[ Upstream commit fd03177c33b287c6541f4048f1d67b7b45a1abc9 ] As reported in [1], the call bfq_init_rq(rq) may return NULL in case of OOM (in particular, if rq->elv.icq is NULL because memory allocation failed in failed in ioc_create_icq()).
This commit handles this circumstance. [1] https://lkml.org/lkml/2019/7/22/824 Cc: Hsin-Yi Wang <hsi...@google.com> Cc: Nicolas Boichat <drink...@chromium.org> Cc: Doug Anderson <diand...@chromium.org> Reported-by: Guenter Roeck <li...@roeck-us.net> Reported-by: Hsin-Yi Wang <hsi...@google.com> Reviewed-by: Guenter Roeck <li...@roeck-us.net> Signed-off-by: Paolo Valente <paolo.vale...@linaro.org> Signed-off-by: Jens Axboe <ax...@kernel.dk> Signed-off-by: Sasha Levin <sas...@kernel.org> --- block/bfq-iosched.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index becd793a258c8..d8d2ac294b0c0 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -1886,9 +1886,14 @@ static void bfq_request_merged(struct request_queue *q, struct request *req, blk_rq_pos(container_of(rb_prev(&req->rb_node), struct request, rb_node))) { struct bfq_queue *bfqq = bfq_init_rq(req); - struct bfq_data *bfqd = bfqq->bfqd; + struct bfq_data *bfqd; struct request *prev, *next_rq; + if (!bfqq) + return; + + bfqd = bfqq->bfqd; + /* Reposition request in its sort_list */ elv_rb_del(&bfqq->sort_list, req); elv_rb_add(&bfqq->sort_list, req); @@ -1930,6 +1935,9 @@ static void bfq_requests_merged(struct request_queue *q, struct request *rq, struct bfq_queue *bfqq = bfq_init_rq(rq), *next_bfqq = bfq_init_rq(next); + if (!bfqq) + return; + /* * If next and rq belong to the same bfq_queue and next is older * than rq, then reposition rq in the fifo (by substituting next @@ -4590,12 +4598,12 @@ static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, spin_lock_irq(&bfqd->lock); bfqq = bfq_init_rq(rq); - if (at_head || blk_rq_is_passthrough(rq)) { + if (!bfqq || at_head || blk_rq_is_passthrough(rq)) { if (at_head) list_add(&rq->queuelist, &bfqd->dispatch); else list_add_tail(&rq->queuelist, &bfqd->dispatch); - } else { /* bfqq is assumed to be non null here */ + } else { idle_timer_disabled = __bfq_insert_request(bfqd, rq); /* * Update bfqq, because, if a queue merge has occurred -- 2.20.1
