block: provide bio_clear_hipri() helper
Any case that turns off REQ_HIPRI must also clear BIO_PERCPU_CACHE,
as non-polled IO may complete through hard/soft IRQ and hence isn't
safe for our polled bio alloc cache.
Provide a helper that does just that, and use it in the merging code as
well if we split a bio and turn off polling.
Fixes: be863b9e4348 ("block: clear BIO_PERCPU_CACHE flag if polling isn't supported")
Reported-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk.h b/block/blk.h
index cb01429..5a4652a 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -364,4 +364,11 @@ extern struct device_attribute dev_attr_events;
extern struct device_attribute dev_attr_events_async;
extern struct device_attribute dev_attr_events_poll_msecs;
+static inline void bio_clear_hipri(struct bio *bio)
+{
+ /* can't support alloc cache if we turn off polling */
+ bio_clear_flag(bio, BIO_PERCPU_CACHE);
+ bio->bi_opf &= ~REQ_HIPRI;
+}
+
#endif /* BLK_INTERNAL_H */