servers/fs/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  *   do_stime:          PM informs FS about STIME system call
   6  */
   7
   8 #include "fs.h"
   9 #include <minix/callnr.h>
  10 #include <minix/com.h>
  11 #include "file.h"
  12 #include "fproc.h"
  13 #include "inode.h"
  14 #include "param.h"
  15
  16 /*===========================================================================*
  17  *                              do_utime                                     *
  18  *===========================================================================*/
  19 PUBLIC int do_utime()
  20 {
  21 /* Perform the utime(name, timep) system call. */
  22
  23   register struct inode *rip;
  24   register int len, r;
  25
  26   /* Adjust for case of 'timep' being NULL;
  27    * utime_strlen then holds the actual size: strlen(name)+1.
  28    */
  29   len = m_in.utime_length;
  30   if (len == 0) len = m_in.utime_strlen;
  31
  32   /* Temporarily open the file. */
  33   if (fetch_name(m_in.utime_file, len, M1) != OK) return(err_code);
  34   if ( (rip = eat_path(user_path)) == NIL_INODE) return(err_code);
  35
  36   /* Only the owner of a file or the super_user can change its time. */
  37   r = OK;
  38   if (rip->i_uid != fp->fp_effuid && !super_user) r = EPERM;
  39   if (m_in.utime_length == 0 && r != OK) r = forbidden(rip, W_BIT);
  40   if (read_only(rip) != OK) r = EROFS;  /* not even su can touch if R/O */
  41   if (r == OK) {
  42         if (m_in.utime_length == 0) {
  43                 rip->i_atime = clock_time();
  44                 rip->i_mtime = rip->i_atime;
  45         } else {
  46                 rip->i_atime = m_in.utime_actime;
  47                 rip->i_mtime = m_in.utime_modtime;
  48         }
  49         rip->i_update = CTIME;  /* discard any stale ATIME and MTIME flags */
  50         rip->i_dirt = DIRTY;
  51   }
  52
  53   put_inode(rip);
  54   return(r);
  55 }
  56
  57 /*===========================================================================*
  58  *                              do_stime                                     *
  59  *===========================================================================*/
  60 PUBLIC int do_stime()
  61 {
  62 /* Perform the stime(tp) system call. */
  63   boottime = (long) m_in.pm_stime;
  64   return(OK);
  65 }
  66