diff options
| author | Christoph Hellwig <hch@lst.de> | 2021-08-16 15:46:24 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-08-23 12:54:31 -0600 |
| commit | d152c682f03ceb65c0d9663d4ba6ee2d46aa784d (patch) | |
| tree | 31cc1a85256072b4d65d881472c2f6ace7c10178 /block/blk-wbt.c | |
| parent | 61a35cfc26334fe1c8e970ca8fafeae2daae257d (diff) | |
block: add an explicit ->disk backpointer to the request_queue
Replace the magic lookup through the kobject tree with an explicit
backpointer, given that the device model links are set up and torn
down at times when I/O is still possible, leading to potential
NULL or invalid pointer dereferences.
Fixes: edb0872f44ec ("block: move the bdi from the request_queue to the gendisk")
Reported-by: syzbot <syzbot+aa0801b6b32dca9dda82@syzkaller.appspotmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Link: https://lore.kernel.org/r/20210816134624.GA24234@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-wbt.c')
| -rw-r--r-- | block/blk-wbt.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/block/blk-wbt.c b/block/blk-wbt.c index 31086afaad9c..874c1c37bf0c 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c @@ -97,7 +97,7 @@ static void wb_timestamp(struct rq_wb *rwb, unsigned long *var) */ static bool wb_recent_wait(struct rq_wb *rwb) { - struct bdi_writeback *wb = &queue_to_disk(rwb->rqos.q)->bdi->wb; + struct bdi_writeback *wb = &rwb->rqos.q->disk->bdi->wb; return time_before(jiffies, wb->dirty_sleep + HZ); } @@ -234,7 +234,7 @@ enum { static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat) { - struct backing_dev_info *bdi = queue_to_disk(rwb->rqos.q)->bdi; + struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi; struct rq_depth *rqd = &rwb->rq_depth; u64 thislat; @@ -287,7 +287,7 @@ static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat) static void rwb_trace_step(struct rq_wb *rwb, const char *msg) { - struct backing_dev_info *bdi = queue_to_disk(rwb->rqos.q)->bdi; + struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi; struct rq_depth *rqd = &rwb->rq_depth; trace_wbt_step(bdi, msg, rqd->scale_step, rwb->cur_win_nsec, @@ -359,8 +359,8 @@ static void wb_timer_fn(struct blk_stat_callback *cb) status = latency_exceeded(rwb, cb->stat); - trace_wbt_timer(queue_to_disk(rwb->rqos.q)->bdi, status, - rqd->scale_step, inflight); + trace_wbt_timer(rwb->rqos.q->disk->bdi, status, rqd->scale_step, + inflight); /* * If we exceeded the latency target, step down. If we did not, |