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authorChristoph Hellwig <hch@lst.de>2019-05-08 09:48:27 +0200
committerChristoph Hellwig <hch@lst.de>2019-05-14 17:19:50 +0200
commit32fd90c407680935f84fb3ffc60fb3e020257d38 (patch)
tree5156b2b213d58d07902d227a39b997ace8d0b4c2 /drivers
parent521cfb8e5a5dd6f2f528d675688f07b962fe4545 (diff)
nvme: change locking for the per-subsystem controller list
Life becomes a lot simpler if we just use the global nvme_subsystems_lock to protect this list. Given that it is only accessed during controller probing and removal that isn't a scalability problem either. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/nvme/host/core.c32
1 files changed, 14 insertions, 18 deletions
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index f22925b5eeca..d2d8e6088c46 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2346,13 +2346,13 @@ static int nvme_active_ctrls(struct nvme_subsystem *subsys)
int count = 0;
struct nvme_ctrl *ctrl;
- mutex_lock(&subsys->lock);
+ lockdep_assert_held(&nvme_subsystems_lock);
+
list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
if (ctrl->state != NVME_CTRL_DELETING &&
ctrl->state != NVME_CTRL_DEAD)
count++;
}
- mutex_unlock(&subsys->lock);
return count;
}
@@ -2394,6 +2394,9 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
mutex_lock(&nvme_subsystems_lock);
found = __nvme_find_get_subsystem(subsys->subnqn);
if (found) {
+ __nvme_release_subsystem(subsys);
+ subsys = found;
+
/*
* Verify that the subsystem actually supports multiple
* controllers, else bail out.
@@ -2402,14 +2405,10 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
nvme_active_ctrls(found) && !(id->cmic & (1 << 1))) {
dev_err(ctrl->device,
"ignoring ctrl due to duplicate subnqn (%s).\n",
- found->subnqn);
- nvme_put_subsystem(found);
+ subsys->subnqn);
ret = -EINVAL;
- goto out_unlock;
+ goto out_put_subsystem;
}
-
- __nvme_release_subsystem(subsys);
- subsys = found;
} else {
ret = device_add(&subsys->dev);
if (ret) {
@@ -2421,23 +2420,20 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
list_add_tail(&subsys->entry, &nvme_subsystems);
}
- ctrl->subsys = subsys;
- mutex_unlock(&nvme_subsystems_lock);
-
if (sysfs_create_link(&subsys->dev.kobj, &ctrl->device->kobj,
dev_name(ctrl->device))) {
dev_err(ctrl->device,
"failed to create sysfs link from subsystem.\n");
- /* the transport driver will eventually put the subsystem */
- return -EINVAL;
+ goto out_put_subsystem;
}
- mutex_lock(&subsys->lock);
+ ctrl->subsys = subsys;
list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
- mutex_unlock(&subsys->lock);
-
+ mutex_unlock(&nvme_subsystems_lock);
return 0;
+out_put_subsystem:
+ nvme_put_subsystem(subsys);
out_unlock:
mutex_unlock(&nvme_subsystems_lock);
put_device(&subsys->dev);
@@ -3694,10 +3690,10 @@ static void nvme_free_ctrl(struct device *dev)
__free_page(ctrl->discard_page);
if (subsys) {
- mutex_lock(&subsys->lock);
+ mutex_lock(&nvme_subsystems_lock);
list_del(&ctrl->subsys_entry);
- mutex_unlock(&subsys->lock);
sysfs_remove_link(&subsys->dev.kobj, dev_name(ctrl->device));
+ mutex_unlock(&nvme_subsystems_lock);
}
ctrl->ops->free_ctrl(ctrl);