linux/drivers/dax
Dan Williams 52e73eb287 device-dax: fix percpu_ref_exit ordering
We need to wait until the percpu_ref is released before exit. Otherwise,
we sometimes lose the race and trigger this new warning that was added
in v4.9 (commit a67823c1ed "percpu-refcount: init ->confirm_switch
member properly"):

 WARNING: CPU: 0 PID: 3629 at lib/percpu-refcount.c:107 percpu_ref_exit+0x51/0x60
 [..]
 Call Trace:
  [<ffffffff814bf093>] dump_stack+0x85/0xc2
  [<ffffffff810b15db>] __warn+0xcb/0xf0
  [<ffffffff810b170d>] warn_slowpath_null+0x1d/0x20
  [<ffffffff814d70c1>] percpu_ref_exit+0x51/0x60
  [<ffffffffa005706a>] dax_pmem_percpu_exit+0x1a/0x50 [dax_pmem]
  [<ffffffff81615f1f>] devm_action_release+0xf/0x20

Cc: <stable@vger.kernel.org>
Fixes: ab68f26221 ("/dev/dax, pmem: direct access to persistent memory")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-10-27 17:04:05 -07:00
..
Kconfig nvdimm: make CONFIG_NVDIMM_DAX 'bool' 2016-10-27 16:16:21 -07:00
Makefile /dev/dax, pmem: direct access to persistent memory 2016-05-20 22:02:53 -07:00
dax.c Merge branch 'for-4.9/dax' into libnvdimm-for-next 2016-10-07 16:46:30 -07:00
dax.h dax: convert devm_create_dax_dev to PTR_ERR 2016-10-07 16:45:59 -07:00
pmem.c device-dax: fix percpu_ref_exit ordering 2016-10-27 17:04:05 -07:00