Linux kernel mirror (for testing)
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1/*
2 * Wrapper functions for accessing the file_struct fd array.
3 */
4
5#ifndef __LINUX_FILE_H
6#define __LINUX_FILE_H
7
8#include <asm/atomic.h>
9#include <linux/posix_types.h>
10#include <linux/compiler.h>
11#include <linux/spinlock.h>
12
13/*
14 * The default fd array needs to be at least BITS_PER_LONG,
15 * as this is the granularity returned by copy_fdset().
16 */
17#define NR_OPEN_DEFAULT BITS_PER_LONG
18
19/*
20 * Open file table structure
21 */
22struct files_struct {
23 atomic_t count;
24 spinlock_t file_lock; /* Protects all the below members. Nests inside tsk->alloc_lock */
25 int max_fds;
26 int max_fdset;
27 int next_fd;
28 struct file ** fd; /* current fd array */
29 fd_set *close_on_exec;
30 fd_set *open_fds;
31 fd_set close_on_exec_init;
32 fd_set open_fds_init;
33 struct file * fd_array[NR_OPEN_DEFAULT];
34};
35
36extern void FASTCALL(__fput(struct file *));
37extern void FASTCALL(fput(struct file *));
38
39static inline void fput_light(struct file *file, int fput_needed)
40{
41 if (unlikely(fput_needed))
42 fput(file);
43}
44
45extern struct file * FASTCALL(fget(unsigned int fd));
46extern struct file * FASTCALL(fget_light(unsigned int fd, int *fput_needed));
47extern void FASTCALL(set_close_on_exec(unsigned int fd, int flag));
48extern void put_filp(struct file *);
49extern int get_unused_fd(void);
50extern void FASTCALL(put_unused_fd(unsigned int fd));
51struct kmem_cache_s;
52extern void filp_ctor(void * objp, struct kmem_cache_s *cachep, unsigned long cflags);
53extern void filp_dtor(void * objp, struct kmem_cache_s *cachep, unsigned long dflags);
54
55extern struct file ** alloc_fd_array(int);
56extern void free_fd_array(struct file **, int);
57
58extern fd_set *alloc_fdset(int);
59extern void free_fdset(fd_set *, int);
60
61extern int expand_files(struct files_struct *, int nr);
62
63static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd)
64{
65 struct file * file = NULL;
66
67 if (fd < files->max_fds)
68 file = files->fd[fd];
69 return file;
70}
71
72/*
73 * Check whether the specified fd has an open file.
74 */
75#define fcheck(fd) fcheck_files(current->files, fd)
76
77extern void FASTCALL(fd_install(unsigned int fd, struct file * file));
78
79struct task_struct;
80
81struct files_struct *get_files_struct(struct task_struct *);
82void FASTCALL(put_files_struct(struct files_struct *fs));
83
84#endif /* __LINUX_FILE_H */