minix/servers/fs/time.c

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2005-04-21 16:53:53 +02:00
/* This file takes care of those system calls that deal with time.
*
* The entry points into this file are
* do_utime: perform the UTIME system call
* do_time: perform the TIME system call
* do_stime: perform the STIME system call
* do_tims: perform the TIMES system call
*/
#include "fs.h"
#include <minix/callnr.h>
#include <minix/com.h>
#include "file.h"
#include "fproc.h"
#include "inode.h"
#include "param.h"
/*===========================================================================*
* do_utime *
*===========================================================================*/
PUBLIC int do_utime()
{
/* Perform the utime(name, timep) system call. */
register struct inode *rip;
register int len, r;
/* Adjust for case of 'timep' being NULL;
* utime_strlen then holds the actual size: strlen(name)+1.
*/
len = m_in.utime_length;
if (len == 0) len = m_in.utime_strlen;
/* Temporarily open the file. */
if (fetch_name(m_in.utime_file, len, M1) != OK) return(err_code);
if ( (rip = eat_path(user_path)) == NIL_INODE) return(err_code);
/* Only the owner of a file or the super_user can change its time. */
r = OK;
if (rip->i_uid != fp->fp_effuid && !super_user) r = EPERM;
if (m_in.utime_length == 0 && r != OK) r = forbidden(rip, W_BIT);
if (read_only(rip) != OK) r = EROFS; /* not even su can touch if R/O */
if (r == OK) {
if (m_in.utime_length == 0) {
rip->i_atime = clock_time();
rip->i_mtime = rip->i_atime;
} else {
rip->i_atime = m_in.utime_actime;
rip->i_mtime = m_in.utime_modtime;
}
rip->i_update = CTIME; /* discard any stale ATIME and MTIME flags */
rip->i_dirt = DIRTY;
}
put_inode(rip);
return(r);
}
/*===========================================================================*
* do_time *
*===========================================================================*/
PUBLIC int do_time()
{
/* Perform the time(tp) system call. */
m_out.reply_l1 = clock_time(); /* return time in seconds */
return(OK);
}
/*===========================================================================*
* do_stime *
*===========================================================================*/
PUBLIC int do_stime()
{
/* Perform the stime(tp) system call. Retrieve the system's uptime (ticks
* since boot) and store the time in seconds at system boot in the global
* variable 'boottime'.
*/
register int k;
clock_t uptime;
if (!super_user) return(EPERM);
if ( (k=sys_getuptime(&uptime)) != OK) panic("do_stime error", k);
boottime = (long) m_in.tp - (uptime/HZ);
return(OK);
}
/*===========================================================================*
* do_tims *
*===========================================================================*/
PUBLIC int do_tims()
{
/* Perform the times(buffer) system call. */
clock_t t[5];
sys_times(who, t);
m_out.reply_t1 = t[0];
m_out.reply_t2 = t[1];
m_out.reply_t3 = t[2];
m_out.reply_t4 = t[3];
m_out.reply_t5 = t[4];
return(OK);
}