- ip = namei(ndp);
- if (ip == NULL)
- return;
- dp = ndp->ni_pdir;
- if ((ip->i_mode&IFMT) == IFDIR) {
- register struct direct *d;
-
- d = &ndp->ni_dent;
- /*
- * Avoid ".", "..", and aliases of "." for obvious reasons.
- */
- if ((d->d_namlen == 1 && d->d_name[0] == '.') ||
- (d->d_namlen == 2 && bcmp(d->d_name, "..", 2) == 0) ||
- (dp == ip) || (ip->i_flag & IRENAME)) {
- iput(dp);
- if (dp == ip)
- irele(ip);
- else
- iput(ip);
- u.u_error = EINVAL;
- return;
- }
- ip->i_flag |= IRENAME;
- oldparent = dp->i_number;
- doingdirectory++;
- }
- iput(dp);
-
- /*
- * 1) Bump link count while we're moving stuff
- * around. If we crash somewhere before
- * completing our work, the link count
- * may be wrong, but correctable.
- */
- ip->i_nlink++;
- ip->i_flag |= ICHG;
- iupdat(ip, &time, &time, 1);
- IUNLOCK(ip);
-
- /*
- * When the target exists, both the directory
- * and target inodes are returned locked.
- */
- ndp->ni_nameiop = CREATE | LOCKPARENT | NOCACHE;
- ndp->ni_dirp = (caddr_t)uap->to;
- xp = namei(ndp);
- if (u.u_error) {
- error = u.u_error;
- goto out;
- }
- dp = ndp->ni_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().
- */
- if (oldparent != dp->i_number)
- newparent = dp->i_number;
- if (doingdirectory && newparent) {
- if (access(ip, IWRITE))
- goto bad;
- do {
- dp = ndp->ni_pdir;
- if (xp != NULL)
- iput(xp);
- u.u_error = checkpath(ip, dp);
- if (u.u_error)
- goto out;
- xp = namei(ndp);
- if (u.u_error) {
- error = u.u_error;
- goto out;
- }
- } while (dp != ndp->ni_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 new directory.
- * When source and destination have the same
- * parent we don't fool with the link count.
- */
- if (doingdirectory && newparent) {
- dp->i_nlink++;
- dp->i_flag |= ICHG;
- iupdat(dp, &time, &time, 1);
- }
- error = direnter(ip, ndp);
- 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;
- /*
- * If the parent directory is "sticky", then the user must
- * own the parent directory, or the destination of the rename,
- * otherwise the destination may not be changed (except by
- * root). This implements append-only directories.
- */
- if ((dp->i_mode & ISVTX) && u.u_uid != 0 &&
- u.u_uid != dp->i_uid && xp->i_uid != u.u_uid) {
- error = EPERM;
- 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, dp->i_number) || xp->i_nlink > 2) {
- error = ENOTEMPTY;
- goto bad;
- }
- if (!doingdirectory) {
- error = ENOTDIR;
- goto bad;
- }
- cacheinval(dp);
- } else if (doingdirectory) {