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 | 29 | struct rcu_head rcu; |
9f3acc31 AV |
30 | }; |
31 | ||
1dce27c5 DH |
32 | static inline bool close_on_exec(int fd, const struct fdtable *fdt) |
33 | { | |
1fd36adc | 34 | return test_bit(fd, fdt->close_on_exec); |
1dce27c5 DH |
35 | } |
36 | ||
1dce27c5 DH |
37 | static inline bool fd_is_open(int fd, const struct fdtable *fdt) |
38 | { | |
1fd36adc | 39 | return test_bit(fd, fdt->open_fds); |
1dce27c5 DH |
40 | } |
41 | ||
9f3acc31 AV |
42 | /* |
43 | * Open file table structure | |
44 | */ | |
45 | struct files_struct { | |
46 | /* | |
47 | * read mostly part | |
48 | */ | |
49 | atomic_t count; | |
4d2deb40 | 50 | struct fdtable __rcu *fdt; |
9f3acc31 AV |
51 | struct fdtable fdtab; |
52 | /* | |
53 | * written part on a separate cache line in SMP | |
54 | */ | |
55 | spinlock_t file_lock ____cacheline_aligned_in_smp; | |
56 | int next_fd; | |
1fd36adc DH |
57 | unsigned long close_on_exec_init[1]; |
58 | unsigned long open_fds_init[1]; | |
4d2deb40 | 59 | struct file __rcu * fd_array[NR_OPEN_DEFAULT]; |
9f3acc31 AV |
60 | }; |
61 | ||
9f3acc31 AV |
62 | struct file_operations; |
63 | struct vfsmount; | |
64 | struct dentry; | |
65 | ||
a8d4b834 ON |
66 | #define rcu_dereference_check_fdtable(files, fdtfd) \ |
67 | rcu_dereference_check((fdtfd), lockdep_is_held(&(files)->file_lock)) | |
68 | ||
69 | #define files_fdtable(files) \ | |
70 | rcu_dereference_check_fdtable((files), (files)->fdt) | |
71 | ||
72 | /* | |
73 | * The caller must ensure that fd table isn't shared or hold rcu or file lock | |
74 | */ | |
75 | static inline struct file *__fcheck_files(struct files_struct *files, unsigned int fd) | |
9f3acc31 | 76 | { |
a8d4b834 | 77 | struct fdtable *fdt = rcu_dereference_raw(files->fdt); |
9f3acc31 AV |
78 | |
79 | if (fd < fdt->max_fds) | |
a8d4b834 ON |
80 | return rcu_dereference_raw(fdt->fd[fd]); |
81 | return NULL; | |
82 | } | |
83 | ||
84 | static inline struct file *fcheck_files(struct files_struct *files, unsigned int fd) | |
85 | { | |
86 | rcu_lockdep_assert(rcu_read_lock_held() || | |
87 | lockdep_is_held(&files->file_lock), | |
88 | "suspicious rcu_dereference_check() usage"); | |
89 | return __fcheck_files(files, fd); | |
9f3acc31 AV |
90 | } |
91 | ||
92 | /* | |
93 | * Check whether the specified fd has an open file. | |
94 | */ | |
95 | #define fcheck(fd) fcheck_files(current->files, fd) | |
96 | ||
97 | struct task_struct; | |
98 | ||
99 | struct files_struct *get_files_struct(struct task_struct *); | |
100 | void put_files_struct(struct files_struct *fs); | |
101 | void reset_files_struct(struct files_struct *); | |
102 | int unshare_files(struct files_struct **); | |
02afc626 | 103 | struct files_struct *dup_fd(struct files_struct *, int *); |
6a6d27de | 104 | void do_close_on_exec(struct files_struct *); |
c3c073f8 AV |
105 | int iterate_fd(struct files_struct *, unsigned, |
106 | int (*)(const void *, struct file *, unsigned), | |
107 | const void *); | |
9f3acc31 | 108 | |
dcfadfa4 AV |
109 | extern int __alloc_fd(struct files_struct *files, |
110 | unsigned start, unsigned end, unsigned flags); | |
f869e8a7 AV |
111 | extern void __fd_install(struct files_struct *files, |
112 | unsigned int fd, struct file *file); | |
483ce1d4 AV |
113 | extern int __close_fd(struct files_struct *files, |
114 | unsigned int fd); | |
dcfadfa4 | 115 | |
9f3acc31 AV |
116 | extern struct kmem_cache *files_cachep; |
117 | ||
118 | #endif /* __LINUX_FDTABLE_H */ |