blktrace: Fix output non-blktrace event when blk_classic option enabled

[ Upstream commit f596da3efa ]

When the blk_classic option is enabled, non-blktrace events must be
filtered out. Otherwise, events of other types are output in the blktrace
classic format, which is unexpected.

The problem can be triggered in the following ways:

  # echo 1 > /sys/kernel/debug/tracing/options/blk_classic
  # echo 1 > /sys/kernel/debug/tracing/events/enable
  # echo blk > /sys/kernel/debug/tracing/current_tracer
  # cat /sys/kernel/debug/tracing/trace_pipe

Fixes: c71a896154 ("blktrace: add ftrace plugin")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20221122040410.85113-1-yangjihong1@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yang Jihong 2022-11-22 12:04:10 +08:00 committed by Greg Kroah-Hartman
parent bbb2d35386
commit 8682d0a6ee

View file

@ -1548,7 +1548,8 @@ blk_trace_event_print_binary(struct trace_iterator *iter, int flags,
static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
{
if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
if ((iter->ent->type != TRACE_BLK) ||
!(blk_tracer_flags.val & TRACE_BLK_OPT_CLASSIC))
return TRACE_TYPE_UNHANDLED;
return print_one_line(iter, true);