Messages in this thread | | | Date | Tue, 6 Jan 2009 11:06:34 +0100 | From | Matthias Andree <> | Subject | Re: document ext3 requirements |
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On Sat, 03 Jan 2009, Pavel Machek wrote:
> On Sat 2009-01-03 22:17:15, Duane Griffin wrote: > > [Fixed top-posting] > > > > 2009/1/3 Martin MOKREJŠ <mmokrejs@ribosome.natur.cuni.cz>: > > > Pavel Machek wrote: > > >> readonly mount does actually write to the media in some cases. Document that. > > >> > > > Can one avoid replay of the journal then if it would be unclean? > > > Just curious. > > > > Nope. If the underlying block device is read-only then mounting the > > filesystem will fail. I tried to fix this some time ago, and have a > > set of patches that almost always work, but "almost always" isn't good > > enough. Unfortunately I never managed to figure out a way to finish it > > off without disgusting hacks or major surgery. > > Uhuh, can you just ignore the journal and mount it anyway?
An ext3 file system that needs journal recovery sets one of the ext2 incompatible flags to prevent just that.
> ...basically treating it like an ext2? > > ...ok, that will present "old" version of the filesystem to the > user... violating fsync() semantics. > > Still handy for recovering badly broken filesystems, I'd say.
While you cannot have that, you'll need to dump the file system (possibly with dd_rescue) to another medium and work on the copy. That's what you should do anyways. ;-)
I think if you really want to mount the file system without journal replay, you need to clear the needs-recovery "incompat" flag (on the copy, obviously).
-- Matthias Andree -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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