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SubjectRe: [PATCH 1/3] lightnvm: missing nvm_lock acquire


On 11/25/2015 01:42 PM, Wenwei Tao wrote:
> To avoid race conditions, traverse dev, media manager,
> and targeet lists and also register, unregister entries
> to/from them, should be always under the nvm_lock control.
>
> Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
> ---
> drivers/lightnvm/core.c | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> index f659e60..39aec3a 100644
> --- a/drivers/lightnvm/core.c
> +++ b/drivers/lightnvm/core.c
> @@ -333,19 +333,19 @@ EXPORT_SYMBOL(nvm_register);
>
> void nvm_unregister(char *disk_name)
> {
> + down_write(&nvm_lock);
> struct nvm_dev *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;
> }
>
> - nvm_exit(dev);
> -
> - down_write(&nvm_lock);
> list_del(&dev->devices);
> up_write(&nvm_lock);
> + nvm_exit(dev);
> }
> EXPORT_SYMBOL(nvm_unregister);
>
> @@ -365,12 +365,15 @@ static int nvm_create_target(struct nvm_dev *dev,
> 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)
> + if (ret < 0) {
> + up_write(&nvm_lock);
> return ret; /* initialization failed */
> + }
> if (ret > 0) {
> dev->mt = mt;
> break; /* successfully initialized */
> @@ -379,6 +382,7 @@ static int nvm_create_target(struct nvm_dev *dev,
>
> if (!ret) {
> pr_info("nvm: no compatible nvm manager found.\n");
> + up_write(&nvm_lock);
> return -ENODEV;
> }
> }
> @@ -386,10 +390,10 @@ static int nvm_create_target(struct nvm_dev *dev,
> 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");
> @@ -472,8 +476,9 @@ 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;
> @@ -532,7 +537,9 @@ 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;
>
Thanks Tao, applied.


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