All of lore.kernel.org
 help / color / mirror / Atom feed
* [bug report] block, bfq: bring forward seek&think time update
@ 2019-06-27  8:03 Dan Carpenter
  0 siblings, 0 replies; only message in thread
From: Dan Carpenter @ 2019-06-27  8:03 UTC (permalink / raw)
  To: paolo.valente; +Cc: linux-block

Hello Paolo Valente,

This is a semi-automatic email about new static checker warnings.

The patch a3f9bce3697a: "block, bfq: bring forward seek&think time 
update" from Jun 25, 2019, leads to the following Smatch complaint:

    block/bfq-iosched.c:5353 __bfq_insert_request()
    warn: variable dereferenced before check 'bfqq' (see line 5349)

block/bfq-iosched.c
  5348	
  5349		bfq_update_io_thinktime(bfqd, bfqq);
                                              ^^^^
The patch introduces a new dereference (inside the function)

  5350		bfq_update_has_short_ttime(bfqd, bfqq, RQ_BIC(rq));
  5351		bfq_update_io_seektime(bfqd, bfqq, rq);
  5352	
  5353		waiting = bfqq && bfq_bfqq_wait_request(bfqq);
                          ^^^^
but the old code assumed "bfqq" could be NULL.

  5354		bfq_add_request(rq);
  5355		idle_timer_disabled = waiting && !bfq_bfqq_wait_request(bfqq);

regards,
dan carpenter

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2019-06-27  8:03 UTC | newest]

Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-06-27  8:03 [bug report] block, bfq: bring forward seek&think time update Dan Carpenter

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.