Re: [PATCH] iomap: add a tracepoint for mappings returned by map_blocks

[Dave Chinner <david@fromorbit.com>]

On Thu, Sep 29, 2022 at 11:45:11AM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> Add a new tracepoint so we can see what mapping the filesystem returns
> to writeback a dirty page.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  fs/iomap/buffered-io.c |    1 +
>  fs/iomap/trace.h       |    1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 77d59c159248..91ee0b308e13 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -1360,6 +1360,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
>  		error = wpc->ops->map_blocks(wpc, inode, pos);
>  		if (error)
>  			break;
> +		trace_iomap_writepage_map(inode, &wpc->iomap);
>  		if (WARN_ON_ONCE(wpc->iomap.type == IOMAP_INLINE))
>  			continue;
>  		if (wpc->iomap.type == IOMAP_HOLE)
> diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h
> index d48868fc40d7..f6ea9540d082 100644
> --- a/fs/iomap/trace.h
> +++ b/fs/iomap/trace.h
> @@ -148,6 +148,7 @@ DEFINE_EVENT(iomap_class, name,	\
>  	TP_ARGS(inode, iomap))
>  DEFINE_IOMAP_EVENT(iomap_iter_dstmap);
>  DEFINE_IOMAP_EVENT(iomap_iter_srcmap);
> +DEFINE_IOMAP_EVENT(iomap_writepage_map);
>  
>  TRACE_EVENT(iomap_iter,
>  	TP_PROTO(struct iomap_iter *iter, const void *ops,

Looks fine.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

-- 
Dave Chinner
david@fromorbit.com