510 lines
12 KiB
C
510 lines
12 KiB
C
/* $NetBSD: ustarfs.c,v 1.5 1998/10/30 16:56:30 matt Exp $ */
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/* [Notice revision 2.2]
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* Copyright (c) 1997, 1998 Avalon Computer Systems, Inc.
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* All rights reserved.
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*
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* Author: Ross Harvey
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright and
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* author notice, this list of conditions, and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of Avalon Computer Systems, Inc. nor the names of
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* its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* 4. This copyright will be assigned to The NetBSD Foundation on
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* 1/1/2000 unless these terms (including possibly the assignment
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* date) are updated in writing by Avalon prior to the latest specified
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* assignment date.
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*
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* THIS SOFTWARE IS PROVIDED BY AVALON COMPUTER SYSTEMS, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL AVALON OR THE CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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******************************* USTAR FS *******************************
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*/
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/*
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* Implement an ROFS with an 8K boot area followed by ustar-format data.
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* The point: minimal FS overhead, and it's easy (well, `possible') to
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* split files over multiple volumes.
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*
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* XXX - TODO LIST
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* --- - ---- ----
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* XXX - tag volume numbers and verify that the correct volume is
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* inserted after volume swaps.
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*
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* XXX - stop hardwiring FS metadata for floppies...embed it in a file,
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* file name, or something. (Remember __SYMDEF? :-)
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*
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*/
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#ifdef _STANDALONE
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#include <lib/libkern/libkern.h>
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#else
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#include <string.h>
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#endif
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#include "stand.h"
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#include "ustarfs.h"
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#define BBSIZE 8192
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#define USTAR_NAME_BLOCK 512
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/*
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* Virtual offset: relative to start of ustar archive
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* Logical offset: volume-relative
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* Physical offset: the usual meaning
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*/
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/* virtual offset to volume number */
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#define vda2vn(_v,_volsize) ((_v) / (_volsize))
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/* conversions between the three different levels of disk addresses */
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#define vda2lda(_v,_volsize) ((_v) % (_volsize))
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#define lda2vda(_v,_volsize,_volnumber) ((_v) + (_volsize) * (_volnumber))
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#define lda2pda(_lda) ((_lda) + ustarfs_mode_offset)
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#define pda2lda(_pda) ((_pda) - ustarfs_mode_offset)
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/*
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* Change this to off_t if you want to support big volumes. If we only use
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* ustarfs on floppies it can stay int for libsa code density.
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*
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* It needs to be signed.
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*/
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typedef int ustoffs;
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typedef struct ustar_struct {
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char ust_name[100],
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ust_mode[8],
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ust_uid[8],
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ust_gid[8],
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ust_size[12],
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ust_misc[12 + 8 + 1 + 100],
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ust_magic[6];
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/* there is more, but we don't care */
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} ustar_t;
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/*
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* We buffer one even cylindar of data...it's actually only really one
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* cyl on a 1.44M floppy, but on other devices it's fast enough with any
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* kind of block buffering, so we optimize for the slowest device.
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*/
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typedef struct ust_active_struct {
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ustar_t uas_active;
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char uas_1cyl[18 * 2 * 512];
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ustoffs uas_volsize; /* XXX this is hardwired now */
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ustoffs uas_windowbase; /* relative to volume 0 */
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ustoffs uas_filestart; /* relative to volume 0 */
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ustoffs uas_fseek; /* relative to file */
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ustoffs uas_filesize; /* relative to volume 0 */
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int uas_init_window; /* data present in window */
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int uas_init_fs; /* ust FS actually found */
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int uas_volzerosig; /* ID volume 0 by signature */
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int uas_offset; /* amount of cylinder below lba 0 */
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} ust_active_t;
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static const char formatid[] = "USTARFS",
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metaname[] = "USTAR.volsize.";
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static int ustarfs_mode_offset = BBSIZE;
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static int checksig __P((ust_active_t *));
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static int convert __P((const char *, int, int));
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static int get_volume __P((struct open_file *, int));
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static void setwindow(ust_active_t *, ustoffs, ustoffs);
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static int ustarfs_cylinder_read __P((struct open_file *, ustoffs, int));
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static void ustarfs_sscanf __P((const char *, const char *, int *));
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static int read512block __P((struct open_file *, ustoffs, char block[512]));
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static int
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convert(f, base, fw)
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const char *f;
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int base, fw;
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{
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int i, c, result = 0;
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while(fw > 0 && *f == ' ') {
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--fw;
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++f;
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}
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for(i = 0; i < fw; ++i) {
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c = f[i];
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if ('0' <= c && c < '0' + base) {
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c -= '0';
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result = result * base + c;
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} else break;
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}
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return result;
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}
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static void
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ustarfs_sscanf(s,f,xi)
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const char *s,*f;
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int *xi;
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{
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*xi = convert(s, 8, convert(f + 1, 10, 99));
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}
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static int
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ustarfs_cylinder_read(f, seek2, forcelabel)
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struct open_file *f;
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ustoffs seek2;
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{
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int e = 0; /* XXX work around gcc warning */
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ustoffs lda;
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char *xferbase;
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ust_active_t *ustf;
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size_t xferrqst, xfercount;
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ustf = f->f_fsdata;
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xferrqst = sizeof ustf->uas_1cyl;
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xferbase = ustf->uas_1cyl;
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lda = pda2lda(seek2);
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if (lda < 0) {
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lda = -lda;
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ustf->uas_offset = lda;
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/*
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* don't read the label unless we have to. (Preserve
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* sequential block access so tape boot works.)
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*/
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if (!forcelabel) {
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memset(xferbase, 0, lda);
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xferrqst -= lda;
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xferbase += lda;
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seek2 += lda;
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}
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} else
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ustf->uas_offset = 0;
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while(xferrqst > 0) {
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e = f->f_dev->dv_strategy(f->f_devdata, F_READ, seek2 / 512,
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xferrqst, xferbase, &xfercount);
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if (e)
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break;
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if (xfercount != xferrqst)
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printf("Warning, unexpected short transfer %d/%d\n",
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(int)xfercount, (int)xferrqst);
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xferrqst -= xfercount;
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xferbase += xfercount;
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}
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return e;
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}
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static int
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checksig(ustf)
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ust_active_t *ustf;
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{
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int i, rcs;
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for(i = rcs = 0; i < sizeof ustf->uas_1cyl; ++i)
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rcs += ustf->uas_1cyl[i];
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return rcs;
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}
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static int
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get_volume(f, vn)
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struct open_file *f;
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int vn;
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{
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int e, needvolume, havevolume;
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ust_active_t *ustf;
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ustf = f->f_fsdata;
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havevolume = vda2vn(ustf->uas_windowbase, ustf->uas_volsize);
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needvolume = vn;
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while(havevolume != needvolume) {
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printf("\nPlease ");
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if (havevolume >= 0)
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printf("remove disk %d, ", havevolume + 1);
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printf("insert disk %d, and type return...",
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needvolume + 1);
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getchar();
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printf("\n");
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e = ustarfs_cylinder_read(f, 0, 1);
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if (e)
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return e;
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if(strncmp(formatid, ustf->uas_1cyl, strlen(formatid))) {
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/* no magic, might be OK if we want volume 0 */
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if (ustf->uas_volzerosig == checksig(ustf)) {
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havevolume = 0;
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continue;
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}
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printf("Disk is not from the volume set?!\n");
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havevolume = -2;
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continue;
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}
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ustarfs_sscanf(ustf->uas_1cyl + strlen(formatid), "%9o",
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&havevolume);
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--havevolume;
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}
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return 0;
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}
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static void
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setwindow(ust_active_t *ustf, ustoffs pda, ustoffs vda)
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{
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ustf->uas_windowbase = lda2vda(pda2lda(pda), ustf->uas_volsize,
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vda2vn(vda, ustf->uas_volsize))
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+ ustf->uas_offset;
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ustf->uas_init_window = 1;
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}
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static int
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read512block(f, vda, block)
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struct open_file *f;
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ustoffs vda;
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char block[512];
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{
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ustoffs pda;
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ssize_t e;
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int dienow;
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ust_active_t *ustf;
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dienow = 0;
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ustf = f->f_fsdata;
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if (!ustf->uas_init_window
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&& ustf->uas_windowbase == 0) {
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/*
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* The algorithm doesn't require this, but without it we would
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* need some trick to get the cylinder zero signature computed.
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* That signature is used to identify volume zero, which we
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* don't give a USTARFS label to. (It's platform-dependent.)
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*/
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e = ustarfs_cylinder_read(f, 0, 0);
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if (e)
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return e;
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ustf->uas_volzerosig = checksig(ustf);
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setwindow(ustf, 0, 0);
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}
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/*
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* if (vda in window)
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* copy out and return data
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* if (vda is on some other disk)
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* do disk swap
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* get physical disk address
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* round down to cylinder boundary
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* read cylindar
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* set window (in vda space) and try again
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* [ there is an implicit assumption that windowbase always identifies
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* the current volume, even if initwindow == 0. This way, a
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* windowbase of 0 causes the initial volume to be disk 0 ]
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*/
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tryagain:
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if(ustf->uas_init_window
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&& ustf->uas_windowbase <= vda && vda <
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ustf->uas_windowbase + sizeof ustf->uas_1cyl - ustf->uas_offset) {
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memcpy(block, ustf->uas_1cyl
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+ (vda - ustf->uas_windowbase)
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+ ustf->uas_offset, 512);
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return 0;
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}
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if (dienow++)
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panic("ustarfs read512block");
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ustf->uas_init_window = 0;
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e = get_volume(f, vda2vn(vda, ustf->uas_volsize));
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if (e)
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return e;
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pda = lda2pda(vda2lda(vda, ustf->uas_volsize));
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pda-= pda % sizeof ustf->uas_1cyl;
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e = ustarfs_cylinder_read(f, pda, 0);
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if (e)
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return e;
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setwindow(ustf, pda, vda);
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goto tryagain;
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}
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int
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ustarfs_open(path, f)
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char *path;
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struct open_file *f;
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{
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ust_active_t *ustf;
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ustoffs offset;
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char block[512];
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int filesize;
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int e, e2;
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int newvolblocks;
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if (*path == '/')
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++path;
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e = EINVAL;
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f->f_fsdata = ustf = alloc(sizeof *ustf);
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memset(ustf, 0, sizeof *ustf);
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offset = 0;
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/* default to 2880 sector floppy */
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ustf->uas_volsize = 80 * 2 * 18 * 512 - lda2pda(0);
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ustf->uas_fseek = 0;
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for(;;) {
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ustf->uas_filestart = offset;
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e2 = read512block(f, offset, block);
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if (e2) {
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e = e2;
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break;
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}
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memcpy(&ustf->uas_active, block, sizeof ustf->uas_active);
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if(strncmp(ustf->uas_active.ust_magic, "ustar", 5))
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break;
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e = ENOENT; /* it must be an actual ustarfs */
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ustf->uas_init_fs = 1;
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/* if volume metadata is found, use it */
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if(strncmp(ustf->uas_active.ust_name, metaname,
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strlen(metaname)) == 0) {
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ustarfs_sscanf(ustf->uas_active.ust_name
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+ strlen(metaname), "%99o", &newvolblocks);
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ustf->uas_volsize = newvolblocks * 512
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- lda2pda(0);
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}
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ustarfs_sscanf(ustf->uas_active.ust_size,"%12o",&filesize);
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if(strncmp(ustf->uas_active.ust_name, path,
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sizeof ustf->uas_active.ust_name) == 0) {
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ustf->uas_filesize = filesize;
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e = 0;
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break;
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}
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offset += USTAR_NAME_BLOCK + filesize;
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filesize %= 512;
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if (filesize)
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offset += 512 - filesize;
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}
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if (e) {
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free(ustf, sizeof *ustf);
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f->f_fsdata = 0;
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}
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return e;
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}
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int
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ustarfs_write(f, start, size, resid)
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struct open_file *f;
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void *start;
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size_t size;
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size_t *resid;
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{
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return (EROFS);
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}
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off_t
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ustarfs_seek(f, offs, whence)
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struct open_file *f;
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off_t offs;
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int whence;
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{
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ust_active_t *ustf;
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ustf = f->f_fsdata;
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switch (whence) {
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case SEEK_SET:
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ustf->uas_fseek = offs;
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break;
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case SEEK_CUR:
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ustf->uas_fseek += offs;
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break;
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case SEEK_END:
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ustf->uas_fseek = ustf->uas_filesize - offs;
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break;
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default:
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return -1;
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}
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return ustf->uas_fseek;
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}
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int
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ustarfs_read(f, start, size, resid)
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struct open_file *f;
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void *start;
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size_t size;
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size_t *resid;
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{
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ust_active_t *ustf;
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int e;
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char *space512;
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int blkoffs,
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readoffs,
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bufferoffset;
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size_t seg;
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int infile,
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inbuffer;
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e = 0;
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space512 = alloc(512);
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ustf = f->f_fsdata;
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while(size != 0) {
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if (ustf->uas_fseek >= ustf->uas_filesize)
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break;
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bufferoffset = ustf->uas_fseek % 512;
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blkoffs = ustf->uas_fseek - bufferoffset;
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readoffs = ustf->uas_filestart + 512 + blkoffs;
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e = read512block(f, readoffs, space512);
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if (e)
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break;
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seg = size;
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inbuffer = 512 - bufferoffset;
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if (inbuffer < seg)
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seg = inbuffer;
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infile = ustf->uas_filesize - ustf->uas_fseek;
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if (infile < seg)
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seg = infile;
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memcpy(start, space512 + bufferoffset, seg);
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ustf->uas_fseek += seg;
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start += seg;
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size -= seg;
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}
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if (resid)
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*resid = size;
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free(space512, 512);
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return e;
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}
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int
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ustarfs_stat(f, sb)
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struct open_file *f;
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struct stat *sb;
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{
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int mode, uid, gid;
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ust_active_t *ustf;
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if (f == NULL)
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return EINVAL;
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ustf = f->f_fsdata;
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memset(sb, 0, sizeof *sb);
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ustarfs_sscanf(ustf->uas_active.ust_mode, "%8o", &mode);
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ustarfs_sscanf(ustf->uas_active.ust_uid, "%8o", &uid);
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ustarfs_sscanf(ustf->uas_active.ust_gid, "%8o", &gid);
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sb->st_mode = mode;
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sb->st_uid = uid;
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sb->st_gid = gid;
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sb->st_size = ustf->uas_filesize;
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return 0;
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}
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int
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ustarfs_close(f)
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struct open_file *f;
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{
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if (f == NULL || f->f_fsdata == NULL)
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return EINVAL;
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free(f->f_fsdata, sizeof(ust_active_t));
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f->f_fsdata = 0;
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return 0;
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}
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