2 * linux/include/linux/ext4_fs_i.h
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)
11 * linux/include/linux/minix_fs_i.h
13 * Copyright (C) 1991, 1992 Linus Torvalds
16 #ifndef _LINUX_EXT4_FS_I
17 #define _LINUX_EXT4_FS_I
19 #include <linux/rwsem.h>
20 #include <linux/rbtree.h>
21 #include <linux/seqlock.h>
22 #include <linux/mutex.h>
24 /* data type for block offset of block group */
25 typedef int ext4_grpblk_t;
27 /* data type for filesystem-wide blocks number */
28 typedef unsigned long long ext4_fsblk_t;
30 /* data type for file logical block number */
31 typedef __u32 ext4_lblk_t;
33 /* data type for block group number */
34 typedef unsigned long ext4_group_t;
36 struct ext4_reserve_window {
37 ext4_fsblk_t _rsv_start; /* First byte reserved */
38 ext4_fsblk_t _rsv_end; /* Last byte reserved or 0 */
41 struct ext4_reserve_window_node {
42 struct rb_node rsv_node;
45 struct ext4_reserve_window rsv_window;
48 struct ext4_block_alloc_info {
49 /* information about reservation window */
50 struct ext4_reserve_window_node rsv_window_node;
52 * was i_next_alloc_block in ext4_inode_info
53 * is the logical (file-relative) number of the
54 * most-recently-allocated block in this file.
55 * We use this for detecting linearly ascending allocation requests.
57 ext4_lblk_t last_alloc_logical_block;
59 * Was i_next_alloc_goal in ext4_inode_info
60 * is the *physical* companion to i_next_alloc_block.
61 * it the physical block number of the block which was most-recentl
62 * allocated to this file. This give us the goal (target) for the next
63 * allocation when we detect linearly ascending requests.
65 ext4_fsblk_t last_alloc_physical_block;
68 #define rsv_start rsv_window._rsv_start
69 #define rsv_end rsv_window._rsv_end
72 * storage for cached extent
74 struct ext4_ext_cache {
75 ext4_fsblk_t ec_start;
77 __u32 ec_len; /* must be 32bit to return holes */
82 * third extended file system inode data in memory
84 struct ext4_inode_info {
85 __le32 i_data[15]; /* unconverted */
87 ext4_fsblk_t i_file_acl;
92 * i_block_group is the number of the block group which contains
93 * this file's inode. Constant across the lifetime of the inode,
94 * it is ued for making block allocation decisions - we try to
95 * place a file's data blocks near its inode block, and new inodes
96 * near to their parent directory's inode.
98 ext4_group_t i_block_group;
99 __u32 i_state; /* Dynamic state flags for ext4 */
101 /* block reservation info */
102 struct ext4_block_alloc_info *i_block_alloc_info;
104 ext4_lblk_t i_dir_start_lookup;
105 #ifdef CONFIG_EXT4DEV_FS_XATTR
107 * Extended attributes can be read independently of the main file
108 * data. Taking i_mutex even when reading would cause contention
109 * between readers of EAs and writers of regular file data, so
110 * instead we synchronize on xattr_sem when reading or changing
113 struct rw_semaphore xattr_sem;
115 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
116 struct posix_acl *i_acl;
117 struct posix_acl *i_default_acl;
120 struct list_head i_orphan; /* unlinked but open inodes */
123 * i_disksize keeps track of what the inode size is ON DISK, not
124 * in memory. During truncate, i_size is set to the new size by
125 * the VFS prior to calling ext4_truncate(), but the filesystem won't
126 * set i_disksize to 0 until the truncate is actually under way.
128 * The intent is that i_disksize always represents the blocks which
129 * are used by this file. This allows recovery to restart truncate
130 * on orphans if we crash during truncate. We actually write i_disksize
131 * into the on-disk inode when writing inodes out, instead of i_size.
133 * The only time when i_disksize and i_size may be different is when
134 * a truncate is in progress. The only things which change i_disksize
135 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
139 /* on-disk additional length */
143 * truncate_mutex is for serialising ext4_truncate() against
144 * ext4_getblock(). In the 2.4 ext2 design, great chunks of inode's
145 * data tree are chopped off during truncate. We can't do that in
146 * ext4 because whenever we perform intermediate commits during
147 * truncate, the inode and all the metadata blocks *must* be in a
148 * consistent state which allows truncation of the orphans to restart
149 * during recovery. Hence we must fix the get_block-vs-truncate race
150 * by other means, so we have truncate_mutex.
152 struct mutex truncate_mutex;
153 struct inode vfs_inode;
155 unsigned long i_ext_generation;
156 struct ext4_ext_cache i_cached_extent;
158 * File creation time. Its function is same as that of
159 * struct timespec i_{a,c,m}time in the generic inode.
161 struct timespec i_crtime;
164 #endif /* _LINUX_EXT4_FS_I */