On Tue, 17 Jun 2025 18:09:29 +0530
Neeraj Kumar <s.nee...@samsung.com> wrote:
Add region label update routine
> Added __pmem_region_label_update region label update routine to update
> region label
>
> Signed-off-by: Neeraj Kumar <s.nee...@samsung.com>
A few trivial comments inline.
Jonathan
> ---
> drivers/nvdimm/label.c | 142 ++++++++++++++++++++++++++++++++
> drivers/nvdimm/label.h | 2 +
> drivers/nvdimm/namespace_devs.c | 12 +++
> drivers/nvdimm/nd.h | 20 +++++
> include/linux/libnvdimm.h | 8 ++
> 5 files changed, 184 insertions(+)
>
> diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
> index d5cfaa99f976..7f33d14ce0ef 100644
> --- a/drivers/nvdimm/label.c
> +++ b/drivers/nvdimm/label.c
> @@ -381,6 +381,16 @@ static void nsl_calculate_checksum(struct nvdimm_drvdata
> *ndd,
> nsl_set_checksum(ndd, nd_label, sum);
> }
>
> +static void rgl_calculate_checksum(struct nvdimm_drvdata *ndd,
> + struct cxl_region_label *rg_label)
> +{
> + u64 sum;
> +
> + rgl_set_checksum(rg_label, 0);
> + sum = nd_fletcher64(rg_label, sizeof_namespace_label(ndd), 1);
> + rgl_set_checksum(rg_label, sum);
> +}
> +
> static bool slot_valid(struct nvdimm_drvdata *ndd,
> struct nd_lsa_label *nd_label, u32 slot)
> {
> @@ -1117,6 +1127,138 @@ int nd_pmem_namespace_label_update(struct nd_region
> *nd_region,
> return 0;
> }
>
> +static int __pmem_region_label_update(struct nd_region *nd_region,
> + struct nd_mapping *nd_mapping, int pos, unsigned long flags)
> +{
> + struct nd_interleave_set *nd_set = nd_region->nd_set;
> + struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
> + struct nd_lsa_label *nd_label;
> + struct cxl_region_label *rg_label;
> + struct nd_namespace_index *nsindex;
> + struct nd_label_ent *label_ent;
> + unsigned long *free;
> + u32 nslot, slot;
> + size_t offset;
> + int rc;
> + uuid_t tmp;
> +
> + if (!preamble_next(ndd, &nsindex, &free, &nslot))
> + return -ENXIO;
> +
> + /* allocate and write the label to the staging (next) index */
> + slot = nd_label_alloc_slot(ndd);
> + if (slot == UINT_MAX)
> + return -ENXIO;
> + dev_dbg(ndd->dev, "allocated: %d\n", slot);
> +
> + nd_label = to_label(ndd, slot);
> +
> + memset(nd_label, 0, sizeof_namespace_label(ndd));
> + rg_label = &nd_label->rg_label;
> +
> + /* Set Region Label Format identification UUID */
> + uuid_parse(CXL_REGION_UUID, &tmp);
> + export_uuid(nd_label->rg_label.type, &tmp);
> +
> + /* Set Current Region Label UUID */
> + export_uuid(nd_label->rg_label.uuid, &nd_set->uuid);
> +
> + rg_label->flags = __cpu_to_le32(flags);
> + rg_label->nlabel = __cpu_to_le16(nd_region->ndr_mappings);
> + rg_label->position = __cpu_to_le16(pos);
> + rg_label->dpa = __cpu_to_le64(nd_mapping->start);
> + rg_label->rawsize = __cpu_to_le64(nd_mapping->size);
> + rg_label->hpa = __cpu_to_le64(nd_set->res->start);
> + rg_label->slot = __cpu_to_le32(slot);
> + rg_label->ig = __cpu_to_le32(nd_set->interleave_granularity);
> + rg_label->align = __cpu_to_le16(0);
> +
> + /* Update fletcher64 Checksum */
> + rgl_calculate_checksum(ndd, rg_label);
> +
> + /* update label */
> + offset = nd_label_offset(ndd, nd_label);
> + rc = nvdimm_set_config_data(ndd, offset, nd_label,
> + sizeof_namespace_label(ndd));
> + if (rc < 0) {
> + nd_label_free_slot(ndd, slot);
> + return rc;
> + }
> +
> + /* Garbage collect the previous label */
> + mutex_lock(&nd_mapping->lock);
Perhaps use
guard(mutex)(&nd_mapping->lock);
so you can directly return in the error path below and simplify the flow
a tiny bit.
> + list_for_each_entry(label_ent, &nd_mapping->labels, list) {
> + if (!label_ent->label)
> + continue;
> + if (rgl_uuid_equal(&label_ent->label->rg_label, &nd_set->uuid))
> + reap_victim(nd_mapping, label_ent);
> + }
> +
> + /* update index */
> + rc = nd_label_write_index(ndd, ndd->ns_next,
> + nd_inc_seq(__le32_to_cpu(nsindex->seq)), 0);
> +
With guard this can be
if (rc)
return rec;
list_for_each...
> + if (rc == 0) {
> + list_for_each_entry(label_ent, &nd_mapping->labels, list)
> + if (!label_ent->label) {
> + label_ent->label = nd_label;
> + nd_label = NULL;
> + break;
> + }
> + dev_WARN_ONCE(&nd_region->dev, nd_label,
> + "failed to track label: %d\n",
> + to_slot(ndd, nd_label));
> + if (nd_label)
> + rc = -ENXIO;
> + }
> + mutex_unlock(&nd_mapping->lock);
> +
> + return rc;
> +}
