Re: [PATCH] ndctl: json: Region capabilities are not displayed if any of the BTT, PFN, or DAX are not present

[Donet Tom]

On 2/19/25 22:40, Alison Schofield wrote:

On Wed, Feb 19, 2025 at 03:40:49AM -0600, Donet Tom wrote:


Thanks Tom!

Please v2 with patch prefix and commit msg of:
[ndctl PATCH v2] ndctl/list: display region caps for any of BTT, PFN, DAX

Sure.

If any one of BTT, PFN, or DAX is not present, but the other two
are, then the region capabilities are not displayed in the
ndctl list -R -C command.

This is because util_region_capabilities_to_json() returns NULL
if any one of BTT, PFN, or DAX is not present.

In this patch, we have changed the logic to display all the region
capabilities that are present.

Test Results with CONFIG_BTT disabled
=====================================
Without this patch
------------------
  # ./build/ndctl/ndctl  list -R -C
  [
   {
     "dev":"region1",
     "size":549755813888,
     "align":16777216,
     "available_size":549755813888,
     "max_available_extent":549755813888,
     "type":"pmem",
     "iset_id":11510624209454722969,
     "persistence_domain":"memory_controller"
   },

With this patch
---------------
  # ./build/ndctl/ndctl  list -R -C
  [
   {
     "dev":"region1",
     "size":549755813888,
     "align":16777216,
     "available_size":549755813888,
     "max_available_extent":549755813888,
     "type":"pmem",
     "iset_id":11510624209454722969,
     "capabilities":[
       {
         "mode":"fsdax",
         "alignments":[
           65536,
           16777216
         ]
       },
       {
         "mode":"devdax",
         "alignments":[
           65536,
           16777216
         ]
       }
     ],
     "persistence_domain":"memory_controller"
   },

Please add a formatted fixes tag.
Double check, but I believe this was introduced with commit 965fa02e372f,
util: Distribute 'filter' and 'json' helpers to per-tool objects
It seems we broke it in ndctl release v73.

Sure. I will add.

Signed-off-by: Donet Tom <donet...@linux.ibm.com>
---
  ndctl/json.c | 6 ++----
  1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/ndctl/json.c b/ndctl/json.c
index 23bad7f..3df3bc4 100644
--- a/ndctl/json.c
+++ b/ndctl/json.c
@@ -381,9 +381,6 @@ struct json_object *util_region_capabilities_to_json(struct 
ndctl_region *region
        struct ndctl_pfn *pfn = ndctl_region_get_pfn_seed(region);
        struct ndctl_dax *dax = ndctl_region_get_dax_seed(region);

- if (!btt || !pfn || !dax)

-               return NULL;
-

How about a one line change that avoids getting the jcaps array
needlessly:

        if (!btt && !pfn && !dax)
                return NULL;

Yes . This is the correct fix. I will add it and send V2.

        jcaps = json_object_new_array();
        if (!jcaps)
                return NULL;
@@ -436,7 +433,8 @@ struct json_object *util_region_capabilities_to_json(struct 
ndctl_region *region
                json_object_object_add(jcap, "alignments", jobj);
        }

- return jcaps;

+       if (btt || pfn || dax)
+               return jcaps;
  err:
        json_object_put(jcaps);
        return NULL;
--
2.43.5