| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | */ |
| 22 | struct 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 | |
| 36 | extern void FASTCALL(__fput(struct file *)); |
| 37 | extern void FASTCALL(fput(struct file *)); |
| 38 | |
| 39 | static inline void fput_light(struct file *file, int fput_needed) |
| 40 | { |
| 41 | if (unlikely(fput_needed)) |
| 42 | fput(file); |
| 43 | } |
| 44 | |
| 45 | extern struct file * FASTCALL(fget(unsigned int fd)); |
| 46 | extern struct file * FASTCALL(fget_light(unsigned int fd, int *fput_needed)); |
| 47 | extern void FASTCALL(set_close_on_exec(unsigned int fd, int flag)); |
| 48 | extern void put_filp(struct file *); |
| 49 | extern int get_unused_fd(void); |
| 50 | extern void FASTCALL(put_unused_fd(unsigned int fd)); |
| 51 | struct kmem_cache_s; |
| 52 | extern void filp_ctor(void * objp, struct kmem_cache_s *cachep, unsigned long cflags); |
| 53 | extern void filp_dtor(void * objp, struct kmem_cache_s *cachep, unsigned long dflags); |
| 54 | |
| 55 | extern struct file ** alloc_fd_array(int); |
| 56 | extern void free_fd_array(struct file **, int); |
| 57 | |
| 58 | extern fd_set *alloc_fdset(int); |
| 59 | extern void free_fdset(fd_set *, int); |
| 60 | |
| 61 | extern int expand_files(struct files_struct *, int nr); |
| 62 | |
| 63 | static 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 | |
| 77 | extern void FASTCALL(fd_install(unsigned int fd, struct file * file)); |
| 78 | |
| 79 | struct task_struct; |
| 80 | |
| 81 | struct files_struct *get_files_struct(struct task_struct *); |
| 82 | void FASTCALL(put_files_struct(struct files_struct *fs)); |
| 83 | |
| 84 | #endif /* __LINUX_FILE_H */ |