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
;
32 static inline bool close_on_exec(int fd
, const struct fdtable
*fdt
)
34 return test_bit(fd
, fdt
->close_on_exec
);
37 static inline bool fd_is_open(int fd
, const struct fdtable
*fdt
)
39 return test_bit(fd
, fdt
->open_fds
);
43 * Open file table structure
50 struct fdtable __rcu
*fdt
;
53 * written part on a separate cache line in SMP
55 spinlock_t file_lock ____cacheline_aligned_in_smp
;
57 unsigned long close_on_exec_init
[1];
58 unsigned long open_fds_init
[1];
59 struct file __rcu
* fd_array
[NR_OPEN_DEFAULT
];
62 struct file_operations
;
66 #define rcu_dereference_check_fdtable(files, fdtfd) \
67 rcu_dereference_check((fdtfd), lockdep_is_held(&(files)->file_lock))
69 #define files_fdtable(files) \
70 rcu_dereference_check_fdtable((files), (files)->fdt)
73 * The caller must ensure that fd table isn't shared or hold rcu or file lock
75 static inline struct file
*__fcheck_files(struct files_struct
*files
, unsigned int fd
)
77 struct fdtable
*fdt
= rcu_dereference_raw(files
->fdt
);
79 if (fd
< fdt
->max_fds
)
80 return rcu_dereference_raw(fdt
->fd
[fd
]);
84 static inline struct file
*fcheck_files(struct files_struct
*files
, unsigned int fd
)
86 rcu_lockdep_assert(rcu_read_lock_held() ||
87 lockdep_is_held(&files
->file_lock
),
88 "suspicious rcu_dereference_check() usage");
89 return __fcheck_files(files
, fd
);
93 * Check whether the specified fd has an open file.
95 #define fcheck(fd) fcheck_files(current->files, fd)
99 struct files_struct
*get_files_struct(struct task_struct
*);
100 void put_files_struct(struct files_struct
*fs
);
101 void reset_files_struct(struct files_struct
*);
102 int unshare_files(struct files_struct
**);
103 struct files_struct
*dup_fd(struct files_struct
*, int *);
104 void do_close_on_exec(struct files_struct
*);
105 int iterate_fd(struct files_struct
*, unsigned,
106 int (*)(const void *, struct file
*, unsigned),
109 extern int __alloc_fd(struct files_struct
*files
,
110 unsigned start
, unsigned end
, unsigned flags
);
111 extern void __fd_install(struct files_struct
*files
,
112 unsigned int fd
, struct file
*file
);
113 extern int __close_fd(struct files_struct
*files
,
116 extern struct kmem_cache
*files_cachep
;
118 #endif /* __LINUX_FDTABLE_H */