/* 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_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,