nvme: per-namespace virtual subsystems
Implement a module option 'ns_subsys' to create a virtual subsystem
per namespace to support dispersed namespaces.
Signed-off-by: Hannes Reinecke <hare@suse.de>
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 137354a..8e74d2b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -20,6 +20,7 @@
#include <linux/ptrace.h>
#include <linux/nvme_ioctl.h>
#include <linux/pm_qos.h>
+#include <generated/utsrelease.h>
#include <asm/unaligned.h>
#include "nvme.h"
@@ -88,6 +89,10 @@ module_param(apst_secondary_latency_tol_us, ulong, 0644);
MODULE_PARM_DESC(apst_secondary_latency_tol_us,
"secondary APST latency tolerance in us");
+static bool ns_subsys;
+module_param(ns_subsys, bool, 0644);
+MODULE_PARM_DESC(ns_subsys, "Per-namespace virtual subsystems");
+
/*
* nvme_wq - hosts nvme related works that are not reset or delete
* nvme_reset_wq - hosts nvme reset works
@@ -3903,6 +3908,7 @@ static struct nvme_ns_head *nvme_find_ns_head(struct nvme_subsystem *subsys,
struct nvme_ns_info *info)
{
struct nvme_ns_head *h;
+ unsigned int nsid = ns_subsys ? 1 : info->nsid;
lockdep_assert_held(&subsys->lock);
@@ -3912,7 +3918,7 @@ static struct nvme_ns_head *nvme_find_ns_head(struct nvme_subsystem *subsys,
* In that case we can't use the same ns_head for namespaces
* with the same NSID.
*/
- if (h->ns_id != info->nsid || !(h->shared || info->is_unique))
+ if (h->ns_id != nsid || !(h->shared || info->is_unique))
continue;
if (!list_empty(&h->list) && nvme_tryget_ns_head(h))
return h;
@@ -4034,7 +4040,10 @@ static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_subsystem *subsys,
if (ret)
goto out_ida_remove;
head->subsys = subsys;
- head->ns_id = info->nsid;
+ if (ns_subsys)
+ head->ns_id = 1;
+ else
+ head->ns_id = info->nsid;
head->ids = info->ids;
head->shared = info->is_shared;
kref_init(&head->ref);
@@ -4093,6 +4102,49 @@ static int nvme_global_check_duplicate_ids(struct nvme_subsystem *this,
return ret;
}
+static struct nvme_subsystem *nvme_generate_ns_subsys(struct nvme_ns_info *info)
+{
+ struct nvme_id_ctrl *ns_subsys_id;
+ struct nvme_ns_ids *ids = &info->ids;
+ struct nvme_subsystem *subsys, *found;
+ char serial[10];
+ int ret;
+
+ ns_subsys_id = kzalloc(sizeof(*ns_subsys_id), GFP_KERNEL);
+ if (!ns_subsys_id)
+ return ERR_PTR(-ENOMEM);
+ snprintf(ns_subsys_id->subnqn, NVMF_NQN_SIZE,
+ "nvme.2014.08.org.nvmexpress:uuid.%pU", &ids->uuid);
+ memcpy(ns_subsys_id->mn, "Linux", 6);
+ get_random_bytes(&serial, sizeof(serial));
+ bin2hex(ns_subsys_id->sn, &serial, sizeof(serial));
+ memcpy_and_pad(ns_subsys_id->fr, sizeof(ns_subsys_id->fr),
+ UTS_RELEASE, strlen(UTS_RELEASE), ' ');
+ ns_subsys_id->cmic = NVME_CTRL_CMIC_MULTI_PORT |
+ NVME_CTRL_CMIC_MULTI_CTRL | NVME_CTRL_CMIC_ANA;
+
+ subsys = __nvme_init_subsystem(ns_subsys_id);
+ mutex_lock(&nvme_subsystems_lock);
+ found = __nvme_find_get_subsystem(subsys->subnqn);
+ if (found) {
+ put_device(&subsys->dev);
+ subsys = found;
+ } else {
+ ret = device_add(&subsys->dev);
+ if (ret) {
+ pr_err("failed to register subsystem '%s'.\n",
+ dev_name(&subsys->dev));
+ put_device(&subsys->dev);
+ goto out_unlock;
+ }
+ list_add_tail(&subsys->entry, &nvme_subsystems);
+ }
+out_unlock:
+ mutex_unlock(&nvme_subsystems_lock);
+ kfree(ns_subsys_id);
+ return subsys;
+}
+
static int nvme_init_ns_head(struct nvme_ns *ns, struct nvme_ns_info *info)
{
struct nvme_ctrl *ctrl = ns->ctrl;
@@ -4100,12 +4152,28 @@ static int nvme_init_ns_head(struct nvme_ns *ns, struct nvme_ns_info *info)
struct nvme_ns_head *head = NULL;
int ret;
+ /*
+ * nvme_generate_ns_subsys() increases the subsystem
+ * refcount, so we need to take care to decrease it
+ * again once we leave this function to not end up
+ * with a refcount imbalance and the per-namespace
+ * subsystem never to be deleted.
+ */
+ if (info->is_shared && ns_subsys) {
+ subsys = nvme_generate_ns_subsys(info);
+ if (IS_ERR(subsys)) {
+ dev_err(ctrl->device,
+ "failed to allocate virtual subsys\n");
+ return PTR_ERR(subsys);
+ }
+ }
+
ret = nvme_global_check_duplicate_ids(subsys, &info->ids);
if (ret) {
dev_err(ctrl->device,
"globally duplicate IDs for nsid %d\n", info->nsid);
nvme_print_device_info(ctrl);
- return ret;
+ goto out_put;
}
mutex_lock(&subsys->lock);
@@ -4150,12 +4218,17 @@ static int nvme_init_ns_head(struct nvme_ns *ns, struct nvme_ns_info *info)
list_add_tail_rcu(&ns->siblings, &head->list);
ns->head = head;
mutex_unlock(&subsys->lock);
+ if (subsys != ctrl->subsys)
+ nvme_put_subsystem(subsys);
return 0;
out_put_ns_head:
nvme_put_ns_head(head);
out_unlock:
mutex_unlock(&subsys->lock);
+out_put:
+ if (subsys != ctrl->subsys)
+ nvme_put_subsystem(subsys);
return ret;
}
