summaryrefslogtreecommitdiffstats
path: root/include/linux/ext4_fs_i.h
blob: 86ddfe2089f30ed1d2d14e7f5d976fde318b03f9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
/*
 *  linux/include/linux/ext4_fs_i.h
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/include/linux/minix_fs_i.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#ifndef _LINUX_EXT4_FS_I
#define _LINUX_EXT4_FS_I

#include <linux/rwsem.h>
#include <linux/rbtree.h>
#include <linux/seqlock.h>
#include <linux/mutex.h>

/* data type for block offset of block group */
typedef int ext4_grpblk_t;

/* data type for filesystem-wide blocks number */
typedef unsigned long long ext4_fsblk_t;

struct ext4_reserve_window {
	ext4_fsblk_t	_rsv_start;	/* First byte reserved */
	ext4_fsblk_t	_rsv_end;	/* Last byte reserved or 0 */
};

struct ext4_reserve_window_node {
	struct rb_node		rsv_node;
	__u32			rsv_goal_size;
	__u32			rsv_alloc_hit;
	struct ext4_reserve_window	rsv_window;
};

struct ext4_block_alloc_info {
	/* information about reservation window */
	struct ext4_reserve_window_node rsv_window_node;
	/*
	 * was i_next_alloc_block in ext4_inode_info
	 * is the logical (file-relative) number of the
	 * most-recently-allocated block in this file.
	 * We use this for detecting linearly ascending allocation requests.
	 */
	__u32 last_alloc_logical_block;
	/*
	 * Was i_next_alloc_goal in ext4_inode_info
	 * is the *physical* companion to i_next_alloc_block.
	 * it the physical block number of the block which was most-recentl
	 * allocated to this file.  This give us the goal (target) for the next
	 * allocation when we detect linearly ascending requests.
	 */
	ext4_fsblk_t last_alloc_physical_block;
};

#define rsv_start rsv_window._rsv_start
#define rsv_end rsv_window._rsv_end

/*
 * storage for cached extent
 */
struct ext4_ext_cache {
	ext4_fsblk_t	ec_start;
	__u32		ec_block;
	__u32		ec_len; /* must be 32bit to return holes */
	__u32		ec_type;
};

/*
 * third extended file system inode data in memory
 */
struct ext4_inode_info {
	__le32	i_data[15];	/* unconverted */
	__u32	i_flags;
	ext4_fsblk_t	i_file_acl;
	__u32	i_dir_acl;
	__u32	i_dtime;

	/*
	 * i_block_group is the number of the block group which contains
	 * this file's inode.  Constant across the lifetime of the inode,
	 * it is ued for making block allocation decisions - we try to
	 * place a file's data blocks near its inode block, and new inodes
	 * near to their parent directory's inode.
	 */
	__u32	i_block_group;
	__u32	i_state;		/* Dynamic state flags for ext4 */

	/* block reservation info */
	struct ext4_block_alloc_info *i_block_alloc_info;

	__u32	i_dir_start_lookup;
#ifdef CONFIG_EXT4DEV_FS_XATTR
	/*
	 * Extended attributes can be read independently of the main file
	 * data. Taking i_mutex even when reading would cause contention
	 * between readers of EAs and writers of regular file data, so
	 * instead we synchronize on xattr_sem when reading or changing
	 * EAs.
	 */
	struct rw_semaphore xattr_sem;
#endif
#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
	struct posix_acl	*i_acl;
	struct posix_acl	*i_default_acl;
#endif

	struct list_head i_orphan;	/* unlinked but open inodes */

	/*
	 * i_disksize keeps track of what the inode size is ON DISK, not
	 * in memory.  During truncate, i_size is set to the new size by
	 * the VFS prior to calling ext4_truncate(), but the filesystem won't
	 * set i_disksize to 0 until the truncate is actually under way.
	 *
	 * The intent is that i_disksize always represents the blocks which
	 * are used by this file.  This allows recovery to restart truncate
	 * on orphans if we crash during truncate.  We actually write i_disksize
	 * into the on-disk inode when writing inodes out, instead of i_size.
	 *
	 * The only time when i_disksize and i_size may be different is when
	 * a truncate is in progress.  The only things which change i_disksize
	 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
	 */
	loff_t	i_disksize;

	/* on-disk additional length */
	__u16 i_extra_isize;

	/*
	 * truncate_mutex is for serialising ext4_truncate() against
	 * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
	 * data tree are chopped off during truncate. We can't do that in
	 * ext4 because whenever we perform intermediate commits during
	 * truncate, the inode and all the metadata blocks *must* be in a
	 * consistent state which allows truncation of the orphans to restart
	 * during recovery.  Hence we must fix the get_block-vs-truncate race
	 * by other means, so we have truncate_mutex.
	 */
	struct mutex truncate_mutex;
	struct inode vfs_inode;

	unsigned long i_ext_generation;
	struct ext4_ext_cache i_cached_extent;
	/*
	 * File creation time. Its function is same as that of
	 * struct timespec i_{a,c,m}time in the generic inode.
	 */
	struct timespec i_crtime;
};

#endif	/* _LINUX_EXT4_FS_I */
OpenPOWER on IntegriCloud