Annotation of sys/lib/libsa/read.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: read.c,v 1.7 2003/08/11 06:23:09 deraadt Exp $ */
! 2: /* $NetBSD: read.c,v 1.7 1996/06/21 20:29:28 pk Exp $ */
! 3:
! 4: /*-
! 5: * Copyright (c) 1993
! 6: * The Regents of the University of California. All rights reserved.
! 7: *
! 8: * This code is derived from software contributed to Berkeley by
! 9: * The Mach Operating System project at Carnegie-Mellon University.
! 10: *
! 11: * Redistribution and use in source and binary forms, with or without
! 12: * modification, are permitted provided that the following conditions
! 13: * are met:
! 14: * 1. Redistributions of source code must retain the above copyright
! 15: * notice, this list of conditions and the following disclaimer.
! 16: * 2. Redistributions in binary form must reproduce the above copyright
! 17: * notice, this list of conditions and the following disclaimer in the
! 18: * documentation and/or other materials provided with the distribution.
! 19: * 3. Neither the name of the University nor the names of its contributors
! 20: * may be used to endorse or promote products derived from this software
! 21: * without specific prior written permission.
! 22: *
! 23: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 24: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 25: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 26: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 27: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 28: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 29: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 30: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 31: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 32: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 33: * SUCH DAMAGE.
! 34: *
! 35: * @(#)read.c 8.1 (Berkeley) 6/11/93
! 36: *
! 37: *
! 38: * Copyright (c) 1989, 1990, 1991 Carnegie Mellon University
! 39: * All Rights Reserved.
! 40: *
! 41: * Author: Alessandro Forin
! 42: *
! 43: * Permission to use, copy, modify and distribute this software and its
! 44: * documentation is hereby granted, provided that both the copyright
! 45: * notice and this permission notice appear in all copies of the
! 46: * software, derivative works or modified versions, and any portions
! 47: * thereof, and that both notices appear in supporting documentation.
! 48: *
! 49: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
! 50: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
! 51: * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
! 52: *
! 53: * Carnegie Mellon requests users of this software to return to
! 54: *
! 55: * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
! 56: * School of Computer Science
! 57: * Carnegie Mellon University
! 58: * Pittsburgh PA 15213-3890
! 59: *
! 60: * any improvements or extensions that they make and grant Carnegie the
! 61: * rights to redistribute these changes.
! 62: */
! 63:
! 64: #include <sys/param.h>
! 65: #include "stand.h"
! 66:
! 67: ssize_t
! 68: #ifndef __INTERNAL_LIBSA_CREAD
! 69: read(int fd, void *dest, size_t bcount)
! 70: #else
! 71: oread(int fd, void *dest, size_t bcount)
! 72: #endif
! 73: {
! 74: struct open_file *f = &files[fd];
! 75: size_t resid;
! 76:
! 77: if ((unsigned)fd >= SOPEN_MAX || !(f->f_flags & F_READ)) {
! 78: errno = EBADF;
! 79: return (-1);
! 80: }
! 81: if (f->f_flags & F_RAW) {
! 82: twiddle();
! 83: errno = (f->f_dev->dv_strategy)(f->f_devdata, F_READ,
! 84: btodb(f->f_offset), bcount, dest, &resid);
! 85: if (errno)
! 86: return (-1);
! 87: f->f_offset += resid;
! 88: return (resid);
! 89: }
! 90: resid = bcount;
! 91: if ((errno = (f->f_ops->read)(f, dest, bcount, &resid)))
! 92: return (-1);
! 93: return (ssize_t)(bcount - resid);
! 94: }
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