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Commit d0a712ce authored by Wenwei Tao's avatar Wenwei Tao Committed by Jens Axboe
Browse files

lightnvm: missing nvm_lock acquire 



To avoid race conditions, traverse dev, media manager,
and target lists and also register, unregister entries
to/from them, should be always under the nvm_lock control.

Signed-off-by: default avatarWenwei Tao <ww.tao0320@gmail.com>
Signed-off-by: default avatarMatias Bjørling <m@bjorling.me>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 08236c6b

drivers/lightnvm/core.c

+42 −33
Original line number Diff line number Diff line
@@ -123,6 +123,26 @@ void nvm_unregister_mgr(struct nvmm_type *mt) 
}

EXPORT_SYMBOL(nvm_unregister_mgr);



/* register with device with a supported manager */

static int register_mgr(struct nvm_dev *dev)

{

	struct nvmm_type *mt;

	int ret = 0;



	list_for_each_entry(mt, &nvm_mgrs, list) {

		ret = mt->register_mgr(dev);

		if (ret > 0) {

			dev->mt = mt;

			break; /* successfully initialized */

		}

	}



	if (!ret)

		pr_info("nvm: no compatible nvm manager found.\n");



	return ret;

}



static struct nvm_dev *nvm_find_nvm_dev(const char *name)

{

	struct nvm_dev *dev;
@@ -221,7 +241,6 @@ static void nvm_free(struct nvm_dev *dev) 


static int nvm_init(struct nvm_dev *dev)

{

	struct nvmm_type *mt;

	int ret = -EINVAL;



	if (!dev->q || !dev->ops)
@@ -252,21 +271,13 @@ static int nvm_init(struct nvm_dev *dev) 
		goto err;

	}



	/* register with device with a supported manager */

	list_for_each_entry(mt, &nvm_mgrs, list) {

		ret = mt->register_mgr(dev);

	down_write(&nvm_lock);

	ret = register_mgr(dev);

	up_write(&nvm_lock);

	if (ret < 0)

			goto err; /* initialization failed */

		if (ret > 0) {

			dev->mt = mt;

			break; /* successfully initialized */

		}

	}



	if (!ret) {

		pr_info("nvm: no compatible manager found.\n");

		goto err;

	if (!ret)

		return 0;

	}



	pr_info("nvm: registered %s [%u/%u/%u/%u/%u/%u]\n",

			dev->name, dev->sec_per_pg, dev->nr_planes,
@@ -337,15 +348,17 @@ EXPORT_SYMBOL(nvm_register); 


void nvm_unregister(char *disk_name)

{

	struct nvm_dev *dev = nvm_find_nvm_dev(disk_name);

	struct nvm_dev *dev;



	down_write(&nvm_lock);

	dev = nvm_find_nvm_dev(disk_name);

	if (!dev) {

		pr_err("nvm: could not find device %s to unregister\n",

								disk_name);

		up_write(&nvm_lock);

		return;

	}



	down_write(&nvm_lock);

	list_del(&dev->devices);

	up_write(&nvm_lock);
@@ -363,38 +376,30 @@ static int nvm_create_target(struct nvm_dev *dev, 
{

	struct nvm_ioctl_create_simple *s = &create->conf.s;

	struct request_queue *tqueue;

	struct nvmm_type *mt;

	struct gendisk *tdisk;

	struct nvm_tgt_type *tt;

	struct nvm_target *t;

	void *targetdata;

	int ret = 0;



	down_write(&nvm_lock);

	if (!dev->mt) {

		/* register with device with a supported NVM manager */

		list_for_each_entry(mt, &nvm_mgrs, list) {

			ret = mt->register_mgr(dev);

			if (ret < 0)

				return ret; /* initialization failed */

			if (ret > 0) {

				dev->mt = mt;

				break; /* successfully initialized */

			}

		}



		if (!ret) {

			pr_info("nvm: no compatible nvm manager found.\n");

			return -ENODEV;

		ret = register_mgr(dev);

		if (!ret)

			ret = -ENODEV;

		if (ret < 0) {

			up_write(&nvm_lock);

			return ret;

		}

	}



	tt = nvm_find_target_type(create->tgttype);

	if (!tt) {

		pr_err("nvm: target type %s not found\n", create->tgttype);

		up_write(&nvm_lock);

		return -EINVAL;

	}



	down_write(&nvm_lock);

	list_for_each_entry(t, &dev->online_targets, list) {

		if (!strcmp(create->tgtname, t->disk->disk_name)) {

			pr_err("nvm: target name already exists.\n");
@@ -478,7 +483,9 @@ static int __nvm_configure_create(struct nvm_ioctl_create *create) 
	struct nvm_dev *dev;

	struct nvm_ioctl_create_simple *s;



	down_write(&nvm_lock);

	dev = nvm_find_nvm_dev(create->dev);

	up_write(&nvm_lock);

	if (!dev) {

		pr_err("nvm: device not found\n");

		return -EINVAL;
@@ -537,7 +544,9 @@ static int nvm_configure_show(const char *val) 
		return -EINVAL;

	}



	down_write(&nvm_lock);

	dev = nvm_find_nvm_dev(devname);

	up_write(&nvm_lock);

	if (!dev) {

		pr_err("nvm: device not found\n");

		return -EINVAL;