lightnvm: move target mgmt into media mgr

To enable persistent block management to easily control creation and
removal of targets, we move target management into the media
manager. The LightNVM core continues to maintain which target types are
registered, while the media manager now keeps track of its initialized
targets.

Two new callbacks for the media manager are introduced. create_tgt and
remove_tgt. Note that remove_tgt returns 0 on successfully removing a
target, and returns 1 if the target was not found.

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

1 files changed, 154 insertions, 0 deletions

diff --git a/drivers/lightnvm/gennvm.c b/drivers/lightnvm/gennvm.c
index 3d2762f2a6fe..41760b24bea7 100644
--- a/drivers/lightnvm/gennvm.c
+++ b/drivers/lightnvm/gennvm.c
@@ -20,6 +20,144 @@
 
 #include "gennvm.h"
 
+static struct nvm_target *gen_find_target(struct gen_dev *gn, const char *name)
+{
+	struct nvm_target *tgt;
+
+	list_for_each_entry(tgt, &gn->targets, list)
+		if (!strcmp(name, tgt->disk->disk_name))
+			return tgt;
+
+	return NULL;
+}
+
+static const struct block_device_operations gen_fops = {
+	.owner		= THIS_MODULE,
+};
+
+static int gen_create_tgt(struct nvm_dev *dev, struct nvm_ioctl_create *create)
+{
+	struct gen_dev *gn = dev->mp;
+	struct nvm_ioctl_create_simple *s = &create->conf.s;
+	struct request_queue *tqueue;
+	struct gendisk *tdisk;
+	struct nvm_tgt_type *tt;
+	struct nvm_target *t;
+	void *targetdata;
+
+	tt = nvm_find_target_type(create->tgttype, 1);
+	if (!tt) {
+		pr_err("nvm: target type %s not found\n", create->tgttype);
+		return -EINVAL;
+	}
+
+	mutex_lock(&gn->lock);
+	t = gen_find_target(gn, create->tgtname);
+	if (t) {
+		pr_err("nvm: target name already exists.\n");
+		mutex_unlock(&gn->lock);
+		return -EINVAL;
+	}
+	mutex_unlock(&gn->lock);
+
+	t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
+	if (!t)
+		return -ENOMEM;
+
+	tqueue = blk_alloc_queue_node(GFP_KERNEL, dev->q->node);
+	if (!tqueue)
+		goto err_t;
+	blk_queue_make_request(tqueue, tt->make_rq);
+
+	tdisk = alloc_disk(0);
+	if (!tdisk)
+		goto err_queue;
+
+	sprintf(tdisk->disk_name, "%s", create->tgtname);
+	tdisk->flags = GENHD_FL_EXT_DEVT;
+	tdisk->major = 0;
+	tdisk->first_minor = 0;
+	tdisk->fops = &gen_fops;
+	tdisk->queue = tqueue;
+
+	targetdata = tt->init(dev, tdisk, s->lun_begin, s->lun_end);
+	if (IS_ERR(targetdata))
+		goto err_init;
+
+	tdisk->private_data = targetdata;
+	tqueue->queuedata = targetdata;
+
+	blk_queue_max_hw_sectors(tqueue, 8 * dev->ops->max_phys_sect);
+
+	set_capacity(tdisk, tt->capacity(targetdata));
+	add_disk(tdisk);
+
+	t->type = tt;
+	t->disk = tdisk;
+	t->dev = dev;
+
+	mutex_lock(&gn->lock);
+	list_add_tail(&t->list, &gn->targets);
+	mutex_unlock(&gn->lock);
+
+	return 0;
+err_init:
+	put_disk(tdisk);
+err_queue:
+	blk_cleanup_queue(tqueue);
+err_t:
+	kfree(t);
+	return -ENOMEM;
+}
+
+static void __gen_remove_target(struct nvm_target *t)
+{
+	struct nvm_tgt_type *tt = t->type;
+	struct gendisk *tdisk = t->disk;
+	struct request_queue *q = tdisk->queue;
+
+	del_gendisk(tdisk);
+	blk_cleanup_queue(q);
+
+	if (tt->exit)
+		tt->exit(tdisk->private_data);
+
+	put_disk(tdisk);
+
+	list_del(&t->list);
+	kfree(t);
+}
+
+/**
+ * gen_remove_tgt - Removes a target from the media manager
+ * @dev:	device
+ * @remove:	ioctl structure with target name to remove.
+ *
+ * Returns:
+ * 0: on success
+ * 1: on not found
+ * <0: on error
+ */
+static int gen_remove_tgt(struct nvm_dev *dev, struct nvm_ioctl_remove *remove)
+{
+	struct gen_dev *gn = dev->mp;
+	struct nvm_target *t;
+
+	if (!gn)
+		return 1;
+
+	mutex_lock(&gn->lock);
+	t = gen_find_target(gn, remove->tgtname);
+	if (!t) {
+		mutex_unlock(&gn->lock);
+		return 1;
+	}
+	__gen_remove_target(t);
+	mutex_unlock(&gn->lock);
+
+	return 0;
+}
+
 static int gen_get_area(struct nvm_dev *dev, sector_t *lba, sector_t len)
 {
 	struct gen_dev *gn = dev->mp;
@@ -295,6 +433,8 @@ static int gen_register(struct nvm_dev *dev)
 	gn->dev = dev;
 	gn->nr_luns = dev->nr_luns;
 	INIT_LIST_HEAD(&gn->area_list);
+	mutex_init(&gn->lock);
+	INIT_LIST_HEAD(&gn->targets);
 	dev->mp = gn;
 
 	ret = gen_luns_init(dev, gn);
@@ -318,6 +458,17 @@ err:
 
 static void gen_unregister(struct nvm_dev *dev)
 {
+	struct gen_dev *gn = dev->mp;
+	struct nvm_target *t, *tmp;
+
+	mutex_lock(&gn->lock);
+	list_for_each_entry_safe(t, tmp, &gn->targets, list) {
+		if (t->dev != dev)
+			continue;
+		__gen_remove_target(t);
+	}
+	mutex_unlock(&gn->lock);
+
 	gen_free(dev);
 	module_put(THIS_MODULE);
 }
@@ -515,6 +666,9 @@ static struct nvmm_type gen = {
 	.register_mgr		= gen_register,
 	.unregister_mgr		= gen_unregister,
 
+	.create_tgt		= gen_create_tgt,
+	.remove_tgt		= gen_remove_tgt,
+
 	.get_blk_unlocked	= gen_get_blk_unlocked,
 	.put_blk_unlocked	= gen_put_blk_unlocked,