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From: Szakacsits S. <sz...@si...> - 2004-04-11 00:48:34
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On Fri, 9 Apr 2004, Anton Altaparmakov wrote: > > True. Although the LFS drivers are quite happy to recognise any LFS > version including strange ones likes 0.-1... Hmmm, this also suggests the value isn't really used and LFS is tightened with the current driver (not even NTFS version). > > True from pedantry point of view but I doubt even Microsoft cares. Show me > > an example when LFS is used outside of NTFS. > > I don't know any. I don't think anything other than NTFS uses LFS. My suspicion is that that LFS was overdesigned, then it was realised it doesn't work so great as it was expected (see tons of inconsistent NTFS) so its use got limited and this "volume clean" bit was added (if it indeed means that). If the volume is marked clean, no need to try to recover thus there is less chance to screw up the filesystem. > I have to apologise at this point: I must have somehow managed to muddle > my logfile copies. I took a new copy just now and it is just like you say > and nothing like my old copy. So I must have been working with w2k rather > than xp logfile all along. )-: Yes, I also can not see this bit set on any w2k NTFS images I have. > I can confirm the same as you see. Great news! :) > This makes everything even more difficult. Yes and no. Special case handling, yes. But for now, we could ignore the minority unknown cases (Google Zeitgeist: XP 46%, W2K 18%, NT4 3%). Anyway, the time already working hard to solve the W2K and earlier cases :-) The project is huge and we are badly lacking development resources. We can not solve everybody's problem at once. If we ever want to get anywhere, we must cut corner cases. > We will need to parse the NTFS version and then deal with the logfile > depending on what we see there. So on NTFS 3.1 with LFS 1.1, we will > compare the restart pages (_not_ binary compare but logical compare) Plus we must extend the logical compare inasmuch as you noticed NTFS 3.1 has more fields. > and if identical and flags = 2 we can say clean and dirty otherwise. Well, I hope so it's true :-) But I'd still prefer if somebody would check what's going on in the restart pages during NTFS use from Windows. Unfortunately Captive NTFS isn't ok because it doesn't journal continuously, that's one of the reasons people lose things when Captive crashes: http://www.jankratochvil.net/project/captive/doc/Details.html.pl#logfile I don't have the needed softwares to do this and disassembling would take too long compared to just sniffing. > And on NTFS 1.x, 2.x, and 3.0 with LFS 1.1 we need to check the > restart pages and if identical and the criteria I describe in > ntfs/logfile.h are met (i.e. the logfile is shut, no clients are > registered in use) it is clean If it's true, sounds ok. I can't investigate these at all either, I have only such metadata images and I know nothing about in what state they were imaged. But they must be clean because ntfsresize's consistency check passes otherwise all dirty cases I've ever seen failed the check. Well, actually ntfsclone won't clone if the consistency check doesn't pass. I'll enable cloning inconsistent NTFS for --metadata, when it's possible. > and assumed dirty otherwise (although it could still be clean in that > case but that is too complicated for us to figure out at this point as > it involves parsing the whole logfile and checking that all ops are > checkpointed). Anyway, it is better to be erring on the safe side > IMO. I agree. > We can always provide a force option for ignoring the fact that > we think the journal is dirty. Without the force we just work > read-only. I even don't like the "force" option in these cases: - most people aren't really aware of the consequences. They hope it will work but it won't. I'm not sure we want to debug these cases and hear about the crappy NTFS driver that corrupts data (you can read it anywhere anyway even if it isn't possible for years). - if the option is there it will be used. Some distributor will just configure it by default and people use it without knowing about it. Solution is very easy. No such option, no such problems. If one doesn't like it, he can modify the available, free source code and shot himself in the foot. Such fun definitely deserves some extra work ;) Szaka |
