Re: [PATCH v3 09/17] xfs: abort consistently on dquot flush failure

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Wed, Apr 29, 2020 at 01:21:45PM -0400, Brian Foster wrote:
> The dquot flush handler effectively aborts the dquot flush if the
> filesystem is already shut down, but doesn't actually shut down if
> the flush fails. Update xfs_qm_dqflush() to consistently abort the
> dquot flush and shutdown the fs if the flush fails with an
> unexpected error.
> 
> Signed-off-by: Brian Foster <bfoster@redhat.com>
> Reviewed-by: Dave Chinner <dchinner@redhat.com>
> Reviewed-by: Allison Collins <allison.henderson@oracle.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Looks good to me,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  fs/xfs/xfs_dquot.c | 32 ++++++++++----------------------
>  1 file changed, 10 insertions(+), 22 deletions(-)
> 
> diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
> index 265feb62290d..ffe607733c50 100644
> --- a/fs/xfs/xfs_dquot.c
> +++ b/fs/xfs/xfs_dquot.c
> @@ -1068,6 +1068,7 @@ xfs_qm_dqflush(
>  	struct xfs_buf		**bpp)
>  {
>  	struct xfs_mount	*mp = dqp->q_mount;
> +	struct xfs_log_item	*lip = &dqp->q_logitem.qli_item;
>  	struct xfs_buf		*bp;
>  	struct xfs_dqblk	*dqb;
>  	struct xfs_disk_dquot	*ddqp;
> @@ -1083,32 +1084,16 @@ xfs_qm_dqflush(
>  
>  	xfs_qm_dqunpin_wait(dqp);
>  
> -	/*
> -	 * This may have been unpinned because the filesystem is shutting
> -	 * down forcibly. If that's the case we must not write this dquot
> -	 * to disk, because the log record didn't make it to disk.
> -	 *
> -	 * We also have to remove the log item from the AIL in this case,
> -	 * as we wait for an emptry AIL as part of the unmount process.
> -	 */
> -	if (XFS_FORCED_SHUTDOWN(mp)) {
> -		struct xfs_log_item	*lip = &dqp->q_logitem.qli_item;
> -		dqp->dq_flags &= ~XFS_DQ_DIRTY;
> -
> -		xfs_trans_ail_remove(lip, SHUTDOWN_CORRUPT_INCORE);
> -
> -		error = -EIO;
> -		goto out_unlock;
> -	}
> -
>  	/*
>  	 * Get the buffer containing the on-disk dquot
>  	 */
>  	error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
>  				   mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK,
>  				   &bp, &xfs_dquot_buf_ops);
> -	if (error)
> +	if (error == -EAGAIN)
>  		goto out_unlock;
> +	if (error)
> +		goto out_abort;
>  
>  	/*
>  	 * Calculate the location of the dquot inside the buffer.
> @@ -1123,9 +1108,8 @@ xfs_qm_dqflush(
>  		xfs_alert(mp, "corrupt dquot ID 0x%x in memory at %pS",
>  				be32_to_cpu(dqp->q_core.d_id), fa);
>  		xfs_buf_relse(bp);
> -		xfs_dqfunlock(dqp);
> -		xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
> -		return -EFSCORRUPTED;
> +		error = -EFSCORRUPTED;
> +		goto out_abort;
>  	}
>  
>  	/* This is the only portion of data that needs to persist */
> @@ -1174,6 +1158,10 @@ xfs_qm_dqflush(
>  	*bpp = bp;
>  	return 0;
>  
> +out_abort:
> +	dqp->dq_flags &= ~XFS_DQ_DIRTY;
> +	xfs_trans_ail_remove(lip, SHUTDOWN_CORRUPT_INCORE);
> +	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
>  out_unlock:
>  	xfs_dqfunlock(dqp);
>  	return error;
> -- 
> 2.21.1
>