Commit 32fd90c4 authored by Christoph Hellwig's avatar Christoph Hellwig

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: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
parent 521cfb8e
...@@ -2346,13 +2346,13 @@ static int nvme_active_ctrls(struct nvme_subsystem *subsys) ...@@ -2346,13 +2346,13 @@ static int nvme_active_ctrls(struct nvme_subsystem *subsys)
int count = 0; int count = 0;
struct nvme_ctrl *ctrl; struct nvme_ctrl *ctrl;
mutex_lock(&subsys->lock); lockdep_assert_held(&nvme_subsystems_lock);
list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) { list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
if (ctrl->state != NVME_CTRL_DELETING && if (ctrl->state != NVME_CTRL_DELETING &&
ctrl->state != NVME_CTRL_DEAD) ctrl->state != NVME_CTRL_DEAD)
count++; count++;
} }
mutex_unlock(&subsys->lock);
return count; return count;
} }
...@@ -2394,6 +2394,9 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) ...@@ -2394,6 +2394,9 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
mutex_lock(&nvme_subsystems_lock); mutex_lock(&nvme_subsystems_lock);
found = __nvme_find_get_subsystem(subsys->subnqn); found = __nvme_find_get_subsystem(subsys->subnqn);
if (found) { if (found) {
__nvme_release_subsystem(subsys);
subsys = found;
/* /*
* Verify that the subsystem actually supports multiple * Verify that the subsystem actually supports multiple
* controllers, else bail out. * controllers, else bail out.
...@@ -2402,14 +2405,10 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) ...@@ -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))) { nvme_active_ctrls(found) && !(id->cmic & (1 << 1))) {
dev_err(ctrl->device, dev_err(ctrl->device,
"ignoring ctrl due to duplicate subnqn (%s).\n", "ignoring ctrl due to duplicate subnqn (%s).\n",
found->subnqn); subsys->subnqn);
nvme_put_subsystem(found);
ret = -EINVAL; ret = -EINVAL;
goto out_unlock; goto out_put_subsystem;
} }
__nvme_release_subsystem(subsys);
subsys = found;
} else { } else {
ret = device_add(&subsys->dev); ret = device_add(&subsys->dev);
if (ret) { if (ret) {
...@@ -2421,23 +2420,20 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) ...@@ -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); 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, if (sysfs_create_link(&subsys->dev.kobj, &ctrl->device->kobj,
dev_name(ctrl->device))) { dev_name(ctrl->device))) {
dev_err(ctrl->device, dev_err(ctrl->device,
"failed to create sysfs link from subsystem.\n"); "failed to create sysfs link from subsystem.\n");
/* the transport driver will eventually put the subsystem */ goto out_put_subsystem;
return -EINVAL;
} }
mutex_lock(&subsys->lock); ctrl->subsys = subsys;
list_add_tail(&ctrl->subsys_entry, &subsys->ctrls); list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
mutex_unlock(&subsys->lock); mutex_unlock(&nvme_subsystems_lock);
return 0; return 0;
out_put_subsystem:
nvme_put_subsystem(subsys);
out_unlock: out_unlock:
mutex_unlock(&nvme_subsystems_lock); mutex_unlock(&nvme_subsystems_lock);
put_device(&subsys->dev); put_device(&subsys->dev);
...@@ -3694,10 +3690,10 @@ static void nvme_free_ctrl(struct device *dev) ...@@ -3694,10 +3690,10 @@ static void nvme_free_ctrl(struct device *dev)
__free_page(ctrl->discard_page); __free_page(ctrl->discard_page);
if (subsys) { if (subsys) {
mutex_lock(&subsys->lock); mutex_lock(&nvme_subsystems_lock);
list_del(&ctrl->subsys_entry); list_del(&ctrl->subsys_entry);
mutex_unlock(&subsys->lock);
sysfs_remove_link(&subsys->dev.kobj, dev_name(ctrl->device)); sysfs_remove_link(&subsys->dev.kobj, dev_name(ctrl->device));
mutex_unlock(&nvme_subsystems_lock);
} }
ctrl->ops->free_ctrl(ctrl); ctrl->ops->free_ctrl(ctrl);
......
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