5.3.2.1.4. Super Block Structure
struct super_block {
struct list_head s_list; /* Keep this first */
dev_t s_dev; /* search index; _not_ kdev_t */
unsigned long s_blocksize;
unsigned long s_old_blocksize;
unsigned char s_blocksize_bits;
unsigned char s_dirt;
unsigned long long s_maxbytes; /* Max file size */
struct file_system_type *s_type;
struct super_operations *s_op;
struct dquot_operations *dq_op;
struct quotactl_ops *s_qcop;
struct export_operations *s_export_op;
unsigned long s_flags;
unsigned long s_magic;
struct dentry *s_root;
struct rw_semaphore s_umount;
struct semaphore s_lock;
int s_count;
int s_syncing;
int s_need_sync_fs;
atomic_t s_active;
void *s_security;
struct xattr_handler **s_xattr;
struct list_head s_inodes; /* all inodes */
struct list_head s_dirty; /* dirty inodes */
struct list_head s_io; /* parked for writeback */
struct hlist_head s_anon; /* anonymous dentries for (nfs) exporting */
struct list_head s_files;
struct block_device *s_bdev;
struct list_head s_instances;
struct quota_info s_dquot; /* Diskquota specific options */
int s_frozen;
wait_queue_head_t s_wait_unfrozen;
char s_id[32]; /* Informational name */
void *s_fs_info; /* Filesystem private info */
/*
* The next field is for VFS *only*. No filesystems have any business
* even looking at it. You had been warned.
*/
struct semaphore s_vfs_rename_sem; /* Kludge */
/* Granuality of c/m/atime in ns.
Cannot be worse than a second */
u32 s_time_gran;
};