libnvdimm fixes 5.2-rc1

* Fix a long standing namespace label corruption scenario when
   re-provisioning capacity for a namespace.
 
 * Restore the ability of the dax_pmem module to be built-in.
 
 * Harden the build for the 'nfit_test' unit test modules so that the
   userspace test harness can ensure all required test modules are
   available.
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Merge tag 'libnvdimm-fixes-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "Just a small collection of fixes this time around.

  The new virtio-pmem driver is nearly ready, but some last minute
  device-mapper acks and virtio questions made it prudent to await v5.3.

  Other major topics that were brewing on the linux-nvdimm mailing list
  like sub-section hotplug, and other devm_memremap_pages() reworks will
  go upstream through Andrew's tree.

  Summary:

   - Fix a long standing namespace label corruption scenario when
     re-provisioning capacity for a namespace.

   - Restore the ability of the dax_pmem module to be built-in.

   - Harden the build for the 'nfit_test' unit test modules so that the
     userspace test harness can ensure all required test modules are
     available"

* tag 'libnvdimm-fixes-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  drivers/dax: Allow to include DEV_DAX_PMEM as builtin
  libnvdimm/namespace: Fix label tracking error
  tools/testing/nvdimm: add watermarks for dax_pmem* modules
  dax/pmem: Fix whitespace in dax_pmem

drivers/dax/Kconfig

@@ -23,7 +23,6 @@ config DEV_DAX
 config DEV_DAX_PMEM
 	tristate "PMEM DAX: direct access to persistent memory"
 	depends on LIBNVDIMM && NVDIMM_DAX && DEV_DAX
-	depends on m # until we can kill DEV_DAX_PMEM_COMPAT
 	default DEV_DAX
 	help
 	  Support raw access to persistent memory.  Note that this
@@ -50,7 +49,7 @@ config DEV_DAX_KMEM
 
 config DEV_DAX_PMEM_COMPAT
 	tristate "PMEM DAX: support the deprecated /sys/class/dax interface"
-	depends on DEV_DAX_PMEM
+	depends on m && DEV_DAX_PMEM=m
 	default DEV_DAX_PMEM
 	help
 	  Older versions of the libdaxctl library expect to find all

drivers/nvdimm/label.c

@@ -756,6 +756,17 @@ static const guid_t *to_abstraction_guid(enum nvdimm_claim_class claim_class,
 		return &guid_null;
 }
 
+static void reap_victim(struct nd_mapping *nd_mapping,
+		struct nd_label_ent *victim)
+{
+	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
+	u32 slot = to_slot(ndd, victim->label);
+
+	dev_dbg(ndd->dev, "free: %d\n", slot);
+	nd_label_free_slot(ndd, slot);
+	victim->label = NULL;
+}
+
 static int __pmem_label_update(struct nd_region *nd_region,
 		struct nd_mapping *nd_mapping, struct nd_namespace_pmem *nspm,
 		int pos, unsigned long flags)
@@ -763,9 +774,9 @@ static int __pmem_label_update(struct nd_region *nd_region,
 	struct nd_namespace_common *ndns = &nspm->nsio.common;
 	struct nd_interleave_set *nd_set = nd_region->nd_set;
 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
-	struct nd_label_ent *label_ent, *victim = NULL;
 	struct nd_namespace_label *nd_label;
 	struct nd_namespace_index *nsindex;
+	struct nd_label_ent *label_ent;
 	struct nd_label_id label_id;
 	struct resource *res;
 	unsigned long *free;
@@ -834,18 +845,10 @@ static int __pmem_label_update(struct nd_region *nd_region,
 	list_for_each_entry(label_ent, &nd_mapping->labels, list) {
 		if (!label_ent->label)
 			continue;
-		if (memcmp(nspm->uuid, label_ent->label->uuid,
-					NSLABEL_UUID_LEN) != 0)
-			continue;
-		victim = label_ent;
-		list_move_tail(&victim->list, &nd_mapping->labels);
-		break;
-	}
-	if (victim) {
-		dev_dbg(ndd->dev, "free: %d\n", slot);
-		slot = to_slot(ndd, victim->label);
-		nd_label_free_slot(ndd, slot);
-		victim->label = NULL;
+		if (test_and_clear_bit(ND_LABEL_REAP, &label_ent->flags)
+				|| memcmp(nspm->uuid, label_ent->label->uuid,
+					NSLABEL_UUID_LEN) == 0)
+			reap_victim(nd_mapping, label_ent);
 	}
 
 	/* update index */

drivers/nvdimm/namespace_devs.c

@@ -1247,12 +1247,27 @@ static int namespace_update_uuid(struct nd_region *nd_region,
 	for (i = 0; i < nd_region->ndr_mappings; i++) {
 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
+		struct nd_label_ent *label_ent;
 		struct resource *res;
 
 		for_each_dpa_resource(ndd, res)
 			if (strcmp(res->name, old_label_id.id) == 0)
 				sprintf((void *) res->name, "%s",
 						new_label_id.id);
+
+		mutex_lock(&nd_mapping->lock);
+		list_for_each_entry(label_ent, &nd_mapping->labels, list) {
+			struct nd_namespace_label *nd_label = label_ent->label;
+			struct nd_label_id label_id;
+
+			if (!nd_label)
+				continue;
+			nd_label_gen_id(&label_id, nd_label->uuid,
+					__le32_to_cpu(nd_label->flags));
+			if (strcmp(old_label_id.id, label_id.id) == 0)
+				set_bit(ND_LABEL_REAP, &label_ent->flags);
+		}
+		mutex_unlock(&nd_mapping->lock);
 	}
 	kfree(*old_uuid);
  out:

drivers/nvdimm/nd.h

@@ -113,8 +113,12 @@ struct nd_percpu_lane {
 	spinlock_t lock;
 };
 
+enum nd_label_flags {
+	ND_LABEL_REAP,
+};
 struct nd_label_ent {
 	struct list_head list;
+	unsigned long flags;
 	struct nd_namespace_label *label;
 };
 

tools/testing/nvdimm/Kbuild

@@ -68,8 +68,11 @@ device_dax-y += device_dax_test.o
 device_dax-y += config_check.o
 
 dax_pmem-y := $(DAX_SRC)/pmem/pmem.o
+dax_pmem-y += dax_pmem_test.o
 dax_pmem_core-y := $(DAX_SRC)/pmem/core.o
+dax_pmem_core-y += dax_pmem_core_test.o
 dax_pmem_compat-y := $(DAX_SRC)/pmem/compat.o
+dax_pmem_compat-y += dax_pmem_compat_test.o
 dax_pmem-y += config_check.o
 
 libnvdimm-y := $(NVDIMM_SRC)/core.o

tools/testing/nvdimm/dax_pmem_compat_test.c

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright(c) 2019 Intel Corporation. All rights reserved.
+
+#include <linux/module.h>
+#include <linux/printk.h>
+#include "watermark.h"
+
+nfit_test_watermark(dax_pmem_compat);

tools/testing/nvdimm/dax_pmem_core_test.c

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright(c) 2019 Intel Corporation. All rights reserved.
+
+#include <linux/module.h>
+#include <linux/printk.h>
+#include "watermark.h"
+
+nfit_test_watermark(dax_pmem_core);

tools/testing/nvdimm/dax_pmem_test.c

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright(c) 2019 Intel Corporation. All rights reserved.
+
+#include <linux/module.h>
+#include <linux/printk.h>
+#include "watermark.h"
+
+nfit_test_watermark(dax_pmem);

tools/testing/nvdimm/test/nfit.c

@@ -3171,6 +3171,9 @@ static __init int nfit_test_init(void)
 	acpi_nfit_test();
 	device_dax_test();
 	mcsafe_test();
+	dax_pmem_test();
+	dax_pmem_core_test();
+	dax_pmem_compat_test();
 
 	nfit_test_setup(nfit_test_lookup, nfit_test_evaluate_dsm);
 

tools/testing/nvdimm/watermark.h

@@ -6,6 +6,9 @@ int pmem_test(void);
 int libnvdimm_test(void);
 int acpi_nfit_test(void);
 int device_dax_test(void);
+int dax_pmem_test(void);
+int dax_pmem_core_test(void);
+int dax_pmem_compat_test(void);
 
 /*
  * dummy routine for nfit_test to validate it is linking to the properly