From owner-freebsd-fs@FreeBSD.ORG Tue Jun 21 15:43:31 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 470D31065673 for ; Tue, 21 Jun 2011 15:43:31 +0000 (UTC) (envelope-from will@firepipe.net) Received: from mail-wy0-f182.google.com (mail-wy0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id E12758FC23 for ; Tue, 21 Jun 2011 15:43:30 +0000 (UTC) Received: by wyb33 with SMTP id 33so4588673wyb.13 for ; Tue, 21 Jun 2011 08:43:30 -0700 (PDT) MIME-Version: 1.0 Received: by 10.216.120.201 with SMTP id p51mr3148046weh.89.1308669378425; Tue, 21 Jun 2011 08:16:18 -0700 (PDT) Received: by 10.216.12.8 with HTTP; Tue, 21 Jun 2011 08:16:18 -0700 (PDT) Date: Tue, 21 Jun 2011 09:16:18 -0600 Message-ID: From: Will Andrews To: freebsd-fs@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Subject: bumping mount path lengths in struct statfs X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Jun 2011 15:43:31 -0000 Hi, struct statfs contains the following: 90 char f_mntfromname[MNAMELEN]; /* mounted filesystem */ 91 char f_mntonname[MNAMELEN]; /* directory on which mounted */ Where MNAMELEN is, currently, 88. These limit the length of the path that a filesystem can be mounted to. This is enforced by kern/vfs_mount.c:vfs_donmount(). This limit seems archaic, especially given use cases like virtualization (large filesystem structures to support underlying VMs), builds (which often make extensive use of chroot with nullfs/NFS), ZFS, snapshots, etc. Does anyone object to bumping MNAMELEN to 1024 (PATH_MAX/MAXPATHLEN)? Or some other reasonably large value? --Will.