ext4_fs_i.h 4.7 KB

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  1. /*
  2. * linux/include/linux/ext4_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. #ifndef _LINUX_EXT4_FS_I
  16. #define _LINUX_EXT4_FS_I
  17. #include <linux/rwsem.h>
  18. #include <linux/rbtree.h>
  19. #include <linux/seqlock.h>
  20. #include <linux/mutex.h>
  21. /* data type for block offset of block group */
  22. typedef int ext4_grpblk_t;
  23. /* data type for filesystem-wide blocks number */
  24. typedef unsigned long long ext4_fsblk_t;
  25. struct ext4_reserve_window {
  26. ext4_fsblk_t _rsv_start; /* First byte reserved */
  27. ext4_fsblk_t _rsv_end; /* Last byte reserved or 0 */
  28. };
  29. struct ext4_reserve_window_node {
  30. struct rb_node rsv_node;
  31. __u32 rsv_goal_size;
  32. __u32 rsv_alloc_hit;
  33. struct ext4_reserve_window rsv_window;
  34. };
  35. struct ext4_block_alloc_info {
  36. /* information about reservation window */
  37. struct ext4_reserve_window_node rsv_window_node;
  38. /*
  39. * was i_next_alloc_block in ext4_inode_info
  40. * is the logical (file-relative) number of the
  41. * most-recently-allocated block in this file.
  42. * We use this for detecting linearly ascending allocation requests.
  43. */
  44. __u32 last_alloc_logical_block;
  45. /*
  46. * Was i_next_alloc_goal in ext4_inode_info
  47. * is the *physical* companion to i_next_alloc_block.
  48. * it the physical block number of the block which was most-recentl
  49. * allocated to this file. This give us the goal (target) for the next
  50. * allocation when we detect linearly ascending requests.
  51. */
  52. ext4_fsblk_t last_alloc_physical_block;
  53. };
  54. #define rsv_start rsv_window._rsv_start
  55. #define rsv_end rsv_window._rsv_end
  56. /*
  57. * storage for cached extent
  58. */
  59. struct ext4_ext_cache {
  60. ext4_fsblk_t ec_start;
  61. __u32 ec_block;
  62. __u32 ec_len; /* must be 32bit to return holes */
  63. __u32 ec_type;
  64. };
  65. /*
  66. * third extended file system inode data in memory
  67. */
  68. struct ext4_inode_info {
  69. __le32 i_data[15]; /* unconverted */
  70. __u32 i_flags;
  71. ext4_fsblk_t i_file_acl;
  72. __u32 i_dir_acl;
  73. __u32 i_dtime;
  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 ext4 */
  83. /* block reservation info */
  84. struct ext4_block_alloc_info *i_block_alloc_info;
  85. __u32 i_dir_start_lookup;
  86. #ifdef CONFIG_EXT4DEV_FS_XATTR
  87. /*
  88. * Extended attributes can be read independently of the main file
  89. * data. Taking i_mutex even when reading would cause contention
  90. * between readers of EAs and writers of regular file data, so
  91. * instead we synchronize on xattr_sem when reading or changing
  92. * EAs.
  93. */
  94. struct rw_semaphore xattr_sem;
  95. #endif
  96. #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
  97. struct posix_acl *i_acl;
  98. struct posix_acl *i_default_acl;
  99. #endif
  100. struct list_head i_orphan; /* unlinked but open inodes */
  101. /*
  102. * i_disksize keeps track of what the inode size is ON DISK, not
  103. * in memory. During truncate, i_size is set to the new size by
  104. * the VFS prior to calling ext4_truncate(), but the filesystem won't
  105. * set i_disksize to 0 until the truncate is actually under way.
  106. *
  107. * The intent is that i_disksize always represents the blocks which
  108. * are used by this file. This allows recovery to restart truncate
  109. * on orphans if we crash during truncate. We actually write i_disksize
  110. * into the on-disk inode when writing inodes out, instead of i_size.
  111. *
  112. * The only time when i_disksize and i_size may be different is when
  113. * a truncate is in progress. The only things which change i_disksize
  114. * are ext4_get_block (growth) and ext4_truncate (shrinkth).
  115. */
  116. loff_t i_disksize;
  117. /* on-disk additional length */
  118. __u16 i_extra_isize;
  119. /*
  120. * truncate_mutex is for serialising ext4_truncate() against
  121. * ext4_getblock(). In the 2.4 ext2 design, great chunks of inode's
  122. * data tree are chopped off during truncate. We can't do that in
  123. * ext4 because whenever we perform intermediate commits during
  124. * truncate, the inode and all the metadata blocks *must* be in a
  125. * consistent state which allows truncation of the orphans to restart
  126. * during recovery. Hence we must fix the get_block-vs-truncate race
  127. * by other means, so we have truncate_mutex.
  128. */
  129. struct mutex truncate_mutex;
  130. struct inode vfs_inode;
  131. unsigned long i_ext_generation;
  132. struct ext4_ext_cache i_cached_extent;
  133. /*
  134. * File creation time. Its function is same as that of
  135. * struct timespec i_{a,c,m}time in the generic inode.
  136. */
  137. struct timespec i_crtime;
  138. };
  139. #endif /* _LINUX_EXT4_FS_I */