LXR linux/include/linux/ext3_fs

   1/*
   2 *  linux/include/linux/ext3_fs_i.h
   3 *
   4 * Copyright (C) 1992, 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 *
   9 *  from
  10 *
  11 *  linux/include/linux/minix_fs_i.h
  12 *
  13 *  Copyright (C) 1991, 1992  Linus Torvalds
  14 */
  15
  16#ifndef _LINUX_EXT3_FS_I
  17#define _LINUX_EXT3_FS_I
  18
  19#include <linux/rwsem.h>
  20#include <linux/rbtree.h>
  21#include <linux/seqlock.h>
  22#include <linux/mutex.h>
  23
  24/* data type for block offset of block group */
  25typedef int ext3_grpblk_t;
  26
  27/* data type for filesystem-wide blocks number */
  28typedef unsigned long ext3_fsblk_t;
  29
  30#define E3FSBLK "%lu"
  31
  32struct ext3_reserve_window {
  33        ext3_fsblk_t    _rsv_start;     /* First byte reserved */
  34        ext3_fsblk_t    _rsv_end;       /* Last byte reserved or 0 */
  35};
  36
  37struct ext3_reserve_window_node {
  38        struct rb_node          rsv_node;
  39        __u32                   rsv_goal_size;
  40        __u32                   rsv_alloc_hit;
  41        struct ext3_reserve_window      rsv_window;
  42};
  43
  44struct ext3_block_alloc_info {
  45        /* information about reservation window */
  46        struct ext3_reserve_window_node rsv_window_node;
  47        /*
  48         * was i_next_alloc_block in ext3_inode_info
  49         * is the logical (file-relative) number of the
  50         * most-recently-allocated block in this file.
  51         * We use this for detecting linearly ascending allocation requests.
  52         */
  53        __u32                   last_alloc_logical_block;
  54        /*
  55         * Was i_next_alloc_goal in ext3_inode_info
  56         * is the *physical* companion to i_next_alloc_block.
  57         * it the physical block number of the block which was most-recentl
  58         * allocated to this file.  This give us the goal (target) for the next
  59         * allocation when we detect linearly ascending requests.
  60         */
  61        ext3_fsblk_t            last_alloc_physical_block;
  62};
  63
  64#define rsv_start rsv_window._rsv_start
  65#define rsv_end rsv_window._rsv_end
  66
  67/*
  68 * third extended file system inode data in memory
  69 */
  70struct ext3_inode_info {
  71        __le32  i_data[15];     /* unconverted */
  72        __u32   i_flags;
  73#ifdef EXT3_FRAGMENTS
  74        __u32   i_faddr;
  75        __u8    i_frag_no;
  76        __u8    i_frag_size;
  77#endif
  78        ext3_fsblk_t    i_file_acl;
  79        __u32   i_dir_acl;
  80        __u32   i_dtime;
  81
  82        /*
  83         * i_block_group is the number of the block group which contains
  84         * this file's inode.  Constant across the lifetime of the inode,
  85         * it is ued for making block allocation decisions - we try to
  86         * place a file's data blocks near its inode block, and new inodes
  87         * near to their parent directory's inode.
  88         */
  89        __u32   i_block_group;
  90        __u32   i_state;                /* Dynamic state flags for ext3 */
  91
  92        /* block reservation info */
  93        struct ext3_block_alloc_info *i_block_alloc_info;
  94
  95        __u32   i_dir_start_lookup;
  96#ifdef CONFIG_EXT3_FS_XATTR
  97        /*
  98         * Extended attributes can be read independently of the main file
  99         * data. Taking i_mutex even when reading would cause contention
 100         * between readers of EAs and writers of regular file data, so
 101         * instead we synchronize on xattr_sem when reading or changing
 102         * EAs.
 103         */
 104        struct rw_semaphore xattr_sem;
 105#endif
 106#ifdef CONFIG_EXT3_FS_POSIX_ACL
 107        struct posix_acl        *i_acl;
 108        struct posix_acl        *i_default_acl;
 109#endif
 110
 111        struct list_head i_orphan;      /* unlinked but open inodes */
 112
 113        /*
 114         * i_disksize keeps track of what the inode size is ON DISK, not
 115         * in memory.  During truncate, i_size is set to the new size by
 116         * the VFS prior to calling ext3_truncate(), but the filesystem won't
 117         * set i_disksize to 0 until the truncate is actually under way.
 118         *
 119         * The intent is that i_disksize always represents the blocks which
 120         * are used by this file.  This allows recovery to restart truncate
 121         * on orphans if we crash during truncate.  We actually write i_disksize
 122         * into the on-disk inode when writing inodes out, instead of i_size.
 123         *
 124         * The only time when i_disksize and i_size may be different is when
 125         * a truncate is in progress.  The only things which change i_disksize
 126         * are ext3_get_block (growth) and ext3_truncate (shrinkth).
 127         */
 128        loff_t  i_disksize;
 129
 130        /* on-disk additional length */
 131        __u16 i_extra_isize;
 132
 133        /*
 134         * truncate_mutex is for serialising ext3_truncate() against
 135         * ext3_getblock().  In the 2.4 ext2 design, great chunks of inode's
 136         * data tree are chopped off during truncate. We can't do that in
 137         * ext3 because whenever we perform intermediate commits during
 138         * truncate, the inode and all the metadata blocks *must* be in a
 139         * consistent state which allows truncation of the orphans to restart
 140         * during recovery.  Hence we must fix the get_block-vs-truncate race
 141         * by other means, so we have truncate_mutex.
 142         */
 143        struct mutex truncate_mutex;
 144        struct inode vfs_inode;
 145};
 146
 147#endif  /* _LINUX_EXT3_FS_I */
 148