Re: [PATCH 05/22] xfs: convert raw ag walks to use for_each_perag

[Brian Foster <bfoster@redhat.com>]

On Thu, May 06, 2021 at 05:20:37PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
> 
> Convert the raw walks to an iterator, pulling the current AG out of
> pag->pag_agno instead of the loop iterator variable.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---
>  fs/xfs/libxfs/xfs_types.c |  4 ++-
>  fs/xfs/scrub/bmap.c       |  6 +++--
>  fs/xfs/xfs_log_recover.c  | 55 ++++++++++++++++++---------------------
>  fs/xfs/xfs_reflink.c      |  9 ++++---
>  4 files changed, 39 insertions(+), 35 deletions(-)
> 
...
> diff --git a/fs/xfs/scrub/bmap.c b/fs/xfs/scrub/bmap.c
> index b5ebf1d1b4db..c60a1990d629 100644
> --- a/fs/xfs/scrub/bmap.c
> +++ b/fs/xfs/scrub/bmap.c
...
> @@ -607,8 +609,8 @@ xchk_bmap_check_rmaps(
>  	    (zero_size || ifp->if_nextents > 0))
>  		return 0;
>  
> -	for (agno = 0; agno < sc->mp->m_sb.sb_agcount; agno++) {
> -		error = xchk_bmap_check_ag_rmaps(sc, whichfork, agno);
> +	for_each_perag(sc->mp, agno, pag) {
> +		error = xchk_bmap_check_ag_rmaps(sc, whichfork, pag->pag_agno);
>  		if (error)
>  			return error;

It looks like this loop is missing xfs_perag_put() early breakout
treatment. The rest of the patch LGTM.

Brian

>  		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
> index fee2a4e80241..1227503d2246 100644
> --- a/fs/xfs/xfs_log_recover.c
> +++ b/fs/xfs/xfs_log_recover.c
> @@ -2742,21 +2742,17 @@ STATIC void
>  xlog_recover_process_iunlinks(
>  	struct xlog	*log)
>  {
> -	xfs_mount_t	*mp;
> -	xfs_agnumber_t	agno;
> -	xfs_agi_t	*agi;
> -	struct xfs_buf	*agibp;
> -	xfs_agino_t	agino;
> -	int		bucket;
> -	int		error;
> -
> -	mp = log->l_mp;
> +	struct xfs_mount	*mp = log->l_mp;
> +	struct xfs_perag	*pag;
> +	xfs_agnumber_t		agno;
> +	struct xfs_agi		*agi;
> +	struct xfs_buf		*agibp;
> +	xfs_agino_t		agino;
> +	int			bucket;
> +	int			error;
>  
> -	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
> -		/*
> -		 * Find the agi for this ag.
> -		 */
> -		error = xfs_read_agi(mp, NULL, agno, &agibp);
> +	for_each_perag(mp, agno, pag) {
> +		error = xfs_read_agi(mp, NULL, pag->pag_agno, &agibp);
>  		if (error) {
>  			/*
>  			 * AGI is b0rked. Don't process it.
> @@ -2782,7 +2778,7 @@ xlog_recover_process_iunlinks(
>  			agino = be32_to_cpu(agi->agi_unlinked[bucket]);
>  			while (agino != NULLAGINO) {
>  				agino = xlog_recover_process_one_iunlink(mp,
> -							agno, agino, bucket);
> +						pag->pag_agno, agino, bucket);
>  				cond_resched();
>  			}
>  		}
> @@ -3494,27 +3490,28 @@ xlog_recover_cancel(
>   */
>  STATIC void
>  xlog_recover_check_summary(
> -	struct xlog	*log)
> +	struct xlog		*log)
>  {
> -	xfs_mount_t	*mp;
> -	struct xfs_buf	*agfbp;
> -	struct xfs_buf	*agibp;
> -	xfs_agnumber_t	agno;
> -	uint64_t	freeblks;
> -	uint64_t	itotal;
> -	uint64_t	ifree;
> -	int		error;
> +	struct xfs_mount	*mp = log->l_mp;
> +	struct xfs_perag	*pag;
> +	struct xfs_buf		*agfbp;
> +	struct xfs_buf		*agibp;
> +	xfs_agnumber_t		agno;
> +	uint64_t		freeblks;
> +	uint64_t		itotal;
> +	uint64_t		ifree;
> +	int			error;
>  
>  	mp = log->l_mp;
>  
>  	freeblks = 0LL;
>  	itotal = 0LL;
>  	ifree = 0LL;
> -	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
> -		error = xfs_read_agf(mp, NULL, agno, 0, &agfbp);
> +	for_each_perag(mp, agno, pag) {
> +		error = xfs_read_agf(mp, NULL, pag->pag_agno, 0, &agfbp);
>  		if (error) {
>  			xfs_alert(mp, "%s agf read failed agno %d error %d",
> -						__func__, agno, error);
> +						__func__, pag->pag_agno, error);
>  		} else {
>  			struct xfs_agf	*agfp = agfbp->b_addr;
>  
> @@ -3523,10 +3520,10 @@ xlog_recover_check_summary(
>  			xfs_buf_relse(agfbp);
>  		}
>  
> -		error = xfs_read_agi(mp, NULL, agno, &agibp);
> +		error = xfs_read_agi(mp, NULL, pag->pag_agno, &agibp);
>  		if (error) {
>  			xfs_alert(mp, "%s agi read failed agno %d error %d",
> -						__func__, agno, error);
> +						__func__, pag->pag_agno, error);
>  		} else {
>  			struct xfs_agi	*agi = agibp->b_addr;
>  
> diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> index f297d68a931b..0e430b0c1b16 100644
> --- a/fs/xfs/xfs_reflink.c
> +++ b/fs/xfs/xfs_reflink.c
> @@ -755,16 +755,19 @@ int
>  xfs_reflink_recover_cow(
>  	struct xfs_mount	*mp)
>  {
> +	struct xfs_perag	*pag;
>  	xfs_agnumber_t		agno;
>  	int			error = 0;
>  
>  	if (!xfs_sb_version_hasreflink(&mp->m_sb))
>  		return 0;
>  
> -	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
> -		error = xfs_refcount_recover_cow_leftovers(mp, agno);
> -		if (error)
> +	for_each_perag(mp, agno, pag) {
> +		error = xfs_refcount_recover_cow_leftovers(mp, pag->pag_agno);
> +		if (error) {
> +			xfs_perag_put(pag);
>  			break;
> +		}
>  	}
>  
>  	return error;
> -- 
> 2.31.1
>