NetBSD/sys/msdosfs/msdosfs_conv.c

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brought in fixed/renamed/matching MS-DOS FS code, from Jeff Polk <polk@bsdi.com>. His notes are as follows: ------------------------------------------------------------------------------ July 22, 1993 - Changed name of entire package from PCFS to MSDOSFS - Fixed bugs: root directory size in clusters instead of bytes growing directory didn't update in-core size link, symlink, mknod didn't free locked parent (deadlock) lookup returned real error on create and rename instead of EJUSTRETURN rename changed `.' entry in child instead of name entry in parent rename removed `.' entry in child instead of removing entry in parent when moving a directory from one dir to another createde() left new node locked when write of parent failed (deadlock) removede() decremented refcount even on error (rmdir's which failed due to write errors left in-core cache entries inconsistent) changed validation for filesystem to not check for the boot signature since some disks (e.g., mtools) aren't bootable directories are always show current time as modify time (needed for NFS export since DOS never updates dir mod times -- ctime is true create time). - Added support for cookies changes to the readdir() vnode interface (#ifdef __bsdi__) - Punted on the whole problem of inode generation numbers. This means that there's a chance of using a stale file handle to access a new file, but it doesn't appear to be the common case, and I don't see how to generate reasonable generation numbers without changing something on the disk (which is the way the SVR4 filesystem survival kit guys did it). I don't think it would be very safe to change the on-disk format. Jeff Polk (polk@BSDI.COM) ------------------------------------------------------------------------------
1993-08-13 15:35:13 +04:00
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*
1993-12-18 03:40:47 +03:00
* $Id: msdosfs_conv.c,v 1.2 1993/12/18 00:50:38 mycroft Exp $
brought in fixed/renamed/matching MS-DOS FS code, from Jeff Polk <polk@bsdi.com>. His notes are as follows: ------------------------------------------------------------------------------ July 22, 1993 - Changed name of entire package from PCFS to MSDOSFS - Fixed bugs: root directory size in clusters instead of bytes growing directory didn't update in-core size link, symlink, mknod didn't free locked parent (deadlock) lookup returned real error on create and rename instead of EJUSTRETURN rename changed `.' entry in child instead of name entry in parent rename removed `.' entry in child instead of removing entry in parent when moving a directory from one dir to another createde() left new node locked when write of parent failed (deadlock) removede() decremented refcount even on error (rmdir's which failed due to write errors left in-core cache entries inconsistent) changed validation for filesystem to not check for the boot signature since some disks (e.g., mtools) aren't bootable directories are always show current time as modify time (needed for NFS export since DOS never updates dir mod times -- ctime is true create time). - Added support for cookies changes to the readdir() vnode interface (#ifdef __bsdi__) - Punted on the whole problem of inode generation numbers. This means that there's a chance of using a stale file handle to access a new file, but it doesn't appear to be the common case, and I don't see how to generate reasonable generation numbers without changing something on the disk (which is the way the SVR4 filesystem survival kit guys did it). I don't think it would be very safe to change the on-disk format. Jeff Polk (polk@BSDI.COM) ------------------------------------------------------------------------------
1993-08-13 15:35:13 +04:00
*/
/*
* System include files.
*/
1993-12-18 03:40:47 +03:00
#include <sys/param.h>
#include <sys/time.h>
#include <sys/kernel.h> /* defines tz */
brought in fixed/renamed/matching MS-DOS FS code, from Jeff Polk <polk@bsdi.com>. His notes are as follows: ------------------------------------------------------------------------------ July 22, 1993 - Changed name of entire package from PCFS to MSDOSFS - Fixed bugs: root directory size in clusters instead of bytes growing directory didn't update in-core size link, symlink, mknod didn't free locked parent (deadlock) lookup returned real error on create and rename instead of EJUSTRETURN rename changed `.' entry in child instead of name entry in parent rename removed `.' entry in child instead of removing entry in parent when moving a directory from one dir to another createde() left new node locked when write of parent failed (deadlock) removede() decremented refcount even on error (rmdir's which failed due to write errors left in-core cache entries inconsistent) changed validation for filesystem to not check for the boot signature since some disks (e.g., mtools) aren't bootable directories are always show current time as modify time (needed for NFS export since DOS never updates dir mod times -- ctime is true create time). - Added support for cookies changes to the readdir() vnode interface (#ifdef __bsdi__) - Punted on the whole problem of inode generation numbers. This means that there's a chance of using a stale file handle to access a new file, but it doesn't appear to be the common case, and I don't see how to generate reasonable generation numbers without changing something on the disk (which is the way the SVR4 filesystem survival kit guys did it). I don't think it would be very safe to change the on-disk format. Jeff Polk (polk@BSDI.COM) ------------------------------------------------------------------------------
1993-08-13 15:35:13 +04:00
/*
* MSDOSFS include files.
*/
1993-12-18 03:40:47 +03:00
#include <msdosfs/direntry.h>
brought in fixed/renamed/matching MS-DOS FS code, from Jeff Polk <polk@bsdi.com>. His notes are as follows: ------------------------------------------------------------------------------ July 22, 1993 - Changed name of entire package from PCFS to MSDOSFS - Fixed bugs: root directory size in clusters instead of bytes growing directory didn't update in-core size link, symlink, mknod didn't free locked parent (deadlock) lookup returned real error on create and rename instead of EJUSTRETURN rename changed `.' entry in child instead of name entry in parent rename removed `.' entry in child instead of removing entry in parent when moving a directory from one dir to another createde() left new node locked when write of parent failed (deadlock) removede() decremented refcount even on error (rmdir's which failed due to write errors left in-core cache entries inconsistent) changed validation for filesystem to not check for the boot signature since some disks (e.g., mtools) aren't bootable directories are always show current time as modify time (needed for NFS export since DOS never updates dir mod times -- ctime is true create time). - Added support for cookies changes to the readdir() vnode interface (#ifdef __bsdi__) - Punted on the whole problem of inode generation numbers. This means that there's a chance of using a stale file handle to access a new file, but it doesn't appear to be the common case, and I don't see how to generate reasonable generation numbers without changing something on the disk (which is the way the SVR4 filesystem survival kit guys did it). I don't think it would be very safe to change the on-disk format. Jeff Polk (polk@BSDI.COM) ------------------------------------------------------------------------------
1993-08-13 15:35:13 +04:00
/*
* Days in each month in a regular year.
*/
u_short regyear[] = {
31, 28, 31, 30, 31, 30,
31, 31, 30, 31, 30, 31
};
/*
* Days in each month in a leap year.
*/
u_short leapyear[] = {
31, 29, 31, 30, 31, 30,
31, 31, 30, 31, 30, 31
};
/*
* Variables used to remember parts of the last time conversion. Maybe we
* can avoid a full conversion.
*/
u_long lasttime;
u_long lastday;
union dosdate lastddate;
union dostime lastdtime;
/*
* Convert the unix version of time to dos's idea of time to be used in
* file timestamps. The passed in unix time is assumed to be in GMT.
*/
void
unix2dostime(tvp, ddp, dtp)
struct timeval *tvp;
union dosdate *ddp;
union dostime *dtp;
{
u_long days;
u_long inc;
u_long year;
u_long month;
u_short *months;
/*
* If the time from the last conversion is the same as now, then
* skip the computations and use the saved result.
*/
if (lasttime != tvp->tv_sec) {
lasttime = tvp->tv_sec - (tz.tz_minuteswest * 60)
/* +- daylight savings time correction */ ;
lastdtime.dts.dt_2seconds = (lasttime % 60) >> 1;
lastdtime.dts.dt_minutes = (lasttime / 60) % 60;
lastdtime.dts.dt_hours = (lasttime / (60 * 60)) % 24;
/*
* If the number of days since 1970 is the same as the last
* time we did the computation then skip all this leap year
* and month stuff.
*/
days = lasttime / (24 * 60 * 60);
if (days != lastday) {
lastday = days;
for (year = 1970;; year++) {
inc = year & 0x03 ? 365 : 366;
if (days < inc)
break;
days -= inc;
}
months = year & 0x03 ? regyear : leapyear;
for (month = 0; month < 12; month++) {
if (days < months[month])
break;
days -= months[month];
}
lastddate.dds.dd_day = days + 1;
lastddate.dds.dd_month = month + 1;
/*
* Remember dos's idea of time is relative to 1980.
* unix's is relative to 1970. If somehow we get a
* time before 1980 then don't give totally crazy
* results.
*/
lastddate.dds.dd_year = year < 1980 ? 0 : year - 1980;
}
}
dtp->dti = lastdtime.dti;
ddp->ddi = lastddate.ddi;
}
/*
* The number of seconds between Jan 1, 1970 and Jan 1, 1980. In that
* interval there were 8 regular years and 2 leap years.
*/
#define SECONDSTO1980 (((8 * 365) + (2 * 366)) * (24 * 60 * 60))
union dosdate lastdosdate;
u_long lastseconds;
/*
* Convert from dos' idea of time to unix'. This will probably only be
* called from the stat(), and fstat() system calls and so probably need
* not be too efficient.
*/
void
dos2unixtime(ddp, dtp, tvp)
union dosdate *ddp;
union dostime *dtp;
struct timeval *tvp;
{
u_long seconds;
u_long month;
u_long yr;
u_long days;
u_short *months;
seconds = (dtp->dts.dt_2seconds << 1) +
(dtp->dts.dt_minutes * 60) +
(dtp->dts.dt_hours * 60 * 60);
/*
* If the year, month, and day from the last conversion are the
* same then use the saved value.
*/
if (lastdosdate.ddi != ddp->ddi) {
lastdosdate.ddi = ddp->ddi;
days = 0;
for (yr = 0; yr < ddp->dds.dd_year; yr++) {
days += yr & 0x03 ? 365 : 366;
}
months = yr & 0x03 ? regyear : leapyear;
/*
* Prevent going from 0 to 0xffffffff in the following
* loop.
*/
if (ddp->dds.dd_month == 0) {
printf("dos2unixtime(): month value out of range (%d)\n",
ddp->dds.dd_month);
ddp->dds.dd_month = 1;
}
for (month = 0; month < ddp->dds.dd_month - 1; month++) {
days += months[month];
}
days += ddp->dds.dd_day - 1;
lastseconds = (days * 24 * 60 * 60) + SECONDSTO1980;
}
tvp->tv_sec = seconds + lastseconds + (tz.tz_minuteswest * 60)
/* -+ daylight savings time correction */ ;
tvp->tv_usec = 0;
}
/*
* Cheezy macros to do case detection and conversion for the ascii
* character set. DOESN'T work for ebcdic.
*/
#define isupper(c) (c >= 'A' && c <= 'Z')
#define islower(c) (c >= 'a' && c <= 'z')
#define toupper(c) (c & ~' ')
#define tolower(c) (c | ' ')
/*
* DOS filenames are made of 2 parts, the name part and the extension part.
* The name part is 8 characters long and the extension part is 3
* characters long. They may contain trailing blanks if the name or
* extension are not long enough to fill their respective fields.
*/
/*
* Convert a DOS filename to a unix filename. And, return the number of
* characters in the resulting unix filename excluding the terminating
* null.
*/
int
dos2unixfn(dn, un)
u_char dn[11];
u_char *un;
{
int i;
int ni;
int ei;
int thislong = 0;
u_char c;
u_char *origun = un;
/*
* Find the last character in the name portion of the dos filename.
*/
for (ni = 7; ni >= 0; ni--)
if (dn[ni] != ' ')
break;
/*
* Find the last character in the extension portion of the
* filename.
*/
for (ei = 10; ei >= 8; ei--)
if (dn[ei] != ' ')
break;
/*
* Copy the name portion into the unix filename string. NOTE: DOS
* filenames are usually kept in upper case. To make it more unixy
* we convert all DOS filenames to lower case. Some may like this,
* some may not.
*/
for (i = 0; i <= ni; i++) {
c = dn[i];
*un++ = isupper(c) ? tolower(c) : c;
thislong++;
}
/*
* Now, if there is an extension then put in a period and copy in
* the extension.
*/
if (ei >= 8) {
*un++ = '.';
thislong++;
for (i = 8; i <= ei; i++) {
c = dn[i];
*un++ = isupper(c) ? tolower(c) : c;
thislong++;
}
}
*un++ = 0;
/*
* If first char of the filename is SLOT_E5 (0x05), then the real
* first char of the filename should be 0xe5. But, they couldn't
* just have a 0xe5 mean 0xe5 because that is used to mean a freed
* directory slot. Another dos quirk.
*/
if (*origun == SLOT_E5)
*origun = 0xe5;
return thislong;
}
/*
* Convert a unix filename to a DOS filename. This function does not ensure
* that valid characters for a dos filename are supplied.
*/
void
unix2dosfn(un, dn, unlen)
u_char *un;
u_char dn[11];
int unlen;
{
int i;
u_char c;
/*
* Fill the dos filename string with blanks. These are DOS's pad
* characters.
*/
for (i = 0; i <= 10; i++)
dn[i] = ' ';
/*
* The filenames "." and ".." are handled specially, since they
* don't follow dos filename rules.
*/
if (un[0] == '.' && un[1] == '\0') {
dn[0] = '.';
return;
}
if (un[0] == '.' && un[1] == '.' && un[2] == '\0') {
dn[0] = '.';
dn[1] = '.';
return;
}
/*
* Copy the unix filename into the dos filename string upto the end
* of string, a '.', or 8 characters. Whichever happens first stops
* us. This forms the name portion of the dos filename. Fold to
* upper case.
*/
for (i = 0; i <= 7 && unlen && (c = *un) && c != '.'; i++) {
dn[i] = islower(c) ? toupper(c) : c;
un++;
unlen--;
}
/*
* If the first char of the filename is 0xe5, then translate it to
* 0x05. This is because 0xe5 is the marker for a deleted
* directory slot. I guess this means you can't have filenames
* that start with 0x05. I suppose we should check for this and
* doing something about it.
*/
if (dn[0] == SLOT_DELETED)
dn[0] = SLOT_E5;
/*
* Strip any further characters up to a '.' or the end of the
* string.
*/
while (unlen && (c = *un) && c != '.') {
un++;
unlen--;
}
/*
* If we stopped on a '.', then get past it.
*/
if (c == '.')
un++;
/*
* Copy in the extension part of the name, if any. Force to upper
* case. Note that the extension is allowed to contain '.'s.
* Filenames in this form are probably inaccessable under dos.
*/
for (i = 8; i <= 10 && unlen && (c = *un); i++) {
dn[i] = islower(c) ? toupper(c) : c;
un++;
unlen--;
}
}
/*
* Get rid of these macros before someone discovers we are using such
* hideous things.
*/
#undef isupper
#undef islower
#undef toupper
#undef tolower