On Tue, 25 Jan 2022 09:37:02 -0500
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> > > +TRACE_EVENT(block_rq_error,
> > > +
> > > + TP_PROTO(struct request *rq, int error, unsigned int nr_bytes),
> > > +
> > > + TP_ARGS(rq, error, nr_bytes),
> > > +
> > > + TP_STRUCT__entry(
> > > + __field( dev_t, dev )
> > > + __string( name, rq->rq_disk ? rq->rq_disk->disk_name : "?")
> > > + __field( sector_t, sector )
> > > + __field( unsigned int, nr_sector )
> > > + __field( int, error )
> > > + __array( char, rwbs, RWBS_LEN )
>
> Why is the above not "__string" ?
>
> > > + ),
> > > +
> > > + TP_fast_assign(
> > > + __entry->dev = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
> > > + __assign_str(name, rq->rq_disk ? rq->rq_disk->disk_name : "?");
>
> __assign_str() will not work on an __array() type. It only works here
> because you added it at the end, but it's just shear luck that it didn't
> crash.
Never mind :-p I see the above is for name which is __string, and the
array is for rwbs which is filled below. I need to finish my first cup of
coffee before reviewing patches.
-- Steve
>
>
> > > + __entry->sector = blk_rq_pos(rq);
> > > + __entry->nr_sector = nr_bytes >> 9;
> > > + __entry->error = error;
> > > +
> > > + blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, nr_bytes);
> > > + ),
> > > +
> > > + TP_printk("%d,%d %s %s %llu + %u [%d]",
> > > + MAJOR(__entry->dev), MINOR(__entry->dev),
> > > + __get_str(name), __entry->rwbs,
> > > + (unsigned long long)__entry->sector,
> > > + __entry->nr_sector, __entry->error)
> > > +);
> > > +
