From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Dan Williams <dan.j.williams@intel.com>, vishal.l.verma@intel.com
Cc: linux-nvdimm@lists.01.org
Subject: Re: Picking 0th namespace if it is idle
Date: Tue, 23 Jul 2019 20:30:09 +0530 [thread overview]
Message-ID: <8736iwkd8m.fsf@linux.ibm.com> (raw)
In-Reply-To: <877ea85p64.fsf@linux.ibm.com>
Hi Dan,
Can you help with this question?
-aneesh
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> writes:
> aneesh.kumar@linux.ibm.com (Aneesh Kumar K.V) writes:
>
>> Hi Dan,
>>
>> With the patch series to mark the namespace disabled if we have mismatch
>> in pfn superblock, we can endup with namespace0 marked idle/disabled.
>>
>> I am wondering why do do the below in ndctl.
>>
>>
>> static struct ndctl_namespace *region_get_namespace(struct ndctl_region *region)
>> {
>> struct ndctl_namespace *ndns;
>>
>> /* prefer the 0th namespace if it is idle */
>> ndctl_namespace_foreach(region, ndns)
>> if (ndctl_namespace_get_id(ndns) == 0
>> && !is_namespace_active(ndns))
>> return ndns;
>> return ndctl_region_get_namespace_seed(region);
>> }
>>
>> I have a kernel patch that will create a namespace_seed even if we fail
>> to ename a pfn backing device. Something like below
>>
>> @@ -747,12 +752,23 @@ static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
>> }
>> }
>> if (dev->parent && is_nd_region(dev->parent) && probe) {
>> nd_region = to_nd_region(dev->parent);
>> nvdimm_bus_lock(dev);
>> if (nd_region->ns_seed == dev)
>> nd_region_create_ns_seed(nd_region);
>> nvdimm_bus_unlock(dev);
>> }
>> +
>> + if (dev->parent && is_nd_region(dev->parent) && !probe && (ret == -EOPNOTSUPP)) {
>> + nd_region = to_nd_region(dev->parent);
>> + nvdimm_bus_lock(dev);
>> + if (nd_region->ns_seed == dev)
>> + nd_region_create_ns_seed(nd_region);
>> + nvdimm_bus_unlock(dev);
>> + }
>> +
>>
>> With that we can end up with something like the below after boot.
>> :/sys/bus/nd/devices/region0$ sudo ndctl list -Ni
>> [
>> {
>> "dev":"namespace0.1",
>> "mode":"fsdax",
>> "map":"mem",
>> "size":0,
>> "uuid":"00000000-0000-0000-0000-000000000000",
>> "state":"disabled"
>> },
>> {
>> "dev":"namespace0.0",
>> "mode":"fsdax",
>> "map":"mem",
>> "size":2147483648,
>> "uuid":"094e703b-4bf8-4078-ad42-50bebc03e538",
>> "state":"disabled"
>> }
>> ]
>>
>> namespace0.0 is the one we failed to initialize due to PAGE_SIZE
>> mismatch.
>>
>> We do have namespace_seed pointing to namespacece0.1 correct. But a ndtl
>> create-namespace will pick namespace0.0 even if we have seed file
>> pointing to namespacec0.1.
>>
>>
>> I am trying to resolve the issues related to creation of new namespaces
>> when we have some namespace marked disabled due to pfn_sb setting
>> mismatch.
>>
>> -aneesh
>
> With that ndctl namespace0.0 selection commented out, we do get pick the
> right idle namespace.
>
> #ndctl list -Ni
> [
> {
> "dev":"namespace0.1",
> "mode":"fsdax",
> "map":"mem",
> "size":0,
> "uuid":"00000000-0000-0000-0000-000000000000",
> "state":"disabled"
> },
> {
> "dev":"namespace0.0",
> "mode":"fsdax",
> "map":"mem",
> "size":2147483648,
> "uuid":"0c31ae4b-b053-43c7-82ff-88574e2585b0",
> "state":"disabled"
> }
> ]
>
> after ndctl create-namespace -s 2G -r region0
>
>
> # ndctl list -Ni
> [
> {
> "dev":"namespace0.2",
> "mode":"fsdax",
> "map":"mem",
> "size":0,
> "uuid":"00000000-0000-0000-0000-000000000000",
> "state":"disabled"
> },
> {
> "dev":"namespace0.1",
> "mode":"fsdax",
> "map":"dev",
> "size":2130706432,
> "uuid":"60970059-9412-4eeb-9e7a-b314585a4da3",
> "align":65536,
> "blockdev":"pmem0.1",
> "supported_alignments":[
> 65536
> ]
> },
> {
> "dev":"namespace0.0",
> "mode":"fsdax",
> "map":"mem",
> "size":2147483648,
> "uuid":"0c31ae4b-b053-43c7-82ff-88574e2585b0",
> "state":"disabled"
> }
> ]
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next prev parent reply other threads:[~2019-07-23 15:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87a7f45qik.fsf@linux.ibm.com>
2019-05-30 8:20 ` Picking 0th namespace if it is idle Aneesh Kumar K.V
2019-07-23 15:00 ` Aneesh Kumar K.V [this message]
2019-07-23 18:59 ` Dan Williams
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