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authorNeil Brown <neilb@suse.de>2008-05-14 16:05:54 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-05-14 19:11:15 -0700
commite7e72bf641b1fc7b9df6f40bd2c36dfccd8d647c (patch)
tree81b1db5434c9635bf23fb40415056e10390cd692 /block/blk-settings.c
parent4920916f728fe3c51f54c25ab7b3d271254aab5a (diff)
Remove blkdev warning triggered by using md
As setting and clearing queue flags now requires that we hold a spinlock on the queue, and as blk_queue_stack_limits is called without that lock, get the lock inside blk_queue_stack_limits. For blk_queue_stack_limits to be able to find the right lock, each md personality needs to set q->queue_lock to point to the appropriate lock. Those personalities which didn't previously use a spin_lock, us q->__queue_lock. So always initialise that lock when allocated. With this in place, setting/clearing of the QUEUE_FLAG_PLUGGED bit will no longer cause warnings as it will be clear that the proper lock is held. Thanks to Dan Williams for review and fixing the silly bugs. Signed-off-by: NeilBrown <neilb@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Alistair John Strachan <alistair@devzero.co.uk> Cc: Nick Piggin <npiggin@suse.de> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Jacek Luczak <difrost.kernel@gmail.com> Cc: Prakash Punnoor <prakash@punnoor.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'block/blk-settings.c')
-rw-r--r--block/blk-settings.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c
index bb93d4c32775..8dd86418f35d 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -286,8 +286,14 @@ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
t->max_hw_segments = min(t->max_hw_segments, b->max_hw_segments);
t->max_segment_size = min(t->max_segment_size, b->max_segment_size);
t->hardsect_size = max(t->hardsect_size, b->hardsect_size);
- if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags))
+ if (!t->queue_lock)
+ WARN_ON_ONCE(1);
+ else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) {
+ unsigned long flags;
+ spin_lock_irqsave(t->queue_lock, flags);
queue_flag_clear(QUEUE_FLAG_CLUSTER, t);
+ spin_unlock_irqrestore(t->queue_lock, flags);
+ }
}
EXPORT_SYMBOL(blk_queue_stack_limits);