1  /*
 2   * blockio.cc
 3   *
 4   *
 5   */
 6  
 7  #define _LARGEFILE_SOURCE
 8  #define _FILE_OFFSET_BITS 64
 9  
10  #include "version.h"
11  #include "blockio.h"
12  #include "osutils.h"
13  #include <stdio.h>
14  #include <string.h>
15  #include <sys/types.h>
16  #include <sys/stat.h>
17  #include <fcntl.h>
18  #include <unistd.h>
19  #include <stdint.h>
20  
21  __ID("@(#) $Id$");
22  
23  ssize_t readlogicalblocks(source & s,
24  void * buffer,
25  long long pos, long long count)
26  {
27    long long result = 0;
28  
29    memset(buffer, 0, count*s.blocksize);
30  
31                                                    /* attempt to read past the end of the section */
32    if((s.size>0) && ((pos+count)*s.blocksize>s.size)) return 0;
33  
34    result = lseek(s.fd, s.offset + pos*s.blocksize, SEEK_SET);
35  
36    if(result == -1) return 0;
37  
38    result = read(s.fd, buffer, count*s.blocksize);
39  
40    if(result!=count*s.blocksize)
41      return 0;
42    else
43      return count;
44  }