Messages in this thread | | | Date | Thu, 6 Aug 2020 12:26:37 -0700 | From | Ira Weiny <> | Subject | Re: [PATCH v2 3/3] libnvdimm/security: ensure sysfs poll thread woke up and fetch updated attr |
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On Mon, Aug 03, 2020 at 04:41:39PM -0600, Jane Chu wrote: > commit 7d988097c546 ("acpi/nfit, libnvdimm/security: Add security DSM overwrite support") > adds a sysfs_notify_dirent() to wake up userspace poll thread when the "overwrite" > operation has completed. But the notification is issued before the internal > dimm security state and flags have been updated, so the userspace poll thread > wakes up and fetches the not-yet-updated attr and falls back to sleep, forever. > But if user from another terminal issue "ndctl wait-overwrite nmemX" again, > the command returns instantly. > > Cc: Dave Jiang <dave.jiang@intel.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Fixes: 7d988097c546 ("acpi/nfit, libnvdimm/security: Add security DSM overwrite support") > Signed-off-by: Jane Chu <jane.chu@oracle.com> > Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> --- > drivers/nvdimm/security.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c > index 8f3971c..4b80150 100644 > --- a/drivers/nvdimm/security.c > +++ b/drivers/nvdimm/security.c > @@ -450,14 +450,19 @@ void __nvdimm_security_overwrite_query(struct nvdimm *nvdimm) > else > dev_dbg(&nvdimm->dev, "overwrite completed\n"); > > - if (nvdimm->sec.overwrite_state) > - sysfs_notify_dirent(nvdimm->sec.overwrite_state); > + /* > + * Mark the overwrite work done and update dimm security flags, > + * then send a sysfs event notification to wake up userspace > + * poll threads to picked up the changed state. > + */ > nvdimm->sec.overwrite_tmo = 0; > clear_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags); > clear_bit(NDD_WORK_PENDING, &nvdimm->flags); > - put_device(&nvdimm->dev); > nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER); > nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER); > + if (nvdimm->sec.overwrite_state) > + sysfs_notify_dirent(nvdimm->sec.overwrite_state); > + put_device(&nvdimm->dev); > } > > void nvdimm_security_overwrite_query(struct work_struct *work) > -- > 1.8.3.1 >
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