#include <linux/compiler.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
+#include <linux/types.h>
/*
* The default fd array needs to be at least BITS_PER_LONG,
*/
#define NR_OPEN_DEFAULT BITS_PER_LONG
+/*
+ * The embedded_fd_set is a small fd_set,
+ * suitable for most tasks (which open <= BITS_PER_LONG files)
+ */
+struct embedded_fd_set {
+ unsigned long fds_bits[1];
+};
+
struct fdtable {
unsigned int max_fds;
- int max_fdset;
- int next_fd;
struct file ** fd; /* current fd array */
fd_set *close_on_exec;
fd_set *open_fds;
struct rcu_head rcu;
- struct files_struct *free_files;
struct fdtable *next;
};
* Open file table structure
*/
struct files_struct {
+ /*
+ * read mostly part
+ */
atomic_t count;
struct fdtable *fdt;
struct fdtable fdtab;
- fd_set close_on_exec_init;
- fd_set open_fds_init;
+ /*
+ * written part on a separate cache line in SMP
+ */
+ spinlock_t file_lock ____cacheline_aligned_in_smp;
+ int next_fd;
+ struct embedded_fd_set close_on_exec_init;
+ struct embedded_fd_set open_fds_init;
struct file * fd_array[NR_OPEN_DEFAULT];
- spinlock_t file_lock; /* Protects concurrent writers. Nests inside tsk->alloc_lock */
};
#define files_fdtable(files) (rcu_dereference((files)->fdt))
+extern struct kmem_cache *filp_cachep;
+
extern void FASTCALL(__fput(struct file *));
extern void FASTCALL(fput(struct file *));
extern void FASTCALL(put_unused_fd(unsigned int fd));
struct kmem_cache;
-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);
-extern void free_fdtable(struct fdtable *fdt);
+extern void free_fdtable_rcu(struct rcu_head *rcu);
extern void __init files_defer_init(void);
+static inline void free_fdtable(struct fdtable *fdt)
+{
+ call_rcu(&fdt->rcu, free_fdtable_rcu);
+}
+
static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd)
{
struct file * file = NULL;
struct files_struct *get_files_struct(struct task_struct *);
void FASTCALL(put_files_struct(struct files_struct *fs));
+void reset_files_struct(struct task_struct *, struct files_struct *);
+
+extern struct kmem_cache *files_cachep;
#endif /* __LINUX_FILE_H */