1 /*
2  *  linux/include/linux/ext2_fs_sb.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_sb.h
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  */
15 
16 #ifndef _LINUX_EXT2_FS_SB
17 #define _LINUX_EXT2_FS_SB
18 
19 #include <linux/blockgroup_lock.h>
20 #include <linux/percpu_counter.h>
21 #include <linux/rbtree.h>
22 
23 /* XXX Here for now... not interested in restructing headers JUST now */
24 
25 /* data type for block offset of block group */
26 typedef int ext2_grpblk_t;
27 
28 /* data type for filesystem-wide blocks number */
29 typedef unsigned long ext2_fsblk_t;
30 
31 #define E2FSBLK "%lu"
32 
33 struct ext2_reserve_window {
34 	ext2_fsblk_t		_rsv_start;	/* First byte reserved */
35 	ext2_fsblk_t		_rsv_end;	/* Last byte reserved or 0 */
36 };
37 
38 struct ext2_reserve_window_node {
39 	struct rb_node	 	rsv_node;
40 	__u32			rsv_goal_size;
41 	__u32			rsv_alloc_hit;
42 	struct ext2_reserve_window	rsv_window;
43 };
44 
45 struct ext2_block_alloc_info {
46 	/* information about reservation window */
47 	struct ext2_reserve_window_node	rsv_window_node;
48 	/*
49 	 * was i_next_alloc_block in ext2_inode_info
50 	 * is the logical (file-relative) number of the
51 	 * most-recently-allocated block in this file.
52 	 * We use this for detecting linearly ascending allocation requests.
53 	 */
54 	__u32			last_alloc_logical_block;
55 	/*
56 	 * Was i_next_alloc_goal in ext2_inode_info
57 	 * is the *physical* companion to i_next_alloc_block.
58 	 * it the the physical block number of the block which was most-recentl
59 	 * allocated to this file.  This give us the goal (target) for the next
60 	 * allocation when we detect linearly ascending requests.
61 	 */
62 	ext2_fsblk_t		last_alloc_physical_block;
63 };
64 
65 #define rsv_start rsv_window._rsv_start
66 #define rsv_end rsv_window._rsv_end
67 
68 /*
69  * second extended-fs super-block data in memory
70  */
71 struct ext2_sb_info {
72 	unsigned long s_frag_size;	/* Size of a fragment in bytes */
73 	unsigned long s_frags_per_block;/* Number of fragments per block */
74 	unsigned long s_inodes_per_block;/* Number of inodes per block */
75 	unsigned long s_frags_per_group;/* Number of fragments in a group */
76 	unsigned long s_blocks_per_group;/* Number of blocks in a group */
77 	unsigned long s_inodes_per_group;/* Number of inodes in a group */
78 	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
79 	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
80 	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
81 	unsigned long s_groups_count;	/* Number of groups in the fs */
82 	unsigned long s_overhead_last;  /* Last calculated overhead */
83 	unsigned long s_blocks_last;    /* Last seen block count */
84 	struct buffer_head * s_sbh;	/* Buffer containing the super block */
85 	struct ext2_super_block * s_es;	/* Pointer to the super block in the buffer */
86 	struct buffer_head ** s_group_desc;
87 	unsigned long  s_mount_opt;
88 	unsigned long s_sb_block;
89 	uid_t s_resuid;
90 	gid_t s_resgid;
91 	unsigned short s_mount_state;
92 	unsigned short s_pad;
93 	int s_addr_per_block_bits;
94 	int s_desc_per_block_bits;
95 	int s_inode_size;
96 	int s_first_ino;
97 	spinlock_t s_next_gen_lock;
98 	u32 s_next_generation;
99 	unsigned long s_dir_count;
100 	u8 *s_debts;
101 	struct percpu_counter s_freeblocks_counter;
102 	struct percpu_counter s_freeinodes_counter;
103 	struct percpu_counter s_dirs_counter;
104 	struct blockgroup_lock *s_blockgroup_lock;
105 	/* root of the per fs reservation window tree */
106 	spinlock_t s_rsv_window_lock;
107 	struct rb_root s_rsv_window_root;
108 	struct ext2_reserve_window_node s_rsv_window_head;
109 	/*
110 	 * s_lock protects against concurrent modifications of s_mount_state,
111 	 * s_blocks_last, s_overhead_last and the content of superblock's
112 	 * buffer pointed to by sbi->s_es.
113 	 *
114 	 * Note: It is used in ext2_show_options() to provide a consistent view
115 	 * of the mount options.
116 	 */
117 	spinlock_t s_lock;
118 };
119 
120 static inline spinlock_t *
sb_bgl_lock(struct ext2_sb_info * sbi,unsigned int block_group)121 sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
122 {
123 	return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
124 }
125 
126 #endif	/* _LINUX_EXT2_FS_SB */
127