2 * descriptor table internals; you almost certainly want file.h instead.
5 #ifndef __LINUX_FDTABLE_H
6 #define __LINUX_FDTABLE_H
8 #include <linux/posix_types.h>
9 #include <linux/compiler.h>
10 #include <linux/spinlock.h>
11 #include <linux/rcupdate.h>
12 #include <linux/types.h>
13 #include <linux/init.h>
16 #include <linux/atomic.h>
19 * The default fd array needs to be at least BITS_PER_LONG,
20 * as this is the granularity returned by copy_fdset().
22 #define NR_OPEN_DEFAULT BITS_PER_LONG
26 struct file __rcu
**fd
; /* current fd array */
27 unsigned long *close_on_exec
;
28 unsigned long *open_fds
;
33 static inline void __set_close_on_exec(int fd
, struct fdtable
*fdt
)
35 __set_bit(fd
, fdt
->close_on_exec
);
38 static inline void __clear_close_on_exec(int fd
, struct fdtable
*fdt
)
40 __clear_bit(fd
, fdt
->close_on_exec
);
43 static inline bool close_on_exec(int fd
, const struct fdtable
*fdt
)
45 return test_bit(fd
, fdt
->close_on_exec
);
48 static inline void __set_open_fd(int fd
, struct fdtable
*fdt
)
50 __set_bit(fd
, fdt
->open_fds
);
53 static inline void __clear_open_fd(int fd
, struct fdtable
*fdt
)
55 __clear_bit(fd
, fdt
->open_fds
);
58 static inline bool fd_is_open(int fd
, const struct fdtable
*fdt
)
60 return test_bit(fd
, fdt
->open_fds
);
64 * Open file table structure
71 struct fdtable __rcu
*fdt
;
74 * written part on a separate cache line in SMP
76 spinlock_t file_lock ____cacheline_aligned_in_smp
;
78 unsigned long close_on_exec_init
[1];
79 unsigned long open_fds_init
[1];
80 struct file __rcu
* fd_array
[NR_OPEN_DEFAULT
];
83 #define rcu_dereference_check_fdtable(files, fdtfd) \
84 (rcu_dereference_check((fdtfd), \
85 lockdep_is_held(&(files)->file_lock) || \
86 atomic_read(&(files)->count) == 1 || \
87 rcu_my_thread_group_empty()))
89 #define files_fdtable(files) \
90 (rcu_dereference_check_fdtable((files), (files)->fdt))
92 struct file_operations
;
96 extern int expand_files(struct files_struct
*, int nr
);
97 extern void free_fdtable_rcu(struct rcu_head
*rcu
);
98 extern void __init
files_defer_init(void);
100 static inline void free_fdtable(struct fdtable
*fdt
)
102 call_rcu(&fdt
->rcu
, free_fdtable_rcu
);
105 static inline struct file
* fcheck_files(struct files_struct
*files
, unsigned int fd
)
107 struct file
* file
= NULL
;
108 struct fdtable
*fdt
= files_fdtable(files
);
110 if (fd
< fdt
->max_fds
)
111 file
= rcu_dereference_check_fdtable(files
, fdt
->fd
[fd
]);
116 * Check whether the specified fd has an open file.
118 #define fcheck(fd) fcheck_files(current->files, fd)
122 struct files_struct
*get_files_struct(struct task_struct
*);
123 void put_files_struct(struct files_struct
*fs
);
124 void reset_files_struct(struct files_struct
*);
125 int unshare_files(struct files_struct
**);
126 struct files_struct
*dup_fd(struct files_struct
*, int *);
128 extern struct kmem_cache
*files_cachep
;
130 #endif /* __LINUX_FDTABLE_H */