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>
21 struct reserve_window {
22 struct list_head rsv_list;
25 atomic_t rsv_goal_size;
30 * third extended file system inode data in memory
32 struct ext3_inode_info {
45 * i_block_group is the number of the block group which contains
46 * this file's inode. Constant across the lifetime of the inode,
47 * it is ued for making block allocation decisions - we try to
48 * place a file's data blocks near its inode block, and new inodes
49 * near to their parent directory's inode.
52 __u32 i_state; /* Dynamic state flags for ext3 */
55 * i_next_alloc_block is the logical (file-relative) number of the
56 * most-recently-allocated block in this file. Yes, it is misnamed.
57 * We use this for detecting linearly ascending allocation requests.
59 __u32 i_next_alloc_block;
62 * i_next_alloc_goal is the *physical* companion to i_next_alloc_block.
63 * it the the physical block number of the block which was most-recently
64 * allocated to this file. This give us the goal (target) for the next
65 * allocation when we detect linearly ascending requests.
67 __u32 i_next_alloc_goal;
68 /* block reservation window */
69 struct reserve_window i_rsv_window;
71 __u32 i_dir_start_lookup;
72 #ifdef CONFIG_EXT3_FS_XATTR
74 * Extended attributes can be read independently of the main file
75 * data. Taking i_sem even when reading would cause contention
76 * between readers of EAs and writers of regular file data, so
77 * instead we synchronize on xattr_sem when reading or changing
80 struct rw_semaphore xattr_sem;
82 #ifdef CONFIG_EXT3_FS_POSIX_ACL
83 struct posix_acl *i_acl;
84 struct posix_acl *i_default_acl;
87 struct list_head i_orphan; /* unlinked but open inodes */
90 * i_disksize keeps track of what the inode size is ON DISK, not
91 * in memory. During truncate, i_size is set to the new size by
92 * the VFS prior to calling ext3_truncate(), but the filesystem won't
93 * set i_disksize to 0 until the truncate is actually under way.
95 * The intent is that i_disksize always represents the blocks which
96 * are used by this file. This allows recovery to restart truncate
97 * on orphans if we crash during truncate. We actually write i_disksize
98 * into the on-disk inode when writing inodes out, instead of i_size.
100 * The only time when i_disksize and i_size may be different is when
101 * a truncate is in progress. The only things which change i_disksize
102 * are ext3_get_block (growth) and ext3_truncate (shrinkth).
107 * truncate_sem is for serialising ext3_truncate() against
108 * ext3_getblock(). In the 2.4 ext2 design, great chunks of inode's
109 * data tree are chopped off during truncate. We can't do that in
110 * ext3 because whenever we perform intermediate commits during
111 * truncate, the inode and all the metadata blocks *must* be in a
112 * consistent state which allows truncation of the orphans to restart
113 * during recovery. Hence we must fix the get_block-vs-truncate race
114 * by other means, so we have truncate_sem.
116 struct semaphore truncate_sem;
117 struct inode vfs_inode;
120 #endif /* _LINUX_EXT3_FS_I */