diff --git a/nvm_pages.h b/nvm_pages.h
new file mode 100644
index 0000000..1ed18a8
--- /dev/null
+++ b/nvm_pages.h
@@ -0,0 +1,187 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _BCACHE_NVM_PAGES_H
+#define _BCACHE_NVM_PAGES_H
+
+/*
+ * - struct bch_nvm_pages_sb
+ *   This is the super block allocated on each nvmdimm name space. A nvdimm
+ * set may have multiple namespaces, bch_nvm_pages_sb->set_uuid is used to
+ * mark which nvmdimm set this name space belongs to. Normally we will use
+ * the bcache's cache set UUID to initialize this uuid, to connect this nvdimm
+ * set to a specified bcache cache set.
+ *
+ * - struct bch_owner_list_head
+ *   This is a table for all heads of all owner lists. A owner list records
+ * which page(s) allocated to which owner. After reboot from power failure,
+ * the ownwer may find all its requested and allocated pages from the owner
+ * list by a handler which is converted by a UUID.
+ *
+ * - struct bch_nvm_pages_owner_head
+ *   This is a head of an owner list. Each owner only has one owner list,
+ * and a nvm page only belongs to an specific owner. uuid[] will be set to
+ * owner's uuid, for bcache it is the bcache's cache set uuid. label is not
+ * mandatory, it is a human-readable string for debug purpose. The pointer
+ * recs references to separated nvm page which hold the table of struct
+ * nvm_pgalloc_rec.
+ *
+ *- struct bch_nvm_pgalloc_recs
+ *  This structure occupies a whole page, owner_uuid should match the uuid
+ * in struct bch_nvm_pages_owner_head. recs[] is the real table contains all
+ * allocated records.
+ *
+ * - struct bch_nvm_pgalloc_rec
+ *   Each structure records a range of allocated nvm pages. pgoff is offset
+ * in unit of page size of this allocated nvm page range. The adjoint page
+ * ranges of same owner can be merged into a larger one, therefore pages_nr
+ * is NOT always power of 2.
+ *
+ *
+ * Memory layout on nvdimm namespace 0
+ *
+ *    0 +----------------------------+
+ *      |                            |
+ *  4KB +----------------------------+
+ *      |   bch_nvme_pages_sb        |
+ *  8KB +----------------------------+ <--- bch_nvme_pages_sb.owner_list_head
+ *      |   bch_owner_list_head      |
+ *      |                            |
+ * 16KB +----------------------------+ <--- bch_owner_list_head.heads[0].recs[0]
+ *      |   bch_nvm_pgalloc_recs     |
+ *      | (nvm pages internal usage) |
+ * 24KB +----------------------------+
+ *      |                            |
+ *      |                            |
+ * 1MB  +----------------------------+
+ *      |    allocable nvm pages     |
+ *      |    for buddy allocator     |
+ * end  +----------------------------+
+ *
+ *
+ *
+ * Memory layout on nvdimm namespace N
+ * (doesn't have owner list)
+ *
+ *    0 +----------------------------+
+ *      |                            |
+ *  4KB +----------------------------+
+ *      |     bch_nvme_pages_sb      |
+ *  8KB +----------------------------+
+ *      |                            |
+ *      |                            |
+ *      |                            |
+ *      |                            |
+ *      |                            |
+ *      |                            |
+ * 1MB  +----------------------------+
+ *      |    allocable nvm pages     |
+ *      |    for buddy allocator     |
+ * end  +----------------------------+
+ *
+
+ */
+
+#include <limits.h>
+#include <linux/types.h>
+
+/* In sectors */
+#define BCH_NVM_PAGES_SB_OFFSET			4096
+#define BCH_NVM_PAGES_OFFSET			(16 << 20)
+
+#define BCH_NVM_PAGES_LABEL_SIZE		32
+#define BCH_NVM_PAGES_NAMESPACES_MAX		8
+
+#define BCH_NVM_PAGES_OWNER_LIST_HEAD_OFFSET	(8<<10)
+#define BCH_NVM_PAGES_SYS_RECS_HEAD_OFFSET	(16<<10)
+
+#define BCH_NVM_PAGES_SB_VERSION		0
+#define BCH_NVM_PAGES_SB_VERSION_MAX		0
+
+static const char bch_nvm_pages_magic[] = {
+	0x17, 0xbd, 0x53, 0x7f, 0x1b, 0x23, 0xd6, 0x83,
+	0x46, 0xa4, 0xf8, 0x28, 0x17, 0xda, 0xec, 0xa9 };
+static const char bch_nvm_pages_pgalloc_magic[] = {
+	0x39, 0x25, 0x3f, 0xf7, 0x27, 0x17, 0xd0, 0xb9,
+	0x10, 0xe6, 0xd2, 0xda, 0x38, 0x68, 0x26, 0xae };
+
+struct bch_nvm_pgalloc_rec {
+	__u32			pgoff;
+	__u32			nr;
+};
+
+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_nvm_pgalloc_rec	recs[];
+	};
+	__u8	pad[8192];
+};
+};
+
+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];
+};
+
+/* 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];
+};
+};
+
+
+/* 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;
+	};
+
+	__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;
+
+	/* Just for csum_set() */
+	__u32			keys;
+	__u64			d[0];
+};
+
+
+#endif
