release/src/router/busybox/e2fsprogs/e2p/fgetsetversion.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * fgetversion.c        - Get a file version on an ext2 file system
   4  * fsetversion.c        - Set a file version on an ext2 file system
   5  *
   6  *
   7  * Copyright (C) 1993, 1994  Remy Card <card@masi.ibp.fr>
   8  *                           Laboratoire MASI, Institut Blaise Pascal
   9  *                           Universite Pierre et Marie Curie (Paris VI)
  10  *
  11  * This file can be redistributed under the terms of the GNU Library General
  12  * Public License
  13  */
  14
  15 /*
  16  * History:
  17  * 93/10/30     - Creation
  18  */
  19
  20 #ifdef HAVE_ERRNO_H
  21 #include <errno.h>
  22 #endif
  23 #ifdef HAVE_UNISTD_H
  24 #include <unistd.h>
  25 #endif
  26 #include <fcntl.h>
  27 #include <sys/ioctl.h>
  28
  29 #include "e2p.h"
  30
  31 #ifdef O_LARGEFILE
  32 #define OPEN_FLAGS (O_RDONLY|O_NONBLOCK|O_LARGEFILE)
  33 #else
  34 #define OPEN_FLAGS (O_RDONLY|O_NONBLOCK)
  35 #endif
  36
  37 /*
  38    To do fsetversion:     unsigned long *ptr_version must be set to NULL.
  39                       and unsigned long version must be set to a value
  40    To do fgetversion:     unsigned long *ptr_version must NOT be set to NULL
  41                       and unsigned long version is ignored.
  42         TITO.
  43 */
  44
  45 int fgetsetversion (const char * name, unsigned long * get_version, unsigned long set_version)
  46 {
  47 #ifdef HAVE_EXT2_IOCTLS
  48         int fd, r, ver, save_errno = 0;
  49
  50         fd = open (name, OPEN_FLAGS);
  51         if (fd == -1)
  52                 return -1;
  53         if (!get_version) {
  54                 ver = (int) set_version;
  55                 r = ioctl (fd, EXT2_IOC_SETVERSION, &ver);
  56         } else {
  57                 r = ioctl (fd, EXT2_IOC_GETVERSION, &ver);
  58                 *get_version = ver;
  59         }
  60         if (r == -1)
  61                 save_errno = errno;
  62         close (fd);
  63         if (save_errno)
  64                 errno = save_errno;
  65         return r;
  66 #else /* ! HAVE_EXT2_IOCTLS */
  67         errno = EOPNOTSUPP;
  68         return -1;
  69 #endif /* ! HAVE_EXT2_IOCTLS */
  70 }