Re: [PATCH -next] iomap: add pos and dirty_len into trace_iomap_writepage_map

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Feb 20, 2024 at 07:57:59PM +0800, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
> 
> Since commit fd07e0aa23c4 ("iomap: map multiple blocks at a time"), we
> could map multi-blocks once a time, and the dirty_len indicates the
> expected map length, map_len won't large than it. The pos and dirty_len
> means the dirty range that should be mapped to write, add them into
> trace_iomap_writepage_map() could be more useful for debug.
> 
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

LGTM too
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/iomap/buffered-io.c |  2 +-
>  fs/iomap/trace.h       | 43 +++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 43 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 2ad0e287c704..ae4e2026e59e 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -1776,7 +1776,7 @@ static int iomap_writepage_map_blocks(struct iomap_writepage_ctx *wpc,
>  		error = wpc->ops->map_blocks(wpc, inode, pos, dirty_len);
>  		if (error)
>  			break;
> -		trace_iomap_writepage_map(inode, &wpc->iomap);
> +		trace_iomap_writepage_map(inode, pos, dirty_len, &wpc->iomap);
>  
>  		map_len = min_t(u64, dirty_len,
>  			wpc->iomap.offset + wpc->iomap.length - pos);
> diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h
> index c16fd55f5595..3ef694f9489f 100644
> --- a/fs/iomap/trace.h
> +++ b/fs/iomap/trace.h
> @@ -154,7 +154,48 @@ 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_writepage_map,
> +	TP_PROTO(struct inode *inode, u64 pos, unsigned int dirty_len,
> +		 struct iomap *iomap),
> +	TP_ARGS(inode, pos, dirty_len, iomap),
> +	TP_STRUCT__entry(
> +		__field(dev_t, dev)
> +		__field(u64, ino)
> +		__field(u64, pos)
> +		__field(u64, dirty_len)
> +		__field(u64, addr)
> +		__field(loff_t, offset)
> +		__field(u64, length)
> +		__field(u16, type)
> +		__field(u16, flags)
> +		__field(dev_t, bdev)
> +	),
> +	TP_fast_assign(
> +		__entry->dev = inode->i_sb->s_dev;
> +		__entry->ino = inode->i_ino;
> +		__entry->pos = pos;
> +		__entry->dirty_len = dirty_len;
> +		__entry->addr = iomap->addr;
> +		__entry->offset = iomap->offset;
> +		__entry->length = iomap->length;
> +		__entry->type = iomap->type;
> +		__entry->flags = iomap->flags;
> +		__entry->bdev = iomap->bdev ? iomap->bdev->bd_dev : 0;
> +	),
> +	TP_printk("dev %d:%d ino 0x%llx bdev %d:%d pos 0x%llx dirty len 0x%llx "
> +		  "addr 0x%llx offset 0x%llx length 0x%llx type %s flags %s",
> +		  MAJOR(__entry->dev), MINOR(__entry->dev),
> +		  __entry->ino,
> +		  MAJOR(__entry->bdev), MINOR(__entry->bdev),
> +		  __entry->pos,
> +		  __entry->dirty_len,
> +		  __entry->addr,
> +		  __entry->offset,
> +		  __entry->length,
> +		  __print_symbolic(__entry->type, IOMAP_TYPE_STRINGS),
> +		  __print_flags(__entry->flags, "|", IOMAP_F_FLAGS_STRINGS))
> +);
>  
>  TRACE_EVENT(iomap_iter,
>  	TP_PROTO(struct iomap_iter *iter, const void *ops,
> -- 
> 2.39.2
>