From: "Lukáš Czerner" <lczerner@redhat.com>
To: "Theodore Ts'o" <tytso@mit.edu>
Cc: Lukas Czerner <lczerner@redhat.com>, linux-ext4@vger.kernel.org
Subject: Re: [PATCH] ext4: fix free clusters calculation in bigalloc filesystem
Date: Fri, 22 Feb 2013 08:57:47 +0100 (CET) [thread overview]
Message-ID: <alpine.LFD.2.00.1302220852210.14141@localhost> (raw)
In-Reply-To: <20130222051048.GC13667@thunk.org>
On Fri, 22 Feb 2013, Theodore Ts'o wrote:
> Date: Fri, 22 Feb 2013 00:10:48 -0500
> From: Theodore Ts'o <tytso@mit.edu>
> To: Lukas Czerner <lczerner@redhat.com>
> Cc: linux-ext4@vger.kernel.org
> Subject: Re: [PATCH] ext4: fix free clusters calculation in bigalloc
> filesystem
>
> On Thu, Feb 21, 2013 at 09:01:05AM +0100, Lukas Czerner wrote:
> >
> > Moreover when calculating number of root clusters we should be using
> > macro EXT4_NUM_B2C() instead of EXT4_C2B() otherwise the result will
> > usually be off by one.
>
> That should be "instead of EXT4_B2C()", and I don't think this is
> true, since the number of blocks should always be a multiple of the
> cluster ratio. So the use of EXT4_B2C() is a bit of an optimization
> (it avoids an add and mask operation), but it's probably not a
> measurable optimizatoin in practice.
>
> - Ted
Oh right it was EXT4_B2C(), I'll update the description. Even though
it should always be a multiple of cluster ratio it's really bad
precedence for the use of EXT4_B2C() since it is confusing enough
as it is with blocks/clusters.
I'll resend.
-Lukas
next prev parent reply other threads:[~2013-02-22 7:57 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-21 8:01 [PATCH] ext4: fix free clusters calculation in bigalloc filesystem Lukas Czerner
2013-02-21 12:15 ` [PATCH] ext4: fix overhead calculation in bigalloc filesystem (Re: ... ) Zheng Liu
2013-02-21 12:40 ` Lukáš Czerner
2013-02-21 12:50 ` Lukáš Czerner
2013-02-21 12:52 ` Lukáš Czerner
2013-02-21 13:49 ` Zheng Liu
2013-02-21 14:56 ` Lukáš Czerner
2013-02-22 3:03 ` Zheng Liu
2013-02-22 4:05 ` Theodore Ts'o
2013-02-22 8:04 ` Lukáš Czerner
2013-02-22 13:18 ` Zheng Liu
2013-02-22 15:20 ` Theodore Ts'o
2013-02-22 16:26 ` Zheng Liu
2013-03-24 12:29 ` [PATCH] ext4: fold ext4_generic_write_end into ext4_write_end Zheng Liu
2013-03-25 0:07 ` Theodore Ts'o
2013-02-21 13:12 ` [PATCH] ext4: fix overhead calculation in bigalloc filesystem (Re: ... ) Zheng Liu
2013-02-22 5:10 ` [PATCH] ext4: fix free clusters calculation in bigalloc filesystem Theodore Ts'o
2013-02-22 7:57 ` Lukáš Czerner [this message]
2013-02-22 8:39 ` [PATCH v2] " Lukas Czerner
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