Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> writes: > When add_memory() fails the following BUG is observed: > [ 743.646107] hv_balloon: hot_add memory failed error is -17 > [ 743.679973] > [ 743.680930] ===================================== > [ 743.680930] [ BUG: bad unlock balance detected! ] > [ 743.680930] 3.19.0-rc5_bug1131426+ #552 Not tainted > [ 743.680930] ------------------------------------- > [ 743.680930] kworker/0:2/255 is trying to release lock (&dm_device.ha_region_mutex) at: > [ 743.680930] [<ffffffff81aae5fe>] mutex_unlock+0xe/0x10 > [ 743.680930] but there are no more locks to release! > > This happens as we don't acquire ha_region_mutex and hot_add_req() expects us > to as it does unconditional mutex_unlock(). Acquire the lock on the error path. > > Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > --- > This patch is dependent on the previously posted 'Drivers: hv: hv_balloon: > eliminate the trylock path in acquire/release_region_mutex'. Hi K.Y., I don't see this patch in your '[PATCH 0/7] Drivers: hv: Collection fixes and enhancements' sent to Greg. Please let me know if you see any issues with it as it looks like a pretty important bugfix to me. Thanks, > --- > drivers/hv/hv_balloon.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c > index 1283035..771bf84 100644 > --- a/drivers/hv/hv_balloon.c > +++ b/drivers/hv/hv_balloon.c > @@ -654,6 +654,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size, > } > has->ha_end_pfn -= HA_CHUNK; > has->covered_end_pfn -= processed_pfn; > + mutex_lock(&dm_device.ha_region_mutex); > break; > } -- Vitaly _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
