- /*
- * When the target exists, both the directory
- * and target inodes are returned locked.
- */
- u.u_dirp = (caddr_t)uap->to;
- xp = namei(uchar, CREATE | LOCKPARENT | NOCACHE, 0);
- if (u.u_error) {
- error = u.u_error;
- goto out;
- }
- dp = u.u_pdir;
- /*
- * If ".." must be changed (ie the directory gets a new
- * parent) then the source directory must not be in the
- * directory heirarchy above the target, as this would
- * orphan everything below the source directory. Also
- * the user must have write permission in the source so
- * as to be able to change "..". We must repeat the call
- * to namei, as the parent directory is unlocked by the
- * call to checkpath().
- */
- parentdifferent = oldparent != dp->i_number;
- if (doingdirectory && parentdifferent) {
- if (access(ip, IWRITE))
- goto bad;
- do {
- dp = u.u_pdir;
- if (xp != NULL)
- iput(xp);
- u.u_error = checkpath(ip, dp);
- if (u.u_error)
- goto out;
- u.u_dirp = (caddr_t)uap->to;
- xp = namei(uchar, CREATE | LOCKPARENT | NOCACHE, 0);
- if (u.u_error) {
- error = u.u_error;
- goto out;
- }
- } while (dp != u.u_pdir);
- }
- /*
- * 2) If target doesn't exist, link the target
- * to the source and unlink the source.
- * Otherwise, rewrite the target directory
- * entry to reference the source inode and
- * expunge the original entry's existence.
- */
- if (xp == NULL) {
- if (dp->i_dev != ip->i_dev) {
- error = EXDEV;
- goto bad;
- }
- /*
- * Account for ".." in directory.
- * When source and destination have the
- * same parent we don't fool with the
- * link count -- this isn't required
- * because we do a similar check below.
- */
- if (doingdirectory && parentdifferent) {
- dp->i_nlink++;
- dp->i_flag |= ICHG;
- iupdat(dp, &time, &time, 1);
- }
- error = direnter(ip);
- if (error)
- goto out;
- } else {
- if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev) {
- error = EXDEV;
- goto bad;
- }
- /*
- * Short circuit rename(foo, foo).
- */
- if (xp->i_number == ip->i_number)
- goto bad;
- /*
- * Target must be empty if a directory
- * and have no links to it.
- * Also, insure source and target are
- * compatible (both directories, or both
- * not directories).
- */
- if ((xp->i_mode&IFMT) == IFDIR) {
- if (!dirempty(xp) || xp->i_nlink > 2) {
- error = ENOTEMPTY;
- goto bad;
- }
- if (!doingdirectory) {
- error = ENOTDIR;
- goto bad;
- }
- } else if (doingdirectory) {
- error = EISDIR;
- goto bad;
- }
- dirrewrite(dp, ip);
- if (u.u_error) {
- error = u.u_error;
- goto bad1;
- }
- /*
- * Adjust the link count of the target to
- * reflect the dirrewrite above. If this is
- * a directory it is empty and there are
- * no links to it, so we can squash the inode and
- * any space associated with it. We disallowed
- * renaming over top of a directory with links to
- * it above, as we've no way to determine if
- * we've got a link or the directory itself, and
- * if we get a link, then ".." will be screwed up.
- */
- xp->i_nlink--;
- if (doingdirectory) {
- if (--xp->i_nlink != 0)
- panic("rename: linked directory");
- itrunc(xp, (u_long)0);
- }
- xp->i_flag |= ICHG;
- iput(xp);
- xp = NULL;
- }
-
- /*
- * 3) Unlink the source.
- */
- u.u_dirp = uap->from;
- dp = namei(uchar, DELETE, 0);
- /*
- * Insure directory entry still exists and
- * has not changed since the start of all
- * this. If either has occured, forget about
- * about deleting the original entry and just
- * adjust the link count in the inode.
- */
- if (dp == NULL || u.u_dent.d_ino != ip->i_number) {
- ip->i_nlink--;