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root/fs/ext4/ext4_i.h

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INCLUDED FROM


/*
 *  ext4_i.h
 *
 * 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_i.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#ifndef _EXT4_I
#define _EXT4_I

#include <linux/rwsem.h>
#include <linux/rbtree.h>
#include <linux/seqlock.h>
#include <linux/mutex.h>

/* data type for block offset of block group */
typedef int ext4_grpblk_t;

/* data type for filesystem-wide blocks number */
typedef unsigned long long ext4_fsblk_t;

/* data type for file logical block number */
typedef __u32 ext4_lblk_t;

/* data type for block group number */
typedef unsigned long ext4_group_t;

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

/*
 * storage for cached extent
 */
struct ext4_ext_cache {
        ext4_fsblk_t    ec_start;
        ext4_lblk_t     ec_block;
        __u32           ec_len; /* must be 32bit to return holes */
        __u32           ec_type;
};

/*
 * fourth extended file system inode data in memory
 */
struct ext4_inode_info {
        __le32  i_data[15];     /* unconverted */
        __u32   i_flags;
        ext4_fsblk_t    i_file_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.
         */
        ext4_group_t    i_block_group;
        __u32   i_state;                /* Dynamic state flags for ext4 */

        ext4_lblk_t             i_dir_start_lookup;
#ifdef CONFIG_EXT4_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
#ifdef CONFIG_EXT4_FS_POSIX_ACL
        struct posix_acl        *i_acl;
        struct posix_acl        *i_default_acl;
#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 ext4_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 ext4_get_block (growth) and ext4_truncate (shrinkth).
         */
        loff_t  i_disksize;

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

        /*
         * i_data_sem is for serialising ext4_truncate() against
         * ext4_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
         * ext4 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 i_data_sem.
         */
        struct rw_semaphore i_data_sem;
        struct inode vfs_inode;
        struct jbd2_inode jinode;

        unsigned long i_ext_generation;
        struct ext4_ext_cache i_cached_extent;
        /*
         * File creation time. Its function is same as that of
         * struct timespec i_{a,c,m}time in the generic inode.
         */
        struct timespec i_crtime;

        /* mballoc */
        struct list_head i_prealloc_list;
        spinlock_t i_prealloc_lock;

        /* allocation reservation info for delalloc */
        unsigned long i_reserved_data_blocks;
        unsigned long i_reserved_meta_blocks;
        unsigned long i_allocated_meta_blocks;
        unsigned short i_delalloc_reserved_flag;
        spinlock_t i_block_reservation_lock;
};

#endif  /* _EXT4_I */

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