servers/vfs/time.c

   1 /* This file takes care of those system calls that deal with time.
   2  *
   3  * The entry points into this file are
   4  *   do_utime:          perform the UTIME system call
   5  */
   6
   7 #include "fs.h"
   8 #include <minix/callnr.h>
   9 #include <minix/com.h>
  10 #include "file.h"
  11 #include "fproc.h"
  12 #include "param.h"
  13 #include "vnode.h"
  14 #include <minix/vfsif.h>
  15 #include "vmnt.h"
  16
  17 /*===========================================================================*
  18  *                              do_utime                                     *
  19  *===========================================================================*/
  20 PUBLIC int do_utime()
  21 {
  22 /* Perform the utime(name, timep) system call. */
  23   register int len;
  24   int r;
  25   uid_t uid;
  26   time_t actime, modtime;
  27   struct vnode *vp;
  28
  29   /* Adjust for case of 'timep' being NULL;
  30    * utime_strlen then holds the actual size: strlen(name)+1 */
  31   len = m_in.utime_length;
  32   if(len == 0) len = m_in.utime_strlen;
  33
  34   /* Temporarily open the file */
  35   if (fetch_name(m_in.utime_file, len, M1) != OK) return(err_code);
  36   if ((vp = eat_path(PATH_NOFLAGS)) == NIL_VNODE) return(err_code);
  37
  38   /* Only the owner of a file or the super user can change its name. */
  39   r = OK;
  40   if (vp->v_uid != fp->fp_effuid && fp->fp_effuid != SU_UID) r = EPERM;
  41   if (m_in.utime_length == 0 && r != OK) r = forbidden(vp, W_BIT);
  42   if (read_only(vp) != OK) r = EROFS; /* Not even su can touch if R/O */
  43   if (r == OK) {
  44         /* Issue request */
  45         if(m_in.utime_length == 0) {
  46                 actime = modtime = clock_time();
  47         } else {
  48                 actime = m_in.utime_actime;
  49                 modtime = m_in.utime_modtime;
  50         }
  51         r = req_utime(vp->v_fs_e, vp->v_inode_nr, actime, modtime);
  52   }
  53
  54   put_vnode(vp);
  55   return(r);
  56 }
  57