Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 12 | #include <linux/rcupdate.h> |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 13 | #include <linux/types.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 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 | |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 29 | struct fdtable { |
| 30 | unsigned int max_fds; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 31 | struct file ** fd; /* current fd array */ |
| 32 | fd_set *close_on_exec; |
| 33 | fd_set *open_fds; |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 34 | struct rcu_head rcu; |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 35 | struct fdtable *next; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 36 | }; |
| 37 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | /* |
| 39 | * Open file table structure |
| 40 | */ |
| 41 | struct files_struct { |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 42 | /* |
| 43 | * read mostly part |
| 44 | */ |
Eric Dumazet | 95e861d | 2005-11-13 16:06:24 -0800 | [diff] [blame] | 45 | atomic_t count; |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 46 | struct fdtable *fdt; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 47 | struct fdtable fdtab; |
Eric Dumazet | 0c9e63f | 2006-03-23 03:00:12 -0800 | [diff] [blame] | 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; |
Eric Dumazet | 95e861d | 2005-11-13 16:06:24 -0800 | [diff] [blame] | 55 | struct file * fd_array[NR_OPEN_DEFAULT]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | }; |
| 57 | |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 58 | #define files_fdtable(files) (rcu_dereference((files)->fdt)) |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 59 | |
Christoph Lameter | 8b7d91e | 2006-12-06 20:32:52 -0800 | [diff] [blame] | 60 | extern struct kmem_cache *filp_cachep; |
| 61 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | extern void FASTCALL(__fput(struct file *)); |
| 63 | extern void FASTCALL(fput(struct file *)); |
| 64 | |
| 65 | static inline void fput_light(struct file *file, int fput_needed) |
| 66 | { |
| 67 | if (unlikely(fput_needed)) |
| 68 | fput(file); |
| 69 | } |
| 70 | |
| 71 | extern struct file * FASTCALL(fget(unsigned int fd)); |
| 72 | extern struct file * FASTCALL(fget_light(unsigned int fd, int *fput_needed)); |
| 73 | extern void FASTCALL(set_close_on_exec(unsigned int fd, int flag)); |
| 74 | extern void put_filp(struct file *); |
| 75 | extern int get_unused_fd(void); |
| 76 | extern void FASTCALL(put_unused_fd(unsigned int fd)); |
Pekka J Enberg | 2109a2d | 2005-11-07 00:58:01 -0800 | [diff] [blame] | 77 | struct kmem_cache; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
| 79 | extern struct file ** alloc_fd_array(int); |
| 80 | extern void free_fd_array(struct file **, int); |
| 81 | |
| 82 | extern fd_set *alloc_fdset(int); |
| 83 | extern void free_fdset(fd_set *, int); |
| 84 | |
| 85 | extern int expand_files(struct files_struct *, int nr); |
Vadim Lobanov | 4fd4581 | 2006-12-10 02:21:17 -0800 | [diff] [blame^] | 86 | extern void free_fdtable_rcu(struct rcu_head *rcu); |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 87 | extern void __init files_defer_init(void); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
| 89 | static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) |
| 90 | { |
| 91 | struct file * file = NULL; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 92 | struct fdtable *fdt = files_fdtable(files); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 94 | if (fd < fdt->max_fds) |
Dipankar Sarma | ab2af1f | 2005-09-09 13:04:13 -0700 | [diff] [blame] | 95 | file = rcu_dereference(fdt->fd[fd]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | return file; |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | * Check whether the specified fd has an open file. |
| 101 | */ |
| 102 | #define fcheck(fd) fcheck_files(current->files, fd) |
| 103 | |
| 104 | extern void FASTCALL(fd_install(unsigned int fd, struct file * file)); |
| 105 | |
| 106 | struct task_struct; |
| 107 | |
| 108 | struct files_struct *get_files_struct(struct task_struct *); |
| 109 | void FASTCALL(put_files_struct(struct files_struct *fs)); |
Kirill Korotaev | 3b9b8ab | 2006-09-29 02:00:05 -0700 | [diff] [blame] | 110 | void reset_files_struct(struct task_struct *, struct files_struct *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | |
Christoph Lameter | 5d6538f | 2006-12-06 20:32:50 -0800 | [diff] [blame] | 112 | extern struct kmem_cache *files_cachep; |
| 113 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | #endif /* __LINUX_FILE_H */ |