/*
 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
 *
 * Copyright 1998--1999 Red Hat corp --- All Rights Reserved
 *
 * This file is part of the Linux kernel and is made available under
 * the terms of the GNU General Public License, version 2, or at your
 * option, any later version, incorporated herein by reference.
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/include/linux/minix_fs.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <linux/fs.h>
#include <linux/jbd.h>
#include <linux/magic.h>
#include <linux/bug.h>
#include <linux/blockgroup_lock.h>

/*
 * The second extended filesystem constants/structures
 */

/*
 * Define EXT3FS_DEBUG to produce debug messages
 */
#undef EXT3FS_DEBUG

/*
 * Define EXT3_RESERVATION to reserve data blocks for expanding files
 */
#define EXT3_DEFAULT_RESERVE_BLOCKS     8
/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
#define EXT3_MAX_RESERVE_BLOCKS         1027
#define EXT3_RESERVE_WINDOW_NOT_ALLOCATED 0

/*
 * Debug code
 */
#ifdef EXT3FS_DEBUG
#define ext3_debug(f, a...)                                             \
        do {                                                            \
                printk (KERN_DEBUG "EXT3-fs DEBUG (%s, %d): %s:",       \
                        __FILE__, __LINE__, __func__);          \
                printk (KERN_DEBUG f, ## a);                            \
        } while (0)
#else
#define ext3_debug(f, a...)     do {} while (0)
#endif

/*
 * Special inodes numbers
 */
#define EXT3_BAD_INO             1      /* Bad blocks inode */
#define EXT3_ROOT_INO            2      /* Root inode */
#define EXT3_BOOT_LOADER_INO     5      /* Boot loader inode */
#define EXT3_UNDEL_DIR_INO       6      /* Undelete directory inode */
#define EXT3_RESIZE_INO          7      /* Reserved group descriptors inode */
#define EXT3_JOURNAL_INO         8      /* Journal inode */

/* First non-reserved inode for old ext3 filesystems */
#define EXT3_GOOD_OLD_FIRST_INO 11

/*
 * Maximal count of links to a file
 */
#define EXT3_LINK_MAX           32000

/*
 * Macro-instructions used to manage several block sizes
 */
#define EXT3_MIN_BLOCK_SIZE             1024
#define EXT3_MAX_BLOCK_SIZE             65536
#define EXT3_MIN_BLOCK_LOG_SIZE         10
#define EXT3_BLOCK_SIZE(s)              ((s)->s_blocksize)
#define EXT3_ADDR_PER_BLOCK(s)          (EXT3_BLOCK_SIZE(s) / sizeof (__u32))
#define EXT3_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
#define EXT3_ADDR_PER_BLOCK_BITS(s)     (EXT3_SB(s)->s_addr_per_block_bits)
#define EXT3_INODE_SIZE(s)              (EXT3_SB(s)->s_inode_size)
#define EXT3_FIRST_INO(s)               (EXT3_SB(s)->s_first_ino)

/*
 * Macro-instructions used to manage fragments
 */
#define EXT3_MIN_FRAG_SIZE              1024
#define EXT3_MAX_FRAG_SIZE              4096
#define EXT3_MIN_FRAG_LOG_SIZE            10
#define EXT3_FRAG_SIZE(s)               (EXT3_SB(s)->s_frag_size)
#define EXT3_FRAGS_PER_BLOCK(s)         (EXT3_SB(s)->s_frags_per_block)

/*
 * Structure of a blocks group descriptor
 */
struct ext3_group_desc
{
        __le32  bg_block_bitmap;                /* Blocks bitmap block */
        __le32  bg_inode_bitmap;                /* Inodes bitmap block */
        __le32  bg_inode_table;         /* Inodes table block */
        __le16  bg_free_blocks_count;   /* Free blocks count */
        __le16  bg_free_inodes_count;   /* Free inodes count */
        __le16  bg_used_dirs_count;     /* Directories count */
        __u16   bg_pad;
        __le32  bg_reserved[3];
};

/*
 * Macro-instructions used to manage group descriptors
 */
#define EXT3_BLOCKS_PER_GROUP(s)        (EXT3_SB(s)->s_blocks_per_group)
#define EXT3_DESC_PER_BLOCK(s)          (EXT3_SB(s)->s_desc_per_block)
#define EXT3_INODES_PER_GROUP(s)        (EXT3_SB(s)->s_inodes_per_group)
#define EXT3_DESC_PER_BLOCK_BITS(s)     (EXT3_SB(s)->s_desc_per_block_bits)

/*
 * Constants relative to the data blocks
 */
#define EXT3_NDIR_BLOCKS                12
#define EXT3_IND_BLOCK                  EXT3_NDIR_BLOCKS
#define EXT3_DIND_BLOCK                 (EXT3_IND_BLOCK + 1)
#define EXT3_TIND_BLOCK                 (EXT3_DIND_BLOCK + 1)
#define EXT3_N_BLOCKS                   (EXT3_TIND_BLOCK + 1)

/*
 * Inode flags
 */
#define EXT3_SECRM_FL                   0x00000001 /* Secure deletion */
#define EXT3_UNRM_FL                    0x00000002 /* Undelete */
#define EXT3_COMPR_FL                   0x00000004 /* Compress file */
#define EXT3_SYNC_FL                    0x00000008 /* Synchronous updates */
#define EXT3_IMMUTABLE_FL               0x00000010 /* Immutable file */
#define EXT3_APPEND_FL                  0x00000020 /* writes to file may only append */
#define EXT3_NODUMP_FL                  0x00000040 /* do not dump file */
#define EXT3_NOATIME_FL                 0x00000080 /* do not update atime */
/* Reserved for compression usage... */
#define EXT3_DIRTY_FL                   0x00000100
#define EXT3_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
#define EXT3_NOCOMPR_FL                 0x00000400 /* Don't compress */
#define EXT3_ECOMPR_FL                  0x00000800 /* Compression error */
/* End compression flags --- maybe not all used */
#define EXT3_INDEX_FL                   0x00001000 /* hash-indexed directory */
#define EXT3_IMAGIC_FL                  0x00002000 /* AFS directory */
#define EXT3_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
#define EXT3_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
#define EXT3_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
#define EXT3_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
#define EXT3_RESERVED_FL                0x80000000 /* reserved for ext3 lib */

#define EXT3_FL_USER_VISIBLE            0x0003DFFF /* User visible flags */
#define EXT3_FL_USER_MODIFIABLE         0x000380FF /* User modifiable flags */

/* Flags that should be inherited by new inodes from their parent. */
#define EXT3_FL_INHERITED (EXT3_SECRM_FL | EXT3_UNRM_FL | EXT3_COMPR_FL |\
                           EXT3_SYNC_FL | EXT3_NODUMP_FL |\
                           EXT3_NOATIME_FL | EXT3_COMPRBLK_FL |\
                           EXT3_NOCOMPR_FL | EXT3_JOURNAL_DATA_FL |\
                           EXT3_NOTAIL_FL | EXT3_DIRSYNC_FL)

/* Flags that are appropriate for regular files (all but dir-specific ones). */
#define EXT3_REG_FLMASK (~(EXT3_DIRSYNC_FL | EXT3_TOPDIR_FL))

/* Flags that are appropriate for non-directories/regular files. */
#define EXT3_OTHER_FLMASK (EXT3_NODUMP_FL | EXT3_NOATIME_FL)

/* Mask out flags that are inappropriate for the given type of inode. */
static inline __u32 ext3_mask_flags(umode_t mode, __u32 flags)
{
        if (S_ISDIR(mode))
                return flags;
        else if (S_ISREG(mode))
                return flags & EXT3_REG_FLMASK;
        else
                return flags & EXT3_OTHER_FLMASK;
}

/* Used to pass group descriptor data when online resize is done */
struct ext3_new_group_input {
        __u32 group;            /* Group number for this data */
        __u32 block_bitmap;     /* Absolute block number of block bitmap */
        __u32 inode_bitmap;     /* Absolute block number of inode bitmap */
        __u32 inode_table;      /* Absolute block number of inode table start */
        __u32 blocks_count;     /* Total number of blocks in this group */
        __u16 reserved_blocks;  /* Number of reserved blocks in this group */
        __u16 unused;
};

/* The struct ext3_new_group_input in kernel space, with free_blocks_count */
struct ext3_new_group_data {
        __u32 group;
        __u32 block_bitmap;
        __u32 inode_bitmap;
        __u32 inode_table;
        __u32 blocks_count;
        __u16 reserved_blocks;
        __u16 unused;
        __u32 free_blocks_count;
};


/*
 * ioctl commands
 */
#define EXT3_IOC_GETFLAGS               FS_IOC_GETFLAGS
#define EXT3_IOC_SETFLAGS               FS_IOC_SETFLAGS
#define EXT3_IOC_GETVERSION             _IOR('f', 3, long)
#define EXT3_IOC_SETVERSION             _IOW('f', 4, long)
#define EXT3_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
#define EXT3_IOC_GROUP_ADD              _IOW('f', 8,struct ext3_new_group_input)
#define EXT3_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
#define EXT3_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
#ifdef CONFIG_JBD_DEBUG
#define EXT3_IOC_WAIT_FOR_READONLY      _IOR('f', 99, long)
#endif
#define EXT3_IOC_GETRSVSZ               _IOR('f', 5, long)
#define EXT3_IOC_SETRSVSZ               _IOW('f', 6, long)

/*
 * ioctl commands in 32 bit emulation
 */
#define EXT3_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
#define EXT3_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
#define EXT3_IOC32_GETVERSION           _IOR('f', 3, int)
#define EXT3_IOC32_SETVERSION           _IOW('f', 4, int)
#define EXT3_IOC32_GETRSVSZ             _IOR('f', 5, int)
#define EXT3_IOC32_SETRSVSZ             _IOW('f', 6, int)
#define EXT3_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
#ifdef CONFIG_JBD_DEBUG
#define EXT3_IOC32_WAIT_FOR_READONLY    _IOR('f', 99, int)
#endif
#define EXT3_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
#define EXT3_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION

/* Number of supported quota types */
#define EXT3_MAXQUOTAS 2

/*
 *  Mount options
 */
struct ext3_mount_options {
        unsigned long s_mount_opt;
        kuid_t s_resuid;
        kgid_t s_resgid;
        unsigned long s_commit_interval;
#ifdef CONFIG_QUOTA
        int s_jquota_fmt;
        char *s_qf_names[EXT3_MAXQUOTAS];
#endif
};

/*
 * Structure of an inode on the disk
 */
struct ext3_inode {
        __le16  i_mode;         /* File mode */
        __le16  i_uid;          /* Low 16 bits of Owner Uid */
        __le32  i_size;         /* Size in bytes */
        __le32  i_atime;        /* Access time */
        __le32  i_ctime;        /* Creation time */
        __le32  i_mtime;        /* Modification time */
        __le32  i_dtime;        /* Deletion Time */
        __le16  i_gid;          /* Low 16 bits of Group Id */
        __le16  i_links_count;  /* Links count */
        __le32  i_blocks;       /* Blocks count */
        __le32  i_flags;        /* File flags */
        union {
                struct {
                        __u32  l_i_reserved1;
                } linux1;
                struct {
                        __u32  h_i_translator;
                } hurd1;
                struct {
                        __u32  m_i_reserved1;
                } masix1;
        } osd1;                         /* OS dependent 1 */
        __le32  i_block[EXT3_N_BLOCKS];/* Pointers to blocks */
        __le32  i_generation;   /* File version (for NFS) */
        __le32  i_file_acl;     /* File ACL */
        __le32  i_dir_acl;      /* Directory ACL */
        __le32  i_faddr;        /* Fragment address */
        union {
                struct {
                        __u8    l_i_frag;       /* Fragment number */
                        __u8    l_i_fsize;      /* Fragment size */
                        __u16   i_pad1;
                        __le16  l_i_uid_high;   /* these 2 fields    */
                        __le16  l_i_gid_high;   /* were reserved2[0] */
                        __u32   l_i_reserved2;
                } linux2;
                struct {
                        __u8    h_i_frag;       /* Fragment number */
                        __u8    h_i_fsize;      /* Fragment size */
                        __u16   h_i_mode_high;
                        __u16   h_i_uid_high;
                        __u16   h_i_gid_high;
                        __u32   h_i_author;
                } hurd2;
                struct {
                        __u8    m_i_frag;       /* Fragment number */
                        __u8    m_i_fsize;      /* Fragment size */
                        __u16   m_pad1;
                        __u32   m_i_reserved2[2];
                } masix2;
        } osd2;                         /* OS dependent 2 */
        __le16  i_extra_isize;
        __le16  i_pad1;
};

#define i_size_high     i_dir_acl

#define i_reserved1     osd1.linux1.l_i_reserved1
#define i_frag          osd2.linux2.l_i_frag
#define i_fsize         osd2.linux2.l_i_fsize
#define i_uid_low       i_uid
#define i_gid_low       i_gid
#define i_uid_high      osd2.linux2.l_i_uid_high
#define i_gid_high      osd2.linux2.l_i_gid_high
#define i_reserved2     osd2.linux2.l_i_reserved2

/*
 * File system states
 */
#define EXT3_VALID_FS                   0x0001  /* Unmounted cleanly */
#define EXT3_ERROR_FS                   0x0002  /* Errors detected */
#define EXT3_ORPHAN_FS                  0x0004  /* Orphans being recovered */

/*
 * Misc. filesystem flags
 */
#define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
#define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
#define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */

/*
 * Mount flags
 */
#define EXT3_MOUNT_CHECK                0x00001 /* Do mount-time checks */
/* EXT3_MOUNT_OLDALLOC was there */
#define EXT3_MOUNT_GRPID                0x00004 /* Create files with directory's group */
#define EXT3_MOUNT_DEBUG                0x00008 /* Some debugging messages */
#define EXT3_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
#define EXT3_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
#define EXT3_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
#define EXT3_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
#define EXT3_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
#define EXT3_MOUNT_ABORT                0x00200 /* Fatal error detected */
#define EXT3_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
#define EXT3_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
#define EXT3_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
#define EXT3_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
#define EXT3_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
#define EXT3_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
#define EXT3_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
#define EXT3_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
#define EXT3_MOUNT_RESERVATION          0x10000 /* Preallocation */
#define EXT3_MOUNT_BARRIER              0x20000 /* Use block barriers */
#define EXT3_MOUNT_QUOTA                0x80000 /* Some quota option set */
#define EXT3_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
#define EXT3_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
#define EXT3_MOUNT_DATA_ERR_ABORT       0x400000 /* Abort on file data write
                                                  * error in ordered mode */

/* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
#ifndef _LINUX_EXT2_FS_H
#define clear_opt(o, opt)               o &= ~EXT3_MOUNT_##opt
#define set_opt(o, opt)                 o |= EXT3_MOUNT_##opt
#define test_opt(sb, opt)               (EXT3_SB(sb)->s_mount_opt & \
                                         EXT3_MOUNT_##opt)
#else
#define EXT2_MOUNT_NOLOAD               EXT3_MOUNT_NOLOAD
#define EXT2_MOUNT_ABORT                EXT3_MOUNT_ABORT
#define EXT2_MOUNT_DATA_FLAGS           EXT3_MOUNT_DATA_FLAGS
#endif

#define ext3_set_bit                    __set_bit_le
#define ext3_set_bit_atomic             ext2_set_bit_atomic
#define ext3_clear_bit                  __clear_bit_le
#define ext3_clear_bit_atomic           ext2_clear_bit_atomic
#define ext3_test_bit                   test_bit_le
#define ext3_find_next_zero_bit         find_next_zero_bit_le

/*
 * Maximal mount counts between two filesystem checks
 */
#define EXT3_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
#define EXT3_DFL_CHECKINTERVAL          0       /* Don't use interval check */

/*
 * Behaviour when detecting errors
 */
#define EXT3_ERRORS_CONTINUE            1       /* Continue execution */
#define EXT3_ERRORS_RO                  2       /* Remount fs read-only */
#define EXT3_ERRORS_PANIC               3       /* Panic */
#define EXT3_ERRORS_DEFAULT             EXT3_ERRORS_CONTINUE

/*
 * Structure of the super block
 */
struct ext3_super_block {
/*00*/  __le32  s_inodes_count;         /* Inodes count */
        __le32  s_blocks_count;         /* Blocks count */
        __le32  s_r_blocks_count;       /* Reserved blocks count */
        __le32  s_free_blocks_count;    /* Free blocks count */
/*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
        __le32  s_first_data_block;     /* First Data Block */
        __le32  s_log_block_size;       /* Block size */
        __le32  s_log_frag_size;        /* Fragment size */
/*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
        __le32  s_frags_per_group;      /* # Fragments per group */
        __le32  s_inodes_per_group;     /* # Inodes per group */
        __le32  s_mtime;                /* Mount time */
/*30*/  __le32  s_wtime;                /* Write time */
        __le16  s_mnt_count;            /* Mount count */
        __le16  s_max_mnt_count;        /* Maximal mount count */
        __le16  s_magic;                /* Magic signature */
        __le16  s_state;                /* File system state */
        __le16  s_errors;               /* Behaviour when detecting errors */
        __le16  s_minor_rev_level;      /* minor revision level */
/*40*/  __le32  s_lastcheck;            /* time of last check */
        __le32  s_checkinterval;        /* max. time between checks */
        __le32  s_creator_os;           /* OS */
        __le32  s_rev_level;            /* Revision level */
/*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
        __le16  s_def_resgid;           /* Default gid for reserved blocks */
        /*
         * These fields are for EXT3_DYNAMIC_REV superblocks only.
         *
         * Note: the difference between the compatible feature set and
         * the incompatible feature set is that if there is a bit set
         * in the incompatible feature set that the kernel doesn't
         * know about, it should refuse to mount the filesystem.
         *
         * e2fsck's requirements are more strict; if it doesn't know
         * about a feature in either the compatible or incompatible
         * feature set, it must abort and not try to meddle with
         * things it doesn't understand...
         */
        __le32  s_first_ino;            /* First non-reserved inode */
        __le16   s_inode_size;          /* size of inode structure */
        __le16  s_block_group_nr;       /* block group # of this superblock */
        __le32  s_feature_compat;       /* compatible feature set */
/*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
        __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
/*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
/*78*/  char    s_volume_name[16];      /* volume name */
/*88*/  char    s_last_mounted[64];     /* directory where last mounted */
/*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
        /*
         * Performance hints.  Directory preallocation should only
         * happen if the EXT3_FEATURE_COMPAT_DIR_PREALLOC flag is on.
         */
        __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
        __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
        __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
        /*
         * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
         */
/*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
/*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
        __le32  s_journal_dev;          /* device number of journal file */
        __le32  s_last_orphan;          /* start of list of inodes to delete */
        __le32  s_hash_seed[4];         /* HTREE hash seed */
        __u8    s_def_hash_version;     /* Default hash version to use */
        __u8    s_reserved_char_pad;
        __u16   s_reserved_word_pad;
        __le32  s_default_mount_opts;
        __le32  s_first_meta_bg;        /* First metablock block group */
        __le32  s_mkfs_time;            /* When the filesystem was created */
        __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
        /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
/*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
        __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
        __le32  s_free_blocks_count_hi; /* Free blocks count */
        __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
        __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
        __le32  s_flags;                /* Miscellaneous flags */
        __le16  s_raid_stride;          /* RAID stride */
        __le16  s_mmp_interval;         /* # seconds to wait in MMP checking */
        __le64  s_mmp_block;            /* Block for multi-mount protection */
        __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
        __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
        __u8    s_reserved_char_pad2;
        __le16  s_reserved_pad;
        __u32   s_reserved[162];        /* Padding to the end of the block */
};

/* data type for block offset of block group */
typedef int ext3_grpblk_t;

/* data type for filesystem-wide blocks number */
typedef unsigned long ext3_fsblk_t;

#define E3FSBLK "%lu"

struct ext3_reserve_window {
        ext3_fsblk_t    _rsv_start;     /* First byte reserved */
        ext3_fsblk_t    _rsv_end;       /* Last byte reserved or 0 */
};

struct ext3_reserve_window_node {
        struct rb_node          rsv_node;
        __u32                   rsv_goal_size;
        __u32                   rsv_alloc_hit;
        struct ext3_reserve_window      rsv_window;
};

struct ext3_block_alloc_info {
        /* information about reservation window */
        struct ext3_reserve_window_node rsv_window_node;
        /*
         * was i_next_alloc_block in ext3_inode_info
         * is the logical (file-relative) number of the
         * most-recently-allocated block in this file.
         * We use this for detecting linearly ascending allocation requests.
         */
        __u32                   last_alloc_logical_block;
        /*
         * Was i_next_alloc_goal in ext3_inode_info
         * is the *physical* companion to i_next_alloc_block.
         * it the physical block number of the block which was most-recentl
         * allocated to this file.  This give us the goal (target) for the next
         * allocation when we detect linearly ascending requests.
         */
        ext3_fsblk_t            last_alloc_physical_block;
};

#define rsv_start rsv_window._rsv_start
#define rsv_end rsv_window._rsv_end

/*
 * third extended file system inode data in memory
 */
struct ext3_inode_info {
        __le32  i_data[15];     /* unconverted */
        __u32   i_flags;
#ifdef EXT3_FRAGMENTS
        __u32   i_faddr;
        __u8    i_frag_no;
        __u8    i_frag_size;
#endif
        ext3_fsblk_t    i_file_acl;
        __u32   i_dir_acl;
        __u32   i_dtime;

        /*
         * i_block_group is the number of the block group which contains
         * this file's inode.  Constant across the lifetime of the inode,
         * it is ued for making block allocation decisions - we try to
         * place a file's data blocks near its inode block, and new inodes
         * near to their parent directory's inode.
         */
        __u32   i_block_group;
        unsigned long   i_state_flags;  /* Dynamic state flags for ext3 */

        /* block reservation info */
        struct ext3_block_alloc_info *i_block_alloc_info;

        __u32   i_dir_start_lookup;
#ifdef CONFIG_EXT3_FS_XATTR
        /*
         * Extended attributes can be read independently of the main file
         * data. Taking i_mutex even when reading would cause contention
         * between readers of EAs and writers of regular file data, so
         * instead we synchronize on xattr_sem when reading or changing
         * EAs.
         */
        struct rw_semaphore xattr_sem;
#endif

        struct list_head i_orphan;      /* unlinked but open inodes */

        /*
         * i_disksize keeps track of what the inode size is ON DISK, not
         * in memory.  During truncate, i_size is set to the new size by
         * the VFS prior to calling ext3_truncate(), but the filesystem won't
         * set i_disksize to 0 until the truncate is actually under way.
         *
         * The intent is that i_disksize always represents the blocks which
         * are used by this file.  This allows recovery to restart truncate
         * on orphans if we crash during truncate.  We actually write i_disksize
         * into the on-disk inode when writing inodes out, instead of i_size.
         *
         * The only time when i_disksize and i_size may be different is when
         * a truncate is in progress.  The only things which change i_disksize
         * are ext3_get_block (growth) and ext3_truncate (shrinkth).
         */
        loff_t  i_disksize;

        /* on-disk additional length */
        __u16 i_extra_isize;

        /*
         * truncate_mutex is for serialising ext3_truncate() against
         * ext3_getblock().  In the 2.4 ext2 design, great chunks of inode's
         * data tree are chopped off during truncate. We can't do that in
         * ext3 because whenever we perform intermediate commits during
         * truncate, the inode and all the metadata blocks *must* be in a
         * consistent state which allows truncation of the orphans to restart
         * during recovery.  Hence we must fix the get_block-vs-truncate race
         * by other means, so we have truncate_mutex.
         */
        struct mutex truncate_mutex;

        /*
         * Transactions that contain inode's metadata needed to complete
         * fsync and fdatasync, respectively.
         */
        atomic_t i_sync_tid;
        atomic_t i_datasync_tid;

#ifdef CONFIG_QUOTA
        struct dquot *i_dquot[MAXQUOTAS];
#endif

        struct inode vfs_inode;
};

/*
 * third extended-fs super-block data in memory
 */
struct ext3_sb_info {
        unsigned long s_frag_size;      /* Size of a fragment in bytes */
        unsigned long s_frags_per_block;/* Number of fragments per block */
        unsigned long s_inodes_per_block;/* Number of inodes per block */
        unsigned long s_frags_per_group;/* Number of fragments in a group */
        unsigned long s_blocks_per_group;/* Number of blocks in a group */
        unsigned long s_inodes_per_group;/* Number of inodes in a group */
        unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
        unsigned long s_gdb_count;      /* Number of group descriptor blocks */
        unsigned long s_desc_per_block; /* Number of group descriptors per block */
        unsigned long s_groups_count;   /* Number of groups in the fs */
        unsigned long s_overhead_last;  /* Last calculated overhead */
        unsigned long s_blocks_last;    /* Last seen block count */
        struct buffer_head * s_sbh;     /* Buffer containing the super block */
        struct ext3_super_block * s_es; /* Pointer to the super block in the buffer */
        struct buffer_head ** s_group_desc;
        unsigned long  s_mount_opt;
        ext3_fsblk_t s_sb_block;
        kuid_t s_resuid;
        kgid_t s_resgid;
        unsigned short s_mount_state;
        unsigned short s_pad;
        int s_addr_per_block_bits;
        int s_desc_per_block_bits;
        int s_inode_size;
        int s_first_ino;
        spinlock_t s_next_gen_lock;
        u32 s_next_generation;
        u32 s_hash_seed[4];
        int s_def_hash_version;
        int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
        struct percpu_counter s_freeblocks_counter;
        struct percpu_counter s_freeinodes_counter;
        struct percpu_counter s_dirs_counter;
        struct blockgroup_lock *s_blockgroup_lock;

        /* root of the per fs reservation window tree */
        spinlock_t s_rsv_window_lock;
        struct rb_root s_rsv_window_root;
        struct ext3_reserve_window_node s_rsv_window_head;

        /* Journaling */
        struct inode * s_journal_inode;
        struct journal_s * s_journal;
        struct list_head s_orphan;
        struct mutex s_orphan_lock;
        struct mutex s_resize_lock;
        unsigned long s_commit_interval;
        struct block_device *journal_bdev;
#ifdef CONFIG_QUOTA
        char *s_qf_names[EXT3_MAXQUOTAS];       /* Names of quota files with journalled quota */
        int s_jquota_fmt;                       /* Format of quota to use */
#endif
};

static inline spinlock_t *
sb_bgl_lock(struct ext3_sb_info *sbi, unsigned int block_group)
{
        return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
}

static inline struct ext3_sb_info * EXT3_SB(struct super_block *sb)
{
        return sb->s_fs_info;
}
static inline struct ext3_inode_info *EXT3_I(struct inode *inode)
{
        return container_of(inode, struct ext3_inode_info, vfs_inode);
}

static inline int ext3_valid_inum(struct super_block *sb, unsigned long ino)
{
        return ino == EXT3_ROOT_INO ||
                ino == EXT3_JOURNAL_INO ||
                ino == EXT3_RESIZE_INO ||
                (ino >= EXT3_FIRST_INO(sb) &&
                 ino <= le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count));
}

/*
 * Inode dynamic state flags
 */
enum {
        EXT3_STATE_JDATA,               /* journaled data exists */
        EXT3_STATE_NEW,                 /* inode is newly created */
        EXT3_STATE_XATTR,               /* has in-inode xattrs */
        EXT3_STATE_FLUSH_ON_CLOSE,      /* flush dirty pages on close */
};

static inline int ext3_test_inode_state(struct inode *inode, int bit)
{
        return test_bit(bit, &EXT3_I(inode)->i_state_flags);
}

static inline void ext3_set_inode_state(struct inode *inode, int bit)
{
        set_bit(bit, &EXT3_I(inode)->i_state_flags);
}

static inline void ext3_clear_inode_state(struct inode *inode, int bit)
{
        clear_bit(bit, &EXT3_I(inode)->i_state_flags);
}

#define NEXT_ORPHAN(inode) EXT3_I(inode)->i_dtime

/*
 * Codes for operating systems
 */
#define EXT3_OS_LINUX           0
#define EXT3_OS_HURD            1
#define EXT3_OS_MASIX           2
#define EXT3_OS_FREEBSD         3
#define EXT3_OS_LITES           4

/*
 * Revision levels
 */
#define EXT3_GOOD_OLD_REV       0       /* The good old (original) format */
#define EXT3_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */

#define EXT3_CURRENT_REV        EXT3_GOOD_OLD_REV
#define EXT3_MAX_SUPP_REV       EXT3_DYNAMIC_REV

#define EXT3_GOOD_OLD_INODE_SIZE 128

/*
 * Feature set definitions
 */

#define EXT3_HAS_COMPAT_FEATURE(sb,mask)                        \
        ( EXT3_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
#define EXT3_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
        ( EXT3_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
#define EXT3_HAS_INCOMPAT_FEATURE(sb,mask)                      \
        ( EXT3_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
#define EXT3_SET_COMPAT_FEATURE(sb,mask)                        \
        EXT3_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
#define EXT3_SET_RO_COMPAT_FEATURE(sb,mask)                     \
        EXT3_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
#define EXT3_SET_INCOMPAT_FEATURE(sb,mask)                      \
        EXT3_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
#define EXT3_CLEAR_COMPAT_FEATURE(sb,mask)                      \
        EXT3_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
#define EXT3_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
        EXT3_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
#define EXT3_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
        EXT3_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)

#define EXT3_FEATURE_COMPAT_DIR_PREALLOC        0x0001
#define EXT3_FEATURE_COMPAT_IMAGIC_INODES       0x0002
#define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
#define EXT3_FEATURE_COMPAT_EXT_ATTR            0x0008
#define EXT3_FEATURE_COMPAT_RESIZE_INODE        0x0010
#define EXT3_FEATURE_COMPAT_DIR_INDEX           0x0020

#define EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
#define EXT3_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
#define EXT3_FEATURE_RO_COMPAT_BTREE_DIR        0x0004

#define EXT3_FEATURE_INCOMPAT_COMPRESSION       0x0001
#define EXT3_FEATURE_INCOMPAT_FILETYPE          0x0002
#define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
#define EXT3_FEATURE_INCOMPAT_META_BG           0x0010

#define EXT3_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
#define EXT3_FEATURE_INCOMPAT_SUPP      (EXT3_FEATURE_INCOMPAT_FILETYPE| \
                                         EXT3_FEATURE_INCOMPAT_RECOVER| \
                                         EXT3_FEATURE_INCOMPAT_META_BG)
#define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \
                                         EXT3_FEATURE_RO_COMPAT_LARGE_FILE| \
                                         EXT3_FEATURE_RO_COMPAT_BTREE_DIR)

/*
 * Default values for user and/or group using reserved blocks
 */
#define EXT3_DEF_RESUID         0
#define EXT3_DEF_RESGID         0

/*
 * Default mount options
 */
#define EXT3_DEFM_DEBUG         0x0001
#define EXT3_DEFM_BSDGROUPS     0x0002
#define EXT3_DEFM_XATTR_USER    0x0004
#define EXT3_DEFM_ACL           0x0008
#define EXT3_DEFM_UID16         0x0010
#define EXT3_DEFM_JMODE         0x0060
#define EXT3_DEFM_JMODE_DATA    0x0020
#define EXT3_DEFM_JMODE_ORDERED 0x0040
#define EXT3_DEFM_JMODE_WBACK   0x0060

/*
 * Structure of a directory entry
 */
#define EXT3_NAME_LEN 255

struct ext3_dir_entry {
        __le32  inode;                  /* Inode number */
        __le16  rec_len;                /* Directory entry length */
        __le16  name_len;               /* Name length */
        char    name[EXT3_NAME_LEN];    /* File name */
};

/*
 * The new version of the directory entry.  Since EXT3 structures are
 * stored in intel byte order, and the name_len field could never be
 * bigger than 255 chars, it's safe to reclaim the extra byte for the
 * file_type field.
 */
struct ext3_dir_entry_2 {
        __le32  inode;                  /* Inode number */
        __le16  rec_len;                /* Directory entry length */
        __u8    name_len;               /* Name length */
        __u8    file_type;
        char    name[EXT3_NAME_LEN];    /* File name */
};

/*
 * Ext3 directory file types.  Only the low 3 bits are used.  The
 * other bits are reserved for now.
 */
#define EXT3_FT_UNKNOWN         0
#define EXT3_FT_REG_FILE        1
#define EXT3_FT_DIR             2
#define EXT3_FT_CHRDEV          3
#define EXT3_FT_BLKDEV          4
#define EXT3_FT_FIFO            5
#define EXT3_FT_SOCK            6
#define EXT3_FT_SYMLINK         7

#define EXT3_FT_MAX             8

/*
 * EXT3_DIR_PAD defines the directory entries boundaries
 *
 * NOTE: It must be a multiple of 4
 */
#define EXT3_DIR_PAD                    4
#define EXT3_DIR_ROUND                  (EXT3_DIR_PAD - 1)
#define EXT3_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT3_DIR_ROUND) & \
                                         ~EXT3_DIR_ROUND)
#define EXT3_MAX_REC_LEN                ((1<<16)-1)

/*
 * Tests against MAX_REC_LEN etc were put in place for 64k block
 * sizes; if that is not possible on this arch, we can skip
 * those tests and speed things up.
 */
static inline unsigned ext3_rec_len_from_disk(__le16 dlen)
{
        unsigned len = le16_to_cpu(dlen);

#if (PAGE_CACHE_SIZE >= 65536)
        if (len == EXT3_MAX_REC_LEN)
                return 1 << 16;
#endif
        return len;
}

static inline __le16 ext3_rec_len_to_disk(unsigned len)
{
#if (PAGE_CACHE_SIZE >= 65536)
        if (len == (1 << 16))
                return cpu_to_le16(EXT3_MAX_REC_LEN);
        else if (len > (1 << 16))
                BUG();
#endif
        return cpu_to_le16(len);
}

/*
 * Hash Tree Directory indexing
 * (c) Daniel Phillips, 2001
 */

#define is_dx(dir) (EXT3_HAS_COMPAT_FEATURE(dir->i_sb, \
                                      EXT3_FEATURE_COMPAT_DIR_INDEX) && \
                      (EXT3_I(dir)->i_flags & EXT3_INDEX_FL))
#define EXT3_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT3_LINK_MAX)
#define EXT3_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)

/* Legal values for the dx_root hash_version field: */

#define DX_HASH_LEGACY          0
#define DX_HASH_HALF_MD4        1
#define DX_HASH_TEA             2
#define DX_HASH_LEGACY_UNSIGNED 3
#define DX_HASH_HALF_MD4_UNSIGNED       4
#define DX_HASH_TEA_UNSIGNED            5

/* hash info structure used by the directory hash */
struct dx_hash_info
{
        u32             hash;
        u32             minor_hash;
        int             hash_version;
        u32             *seed;
};


/* 32 and 64 bit signed EOF for dx directories */
#define EXT3_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
#define EXT3_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)


/*
 * Control parameters used by ext3_htree_next_block
 */
#define HASH_NB_ALWAYS          1


/*
 * Describe an inode's exact location on disk and in memory
 */
struct ext3_iloc
{
        struct buffer_head *bh;
        unsigned long offset;
        unsigned long block_group;
};

static inline struct ext3_inode *ext3_raw_inode(struct ext3_iloc *iloc)
{
        return (struct ext3_inode *) (iloc->bh->b_data + iloc->offset);
}

/*
 * This structure is stuffed into the struct file's private_data field
 * for directories.  It is where we put information so that we can do
 * readdir operations in hash tree order.
 */
struct dir_private_info {
        struct rb_root  root;
        struct rb_node  *curr_node;
        struct fname    *extra_fname;
        loff_t          last_pos;
        __u32           curr_hash;
        __u32           curr_minor_hash;
        __u32           next_hash;
};

/* calculate the first block number of the group */
static inline ext3_fsblk_t
ext3_group_first_block_no(struct super_block *sb, unsigned long group_no)
{
        return group_no * (ext3_fsblk_t)EXT3_BLOCKS_PER_GROUP(sb) +
                le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block);
}

/*
 * Special error return code only used by dx_probe() and its callers.
 */
#define ERR_BAD_DX_DIR  -75000

/*
 * Function prototypes
 */

/*
 * Ok, these declarations are also in <linux/kernel.h> but none of the
 * ext3 source programs needs to include it so they are duplicated here.
 */
# define NORET_TYPE    /**/
# define ATTRIB_NORET  __attribute__((noreturn))
# define NORET_AND     noreturn,

/* balloc.c */
extern int ext3_bg_has_super(struct super_block *sb, int group);
extern unsigned long ext3_bg_num_gdb(struct super_block *sb, int group);
extern ext3_fsblk_t ext3_new_block (handle_t *handle, struct inode *inode,
                        ext3_fsblk_t goal, int *errp);

extern ext3_fsblk_t ext3_new_blocks (handle_t *handle, struct inode *inode,
                        ext3_fsblk_t goal, unsigned long *count, int *errp);
extern void ext3_free_blocks (handle_t *handle, struct inode *inode,
                        ext3_fsblk_t block, unsigned long count);
extern void ext3_free_blocks_sb (handle_t *handle, struct super_block *sb,
                                 ext3_fsblk_t block, unsigned long count,
                                unsigned long *pdquot_freed_blocks);
extern ext3_fsblk_t ext3_count_free_blocks (struct super_block *);
extern void ext3_check_blocks_bitmap (struct super_block *);
extern struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb,
                                                    unsigned int block_group,
                                                    struct buffer_head ** bh);
extern int ext3_should_retry_alloc(struct super_block *sb, int *retries);
extern void ext3_init_block_alloc_info(struct inode *);
extern void ext3_rsv_window_add(struct super_block *sb, struct ext3_reserve_window_node *rsv);
extern int ext3_trim_fs(struct super_block *sb, struct fstrim_range *range);

/* dir.c */
extern int ext3_check_dir_entry(const char *, struct inode *,
                                struct ext3_dir_entry_2 *,
                                struct buffer_head *, unsigned long);
extern int ext3_htree_store_dirent(struct file *dir_file, __u32 hash,
                                    __u32 minor_hash,
                                    struct ext3_dir_entry_2 *dirent);
extern void ext3_htree_free_dir_info(struct dir_private_info *p);

/* fsync.c */
extern int ext3_sync_file(struct file *, loff_t, loff_t, int);

/* hash.c */
extern int ext3fs_dirhash(const char *name, int len, struct
                          dx_hash_info *hinfo);

/* ialloc.c */
extern struct inode * ext3_new_inode (handle_t *, struct inode *,
                                      const struct qstr *, umode_t);
extern void ext3_free_inode (handle_t *, struct inode *);
extern struct inode * ext3_orphan_get (struct super_block *, unsigned long);
extern unsigned long ext3_count_free_inodes (struct super_block *);
extern unsigned long ext3_count_dirs (struct super_block *);
extern void ext3_check_inodes_bitmap (struct super_block *);
extern unsigned long ext3_count_free (struct buffer_head *, unsigned);


/* inode.c */
int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
                struct buffer_head *bh, ext3_fsblk_t blocknr);
struct buffer_head * ext3_getblk (handle_t *, struct inode *, long, int, int *);
struct buffer_head * ext3_bread (handle_t *, struct inode *, int, int, int *);
int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
        sector_t iblock, unsigned long maxblocks, struct buffer_head *bh_result,
        int create);

extern struct inode *ext3_iget(struct super_block *, unsigned long);
extern int  ext3_write_inode (struct inode *, struct writeback_control *);
extern int  ext3_setattr (struct dentry *, struct iattr *);
extern void ext3_evict_inode (struct inode *);
extern int  ext3_sync_inode (handle_t *, struct inode *);
extern void ext3_discard_reservation (struct inode *);
extern void ext3_dirty_inode(struct inode *, int);
extern int ext3_change_inode_journal_flag(struct inode *, int);
extern int ext3_get_inode_loc(struct inode *, struct ext3_iloc *);
extern int ext3_can_truncate(struct inode *inode);
extern void ext3_truncate(struct inode *inode);
extern void ext3_set_inode_flags(struct inode *);
extern void ext3_get_inode_flags(struct ext3_inode_info *);
extern void ext3_set_aops(struct inode *inode);
extern int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                       u64 start, u64 len);

/* ioctl.c */
extern long ext3_ioctl(struct file *, unsigned int, unsigned long);
extern long ext3_compat_ioctl(struct file *, unsigned int, unsigned long);

/* namei.c */
extern int ext3_orphan_add(handle_t *, struct inode *);
extern int ext3_orphan_del(handle_t *, struct inode *);
extern int ext3_htree_fill_tree(struct file *dir_file, __u32 start_hash,
                                __u32 start_minor_hash, __u32 *next_hash);

/* resize.c */
extern int ext3_group_add(struct super_block *sb,
                                struct ext3_new_group_data *input);
extern int ext3_group_extend(struct super_block *sb,
                                struct ext3_super_block *es,
                                ext3_fsblk_t n_blocks_count);

/* super.c */
extern __printf(3, 4)
void ext3_error(struct super_block *, const char *, const char *, ...);
extern void __ext3_std_error (struct super_block *, const char *, int);
extern __printf(3, 4)
void ext3_abort(struct super_block *, const char *, const char *, ...);
extern __printf(3, 4)
void ext3_warning(struct super_block *, const char *, const char *, ...);
extern __printf(3, 4)
void ext3_msg(struct super_block *, const char *, const char *, ...);
extern void ext3_update_dynamic_rev (struct super_block *sb);

#define ext3_std_error(sb, errno)                               \
do {                                                            \
        if ((errno))                                            \
                __ext3_std_error((sb), __func__, (errno));      \
} while (0)

/*
 * Inodes and files operations
 */

/* dir.c */
extern const struct file_operations ext3_dir_operations;

/* file.c */
extern const struct inode_operations ext3_file_inode_operations;
extern const struct file_operations ext3_file_operations;

/* namei.c */
extern const struct inode_operations ext3_dir_inode_operations;
extern const struct inode_operations ext3_special_inode_operations;

/* symlink.c */
extern const struct inode_operations ext3_symlink_inode_operations;
extern const struct inode_operations ext3_fast_symlink_inode_operations;

#define EXT3_JOURNAL(inode)     (EXT3_SB((inode)->i_sb)->s_journal)

/* Define the number of blocks we need to account to a transaction to
 * modify one block of data.
 *
 * We may have to touch one inode, one bitmap buffer, up to three
 * indirection blocks, the group and superblock summaries, and the data
 * block to complete the transaction.  */

#define EXT3_SINGLEDATA_TRANS_BLOCKS    8U

/* Extended attribute operations touch at most two data buffers,
 * two bitmap buffers, and two group summaries, in addition to the inode
 * and the superblock, which are already accounted for. */

#define EXT3_XATTR_TRANS_BLOCKS         6U

/* Define the minimum size for a transaction which modifies data.  This
 * needs to take into account the fact that we may end up modifying two
 * quota files too (one for the group, one for the user quota).  The
 * superblock only gets updated once, of course, so don't bother
 * counting that again for the quota updates. */

#define EXT3_DATA_TRANS_BLOCKS(sb)      (EXT3_SINGLEDATA_TRANS_BLOCKS + \
                                         EXT3_XATTR_TRANS_BLOCKS - 2 + \
                                         EXT3_MAXQUOTAS_TRANS_BLOCKS(sb))

/* Delete operations potentially hit one directory's namespace plus an
 * entire inode, plus arbitrary amounts of bitmap/indirection data.  Be
 * generous.  We can grow the delete transaction later if necessary. */

#define EXT3_DELETE_TRANS_BLOCKS(sb)   (EXT3_MAXQUOTAS_TRANS_BLOCKS(sb) + 64)

/* Define an arbitrary limit for the amount of data we will anticipate
 * writing to any given transaction.  For unbounded transactions such as
 * write(2) and truncate(2) we can write more than this, but we always
 * start off at the maximum transaction size and grow the transaction
 * optimistically as we go. */

#define EXT3_MAX_TRANS_DATA             64U

/* We break up a large truncate or write transaction once the handle's
 * buffer credits gets this low, we need either to extend the
 * transaction or to start a new one.  Reserve enough space here for
 * inode, bitmap, superblock, group and indirection updates for at least
 * one block, plus two quota updates.  Quota allocations are not
 * needed. */

#define EXT3_RESERVE_TRANS_BLOCKS       12U

#define EXT3_INDEX_EXTRA_TRANS_BLOCKS   8

#ifdef CONFIG_QUOTA
/* Amount of blocks needed for quota update - we know that the structure was
 * allocated so we need to update only inode+data */
#define EXT3_QUOTA_TRANS_BLOCKS(sb) (test_opt(sb, QUOTA) ? 2 : 0)
/* Amount of blocks needed for quota insert/delete - we do some block writes
 * but inode, sb and group updates are done only once */
#define EXT3_QUOTA_INIT_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_INIT_ALLOC*\
                (EXT3_SINGLEDATA_TRANS_BLOCKS-3)+3+DQUOT_INIT_REWRITE) : 0)
#define EXT3_QUOTA_DEL_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_DEL_ALLOC*\
                (EXT3_SINGLEDATA_TRANS_BLOCKS-3)+3+DQUOT_DEL_REWRITE) : 0)
#else
#define EXT3_QUOTA_TRANS_BLOCKS(sb) 0
#define EXT3_QUOTA_INIT_BLOCKS(sb) 0
#define EXT3_QUOTA_DEL_BLOCKS(sb) 0
#endif
#define EXT3_MAXQUOTAS_TRANS_BLOCKS(sb) (EXT3_MAXQUOTAS*EXT3_QUOTA_TRANS_BLOCKS(sb))
#define EXT3_MAXQUOTAS_INIT_BLOCKS(sb) (EXT3_MAXQUOTAS*EXT3_QUOTA_INIT_BLOCKS(sb))
#define EXT3_MAXQUOTAS_DEL_BLOCKS(sb) (EXT3_MAXQUOTAS*EXT3_QUOTA_DEL_BLOCKS(sb))

int
ext3_mark_iloc_dirty(handle_t *handle,
                     struct inode *inode,
                     struct ext3_iloc *iloc);

/*
 * On success, We end up with an outstanding reference count against
 * iloc->bh.  This _must_ be cleaned up later.
 */

int ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
                        struct ext3_iloc *iloc);

int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode);

/*
 * Wrapper functions with which ext3 calls into JBD.  The intent here is
 * to allow these to be turned into appropriate stubs so ext3 can control
 * ext2 filesystems, so ext2+ext3 systems only nee one fs.  This work hasn't
 * been done yet.
 */

static inline void ext3_journal_release_buffer(handle_t *handle,
                                                struct buffer_head *bh)
{
        journal_release_buffer(handle, bh);
}

void ext3_journal_abort_handle(const char *caller, const char *err_fn,
                struct buffer_head *bh, handle_t *handle, int err);

int __ext3_journal_get_undo_access(const char *where, handle_t *handle,
                                struct buffer_head *bh);

int __ext3_journal_get_write_access(const char *where, handle_t *handle,
                                struct buffer_head *bh);

int __ext3_journal_forget(const char *where, handle_t *handle,
                                struct buffer_head *bh);

int __ext3_journal_revoke(const char *where, handle_t *handle,
                                unsigned long blocknr, struct buffer_head *bh);

int __ext3_journal_get_create_access(const char *where,
                                handle_t *handle, struct buffer_head *bh);

int __ext3_journal_dirty_metadata(const char *where,
                                handle_t *handle, struct buffer_head *bh);

#define ext3_journal_get_undo_access(handle, bh) \
        __ext3_journal_get_undo_access(__func__, (handle), (bh))
#define ext3_journal_get_write_access(handle, bh) \
        __ext3_journal_get_write_access(__func__, (handle), (bh))
#define ext3_journal_revoke(handle, blocknr, bh) \
        __ext3_journal_revoke(__func__, (handle), (blocknr), (bh))
#define ext3_journal_get_create_access(handle, bh) \
        __ext3_journal_get_create_access(__func__, (handle), (bh))
#define ext3_journal_dirty_metadata(handle, bh) \
        __ext3_journal_dirty_metadata(__func__, (handle), (bh))
#define ext3_journal_forget(handle, bh) \
        __ext3_journal_forget(__func__, (handle), (bh))

int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh);

handle_t *ext3_journal_start_sb(struct super_block *sb, int nblocks);
int __ext3_journal_stop(const char *where, handle_t *handle);

static inline handle_t *ext3_journal_start(struct inode *inode, int nblocks)
{
        return ext3_journal_start_sb(inode->i_sb, nblocks);
}

#define ext3_journal_stop(handle) \
        __ext3_journal_stop(__func__, (handle))

static inline handle_t *ext3_journal_current_handle(void)
{
        return journal_current_handle();
}

static inline int ext3_journal_extend(handle_t *handle, int nblocks)
{
        return journal_extend(handle, nblocks);
}

static inline int ext3_journal_restart(handle_t *handle, int nblocks)
{
        return journal_restart(handle, nblocks);
}

static inline int ext3_journal_blocks_per_page(struct inode *inode)
{
        return journal_blocks_per_page(inode);
}

static inline int ext3_journal_force_commit(journal_t *journal)
{
        return journal_force_commit(journal);
}

/* super.c */
int ext3_force_commit(struct super_block *sb);

static inline int ext3_should_journal_data(struct inode *inode)
{
        if (!S_ISREG(inode->i_mode))
                return 1;
        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA)
                return 1;
        if (EXT3_I(inode)->i_flags & EXT3_JOURNAL_DATA_FL)
                return 1;
        return 0;
}

static inline int ext3_should_order_data(struct inode *inode)
{
        if (!S_ISREG(inode->i_mode))
                return 0;
        if (EXT3_I(inode)->i_flags & EXT3_JOURNAL_DATA_FL)
                return 0;
        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA)
                return 1;
        return 0;
}

static inline int ext3_should_writeback_data(struct inode *inode)
{
        if (!S_ISREG(inode->i_mode))
                return 0;
        if (EXT3_I(inode)->i_flags & EXT3_JOURNAL_DATA_FL)
                return 0;
        if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_WRITEBACK_DATA)
                return 1;
        return 0;
}

#include <trace/events/ext3.h>