[PATCH 30/60] bcache: set flag of QUEUE_FLAG_SPLIT_MP

[Ming Lei <tom.leiming@gmail.com>]

It isn't safe(such as bch_data_verify()) to let bcache deal with
more than 1M bio from multipage bvec, so set this flag and size of
incoming bio won't be bigger than BIO_SP_MAX_SECTORS.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 drivers/md/bcache/super.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 52876fcf2b36..fca023a1a026 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -821,6 +821,12 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,
 
 	blk_queue_write_cache(q, true, true);
 
+	/*
+	 * Once bcache is audited that it is ready to deal with big
+	 * incoming bio with multipage bvecs, we can remove the flag.
+	 */
+	set_bit(QUEUE_FLAG_SPLIT_MP,	&d->disk->queue->queue_flags);
+
 	return 0;
 }
 
-- 
2.7.4