libnvdimm, namespace: enable allocation of multiple pmem namespaces
Now that we have nd_region_available_dpa() able to handle the presence
of multiple PMEM allocations in aliased PMEM regions, reuse that same
infrastructure to track allocations from free space. In particular
handle allocating from an aliased PMEM region in the case where there
are dis-contiguous holes. The allocation for BLK and PMEM are
documented in the space_valid() helper:
BLK-space is valid as long as it does not precede a PMEM
allocation in a given region. PMEM-space must be contiguous
and adjacent to an existing existing allocation (if one
exists).
Signed-off-by: Dan Williams <dan.j.williams@intel.com>diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 4b0296c..d614493 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -386,13 +386,7 @@
}
EXPORT_SYMBOL_GPL(nvdimm_create);
-struct blk_alloc_info {
- struct nd_mapping *nd_mapping;
- resource_size_t available, busy;
- struct resource *res;
-};
-
-static int alias_dpa_busy(struct device *dev, void *data)
+int alias_dpa_busy(struct device *dev, void *data)
{
resource_size_t map_end, blk_start, new, busy;
struct blk_alloc_info *info = data;
@@ -418,6 +412,20 @@
ndd = to_ndd(nd_mapping);
map_end = nd_mapping->start + nd_mapping->size - 1;
blk_start = nd_mapping->start;
+
+ /*
+ * In the allocation case ->res is set to free space that we are
+ * looking to validate against PMEM aliasing collision rules
+ * (i.e. BLK is allocated after all aliased PMEM).
+ */
+ if (info->res) {
+ if (info->res->start >= nd_mapping->start
+ && info->res->start < map_end)
+ /* pass */;
+ else
+ return 0;
+ }
+
retry:
/*
* Find the free dpa from the end of the last pmem allocation to
@@ -447,7 +455,16 @@
}
}
+ /* update the free space range with the probed blk_start */
+ if (info->res && blk_start > info->res->start) {
+ info->res->start = max(info->res->start, blk_start);
+ if (info->res->start > info->res->end)
+ info->res->end = info->res->start - 1;
+ return 1;
+ }
+
info->available -= blk_start - nd_mapping->start + busy;
+
return 0;
}
@@ -508,6 +525,7 @@
struct blk_alloc_info info = {
.nd_mapping = nd_mapping,
.available = nd_mapping->size,
+ .res = NULL,
};
struct resource *res;