On 3/17/21 11:10 PM, Qiaowei Ren wrote:
> From: Jianpeng Ma <jianpeng.ma@xxxxxxxxx>
>
> This nvm pages allocator will implement the simple buddy to manage the
> nvm address space. This patch initializes this buddy for new namespace.
>
> the unit of alloc/free of the buddy is page. DAX device has their
> struct page(in dram or PMEM).
>
> struct { /* ZONE_DEVICE pages */
> /** @pgmap: Points to the hosting device page map. */
> struct dev_pagemap *pgmap;
> void *zone_device_data;
> /*
> * ZONE_DEVICE private pages are counted as being
> * mapped so the next 3 words hold the mapping, index,
> * and private fields from the source anonymous or
> * page cache page while the page is migrated to device
> * private memory.
> * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also
> * use the mapping, index, and private fields when
> * pmem backed DAX files are mapped.
> */
> };
>
> ZONE_DEVICE pages only use pgmap. Other 4 words[16/32 bytes] don't use.
> So the second/third word will be used as 'struct list_head ' which list
> in buddy. The fourth word(that is normal struct page::index) store pgoff
> which the page-offset in the dax device. And the fifth word (that is
> normal struct page::private) store order of buddy. page_type will be used
> to store buddy flags.
>
> Signed-off-by: Jianpeng Ma <jianpeng.ma@xxxxxxxxx>
> Co-authored-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx>
> ---
> drivers/md/bcache/nvm-pages.c | 142 +++++++++++++++++++++++++++++++-
> drivers/md/bcache/nvm-pages.h | 6 ++
> include/uapi/linux/bcache-nvm.h | 8 ++
> 3 files changed, 152 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/md/bcache/nvm-pages.c b/drivers/md/bcache/nvm-pages.c
> index 9335371c9d91..1f99965920a1 100644
> --- a/drivers/md/bcache/nvm-pages.c
> +++ b/drivers/md/bcache/nvm-pages.c
> @@ -41,6 +41,10 @@ static void release_nvm_namespaces(struct bch_nvm_set *nvm_set)
> for (i = 0; i < nvm_set->total_namespaces_nr; i++) {
> ns = nvm_set->nss[i];
> if (ns) {
> + kvfree(ns->pages_bitmap);
> + if (ns->pgalloc_recs_bitmap)
> + bitmap_free(ns->pgalloc_recs_bitmap);
> +
> blkdev_put(ns->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXEC);
> kfree(ns);
> }
> @@ -55,17 +59,122 @@ static void release_nvm_set(struct bch_nvm_set *nvm_set)
> kfree(nvm_set);
> }
>
> +static struct page *nvm_vaddr_to_page(struct bch_nvm_namespace *ns, void *addr)
> +{
> + return virt_to_page(addr);
> +}
> +
> +static void *nvm_pgoff_to_vaddr(struct bch_nvm_namespace *ns, pgoff_t pgoff)
> +{
> + return ns->kaddr + (pgoff << PAGE_SHIFT);
> +}
> +
> +static inline void remove_owner_space(struct bch_nvm_namespace *ns,
> + pgoff_t pgoff, u32 nr)
> +{
> + bitmap_set(ns->pages_bitmap, pgoff, nr);
> +}
> +
> static int init_owner_info(struct bch_nvm_namespace *ns)
> {
> struct bch_owner_list_head *owner_list_head = ns->sb->owner_list_head;
> + struct bch_nvm_pgalloc_recs *sys_recs;
> + int i, j, k, rc = 0;
>
> mutex_lock(&only_set->lock);
> only_set->owner_list_head = owner_list_head;
> only_set->owner_list_size = owner_list_head->size;
> only_set->owner_list_used = owner_list_head->used;
> +
> + /*remove used space*/
> + remove_owner_space(ns, 0, ns->pages_offset/ns->page_size);
> +
> + sys_recs = ns->kaddr + BCH_NVM_PAGES_SYS_RECS_HEAD_OFFSET;
> + // suppose no hole in array
We don't use such code comments format, please follow the comments style
of existing bcache code.
There are also other locations using "//" for code comments, they should
be modified as well.
Thanks.
Coly Li
[snipped]
