Re: [BUG][reiserfs] page fault during kernel boot

From: Frederic Weisbecker
Date: Tue Aug 17 2010 - 18:20:30 EST


On Tue, Aug 17, 2010 at 11:25:25AM +0300, Marin Mitov wrote:
> Hi all,
>
> The function: reiserfs_evict_inode() ends with:
>
> <snip>
> out:
> end_writeback(inode); /* note this must go after the journal_end to prevent deadlock */
> dquot_drop(inode);
> inode->i_blocks = 0;
> reiserfs_write_unlock_once(inode->i_sb, depth);
>
> no_delete:
> end_writeback(inode);
> dquot_drop(inode);
> }
> <snip>
>
> When goto out path is taken,
>
> end_writeback(inode);
> dquot_drop(inode);
>
> are executed twice, leading to page fault (in my case) during the kernel boot.


Indeed. More precisely it triggers a BUG in end_writeback():

BUG_ON(inode->i_state & I_CLEAR);

that because we call it twice.


> Add return; before no_delete label (but I am not quite sure that this is correct :-).



That looks correct.

Also Andrew Benton reported this issue and tested almost
the same patch and it seemed to solve the issue.

Thanks.



> Signed-off-by: Marin Mitov <mitov@xxxxxxxxxxx>
>
> ====================================================================
> --- a/fs/reiserfs/inode.c 2010-08-17 09:51:27.000000000 +0300
> +++ b/fs/reiserfs/inode.c 2010-08-17 10:45:20.000000000 +0300
> @@ -78,11 +78,12 @@ void reiserfs_evict_inode(struct inode *
> /* no object items are in the tree */
> ;
> }
> - out:
> +out:
> end_writeback(inode); /* note this must go after the journal_end to prevent deadlock */
> dquot_drop(inode);
> inode->i_blocks = 0;
> reiserfs_write_unlock_once(inode->i_sb, depth);
> + return;
>
> no_delete:
> end_writeback(inode);
> --
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