Re: [PATCH 06/20] xfs: don't use xfs_trans_free_items in the commit path

[Brian Foster <bfoster@redhat.com>]

On Fri, May 17, 2019 at 09:31:05AM +0200, Christoph Hellwig wrote:
> While commiting items looks very similar to freeing them on error it is
> a different operation, and they will diverge a bit soon.
> 
> Split out the commit case from xfs_trans_free_items, inline it into
> xfs_log_commit_cil and give it a separate trace point.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  fs/xfs/xfs_log_cil.c    | 13 ++++++++++---
>  fs/xfs/xfs_trace.h      |  1 +
>  fs/xfs/xfs_trans.c      | 10 +++-------
>  fs/xfs/xfs_trans_priv.h |  2 --
>  4 files changed, 14 insertions(+), 12 deletions(-)
> 
> diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
> index 49f37905c7a7..c856bfce5bf2 100644
> --- a/fs/xfs/xfs_log_cil.c
> +++ b/fs/xfs/xfs_log_cil.c
> @@ -985,6 +985,7 @@ xfs_log_commit_cil(
>  {
>  	struct xlog		*log = mp->m_log;
>  	struct xfs_cil		*cil = log->l_cilp;
> +	struct xfs_log_item	*lip, *next;
>  	xfs_lsn_t		xc_commit_lsn;
>  
>  	/*
> @@ -1009,7 +1010,7 @@ xfs_log_commit_cil(
>  
>  	/*
>  	 * Once all the items of the transaction have been copied to the CIL,
> -	 * the items can be unlocked and freed.
> +	 * the items can be unlocked and possibly freed.
>  	 *
>  	 * This needs to be done before we drop the CIL context lock because we
>  	 * have to update state in the log items and unlock them before they go
> @@ -1018,8 +1019,14 @@ xfs_log_commit_cil(
>  	 * the log items. This affects (at least) processing of stale buffers,
>  	 * inodes and EFIs.
>  	 */
> -	xfs_trans_free_items(tp, xc_commit_lsn, false);
> -
> +	trace_xfs_trans_commit_items(tp, _RET_IP_);
> +	list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) {
> +		xfs_trans_del_item(lip);
> +		if (lip->li_ops->iop_committing)
> +			lip->li_ops->iop_committing(lip, xc_commit_lsn);
> +		if (lip->li_ops->iop_unlock)
> +			lip->li_ops->iop_unlock(lip);
> +	}
>  	xlog_cil_push_background(log);
>  
>  	up_read(&cil->xc_ctx_lock);
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index 2464ea351f83..195a9cdb954e 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -3360,6 +3360,7 @@ DEFINE_TRANS_EVENT(xfs_trans_dup);
>  DEFINE_TRANS_EVENT(xfs_trans_free);
>  DEFINE_TRANS_EVENT(xfs_trans_roll);
>  DEFINE_TRANS_EVENT(xfs_trans_add_item);
> +DEFINE_TRANS_EVENT(xfs_trans_commit_items);
>  DEFINE_TRANS_EVENT(xfs_trans_free_items);
>  
>  TRACE_EVENT(xfs_iunlink_update_bucket,
> diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
> index ed7547b9f66b..4ed5d032b26f 100644
> --- a/fs/xfs/xfs_trans.c
> +++ b/fs/xfs/xfs_trans.c
> @@ -767,10 +767,9 @@ xfs_trans_del_item(
>  }
>  
>  /* Detach and unlock all of the items in a transaction */
> -void
> +static void
>  xfs_trans_free_items(
>  	struct xfs_trans	*tp,
> -	xfs_lsn_t		commit_lsn,
>  	bool			abort)
>  {
>  	struct xfs_log_item	*lip, *next;
> @@ -779,9 +778,6 @@ xfs_trans_free_items(
>  
>  	list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) {
>  		xfs_trans_del_item(lip);
> -		if (commit_lsn != NULLCOMMITLSN &&
> -		    lip->li_ops->iop_committing)
> -			lip->li_ops->iop_committing(lip, commit_lsn);
>  		if (abort)
>  			set_bit(XFS_LI_ABORTED, &lip->li_flags);
>  
> @@ -1007,7 +1003,7 @@ __xfs_trans_commit(
>  		tp->t_ticket = NULL;
>  	}
>  	current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
> -	xfs_trans_free_items(tp, NULLCOMMITLSN, !!error);
> +	xfs_trans_free_items(tp, !!error);
>  	xfs_trans_free(tp);
>  
>  	XFS_STATS_INC(mp, xs_trans_empty);
> @@ -1069,7 +1065,7 @@ xfs_trans_cancel(
>  	/* mark this thread as no longer being in a transaction */
>  	current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
>  
> -	xfs_trans_free_items(tp, NULLCOMMITLSN, dirty);
> +	xfs_trans_free_items(tp, dirty);
>  	xfs_trans_free(tp);
>  }
>  
> diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h
> index 091eae9f4e74..bef1ebf933ed 100644
> --- a/fs/xfs/xfs_trans_priv.h
> +++ b/fs/xfs/xfs_trans_priv.h
> @@ -16,8 +16,6 @@ struct xfs_log_vec;
>  void	xfs_trans_init(struct xfs_mount *);
>  void	xfs_trans_add_item(struct xfs_trans *, struct xfs_log_item *);
>  void	xfs_trans_del_item(struct xfs_log_item *);
> -void	xfs_trans_free_items(struct xfs_trans *tp, xfs_lsn_t commit_lsn,
> -				bool abort);
>  void	xfs_trans_unreserve_and_mod_sb(struct xfs_trans *tp);
>  
>  void	xfs_trans_committed_bulk(struct xfs_ail *ailp, struct xfs_log_vec *lv,
> -- 
> 2.20.1
>