lightnvm: introduce factory reset

Now that a device can be managed using the system blocks, a method to
reset the device is necessary as well. This patch introduces logic to
reset the device easily to factory state and exposes it through an
ioctl.

The ioctl takes the following flags:

  NVM_FACTORY_ERASE_ONLY_USER
      By default all blocks, except host-reserved blocks are erased upon
      factory reset. Instead of this, only erase host-reserved blocks.
  NVM_FACTORY_RESET_HOST_BLKS
      Mark host-reserved blocks to be erased and set their type to free.
  NVM_FACTORY_RESET_GRWN_BBLKS
      Mark "grown bad blocks" to be erased and set their type to free.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index 9e5712dda062..33224cb91c5b 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -1088,6 +1088,38 @@ static long nvm_ioctl_dev_init(struct file *file, void __user *arg)
 	return __nvm_ioctl_dev_init(&init);
 }
 
+static long nvm_ioctl_dev_factory(struct file *file, void __user *arg)
+{
+	struct nvm_ioctl_dev_factory fact;
+	struct nvm_dev *dev;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (copy_from_user(&fact, arg, sizeof(struct nvm_ioctl_dev_factory)))
+		return -EFAULT;
+
+	fact.dev[DISK_NAME_LEN - 1] = '\0';
+
+	if (fact.flags & ~(NVM_FACTORY_NR_BITS - 1))
+		return -EINVAL;
+
+	down_write(&nvm_lock);
+	dev = nvm_find_nvm_dev(fact.dev);
+	up_write(&nvm_lock);
+	if (!dev) {
+		pr_err("nvm: device not found\n");
+		return -EINVAL;
+	}
+
+	if (dev->mt) {
+		dev->mt->unregister_mgr(dev);
+		dev->mt = NULL;
+	}
+
+	return nvm_dev_factory(dev, fact.flags);
+}
+
 static long nvm_ctl_ioctl(struct file *file, uint cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
@@ -1103,6 +1135,8 @@ static long nvm_ctl_ioctl(struct file *file, uint cmd, unsigned long arg)
 		return nvm_ioctl_dev_remove(file, argp);
 	case NVM_DEV_INIT:
 		return nvm_ioctl_dev_init(file, argp);
+	case NVM_DEV_FACTORY:
+		return nvm_ioctl_dev_factory(file, argp);
 	}
 	return 0;
 }