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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
16#ifndef _LINUX_EXT4_FS_I
17#define _LINUX_EXT4_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 */
25typedef int ext4_grpblk_t;
26
27/* data type for filesystem-wide blocks number */
28typedef unsigned long long ext4_fsblk_t;
29
30struct ext4_reserve_window {
31 ext4_fsblk_t _rsv_start; /* First byte reserved */
32 ext4_fsblk_t _rsv_end; /* Last byte reserved or 0 */
33};
34
35struct ext4_reserve_window_node {
36 struct rb_node rsv_node;
37 __u32 rsv_goal_size;
38 __u32 rsv_alloc_hit;
39 struct ext4_reserve_window rsv_window;
40};
41
42struct ext4_block_alloc_info {
43 /* information about reservation window */
44 struct ext4_reserve_window_node rsv_window_node;
45 /*
46 * was i_next_alloc_block in ext4_inode_info
47 * is the logical (file-relative) number of the
48 * most-recently-allocated block in this file.
49 * We use this for detecting linearly ascending allocation requests.
50 */
51 __u32 last_alloc_logical_block;
52 /*
53 * Was i_next_alloc_goal in ext4_inode_info
54 * is the *physical* companion to i_next_alloc_block.
55 * it the the physical block number of the block which was most-recentl
56 * allocated to this file. This give us the goal (target) for the next
57 * allocation when we detect linearly ascending requests.
58 */
59 ext4_fsblk_t last_alloc_physical_block;
60};
61
62#define rsv_start rsv_window._rsv_start
63#define rsv_end rsv_window._rsv_end
64
65/*
66 * storage for cached extent
67 */
68struct ext4_ext_cache {
69 ext4_fsblk_t ec_start;
70 __u32 ec_block;
71 __u32 ec_len; /* must be 32bit to return holes */
72 __u32 ec_type;
73};
74
75/*
76 * third extended file system inode data in memory
77 */
78struct ext4_inode_info {
79 __le32 i_data[15]; /* unconverted */
80 __u32 i_flags;
81#ifdef EXT4_FRAGMENTS
82 __u32 i_faddr;
83 __u8 i_frag_no;
84 __u8 i_frag_size;
85#endif
86 ext4_fsblk_t i_file_acl;
87 __u32 i_dir_acl;
88 __u32 i_dtime;
89
90 /*
91 * i_block_group is the number of the block group which contains
92 * this file's inode. Constant across the lifetime of the inode,
93 * it is ued for making block allocation decisions - we try to
94 * place a file's data blocks near its inode block, and new inodes
95 * near to their parent directory's inode.
96 */
97 __u32 i_block_group;
98 __u32 i_state; /* Dynamic state flags for ext4 */
99
100 /* block reservation info */
101 struct ext4_block_alloc_info *i_block_alloc_info;
102
103 __u32 i_dir_start_lookup;
104#ifdef CONFIG_EXT4DEV_FS_XATTR
105 /*
106 * Extended attributes can be read independently of the main file
107 * data. Taking i_mutex even when reading would cause contention
108 * between readers of EAs and writers of regular file data, so
109 * instead we synchronize on xattr_sem when reading or changing
110 * EAs.
111 */
112 struct rw_semaphore xattr_sem;
113#endif
114#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
115 struct posix_acl *i_acl;
116 struct posix_acl *i_default_acl;
117#endif
118
119 struct list_head i_orphan; /* unlinked but open inodes */
120
121 /*
122 * i_disksize keeps track of what the inode size is ON DISK, not
123 * in memory. During truncate, i_size is set to the new size by
124 * the VFS prior to calling ext4_truncate(), but the filesystem won't
125 * set i_disksize to 0 until the truncate is actually under way.
126 *
127 * The intent is that i_disksize always represents the blocks which
128 * are used by this file. This allows recovery to restart truncate
129 * on orphans if we crash during truncate. We actually write i_disksize
130 * into the on-disk inode when writing inodes out, instead of i_size.
131 *
132 * The only time when i_disksize and i_size may be different is when
133 * a truncate is in progress. The only things which change i_disksize
134 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
135 */
136 loff_t i_disksize;
137
138 /* on-disk additional length */
139 __u16 i_extra_isize;
140
141 /*
142 * truncate_mutex is for serialising ext4_truncate() against
143 * ext4_getblock(). In the 2.4 ext2 design, great chunks of inode's
144 * data tree are chopped off during truncate. We can't do that in
145 * ext4 because whenever we perform intermediate commits during
146 * truncate, the inode and all the metadata blocks *must* be in a
147 * consistent state which allows truncation of the orphans to restart
148 * during recovery. Hence we must fix the get_block-vs-truncate race
149 * by other means, so we have truncate_mutex.
150 */
151 struct mutex truncate_mutex;
152 struct inode vfs_inode;
153
154 unsigned long i_ext_generation;
155 struct ext4_ext_cache i_cached_extent;
156};
157
158#endif /* _LINUX_EXT4_FS_I */