diff options
Diffstat (limited to 'include/linux/file.h')
-rw-r--r-- | include/linux/file.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/include/linux/file.h b/include/linux/file.h new file mode 100644 index 000000000000..5206beb9a80e --- /dev/null +++ b/include/linux/file.h @@ -0,0 +1,84 @@ +/* + * Wrapper functions for accessing the file_struct fd array. + */ + +#ifndef __LINUX_FILE_H +#define __LINUX_FILE_H + +#include <asm/atomic.h> +#include <linux/posix_types.h> +#include <linux/compiler.h> +#include <linux/spinlock.h> + +/* + * The default fd array needs to be at least BITS_PER_LONG, + * as this is the granularity returned by copy_fdset(). + */ +#define NR_OPEN_DEFAULT BITS_PER_LONG + +/* + * Open file table structure + */ +struct files_struct { + atomic_t count; + spinlock_t file_lock; /* Protects all the below members. Nests inside tsk->alloc_lock */ + int max_fds; + int max_fdset; + int next_fd; + struct file ** fd; /* current fd array */ + fd_set *close_on_exec; + fd_set *open_fds; + fd_set close_on_exec_init; + fd_set open_fds_init; + struct file * fd_array[NR_OPEN_DEFAULT]; +}; + +extern void FASTCALL(__fput(struct file *)); +extern void FASTCALL(fput(struct file *)); + +static inline void fput_light(struct file *file, int fput_needed) +{ + if (unlikely(fput_needed)) + fput(file); +} + +extern struct file * FASTCALL(fget(unsigned int fd)); +extern struct file * FASTCALL(fget_light(unsigned int fd, int *fput_needed)); +extern void FASTCALL(set_close_on_exec(unsigned int fd, int flag)); +extern void put_filp(struct file *); +extern int get_unused_fd(void); +extern void FASTCALL(put_unused_fd(unsigned int fd)); +struct kmem_cache_s; +extern void filp_ctor(void * objp, struct kmem_cache_s *cachep, unsigned long cflags); +extern void filp_dtor(void * objp, struct kmem_cache_s *cachep, unsigned long dflags); + +extern struct file ** alloc_fd_array(int); +extern void free_fd_array(struct file **, int); + +extern fd_set *alloc_fdset(int); +extern void free_fdset(fd_set *, int); + +extern int expand_files(struct files_struct *, int nr); + +static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd) +{ + struct file * file = NULL; + + if (fd < files->max_fds) + file = files->fd[fd]; + return file; +} + +/* + * Check whether the specified fd has an open file. + */ +#define fcheck(fd) fcheck_files(current->files, fd) + +extern void FASTCALL(fd_install(unsigned int fd, struct file * file)); + +struct task_struct; + +struct files_struct *get_files_struct(struct task_struct *); +void FASTCALL(put_files_struct(struct files_struct *fs)); + +#endif /* __LINUX_FILE_H */ |