$B?^(B? $BJ}K!#1(B
$B?^(B? $BJ}K!#2(B
$B?^(B? $BJ}K!#3(B
$B"!(Bstruct file_operations
$B%G%P%$%9%I%i%$%P$N2s(B
$B$G$bEP>l$7$F$$$k!#(B
struct file$B$NA`:n$O!"$?$H$($P
struct file *file;
file->f_op->read(file, buf, count, pos);
f_op $B$K$O!"
linux-5.10.3/include/linux/fs.h
1822: struct file_operations {
1823: struct module *owner;
1824: loff_t (*llseek) (struct file *, loff_t, int);
1825: ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
1826: ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1827: ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
1828: ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
1829: int (*iopoll)(struct kiocb *kiocb, bool spin);
1830: int (*iterate) (struct file *, struct dir_context *);
1831: int (*iterate_shared) (struct file *, struct dir_context *);
1832: __poll_t (*poll) (struct file *, struct poll_table_struct *);
1833: long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
1834: long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
1835: int (*mmap) (struct file *, struct vm_area_struct *);
1836: unsigned long mmap_supported_flags;
1837: int (*open) (struct inode *, struct file *);
1838: int (*flush) (struct file *, fl_owner_t id);
1839: int (*release) (struct inode *, struct file *);
1840: int (*fsync) (struct file *, loff_t, loff_t, int datasync);
1841: int (*fasync) (int, struct file *, int);
1842: int (*lock) (struct file *, int, struct file_lock *);
1843: ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
1844: unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1845: int (*check_flags)(int);
1846: int (*flock) (struct file *, int, struct file_lock *);
1847: ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
1848: ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1849: int (*setlease)(struct file *, long, struct file_lock **, void **);
1850: long (*fallocate)(struct file *file, int mode, loff_t offset,
1851: loff_t len);
1852: void (*show_fdinfo)(struct seq_file *m, struct file *f);
1853: #ifndef CONFIG_MMU
1854: unsigned (*mmap_capabilities)(struct file *);
1855: #endif
1856: ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
1857: loff_t, size_t, unsigned int);
1858: loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
1859: struct file *file_out, loff_t pos_out,
1860: loff_t len, unsigned int remap_flags);
1861: int (*fadvise)(struct file *, loff_t, loff_t, int);
1862: } __randomize_layout;
$B
$BB?$/$OF1L>$N%7%9%F%`!&%3!<%k$r
$B"!(Bstruct dentry
struct dentry $B$O!"%G%#%l%/%H%j$K4^$^$l$F$$$kL>A0$NMWAG(B($B!V(B/$B!W$r4^$^$J$$(B
$BL>A0(B)$B$rI=$99=B$BN!#(B
struct dentry $B$O!"%a%b%jCf$K$N$_B8:_$9$k!#%G%#%9%/Cf$KBP1~$9$k%G!<%?$O(B
$B$J$$!#%G%#%l%/%H%j$GL>A0$r8!:w$7$?$j%U%!%$%k$r:n@.$9$k;~$K%a%b%jCf$K:n(B
$B$i$l$k!#(B
linux-5.10.3/include/linux/dcache.h
89: struct dentry {
...
94: struct dentry *d_parent; /* parent directory */
95: struct qstr d_name;
96: struct inode *d_inode; /* Where the name belongs to - NULL is
97: * negative */
98: unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
99:
100: /* Ref lookup also touches following */
101: struct lockref d_lockref; /* per-dentry lock and refcount */
102: const struct dentry_operations *d_op;
103: struct super_block *d_sb; /* The root of the dentry tree */
...
105: void *d_fsdata; /* fs-specific data */
...
111: struct list_head d_child; /* child of parent list */
112: struct list_head d_subdirs; /* our children */
...
121: } __randomize_layout;
286: static inline unsigned d_count(const struct dentry *dentry)
287: {
288: return dentry->d_lockref.count;
289: }
33: #define HASH_LEN_DECLARE u32 hash; u32 len
47: struct qstr {
48: union {
49: struct {
50: HASH_LEN_DECLARE;
51: };
52: u64 hash_len;
53: };
54: const unsigned char *name;
55: };
83: # define DNAME_INLINE_LEN 40 /* 128 bytes */
- d_inode: $B$3$N(B dentry $B$KBP1~$7$F$$$k(B inode $B!#(BNULL $B$J$iBP1~$7$F$$$k(B
$B$b$N$,$J$$(B($B%M%,%F%#%V%-%c%C%7%e(B)$B!#(B
- d_name, d_iname[]: $BJ8;zNs$NL>A0$rJ];}$9$k!#(B
$BC;$$$b$N(B(DNAME_INLINE_LEN-1$B0J2<(B)$B$O!"(Bdentry $B9=B$BNCf$N(B d_iname[] $B$KF~$l$k!#D9$$$b$N$O!"(B
$BJL$N>l=j$K%a%b%j$r3NJ]$7$FJ]B8$9$k!#(B
- d_lockref.count: $B;2>H%+%&%s%?!#(B
- d_op: dentry $B$rA`:n$9$k$?$a$N d_sb: superblock $B$X$N%]%$%s%?(B
- d_parent: $B$=$N(B dentry $B$r4^$s$G$$$k%G%#%l%/%H%j$N(B dentry $B!#$?$H$($P!"(B
/home/yas $B$H$$$&%Q%9L>$G!"(Byas $B$N(B d_parent $B$O!"(Bhome $B$N(B dentry $B$r;X$9!#(B
home $B$N(B dentry $B$O!"(B/ $B$N(B dentry $B$r;X$9!#(B
- d_child: $B6&DL$N(B d_parent $B$K4^$^$l$F$$$k(B d_entry $B$r$D$J$0!#(B
- d_subdirs: $B<+J,<+?H$N;R6!$N%G%#%l%/%H%j(B
- d_fsdata: $B%U%!%$%k%7%9%F%`8GM-$N%G!<%?!#(B
dentry $B$O!"(B
$B%9%i%V%"%m%1!<%?(B
(kmem_cache_create(),kmem_cache_alloc(),kmem_cache_free())$B$G4IM}$5$l$F(B
$B$$$k!#(B
$B"!(Bdentry$B$N>uBV(B
- $B;HMQCf(B: count $B$,(B 0 $B0J>e!#M-8z$J(Binode$B$rJ];}!#(B
- $B6u$-(B: count $B$,(B 0$B!#M-8z$J(Binode$B$rJ];}!#%-%c%C%7%e$H$7$F%a%b%jCf$KB8:_$9$k!#(B
$BF1$8%U%!%$%k$r:F$S(B open() $B$7$?;~$K9bB.!#(B
$B%a%b%j$,ITB-$7$F$-$?$i>C$5$l$k$3$H$,$"$k(B>
- $B%M%,%F%#%V!&%-%c%C%7%e(B: count $B$,Ii!#M-8z$J(B inode $B$rJ];}$7$F$$$J$$!#(B
$B%U%!%$%k$,:o=|$5$l$?$+!"B8:_$7$J$$%U%!%$%k$r(B open() $B$7$h$&$H$7$?;~$K$=(B
$B$N$h$&$J(B dentry $B$,:n$i$l$k!#(B
$BB8:_$7$J$$%U%!%$%k$r7+$jJV$7(B open() $B$7$?;~$K%G%#%9%/$K9T$+$J$/$F$b%(%i!<(B
ENOENT $B$,JV$;$k(B($B%M%,%F%#%V!&%-%c%C%7%e(B)$B!#(B
$B"!(Bstruct inode
struct inode $B$O!"A4$F$N%U%!%$%k!&%7%9%F%`$G6&DL$NMWAG$rJ];}$9$k!"%a%b%j(B
$BCf$N9=B$BN!#3F%U%!%$%k!&%7%9%F%`$O!"$3$l$K4^$^$l$k$h$&$J%G!<%?$r$=$l$>(B
$B$lFH<+$NJ}K!$G%G%#%9%/$KJ]B8$9$k!#(B
linux-5.10.3/include/linux/fs.h
610: struct inode {
611: umode_t i_mode;
612: unsigned short i_opflags;
613: kuid_t i_uid;
614: kgid_t i_gid;
...
622: const struct inode_operations *i_op;
623: struct super_block *i_sb;
...
631: unsigned long i_ino;
...
640: const unsigned int i_nlink;
...
643: dev_t i_rdev;
644: loff_t i_size;
645: struct timespec64 i_atime;
646: struct timespec64 i_mtime;
647: struct timespec64 i_ctime;
648: spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
649: unsigned short i_bytes;
650: u8 i_blkbits;
651: u8 i_write_hint;
652: blkcnt_t i_blocks;
...
665: struct hlist_node i_hash;
...
679: struct hlist_head i_dentry;
...
684: atomic_t i_count;
...
720: void *i_private; /* fs or device private pointer */
721: } __randomize_layout;
- i_ino: inode$BHV9f!#%U%!%$%k%7%9%F%`$G%f%K!<%/!#(B
- i_uid, i_gid, i_nlink, i_uid, i_gid, i_rdev, i_blkbits, i_size, i_atime,
i_mtime, i_ctime, i_blocks, i_bytes, i_mode: $BB0@-!#(Bstat() $B%7%9%F%`!&%3!<(B
$B%k$GJV$5$l$k!#(Bls -l $B$GI=<($5$l$k!#(B
- i_op: $B$=$N(Binode$B$K8GM-$N i_sb: $BB0$7$F$$$k%U%!%$%k%7%9%F%`$N(B superblock $B$X$N%]%$%s%?!#(B
- i_state: inode$B$N>uBV(B(dirty $B$+$I$&$+!"%G%#%9%/$X$N(B
$B=q$-9~$_$r9T$C$F$$$k$+$I$&$+!"Ey(B)$B$rI=$9!#(B
- i_hash: $B%U%!%$%k$r3+$/$3$H$N9bB.$N$?$a$N%O%C%7%eI=$r:n$k$?$a$N%U%#!<(B
$B%k%I!#!!(B
- i_dentry: $B$=$N(Binode$B$r4^$s$G$$$k(B dentry $B9=B$BN$N%j%9%H!#(B
- i_count: $B;2>H%+%&%s%?!#(B0 $B$,L$;HMQ$N0UL#!#(B
$B"!(Bstruct inode_operations
inode$B$NA`:n$O!"$?$H$($P
struct inode *inode;
...
inode->i_op->create(inode, name, mode, true);
i_op $B$K$O!"
linux-5.10.3/include/linux/fs.h
1864: struct inode_operations {
1865: struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
1866: const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
1867: int (*permission) (struct inode *, int);
1868: struct posix_acl * (*get_acl)(struct inode *, int);
1869:
1870: int (*readlink) (struct dentry *, char __user *,int);
1871:
1872: int (*create) (struct inode *,struct dentry *, umode_t, bool);
1873: int (*link) (struct dentry *,struct inode *,struct dentry *);
1874: int (*unlink) (struct inode *,struct dentry *);
1875: int (*symlink) (struct inode *,struct dentry *,const char *);
1876: int (*mkdir) (struct inode *,struct dentry *,umode_t);
1877: int (*rmdir) (struct inode *,struct dentry *);
1878: int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
1879: int (*rename) (struct inode *, struct dentry *,
1880: struct inode *, struct dentry *, unsigned int);
1881: int (*setattr) (struct dentry *, struct iattr *);
1882: int (*getattr) (const struct path *, struct kstat *, u32, unsigned int);
1883: ssize_t (*listxattr) (struct dentry *, char *, size_t);
1884: int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
1885: u64 len);
1886: int (*update_time)(struct inode *, struct timespec64 *, int);
1887: int (*atomic_open)(struct inode *, struct dentry *,
1888: struct file *, unsigned open_flag,
1889: umode_t create_mode);
1890: int (*tmpfile) (struct inode *, struct dentry *, umode_t);
1891: int (*set_acl)(struct inode *, struct posix_acl *, int);
1892: } ____cacheline_aligned;
- $BB?$/$N$b$N$O!"F1L>$N%7%9%F%`!&%3!<%k$H4XO"$7$F$$$k!#(B
- create(): open() $B%7%9%F%`!&%3!<%k$d(B creat() $B%7%9%F%`!&%3!<%k$G!"%U%!(B
$B%$%k$r:n@.$9$k;~$K8F$P$l$k!#0z?t$O!"%G%#%l%/%H%j$N(B inode$B!"$=$N%G%#%l%/(B
$B%H%j$NCf$NL>A0$r<($9(B dentry$B!"L>A02r7h$G;H$&%G!<%?!#(B
- lookup(): $B%U%!%$%kL>$r0z?t$K$9$k%7%9%F%`!&%3!<%k$N follow_link(), put_link(): $B%7%s%\%j%C%/!&%j%s%/$r$?$I$kA`:n$GMQ$$$k!#(B
- permission(), check_acl(): $B%"%/%;%98"$N%A%'%C%/$GMQ$$$k!#(B
- kstat, iattr $B$OB0@-!#(B
$B"!(Bstruct super_block
$B%9!<%Q!<%V%m%C%/$O!"%U%!%$%k%7%9%F%`$N5/E@$H$J$k%G!<%?9=B$!#$=$N%U%!%$(B
$B%k!&%7%9%F%`$K4^$^$l$F$$$k(B inode $B$d(B dentry $B$r4IM}$9$k!#(B
linux-5.10.3/include/linux/fs.h
1416: struct super_block {
...
1421: loff_t s_maxbytes; /* Max file size */
1422: struct file_system_type *s_type;
1423: const struct super_operations *s_op;
...
1430: struct dentry *s_root;
...
1465: void *s_fs_info; /* Filesystem private info */
...
1532: struct list_lru s_dentry_lru;
1533: struct list_lru s_inode_lru;
...
1546: struct list_head s_inodes; /* all inodes */
...
1550: } __randomize_layout;
- s_maxbytes: $B:n@.$G$-$k%U%!%$%k$NBg$-$5$N:GBg!#(B
- s_type: $B%U%!%$%k%7%9%F%`8GM-$N%G!<%?!#%/%i%9JQ?t!#(B
- s_op: $B%U%!%$%k%7%9%F%`8GM-$N s_fs_info: $B%U%!%$%k%7%9%F%`$N%$%s%9%?%s%9!J%^%&%s%H$4$H$K0[$J$k!K(B
$B$K8GM-$N%G!<%?!#%$%s%9%?%s%9JQ?t!#(B
- s_root: $B$I$3$K%^%&%s%H$7$F$$$k$+$r$7$a$9%G%#%l%/%H%j(B
- s_inodes, s_dentry_lru, s_inode_lru: $B%U%!%$%k%7%9%F%`$K4^$^$l$F$$(B
$B$k(Binode $B$d(B dentry $B$r4IM}$9$k$?$a$N%U%#!<%k%I!#(B
$B"!(Btask_struct $B$H(B struct file
struct task_struct $B$+$i;X$5$l$k!#%U%!%$%k5-=R;R(Bfd$B$O!"(Bstruct
task_struct *p; $B$N;~!"(Bp->files->fdt->fd[fd] $B$N(B struct file $B$rI=(B
$B$9!#3+$$$F$$$k%U%!%$%k$N?t$,>.$5$$;~$O!"(B
p->files->fd_array[fd]$B$HF1$8!#(B
$BB?$/$N%U%!%$%k$r3+$/%W%m%;%9$G$O!"(B
p->files->fd_array[NR_OPEN_DEFAULT]$B$GB-$j$J$/$J$C$?;~$O!"(B
expand_files(), expand_fdtable() $B$G3HD%$9$k!#(B
$B$3$l$i$N4X?t$G$O!"(Bkmalloc() $BEy$G%a%b%j$r3d$jEv$F$k!#(B
linux-5.10.3/include/linux/sched.h
640: struct task_struct {
...
959: struct files_struct *files;
...
1366: };
linux-5.10.3/include/linux/fdtable.h
24: #define NR_OPEN_DEFAULT BITS_PER_LONG
49: struct files_struct {
...
57: struct fdtable __rcu *fdt;
58: struct fdtable fdtab;
...
67: struct file __rcu * fd_array[NR_OPEN_DEFAULT];
68: };
linux-5.10.3/include/asm-generic/bitsperlong.h
8: #ifdef CONFIG_64BIT
9: #define BITS_PER_LONG 64
10: #else
11: #define BITS_PER_LONG 32
12: #endif /* CONFIG_64BIT */
files->fd_array[fd]">
$B?^(B? task_struct$B!"%U%!%$%k5-=R;R!"(Bfile$B9=B$BN!"$=$NB>(B
$B"#(Bread() $B%7%9%F%`%3!<%k$H(B Ext4 $B%U%!%$%k%7%9%F%`(B
read() $B%7%9%F%`!&%3!<%k$N$B"!(Bread() $B%7%9%F%`!&%3!<%k(B