On Tue, Mar 03, 2020 at 02:07:32PM +0300, Cengiz Can wrote: > Added a reassignment into the NULL check block to fix the issue. > > Fixes: c780e86dd48 ("blktrace: Protect q->blk_trace with RCU") > > Signed-off-by: Cengiz Can <cengiz@xxxxxxxxxx> > --- > kernel/trace/blktrace.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c > index 4560878f0bac..29ea88f10b87 100644 > --- a/kernel/trace/blktrace.c > +++ b/kernel/trace/blktrace.c > @@ -1896,8 +1896,10 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev, > } > > ret = 0; > - if (bt == NULL) > + if (bt == NULL) { > ret = blk_trace_setup_queue(q, bdev); > + bt = q->blk_trace; > + } > > if (ret == 0) { > if (attr == &dev_attr_act_mask) > -- > 2.25.1 > <formletter> This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly. </formletter>