Re: [PATCH 13/31] fuse_trace: implement direct IO with iomap

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

On Thu, Feb 05, 2026 at 11:16:54AM -0800, Chris Mason wrote:
> "Darrick J. Wong" <djwong@kernel.org> wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> > 
> > Add tracepoints for the previous patch.
> > 
> 
> commit 3fad15ebe8d51187a2b6820ed6db4774a8b065b0
> Author: Darrick J. Wong <djwong@kernel.org>
> 
> fuse_trace: implement direct IO with iomap
> 
> Add tracepoints for the previous patch.
> 
> > diff --git a/fs/fuse/fuse_trace.h b/fs/fuse/fuse_trace.h
> > index 730ab8bce4445..efba6ecbbf670 100644
> > --- a/fs/fuse/fuse_trace.h
> > +++ b/fs/fuse/fuse_trace.h
> 
> [ ... ]
> 
> > @@ -484,6 +499,75 @@ TRACE_EVENT(fuse_iomap_end_error,
> > +TRACE_EVENT(fuse_iomap_ioend,
> > +	TP_PROTO(const struct inode *inode,
> > +		 const struct fuse_iomap_ioend_in *inarg),
> > +
> > +	TP_ARGS(inode, inarg),
> > +
> > +	TP_STRUCT__entry(
> > +		FUSE_IO_RANGE_FIELDS()
> > +		__field(unsigned,		ioendflags)
> > +		__field(int,			error)
> > +		__field(uint32_t,		dev)
> > +		__field(uint64_t,		new_addr)
> > +	),
> > +
> > +	TP_fast_assign(
> > +		FUSE_INODE_ASSIGN(inode, fi, fm);
> > +		__entry->offset		=	inarg->pos;
> > +		__entry->length		=	inarg->written;
> > +		__entry->ioendflags	=	inarg->flags;
> > +		__entry->error		=	inarg->error;
> > +		__entry->dev		=	inarg->dev;
> > +		__entry->new_addr	=	inarg->new_addr;
> > +	),
> > +
> > +	TP_printk(FUSE_IO_RANGE_FMT() " ioendflags (%s) error %d dev %u new_addr 0x%llx",
> > +		  FUSE_IO_RANGE_PRINTK_ARGS(),
> > +		  __print_flags(__entry->ioendflags, "|", FUSE_IOMAP_IOEND_STRINGS),
> > +		  __entry->dev,
> > +		  __entry->error,
> > +		  __entry->new_addr)
>                   ^^^^
> 
> Are the error and dev fields swapped in the argument list?
> 
> The format string expects 'error %d dev %u' but the arguments are
> provided as __entry->dev, __entry->error. This would cause the trace
> output to display the dev value as error and the error value as dev.
> 
> > +);
> > +
> > +TRACE_EVENT(fuse_iomap_ioend_error,
> > +	TP_PROTO(const struct inode *inode,
> > +		 const struct fuse_iomap_ioend_in *inarg,
> > +		 const struct fuse_iomap_ioend_out *outarg,
> > +		 int error),
> > +
> > +	TP_ARGS(inode, inarg, outarg, error),
> > +
> > +	TP_STRUCT__entry(
> > +		FUSE_IO_RANGE_FIELDS()
> > +		__field(unsigned,		ioendflags)
> > +		__field(int,			error)
> > +		__field(uint32_t,		dev)
> > +		__field(uint64_t,		new_addr)
> > +		__field(uint64_t,		new_size)
> > +	),
> > +
> > +	TP_fast_assign(
> > +		FUSE_INODE_ASSIGN(inode, fi, fm);
> > +		__entry->offset		=	inarg->pos;
> > +		__entry->length		=	inarg->written;
> > +		__entry->ioendflags	=	inarg->flags;
> > +		__entry->error		=	error;
> > +		__entry->dev		=	inarg->dev;
> > +		__entry->new_addr	=	inarg->new_addr;
> > +		__entry->new_size	=	outarg->newsize;
> > +	),
> > +
> > +	TP_printk(FUSE_IO_RANGE_FMT() " ioendflags (%s) error %d dev %u new_addr 0x%llx new_size 0x%llx",
> > +		  FUSE_IO_RANGE_PRINTK_ARGS(),
> > +		  __print_flags(__entry->ioendflags, "|", FUSE_IOMAP_IOEND_STRINGS),
> > +		  __entry->dev,
> > +		  __entry->error,
> > +		  __entry->new_addr,
> > +		  __entry->new_size)
>                   ^^^^
> 
> Same issue here. The format string expects 'error %d dev %u' but the
> arguments are provided as __entry->dev, __entry->error, swapping the
> values in the trace output.

Yep, both wrong, both fixed.  Thanks!

--D

> 
> > +);
> > +
> 
> [ ... ]
> 
>