Re: [PATCH] quota: add missing use of dq_data_lock in __dquot_initialize

[Jan Kara <jack@suse.cz>]

On Wed 27-02-13 14:43:09, Jeff Mahoney wrote:
> The bulk of __dquot_initialize runs under the dqptr_sem which
> protects the inode->i_dquot pointers. It doesn't protect the
> dereferenced contents, though. Those are protected by the
> dq_data_lock, which is missing around the dquot_resv_space call.
> 
> Cc: Jan Kara <jack@suse.com>
> Signed-off-by: Jeff Mahoney <jeffm@suse.com>
  Thanks! I've merged the patch. Just one small nitpick - git(1) expects
diffstat to be separated by three dashes (not two) so I had to fix that up
so that it doesn't appear in the commit message. Not sure how that happened
in your submission but I wanted to point that out just in case it was some
systematic error...

								Honza
> --
> 
>  fs/quota/dquot.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> --- a/fs/quota/dquot.c
> +++ b/fs/quota/dquot.c
> @@ -1439,8 +1439,11 @@ static void __dquot_initialize(struct in
>  			 * did a write before quota was turned on
>  			 */
>  			rsv = inode_get_rsv_space(inode);
> -			if (unlikely(rsv))
> +			if (unlikely(rsv)) {
> +				spin_lock(&dq_data_lock);
>  				dquot_resv_space(inode->i_dquot[cnt], rsv);
> +				spin_unlock(&dq_data_lock);
> +			}
>  		}
>  	}
>  out_err:
> 
> -- 
> Jeff Mahoney
> SUSE Labs
> --
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-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR