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 ext4_fsblk_t;
32 struct ext4_reserve_window {
33 ext4_fsblk_t _rsv_start; /* First byte reserved */
34 ext4_fsblk_t _rsv_end; /* Last byte reserved or 0 */
37 struct ext4_reserve_window_node {
38 struct rb_node rsv_node;
41 struct ext4_reserve_window rsv_window;
44 struct ext4_block_alloc_info {
45 /* information about reservation window */
46 struct ext4_reserve_window_node rsv_window_node;
48 * was i_next_alloc_block in ext4_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.
53 __u32 last_alloc_logical_block;
55 * Was i_next_alloc_goal in ext4_inode_info
56 * is the *physical* companion to i_next_alloc_block.
57 * it the 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.
61 ext4_fsblk_t last_alloc_physical_block;
64 #define rsv_start rsv_window._rsv_start
65 #define rsv_end rsv_window._rsv_end
68 * storage for cached extent
70 struct ext4_ext_cache {
73 __u32 ec_len; /* must be 32bit to return holes */
78 * third extended file system inode data in memory
80 struct ext4_inode_info {
81 __le32 i_data[15]; /* unconverted */
88 ext4_fsblk_t i_file_acl;
93 * i_block_group is the number of the block group which contains
94 * this file's inode. Constant across the lifetime of the inode,
95 * it is ued for making block allocation decisions - we try to
96 * place a file's data blocks near its inode block, and new inodes
97 * near to their parent directory's inode.
100 __u32 i_state; /* Dynamic state flags for ext4 */
102 /* block reservation info */
103 struct ext4_block_alloc_info *i_block_alloc_info;
105 __u32 i_dir_start_lookup;
106 #ifdef CONFIG_EXT4DEV_FS_XATTR
108 * Extended attributes can be read independently of the main file
109 * data. Taking i_mutex even when reading would cause contention
110 * between readers of EAs and writers of regular file data, so
111 * instead we synchronize on xattr_sem when reading or changing
114 struct rw_semaphore xattr_sem;
116 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
117 struct posix_acl *i_acl;
118 struct posix_acl *i_default_acl;
121 struct list_head i_orphan; /* unlinked but open inodes */
124 * i_disksize keeps track of what the inode size is ON DISK, not
125 * in memory. During truncate, i_size is set to the new size by
126 * the VFS prior to calling ext4_truncate(), but the filesystem won't
127 * set i_disksize to 0 until the truncate is actually under way.
129 * The intent is that i_disksize always represents the blocks which
130 * are used by this file. This allows recovery to restart truncate
131 * on orphans if we crash during truncate. We actually write i_disksize
132 * into the on-disk inode when writing inodes out, instead of i_size.
134 * The only time when i_disksize and i_size may be different is when
135 * a truncate is in progress. The only things which change i_disksize
136 * are ext4_get_block (growth) and ext4_truncate (shrinkth).
140 /* on-disk additional length */
144 * truncate_mutex is for serialising ext4_truncate() against
145 * ext4_getblock(). In the 2.4 ext2 design, great chunks of inode's
146 * data tree are chopped off during truncate. We can't do that in
147 * ext4 because whenever we perform intermediate commits during
148 * truncate, the inode and all the metadata blocks *must* be in a
149 * consistent state which allows truncation of the orphans to restart
150 * during recovery. Hence we must fix the get_block-vs-truncate race
151 * by other means, so we have truncate_mutex.
153 struct mutex truncate_mutex;
154 struct inode vfs_inode;
156 unsigned long i_ext_generation;
157 struct ext4_ext_cache i_cached_extent;
160 #endif /* _LINUX_EXT4_FS_I */