Re: [PATCH 5/8] xfs: remove xlog_verify_dest_ptr

[Brian Foster <bfoster@redhat.com>]

On Wed, Jun 16, 2021 at 06:32:09PM +0200, Christoph Hellwig wrote:
> Just check that the offset in xlog_write_vec is smaller than the iclog
> size and remove the expensive cycling through all iclogs.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---

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

>  fs/xfs/xfs_log.c      | 35 +----------------------------------
>  fs/xfs/xfs_log_priv.h |  4 ----
>  2 files changed, 1 insertion(+), 38 deletions(-)
> 
> diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
> index 1bc32f056a5bcf..5d55d4fff63035 100644
> --- a/fs/xfs/xfs_log.c
> +++ b/fs/xfs/xfs_log.c
> @@ -59,10 +59,6 @@ xlog_sync(
>  	struct xlog_ticket	*ticket);
>  #if defined(DEBUG)
>  STATIC void
> -xlog_verify_dest_ptr(
> -	struct xlog		*log,
> -	void			*ptr);
> -STATIC void
>  xlog_verify_grant_tail(
>  	struct xlog *log);
>  STATIC void
> @@ -76,7 +72,6 @@ xlog_verify_tail_lsn(
>  	struct xlog_in_core	*iclog,
>  	xfs_lsn_t		tail_lsn);
>  #else
> -#define xlog_verify_dest_ptr(a,b)
>  #define xlog_verify_grant_tail(a)
>  #define xlog_verify_iclog(a,b,c)
>  #define xlog_verify_tail_lsn(a,b,c)
> @@ -1501,9 +1496,6 @@ xlog_alloc_log(
>  						KM_MAYFAIL | KM_ZERO);
>  		if (!iclog->ic_data)
>  			goto out_free_iclog;
> -#ifdef DEBUG
> -		log->l_iclog_bak[i] = &iclog->ic_header;
> -#endif
>  		head = &iclog->ic_header;
>  		memset(head, 0, sizeof(xlog_rec_header_t));
>  		head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
> @@ -2134,6 +2126,7 @@ xlog_write_iovec(
>  	uint32_t		*record_cnt,
>  	uint32_t		*data_cnt)
>  {
> +	ASSERT(*log_offset < iclog->ic_log->l_iclog_size);
>  	ASSERT(*log_offset % sizeof(int32_t) == 0);
>  	ASSERT(write_len % sizeof(int32_t) == 0);
>  
> @@ -2258,7 +2251,6 @@ xlog_write_partial(
>  	struct xfs_log_vec	*lv = log_vector;
>  	struct xfs_log_iovec	*reg;
>  	struct xlog_op_header	*ophdr;
> -	void			*ptr;
>  	int			index = 0;
>  	uint32_t		rlen;
>  	int			error;
> @@ -2297,7 +2289,6 @@ xlog_write_partial(
>  		if (rlen != reg->i_len)
>  			ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
>  
> -		xlog_verify_dest_ptr(log, iclog->ic_datap + *log_offset);
>  		xlog_write_iovec(iclog, log_offset, reg->i_addr, rlen, len,
>  				 record_cnt, data_cnt);
>  
> @@ -2363,7 +2354,6 @@ xlog_write_partial(
>  			rlen = min_t(uint32_t, rlen, iclog->ic_size - *log_offset);
>  			ophdr->oh_len = cpu_to_be32(rlen);
>  
> -			xlog_verify_dest_ptr(log, iclog->ic_datap + *log_offset);
>  			xlog_write_iovec(iclog, log_offset,
>  					 reg->i_addr + reg_offset, rlen, len,
>  					 record_cnt, data_cnt);
> @@ -3466,29 +3456,6 @@ xlog_ticket_alloc(
>  }
>  
>  #if defined(DEBUG)
> -/*
> - * Make sure that the destination ptr is within the valid data region of
> - * one of the iclogs.  This uses backup pointers stored in a different
> - * part of the log in case we trash the log structure.
> - */
> -STATIC void
> -xlog_verify_dest_ptr(
> -	struct xlog	*log,
> -	void		*ptr)
> -{
> -	int i;
> -	int good_ptr = 0;
> -
> -	for (i = 0; i < log->l_iclog_bufs; i++) {
> -		if (ptr >= log->l_iclog_bak[i] &&
> -		    ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
> -			good_ptr++;
> -	}
> -
> -	if (!good_ptr)
> -		xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
> -}
> -
>  /*
>   * Check to make sure the grant write head didn't just over lap the tail.  If
>   * the cycles are the same, we can't be overlapping.  Otherwise, make sure that
> diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
> index 1b3b3d2bb8a5d1..b829d8ba5c6a3f 100644
> --- a/fs/xfs/xfs_log_priv.h
> +++ b/fs/xfs/xfs_log_priv.h
> @@ -434,10 +434,6 @@ struct xlog {
>  
>  	struct xfs_kobj		l_kobj;
>  
> -	/* The following field are used for debugging; need to hold icloglock */
> -#ifdef DEBUG
> -	void			*l_iclog_bak[XLOG_MAX_ICLOGS];
> -#endif
>  	/* log recovery lsn tracking (for buffer submission */
>  	xfs_lsn_t		l_recovery_lsn;
>  
> -- 
> 2.30.2
>