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| author |   Dan Williams <dan.j.williams@intel.com> | 2016-10-27 17:04:05 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2016-10-27 17:04:05 -0700 |
| commit | 52e73eb2872c9af6f382b2b22954ca8214397a4e (patch) | |
| tree | 535f1b0672bf4b1ad826a67e26437441ead156c7 /drivers/dax | |
| parent | nvdimm: make CONFIG_NVDIMM_DAX 'bool' (diff) | |
| download | linux-dev-52e73eb2872c9af6f382b2b22954ca8214397a4e.tar.xz linux-dev-52e73eb2872c9af6f382b2b22954ca8214397a4e.zip | |
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 a67823c1ed10 "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: ab68f2622136 ("/dev/dax, pmem: direct access to persistent memory")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dax')
| -rw-r--r-- | drivers/dax/pmem.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index 9630d8837ba9..4a15fa5df98b 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -44,7 +44,6 @@ static void dax_pmem_percpu_exit(void *data) dev_dbg(dax_pmem->dev, "%s\n", __func__); percpu_ref_exit(ref); - wait_for_completion(&dax_pmem->cmp); } static void dax_pmem_percpu_kill(void *data) @@ -54,6 +53,7 @@ static void dax_pmem_percpu_kill(void *data) dev_dbg(dax_pmem->dev, "%s\n", __func__); percpu_ref_kill(ref); + wait_for_completion(&dax_pmem->cmp); } static int dax_pmem_probe(struct device *dev) |