From: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
To: dsterba@suse.cz, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] Btrfs: add a check of whether fs_info->fs_root is NULL in btrfs_async_reclaim_metadata_space()
Date: Thu, 22 Oct 2015 08:39:35 +0900 [thread overview]
Message-ID: <56282237.5090408@jp.fujitsu.com> (raw)
In-Reply-To: <20151021112742.GD13624@twin.jikos.cz>
On 2015/10/21 20:27, David Sterba wrote:
> On Wed, Oct 21, 2015 at 04:20:00PM +0900, Tsutomu Itoh wrote:
>> Kernel panic occurred due to NULL pointer reference in can_overcommit().
>> Because btrfs_async_reclaim_metadata_space() passed NULL pointer to
>> btrfs_calc_reclaim_metadata_size().
>
>> fs_info->fs_root is referred in btrfs_async_reclaim_metadata_space()
>> when mount kicked kworker(btrfs_async_reclaim_metadata_space).
>>
>> But at this time, fs_info->fs_root had not been initialized yet,
>> so NULL pointer passed to btrfs_calc_reclaim_metadata_size().
>
> I don't think it's the right fix, the initialization sequence should
> take care of such situations. The fs_tree must exist at the time we
> reach the point where it crashed, the code expects it.
OK. I will try to change initialization sequence.
Thanks,
Tsutomu
prev parent reply other threads:[~2015-10-21 23:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-21 7:20 [PATCH] Btrfs: add a check of whether fs_info->fs_root is NULL in btrfs_async_reclaim_metadata_space() Tsutomu Itoh
2015-10-21 11:27 ` David Sterba
2015-10-21 23:39 ` Tsutomu Itoh [this message]
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