root/include/linux/ext3_fs_i.h

INCLUDED FROM

/*
 *  linux/include/linux/ext3_fs_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 _LINUX_EXT3_FS_I
#define _LINUX_EXT3_FS_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 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;
        __u32   i_state;                /* 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
#ifdef CONFIG_EXT3_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 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;
        struct inode vfs_inode;
};

#endif  /* _LINUX_EXT3_FS_I */