2 * linux/include/linux/ext3_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_EXT3_FS_I
17 #define _LINUX_EXT3_FS_I
19 #include <linux/rwsem.h>
20 #include <linux/rbtree.h>
21 #include <linux/seqlock.h>
23 struct ext3_reserve_window {
24 __u32 _rsv_start; /* First byte reserved */
25 __u32 _rsv_end; /* Last byte reserved or 0 */
28 struct ext3_reserve_window_node {
29 struct rb_node rsv_node;
30 atomic_t rsv_goal_size;
31 atomic_t rsv_alloc_hit;
32 seqlock_t rsv_seqlock;
33 struct ext3_reserve_window rsv_window;
36 #define rsv_start rsv_window._rsv_start
37 #define rsv_end rsv_window._rsv_end
40 * third extended file system inode data in memory
42 struct ext3_inode_info {
43 __le32 i_data[15]; /* unconverted */
55 * i_block_group is the number of the block group which contains
56 * this file's inode. Constant across the lifetime of the inode,
57 * it is ued for making block allocation decisions - we try to
58 * place a file's data blocks near its inode block, and new inodes
59 * near to their parent directory's inode.
62 __u32 i_state; /* Dynamic state flags for ext3 */
65 * i_next_alloc_block is the logical (file-relative) number of the
66 * most-recently-allocated block in this file. Yes, it is misnamed.
67 * We use this for detecting linearly ascending allocation requests.
69 __u32 i_next_alloc_block;
72 * i_next_alloc_goal is the *physical* companion to i_next_alloc_block.
73 * it the the physical block number of the block which was most-recently
74 * allocated to this file. This give us the goal (target) for the next
75 * allocation when we detect linearly ascending requests.
77 __u32 i_next_alloc_goal;
78 /* block reservation window */
79 struct ext3_reserve_window_node i_rsv_window;
81 __u32 i_dir_start_lookup;
82 #ifdef CONFIG_EXT3_FS_XATTR
84 * Extended attributes can be read independently of the main file
85 * data. Taking i_sem even when reading would cause contention
86 * between readers of EAs and writers of regular file data, so
87 * instead we synchronize on xattr_sem when reading or changing
90 struct rw_semaphore xattr_sem;
92 #ifdef CONFIG_EXT3_FS_POSIX_ACL
93 struct posix_acl *i_acl;
94 struct posix_acl *i_default_acl;
97 struct list_head i_orphan; /* unlinked but open inodes */
100 * i_disksize keeps track of what the inode size is ON DISK, not
101 * in memory. During truncate, i_size is set to the new size by
102 * the VFS prior to calling ext3_truncate(), but the filesystem won't
103 * set i_disksize to 0 until the truncate is actually under way.
105 * The intent is that i_disksize always represents the blocks which
106 * are used by this file. This allows recovery to restart truncate
107 * on orphans if we crash during truncate. We actually write i_disksize
108 * into the on-disk inode when writing inodes out, instead of i_size.
110 * The only time when i_disksize and i_size may be different is when
111 * a truncate is in progress. The only things which change i_disksize
112 * are ext3_get_block (growth) and ext3_truncate (shrinkth).
116 /* on-disk additional length */
120 * truncate_sem is for serialising ext3_truncate() against
121 * ext3_getblock(). In the 2.4 ext2 design, great chunks of inode's
122 * data tree are chopped off during truncate. We can't do that in
123 * ext3 because whenever we perform intermediate commits during
124 * truncate, the inode and all the metadata blocks *must* be in a
125 * consistent state which allows truncation of the orphans to restart
126 * during recovery. Hence we must fix the get_block-vs-truncate race
127 * by other means, so we have truncate_sem.
129 struct semaphore truncate_sem;
130 struct inode vfs_inode;
133 #endif /* _LINUX_EXT3_FS_I */