2 * descriptor table internals; you almost certainly want file.h instead.
5 #ifndef __LINUX_FDTABLE_H
6 #define __LINUX_FDTABLE_H
8 #include <asm/atomic.h>
9 #include <linux/posix_types.h>
10 #include <linux/compiler.h>
11 #include <linux/spinlock.h>
12 #include <linux/rcupdate.h>
13 #include <linux/types.h>
16 * The default fd array needs to be at least BITS_PER_LONG,
17 * as this is the granularity returned by copy_fdset().
19 #define NR_OPEN_DEFAULT BITS_PER_LONG
22 * The embedded_fd_set is a small fd_set,
23 * suitable for most tasks (which open <= BITS_PER_LONG files)
25 struct embedded_fd_set {
26 unsigned long fds_bits[1];
31 struct file ** fd; /* current fd array */
32 fd_set *close_on_exec;
39 * Open file table structure
49 * written part on a separate cache line in SMP
51 spinlock_t file_lock ____cacheline_aligned_in_smp;
53 struct embedded_fd_set close_on_exec_init;
54 struct embedded_fd_set open_fds_init;
55 struct file * fd_array[NR_OPEN_DEFAULT];
58 #define files_fdtable(files) (rcu_dereference((files)->fdt))
60 struct file_operations;
64 extern int expand_files(struct files_struct *, int nr);
65 extern void free_fdtable_rcu(struct rcu_head *rcu);
66 extern void __init files_defer_init(void);
68 static inline void free_fdtable(struct fdtable *fdt)
70 call_rcu(&fdt->rcu, free_fdtable_rcu);
73 static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd)
75 struct file * file = NULL;
76 struct fdtable *fdt = files_fdtable(files);
78 if (fd < fdt->max_fds)
79 file = rcu_dereference(fdt->fd[fd]);
84 * Check whether the specified fd has an open file.
86 #define fcheck(fd) fcheck_files(current->files, fd)
90 struct files_struct *get_files_struct(struct task_struct *);
91 void put_files_struct(struct files_struct *fs);
92 void reset_files_struct(struct files_struct *);
93 int unshare_files(struct files_struct **);
94 struct files_struct *dup_fd(struct files_struct *, int *);
96 extern struct kmem_cache *files_cachep;
98 #endif /* __LINUX_FDTABLE_H */