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SubjectRe: [PATCH 2/3] lightnvm: handle targets when corresponding nvm device exit
On 11/25/2015 01:42 PM, Wenwei Tao wrote:
> block creations of new targets, remove exiting targets when
> underlying device was gone.
>
> Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
> ---
> drivers/lightnvm/core.c | 127 ++++++++++++++++++++++++++++++-----------------
> include/linux/lightnvm.h | 3 ++
> 2 files changed, 85 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
> index 39aec3a..0b71dd2 100644
> --- a/drivers/lightnvm/core.c
> +++ b/drivers/lightnvm/core.c
> @@ -33,6 +33,17 @@ static LIST_HEAD(nvm_targets);
> static LIST_HEAD(nvm_mgrs);
> static LIST_HEAD(nvm_devices);
> static DECLARE_RWSEM(nvm_lock);
> +#define NVM_EXITING 1
> +
> +static inline int NvmExiting(struct nvm_dev *dev)
> +{
> + return ((unsigned long)dev->ppalist_pool & NVM_EXITING) != 0;
> +}
> +
> +static inline void *ppalist_pool(struct nvm_dev *dev)
> +{
> + return (void *)((unsigned long)dev->ppalist_pool & ~NVM_EXITING);
> +}
>

I think I rather want to have a state variable (so we have a state
machine for three state. Initializing, running, and stopping.

What was the reason you'll like to put it in the ppalist_pool?

ps. could you rebase it on top of the latest master. Then I'll review
the rest of it.

> static struct nvm_tgt_type *nvm_find_target_type(const char *name)
> {
> @@ -74,7 +85,7 @@ EXPORT_SYMBOL(nvm_unregister_target);
> void *nvm_dev_dma_alloc(struct nvm_dev *dev, gfp_t mem_flags,
> dma_addr_t *dma_handler)
> {
> - return dev->ops->dev_dma_alloc(dev->q, dev->ppalist_pool, mem_flags,
> + return dev->ops->dev_dma_alloc(dev->q, ppalist_pool(dev), mem_flags,
> dma_handler);
> }
> EXPORT_SYMBOL(nvm_dev_dma_alloc);
> @@ -82,7 +93,7 @@ EXPORT_SYMBOL(nvm_dev_dma_alloc);
> void nvm_dev_dma_free(struct nvm_dev *dev, void *ppa_list,
> dma_addr_t dma_handler)
> {
> - dev->ops->dev_dma_free(dev->ppalist_pool, ppa_list, dma_handler);
> + dev->ops->dev_dma_free(ppalist_pool(dev), ppa_list, dma_handler);
> }
> EXPORT_SYMBOL(nvm_dev_dma_free);
>
> @@ -206,17 +217,6 @@ static int nvm_core_init(struct nvm_dev *dev)
> return 0;
> }
>
> -static void nvm_free(struct nvm_dev *dev)
> -{
> - if (!dev)
> - return;
> -
> - if (dev->mt)
> - dev->mt->unregister_mgr(dev);
> -
> - nvm_core_free(dev);
> -}
> -
> static int nvm_init(struct nvm_dev *dev)
> {
> struct nvmm_type *mt;
> @@ -262,6 +262,7 @@ static int nvm_init(struct nvm_dev *dev)
> }
> }
>
> + kref_init(&dev->kref);
> if (!ret) {
> pr_info("nvm: no compatible manager found.\n");
> return 0;
> @@ -278,11 +279,47 @@ err:
> return ret;
> }
>
> -static void nvm_exit(struct nvm_dev *dev)
> +static void nvm_remove_target(struct nvm_target *t)
> {
> - if (dev->ppalist_pool)
> - dev->ops->destroy_dma_pool(dev->ppalist_pool);
> - nvm_free(dev);
> + struct nvm_tgt_type *tt = t->type;
> + struct gendisk *tdisk = t->disk;
> + struct request_queue *q = tdisk->queue;
> +
> + lockdep_assert_held(&nvm_lock);
> +
> + del_gendisk(tdisk);
> + if (tt->exit)
> + tt->exit(tdisk->private_data);
> +
> + blk_cleanup_queue(q);
> +
> + put_disk(tdisk);
> +
> + list_del(&t->list);
> + kfree(t);
> +}
> +
> +static inline void nvm_remove_targets(struct nvm_dev *dev)
> +{
> + struct nvm_target *t, *n;
> +
> + list_for_each_entry_safe(t, n, &dev->online_targets, list)
> + nvm_remove_target(t);
> +}
> +
> +static void nvm_exit(struct kref *kref)
> +{
> + struct nvm_dev *dev;
> +
> + dev = container_of(kref, struct nvm_dev, kref);
> + if (ppalist_pool(dev))
> + dev->ops->destroy_dma_pool(ppalist_pool(dev));
> +
> + if (dev->mt)
> + dev->mt->unregister_mgr(dev);
> +
> + if (dev->ops->dev_remove)
> + dev->ops->dev_remove(dev->q);
>
> pr_info("nvm: successfully unloaded\n");
> }
> @@ -344,8 +381,10 @@ void nvm_unregister(char *disk_name)
> }
>
> list_del(&dev->devices);
> + nvm_remove_targets(dev);
> + dev->ppalist_pool += NVM_EXITING;
> up_write(&nvm_lock);
> - nvm_exit(dev);
> + kref_put(&dev->kref, nvm_exit);
> }
> EXPORT_SYMBOL(nvm_unregister);
>
> @@ -366,6 +405,10 @@ static int nvm_create_target(struct nvm_dev *dev,
> int ret = 0;
>
> down_write(&nvm_lock);
> + if (NvmExiting(dev)) {
> + up_write(&nvm_lock);
> + return -ENODEV;
> + }
> if (!dev->mt) {
> /* register with device with a supported NVM manager */
> list_for_each_entry(mt, &nvm_mgrs, list) {
> @@ -439,10 +482,16 @@ static int nvm_create_target(struct nvm_dev *dev,
> t->disk = tdisk;
>
> down_write(&nvm_lock);
> + if (NvmExiting(dev)) {
> + up_write(&nvm_lock);
> + goto err_nvm_exiting;
> + }
> list_add_tail(&t->list, &dev->online_targets);
> up_write(&nvm_lock);
>
> return 0;
> +err_nvm_exiting:
> + del_gendisk(tdisk);
> err_init:
> put_disk(tdisk);
> err_queue:
> @@ -452,62 +501,50 @@ err_t:
> return -ENOMEM;
> }
>
> -static void nvm_remove_target(struct nvm_target *t)
> -{
> - struct nvm_tgt_type *tt = t->type;
> - struct gendisk *tdisk = t->disk;
> - struct request_queue *q = tdisk->queue;
> -
> - lockdep_assert_held(&nvm_lock);
> -
> - del_gendisk(tdisk);
> - if (tt->exit)
> - tt->exit(tdisk->private_data);
> -
> - blk_cleanup_queue(q);
> -
> - put_disk(tdisk);
> -
> - list_del(&t->list);
> - kfree(t);
> -}
> -
> static int __nvm_configure_create(struct nvm_ioctl_create *create)
> {
> struct nvm_dev *dev;
> struct nvm_ioctl_create_simple *s;
> + int ret = -EINVAL;
> +
> 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;
> + up_write(&nvm_lock);
> + goto out;
> }
> + kref_get(&dev->kref);
> + up_write(&nvm_lock);
>
> if (create->conf.type != NVM_CONFIG_TYPE_SIMPLE) {
> pr_err("nvm: config type not valid\n");
> - return -EINVAL;
> + goto out;
> }
> s = &create->conf.s;
>
> if (s->lun_begin > s->lun_end || s->lun_end > dev->nr_luns) {
> pr_err("nvm: lun out of bound (%u:%u > %u)\n",
> s->lun_begin, s->lun_end, dev->nr_luns);
> - return -EINVAL;
> + goto out;
> }
>
> - return nvm_create_target(dev, create);
> + ret = nvm_create_target(dev, create);
> +out:
> + if (dev)
> + kref_put(&dev->kref, nvm_exit);
> + return ret;
> }
>
> static int __nvm_configure_remove(struct nvm_ioctl_remove *remove)
> {
> - struct nvm_target *t = NULL;
> + struct nvm_target *n, *t = NULL;
> struct nvm_dev *dev;
> int ret = -1;
>
> down_write(&nvm_lock);
> list_for_each_entry(dev, &nvm_devices, devices)
> - list_for_each_entry(t, &dev->online_targets, list) {
> + list_for_each_entry_safe(t, n, &dev->online_targets, list) {
> if (!strcmp(remove->tgtname, t->disk->disk_name)) {
> nvm_remove_target(t);
> ret = 0;
> diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
> index 69c9057..1b42305 100644
> --- a/include/linux/lightnvm.h
> +++ b/include/linux/lightnvm.h
> @@ -205,6 +205,7 @@ typedef void (nvm_destroy_dma_pool_fn)(void *);
> typedef void *(nvm_dev_dma_alloc_fn)(struct request_queue *, void *, gfp_t,
> dma_addr_t *);
> typedef void (nvm_dev_dma_free_fn)(void *, void*, dma_addr_t);
> +typedef void (nvm_dev_remove_fn) (struct request_queue *);
>
> struct nvm_dev_ops {
> nvm_id_fn *identity;
> @@ -219,6 +220,7 @@ struct nvm_dev_ops {
> nvm_destroy_dma_pool_fn *destroy_dma_pool;
> nvm_dev_dma_alloc_fn *dev_dma_alloc;
> nvm_dev_dma_free_fn *dev_dma_free;
> + nvm_dev_remove_fn *dev_remove;
>
> uint8_t max_phys_sect;
> };
> @@ -252,6 +254,7 @@ struct nvm_dev {
>
> /* Media manager */
> struct nvmm_type *mt;
> + struct kref kref;
> void *mp;
>
> /* Device information */
>


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