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 bool resize_in_progress
;
51 wait_queue_head_t resize_wait
;
53 struct fdtable __rcu
*fdt
;
56 * written part on a separate cache line in SMP
58 spinlock_t file_lock ____cacheline_aligned_in_smp
;
60 unsigned long close_on_exec_init
[1];
61 unsigned long open_fds_init
[1];
62 struct file __rcu
* fd_array
[NR_OPEN_DEFAULT
];
65 struct file_operations
;
69 #define rcu_dereference_check_fdtable(files, fdtfd) \
70 rcu_dereference_check((fdtfd), lockdep_is_held(&(files)->file_lock))
72 #define files_fdtable(files) \
73 rcu_dereference_check_fdtable((files), (files)->fdt)
76 * The caller must ensure that fd table isn't shared or hold rcu or file lock
78 static inline struct file
*__fcheck_files(struct files_struct
*files
, unsigned int fd
)
80 struct fdtable
*fdt
= rcu_dereference_raw(files
->fdt
);
82 if (fd
< fdt
->max_fds
)
83 return rcu_dereference_raw(fdt
->fd
[fd
]);
87 static inline struct file
*fcheck_files(struct files_struct
*files
, unsigned int fd
)
89 rcu_lockdep_assert(rcu_read_lock_held() ||
90 lockdep_is_held(&files
->file_lock
),
91 "suspicious rcu_dereference_check() usage");
92 return __fcheck_files(files
, fd
);
96 * Check whether the specified fd has an open file.
98 #define fcheck(fd) fcheck_files(current->files, fd)
102 struct files_struct
*get_files_struct(struct task_struct
*);
103 void put_files_struct(struct files_struct
*fs
);
104 void reset_files_struct(struct files_struct
*);
105 int unshare_files(struct files_struct
**);
106 struct files_struct
*dup_fd(struct files_struct
*, int *);
107 void do_close_on_exec(struct files_struct
*);
108 int iterate_fd(struct files_struct
*, unsigned,
109 int (*)(const void *, struct file
*, unsigned),
112 extern int __alloc_fd(struct files_struct
*files
,
113 unsigned start
, unsigned end
, unsigned flags
);
114 extern void __fd_install(struct files_struct
*files
,
115 unsigned int fd
, struct file
*file
);
116 extern int __close_fd(struct files_struct
*files
,
119 extern struct kmem_cache
*files_cachep
;
121 #endif /* __LINUX_FDTABLE_H */