4.1cBSD/a/sys/sys/sys_directory.c

/*	sys_directory.c	5.8	83/01/01	*/

#include "../machine/reg.h"

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/inode.h"
#include "../h/proc.h"
#include "../h/timeb.h"
#include "../h/times.h"
#include "../h/reboot.h"
#include "../h/fs.h"
#include "../h/conf.h"
#include "../h/buf.h"
#include "../h/mount.h"
#include "../h/quota.h"
#include "../h/nami.h"
#include "../h/kernel.h"
#include "../h/uio.h"

/*
 * A virgin directory (no blushing please).
 */
struct dirtemplate dirtemplate = {
	0, 12, 1, ".",
	0, DIRBLKSIZ - 12, 2, ".."
};

/*
 * Mkdir system call
 */
mkdir()
{
	struct a {
		char	*name;
		int	dmode;
	} *uap;
	register struct inode *ip, *dp;

	uap = (struct a *)u.u_ap;
	ip = namei(uchar, CREATE, 0);
	if (u.u_error)
		return;
	if (ip != NULL) {
		iput(ip);
		u.u_error = EEXIST;
		return;
	}
	dp = u.u_pdir;
	uap->dmode &= 0777;
	uap->dmode |= IFDIR;
	/*
	 * Must simulate part of maknode here
	 * in order to acquire the inode, but
	 * not have it entered in the parent
	 * directory.  The entry is made later
	 * after writing "." and ".." entries out.
	 */
	ip = ialloc(dp, dirpref(dp->i_fs), uap->dmode);
	if (ip == NULL) {
		iput(dp);
		return;
	}
#ifdef QUOTA
	if (ip->i_dquot != NODQUOT)
		panic("mkdir: dquot");
#endif
	ip->i_flag |= IACC|IUPD|ICHG;
	ip->i_mode = uap->dmode & ~u.u_cmask;
	ip->i_nlink = 2;
	ip->i_uid = u.u_uid;
	ip->i_gid = dp->i_gid;
#ifdef QUOTA
	ip->i_dquot = inoquota(ip);
#endif
	iupdat(ip, &time, &time, 1);

	/*
	 * Bump link count in parent directory
	 * to reflect work done below.  Should
	 * be done before reference is created
	 * so reparation is possible if we crash.
	 */
	dp->i_nlink++;
	dp->i_flag |= ICHG;
	iupdat(dp, &time, &time, 1);

	/*
	 * Initialize directory with "."
	 * and ".." from static template.
	 */
	dirtemplate.dot_ino = ip->i_number;
	dirtemplate.dotdot_ino = dp->i_number;
	u.u_error = rdwri(UIO_WRITE, ip, (caddr_t)&dirtemplate,
		sizeof (dirtemplate), (off_t)0, 1, (int *)0);
	if (u.u_error) {
		dp->i_nlink--;
		dp->i_flag |= ICHG;
		goto bad;
	}
	/*
	 * Directory all set up, now
	 * install the entry for it in
	 * the parent directory.
	 */
	direnter(ip);
	dp = NULL;
	if (u.u_error) {
		u.u_dirp = uap->name;
		dp = namei(uchar, LOOKUP, 0);
		if (dp) {
			dp->i_nlink--;
			dp->i_flag |= ICHG;
		}
	}
bad:
	/*
	 * No need to do an explicit itrunc here,
	 * irele will do this for us because we set
	 * the link count to 0.
	 */
	if (u.u_error) {
		ip->i_nlink = 0;
		ip->i_flag |= ICHG;
	}
	if (dp)
		iput(dp);
	iput(ip);
}

/*
 * Rmdir system call.
 */
rmdir()
{
	struct a {
		char	*name;
	};
	register struct inode *ip, *dp;

	ip = namei(uchar, DELETE | LOCKPARENT, 0);
	if (ip == NULL)
		return;
	dp = u.u_pdir;
	/*
	 * No rmdir "." please.
	 */
	if (dp == ip) {
		irele(dp);
		iput(ip);
		u.u_error = EINVAL;
		return;
	}
	if ((ip->i_mode&IFMT) != IFDIR) {
		u.u_error = ENOTDIR;
		goto out;
	}
	/*
	 * Don't remove a mounted on directory.
	 */
	if (ip->i_dev != dp->i_dev) {
		u.u_error = EBUSY;
		goto out;
	}
	/*
	 * Verify the directory is empty.
	 * (Rmdir ".." won't be valid since
	 *  ".." will contain a reference to
	 *  the current directory and thus be
	 *  non-empty.)
	 */
	if (!dirempty(ip)) {
		u.u_error = ENOTEMPTY;
		goto out;
	}
	/*
	 * Delete reference to directory before purging
	 * inode.  If we crash in between, the directory
	 * will be reattached to lost+found,
	 */
	if (dirremove() == 0)
		goto out;
	dp->i_nlink--;
	dp->i_flag |= ICHG;
	iput(dp);
	dp = NULL;
	/*
	 * Truncate inode.  The only stuff left
	 * in the directory is "." and "..".  The
	 * "." reference is inconsequential since
	 * we're quashing it.  The ".." reference
	 * has already been adjusted above.
	 */
	ip->i_nlink = 0;
	itrunc(ip, (u_long)0);
out:
	if (dp)
		iput(dp);
	iput(ip);
}