This patch adds a counter, which is responsible for tracking inflight target creations.
When creation process is still in progress, target is not yet on targets list. This causes a chance for removing whole lightnvm subsystem by calling nvm_unregister() in the meantime and finally by causing kernel panic inside target init function. With this patch we are able to track such a scenarios and wait with completing nvm_unregister() and freeing memory until target creation will be completed. Signed-off-by: Igor Konopko <[email protected]> --- drivers/lightnvm/core.c | 19 ++++++++++++++++++- include/linux/lightnvm.h | 2 ++ 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c index 838c3d8..490ec6e 100644 --- a/drivers/lightnvm/core.c +++ b/drivers/lightnvm/core.c @@ -1083,6 +1083,7 @@ static int nvm_core_init(struct nvm_dev *dev) INIT_LIST_HEAD(&dev->targets); mutex_init(&dev->mlock); spin_lock_init(&dev->lock); + dev->create_inflight = 0; ret = nvm_register_map(dev); if (ret) @@ -1180,6 +1181,11 @@ void nvm_unregister(struct nvm_dev *dev) struct nvm_target *t, *tmp; mutex_lock(&dev->mlock); + while (dev->create_inflight > 0) { + mutex_unlock(&dev->mlock); + io_schedule(); + mutex_lock(&dev->mlock); + } list_for_each_entry_safe(t, tmp, &dev->targets, list) { if (t->dev->parent != dev) continue; @@ -1213,6 +1219,7 @@ static void nvm_normalize_path(char *path) static int __nvm_configure_create(struct nvm_ioctl_create *create) { struct nvm_dev *dev; + int ret; down_write(&nvm_lock); dev = nvm_find_nvm_dev(create->dev); @@ -1223,7 +1230,17 @@ static int __nvm_configure_create(struct nvm_ioctl_create *create) return -EINVAL; } - return nvm_create_tgt(dev, create); + mutex_lock(&dev->mlock); + dev->create_inflight++; + mutex_unlock(&dev->mlock); + + ret = nvm_create_tgt(dev, create); + + mutex_lock(&dev->mlock); + dev->create_inflight--; + mutex_unlock(&dev->mlock); + + return ret; } static long nvm_ioctl_info(struct file *file, void __user *arg) diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h index d3b0270..e462d1d 100644 --- a/include/linux/lightnvm.h +++ b/include/linux/lightnvm.h @@ -428,6 +428,8 @@ struct nvm_dev { char name[DISK_NAME_LEN]; void *private_data; + int create_inflight; + void *rmap; struct mutex mlock; -- 2.9.5
