libnvdimm: write pmem label set
After 'uuid', 'size', and optionally 'alt_name' have been set to valid
values the labels on the dimms can be updated.
Write procedure is:
1/ Allocate and write new labels in the "next" index
2/ Free the old labels in the working copy
3/ Write the bitmap and the label space on the dimm
4/ Write the index to make the update valid
Label ranges directly mirror the dpa resource values for the given
label_id of the namespace.
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index ad0ec09..546e77e 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -149,20 +149,53 @@
return size;
}
+static int nd_namespace_label_update(struct nd_region *nd_region,
+ struct device *dev)
+{
+ dev_WARN_ONCE(dev, dev->driver,
+ "namespace must be idle during label update\n");
+ if (dev->driver)
+ return 0;
+
+ /*
+ * Only allow label writes that will result in a valid namespace
+ * or deletion of an existing namespace.
+ */
+ if (is_namespace_pmem(dev)) {
+ struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
+ struct resource *res = &nspm->nsio.res;
+ resource_size_t size = resource_size(res);
+
+ if (size == 0 && nspm->uuid)
+ /* delete allocation */;
+ else if (!nspm->uuid)
+ return 0;
+
+ return nd_pmem_namespace_label_update(nd_region, nspm, size);
+ } else if (is_namespace_blk(dev)) {
+ /* TODO: implement blk labels */
+ return 0;
+ } else
+ return -ENXIO;
+}
+
static ssize_t alt_name_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
+ struct nd_region *nd_region = to_nd_region(dev->parent);
ssize_t rc;
device_lock(dev);
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
rc = __alt_name_store(dev, buf, len);
+ if (rc >= 0)
+ rc = nd_namespace_label_update(nd_region, dev);
dev_dbg(dev, "%s: %s(%zd)\n", __func__, rc < 0 ? "fail " : "", rc);
nvdimm_bus_unlock(dev);
device_unlock(dev);
- return rc;
+ return rc < 0 ? rc : len;
}
static ssize_t alt_name_show(struct device *dev,
@@ -709,6 +742,7 @@
static ssize_t size_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t len)
{
+ struct nd_region *nd_region = to_nd_region(dev->parent);
unsigned long long val;
u8 **uuid = NULL;
int rc;
@@ -721,6 +755,8 @@
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
rc = __size_store(dev, val);
+ if (rc >= 0)
+ rc = nd_namespace_label_update(nd_region, dev);
if (is_namespace_pmem(dev)) {
struct nd_namespace_pmem *nspm = to_nd_namespace_pmem(dev);
@@ -744,7 +780,7 @@
nvdimm_bus_unlock(dev);
device_unlock(dev);
- return rc ? rc : len;
+ return rc < 0 ? rc : len;
}
static ssize_t size_show(struct device *dev,
@@ -804,17 +840,34 @@
u32 flags = is_namespace_blk(dev) ? NSLABEL_FLAG_LOCAL : 0;
struct nd_label_id old_label_id;
struct nd_label_id new_label_id;
- int i, rc;
+ int i;
- rc = nd_is_uuid_unique(dev, new_uuid) ? 0 : -EINVAL;
- if (rc) {
- kfree(new_uuid);
- return rc;
- }
+ if (!nd_is_uuid_unique(dev, new_uuid))
+ return -EINVAL;
if (*old_uuid == NULL)
goto out;
+ /*
+ * If we've already written a label with this uuid, then it's
+ * too late to rename because we can't reliably update the uuid
+ * without losing the old namespace. Userspace must delete this
+ * namespace to abandon the old uuid.
+ */
+ for (i = 0; i < nd_region->ndr_mappings; i++) {
+ struct nd_mapping *nd_mapping = &nd_region->mapping[i];
+
+ /*
+ * This check by itself is sufficient because old_uuid
+ * would be NULL above if this uuid did not exist in the
+ * currently written set.
+ *
+ * FIXME: can we delete uuid with zero dpa allocated?
+ */
+ if (nd_mapping->labels)
+ return -EBUSY;
+ }
+
nd_label_gen_id(&old_label_id, *old_uuid, flags);
nd_label_gen_id(&new_label_id, new_uuid, flags);
for (i = 0; i < nd_region->ndr_mappings; i++) {
@@ -858,12 +911,16 @@
rc = nd_uuid_store(dev, &uuid, buf, len);
if (rc >= 0)
rc = namespace_update_uuid(nd_region, dev, uuid, ns_uuid);
+ if (rc >= 0)
+ rc = nd_namespace_label_update(nd_region, dev);
+ else
+ kfree(uuid);
dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
rc, buf, buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
device_unlock(dev);
- return rc ? rc : len;
+ return rc < 0 ? rc : len;
}
static DEVICE_ATTR_RW(uuid);
@@ -907,6 +964,7 @@
struct device_attribute *attr, const char *buf, size_t len)
{
struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
+ struct nd_region *nd_region = to_nd_region(dev->parent);
ssize_t rc;
if (!is_namespace_blk(dev))
@@ -916,8 +974,11 @@
nvdimm_bus_lock(dev);
rc = nd_sector_size_store(dev, buf, &nsblk->lbasize,
ns_lbasize_supported);
- dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
- rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+ if (rc >= 0)
+ rc = nd_namespace_label_update(nd_region, dev);
+ dev_dbg(dev, "%s: result: %zd %s: %s%s", __func__,
+ rc, rc < 0 ? "tried" : "wrote", buf,
+ buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
device_unlock(dev);