/*
   * This file is part of UBIFS.
   *
   * Copyright (C) 2006-2008 Nokia Corporation
   *
   * (C) Copyright 2008-2009
   * Stefan Roese, DENX Software Engineering, sr@denx.de.
   *
   * SPDX-License-Identifier:	GPL-2.0+
   *
   * Authors: Artem Bityutskiy (Битюцкий Артём)
   *          Adrian Hunter
   */
  
  #ifndef __UBIFS_H__
  #define __UBIFS_H__
  
  #ifndef __UBOOT__
  #include <asm/div64.h>
  #include <linux/statfs.h>
  #include <linux/fs.h>
  #include <linux/err.h>
  #include <linux/sched.h>
  #include <linux/slab.h>
  #include <linux/vmalloc.h>
  #include <linux/spinlock.h>
  #include <linux/mutex.h>
  #include <linux/rwsem.h>
  #include <linux/mtd/ubi.h>
  #include <linux/pagemap.h>
  #include <linux/backing-dev.h>
  #include "ubifs-media.h"
  #else
  #include <asm/atomic.h>
  #include <asm-generic/atomic-long.h>
  #include <ubi_uboot.h>
  
  #include <linux/ctype.h>
  #include <linux/time.h>
  #include <linux/math64.h>
  #include "ubifs-media.h"
  
  struct dentry;
  struct file;
  struct iattr;
  struct kstat;
  struct vfsmount;
  
  extern struct super_block *ubifs_sb;
  
  extern unsigned int ubifs_msg_flags;
  extern unsigned int ubifs_chk_flags;
  extern unsigned int ubifs_tst_flags;
  
  #define pgoff_t		unsigned long
  
  /*
   * We "simulate" the Linux page struct much simpler here
   */
  struct page {
  	pgoff_t index;
  	void *addr;
  	struct inode *inode;
  };
  
  void iput(struct inode *inode);
  
  /* linux/include/time.h */
  #define NSEC_PER_SEC	1000000000L
  #define get_seconds()	0
  #define CURRENT_TIME_SEC	((struct timespec) { get_seconds(), 0 })
  
  struct timespec {
  	time_t	tv_sec;		/* seconds */
  	long	tv_nsec;	/* nanoseconds */
  };
  
  static struct timespec current_fs_time(struct super_block *sb)
  {
  	struct timespec now;
  	now.tv_sec = 0;
  	now.tv_nsec = 0;
  	return now;
  };
  
  /* linux/include/dcache.h */
  
  /*
   * "quick string" -- eases parameter passing, but more importantly
   * saves "metadata" about the string (ie length and the hash).
   *
   * hash comes first so it snuggles against d_parent in the
   * dentry.
   */
  struct qstr {
  	unsigned int hash;
  	unsigned int len;
  #ifndef __UBOOT__
  	const char *name;
  #else
  	char *name;
  #endif
  };
  
  /* include/linux/fs.h */
  
  /* Possible states of 'frozen' field */
  enum {
  	SB_UNFROZEN = 0,		/* FS is unfrozen */
  	SB_FREEZE_WRITE	= 1,		/* Writes, dir ops, ioctls frozen */
  	SB_FREEZE_PAGEFAULT = 2,	/* Page faults stopped as well */
  	SB_FREEZE_FS = 3,		/* For internal FS use (e.g. to stop
  					 * internal threads if needed) */
  	SB_FREEZE_COMPLETE = 4,		/* ->freeze_fs finished successfully */
  };
  
  #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
  
  struct sb_writers {
  #ifndef __UBOOT__
  	/* Counters for counting writers at each level */
  	struct percpu_counter	counter[SB_FREEZE_LEVELS];
  #endif
  	wait_queue_head_t	wait;		/* queue for waiting for
  						   writers / faults to finish */
  	int			frozen;		/* Is sb frozen? */
  	wait_queue_head_t	wait_unfrozen;	/* queue for waiting for
  						   sb to be thawed */
  #ifdef CONFIG_DEBUG_LOCK_ALLOC
  	struct lockdep_map	lock_map[SB_FREEZE_LEVELS];
  #endif
  };
  
  struct address_space {
  	struct inode		*host;		/* owner: inode, block_device */
  #ifndef __UBOOT__
  	struct radix_tree_root	page_tree;	/* radix tree of all pages */
  #endif
  	spinlock_t		tree_lock;	/* and lock protecting it */
  	unsigned int		i_mmap_writable;/* count VM_SHARED mappings */
  	struct rb_root		i_mmap;		/* tree of private and shared mappings */
  	struct list_head	i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
  	struct mutex		i_mmap_mutex;	/* protect tree, count, list */
  	/* Protected by tree_lock together with the radix tree */
  	unsigned long		nrpages;	/* number of total pages */
  	pgoff_t			writeback_index;/* writeback starts here */
  	const struct address_space_operations *a_ops;	/* methods */
  	unsigned long		flags;		/* error bits/gfp mask */
  #ifndef __UBOOT__
  	struct backing_dev_info *backing_dev_info; /* device readahead, etc */
  #endif
  	spinlock_t		private_lock;	/* for use by the address_space */
  	struct list_head	private_list;	/* ditto */
  	void			*private_data;	/* ditto */
  } __attribute__((aligned(sizeof(long))));
  
  /*
   * Keep mostly read-only and often accessed (especially for
   * the RCU path lookup and 'stat' data) fields at the beginning
   * of the 'struct inode'
   */
  struct inode {
  	umode_t			i_mode;
  	unsigned short		i_opflags;
  	kuid_t			i_uid;
  	kgid_t			i_gid;
  	unsigned int		i_flags;
  
  #ifdef CONFIG_FS_POSIX_ACL
  	struct posix_acl	*i_acl;
  	struct posix_acl	*i_default_acl;
  #endif
  
  	const struct inode_operations	*i_op;
  	struct super_block	*i_sb;
  	struct address_space	*i_mapping;
  
  #ifdef CONFIG_SECURITY
  	void			*i_security;
  #endif
  
  	/* Stat data, not accessed from path walking */
  	unsigned long		i_ino;
  	/*
  	 * Filesystems may only read i_nlink directly.  They shall use the
  	 * following functions for modification:
  	 *
  	 *    (set|clear|inc|drop)_nlink
  	 *    inode_(inc|dec)_link_count
  	 */
  	union {
  		const unsigned int i_nlink;
  		unsigned int __i_nlink;
  	};
  	dev_t			i_rdev;
  	loff_t			i_size;
  	struct timespec		i_atime;
  	struct timespec		i_mtime;
  	struct timespec		i_ctime;
  	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
  	unsigned short          i_bytes;
  	unsigned int		i_blkbits;
  	blkcnt_t		i_blocks;
  
  #ifdef __NEED_I_SIZE_ORDERED
  	seqcount_t		i_size_seqcount;
  #endif
  
  	/* Misc */
  	unsigned long		i_state;
  	struct mutex		i_mutex;
  
  	unsigned long		dirtied_when;	/* jiffies of first dirtying */
  
  	struct hlist_node	i_hash;
  	struct list_head	i_wb_list;	/* backing dev IO list */
  	struct list_head	i_lru;		/* inode LRU list */
  	struct list_head	i_sb_list;
  	union {
  		struct hlist_head	i_dentry;
  		struct rcu_head		i_rcu;
  	};
  	u64			i_version;
  	atomic_t		i_count;
  	atomic_t		i_dio_count;
  	atomic_t		i_writecount;
  	const struct file_operations	*i_fop;	/* former ->i_op->default_file_ops */
  	struct file_lock	*i_flock;
  	struct address_space	i_data;
  #ifdef CONFIG_QUOTA
  	struct dquot		*i_dquot[MAXQUOTAS];
  #endif
  	struct list_head	i_devices;
  	union {
  		struct pipe_inode_info	*i_pipe;
  		struct block_device	*i_bdev;
  		struct cdev		*i_cdev;
  	};
  
  	__u32			i_generation;
  
  #ifdef CONFIG_FSNOTIFY
  	__u32			i_fsnotify_mask; /* all events this inode cares about */
  	struct hlist_head	i_fsnotify_marks;
  #endif
  
  #ifdef CONFIG_IMA
  	atomic_t		i_readcount; /* struct files open RO */
  #endif
  	void			*i_private; /* fs or device private pointer */
  };
  
  struct super_operations {
     	struct inode *(*alloc_inode)(struct super_block *sb);
  	void (*destroy_inode)(struct inode *);
  
     	void (*dirty_inode) (struct inode *, int flags);
  	int (*write_inode) (struct inode *, struct writeback_control *wbc);
  	int (*drop_inode) (struct inode *);
  	void (*evict_inode) (struct inode *);
  	void (*put_super) (struct super_block *);
  	int (*sync_fs)(struct super_block *sb, int wait);
  	int (*freeze_fs) (struct super_block *);
  	int (*unfreeze_fs) (struct super_block *);
  #ifndef __UBOOT__
  	int (*statfs) (struct dentry *, struct kstatfs *);
  #endif
  	int (*remount_fs) (struct super_block *, int *, char *);
  	void (*umount_begin) (struct super_block *);
  
  #ifndef __UBOOT__
  	int (*show_options)(struct seq_file *, struct dentry *);
  	int (*show_devname)(struct seq_file *, struct dentry *);
  	int (*show_path)(struct seq_file *, struct dentry *);
  	int (*show_stats)(struct seq_file *, struct dentry *);
  #endif
  #ifdef CONFIG_QUOTA
  	ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
  	ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
  #endif
  	int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
  	long (*nr_cached_objects)(struct super_block *, int);
  	long (*free_cached_objects)(struct super_block *, long, int);
  };
  
  struct super_block {
  	struct list_head	s_list;		/* Keep this first */
  	dev_t			s_dev;		/* search index; _not_ kdev_t */
  	unsigned char		s_blocksize_bits;
  	unsigned long		s_blocksize;
  	loff_t			s_maxbytes;	/* Max file size */
  	struct file_system_type	*s_type;
  	const struct super_operations	*s_op;
  	const struct dquot_operations	*dq_op;
  	const struct quotactl_ops	*s_qcop;
  	const struct export_operations *s_export_op;
  	unsigned long		s_flags;
  	unsigned long		s_magic;
  	struct dentry		*s_root;
  	struct rw_semaphore	s_umount;
  	int			s_count;
  	atomic_t		s_active;
  #ifdef CONFIG_SECURITY
  	void                    *s_security;
  #endif
  	const struct xattr_handler **s_xattr;
  
  	struct list_head	s_inodes;	/* all inodes */
  #ifndef __UBOOT__
  	struct hlist_bl_head	s_anon;		/* anonymous dentries for (nfs) exporting */
  #endif
  	struct list_head	s_mounts;	/* list of mounts; _not_ for fs use */
  	struct block_device	*s_bdev;
  #ifndef __UBOOT__
  	struct backing_dev_info *s_bdi;
  #endif
  	struct mtd_info		*s_mtd;
  	struct hlist_node	s_instances;
  #ifndef __UBOOT__
  	struct quota_info	s_dquot;	/* Diskquota specific options */
  #endif
  
  	struct sb_writers	s_writers;
  
  	char s_id[32];				/* Informational name */
  	u8 s_uuid[16];				/* UUID */
  
  	void 			*s_fs_info;	/* Filesystem private info */
  	unsigned int		s_max_links;
  #ifndef __UBOOT__
  	fmode_t			s_mode;
  #endif
  
  	/* Granularity of c/m/atime in ns.
  	   Cannot be worse than a second */
  	u32		   s_time_gran;
  
  	/*
  	 * The next field is for VFS *only*. No filesystems have any business
  	 * even looking at it. You had been warned.
  	 */
  	struct mutex s_vfs_rename_mutex;	/* Kludge */
  
  	/*
  	 * Filesystem subtype.  If non-empty the filesystem type field
  	 * in /proc/mounts will be "type.subtype"
  	 */
  	char *s_subtype;
  
  #ifndef __UBOOT__
  	/*
  	 * Saved mount options for lazy filesystems using
  	 * generic_show_options()
  	 */
  	char __rcu *s_options;
  #endif
  	const struct dentry_operations *s_d_op; /* default d_op for dentries */
  
  	/*
  	 * Saved pool identifier for cleancache (-1 means none)
  	 */
  	int cleancache_poolid;
  
  #ifndef __UBOOT__
  	struct shrinker s_shrink;	/* per-sb shrinker handle */
  #endif
  
  	/* Number of inodes with nlink == 0 but still referenced */
  	atomic_long_t s_remove_count;
  
  	/* Being remounted read-only */
  	int s_readonly_remount;
  
  	/* AIO completions deferred from interrupt context */
  	struct workqueue_struct *s_dio_done_wq;
  
  #ifndef __UBOOT__
  	/*
  	 * Keep the lru lists last in the structure so they always sit on their
  	 * own individual cachelines.
  	 */
  	struct list_lru		s_dentry_lru ____cacheline_aligned_in_smp;
  	struct list_lru		s_inode_lru ____cacheline_aligned_in_smp;
  #endif
  	struct rcu_head		rcu;
  };
  
  struct file_system_type {
  	const char *name;
  	int fs_flags;
  #define FS_REQUIRES_DEV		1 
  #define FS_BINARY_MOUNTDATA	2
  #define FS_HAS_SUBTYPE		4
  #define FS_USERNS_MOUNT		8	/* Can be mounted by userns root */
  #define FS_USERNS_DEV_MOUNT	16 /* A userns mount does not imply MNT_NODEV */
  #define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move() during rename() internally. */
  	struct dentry *(*mount) (struct file_system_type *, int,
  		       const char *, void *);
  	void (*kill_sb) (struct super_block *);
  	struct module *owner;
  	struct file_system_type * next;
  	struct hlist_head fs_supers;
  
  #ifndef __UBOOT__
  	struct lock_class_key s_lock_key;
  	struct lock_class_key s_umount_key;
  	struct lock_class_key s_vfs_rename_key;
  	struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
  
  	struct lock_class_key i_lock_key;
  	struct lock_class_key i_mutex_key;
  	struct lock_class_key i_mutex_dir_key;
  #endif
  };
  
  /* include/linux/mount.h */
  struct vfsmount {
  	struct dentry *mnt_root;	/* root of the mounted tree */
  	struct super_block *mnt_sb;	/* pointer to superblock */
  	int mnt_flags;
  };
  
  struct path {
  	struct vfsmount *mnt;
  	struct dentry *dentry;
  };
  
  struct file {
  	struct path		f_path;
  #define f_dentry	f_path.dentry
  #define f_vfsmnt	f_path.mnt
  	const struct file_operations	*f_op;
  	unsigned int 		f_flags;
  	loff_t			f_pos;
  	unsigned int		f_uid, f_gid;
  
  	u64			f_version;
  #ifdef CONFIG_SECURITY
  	void			*f_security;
  #endif
  	/* needed for tty driver, and maybe others */
  	void			*private_data;
  
  #ifdef CONFIG_EPOLL
  	/* Used by fs/eventpoll.c to link all the hooks to this file */
  	struct list_head	f_ep_links;
  	spinlock_t		f_ep_lock;
  #endif /* #ifdef CONFIG_EPOLL */
  #ifdef CONFIG_DEBUG_WRITECOUNT
  	unsigned long f_mnt_write_state;
  #endif
  };
  
  /*
   * get_seconds() not really needed in the read-only implmentation
   */
  #define get_seconds()		0
  
  /* 4k page size */
  #define PAGE_CACHE_SHIFT	12
  #define PAGE_CACHE_SIZE		(1 << PAGE_CACHE_SHIFT)
  
  /* Page cache limit. The filesystems should put that into their s_maxbytes
     limits, otherwise bad things can happen in VM. */
  #if BITS_PER_LONG==32
  #define MAX_LFS_FILESIZE	(((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
  #elif BITS_PER_LONG==64
  #define MAX_LFS_FILESIZE 	0x7fffffffffffffffUL
  #endif
  
  /*
   * These are the fs-independent mount-flags: up to 32 flags are supported
   */
  #define MS_RDONLY	 1	/* Mount read-only */
  #define MS_NOSUID	 2	/* Ignore suid and sgid bits */
  #define MS_NODEV	 4	/* Disallow access to device special files */
  #define MS_NOEXEC	 8	/* Disallow program execution */
  #define MS_SYNCHRONOUS	16	/* Writes are synced at once */
  #define MS_REMOUNT	32	/* Alter flags of a mounted FS */
  #define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
  #define MS_DIRSYNC	128	/* Directory modifications are synchronous */
  #define MS_NOATIME	1024	/* Do not update access times. */
  #define MS_NODIRATIME	2048	/* Do not update directory access times */
  #define MS_BIND		4096
  #define MS_MOVE		8192
  #define MS_REC		16384
  #define MS_VERBOSE	32768	/* War is peace. Verbosity is silence.
  				   MS_VERBOSE is deprecated. */
  #define MS_SILENT	32768
  #define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */
  #define MS_UNBINDABLE	(1<<17)	/* change to unbindable */
  #define MS_PRIVATE	(1<<18)	/* change to private */
  #define MS_SLAVE	(1<<19)	/* change to slave */
  #define MS_SHARED	(1<<20)	/* change to shared */
  #define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */
  #define MS_KERNMOUNT	(1<<22) /* this is a kern_mount call */
  #define MS_I_VERSION	(1<<23) /* Update inode I_version field */
  #define MS_ACTIVE	(1<<30)
  #define MS_NOUSER	(1<<31)
  
  #define I_NEW			8
  
  /* Inode flags - they have nothing to superblock flags now */
  
  #define S_SYNC		1	/* Writes are synced at once */
  #define S_NOATIME	2	/* Do not update access times */
  #define S_APPEND	4	/* Append-only file */
  #define S_IMMUTABLE	8	/* Immutable file */
  #define S_DEAD		16	/* removed, but still open directory */
  #define S_NOQUOTA	32	/* Inode is not counted to quota */
  #define S_DIRSYNC	64	/* Directory modifications are synchronous */
  #define S_NOCMTIME	128	/* Do not update file c/mtime */
  #define S_SWAPFILE	256	/* Do not truncate: swapon got its bmaps */
  #define S_PRIVATE	512	/* Inode is fs-internal */
  
  /* include/linux/stat.h */
  
  #define S_IFMT  00170000
  #define S_IFSOCK 0140000
  #define S_IFLNK	 0120000
  #define S_IFREG  0100000
  #define S_IFBLK  0060000
  #define S_IFDIR  0040000
  #define S_IFCHR  0020000
  #define S_IFIFO  0010000
  #define S_ISUID  0004000
  #define S_ISGID  0002000
  #define S_ISVTX  0001000
  
  /* include/linux/fs.h */
  
  /*
   * File types
   *
   * NOTE! These match bits 12..15 of stat.st_mode
   * (ie "(i_mode >> 12) & 15").
   */
  #define DT_UNKNOWN	0
  #define DT_FIFO		1
  #define DT_CHR		2
  #define DT_DIR		4
  #define DT_BLK		6
  #define DT_REG		8
  #define DT_LNK		10
  #define DT_SOCK		12
  #define DT_WHT		14
  
  #define I_DIRTY_SYNC		1
  #define I_DIRTY_DATASYNC	2
  #define I_DIRTY_PAGES		4
  #define I_NEW			8
  #define I_WILL_FREE		16
  #define I_FREEING		32
  #define I_CLEAR			64
  #define __I_LOCK		7
  #define I_LOCK			(1 << __I_LOCK)
  #define __I_SYNC		8
  #define I_SYNC			(1 << __I_SYNC)
  
  #define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
  
  /* linux/include/dcache.h */
  
  #define DNAME_INLINE_LEN_MIN 36
  
  struct dentry {
  	unsigned int d_flags;		/* protected by d_lock */
  	spinlock_t d_lock;		/* per dentry lock */
  	struct inode *d_inode;		/* Where the name belongs to - NULL is
  					 * negative */
  	/*
  	 * The next three fields are touched by __d_lookup.  Place them here
  	 * so they all fit in a cache line.
  	 */
  	struct hlist_node d_hash;	/* lookup hash list */
  	struct dentry *d_parent;	/* parent directory */
  	struct qstr d_name;
  
  	struct list_head d_lru;		/* LRU list */
  	/*
  	 * d_child and d_rcu can share memory
  	 */
  	struct list_head d_subdirs;	/* our children */
  	struct list_head d_alias;	/* inode alias list */
  	unsigned long d_time;		/* used by d_revalidate */
  	struct super_block *d_sb;	/* The root of the dentry tree */
  	void *d_fsdata;			/* fs-specific data */
  #ifdef CONFIG_PROFILING
  	struct dcookie_struct *d_cookie; /* cookie, if any */
  #endif
  	int d_mounted;
  	unsigned char d_iname[DNAME_INLINE_LEN_MIN];	/* small names */
  };
  
  static inline ino_t parent_ino(struct dentry *dentry)
  {
  	ino_t res;
  
  	spin_lock(&dentry->d_lock);
  	res = dentry->d_parent->d_inode->i_ino;
  	spin_unlock(&dentry->d_lock);
  	return res;
  }
  
  /* debug.c */
  
  #define module_param_named(...)
  
  /* misc.h */
  #define mutex_lock_nested(...)
  #define mutex_unlock_nested(...)
  #define mutex_is_locked(...)	0
  #endif
  
  /* Version of this UBIFS implementation */
  #define UBIFS_VERSION 1
  
  /* Normal UBIFS messages */
  #define ubifs_msg(fmt, ...) pr_notice("UBIFS: " fmt "
  ", ##__VA_ARGS__)
  /* UBIFS error messages */
  #ifndef __UBOOT__
  #define ubifs_err(fmt, ...)                                         \
  	pr_err("UBIFS error (pid %d): %s: " fmt "
  ", current->pid, \
  	       __func__, ##__VA_ARGS__)
  /* UBIFS warning messages */
  #define ubifs_warn(fmt, ...)                                        \
  	pr_warn("UBIFS warning (pid %d): %s: " fmt "
  ",            \
  		current->pid, __func__, ##__VA_ARGS__)
  #else
  #define ubifs_err(fmt, ...)                                         \
  	pr_err("UBIFS error: %s: " fmt "
  ", __func__, ##__VA_ARGS__)
  /* UBIFS warning messages */
  #define ubifs_warn(fmt, ...)                                        \
  	pr_warn("UBIFS warning: %s: " fmt "
  ", __func__, ##__VA_ARGS__)
  #endif
  
  /* UBIFS file system VFS magic number */
  #define UBIFS_SUPER_MAGIC 0x24051905
  
  /* Number of UBIFS blocks per VFS page */
  #define UBIFS_BLOCKS_PER_PAGE (PAGE_CACHE_SIZE / UBIFS_BLOCK_SIZE)
  #define UBIFS_BLOCKS_PER_PAGE_SHIFT (PAGE_CACHE_SHIFT - UBIFS_BLOCK_SHIFT)
  
  /* "File system end of life" sequence number watermark */
  #define SQNUM_WARN_WATERMARK 0xFFFFFFFF00000000ULL
  #define SQNUM_WATERMARK      0xFFFFFFFFFF000000ULL
  
  /*
   * Minimum amount of LEBs reserved for the index. At present the index needs at
   * least 2 LEBs: one for the index head and one for in-the-gaps method (which
   * currently does not cater for the index head and so excludes it from
   * consideration).
   */
  #define MIN_INDEX_LEBS 2
  
  /* Minimum amount of data UBIFS writes to the flash */
  #define MIN_WRITE_SZ (UBIFS_DATA_NODE_SZ + 8)
  
  /*
   * Currently we do not support inode number overlapping and re-using, so this
   * watermark defines dangerous inode number level. This should be fixed later,
   * although it is difficult to exceed current limit. Another option is to use
   * 64-bit inode numbers, but this means more overhead.
   */
  #define INUM_WARN_WATERMARK 0xFFF00000
  #define INUM_WATERMARK      0xFFFFFF00
  
  /* Maximum number of entries in each LPT (LEB category) heap */
  #define LPT_HEAP_SZ 256
  
  /*
   * Background thread name pattern. The numbers are UBI device and volume
   * numbers.
   */
  #define BGT_NAME_PATTERN "ubifs_bgt%d_%d"
  
  /* Write-buffer synchronization timeout interval in seconds */
  #define WBUF_TIMEOUT_SOFTLIMIT 3
  #define WBUF_TIMEOUT_HARDLIMIT 5
  
  /* Maximum possible inode number (only 32-bit inodes are supported now) */
  #define MAX_INUM 0xFFFFFFFF
  
  /* Number of non-data journal heads */
  #define NONDATA_JHEADS_CNT 2
  
  /* Shorter names for journal head numbers for internal usage */
  #define GCHD   UBIFS_GC_HEAD
  #define BASEHD UBIFS_BASE_HEAD
  #define DATAHD UBIFS_DATA_HEAD
  
  /* 'No change' value for 'ubifs_change_lp()' */
  #define LPROPS_NC 0x80000001
  
  /*
   * There is no notion of truncation key because truncation nodes do not exist
   * in TNC. However, when replaying, it is handy to introduce fake "truncation"
   * keys for truncation nodes because the code becomes simpler. So we define
   * %UBIFS_TRUN_KEY type.
   *
   * But otherwise, out of the journal reply scope, the truncation keys are
   * invalid.
   */
  #define UBIFS_TRUN_KEY    UBIFS_KEY_TYPES_CNT
  #define UBIFS_INVALID_KEY UBIFS_KEY_TYPES_CNT
  
  /*
   * How much a directory entry/extended attribute entry adds to the parent/host
   * inode.
   */
  #define CALC_DENT_SIZE(name_len) ALIGN(UBIFS_DENT_NODE_SZ + (name_len) + 1, 8)
  
  /* How much an extended attribute adds to the host inode */
  #define CALC_XATTR_BYTES(data_len) ALIGN(UBIFS_INO_NODE_SZ + (data_len) + 1, 8)
  
  /*
   * Znodes which were not touched for 'OLD_ZNODE_AGE' seconds are considered
   * "old", and znode which were touched last 'YOUNG_ZNODE_AGE' seconds ago are
   * considered "young". This is used by shrinker when selecting znode to trim
   * off.
   */
  #define OLD_ZNODE_AGE 20
  #define YOUNG_ZNODE_AGE 5
  
  /*
   * Some compressors, like LZO, may end up with more data then the input buffer.
   * So UBIFS always allocates larger output buffer, to be sure the compressor
   * will not corrupt memory in case of worst case compression.
   */
  #define WORST_COMPR_FACTOR 2
  
  /*
   * How much memory is needed for a buffer where we comress a data node.
   */
  #define COMPRESSED_DATA_NODE_BUF_SZ \
  	(UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR)
  
  /* Maximum expected tree height for use by bottom_up_buf */
  #define BOTTOM_UP_HEIGHT 64
  
  /* Maximum number of data nodes to bulk-read */
  #define UBIFS_MAX_BULK_READ 32
  
  /*
   * Lockdep classes for UBIFS inode @ui_mutex.
   */
  enum {
  	WB_MUTEX_1 = 0,
  	WB_MUTEX_2 = 1,
  	WB_MUTEX_3 = 2,
  };
  
  /*
   * Znode flags (actually, bit numbers which store the flags).
   *
   * DIRTY_ZNODE: znode is dirty
   * COW_ZNODE: znode is being committed and a new instance of this znode has to
   *            be created before changing this znode
   * OBSOLETE_ZNODE: znode is obsolete, which means it was deleted, but it is
   *                 still in the commit list and the ongoing commit operation
   *                 will commit it, and delete this znode after it is done
   */
  enum {
  	DIRTY_ZNODE    = 0,
  	COW_ZNODE      = 1,
  	OBSOLETE_ZNODE = 2,
  };
  
  /*
   * Commit states.
   *
   * COMMIT_RESTING: commit is not wanted
   * COMMIT_BACKGROUND: background commit has been requested
   * COMMIT_REQUIRED: commit is required
   * COMMIT_RUNNING_BACKGROUND: background commit is running
   * COMMIT_RUNNING_REQUIRED: commit is running and it is required
   * COMMIT_BROKEN: commit failed
   */
  enum {
  	COMMIT_RESTING = 0,
  	COMMIT_BACKGROUND,
  	COMMIT_REQUIRED,
  	COMMIT_RUNNING_BACKGROUND,
  	COMMIT_RUNNING_REQUIRED,
  	COMMIT_BROKEN,
  };
  
  /*
   * 'ubifs_scan_a_node()' return values.
   *
   * SCANNED_GARBAGE:  scanned garbage
   * SCANNED_EMPTY_SPACE: scanned empty space
   * SCANNED_A_NODE: scanned a valid node
   * SCANNED_A_CORRUPT_NODE: scanned a corrupted node
   * SCANNED_A_BAD_PAD_NODE: scanned a padding node with invalid pad length
   *
   * Greater than zero means: 'scanned that number of padding bytes'
   */
  enum {
  	SCANNED_GARBAGE        = 0,
  	SCANNED_EMPTY_SPACE    = -1,
  	SCANNED_A_NODE         = -2,
  	SCANNED_A_CORRUPT_NODE = -3,
  	SCANNED_A_BAD_PAD_NODE = -4,
  };
  
  /*
   * LPT cnode flag bits.
   *
   * DIRTY_CNODE: cnode is dirty
   * OBSOLETE_CNODE: cnode is being committed and has been copied (or deleted),
   *                 so it can (and must) be freed when the commit is finished
   * COW_CNODE: cnode is being committed and must be copied before writing
   */
  enum {
  	DIRTY_CNODE    = 0,
  	OBSOLETE_CNODE = 1,
  	COW_CNODE      = 2,
  };
  
  /*
   * Dirty flag bits (lpt_drty_flgs) for LPT special nodes.
   *
   * LTAB_DIRTY: ltab node is dirty
   * LSAVE_DIRTY: lsave node is dirty
   */
  enum {
  	LTAB_DIRTY  = 1,
  	LSAVE_DIRTY = 2,
  };
  
  /*
   * Return codes used by the garbage collector.
   * @LEB_FREED: the logical eraseblock was freed and is ready to use
   * @LEB_FREED_IDX: indexing LEB was freed and can be used only after the commit
   * @LEB_RETAINED: the logical eraseblock was freed and retained for GC purposes
   */
  enum {
  	LEB_FREED,
  	LEB_FREED_IDX,
  	LEB_RETAINED,
  };
  
  /**
   * struct ubifs_old_idx - index node obsoleted since last commit start.
   * @rb: rb-tree node
   * @lnum: LEB number of obsoleted index node
   * @offs: offset of obsoleted index node
   */
  struct ubifs_old_idx {
  	struct rb_node rb;
  	int lnum;
  	int offs;
  };
  
  /* The below union makes it easier to deal with keys */
  union ubifs_key {
  	uint8_t u8[UBIFS_SK_LEN];
  	uint32_t u32[UBIFS_SK_LEN/4];
  	uint64_t u64[UBIFS_SK_LEN/8];
  	__le32 j32[UBIFS_SK_LEN/4];
  };
  
  /**
   * struct ubifs_scan_node - UBIFS scanned node information.
   * @list: list of scanned nodes
   * @key: key of node scanned (if it has one)
   * @sqnum: sequence number
   * @type: type of node scanned
   * @offs: offset with LEB of node scanned
   * @len: length of node scanned
   * @node: raw node
   */
  struct ubifs_scan_node {
  	struct list_head list;
  	union ubifs_key key;
  	unsigned long long sqnum;
  	int type;
  	int offs;
  	int len;
  	void *node;
  };
  
  /**
   * struct ubifs_scan_leb - UBIFS scanned LEB information.
   * @lnum: logical eraseblock number
   * @nodes_cnt: number of nodes scanned
   * @nodes: list of struct ubifs_scan_node
   * @endpt: end point (and therefore the start of empty space)
   * @ecc: read returned -EBADMSG
   * @buf: buffer containing entire LEB scanned
   */
  struct ubifs_scan_leb {
  	int lnum;
  	int nodes_cnt;
  	struct list_head nodes;
  	int endpt;
  	int ecc;
  	void *buf;
  };
  
  /**
   * struct ubifs_gced_idx_leb - garbage-collected indexing LEB.
   * @list: list
   * @lnum: LEB number
   * @unmap: OK to unmap this LEB
   *
   * This data structure is used to temporary store garbage-collected indexing
   * LEBs - they are not released immediately, but only after the next commit.
   * This is needed to guarantee recoverability.
   */
  struct ubifs_gced_idx_leb {
  	struct list_head list;
  	int lnum;
  	int unmap;
  };
  
  /**
   * struct ubifs_inode - UBIFS in-memory inode description.
   * @vfs_inode: VFS inode description object
   * @creat_sqnum: sequence number at time of creation
   * @del_cmtno: commit number corresponding to the time the inode was deleted,
   *             protected by @c->commit_sem;
   * @xattr_size: summarized size of all extended attributes in bytes
   * @xattr_cnt: count of extended attributes this inode has
   * @xattr_names: sum of lengths of all extended attribute names belonging to
   *               this inode
   * @dirty: non-zero if the inode is dirty
   * @xattr: non-zero if this is an extended attribute inode
   * @bulk_read: non-zero if bulk-read should be used
   * @ui_mutex: serializes inode write-back with the rest of VFS operations,
   *            serializes "clean <-> dirty" state changes, serializes bulk-read,
   *            protects @dirty, @bulk_read, @ui_size, and @xattr_size
   * @ui_lock: protects @synced_i_size
   * @synced_i_size: synchronized size of inode, i.e. the value of inode size
   *                 currently stored on the flash; used only for regular file
   *                 inodes
   * @ui_size: inode size used by UBIFS when writing to flash
   * @flags: inode flags (@UBIFS_COMPR_FL, etc)
   * @compr_type: default compression type used for this inode
   * @last_page_read: page number of last page read (for bulk read)
   * @read_in_a_row: number of consecutive pages read in a row (for bulk read)
   * @data_len: length of the data attached to the inode
   * @data: inode's data
   *
   * @ui_mutex exists for two main reasons. At first it prevents inodes from
   * being written back while UBIFS changing them, being in the middle of an VFS
   * operation. This way UBIFS makes sure the inode fields are consistent. For
   * example, in 'ubifs_rename()' we change 3 inodes simultaneously, and
   * write-back must not write any of them before we have finished.
   *
   * The second reason is budgeting - UBIFS has to budget all operations. If an
   * operation is going to mark an inode dirty, it has to allocate budget for
   * this. It cannot just mark it dirty because there is no guarantee there will
   * be enough flash space to write the inode back later. This means UBIFS has
   * to have full control over inode "clean <-> dirty" transitions (and pages
   * actually). But unfortunately, VFS marks inodes dirty in many places, and it
   * does not ask the file-system if it is allowed to do so (there is a notifier,
   * but it is not enough), i.e., there is no mechanism to synchronize with this.
   * So UBIFS has its own inode dirty flag and its own mutex to serialize
   * "clean <-> dirty" transitions.
   *
   * The @synced_i_size field is used to make sure we never write pages which are
   * beyond last synchronized inode size. See 'ubifs_writepage()' for more
   * information.
   *
   * The @ui_size is a "shadow" variable for @inode->i_size and UBIFS uses
   * @ui_size instead of @inode->i_size. The reason for this is that UBIFS cannot
   * make sure @inode->i_size is always changed under @ui_mutex, because it
   * cannot call 'truncate_setsize()' with @ui_mutex locked, because it would
   * deadlock with 'ubifs_writepage()' (see file.c). All the other inode fields
   * are changed under @ui_mutex, so they do not need "shadow" fields. Note, one
   * could consider to rework locking and base it on "shadow" fields.
   */
  struct ubifs_inode {
  	struct inode vfs_inode;
  	unsigned long long creat_sqnum;
  	unsigned long long del_cmtno;
  	unsigned int xattr_size;
  	unsigned int xattr_cnt;
  	unsigned int xattr_names;
  	unsigned int dirty:1;
  	unsigned int xattr:1;
  	unsigned int bulk_read:1;
  	unsigned int compr_type:2;
  	struct mutex ui_mutex;
  	spinlock_t ui_lock;
  	loff_t synced_i_size;
  	loff_t ui_size;
  	int flags;
  	pgoff_t last_page_read;
  	pgoff_t read_in_a_row;
  	int data_len;
  	void *data;
  };
  
  /**
   * struct ubifs_unclean_leb - records a LEB recovered under read-only mode.
   * @list: list
   * @lnum: LEB number of recovered LEB
   * @endpt: offset where recovery ended
   *
   * This structure records a LEB identified during recovery that needs to be
   * cleaned but was not because UBIFS was mounted read-only. The information
   * is used to clean the LEB when remounting to read-write mode.
   */
  struct ubifs_unclean_leb {
  	struct list_head list;
  	int lnum;
  	int endpt;
  };
  
  /*
   * LEB properties flags.
   *
   * LPROPS_UNCAT: not categorized
   * LPROPS_DIRTY: dirty > free, dirty >= @c->dead_wm, not index
   * LPROPS_DIRTY_IDX: dirty + free > @c->min_idx_node_sze and index
   * LPROPS_FREE: free > 0, dirty < @c->dead_wm, not empty, not index
   * LPROPS_HEAP_CNT: number of heaps used for storing categorized LEBs
   * LPROPS_EMPTY: LEB is empty, not taken
   * LPROPS_FREEABLE: free + dirty == leb_size, not index, not taken
   * LPROPS_FRDI_IDX: free + dirty == leb_size and index, may be taken
   * LPROPS_CAT_MASK: mask for the LEB categories above
   * LPROPS_TAKEN: LEB was taken (this flag is not saved on the media)
   * LPROPS_INDEX: LEB contains indexing nodes (this flag also exists on flash)
   */
  enum {
  	LPROPS_UNCAT     =  0,
  	LPROPS_DIRTY     =  1,
  	LPROPS_DIRTY_IDX =  2,
  	LPROPS_FREE      =  3,
  	LPROPS_HEAP_CNT  =  3,
  	LPROPS_EMPTY     =  4,
  	LPROPS_FREEABLE  =  5,
  	LPROPS_FRDI_IDX  =  6,
  	LPROPS_CAT_MASK  = 15,
  	LPROPS_TAKEN     = 16,
  	LPROPS_INDEX     = 32,
  };
  
  /**
   * struct ubifs_lprops - logical eraseblock properties.
   * @free: amount of free space in bytes
   * @dirty: amount of dirty space in bytes
   * @flags: LEB properties flags (see above)
   * @lnum: LEB number
   * @list: list of same-category lprops (for LPROPS_EMPTY and LPROPS_FREEABLE)
   * @hpos: heap position in heap of same-category lprops (other categories)
   */
  struct ubifs_lprops {
  	int free;
  	int dirty;
  	int flags;
  	int lnum;
  	union {
  		struct list_head list;
  		int hpos;
  	};
  };
  
  /**
   * struct ubifs_lpt_lprops - LPT logical eraseblock properties.
   * @free: amount of free space in bytes
   * @dirty: amount of dirty space in bytes
   * @tgc: trivial GC flag (1 => unmap after commit end)
   * @cmt: commit flag (1 => reserved for commit)
   */
  struct ubifs_lpt_lprops {
  	int free;
  	int dirty;
  	unsigned tgc:1;
  	unsigned cmt:1;
  };
  
  /**
   * struct ubifs_lp_stats - statistics of eraseblocks in the main area.
   * @empty_lebs: number of empty LEBs
   * @taken_empty_lebs: number of taken LEBs
   * @idx_lebs: number of indexing LEBs
   * @total_free: total free space in bytes (includes all LEBs)
   * @total_dirty: total dirty space in bytes (includes all LEBs)
   * @total_used: total used space in bytes (does not include index LEBs)
   * @total_dead: total dead space in bytes (does not include index LEBs)
   * @total_dark: total dark space in bytes (does not include index LEBs)
   *
   * The @taken_empty_lebs field counts the LEBs that are in the transient state
   * of having been "taken" for use but not yet written to. @taken_empty_lebs is
   * needed to account correctly for @gc_lnum, otherwise @empty_lebs could be
   * used by itself (in which case 'unused_lebs' would be a better name). In the
   * case of @gc_lnum, it is "taken" at mount time or whenever a LEB is retained
   * by GC, but unlike other empty LEBs that are "taken", it may not be written
   * straight away (i.e. before the next commit start or unmount), so either
   * @gc_lnum must be specially accounted for, or the current approach followed
   * i.e. count it under @taken_empty_lebs.
   *
   * @empty_lebs includes @taken_empty_lebs.
   *
   * @total_used, @total_dead and @total_dark fields do not account indexing
   * LEBs.
   */
  struct ubifs_lp_stats {
  	int empty_lebs;
  	int taken_empty_lebs;
  	int idx_lebs;
  	long long total_free;
  	long long total_dirty;
  	long long total_used;
  	long long total_dead;
  	long long total_dark;
  };
  
  struct ubifs_nnode;
  
  /**
   * struct ubifs_cnode - LEB Properties Tree common node.
   * @parent: parent nnode
   * @cnext: next cnode to commit
   * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE)
   * @iip: index in parent
   * @level: level in the tree (zero for pnodes, greater than zero for nnodes)
   * @num: node number
   */
  struct ubifs_cnode {
  	struct ubifs_nnode *parent;
  	struct ubifs_cnode *cnext;
  	unsigned long flags;
  	int iip;
  	int level;
  	int num;
  };
  
  /**
   * struct ubifs_pnode - LEB Properties Tree leaf node.
   * @parent: parent nnode
   * @cnext: next cnode to commit
   * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE)
   * @iip: index in parent
   * @level: level in the tree (always zero for pnodes)
   * @num: node number
   * @lprops: LEB properties array
   */
  struct ubifs_pnode {
  	struct ubifs_nnode *parent;
  	struct ubifs_cnode *cnext;
  	unsigned long flags;
  	int iip;
  	int level;
  	int num;
  	struct ubifs_lprops lprops[UBIFS_LPT_FANOUT];
  };
  
  /**
   * struct ubifs_nbranch - LEB Properties Tree internal node branch.
   * @lnum: LEB number of child
   * @offs: offset of child
   * @nnode: nnode child
   * @pnode: pnode child
   * @cnode: cnode child
   */
  struct ubifs_nbranch {
  	int lnum;
  	int offs;
  	union {
  		struct ubifs_nnode *nnode;
  		struct ubifs_pnode *pnode;
  		struct ubifs_cnode *cnode;
  	};
  };
  
  /**
   * struct ubifs_nnode - LEB Properties Tree internal node.
   * @parent: parent nnode
   * @cnext: next cnode to commit
   * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE)
   * @iip: index in parent
   * @level: level in the tree (always greater than zero for nnodes)
   * @num: node number
   * @nbranch: branches to child nodes
   */
  struct ubifs_nnode {
  	struct ubifs_nnode *parent;
  	struct ubifs_cnode *cnext;
  	unsigned long flags;
  	int iip;
  	int level;
  	int num;
  	struct ubifs_nbranch nbranch[UBIFS_LPT_FANOUT];
  };
  
  /**
   * struct ubifs_lpt_heap - heap of categorized lprops.
   * @arr: heap array
   * @cnt: number in heap
   * @max_cnt: maximum number allowed in heap
   *
   * There are %LPROPS_HEAP_CNT heaps.
   */
  struct ubifs_lpt_heap {
  	struct ubifs_lprops **arr;
  	int cnt;
  	int max_cnt;
  };
  
  /*
   * Return codes for LPT scan callback function.
   *
   * LPT_SCAN_CONTINUE: continue scanning
   * LPT_SCAN_ADD: add the LEB properties scanned to the tree in memory
   * LPT_SCAN_STOP: stop scanning
   */
  enum {
  	LPT_SCAN_CONTINUE = 0,
  	LPT_SCAN_ADD = 1,
  	LPT_SCAN_STOP = 2,
  };
  
  struct ubifs_info;
  
  /* Callback used by the 'ubifs_lpt_scan_nolock()' function */
  typedef int (*ubifs_lpt_scan_callback)(struct ubifs_info *c,
  				       const struct ubifs_lprops *lprops,
  				       int in_tree, void *data);
  
  /**
   * struct ubifs_wbuf - UBIFS write-buffer.
   * @c: UBIFS file-system description object
   * @buf: write-buffer (of min. flash I/O unit size)
   * @lnum: logical eraseblock number the write-buffer points to
   * @offs: write-buffer offset in this logical eraseblock
   * @avail: number of bytes available in the write-buffer
   * @used:  number of used bytes in the write-buffer
   * @size: write-buffer size (in [@c->min_io_size, @c->max_write_size] range)
   * @jhead: journal head the mutex belongs to (note, needed only to shut lockdep
   *         up by 'mutex_lock_nested()).
   * @sync_callback: write-buffer synchronization callback
   * @io_mutex: serializes write-buffer I/O
   * @lock: serializes @buf, @lnum, @offs, @avail, @used, @next_ino and @inodes
   *        fields
   * @softlimit: soft write-buffer timeout interval
   * @delta: hard and soft timeouts delta (the timer expire inteval is @softlimit
   *         and @softlimit + @delta)
   * @timer: write-buffer timer
   * @no_timer: non-zero if this write-buffer does not have a timer
   * @need_sync: non-zero if the timer expired and the wbuf needs sync'ing
   * @next_ino: points to the next position of the following inode number
   * @inodes: stores the inode numbers of the nodes which are in wbuf
   *
   * The write-buffer synchronization callback is called when the write-buffer is
   * synchronized in order to notify how much space was wasted due to
   * write-buffer padding and how much free space is left in the LEB.
   *
   * Note: the fields @buf, @lnum, @offs, @avail and @used can be read under
   * spin-lock or mutex because they are written under both mutex and spin-lock.
   * @buf is appended to under mutex but overwritten under both mutex and
   * spin-lock. Thus the data between @buf and @buf + @used can be read under
   * spinlock.
   */
  struct ubifs_wbuf {
  	struct ubifs_info *c;
  	void *buf;
  	int lnum;
  	int offs;
  	int avail;
  	int used;
  	int size;
  	int jhead;
  	int (*sync_callback)(struct ubifs_info *c, int lnum, int free, int pad);
  	struct mutex io_mutex;
  	spinlock_t lock;
  //	ktime_t softlimit;
  //	unsigned long long delta;
  //	struct hrtimer timer;
  	unsigned int no_timer:1;
  	unsigned int need_sync:1;
  	int next_ino;
  	ino_t *inodes;
  };
  
  /**
   * struct ubifs_bud - bud logical eraseblock.
   * @lnum: logical eraseblock number
   * @start: where the (uncommitted) bud data starts
   * @jhead: journal head number this bud belongs to
   * @list: link in the list buds belonging to the same journal head
   * @rb: link in the tree of all buds
   */
  struct ubifs_bud {
  	int lnum;
  	int start;
  	int jhead;
  	struct list_head list;
  	struct rb_node rb;
  };
  
  /**
   * struct ubifs_jhead - journal head.
   * @wbuf: head's write-buffer
   * @buds_list: list of bud LEBs belonging to this journal head
   * @grouped: non-zero if UBIFS groups nodes when writing to this journal head
   *
   * Note, the @buds list is protected by the @c->buds_lock.
   */
  struct ubifs_jhead {
  	struct ubifs_wbuf wbuf;
  	struct list_head buds_list;
  	unsigned int grouped:1;
  };
  
  /**
   * struct ubifs_zbranch - key/coordinate/length branch stored in znodes.
   * @key: key
   * @znode: znode address in memory
   * @lnum: LEB number of the target node (indexing node or data node)
   * @offs: target node offset within @lnum
   * @len: target node length
   */
  struct ubifs_zbranch {
  	union ubifs_key key;
  	union {
  		struct ubifs_znode *znode;
  		void *leaf;
  	};
  	int lnum;
  	int offs;
  	int len;
  };
  
  /**
   * struct ubifs_znode - in-memory representation of an indexing node.
   * @parent: parent znode or NULL if it is the root
   * @cnext: next znode to commit
   * @flags: znode flags (%DIRTY_ZNODE, %COW_ZNODE or %OBSOLETE_ZNODE)
   * @time: last access time (seconds)
   * @level: level of the entry in the TNC tree
   * @child_cnt: count of child znodes
   * @iip: index in parent's zbranch array
   * @alt: lower bound of key range has altered i.e. child inserted at slot 0
   * @lnum: LEB number of the corresponding indexing node
   * @offs: offset of the corresponding indexing node
   * @len: length  of the corresponding indexing node
   * @zbranch: array of znode branches (@c->fanout elements)
   *
   * Note! The @lnum, @offs, and @len fields are not really needed - we have them
   * only for internal consistency check. They could be removed to save some RAM.
   */
  struct ubifs_znode {
  	struct ubifs_znode *parent;
  	struct ubifs_znode *cnext;
  	unsigned long flags;
  	unsigned long time;
  	int level;
  	int child_cnt;
  	int iip;
  	int alt;
  	int lnum;
  	int offs;
  	int len;
  	struct ubifs_zbranch zbranch[];
  };
  
  /**
   * struct bu_info - bulk-read information.
   * @key: first data node key
   * @zbranch: zbranches of data nodes to bulk read
   * @buf: buffer to read into
   * @buf_len: buffer length
   * @gc_seq: GC sequence number to detect races with GC
   * @cnt: number of data nodes for bulk read
   * @blk_cnt: number of data blocks including holes
   * @oef: end of file reached
   */
  struct bu_info {
  	union ubifs_key key;
  	struct ubifs_zbranch zbranch[UBIFS_MAX_BULK_READ];
  	void *buf;
  	int buf_len;
  	int gc_seq;
  	int cnt;
  	int blk_cnt;
  	int eof;
  };
  
  /**
   * struct ubifs_node_range - node length range description data structure.
   * @len: fixed node length
   * @min_len: minimum possible node length
   * @max_len: maximum possible node length
   *
   * If @max_len is %0, the node has fixed length @len.
   */
  struct ubifs_node_range {
  	union {
  		int len;
  		int min_len;
  	};
  	int max_len;
  };
  
  /**
   * struct ubifs_compressor - UBIFS compressor description structure.
   * @compr_type: compressor type (%UBIFS_COMPR_LZO, etc)
   * @cc: cryptoapi compressor handle
   * @comp_mutex: mutex used during compression
   * @decomp_mutex: mutex used during decompression
   * @name: compressor name
   * @capi_name: cryptoapi compressor name
   */
  struct ubifs_compressor {
  	int compr_type;
  	struct crypto_comp *cc;
  	struct mutex *comp_mutex;
  	struct mutex *decomp_mutex;
  	const char *name;
  	const char *capi_name;
  #ifdef __UBOOT__
  	int (*decompress)(const unsigned char *in, size_t in_len,
  			  unsigned char *out, size_t *out_len);
  #endif
  };
  
  /**
   * struct ubifs_budget_req - budget requirements of an operation.
   *
   * @fast: non-zero if the budgeting should try to acquire budget quickly and
   *        should not try to call write-back
   * @recalculate: non-zero if @idx_growth, @data_growth, and @dd_growth fields
   *               have to be re-calculated
   * @new_page: non-zero if the operation adds a new page
   * @dirtied_page: non-zero if the operation makes a page dirty
   * @new_dent: non-zero if the operation adds a new directory entry
   * @mod_dent: non-zero if the operation removes or modifies an existing
   *            directory entry
   * @new_ino: non-zero if the operation adds a new inode
   * @new_ino_d: now much data newly created inode contains
   * @dirtied_ino: how many inodes the operation makes dirty
   * @dirtied_ino_d: now much data dirtied inode contains
   * @idx_growth: how much the index will supposedly grow
   * @data_growth: how much new data the operation will supposedly add
   * @dd_growth: how much data that makes other data dirty the operation will
   *             supposedly add
   *
   * @idx_growth, @data_growth and @dd_growth are not used in budget request. The
   * budgeting subsystem caches index and data growth values there to avoid
   * re-calculating them when the budget is released. However, if @idx_growth is
   * %-1, it is calculated by the release function using other fields.
   *
   * An inode may contain 4KiB of data at max., thus the widths of @new_ino_d
   * is 13 bits, and @dirtied_ino_d - 15, because up to 4 inodes may be made
   * dirty by the re-name operation.
   *
   * Note, UBIFS aligns node lengths to 8-bytes boundary, so the requester has to
   * make sure the amount of inode data which contribute to @new_ino_d and
   * @dirtied_ino_d fields are aligned.
   */
  struct ubifs_budget_req {
  	unsigned int fast:1;
  	unsigned int recalculate:1;
  #ifndef UBIFS_DEBUG
  	unsigned int new_page:1;
  	unsigned int dirtied_page:1;
  	unsigned int new_dent:1;
  	unsigned int mod_dent:1;
  	unsigned int new_ino:1;
  	unsigned int new_ino_d:13;
  	unsigned int dirtied_ino:4;
  	unsigned int dirtied_ino_d:15;
  #else
  	/* Not bit-fields to check for overflows */
  	unsigned int new_page;
  	unsigned int dirtied_page;
  	unsigned int new_dent;
  	unsigned int mod_dent;
  	unsigned int new_ino;
  	unsigned int new_ino_d;
  	unsigned int dirtied_ino;
  	unsigned int dirtied_ino_d;
  #endif
  	int idx_growth;
  	int data_growth;
  	int dd_growth;
  };
  
  /**
   * struct ubifs_orphan - stores the inode number of an orphan.
   * @rb: rb-tree node of rb-tree of orphans sorted by inode number
   * @list: list head of list of orphans in order added
   * @new_list: list head of list of orphans added since the last commit
   * @cnext: next orphan to commit
   * @dnext: next orphan to delete
   * @inum: inode number
   * @new: %1 => added since the last commit, otherwise %0
   * @cmt: %1 => commit pending, otherwise %0
   * @del: %1 => delete pending, otherwise %0
   */
  struct ubifs_orphan {
  	struct rb_node rb;
  	struct list_head list;
  	struct list_head new_list;
  	struct ubifs_orphan *cnext;
  	struct ubifs_orphan *dnext;
  	ino_t inum;
  	unsigned new:1;
  	unsigned cmt:1;
  	unsigned del:1;
  };
  
  /**
   * struct ubifs_mount_opts - UBIFS-specific mount options information.
   * @unmount_mode: selected unmount mode (%0 default, %1 normal, %2 fast)
   * @bulk_read: enable/disable bulk-reads (%0 default, %1 disabe, %2 enable)
   * @chk_data_crc: enable/disable CRC data checking when reading data nodes
   *                (%0 default, %1 disabe, %2 enable)
   * @override_compr: override default compressor (%0 - do not override and use
   *                  superblock compressor, %1 - override and use compressor
   *                  specified in @compr_type)
   * @compr_type: compressor type to override the superblock compressor with
   *              (%UBIFS_COMPR_NONE, etc)
   */
  struct ubifs_mount_opts {
  	unsigned int unmount_mode:2;
  	unsigned int bulk_read:2;
  	unsigned int chk_data_crc:2;
  	unsigned int override_compr:1;
  	unsigned int compr_type:2;
  };
  
  /**
   * struct ubifs_budg_info - UBIFS budgeting information.
   * @idx_growth: amount of bytes budgeted for index growth
   * @data_growth: amount of bytes budgeted for cached data
   * @dd_growth: amount of bytes budgeted for cached data that will make
   *             other data dirty
   * @uncommitted_idx: amount of bytes were budgeted for growth of the index, but
   *                   which still have to be taken into account because the index
   *                   has not been committed so far
   * @old_idx_sz: size of index on flash
   * @min_idx_lebs: minimum number of LEBs required for the index
   * @nospace: non-zero if the file-system does not have flash space (used as
   *           optimization)
   * @nospace_rp: the same as @nospace, but additionally means that even reserved
   *              pool is full
   * @page_budget: budget for a page (constant, nenver changed after mount)
   * @inode_budget: budget for an inode (constant, nenver changed after mount)
   * @dent_budget: budget for a directory entry (constant, nenver changed after
   *               mount)
   */
  struct ubifs_budg_info {
  	long long idx_growth;
  	long long data_growth;
  	long long dd_growth;
  	long long uncommitted_idx;
  	unsigned long long old_idx_sz;
  	int min_idx_lebs;
  	unsigned int nospace:1;
  	unsigned int nospace_rp:1;
  	int page_budget;
  	int inode_budget;
  	int dent_budget;
  };
  
  struct ubifs_debug_info;
  
  /**
   * struct ubifs_info - UBIFS file-system description data structure
   * (per-superblock).
   * @vfs_sb: VFS @struct super_block object
   * @bdi: backing device info object to make VFS happy and disable read-ahead
   *
   * @highest_inum: highest used inode number
   * @max_sqnum: current global sequence number
   * @cmt_no: commit number of the last successfully completed commit, protected
   *          by @commit_sem
   * @cnt_lock: protects @highest_inum and @max_sqnum counters
   * @fmt_version: UBIFS on-flash format version
   * @ro_compat_version: R/O compatibility version
   * @uuid: UUID from super block
   *
   * @lhead_lnum: log head logical eraseblock number
   * @lhead_offs: log head offset
   * @ltail_lnum: log tail logical eraseblock number (offset is always 0)
   * @log_mutex: protects the log, @lhead_lnum, @lhead_offs, @ltail_lnum, and
   *             @bud_bytes
   * @min_log_bytes: minimum required number of bytes in the log
   * @cmt_bud_bytes: used during commit to temporarily amount of bytes in
   *                 committed buds
   *
   * @buds: tree of all buds indexed by bud LEB number
   * @bud_bytes: how many bytes of flash is used by buds
   * @buds_lock: protects the @buds tree, @bud_bytes, and per-journal head bud
   *             lists
   * @jhead_cnt: count of journal heads
   * @jheads: journal heads (head zero is base head)
   * @max_bud_bytes: maximum number of bytes allowed in buds
   * @bg_bud_bytes: number of bud bytes when background commit is initiated
   * @old_buds: buds to be released after commit ends
   * @max_bud_cnt: maximum number of buds
   *
   * @commit_sem: synchronizes committer with other processes
   * @cmt_state: commit state
   * @cs_lock: commit state lock
   * @cmt_wq: wait queue to sleep on if the log is full and a commit is running
   *
   * @big_lpt: flag that LPT is too big to write whole during commit
   * @space_fixup: flag indicating that free space in LEBs needs to be cleaned up
   * @no_chk_data_crc: do not check CRCs when reading data nodes (except during
   *                   recovery)
   * @bulk_read: enable bulk-reads
   * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
   * @rw_incompat: the media is not R/W compatible
   *
   * @tnc_mutex: protects the Tree Node Cache (TNC), @zroot, @cnext, @enext, and
   *             @calc_idx_sz
   * @zroot: zbranch which points to the root index node and znode
   * @cnext: next znode to commit
   * @enext: next znode to commit to empty space
   * @gap_lebs: array of LEBs used by the in-gaps commit method
   * @cbuf: commit buffer
   * @ileb_buf: buffer for commit in-the-gaps method
   * @ileb_len: length of data in ileb_buf
   * @ihead_lnum: LEB number of index head
   * @ihead_offs: offset of index head
   * @ilebs: pre-allocated index LEBs
   * @ileb_cnt: number of pre-allocated index LEBs
   * @ileb_nxt: next pre-allocated index LEBs
   * @old_idx: tree of index nodes obsoleted since the last commit start
   * @bottom_up_buf: a buffer which is used by 'dirty_cow_bottom_up()' in tnc.c
   *
   * @mst_node: master node
   * @mst_offs: offset of valid master node
   * @mst_mutex: protects the master node area, @mst_node, and @mst_offs
   *
   * @max_bu_buf_len: maximum bulk-read buffer length
   * @bu_mutex: protects the pre-allocated bulk-read buffer and @c->bu
   * @bu: pre-allocated bulk-read information
   *
   * @write_reserve_mutex: protects @write_reserve_buf
   * @write_reserve_buf: on the write path we allocate memory, which might
   *                     sometimes be unavailable, in which case we use this
   *                     write reserve buffer
   *
   * @log_lebs: number of logical eraseblocks in the log
   * @log_bytes: log size in bytes
   * @log_last: last LEB of the log
   * @lpt_lebs: number of LEBs used for lprops table
   * @lpt_first: first LEB of the lprops table area
   * @lpt_last: last LEB of the lprops table area
   * @orph_lebs: number of LEBs used for the orphan area
   * @orph_first: first LEB of the orphan area
   * @orph_last: last LEB of the orphan area
   * @main_lebs: count of LEBs in the main area
   * @main_first: first LEB of the main area
   * @main_bytes: main area size in bytes
   *
   * @key_hash_type: type of the key hash
   * @key_hash: direntry key hash function
   * @key_fmt: key format
   * @key_len: key length
   * @fanout: fanout of the index tree (number of links per indexing node)
   *
   * @min_io_size: minimal input/output unit size
   * @min_io_shift: number of bits in @min_io_size minus one
   * @max_write_size: maximum amount of bytes the underlying flash can write at a
   *                  time (MTD write buffer size)
   * @max_write_shift: number of bits in @max_write_size minus one
   * @leb_size: logical eraseblock size in bytes
   * @leb_start: starting offset of logical eraseblocks within physical
   *             eraseblocks
   * @half_leb_size: half LEB size
   * @idx_leb_size: how many bytes of an LEB are effectively available when it is
   *                used to store indexing nodes (@leb_size - @max_idx_node_sz)
   * @leb_cnt: count of logical eraseblocks
   * @max_leb_cnt: maximum count of logical eraseblocks
   * @old_leb_cnt: count of logical eraseblocks before re-size
   * @ro_media: the underlying UBI volume is read-only
   * @ro_mount: the file-system was mounted as read-only
   * @ro_error: UBIFS switched to R/O mode because an error happened
   *
   * @dirty_pg_cnt: number of dirty pages (not used)
   * @dirty_zn_cnt: number of dirty znodes
   * @clean_zn_cnt: number of clean znodes
   *
   * @space_lock: protects @bi and @lst
   * @lst: lprops statistics
   * @bi: budgeting information
   * @calc_idx_sz: temporary variable which is used to calculate new index size
   *               (contains accurate new index size at end of TNC commit start)
   *
   * @ref_node_alsz: size of the LEB reference node aligned to the min. flash
   *                 I/O unit
   * @mst_node_alsz: master node aligned size
   * @min_idx_node_sz: minimum indexing node aligned on 8-bytes boundary
   * @max_idx_node_sz: maximum indexing node aligned on 8-bytes boundary
   * @max_inode_sz: maximum possible inode size in bytes
   * @max_znode_sz: size of znode in bytes
   *
   * @leb_overhead: how many bytes are wasted in an LEB when it is filled with
   *                data nodes of maximum size - used in free space reporting
   * @dead_wm: LEB dead space watermark
   * @dark_wm: LEB dark space watermark
   * @block_cnt: count of 4KiB blocks on the FS
   *
   * @ranges: UBIFS node length ranges
   * @ubi: UBI volume descriptor
   * @di: UBI device information
   * @vi: UBI volume information
   *
   * @orph_tree: rb-tree of orphan inode numbers
   * @orph_list: list of orphan inode numbers in order added
   * @orph_new: list of orphan inode numbers added since last commit
   * @orph_cnext: next orphan to commit
   * @orph_dnext: next orphan to delete
   * @orphan_lock: lock for orph_tree and orph_new
   * @orph_buf: buffer for orphan nodes
   * @new_orphans: number of orphans since last commit
   * @cmt_orphans: number of orphans being committed
   * @tot_orphans: number of orphans in the rb_tree
   * @max_orphans: maximum number of orphans allowed
   * @ohead_lnum: orphan head LEB number
   * @ohead_offs: orphan head offset
   * @no_orphs: non-zero if there are no orphans
   *
   * @bgt: UBIFS background thread
   * @bgt_name: background thread name
   * @need_bgt: if background thread should run
   * @need_wbuf_sync: if write-buffers have to be synchronized
   *
   * @gc_lnum: LEB number used for garbage collection
   * @sbuf: a buffer of LEB size used by GC and replay for scanning
   * @idx_gc: list of index LEBs that have been garbage collected
   * @idx_gc_cnt: number of elements on the idx_gc list
   * @gc_seq: incremented for every non-index LEB garbage collected
   * @gced_lnum: last non-index LEB that was garbage collected
   *
   * @infos_list: links all 'ubifs_info' objects
   * @umount_mutex: serializes shrinker and un-mount
   * @shrinker_run_no: shrinker run number
   *
   * @space_bits: number of bits needed to record free or dirty space
   * @lpt_lnum_bits: number of bits needed to record a LEB number in the LPT
   * @lpt_offs_bits: number of bits needed to record an offset in the LPT
   * @lpt_spc_bits: number of bits needed to space in the LPT
   * @pcnt_bits: number of bits needed to record pnode or nnode number
   * @lnum_bits: number of bits needed to record LEB number
   * @nnode_sz: size of on-flash nnode
   * @pnode_sz: size of on-flash pnode
   * @ltab_sz: size of on-flash LPT lprops table
   * @lsave_sz: size of on-flash LPT save table
   * @pnode_cnt: number of pnodes
   * @nnode_cnt: number of nnodes
   * @lpt_hght: height of the LPT
   * @pnodes_have: number of pnodes in memory
   *
   * @lp_mutex: protects lprops table and all the other lprops-related fields
   * @lpt_lnum: LEB number of the root nnode of the LPT
   * @lpt_offs: offset of the root nnode of the LPT
   * @nhead_lnum: LEB number of LPT head
   * @nhead_offs: offset of LPT head
   * @lpt_drty_flgs: dirty flags for LPT special nodes e.g. ltab
   * @dirty_nn_cnt: number of dirty nnodes
   * @dirty_pn_cnt: number of dirty pnodes
   * @check_lpt_free: flag that indicates LPT GC may be needed
   * @lpt_sz: LPT size
   * @lpt_nod_buf: buffer for an on-flash nnode or pnode
   * @lpt_buf: buffer of LEB size used by LPT
   * @nroot: address in memory of the root nnode of the LPT
   * @lpt_cnext: next LPT node to commit
   * @lpt_heap: array of heaps of categorized lprops
   * @dirty_idx: a (reverse sorted) copy of the LPROPS_DIRTY_IDX heap as at
   *             previous commit start
   * @uncat_list: list of un-categorized LEBs
   * @empty_list: list of empty LEBs
   * @freeable_list: list of freeable non-index LEBs (free + dirty == @leb_size)
   * @frdi_idx_list: list of freeable index LEBs (free + dirty == @leb_size)
   * @freeable_cnt: number of freeable LEBs in @freeable_list
   * @in_a_category_cnt: count of lprops which are in a certain category, which
   *                     basically meants that they were loaded from the flash
   *
   * @ltab_lnum: LEB number of LPT's own lprops table
   * @ltab_offs: offset of LPT's own lprops table
   * @ltab: LPT's own lprops table
   * @ltab_cmt: LPT's own lprops table (commit copy)
   * @lsave_cnt: number of LEB numbers in LPT's save table
   * @lsave_lnum: LEB number of LPT's save table
   * @lsave_offs: offset of LPT's save table
   * @lsave: LPT's save table
   * @lscan_lnum: LEB number of last LPT scan
   *
   * @rp_size: size of the reserved pool in bytes
   * @report_rp_size: size of the reserved pool reported to user-space
   * @rp_uid: reserved pool user ID
   * @rp_gid: reserved pool group ID
   *
   * @empty: %1 if the UBI device is empty
   * @need_recovery: %1 if the file-system needs recovery
   * @replaying: %1 during journal replay
   * @mounting: %1 while mounting
   * @remounting_rw: %1 while re-mounting from R/O mode to R/W mode
   * @replay_list: temporary list used during journal replay
   * @replay_buds: list of buds to replay
   * @cs_sqnum: sequence number of first node in the log (commit start node)
   * @replay_sqnum: sequence number of node currently being replayed
   * @unclean_leb_list: LEBs to recover when re-mounting R/O mounted FS to R/W
   *                    mode
   * @rcvrd_mst_node: recovered master node to write when re-mounting R/O mounted
   *                  FS to R/W mode
   * @size_tree: inode size information for recovery
   * @mount_opts: UBIFS-specific mount options
   *
   * @dbg: debugging-related information
   */
  struct ubifs_info {
  	struct super_block *vfs_sb;
  #ifndef __UBOOT__
  	struct backing_dev_info bdi;
  #endif
  
  	ino_t highest_inum;
  	unsigned long long max_sqnum;
  	unsigned long long cmt_no;
  	spinlock_t cnt_lock;
  	int fmt_version;
  	int ro_compat_version;
  	unsigned char uuid[16];
  
  	int lhead_lnum;
  	int lhead_offs;
  	int ltail_lnum;
  	struct mutex log_mutex;
  	int min_log_bytes;
  	long long cmt_bud_bytes;
  
  	struct rb_root buds;
  	long long bud_bytes;
  	spinlock_t buds_lock;
  	int jhead_cnt;
  	struct ubifs_jhead *jheads;
  	long long max_bud_bytes;
  	long long bg_bud_bytes;
  	struct list_head old_buds;
  	int max_bud_cnt;
  
  	struct rw_semaphore commit_sem;
  	int cmt_state;
  	spinlock_t cs_lock;
  	wait_queue_head_t cmt_wq;
  
  	unsigned int big_lpt:1;
  	unsigned int space_fixup:1;
  	unsigned int no_chk_data_crc:1;
  	unsigned int bulk_read:1;
  	unsigned int default_compr:2;
  	unsigned int rw_incompat:1;
  
  	struct mutex tnc_mutex;
  	struct ubifs_zbranch zroot;
  	struct ubifs_znode *cnext;
  	struct ubifs_znode *enext;
  	int *gap_lebs;
  	void *cbuf;
  	void *ileb_buf;
  	int ileb_len;
  	int ihead_lnum;
  	int ihead_offs;
  	int *ilebs;
  	int ileb_cnt;
  	int ileb_nxt;
  	struct rb_root old_idx;
  	int *bottom_up_buf;
  
  	struct ubifs_mst_node *mst_node;
  	int mst_offs;
  	struct mutex mst_mutex;
  
  	int max_bu_buf_len;
  	struct mutex bu_mutex;
  	struct bu_info bu;
  
  	struct mutex write_reserve_mutex;
  	void *write_reserve_buf;
  
  	int log_lebs;
  	long long log_bytes;
  	int log_last;
  	int lpt_lebs;
  	int lpt_first;
  	int lpt_last;
  	int orph_lebs;
  	int orph_first;
  	int orph_last;
  	int main_lebs;
  	int main_first;
  	long long main_bytes;
  
  	uint8_t key_hash_type;
  	uint32_t (*key_hash)(const char *str, int len);
  	int key_fmt;
  	int key_len;
  	int fanout;
  
  	int min_io_size;
  	int min_io_shift;
  	int max_write_size;
  	int max_write_shift;
  	int leb_size;
  	int leb_start;
  	int half_leb_size;
  	int idx_leb_size;
  	int leb_cnt;
  	int max_leb_cnt;
  	int old_leb_cnt;
  	unsigned int ro_media:1;
  	unsigned int ro_mount:1;
  	unsigned int ro_error:1;
  
  	atomic_long_t dirty_pg_cnt;
  	atomic_long_t dirty_zn_cnt;
  	atomic_long_t clean_zn_cnt;
  
  	spinlock_t space_lock;
  	struct ubifs_lp_stats lst;
  	struct ubifs_budg_info bi;
  	unsigned long long calc_idx_sz;
  
  	int ref_node_alsz;
  	int mst_node_alsz;
  	int min_idx_node_sz;
  	int max_idx_node_sz;
  	long long max_inode_sz;
  	int max_znode_sz;
  
  	int leb_overhead;
  	int dead_wm;
  	int dark_wm;
  	int block_cnt;
  
  	struct ubifs_node_range ranges[UBIFS_NODE_TYPES_CNT];
  	struct ubi_volume_desc *ubi;
  	struct ubi_device_info di;
  	struct ubi_volume_info vi;
  
  	struct rb_root orph_tree;
  	struct list_head orph_list;
  	struct list_head orph_new;
  	struct ubifs_orphan *orph_cnext;
  	struct ubifs_orphan *orph_dnext;
  	spinlock_t orphan_lock;
  	void *orph_buf;
  	int new_orphans;
  	int cmt_orphans;
  	int tot_orphans;
  	int max_orphans;
  	int ohead_lnum;
  	int ohead_offs;
  	int no_orphs;
  
  	struct task_struct *bgt;
  	char bgt_name[sizeof(BGT_NAME_PATTERN) + 9];
  	int need_bgt;
  	int need_wbuf_sync;
  
  	int gc_lnum;
  	void *sbuf;
  	struct list_head idx_gc;
  	int idx_gc_cnt;
  	int gc_seq;
  	int gced_lnum;
  
  	struct list_head infos_list;
  	struct mutex umount_mutex;
  	unsigned int shrinker_run_no;
  
  	int space_bits;
  	int lpt_lnum_bits;
  	int lpt_offs_bits;
  	int lpt_spc_bits;
  	int pcnt_bits;
  	int lnum_bits;
  	int nnode_sz;
  	int pnode_sz;
  	int ltab_sz;
  	int lsave_sz;
  	int pnode_cnt;
  	int nnode_cnt;
  	int lpt_hght;
  	int pnodes_have;
  
  	struct mutex lp_mutex;
  	int lpt_lnum;
  	int lpt_offs;
  	int nhead_lnum;
  	int nhead_offs;
  	int lpt_drty_flgs;
  	int dirty_nn_cnt;
  	int dirty_pn_cnt;
  	int check_lpt_free;
  	long long lpt_sz;
  	void *lpt_nod_buf;
  	void *lpt_buf;
  	struct ubifs_nnode *nroot;
  	struct ubifs_cnode *lpt_cnext;
  	struct ubifs_lpt_heap lpt_heap[LPROPS_HEAP_CNT];
  	struct ubifs_lpt_heap dirty_idx;
  	struct list_head uncat_list;
  	struct list_head empty_list;
  	struct list_head freeable_list;
  	struct list_head frdi_idx_list;
  	int freeable_cnt;
  	int in_a_category_cnt;
  
  	int ltab_lnum;
  	int ltab_offs;
  	struct ubifs_lpt_lprops *ltab;
  	struct ubifs_lpt_lprops *ltab_cmt;
  	int lsave_cnt;
  	int lsave_lnum;
  	int lsave_offs;
  	int *lsave;
  	int lscan_lnum;
  
  	long long rp_size;
  	long long report_rp_size;
  	kuid_t rp_uid;
  	kgid_t rp_gid;
  
  	/* The below fields are used only during mounting and re-mounting */
  	unsigned int empty:1;
  	unsigned int need_recovery:1;
  	unsigned int replaying:1;
  	unsigned int mounting:1;
  	unsigned int remounting_rw:1;
  	struct list_head replay_list;
  	struct list_head replay_buds;
  	unsigned long long cs_sqnum;
  	unsigned long long replay_sqnum;
  	struct list_head unclean_leb_list;
  	struct ubifs_mst_node *rcvrd_mst_node;
  	struct rb_root size_tree;
  	struct ubifs_mount_opts mount_opts;
  
  #ifndef __UBOOT__
  	struct ubifs_debug_info *dbg;
  #endif
  };
  
  extern struct list_head ubifs_infos;
  extern spinlock_t ubifs_infos_lock;
  extern atomic_long_t ubifs_clean_zn_cnt;
  extern struct kmem_cache *ubifs_inode_slab;
  extern const struct super_operations ubifs_super_operations;
  extern const struct address_space_operations ubifs_file_address_operations;
  extern const struct file_operations ubifs_file_operations;
  extern const struct inode_operations ubifs_file_inode_operations;
  extern const struct file_operations ubifs_dir_operations;
  extern const struct inode_operations ubifs_dir_inode_operations;
  extern const struct inode_operations ubifs_symlink_inode_operations;
  extern struct backing_dev_info ubifs_backing_dev_info;
  extern struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];
  
  /* io.c */
  void ubifs_ro_mode(struct ubifs_info *c, int err);
  int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs,
  		   int len, int even_ebadmsg);
  int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs,
  		    int len);
  int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len);
  int ubifs_leb_unmap(struct ubifs_info *c, int lnum);
  int ubifs_leb_map(struct ubifs_info *c, int lnum);
  int ubifs_is_mapped(const struct ubifs_info *c, int lnum);
  int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len);
  int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs);
  int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf);
  int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len,
  		    int lnum, int offs);
  int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len,
  			 int lnum, int offs);
  int ubifs_write_node(struct ubifs_info *c, void *node, int len, int lnum,
  		     int offs);
  int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum,
  		     int offs, int quiet, int must_chk_crc);
  void ubifs_prepare_node(struct ubifs_info *c, void *buf, int len, int pad);
  void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last);
  int ubifs_io_init(struct ubifs_info *c);
  void ubifs_pad(const struct ubifs_info *c, void *buf, int pad);
  int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf);
  int ubifs_bg_wbufs_sync(struct ubifs_info *c);
  void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum);
  int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode);
  
  /* scan.c */
  struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum,
  				  int offs, void *sbuf, int quiet);
  void ubifs_scan_destroy(struct ubifs_scan_leb *sleb);
  int ubifs_scan_a_node(const struct ubifs_info *c, void *buf, int len, int lnum,
  		      int offs, int quiet);
  struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum,
  					int offs, void *sbuf);
  void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
  		    int lnum, int offs);
  int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
  		   void *buf, int offs);
  void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs,
  			      void *buf);
  
  /* log.c */
  void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud);
  void ubifs_create_buds_lists(struct ubifs_info *c);
  int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs);
  struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum);
  struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum);
  int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum);
  int ubifs_log_end_commit(struct ubifs_info *c, int new_ltail_lnum);
  int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum);
  int ubifs_consolidate_log(struct ubifs_info *c);
  
  /* journal.c */
  int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
  		     const struct qstr *nm, const struct inode *inode,
  		     int deletion, int xent);
  int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
  			 const union ubifs_key *key, const void *buf, int len);
  int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode);
  int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode);
  int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
  		     const struct dentry *old_dentry,
  		     const struct inode *new_dir,
  		     const struct dentry *new_dentry, int sync);
  int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
  		       loff_t old_size, loff_t new_size);
  int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host,
  			   const struct inode *inode, const struct qstr *nm);
  int ubifs_jnl_change_xattr(struct ubifs_info *c, const struct inode *inode1,
  			   const struct inode *inode2);
  
  /* budget.c */
  int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req);
  void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req);
  void ubifs_release_dirty_inode_budget(struct ubifs_info *c,
  				      struct ubifs_inode *ui);
  int ubifs_budget_inode_op(struct ubifs_info *c, struct inode *inode,
  			  struct ubifs_budget_req *req);
  void ubifs_release_ino_dirty(struct ubifs_info *c, struct inode *inode,
  				struct ubifs_budget_req *req);
  void ubifs_cancel_ino_op(struct ubifs_info *c, struct inode *inode,
  			 struct ubifs_budget_req *req);
  long long ubifs_get_free_space(struct ubifs_info *c);
  long long ubifs_get_free_space_nolock(struct ubifs_info *c);
  int ubifs_calc_min_idx_lebs(struct ubifs_info *c);
  void ubifs_convert_page_budget(struct ubifs_info *c);
  long long ubifs_reported_space(const struct ubifs_info *c, long long free);
  long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs);
  
  /* find.c */
  int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *offs,
  			  int squeeze);
  int ubifs_find_free_leb_for_idx(struct ubifs_info *c);
  int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
  			 int min_space, int pick_free);
  int ubifs_find_dirty_idx_leb(struct ubifs_info *c);
  int ubifs_save_dirty_idx_lnums(struct ubifs_info *c);
  
  /* tnc.c */
  int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key,
  			struct ubifs_znode **zn, int *n);
  int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
  			void *node, const struct qstr *nm);
  int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key,
  		     void *node, int *lnum, int *offs);
  int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
  		  int offs, int len);
  int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key,
  		      int old_lnum, int old_offs, int lnum, int offs, int len);
  int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
  		     int lnum, int offs, int len, const struct qstr *nm);
  int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key);
  int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key,
  			const struct qstr *nm);
  int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key,
  			   union ubifs_key *to_key);
  int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum);
  struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c,
  					   union ubifs_key *key,
  					   const struct qstr *nm);
  void ubifs_tnc_close(struct ubifs_info *c);
  int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level,
  		       int lnum, int offs, int is_idx);
  int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level,
  			 int lnum, int offs);
  /* Shared by tnc.c for tnc_commit.c */
  void destroy_old_idx(struct ubifs_info *c);
  int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level,
  		       int lnum, int offs);
  int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode);
  int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu);
  int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu);
  
  /* tnc_misc.c */
  struct ubifs_znode *ubifs_tnc_levelorder_next(struct ubifs_znode *zr,
  					      struct ubifs_znode *znode);
  int ubifs_search_zbranch(const struct ubifs_info *c,
  			 const struct ubifs_znode *znode,
  			 const union ubifs_key *key, int *n);
  struct ubifs_znode *ubifs_tnc_postorder_first(struct ubifs_znode *znode);
  struct ubifs_znode *ubifs_tnc_postorder_next(struct ubifs_znode *znode);
  long ubifs_destroy_tnc_subtree(struct ubifs_znode *zr);
  struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c,
  				     struct ubifs_zbranch *zbr,
  				     struct ubifs_znode *parent, int iip);
  int ubifs_tnc_read_node(struct ubifs_info *c, struct ubifs_zbranch *zbr,
  			void *node);
  
  /* tnc_commit.c */
  int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot);
  int ubifs_tnc_end_commit(struct ubifs_info *c);
  
  #ifndef __UBOOT__
  /* shrinker.c */
  unsigned long ubifs_shrink_scan(struct shrinker *shrink,
  				struct shrink_control *sc);
  unsigned long ubifs_shrink_count(struct shrinker *shrink,
  				 struct shrink_control *sc);
  #endif
  
  /* commit.c */
  int ubifs_bg_thread(void *info);
  void ubifs_commit_required(struct ubifs_info *c);
  void ubifs_request_bg_commit(struct ubifs_info *c);
  int ubifs_run_commit(struct ubifs_info *c);
  void ubifs_recovery_commit(struct ubifs_info *c);
  int ubifs_gc_should_commit(struct ubifs_info *c);
  void ubifs_wait_for_commit(struct ubifs_info *c);
  
  /* master.c */
  int ubifs_read_master(struct ubifs_info *c);
  int ubifs_write_master(struct ubifs_info *c);
  
  /* sb.c */
  int ubifs_read_superblock(struct ubifs_info *c);
  struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c);
  int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup);
  int ubifs_fixup_free_space(struct ubifs_info *c);
  
  /* replay.c */
  int ubifs_validate_entry(struct ubifs_info *c,
  			 const struct ubifs_dent_node *dent);
  int ubifs_replay_journal(struct ubifs_info *c);
  
  /* gc.c */
  int ubifs_garbage_collect(struct ubifs_info *c, int anyway);
  int ubifs_gc_start_commit(struct ubifs_info *c);
  int ubifs_gc_end_commit(struct ubifs_info *c);
  void ubifs_destroy_idx_gc(struct ubifs_info *c);
  int ubifs_get_idx_gc_leb(struct ubifs_info *c);
  int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp);
  
  /* orphan.c */
  int ubifs_add_orphan(struct ubifs_info *c, ino_t inum);
  void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum);
  int ubifs_orphan_start_commit(struct ubifs_info *c);
  int ubifs_orphan_end_commit(struct ubifs_info *c);
  int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only);
  int ubifs_clear_orphans(struct ubifs_info *c);
  
  /* lpt.c */
  int ubifs_calc_lpt_geom(struct ubifs_info *c);
  int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
  			  int *lpt_lebs, int *big_lpt);
  int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr);
  struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum);
  struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum);
  int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
  			  ubifs_lpt_scan_callback scan_cb, void *data);
  
  /* Shared by lpt.c for lpt_commit.c */
  void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave);
  void ubifs_pack_ltab(struct ubifs_info *c, void *buf,
  		     struct ubifs_lpt_lprops *ltab);
  void ubifs_pack_pnode(struct ubifs_info *c, void *buf,
  		      struct ubifs_pnode *pnode);
  void ubifs_pack_nnode(struct ubifs_info *c, void *buf,
  		      struct ubifs_nnode *nnode);
  struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
  				    struct ubifs_nnode *parent, int iip);
  struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
  				    struct ubifs_nnode *parent, int iip);
  int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip);
  void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty);
  void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode);
  uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits);
  struct ubifs_nnode *ubifs_first_nnode(struct ubifs_info *c, int *hght);
  /* Needed only in debugging code in lpt_commit.c */
  int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
  		       struct ubifs_nnode *nnode);
  
  /* lpt_commit.c */
  int ubifs_lpt_start_commit(struct ubifs_info *c);
  int ubifs_lpt_end_commit(struct ubifs_info *c);
  int ubifs_lpt_post_commit(struct ubifs_info *c);
  void ubifs_lpt_free(struct ubifs_info *c, int wr_only);
  
  /* lprops.c */
  const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
  					   const struct ubifs_lprops *lp,
  					   int free, int dirty, int flags,
  					   int idx_gc_cnt);
  void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst);
  void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
  		      int cat);
  void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
  		       struct ubifs_lprops *new_lprops);
  void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops);
  int ubifs_categorize_lprops(const struct ubifs_info *c,
  			    const struct ubifs_lprops *lprops);
  int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
  			int flags_set, int flags_clean, int idx_gc_cnt);
  int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
  			int flags_set, int flags_clean);
  int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp);
  const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c);
  const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c);
  const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c);
  const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c);
  int ubifs_calc_dark(const struct ubifs_info *c, int spc);
  
  /* file.c */
  int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync);
  int ubifs_setattr(struct dentry *dentry, struct iattr *attr);
  
  /* dir.c */
  struct inode *ubifs_new_inode(struct ubifs_info *c, const struct inode *dir,
  			      umode_t mode);
  int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
  		  struct kstat *stat);
  
  /* xattr.c */
  int ubifs_setxattr(struct dentry *dentry, const char *name,
  		   const void *value, size_t size, int flags);
  ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
  		       size_t size);
  ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size);
  int ubifs_removexattr(struct dentry *dentry, const char *name);
  
  /* super.c */
  struct inode *ubifs_iget(struct super_block *sb, unsigned long inum);
  int ubifs_iput(struct inode *inode);
  
  /* recovery.c */
  int ubifs_recover_master_node(struct ubifs_info *c);
  int ubifs_write_rcvrd_mst_node(struct ubifs_info *c);
  struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
  					 int offs, void *sbuf, int jhead);
  struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum,
  					     int offs, void *sbuf);
  int ubifs_recover_inl_heads(struct ubifs_info *c, void *sbuf);
  int ubifs_clean_lebs(struct ubifs_info *c, void *sbuf);
  int ubifs_rcvry_gc_commit(struct ubifs_info *c);
  int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key,
  			     int deletion, loff_t new_size);
  int ubifs_recover_size(struct ubifs_info *c);
  void ubifs_destroy_size_tree(struct ubifs_info *c);
  
  /* ioctl.c */
  long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
  void ubifs_set_inode_flags(struct inode *inode);
  #ifdef CONFIG_COMPAT
  long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
  #endif
  
  /* compressor.c */
  int __init ubifs_compressors_init(void);
  void ubifs_compressors_exit(void);
  void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len,
  		    int *compr_type);
  int ubifs_decompress(const void *buf, int len, void *out, int *out_len,
  		     int compr_type);
  
  #include "debug.h"
  #include "misc.h"
  #include "key.h"
  
  #ifdef __UBOOT__
  /* these are used in cmd_ubifs.c */
  int ubifs_init(void);
  int uboot_ubifs_mount(char *vol_name);
  void ubifs_umount(struct ubifs_info *c);
  int ubifs_ls(char *dir_name);
  int ubifs_load(char *filename, u32 addr, u32 size);
  #endif
  #endif /* !__UBIFS_H__ */