439 		so = VTOSO(vp);
440 		wroff = so->so_proto_props.sopp_wroff;
441 		tail_len = so->so_proto_props.sopp_tail;
442 	}
443 
444 	extra = wroff + tail_len;
445 
446 	buf_left = MIN(total_size, maxblk);
447 	head = dmp = allocb(buf_left + extra, BPRI_HI);
448 	if (head == NULL)
449 		return (ENOMEM);
450 	head->b_wptr = head->b_rptr = head->b_rptr + wroff;
451 	bzero(&msg, sizeof (msg));
452 
453 	auio.uio_extflg = UIO_COPY_DEFAULT;
454 	for (i = 0; i < copy_cnt; i++) {
455 		if (ISSIG(curthread, JUSTLOOKING)) {
456 			freemsg(head);
457 			return (EINTR);
458 		}
459 
460 		/*
461 		 * Do similar checks as "write" as we are writing
462 		 * sfv_len bytes into "vp".
463 		 */
464 		sfv_len = (ssize_t)sfv->sfv_len;
465 
466 		if (sfv_len == 0) {
467 			sfv++;
468 			continue;
469 		}
470 
471 		/* Check for overflow */
472 #ifdef _SYSCALL32_IMPL
473 		if (model == DATAMODEL_ILP32) {
474 			if (((ssize32_t)(*count + sfv_len)) < 0) {
475 				freemsg(head);
476 				return (EINVAL);
477 			}
478 		} else
479 #endif
480 		if ((*count + sfv_len) < 0) {
481 			freemsg(head);
482 			return (EINVAL);
483 		}
484 
485 		sfv_off = (u_offset_t)(ulong_t)sfv->sfv_off;
486 
487 		if (sfv->sfv_fd == SFV_FD_SELF) {
488 			while (sfv_len > 0) {
489 				if (buf_left == 0) {
490 					tmp = dmp;
491 					buf_left = MIN(total_size, maxblk);
492 					iov_len = MIN(buf_left, sfv_len);
493 					dmp = allocb(buf_left + extra, BPRI_HI);
494 					if (dmp == NULL) {
495 						freemsg(head);
496 						return (ENOMEM);
497 					}
498 					dmp->b_wptr = dmp->b_rptr =
499 					    dmp->b_rptr + wroff;
500 					tmp->b_cont = dmp;
501 				} else {
502 					iov_len = MIN(buf_left, sfv_len);
503 				}
504 
505 				aiov.iov_len = iov_len;
506 				aiov.iov_base = (caddr_t)(uintptr_t)sfv_off;
507 				auio.uio_loffset = *fileoff;
508 				auio.uio_iovcnt = 1;
509 				auio.uio_resid = iov_len;
510 				auio.uio_iov = &aiov;
511 				auio.uio_segflg = UIO_USERSPACE;
512 				auio.uio_llimit = curproc->p_fsz_ctl;
513 				auio.uio_fmode = fflag;
514 
515 				buf_left -= iov_len;
516 				total_size -= iov_len;
517 				sfv_len -= iov_len;
518 				sfv_off += iov_len;
519 
520 				error = uiomove((caddr_t)dmp->b_wptr,
521 				    iov_len, UIO_WRITE, &auio);
522 				if (error != 0) {
523 					freemsg(head);
524 					return (error);
525 				}
526 				dmp->b_wptr += iov_len;
527 			}
528 		} else {
529 			file_t	*ffp;
530 			vnode_t	*readvp;
531 
532 			if ((ffp = getf(sfv->sfv_fd)) == NULL) {
533 				freemsg(head);
534 				return (EBADF);
535 			}
536 
537 			if ((ffp->f_flag & FREAD) == 0) {
538 				releasef(sfv->sfv_fd);
539 				freemsg(head);
540 				return (EACCES);
541 			}
542 
543 			readvp = ffp->f_vnode;
544 			if (readvp->v_type != VREG) {
545 				releasef(sfv->sfv_fd);
546 				freemsg(head);
547 				return (EINVAL);
548 			}
549 
550 			/*
551 			 * No point reading and writing to same vp,
552 			 * as long as both are regular files. readvp is not
553 			 * locked; but since we got it from an open file the
554 			 * contents will be valid during the time of access.
555 			 */
556 
557 			if (vn_compare(vp, readvp)) {
558 				releasef(sfv->sfv_fd);
559 				freemsg(head);
560 				return (EINVAL);
561 			}
562 
563 			/*
564 			 * Note: we assume readvp != vp. "vp" is already
565 			 * locked, and "readvp" must not be.
566 			 */
567 
568 			if (readvp < vp) {
569 				VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
570 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
571 				    NULL);
572 				(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
573 			} else {
574 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
575 				    NULL);
576 			}
577 
578 			/* Same checks as in pread */
579 			if (sfv_off > maxoff) {
580 				VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
581 				releasef(sfv->sfv_fd);
582 				freemsg(head);
583 				return (EINVAL);
584 			}
585 			if (sfv_off + sfv_len > maxoff) {
586 				total_size -= (sfv_off + sfv_len - maxoff);
587 				sfv_len = (ssize_t)((offset_t)maxoff -
588 				    sfv_off);
589 			}
590 
591 			while (sfv_len > 0) {
592 				if (buf_left == 0) {
593 					tmp = dmp;
594 					buf_left = MIN(total_size, maxblk);
595 					iov_len = MIN(buf_left, sfv_len);
596 					dmp = allocb(buf_left + extra, BPRI_HI);
597 					if (dmp == NULL) {
598 						VOP_RWUNLOCK(readvp,
599 						    V_WRITELOCK_FALSE, NULL);
600 						releasef(sfv->sfv_fd);
601 						freemsg(head);
602 						return (ENOMEM);
603 					}
604 					dmp->b_wptr = dmp->b_rptr =
605 					    dmp->b_rptr + wroff;
606 					tmp->b_cont = dmp;
607 				} else {
608 					iov_len = MIN(buf_left, sfv_len);
609 				}
610 				aiov.iov_base = (caddr_t)dmp->b_wptr;
611 				aiov.iov_len = iov_len;
612 				auio.uio_loffset = sfv_off;
613 				auio.uio_iov = &aiov;
614 				auio.uio_iovcnt = 1;
615 				auio.uio_resid = iov_len;
616 				auio.uio_segflg = UIO_SYSSPACE;
617 				auio.uio_llimit = MAXOFFSET_T;
618 				auio.uio_fmode = ffp->f_flag;
619 				ioflag = auio.uio_fmode &
620 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
621 
622 				/*
623 				 * If read sync is not asked for,
624 				 * filter sync flags
625 				 */
626 				if ((ioflag & FRSYNC) == 0)
627 					ioflag &= ~(FSYNC|FDSYNC);
628 				error = VOP_READ(readvp, &auio, ioflag,
629 				    fp->f_cred, NULL);
630 				if (error != 0) {
631 					/*
632 					 * If we were reading a pipe (currently
633 					 * not implemented), we may now loose
634 					 * data.
635 					 */
636 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
637 					    NULL);
638 					releasef(sfv->sfv_fd);
639 					freemsg(head);
640 					return (error);
641 				}
642 
643 				/*
644 				 * Check how much data was really read.
645 				 * Decrement the 'len' and increment the
646 				 * 'off' appropriately.
647 				 */
648 				cnt = iov_len - auio.uio_resid;
649 				if (cnt == 0) {
650 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
651 					    NULL);
652 					releasef(sfv->sfv_fd);
653 					freemsg(head);
654 					return (EINVAL);
655 				}
656 				sfv_len -= cnt;
657 				sfv_off += cnt;
658 				total_size -= cnt;
659 				buf_left -= cnt;
660 
661 				dmp->b_wptr += cnt;
662 			}
663 			VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
664 			releasef(sfv->sfv_fd);
665 		}
666 		sfv++;
667 	}
668 
669 	ASSERT(total_size == 0);
670 	error = socket_sendmblk(VTOSO(vp), &msg, fflag, CRED(), &head);
671 	if (error != 0) {
672 		if (head != NULL)
673 			freemsg(head);
674 		return (error);
675 	}
676 	ttolwp(curthread)->lwp_ru.ioch += (ulong_t)size;
677 	*count += size;
678 
679 	return (0);
680 }
681 
682 
683 int
684 sendvec_chunk(file_t *fp, u_offset_t *fileoff, struct sendfilevec *sfv,
685     int copy_cnt, ssize_t *count)
686 {
687 	struct vnode *vp;
688 	struct uio auio;
689 	struct iovec aiov;
690 	ushort_t fflag;
691 	int ioflag;
692 	int i, error;
693 	size_t cnt;
694 	ssize_t sfv_len;
695 	u_offset_t sfv_off;
696 #ifdef _SYSCALL32_IMPL
697 	model_t model = get_udatamodel();
698 	u_offset_t maxoff = (model == DATAMODEL_ILP32) ?
699 	    MAXOFF32_T : MAXOFFSET_T;
700 #else
701 	const u_offset_t maxoff = MAXOFF32_T;
702 #endif
703 	mblk_t	*dmp = NULL;
704 	char	*buf = NULL;
705 	size_t  extra;
706 	int maxblk, wroff, tail_len;
707 	struct sonode *so;
708 	stdata_t *stp;
709 	struct nmsghdr msg;
710 
711 	fflag = fp->f_flag;
712 	vp = fp->f_vnode;
713 
714 	if (vp->v_type == VSOCK) {
715 		so = VTOSO(vp);
716 		if (vp->v_stream != NULL) {
717 			stp = vp->v_stream;
718 			wroff = (int)stp->sd_wroff;
719 			tail_len = (int)stp->sd_tail;
720 			maxblk = (int)stp->sd_maxblk;
721 		} else {
722 			stp = NULL;
723 			wroff = so->so_proto_props.sopp_wroff;
724 			tail_len = so->so_proto_props.sopp_tail;
725 			maxblk = so->so_proto_props.sopp_maxblk;
726 		}
727 		extra = wroff + tail_len;
728 	}
729 
730 	bzero(&msg, sizeof (msg));
731 	auio.uio_extflg = UIO_COPY_DEFAULT;
732 	for (i = 0; i < copy_cnt; i++) {
733 		if (ISSIG(curthread, JUSTLOOKING))
734 			return (EINTR);
735 
736 		/*
737 		 * Do similar checks as "write" as we are writing
738 		 * sfv_len bytes into "vp".
739 		 */
740 		sfv_len = (ssize_t)sfv->sfv_len;
741 
742 		if (sfv_len == 0) {
743 			sfv++;
744 			continue;
745 		}
746 
747 		if (vp->v_type == VREG) {
748 			if (*fileoff >= curproc->p_fsz_ctl) {
749 				mutex_enter(&curproc->p_lock);
750 				(void) rctl_action(
751 				    rctlproc_legacy[RLIMIT_FSIZE],
752 				    curproc->p_rctls, curproc, RCA_SAFE);
753 				mutex_exit(&curproc->p_lock);
754 
755 				return (EFBIG);
756 			}
757 
758 			if (*fileoff >= maxoff)
759 				return (EFBIG);
760 
761 			if (*fileoff + sfv_len > maxoff)
762 				return (EINVAL);
763 		}
764 
765 		/* Check for overflow */
766 #ifdef _SYSCALL32_IMPL
767 		if (model == DATAMODEL_ILP32) {
768 			if (((ssize32_t)(*count + sfv_len)) < 0)
769 				return (EINVAL);
770 		} else
771 #endif
772 		if ((*count + sfv_len) < 0)
773 			return (EINVAL);
774 
775 		sfv_off = (u_offset_t)(ulong_t)sfv->sfv_off;
776 
777 		if (sfv->sfv_fd == SFV_FD_SELF) {
778 			if (vp->v_type == VSOCK) {
779 				while (sfv_len > 0) {
780 					size_t iov_len;
781 
782 					iov_len = sfv_len;
783 					/*
784 					 * Socket filters can limit the mblk
785 					 * size, so limit reads to maxblk if
786 					 * there are filters present.
787 					 */
788 					if (so->so_filter_active > 0 &&
789 					    maxblk != INFPSZ)
790 						iov_len = MIN(iov_len, maxblk);
791 
792 					aiov.iov_len = iov_len;
793 					aiov.iov_base =
794 					    (caddr_t)(uintptr_t)sfv_off;
795 
796 					auio.uio_iov = &aiov;
797 					auio.uio_iovcnt = 1;
798 					auio.uio_loffset = *fileoff;
799 					auio.uio_segflg = UIO_USERSPACE;
800 					auio.uio_fmode = fflag;
801 					auio.uio_llimit = curproc->p_fsz_ctl;
802 					auio.uio_resid = iov_len;
803 
804 					dmp = allocb(iov_len + extra, BPRI_HI);
805 					if (dmp == NULL)
806 						return (ENOMEM);
807 					dmp->b_wptr = dmp->b_rptr =
808 					    dmp->b_rptr + wroff;
809 					error = uiomove((caddr_t)dmp->b_wptr,
810 					    iov_len, UIO_WRITE, &auio);
811 					if (error != 0) {
812 						freeb(dmp);
813 						return (error);
814 					}
815 					dmp->b_wptr += iov_len;
816 					error = socket_sendmblk(VTOSO(vp),
817 					    &msg, fflag, CRED(), &dmp);
818 
819 					if (error != 0) {
820 						if (dmp != NULL)
821 							freeb(dmp);
822 						return (error);
823 					}
824 					ttolwp(curthread)->lwp_ru.ioch +=
825 					    (ulong_t)iov_len;
826 					*count += iov_len;
827 					sfv_len -= iov_len;
828 					sfv_off += iov_len;
829 				}
830 			} else {
831 				aiov.iov_len = sfv_len;
832 				aiov.iov_base = (caddr_t)(uintptr_t)sfv_off;
833 
834 				auio.uio_iov = &aiov;
835 				auio.uio_iovcnt = 1;
836 				auio.uio_loffset = *fileoff;
837 				auio.uio_segflg = UIO_USERSPACE;
838 				auio.uio_fmode = fflag;
839 				auio.uio_llimit = curproc->p_fsz_ctl;
840 				auio.uio_resid = sfv_len;
841 
842 				ioflag = auio.uio_fmode &
843 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
844 				while (sfv_len > 0) {
845 					error = VOP_WRITE(vp, &auio, ioflag,
846 					    fp->f_cred, NULL);
847 					cnt = sfv_len - auio.uio_resid;
848 					sfv_len -= cnt;
849 					ttolwp(curthread)->lwp_ru.ioch +=
850 					    (ulong_t)cnt;
851 					*fileoff += cnt;
852 					*count += cnt;
853 					if (error != 0)
854 						return (error);
855 				}
856 			}
857 		} else {
858 			int segmapit = 0;
859 			file_t	*ffp;
860 			vnode_t	*readvp;
861 			struct vnode *realvp;
862 			size_t	size;
863 			caddr_t	ptr;
864 
865 			if ((ffp = getf(sfv->sfv_fd)) == NULL)
866 				return (EBADF);
867 
868 			if ((ffp->f_flag & FREAD) == 0) {
869 				releasef(sfv->sfv_fd);
870 				return (EBADF);
871 			}
872 
873 			readvp = ffp->f_vnode;
874 			if (VOP_REALVP(readvp, &realvp, NULL) == 0)
875 				readvp = realvp;
876 			if (readvp->v_type != VREG) {
877 				releasef(sfv->sfv_fd);
878 				return (EINVAL);
879 			}
880 
881 			/*
882 			 * No point reading and writing to same vp,
883 			 * as long as both are regular files. readvp is not
884 			 * locked; but since we got it from an open file the
885 			 * contents will be valid during the time of access.
886 			 */
887 			if (vn_compare(vp, readvp)) {
888 				releasef(sfv->sfv_fd);
889 				return (EINVAL);
890 			}
891 
892 			/*
893 			 * Note: we assume readvp != vp. "vp" is already
894 			 * locked, and "readvp" must not be.
895 			 */
896 			if (readvp < vp) {
897 				VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
898 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
899 				    NULL);
900 				(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
901 			} else {
902 				(void) VOP_RWLOCK(readvp, V_WRITELOCK_FALSE,
903 				    NULL);
904 			}
905 
906 			/* Same checks as in pread */
907 			if (sfv_off > maxoff) {
908 				VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
909 				releasef(sfv->sfv_fd);
910 				return (EINVAL);
911 			}
912 			if (sfv_off + sfv_len > maxoff) {
913 				sfv_len = (ssize_t)((offset_t)maxoff -
914 				    sfv_off);
915 			}
916 			/* Find the native blocksize to transfer data */
917 			size = MIN(vp->v_vfsp->vfs_bsize,
918 			    readvp->v_vfsp->vfs_bsize);
919 			size = sfv_len < size ? sfv_len : size;
920 
921 			if (vp->v_type != VSOCK) {
922 				segmapit = 0;
923 				buf = kmem_alloc(size, KM_NOSLEEP);
924 				if (buf == NULL) {
925 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
926 					    NULL);
927 					releasef(sfv->sfv_fd);
928 					return (ENOMEM);
929 				}
930 			} else {
931 				uint_t	copyflag;
932 
933 				copyflag = stp != NULL ? stp->sd_copyflag :
934 				    so->so_proto_props.sopp_zcopyflag;
935 
936 				/*
937 				 * Socket filters can limit the mblk size,
938 				 * so limit reads to maxblk if there are
939 				 * filters present.
940 				 */
941 				if (so->so_filter_active > 0 &&
942 				    maxblk != INFPSZ)
943 					size = MIN(size, maxblk);
944 
945 				if (vn_has_flocks(readvp) ||
946 				    readvp->v_flag & VNOMAP ||
947 				    copyflag & STZCVMUNSAFE) {
948 					segmapit = 0;
949 				} else if (copyflag & STZCVMSAFE) {
950 					segmapit = 1;
951 				} else {
952 					int on = 1;
953 					if (socket_setsockopt(VTOSO(vp),
954 					    SOL_SOCKET, SO_SND_COPYAVOID,
955 					    &on, sizeof (on), CRED()) == 0)
956 					segmapit = 1;
957 				}
958 			}
959 
960 			if (segmapit) {
961 				boolean_t nowait;
962 
963 				nowait = (sfv->sfv_flag & SFV_NOWAIT) != 0;
964 				error = snf_segmap(fp, readvp, sfv_off,
965 				    (u_offset_t)sfv_len, (ssize_t *)&cnt,
966 				    nowait);
967 				releasef(sfv->sfv_fd);
968 				*count += cnt;
969 				if (error)
970 					return (error);
971 				sfv++;
972 				continue;
973 			}
974 
975 			while (sfv_len > 0) {
976 				size_t	iov_len;
977 
978 				iov_len = MIN(size, sfv_len);
979 
980 				if (vp->v_type == VSOCK) {
981 					dmp = allocb(iov_len + extra, BPRI_HI);
982 					if (dmp == NULL) {
983 						VOP_RWUNLOCK(readvp,
984 						    V_WRITELOCK_FALSE, NULL);
985 						releasef(sfv->sfv_fd);
986 						return (ENOMEM);
987 					}
988 					dmp->b_wptr = dmp->b_rptr =
989 					    dmp->b_rptr + wroff;
990 					ptr = (caddr_t)dmp->b_rptr;
991 				} else {
992 					ptr = buf;
993 				}
994 
995 				aiov.iov_base = ptr;
996 				aiov.iov_len = iov_len;
997 				auio.uio_loffset = sfv_off;
998 				auio.uio_iov = &aiov;
999 				auio.uio_iovcnt = 1;
1000 				auio.uio_resid = iov_len;
1001 				auio.uio_segflg = UIO_SYSSPACE;
1002 				auio.uio_llimit = MAXOFFSET_T;
1003 				auio.uio_fmode = ffp->f_flag;
1004 				ioflag = auio.uio_fmode &
1005 				    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
1006 
1007 				/*
1008 				 * If read sync is not asked for,
1009 				 * filter sync flags
1010 				 */
1011 				if ((ioflag & FRSYNC) == 0)
1012 					ioflag &= ~(FSYNC|FDSYNC);
1013 				error = VOP_READ(readvp, &auio, ioflag,
1014 				    fp->f_cred, NULL);
1015 				if (error != 0) {
1016 					/*
1017 					 * If we were reading a pipe (currently
1018 					 * not implemented), we may now lose
1019 					 * data.
1020 					 */
1021 					if (vp->v_type == VSOCK)
1022 						freeb(dmp);
1023 					else
1024 						kmem_free(buf, size);
1025 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
1026 					    NULL);
1027 					releasef(sfv->sfv_fd);
1028 					return (error);
1029 				}
1030 
1031 				/*
1032 				 * Check how much data was really read.
1033 				 * Decrement the 'len' and increment the
1034 				 * 'off' appropriately.
1035 				 */
1036 				cnt = iov_len - auio.uio_resid;
1037 				if (cnt == 0) {
1038 					if (vp->v_type == VSOCK)
1039 						freeb(dmp);
1040 					else
1041 						kmem_free(buf, size);
1042 					VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE,
1043 					    NULL);
1044 					releasef(sfv->sfv_fd);
1045 					return (EINVAL);
1046 				}
1047 				sfv_len -= cnt;
1048 				sfv_off += cnt;
1049 
1050 				if (vp->v_type == VSOCK) {
1051 					dmp->b_wptr = dmp->b_rptr + cnt;
1052 
1053 					error = socket_sendmblk(VTOSO(vp),
1054 					    &msg, fflag, CRED(), &dmp);
1055 
1056 					if (error != 0) {
1057 						if (dmp != NULL)
1058 							freeb(dmp);
1059 						VOP_RWUNLOCK(readvp,
1060 						    V_WRITELOCK_FALSE, NULL);
1061 						releasef(sfv->sfv_fd);
1062 						return (error);
1063 					}
1064 
1065 					ttolwp(curthread)->lwp_ru.ioch +=
1066 					    (ulong_t)cnt;
1067 					*count += cnt;
1068 				} else {
1069 
1070 					aiov.iov_base = ptr;
1071 					aiov.iov_len = cnt;
1072 					auio.uio_loffset = *fileoff;
1073 					auio.uio_resid = cnt;
1074 					auio.uio_iov = &aiov;
1075 					auio.uio_iovcnt = 1;
1076 					auio.uio_segflg = UIO_SYSSPACE;
1077 					auio.uio_llimit = curproc->p_fsz_ctl;
1078 					auio.uio_fmode = fflag;
1079 					ioflag = auio.uio_fmode &
1080 					    (FAPPEND|FSYNC|FDSYNC|FRSYNC);
1081 					error = VOP_WRITE(vp, &auio, ioflag,
1082 					    fp->f_cred, NULL);
1083 
1084 					/*
1085 					 * Check how much data was written.
1086 					 * Increment the 'len' and decrement the
1087 					 * 'off' if all the data was not
1088 					 * written.
1089 					 */
1090 					cnt -= auio.uio_resid;
1091 					sfv_len += auio.uio_resid;
1092 					sfv_off -= auio.uio_resid;
1093 					ttolwp(curthread)->lwp_ru.ioch +=
1094 					    (ulong_t)cnt;
1095 					*fileoff += cnt;
1096 					*count += cnt;
1097 					if (error != 0) {
1098 						kmem_free(buf, size);
1099 						VOP_RWUNLOCK(readvp,
1100 						    V_WRITELOCK_FALSE, NULL);
1101 						releasef(sfv->sfv_fd);
1102 						return (error);
1103 					}
1104 				}
1105 			}
1106 			if (buf) {
1107 				kmem_free(buf, size);
1108 				buf = NULL;
1109 			}
1110 			VOP_RWUNLOCK(readvp, V_WRITELOCK_FALSE, NULL);
1111 			releasef(sfv->sfv_fd);
1112 		}
1113 		sfv++;
1114 	}
1115 	return (0);
1116 }
1117 
1118 ssize_t
1119 sendfilev(int opcode, int fildes, const struct sendfilevec *vec, int sfvcnt,
1120     size_t *xferred)
1121 {
1122 	int error = 0;
1123 	int first_vector_error = 0;
1124 	file_t *fp;
1125 	struct vnode *vp;
1126 	struct sonode *so;
1127 	u_offset_t fileoff;
1128 	int copy_cnt;
1129 	const struct sendfilevec *copy_vec;
1130 	struct sendfilevec sfv[SEND_MAX_CHUNK];
1131 	ssize_t count = 0;
1132 #ifdef _SYSCALL32_IMPL
1133 	struct ksendfilevec32 sfv32[SEND_MAX_CHUNK];
1134 #endif
1135 	ssize_t total_size;
1136 	int i;
1137 	boolean_t is_sock = B_FALSE;
1138 	int maxblk = 0;
1139 
1140 	if (sfvcnt <= 0)
1141 		return (set_errno(EINVAL));
1142 
1143 	if ((fp = getf(fildes)) == NULL)
1144 		return (set_errno(EBADF));
1145 
1146 	if (((fp->f_flag) & FWRITE) == 0) {
1147 		error = EBADF;
1148 		goto err;
1149 	}
1150 
1151 	fileoff = fp->f_offset;
1152 	vp = fp->f_vnode;
1153 
1154 	switch (vp->v_type) {
1155 	case VSOCK:
1156 		so = VTOSO(vp);
1157 		is_sock = B_TRUE;
1158 		if (SOCK_IS_NONSTR(so)) {
1159 			maxblk = so->so_proto_props.sopp_maxblk;
1160 		} else {
1161 			maxblk = (int)vp->v_stream->sd_maxblk;
1162 		}
1163 		break;
1164 	case VREG:
1165 		break;
1166 	default:
1167 		error = EINVAL;
1168 		goto err;
1169 	}
1170 
1171 	switch (opcode) {
1172 	case SENDFILEV :
1173 		break;
1174 #if defined(_SYSCALL32_IMPL) || defined(_ILP32)
1175 	case SENDFILEV64 :
1176 		return (sendvec64(fp, (struct ksendfilevec64 *)vec, sfvcnt,
1177 		    (size32_t *)xferred, fildes));
1178 #endif
1179 	default :
1180 		error = ENOSYS;
1181 		break;
1182 	}
1183 
1184 	(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
1185 	copy_vec = vec;
1186 
1187 	do {
1188 		total_size = 0;
1189 		copy_cnt = MIN(sfvcnt, SEND_MAX_CHUNK);
1190 #ifdef _SYSCALL32_IMPL
1191 		/* 32-bit callers need to have their iovec expanded. */
1192 		if (get_udatamodel() == DATAMODEL_ILP32) {
1193 			if (copyin(copy_vec, sfv32,
1194 			    copy_cnt * sizeof (ksendfilevec32_t))) {
1195 				error = EFAULT;
1196 				break;
1197 			}
1198 
1199 			for (i = 0; i < copy_cnt; i++) {
1200 				sfv[i].sfv_fd = sfv32[i].sfv_fd;
1201 				sfv[i].sfv_off =
1202 				    (off_t)(uint32_t)sfv32[i].sfv_off;
1203 				sfv[i].sfv_len = (size_t)sfv32[i].sfv_len;
1204 				total_size += sfv[i].sfv_len;
1205 				sfv[i].sfv_flag = sfv32[i].sfv_flag;
1206 				/*
1207 				 * Individual elements of the vector must not
1208 				 * wrap or overflow, as later math is signed.
1209 				 * Equally total_size needs to be checked after
1210 				 * each vector is added in, to be sure that
1211 				 * rogue values haven't overflowed the counter.
1212 				 */
1213 				if (((ssize32_t)sfv[i].sfv_len < 0) ||
1214 				    ((ssize32_t)total_size < 0)) {
1215 					/*
1216 					 * Truncate the vector to send data
1217 					 * described by elements before the
1218 					 * error.
1219 					 */
1220 					copy_cnt = i;
1221 					first_vector_error = EINVAL;
1222 					/* total_size can't be trusted */
1223 					if ((ssize32_t)total_size < 0)
1224 						error = EINVAL;
1225 					break;
1226 				}
1227 			}
1228 			/* Nothing to do, process errors */
1229 			if (copy_cnt == 0)
1230 				break;
1231 
1232 		} else {
1233 #endif
1234 			if (copyin(copy_vec, sfv,
1235 			    copy_cnt * sizeof (sendfilevec_t))) {
1236 				error = EFAULT;
1237 				break;
1238 			}
1239 
1240 			for (i = 0; i < copy_cnt; i++) {
1241 				total_size += sfv[i].sfv_len;
1242 				/*
1243 				 * Individual elements of the vector must not
1244 				 * wrap or overflow, as later math is signed.
1245 				 * Equally total_size needs to be checked after
1246 				 * each vector is added in, to be sure that
1247 				 * rogue values haven't overflowed the counter.
1248 				 */
1249 				if (((ssize_t)sfv[i].sfv_len < 0) ||
1250 				    (total_size < 0)) {
1251 					/*
1252 					 * Truncate the vector to send data
1253 					 * described by elements before the
1254 					 * error.
1255 					 */
1256 					copy_cnt = i;
1257 					first_vector_error = EINVAL;
1258 					/* total_size can't be trusted */
1259 					if (total_size < 0)
1260 						error = EINVAL;
1261 					break;
1262 				}
1263 			}
1264 			/* Nothing to do, process errors */
1265 			if (copy_cnt == 0)
1266 				break;
1267 #ifdef _SYSCALL32_IMPL
1268 		}
1269 #endif
1270 
1271 		/*
1272 		 * The task between deciding to use sendvec_small_chunk
1273 		 * and sendvec_chunk is dependant on multiple things:
1274 		 *
1275 		 * i) latency is important for smaller files. So if the
1276 		 * data is smaller than 'tcp_slow_start_initial' times
1277 		 * maxblk, then use sendvec_small_chunk which creates
1278 		 * maxblk size mblks and chains them together and sends
1279 		 * them to TCP in one shot. It also leaves 'wroff' size
1280 		 * space for the headers in each mblk.
1281 		 *
1282 		 * ii) for total size bigger than 'tcp_slow_start_initial'
1283 		 * time maxblk, its probably real file data which is
1284 		 * dominating. So its better to use sendvec_chunk because
1285 		 * performance goes to dog if we don't do pagesize reads.
1286 		 * sendvec_chunk will do pagesize reads and write them
1287 		 * in pagesize mblks to TCP.
1288 		 *
1289 		 * Side Notes: A write to file has not been optimized.
1290 		 * Future zero copy code will plugin into sendvec_chunk
1291 		 * only because doing zero copy for files smaller then
1292 		 * pagesize is useless.
1293 		 *
1294 		 * Note, if socket has NL7C enabled then call NL7C's
1295 		 * senfilev() function to consume the sfv[].
1296 		 */
1297 		if (is_sock) {
1298 			if (!SOCK_IS_NONSTR(so) &&
1299 			    _SOTOTPI(so)->sti_nl7c_flags != 0) {
1300 				error = nl7c_sendfilev(so, &fileoff,
1301 				    sfv, copy_cnt, &count);
1302 			} else if ((total_size <= (4 * maxblk)) &&
1303 			    error == 0) {
1304 				error = sendvec_small_chunk(fp,
1305 				    &fileoff, sfv, copy_cnt,
1306 				    total_size, maxblk, &count);
1307 			} else {
1308 				error = sendvec_chunk(fp, &fileoff,
1309 				    sfv, copy_cnt, &count);
1310 			}
1311 		} else {
1312 			ASSERT(vp->v_type == VREG);
1313 			error = sendvec_chunk(fp, &fileoff, sfv, copy_cnt,
1314 			    &count);
1315 		}
1316 
1317 
1318 #ifdef _SYSCALL32_IMPL
1319 	if (get_udatamodel() == DATAMODEL_ILP32)
1320 		copy_vec = (const struct sendfilevec *)((char *)copy_vec +
1321 		    (copy_cnt * sizeof (ksendfilevec32_t)));
1322 	else
1323 #endif
1324 		copy_vec += copy_cnt;
1325 		sfvcnt -= copy_cnt;
1326 
1327 	/* Process all vector members up to first error */
1328 	} while ((sfvcnt > 0) && first_vector_error == 0 && error == 0);
1329 
1330 	if (vp->v_type == VREG)
1331 		fp->f_offset += count;
1332 
1333 	VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
1334 
1335 #ifdef _SYSCALL32_IMPL
1336 	if (get_udatamodel() == DATAMODEL_ILP32) {
1337 		ssize32_t count32 = (ssize32_t)count;
1338 		if (copyout(&count32, xferred, sizeof (count32)))
1339 			error = EFAULT;
1340 		releasef(fildes);
1341 		if (error != 0)
1342 			return (set_errno(error));
1343 		if (first_vector_error != 0)
1344 			return (set_errno(first_vector_error));
1345 		return (count32);
1346 	}
1347 #endif
1348 	if (copyout(&count, xferred, sizeof (count)))
1349 		error = EFAULT;
1350 	releasef(fildes);
1351 	if (error != 0)
1352 		return (set_errno(error));
1353 	if (first_vector_error != 0)
1354 		return (set_errno(first_vector_error));
1355 	return (count);
1356 err:
1357 	ASSERT(error != 0);
1358 	releasef(fildes);
1359 	return (set_errno(error));
1360 }
1361