LDD和各种结构体的故事

struct scull_dev     位置：scull/scull.h

struct scull_dev {
	struct scull_qset *data;  /* Pointer to first quantum set */
	int quantum;              /* the current quantum size */
	int qset;                 /* the current array size */
	unsigned long size;       /* amount of data stored here */
	unsigned int access_key;  /* used by sculluid and scullpriv */
	struct mutex mutex;     /* mutual exclusion semaphore     */
	struct cdev cdev;	  /* Char device structure		*/
};

struct mutex       位置：/usr/src/linux-source/include/linux/

struct mutex {
        /* 1: unlocked, 0: locked, negative: locked, possible waiters */
        atomic_t                count;
        spinlock_t              wait_lock;
        struct list_head        wait_list;
#if defined(CONFIG_DEBUG_MUTEXES) || defined(CONFIG_SMP)
        struct task_struct      *owner;
#endif
#ifdef CONFIG_DEBUG_MUTEXES
        const char              *name;
        void                    *magic;
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
        struct lockdep_map      dep_map;
#endif
};

这个有点点长哇。。。

struct inode    位置：/usr/src/linux-source/include/linux/fs.h

/*
 * Keep mostly read-only and often accessed (especially for
 * the RCU path lookup and 'stat' data) fields at the beginning
 * of the 'struct inode'
 */
struct inode {
        umode_t                 i_mode;
        unsigned short          i_opflags;
        kuid_t                  i_uid;
        kgid_t                  i_gid;
        unsigned int            i_flags;

#ifdef CONFIG_FS_POSIX_ACL
        struct posix_acl        *i_acl;
        struct posix_acl        *i_default_acl;
#endif

        const struct inode_operations   *i_op;
        struct super_block      *i_sb;
        struct address_space    *i_mapping;

#ifdef CONFIG_SECURITY
        void                    *i_security;
#endif

        /* Stat data, not accessed from path walking */
        unsigned long           i_ino;
        /*
         * Filesystems may only read i_nlink directly.  They shall use the
         * following functions for modification:
         *
         *    (set|clear|inc|drop)_nlink
         *    inode_(inc|dec)_link_count
         */
        union {
                const unsigned int i_nlink;
                unsigned int __i_nlink;
        };
        dev_t                   i_rdev;
        loff_t                  i_size;
        struct timespec         i_atime;
        struct timespec         i_mtime;
        struct timespec         i_ctime;
        spinlock_t              i_lock; /* i_blocks, i_bytes, maybe i_size */
        unsigned short          i_bytes;
        unsigned int            i_blkbits;
        blkcnt_t                i_blocks;

#ifdef __NEED_I_SIZE_ORDERED
        seqcount_t              i_size_seqcount;
#endif

        /* Misc */

        unsigned long           i_state;
        struct mutex            i_mutex;

        unsigned long           dirtied_when;   /* jiffies of first dirtying */

        struct hlist_node       i_hash;
        struct list_head        i_wb_list;      /* backing dev IO list */
        struct list_head        i_lru;          /* inode LRU list */
        struct list_head        i_sb_list;
        union {
                struct hlist_head       i_dentry;
                struct rcu_head         i_rcu;
        };
        u64                     i_version;
        atomic_t                i_count;
        atomic_t                i_dio_count;
        atomic_t                i_writecount;
        const struct file_operations    *i_fop; /* former ->i_op->default_file_ops */
        struct file_lock        *i_flock;
        struct address_space    i_data;
#ifdef CONFIG_QUOTA
        struct dquot            *i_dquot[MAXQUOTAS];
#endif
        struct list_head        i_devices;
        union {
                struct pipe_inode_info  *i_pipe;
                struct block_device     *i_bdev;
                struct cdev             *i_cdev;
        };
        __u32                   i_generation;

#ifdef CONFIG_FSNOTIFY
        __u32                   i_fsnotify_mask; /* all events this inode cares about */
        struct hlist_head       i_fsnotify_marks;
#endif

#ifdef CONFIG_IMA
        atomic_t                i_readcount; /* struct files open RO */
#endif
        void                    *i_private; /* fs or device private pointer */
};

struct file      位置：/usr/src/linux-source/include/linux/fs.h

struct file {
        /*
         * fu_list becomes invalid after file_free is called and queued via
         * fu_rcuhead for RCU freeing
         */
        union {
                struct list_head        fu_list;
                struct rcu_head         fu_rcuhead;
        } f_u;
        struct path             f_path;
#define f_dentry        f_path.dentry
#define f_vfsmnt        f_path.mnt
        const struct file_operations    *f_op;

        /*
         * Protects f_ep_links, f_flags, f_pos vs i_size in lseek SEEK_CUR.
         * Must not be taken from IRQ context.
         */
        spinlock_t              f_lock;
#ifdef CONFIG_SMP
        int                     f_sb_list_cpu;
#endif
        atomic_long_t           f_count;
        unsigned int            f_flags;
        fmode_t                 f_mode;
        loff_t                  f_pos;
        struct fown_struct      f_owner;
        const struct cred       *f_cred;
        struct file_ra_state    f_ra;

        u64                     f_version;
#ifdef CONFIG_SECURITY
        void                    *f_security;
#endif
        /* needed for tty driver, and maybe others */
        void                    *private_data;

#ifdef CONFIG_EPOLL
        /* Used by fs/eventpoll.c to link all the hooks to this file */
        struct list_head        f_ep_links;
        struct list_head        f_tfile_llink;
#endif /* #ifdef CONFIG_EPOLL */
        struct address_space    *f_mapping;
#ifdef CONFIG_DEBUG_WRITECOUNT
        unsigned long f_mnt_write_state;
#endif
};

struct cdev      位置：/usr/src/linux-source/include/linux/cdev.h

struct cdev {
        struct kobject kobj;
        struct module *owner;
        const struct file_operations *ops;
        struct list_head list;
        dev_t dev;
        unsigned int count;
};

struct scull_qset                             位置：scull/scull.h

struct scull_qset {
	void **data;
	struct scull_qset *next;
};