Root/
1 | /* |
2 | * descriptor table internals; you almost certainly want file.h instead. |
3 | */ |
4 | |
5 | #ifndef __LINUX_FDTABLE_H |
6 | #define __LINUX_FDTABLE_H |
7 | |
8 | #include <linux/posix_types.h> |
9 | #include <linux/compiler.h> |
10 | #include <linux/spinlock.h> |
11 | #include <linux/rcupdate.h> |
12 | #include <linux/types.h> |
13 | #include <linux/init.h> |
14 | #include <linux/fs.h> |
15 | |
16 | #include <asm/atomic.h> |
17 | |
18 | /* |
19 | * The default fd array needs to be at least BITS_PER_LONG, |
20 | * as this is the granularity returned by copy_fdset(). |
21 | */ |
22 | #define NR_OPEN_DEFAULT BITS_PER_LONG |
23 | |
24 | /* |
25 | * The embedded_fd_set is a small fd_set, |
26 | * suitable for most tasks (which open <= BITS_PER_LONG files) |
27 | */ |
28 | struct embedded_fd_set { |
29 | unsigned long fds_bits[1]; |
30 | }; |
31 | |
32 | struct fdtable { |
33 | unsigned int max_fds; |
34 | struct file __rcu **fd; /* current fd array */ |
35 | fd_set *close_on_exec; |
36 | fd_set *open_fds; |
37 | struct rcu_head rcu; |
38 | struct fdtable *next; |
39 | }; |
40 | |
41 | /* |
42 | * Open file table structure |
43 | */ |
44 | struct files_struct { |
45 | /* |
46 | * read mostly part |
47 | */ |
48 | atomic_t count; |
49 | struct fdtable __rcu *fdt; |
50 | struct fdtable fdtab; |
51 | /* |
52 | * written part on a separate cache line in SMP |
53 | */ |
54 | spinlock_t file_lock ____cacheline_aligned_in_smp; |
55 | int next_fd; |
56 | struct embedded_fd_set close_on_exec_init; |
57 | struct embedded_fd_set open_fds_init; |
58 | struct file __rcu * fd_array[NR_OPEN_DEFAULT]; |
59 | }; |
60 | |
61 | #define rcu_dereference_check_fdtable(files, fdtfd) \ |
62 | (rcu_dereference_check((fdtfd), \ |
63 | rcu_read_lock_held() || \ |
64 | lockdep_is_held(&(files)->file_lock) || \ |
65 | atomic_read(&(files)->count) == 1 || \ |
66 | rcu_my_thread_group_empty())) |
67 | |
68 | #define files_fdtable(files) \ |
69 | (rcu_dereference_check_fdtable((files), (files)->fdt)) |
70 | |
71 | struct file_operations; |
72 | struct vfsmount; |
73 | struct dentry; |
74 | |
75 | extern int expand_files(struct files_struct *, int nr); |
76 | extern void free_fdtable_rcu(struct rcu_head *rcu); |
77 | extern void __init files_defer_init(void); |
78 | |
79 | static inline void free_fdtable(struct fdtable *fdt) |
80 | { |
81 | call_rcu(&fdt->rcu, free_fdtable_rcu); |
82 | } |
83 | |
84 | static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) |
85 | { |
86 | struct file * file = NULL; |
87 | struct fdtable *fdt = files_fdtable(files); |
88 | |
89 | if (fd < fdt->max_fds) |
90 | file = rcu_dereference_check_fdtable(files, fdt->fd[fd]); |
91 | return file; |
92 | } |
93 | |
94 | /* |
95 | * Check whether the specified fd has an open file. |
96 | */ |
97 | #define fcheck(fd) fcheck_files(current->files, fd) |
98 | |
99 | struct task_struct; |
100 | |
101 | struct files_struct *get_files_struct(struct task_struct *); |
102 | void put_files_struct(struct files_struct *fs); |
103 | void reset_files_struct(struct files_struct *); |
104 | int unshare_files(struct files_struct **); |
105 | struct files_struct *dup_fd(struct files_struct *, int *); |
106 | |
107 | extern struct kmem_cache *files_cachep; |
108 | |
109 | #endif /* __LINUX_FDTABLE_H */ |
110 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9