[CONNECTOR]: Update documentation to match reality.
[linux-2.6/verdex.git] / include / linux / file.h
blobf5bbd4c508b3da00b3af27dc20f2178996cc9496
1 /*
2 * Wrapper functions for accessing the file_struct fd array.
3 */
5 #ifndef __LINUX_FILE_H
6 #define __LINUX_FILE_H
8 #include <asm/atomic.h>
9 #include <linux/posix_types.h>
10 #include <linux/compiler.h>
11 #include <linux/spinlock.h>
12 #include <linux/rcupdate.h>
15 * The default fd array needs to be at least BITS_PER_LONG,
16 * as this is the granularity returned by copy_fdset().
18 #define NR_OPEN_DEFAULT BITS_PER_LONG
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;
27 struct rcu_head rcu;
28 struct files_struct *free_files;
29 struct fdtable *next;
33 * Open file table structure
35 struct files_struct {
36 atomic_t count;
37 spinlock_t file_lock; /* Protects all the below members. Nests inside tsk->alloc_lock */
38 struct fdtable *fdt;
39 struct fdtable fdtab;
40 fd_set close_on_exec_init;
41 fd_set open_fds_init;
42 struct file * fd_array[NR_OPEN_DEFAULT];
45 #define files_fdtable(files) (rcu_dereference((files)->fdt))
47 extern void FASTCALL(__fput(struct file *));
48 extern void FASTCALL(fput(struct file *));
50 static inline void fput_light(struct file *file, int fput_needed)
52 if (unlikely(fput_needed))
53 fput(file);
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);
66 extern struct file ** alloc_fd_array(int);
67 extern void free_fd_array(struct file **, int);
69 extern fd_set *alloc_fdset(int);
70 extern void free_fdset(fd_set *, int);
72 extern int expand_files(struct files_struct *, int nr);
73 extern void free_fdtable(struct fdtable *fdt);
74 extern void __init files_defer_init(void);
76 static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd)
78 struct file * file = NULL;
79 struct fdtable *fdt = files_fdtable(files);
81 if (fd < fdt->max_fds)
82 file = rcu_dereference(fdt->fd[fd]);
83 return file;
87 * Check whether the specified fd has an open file.
89 #define fcheck(fd) fcheck_files(current->files, fd)
91 extern void FASTCALL(fd_install(unsigned int fd, struct file * file));
93 struct task_struct;
95 struct files_struct *get_files_struct(struct task_struct *);
96 void FASTCALL(put_files_struct(struct files_struct *fs));
98 #endif /* __LINUX_FILE_H */