[RFC v2 04/83] NOVA inode definition.

[Andiry Xu <jix024@eng.ucsd.edu>]

From: Andiry Xu <jix024@cs.ucsd.edu>

inode.h defines the non-volatile and volatile NOVA inode data structures.

The non-volatile NOVA inode (nova_inode) is aligned to 128 bytes and contains
file/directory metadata information. The most important fields
are log_head and log_tail. log_head points to the start of
the log, and log_tail points to the end of the latest committed
log entry. NOVA make updates to the inode by appending
to the log tail and update the log_tail pointer atomically.

The volatile NOVA inode (nova_inode_info) contains necessary
information to limit access to the non-volatile NOVA inode during runtime.
It has a radix tree to map file offset or filenames to the corresponding
log entries.

Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
---
 fs/nova/inode.h | 187 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 187 insertions(+)
 create mode 100644 fs/nova/inode.h

diff --git a/fs/nova/inode.h b/fs/nova/inode.h
new file mode 100644
index 0000000..f9187e3
--- /dev/null
+++ b/fs/nova/inode.h
@@ -0,0 +1,187 @@
+#ifndef __INODE_H
+#define __INODE_H
+
+struct nova_inode_info_header;
+struct nova_inode;
+
+#include "super.h"
+
+enum nova_new_inode_type {
+	TYPE_CREATE = 0,
+	TYPE_MKNOD,
+	TYPE_SYMLINK,
+	TYPE_MKDIR
+};
+
+
+/*
+ * Structure of an inode in PMEM
+ * Keep the inode size to within 120 bytes: We use the last eight bytes
+ * as inode table tail pointer.
+ */
+struct nova_inode {
+
+	/* first 40 bytes */
+	u8	i_rsvd;		 /* reserved. used to be checksum */
+	u8	valid;		 /* Is this inode valid? */
+	u8	deleted;	 /* Is this inode deleted? */
+	u8	i_blk_type;	 /* data block size this inode uses */
+	__le32	i_flags;	 /* Inode flags */
+	__le64	i_size;		 /* Size of data in bytes */
+	__le32	i_ctime;	 /* Inode modification time */
+	__le32	i_mtime;	 /* Inode b-tree Modification time */
+	__le32	i_atime;	 /* Access time */
+	__le16	i_mode;		 /* File mode */
+	__le16	i_links_count;	 /* Links count */
+
+	__le64	i_xattr;	 /* Extended attribute block */
+
+	/* second 40 bytes */
+	__le32	i_uid;		 /* Owner Uid */
+	__le32	i_gid;		 /* Group Id */
+	__le32	i_generation;	 /* File version (for NFS) */
+	__le32	i_create_time;	 /* Create time */
+	__le64	nova_ino;	 /* nova inode number */
+
+	__le64	log_head;	 /* Log head pointer */
+	__le64	log_tail;	 /* Log tail pointer */
+
+	/* last 40 bytes */
+	__le64	create_epoch_id; /* Transaction ID when create */
+	__le64	delete_epoch_id; /* Transaction ID when deleted */
+
+	struct {
+		__le32 rdev;	 /* major/minor # */
+	} dev;			 /* device inode */
+
+	__le32	csum;            /* CRC32 checksum */
+
+	/* Leave 8 bytes for inode table tail pointer */
+} __attribute((__packed__));
+
+/*
+ * NOVA-specific inode state kept in DRAM
+ */
+struct nova_inode_info_header {
+	/* For files, tree holds a map from file offsets to
+	 * write log entries.
+	 *
+	 * For directories, tree holds a map from a hash of the file name to
+	 * dentry log entry.
+	 */
+	struct radix_tree_root tree;
+	struct rw_semaphore i_sem;	/* Protect log and tree */
+	unsigned short i_mode;		/* Dir or file? */
+	unsigned int i_flags;
+	unsigned long log_pages;	/* Num of log pages */
+	unsigned long i_size;
+	unsigned long i_blocks;
+	unsigned long ino;
+	unsigned long pi_addr;
+	unsigned long valid_entries;	/* For thorough GC */
+	unsigned long num_entries;	/* For thorough GC */
+	u64 last_setattr;		/* Last setattr entry */
+	u64 last_link_change;		/* Last link change entry */
+	u64 last_dentry;		/* Last updated dentry */
+	u64 trans_id;			/* Transaction ID */
+	u64 log_head;			/* Log head pointer */
+	u64 log_tail;			/* Log tail pointer */
+	u8  i_blk_type;
+};
+
+/*
+ * DRAM state for inodes
+ */
+struct nova_inode_info {
+	struct nova_inode_info_header header;
+	struct inode vfs_inode;
+};
+
+
+static inline struct nova_inode_info *NOVA_I(struct inode *inode)
+{
+	return container_of(inode, struct nova_inode_info, vfs_inode);
+}
+
+static inline void sih_lock(struct nova_inode_info_header *header)
+{
+	down_write(&header->i_sem);
+}
+
+static inline void sih_unlock(struct nova_inode_info_header *header)
+{
+	up_write(&header->i_sem);
+}
+
+static inline void sih_lock_shared(struct nova_inode_info_header *header)
+{
+	down_read(&header->i_sem);
+}
+
+static inline void sih_unlock_shared(struct nova_inode_info_header *header)
+{
+	up_read(&header->i_sem);
+}
+
+static inline unsigned int
+nova_inode_blk_shift(struct nova_inode_info_header *sih)
+{
+	return blk_type_to_shift[sih->i_blk_type];
+}
+
+static inline uint32_t nova_inode_blk_size(struct nova_inode_info_header *sih)
+{
+	return blk_type_to_size[sih->i_blk_type];
+}
+
+static inline u64 nova_get_reserved_inode_addr(struct super_block *sb,
+	u64 inode_number)
+{
+	return (NOVA_DEF_BLOCK_SIZE_4K * RESERVE_INODE_START) +
+			inode_number * NOVA_INODE_SIZE;
+}
+
+static inline struct nova_inode *nova_get_reserved_inode(struct super_block *sb,
+	u64 inode_number)
+{
+	struct nova_sb_info *sbi = NOVA_SB(sb);
+	u64 addr;
+
+	addr = nova_get_reserved_inode_addr(sb, inode_number);
+
+	return (struct nova_inode *)(sbi->virt_addr + addr);
+}
+
+static inline struct nova_inode *nova_get_inode_by_ino(struct super_block *sb,
+						  u64 ino)
+{
+	if (ino == 0 || ino >= NOVA_NORMAL_INODE_START)
+		return NULL;
+
+	return nova_get_reserved_inode(sb, ino);
+}
+
+static inline struct nova_inode *nova_get_inode(struct super_block *sb,
+	struct inode *inode)
+{
+	struct nova_inode_info *si = NOVA_I(inode);
+	struct nova_inode_info_header *sih = &si->header;
+	struct nova_inode fake_pi;
+	void *addr;
+	int rc;
+
+	addr = nova_get_block(sb, sih->pi_addr);
+	rc = memcpy_mcsafe(&fake_pi, addr, sizeof(struct nova_inode));
+	if (rc)
+		return NULL;
+
+	return (struct nova_inode *)addr;
+}
+
+static inline int nova_persist_inode(struct nova_inode *pi)
+{
+	nova_flush_buffer(pi, sizeof(struct nova_inode), 1);
+	return 0;
+}
+
+#endif
-- 
2.7.4