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; | |
f3f86e33 | 29 | unsigned long *full_fds_bits; |
9f3acc31 | 30 | struct rcu_head rcu; |
9f3acc31 AV |
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; | |
8a81252b ED |
51 | bool resize_in_progress; |
52 | wait_queue_head_t resize_wait; | |
53 | ||
4d2deb40 | 54 | struct fdtable __rcu *fdt; |
9f3acc31 AV |
55 | struct fdtable fdtab; |
56 | /* | |
57 | * written part on a separate cache line in SMP | |
58 | */ | |
59 | spinlock_t file_lock ____cacheline_aligned_in_smp; | |
60 | int next_fd; | |
1fd36adc DH |
61 | unsigned long close_on_exec_init[1]; |
62 | unsigned long open_fds_init[1]; | |
f3f86e33 | 63 | unsigned long full_fds_bits_init[1]; |
4d2deb40 | 64 | struct file __rcu * fd_array[NR_OPEN_DEFAULT]; |
9f3acc31 AV |
65 | }; |
66 | ||
9f3acc31 AV |
67 | struct file_operations; |
68 | struct vfsmount; | |
69 | struct dentry; | |
70 | ||
a8d4b834 ON |
71 | #define rcu_dereference_check_fdtable(files, fdtfd) \ |
72 | rcu_dereference_check((fdtfd), lockdep_is_held(&(files)->file_lock)) | |
73 | ||
74 | #define files_fdtable(files) \ | |
75 | rcu_dereference_check_fdtable((files), (files)->fdt) | |
76 | ||
77 | /* | |
78 | * The caller must ensure that fd table isn't shared or hold rcu or file lock | |
79 | */ | |
80 | static inline struct file *__fcheck_files(struct files_struct *files, unsigned int fd) | |
9f3acc31 | 81 | { |
a8d4b834 | 82 | struct fdtable *fdt = rcu_dereference_raw(files->fdt); |
9f3acc31 AV |
83 | |
84 | if (fd < fdt->max_fds) | |
a8d4b834 ON |
85 | return rcu_dereference_raw(fdt->fd[fd]); |
86 | return NULL; | |
87 | } | |
88 | ||
89 | static inline struct file *fcheck_files(struct files_struct *files, unsigned int fd) | |
90 | { | |
f78f5b90 PM |
91 | RCU_LOCKDEP_WARN(!rcu_read_lock_held() && |
92 | !lockdep_is_held(&files->file_lock), | |
a8d4b834 ON |
93 | "suspicious rcu_dereference_check() usage"); |
94 | return __fcheck_files(files, fd); | |
9f3acc31 AV |
95 | } |
96 | ||
97 | /* | |
98 | * Check whether the specified fd has an open file. | |
99 | */ | |
100 | #define fcheck(fd) fcheck_files(current->files, fd) | |
101 | ||
102 | struct task_struct; | |
103 | ||
104 | struct files_struct *get_files_struct(struct task_struct *); | |
105 | void put_files_struct(struct files_struct *fs); | |
106 | void reset_files_struct(struct files_struct *); | |
107 | int unshare_files(struct files_struct **); | |
02afc626 | 108 | struct files_struct *dup_fd(struct files_struct *, int *); |
6a6d27de | 109 | void do_close_on_exec(struct files_struct *); |
c3c073f8 AV |
110 | int iterate_fd(struct files_struct *, unsigned, |
111 | int (*)(const void *, struct file *, unsigned), | |
112 | const void *); | |
9f3acc31 | 113 | |
dcfadfa4 AV |
114 | extern int __alloc_fd(struct files_struct *files, |
115 | unsigned start, unsigned end, unsigned flags); | |
f869e8a7 AV |
116 | extern void __fd_install(struct files_struct *files, |
117 | unsigned int fd, struct file *file); | |
483ce1d4 AV |
118 | extern int __close_fd(struct files_struct *files, |
119 | unsigned int fd); | |
dcfadfa4 | 120 | |
9f3acc31 AV |
121 | extern struct kmem_cache *files_cachep; |
122 | ||
123 | #endif /* __LINUX_FDTABLE_H */ |