text: /*
   * fs/f2fs/f2fs.h
   *
   * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   *             http://www.samsung.com/
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  #ifndef _LINUX_F2FS_H
  #define _LINUX_F2FS_H
  
  #include <linux/types.h>
  #include <linux/page-flags.h>
  #include <linux/buffer_head.h>
  #include <linux/slab.h>
  #include <linux/crc32.h>
  #include <linux/magic.h>
  #include <linux/kobject.h>
  #include <linux/sched.h>
  
  #ifdef CONFIG_F2FS_CHECK_FS
  #define f2fs_bug_on(condition)	BUG_ON(condition)
  #define f2fs_down_write(x, y)	down_write_nest_lock(x, y)
  #else
  #define f2fs_bug_on(condition)
  #define f2fs_down_write(x, y)	down_write(x)
  #endif
  
  /*
   * For mount options
   */
  #define F2FS_MOUNT_BG_GC		0x00000001
  #define F2FS_MOUNT_DISABLE_ROLL_FORWARD	0x00000002
  #define F2FS_MOUNT_DISCARD		0x00000004
  #define F2FS_MOUNT_NOHEAP		0x00000008
  #define F2FS_MOUNT_XATTR_USER		0x00000010
  #define F2FS_MOUNT_POSIX_ACL		0x00000020
  #define F2FS_MOUNT_DISABLE_EXT_IDENTIFY	0x00000040
  #define F2FS_MOUNT_INLINE_XATTR		0x00000080
  #define F2FS_MOUNT_INLINE_DATA		0x00000100
  
  #define clear_opt(sbi, option)	(sbi->mount_opt.opt &= ~F2FS_MOUNT_##option)
  #define set_opt(sbi, option)	(sbi->mount_opt.opt |= F2FS_MOUNT_##option)
  #define test_opt(sbi, option)	(sbi->mount_opt.opt & F2FS_MOUNT_##option)
  
  #define ver_after(a, b)	(typecheck(unsigned long long, a) &&		\
  		typecheck(unsigned long long, b) &&			\
  		((long long)((a) - (b)) > 0))
  
  typedef u32 block_t;	/*
  			 * should not change u32, since it is the on-disk block
  			 * address format, __le32.
  			 */
  typedef u32 nid_t;
  
  struct f2fs_mount_info {
  	unsigned int	opt;
  };
  
  #define CRCPOLY_LE 0xedb88320
  
  static inline __u32 f2fs_crc32(void *buf, size_t len)
  {
  	unsigned char *p = (unsigned char *)buf;
  	__u32 crc = F2FS_SUPER_MAGIC;
  	int i;
  
  	while (len--) {
  		crc ^= *p++;
  		for (i = 0; i < 8; i++)
  			crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
  	}
  	return crc;
  }
  
  static inline bool f2fs_crc_valid(__u32 blk_crc, void *buf, size_t buf_size)
  {
  	return f2fs_crc32(buf, buf_size) == blk_crc;
  }
  
  /*
   * For checkpoint manager
   */
  enum {
  	NAT_BITMAP,
  	SIT_BITMAP
  };
  
  /* for the list of orphan inodes */
  struct orphan_inode_entry {
  	struct list_head list;	/* list head */
  	nid_t ino;		/* inode number */
  };
  
  /* for the list of directory inodes */
  struct dir_inode_entry {
  	struct list_head list;	/* list head */
  	struct inode *inode;	/* vfs inode pointer */
  };
  
  /* for the list of blockaddresses to be discarded */
  struct discard_entry {
  	struct list_head list;	/* list head */
  	block_t blkaddr;	/* block address to be discarded */
  	int len;		/* # of consecutive blocks of the discard */
  };
  
  /* for the list of fsync inodes, used only during recovery */
  struct fsync_inode_entry {
  	struct list_head list;	/* list head */
  	struct inode *inode;	/* vfs inode pointer */
  	block_t blkaddr;	/* block address locating the last inode */
  };
  
  #define nats_in_cursum(sum)		(le16_to_cpu(sum->n_nats))
  #define sits_in_cursum(sum)		(le16_to_cpu(sum->n_sits))
  
  #define nat_in_journal(sum, i)		(sum->nat_j.entries[i].ne)
  #define nid_in_journal(sum, i)		(sum->nat_j.entries[i].nid)
  #define sit_in_journal(sum, i)		(sum->sit_j.entries[i].se)
  #define segno_in_journal(sum, i)	(sum->sit_j.entries[i].segno)
  
  static inline int update_nats_in_cursum(struct f2fs_summary_block *rs, int i)
  {
  	int before = nats_in_cursum(rs);
  	rs->n_nats = cpu_to_le16(before + i);
  	return before;
  }
  
  static inline int update_sits_in_cursum(struct f2fs_summary_block *rs, int i)
  {
  	int before = sits_in_cursum(rs);
  	rs->n_sits = cpu_to_le16(before + i);
  	return before;
  }
  
  /*
   * ioctl commands
   */
  #define F2FS_IOC_GETFLAGS               FS_IOC_GETFLAGS
  #define F2FS_IOC_SETFLAGS               FS_IOC_SETFLAGS
  
  #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
  /*
   * ioctl commands in 32 bit emulation
   */
  #define F2FS_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
  #define F2FS_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
  #endif
  
  /*
   * For INODE and NODE manager
   */
  /*
   * XATTR_NODE_OFFSET stores xattrs to one node block per file keeping -1
   * as its node offset to distinguish from index node blocks.
   * But some bits are used to mark the node block.
   */
  #define XATTR_NODE_OFFSET	((((unsigned int)-1) << OFFSET_BIT_SHIFT) \
  				>> OFFSET_BIT_SHIFT)
  enum {
  	ALLOC_NODE,			/* allocate a new node page if needed */
  	LOOKUP_NODE,			/* look up a node without readahead */
  	LOOKUP_NODE_RA,			/*
  					 * look up a node with readahead called
  					 * by get_data_block.
  					 */
  };
  
  #define F2FS_LINK_MAX		32000	/* maximum link count per file */
  
  /* for in-memory extent cache entry */
  #define F2FS_MIN_EXTENT_LEN	16	/* minimum extent length */
  
  struct extent_info {
  	rwlock_t ext_lock;	/* rwlock for consistency */
  	unsigned int fofs;	/* start offset in a file */
  	u32 blk_addr;		/* start block address of the extent */
  	unsigned int len;	/* length of the extent */
  };
  
  /*
   * i_advise uses FADVISE_XXX_BIT. We can add additional hints later.
   */
  #define FADVISE_COLD_BIT	0x01
  #define FADVISE_LOST_PINO_BIT	0x02
  
  struct f2fs_inode_info {
  	struct inode vfs_inode;		/* serve a vfs inode */
  	unsigned long i_flags;		/* keep an inode flags for ioctl */
  	unsigned char i_advise;		/* use to give file attribute hints */
  	unsigned int i_current_depth;	/* use only in directory structure */
  	unsigned int i_pino;		/* parent inode number */
  	umode_t i_acl_mode;		/* keep file acl mode temporarily */
  
  	/* Use below internally in f2fs*/
  	unsigned long flags;		/* use to pass per-file flags */
  	atomic_t dirty_dents;		/* # of dirty dentry pages */
  	f2fs_hash_t chash;		/* hash value of given file name */
  	unsigned int clevel;		/* maximum level of given file name */
  	nid_t i_xattr_nid;		/* node id that contains xattrs */
  	unsigned long long xattr_ver;	/* cp version of xattr modification */
  	struct extent_info ext;		/* in-memory extent cache entry */
  };
  
  static inline void get_extent_info(struct extent_info *ext,
  					struct f2fs_extent i_ext)
  {
  	write_lock(&ext->ext_lock);
  	ext->fofs = le32_to_cpu(i_ext.fofs);
  	ext->blk_addr = le32_to_cpu(i_ext.blk_addr);
  	ext->len = le32_to_cpu(i_ext.len);
  	write_unlock(&ext->ext_lock);
  }
  
  static inline void set_raw_extent(struct extent_info *ext,
  					struct f2fs_extent *i_ext)
  {
  	read_lock(&ext->ext_lock);
  	i_ext->fofs = cpu_to_le32(ext->fofs);
  	i_ext->blk_addr = cpu_to_le32(ext->blk_addr);
  	i_ext->len = cpu_to_le32(ext->len);
  	read_unlock(&ext->ext_lock);
  }
  
  struct f2fs_nm_info {
  	block_t nat_blkaddr;		/* base disk address of NAT */
  	nid_t max_nid;			/* maximum possible node ids */
  	nid_t next_scan_nid;		/* the next nid to be scanned */
  
  	/* NAT cache management */
  	struct radix_tree_root nat_root;/* root of the nat entry cache */
  	rwlock_t nat_tree_lock;		/* protect nat_tree_lock */
  	unsigned int nat_cnt;		/* the # of cached nat entries */
  	struct list_head nat_entries;	/* cached nat entry list (clean) */
  	struct list_head dirty_nat_entries; /* cached nat entry list (dirty) */
  
  	/* free node ids management */
  	struct list_head free_nid_list;	/* a list for free nids */
  	spinlock_t free_nid_list_lock;	/* protect free nid list */
  	unsigned int fcnt;		/* the number of free node id */
  	struct mutex build_lock;	/* lock for build free nids */
  
  	/* for checkpoint */
  	char *nat_bitmap;		/* NAT bitmap pointer */
  	int bitmap_size;		/* bitmap size */
  };
  
  /*
   * this structure is used as one of function parameters.
   * all the information are dedicated to a given direct node block determined
   * by the data offset in a file.
   */
  struct dnode_of_data {
  	struct inode *inode;		/* vfs inode pointer */
  	struct page *inode_page;	/* its inode page, NULL is possible */
  	struct page *node_page;		/* cached direct node page */
  	nid_t nid;			/* node id of the direct node block */
  	unsigned int ofs_in_node;	/* data offset in the node page */
  	bool inode_page_locked;		/* inode page is locked or not */
  	block_t	data_blkaddr;		/* block address of the node block */
  };
  
  static inline void set_new_dnode(struct dnode_of_data *dn, struct inode *inode,
  		struct page *ipage, struct page *npage, nid_t nid)
  {
  	memset(dn, 0, sizeof(*dn));
  	dn->inode = inode;
  	dn->inode_page = ipage;
  	dn->node_page = npage;
  	dn->nid = nid;
  }
  
  /*
   * For SIT manager
   *
   * By default, there are 6 active log areas across the whole main area.
   * When considering hot and cold data separation to reduce cleaning overhead,
   * we split 3 for data logs and 3 for node logs as hot, warm, and cold types,
   * respectively.
   * In the current design, you should not change the numbers intentionally.
   * Instead, as a mount option such as active_logs=x, you can use 2, 4, and 6
   * logs individually according to the underlying devices. (default: 6)
   * Just in case, on-disk layout covers maximum 16 logs that consist of 8 for
   * data and 8 for node logs.
   */
  #define	NR_CURSEG_DATA_TYPE	(3)
  #define NR_CURSEG_NODE_TYPE	(3)
  #define NR_CURSEG_TYPE	(NR_CURSEG_DATA_TYPE + NR_CURSEG_NODE_TYPE)
  
  enum {
  	CURSEG_HOT_DATA	= 0,	/* directory entry blocks */
  	CURSEG_WARM_DATA,	/* data blocks */
  	CURSEG_COLD_DATA,	/* multimedia or GCed data blocks */
  	CURSEG_HOT_NODE,	/* direct node blocks of directory files */
  	CURSEG_WARM_NODE,	/* direct node blocks of normal files */
  	CURSEG_COLD_NODE,	/* indirect node blocks */
  	NO_CHECK_TYPE
  };
  
  struct f2fs_sm_info {
  	struct sit_info *sit_info;		/* whole segment information */
  	struct free_segmap_info *free_info;	/* free segment information */
  	struct dirty_seglist_info *dirty_info;	/* dirty segment information */
  	struct curseg_info *curseg_array;	/* active segment information */
  
  	struct list_head wblist_head;	/* list of under-writeback pages */
  	spinlock_t wblist_lock;		/* lock for checkpoint */
  
  	block_t seg0_blkaddr;		/* block address of 0'th segment */
  	block_t main_blkaddr;		/* start block address of main area */
  	block_t ssa_blkaddr;		/* start block address of SSA area */
  
  	unsigned int segment_count;	/* total # of segments */
  	unsigned int main_segments;	/* # of segments in main area */
  	unsigned int reserved_segments;	/* # of reserved segments */
  	unsigned int ovp_segments;	/* # of overprovision segments */
  
  	/* a threshold to reclaim prefree segments */
  	unsigned int rec_prefree_segments;
  
  	/* for small discard management */
  	struct list_head discard_list;		/* 4KB discard list */
  	int nr_discards;			/* # of discards in the list */
  	int max_discards;			/* max. discards to be issued */
  
  	unsigned int ipu_policy;	/* in-place-update policy */
  	unsigned int min_ipu_util;	/* in-place-update threshold */
  };
  
  /*
   * For superblock
   */
  /*
   * COUNT_TYPE for monitoring
   *
   * f2fs monitors the number of several block types such as on-writeback,
   * dirty dentry blocks, dirty node blocks, and dirty meta blocks.
   */
  enum count_type {
  	F2FS_WRITEBACK,
  	F2FS_DIRTY_DENTS,
  	F2FS_DIRTY_NODES,
  	F2FS_DIRTY_META,
  	NR_COUNT_TYPE,
  };
  
  /*
   * The below are the page types of bios used in submti_bio().
   * The available types are:
   * DATA			User data pages. It operates as async mode.
   * NODE			Node pages. It operates as async mode.
   * META			FS metadata pages such as SIT, NAT, CP.
   * NR_PAGE_TYPE		The number of page types.
   * META_FLUSH		Make sure the previous pages are written
   *			with waiting the bio's completion
   * ...			Only can be used with META.
   */
  #define PAGE_TYPE_OF_BIO(type)	((type) > META ? META : (type))
  enum page_type {
  	DATA,
  	NODE,
  	META,
  	NR_PAGE_TYPE,
  	META_FLUSH,
  };
  
  struct f2fs_io_info {
  	enum page_type type;	/* contains DATA/NODE/META/META_FLUSH */
  	int rw;			/* contains R/RS/W/WS with REQ_META/REQ_PRIO */
  };
  
  #define is_read_io(rw)	(((rw) & 1) == READ)
  struct f2fs_bio_info {
  	struct f2fs_sb_info *sbi;	/* f2fs superblock */
  	struct bio *bio;		/* bios to merge */
  	sector_t last_block_in_bio;	/* last block number */
  	struct f2fs_io_info fio;	/* store buffered io info. */
  	struct mutex io_mutex;		/* mutex for bio */
  };
  
  struct f2fs_sb_info {
  	unsigned long long gc_fg_count;
  	unsigned long long gc_bg_count;
  
  	struct super_block *sb;			/* pointer to VFS super block */
  	struct proc_dir_entry *s_proc;		/* proc entry */
  	struct buffer_head *raw_super_buf;	/* buffer head of raw sb */
  	struct f2fs_super_block *raw_super;	/* raw super block pointer */
  	int s_dirty;				/* dirty flag for checkpoint */
  
  	/* for node-related operations */
  	struct f2fs_nm_info *nm_info;		/* node manager */
  	struct inode *node_inode;		/* cache node blocks */
  
  	/* for segment-related operations */
  	struct f2fs_sm_info *sm_info;		/* segment manager */
  
  	/* for bio operations */
  	struct f2fs_bio_info read_io;			/* for read bios */
  	struct f2fs_bio_info write_io[NR_PAGE_TYPE];	/* for write bios */
  
  	/* for checkpoint */
  	struct f2fs_checkpoint *ckpt;		/* raw checkpoint pointer */
  	struct inode *meta_inode;		/* cache meta blocks */
  	struct mutex cp_mutex;			/* checkpoint procedure lock */
  	struct rw_semaphore cp_rwsem;		/* blocking FS operations */
  	struct mutex node_write;		/* locking node writes */
  	struct mutex writepages;		/* mutex for writepages() */
  	bool por_doing;				/* recovery is doing or not */
  	bool on_build_free_nids;		/* build_free_nids is doing */
  	wait_queue_head_t cp_wait;
  
  	/* for orphan inode management */
  	struct list_head orphan_inode_list;	/* orphan inode list */
  	spinlock_t orphan_inode_lock;		/* for orphan inode list */
  	unsigned int n_orphans;			/* # of orphan inodes */
  	unsigned int max_orphans;		/* max orphan inodes */
  
  	/* for directory inode management */
  	struct list_head dir_inode_list;	/* dir inode list */
  	spinlock_t dir_inode_lock;		/* for dir inode list lock */
  
  	/* basic file system units */
  	unsigned int log_sectors_per_block;	/* log2 sectors per block */
  	unsigned int log_blocksize;		/* log2 block size */
  	unsigned int blocksize;			/* block size */
  	unsigned int root_ino_num;		/* root inode number*/
  	unsigned int node_ino_num;		/* node inode number*/
  	unsigned int meta_ino_num;		/* meta inode number*/
  	unsigned int log_blocks_per_seg;	/* log2 blocks per segment */
  	unsigned int blocks_per_seg;		/* blocks per segment */
  	unsigned int segs_per_sec;		/* segments per section */
  	unsigned int secs_per_zone;		/* sections per zone */
  	unsigned int total_sections;		/* total section count */
  	unsigned int total_node_count;		/* total node block count */
  	unsigned int total_valid_node_count;	/* valid node block count */
  	unsigned int total_valid_inode_count;	/* valid inode count */
  	int active_logs;			/* # of active logs */
  
  	block_t user_block_count;		/* # of user blocks */
  	block_t total_valid_block_count;	/* # of valid blocks */
  	block_t alloc_valid_block_count;	/* # of allocated blocks */
  	block_t last_valid_block_count;		/* for recovery */
  	u32 s_next_generation;			/* for NFS support */
  	atomic_t nr_pages[NR_COUNT_TYPE];	/* # of pages, see count_type */
  
  	struct f2fs_mount_info mount_opt;	/* mount options */
  
  	/* for cleaning operations */
  	struct mutex gc_mutex;			/* mutex for GC */
  	struct f2fs_gc_kthread	*gc_thread;	/* GC thread */
  	unsigned int cur_victim_sec;		/* current victim section num */
  
  	/* maximum # of trials to find a victim segment for SSR and GC */
  	unsigned int max_victim_search;
  
  	/*
  	 * for stat information.
  	 * one is for the LFS mode, and the other is for the SSR mode.
  	 */
  #ifdef CONFIG_F2FS_STAT_FS
  	struct f2fs_stat_info *stat_info;	/* FS status information */
  	unsigned int segment_count[2];		/* # of allocated segments */
  	unsigned int block_count[2];		/* # of allocated blocks */
  	int total_hit_ext, read_hit_ext;	/* extent cache hit ratio */
  	int inline_inode;			/* # of inline_data inodes */
  	int bg_gc;				/* background gc calls */
  	unsigned int n_dirty_dirs;		/* # of dir inodes */
  #endif
  	unsigned int last_victim[2];		/* last victim segment # */
  	spinlock_t stat_lock;			/* lock for stat operations */
  
  	/* For sysfs suppport */
  	struct kobject s_kobj;
  	struct completion s_kobj_unregister;
  };
  
  /*
   * Inline functions
   */
  static inline struct f2fs_inode_info *F2FS_I(struct inode *inode)
  {
  	return container_of(inode, struct f2fs_inode_info, vfs_inode);
  }
  
  static inline struct f2fs_sb_info *F2FS_SB(struct super_block *sb)
  {
  	return sb->s_fs_info;
  }
  
  static inline struct f2fs_super_block *F2FS_RAW_SUPER(struct f2fs_sb_info *sbi)
  {
  	return (struct f2fs_super_block *)(sbi->raw_super);
  }
  
  static inline struct f2fs_checkpoint *F2FS_CKPT(struct f2fs_sb_info *sbi)
  {
  	return (struct f2fs_checkpoint *)(sbi->ckpt);
  }
  
  static inline struct f2fs_node *F2FS_NODE(struct page *page)
  {
  	return (struct f2fs_node *)page_address(page);
  }
  
  static inline struct f2fs_inode *F2FS_INODE(struct page *page)
  {
  	return &((struct f2fs_node *)page_address(page))->i;
  }
  
  static inline struct f2fs_nm_info *NM_I(struct f2fs_sb_info *sbi)
  {
  	return (struct f2fs_nm_info *)(sbi->nm_info);
  }
  
  static inline struct f2fs_sm_info *SM_I(struct f2fs_sb_info *sbi)
  {
  	return (struct f2fs_sm_info *)(sbi->sm_info);
  }
  
  static inline struct sit_info *SIT_I(struct f2fs_sb_info *sbi)
  {
  	return (struct sit_info *)(SM_I(sbi)->sit_info);
  }
  
  static inline struct free_segmap_info *FREE_I(struct f2fs_sb_info *sbi)
  {
  	return (struct free_segmap_info *)(SM_I(sbi)->free_info);
  }
  
  static inline struct dirty_seglist_info *DIRTY_I(struct f2fs_sb_info *sbi)
  {
  	return (struct dirty_seglist_info *)(SM_I(sbi)->dirty_info);
  }
  
  static inline struct address_space *META_MAPPING(struct f2fs_sb_info *sbi)
  {
  	return sbi->meta_inode->i_mapping;
  }
  
  static inline struct address_space *NODE_MAPPING(struct f2fs_sb_info *sbi)
  {
  	return sbi->node_inode->i_mapping;
  }
  
  static inline void F2FS_SET_SB_DIRT(struct f2fs_sb_info *sbi)
  {
  	sbi->s_dirty = 1;
  }
  
  static inline void F2FS_RESET_SB_DIRT(struct f2fs_sb_info *sbi)
  {
  	sbi->s_dirty = 0;
  }
  
  static inline unsigned long long cur_cp_version(struct f2fs_checkpoint *cp)
  {
  	return le64_to_cpu(cp->checkpoint_ver);
  }
  
  static inline bool is_set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
  {
  	unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
  	return ckpt_flags & f;
  }
  
  static inline void set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
  {
  	unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
  	ckpt_flags |= f;
  	cp->ckpt_flags = cpu_to_le32(ckpt_flags);
  }
  
  static inline void clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
  {
  	unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
  	ckpt_flags &= (~f);
  	cp->ckpt_flags = cpu_to_le32(ckpt_flags);
  }
  
  static inline void f2fs_lock_op(struct f2fs_sb_info *sbi)
  {
  	down_read(&sbi->cp_rwsem);
  }
  
  static inline void f2fs_unlock_op(struct f2fs_sb_info *sbi)
  {
  	up_read(&sbi->cp_rwsem);
  }
  
  static inline void f2fs_lock_all(struct f2fs_sb_info *sbi)
  {
  	f2fs_down_write(&sbi->cp_rwsem, &sbi->cp_mutex);
  }
  
  static inline void f2fs_unlock_all(struct f2fs_sb_info *sbi)
  {
  	up_write(&sbi->cp_rwsem);
  }
  
  /*
   * Check whether the given nid is within node id range.
   */
  static inline int check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
  {
  	WARN_ON((nid >= NM_I(sbi)->max_nid));
  	if (unlikely(nid >= NM_I(sbi)->max_nid))
  		return -EINVAL;
  	return 0;
  }
  
  #define F2FS_DEFAULT_ALLOCATED_BLOCKS	1
  
  /*
   * Check whether the inode has blocks or not
   */
  static inline int F2FS_HAS_BLOCKS(struct inode *inode)
  {
  	if (F2FS_I(inode)->i_xattr_nid)
  		return inode->i_blocks > F2FS_DEFAULT_ALLOCATED_BLOCKS + 1;
  	else
  		return inode->i_blocks > F2FS_DEFAULT_ALLOCATED_BLOCKS;
  }
  
  static inline bool inc_valid_block_count(struct f2fs_sb_info *sbi,
  				 struct inode *inode, blkcnt_t count)
  {
  	block_t	valid_block_count;
  
  	spin_lock(&sbi->stat_lock);
  	valid_block_count =
  		sbi->total_valid_block_count + (block_t)count;
  	if (unlikely(valid_block_count > sbi->user_block_count)) {
  		spin_unlock(&sbi->stat_lock);
  		return false;
  	}
  	inode->i_blocks += count;
  	sbi->total_valid_block_count = valid_block_count;
  	sbi->alloc_valid_block_count += (block_t)count;
  	spin_unlock(&sbi->stat_lock);
  	return true;
  }
  
  static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
  						struct inode *inode,
  						blkcnt_t count)
  {
  	spin_lock(&sbi->stat_lock);
  	f2fs_bug_on(sbi->total_valid_block_count < (block_t) count);
  	f2fs_bug_on(inode->i_blocks < count);
  	inode->i_blocks -= count;
  	sbi->total_valid_block_count -= (block_t)count;
  	spin_unlock(&sbi->stat_lock);
  }
  
  static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type)
  {
  	atomic_inc(&sbi->nr_pages[count_type]);
  	F2FS_SET_SB_DIRT(sbi);
  }
  
  static inline void inode_inc_dirty_dents(struct inode *inode)
  {
  	atomic_inc(&F2FS_I(inode)->dirty_dents);
  }
  
  static inline void dec_page_count(struct f2fs_sb_info *sbi, int count_type)
  {
  	atomic_dec(&sbi->nr_pages[count_type]);
  }
  
  static inline void inode_dec_dirty_dents(struct inode *inode)
  {
  	atomic_dec(&F2FS_I(inode)->dirty_dents);
  }
  
  static inline int get_pages(struct f2fs_sb_info *sbi, int count_type)
  {
  	return atomic_read(&sbi->nr_pages[count_type]);
  }
  
  static inline int get_blocktype_secs(struct f2fs_sb_info *sbi, int block_type)
  {
  	unsigned int pages_per_sec = sbi->segs_per_sec *
  					(1 << sbi->log_blocks_per_seg);
  	return ((get_pages(sbi, block_type) + pages_per_sec - 1)
  			>> sbi->log_blocks_per_seg) / sbi->segs_per_sec;
  }
  
  static inline block_t valid_user_blocks(struct f2fs_sb_info *sbi)
  {
  	block_t ret;
  	spin_lock(&sbi->stat_lock);
  	ret = sbi->total_valid_block_count;
  	spin_unlock(&sbi->stat_lock);
  	return ret;
  }
  
  static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
  {
  	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
  
  	/* return NAT or SIT bitmap */
  	if (flag == NAT_BITMAP)
  		return le32_to_cpu(ckpt->nat_ver_bitmap_bytesize);
  	else if (flag == SIT_BITMAP)
  		return le32_to_cpu(ckpt->sit_ver_bitmap_bytesize);
  
  	return 0;
  }
  
  static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
  {
  	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
  	int offset = (flag == NAT_BITMAP) ?
  			le32_to_cpu(ckpt->sit_ver_bitmap_bytesize) : 0;
  	return &ckpt->sit_nat_version_bitmap + offset;
  }
  
  static inline block_t __start_cp_addr(struct f2fs_sb_info *sbi)
  {
  	block_t start_addr;
  	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
  	unsigned long long ckpt_version = cur_cp_version(ckpt);
  
  	start_addr = le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_blkaddr);
  
  	/*
  	 * odd numbered checkpoint should at cp segment 0
  	 * and even segent must be at cp segment 1
  	 */
  	if (!(ckpt_version & 1))
  		start_addr += sbi->blocks_per_seg;
  
  	return start_addr;
  }
  
  static inline block_t __start_sum_addr(struct f2fs_sb_info *sbi)
  {
  	return le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_start_sum);
  }
  
  static inline bool inc_valid_node_count(struct f2fs_sb_info *sbi,
  						struct inode *inode)
  {
  	block_t	valid_block_count;
  	unsigned int valid_node_count;
  
  	spin_lock(&sbi->stat_lock);
  
  	valid_block_count = sbi->total_valid_block_count + 1;
  	if (unlikely(valid_block_count > sbi->user_block_count)) {
  		spin_unlock(&sbi->stat_lock);
  		return false;
  	}
  
  	valid_node_count = sbi->total_valid_node_count + 1;
  	if (unlikely(valid_node_count > sbi->total_node_count)) {
  		spin_unlock(&sbi->stat_lock);
  		return false;
  	}
  
  	if (inode)
  		inode->i_blocks++;
  
  	sbi->alloc_valid_block_count++;
  	sbi->total_valid_node_count++;
  	sbi->total_valid_block_count++;
  	spin_unlock(&sbi->stat_lock);
  
  	return true;
  }
  
  static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
  						struct inode *inode)
  {
  	spin_lock(&sbi->stat_lock);
  
  	f2fs_bug_on(!sbi->total_valid_block_count);
  	f2fs_bug_on(!sbi->total_valid_node_count);
  	f2fs_bug_on(!inode->i_blocks);
  
  	inode->i_blocks--;
  	sbi->total_valid_node_count--;
  	sbi->total_valid_block_count--;
  
  	spin_unlock(&sbi->stat_lock);
  }
  
  static inline unsigned int valid_node_count(struct f2fs_sb_info *sbi)
  {
  	unsigned int ret;
  	spin_lock(&sbi->stat_lock);
  	ret = sbi->total_valid_node_count;
  	spin_unlock(&sbi->stat_lock);
  	return ret;
  }
  
  static inline void inc_valid_inode_count(struct f2fs_sb_info *sbi)
  {
  	spin_lock(&sbi->stat_lock);
  	f2fs_bug_on(sbi->total_valid_inode_count == sbi->total_node_count);
  	sbi->total_valid_inode_count++;
  	spin_unlock(&sbi->stat_lock);
  }
  
  static inline void dec_valid_inode_count(struct f2fs_sb_info *sbi)
  {
  	spin_lock(&sbi->stat_lock);
  	f2fs_bug_on(!sbi->total_valid_inode_count);
  	sbi->total_valid_inode_count--;
  	spin_unlock(&sbi->stat_lock);
  }
  
  static inline unsigned int valid_inode_count(struct f2fs_sb_info *sbi)
  {
  	unsigned int ret;
  	spin_lock(&sbi->stat_lock);
  	ret = sbi->total_valid_inode_count;
  	spin_unlock(&sbi->stat_lock);
  	return ret;
  }
  
  static inline void f2fs_put_page(struct page *page, int unlock)
  {
  	if (!page)
  		return;
  
  	if (unlock) {
  		f2fs_bug_on(!PageLocked(page));
  		unlock_page(page);
  	}
  	page_cache_release(page);
  }
  
  static inline void f2fs_put_dnode(struct dnode_of_data *dn)
  {
  	if (dn->node_page)
  		f2fs_put_page(dn->node_page, 1);
  	if (dn->inode_page && dn->node_page != dn->inode_page)
  		f2fs_put_page(dn->inode_page, 0);
  	dn->node_page = NULL;
  	dn->inode_page = NULL;
  }
  
  static inline struct kmem_cache *f2fs_kmem_cache_create(const char *name,
  					size_t size, void (*ctor)(void *))
  {
  	return kmem_cache_create(name, size, 0, SLAB_RECLAIM_ACCOUNT, ctor);
  }
  
  static inline void *f2fs_kmem_cache_alloc(struct kmem_cache *cachep,
  						gfp_t flags)
  {
  	void *entry;
  retry:
  	entry = kmem_cache_alloc(cachep, flags);
  	if (!entry) {
  		cond_resched();
  		goto retry;
  	}
  
  	return entry;
  }
  
  #define RAW_IS_INODE(p)	((p)->footer.nid == (p)->footer.ino)
  
  static inline bool IS_INODE(struct page *page)
  {
  	struct f2fs_node *p = F2FS_NODE(page);
  	return RAW_IS_INODE(p);
  }
  
  static inline __le32 *blkaddr_in_node(struct f2fs_node *node)
  {
  	return RAW_IS_INODE(node) ? node->i.i_addr : node->dn.addr;
  }
  
  static inline block_t datablock_addr(struct page *node_page,
  		unsigned int offset)
  {
  	struct f2fs_node *raw_node;
  	__le32 *addr_array;
  	raw_node = F2FS_NODE(node_page);
  	addr_array = blkaddr_in_node(raw_node);
  	return le32_to_cpu(addr_array[offset]);
  }
  
  static inline int f2fs_test_bit(unsigned int nr, char *addr)
  {
  	int mask;
  
  	addr += (nr >> 3);
  	mask = 1 << (7 - (nr & 0x07));
  	return mask & *addr;
  }
  
  static inline int f2fs_set_bit(unsigned int nr, char *addr)
  {
  	int mask;
  	int ret;
  
  	addr += (nr >> 3);
  	mask = 1 << (7 - (nr & 0x07));
  	ret = mask & *addr;
  	*addr |= mask;
  	return ret;
  }
  
  static inline int f2fs_clear_bit(unsigned int nr, char *addr)
  {
  	int mask;
  	int ret;
  
  	addr += (nr >> 3);
  	mask = 1 << (7 - (nr & 0x07));
  	ret = mask & *addr;
  	*addr &= ~mask;
  	return ret;
  }
  
  /* used for f2fs_inode_info->flags */
  enum {
  	FI_NEW_INODE,		/* indicate newly allocated inode */
  	FI_DIRTY_INODE,		/* indicate inode is dirty or not */
  	FI_INC_LINK,		/* need to increment i_nlink */
  	FI_ACL_MODE,		/* indicate acl mode */
  	FI_NO_ALLOC,		/* should not allocate any blocks */
  	FI_UPDATE_DIR,		/* should update inode block for consistency */
  	FI_DELAY_IPUT,		/* used for the recovery */
  	FI_NO_EXTENT,		/* not to use the extent cache */
  	FI_INLINE_XATTR,	/* used for inline xattr */
  	FI_INLINE_DATA,		/* used for inline data*/
  };
  
  static inline void set_inode_flag(struct f2fs_inode_info *fi, int flag)
  {
  	set_bit(flag, &fi->flags);
  }
  
  static inline int is_inode_flag_set(struct f2fs_inode_info *fi, int flag)
  {
  	return test_bit(flag, &fi->flags);
  }
  
  static inline void clear_inode_flag(struct f2fs_inode_info *fi, int flag)
  {
  	clear_bit(flag, &fi->flags);
  }
  
  static inline void set_acl_inode(struct f2fs_inode_info *fi, umode_t mode)
  {
  	fi->i_acl_mode = mode;
  	set_inode_flag(fi, FI_ACL_MODE);
  }
  
  static inline int cond_clear_inode_flag(struct f2fs_inode_info *fi, int flag)
  {
  	if (is_inode_flag_set(fi, FI_ACL_MODE)) {
  		clear_inode_flag(fi, FI_ACL_MODE);
  		return 1;
  	}
  	return 0;
  }
  
  static inline void get_inline_info(struct f2fs_inode_info *fi,
  					struct f2fs_inode *ri)
  {
  	if (ri->i_inline & F2FS_INLINE_XATTR)
  		set_inode_flag(fi, FI_INLINE_XATTR);
  	if (ri->i_inline & F2FS_INLINE_DATA)
  		set_inode_flag(fi, FI_INLINE_DATA);
  }
  
  static inline void set_raw_inline(struct f2fs_inode_info *fi,
  					struct f2fs_inode *ri)
  {
  	ri->i_inline = 0;
  
  	if (is_inode_flag_set(fi, FI_INLINE_XATTR))
  		ri->i_inline |= F2FS_INLINE_XATTR;
  	if (is_inode_flag_set(fi, FI_INLINE_DATA))
  		ri->i_inline |= F2FS_INLINE_DATA;
  }
  
  static inline unsigned int addrs_per_inode(struct f2fs_inode_info *fi)
  {
  	if (is_inode_flag_set(fi, FI_INLINE_XATTR))
  		return DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS;
  	return DEF_ADDRS_PER_INODE;
  }
  
  static inline void *inline_xattr_addr(struct page *page)
  {
  	struct f2fs_inode *ri;
  	ri = (struct f2fs_inode *)page_address(page);
  	return (void *)&(ri->i_addr[DEF_ADDRS_PER_INODE -
  					F2FS_INLINE_XATTR_ADDRS]);
  }
  
  static inline int inline_xattr_size(struct inode *inode)
  {
  	if (is_inode_flag_set(F2FS_I(inode), FI_INLINE_XATTR))
  		return F2FS_INLINE_XATTR_ADDRS << 2;
  	else
  		return 0;
  }
  
  static inline int f2fs_has_inline_data(struct inode *inode)
  {
  	return is_inode_flag_set(F2FS_I(inode), FI_INLINE_DATA);
  }
  
  static inline void *inline_data_addr(struct page *page)
  {
  	struct f2fs_inode *ri;
  	ri = (struct f2fs_inode *)page_address(page);
  	return (void *)&(ri->i_addr[1]);
  }
  
  static inline int f2fs_readonly(struct super_block *sb)
  {
  	return sb->s_flags & MS_RDONLY;
  }
  
  #define get_inode_mode(i) \
  	((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
  	 (F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
  
  /*
   * file.c
   */
  int f2fs_sync_file(struct file *, loff_t, loff_t, int);
  void truncate_data_blocks(struct dnode_of_data *);
  int truncate_blocks(struct inode *, u64);
  void f2fs_truncate(struct inode *);
  int f2fs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
  int f2fs_setattr(struct dentry *, struct iattr *);
  int truncate_hole(struct inode *, pgoff_t, pgoff_t);
  int truncate_data_blocks_range(struct dnode_of_data *, int);
  long f2fs_ioctl(struct file *, unsigned int, unsigned long);
  long f2fs_compat_ioctl(struct file *, unsigned int, unsigned long);
  
  /*
   * inode.c
   */
  void f2fs_set_inode_flags(struct inode *);
  struct inode *f2fs_iget(struct super_block *, unsigned long);
  int try_to_free_nats(struct f2fs_sb_info *, int);
  void update_inode(struct inode *, struct page *);
  int update_inode_page(struct inode *);
  int f2fs_write_inode(struct inode *, struct writeback_control *);
  void f2fs_evict_inode(struct inode *);
  
  /*
   * namei.c
   */
  struct dentry *f2fs_get_parent(struct dentry *child);
  
  /*
   * dir.c
   */
  struct f2fs_dir_entry *f2fs_find_entry(struct inode *, struct qstr *,
  							struct page **);
  struct f2fs_dir_entry *f2fs_parent_dir(struct inode *, struct page **);
  ino_t f2fs_inode_by_name(struct inode *, struct qstr *);
  void f2fs_set_link(struct inode *, struct f2fs_dir_entry *,
  				struct page *, struct inode *);
  int update_dent_inode(struct inode *, const struct qstr *);
  int __f2fs_add_link(struct inode *, const struct qstr *, struct inode *);
  void f2fs_delete_entry(struct f2fs_dir_entry *, struct page *, struct inode *);
  int f2fs_make_empty(struct inode *, struct inode *);
  bool f2fs_empty_dir(struct inode *);
  
  static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)
  {
  	return __f2fs_add_link(dentry->d_parent->d_inode, &dentry->d_name,
  				inode);
  }
  
  /*
   * super.c
   */
  int f2fs_sync_fs(struct super_block *, int);
  extern __printf(3, 4)
  void f2fs_msg(struct super_block *, const char *, const char *, ...);
  
  /*
   * hash.c
   */
  f2fs_hash_t f2fs_dentry_hash(const char *, size_t);
  
  /*
   * node.c
   */
  struct dnode_of_data;
  struct node_info;
  
  int is_checkpointed_node(struct f2fs_sb_info *, nid_t);
  void get_node_info(struct f2fs_sb_info *, nid_t, struct node_info *);
  int get_dnode_of_data(struct dnode_of_data *, pgoff_t, int);
  int truncate_inode_blocks(struct inode *, pgoff_t);
  int truncate_xattr_node(struct inode *, struct page *);
  int wait_on_node_pages_writeback(struct f2fs_sb_info *, nid_t);
  void remove_inode_page(struct inode *);
  struct page *new_inode_page(struct inode *, const struct qstr *);
  struct page *new_node_page(struct dnode_of_data *, unsigned int, struct page *);
  void ra_node_page(struct f2fs_sb_info *, nid_t);
  struct page *get_node_page(struct f2fs_sb_info *, pgoff_t);
  struct page *get_node_page_ra(struct page *, int);
  void sync_inode_page(struct dnode_of_data *);
  int sync_node_pages(struct f2fs_sb_info *, nid_t, struct writeback_control *);
  bool alloc_nid(struct f2fs_sb_info *, nid_t *);
  void alloc_nid_done(struct f2fs_sb_info *, nid_t);
  void alloc_nid_failed(struct f2fs_sb_info *, nid_t);
  void recover_node_page(struct f2fs_sb_info *, struct page *,
  		struct f2fs_summary *, struct node_info *, block_t);
  int recover_inode_page(struct f2fs_sb_info *, struct page *);
  int restore_node_summary(struct f2fs_sb_info *, unsigned int,
  				struct f2fs_summary_block *);
  void flush_nat_entries(struct f2fs_sb_info *);
  int build_node_manager(struct f2fs_sb_info *);
  void destroy_node_manager(struct f2fs_sb_info *);
  int __init create_node_manager_caches(void);
  void destroy_node_manager_caches(void);
  
  /*
   * segment.c
   */
  void f2fs_balance_fs(struct f2fs_sb_info *);
  void f2fs_balance_fs_bg(struct f2fs_sb_info *);
  void invalidate_blocks(struct f2fs_sb_info *, block_t);
  void clear_prefree_segments(struct f2fs_sb_info *);
  int npages_for_summary_flush(struct f2fs_sb_info *);
  void allocate_new_segments(struct f2fs_sb_info *);
  struct page *get_sum_page(struct f2fs_sb_info *, unsigned int);
  void write_meta_page(struct f2fs_sb_info *, struct page *);
  void write_node_page(struct f2fs_sb_info *, struct page *,
  		struct f2fs_io_info *, unsigned int, block_t, block_t *);
  void write_data_page(struct page *, struct dnode_of_data *, block_t *,
  					struct f2fs_io_info *);
  void rewrite_data_page(struct page *, block_t, struct f2fs_io_info *);
  void recover_data_page(struct f2fs_sb_info *, struct page *,
  				struct f2fs_summary *, block_t, block_t);
  void rewrite_node_page(struct f2fs_sb_info *, struct page *,
  				struct f2fs_summary *, block_t, block_t);
  void allocate_data_block(struct f2fs_sb_info *, struct page *,
  		block_t, block_t *, struct f2fs_summary *, int);
  void f2fs_wait_on_page_writeback(struct page *, enum page_type);
  void write_data_summaries(struct f2fs_sb_info *, block_t);
  void write_node_summaries(struct f2fs_sb_info *, block_t);
  int lookup_journal_in_cursum(struct f2fs_summary_block *,
  					int, unsigned int, int);
  void flush_sit_entries(struct f2fs_sb_info *);
  int build_segment_manager(struct f2fs_sb_info *);
  void destroy_segment_manager(struct f2fs_sb_info *);
  int __init create_segment_manager_caches(void);
  void destroy_segment_manager_caches(void);
  
  /*
   * checkpoint.c
   */
  struct page *grab_meta_page(struct f2fs_sb_info *, pgoff_t);
  struct page *get_meta_page(struct f2fs_sb_info *, pgoff_t);
  long sync_meta_pages(struct f2fs_sb_info *, enum page_type, long);
  int acquire_orphan_inode(struct f2fs_sb_info *);
  void release_orphan_inode(struct f2fs_sb_info *);
  void add_orphan_inode(struct f2fs_sb_info *, nid_t);
  void remove_orphan_inode(struct f2fs_sb_info *, nid_t);
  void recover_orphan_inodes(struct f2fs_sb_info *);
  int get_valid_checkpoint(struct f2fs_sb_info *);
  void set_dirty_dir_page(struct inode *, struct page *);
  void add_dirty_dir_inode(struct inode *);
  void remove_dirty_dir_inode(struct inode *);
  struct inode *check_dirty_dir_inode(struct f2fs_sb_info *, nid_t);
  void sync_dirty_dir_inodes(struct f2fs_sb_info *);
  void write_checkpoint(struct f2fs_sb_info *, bool);
  void init_orphan_info(struct f2fs_sb_info *);
  int __init create_checkpoint_caches(void);
  void destroy_checkpoint_caches(void);
  
  /*
   * data.c
   */
  void f2fs_submit_merged_bio(struct f2fs_sb_info *, enum page_type, int);
  int f2fs_submit_page_bio(struct f2fs_sb_info *, struct page *, block_t, int);
  void f2fs_submit_page_mbio(struct f2fs_sb_info *, struct page *, block_t,
  						struct f2fs_io_info *);
  int reserve_new_block(struct dnode_of_data *);
  int f2fs_reserve_block(struct dnode_of_data *, pgoff_t);
  void update_extent_cache(block_t, struct dnode_of_data *);
  struct page *find_data_page(struct inode *, pgoff_t, bool);
  struct page *get_lock_data_page(struct inode *, pgoff_t);
  struct page *get_new_data_page(struct inode *, struct page *, pgoff_t, bool);
  int do_write_data_page(struct page *, struct f2fs_io_info *);
  
  /*
   * gc.c
   */
  int start_gc_thread(struct f2fs_sb_info *);
  void stop_gc_thread(struct f2fs_sb_info *);
  block_t start_bidx_of_node(unsigned int, struct f2fs_inode_info *);
  int f2fs_gc(struct f2fs_sb_info *);
  void build_gc_manager(struct f2fs_sb_info *);
  int __init create_gc_caches(void);
  void destroy_gc_caches(void);
  
  /*
   * recovery.c
   */
  int recover_fsync_data(struct f2fs_sb_info *);
  bool space_for_roll_forward(struct f2fs_sb_info *);
  
  /*
   * debug.c
   */
  #ifdef CONFIG_F2FS_STAT_FS
  struct f2fs_stat_info {
  	struct list_head stat_list;
  	struct f2fs_sb_info *sbi;
  	struct mutex stat_lock;
  	int all_area_segs, sit_area_segs, nat_area_segs, ssa_area_segs;
  	int main_area_segs, main_area_sections, main_area_zones;
  	int hit_ext, total_ext;
  	int ndirty_node, ndirty_dent, ndirty_dirs, ndirty_meta;
  	int nats, sits, fnids;
  	int total_count, utilization;
  	int bg_gc, inline_inode;
  	unsigned int valid_count, valid_node_count, valid_inode_count;
  	unsigned int bimodal, avg_vblocks;
  	int util_free, util_valid, util_invalid;
  	int rsvd_segs, overp_segs;
  	int dirty_count, node_pages, meta_pages;
  	int prefree_count, call_count;
  	int tot_segs, node_segs, data_segs, free_segs, free_secs;
  	int tot_blks, data_blks, node_blks;
  	int curseg[NR_CURSEG_TYPE];
  	int cursec[NR_CURSEG_TYPE];
  	int curzone[NR_CURSEG_TYPE];
  
  	unsigned int segment_count[2];
  	unsigned int block_count[2];
  	unsigned base_mem, cache_mem;
  };
  
  static inline struct f2fs_stat_info *F2FS_STAT(struct f2fs_sb_info *sbi)
  {
  	return (struct f2fs_stat_info *)sbi->stat_info;
  }
  
  #define stat_inc_call_count(si)		((si)->call_count++)
  #define stat_inc_bggc_count(sbi)	((sbi)->bg_gc++)
  #define stat_inc_dirty_dir(sbi)		((sbi)->n_dirty_dirs++)
  #define stat_dec_dirty_dir(sbi)		((sbi)->n_dirty_dirs--)
  #define stat_inc_total_hit(sb)		((F2FS_SB(sb))->total_hit_ext++)
  #define stat_inc_read_hit(sb)		((F2FS_SB(sb))->read_hit_ext++)
  #define stat_inc_inline_inode(inode)					\
  	do {								\
  		if (f2fs_has_inline_data(inode))			\
  			((F2FS_SB(inode->i_sb))->inline_inode++);	\
  	} while (0)
  #define stat_dec_inline_inode(inode)					\
  	do {								\
  		if (f2fs_has_inline_data(inode))			\
  			((F2FS_SB(inode->i_sb))->inline_inode--);	\
  	} while (0)
  
  #define stat_inc_seg_type(sbi, curseg)					\
  		((sbi)->segment_count[(curseg)->alloc_type]++)
  #define stat_inc_block_count(sbi, curseg)				\
  		((sbi)->block_count[(curseg)->alloc_type]++)
  
  #define stat_inc_seg_count(sbi, type)					\
  	do {								\
  		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
  		(si)->tot_segs++;					\
  		if (type == SUM_TYPE_DATA)				\
  			si->data_segs++;				\
  		else							\
  			si->node_segs++;				\
  	} while (0)
  
  #define stat_inc_tot_blk_count(si, blks)				\
  	(si->tot_blks += (blks))
  
  #define stat_inc_data_blk_count(sbi, blks)				\
  	do {								\
  		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
  		stat_inc_tot_blk_count(si, blks);			\
  		si->data_blks += (blks);				\
  	} while (0)
  
  #define stat_inc_node_blk_count(sbi, blks)				\
  	do {								\
  		struct f2fs_stat_info *si = F2FS_STAT(sbi);		\
  		stat_inc_tot_blk_count(si, blks);			\
  		si->node_blks += (blks);				\
  	} while (0)
  
  int f2fs_build_stats(struct f2fs_sb_info *);
  void f2fs_destroy_stats(struct f2fs_sb_info *);
  void __init f2fs_create_root_stats(void);
  void f2fs_destroy_root_stats(void);
  #else
  #define stat_inc_call_count(si)
  #define stat_inc_bggc_count(si)
  #define stat_inc_dirty_dir(sbi)
  #define stat_dec_dirty_dir(sbi)
  #define stat_inc_total_hit(sb)
  #define stat_inc_read_hit(sb)
  #define stat_inc_inline_inode(inode)
  #define stat_dec_inline_inode(inode)
  #define stat_inc_seg_type(sbi, curseg)
  #define stat_inc_block_count(sbi, curseg)
  #define stat_inc_seg_count(si, type)
  #define stat_inc_tot_blk_count(si, blks)
  #define stat_inc_data_blk_count(si, blks)
  #define stat_inc_node_blk_count(sbi, blks)
  
  static inline int f2fs_build_stats(struct f2fs_sb_info *sbi) { return 0; }
  static inline void f2fs_destroy_stats(struct f2fs_sb_info *sbi) { }
  static inline void __init f2fs_create_root_stats(void) { }
  static inline void f2fs_destroy_root_stats(void) { }
  #endif
  
  extern const struct file_operations f2fs_dir_operations;
  extern const struct file_operations f2fs_file_operations;
  extern const struct inode_operations f2fs_file_inode_operations;
  extern const struct address_space_operations f2fs_dblock_aops;
  extern const struct address_space_operations f2fs_node_aops;
  extern const struct address_space_operations f2fs_meta_aops;
  extern const struct inode_operations f2fs_dir_inode_operations;
  extern const struct inode_operations f2fs_symlink_inode_operations;
  extern const struct inode_operations f2fs_special_inode_operations;
  
  /*
   * inline.c
   */
  bool f2fs_may_inline(struct inode *);
  int f2fs_read_inline_data(struct inode *, struct page *);
  int f2fs_convert_inline_data(struct inode *, pgoff_t);
  int f2fs_write_inline_data(struct inode *, struct page *, unsigned int);
  int recover_inline_data(struct inode *, struct page *);
  #endif
  