[PATCH 08/11] xfs: use xfs_ilock_data_map_shared in xfs_qm_dqiterate

[Dave Chinner]

On Fri, Dec 06, 2013 at 12:30:14PM -0800, Christoph Hellwig wrote:
> We might not have read in the extent list at this point, so make sure we
> take the ilock exclusively if we have to do so.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> 
> Index: xfs/fs/xfs/xfs_qm.c
> ===================================================================
> --- xfs.orig/fs/xfs/xfs_qm.c	2013-12-06 17:20:27.491331600 +0100
> +++ xfs/fs/xfs/xfs_qm.c	2013-12-06 19:39:27.251160455 +0100
> @@ -1193,16 +1193,18 @@ xfs_qm_dqiterate(
>  	lblkno = 0;
>  	maxlblkcnt = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
>  	do {
> +		uint		lock_mode;
> +
>  		nmaps = XFS_DQITER_MAP_SIZE;
>  		/*
>  		 * We aren't changing the inode itself. Just changing
>  		 * some of its data. No new blocks are added here, and
>  		 * the inode is never added to the transaction.
>  		 */
> -		xfs_ilock(qip, XFS_ILOCK_SHARED);
> +		lock_mode = xfs_ilock_data_map_shared(qip);
>  		error = xfs_bmapi_read(qip, lblkno, maxlblkcnt - lblkno,
>  				       map, &nmaps, 0);
> -		xfs_iunlock(qip, XFS_ILOCK_SHARED);
> +		xfs_iunlock(qip, lock_mode);
>  		if (error)
>  			break;

looks good.

Reviewed-by: Dave Chinner <dchinner at redhat.com>
-- 
Dave Chinner
david at fromorbit.com