- 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;
- /*
- * 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) {
- error = EISDIR;
- goto bad;
- }
- dirrewrite(dp, ip, ndp);
- 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 the remaining link would point to
- * a directory without "." or ".." entries.
- */
- 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.
- */
- ndp->ni_nameiop = DELETE | LOCKPARENT;
- ndp->ni_segflg = UIO_USERSPACE;
- ndp->ni_dirp = uap->from;
- xp = namei(ndp);
- if (xp != NULL)
- dp = ndp->ni_pdir;
- else
- dp = NULL;
- /*
- * Insure that the directory entry still exists and has not
- * changed while the new name has been entered. If the source is
- * a file then the entry may have been unlinked or renamed. In
- * either case there is no further work to be done. If the source
- * is a directory then it cannot have been rmdir'ed; its link
- * count of three would cause a rmdir to fail with ENOTEMPTY.
- * The IRENAME flag insures that it cannot be moved by another
- * rename.
- */
- if (xp != ip) {
- if (doingdirectory)
- panic("rename: lost dir entry");
- } else {
- /*
- * If the source is a directory with a
- * new parent, the link count of the old
- * parent directory must be decremented
- * and ".." set to point to the new parent.
- */
- if (doingdirectory && newparent) {
- dp->i_nlink--;
- dp->i_flag |= ICHG;
- error = rdwri(UIO_READ, xp, (caddr_t)&dirbuf,
- sizeof (struct dirtemplate), (off_t)0, 1,
- (int *)0);
- if (error == 0) {
- if (dirbuf.dotdot_namlen != 2 ||
- dirbuf.dotdot_name[0] != '.' ||
- dirbuf.dotdot_name[1] != '.') {
- printf("rename: mangled dir\n");
- } else {
- dirbuf.dotdot_ino = newparent;
- (void) rdwri(UIO_WRITE, xp,
- (caddr_t)&dirbuf,
- sizeof (struct dirtemplate),
- (off_t)0, 1, (int *)0);
- cacheinval(dp);
- }
- }
- }
- if (dirremove(ndp)) {
- xp->i_nlink--;
- xp->i_flag |= ICHG;
- }
- xp->i_flag &= ~IRENAME;
- if (error == 0) /* XXX conservative */
- error = u.u_error;
- }
- if (dp)
- iput(dp);
- if (xp)
- iput(xp);
- irele(ip);
- if (error)
- u.u_error = error;
- return;
-
-bad:
- iput(dp);
-bad1:
- if (xp)
- iput(xp);
-out:
- ip->i_nlink--;
- ip->i_flag |= ICHG;
- irele(ip);
- if (error)
- u.u_error = error;