From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
linux-nvdimm <linux-nvdimm@lists.01.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [RFC PATCH 1/4] libnvdimm/namespace: Make namespace size validation arch dependent
Date: Mon, 18 Nov 2019 15:21:57 +0530 [thread overview]
Message-ID: <87o8x9h5qa.fsf@linux.ibm.com> (raw)
In-Reply-To: <CAPcyv4hroohsrXT1YHQB-L8ZFa2kUW+bKy03We4Mt7afeJgu3Q@mail.gmail.com>
Dan Williams <dan.j.williams@intel.com> writes:
> On Sat, Nov 16, 2019 at 4:15 AM Aneesh Kumar K.V
> <aneesh.kumar@linux.ibm.com> wrote:
>>
....
>>
>> Considering the direct-map map size is not going to be user selectable,
>> do you agree that we can skip the above step 0 configuration you
>> suggested.
>>
>> The changes proposed in the patch series essentially does the rest.
>>
>> 1) It validate the size against the arch specific limit during
>> namespace creation. (part of step 1)
>
> This validation is a surprise failure to ndctl.
>
>> 2) It also disable initializing a region if it find the size not
>> correctly aligned as per the platform requirement.
>
> There needs to be a way for the user to discover the correct alignment
> that the kernel will accept.
>
>> 3) Direct map mapping size is different from supported_alignment for a
>> namespace. The supported alignment controls what possible PAGE SIZE user want the
>> namespace to be mapped to user space.
>
> No, the namespace alignment is different than the page mapping size.
> The alignment is only interpreted as a mapping size at the device-dax
> level, otherwise at the raw namespace level it's just an arbitrary
> alignment.
>
>> With the above do you think the current patch series is good?
>
> I don't think we've quite converged on a solution.
How about we make it a property of seed device. ie,
we add `supported_size_align` RO attribute to the seed device. ndctl can
use this to validate the size value. So this now becomes step0
sys/bus/nd/devices/region0> cat btt0.0/supported_size_align
16777216
/sys/bus/nd/devices/region0> cat pfn0.0/supported_size_align
16777216
/sys/bus/nd/devices/region0> cat dax0.0/supported_size_align
16777216
/sys/bus/nd/devices/region0>
We follow that up with validating the size value written to size
attribute(step 1).
While initializing the namespaces already present in a region we again
validate the size and if not properly aligned we mark the region
disabled.
-aneesh
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
WARNING: multiple messages have this Message-ID (diff)
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
linux-nvdimm <linux-nvdimm@lists.01.org>
Subject: Re: [RFC PATCH 1/4] libnvdimm/namespace: Make namespace size validation arch dependent
Date: Mon, 18 Nov 2019 15:21:57 +0530 [thread overview]
Message-ID: <87o8x9h5qa.fsf@linux.ibm.com> (raw)
In-Reply-To: <CAPcyv4hroohsrXT1YHQB-L8ZFa2kUW+bKy03We4Mt7afeJgu3Q@mail.gmail.com>
Dan Williams <dan.j.williams@intel.com> writes:
> On Sat, Nov 16, 2019 at 4:15 AM Aneesh Kumar K.V
> <aneesh.kumar@linux.ibm.com> wrote:
>>
....
>>
>> Considering the direct-map map size is not going to be user selectable,
>> do you agree that we can skip the above step 0 configuration you
>> suggested.
>>
>> The changes proposed in the patch series essentially does the rest.
>>
>> 1) It validate the size against the arch specific limit during
>> namespace creation. (part of step 1)
>
> This validation is a surprise failure to ndctl.
>
>> 2) It also disable initializing a region if it find the size not
>> correctly aligned as per the platform requirement.
>
> There needs to be a way for the user to discover the correct alignment
> that the kernel will accept.
>
>> 3) Direct map mapping size is different from supported_alignment for a
>> namespace. The supported alignment controls what possible PAGE SIZE user want the
>> namespace to be mapped to user space.
>
> No, the namespace alignment is different than the page mapping size.
> The alignment is only interpreted as a mapping size at the device-dax
> level, otherwise at the raw namespace level it's just an arbitrary
> alignment.
>
>> With the above do you think the current patch series is good?
>
> I don't think we've quite converged on a solution.
How about we make it a property of seed device. ie,
we add `supported_size_align` RO attribute to the seed device. ndctl can
use this to validate the size value. So this now becomes step0
sys/bus/nd/devices/region0> cat btt0.0/supported_size_align
16777216
/sys/bus/nd/devices/region0> cat pfn0.0/supported_size_align
16777216
/sys/bus/nd/devices/region0> cat dax0.0/supported_size_align
16777216
/sys/bus/nd/devices/region0>
We follow that up with validating the size value written to size
attribute(step 1).
While initializing the namespaces already present in a region we again
validate the size and if not properly aligned we mark the region
disabled.
-aneesh
next prev parent reply other threads:[~2019-11-18 9:52 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-28 9:48 [RFC PATCH 1/4] libnvdimm/namespace: Make namespace size validation arch dependent Aneesh Kumar K.V
2019-10-28 9:48 ` Aneesh Kumar K.V
2019-10-28 9:48 ` [RFC PATCH 2/4] libnvdimm/namespace: Disable the region if the namespace size is not aligned correctly Aneesh Kumar K.V
2019-10-28 9:48 ` Aneesh Kumar K.V
2019-10-30 9:12 ` kbuild test robot
2019-10-28 9:48 ` [RFC PATCH 3/4] libnvdimm/namespace: Use direct-mapping page size to validate namespace size Aneesh Kumar K.V
2019-10-28 9:48 ` Aneesh Kumar K.V
2019-10-28 9:48 ` [RFC PATCH 4/4] libnvdimm/namespace: Add debug check while initializing namespace resource size Aneesh Kumar K.V
2019-10-28 9:48 ` Aneesh Kumar K.V
2019-10-28 21:21 ` [RFC PATCH 1/4] libnvdimm/namespace: Make namespace size validation arch dependent Ira Weiny
2019-10-28 21:21 ` Ira Weiny
2019-10-29 4:34 ` Aneesh Kumar K.V
2019-10-29 4:34 ` Aneesh Kumar K.V
2019-10-28 23:08 ` Dan Williams
2019-10-28 23:08 ` Dan Williams
2019-10-29 4:34 ` Aneesh Kumar K.V
2019-10-29 4:34 ` Aneesh Kumar K.V
2019-10-29 5:30 ` Dan Williams
2019-10-29 5:30 ` Dan Williams
2019-10-31 5:35 ` Aneesh Kumar K.V
2019-10-31 5:35 ` Aneesh Kumar K.V
2019-10-31 6:30 ` Dan Williams
2019-10-31 6:30 ` Dan Williams
2019-10-31 8:37 ` Aneesh Kumar K.V
2019-10-31 8:37 ` Aneesh Kumar K.V
2019-10-31 15:53 ` Dan Williams
2019-10-31 15:53 ` Dan Williams
2019-11-06 10:44 ` Aneesh Kumar K.V
2019-11-06 10:44 ` Aneesh Kumar K.V
2019-11-16 12:15 ` Aneesh Kumar K.V
2019-11-16 12:15 ` Aneesh Kumar K.V
2019-11-16 18:50 ` Dan Williams
2019-11-16 18:50 ` Dan Williams
2019-11-18 9:51 ` Aneesh Kumar K.V [this message]
2019-11-18 9:51 ` Aneesh Kumar K.V
2019-11-19 17:58 ` Dan Williams
2019-11-19 17:58 ` Dan Williams
2019-11-20 3:19 ` Aneesh Kumar K.V
2019-11-20 3:19 ` Aneesh Kumar K.V
2019-11-20 3:46 ` Dan Williams
2019-11-20 3:46 ` Dan Williams
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87o8x9h5qa.fsf@linux.ibm.com \
--to=aneesh.kumar@linux.ibm.com \
--cc=dan.j.williams@intel.com \
--cc=linux-nvdimm@lists.01.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.