From: tridge-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org Subject: Re: [PATCH 02/18] xstat: Add a pair of system calls to make extended file stats available [ver #6] Date: Fri, 23 Jul 2010 12:12:47 +1000 Message-ID: <19528.64159.999224.437890@samba.org> References: <20100715021709.5544.64506.stgit@warthog.procyon.org.uk> <20100715021712.5544.44845.stgit@warthog.procyon.org.uk> <30448.1279800887@redhat.com> <20100722162712.GB10352@jeremy-laptop> <19528.60019.28495.655512@samba.org> <20100723012130.GD16373@thunk.org> Reply-To: tridge-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: Linus Torvalds , Jeremy Allison , linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Volker.Lendecke-3ekOc4rQMZmzQB+pC5nmwQ@public.gmane.org, samba-technical-w/Ol4Ecudpl8XjKLYN78aQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jan Engelhardt , David Howells , viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ted Ts'o Return-path: In-Reply-To: <20100723012130.GD16373-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org> Sender: linux-nfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-ext4.vger.kernel.org Hi Ted, > Does it literally mean "file creation time" in terms of when the OS > created the file, or does it mean "file" in the sense of > application contents. For example, if an application edits the > file and saves it out using "write file to foo.new; sync; rename > foo to foo.bak; rename foo.new to foo", should the creation time > for the newly written file "foo" be the time when the editor saved > out the file (i.e., when "foo.new" was created), or copied from the > original file "foo"'s creation time. In Windows this is can be controlled by applications, but it also is done at the filesystem level in NTFS using a technique that Microsoft call "File System Tunneling". If you create a file with the same name within a short time (default 15s and settable in the registry) of when the file previously existed then it will get the same CreationTime as the previous file. For details see http://support.microsoft.com/kb/172190 Some applications also do this regardless of the registry setting for MaximumTunnelEntryAgeInSeconds. They use the ability to set the CreationTime to get the same behaviour. Cheers, Tridge -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html