148 lines
4.6 KiB
C
148 lines
4.6 KiB
C
/* This file contains a few general purpose utility routines.
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*
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* The entry points into this file are
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* clock_time: ask the clock task for the real time
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* copy: copy a block of data
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* fetch_name: go get a path name from user space
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* no_sys: reject a system call that FS does not handle
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* panic: something awful has occurred; MINIX cannot continue
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* conv2: do byte swapping on a 16-bit int
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* conv4: do byte swapping on a 32-bit long
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*/
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#include "fs.h"
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#include <minix/com.h>
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#include <unistd.h>
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#include "buf.h"
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#include "file.h"
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#include "fproc.h"
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#include "inode.h"
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#include "param.h"
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PRIVATE int panicking; /* inhibits recursive panics during sync */
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/*===========================================================================*
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* clock_time *
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*===========================================================================*/
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PUBLIC time_t clock_time()
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{
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/* This routine returns the time in seconds since 1.1.1970. MINIX is an
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* astrophysically naive system that assumes the earth rotates at a constant
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* rate and that such things as leap seconds do not exist.
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*/
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register int k;
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clock_t uptime;
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if ( (k=getuptime(&uptime)) != OK) panic(__FILE__,"clock_time err", k);
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return( (time_t) (boottime + (uptime/HZ)));
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}
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/*===========================================================================*
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* fetch_name *
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*===========================================================================*/
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PUBLIC int fetch_name(path, len, flag)
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char *path; /* pointer to the path in user space */
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int len; /* path length, including 0 byte */
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int flag; /* M3 means path may be in message */
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{
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/* Go get path and put it in 'user_path'.
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* If 'flag' = M3 and 'len' <= M3_STRING, the path is present in 'message'.
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* If it is not, go copy it from user space.
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*/
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register char *rpu, *rpm;
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int r;
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/* Check name length for validity. */
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if (len <= 0) {
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err_code = EINVAL;
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return(EGENERIC);
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}
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if (len > PATH_MAX) {
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err_code = ENAMETOOLONG;
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return(EGENERIC);
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}
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if (flag == M3 && len <= M3_STRING) {
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/* Just copy the path from the message to 'user_path'. */
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rpu = &user_path[0];
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rpm = m_in.pathname; /* contained in input message */
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do { *rpu++ = *rpm++; } while (--len);
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r = OK;
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} else {
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/* String is not contained in the message. Get it from user space. */
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r = sys_datacopy(who, (vir_bytes) path,
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FS_PROC_NR, (vir_bytes) user_path, (phys_bytes) len);
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}
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return(r);
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}
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/*===========================================================================*
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* no_sys *
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*===========================================================================*/
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PUBLIC int no_sys()
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{
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/* Somebody has used an illegal system call number */
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return(EINVAL);
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}
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/*===========================================================================*
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* panic *
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*===========================================================================*/
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PUBLIC void panic(who, mess, num)
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char *who; /* who caused the panic */
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char *mess; /* panic message string */
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int num; /* number to go with it */
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{
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/* Something awful has happened. Panics are caused when an internal
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* inconsistency is detected, e.g., a programming error or illegal value of a
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* defined constant.
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*/
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int i;
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if (panicking) return; /* do not panic during a sync */
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panicking = TRUE; /* prevent another panic during the sync */
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printf("FS panic (%s): %s ", who, mess);
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if (num != NO_NUM) printf("%d",num);
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(void) do_sync(); /* flush everything to the disk */
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sys_exit(1);
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}
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/*===========================================================================*
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* conv2 *
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*===========================================================================*/
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PUBLIC unsigned conv2(norm, w)
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int norm; /* TRUE if no swap, FALSE for byte swap */
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int w; /* promotion of 16-bit word to be swapped */
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{
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/* Possibly swap a 16-bit word between 8086 and 68000 byte order. */
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if (norm) return( (unsigned) w & 0xFFFF);
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return( ((w&BYTE) << 8) | ( (w>>8) & BYTE));
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}
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/*===========================================================================*
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* conv4 *
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*===========================================================================*/
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PUBLIC long conv4(norm, x)
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int norm; /* TRUE if no swap, FALSE for byte swap */
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long x; /* 32-bit long to be byte swapped */
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{
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/* Possibly swap a 32-bit long between 8086 and 68000 byte order. */
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unsigned lo, hi;
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long l;
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if (norm) return(x); /* byte order was already ok */
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lo = conv2(FALSE, (int) x & 0xFFFF); /* low-order half, byte swapped */
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hi = conv2(FALSE, (int) (x>>16) & 0xFFFF); /* high-order half, swapped */
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l = ( (long) lo <<16) | hi;
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return(l);
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}
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