A new version of the format for Samba server related file system extended attributes is expected in the next version of Samba so the topic of create time and nanosecond timestamps for Linux has come up again. Since some file systems don't support storing create time (birth time), and none support updating create time, or for that matter for storing any nanosecond timestamps at all (a millisecond seems like a much longer time today than when the stat structure was defined), and dos attributes, Samba server stores these in extended attributes, which is awkward on those file systems which store (different) versions of these on disk. In the absence of any syscalls for utimes (nanosecond granularity) and no syscall for returning (or setting) create time (birth time), and ext4 likely to become popular (ext4 stores nanosecond timestamps, and create time), Samba developers (and probably other apps such as backup applications) need a way to modify the inode's nanosecond timestamps and get at file create time, perhaps via ioctl and/or xattr. I think the chance of adding new syscalls for these and libc getting modified for this is near zero, so any opinions about the best way for Samba server to get at this information? Mingming Cao wrote: > 1) Ext4 adds support for date-created timestamps. But, current stat()interface > doesn't support the file creation time/delete time. As far as I know, it is hard > to modify or add the necessary systemcall to export this info out to > user programs for now. These changes would require coordination of many projects. >2) from the linux man page utimes seems only allow to set microsecond timestamp -- 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
