Messages in this thread | | | Date | Fri, 30 Jul 2010 14:38:19 -0400 | Subject | Re: [PATCH 02/18] xstat: Add a pair of system calls to make extended file stats available [ver #6] | From | "J. Bruce Fields" <> |
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On Thu, Jul 29, 2010 at 09:04:01AM +1000, Neil Brown wrote: > On Wed, 28 Jul 2010 18:28:02 +0100 > David Howells <dhowells@redhat.com> wrote: > > > Neil Brown <neilb@suse.de> wrote: > > > > > ctime and mtime have real cache-coherence semantics which require them being > > > updated by the kernel (whether the cache is on an NFS client, in a backup > > > archive, or in a .o translation of a .c file). > > > > So does creation time, at least for CIFS caching. Creation time has potential > > for spotting when the object at a pathname has changed for something else, > > given the lack of inode number and inode generation from windows servers. > > Creation time gives us one more datum to use. > > This justifies for me why a CIFS client would want to extract the > creation-time from the CIFS protocol, but not why you want to expose it via a > generic interface. > The kernel/filesystem doesn't need to maintain creation-time to meet this > need, only the CIFS server needs to maintain it
For what it's worth, the NFSv4 server would also export creation time if we had it.
--b.
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