On Sep 05, 2024 / 14:53, Vincent Fu wrote:
> Hello Shin'ichiro,
>
> Coverity reported the issue below with the "stat: reduce arguments of
> add_log_sample()" commit.
Hello Vincent, thank you for finding out the failure. I looked in the detail,
and found my commit 14d3134a5fc0 ("introduce the log_issue_time option")
triggered the failure.
>
> ** CID 509196: Null pointer dereferences (FORWARD_NULL)
>
> ________________________________________________________________________________________________________
> *** CID 509196: Null pointer dereferences (FORWARD_NULL)
> /stat.c: 3342 in add_clat_sample()
> 3336 */
> 3337 if (!ts->lat_percentiles)
> 3338 add_stat_prio_sample(ts->clat_prio[ddir], clat_prio_index,
> 3339 nsec);
> 3340
> 3341 if (td->clat_log) {
> >>> CID 509196: Null pointer dereferences (FORWARD_NULL)
> >>> Passing null pointer "&io_u->issue_time" to "ntime_since", which
> dereferences it.
> 3342 struct log_sample sample = { sample_val(nsec), ddir, bs,
> 3343 offset, ioprio,
> 3344 ntime_since(&td->epoch, &io_u->issue_time) };
> 3345
> 3346 add_log_sample(td, td->clat_log, &sample);
> 3347 }
>
> It appears that with the refactoring it is no longer possible to carry out
> latency logging with the file operation ioengines since their calls set io_u
> to NULL. Would you be able to devise a way to restore this?
Sorry for the trouble. Will post fix patches soon.
