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Commit a038e2536472b4dd932399b5277e65f188811de5

Authored by Paolo 'Blaisorblade' Giarrusso
Committed by Jens Axboe
1 parent bae386f788
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

[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 <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jens Axboe <axboe@suse.de>

Showing 1 changed file with 4 additions and 1 deletions Side-by-side Diff

... ... @@ -1663,6 +1663,8 @@
1663 1663 **/
1664 1664 void blk_start_queue(request_queue_t *q)
1665 1665 {
  1666 + WARN_ON(!irqs_disabled());
  1667 +
1666 1668 clear_bit(QUEUE_FLAG_STOPPED, &q->queue_flags);
1667 1669  
1668 1670 /*
... ... @@ -1878,7 +1880,8 @@
1878 1880 * get dealt with eventually.
1879 1881 *
1880 1882 * The queue spin lock must be held while manipulating the requests on the
1881   - * request queue.
  1883 + * request queue; this lock will be taken also from interrupt context, so irq
  1884 + * disabling is needed for it.
1882 1885 *
1883 1886 * Function returns a pointer to the initialized request queue, or NULL if
1884 1887 * it didn't succeed.