On Tue, Jun 29, 2010 at 5:13 PM, Ulrich Drepper <drepper@xxxxxxxxx> wrote: > On Tue, Jun 29, 2010 at 13:03, David Howells <dhowells@xxxxxxxxxx> wrote: >> Add a pair of system calls to make extended file stats available, including >> file creation time, inode version and data version where available through the >> underlying filesystem: > > If you add something like this you might want to integrate another > extension. This has been discussed a long time ago. In almost no > situation all the information is needed. Some of the pieces of > information returned by the syscall might be harder to collect than > other. It makes sense in such a situation to allow the caller to > specify what she is interested in. A bitmask of some sort. This was > brought up by the HPC people with gigantic filesystems. > > For this the syscall interface should have a parameter to specify what > is requested and the stat-like structure should have a field > specifying what is actually present. The latter bitmask must be a > superset of the former. > > Previous discussions centered around reusing the stat data structure > and somehow make it work. But no clean solution was found. If a new > structure is added anyway this could solve the issue. That makes sense, especially for network file systems. NFSv4 protocol spec anticipates that: "With the NFS version 4 protocol, the client is able query what attributes the server supports and construct requests with only those supported attributes (or a subset thereof)." and we were talking about something similar for SMB2 Unix Extensions (posix extensions) at the last plugfest (for SMB2 kernel client to Samba) and testing events. -- Thanks, Steve -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
