Hi Jens,
Will you consider this patch ?
Thanks
2018-01-15 23:53 GMT+08:00 weiping zhang <zhangweiping@xxxxxxxxxxxxxxx>:
> if we run blktrace on same device twice, the second time will failed
> to ioctl(BLKTRACESETUP), then it will call __stop_tracer, which lead
> the first blktrace failed to access debugfs entries. So this patch add
> a check to handle this case, to avoid stop tracer uncondionally.
>
> Signed-off-by: weiping zhang <zhangweiping@xxxxxxxxxxxxxxx>
> ---
> blktrace.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/blktrace.c b/blktrace.c
> index e048f68..d0d271f 100644
> --- a/blktrace.c
> +++ b/blktrace.c
> @@ -112,6 +112,7 @@ struct devpath {
> struct cl_host *ch;
> u32 cl_id;
> time_t cl_connect_time;
> + int setup_done; /* ioctl BLKTRACESETUP done */
> struct io_info *ios;
> };
>
> @@ -1083,6 +1084,7 @@ static int setup_buts(void)
> if (ioctl(dpp->fd, BLKTRACESETUP, &buts) >= 0) {
> dpp->ncpus = max_cpus;
> dpp->buts_name = strdup(buts.name);
> + dpp->setup_done = 1;
> if (dpp->stats)
> free(dpp->stats);
> dpp->stats = calloc(dpp->ncpus, sizeof(*dpp->stats));
> @@ -1285,7 +1287,8 @@ static void rel_devpaths(void)
> struct devpath *dpp = list_entry(p, struct devpath, head);
>
> list_del(&dpp->head);
> - __stop_trace(dpp->fd);
> + if (dpp->setup_done)
> + __stop_trace(dpp->fd);
> close(dpp->fd);
>
> if (dpp->heads)
> --
> 1.8.3.1
>
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