include/linux/ext3_fs_i.h

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