Commit | Line | Data |
---|---|---|
9f3acc31 AV |
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 | ||
9f3acc31 AV |
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> | |
21e54459 | 13 | #include <linux/init.h> |
2c666df8 | 14 | #include <linux/fs.h> |
21e54459 | 15 | |
60063497 | 16 | #include <linux/atomic.h> |
9f3acc31 AV |
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 | ||
9f3acc31 AV |
24 | struct fdtable { |
25 | unsigned int max_fds; | |
4d2deb40 | 26 | struct file __rcu **fd; /* current fd array */ |
1fd36adc DH |
27 | unsigned long *close_on_exec; |
28 | unsigned long *open_fds; | |
9f3acc31 AV |
29 | struct rcu_head rcu; |
30 | struct fdtable *next; | |
31 | }; | |
32 | ||
1dce27c5 DH |
33 | static inline bool close_on_exec(int fd, const struct fdtable *fdt) |
34 | { | |
1fd36adc | 35 | return test_bit(fd, fdt->close_on_exec); |
1dce27c5 DH |
36 | } |
37 | ||
1dce27c5 DH |
38 | static inline bool fd_is_open(int fd, const struct fdtable *fdt) |
39 | { | |
1fd36adc | 40 | return test_bit(fd, fdt->open_fds); |
1dce27c5 DH |
41 | } |
42 | ||
9f3acc31 AV |
43 | /* |
44 | * Open file table structure | |
45 | */ | |
46 | struct files_struct { | |
47 | /* | |
48 | * read mostly part | |
49 | */ | |
50 | atomic_t count; | |
4d2deb40 | 51 | struct fdtable __rcu *fdt; |
9f3acc31 AV |
52 | struct fdtable fdtab; |
53 | /* | |
54 | * written part on a separate cache line in SMP | |
55 | */ | |
56 | spinlock_t file_lock ____cacheline_aligned_in_smp; | |
57 | int next_fd; | |
1fd36adc DH |
58 | unsigned long close_on_exec_init[1]; |
59 | unsigned long open_fds_init[1]; | |
4d2deb40 | 60 | struct file __rcu * fd_array[NR_OPEN_DEFAULT]; |
9f3acc31 AV |
61 | }; |
62 | ||
af61b96b PM |
63 | #define rcu_dereference_check_fdtable(files, fdtfd) \ |
64 | (rcu_dereference_check((fdtfd), \ | |
7dc52157 | 65 | lockdep_is_held(&(files)->file_lock) || \ |
844b9a87 PM |
66 | atomic_read(&(files)->count) == 1 || \ |
67 | rcu_my_thread_group_empty())) | |
af61b96b PM |
68 | |
69 | #define files_fdtable(files) \ | |
70 | (rcu_dereference_check_fdtable((files), (files)->fdt)) | |
9f3acc31 | 71 | |
9f3acc31 AV |
72 | struct file_operations; |
73 | struct vfsmount; | |
74 | struct dentry; | |
75 | ||
9f3acc31 AV |
76 | extern void __init files_defer_init(void); |
77 | ||
9f3acc31 AV |
78 | static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) |
79 | { | |
80 | struct file * file = NULL; | |
81 | struct fdtable *fdt = files_fdtable(files); | |
82 | ||
83 | if (fd < fdt->max_fds) | |
af61b96b | 84 | file = rcu_dereference_check_fdtable(files, fdt->fd[fd]); |
9f3acc31 AV |
85 | return file; |
86 | } | |
87 | ||
88 | /* | |
89 | * Check whether the specified fd has an open file. | |
90 | */ | |
91 | #define fcheck(fd) fcheck_files(current->files, fd) | |
92 | ||
93 | struct task_struct; | |
94 | ||
95 | struct files_struct *get_files_struct(struct task_struct *); | |
96 | void put_files_struct(struct files_struct *fs); | |
97 | void reset_files_struct(struct files_struct *); | |
864bdb3b | 98 | void daemonize_descriptors(void); |
9f3acc31 | 99 | int unshare_files(struct files_struct **); |
02afc626 | 100 | struct files_struct *dup_fd(struct files_struct *, int *); |
6a6d27de | 101 | void do_close_on_exec(struct files_struct *); |
c3c073f8 AV |
102 | int iterate_fd(struct files_struct *, unsigned, |
103 | int (*)(const void *, struct file *, unsigned), | |
104 | const void *); | |
9f3acc31 | 105 | |
dcfadfa4 AV |
106 | extern int __alloc_fd(struct files_struct *files, |
107 | unsigned start, unsigned end, unsigned flags); | |
f869e8a7 AV |
108 | extern void __fd_install(struct files_struct *files, |
109 | unsigned int fd, struct file *file); | |
483ce1d4 AV |
110 | extern int __close_fd(struct files_struct *files, |
111 | unsigned int fd); | |
dcfadfa4 | 112 | |
9f3acc31 AV |
113 | extern struct kmem_cache *files_cachep; |
114 | ||
115 | #endif /* __LINUX_FDTABLE_H */ |