From a038e2536472b4dd932399b5277e65f188811de5 Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Mon, 5 Jun 2006 12:09:01 +0200 Subject: [PATCH] blk_start_queue() must be called with irq disabled - add warning The queue lock can be taken from interrupts so it must always be taken with irq disabling primitives. Some primitives already verify this. blk_start_queue() is called under this lock, so interrupts must be disabled. Also document this requirement clearly in blk_init_queue(), where the queue spinlock is set. Signed-off-by: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe --- block/ll_rw_blk.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index 465b54312c59..17c42ddd31db 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -1663,6 +1663,8 @@ static void blk_unplug_timeout(unsigned long data) **/ void blk_start_queue(request_queue_t *q) { + WARN_ON(!irqs_disabled()); + clear_bit(QUEUE_FLAG_STOPPED, &q->queue_flags); /* @@ -1878,7 +1880,8 @@ EXPORT_SYMBOL(blk_alloc_queue_node); * get dealt with eventually. * * The queue spin lock must be held while manipulating the requests on the - * request queue. + * request queue; this lock will be taken also from interrupt context, so irq + * disabling is needed for it. * * Function returns a pointer to the initialized request queue, or NULL if * it didn't succeed. -- cgit v1.2.2