minix/lib/posix/_fcntl.c
Ben Gras 50b06261b6 Implementation of truncate(), ftruncate() and the F_FREESP fcntl().
Implemented by changing write_map to accept a WMAP_FREE flag. In that
case, it doesn't update the datablock (creating indirect zones as
necessary) pointer, but it frees the datablock if present. Also it
frees the single and double indirect blocks if unused.

This makes the implementation of truncate_inode() simpler.
truncate_inode() now accepts a truncation length which makes
implementing truncate() and ftruncate() simple.

This also allowed implementing the F_FREESP fcntl().
2006-01-11 17:14:51 +00:00

45 lines
829 B
C
Executable file

#include <lib.h>
#define fcntl _fcntl
#include <fcntl.h>
#include <stdarg.h>
#if _ANSI
PUBLIC int fcntl(int fd, int cmd, ...)
#else
PUBLIC int fcntl(fd, cmd)
int fd;
int cmd;
#endif
{
va_list argp;
message m;
va_start(argp, cmd);
/* Set up for the sensible case where there is no variable parameter. This
* covers F_GETFD, F_GETFL and invalid commands.
*/
m.m1_i3 = 0;
m.m1_p1 = NIL_PTR;
/* Adjust for the stupid cases. */
switch(cmd) {
case F_DUPFD:
case F_SETFD:
case F_SETFL:
m.m1_i3 = va_arg(argp, int);
break;
case F_GETLK:
case F_SETLK:
case F_SETLKW:
case F_FREESP:
m.m1_p1 = (char *) va_arg(argp, struct flock *);
break;
}
/* Clean up and make the system call. */
va_end(argp);
m.m1_i1 = fd;
m.m1_i2 = cmd;
return(_syscall(FS, FCNTL, &m));
}