linux-ext4 - Re: [PATCH] ext4: Memory leak fix ext4_group

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Message-ID: <20090717130118.GI8508@mit.edu>
Date:	Fri, 17 Jul 2009 09:01:18 -0400
From:	Theodore Tso <tytso@....edu>
To:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Cc:	cmm@...ibm.com, sandeen@...hat.com, linux-ext4@...r.kernel.org
Subject: Re: [PATCH] ext4: Memory leak fix ext4_group_info allocation.

On Wed, Jul 15, 2009 at 08:25:34PM +0530, Aneesh Kumar K.V wrote:
> commit 5f21b0e642d7bf6fe4434c9ba12bc9cb96b17cf7  was done to
> reallocate groupinfo struct during resize properly. That goal
> was to allocate new groupinfo struct when we are adding new block
> groups during resize. Calling ext4_mb_add_group_info in the
> mballoc initialization code path resulted in we reallocating
> the group info struct . Fix this by not separately allocating
> group info in the mballoc init path and always depend on
> ext4_mb_add_group_info to allocate group info struct.
> 
> The earlier code also had a bug that we allocated less number of
> group info struct for the last meta group. But on resize we
> expected that we had EXT4_DESC_PER_BLOCK group info struct for
> each meta group.

Added to the ext4 patch queue, although I did rewrite the patch
description:

ext4: Fix memory leak fix when mounting an ext4 filesystem

From: "Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>

The allocation of the ext4_group_info array was moved to a new
function ext4_mb_add_group_info() in commit 5f21b0e6 so that online
resize would use a common (and correct) codepath.  Unfortunately, the
call to the new ext4_mb_add_group_info() function was added without
removing the code which originally allocated the array.  This caused a
memory leak each time an ext4 filesystem was mounted.

The fix is simple; remove the code that did the original allocation,
since it is no longer needed.

Reported-by: Catalin Marinas <catalin.marinas@....com>
Tested-by: Catalin Marinas <catalin.marinas@....com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@...ux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@....edu>

					- Ted
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