text: /*
   * Copyright (c) 2002 Juli Mallett.  All rights reserved.
   *
   * This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
   * FreeBSD project.  Redistribution and use in source and binary forms, with
   * or without modification, are permitted provided that the following
   * conditions are met:
   *
   * 1. Redistribution of source code must retain the above copyright notice,
   *    this list of conditions and the following disclaimer.
   * 2. Redistribution in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
   * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD: src/lib/libufs/block.c,v 1.10 2003/10/07 07:12:22 phk Exp $");
  
  #include <sys/param.h>
  #include <sys/mount.h>
  #include <sys/disklabel.h>
  #include <sys/stat.h>
  
  #include <ufs/ufs/ufsmount.h>
  #include <ufs/ufs/dinode.h>
  #include <ufs/ffs/fs.h>
  
  #include <errno.h>
  #include <fcntl.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #include <libufs.h>
  
  ssize_t
  bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
  {
  	void *p2;
  	ssize_t cnt;
  
  	ERROR(disk, NULL);
  
  	p2 = data;
  	/*
  	 * XXX: various disk controllers require alignment of our buffer
  	 * XXX: which is stricter than struct alignment.
  	 * XXX: Bounce the buffer if not 64 byte aligned.
  	 * XXX: this can be removed if/when the kernel is fixed
  	 */
  	if (((intptr_t)data) & 0x3f) {
  		p2 = malloc(size);
  		if (p2 == NULL)
  			ERROR(disk, "allocate bounce buffer");
  	}
  	cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
  	if (cnt == -1) {
  		ERROR(disk, "read error from block device");
  		goto fail;
  	}
  	if (cnt == 0) {
  		ERROR(disk, "end of file from block device");
  		goto fail;
  	}
  	if ((size_t)cnt != size) {
  		ERROR(disk, "short read or read error from block device");
  		goto fail;
  	}
  	if (p2 != data) {
  		memcpy(data, p2, size);
  		free(p2);
  	}
  	return (cnt);
  fail:	memset(data, 0, size);
  	if (p2 != data) {
  		free(p2);
  	}
  	return (-1);
  }
  
  ssize_t
  bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
  {
  	ssize_t cnt;
  	int rv;
  	void *p2 = NULL;
  
  	ERROR(disk, NULL);
  
  	rv = ufs_disk_write(disk);
  	if (rv == -1) {
  		ERROR(disk, "failed to open disk for writing");
  		return (-1);
  	}
  
  	/*
  	 * XXX: various disk controllers require alignment of our buffer
  	 * XXX: which is stricter than struct alignment.
  	 * XXX: Bounce the buffer if not 64 byte aligned.
  	 * XXX: this can be removed if/when the kernel is fixed
  	 */
  	if (((intptr_t)data) & 0x3f) {
  		p2 = malloc(size);
  		if (p2 == NULL)
  			ERROR(disk, "allocate bounce buffer");
  		memcpy(p2, data, size);
  		data = p2;
  	}
  	cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
  	if (p2 != NULL)
  		free(p2);
  	if (cnt == -1) {
  		ERROR(disk, "write error to block device");
  		return (-1);
  	}
  	if ((size_t)cnt != size) {
  		ERROR(disk, "short write to block device");
  		return (-1);
  	}
  
  	return (cnt);
  }
  