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.
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.
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]
22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
27 /* All Rights Reserved */
30 * University Copyright- Copyright (c) 1982, 1986, 1988
31 * The Regents of the University of California
34 * University Acknowledgment- Portions of this document are derived from
35 * software developed by the University of California, Berkeley, and its
39 * Copyright (c) 2015 by Chunwei Chen. All rights reserved.
43 * The uio support from OpenSolaris has been added as a short term
44 * work around. The hope is to adopt native Linux type and drop the
45 * use of uio's entirely. Under Linux they only add overhead and
46 * when possible we want to use native APIs for the ZPL layer.
50 #include <sys/types.h>
51 #include <sys/uio_impl.h>
52 #include <sys/sysmacros.h>
53 #include <sys/strings.h>
54 #include <linux/kmap_compat.h>
55 #include <linux/uaccess.h>
58 * Move "n" bytes at byte address "p"; "rw" indicates the direction
59 * of the move, and the I/O parameters are provided in "uio", which is
60 * update to reflect the data which was moved. Returns 0 on success or
61 * a non-zero errno on failure.
64 uiomove_iov(void *p, size_t n, enum uio_rw rw, struct uio *uio)
66 const struct iovec *iov = uio->uio_iov;
67 size_t skip = uio->uio_skip;
70 while (n && uio->uio_resid) {
71 cnt = MIN(iov->iov_len - skip, n);
72 switch (uio->uio_segflg) {
76 * p = kernel data pointer
77 * iov->iov_base = user data pointer
80 if (copy_to_user(iov->iov_base+skip, p, cnt))
83 if (uio->uio_fault_disable) {
84 if (!zfs_access_ok(VERIFY_READ,
85 (iov->iov_base + skip), cnt)) {
89 if (__copy_from_user_inatomic(p,
90 (iov->iov_base + skip), cnt)) {
97 (iov->iov_base + skip), cnt))
104 bcopy(p, iov->iov_base + skip, cnt);
106 bcopy(iov->iov_base + skip, p, cnt);
112 if (skip == iov->iov_len) {
114 uio->uio_iov = (++iov);
117 uio->uio_skip = skip;
118 uio->uio_resid -= cnt;
119 uio->uio_loffset += cnt;
120 p = (caddr_t)p + cnt;
127 uiomove_bvec(void *p, size_t n, enum uio_rw rw, struct uio *uio)
129 const struct bio_vec *bv = uio->uio_bvec;
130 size_t skip = uio->uio_skip;
133 while (n && uio->uio_resid) {
135 cnt = MIN(bv->bv_len - skip, n);
137 paddr = zfs_kmap_atomic(bv->bv_page, KM_USER1);
139 bcopy(p, paddr + bv->bv_offset + skip, cnt);
141 bcopy(paddr + bv->bv_offset + skip, p, cnt);
142 zfs_kunmap_atomic(paddr, KM_USER1);
145 if (skip == bv->bv_len) {
147 uio->uio_bvec = (++bv);
150 uio->uio_skip = skip;
151 uio->uio_resid -= cnt;
152 uio->uio_loffset += cnt;
153 p = (caddr_t)p + cnt;
160 uiomove(void *p, size_t n, enum uio_rw rw, struct uio *uio)
162 if (uio->uio_segflg != UIO_BVEC)
163 return (uiomove_iov(p, n, rw, uio));
165 return (uiomove_bvec(p, n, rw, uio));
167 EXPORT_SYMBOL(uiomove);
169 #define fuword8(uptr, vptr) get_user((*vptr), (uptr))
172 * Fault in the pages of the first n bytes specified by the uio structure.
173 * 1 byte in each page is touched and the uio struct is unmodified. Any
174 * error will terminate the process as this is only a best attempt to get
175 * the pages resident.
178 uio_prefaultpages(ssize_t n, struct uio *uio)
180 const struct iovec *iov;
187 /* no need to fault in kernel pages */
188 switch (uio->uio_segflg) {
200 iovcnt = uio->uio_iovcnt;
201 skip = uio->uio_skip;
203 for (; n > 0 && iovcnt > 0; iov++, iovcnt--, skip = 0) {
204 cnt = MIN(iov->iov_len - skip, n);
210 * touch each page in this segment.
212 p = iov->iov_base + skip;
214 if (fuword8((uint8_t *)p, &tmp))
216 incr = MIN(cnt, PAGESIZE);
221 * touch the last byte in case it straddles a page.
224 if (fuword8((uint8_t *)p, &tmp))
230 EXPORT_SYMBOL(uio_prefaultpages);
233 * same as uiomove() but doesn't modify uio structure.
234 * return in cbytes how many bytes were copied.
237 uiocopy(void *p, size_t n, enum uio_rw rw, struct uio *uio, size_t *cbytes)
242 bcopy(uio, &uio_copy, sizeof (struct uio));
243 ret = uiomove(p, n, rw, &uio_copy);
244 *cbytes = uio->uio_resid - uio_copy.uio_resid;
247 EXPORT_SYMBOL(uiocopy);
250 * Drop the next n chars out of *uiop.
253 uioskip(uio_t *uiop, size_t n)
255 if (n > uiop->uio_resid)
259 if (uiop->uio_segflg != UIO_BVEC) {
260 while (uiop->uio_iovcnt &&
261 uiop->uio_skip >= uiop->uio_iov->iov_len) {
262 uiop->uio_skip -= uiop->uio_iov->iov_len;
267 while (uiop->uio_iovcnt &&
268 uiop->uio_skip >= uiop->uio_bvec->bv_len) {
269 uiop->uio_skip -= uiop->uio_bvec->bv_len;
274 uiop->uio_loffset += n;
275 uiop->uio_resid -= n;
277 EXPORT_SYMBOL(uioskip);