On 2021/3/29 11:02, Keith Busch wrote:
On Sun, Mar 28, 2021 at 10:23:37PM -0400, Yufen Yu wrote:
static struct bio *__bio_chain_endio(struct bio *bio)
{
struct bio *parent = bio->bi_private;
+ unsigned long flags;
+ spin_lock_irqsave(&parent->bi_lock, flags);
if (!parent->bi_status)
parent->bi_status = bio->bi_status;
+ spin_unlock_irqrestore(&parent->bi_lock, flags);
I don't see a spin_lock_init() on this new lock, though a spinlock seems
overkill here. If you need an atomic update, you could do:
cmpxchg(&parent->bi_status, 0, bio->bi_status);
But I don't even think that's necessary. There really is no need to set
parent->bi_status if bio->bi_status is 0, so something like this should
be fine:
if (bio->bi_status && !parent->bi_status)
parent->bi_status = bio->bi_status;
.
Yeah, this is more smart. Thanks a lot for your suggestion.
I will send v2.
Thanks,
Yufen
