/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright 1996, 1997, 1998 Hans Reiser, see reiserfs/README for
 * licensing and copyright details
 */

#include <linux/reiserfs_fs.h>

#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/bug.h>
#include <linux/workqueue.h>
#include <asm/unaligned.h>
#include <linux/bitops.h>
#include <linux/proc_fs.h>
#include <linux/buffer_head.h>

/* the 32 bit compat definitions with int argument */
#define REISERFS_IOC32_UNPACK		_IOW(0xCD, 1, int)
#define REISERFS_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
#define REISERFS_IOC32_SETFLAGS		FS_IOC32_SETFLAGS
#define REISERFS_IOC32_GETVERSION	FS_IOC32_GETVERSION
#define REISERFS_IOC32_SETVERSION	FS_IOC32_SETVERSION

struct reiserfs_journal_list;

/* bitmasks for i_flags field in reiserfs-specific part of inode */
typedef enum {
	/*
	 * this says what format of key do all items (but stat data) of
	 * an object have.  If this is set, that format is 3.6 otherwise - 3.5
	 */
	i_item_key_version_mask = 0x0001,

	/*
	 * If this is unset, object has 3.5 stat data, otherwise,
	 * it has 3.6 stat data with 64bit size, 32bit nlink etc.
	 */
	i_stat_data_version_mask = 0x0002,

	/* file might need tail packing on close */
	i_pack_on_close_mask = 0x0004,

	/* don't pack tail of file */
	i_nopack_mask = 0x0008,

	/*
	 * If either of these are set, "safe link" was created for this
	 * file during truncate or unlink. Safe link is used to avoid
	 * leakage of disk space on crash with some files open, but unlinked.
	 */
	i_link_saved_unlink_mask = 0x0010,
	i_link_saved_truncate_mask = 0x0020,

	i_has_xattr_dir = 0x0040,
	i_data_log = 0x0080,
} reiserfs_inode_flags;

struct reiserfs_inode_info {
	__u32 i_key[4];		/* key is still 4 32 bit integers */

	/*
	 * transient inode flags that are never stored on disk. Bitmasks
	 * for this field are defined above.
	 */
	__u32 i_flags;

	/* offset of first byte stored in direct item. */
	__u32 i_first_direct_byte;

	/* copy of persistent inode flags read from sd_attrs. */
	__u32 i_attrs;

	/* first unused block of a sequence of unused blocks */
	int i_prealloc_block;
	int i_prealloc_count;	/* length of that sequence */

	/* per-transaction list of inodes which  have preallocated blocks */
	struct list_head i_prealloc_list;

	/*
	 * new_packing_locality is created; new blocks for the contents
	 * of this directory should be displaced
	 */
	unsigned new_packing_locality:1;

	/*
	 * we use these for fsync or O_SYNC to decide which transaction
	 * needs to be committed in order for this inode to be properly
	 * flushed
	 */
	unsigned int i_trans_id;

	struct reiserfs_journal_list *i_jl;
	atomic_t openers;
	struct mutex tailpack;
#ifdef CONFIG_REISERFS_FS_XATTR
	struct rw_semaphore i_xattr_sem;
#endif
#ifdef CONFIG_QUOTA
	struct dquot *i_dquot[MAXQUOTAS];
#endif

	struct inode vfs_inode;
};

typedef enum {
	reiserfs_attrs_cleared = 0x00000001,
} reiserfs_super_block_flags;

/*
 * struct reiserfs_super_block accessors/mutators since this is a disk
 * structure, it will always be in little endian format.
 */
#define sb_block_count(sbp)         (le32_to_cpu((sbp)->s_v1.s_block_count))
#define set_sb_block_count(sbp,v)   ((sbp)->s_v1.s_block_count = cpu_to_le32(v))
#define sb_free_blocks(sbp)         (le32_to_cpu((sbp)->s_v1.s_free_blocks))
#define set_sb_free_blocks(sbp,v)   ((sbp)->s_v1.s_free_blocks = cpu_to_le32(v))
#define sb_root_block(sbp)          (le32_to_cpu((sbp)->s_v1.s_root_block))
#define set_sb_root_block(sbp,v)    ((sbp)->s_v1.s_root_block = cpu_to_le32(v))

#define sb_jp_journal_1st_block(sbp)  \
              (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_1st_block))
#define set_sb_jp_journal_1st_block(sbp,v) \
              ((sbp)->s_v1.s_journal.jp_journal_1st_block = cpu_to_le32(v))
#define sb_jp_journal_dev(sbp) \
              (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_dev))
#define set_sb_jp_journal_dev(sbp,v) \
              ((sbp)->s_v1.s_journal.jp_journal_dev = cpu_to_le32(v))
#define sb_jp_journal_size(sbp) \
              (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_size))
#define set_sb_jp_journal_size(sbp,v) \
              ((sbp)->s_v1.s_journal.jp_journal_size = cpu_to_le32(v))
#define sb_jp_journal_trans_max(sbp) \
              (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_trans_max))
#define set_sb_jp_journal_trans_max(sbp,v) \
              ((sbp)->s_v1.s_journal.jp_journal_trans_max = cpu_to_le32(v))
#define sb_jp_journal_magic(sbp) \
              (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_magic))
#define set_sb_jp_journal_magic(sbp,v) \
              ((sbp)->s_v1.s_journal.jp_journal_magic = cpu_to_le32(v))
#define sb_jp_journal_max_batch(sbp) \
              (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_max_batch))
#define set_sb_jp_journal_max_batch(sbp,v) \
              ((sbp)->s_v1.s_journal.jp_journal_max_batch = cpu_to_le32(v))
#define sb_jp_jourmal_max_commit_age(sbp) \
              (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_max_commit_age))
#define set_sb_jp_journal_max_commit_age(sbp,v) \
              ((sbp)->s_v1.s_journal.jp_journal_max_commit_age = cpu_to_le32(v))

#define sb_blocksize(sbp)          (le16_to_cpu((sbp)->s_v1.s_blocksize))
#define set_sb_blocksize(sbp,v)    ((sbp)->s_v1.s_blocksize = cpu_to_le16(v))
#define sb_oid_maxsize(sbp)        (le16_to_cpu((sbp)->s_v1.s_oid_maxsize))
#define set_sb_oid_maxsize(sbp,v)  ((sbp)->s_v1.s_oid_maxsize = cpu_to_le16(v))
#define sb_oid_cursize(sbp)        (le16_to_cpu((sbp)->s_v1.s_oid_cursize))
#define set_sb_oid_cursize(sbp,v)  ((sbp)->s_v1.s_oid_cursize = cpu_to_le16(v))
#define sb_umount_state(sbp)       (le16_to_cpu((sbp)->s_v1.s_umount_state))
#define set_sb_umount_state(sbp,v) ((sbp)->s_v1.s_umount_state = cpu_to_le16(v))
#define sb_fs_state(sbp)           (le16_to_cpu((sbp)->s_v1.s_fs_state))
#define set_sb_fs_state(sbp,v)     ((sbp)->s_v1.s_fs_state = cpu_to_le16(v))
#define sb_hash_function_code(sbp) \
              (le32_to_cpu((sbp)->s_v1.s_hash_function_code))
#define set_sb_hash_function_code(sbp,v) \
              ((sbp)->s_v1.s_hash_function_code = cpu_to_le32(v))
#define sb_tree_height(sbp)        (le16_to_cpu((sbp)->s_v1.s_tree_height))
#define set_sb_tree_height(sbp,v)  ((sbp)->s_v1.s_tree_height = cpu_to_le16(v))
#define sb_bmap_nr(sbp)            (le16_to_cpu((sbp)->s_v1.s_bmap_nr))
#define set_sb_bmap_nr(sbp,v)      ((sbp)->s_v1.s_bmap_nr = cpu_to_le16(v))
#define sb_version(sbp)            (le16_to_cpu((sbp)->s_v1.s_version))
#define set_sb_version(sbp,v)      ((sbp)->s_v1.s_version = cpu_to_le16(v))

#define sb_mnt_count(sbp)	   (le16_to_cpu((sbp)->s_mnt_count))
#define set_sb_mnt_count(sbp, v)   ((sbp)->s_mnt_count = cpu_to_le16(v))

#define sb_reserved_for_journal(sbp) \
              (le16_to_cpu((sbp)->s_v1.s_reserved_for_journal))
#define set_sb_reserved_for_journal(sbp,v) \
              ((sbp)->s_v1.s_reserved_for_journal = cpu_to_le16(v))

/* LOGGING -- */

/*
 * These all interelate for performance.
 *
 * If the journal block count is smaller than n transactions, you lose speed.
 * I don't know what n is yet, I'm guessing 8-16.
 *
 * typical transaction size depends on the application, how often fsync is
 * called, and how many metadata blocks you dirty in a 30 second period.
 * The more small files (<16k) you use, the larger your transactions will
 * be.
 *
 * If your journal fills faster than dirty buffers get flushed to disk, it
 * must flush them before allowing the journal to wrap, which slows things
 * down.  If you need high speed meta data updates, the journal should be
 * big enough to prevent wrapping before dirty meta blocks get to disk.
 *
 * If the batch max is smaller than the transaction max, you'll waste space
 * at the end of the journal because journal_end sets the next transaction
 * to start at 0 if the next transaction has any chance of wrapping.
 *
 * The large the batch max age, the better the speed, and the more meta
 * data changes you'll lose after a crash.
 */

/* don't mess with these for a while */
/* we have a node size define somewhere in reiserfs_fs.h. -Hans */
#define JOURNAL_BLOCK_SIZE  4096	/* BUG gotta get rid of this */
#define JOURNAL_MAX_CNODE   1500	/* max cnodes to allocate. */
#define JOURNAL_HASH_SIZE 8192

/* number of copies of the bitmaps to have floating.  Must be >= 2 */
#define JOURNAL_NUM_BITMAPS 5

/*
 * One of these for every block in every transaction
 * Each one is in two hash tables.  First, a hash of the current transaction,
 * and after journal_end, a hash of all the in memory transactions.
 * next and prev are used by the current transaction (journal_hash).
 * hnext and hprev are used by journal_list_hash.  If a block is in more
 * than one transaction, the journal_list_hash links it in multiple times.
 * This allows flush_journal_list to remove just the cnode belonging to a
 * given transaction.
 */
struct reiserfs_journal_cnode {
	struct buffer_head *bh;	/* real buffer head */
	struct super_block *sb;	/* dev of real buffer head */

	/* block number of real buffer head, == 0 when buffer on disk */
	__u32 blocknr;

	unsigned long state;

	/* journal list this cnode lives in */
	struct reiserfs_journal_list *jlist;

	struct reiserfs_journal_cnode *next;	/* next in transaction list */
	struct reiserfs_journal_cnode *prev;	/* prev in transaction list */
	struct reiserfs_journal_cnode *hprev;	/* prev in hash list */
	struct reiserfs_journal_cnode *hnext;	/* next in hash list */
};

struct reiserfs_bitmap_node {
	int id;
	char *data;
	struct list_head list;
};

struct reiserfs_list_bitmap {
	struct reiserfs_journal_list *journal_list;
	struct reiserfs_bitmap_node **bitmaps;
};

/*
 * one of these for each transaction.  The most important part here is the
 * j_realblock.  this list of cnodes is used to hash all the blocks in all
 * the commits, to mark all the real buffer heads dirty once all the commits
 * hit the disk, and to make sure every real block in a transaction is on
 * disk before allowing the log area to be overwritten
 */
struct reiserfs_journal_list {
	unsigned long j_start;
	unsigned long j_state;
	unsigned long j_len;
	atomic_t j_nonzerolen;
	atomic_t j_commit_left;

	/* all commits older than this on disk */
	atomic_t j_older_commits_done;

	struct mutex j_commit_mutex;
	unsigned int j_trans_id;
	time64_t j_timestamp; /* write-only but useful for crash dump analysis */
	struct reiserfs_list_bitmap *j_list_bitmap;
	struct buffer_head *j_commit_bh;	/* commit buffer head */
	struct reiserfs_journal_cnode *j_realblock;
	struct reiserfs_journal_cnode *j_freedlist;	/* list of buffers that were freed during this trans.  free each of these on flush */
	/* time ordered list of all active transactions */
	struct list_head j_list;

	/*
	 * time ordered list of all transactions we haven't tried
	 * to flush yet
	 */
	struct list_head j_working_list;

	/* list of tail conversion targets in need of flush before commit */
	struct list_head j_tail_bh_list;

	/* list of data=ordered buffers in need of flush before commit */
	struct list_head j_bh_list;
	int j_refcount;
};

struct reiserfs_journal {
	struct buffer_head **j_ap_blocks;	/* journal blocks on disk */
	/* newest journal block */
	struct reiserfs_journal_cnode *j_last;

	/* oldest journal block.  start here for traverse */
	struct reiserfs_journal_cnode *j_first;

	struct block_device *j_dev_bd;
	fmode_t j_dev_mode;

	/* first block on s_dev of reserved area journal */
	int j_1st_reserved_block;

	unsigned long j_state;
	unsigned int j_trans_id;
	unsigned long j_mount_id;

	/* start of current waiting commit (index into j_ap_blocks) */
	unsigned long j_start;
	unsigned long j_len;	/* length of current waiting commit */

	/* number of buffers requested by journal_begin() */
	unsigned long j_len_alloc;

	atomic_t j_wcount;	/* count of writers for current commit */

	/* batch count. allows turning X transactions into 1 */
	unsigned long j_bcount;

	/* first unflushed transactions offset */
	unsigned long j_first_unflushed_offset;

	/* last fully flushed journal timestamp */
	unsigned j_last_flush_trans_id;

	struct buffer_head *j_header_bh;

	time64_t j_trans_start_time;	/* time this transaction started */
	struct mutex j_mutex;
	struct mutex j_flush_mutex;

	/* wait for current transaction to finish before starting new one */
	wait_queue_head_t j_join_wait;

	atomic_t j_jlock;		/* lock for j_join_wait */
	int j_list_bitmap_index;	/* number of next list bitmap to use */

	/* no more journal begins allowed. MUST sleep on j_join_wait */
	int j_must_wait;

	/* next journal_end will flush all journal list */
	int j_next_full_flush;

	/* next journal_end will flush all async commits */
	int j_next_async_flush;

	int j_cnode_used;	/* number of cnodes on the used list */
	int j_cnode_free;	/* number of cnodes on the free list */

	/* max number of blocks in a transaction.  */
	unsigned int j_trans_max;

	/* max number of blocks to batch into a trans */
	unsigned int j_max_batch;

	/* in seconds, how old can an async commit be */
	unsigned int j_max_commit_age;

	/* in seconds, how old can a transaction be */
	unsigned int j_max_trans_age;

	/* the default for the max commit age */
	unsigned int j_default_max_commit_age;

	struct reiserfs_journal_cnode *j_cnode_free_list;

	/* orig pointer returned from vmalloc */
	struct reiserfs_journal_cnode *j_cnode_free_orig;

	struct reiserfs_journal_list *j_current_jl;
	int j_free_bitmap_nodes;
	int j_used_bitmap_nodes;

	int j_num_lists;	/* total number of active transactions */
	int j_num_work_lists;	/* number that need attention from kreiserfsd */

	/* debugging to make sure things are flushed in order */
	unsigned int j_last_flush_id;

	/* debugging to make sure things are committed in order */
	unsigned int j_last_commit_id;

	struct list_head j_bitmap_nodes;
	struct list_head j_dirty_buffers;
	spinlock_t j_dirty_buffers_lock;	/* protects j_dirty_buffers */

	/* list of all active transactions */
	struct list_head j_journal_list;

	/* lists that haven't been touched by writeback attempts */
	struct list_head j_working_list;

	/* hash table for real buffer heads in current trans */
	struct reiserfs_journal_cnode *j_hash_table[JOURNAL_HASH_SIZE];

	/* hash table for all the real buffer heads in all the transactions */
	struct reiserfs_journal_cnode *j_list_hash_table[JOURNAL_HASH_SIZE];

	/* array of bitmaps to record the deleted blocks */
	struct reiserfs_list_bitmap j_list_bitmap[JOURNAL_NUM_BITMAPS];

	/* list of inodes which have preallocated blocks */
	struct list_head j_prealloc_list;
	int j_persistent_trans;
	unsigned long j_max_trans_size;
	unsigned long j_max_batch_size;

	int j_errno;

	/* when flushing ordered buffers, throttle new ordered writers */
	struct delayed_work j_work;
	struct super_block *j_work_sb;
	atomic_t j_async_throttle;
};

enum journal_state_bits {
	J_WRITERS_BLOCKED = 1,	/* set when new writers not allowed */
	J_WRITERS_QUEUED,    /* set when log is full due to too many writers */
	J_ABORTED,           /* set when log is aborted */
};

/* ick.  magic string to find desc blocks in the journal */
#define JOURNAL_DESC_MAGIC "ReIsErLB"

typedef __u32(*hashf_t) (const signed char *, int);

struct reiserfs_bitmap_info {
	__u32 free_count;
};

struct proc_dir_entry;

#if defined( CONFIG_PROC_FS ) && defined( CONFIG_REISERFS_PROC_INFO )
typedef unsigned long int stat_cnt_t;
typedef struct reiserfs_proc_info_data {
	spinlock_t lock;
	int exiting;
	int max_hash_collisions;

	stat_cnt_t breads;
	stat_cnt_t bread_miss;
	stat_cnt_t search_by_key;
	stat_cnt_t search_by_key_fs_changed;
	stat_cnt_t search_by_key_restarted;

	stat_cnt_t insert_item_restarted;
	stat_cnt_t paste_into_item_restarted;
	stat_cnt_t cut_from_item_restarted;
	stat_cnt_t delete_solid_item_restarted;
	stat_cnt_t delete_item_restarted;

	stat_cnt_t leaked_oid;
	stat_cnt_t leaves_removable;

	/*
	 * balances per level.
	 * Use explicit 5 as MAX_HEIGHT is not visible yet.
	 */
	stat_cnt_t balance_at[5];	/* XXX */
	/* sbk == search_by_key */
	stat_cnt_t sbk_read_at[5];	/* XXX */
	stat_cnt_t sbk_fs_changed[5];
	stat_cnt_t sbk_restarted[5];
	stat_cnt_t items_at[5];	/* XXX */
	stat_cnt_t free_at[5];	/* XXX */
	stat_cnt_t can_node_be_removed[5];	/* XXX */
	long int lnum[5];	/* XXX */
	long int rnum[5];	/* XXX */
	long int lbytes[5];	/* XXX */
	long int rbytes[5];	/* XXX */
	stat_cnt_t get_neighbors[5];
	stat_cnt_t get_neighbors_restart[5];
	stat_cnt_t need_l_neighbor[5];
	stat_cnt_t need_r_neighbor[5];

	stat_cnt_t free_block;
	struct __scan_bitmap_stats {
		stat_cnt_t call;
		stat_cnt_t wait;
		stat_cnt_t bmap;
		stat_cnt_t retry;
		stat_cnt_t in_journal_hint;
		stat_cnt_t in_journal_nohint;
		stat_cnt_t stolen;
	} scan_bitmap;
	struct __journal_stats {
		stat_cnt_t in_journal;
		stat_cnt_t in_journal_bitmap;
		stat_cnt_t in_journal_reusable;
		stat_cnt_t lock_journal;
		stat_cnt_t lock_journal_wait;
		stat_cnt_t journal_being;
		stat_cnt_t journal_relock_writers;
		stat_cnt_t journal_relock_wcount;
		stat_cnt_t mark_dirty;
		stat_cnt_t mark_dirty_already;
		stat_cnt_t mark_dirty_notjournal;
		stat_cnt_t restore_prepared;
		stat_cnt_t prepare;
		stat_cnt_t prepare_retry;
	} journal;
} reiserfs_proc_info_data_t;
#else
typedef struct reiserfs_proc_info_data {
} reiserfs_proc_info_data_t;
#endif

/* Number of quota types we support */
#define REISERFS_MAXQUOTAS 2

/* reiserfs union of in-core super block data */
struct reiserfs_sb_info {
	/* Buffer containing the super block */
	struct buffer_head *s_sbh;

	/* Pointer to the on-disk super block in the buffer */
	struct reiserfs_super_block *s_rs;
	struct reiserfs_bitmap_info *s_ap_bitmap;

	/* pointer to journal information */
	struct reiserfs_journal *s_journal;

	unsigned short s_mount_state;	/* reiserfs state (valid, invalid) */

	/* Serialize writers access, replace the old bkl */
	struct mutex lock;

	/* Owner of the lock (can be recursive) */
	struct task_struct *lock_owner;

	/* Depth of the lock, start from -1 like the bkl */
	int lock_depth;

	struct workqueue_struct *commit_wq;

	/* Comment? -Hans */
	void (*end_io_handler) (struct buffer_head *, int);

	/*
	 * pointer to function which is used to sort names in directory.
	 * Set on mount
	 */
	hashf_t s_hash_function;

	/* reiserfs's mount options are set here */
	unsigned long s_mount_opt;

	/* This is a structure that describes block allocator options */
	struct {
		/* Bitfield for enable/disable kind of options */
		unsigned long bits;

		/*
		 * size started from which we consider file
		 * to be a large one (in blocks)
		 */
		unsigned long large_file_size;

		int border;	/* percentage of disk, border takes */

		/*
		 * Minimal file size (in blocks) starting
		 * from which we do preallocations
		 */
		int preallocmin;

		/*
		 * Number of blocks we try to prealloc when file
		 * reaches preallocmin size (in blocks) or prealloc_list
		 is empty.
		 */
		int preallocsize;
	} s_alloc_options;

	/* Comment? -Hans */
	wait_queue_head_t s_wait;
	/* increased by one every time the  tree gets re-balanced */
	atomic_t s_generation_counter;

	/* File system properties. Currently holds on-disk FS format */
	unsigned long s_properties;

	/* session statistics */
	int s_disk_reads;
	int s_disk_writes;
	int s_fix_nodes;
	int s_do_balance;
	int s_unneeded_left_neighbor;
	int s_good_search_by_key_reada;
	int s_bmaps;
	int s_bmaps_without_search;
	int s_direct2indirect;
	int s_indirect2direct;

	/*
	 * set up when it's ok for reiserfs_read_inode2() to read from
	 * disk inode with nlink==0. Currently this is only used during
	 * finish_unfinished() processing at mount time
	 */
	int s_is_unlinked_ok;

	reiserfs_proc_info_data_t s_proc_info_data;
	struct proc_dir_entry *procdir;

	/* amount of blocks reserved for further allocations */
	int reserved_blocks;


	/* this lock on now only used to protect reserved_blocks variable */
	spinlock_t bitmap_lock;
	struct dentry *priv_root;	/* root of /.reiserfs_priv */
	struct dentry *xattr_root;	/* root of /.reiserfs_priv/xattrs */
	int j_errno;

	int work_queued;              /* non-zero delayed work is queued */
	struct delayed_work old_work; /* old transactions flush delayed work */
	spinlock_t old_work_lock;     /* protects old_work and work_queued */

#ifdef CONFIG_QUOTA
	char *s_qf_names[REISERFS_MAXQUOTAS];
	int s_jquota_fmt;
#endif
	char *s_jdev;		/* Stored jdev for mount option showing */
#ifdef CONFIG_REISERFS_CHECK

	/*
	 * Detects whether more than one copy of tb exists per superblock
	 * as a means of checking whether do_balance is executing
	 * concurrently against another tree reader/writer on a same
	 * mount point.
	 */
	struct tree_balance *cur_tb;
#endif
};

/* Definitions of reiserfs on-disk properties: */
#define REISERFS_3_5 0
#define REISERFS_3_6 1
#define REISERFS_OLD_FORMAT 2

/* Mount options */
enum reiserfs_mount_options {
	/* large tails will be created in a session */
	REISERFS_LARGETAIL,
	/*
	 * small (for files less than block size) tails will
	 * be created in a session
	 */
	REISERFS_SMALLTAIL,

	/* replay journal and return 0. Use by fsck */
	REPLAYONLY,

	/*
	 * -o conv: causes conversion of old format super block to the
	 * new format. If not specified - old partition will be dealt
	 * with in a manner of 3.5.x
	 */
	REISERFS_CONVERT,

	/*
	 * -o hash={tea, rupasov, r5, detect} is meant for properly mounting
	 * reiserfs disks from 3.5.19 or earlier.  99% of the time, this
	 * option is not required.  If the normal autodection code can't
	 * determine which hash to use (because both hashes had the same
	 * value for a file) use this option to force a specific hash.
	 * It won't allow you to override the existing hash on the FS, so
	 * if you have a tea hash disk, and mount with -o hash=rupasov,
	 * the mount will fail.
	 */
	FORCE_TEA_HASH,		/* try to force tea hash on mount */
	FORCE_RUPASOV_HASH,	/* try to force rupasov hash on mount */
	FORCE_R5_HASH,		/* try to force rupasov hash on mount */
	FORCE_HASH_DETECT,	/* try to detect hash function on mount */

	REISERFS_DATA_LOG,
	REISERFS_DATA_ORDERED,
	REISERFS_DATA_WRITEBACK,

	/*
	 * used for testing experimental features, makes benchmarking new
	 * features with and without more convenient, should never be used by
	 * users in any code shipped to users (ideally)
	 */

	REISERFS_NO_BORDER,
	REISERFS_NO_UNHASHED_RELOCATION,
	REISERFS_HASHED_RELOCATION,
	REISERFS_ATTRS,
	REISERFS_XATTRS_USER,
	REISERFS_POSIXACL,
	REISERFS_EXPOSE_PRIVROOT,
	REISERFS_BARRIER_NONE,
	REISERFS_BARRIER_FLUSH,

	/* Actions on error */
	REISERFS_ERROR_PANIC,
	REISERFS_ERROR_RO,
	REISERFS_ERROR_CONTINUE,

	REISERFS_USRQUOTA,	/* User quota option specified */
	REISERFS_GRPQUOTA,	/* Group quota option specified */

	REISERFS_TEST1,
	REISERFS_TEST2,
	REISERFS_TEST3,
	REISERFS_TEST4,
	REISERFS_UNSUPPORTED_OPT,
};

#define reiserfs_r5_hash(s) (REISERFS_SB(s)->s_mount_opt & (1 << FORCE_R5_HASH))
#define reiserfs_rupasov_hash(s) (REISERFS_SB(s)->s_mount_opt & (1 << FORCE_RUPASOV_HASH))
#define reiserfs_tea_hash(s) (REISERFS_SB(s)->s_mount_opt & (1 << FORCE_TEA_HASH))
#define reiserfs_hash_detect(s) (REISERFS_SB(s)->s_mount_opt & (1 << FORCE_HASH_DETECT))
#define reiserfs_no_border(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_NO_BORDER))
#define reiserfs_no_unhashed_relocation(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_NO_UNHASHED_RELOCATION))
#define reiserfs_hashed_relocation(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_HASHED_RELOCATION))
#define reiserfs_test4(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_TEST4))

#define have_large_tails(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_LARGETAIL))
#define have_small_tails(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_SMALLTAIL))
#define replay_only(s) (REISERFS_SB(s)->s_mount_opt & (1 << REPLAYONLY))
#define reiserfs_attrs(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_ATTRS))
#define old_format_only(s) (REISERFS_SB(s)->s_properties & (1 << REISERFS_3_5))
#define convert_reiserfs(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_CONVERT))
#define reiserfs_data_log(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_LOG))
#define reiserfs_data_ordered(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_ORDERED))
#define reiserfs_data_writeback(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_WRITEBACK))
#define reiserfs_xattrs_user(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_XATTRS_USER))
#define reiserfs_posixacl(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_POSIXACL))
#define reiserfs_expose_privroot(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_EXPOSE_PRIVROOT))
#define reiserfs_xattrs_optional(s) (reiserfs_xattrs_user(s) || reiserfs_posixacl(s))
#define reiserfs_barrier_none(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_BARRIER_NONE))
#define reiserfs_barrier_flush(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_BARRIER_FLUSH))

#define reiserfs_error_panic(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_ERROR_PANIC))
#define reiserfs_error_ro(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_ERROR_RO))

void reiserfs_file_buffer(struct buffer_head *bh, int list);
extern struct file_system_type reiserfs_fs_type;
int reiserfs_resize(struct super_block *, unsigned long);

#define CARRY_ON                0
#define SCHEDULE_OCCURRED       1

#define SB_BUFFER_WITH_SB(s) (REISERFS_SB(s)->s_sbh)
#define SB_JOURNAL(s) (REISERFS_SB(s)->s_journal)
#define SB_JOURNAL_1st_RESERVED_BLOCK(s) (SB_JOURNAL(s)->j_1st_reserved_block)
#define SB_JOURNAL_LEN_FREE(s) (SB_JOURNAL(s)->j_journal_len_free)
#define SB_AP_BITMAP(s) (REISERFS_SB(s)->s_ap_bitmap)

#define SB_DISK_JOURNAL_HEAD(s) (SB_JOURNAL(s)->j_header_bh->)

#define reiserfs_is_journal_aborted(journal) (unlikely (__reiserfs_is_journal_aborted (journal)))
static inline int __reiserfs_is_journal_aborted(struct reiserfs_journal
						*journal)
{
	return test_bit(J_ABORTED, &journal->j_state);
}

/*
 * Locking primitives. The write lock is a per superblock
 * special mutex that has properties close to the Big Kernel Lock
 * which was used in the previous locking scheme.
 */
void reiserfs_write_lock(struct super_block *s);
void reiserfs_write_unlock(struct super_block *s);
int __must_check reiserfs_write_unlock_nested(struct super_block *s);
void reiserfs_write_lock_nested(struct super_block *s, int depth);

#ifdef CONFIG_REISERFS_CHECK
void reiserfs_lock_check_recursive(struct super_block *s);
#else
static inline void reiserfs_lock_check_recursive(struct super_block *s) { }
#endif

/*
 * Several mutexes depend on the write lock.
 * However sometimes we want to relax the write lock while we hold
 * these mutexes, according to the release/reacquire on schedule()
 * properties of the Bkl that were used.
 * Reiserfs performances and locking were based on this scheme.
 * Now that the write lock is a mutex and not the bkl anymore, doing so
 * may result in a deadlock:
 *
 * A acquire write_lock
 * A acquire j_commit_mutex
 * A release write_lock and wait for something
 * B acquire write_lock
 * B can't acquire j_commit_mutex and sleep
 * A can't acquire write lock anymore
 * deadlock
 *
 * What we do here is avoiding such deadlock by playing the same game
 * than the Bkl: if we can't acquire a mutex that depends on the write lock,
 * we release the write lock, wait a bit and then retry.
 *
 * The mutexes concerned by this hack are:
 * - The commit mutex of a journal list
 * - The flush mutex
 * - The journal lock
 * - The inode mutex
 */
static inline void reiserfs_mutex_lock_safe(struct mutex *m,
					    struct super_block *s)
{
	int depth;

	depth = reiserfs_write_unlock_nested(s);
	mutex_lock(m);
	reiserfs_write_lock_nested(s, depth);
}

static inline void
reiserfs_mutex_lock_nested_safe(struct mutex *m, unsigned int subclass,
				struct super_block *s)
{
	int depth;

	depth = reiserfs_write_unlock_nested(s);
	mutex_lock_nested(m, subclass);
	reiserfs_write_lock_nested(s, depth);
}

static inline void
reiserfs_down_read_safe(struct rw_semaphore *sem, struct super_block *s)
{
       int depth;
       depth = reiserfs_write_unlock_nested(s);
       down_read(sem);
       reiserfs_write_lock_nested(s, depth);
}

/*
 * When we schedule, we usually want to also release the write lock,
 * according to the previous bkl based locking scheme of reiserfs.
 */
static inline void reiserfs_cond_resched(struct super_block *s)
{
	if (need_resched()) {
		int depth;

		depth = reiserfs_write_unlock_nested(s);
		schedule();
		reiserfs_write_lock_nested(s, depth);
	}
}

struct fid;

/*
 * in reading the #defines, it may help to understand that they employ
 *  the following abbreviations:
 *
 *  B = Buffer
 *  I = Item header
 *  H = Height within the tree (should be changed to LEV)
 *  N = Number of the item in the node
 *  STAT = stat data
 *  DEH = Directory Entry Header
 *  EC = Entry Count
 *  E = Entry number
 *  UL = Unsigned Long
 *  BLKH = BLocK Header
 *  UNFM = UNForMatted node
 *  DC = Disk Child
 *  P = Path
 *
 *  These #defines are named by concatenating these abbreviations,
 *  where first comes the arguments, and last comes the return value,
 *  of the macro.
 */

#define USE_INODE_GENERATION_COUNTER

#define REISERFS_PREALLOCATE
#define DISPLACE_NEW_PACKING_LOCALITIES
#define PREALLOCATION_SIZE 9

/* n must be power of 2 */
#define _ROUND_UP(x,n) (((x)+(n)-1u) & ~((n)-1u))

/*
 * to be ok for alpha and others we have to align structures to 8 byte
 * boundary.
 * FIXME: do not change 4 by anything else: there is code which relies on that
 */
#define ROUND_UP(x) _ROUND_UP(x,8LL)

/*
 * debug levels.  Right now, CONFIG_REISERFS_CHECK means print all debug
 * messages.
 */
#define REISERFS_DEBUG_CODE 5	/* extra messages to help find/debug errors */

void __reiserfs_warning(struct super_block *s, const char *id,
			 const char *func, const char *fmt, ...);
#define reiserfs_warning(s, id, fmt, args...) \
	 __reiserfs_warning(s, id, __func__, fmt, ##args)
/* assertions handling */

/* always check a condition and panic if it's false. */
#define __RASSERT(cond, scond, format, args...)			\
do {									\
	if (!(cond))							\
		reiserfs_panic(NULL, "assertion failure", "(" #cond ") at " \
			       __FILE__ ":%i:%s: " format "\n",		\
			       __LINE__, __func__ , ##args);		\
} while (0)

#define RASSERT(cond, format, args...) __RASSERT(cond, #cond, format, ##args)

#if defined( CONFIG_REISERFS_CHECK )
#define RFALSE(cond, format, args...) __RASSERT(!(cond), "!(" #cond ")", format, ##args)
#else
#define RFALSE( cond, format, args... ) do {;} while( 0 )
#endif

#define CONSTF __attribute_const__
/*
 * Disk Data Structures
 */

/***************************************************************************
 *                             SUPER BLOCK                                 *
 ***************************************************************************/

/*
 * Structure of super block on disk, a version of which in RAM is often
 * accessed as REISERFS_SB(s)->s_rs. The version in RAM is part of a larger
 * structure containing fields never written to disk.
 */
#define UNSET_HASH 0	/* Detect hash on disk */
#define TEA_HASH  1
#define YURA_HASH 2
#define R5_HASH   3
#define DEFAULT_HASH R5_HASH

struct journal_params {
	/* where does journal start from on its * device */
	__le32 jp_journal_1st_block;

	/* journal device st_rdev */
	__le32 jp_journal_dev;

	/* size of the journal */
	__le32 jp_journal_size;

	/* max number of blocks in a transaction. */
	__le32 jp_journal_trans_max;

	/*
	 * random value made on fs creation
	 * (this was sb_journal_block_count)
	 */
	__le32 jp_journal_magic;

	/* max number of blocks to batch into a trans */
	__le32 jp_journal_max_batch;

	/* in seconds, how old can an async  commit be */
	__le32 jp_journal_max_commit_age;

	/* in seconds, how old can a transaction be */
	__le32 jp_journal_max_trans_age;
};

/* this is the super from 3.5.X, where X >= 10 */
struct reiserfs_super_block_v1 {
	__le32 s_block_count;	/* blocks count         */
	__le32 s_free_blocks;	/* free blocks count    */
	__le32 s_root_block;	/* root block number    */
	struct journal_params s_journal;
	__le16 s_blocksize;	/* block size */

	/* max size of object id array, see get_objectid() commentary  */
	__le16 s_oid_maxsize;
	__le16 s_oid_cursize;	/* current size of object id array */

	/* this is set to 1 when filesystem was umounted, to 2 - when not */
	__le16 s_umount_state;

	/*
	 * reiserfs magic string indicates that file system is reiserfs:
	 * "ReIsErFs" or "ReIsEr2Fs" or "ReIsEr3Fs"
	 */
	char s_magic[10];

	/*
	 * it is set to used by fsck to mark which
	 * phase of rebuilding is done
	 */
	__le16 s_fs_state;
	/*
	 * indicate, what hash function is being use
	 * to sort names in a directory
	 */
	__le32 s_hash_function_code;
	__le16 s_tree_height;	/* height of disk tree */

	/*
	 * amount of bitmap blocks needed to address
	 * each block of file system
	 */
	__le16 s_bmap_nr;

	/*
	 * this field is only reliable on filesystem with non-standard journal
	 */
	__le16 s_version;

	/*
	 * size in blocks of journal area on main device, we need to
	 * keep after making fs with non-standard journal
	 */
	__le16 s_reserved_for_journal;
} __attribute__ ((__packed__));

#define SB_SIZE_V1 (sizeof(struct reiserfs_super_block_v1))

/* this is the on disk super block */
struct reiserfs_super_block {
	struct reiserfs_super_block_v1 s_v1;
	__le32 s_inode_generation;

	/* Right now used only by inode-attributes, if enabled */
	__le32 s_flags;

	unsigned char s_uuid[16];	/* filesystem unique identifier */
	unsigned char s_label[16];	/* filesystem volume label */
	__le16 s_mnt_count;		/* Count of mounts since last fsck */
	__le16 s_max_mnt_count;		/* Maximum mounts before check */
	__le32 s_lastcheck;		/* Timestamp of last fsck */
	__le32 s_check_interval;	/* Interval between checks */

	/*
	 * zero filled by mkreiserfs and reiserfs_convert_objectid_map_v1()
	 * so any additions must be updated there as well. */
	char s_unused[76];
} __attribute__ ((__packed__));

#define SB_SIZE (sizeof(struct reiserfs_super_block))

#define REISERFS_VERSION_1 0
#define REISERFS_VERSION_2 2

/* on-disk super block fields converted to cpu form */
#define SB_DISK_SUPER_BLOCK(s) (REISERFS_SB(s)->s_rs)
#define SB_V1_DISK_SUPER_BLOCK(s) (&(SB_DISK_SUPER_BLOCK(s)->s_v1))
#define SB_BLOCKSIZE(s) \
        le32_to_cpu ((SB_V1_DISK_SUPER_BLOCK(s)->s_blocksize))
#define SB_BLOCK_COUNT(s) \
        le32_to_cpu ((SB_V1_DISK_SUPER_BLOCK(s)->s_block_count))
#define SB_FREE_BLOCKS(s) \
        le32_to_cpu ((SB_V1_DISK_SUPER_BLOCK(s)->s_free_blocks))
#define SB_REISERFS_MAGIC(s) \
        (SB_V1_DISK_SUPER_BLOCK(s)->s_magic)
#define SB_ROOT_BLOCK(s) \
        le32_to_cpu ((SB_V1_DISK_SUPER_BLOCK(s)->s_root_block))
#define SB_TREE_HEIGHT(s) \
        le16_to_cpu ((SB_V1_DISK_SUPER_BLOCK(s)->s_tree_height))
#define SB_REISERFS_STATE(s) \
        le16_to_cpu ((SB_V1_DISK_SUPER_BLOCK(s)->s_umount_state))
#define SB_VERSION(s) le16_to_cpu ((SB_V1_DISK_SUPER_BLOCK(s)->s_version))
#define SB_BMAP_NR(s) le16_to_cpu ((SB_V1_DISK_SUPER_BLOCK(s)->s_bmap_nr))

#define PUT_SB_BLOCK_COUNT(s, val) \
   do { SB_V1_DISK_SUPER_BLOCK(s)->s_block_count = cpu_to_le32(val); } while (0)
#define PUT_SB_FREE_BLOCKS(s, val) \
   do { SB_V1_DISK_SUPER_BLOCK(s)->s_free_blocks = cpu_to_le32(val); } while (0)
#define PUT_SB_ROOT_BLOCK(s, val) \
   do { SB_V1_DISK_SUPER_BLOCK(s)->s_root_block = cpu_to_le32(val); } while (0)
#define PUT_SB_TREE_HEIGHT(s, val) \
   do { SB_V1_DISK_SUPER_BLOCK(s)->s_tree_height = cpu_to_le16(val); } while (0)
#define PUT_SB_REISERFS_STATE(s, val) \
   do { SB_V1_DISK_SUPER_BLOCK(s)->s_umount_state = cpu_to_le16(val); } while (0)
#define PUT_SB_VERSION(s, val) \
   do { SB_V1_DISK_SUPER_BLOCK(s)->s_version = cpu_to_le16(val); } while (0)
#define PUT_SB_BMAP_NR(s, val) \
   do { SB_V1_DISK_SUPER_BLOCK(s)->s_bmap_nr = cpu_to_le16 (val); } while (0)

#define SB_ONDISK_JP(s) (&SB_V1_DISK_SUPER_BLOCK(s)->s_journal)
#define SB_ONDISK_JOURNAL_SIZE(s) \
         le32_to_cpu ((SB_ONDISK_JP(s)->jp_journal_size))
#define SB_ONDISK_JOURNAL_1st_BLOCK(s) \
         le32_to_cpu ((SB_ONDISK_JP(s)->jp_journal_1st_block))
#define SB_ONDISK_JOURNAL_DEVICE(s) \
         le32_to_cpu ((SB_ONDISK_JP(s)->jp_journal_dev))
#define SB_ONDISK_RESERVED_FOR_JOURNAL(s) \
         le16_to_cpu ((SB_V1_DISK_SUPER_BLOCK(s)->s_reserved_for_journal))

#define is_block_in_log_or_reserved_area(s, block) \
         block >= SB_JOURNAL_1st_RESERVED_BLOCK(s) \
         && block < SB_JOURNAL_1st_RESERVED_BLOCK(s) +  \
         ((!is_reiserfs_jr(SB_DISK_SUPER_BLOCK(s)) ? \
         SB_ONDISK_JOURNAL_SIZE(s) + 1 : SB_ONDISK_RESERVED_FOR_JOURNAL(s)))

int is_reiserfs_3_5(struct reiserfs_super_block *rs);
int is_reiserfs_3_6(struct reiserfs_super_block *rs);
int is_reiserfs_jr(struct reiserfs_super_block *rs);

/*
 * ReiserFS leaves the first 64k unused, so that partition labels have
 * enough space.  If someone wants to write a fancy bootloader that
 * needs more than 64k, let us know, and this will be increased in size.
 * This number must be larger than the largest block size on any
 * platform, or code will break.  -Hans
 */
#define REISERFS_DISK_OFFSET_IN_BYTES (64 * 1024)
#define REISERFS_FIRST_BLOCK unused_define
#define REISERFS_JOURNAL_OFFSET_IN_BYTES REISERFS_DISK_OFFSET_IN_BYTES

/* the spot for the super in versions 3.5 - 3.5.10 (inclusive) */
#define REISERFS_OLD_DISK_OFFSET_IN_BYTES (8 * 1024)

/* reiserfs internal error code (used by search_by_key and fix_nodes)) */
#define CARRY_ON      0
#define REPEAT_SEARCH -1
#define IO_ERROR      -2
#define NO_DISK_SPACE -3
#define NO_BALANCING_NEEDED  (-4)
#define NO_MORE_UNUSED_CONTIGUOUS_BLOCKS (-5)
#define QUOTA_EXCEEDED -6

typedef __u32 b_blocknr_t;
typedef __le32 unp_t;

struct unfm_nodeinfo {
	unp_t unfm_nodenum;
	unsigned short unfm_freespace;
};

/* there are two formats of keys: 3.5 and 3.6 */
#define KEY_FORMAT_3_5 0
#define KEY_FORMAT_3_6 1

/* there are two stat datas */
#define STAT_DATA_V1 0
#define STAT_DATA_V2 1

static inline struct reiserfs_inode_info *REISERFS_I(const struct inode *inode)
{
	return container_of(inode, struct reiserfs_inode_info, vfs_inode);
}

static inline struct reiserfs_sb_info *REISERFS_SB(const struct super_block *sb)
{
	return sb->s_fs_info;
}

/*
 * Don't trust REISERFS_SB(sb)->s_bmap_nr, it's a u16
 * which overflows on large file systems.
 */
static inline __u32 reiserfs_bmap_count(struct super_block *sb)
{
	return (SB_BLOCK_COUNT(sb) - 1) / (sb->s_blocksize * 8) + 1;
}

static inline int bmap_would_wrap(unsigned bmap_nr)
{
	return bmap_nr > ((1LL << 16) - 1);
}

extern const struct xattr_handler *reiserfs_xattr_handlers[];

/*
 * this says about version of key of all items (but stat data) the
 * object consists of
 */
#define get_inode_item_key_version( inode )                                    \
    ((REISERFS_I(inode)->i_flags & i_item_key_version_mask) ? KEY_FORMAT_3_6 : KEY_FORMAT_3_5)

#define set_inode_item_key_version( inode, version )                           \
         ({ if((version)==KEY_FORMAT_3_6)                                      \
                REISERFS_I(inode)->i_flags |= i_item_key_version_mask;      \
            else                                                               \
                REISERFS_I(inode)->i_flags &= ~i_item_key_version_mask; })

#define get_inode_sd_version(inode)                                            \
    ((REISERFS_I(inode)->i_flags & i_stat_data_version_mask) ? STAT_DATA_V2 : STAT_DATA_V1)

#define set_inode_sd_version(inode, version)                                   \
         ({ if((version)==STAT_DATA_V2)                                        \
                REISERFS_I(inode)->i_flags |= i_stat_data_version_mask;     \
            else                                                               \
                REISERFS_I(inode)->i_flags &= ~i_stat_data_version_mask; })

/*
 * This is an aggressive tail suppression policy, I am hoping it
 * improves our benchmarks. The principle behind it is that percentage
 * space saving is what matters, not absolute space saving.  This is
 * non-intuitive, but it helps to understand it if you consider that the
 * cost to access 4 blocks is not much more than the cost to access 1
 * block, if you have to do a seek and rotate.  A tail risks a
 * non-linear disk access that is significant as a percentage of total
 * time cost for a 4 block file and saves an amount of space that is
 * less significant as a percentage of space, or so goes the hypothesis.
 * -Hans
 */
#define STORE_TAIL_IN_UNFM_S1(n_file_size,n_tail_size,n_block_size) \
(\
  (!(n_tail_size)) || \
  (((n_tail_size) > MAX_DIRECT_ITEM_LEN(n_block_size)) || \
   ( (n_file_size) >= (n_block_size) * 4 ) || \
   ( ( (n_file_size) >= (n_block_size) * 3 ) && \
     ( (n_tail_size) >=   (MAX_DIRECT_ITEM_LEN(n_block_size))/4) ) || \
   ( ( (n_file_size) >= (n_block_size) * 2 ) && \
     ( (n_tail_size) >=   (MAX_DIRECT_ITEM_LEN(n_block_size))/2) ) || \
   ( ( (n_file_size) >= (n_block_size) ) && \
     ( (n_tail_size) >=   (MAX_DIRECT_ITEM_LEN(n_block_size) * 3)/4) ) ) \
)

/*
 * Another strategy for tails, this one means only create a tail if all the
 * file would fit into one DIRECT item.
 * Primary intention for this one is to increase performance by decreasing
 * seeking.
*/
#define STORE_TAIL_IN_UNFM_S2(n_file_size,n_tail_size,n_block_size) \
(\
  (!(n_tail_size)) || \
  (((n_file_size) > MAX_DIRECT_ITEM_LEN(n_block_size)) ) \
)

/*
 * values for s_umount_state field
 */
#define REISERFS_VALID_FS    1
#define REISERFS_ERROR_FS    2

/*
 * there are 5 item types currently
 */
#define TYPE_STAT_DATA 0
#define TYPE_INDIRECT 1
#define TYPE_DIRECT 2
#define TYPE_DIRENTRY 3
#define TYPE_MAXTYPE 3
#define TYPE_ANY 15		/* FIXME: comment is required */

/***************************************************************************
 *                       KEY & ITEM HEAD                                   *
 ***************************************************************************/

/* * directories use this key as well as old files */
struct offset_v1 {
	__le32 k_offset;
	__le32 k_uniqueness;
} __attribute__ ((__packed__));

struct offset_v2 {
	__le64 v;
} __attribute__ ((__packed__));

static inline __u16 offset_v2_k_type(const struct offset_v2 *v2)
{
	__u8 type = le64_to_cpu(v2->v) >> 60;
	return (type <= TYPE_MAXTYPE) ? type : TYPE_ANY;
}

static inline void set_offset_v2_k_type(struct offset_v2 *v2, int type)
{
	v2->v =
	    (v2->v & cpu_to_le64(~0ULL >> 4)) | cpu_to_le64((__u64) type << 60);
}

static inline loff_t offset_v2_k_offset(const struct offset_v2 *v2)
{
	return le64_to_cpu(v2->v) & (~0ULL >> 4);
}

static inline void set_offset_v2_k_offset(struct offset_v2 *v2, loff_t offset)
{
	offset &= (~0ULL >> 4);
	v2->v = (v2->v & cpu_to_le64(15ULL << 60)) | cpu_to_le64(offset);
}

/*
 * Key of an item determines its location in the S+tree, and
 * is composed of 4 components
 */
struct reiserfs_key {
	/* packing locality: by default parent directory object id */
	__le32 k_dir_id;

	__le32 k_objectid;	/* object identifier */
	union {
		struct offset_v1 k_offset_v1;
		struct offset_v2 k_offset_v2;
	} __attribute__ ((__packed__)) u;
} __attribute__ ((__packed__));

struct in_core_key {
	/* packing locality: by default parent directory object id */
	__u32 k_dir_id;
	__u32 k_objectid;	/* object identifier */
	__u64 k_offset;
	__u8 k_type;
};

struct cpu_key {
	struct in_core_key on_disk_key;
	int version;
	/* 3 in all cases but direct2indirect and indirect2direct conversion */
	int key_length;
};

/*
 * Our function for comparing keys can compare keys of different
 * lengths.  It takes as a parameter the length of the keys it is to
 * compare.  These defines are used in determining what is to be passed
 * to it as that parameter.
 */
#define REISERFS_FULL_KEY_LEN     4
#define REISERFS_SHORT_KEY_LEN    2

/* The result of the key compare */
#define FIRST_GREATER 1
#define SECOND_GREATER -1
#define KEYS_IDENTICAL 0
#define KEY_FOUND 1
#define KEY_NOT_FOUND 0

#define KEY_SIZE (sizeof(struct reiserfs_key))

/* return values for search_by_key and clones */
#define ITEM_FOUND 1
#define ITEM_NOT_FOUND 0
#define ENTRY_FOUND 1
#define ENTRY_NOT_FOUND 0
#define DIRECTORY_NOT_FOUND -1
#define REGULAR_FILE_FOUND -2
#define DIRECTORY_FOUND -3
#define BYTE_FOUND 1
#define BYTE_NOT_FOUND 0
#define FILE_NOT_FOUND -1

#define POSITION_FOUND 1
#define POSITION_NOT_FOUND 0

/* return values for reiserfs_find_entry and search_by_entry_key */
#define NAME_FOUND 1
#define NAME_NOT_FOUND 0
#define GOTO_PREVIOUS_ITEM 2
#define NAME_FOUND_INVISIBLE 3

/*
 * Everything in the filesystem is stored as a set of items.  The
 * item head contains the key of the item, its free space (for
 * indirect items) and specifies the location of the item itself
 * within the block.
 */

struct item_head {
	/*
	 * Everything in the tree is found by searching for it based on
	 * its key.
	 */
	struct reiserfs_key ih_key;
	union {
		/*
		 * The free space in the last unformatted node of an
		 * indirect item if this is an indirect item.  This
		 * equals 0xFFFF iff this is a direct item or stat data
		 * item. Note that the key, not this field, is used to
		 * determine the item type, and thus which field this
		 * union contains.
		 */
		__le16 ih_free_space_reserved;

		/*
		 * Iff this is a directory item, this field equals the
		 * number of directory entries in the directory item.
		 */
		__le16 ih_entry_count;
	} __attribute__ ((__packed__)) u;
	__le16 ih_item_len;	/* total size of the item body */

	/* an offset to the item body within the block */
	__le16 ih_item_location;

	/*
	 * 0 for all old items, 2 for new ones. Highest bit is set by fsck
	 * temporary, cleaned after all done
	 */
	__le16 ih_version;
} __attribute__ ((__packed__));
/* size of item header     */
#define IH_SIZE (sizeof(struct item_head))

#define ih_free_space(ih)            le16_to_cpu((ih)->u.ih_free_space_reserved)
#define ih_version(ih)               le16_to_cpu((ih)->ih_version)
#define ih_entry_count(ih)           le16_to_cpu((ih)->u.ih_entry_count)
#define ih_location(ih)              le16_to_cpu((ih)->ih_item_location)
#define ih_item_len(ih)              le16_to_cpu((ih)->ih_item_len)

#define put_ih_free_space(ih, val)   do { (ih)->u.ih_free_space_reserved = cpu_to_le16(val); } while(0)
#define put_ih_version(ih, val)      do { (ih)->ih_version = cpu_to_le16(val); } while (0)
#define put_ih_entry_count(ih, val)  do { (ih)->u.ih_entry_count = cpu_to_le16(val); } while (0)
#define put_ih_location(ih, val)     do { (ih)->ih_item_location = cpu_to_le16(val); } while (0)
#define put_ih_item_len(ih, val)     do { (ih)->ih_item_len = cpu_to_le16(val); } while (0)

#define unreachable_item(ih) (ih_version(ih) & (1 << 15))

#define get_ih_free_space(ih) (ih_version (ih) == KEY_FORMAT_3_6 ? 0 : ih_free_space (ih))
#define set_ih_free_space(ih,val) put_ih_free_space((ih), ((ih_version(ih) == KEY_FORMAT_3_6) ? 0 : (val)))

/*
 * these operate on indirect items, where you've got an array of ints
 * at a possibly unaligned location.  These are a noop on ia32
 *
 * p is the array of __u32, i is the index into the array, v is the value
 * to store there.
 */
#define get_block_num(p, i) get_unaligned_le32((p) + (i))
#define put_block_num(p, i, v) put_unaligned_le32((v), (p) + (i))

/* * in old version uniqueness field shows key type */
#define V1_SD_UNIQUENESS 0
#define V1_INDIRECT_UNIQUENESS 0xfffffffe
#define V1_DIRECT_UNIQUENESS 0xffffffff
#define V1_DIRENTRY_UNIQUENESS 500
#define V1_ANY_UNIQUENESS 555	/* FIXME: comment is required */

/* here are conversion routines */
static inline int uniqueness2type(__u32 uniqueness) CONSTF;
static inline int uniqueness2type(__u32 uniqueness)
{
	switch ((int)uniqueness) {
	case V1_SD_UNIQUENESS:
		return TYPE_STAT_DATA;
	case V1_INDIRECT_UNIQUENESS:
		return TYPE_INDIRECT;
	case V1_DIRECT_UNIQUENESS:
		return TYPE_DIRECT;
	case V1_DIRENTRY_UNIQUENESS:
		return TYPE_DIRENTRY;
	case V1_ANY_UNIQUENESS:
	default:
		return TYPE_ANY;
	}
}

static inline __u32 type2uniqueness(int type) CONSTF;
static inline __u32 type2uniqueness(int type)
{
	switch (type) {
	case TYPE_STAT_DATA:
		return V1_SD_UNIQUENESS;
	case TYPE_INDIRECT:
		return V1_INDIRECT_UNIQUENESS;
	case TYPE_DIRECT:
		return V1_DIRECT_UNIQUENESS;
	case TYPE_DIRENTRY:
		return V1_DIRENTRY_UNIQUENESS;
	case TYPE_ANY:
	default:
		return V1_ANY_UNIQUENESS;
	}
}

/*
 * key is pointer to on disk key which is stored in le, result is cpu,
 * there is no way to get version of object from key, so, provide
 * version to these defines
 */
static inline loff_t le_key_k_offset(int version,
				     const struct reiserfs_key *key)
{
	return (version == KEY_FORMAT_3_5) ?
	    le32_to_cpu(key->u.k_offset_v1.k_offset) :
	    offset_v2_k_offset(&(key->u.k_offset_v2));
}

static inline loff_t le_ih_k_offset(const struct item_head *ih)
{
	return le_key_k_offset(ih_version(ih), &(ih->ih_key));
}

static inline loff_t le_key_k_type(int version, const struct reiserfs_key *key)
{
	if (version == KEY_FORMAT_3_5) {
		loff_t val = le32_to_cpu(key->u.k_offset_v1.k_uniqueness);
		return uniqueness2type(val);
	} else
		return offset_v2_k_type(&(key->u.k_offset_v2));
}

static inline loff_t le_ih_k_type(const struct item_head *ih)
{
	return le_key_k_type(ih_version(ih), &(ih->ih_key));
}

static inline void set_le_key_k_offset(int version, struct reiserfs_key *key,
				       loff_t offset)
{
	if (version == KEY_FORMAT_3_5)
		key->u.k_offset_v1.k_offset = cpu_to_le32(offset);
	else
		set_offset_v2_k_offset(&key->u.k_offset_v2, offset);
}

static inline void add_le_key_k_offset(int version, struct reiserfs_key *key,
				       loff_t offset)
{
	set_le_key_k_offset(version, key,
			    le_key_k_offset(version, key) + offset);
}

static inline void add_le_ih_k_offset(struct item_head *ih, loff_t offset)
{
	add_le_key_k_offset(ih_version(ih), &(ih->ih_key), offset);
}

static inline void set_le_ih_k_offset(struct item_head *ih, loff_t offset)
{
	set_le_key_k_offset(ih_version(ih), &(ih->ih_key), offset);
}

static inline void set_le_key_k_type(int version, struct reiserfs_key *key,
				     int type)
{
	if (version == KEY_FORMAT_3_5) {
		type = type2uniqueness(type);
		key->u.k_offset_v1.k_uniqueness = cpu_to_le32(type);
	} else
	       set_offset_v2_k_type(&key->u.k_offset_v2, type);
}

static inline void set_le_ih_k_type(struct item_head *ih, int type)
{
	set_le_key_k_type(ih_version(ih), &(ih->ih_key), type);
}

static inline int is_direntry_le_key(int version, struct reiserfs_key *key)
{
	return le_key_k_type(version, key) == TYPE_DIRENTRY;
}

static inline int is_direct_le_key(int version, struct reiserfs_key *key)
{
	return le_key_k_type(version, key) == TYPE_DIRECT;
}

static inline int is_indirect_le_key(int version, struct reiserfs_key *key)
{
	return le_key_k_type(version, key) == TYPE_INDIRECT;
}

static inline int is_statdata_le_key(int version, struct reiserfs_key *key)
{
	return le_key_k_type(version, key) == TYPE_STAT_DATA;
}

/* item header has version.  */
static inline int is_direntry_le_ih(struct item_head *ih)
{
	return is_direntry_le_key(ih_version(ih), &ih->ih_key);
}

static inline int is_direct_le_ih(struct item_head *ih)
{
	return is_direct_le_key(ih_version(ih), &ih->ih_key);
}

static inline int is_indirect_le_ih(struct item_head *ih)
{
	return is_indirect_le_key(ih_version(ih), &ih->ih_key);
}

static inline int is_statdata_le_ih(struct item_head *ih)
{
	return is_statdata_le_key(ih_version(ih), &ih->ih_key);
}

/* key is pointer to cpu key, result is cpu */
static inline loff_t cpu_key_k_offset(const struct cpu_key *key)
{
	return key->on_disk_key.k_offset;
}

static inline loff_t cpu_key_k_type(const struct cpu_key *key)
{
	return key->on_disk_key.k_type;
}

static inline void set_cpu_key_k_offset(struct cpu_key *key, loff_t offset)
{
	key->on_disk_key.k_offset = offset;
}

static inline void set_cpu_key_k_type(struct cpu_key *key, int type)
{
	key->on_disk_key.k_type = type;
}

static inline void cpu_key_k_offset_dec(struct cpu_key *key)
{
	key->on_disk_key.k_offset--;
}

#define is_direntry_cpu_key(key) (cpu_key_k_type (key) == TYPE_DIRENTRY)
#define is_direct_cpu_key(key) (cpu_key_k_type (key) == TYPE_DIRECT)
#define is_indirect_cpu_key(key) (cpu_key_k_type (key) == TYPE_INDIRECT)
#define is_statdata_cpu_key(key) (cpu_key_k_type (key) == TYPE_STAT_DATA)

/* are these used ? */
#define is_direntry_cpu_ih(ih) (is_direntry_cpu_key (&((ih)->ih_key)))
#define is_direct_cpu_ih(ih) (is_direct_cpu_key (&((ih)->ih_key)))
#define is_indirect_cpu_ih(ih) (is_indirect_cpu_key (&((ih)->ih_key)))
#define is_statdata_cpu_ih(ih) (is_statdata_cpu_key (&((ih)->ih_key)))

#define I_K_KEY_IN_ITEM(ih, key, n_blocksize) \
    (!COMP_SHORT_KEYS(ih, key) && \
	  I_OFF_BYTE_IN_ITEM(ih, k_offset(key), n_blocksize))

/* maximal length of item */
#define MAX_ITEM_LEN(block_size) (block_size - BLKH_SIZE - IH_SIZE)
#define MIN_ITEM_LEN 1

/* object identifier for root dir */
#define REISERFS_ROOT_OBJECTID 2
#define REISERFS_ROOT_PARENT_OBJECTID 1

extern struct reiserfs_key root_key;

/*
 * Picture represents a leaf of the S+tree
 *  ______________________________________________________
 * |      |  Array of     |                   |           |
 * |Block |  Object-Item  |      F r e e      |  Objects- |
 * | head |  Headers      |     S p a c e     |   Items   |
 * |______|_______________|___________________|___________|
 */

/*
 * Header of a disk block.  More precisely, header of a formatted leaf
 * or internal node, and not the header of an unformatted node.
 */
struct block_head {
	__le16 blk_level;	/* Level of a block in the tree. */
	__le16 blk_nr_item;	/* Number of keys/items in a block. */
	__le16 blk_free_space;	/* Block free space in bytes. */
	__le16 blk_reserved;
	/* dump this in v4/planA */

	/* kept only for compatibility */
	struct reiserfs_key blk_right_delim_key;
};

#define BLKH_SIZE                     (sizeof(struct block_head))
#define blkh_level(p_blkh)            (le16_to_cpu((p_blkh)->blk_level))
#define blkh_nr_item(p_blkh)          (le16_to_cpu((p_blkh)->blk_nr_item))
#define blkh_free_space(p_blkh)       (le16_to_cpu((p_blkh)->blk_free_space))
#define blkh_reserved(p_blkh)         (le16_to_cpu((p_blkh)->blk_reserved))
#define set_blkh_level(p_blkh,val)    ((p_blkh)->blk_level = cpu_to_le16(val))
#define set_blkh_nr_item(p_blkh,val)  ((p_blkh)->blk_nr_item = cpu_to_le16(val))
#define set_blkh_free_space(p_blkh,val) ((p_blkh)->blk_free_space = cpu_to_le16(val))
#define set_blkh_reserved(p_blkh,val) ((p_blkh)->blk_reserved = cpu_to_le16(val))
#define blkh_right_delim_key(p_blkh)  ((p_blkh)->blk_right_delim_key)
#define set_blkh_right_delim_key(p_blkh,val)  ((p_blkh)->blk_right_delim_key = val)

/* values for blk_level field of the struct block_head */

/*
 * When node gets removed from the tree its blk_level is set to FREE_LEVEL.
 * It is then  used to see whether the node is still in the tree
 */
#define FREE_LEVEL 0

#define DISK_LEAF_NODE_LEVEL  1	/* Leaf node level. */

/*
 * Given the buffer head of a formatted node, resolve to the
 * block head of that node.
 */
#define B_BLK_HEAD(bh)			((struct block_head *)((bh)->b_data))
/* Number of items that are in buffer. */
#define B_NR_ITEMS(bh)			(blkh_nr_item(B_BLK_HEAD(bh)))
#define B_LEVEL(bh)			(blkh_level(B_BLK_HEAD(bh)))
#define B_FREE_SPACE(bh)		(blkh_free_space(B_BLK_HEAD(bh)))

#define PUT_B_NR_ITEMS(bh, val)		do { set_blkh_nr_item(B_BLK_HEAD(bh), val); } while (0)
#define PUT_B_LEVEL(bh, val)		do { set_blkh_level(B_BLK_HEAD(bh), val); } while (0)
#define PUT_B_FREE_SPACE(bh, val)	do { set_blkh_free_space(B_BLK_HEAD(bh), val); } while (0)

/* Get right delimiting key. -- little endian */
#define B_PRIGHT_DELIM_KEY(bh)		(&(blk_right_delim_key(B_BLK_HEAD(bh))))

/* Does the buffer contain a disk leaf. */
#define B_IS_ITEMS_LEVEL(bh)		(B_LEVEL(bh) == DISK_LEAF_NODE_LEVEL)

/* Does the buffer contain a disk internal node */
#define B_IS_KEYS_LEVEL(bh)      (B_LEVEL(bh) > DISK_LEAF_NODE_LEVEL \
					    && B_LEVEL(bh) <= MAX_HEIGHT)

/***************************************************************************
 *                             STAT DATA                                   *
 ***************************************************************************/

/*
 * old stat data is 32 bytes long. We are going to distinguish new one by
 * different size
*/
struct stat_data_v1 {
	__le16 sd_mode;		/* file type, permissions */
	__le16 sd_nlink;	/* number of hard links */
	__le16 sd_uid;		/* owner */
	__le16 sd_gid;		/* group */
	__le32 sd_size;		/* file size */
	__le32 sd_atime;	/* time of last access */
	__le32 sd_mtime;	/* time file was last modified  */

	/*
	 * time inode (stat data) was last changed
	 * (except changes to sd_atime and sd_mtime)
	 */
	__le32 sd_ctime;
	union {
		__le32 sd_rdev;
		__le32 sd_blocks;	/* number of blocks file uses */
	} __attribute__ ((__packed__)) u;

	/*
	 * first byte of file which is stored in a direct item: except that if
	 * it equals 1 it is a symlink and if it equals ~(__u32)0 there is no
	 * direct item.  The existence of this field really grates on me.
	 * Let's replace it with a macro based on sd_size and our tail
	 * suppression policy.  Someday.  -Hans
	 */
	__le32 sd_first_direct_byte;
} __attribute__ ((__packed__));

#define SD_V1_SIZE              (sizeof(struct stat_data_v1))
#define stat_data_v1(ih)        (ih_version (ih) == KEY_FORMAT_3_5)
#define sd_v1_mode(sdp)         (le16_to_cpu((sdp)->sd_mode))
#define set_sd_v1_mode(sdp,v)   ((sdp)->sd_mode = cpu_to_le16(v))
#define sd_v1_nlink(sdp)        (le16_to_cpu((sdp)->sd_nlink))
#define set_sd_v1_nlink(sdp,v)  ((sdp)->sd_nlink = cpu_to_le16(v))
#define sd_v1_uid(sdp)          (le16_to_cpu((sdp)->sd_uid))
#define set_sd_v1_uid(sdp,v)    ((sdp)->sd_uid = cpu_to_le16(v))
#define sd_v1_gid(sdp)          (le16_to_cpu((sdp)->sd_gid))
#define set_sd_v1_gid(sdp,v)    ((sdp)->sd_gid = cpu_to_le16(v))
#define sd_v1_size(sdp)         (le32_to_cpu((sdp)->sd_size))
#define set_sd_v1_size(sdp,v)   ((sdp)->sd_size = cpu_to_le32(v))
#define sd_v1_atime(sdp)        (le32_to_cpu((sdp)->sd_atime))
#define set_sd_v1_atime(sdp,v)  ((sdp)->sd_atime = cpu_to_le32(v))
#define sd_v1_mtime(sdp)        (le32_to_cpu((sdp)->sd_mtime))
#define set_sd_v1_mtime(sdp,v)  ((sdp)->sd_mtime = cpu_to_le32(v))
#define sd_v1_ctime(sdp)        (le32_to_cpu((sdp)->sd_ctime))
#define set_sd_v1_ctime(sdp,v)  ((sdp)->sd_ctime = cpu_to_le32(v))
#define sd_v1_rdev(sdp)         (le32_to_cpu((sdp)->u.sd_rdev))
#define set_sd_v1_rdev(sdp,v)   ((sdp)->u.sd_rdev = cpu_to_le32(v))
#define sd_v1_blocks(sdp)       (le32_to_cpu((sdp)->u.sd_blocks))
#define set_sd_v1_blocks(sdp,v) ((sdp)->u.sd_blocks = cpu_to_le32(v))
#define sd_v1_first_direct_byte(sdp) \
                                (le32_to_cpu((sdp)->sd_first_direct_byte))
#define set_sd_v1_first_direct_byte(sdp,v) \
                                ((sdp)->sd_first_direct_byte = cpu_to_le32(v))

/* inode flags stored in sd_attrs (nee sd_reserved) */

/*
 * we want common flags to have the same values as in ext2,
 * so chattr(1) will work without problems
 */
#define REISERFS_IMMUTABLE_FL FS_IMMUTABLE_FL
#define REISERFS_APPEND_FL    FS_APPEND_FL
#define REISERFS_SYNC_FL      FS_SYNC_FL
#define REISERFS_NOATIME_FL   FS_NOATIME_FL
#define REISERFS_NODUMP_FL    FS_NODUMP_FL
#define REISERFS_SECRM_FL     FS_SECRM_FL
#define REISERFS_UNRM_FL      FS_UNRM_FL
#define REISERFS_COMPR_FL     FS_COMPR_FL
#define REISERFS_NOTAIL_FL    FS_NOTAIL_FL

/* persistent flags that file inherits from the parent directory */
#define REISERFS_INHERIT_MASK ( REISERFS_IMMUTABLE_FL |	\
				REISERFS_SYNC_FL |	\
				REISERFS_NOATIME_FL |	\
				REISERFS_NODUMP_FL |	\
				REISERFS_SECRM_FL |	\
				REISERFS_COMPR_FL |	\
				REISERFS_NOTAIL_FL )

/*
 * Stat Data on disk (reiserfs version of UFS disk inode minus the
 * address blocks)
 */
struct stat_data {
	__le16 sd_mode;		/* file type, permissions */
	__le16 sd_attrs;	/* persistent inode flags */
	__le32 sd_nlink;	/* number of hard links */
	__le64 sd_size;		/* file size */
	__le32 sd_uid;		/* owner */
	__le32 sd_gid;		/* group */
	__le32 sd_atime;	/* time of last access */
	__le32 sd_mtime;	/* time file was last modified  */

	/*
	 * time inode (stat data) was last changed
	 * (except changes to sd_atime and sd_mtime)
	 */
	__le32 sd_ctime;
	__le32 sd_blocks;
	union {
		__le32 sd_rdev;
		__le32 sd_generation;
	} __attribute__ ((__packed__)) u;
} __attribute__ ((__packed__));

/* this is 44 bytes long */
#define SD_SIZE (sizeof(struct stat_data))
#define SD_V2_SIZE              SD_SIZE
#define stat_data_v2(ih)        (ih_version (ih) == KEY_FORMAT_3_6)
#define sd_v2_mode(sdp)         (le16_to_cpu((sdp)->sd_mode))
#define set_sd_v2_mode(sdp,v)   ((sdp)->sd_mode = cpu_to_le16(v))
/* sd_reserved */
/* set_sd_reserved */
#define sd_v2_nlink(sdp)        (le32_to_cpu((sdp)->sd_nlink))
#define set_sd_v2_nlink(sdp,v)  ((sdp)->sd_nlink = cpu_to_le32(v))
#define sd_v2_size(sdp)         (le64_to_cpu((sdp)->sd_size))
#define set_sd_v2_size(sdp,v)   ((sdp)->sd_size = cpu_to_le64(v))
#define sd_v2_uid(sdp)          (le32_to_cpu((sdp)->sd_uid))
#define set_sd_v2_uid(sdp,v)    ((sdp)->sd_uid = cpu_to_le32(v))
#define sd_v2_gid(sdp)          (le32_to_cpu((sdp)->sd_gid))
#define set_sd_v2_gid(sdp,v)    ((sdp)->sd_gid = cpu_to_le32(v))
#define sd_v2_atime(sdp)        (le32_to_cpu((sdp)->sd_atime))
#define set_sd_v2_atime(sdp,v)  ((sdp)->sd_atime = cpu_to_le32(v))
#define sd_v2_mtime(sdp)        (le32_to_cpu((sdp)->sd_mtime))
#define set_sd_v2_mtime(sdp,v)  ((sdp)->sd_mtime = cpu_to_le32(v))
#define sd_v2_ctime(sdp)        (le32_to_cpu((sdp)->sd_ctime))
#define set_sd_v2_ctime(sdp,v)  ((sdp)->sd_ctime = cpu_to_le32(v))
#define sd_v2_blocks(sdp)       (le32_to_cpu((sdp)->sd_blocks))
#define set_sd_v2_blocks(sdp,v) ((sdp)->sd_blocks = cpu_to_le32(v))
#define sd_v2_rdev(sdp)         (le32_to_cpu((sdp)->u.sd_rdev))
#define set_sd_v2_rdev(sdp,v)   ((sdp)->u.sd_rdev = cpu_to_le32(v))
#define sd_v2_generation(sdp)   (le32_to_cpu((sdp)->u.sd_generation))
#define set_sd_v2_generation(sdp,v) ((sdp)->u.sd_generation = cpu_to_le32(v))
#define sd_v2_attrs(sdp)         (le16_to_cpu((sdp)->sd_attrs))
#define set_sd_v2_attrs(sdp,v)   ((sdp)->sd_attrs = cpu_to_le16(v))

/***************************************************************************
 *                      DIRECTORY STRUCTURE                                *
 ***************************************************************************/
/*
 * Picture represents the structure of directory items
 * ________________________________________________
 * |  Array of     |   |     |        |       |   |
 * | directory     |N-1| N-2 | ....   |   1st |0th|
 * | entry headers |   |     |        |       |   |
 * |_______________|___|_____|________|_______|___|
 *                  <----   directory entries         ------>
 *
 * First directory item has k_offset component 1. We store "." and ".."
 * in one item, always, we never split "." and ".." into differing
 * items.  This makes, among other things, the code for removing
 * directories simpler.
 */
#define SD_OFFSET  0
#define SD_UNIQUENESS 0
#define DOT_OFFSET 1
#define DOT_DOT_OFFSET 2
#define DIRENTRY_UNIQUENESS 500

#define FIRST_ITEM_OFFSET 1

/*
 * Q: How to get key of object pointed to by entry from entry?
 *
 * A: Each directory entry has its header. This header has deh_dir_id
 *    and deh_objectid fields, those are key of object, entry points to
 */

/*
 * NOT IMPLEMENTED:
 * Directory will someday contain stat data of object
 */

struct reiserfs_de_head {
	__le32 deh_offset;	/* third component of the directory entry key */

	/*
	 * objectid of the parent directory of the object, that is referenced
	 * by directory entry
	 */
	__le32 deh_dir_id;

	/* objectid of the object, that is referenced by directory entry */
	__le32 deh_objectid;
	__le16 deh_location;	/* offset of name in the whole item */

	/*
	 * whether 1) entry contains stat data (for future), and
	 * 2) whether entry is hidden (unlinked)
	 */
	__le16 deh_state;
} __attribute__ ((__packed__));
#define DEH_SIZE                  sizeof(struct reiserfs_de_head)
#define deh_offset(p_deh)         (le32_to_cpu((p_deh)->deh_offset))
#define deh_dir_id(p_deh)         (le32_to_cpu((p_deh)->deh_dir_id))
#define deh_objectid(p_deh)       (le32_to_cpu((p_deh)->deh_objectid))
#define deh_location(p_deh)       (le16_to_cpu((p_deh)->deh_location))
#define deh_state(p_deh)          (le16_to_cpu((p_deh)->deh_state))

#define put_deh_offset(p_deh,v)   ((p_deh)->deh_offset = cpu_to_le32((v)))
#define put_deh_dir_id(p_deh,v)   ((p_deh)->deh_dir_id = cpu_to_le32((v)))
#define put_deh_objectid(p_deh,v) ((p_deh)->deh_objectid = cpu_to_le32((v)))
#define put_deh_location(p_deh,v) ((p_deh)->deh_location = cpu_to_le16((v)))
#define put_deh_state(p_deh,v)    ((p_deh)->deh_state = cpu_to_le16((v)))

/* empty directory contains two entries "." and ".." and their headers */
#define EMPTY_DIR_SIZE \
(DEH_SIZE * 2 + ROUND_UP (sizeof(".") - 1) + ROUND_UP (sizeof("..") - 1))

/* old format directories have this size when empty */
#define EMPTY_DIR_SIZE_V1 (DEH_SIZE * 2 + 3)

#define DEH_Statdata 0		/* not used now */
#define DEH_Visible 2

/* 64 bit systems (and the S/390) need to be aligned explicitly -jdm */
#if BITS_PER_LONG == 64 || defined(__s390__) || defined(__hppa__)
#   define ADDR_UNALIGNED_BITS  (3)
#endif

/*
 * These are only used to manipulate deh_state.
 * Because of this, we'll use the ext2_ bit routines,
 * since they are little endian
 */
#ifdef ADDR_UNALIGNED_BITS

#   define aligned_address(addr)           ((void *)((long)(addr) & ~((1UL << ADDR_UNALIGNED_BITS) - 1)))
#   define unaligned_offset(addr)          (((int)((long)(addr) & ((1 << ADDR_UNALIGNED_BITS) - 1))) << 3)

#   define set_bit_unaligned(nr, addr)	\
	__test_and_set_bit_le((nr) + unaligned_offset(addr), aligned_address(addr))
#   define clear_bit_unaligned(nr, addr)	\
	__test_and_clear_bit_le((nr) + unaligned_offset(addr), aligned_address(addr))
#   define test_bit_unaligned(nr, addr)	\
	test_bit_le((nr) + unaligned_offset(addr), aligned_address(addr))

#else

#   define set_bit_unaligned(nr, addr)	__test_and_set_bit_le(nr, addr)
#   define clear_bit_unaligned(nr, addr)	__test_and_clear_bit_le(nr, addr)
#   define test_bit_unaligned(nr, addr)	test_bit_le(nr, addr)

#endif

#define mark_de_with_sd(deh)        set_bit_unaligned (DEH_Statdata, &((deh)->deh_state))
#define mark_de_without_sd(deh)     clear_bit_unaligned (DEH_Statdata, &((deh)->deh_state))
#define mark_de_visible(deh)	    set_bit_unaligned (DEH_Visible, &((deh)->deh_state))
#define mark_de_hidden(deh)	    clear_bit_unaligned (DEH_Visible, &((deh)->deh_state))

#define de_with_sd(deh)		    test_bit_unaligned (DEH_Statdata, &((deh)->deh_state))
#define de_visible(deh)	    	    test_bit_unaligned (DEH_Visible, &((deh)->deh_state))
#define de_hidden(deh)	    	    !test_bit_unaligned (DEH_Visible, &((deh)->deh_state))

extern void make_empty_dir_item_v1(char *body, __le32 dirid, __le32 objid,
				   __le32 par_dirid, __le32 par_objid);
extern void make_empty_dir_item(char *body, __le32 dirid, __le32 objid,
				__le32 par_dirid, __le32 par_objid);

/* two entries per block (at least) */
#define REISERFS_MAX_NAME(block_size) 255

/*
 * this structure is used for operations on directory entries. It is
 * not a disk structure.
 *
 * When reiserfs_find_entry or search_by_entry_key find directory
 * entry, they return filled reiserfs_dir_entry structure
 */
struct reiserfs_dir_entry {
	struct buffer_head *de_bh;
	int de_item_num;
	struct item_head *de_ih;
	int de_entry_num;
	struct reiserfs_de_head *de_deh;
	int de_entrylen;
	int de_namelen;
	char *de_name;
	unsigned long *de_gen_number_bit_string;

	__u32 de_dir_id;
	__u32 de_objectid;

	struct cpu_key de_entry_key;
};

/*
 * these defines are useful when a particular member of
 * a reiserfs_dir_entry is needed
 */

/* pointer to file name, stored in entry */
#define B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh) \
				(ih_item_body(bh, ih) + deh_location(deh))

/* length of name */
#define I_DEH_N_ENTRY_FILE_NAME_LENGTH(ih,deh,entry_num) \
(I_DEH_N_ENTRY_LENGTH (ih, deh, entry_num) - (de_with_sd (deh) ? SD_SIZE : 0))

/* hash value occupies bits from 7 up to 30 */
#define GET_HASH_VALUE(offset) ((offset) & 0x7fffff80LL)
/* generation number occupies 7 bits starting from 0 up to 6 */
#define GET_GENERATION_NUMBER(offset) ((offset) & 0x7fLL)
#define MAX_GENERATION_NUMBER  127

#define SET_GENERATION_NUMBER(offset,gen_number) (GET_HASH_VALUE(offset)|(gen_number))

/*
 * Picture represents an internal node of the reiserfs tree
 *  ______________________________________________________
 * |      |  Array of     |  Array of         |  Free     |
 * |block |    keys       |  pointers         | space     |
 * | head |      N        |      N+1          |           |
 * |______|_______________|___________________|___________|
 */

/***************************************************************************
 *                      DISK CHILD                                         *
 ***************************************************************************/
/*
 * Disk child pointer:
 * The pointer from an internal node of the tree to a node that is on disk.
 */
struct disk_child {
	__le32 dc_block_number;	/* Disk child's block number. */
	__le16 dc_size;		/* Disk child's used space.   */
	__le16 dc_reserved;
};

#define DC_SIZE (sizeof(struct disk_child))
#define dc_block_number(dc_p)	(le32_to_cpu((dc_p)->dc_block_number))
#define dc_size(dc_p)		(le16_to_cpu((dc_p)->dc_size))
#define put_dc_block_number(dc_p, val)   do { (dc_p)->dc_block_number = cpu_to_le32(val); } while(0)
#define put_dc_size(dc_p, val)   do { (dc_p)->dc_size = cpu_to_le16(val); } while(0)

/* Get disk child by buffer header and position in the tree node. */
#define B_N_CHILD(bh, n_pos)  ((struct disk_child *)\
((bh)->b_data + BLKH_SIZE + B_NR_ITEMS(bh) * KEY_SIZE + DC_SIZE * (n_pos)))

/* Get disk child number by buffer header and position in the tree node. */
#define B_N_CHILD_NUM(bh, n_pos) (dc_block_number(B_N_CHILD(bh, n_pos)))
#define PUT_B_N_CHILD_NUM(bh, n_pos, val) \
				(put_dc_block_number(B_N_CHILD(bh, n_pos), val))

 /* maximal value of field child_size in structure disk_child */
 /* child size is the combined size of all items and their headers */
#define MAX_CHILD_SIZE(bh) ((int)( (bh)->b_size - BLKH_SIZE ))

/* amount of used space in buffer (not including block head) */
#define B_CHILD_SIZE(cur) (MAX_CHILD_SIZE(cur)-(B_FREE_SPACE(cur)))

/* max and min number of keys in internal node */
#define MAX_NR_KEY(bh) ( (MAX_CHILD_SIZE(bh)-DC_SIZE)/(KEY_SIZE+DC_SIZE) )
#define MIN_NR_KEY(bh)    (MAX_NR_KEY(bh)/2)

/***************************************************************************
 *                      PATH STRUCTURES AND DEFINES                        *
 ***************************************************************************/

/*
 * search_by_key fills up the path from the root to the leaf as it descends
 * the tree looking for the key.  It uses reiserfs_bread to try to find
 * buffers in the cache given their block number.  If it does not find
 * them in the cache it reads them from disk.  For each node search_by_key
 * finds using reiserfs_bread it then uses bin_search to look through that
 * node.  bin_search will find the position of the block_number of the next
 * node if it is looking through an internal node.  If it is looking through
 * a leaf node bin_search will find the position of the item which has key
 * either equal to given key, or which is the maximal key less than the
 * given key.
 */

struct path_element {
	/* Pointer to the buffer at the path in the tree. */
	struct buffer_head *pe_buffer;
	/* Position in the tree node which is placed in the buffer above. */
	int pe_position;
};

/*
 * maximal height of a tree. don't change this without
 * changing JOURNAL_PER_BALANCE_CNT
 */
#define MAX_HEIGHT 5

/* Must be equals MAX_HEIGHT + FIRST_PATH_ELEMENT_OFFSET */
#define EXTENDED_MAX_HEIGHT         7

/* Must be equal to at least 2. */
#define FIRST_PATH_ELEMENT_OFFSET   2

/* Must be equal to FIRST_PATH_ELEMENT_OFFSET - 1 */
#define ILLEGAL_PATH_ELEMENT_OFFSET 1

/* this MUST be MAX_HEIGHT + 1. See about FEB below */
#define MAX_FEB_SIZE 6

/*
 * We need to keep track of who the ancestors of nodes are.  When we
 * perform a search we record which nodes were visited while
 * descending the tree looking for the node we searched for. This list
 * of nodes is called the path.  This information is used while
 * performing balancing.  Note that this path information may become
 * invalid, and this means we must check it when using it to see if it
 * is still valid. You'll need to read search_by_key and the comments
 * in it, especially about decrement_counters_in_path(), to understand
 * this structure.
 *
 * Paths make the code so much harder to work with and debug.... An
 * enormous number of bugs are due to them, and trying to write or modify
 * code that uses them just makes my head hurt.  They are based on an
 * excessive effort to avoid disturbing the precious VFS code.:-( The
 * gods only know how we are going to SMP the code that uses them.
 * znodes are the way!
 */

#define PATH_READA	0x1	/* do read ahead */
#define PATH_READA_BACK 0x2	/* read backwards */

struct treepath {
	int path_length;	/* Length of the array above.   */
	int reada;
	/* Array of the path elements.  */
	struct path_element path_elements[EXTENDED_MAX_HEIGHT];
	int pos_in_item;
};

#define pos_in_item(path) ((path)->pos_in_item)

#define INITIALIZE_PATH(var) \
struct treepath var = {.path_length = ILLEGAL_PATH_ELEMENT_OFFSET, .reada = 0,}

/* Get path element by path and path position. */
#define PATH_OFFSET_PELEMENT(path, n_offset)  ((path)->path_elements + (n_offset))

/* Get buffer header at the path by path and path position. */
#define PATH_OFFSET_PBUFFER(path, n_offset)   (PATH_OFFSET_PELEMENT(path, n_offset)->pe_buffer)

/* Get position in the element at the path by path and path position. */
#define PATH_OFFSET_POSITION(path, n_offset) (PATH_OFFSET_PELEMENT(path, n_offset)->pe_position)

#define PATH_PLAST_BUFFER(path) (PATH_OFFSET_PBUFFER((path), (path)->path_length))

/*
 * you know, to the person who didn't write this the macro name does not
 * at first suggest what it does.  Maybe POSITION_FROM_PATH_END? Or
 * maybe we should just focus on dumping paths... -Hans
 */
#define PATH_LAST_POSITION(path) (PATH_OFFSET_POSITION((path), (path)->path_length))

/*
 * in do_balance leaf has h == 0 in contrast with path structure,
 * where root has level == 0. That is why we need these defines
 */

/* tb->S[h] */
#define PATH_H_PBUFFER(path, h) \
			PATH_OFFSET_PBUFFER(path, path->path_length - (h))

/* tb->F[h] or tb->S[0]->b_parent */
#define PATH_H_PPARENT(path, h) PATH_H_PBUFFER(path, (h) + 1)

#define PATH_H_POSITION(path, h) \
			PATH_OFFSET_POSITION(path, path->path_length - (h))

/* tb->S[h]->b_item_order */
#define PATH_H_B_ITEM_ORDER(path, h) PATH_H_POSITION(path, h + 1)

#define PATH_H_PATH_OFFSET(path, n_h) ((path)->path_length - (n_h))

static inline void *reiserfs_node_data(const struct buffer_head *bh)
{
	return bh->b_data + sizeof(struct block_head);
}

/* get key from internal node */
static inline struct reiserfs_key *internal_key(struct buffer_head *bh,
						int item_num)
{
	struct reiserfs_key *key = reiserfs_node_data(bh);

	return &key[item_num];
}

/* get the item header from leaf node */
static inline struct item_head *item_head(const struct buffer_head *bh,
					  int item_num)
{
	struct item_head *ih = reiserfs_node_data(bh);

	return &ih[item_num];
}

/* get the key from leaf node */
static inline struct reiserfs_key *leaf_key(const struct buffer_head *bh,
					    int item_num)
{
	return &item_head(bh, item_num)->ih_key;
}

static inline void *ih_item_body(const struct buffer_head *bh,
				 const struct item_head *ih)
{
	return bh->b_data + ih_location(ih);
}

/* get item body from leaf node */
static inline void *item_body(const struct buffer_head *bh, int item_num)
{
	return ih_item_body(bh, item_head(bh, item_num));
}

static inline struct item_head *tp_item_head(const struct treepath *path)
{
	return item_head(PATH_PLAST_BUFFER(path), PATH_LAST_POSITION(path));
}

static inline void *tp_item_body(const struct treepath *path)
{
	return item_body(PATH_PLAST_BUFFER(path), PATH_LAST_POSITION(path));
}

#define get_last_bh(path) PATH_PLAST_BUFFER(path)
#define get_item_pos(path) PATH_LAST_POSITION(path)
#define item_moved(ih,path) comp_items(ih, path)
#define path_changed(ih,path) comp_items (ih, path)

/* array of the entry headers */
 /* get item body */
#define B_I_DEH(bh, ih) ((struct reiserfs_de_head *)(ih_item_body(bh, ih)))

/*
 * length of the directory entry in directory item. This define
 * calculates length of i-th directory entry using directory entry
 * locations from dir entry head. When it calculates length of 0-th
 * directory entry, it uses length of whole item in place of entry
 * location of the non-existent following entry in the calculation.
 * See picture above.
 */
static inline int entry_length(const struct buffer_head *bh,
			       const struct item_head *ih, int pos_in_item)
{
	struct reiserfs_de_head *deh;

	deh = B_I_DEH(bh, ih) + pos_in_item;
	if (pos_in_item)
		return deh_location(deh - 1) - deh_location(deh);

	return ih_item_len(ih) - deh_location(deh);
}

/***************************************************************************
 *                       MISC                                              *
 ***************************************************************************/

/* Size of pointer to the unformatted node. */
#define UNFM_P_SIZE (sizeof(unp_t))
#define UNFM_P_SHIFT 2

/* in in-core inode key is stored on le form */
#define INODE_PKEY(inode) ((struct reiserfs_key *)(REISERFS_I(inode)->i_key))

#define MAX_UL_INT 0xffffffff
#define MAX_INT    0x7ffffff
#define MAX_US_INT 0xffff

// reiserfs version 2 has max offset 60 bits. Version 1 - 32 bit offset
static inline loff_t max_reiserfs_offset(struct inode *inode)
{
	if (get_inode_item_key_version(inode) == KEY_FORMAT_3_5)
		return (loff_t) U32_MAX;

	return (loff_t) ((~(__u64) 0) >> 4);
}

#define MAX_KEY_OBJECTID	MAX_UL_INT

#define MAX_B_NUM  MAX_UL_INT
#define MAX_FC_NUM MAX_US_INT

/* the purpose is to detect overflow of an unsigned short */
#define REISERFS_LINK_MAX (MAX_US_INT - 1000)

/*
 * The following defines are used in reiserfs_insert_item
 * and reiserfs_append_item
 */
#define REISERFS_KERNEL_MEM		0	/* kernel memory mode */
#define REISERFS_USER_MEM		1	/* user memory mode */

#define fs_generation(s) (REISERFS_SB(s)->s_generation_counter)
#define get_generation(s) atomic_read (&fs_generation(s))
#define FILESYSTEM_CHANGED_TB(tb)  (get_generation((tb)->tb_sb) != (tb)->fs_gen)
#define __fs_changed(gen,s) (gen != get_generation (s))
#define fs_changed(gen,s)		\
({					\
	reiserfs_cond_resched(s);	\
	__fs_changed(gen, s);		\
})

/***************************************************************************
 *                  FIXATE NODES                                           *
 ***************************************************************************/

#define VI_TYPE_LEFT_MERGEABLE 1
#define VI_TYPE_RIGHT_MERGEABLE 2

/*
 * To make any changes in the tree we always first find node, that
 * contains item to be changed/deleted or place to insert a new
 * item. We call this node S. To do balancing we need to decide what
 * we will shift to left/right neighbor, or to a new node, where new
 * item will be etc. To make this analysis simpler we build virtual
 * node. Virtual node is an array of items, that will replace items of
 * node S. (For instance if we are going to delete an item, virtual
 * node does not contain it). Virtual node keeps information about
 * item sizes and types, mergeability of first and last items, sizes
 * of all entries in directory item. We use this array of items when
 * calculating what we can shift to neighbors and how many nodes we
 * have to have if we do not any shiftings, if we shift to left/right
 * neighbor or to both.
 */
struct virtual_item {
	int vi_index;		/* index in the array of item operations */
	unsigned short vi_type;	/* left/right mergeability */

	/* length of item that it will have after balancing */
	unsigned short vi_item_len;

	struct item_head *vi_ih;
	const char *vi_item;	/* body of item (old or new) */
	const void *vi_new_data;	/* 0 always but paste mode */
	void *vi_uarea;		/* item specific area */
};

struct virtual_node {
	/* this is a pointer to the free space in the buffer */
	char *vn_free_ptr;

	unsigned short vn_nr_item;	/* number of items in virtual node */

	/*
	 * size of node , that node would have if it has
	 * unlimited size and no balancing is performed
	 */
	short vn_size;

	/* mode of balancing (paste, insert, delete, cut) */
	short vn_mode;

	short vn_affected_item_num;
	short vn_pos_in_item;

	/* item header of inserted item, 0 for other modes */
	struct item_head *vn_ins_ih;
	const void *vn_data;

	/* array of items (including a new one, excluding item to be deleted) */
	struct virtual_item *vn_vi;
};

/* used by directory items when creating virtual nodes */
struct direntry_uarea {
	int flags;
	__u16 entry_count;
	__u16 entry_sizes[1];
} __attribute__ ((__packed__));

/***************************************************************************
 *                  TREE BALANCE                                           *
 ***************************************************************************/

/*
 * This temporary structure is used in tree balance algorithms, and
 * constructed as we go to the extent that its various parts are
 * needed.  It contains arrays of nodes that can potentially be
 * involved in the balancing of node S, and parameters that define how
 * each of the nodes must be balanced.  Note that in these algorithms
 * for balancing the worst case is to need to balance the current node
 * S and the left and right neighbors and all of their parents plus
 * create a new node.  We implement S1 balancing for the leaf nodes
 * and S0 balancing for the internal nodes (S1 and S0 are defined in
 * our papers.)
 */

/* size of the array of buffers to free at end of do_balance */
#define MAX_FREE_BLOCK 7

/* maximum number of FEB blocknrs on a single level */
#define MAX_AMOUNT_NEEDED 2

/* someday somebody will prefix every field in this struct with tb_ */
struct tree_balance {
	int tb_mode;
	int need_balance_dirty;
	struct super_block *tb_sb;
	struct reiserfs_transaction_handle *transaction_handle;
	struct treepath *tb_path;

	/* array of left neighbors of nodes in the path */
	struct buffer_head *L[MAX_HEIGHT];

	/* array of right neighbors of nodes in the path */
	struct buffer_head *R[MAX_HEIGHT];

	/* array of fathers of the left neighbors */
	struct buffer_head *FL[MAX_HEIGHT];

	/* array of fathers of the right neighbors */
	struct buffer_head *FR[MAX_HEIGHT];
	/* array of common parents of center node and its left neighbor */
	struct buffer_head *CFL[MAX_HEIGHT];

	/* array of common parents of center node and its right neighbor */
	struct buffer_head *CFR[MAX_HEIGHT];

	/*
	 * array of empty buffers. Number of buffers in array equals
	 * cur_blknum.
	 */
	struct buffer_head *FEB[MAX_FEB_SIZE];
	struct buffer_head *used[MAX_FEB_SIZE];
	struct buffer_head *thrown[MAX_FEB_SIZE];

	/*
	 * array of number of items which must be shifted to the left in
	 * order to balance the current node; for leaves includes item that
	 * will be partially shifted; for internal nodes, it is the number
	 * of child pointers rather than items. It includes the new item
	 * being created. The code sometimes subtracts one to get the
	 * number of wholly shifted items for other purposes.
	 */
	int lnum[MAX_HEIGHT];

	/* substitute right for left in comment above */
	int rnum[MAX_HEIGHT];

	/*
	 * array indexed by height h mapping the key delimiting L[h] and
	 * S[h] to its item number within the node CFL[h]
	 */
	int lkey[MAX_HEIGHT];

	/* substitute r for l in comment above */
	int rkey[MAX_HEIGHT];

	/*
	 * the number of bytes by we are trying to add or remove from
	 * S[h]. A negative value means removing.
	 */
	int insert_size[MAX_HEIGHT];

	/*
	 * number of nodes that will replace node S[h] after balancing
	 * on the level h of the tree.  If 0 then S is being deleted,
	 * if 1 then S is remaining and no new nodes are being created,
	 * if 2 or 3 then 1 or 2 new nodes is being created
	 */
	int blknum[MAX_HEIGHT];

	/* fields that are used only for balancing leaves of the tree */

	/* number of empty blocks having been already allocated */
	int cur_blknum;

	/* number of items that fall into left most node when S[0] splits */
	int s0num;

	/*
	 * number of bytes which can flow to the left neighbor from the left
	 * most liquid item that cannot be shifted from S[0] entirely
	 * if -1 then nothing will be partially shifted
	 */
	int lbytes;

	/*
	 * number of bytes which will flow to the right neighbor from the right
	 * most liquid item that cannot be shifted from S[0] entirely
	 * if -1 then nothing will be partially shifted
	 */
	int rbytes;


	/*
	 * index into the array of item headers in
	 * S[0] of the affected item
	 */
	int item_pos;

	/* new nodes allocated to hold what could not fit into S */
	struct buffer_head *S_new[2];

	/*
	 * number of items that will be placed into nodes in S_new
	 * when S[0] splits
	 */
	int snum[2];

	/*
	 * number of bytes which flow to nodes in S_new when S[0] splits
	 * note: if S[0] splits into 3 nodes, then items do not need to be cut
	 */
	int sbytes[2];

	int pos_in_item;
	int zeroes_num;

	/*
	 * buffers which are to be freed after do_balance finishes
	 * by unfix_nodes
	 */
	struct buffer_head *buf_to_free[MAX_FREE_BLOCK];

	/*
	 * kmalloced memory. Used to create virtual node and keep
	 * map of dirtied bitmap blocks
	 */
	char *vn_buf;

	int vn_buf_size;	/* size of the vn_buf */

	/* VN starts after bitmap of bitmap blocks */
	struct virtual_node *tb_vn;

	/*
	 * saved value of `reiserfs_generation' counter see
	 * FILESYSTEM_CHANGED() macro in reiserfs_fs.h
	 */
	int fs_gen;

#ifdef DISPLACE_NEW_PACKING_LOCALITIES
	/*
	 * key pointer, to pass to block allocator or
	 * another low-level subsystem
	 */
	struct in_core_key key;
#endif
};

/* These are modes of balancing */

/* When inserting an item. */
#define M_INSERT	'i'
/*
 * When inserting into (directories only) or appending onto an already
 * existent item.
 */
#define M_PASTE		'p'
/* When deleting an item. */
#define M_DELETE	'd'
/* When truncating an item or removing an entry from a (directory) item. */
#define M_CUT		'c'

/* used when balancing on leaf level skipped (in reiserfsck) */
#define M_INTERNAL	'n'

/*
 * When further balancing is not needed, then do_balance does not need
 * to be called.
 */
#define M_SKIP_BALANCING		's'
#define M_CONVERT	'v'

/* modes of leaf_move_items */
#define LEAF_FROM_S_TO_L 0
#define LEAF_FROM_S_TO_R 1
#define LEAF_FROM_R_TO_L 2
#define LEAF_FROM_L_TO_R 3
#define LEAF_FROM_S_TO_SNEW 4

#define FIRST_TO_LAST 0
#define LAST_TO_FIRST 1

/*
 * used in do_balance for passing parent of node information that has
 * been gotten from tb struct
 */
struct buffer_info {
	struct tree_balance *tb;
	struct buffer_head *bi_bh;
	struct buffer_head *bi_parent;
	int bi_position;
};

static inline struct super_block *sb_from_tb(struct tree_balance *tb)
{
	return tb ? tb->tb_sb : NULL;
}

static inline struct super_block *sb_from_bi(struct buffer_info *bi)
{
	return bi ? sb_from_tb(bi->tb) : NULL;
}

/*
 * there are 4 types of items: stat data, directory item, indirect, direct.
 * +-------------------+------------+--------------+------------+
 * |                   |  k_offset  | k_uniqueness | mergeable? |
 * +-------------------+------------+--------------+------------+
 * |     stat data     |     0      |      0       |   no       |
 * +-------------------+------------+--------------+------------+
 * | 1st directory item| DOT_OFFSET | DIRENTRY_ .. |   no       |
 * | non 1st directory | hash value | UNIQUENESS   |   yes      |
 * |     item          |            |              |            |
 * +-------------------+------------+--------------+------------+
 * | indirect item     | offset + 1 |TYPE_INDIRECT |    [1]	|
 * +-------------------+------------+--------------+------------+
 * | direct item       | offset + 1 |TYPE_DIRECT   |    [2]     |
 * +-------------------+------------+--------------+------------+
 *
 * [1] if this is not the first indirect item of the object
 * [2] if this is not the first direct item of the object
*/

struct item_operations {
	int (*bytes_number) (struct item_head * ih, int block_size);
	void (*decrement_key) (struct cpu_key *);
	int (*is_left_mergeable) (struct reiserfs_key * ih,
				  unsigned long bsize);
	void (*print_item) (struct item_head *, char *item);
	void (*check_item) (struct item_head *, char *item);

	int (*create_vi) (struct virtual_node * vn, struct virtual_item * vi,
			  int is_affected, int insert_size);
	int (*check_left) (struct virtual_item * vi, int free,
			   int start_skip, int end_skip);
	int (*check_right) (struct virtual_item * vi, int free);
	int (*part_size) (struct virtual_item * vi, int from, int to);
	int (*unit_num) (struct virtual_item * vi);
	void (*print_vi) (struct virtual_item * vi);
};

extern struct item_operations *item_ops[TYPE_ANY + 1];

#define op_bytes_number(ih,bsize)                    item_ops[le_ih_k_type (ih)]->bytes_number (ih, bsize)
#define op_is_left_mergeable(key,bsize)              item_ops[le_key_k_type (le_key_version (key), key)]->is_left_mergeable (key, bsize)
#define op_print_item(ih,item)                       item_ops[le_ih_k_type (ih)]->print_item (ih, item)
#define op_check_item(ih,item)                       item_ops[le_ih_k_type (ih)]->check_item (ih, item)
#define op_create_vi(vn,vi,is_affected,insert_size)  item_ops[le_ih_k_type ((vi)->vi_ih)]->create_vi (vn,vi,is_affected,insert_size)
#define op_check_left(vi,free,start_skip,end_skip) item_ops[(vi)->vi_index]->check_left (vi, free, start_skip, end_skip)
#define op_check_right(vi,free)                      item_ops[(vi)->vi_index]->check_right (vi, free)
#define op_part_size(vi,from,to)                     item_ops[(vi)->vi_index]->part_size (vi, from, to)
#define op_unit_num(vi)				     item_ops[(vi)->vi_index]->unit_num (vi)
#define op_print_vi(vi)                              item_ops[(vi)->vi_index]->print_vi (vi)

#define COMP_SHORT_KEYS comp_short_keys

/* number of blocks pointed to by the indirect item */
#define I_UNFM_NUM(ih)	(ih_item_len(ih) / UNFM_P_SIZE)

/*
 * the used space within the unformatted node corresponding
 * to pos within the item pointed to by ih
 */
#define I_POS_UNFM_SIZE(ih,pos,size) (((pos) == I_UNFM_NUM(ih) - 1 ) ? (size) - ih_free_space(ih) : (size))

/*
 * number of bytes contained by the direct item or the
 * unformatted nodes the indirect item points to
 */

/* following defines use reiserfs buffer header and item header */

/* get stat-data */
#define B_I_STAT_DATA(bh, ih) ( (struct stat_data * )((bh)->b_data + ih_location(ih)) )

/* this is 3976 for size==4096 */
#define MAX_DIRECT_ITEM_LEN(size) ((size) - BLKH_SIZE - 2*IH_SIZE - SD_SIZE - UNFM_P_SIZE)

/*
 * indirect items consist of entries which contain blocknrs, pos
 * indicates which entry, and B_I_POS_UNFM_POINTER resolves to the
 * blocknr contained by the entry pos points to
 */
#define B_I_POS_UNFM_POINTER(bh, ih, pos)				\
	le32_to_cpu(*(((unp_t *)ih_item_body(bh, ih)) + (pos)))
#define PUT_B_I_POS_UNFM_POINTER(bh, ih, pos, val)			\
	(*(((unp_t *)ih_item_body(bh, ih)) + (pos)) = cpu_to_le32(val))

struct reiserfs_iget_args {
	__u32 objectid;
	__u32 dirid;
};

/***************************************************************************
 *                    FUNCTION DECLARATIONS                                *
 ***************************************************************************/

#define get_journal_desc_magic(bh) (bh->b_data + bh->b_size - 12)

#define journal_trans_half(blocksize) \
	((blocksize - sizeof (struct reiserfs_journal_desc) + sizeof (__u32) - 12) / sizeof (__u32))

/* journal.c see journal.c for all the comments here */

/* first block written in a commit.  */
struct reiserfs_journal_desc {
	__le32 j_trans_id;	/* id of commit */

	/* length of commit. len +1 is the commit block */
	__le32 j_len;

	__le32 j_mount_id;	/* mount id of this trans */
	__le32 j_realblock[1];	/* real locations for each block */
};

#define get_desc_trans_id(d)   le32_to_cpu((d)->j_trans_id)
#define get_desc_trans_len(d)  le32_to_cpu((d)->j_len)
#define get_desc_mount_id(d)   le32_to_cpu((d)->j_mount_id)

#define set_desc_trans_id(d,val)       do { (d)->j_trans_id = cpu_to_le32 (val); } while (0)
#define set_desc_trans_len(d,val)      do { (d)->j_len = cpu_to_le32 (val); } while (0)
#define set_desc_mount_id(d,val)       do { (d)->j_mount_id = cpu_to_le32 (val); } while (0)

/* last block written in a commit */
struct reiserfs_journal_commit {
	__le32 j_trans_id;	/* must match j_trans_id from the desc block */
	__le32 j_len;		/* ditto */
	__le32 j_realblock[1];	/* real locations for each block */
};

#define get_commit_trans_id(c) le32_to_cpu((c)->j_trans_id)
#define get_commit_trans_len(c)        le32_to_cpu((c)->j_len)
#define get_commit_mount_id(c) le32_to_cpu((c)->j_mount_id)

#define set_commit_trans_id(c,val)     do { (c)->j_trans_id = cpu_to_le32 (val); } while (0)
#define set_commit_trans_len(c,val)    do { (c)->j_len = cpu_to_le32 (val); } while (0)

/*
 * this header block gets written whenever a transaction is considered
 * fully flushed, and is more recent than the last fully flushed transaction.
 * fully flushed means all the log blocks and all the real blocks are on
 * disk, and this transaction does not need to be replayed.
 */
struct reiserfs_journal_header {
	/* id of last fully flushed transaction */
	__le32 j_last_flush_trans_id;

	/* offset in the log of where to start replay after a crash */
	__le32 j_first_unflushed_offset;

	__le32 j_mount_id;
	/* 12 */ struct journal_params jh_journal;
};

/* biggest tunable defines are right here */
#define JOURNAL_BLOCK_COUNT 8192	/* number of blocks in the journal */

/* biggest possible single transaction, don't change for now (8/3/99) */
#define JOURNAL_TRANS_MAX_DEFAULT 1024
#define JOURNAL_TRANS_MIN_DEFAULT 256

/*
 * max blocks to batch into one transaction,
 * don't make this any bigger than 900
 */
#define JOURNAL_MAX_BATCH_DEFAULT   900
#define JOURNAL_MIN_RATIO 2
#define JOURNAL_MAX_COMMIT_AGE 30
#define JOURNAL_MAX_TRANS_AGE 30
#define JOURNAL_PER_BALANCE_CNT (3 * (MAX_HEIGHT-2) + 9)
#define JOURNAL_BLOCKS_PER_OBJECT(sb)  (JOURNAL_PER_BALANCE_CNT * 3 + \
					 2 * (REISERFS_QUOTA_INIT_BLOCKS(sb) + \
					      REISERFS_QUOTA_TRANS_BLOCKS(sb)))

#ifdef CONFIG_QUOTA
#define REISERFS_QUOTA_OPTS ((1 << REISERFS_USRQUOTA) | (1 << REISERFS_GRPQUOTA))
/* We need to update data and inode (atime) */
#define REISERFS_QUOTA_TRANS_BLOCKS(s) (REISERFS_SB(s)->s_mount_opt & REISERFS_QUOTA_OPTS ? 2 : 0)
/* 1 balancing, 1 bitmap, 1 data per write + stat data update */
#define REISERFS_QUOTA_INIT_BLOCKS(s) (REISERFS_SB(s)->s_mount_opt & REISERFS_QUOTA_OPTS ? \
(DQUOT_INIT_ALLOC*(JOURNAL_PER_BALANCE_CNT+2)+DQUOT_INIT_REWRITE+1) : 0)
/* same as with INIT */
#define REISERFS_QUOTA_DEL_BLOCKS(s) (REISERFS_SB(s)->s_mount_opt & REISERFS_QUOTA_OPTS ? \
(DQUOT_DEL_ALLOC*(JOURNAL_PER_BALANCE_CNT+2)+DQUOT_DEL_REWRITE+1) : 0)
#else
#define REISERFS_QUOTA_TRANS_BLOCKS(s) 0
#define REISERFS_QUOTA_INIT_BLOCKS(s) 0
#define REISERFS_QUOTA_DEL_BLOCKS(s) 0
#endif

/*
 * both of these can be as low as 1, or as high as you want.  The min is the
 * number of 4k bitmap nodes preallocated on mount. New nodes are allocated
 * as needed, and released when transactions are committed.  On release, if
 * the current number of nodes is > max, the node is freed, otherwise,
 * it is put on a free list for faster use later.
*/
#define REISERFS_MIN_BITMAP_NODES 10
#define REISERFS_MAX_BITMAP_NODES 100

/* these are based on journal hash size of 8192 */
#define JBH_HASH_SHIFT 13
#define JBH_HASH_MASK 8191

#define _jhashfn(sb,block)	\
	(((unsigned long)sb>>L1_CACHE_SHIFT) ^ \
	 (((block)<<(JBH_HASH_SHIFT - 6)) ^ ((block) >> 13) ^ ((block) << (JBH_HASH_SHIFT - 12))))
#define journal_hash(t,sb,block) ((t)[_jhashfn((sb),(block)) & JBH_HASH_MASK])

/* We need these to make journal.c code more readable */
#define journal_find_get_block(s, block) __find_get_block(SB_JOURNAL(s)->j_dev_bd, block, s->s_blocksize)
#define journal_getblk(s, block) __getblk(SB_JOURNAL(s)->j_dev_bd, block, s->s_blocksize)
#define journal_bread(s, block) __bread(SB_JOURNAL(s)->j_dev_bd, block, s->s_blocksize)

enum reiserfs_bh_state_bits {
	BH_JDirty = BH_PrivateStart,	/* buffer is in current transaction */
	BH_JDirty_wait,
	/*
	 * disk block was taken off free list before being in a
	 * finished transaction, or written to disk. Can be reused immed.
	 */
	BH_JNew,
	BH_JPrepared,
	BH_JRestore_dirty,
	BH_JTest,		/* debugging only will go away */
};

BUFFER_FNS(JDirty, journaled);
TAS_BUFFER_FNS(JDirty, journaled);
BUFFER_FNS(JDirty_wait, journal_dirty);
TAS_BUFFER_FNS(JDirty_wait, journal_dirty);
BUFFER_FNS(JNew, journal_new);
TAS_BUFFER_FNS(JNew, journal_new);
BUFFER_FNS(JPrepared, journal_prepared);
TAS_BUFFER_FNS(JPrepared, journal_prepared);
BUFFER_FNS(JRestore_dirty, journal_restore_dirty);
TAS_BUFFER_FNS(JRestore_dirty, journal_restore_dirty);
BUFFER_FNS(JTest, journal_test);
TAS_BUFFER_FNS(JTest, journal_test);

/* transaction handle which is passed around for all journal calls */
struct reiserfs_transaction_handle {
	/*
	 * super for this FS when journal_begin was called. saves calls to
	 * reiserfs_get_super also used by nested transactions to make
	 * sure they are nesting on the right FS _must_ be first
	 * in the handle
	 */
	struct super_block *t_super;

	int t_refcount;
	int t_blocks_logged;	/* number of blocks this writer has logged */
	int t_blocks_allocated;	/* number of blocks this writer allocated */

	/* sanity check, equals the current trans id */
	unsigned int t_trans_id;

	void *t_handle_save;	/* save existing current->journal_info */

	/*
	 * if new block allocation occurres, that block
	 * should be displaced from others
	 */
	unsigned displace_new_blocks:1;

	struct list_head t_list;
};

/*
 * used to keep track of ordered and tail writes, attached to the buffer
 * head through b_journal_head.
 */
struct reiserfs_jh {
	struct reiserfs_journal_list *jl;
	struct buffer_head *bh;
	struct list_head list;
};

void reiserfs_free_jh(struct buffer_head *bh);
int reiserfs_add_tail_list(struct inode *inode, struct buffer_head *bh);
int reiserfs_add_ordered_list(struct inode *inode, struct buffer_head *bh);
int journal_mark_dirty(struct reiserfs_transaction_handle *,
		       struct buffer_head *bh);

static inline int reiserfs_file_data_log(struct inode *inode)
{
	if (reiserfs_data_log(inode->i_sb) ||
	    (REISERFS_I(inode)->i_flags & i_data_log))
		return 1;
	return 0;
}

static inline int reiserfs_transaction_running(struct super_block *s)
{
	struct reiserfs_transaction_handle *th = current->journal_info;
	if (th && th->t_super == s)
		return 1;
	if (th && th->t_super == NULL)
		BUG();
	return 0;
}

static inline int reiserfs_transaction_free_space(struct reiserfs_transaction_handle *th)
{
	return th->t_blocks_allocated - th->t_blocks_logged;
}

struct reiserfs_transaction_handle *reiserfs_persistent_transaction(struct
								    super_block
								    *,
								    int count);
int reiserfs_end_persistent_transaction(struct reiserfs_transaction_handle *);
void reiserfs_vfs_truncate_file(struct inode *inode);
int reiserfs_commit_page(struct inode *inode, struct page *page,
			 unsigned from, unsigned to);
void reiserfs_flush_old_commits(struct super_block *);
int reiserfs_commit_for_inode(struct inode *);
int reiserfs_inode_needs_commit(struct inode *);
void reiserfs_update_inode_transaction(struct inode *);
void reiserfs_wait_on_write_block(struct super_block *s);
void reiserfs_block_writes(struct reiserfs_transaction_handle *th);
void reiserfs_allow_writes(struct super_block *s);
void reiserfs_check_lock_depth(struct super_block *s, char *caller);
int reiserfs_prepare_for_journal(struct super_block *, struct buffer_head *bh,
				 int wait);
void reiserfs_restore_prepared_buffer(struct super_block *,
				      struct buffer_head *bh);
int journal_init(struct super_block *, const char *j_dev_name, int old_format,
		 unsigned int);
int journal_release(struct reiserfs_transaction_handle *, struct super_block *);
int journal_release_error(struct reiserfs_transaction_handle *,
			  struct super_block *);
int journal_end(struct reiserfs_transaction_handle *);
int journal_end_sync(struct reiserfs_transaction_handle *);
int journal_mark_freed(struct reiserfs_transaction_handle *,
		       struct super_block *, b_blocknr_t blocknr);
int journal_transaction_should_end(struct reiserfs_transaction_handle *, int);
int reiserfs_in_journal(struct super_block *sb, unsigned int bmap_nr,
			 int bit_nr, int searchall, b_blocknr_t *next);
int journal_begin(struct reiserfs_transaction_handle *,
		  struct super_block *sb, unsigned long);
int journal_join_abort(struct reiserfs_transaction_handle *,
		       struct super_block *sb);
void reiserfs_abort_journal(struct super_block *sb, int errno);
void reiserfs_abort(struct super_block *sb, int errno, const char *fmt, ...);
int reiserfs_allocate_list_bitmaps(struct super_block *s,
				   struct reiserfs_list_bitmap *, unsigned int);

void reiserfs_schedule_old_flush(struct super_block *s);
void reiserfs_cancel_old_flush(struct super_block *s);
void add_save_link(struct reiserfs_transaction_handle *th,
		   struct inode *inode, int truncate);
int remove_save_link(struct inode *inode, int truncate);

/* objectid.c */
__u32 reiserfs_get_unused_objectid(struct reiserfs_transaction_handle *th);
void reiserfs_release_objectid(struct reiserfs_transaction_handle *th,
			       __u32 objectid_to_release);
int reiserfs_convert_objectid_map_v1(struct super_block *);

/* stree.c */
int B_IS_IN_TREE(const struct buffer_head *);
extern void copy_item_head(struct item_head *to,
			   const struct item_head *from);

/* first key is in cpu form, second - le */
extern int comp_short_keys(const struct reiserfs_key *le_key,
			   const struct cpu_key *cpu_key);
extern void le_key2cpu_key(struct cpu_key *to, const struct reiserfs_key *from);

/* both are in le form */
extern int comp_le_keys(const struct reiserfs_key *,
			const struct reiserfs_key *);
extern int comp_short_le_keys(const struct reiserfs_key *,
			      const struct reiserfs_key *);

/* * get key version from on disk key - kludge */
static inline int le_key_version(const struct reiserfs_key *key)
{
	int type;

	type = offset_v2_k_type(&(key->u.k_offset_v2));
	if (type != TYPE_DIRECT && type != TYPE_INDIRECT
	    && type != TYPE_DIRENTRY)
		return KEY_FORMAT_3_5;

	return KEY_FORMAT_3_6;

}

static inline void copy_key(struct reiserfs_key *to,
			    const struct reiserfs_key *from)
{
	memcpy(to, from, KEY_SIZE);
}

int comp_items(const struct item_head *stored_ih, const struct treepath *path);
const struct reiserfs_key *get_rkey(const struct treepath *chk_path,
				    const struct super_block *sb);
int search_by_key(struct super_block *, const struct cpu_key *,
		  struct treepath *, int);
#define search_item(s,key,path) search_by_key (s, key, path, DISK_LEAF_NODE_LEVEL)
int search_for_position_by_key(struct super_block *sb,
			       const struct cpu_key *cpu_key,
			       struct treepath *search_path);
extern void decrement_bcount(struct buffer_head *bh);
void decrement_counters_in_path(struct treepath *search_path);
void pathrelse(struct treepath *search_path);
int reiserfs_check_path(struct treepath *p);
void pathrelse_and_restore(struct super_block *s, struct treepath *search_path);

int reiserfs_insert_item(struct reiserfs_transaction_handle *th,
			 struct treepath *path,
			 const struct cpu_key *key,
			 struct item_head *ih,
			 struct inode *inode, const char *body);

int reiserfs_paste_into_item(struct reiserfs_transaction_handle *th,
			     struct treepath *path,
			     const struct cpu_key *key,
			     struct inode *inode,
			     const char *body, int paste_size);

int reiserfs_cut_from_item(struct reiserfs_transaction_handle *th,
			   struct treepath *path,
			   struct cpu_key *key,
			   struct inode *inode,
			   struct page *page, loff_t new_file_size);

int reiserfs_delete_item(struct reiserfs_transaction_handle *th,
			 struct treepath *path,
			 const struct cpu_key *key,
			 struct inode *inode, struct buffer_head *un_bh);

void reiserfs_delete_solid_item(struct reiserfs_transaction_handle *th,
				struct inode *inode, struct reiserfs_key *key);
int reiserfs_delete_object(struct reiserfs_transaction_handle *th,
			   struct inode *inode);
int reiserfs_do_truncate(struct reiserfs_transaction_handle *th,
			 struct inode *inode, struct page *,
			 int update_timestamps);

#define i_block_size(inode) ((inode)->i_sb->s_blocksize)
#define file_size(inode) ((inode)->i_size)
#define tail_size(inode) (file_size (inode) & (i_block_size (inode) - 1))

#define tail_has_to_be_packed(inode) (have_large_tails ((inode)->i_sb)?\
!STORE_TAIL_IN_UNFM_S1(file_size (inode), tail_size(inode), inode->i_sb->s_blocksize):have_small_tails ((inode)->i_sb)?!STORE_TAIL_IN_UNFM_S2(file_size (inode), tail_size(inode), inode->i_sb->s_blocksize):0 )

void padd_item(char *item, int total_length, int length);

/* inode.c */
/* args for the create parameter of reiserfs_get_block */
#define GET_BLOCK_NO_CREATE 0	 /* don't create new blocks or convert tails */
#define GET_BLOCK_CREATE 1	 /* add anything you need to find block */
#define GET_BLOCK_NO_HOLE 2	 /* return -ENOENT for file holes */
#define GET_BLOCK_READ_DIRECT 4	 /* read the tail if indirect item not found */
#define GET_BLOCK_NO_IMUX     8	 /* i_mutex is not held, don't preallocate */
#define GET_BLOCK_NO_DANGLE   16 /* don't leave any transactions running */

void reiserfs_read_locked_inode(struct inode *inode,
				struct reiserfs_iget_args *args);
int reiserfs_find_actor(struct inode *inode, void *p);
int reiserfs_init_locked_inode(struct inode *inode, void *p);
void reiserfs_evict_inode(struct inode *inode);
int reiserfs_write_inode(struct inode *inode, struct writeback_control *wbc);
int reiserfs_get_block(struct inode *inode, sector_t block,
		       struct buffer_head *bh_result, int create);
struct dentry *reiserfs_fh_to_dentry(struct super_block *sb, struct fid *fid,
				     int fh_len, int fh_type);
struct dentry *reiserfs_fh_to_parent(struct super_block *sb, struct fid *fid,
				     int fh_len, int fh_type);
int reiserfs_encode_fh(struct inode *inode, __u32 * data, int *lenp,
		       struct inode *parent);

int reiserfs_truncate_file(struct inode *, int update_timestamps);
void make_cpu_key(struct cpu_key *cpu_key, struct inode *inode, loff_t offset,
		  int type, int key_length);
void make_le_item_head(struct item_head *ih, const struct cpu_key *key,
		       int version,
		       loff_t offset, int type, int length, int entry_count);
struct inode *reiserfs_iget(struct super_block *s, const struct cpu_key *key);

struct reiserfs_security_handle;
int reiserfs_new_inode(struct reiserfs_transaction_handle *th,
		       struct inode *dir, umode_t mode,
		       const char *symname, loff_t i_size,
		       struct dentry *dentry, struct inode *inode,
		       struct reiserfs_security_handle *security);

void reiserfs_update_sd_size(struct reiserfs_transaction_handle *th,
			     struct inode *inode, loff_t size);

static inline void reiserfs_update_sd(struct reiserfs_transaction_handle *th,
				      struct inode *inode)
{
	reiserfs_update_sd_size(th, inode, inode->i_size);
}

void sd_attrs_to_i_attrs(__u16 sd_attrs, struct inode *inode);
int reiserfs_setattr(struct dentry *dentry, struct iattr *attr);

int __reiserfs_write_begin(struct page *page, unsigned from, unsigned len);

/* namei.c */
void set_de_name_and_namelen(struct reiserfs_dir_entry *de);
int search_by_entry_key(struct super_block *sb, const struct cpu_key *key,
			struct treepath *path, struct reiserfs_dir_entry *de);
struct dentry *reiserfs_get_parent(struct dentry *);

#ifdef CONFIG_REISERFS_PROC_INFO
int reiserfs_proc_info_init(struct super_block *sb);
int reiserfs_proc_info_done(struct super_block *sb);
int reiserfs_proc_info_global_init(void);
int reiserfs_proc_info_global_done(void);

#define PROC_EXP( e )   e

#define __PINFO( sb ) REISERFS_SB(sb) -> s_proc_info_data
#define PROC_INFO_MAX( sb, field, value )								\
    __PINFO( sb ).field =												\
        max( REISERFS_SB( sb ) -> s_proc_info_data.field, value )
#define PROC_INFO_INC( sb, field ) ( ++ ( __PINFO( sb ).field ) )
#define PROC_INFO_ADD( sb, field, val ) ( __PINFO( sb ).field += ( val ) )
#define PROC_INFO_BH_STAT( sb, bh, level )							\
    PROC_INFO_INC( sb, sbk_read_at[ ( level ) ] );						\
    PROC_INFO_ADD( sb, free_at[ ( level ) ], B_FREE_SPACE( bh ) );	\
    PROC_INFO_ADD( sb, items_at[ ( level ) ], B_NR_ITEMS( bh ) )
#else
static inline int reiserfs_proc_info_init(struct super_block *sb)
{
	return 0;
}

static inline int reiserfs_proc_info_done(struct super_block *sb)
{
	return 0;
}

static inline int reiserfs_proc_info_global_init(void)
{
	return 0;
}

static inline int reiserfs_proc_info_global_done(void)
{
	return 0;
}

#define PROC_EXP( e )
#define VOID_V ( ( void ) 0 )
#define PROC_INFO_MAX( sb, field, value ) VOID_V
#define PROC_INFO_INC( sb, field ) VOID_V
#define PROC_INFO_ADD( sb, field, val ) VOID_V
#define PROC_INFO_BH_STAT(sb, bh, n_node_level) VOID_V
#endif

/* dir.c */
extern const struct inode_operations reiserfs_dir_inode_operations;
extern const struct inode_operations reiserfs_symlink_inode_operations;
extern const struct inode_operations reiserfs_special_inode_operations;
extern const struct file_operations reiserfs_dir_operations;
int reiserfs_readdir_inode(struct inode *, struct dir_context *);

/* tail_conversion.c */
int direct2indirect(struct reiserfs_transaction_handle *, struct inode *,
		    struct treepath *, struct buffer_head *, loff_t);
int indirect2direct(struct reiserfs_transaction_handle *, struct inode *,
		    struct page *, struct treepath *, const struct cpu_key *,
		    loff_t, char *);
void reiserfs_unmap_buffer(struct buffer_head *);

/* file.c */
extern const struct inode_operations reiserfs_file_inode_operations;
extern const struct file_operations reiserfs_file_operations;
extern const struct address_space_operations reiserfs_address_space_operations;

/* fix_nodes.c */

int fix_nodes(int n_op_mode, struct tree_balance *tb,
	      struct item_head *ins_ih, const void *);
void unfix_nodes(struct tree_balance *);

/* prints.c */
void __reiserfs_panic(struct super_block *s, const char *id,
		      const char *function, const char *fmt, ...)
    __attribute__ ((noreturn));
#define reiserfs_panic(s, id, fmt, args...) \
	__reiserfs_panic(s, id, __func__, fmt, ##args)
void __reiserfs_error(struct super_block *s, const char *id,
		      const char *function, const char *fmt, ...);
#define reiserfs_error(s, id, fmt, args...) \
	 __reiserfs_error(s, id, __func__, fmt, ##args)
void reiserfs_info(struct super_block *s, const char *fmt, ...);
void reiserfs_debug(struct super_block *s, int level, const char *fmt, ...);
void print_indirect_item(struct buffer_head *bh, int item_num);
void store_print_tb(struct tree_balance *tb);
void print_cur_tb(char *mes);
void print_de(struct reiserfs_dir_entry *de);
void print_bi(struct buffer_info *bi, char *mes);
#define PRINT_LEAF_ITEMS 1	/* print all items */
#define PRINT_DIRECTORY_ITEMS 2	/* print directory items */
#define PRINT_DIRECT_ITEMS 4	/* print contents of direct items */
void print_block(struct buffer_head *bh, ...);
void print_bmap(struct super_block *s, int silent);
void print_bmap_block(int i, char *data, int size, int silent);
/*void print_super_block (struct super_block * s, char * mes);*/
void print_objectid_map(struct super_block *s);
void print_block_head(struct buffer_head *bh, char *mes);
void check_leaf(struct buffer_head *bh);
void check_internal(struct buffer_head *bh);
void print_statistics(struct super_block *s);
char *reiserfs_hashname(int code);

/* lbalance.c */
int leaf_move_items(int shift_mode, struct tree_balance *tb, int mov_num,
		    int mov_bytes, struct buffer_head *Snew);
int leaf_shift_left(struct tree_balance *tb, int shift_num, int shift_bytes);
int leaf_shift_right(struct tree_balance *tb, int shift_num, int shift_bytes);
void leaf_delete_items(struct buffer_info *cur_bi, int last_first, int first,
		       int del_num, int del_bytes);
void leaf_insert_into_buf(struct buffer_info *bi, int before,
			  struct item_head * const inserted_item_ih,
			  const char * const inserted_item_body,
			  int zeros_number);
void leaf_paste_in_buffer(struct buffer_info *bi, int pasted_item_num,
			  int pos_in_item, int paste_size,
			  const char * const body, int zeros_number);
void leaf_cut_from_buffer(struct buffer_info *bi, int cut_item_num,
			  int pos_in_item, int cut_size);
void leaf_paste_entries(struct buffer_info *bi, int item_num, int before,
			int new_entry_count, struct reiserfs_de_head *new_dehs,
			const char *records, int paste_size);
/* ibalance.c */
int balance_internal(struct tree_balance *, int, int, struct item_head *,
		     struct buffer_head **);

/* do_balance.c */
void do_balance_mark_leaf_dirty(struct tree_balance *tb,
				struct buffer_head *bh, int flag);
#define do_balance_mark_internal_dirty do_balance_mark_leaf_dirty
#define do_balance_mark_sb_dirty do_balance_mark_leaf_dirty

void do_balance(struct tree_balance *tb, struct item_head *ih,
		const char *body, int flag);
void reiserfs_invalidate_buffer(struct tree_balance *tb,
				struct buffer_head *bh);

int get_left_neighbor_position(struct tree_balance *tb, int h);
int get_right_neighbor_position(struct tree_balance *tb, int h);
void replace_key(struct tree_balance *tb, struct buffer_head *, int,
		 struct buffer_head *, int);
void make_empty_node(struct buffer_info *);
struct buffer_head *get_FEB(struct tree_balance *);

/* bitmap.c */

/*
 * structure contains hints for block allocator, and it is a container for
 * arguments, such as node, search path, transaction_handle, etc.
 */
struct __reiserfs_blocknr_hint {
	/* inode passed to allocator, if we allocate unf. nodes */
	struct inode *inode;

	sector_t block;		/* file offset, in blocks */
	struct in_core_key key;

	/*
	 * search path, used by allocator to deternine search_start by
	 * various ways
	 */
	struct treepath *path;

	/*
	 * transaction handle is needed to log super blocks
	 * and bitmap blocks changes
	 */
	struct reiserfs_transaction_handle *th;

	b_blocknr_t beg, end;

	/*
	 * a field used to transfer search start value (block number)
	 * between different block allocator procedures
	 * (determine_search_start() and others)
	 */
	b_blocknr_t search_start;

	/*
	 * is set in determine_prealloc_size() function,
	 * used by underlayed function that do actual allocation
	 */
	int prealloc_size;

	/*
	 * the allocator uses different polices for getting disk
	 * space for formatted/unformatted blocks with/without preallocation
	 */
	unsigned formatted_node:1;
	unsigned preallocate:1;
};

typedef struct __reiserfs_blocknr_hint reiserfs_blocknr_hint_t;

int reiserfs_parse_alloc_options(struct super_block *, char *);
void reiserfs_init_alloc_options(struct super_block *s);

/*
 * given a directory, this will tell you what packing locality
 * to use for a new object underneat it.  The locality is returned
 * in disk byte order (le).
 */
__le32 reiserfs_choose_packing(struct inode *dir);

void show_alloc_options(struct seq_file *seq, struct super_block *s);
int reiserfs_init_bitmap_cache(struct super_block *sb);
void reiserfs_free_bitmap_cache(struct super_block *sb);
void reiserfs_cache_bitmap_metadata(struct super_block *sb, struct buffer_head *bh, struct reiserfs_bitmap_info *info);
struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb, unsigned int bitmap);
int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value);
void reiserfs_free_block(struct reiserfs_transaction_handle *th, struct inode *,
			 b_blocknr_t, int for_unformatted);
int reiserfs_allocate_blocknrs(reiserfs_blocknr_hint_t *, b_blocknr_t *, int,
			       int);
static inline int reiserfs_new_form_blocknrs(struct tree_balance *tb,
					     b_blocknr_t * new_blocknrs,
					     int amount_needed)
{
	reiserfs_blocknr_hint_t hint = {
		.th = tb->transaction_handle,
		.path = tb->tb_path,
		.inode = NULL,
		.key = tb->key,
		.block = 0,
		.formatted_node = 1
	};
	return reiserfs_allocate_blocknrs(&hint, new_blocknrs, amount_needed,
					  0);
}

static inline int reiserfs_new_unf_blocknrs(struct reiserfs_transaction_handle
					    *th, struct inode *inode,
					    b_blocknr_t * new_blocknrs,
					    struct treepath *path,
					    sector_t block)
{
	reiserfs_blocknr_hint_t hint = {
		.th = th,
		.path = path,
		.inode = inode,
		.block = block,
		.formatted_node = 0,
		.preallocate = 0
	};
	return reiserfs_allocate_blocknrs(&hint, new_blocknrs, 1, 0);
}

#ifdef REISERFS_PREALLOCATE
static inline int reiserfs_new_unf_blocknrs2(struct reiserfs_transaction_handle
					     *th, struct inode *inode,
					     b_blocknr_t * new_blocknrs,
					     struct treepath *path,
					     sector_t block)
{
	reiserfs_blocknr_hint_t hint = {
		.th = th,
		.path = path,
		.inode = inode,
		.block = block,
		.formatted_node = 0,
		.preallocate = 1
	};
	return reiserfs_allocate_blocknrs(&hint, new_blocknrs, 1, 0);
}

void reiserfs_discard_prealloc(struct reiserfs_transaction_handle *th,
			       struct inode *inode);
void reiserfs_discard_all_prealloc(struct reiserfs_transaction_handle *th);
#endif

/* hashes.c */
__u32 keyed_hash(const signed char *msg, int len);
__u32 yura_hash(const signed char *msg, int len);
__u32 r5_hash(const signed char *msg, int len);

#define reiserfs_set_le_bit		__set_bit_le
#define reiserfs_test_and_set_le_bit	__test_and_set_bit_le
#define reiserfs_clear_le_bit		__clear_bit_le
#define reiserfs_test_and_clear_le_bit	__test_and_clear_bit_le
#define reiserfs_test_le_bit		test_bit_le
#define reiserfs_find_next_zero_le_bit	find_next_zero_bit_le

/*
 * sometimes reiserfs_truncate may require to allocate few new blocks
 * to perform indirect2direct conversion. People probably used to
 * think, that truncate should work without problems on a filesystem
 * without free disk space. They may complain that they can not
 * truncate due to lack of free disk space. This spare space allows us
 * to not worry about it. 500 is probably too much, but it should be
 * absolutely safe
 */
#define SPARE_SPACE 500

/* prototypes from ioctl.c */
long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
long reiserfs_compat_ioctl(struct file *filp,
		   unsigned int cmd, unsigned long arg);
int reiserfs_unpack(struct inode *inode, struct file *filp);
