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 
21 /*
22  * second extended file system inode data in memory
23  */
24 struct ext3_inode_info {
25 	__u32	i_data[15];
26 	__u32	i_flags;
27 #ifdef EXT3_FRAGMENTS
28 	__u32	i_faddr;
29 	__u8	i_frag_no;
30 	__u8	i_frag_size;
31 	__u16	unused;			/* formerly i_osync */
32 #endif
33 	__u32	i_file_acl;
34 	__u32	i_dir_acl;
35 	__u32	i_dtime;
36 	__u32	i_block_group;
37 	__u32	i_state;		/* Dynamic state flags for ext3 */
38 	__u32	i_next_alloc_block;
39 	__u32	i_next_alloc_goal;
40 #ifdef EXT3_PREALLOCATE
41 	__u32	i_prealloc_block;
42 	__u32	i_prealloc_count;
43 #endif
44 	__u32	i_dir_start_lookup;
45 
46 	struct list_head i_orphan;	/* unlinked but open inodes */
47 
48 	/*
49 	 * i_disksize keeps track of what the inode size is ON DISK, not
50 	 * in memory.  During truncate, i_size is set to the new size by
51 	 * the VFS prior to calling ext3_truncate(), but the filesystem won't
52 	 * set i_disksize to 0 until the truncate is actually under way.
53 	 *
54 	 * The intent is that i_disksize always represents the blocks which
55 	 * are used by this file.  This allows recovery to restart truncate
56 	 * on orphans if we crash during truncate.  We actually write i_disksize
57 	 * into the on-disk inode when writing inodes out, instead of i_size.
58 	 *
59 	 * The only time when i_disksize and i_size may be different is when
60 	 * a truncate is in progress.  The only things which change i_disksize
61 	 * are ext3_get_block (growth) and ext3_truncate (shrinkth).
62 	 */
63 	loff_t	i_disksize;
64 
65 	/*
66 	 * truncate_sem is for serialising ext3_truncate() against
67 	 * ext3_getblock().  In the 2.4 ext2 design, great chunks of inode's
68 	 * data tree are chopped off during truncate. We can't do that in
69 	 * ext3 because whenever we perform intermediate commits during
70 	 * truncate, the inode and all the metadata blocks *must* be in a
71 	 * consistent state which allows truncation of the orphans to restart
72 	 * during recovery.  Hence we must fix the get_block-vs-truncate race
73 	 * by other means, so we have truncate_sem.
74 	 */
75 	struct rw_semaphore truncate_sem;
76 };
77 
78 #endif	/* _LINUX_EXT3_FS_I */
79