Re: [PATCH 07/20] bcache: add initial data structures for nvm pages

[Jens Axboe <axboe@kernel.dk>]

On 2/9/21 10:07 PM, Coly Li wrote:
> +struct bch_nvm_pgalloc_recs {
> +union {
> +	struct {
> +		struct bch_nvm_pages_owner_head	*owner;
> +		struct bch_nvm_pgalloc_recs	*next;
> +		__u8				magic[16];
> +		__u8				owner_uuid[16];
> +		__u32				size;
> +		__u32				used;
> +		__u64				_pad[4];
> +		struct bch_pgalloc_rec		recs[];
> +	};
> +	__u8	pad[8192];
> +};
> +};

This doesn't look right in a user header, any user API should be 32-bit
and 64-bit agnostic.

> +struct bch_nvm_pages_owner_head {
> +	__u8			uuid[16];
> +	char			label[BCH_NVM_PAGES_LABEL_SIZE];
> +	/* Per-namespace own lists */
> +	struct bch_nvm_pgalloc_recs	*recs[BCH_NVM_PAGES_NAMESPACES_MAX];
> +};

Same here.

> +/* heads[0] is always for nvm_pages internal usage */
> +struct bch_owner_list_head {
> +union {
> +	struct {
> +		__u32				size;
> +		__u32				used;
> +		__u64				_pad[4];
> +		struct bch_nvm_pages_owner_head	heads[];
> +	};
> +	__u8	pad[8192];
> +};
> +};

And here.

> +#define BCH_MAX_OWNER_LIST				\
> +	((sizeof(struct bch_owner_list_head) -		\
> +	 offsetof(struct bch_owner_list_head, heads)) /	\
> +	 sizeof(struct bch_nvm_pages_owner_head))
> +
> +/* The on-media bit order is local CPU order */
> +struct bch_nvm_pages_sb {
> +	__u64			csum;
> +	__u64			ns_start;
> +	__u64			sb_offset;
> +	__u64			version;
> +	__u8			magic[16];
> +	__u8			uuid[16];
> +	__u32			page_size;
> +	__u32			total_namespaces_nr;
> +	__u32			this_namespace_nr;
> +	union {
> +		__u8		set_uuid[16];
> +		__u64		set_magic;
> +	};

This doesn't look like it packs right either.

> +
> +	__u64			flags;
> +	__u64			seq;
> +
> +	__u64			feature_compat;
> +	__u64			feature_incompat;
> +	__u64			feature_ro_compat;
> +
> +	/* For allocable nvm pages from buddy systems */
> +	__u64			pages_offset;
> +	__u64			pages_total;
> +
> +	__u64			pad[8];
> +
> +	/* Only on the first name space */
> +	struct bch_owner_list_head	*owner_list_head;

And here's another pointer...

-- 
Jens Axboe