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| author |   Vitaly Kuznetsov <vkuznets@redhat.com> | 2015-03-18 12:29:22 -0700 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-25 11:53:54 +0100 |
| commit | f3f6eb80872becdbce07f7d2670d3f8ae5119752 (patch) | |
| tree | ed64c447de26e00eb51f54ddfa9052b69bcca3c3 /drivers/hv | |
| parent | Drivers: hv: vmbus: Perform device register in the per-channel work element (diff) | |
| download | linux-dev-f3f6eb80872becdbce07f7d2670d3f8ae5119752.tar.xz linux-dev-f3f6eb80872becdbce07f7d2670d3f8ae5119752.zip | |
Drivers: hv: hv_balloon: keep locks balanced on add_memory() failure
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.
The current char-next branch is broken and this patch fixes
the bug.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv')
| -rw-r--r-- | drivers/hv/hv_balloon.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index c5bb87244dd7..f1f17c5ad8d8 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -652,6 +652,7 @@ 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; } |