* [ndctl PATCH v4 2/2] ndctl/namespace: introduce ndctl_namespace_is_configuration_idle()
2019-11-04 22:26 [ndctl PATCH v4 1/2] ndctl/namespace: remove open coded is_namespace_active() Vishal Verma
@ 2019-11-04 22:26 ` Vishal Verma
0 siblings, 0 replies; 2+ messages in thread
From: Vishal Verma @ 2019-11-04 22:26 UTC (permalink / raw)
To: linux-nvdimm; +Cc: Aneesh Kumar K.V
The motivation for this change is that we want to refrain from
(re)configuring what appear to be partially configured namespaces.
Namespaces may end up in a state that looks partially configured when
the kernel isn't able to enable a namespace due to mismatched
PAGE_SIZE expectations. In such cases, ndctl should not treat those
as unconfigured 'seed' namespaces, and reuse them.
Add a new ndctl_namespace_is_configuration_idle API, whish tests whether a
namespace is active, and whether it is partially configured. If neither
are true, then it can be used for (re)configuration. Additionally, deal
with the corner case of ND_DEVICE_NAMESPACE_IO (legacy PMEM) namespaces
which always appear as configured, since their size cannot be changed,
but they are also always re-configurable.
Use this API in namespace_reconfig() and namespace_create() to enable
this partial configuration detection.
Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
Changes in v4:
- Patch 1 was broken - one of the instances of the _is_active conversion
flipped the polarity. Patch 2 fixed it, so the breakage would've been
limited to a future bisect. This revision fixes it up so it is always
correct.
Changes in v3:
- Remove stray leftovers in sysfs.{c,h} and namespace_is_writable() from
libndctl.c
Changes in v2:
- Remove sysfs_attr_writable, and just check for the nstype of
ND_DEVICE_NAMESPACE_IO (Dan)
- Rename ndctl_namespace_is_configurable to
ndctl_namespace_is_configuration_idle (Dan)
ndctl/lib/libndctl.c | 21 +++++++++++++++++++++
ndctl/lib/libndctl.sym | 4 ++++
ndctl/libndctl.h | 1 +
ndctl/namespace.c | 6 +++---
4 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/ndctl/lib/libndctl.c b/ndctl/lib/libndctl.c
index 6596f94..d6a2800 100644
--- a/ndctl/lib/libndctl.c
+++ b/ndctl/lib/libndctl.c
@@ -4182,6 +4182,27 @@ NDCTL_EXPORT int ndctl_namespace_is_configured(struct ndctl_namespace *ndns)
}
}
+/*
+ * Check if a given 'seed' namespace is ok to configure.
+ * If a size or uuid is present, it is considered not configuration-idle,
+ * except in the case of legacy (ND_DEVICE_NAMESPACE_IO) namespaces. In
+ * that case, the size is never zero, but the namespace can still be
+ * reconfigured.
+ */
+NDCTL_EXPORT int ndctl_namespace_is_configuration_idle(
+ struct ndctl_namespace *ndns)
+{
+ if (ndctl_namespace_is_active(ndns))
+ return 0;
+ if (ndctl_namespace_is_configured(ndns)) {
+ if (ndctl_namespace_get_type(ndns) == ND_DEVICE_NAMESPACE_IO)
+ return 1;
+ return 0;
+ }
+ /* !active and !configured is configuration-idle */
+ return 1;
+}
+
NDCTL_EXPORT void ndctl_namespace_get_uuid(struct ndctl_namespace *ndns, uuid_t uu)
{
memcpy(uu, ndns->uuid, sizeof(uuid_t));
diff --git a/ndctl/lib/libndctl.sym b/ndctl/lib/libndctl.sym
index c93c1ee..4e76778 100644
--- a/ndctl/lib/libndctl.sym
+++ b/ndctl/lib/libndctl.sym
@@ -423,3 +423,7 @@ LIBNDCTL_21 {
LIBNDCTL_22 {
ndctl_dimm_security_is_frozen;
} LIBNDCTL_21;
+
+LIBNDCTL_23 {
+ ndctl_namespace_is_configuration_idle;
+} LIBNDCTL_22;
diff --git a/ndctl/libndctl.h b/ndctl/libndctl.h
index db398b3..9a53049 100644
--- a/ndctl/libndctl.h
+++ b/ndctl/libndctl.h
@@ -491,6 +491,7 @@ int ndctl_namespace_disable_safe(struct ndctl_namespace *ndns);
bool ndctl_namespace_is_active(struct ndctl_namespace *ndns);
int ndctl_namespace_is_valid(struct ndctl_namespace *ndns);
int ndctl_namespace_is_configured(struct ndctl_namespace *ndns);
+int ndctl_namespace_is_configuration_idle(struct ndctl_namespace *ndns);
int ndctl_namespace_delete(struct ndctl_namespace *ndns);
int ndctl_namespace_set_uuid(struct ndctl_namespace *ndns, uuid_t uu);
void ndctl_namespace_get_uuid(struct ndctl_namespace *ndns, uuid_t uu);
diff --git a/ndctl/namespace.c b/ndctl/namespace.c
index 8d1044a..a07d7e2 100644
--- a/ndctl/namespace.c
+++ b/ndctl/namespace.c
@@ -779,7 +779,7 @@ static struct ndctl_namespace *region_get_namespace(struct ndctl_region *region)
/* prefer the 0th namespace if it is idle */
ndctl_namespace_foreach(region, ndns)
if (ndctl_namespace_get_id(ndns) == 0
- && !ndctl_namespace_is_active(ndns))
+ && ndctl_namespace_is_configuration_idle(ndns))
return ndns;
return ndctl_region_get_namespace_seed(region);
}
@@ -819,7 +819,7 @@ static int namespace_create(struct ndctl_region *region)
p.size = available;
ndns = region_get_namespace(region);
- if (!ndns || ndctl_namespace_is_active(ndns)) {
+ if (!ndns || !ndctl_namespace_is_configuration_idle(ndns)) {
debug("%s: no %s namespace seed\n", devname,
ndns ? "idle" : "available");
return -EAGAIN;
@@ -1066,7 +1066,7 @@ static int namespace_reconfig(struct ndctl_region *region,
}
ndns = region_get_namespace(region);
- if (!ndns || ndctl_namespace_is_active(ndns)) {
+ if (!ndns || !ndctl_namespace_is_configuration_idle(ndns)) {
debug("%s: no %s namespace seed\n",
ndctl_region_get_devname(region),
ndns ? "idle" : "available");
--
2.20.1
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