/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2009 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ /* All Rights Reserved */ /* * University Copyright- Copyright (c) 1982, 1986, 1988 * The Regents of the University of California * All Rights Reserved * * University Acknowledgment- Portions of this document are derived from * software developed by the University of California, Berkeley, and its * contributors. */ /* * Copyright (c) 2015 by Chunwei Chen. All rights reserved. */ /* * The uio support from OpenSolaris has been added as a short term * work around. The hope is to adopt native Linux type and drop the * use of uio's entirely. Under Linux they only add overhead and * when possible we want to use native APIs for the ZPL layer. */ #ifdef _KERNEL #include #include #include #include /* * Move "n" bytes at byte address "p"; "rw" indicates the direction * of the move, and the I/O parameters are provided in "uio", which is * update to reflect the data which was moved. Returns 0 on success or * a non-zero errno on failure. */ static int uiomove_iov(void *p, size_t n, enum uio_rw rw, struct uio *uio) { const struct iovec *iov = uio->uio_iov; size_t skip = uio->uio_skip; ulong_t cnt; while (n && uio->uio_resid) { cnt = MIN(iov->iov_len - skip, n); switch (uio->uio_segflg) { case UIO_USERSPACE: case UIO_USERISPACE: /* * p = kernel data pointer * iov->iov_base = user data pointer */ if (rw == UIO_READ) { if (copy_to_user(iov->iov_base+skip, p, cnt)) return (EFAULT); } else { if (uio->uio_fault_disable) { if (!zfs_access_ok(VERIFY_READ, (iov->iov_base + skip), cnt)) { return (EFAULT); } pagefault_disable(); if (__copy_from_user_inatomic(p, (iov->iov_base + skip), cnt)) { pagefault_enable(); return (EFAULT); } pagefault_enable(); } else { if (copy_from_user(p, (iov->iov_base + skip), cnt)) return (EFAULT); } } break; case UIO_SYSSPACE: if (rw == UIO_READ) bcopy(p, iov->iov_base + skip, cnt); else bcopy(iov->iov_base + skip, p, cnt); break; default: ASSERT(0); } skip += cnt; if (skip == iov->iov_len) { skip = 0; uio->uio_iov = (++iov); uio->uio_iovcnt--; } uio->uio_skip = skip; uio->uio_resid -= cnt; uio->uio_loffset += cnt; p = (caddr_t)p + cnt; n -= cnt; } return (0); } static int uiomove_bvec(void *p, size_t n, enum uio_rw rw, struct uio *uio) { const struct bio_vec *bv = uio->uio_bvec; size_t skip = uio->uio_skip; ulong_t cnt; while (n && uio->uio_resid) { void *paddr; cnt = MIN(bv->bv_len - skip, n); paddr = zfs_kmap_atomic(bv->bv_page, KM_USER1); if (rw == UIO_READ) bcopy(p, paddr + bv->bv_offset + skip, cnt); else bcopy(paddr + bv->bv_offset + skip, p, cnt); zfs_kunmap_atomic(paddr, KM_USER1); skip += cnt; if (skip == bv->bv_len) { skip = 0; uio->uio_bvec = (++bv); uio->uio_iovcnt--; } uio->uio_skip = skip; uio->uio_resid -= cnt; uio->uio_loffset += cnt; p = (caddr_t)p + cnt; n -= cnt; } return (0); } int uiomove(void *p, size_t n, enum uio_rw rw, struct uio *uio) { if (uio->uio_segflg != UIO_BVEC) return (uiomove_iov(p, n, rw, uio)); else return (uiomove_bvec(p, n, rw, uio)); } EXPORT_SYMBOL(uiomove); #define fuword8(uptr, vptr) get_user((*vptr), (uptr)) /* * Fault in the pages of the first n bytes specified by the uio structure. * 1 byte in each page is touched and the uio struct is unmodified. Any * error will terminate the process as this is only a best attempt to get * the pages resident. */ int uio_prefaultpages(ssize_t n, struct uio *uio) { const struct iovec *iov; ulong_t cnt, incr; caddr_t p; uint8_t tmp; int iovcnt; size_t skip; /* no need to fault in kernel pages */ switch (uio->uio_segflg) { case UIO_SYSSPACE: case UIO_BVEC: return (0); case UIO_USERSPACE: case UIO_USERISPACE: break; default: ASSERT(0); } iov = uio->uio_iov; iovcnt = uio->uio_iovcnt; skip = uio->uio_skip; for (; n > 0 && iovcnt > 0; iov++, iovcnt--, skip = 0) { cnt = MIN(iov->iov_len - skip, n); /* empty iov */ if (cnt == 0) continue; n -= cnt; /* * touch each page in this segment. */ p = iov->iov_base + skip; while (cnt) { if (fuword8((uint8_t *)p, &tmp)) return (EFAULT); incr = MIN(cnt, PAGESIZE); p += incr; cnt -= incr; } /* * touch the last byte in case it straddles a page. */ p--; if (fuword8((uint8_t *)p, &tmp)) return (EFAULT); } return (0); } EXPORT_SYMBOL(uio_prefaultpages); /* * same as uiomove() but doesn't modify uio structure. * return in cbytes how many bytes were copied. */ int uiocopy(void *p, size_t n, enum uio_rw rw, struct uio *uio, size_t *cbytes) { struct uio uio_copy; int ret; bcopy(uio, &uio_copy, sizeof (struct uio)); ret = uiomove(p, n, rw, &uio_copy); *cbytes = uio->uio_resid - uio_copy.uio_resid; return (ret); } EXPORT_SYMBOL(uiocopy); /* * Drop the next n chars out of *uiop. */ void uioskip(uio_t *uiop, size_t n) { if (n > uiop->uio_resid) return; uiop->uio_skip += n; if (uiop->uio_segflg != UIO_BVEC) { while (uiop->uio_iovcnt && uiop->uio_skip >= uiop->uio_iov->iov_len) { uiop->uio_skip -= uiop->uio_iov->iov_len; uiop->uio_iov++; uiop->uio_iovcnt--; } } else { while (uiop->uio_iovcnt && uiop->uio_skip >= uiop->uio_bvec->bv_len) { uiop->uio_skip -= uiop->uio_bvec->bv_len; uiop->uio_bvec++; uiop->uio_iovcnt--; } } uiop->uio_loffset += n; uiop->uio_resid -= n; } EXPORT_SYMBOL(uioskip); #endif /* _KERNEL */