| Message ID | 154922213038.3561630.15221922065373676874.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 0171b6b78131110a6870d4b7296bc9dfc392116a |
| Headers | show |
| Series | acpi/nfit: Require opt-in for read-only label configurations | expand |
> From: Dan Williams <dan.j.williams@intel.com> > Sent: Sunday, February 3, 2019 11:29 AM > ... > Recent fixes to command handling enabled Linux to read label > configurations that it could not before. Unfortunately that means that > configurations that were operating in label-less mode will be broken as > the kernel ignores the existing namespace configuration and tries to > honor the new found labels. > > Fortunately this seems limited to a case where Linux can quirk the > behavior and maintain the existing label-less semantics by default. > When the platform does not emit an _LSW method, disable all label access > methods. Provide a 'force_labels' module parameter to allow read-only > label operation. > > Fixes: 11189c1089da ("acpi/nfit: Fix command-supported detection") > Reported-by: Dexuan Cui <decui@microsoft.com> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> Hi Dan, Thanks for the patch and all the detailed explanation! With this patch, the "fsdax" namespace can be properly detected now! Thanks, -- Dexuan
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 811c399a3a76..5b5e802de7b8 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -56,6 +56,10 @@ static bool no_init_ars; module_param(no_init_ars, bool, 0644); MODULE_PARM_DESC(no_init_ars, "Skip ARS run at nfit init time"); +static bool force_labels; +module_param(force_labels, bool, 0444); +MODULE_PARM_DESC(force_labels, "Opt-in to labels despite missing methods"); + LIST_HEAD(acpi_descs); DEFINE_MUTEX(acpi_desc_lock); @@ -1916,6 +1920,19 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc, dev_dbg(dev, "%s: has _LSW\n", dev_name(&adev_dimm->dev)); set_bit(NFIT_MEM_LSW, &nfit_mem->flags); } + + /* + * Quirk read-only label configurations to preserve + * access to label-less namespaces by default. + */ + if (!test_bit(NFIT_MEM_LSW, &nfit_mem->flags) + && !force_labels) { + dev_dbg(dev, "%s: No _LSW, disable labels\n", + dev_name(&adev_dimm->dev)); + clear_bit(NFIT_MEM_LSR, &nfit_mem->flags); + } else + dev_dbg(dev, "%s: Force enable labels\n", + dev_name(&adev_dimm->dev)); } populate_shutdown_status(nfit_mem);
Recent fixes to command handling enabled Linux to read label configurations that it could not before. Unfortunately that means that configurations that were operating in label-less mode will be broken as the kernel ignores the existing namespace configuration and tries to honor the new found labels. Fortunately this seems limited to a case where Linux can quirk the behavior and maintain the existing label-less semantics by default. When the platform does not emit an _LSW method, disable all label access methods. Provide a 'force_labels' module parameter to allow read-only label operation. Fixes: 11189c1089da ("acpi/nfit: Fix command-supported detection") Reported-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/acpi/nfit/core.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)