Linux 超级块

Linux 超级块的结构

 1 //come from /usr/src/kernel/'uname –r'/include/linux/fs.h 
 2 struct super_block { 
 3         struct list_head s_list; /* Keep this first */ 
 4         dev_t s_dev;                                 /* search index; _not_ kdev_t */ 
 5         unsigned long s_blocksize;                     //数据块大小 
 6         unsigned char s_blocksize_bits;             //块大小占用的位数 
 7         unsigned char s_dirt;                         //脏位，如果该位置位，说明超级块被修改 
 8         unsigned long long s_maxbytes;                //单个文件最大体积 
 9         struct file_system_type *s_type;             //文件系统结构 
10         struct super_operations *s_op;                 //超级块支持的操作
11         struct dquot_operations *dq_op;             //
12         struct quotactl_ops *s_qcop;                 //用户配额限制
13         struct export_operations *s_export_op;        //
14 
15         unsigned longs_flags; 
16         unsigned long s_magic;                         //区块的magic数
17         struct dentry *s_root;                         //根目录
18         struct rw_semaphore s_umount;                 //
19         struct mutex s_lock;                         //
20         int s_count;                                 //
21         int s_syncing;                                 //
22         int s_need_sync_fs;                         //
23         atomic_t s_active;                             //是否活动
24         void *s_security;                             //
25         struct xattr_handler **s_xattr;                //
26 
27         struct list_head s_inodes;                    //所有inode 
28         struct list_head s_dirty;                     //脏inode 
29         struct list_head s_io;                        //用于写回的缓存 
30         struct hlist_head s_anon;                     //nfs匿名入口 
31         struct list_head s_files;                    //文件链表头
32 
33         struct block_device *s_bdev; 
34         struct list_head s_instances; 
35         struct quota_info s_dquot;                     //配额定制选项
36 
37         int s_frozen;                     
38         wait_queue_head_t s_wait_unfrozen;
39 
40         char s_id[32];                                //名字
41 
42         void *s_fs_info; /* Filesystem private info */ 
43         /** The next field is for VFS *only*. No filesystems have any business 
44         * even looking at it. You had been warned. */ 
45         struct mutex s_vfs_rename_mutex; /* Kludge */ 
46         /* Granularity of c/m/atime in ns. Cannot be worse than a second */ 
47         u32 s_time_gran; 
48 };