From: Ion Badulescu Subject: Re: Re: [autofs] Server/client mismatch over status of a mount ... Date: Wed, 19 Feb 2003 08:58:14 -0500 Sender: nfs-admin@lists.sourceforge.net Message-ID: <200302191358.h1JDwECX026719@buggy.badula.org> References: <1199.195.252.45.39.1045648619.squirrel@www.zytor.com> Cc: , , , Return-path: Received: from ool-4351594a.dyn.optonline.net ([67.81.89.74] helo=badula.org) by sc8-sf-list1.sourceforge.net with esmtp (Cipher TLSv1:DES-CBC3-SHA:168) (Exim 3.31-VA-mm2 #1 (Debian)) id 18lUk9-0006O2-00 for ; Wed, 19 Feb 2003 05:58:37 -0800 To: "H. Peter Anvin" In-Reply-To: <1199.195.252.45.39.1045648619.squirrel@www.zytor.com> Errors-To: nfs-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Unsubscribe: , List-Archive: On Wed, 19 Feb 2003 01:56:59 -0800 (PST), H. Peter Anvin wrote: > Well, it does, but the test is a sieve, rather than a true test, as there > is no protection against race conditions. It's mostly there to avoid the > high overheard of the umount operation when it's not necessary or > desirable. > > A user can come in between the test and the umount request, and autofs > depends on /bin/umount signalling error without harmful side effects. Isn't autofs v4 supposed to fix this? I remember Jeremy mentioning that the filesystem would lock all accesses to a dentry scheduled to be unmounted until the daemon replied to the request. In fact, from his web page: Previously, when the kernel sent an expire message to the daemon it was more an hint than anything else. Now the kernel makes certain that the tree isn't busy before sending an expire message to the daemon. It also blocks all new users of the tree until the umount is complete, so that they can't see a partially mounted tree. Ion -- It is better to keep your mouth shut and be thought a fool, than to open it and remove all doubt. ------------------------------------------------------- This SF.net email is sponsored by: SlickEdit Inc. Develop an edge. The most comprehensive and flexible code editor you can use. Code faster. C/C++, C#, Java, HTML, XML, many more. FREE 30-Day Trial. www.slickedit.com/sourceforge _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs