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| author | Paolo Valente <paolo.valente@linaro.org> | 2019-08-07 19:21:11 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-08-08 07:31:50 -0600 |
| commit | fd03177c33b287c6541f4048f1d67b7b45a1abc9 (patch) | |
| tree | 1e95e71d6ba6bd86620b9d1267b89e463ed4df2c /block/bfq-iosched.c | |
| parent | 3f758e844aa9800eb660d60ee10226fa802594d4 (diff) | |
| download | lwn-fd03177c33b287c6541f4048f1d67b7b45a1abc9.tar.gz lwn-fd03177c33b287c6541f4048f1d67b7b45a1abc9.zip | |
block, bfq: handle NULL return value by bfq_init_rq()
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 <hsinyi@google.com>
Cc: Nicolas Boichat <drinkcat@chromium.org>
Cc: Doug Anderson <dianders@chromium.org>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Hsin-Yi Wang <hsinyi@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bfq-iosched.c')
| -rw-r--r-- | block/bfq-iosched.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 5f477501bb3d..b33be928d164 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2251,9 +2251,14 @@ 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); @@ -2300,6 +2305,9 @@ 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 @@ -5454,12 +5462,12 @@ 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 |