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Message-Id: <20180525125322.15398-2-jthumshirn@suse.de>
Date: Fri, 25 May 2018 14:53:20 +0200
From: Johannes Thumshirn <jthumshirn@...e.de>
To: Christoph Hellwig <hch@....de>,
Keith Busch <keith.busch@...el.com>,
Sagi Grimberg <sagi@...mberg.me>
Cc: Hannes Reinecke <hare@...e.de>, Mike Snitzer <snitzer@...hat.com>,
Laurence Oberman <loberman@...hat.com>,
Ewan Milne <emilne@...hat.com>,
James Smart <james.smart@...adcom.com>,
Linux Kernel Mailinglist <linux-kernel@...r.kernel.org>,
Linux NVMe Mailinglist <linux-nvme@...ts.infradead.org>,
"Martin K . Petersen" <martin.petersen@...cle.com>,
Martin George <marting@...app.com>,
John Meneghini <John.Meneghini@...app.com>,
Johannes Thumshirn <jthumshirn@...e.de>
Subject: [PATCH 1/3] nvme: provide a way to disable nvme mpath per subsystem
Provide a way to disable NVMe native multipathing on a per-subsystem
basis to enable a user to use dm-mpath and nvme native multipathing on
the same host for different nvme devices.
Signed-off-by: Johannes Thumshirn <jthumshirn@...e.de>
---
drivers/nvme/host/core.c | 63 +++++++++++++++++++++++++++++++++++++++++++
drivers/nvme/host/multipath.c | 34 +++++++++++++++++++----
drivers/nvme/host/nvme.h | 8 ++++++
3 files changed, 100 insertions(+), 5 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 99b857e5a7a9..3a1c70bd9008 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2082,6 +2082,10 @@ static struct nvme_subsystem *__nvme_find_get_subsystem(const char *subsysnqn)
return NULL;
}
+#define SUBSYS_ATTR_RW(_name) \
+ struct device_attribute subsys_attr_##_name = \
+ __ATTR_RW(_name)
+
#define SUBSYS_ATTR_RO(_name, _mode, _show) \
struct device_attribute subsys_attr_##_name = \
__ATTR(_name, _mode, _show, NULL)
@@ -2112,11 +2116,62 @@ nvme_subsys_show_str_function(model);
nvme_subsys_show_str_function(serial);
nvme_subsys_show_str_function(firmware_rev);
+
+#ifdef CONFIG_NVME_MULTIPATH
+static ssize_t mpath_personality_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_subsystem *subsys =
+ container_of(dev, struct nvme_subsystem, dev);
+ ssize_t ret;
+
+ if (subsys->native_mpath)
+ ret = scnprintf(buf, PAGE_SIZE, "[native] other\n");
+ else
+ ret = scnprintf(buf, PAGE_SIZE, "native [other]\n");
+
+ return ret;
+}
+
+static ssize_t mpath_personality_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct nvme_subsystem *subsys =
+ container_of(dev, struct nvme_subsystem, dev);
+ bool native_mpath = false;
+ int ret = 0;
+
+ if (!strncmp(buf, "native", strlen("native")))
+ native_mpath = true;
+ else if (!strncmp(buf, "other", strlen("other")))
+ native_mpath = false;
+ else {
+ pr_warn("unknown value %s\n", buf);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (subsys->native_mpath != native_mpath) {
+ subsys->native_mpath = native_mpath;
+ ret = nvme_mpath_change_personality(subsys);
+ }
+
+out:
+ return ret ? ret : count;
+}
+static SUBSYS_ATTR_RW(mpath_personality);
+#endif
+
static struct attribute *nvme_subsys_attrs[] = {
&subsys_attr_model.attr,
&subsys_attr_serial.attr,
&subsys_attr_firmware_rev.attr,
&subsys_attr_subsysnqn.attr,
+#ifdef CONFIG_NVME_MULTIPATH
+ &subsys_attr_mpath_personality.attr,
+#endif
NULL,
};
@@ -2220,6 +2275,10 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
mutex_unlock(&subsys->lock);
+#ifdef CONFIG_NVME_MULTIPATH
+ subsys->native_mpath = nvme_multipath;
+#endif
+
return 0;
out_unlock:
@@ -2850,6 +2909,10 @@ static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
head->ns_id = nsid;
kref_init(&head->ref);
+#ifdef CONFIG_NVME_MULTIPATH
+ head->native_mpath = ctrl->subsys->native_mpath;
+#endif
+
nvme_report_ns_ids(ctrl, nsid, id, &head->ids);
ret = __nvme_check_ids(ctrl->subsys, head);
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index d7b664ae5923..53d2610605ca 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -14,8 +14,8 @@
#include <linux/moduleparam.h>
#include "nvme.h"
-static bool multipath = true;
-module_param(multipath, bool, 0444);
+bool nvme_multipath = true;
+module_param_named(multipath, nvme_multipath, bool, 0444);
MODULE_PARM_DESC(multipath,
"turn on native support for multiple controllers per subsystem");
@@ -29,7 +29,7 @@ MODULE_PARM_DESC(multipath,
void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
struct nvme_ctrl *ctrl, int *flags)
{
- if (!multipath) {
+ if (!ctrl->subsys->native_mpath) {
sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
} else if (ns->head->disk) {
sprintf(disk_name, "nvme%dc%dn%d", ctrl->subsys->instance,
@@ -181,7 +181,7 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
* We also do this for private namespaces as the namespace sharing data could
* change after a rescan.
*/
- if (!(ctrl->subsys->cmic & (1 << 1)) || !multipath)
+ if (!(ctrl->subsys->cmic & (1 << 1)) || !ctrl->subsys->native_mpath)
return 0;
q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE, NULL);
@@ -218,7 +218,7 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
void nvme_mpath_add_disk(struct nvme_ns_head *head)
{
- if (!head->disk)
+ if (!head->disk || !head->native_mpath)
return;
mutex_lock(&head->subsys->lock);
@@ -246,3 +246,27 @@ void nvme_mpath_remove_disk(struct nvme_ns_head *head)
blk_cleanup_queue(head->disk->queue);
put_disk(head->disk);
}
+
+int nvme_mpath_change_personality(struct nvme_subsystem *subsys)
+{
+ struct nvme_ctrl *ctrl;
+ int ret = 0;
+
+restart:
+ mutex_lock(&subsys->lock);
+ list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
+ if (!list_empty(&ctrl->namespaces)) {
+ mutex_unlock(&subsys->lock);
+ nvme_remove_namespaces(ctrl);
+ goto restart;
+ }
+ }
+ mutex_unlock(&subsys->lock);
+
+ mutex_lock(&subsys->lock);
+ list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
+ nvme_queue_scan(ctrl);
+ mutex_unlock(&subsys->lock);
+
+ return ret;
+}
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 17d2f7cf3fed..f7253c074a89 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -32,6 +32,8 @@ extern unsigned int admin_timeout;
#define NVME_DEFAULT_KATO 5
#define NVME_KATO_GRACE 10
+extern bool nvme_multipath;
+
extern struct workqueue_struct *nvme_wq;
extern struct workqueue_struct *nvme_reset_wq;
extern struct workqueue_struct *nvme_delete_wq;
@@ -232,6 +234,10 @@ struct nvme_subsystem {
u8 cmic;
u16 vendor_id;
struct ida ns_ida;
+
+#ifdef CONFIG_NVME_MULTIPATH
+ bool native_mpath;
+#endif
};
/*
@@ -257,6 +263,7 @@ struct nvme_ns_head {
struct bio_list requeue_list;
spinlock_t requeue_lock;
struct work_struct requeue_work;
+ bool native_mpath;
#endif
struct list_head list;
struct srcu_struct srcu;
@@ -449,6 +456,7 @@ void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl);
int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,struct nvme_ns_head *head);
void nvme_mpath_add_disk(struct nvme_ns_head *head);
void nvme_mpath_remove_disk(struct nvme_ns_head *head);
+int nvme_mpath_change_personality(struct nvme_subsystem *subsys);
static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
{
--
2.16.3
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