block: sysfs store function needs to grab queue_lock and use queue_flag_*()

Concurrency isn't a big deal here since we have requests in flight
at this point, but do the locked variant to set a better example.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index e85c401..304ec73 100644 (file)
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -146,11 +146,13 @@ static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
        unsigned long nm;
        ssize_t ret = queue_var_store(&nm, page, count);
 
+       spin_lock_irq(q->queue_lock);
        if (nm)
-              set_bit(QUEUE_FLAG_NOMERGES, &q->queue_flags);
+               queue_flag_set(QUEUE_FLAG_NOMERGES, q);
        else
-              clear_bit(QUEUE_FLAG_NOMERGES, &q->queue_flags);
+               queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
 
+       spin_unlock_irq(q->queue_lock);
        return ret;
 }