Commit | Line | Data |
---|---|---|
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> |
0c9e63fd | 13 | #include <linux/types.h> |
1da177e4 LT |
14 | |
15 | /* | |
16 | * The default fd array needs to be at least BITS_PER_LONG, | |
17 | * as this is the granularity returned by copy_fdset(). | |
18 | */ | |
19 | #define NR_OPEN_DEFAULT BITS_PER_LONG | |
20 | ||
0c9e63fd ED |
21 | /* |
22 | * The embedded_fd_set is a small fd_set, | |
23 | * suitable for most tasks (which open <= BITS_PER_LONG files) | |
24 | */ | |
25 | struct embedded_fd_set { | |
26 | unsigned long fds_bits[1]; | |
27 | }; | |
28 | ||
badf1662 DS |
29 | struct fdtable { |
30 | unsigned int max_fds; | |
badf1662 DS |
31 | struct file ** fd; /* current fd array */ |
32 | fd_set *close_on_exec; | |
33 | fd_set *open_fds; | |
ab2af1f5 | 34 | struct rcu_head rcu; |
ab2af1f5 | 35 | struct fdtable *next; |
badf1662 DS |
36 | }; |
37 | ||
1da177e4 LT |
38 | /* |
39 | * Open file table structure | |
40 | */ | |
41 | struct files_struct { | |
0c9e63fd ED |
42 | /* |
43 | * read mostly part | |
44 | */ | |
95e861db | 45 | atomic_t count; |
ab2af1f5 | 46 | struct fdtable *fdt; |
badf1662 | 47 | struct fdtable fdtab; |
0c9e63fd ED |
48 | /* |
49 | * written part on a separate cache line in SMP | |
50 | */ | |
51 | spinlock_t file_lock ____cacheline_aligned_in_smp; | |
52 | int next_fd; | |
53 | struct embedded_fd_set close_on_exec_init; | |
54 | struct embedded_fd_set open_fds_init; | |
95e861db | 55 | struct file * fd_array[NR_OPEN_DEFAULT]; |
1da177e4 LT |
56 | }; |
57 | ||
ab2af1f5 | 58 | #define files_fdtable(files) (rcu_dereference((files)->fdt)) |
badf1662 | 59 | |
8b7d91eb CL |
60 | extern struct kmem_cache *filp_cachep; |
61 | ||
1da177e4 LT |
62 | extern void FASTCALL(__fput(struct file *)); |
63 | extern void FASTCALL(fput(struct file *)); | |
64 | ||
ce8d2cdf DH |
65 | struct file_operations; |
66 | struct vfsmount; | |
67 | struct dentry; | |
68 | extern int init_file(struct file *, struct vfsmount *mnt, | |
69 | struct dentry *dentry, mode_t mode, | |
70 | const struct file_operations *fop); | |
71 | extern struct file *alloc_file(struct vfsmount *, struct dentry *dentry, | |
72 | mode_t mode, const struct file_operations *fop); | |
73 | ||
1da177e4 LT |
74 | static inline void fput_light(struct file *file, int fput_needed) |
75 | { | |
76 | if (unlikely(fput_needed)) | |
77 | fput(file); | |
78 | } | |
79 | ||
80 | extern struct file * FASTCALL(fget(unsigned int fd)); | |
81 | extern struct file * FASTCALL(fget_light(unsigned int fd, int *fput_needed)); | |
82 | extern void FASTCALL(set_close_on_exec(unsigned int fd, int flag)); | |
83 | extern void put_filp(struct file *); | |
84 | extern int get_unused_fd(void); | |
4a19542e | 85 | extern int get_unused_fd_flags(int flags); |
1da177e4 | 86 | extern void FASTCALL(put_unused_fd(unsigned int fd)); |
2109a2d1 | 87 | struct kmem_cache; |
1da177e4 | 88 | |
1da177e4 | 89 | extern int expand_files(struct files_struct *, int nr); |
4fd45812 | 90 | extern void free_fdtable_rcu(struct rcu_head *rcu); |
ab2af1f5 | 91 | extern void __init files_defer_init(void); |
1da177e4 | 92 | |
01b2d93c VL |
93 | static inline void free_fdtable(struct fdtable *fdt) |
94 | { | |
95 | call_rcu(&fdt->rcu, free_fdtable_rcu); | |
96 | } | |
97 | ||
1da177e4 LT |
98 | static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) |
99 | { | |
100 | struct file * file = NULL; | |
badf1662 | 101 | struct fdtable *fdt = files_fdtable(files); |
1da177e4 | 102 | |
badf1662 | 103 | if (fd < fdt->max_fds) |
ab2af1f5 | 104 | file = rcu_dereference(fdt->fd[fd]); |
1da177e4 LT |
105 | return file; |
106 | } | |
107 | ||
108 | /* | |
109 | * Check whether the specified fd has an open file. | |
110 | */ | |
111 | #define fcheck(fd) fcheck_files(current->files, fd) | |
112 | ||
113 | extern void FASTCALL(fd_install(unsigned int fd, struct file * file)); | |
114 | ||
115 | struct task_struct; | |
116 | ||
117 | struct files_struct *get_files_struct(struct task_struct *); | |
118 | void FASTCALL(put_files_struct(struct files_struct *fs)); | |
3b9b8ab6 | 119 | void reset_files_struct(struct task_struct *, struct files_struct *); |
1da177e4 | 120 | |
5d6538fc CL |
121 | extern struct kmem_cache *files_cachep; |
122 | ||
1da177e4 | 123 | #endif /* __LINUX_FILE_H */ |