Re: document ext3 requirements

Duane Griffin
2009-01-03T23:12:56Z

2009/1/3 Pavel Machek <pavel@suse.cz>:
> 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?
> ...basically treating it like an ext2?

I'm afraid not, ext2 won't mount an FS with EXT3_FEATURE_INCOMPAT_RECOVER set.

> ...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.
>
> Pavel

Cheers,
Duane.

--
"I never could learn to drink that blood and call it wine" - Bob Dylan