From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To: Lukas Czerner <lczerner@redhat.com>
Cc: Kyungmin Park <kmpark@infradead.org>, Arnd Bergmann <arnd@arndb.de>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v6] fat: Batched discard support for fat
References: <20110328103431.GA22323@july> <201103301620.50263.arnd@arndb.de>
	<AANLkTi=QVe0UK3Q_xKG17_aHH7g4Y=miWu7UT7ogisyP@mail.gmail.com>
	<201103301706.36214.arnd@arndb.de>
	<BANLkTi=DizSrow6hW6QGZcP=ios7BDshUQ@mail.gmail.com>
	<87wrhgk8lp.fsf@devron.myhome.or.jp>
	<BANLkTi=7C3Lv2WkPoZzBCh2S87cVFcbp3Q@mail.gmail.com>
	<87r57ok3fp.fsf@devron.myhome.or.jp>
	<BANLkTi=i5S1Pj6xOm1cY1XSUxx0jByq+JQ@mail.gmail.com>
	<87mxick0zj.fsf@devron.myhome.or.jp>
	<alpine.LFD.2.00.1105241102200.5457@dhcp-27-109.brq.redhat.com>
	<874o4kjtsy.fsf@devron.myhome.or.jp>
	<alpine.LFD.2.00.1105241211100.4028@dhcp-27-109.brq.redhat.com>
Date: Tue, 24 May 2011 20:14:38 +0900
In-Reply-To: <alpine.LFD.2.00.1105241211100.4028@dhcp-27-109.brq.redhat.com>
	(Lukas Czerner's message of "Tue, 24 May 2011 12:44:22 +0200 (CEST)")
Message-ID: <87y61wic4h.fsf@devron.myhome.or.jp>
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Lukas Czerner <lczerner@redhat.com> writes:

>> No. If you want to trim whole with some chunk like 1GB and periodically
>> (IIRC in xfstest), what do? We have to trim until ULLONG_MAX for each
>> 1GB?
>> 
>> Thanks.
>> 
>
> What ? No, of course not. As I said, just go through 1G worth of filesystem
> blocks skipping metadata. However we do have a special case when we
> adjust start and len according to the first data block (which is only
> the case of 1024B blocksize).
>
> 	if (start < first_data_blk) {
> 		len -= first_data_blk - start;
> 		start = first_data_blk;
> 	}
>
> Which means that we just skip the first block (or whatever first data
> block is). And this is the same as skipping metadata.

Are you read my email? So, FAT adjust 2 blocks, ext* 1 block, and what
is other? The middle was guaranteed as continued? So, which is end of
blocks?
-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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