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 */
25 typedef int ext3_grpblk_t;
26 
27 /* data type for filesystem-wide blocks number */
28 typedef unsigned long ext3_fsblk_t;
29 
30 #define E3FSBLK "%lu"
31 
32 struct 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 
37 struct 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 
44 struct 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  */
70 struct 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 	unsigned long	i_state_flags;	/* 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 
107 	struct list_head i_orphan;	/* unlinked but open inodes */
108 
109 	/*
110 	 * i_disksize keeps track of what the inode size is ON DISK, not
111 	 * in memory.  During truncate, i_size is set to the new size by
112 	 * the VFS prior to calling ext3_truncate(), but the filesystem won't
113 	 * set i_disksize to 0 until the truncate is actually under way.
114 	 *
115 	 * The intent is that i_disksize always represents the blocks which
116 	 * are used by this file.  This allows recovery to restart truncate
117 	 * on orphans if we crash during truncate.  We actually write i_disksize
118 	 * into the on-disk inode when writing inodes out, instead of i_size.
119 	 *
120 	 * The only time when i_disksize and i_size may be different is when
121 	 * a truncate is in progress.  The only things which change i_disksize
122 	 * are ext3_get_block (growth) and ext3_truncate (shrinkth).
123 	 */
124 	loff_t	i_disksize;
125 
126 	/* on-disk additional length */
127 	__u16 i_extra_isize;
128 
129 	/*
130 	 * truncate_mutex is for serialising ext3_truncate() against
131 	 * ext3_getblock().  In the 2.4 ext2 design, great chunks of inode's
132 	 * data tree are chopped off during truncate. We can't do that in
133 	 * ext3 because whenever we perform intermediate commits during
134 	 * truncate, the inode and all the metadata blocks *must* be in a
135 	 * consistent state which allows truncation of the orphans to restart
136 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
137 	 * by other means, so we have truncate_mutex.
138 	 */
139 	struct mutex truncate_mutex;
140 
141 	/*
142 	 * Transactions that contain inode's metadata needed to complete
143 	 * fsync and fdatasync, respectively.
144 	 */
145 	atomic_t i_sync_tid;
146 	atomic_t i_datasync_tid;
147 
148 	struct inode vfs_inode;
149 };
150 
151 #endif	/* _LINUX_EXT3_FS_I */
152