From: Theodore Ts'o <tytso@mit.edu>
To: Lukas Czerner <lczerner@redhat.com>
Cc: linux-ext4@vger.kernel.org
Subject: Re: [PATCH 1/2] ext4: Make ext4_block_in_group() much more efficient
Date: Tue, 26 Mar 2013 23:05:55 -0400 [thread overview]
Message-ID: <20130327030555.GB5861@thunk.org> (raw)
In-Reply-To: <1364207051-27037-1-git-send-email-lczerner@redhat.com>
On Mon, Mar 25, 2013 at 11:24:10AM +0100, Lukas Czerner wrote:
> + actual_group = (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) +
> + block) >>
> + (EXT4_BLOCK_SIZE_BITS(sb) + EXT4_CLUSTER_BITS(sb) + 3);
The problem with this change is that you are assuming that the number
of blocks per group is equal to block_size * 8. This is not always
the case; a nonstandard number of blocks per group can be set using
mke2fs's -g option.
- Ted
prev parent reply other threads:[~2013-03-27 3:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-25 10:24 [PATCH 1/2] ext4: Make ext4_block_in_group() much more efficient Lukas Czerner
2013-03-25 10:24 ` [PATCH 2/2] ext4: introduce ext4_get_group_number() Lukas Czerner
2013-03-27 3:12 ` Theodore Ts'o
2013-03-27 3:44 ` Theodore Ts'o
2013-03-27 3:05 ` Theodore Ts'o [this message]
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