After takin' a swig o' grog, Bob Hauck belched out
this bit o' wisdom:
> On Wed, 25 Mar 2009 11:00:01 -0500, Erik Funkenbusch
> <erik@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>> Linus Torvolds calls ext3 "moronic".
More /lying/ again, Erik?
This is why I absolutely _detest_ the idiotic ext3 writeback behavior.
That's the behavior of the writeback option that is idiotic, not ext3.
>> "This is why I absolutely _detest_ the idiotic ext3 writeback behavior. It
>> literally does everything the wrong way around - writing data later than
>> the metadata that points to it. Whoever came up with that solution was a
>> moron. No ifs, buts, or maybes about it."
> But unless things have changed, writeback is not the default. Ordered
> is. And ordered mode writes the data first, then the metadata, which
> apparently Linus agrees with.
> So I don't think this is a general criticism of ext3 but rather a
> criticism of the worth of that particular mount option (and presumably
> of ext4 as well, I don't feel like reading the whole thread).
You don't have to. You can simply read the post Linus responded to,
which Erik either did not do, or ignored for purposes of FUD.
That difference between ext4 and ext3-in-writeback-mode is this: If
you get a crash in the narrow window *after* writing initial metadata
and before writing the data, ext4 will give you a zero length file,
whereas ext3-in-writeback-mode will give you a proper-length file
filled with whatever used to be on disk (might be the contents of a
previous /etc/shadow, or maybe somebody's finance files).
In that same situation, ext3 in data-ordered or data-journal mode will
"close" the window by preventing anybody else from making forward
progress until the data and the metadata are both updated. The thing
is, even on ext3 I can get exactly the same kind of behavior with an
appropriately timed "kill -STOP $dumb_program", followed by a power
failure 60 seconds later. It's a relatively obvious race condition...
Yeah, like we're really going to believe Linus would /allow/ a truly
moronic filesystem into /his/ kernel.
Geez, what a hypocrite. You blast Roy for his omissions, and then look what
A feature is nothing more than a bug with seniority.
-- Unknown source