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Commit | Line | Data |
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1da177e4 LT |
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> | |
ab2af1f5 | 12 | #include <linux/rcupdate.h> |
1da177e4 LT |
13 | |
14 | /* | |
15 | * The default fd array needs to be at least BITS_PER_LONG, | |
16 | * as this is the granularity returned by copy_fdset(). | |
17 | */ | |
18 | #define NR_OPEN_DEFAULT BITS_PER_LONG | |
19 | ||
badf1662 DS |
20 | struct fdtable { |
21 | unsigned int max_fds; | |
22 | int max_fdset; | |
23 | int next_fd; | |
24 | struct file ** fd; /* current fd array */ | |
25 | fd_set *close_on_exec; | |
26 | fd_set *open_fds; | |
ab2af1f5 DS |
27 | struct rcu_head rcu; |
28 | struct files_struct *free_files; | |
29 | struct fdtable *next; | |
badf1662 DS |
30 | }; |
31 | ||
1da177e4 LT |
32 | /* |
33 | * Open file table structure | |
34 | */ | |
35 | struct files_struct { | |
36 | atomic_t count; | |
37 | spinlock_t file_lock; /* Protects all the below members. Nests inside tsk->alloc_lock */ | |
ab2af1f5 | 38 | struct fdtable *fdt; |
badf1662 | 39 | struct fdtable fdtab; |
1da177e4 LT |
40 | fd_set close_on_exec_init; |
41 | fd_set open_fds_init; | |
42 | struct file * fd_array[NR_OPEN_DEFAULT]; | |
43 | }; | |
44 | ||
ab2af1f5 | 45 | #define files_fdtable(files) (rcu_dereference((files)->fdt)) |
badf1662 | 46 | |
1da177e4 LT |
47 | extern void FASTCALL(__fput(struct file *)); |
48 | extern void FASTCALL(fput(struct file *)); | |
49 | ||
50 | static inline void fput_light(struct file *file, int fput_needed) | |
51 | { | |
52 | if (unlikely(fput_needed)) | |
53 | fput(file); | |
54 | } | |
55 | ||
56 | extern struct file * FASTCALL(fget(unsigned int fd)); | |
57 | extern struct file * FASTCALL(fget_light(unsigned int fd, int *fput_needed)); | |
58 | extern void FASTCALL(set_close_on_exec(unsigned int fd, int flag)); | |
59 | extern void put_filp(struct file *); | |
60 | extern int get_unused_fd(void); | |
61 | extern void FASTCALL(put_unused_fd(unsigned int fd)); | |
62 | struct kmem_cache_s; | |
63 | extern void filp_ctor(void * objp, struct kmem_cache_s *cachep, unsigned long cflags); | |
64 | extern void filp_dtor(void * objp, struct kmem_cache_s *cachep, unsigned long dflags); | |
65 | ||
66 | extern struct file ** alloc_fd_array(int); | |
67 | extern void free_fd_array(struct file **, int); | |
68 | ||
69 | extern fd_set *alloc_fdset(int); | |
70 | extern void free_fdset(fd_set *, int); | |
71 | ||
72 | extern int expand_files(struct files_struct *, int nr); | |
ab2af1f5 DS |
73 | extern void free_fdtable(struct fdtable *fdt); |
74 | extern void __init files_defer_init(void); | |
1da177e4 LT |
75 | |
76 | static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) | |
77 | { | |
78 | struct file * file = NULL; | |
badf1662 | 79 | struct fdtable *fdt = files_fdtable(files); |
1da177e4 | 80 | |
badf1662 | 81 | if (fd < fdt->max_fds) |
ab2af1f5 | 82 | file = rcu_dereference(fdt->fd[fd]); |
1da177e4 LT |
83 | return file; |
84 | } | |
85 | ||
86 | /* | |
87 | * Check whether the specified fd has an open file. | |
88 | */ | |
89 | #define fcheck(fd) fcheck_files(current->files, fd) | |
90 | ||
91 | extern void FASTCALL(fd_install(unsigned int fd, struct file * file)); | |
92 | ||
93 | struct task_struct; | |
94 | ||
95 | struct files_struct *get_files_struct(struct task_struct *); | |
96 | void FASTCALL(put_files_struct(struct files_struct *fs)); | |
97 | ||
98 | #endif /* __LINUX_FILE_H */ |