Re: [PATCH 5/8] xfs: factor and move some code in xfs_log_cil.c

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, 2022-03-15 at 09:06 +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
> 
> In preparation for adding support for intent item whiteouts.
> 
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> ---
>  fs/xfs/xfs_log_cil.c | 119 ++++++++++++++++++++++++-----------------
> --
>  1 file changed, 67 insertions(+), 52 deletions(-)
> 
> diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
> index 5179436b6603..dda71f1a25c5 100644
> --- a/fs/xfs/xfs_log_cil.c
> +++ b/fs/xfs/xfs_log_cil.c
> @@ -47,6 +47,38 @@ xlog_cil_ticket_alloc(
>  	return tic;
>  }
>  
> +/*
> + * Check if the current log item was first committed in this
> sequence.
> + * We can't rely on just the log item being in the CIL, we have to
> check
> + * the recorded commit sequence number.
> + *
> + * Note: for this to be used in a non-racy manner, it has to be
> called with
> + * CIL flushing locked out. As a result, it should only be used
> during the
> + * transaction commit process when deciding what to format into the
> item.
> + */
> +static bool
> +xlog_item_in_current_chkpt(
> +	struct xfs_cil		*cil,
> +	struct xfs_log_item	*lip)
> +{
> +	if (list_empty(&lip->li_cil))
> +		return false;
> +
> +	/*
> +	 * li_seq is written on the first commit of a log item to
> record the
> +	 * first checkpoint it is written to. Hence if it is different
> to the
> +	 * current sequence, we're in a new checkpoint.
> +	 */
> +	return lip->li_seq == READ_ONCE(cil->xc_current_sequence);
> +}
> +
> +bool
> +xfs_log_item_in_current_chkpt(
> +	struct xfs_log_item *lip)
> +{
> +	return xlog_item_in_current_chkpt(lip->li_mountp->m_log-
> >l_cilp, lip);

I think this turns into "lip->li_log->l_mp->m_log->l_cilp" in the new
code base

> +}
> +
>  /*
>   * Unavoidable forward declaration - xlog_cil_push_work() calls
>   * xlog_cil_ctx_alloc() itself.
> @@ -924,6 +956,40 @@ xlog_cil_build_trans_hdr(
>  	tic->t_curr_res -= lvhdr->lv_bytes;
>  }
>  
> +/*
> + * Pull all the log vectors off the items in the CIL, and remove the
> items from
> + * the CIL. We don't need the CIL lock here because it's only needed
> on the
> + * transaction commit side which is currently locked out by the
> flush lock.
> + */
> +static void
> +xlog_cil_build_lv_chain(
> +	struct xfs_cil		*cil,
> +	struct xfs_cil_ctx	*ctx,
> +	uint32_t		*num_iovecs,
> +	uint32_t		*num_bytes)
> +{
> +	struct xfs_log_vec	*lv = NULL;
> +
> +	while (!list_empty(&cil->xc_cil)) {
> +		struct xfs_log_item	*item;
> +
> +		item = list_first_entry(&cil->xc_cil,
> +					struct xfs_log_item, li_cil);
> +		list_del_init(&item->li_cil);
> +		if (!ctx->lv_chain)
> +			ctx->lv_chain = item->li_lv;
> +		else
> +			lv->lv_next = item->li_lv;
> +		lv = item->li_lv;
> +		item->li_lv = NULL;
> +		*num_iovecs += lv->lv_niovecs;
> 

This part below does not appear in the new rebase, so this would go
away in the hoisted helper

> +
> +		/* we don't write ordered log vectors */
> +		if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED)
> +			*num_bytes += lv->lv_bytes;
> +	}
> +}
> +
>  /*
>   * Push the Committed Item List to the log.
>   *
> @@ -946,7 +1012,6 @@ xlog_cil_push_work(
>  		container_of(work, struct xfs_cil_ctx, push_work);
>  	struct xfs_cil		*cil = ctx->cil;
>  	struct xlog		*log = cil->xc_log;
> -	struct xfs_log_vec	*lv;
>  	struct xfs_cil_ctx	*new_ctx;
>  	int			num_iovecs = 0;

For me, I had to add the new num_bytes variable here:
	int			num_iovecs, num_bytes;

I think the new helper does not need the num_bytes parameter in the new
rebase, so we may be able to just remove num_bytes  entirely.

Otherwise these hoists look straight forward.

Allison

>  	int			num_bytes = 0;
> @@ -1043,31 +1108,7 @@ xlog_cil_push_work(
>  	xfs_flush_bdev_async(&bio, log->l_mp->m_ddev_targp->bt_bdev,
>  				&bdev_flush);
>  
> -	/*
> -	 * Pull all the log vectors off the items in the CIL, and
> remove the
> -	 * items from the CIL. We don't need the CIL lock here because
> it's only
> -	 * needed on the transaction commit side which is currently
> locked out
> -	 * by the flush lock.
> -	 */
> -	lv = NULL;
> -	while (!list_empty(&cil->xc_cil)) {
> -		struct xfs_log_item	*item;
> -
> -		item = list_first_entry(&cil->xc_cil,
> -					struct xfs_log_item, li_cil);
> -		list_del_init(&item->li_cil);
> -		if (!ctx->lv_chain)
> -			ctx->lv_chain = item->li_lv;
> -		else
> -			lv->lv_next = item->li_lv;
> -		lv = item->li_lv;
> -		item->li_lv = NULL;
> -		num_iovecs += lv->lv_niovecs;
> -
> -		/* we don't write ordered log vectors */
> -		if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED)
> -			num_bytes += lv->lv_bytes;
> -	}
> +	xlog_cil_build_lv_chain(cil, ctx, &num_iovecs, &num_bytes);
>  
>  	/*
>  	 * Switch the contexts so we can drop the context lock and move
> out
> @@ -1508,32 +1549,6 @@ xlog_cil_force_seq(
>  	return 0;
>  }
>  
> -/*
> - * Check if the current log item was first committed in this
> sequence.
> - * We can't rely on just the log item being in the CIL, we have to
> check
> - * the recorded commit sequence number.
> - *
> - * Note: for this to be used in a non-racy manner, it has to be
> called with
> - * CIL flushing locked out. As a result, it should only be used
> during the
> - * transaction commit process when deciding what to format into the
> item.
> - */
> -bool
> -xfs_log_item_in_current_chkpt(
> -	struct xfs_log_item	*lip)
> -{
> -	struct xfs_cil		*cil = lip->li_mountp->m_log->l_cilp;
> -
> -	if (list_empty(&lip->li_cil))
> -		return false;
> -
> -	/*
> -	 * li_seq is written on the first commit of a log item to
> record the
> -	 * first checkpoint it is written to. Hence if it is different
> to the
> -	 * current sequence, we're in a new checkpoint.
> -	 */
> -	return lip->li_seq == READ_ONCE(cil->xc_current_sequence);
> -}
> -
>  /*
>   * Perform initial CIL structure initialisation.
>   */




[Index of Archives]     [XFS Filesystem Development (older mail)]     [Linux Filesystem Development]     [Linux Audio Users]     [Yosemite Trails]     [Linux Kernel]     [Linux RAID]     [Linux SCSI]


  Powered by Linux