linux-ext4 - Re: [PATCH 0/6 v2] Introduce FALLOC_FL_ZERO

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Date:	Mon, 17 Mar 2014 16:57:41 -0400
From:	tytso@....edu
To:	Lukáš Czerner <lczerner@...hat.com>@thunk.org
Cc:	Lukáš Czerner <lczerner@...hat.com>,
	Lukáš Czerner <lczerner@...hat.com>@thunk.o@...nk.org,
	rg@...nk.org, linux-ext4@...r.kernel.org
Subject: Re: [PATCH 0/6 v2] Introduce FALLOC_FL_ZERO_RANGE flag for fallocate

On Mon, Mar 17, 2014 at 04:10:52PM +0100, Lukáš Czerner wrote:
> Yes, shared/243 is actually looking at the file system using debugfs
> trying to figure out whether this flag is set or not. And that is
> what is failing.
> 
> See the 243.full output:
> 
> Test 1: Fallocate 40960 bytes and write 4096 bytes (buffered io).
> EOFBLOCK_FL bit is not set.
> Error: Current bit state incorrect.
> 
> However I am not really sure why is this in shared since this is
> only useful for ext4.

Ah, I agree, it's confusing/wrong for this test to be in shared/243;
we should probably rename it to ext4/243 for now.

> I believe that we're not very consistent with that anyway. That was
> part of the reason why we got rid of it in e2fsck. However I agree
> that this might cause additional problems. So it might be better to
> just keep this in kernel for now...

Yeah, there are some really otherwise hard to solve races were we
might not set EOFBLOCK_FL.  We kept tripping over them when running
xfstests, but it was otherwise pretty hard to hit.

Perhaps we should set a date, say in another two years, when we make
this go away.

					- Ted
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