UBIFS: Implement read-only UBIFS support in U-Boot

The U-Boot UBIFS implementation is largely a direct copy from the current
Linux version (2.6.29-rc6). As already done in the UBI version we have an
"abstraction layer" to redefine or remove some OS calls (e.g. mutex_lock()
...). This makes it possible to use the original Linux code with very
little changes. And by this we can better update to later Linux versions.

I removed some of the Linux features that are not used in the U-Boot
version (e.g. garbage-collection, write support).

Signed-off-by: Stefan Roese <sr@denx.de>
CC: Artem Bityutskiy <dedekind@infradead.org>
CC: Adrian Hunter <ext-Adrian.Hunter@nokia.com>

1 files changed, 2173 insertions, 0 deletions

diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
new file mode 100644
index 0000000..f342dd8
--- /dev/null
+++ b/fs/ubifs/ubifs.h
@@ -0,0 +1,2173 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation
+ *
+ * (C) Copyright 2008-2009
+ * Stefan Roese, DENX Software Engineering, sr@denx.de.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ */
+
+#ifndef __UBIFS_H__
+#define __UBIFS_H__
+
+#if 0	/* Enable for debugging output */
+#define CONFIG_UBIFS_FS_DEBUG
+#define CONFIG_UBIFS_FS_DEBUG_MSG_LVL	3
+#endif
+
+#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);
+
+/*
+ * The atomic operations are used for budgeting etc which is not
+ * needed for the read-only U-Boot implementation:
+ */
+#define atomic_long_inc(a)
+#define atomic_long_dec(a)
+#define	atomic_long_sub(a, b)
+
+/* linux/include/time.h */
+
+struct timespec {
+	time_t	tv_sec;		/* seconds */
+	long	tv_nsec;	/* nanoseconds */
+};
+
+/* 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;
+	const char *name;
+};
+
+struct inode {
+	struct hlist_node	i_hash;
+	struct list_head	i_list;
+	struct list_head	i_sb_list;
+	struct list_head	i_dentry;
+	unsigned long		i_ino;
+	unsigned int		i_nlink;
+	uid_t			i_uid;
+	gid_t			i_gid;
+	dev_t			i_rdev;
+	u64			i_version;
+	loff_t			i_size;
+#ifdef __NEED_I_SIZE_ORDERED
+	seqcount_t		i_size_seqcount;
+#endif
+	struct timespec		i_atime;
+	struct timespec		i_mtime;
+	struct timespec		i_ctime;
+	unsigned int		i_blkbits;
+	unsigned short          i_bytes;
+	umode_t			i_mode;
+	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
+	struct mutex		i_mutex;
+	struct rw_semaphore	i_alloc_sem;
+	const struct inode_operations	*i_op;
+	const struct file_operations	*i_fop;	/* former ->i_op->default_file_ops */
+	struct super_block	*i_sb;
+	struct file_lock	*i_flock;
+#ifdef CONFIG_QUOTA
+	struct dquot		*i_dquot[MAXQUOTAS];
+#endif
+	struct list_head	i_devices;
+	int			i_cindex;
+
+	__u32			i_generation;
+
+#ifdef CONFIG_DNOTIFY
+	unsigned long		i_dnotify_mask; /* Directory notify events */
+	struct dnotify_struct	*i_dnotify; /* for directory notifications */
+#endif
+
+#ifdef CONFIG_INOTIFY
+	struct list_head	inotify_watches; /* watches on this inode */
+	struct mutex		inotify_mutex;	/* protects the watches list */
+#endif
+
+	unsigned long		i_state;
+	unsigned long		dirtied_when;	/* jiffies of first dirtying */
+
+	unsigned int		i_flags;
+
+#ifdef CONFIG_SECURITY
+	void			*i_security;
+#endif
+	void			*i_private; /* fs or device private pointer */
+};
+
+struct super_block {
+	struct list_head	s_list;		/* Keep this first */
+	dev_t			s_dev;		/* search index; _not_ kdev_t */
+	unsigned long		s_blocksize;
+	unsigned char		s_blocksize_bits;
+	unsigned char		s_dirt;
+	unsigned long long	s_maxbytes;	/* Max file size */
+	struct file_system_type	*s_type;
+	const struct super_operations	*s_op;
+	struct dquot_operations	*dq_op;
+	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;
+	struct mutex		s_lock;
+	int			s_count;
+	int			s_syncing;
+	int			s_need_sync_fs;
+#ifdef CONFIG_SECURITY
+	void                    *s_security;
+#endif
+	struct xattr_handler	**s_xattr;
+
+	struct list_head	s_inodes;	/* all inodes */
+	struct list_head	s_dirty;	/* dirty inodes */
+	struct list_head	s_io;		/* parked for writeback */
+	struct list_head	s_more_io;	/* parked for more writeback */
+	struct hlist_head	s_anon;		/* anonymous dentries for (nfs) exporting */
+	struct list_head	s_files;
+	/* s_dentry_lru and s_nr_dentry_unused are protected by dcache_lock */
+	struct list_head	s_dentry_lru;	/* unused dentry lru */
+	int			s_nr_dentry_unused;	/* # of dentry on lru */
+
+	struct block_device	*s_bdev;
+	struct mtd_info		*s_mtd;
+	struct list_head	s_instances;
+
+	int			s_frozen;
+	wait_queue_head_t	s_wait_unfrozen;
+
+	char s_id[32];				/* Informational name */
+
+	void 			*s_fs_info;	/* Filesystem private info */
+
+	/*
+	 * 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 */
+
+	/* Granularity of c/m/atime in ns.
+	   Cannot be worse than a second */
+	u32		   s_time_gran;
+
+	/*
+	 * Filesystem subtype.  If non-empty the filesystem type field
+	 * in /proc/mounts will be "type.subtype"
+	 */
+	char *s_subtype;
+
+	/*
+	 * Saved mount options for lazy filesystems using
+	 * generic_show_options()
+	 */
+	char *s_options;
+};
+
+struct file_system_type {
+	const char *name;
+	int fs_flags;
+	int (*get_sb) (struct file_system_type *, int,
+		       const char *, void *, struct vfsmount *);
+	void (*kill_sb) (struct super_block *);
+	struct module *owner;
+	struct file_system_type * next;
+	struct list_head fs_supers;
+};
+
+struct vfsmount {
+	struct list_head mnt_hash;
+	struct vfsmount *mnt_parent;	/* fs we are mounted on */
+	struct dentry *mnt_mountpoint;	/* dentry of mountpoint */
+	struct dentry *mnt_root;	/* root of the mounted tree */
+	struct super_block *mnt_sb;	/* pointer to superblock */
+	struct list_head mnt_mounts;	/* list of children, anchored here */
+	struct list_head mnt_child;	/* and going through their mnt_child */
+	int mnt_flags;
+	/* 4 bytes hole on 64bits arches */
+	const char *mnt_devname;	/* Name of device e.g. /dev/dsk/hda1 */
+	struct list_head mnt_list;
+	struct list_head mnt_expire;	/* link in fs-specific expiry list */
+	struct list_head mnt_share;	/* circular list of shared mounts */
+	struct list_head mnt_slave_list;/* list of slave mounts */
+	struct list_head mnt_slave;	/* slave list entry */
+	struct vfsmount *mnt_master;	/* slave is on master->mnt_slave_list */
+	struct mnt_namespace *mnt_ns;	/* containing namespace */
+	int mnt_id;			/* mount identifier */
+	int mnt_group_id;		/* peer group identifier */
+	/*
+	 * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
+	 * to let these frequently modified fields in a separate cache line
+	 * (so that reads of mnt_flags wont ping-pong on SMP machines)
+	 */
+	int mnt_expiry_mark;		/* true if marked for expiry */
+	int mnt_pinned;
+	int mnt_ghosts;
+	/*
+	 * This value is not stable unless all of the mnt_writers[] spinlocks
+	 * are held, and all mnt_writer[]s on this mount have 0 as their ->count
+	 */
+};
+
+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
+
+#define INT_MAX		((int)(~0U>>1))
+#define INT_MIN		(-INT_MAX - 1)
+#define LLONG_MAX	((long long)(~0ULL>>1))
+
+/*
+ * 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;
+}
+
+/* linux/include/linux/bitops.h */
+
+#define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))
+#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
+
+/* linux/include/asm-generic/bitops/non-atomic.h */
+
+/**
+ * __set_bit - Set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * Unlike set_bit(), this function is non-atomic and may be reordered.
+ * If it's called on the same region of memory simultaneously, the effect
+ * may be that only one operation succeeds.
+ */
+static inline void __set_bit(int nr, volatile unsigned long *addr)
+{
+	unsigned long mask = BIT_MASK(nr);
+	unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+
+	*p  |= mask;
+}
+
+static inline void __clear_bit(int nr, volatile unsigned long *addr)
+{
+	unsigned long mask = BIT_MASK(nr);
+	unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+
+	*p &= ~mask;
+}
+
+/* debug.c */
+
+#define DEFINE_SPINLOCK(...)
+#define module_param_named(...)
+
+/* misc.h */
+#define mutex_lock_nested(...)
+#define mutex_unlock_nested(...)
+#define mutex_is_locked(...)	0
+
+/* Version of this UBIFS implementation */
+#define UBIFS_VERSION 1
+
+/* Normal UBIFS messages */
+#define ubifs_msg(fmt, ...) \
+		printk(KERN_NOTICE "UBIFS: " fmt "\n", ##__VA_ARGS__)
+/* UBIFS error messages */
+#define ubifs_err(fmt, ...)                                                  \
+	printk(KERN_ERR "UBIFS error (pid %d): %s: " fmt "\n", 0, \
+	       __func__, ##__VA_ARGS__)
+/* UBIFS warning messages */
+#define ubifs_warn(fmt, ...)                                         \
+	printk(KERN_WARNING "UBIFS warning (pid %d): %s: " fmt "\n", \
+	       0, __func__, ##__VA_ARGS__)
+
+/* 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
+
+/* Largest key size supported in this implementation */
+#define CUR_MAX_KEY_LEN UBIFS_SK_LEN
+
+/* 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"
+
+/* Default write-buffer synchronization timeout (5 secs) */
+#define DEFAULT_WBUF_TIMEOUT (5 * HZ)
+
+/* 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
+
+/* Garbage collector head */
+#define GCHD   0
+/* Base journal head number */
+#define BASEHD 1
+/* First "general purpose" journal head */
+#define DATAHD 2
+
+/* '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.
+ */
+#define UBIFS_TRUN_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
+
+/* 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
+ * COW_CNODE: cnode is being committed and must be copied before writing
+ * OBSOLETE_CNODE: cnode is being committed and has been copied (or deleted),
+ * so it can (and must) be freed when the commit is finished
+ */
+enum {
+	DIRTY_CNODE    = 0,
+	COW_CNODE      = 1,
+	OBSOLETE_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[CUR_MAX_KEY_LEN];
+	uint32_t u32[CUR_MAX_KEY_LEN/4];
+	uint64_t u64[CUR_MAX_KEY_LEN/8];
+	__le32 j32[CUR_MAX_KEY_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 'vmtruncate()' 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
+ * @dtype: type of data stored in this LEB (%UBI_LONGTERM, %UBI_SHORTTERM,
+ * %UBI_UNKNOWN)
+ * @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
+ * @timer: write-buffer timer
+ * @timeout: timer expire interval in jiffies
+ * @need_sync: it is set if its timer expired and needs sync
+ * @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 dtype;
+	int jhead;
+	int (*sync_callback)(struct ubifs_info *c, int lnum, int free, int pad);
+	struct mutex io_mutex;
+	spinlock_t lock;
+	int timeout;
+	int need_sync;
+	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
+ *
+ * Note, the @buds list is protected by the @c->buds_lock.
+ */
+struct ubifs_jhead {
+	struct ubifs_wbuf wbuf;
+	struct list_head buds_list;
+};
+
+/**
+ * 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)
+ */
+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;
+#ifdef CONFIG_UBIFS_FS_DEBUG
+	int lnum, offs, len;
+#endif
+	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;
+	char *name;
+	char *capi_name;
+	int (*decompress)(const unsigned char *in, size_t in_len,
+			  unsigned char *out, size_t *out_len);
+};
+
+/**
+ * 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
+ */
+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;
+	int new;
+};
+
+/**
+ * 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_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
+ * @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
+ * @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)
+ *
+ * @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
+ *
+ * @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
+ * @leb_size: logical eraseblock size in bytes
+ * @half_leb_size: half LEB size
+ * @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
+ *
+ * @dirty_pg_cnt: number of dirty pages (not used)
+ * @dirty_zn_cnt: number of dirty znodes
+ * @clean_zn_cnt: number of clean znodes
+ *
+ * @budg_idx_growth: amount of bytes budgeted for index growth
+ * @budg_data_growth: amount of bytes budgeted for cached data
+ * @budg_dd_growth: amount of bytes budgeted for cached data that will make
+ *                  other data dirty
+ * @budg_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
+ * @space_lock: protects @budg_idx_growth, @budg_data_growth, @budg_dd_growth,
+ *              @budg_uncommited_idx, @min_idx_lebs, @old_idx_sz, @lst,
+ *              @nospace, and @nospace_rp;
+ * @min_idx_lebs: minimum number of LEBs required for the index
+ * @old_idx_sz: size of index on flash
+ * @calc_idx_sz: temporary variable which is used to calculate new index size
+ *               (contains accurate new index size at end of TNC commit start)
+ * @lst: lprops statistics
+ * @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
+ * @inode_budget: budget for an inode
+ * @dent_budget: budget for a directory entry
+ *
+ * @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
+ *
+ * @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: if the UBI device is empty
+ * @replay_tree: temporary tree used during journal replay
+ * @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
+ * @need_recovery: file-system needs recovery
+ * @replaying: set to %1 during journal replay
+ * @unclean_leb_list: LEBs to recover when mounting ro to rw
+ * @rcvrd_mst_node: recovered master node to write when mounting ro to rw
+ * @size_tree: inode size information for recovery
+ * @remounting_rw: set while remounting from ro to rw (sb flags have MS_RDONLY)
+ * @always_chk_crc: always check CRCs (while mounting and remounting rw)
+ * @mount_opts: UBIFS-specific mount options
+ *
+ * @dbg: debugging-related information
+ */
+struct ubifs_info {
+	struct super_block *vfs_sb;
+
+	ino_t highest_inum;
+	unsigned long long max_sqnum;
+	unsigned long long cmt_no;
+	spinlock_t cnt_lock;
+	int fmt_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 no_chk_data_crc:1;
+	unsigned int bulk_read:1;
+	unsigned int default_compr:2;
+
+	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;
+
+	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 leb_size;
+	int half_leb_size;
+	int leb_cnt;
+	int max_leb_cnt;
+	int old_leb_cnt;
+	int ro_media;
+
+	long long budg_idx_growth;
+	long long budg_data_growth;
+	long long budg_dd_growth;
+	long long budg_uncommitted_idx;
+	spinlock_t space_lock;
+	int min_idx_lebs;
+	unsigned long long old_idx_sz;
+	unsigned long long calc_idx_sz;
+	struct ubifs_lp_stats lst;
+	unsigned int nospace:1;
+	unsigned int nospace_rp:1;
+
+	int page_budget;
+	int inode_budget;
+	int dent_budget;
+
+	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 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;
+	uid_t rp_uid;
+	gid_t rp_gid;
+
+	/* The below fields are used only during mounting and re-mounting */
+	int empty;
+	struct rb_root replay_tree;
+	struct list_head replay_list;
+	struct list_head replay_buds;
+	unsigned long long cs_sqnum;
+	unsigned long long replay_sqnum;
+	int need_recovery;
+	int replaying;
+	struct list_head unclean_leb_list;
+	struct ubifs_mst_node *rcvrd_mst_node;
+	struct rb_root size_tree;
+	int remounting_rw;
+	int always_chk_crc;
+	struct ubifs_mount_opts mount_opts;
+
+#ifdef CONFIG_UBIFS_FS_DEBUG
+	struct ubifs_debug_info *dbg;
+#endif
+};
+
+extern spinlock_t ubifs_infos_lock;
+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_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 dtype);
+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 dtype);
+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);
+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 *free,
+			  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);
+
+/* shrinker.c */
+int ubifs_shrinker(int nr_to_scan, gfp_t gfp_mask);
+
+/* 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);
+
+/* 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);
+
+/* file.c */
+int ubifs_fsync(struct file *file, struct dentry *dentry, 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,
+			      int 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 grouped);
+struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum,
+					     int offs, void *sbuf);
+int ubifs_recover_inl_heads(const struct ubifs_info *c, void *sbuf);
+int ubifs_clean_lebs(const 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 __exit 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"
+
+/* todo: Move these to a common U-Boot header */
+int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
+			  unsigned char *out, size_t *out_len);
+int gunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp);
+
+#endif /* !__UBIFS_H__ */