Messages in this thread | | | Date | Fri, 27 Nov 1998 16:45:04 -0800 (PST) | From | a sun <> | Subject | Re: kernel knowledge of localtime (user-level implememntation) |
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I certainly agree that timesone is a mountpoint option, not a system option. (Making the time zones loadable modules is hopefully the obvious hack.)
i still think that the kernel knowing about the actual timezone is not the thing to do. it looks like what you want is to somehow convert (network) filesystems that use local time to using utc. unfortunately, you can't. you can't even do it on a mountpoint basis as files are what get assigned dates. it's much simpler to admit that such usage is broken and always convert to local time from the perspective of where you are. think about the following situation:
on a broken filesystem, write a memo in PST, switch to EST, and then write another memo. switch back to PST and you've somehow created a file in the future. if you think about it, that's actually what's supposed to happen. in essence, using local time allows us to experience time travel in the safety of our computers and without the inconvenience of jet lag.
conceptually, switching back and forth from DST is just the same as switching timezones. you have to go through all the same steps. if you think of time as local time, you really do experience the gain/lose of an hour when you do DST switching.
The problem comes that the kernel needs to be able to do bidirectional conversion, and sometimes it gets tricky.
actually, we can solve most of the problems by just periodically calculating a delta between the two machines concepts of local time and using that for time conversion. that's actually what i suggested to petr for ncpfs. if we do the same thing for smbfs, we're set. we just need to make sure that linux' kernel concept of local time gets updated correctly as well. that, of course, brings us back to my initial query about where to stick periodic timezone setting.
so, where do people think a timezone updater should be stuck? do people not like using the update daemon?
-a
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