fs/ext4/ext4_i.h

   1 /*
   2  *  ext4_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 _EXT4_I
  17 #define _EXT4_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 */
  25 typedef int ext4_grpblk_t;
  26
  27 /* data type for filesystem-wide blocks number */
  28 typedef unsigned long long ext4_fsblk_t;
  29
  30 /* data type for file logical block number */
  31 typedef __u32 ext4_lblk_t;
  32
  33 /* data type for block group number */
  34 typedef unsigned int ext4_group_t;
  35
  36 /*
  37  * storage for cached extent
  38  */
  39 struct ext4_ext_cache {
  40         ext4_fsblk_t    ec_start;
  41         ext4_lblk_t     ec_block;
  42         __u32           ec_len; /* must be 32bit to return holes */
  43         __u32           ec_type;
  44 };
  45
  46 /*
  47  * fourth extended file system inode data in memory
  48  */
  49 struct ext4_inode_info {
  50         __le32  i_data[15];     /* unconverted */
  51         __u32   i_flags;
  52         ext4_fsblk_t    i_file_acl;
  53         __u32   i_dtime;
  54
  55         /*
  56          * i_block_group is the number of the block group which contains
  57          * this file's inode.  Constant across the lifetime of the inode,
  58          * it is ued for making block allocation decisions - we try to
  59          * place a file's data blocks near its inode block, and new inodes
  60          * near to their parent directory's inode.
  61          */
  62         ext4_group_t    i_block_group;
  63         __u32   i_state;                /* Dynamic state flags for ext4 */
  64
  65         ext4_lblk_t             i_dir_start_lookup;
  66 #ifdef CONFIG_EXT4_FS_XATTR
  67         /*
  68          * Extended attributes can be read independently of the main file
  69          * data. Taking i_mutex even when reading would cause contention
  70          * between readers of EAs and writers of regular file data, so
  71          * instead we synchronize on xattr_sem when reading or changing
  72          * EAs.
  73          */
  74         struct rw_semaphore xattr_sem;
  75 #endif
  76 #ifdef CONFIG_EXT4_FS_POSIX_ACL
  77         struct posix_acl        *i_acl;
  78         struct posix_acl        *i_default_acl;
  79 #endif
  80
  81         struct list_head i_orphan;      /* unlinked but open inodes */
  82
  83         /*
  84          * i_disksize keeps track of what the inode size is ON DISK, not
  85          * in memory.  During truncate, i_size is set to the new size by
  86          * the VFS prior to calling ext4_truncate(), but the filesystem won't
  87          * set i_disksize to 0 until the truncate is actually under way.
  88          *
  89          * The intent is that i_disksize always represents the blocks which
  90          * are used by this file.  This allows recovery to restart truncate
  91          * on orphans if we crash during truncate.  We actually write i_disksize
  92          * into the on-disk inode when writing inodes out, instead of i_size.
  93          *
  94          * The only time when i_disksize and i_size may be different is when
  95          * a truncate is in progress.  The only things which change i_disksize
  96          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
  97          */
  98         loff_t  i_disksize;
  99
 100         /*
 101          * i_data_sem is for serialising ext4_truncate() against
 102          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
 103          * data tree are chopped off during truncate. We can't do that in
 104          * ext4 because whenever we perform intermediate commits during
 105          * truncate, the inode and all the metadata blocks *must* be in a
 106          * consistent state which allows truncation of the orphans to restart
 107          * during recovery.  Hence we must fix the get_block-vs-truncate race
 108          * by other means, so we have i_data_sem.
 109          */
 110         struct rw_semaphore i_data_sem;
 111         struct inode vfs_inode;
 112         struct jbd2_inode jinode;
 113
 114         struct ext4_ext_cache i_cached_extent;
 115         /*
 116          * File creation time. Its function is same as that of
 117          * struct timespec i_{a,c,m}time in the generic inode.
 118          */
 119         struct timespec i_crtime;
 120
 121         /* mballoc */
 122         struct list_head i_prealloc_list;
 123         spinlock_t i_prealloc_lock;
 124
 125         /* ialloc */
 126         ext4_group_t    i_last_alloc_group;
 127
 128         /* allocation reservation info for delalloc */
 129         unsigned int i_reserved_data_blocks;
 130         unsigned int i_reserved_meta_blocks;
 131         unsigned int i_allocated_meta_blocks;
 132         unsigned short i_delalloc_reserved_flag;
 133
 134         /* on-disk additional length */
 135         __u16 i_extra_isize;
 136
 137         spinlock_t i_block_reservation_lock;
 138 };
 139
 140 #endif  /* _EXT4_I */