Re: [PATCH v3 34/35] xfs: add fsverity traces

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

On Wed, Feb 18, 2026 at 12:19:34AM +0100, Andrey Albershteyn wrote:
> Even though fsverity has traces, debugging issues with varying block
> sizes could be a bit less transparent without read/write traces.
> 
> Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
> ---
>  fs/xfs/xfs_fsverity.c | 10 ++++++++++
>  fs/xfs/xfs_trace.h    | 46 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 56 insertions(+)
> 
> diff --git a/fs/xfs/xfs_fsverity.c b/fs/xfs/xfs_fsverity.c
> index d89512d59328..69f1c22e1ba8 100644
> --- a/fs/xfs/xfs_fsverity.c
> +++ b/fs/xfs/xfs_fsverity.c
> @@ -176,6 +176,8 @@ xfs_fsverity_get_descriptor(
>  	uint32_t		blocksize = i_blocksize(VFS_I(ip));
>  	xfs_fileoff_t		last_block_offset;
>  
> +	trace_xfs_fsverity_get_descriptor(ip);
> +
>  	ASSERT(inode->i_flags & S_VERITY);
>  	error = xfs_bmap_last_extent(NULL, ip, XFS_DATA_FORK, &rec, &is_empty);
>  	if (error)
> @@ -419,6 +421,8 @@ xfs_fsverity_read_merkle(
>  		(fsverity_metadata_offset(inode) >> PAGE_SHIFT);
>  	pgoff_t			idx = index + metadata_idx;
>  
> +	trace_xfs_fsverity_read_merkle(XFS_I(inode), idx, PAGE_SIZE);
> +
>  	return generic_read_merkle_tree_page(inode, idx);
>  }
>  
> @@ -435,6 +439,8 @@ xfs_fsverity_readahead_merkle_tree(
>  		(fsverity_metadata_offset(inode) >> PAGE_SHIFT);
>  	pgoff_t			idx = index + metadata_idx;
>  
> +	trace_xfs_fsverity_read_merkle(XFS_I(inode), idx, PAGE_SIZE);
> +
>  	generic_readahead_merkle_tree(inode, idx, nr_pages);
>  }
>  
> @@ -456,6 +462,8 @@ xfs_fsverity_write_merkle(
>  	const char		*p;
>  	unsigned int		i;
>  
> +	trace_xfs_fsverity_write_merkle(XFS_I(inode), position, size);
> +
>  	if (position + size > inode->i_sb->s_maxbytes)
>  		return -EFBIG;
>  
> @@ -487,6 +495,8 @@ xfs_fsverity_file_corrupt(
>  	loff_t			pos,
>  	size_t			len)
>  {
> +	trace_xfs_fsverity_file_corrupt(XFS_I(inode), pos, len);
> +
>  	xfs_inode_mark_sick(XFS_I(inode), XFS_SICK_INO_DATA);
>  }
>  
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index f70afbf3cb19..a5562921611a 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -5906,6 +5906,52 @@ DEFINE_EVENT(xfs_freeblocks_resv_class, name, \
>  DEFINE_FREEBLOCKS_RESV_EVENT(xfs_freecounter_reserved);
>  DEFINE_FREEBLOCKS_RESV_EVENT(xfs_freecounter_enospc);
>  
> +TRACE_EVENT(xfs_fsverity_get_descriptor,
> +	TP_PROTO(struct xfs_inode *ip),
> +	TP_ARGS(ip),
> +	TP_STRUCT__entry(
> +		__field(dev_t, dev)
> +		__field(xfs_ino_t, ino)
> +	),
> +	TP_fast_assign(
> +		__entry->dev = VFS_I(ip)->i_sb->s_dev;
> +		__entry->ino = ip->i_ino;
> +	),
> +	TP_printk("dev %d:%d ino 0x%llx",
> +		  MAJOR(__entry->dev), MINOR(__entry->dev),
> +		  __entry->ino)
> +);
> +
> +DECLARE_EVENT_CLASS(xfs_fsverity_class,
> +	TP_PROTO(struct xfs_inode *ip, u64 pos, unsigned int length),

I wonder if @length ought to be size_t instead of unsigned int?
Probably doesn't matter at this point, fsverity isn't going to send huge
multigigabyte IOs.

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

--D

> +	TP_ARGS(ip, pos, length),
> +	TP_STRUCT__entry(
> +		__field(dev_t, dev)
> +		__field(xfs_ino_t, ino)
> +		__field(u64, pos)
> +		__field(unsigned int, length)
> +	),
> +	TP_fast_assign(
> +		__entry->dev = VFS_I(ip)->i_sb->s_dev;
> +		__entry->ino = ip->i_ino;
> +		__entry->pos = pos;
> +		__entry->length = length;
> +	),
> +	TP_printk("dev %d:%d ino 0x%llx pos 0x%llx length 0x%x",
> +		  MAJOR(__entry->dev), MINOR(__entry->dev),
> +		  __entry->ino,
> +		  __entry->pos,
> +		  __entry->length)
> +)
> +
> +#define DEFINE_FSVERITY_EVENT(name) \
> +DEFINE_EVENT(xfs_fsverity_class, name, \
> +	TP_PROTO(struct xfs_inode *ip, u64 pos, unsigned int length), \
> +	TP_ARGS(ip, pos, length))
> +DEFINE_FSVERITY_EVENT(xfs_fsverity_read_merkle);
> +DEFINE_FSVERITY_EVENT(xfs_fsverity_write_merkle);
> +DEFINE_FSVERITY_EVENT(xfs_fsverity_file_corrupt);
> +
>  #endif /* _TRACE_XFS_H */
>  
>  #undef TRACE_INCLUDE_PATH
> -- 
> 2.51.2
> 
>