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| author | Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> | 2006-06-05 12:09:01 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@nelson.home.kernel.dk> | 2006-06-23 17:10:38 +0200 |
| commit | a038e2536472b4dd932399b5277e65f188811de5 (patch) | |
| tree | 15b311da1a9aa36b24f98ae914456ecb90e247f3 /block | |
| parent | bae386f7884aa3720cc7880b36a41a1d2b9c327b (diff) | |
| download | linux-a038e2536472b4dd932399b5277e65f188811de5.tar.gz linux-a038e2536472b4dd932399b5277e65f188811de5.tar.bz2 linux-a038e2536472b4dd932399b5277e65f188811de5.zip | |
[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>
Diffstat (limited to 'block')
| -rw-r--r-- | block/ll_rw_blk.c | 5 |
1 files changed, 4 insertions, 1 deletions
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. |