blk-mq: I/O and timer unplugs are inverted in blktrace

BugLink: https://bugs.launchpad.net/bugs/1836426
commit 587562d0c7cd6861f4f90a2eb811cccb1a376f5f upstream.

trace_block_unplug() takes true for explicit unplugs and false for
implicit unplugs.  schedule() unplugs are implicit and should be
reported as timer unplugs.  While correct in the legacy code, this has
been inverted in blk-mq since 4.11.

Cc: stable@vger.kernel.org
Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers")
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index be342d0aca34cebb2da25f9d6abb48c852d184d5..dcc19e2d370ced4c27d8392760b87bb66cc5cc68 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1611,7 +1611,7 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
                BUG_ON(!rq->q);
                if (rq->mq_ctx != this_ctx) {
                        if (this_ctx) {
-                               trace_block_unplug(this_q, depth, from_schedule);
+                               trace_block_unplug(this_q, depth, !from_schedule);
                                blk_mq_sched_insert_requests(this_q, this_ctx,
                                                                &ctx_list,
                                                                from_schedule);
@@ -1631,7 +1631,7 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
         * on 'ctx_list'. Do those.
         */
        if (this_ctx) {
-               trace_block_unplug(this_q, depth, from_schedule);
+               trace_block_unplug(this_q, depth, !from_schedule);
                blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list,
                                                from_schedule);
        }