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authorChristoph Hellwig <hch@lst.de>2021-08-16 16:46:24 +0300
committerJens Axboe <axboe@kernel.dk>2021-08-23 21:54:31 +0300
commitd152c682f03ceb65c0d9663d4ba6ee2d46aa784d (patch)
tree31cc1a85256072b4d65d881472c2f6ace7c10178 /block/blk-wbt.c
parent61a35cfc26334fe1c8e970ca8fafeae2daae257d (diff)
downloadlinux-d152c682f03ceb65c0d9663d4ba6ee2d46aa784d.tar.xz
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.c10
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,