Messages in this thread | | | Date | Wed, 18 Mar 2015 17:07:11 -0600 | From | Jens Axboe <> | Subject | Re: [PATCH v2] blkmq: Fix NULL pointer deref when all reserved tags in use |
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On 03/18/2015 05:07 PM, Sam Bradshaw wrote: > When allocating from the reserved tags pool, bt_get() is called with > a NULL hctx. If all tags are in use, the hw queue is kicked to push > out any pending IO, potentially freeing tags, and tag allocation is > retried. The problem is that blk_mq_run_hw_queue() doesn't check for > a NULL hctx. So we avoid it with a simple NULL hctx test. > > This issue was introduced by: > b32232073e80: blk-mq: fix hang in bt_get() > > Tested by hammering mtip32xx with concurrent smartctl/hdparm. > > Signed-off-by: Sam Bradshaw <sbradshaw@micron.com> > Signed-off-by: Selvan Mani <smani@micron.com>
Thanks Sam, added to the current series.
-- Jens Axboe
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