1 struct super_block {
  2     struct list_head    s_list;        /* Keep this first 指向超级块链表的指针*/
  3     dev_t            s_dev;        /* search index; _not_ kdev_t 具体文件系统的块设备描述符*/
  4     unsigned char        s_blocksize_bits;
  5     unsigned long        s_blocksize; /*以字节为单位的数据块的大小*/
  6     loff_t            s_maxbytes;    /* Max file size */
  7     struct file_system_type    *s_type; /*文件系统类型*/
  8     const struct super_operations    *s_op; /*指向超级块操作的函数集合*/
  9     const struct dquot_operations    *dq_op;
 10     const struct quotactl_ops    *s_qcop;
 11     const struct export_operations *s_export_op;
 12     unsigned long        s_flags;
 13     unsigned long        s_iflags;    /* internal SB_I_* flags */
 14     unsigned long        s_magic;
 15     struct dentry        *s_root;
 16     struct rw_semaphore    s_umount;
 17     int            s_count;
 18     atomic_t        s_active;
 19 #ifdef CONFIG_SECURITY
 20     void                    *s_security;
 21 #endif
 22     const struct xattr_handler **s_xattr;
 23
 24     struct hlist_bl_head    s_anon;        /* anonymous dentries for (nfs) exporting */
 25     struct list_head    s_mounts;    /* list of mounts; _not_ for fs use */
 26     struct block_device    *s_bdev;
 27     struct backing_dev_info *s_bdi;
 28     struct mtd_info        *s_mtd;
 29     struct hlist_node    s_instances;
 30     unsigned int        s_quota_types;    /* Bitmask of supported quota types */
 31     struct quota_info    s_dquot;    /* Diskquota specific options */
 32
 33     struct sb_writers    s_writers;
 34
 35     char s_id[32];                /* Informational name */
 36     u8 s_uuid[16];                /* UUID */
 37
 38     void             *s_fs_info;    /* Filesystem private info 具体文件系统的私有数据*/
 39     unsigned int        s_max_links;
 40     fmode_t            s_mode;
 41
 42     /* Granularity of c/m/atime in ns.
 43        Cannot be worse than a second */
 44     u32           s_time_gran;
 45
 46     /*
 47      * The next field is for VFS *only*. No filesystems have any business
 48      * even looking at it. You had been warned.
 49      */
 50     struct mutex s_vfs_rename_mutex;    /* Kludge */
 51
 52     /*
 53      * Filesystem subtype.  If non-empty the filesystem type field
 54      * in /proc/mounts will be "type.subtype"
 55      */
 56     char *s_subtype;
 57
 58     /*
 59      * Saved mount options for lazy filesystems using
 60      * generic_show_options()
 61      */
 62     char __rcu *s_options;
 63     const struct dentry_operations *s_d_op; /* default d_op for dentries */
 64
 65     /*
 66      * Saved pool identifier for cleancache (-1 means none)
 67      */
 68     int cleancache_poolid;
 69
 70     struct shrinker s_shrink;    /* per-sb shrinker handle */
 71
 72     /* Number of inodes with nlink == 0 but still referenced */
 73     atomic_long_t s_remove_count;
 74
 75     /* Being remounted read-only */
 76     int s_readonly_remount;
 77
 78     /* AIO completions deferred from interrupt context */
 79     struct workqueue_struct *s_dio_done_wq;
 80     struct hlist_head s_pins;
 81
 82     /*
 83      * Keep the lru lists last in the structure so they always sit on their
 84      * own individual cachelines.
 85      */
 86     struct list_lru        s_dentry_lru ____cacheline_aligned_in_smp;
 87     struct list_lru        s_inode_lru ____cacheline_aligned_in_smp;
 88     struct rcu_head        rcu;
 89     struct work_struct    destroy_work;
 90
 91     struct mutex        s_sync_lock;    /* sync serialisation lock */
 92
 93     /*
 94      * Indicates how deep in a filesystem stack this SB is
 95      */
 96     int s_stack_depth;
 97
 98     /* s_inode_list_lock protects s_inodes */
 99     spinlock_t        s_inode_list_lock ____cacheline_aligned_in_smp;
100     struct list_head    s_inodes;    /* all inodes 所有的inodes*/
101 };

 1 struct inode {
 2     umode_t            i_mode;
 3     unsigned short        i_opflags;
 4     kuid_t            i_uid;
 5     kgid_t            i_gid;
 6     unsigned int        i_flags;
 7
 8 #ifdef CONFIG_FS_POSIX_ACL
 9     struct posix_acl    *i_acl;
10     struct posix_acl    *i_default_acl;
11 #endif
12
13     const struct inode_operations    *i_op;
14     struct super_block    *i_sb;
15     struct address_space    *i_mapping;
16
17 #ifdef CONFIG_SECURITY
18     void            *i_security;
19 #endif
20
21     /* Stat data, not accessed from path walking */
22     unsigned long        i_ino;
23     /*
24      * Filesystems may only read i_nlink directly.  They shall use the
25      * following functions for modification:
26      *
27      *    (set|clear|inc|drop)_nlink
28      *    inode_(inc|dec)_link_count
29      */
30     union {
31         const unsigned int i_nlink;
32         unsigned int __i_nlink;
33     };
34     dev_t            i_rdev;
35     loff_t            i_size;
36     struct timespec        i_atime;
37     struct timespec        i_mtime;
38     struct timespec        i_ctime;
39     spinlock_t        i_lock;    /* i_blocks, i_bytes, maybe i_size */
40     unsigned short          i_bytes;
41     unsigned int        i_blkbits;
42     blkcnt_t        i_blocks;
43
44 #ifdef __NEED_I_SIZE_ORDERED
45     seqcount_t        i_size_seqcount;
46 #endif
47
48     /* Misc */
49     unsigned long        i_state; /*索引节点的状态标志*/
50     struct mutex        i_mutex;
51
52     unsigned long        dirtied_when;    /* jiffies of first dirtying */
53     unsigned long        dirtied_time_when;
54
55     struct hlist_node    i_hash; /*指向哈希链表的指针*/
56     struct list_head    i_io_list;    /* backing dev IO list */
57 #ifdef CONFIG_CGROUP_WRITEBACK
58     struct bdi_writeback    *i_wb;        /* the associated cgroup wb */
59
60     /* foreign inode detection, see wbc_detach_inode() */
61     int            i_wb_frn_winner;
62     u16            i_wb_frn_avg_time;
63     u16            i_wb_frn_history;
64 #endif
65     struct list_head    i_lru;        /* inode LRU list 指向索引节点链表的指针*/
66     struct list_head    i_sb_list; /*指向超级块的指针*/
67     union {
68         struct hlist_head    i_dentry;
69         struct rcu_head        i_rcu;
70     };
71     u64            i_version;
72     atomic_t        i_count;
73     atomic_t        i_dio_count;
74     atomic_t        i_writecount;
75 #ifdef CONFIG_IMA
76     atomic_t        i_readcount; /* struct files open RO */
77 #endif
78     const struct file_operations    *i_fop;    /* former ->i_op->default_file_ops */
79     struct file_lock_context    *i_flctx;
80     struct address_space    i_data;
81     struct list_head    i_devices;
82     union {
83         struct pipe_inode_info    *i_pipe;
84         struct block_device    *i_bdev;
85         struct cdev        *i_cdev;
86         char            *i_link;
87     };
88
89     __u32            i_generation;
90
91 #ifdef CONFIG_FSNOTIFY
92     __u32            i_fsnotify_mask; /* all events this inode cares about */
93     struct hlist_head    i_fsnotify_marks;
94 #endif
95
96     void            *i_private; /* fs or device private pointer */
97 };

84    struct dentry {
85        /* RCU lookup touched fields */
86        unsigned int d_flags;        /* protected by d_lock */
87        seqcount_t d_seq;        /* per dentry seqlock */
88        struct hlist_bl_node d_hash;    /* lookup hash list */
89        struct dentry *d_parent;    /* parent directory */
90        struct qstr d_name;
91        struct inode *d_inode;        /* Where the name belongs to - NULL is
92                         * negative */
93        unsigned char d_iname[DNAME_INLINE_LEN];    /* small names */
94
95        /* Ref lookup also touches following */
96        struct lockref d_lockref;    /* per-dentry lock and refcount */
97        const struct dentry_operations *d_op;
98        struct super_block *d_sb;    /* The root of the dentry tree */
99        unsigned long d_time;        /* used by d_revalidate */
100        void *d_fsdata;            /* fs-specific data */
101
102        union {
103            struct list_head d_lru;        /* LRU list */
104            wait_queue_head_t *d_wait;    /* in-lookup ones only */
105        };
106        struct list_head d_child;    /* child of parent list */
107        struct list_head d_subdirs;    /* our children */
108        /*
109         * d_alias and d_rcu can share memory
110         */
111        union {
112            struct hlist_node d_alias;    /* inode alias list */
113            struct hlist_bl_node d_in_lookup_hash;    /* only for in-lookup ones */
114             struct rcu_head d_rcu;
115        } d_u;
116    };

struct file {
836        union {
837            struct llist_node    fu_llist;//文件对象链表
838            struct rcu_head     fu_rcuhead; //释放之后的RCU链表
839        } f_u;
840        struct path        f_path;
841        struct inode        *f_inode;    /* cached value */
842        const struct file_operations    *f_op;
843
844        /*
845         * Protects f_ep_links, f_flags.
846         * Must not be taken from IRQ context.
847         */
848        spinlock_t        f_lock;
849        atomic_long_t        f_count;   //文件对象的使用计数
850        unsigned int         f_flags;  //当打开文件时所使用的标志
851        fmode_t            f_mode;     //文件的访问模式
852        struct mutex        f_pos_lock;
853        loff_t            f_pos;       //文件当前的位移量
854        struct fown_struct    f_owner;  //拥有者通过信号量进行异步I/O传输
855        const struct cred    *f_cred;
856        struct file_ra_state    f_ra;
857
858        u64            f_version;
859    #ifdef CONFIG_SECURITY
860        void            *f_security;  //安全模块
861    #endif
862        /* needed for tty driver, and maybe others */
863        void            *private_data;  //tty 设备驱动的钩子
864
865    #ifdef CONFIG_EPOLL
866        /* Used by fs/eventpoll.c to link all the hooks to this file */
867        struct list_head    f_ep_links;  //事件池锁
868        struct list_head    f_tfile_llink;
869    #endif /* #ifdef CONFIG_EPOLL */
870        struct address_space    *f_mapping;  //页缓存映射
871    } __attribute__((aligned(4)));    /* lest something weird decides that 2 is OK */

8    struct fs_struct {
9        int users;
10        spinlock_t lock;
11        seqcount_t seq;
12        int umask;  //用于为新创建的文件设置初始文件许可权限
13        int in_exec;
14        struct path root, pwd;
15    };