rrfile_create.c

一款类linux的操作系统源码

/* 
 *  Roadrunner/pk
 *    Copyright (C) 1989-2001  Cornfed Systems, Inc.
 *
 *  The Roadrunner/pk operating system is free software; you can
 *  redistribute and/or modify it under the terms of the GNU General
 *  Public License, version 2, as published by the Free Software
 *  Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public
 *  License along with this program; if not, write to the Free
 *  Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *  MA 02111-1307 USA
 *
 *  More information about the Roadrunner/pk operating system of
 *  which this file is a part is available on the World-Wide Web
 *  at: http://www.cornfed.com.
 *
 */

#include <errno.h>
#include <fcntl.h>
#include <fs/rrfs.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys.h>
#include <sys/mem.h>
#include <sys/time.h>
#include <sys/time2tm.h>

static void
rrfs_deinit(direntry_t de, char *fname, int directory)
{
    time_t t;
    struct tm tm;

    bzero(de, sizeof(struct direntry));

    strncpy(de->name, fname, DE_NAME_LENGTH);
    de->attr = (DE_ATTR_READ | DE_ATTR_WRITE);
    if (directory)
	de->attr |= DE_ATTR_DIR;

    t = time();
    time2tm(t, &tm);
    de->time[DE_TIME_HOUR] = tm.tm_hour;
    de->time[DE_TIME_MIN] = tm.tm_min;
    de->time[DE_TIME_SEC] = tm.tm_sec;
    de->date[DE_DATE_MON] = tm.tm_mon;
    de->date[DE_DATE_DAY] = tm.tm_mday;
    de->date[DE_DATE_YEAR] = tm.tm_year;
}

int
rrfile_create(file_t file, int directory)
{
    file_t tmpfile = file;
    rrfile_t rrfile;
    char *dir, *fulldir, *fname;
    u_long declust, deoff;
    int found, result;
    direntry_t de;

    dir = (char *) malloc(3 * PATH_LENGTH);
    if (dir == NULL)
	return ENOMEM;

    bzero(dir, 3 * PATH_LENGTH);
    fulldir = dir + PATH_LENGTH;
    fname = dir + 2 * PATH_LENGTH;

    getdir(file->path, dir);
    mkpath(file->fs->path, dir, fulldir);
    getname(file->path, fname);

    if ((result = file_open(fulldir, O_RDONLY, &file)) < 0) {
#if _DEBUG
	kprintf("rrfile_create: could not open %s (%s)\n",
		fulldir, strerror(result));
#endif
	goto createerror;
    }
    if (!(file->flags & F_DIR)) {
#if _DEBUG
	kprintf("rrfile_create: %s is not a directory\n", fulldir);
#endif
	file_close(file);
	result = ENOTDIR;
	goto createerror;
    }
    rrfile = (rrfile_t) file->data;

    /* This is directory entry data for the new file */
    declust = rrfile->firstclust;
    deoff = 0;

    /* Loop over the directory entries looking for a free slot */
    for (rrfile->currclust = rrfile->firstclust, found = 0;;) {
	u_int clust;

	for (bpos(file->buf) = 0;
	     bpos(file->buf) < file->bufsize; bpos(file->buf) += DE_SIZE) {
	    u_char ch;

	    ch = *((u_char *)
		   (bstart(file->buf) + bpos(file->buf)));
	    if (ch == (u_char) DE_UNUSED || ch == (u_char) DE_DELETED) {
		found = 1;
		break;
	    }
	}
	if (found)
	    break;
	deoff += file->bufsize;

	if (file->buf != NULL)
	    brel(file->buf);
	file->buf = bget(file->bufsize);
	blen(file->buf) = file->bufsize;

	clust = rrfs_nextclust(file->fs, rrfile->currclust);
	if (clust == FAT_CHAIN_END) {
	    /* 
	     * Assume we've filled up the last cluster in the directory chain
	     * and need to add a new cluster to the end
	     */
	    clust = rrfs_clustappend(file->fs, rrfile->currclust);
	    if (clust == FAT_CHAIN_END) {
#if _DEBUG
		kprintf("rrfile_create: cluster append failed\n");
#endif
		file_close(file);
		result = ENOSPC;
		goto createerror;
	    }
	    rrfile->currclust = clust;
	    result = rrfs_readclust(file, rrfile->currclust, &(file->buf));
	    if (result < 0) {
#if _DEBUG
		kprintf
		    ("rrfile_create: read cluster failed (%s)\n",
		     strerror(result));
#endif
		file_close(file);
		goto createerror;
	    }
	    bzero(bstart(file->buf), file->bufsize);
	    continue;
	}
	rrfile->currclust = clust;
	result = rrfs_readclust(file, rrfile->currclust, &(file->buf));
	if (result < 0) {
#if _DEBUG
	    kprintf("rrfile_create: read cluster failed (%s)\n",
		    strerror(result));
#endif
	    file_close(file);
	    goto createerror;
	}
    }
    deoff += bpos(file->buf);

    /* Initialize directory entry fields */
    de = (direntry_t) (bstart(file->buf) + bpos(file->buf));
    rrfs_deinit(de, fname, directory);

    /* Write directory entry */
    result = rrfs_writeclust(file, rrfile->currclust, &(file->buf));
    if (result < 0) {
#if _DEBUG
	kprintf("rrfile_create: write cluster failed (%s)\n",
		strerror(result));
#endif
	file_close(file);
	goto createerror;
    }
    file_close(file);
    file = tmpfile;
    rrfile = (rrfile_t) file->data;
    rrfile->declust = declust;
    rrfile->deoff = deoff;

  createerror:
    free(dir);
    return result;
}