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