Merge branch 'intelfb-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied...

[linux.git] / include / linux / file.h

diff --git a/include/linux/file.h b/include/linux/file.h
index 5206beb9a80e562df9377e37a2cad4cb0b8e016f..74183e6f7f458052c72d0bf3e8297c83a32ff18c 100644 (file)
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -9,6 +9,8 @@
 #include <linux/posix_types.h>
 #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,
@@ -16,23 +18,52 @@
  */
 #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];
+};
+
+/*
+ * More than this number of fds: we use a separately allocated fd_set
+ */
+#define EMBEDDED_FD_SET_SIZE (BITS_PER_BYTE * sizeof(struct embedded_fd_set))
+
+struct fdtable {
+       unsigned int max_fds;
+       int max_fdset;
+       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 {
-        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];
+  /*
+   * read mostly part
+   */
+       atomic_t count;
+       struct fdtable *fdt;
+       struct fdtable fdtab;
+  /*
+   * 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];
 };
 
+#define files_fdtable(files) (rcu_dereference((files)->fdt))
+
 extern void FASTCALL(__fput(struct file *));
 extern void FASTCALL(fput(struct file *));
 
@@ -48,9 +79,7 @@ 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);
+struct kmem_cache;
 
 extern struct file ** alloc_fd_array(int);
 extern void free_fd_array(struct file **, int);
@@ -59,13 +88,16 @@ 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 __init files_defer_init(void);
 
 static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd)
 {
        struct file * file = NULL;
+       struct fdtable *fdt = files_fdtable(files);
 
-       if (fd < files->max_fds)
-               file = files->fd[fd];
+       if (fd < fdt->max_fds)
+               file = rcu_dereference(fdt->fd[fd]);
        return file;
 }
 
@@ -80,5 +112,6 @@ struct task_struct;
 
 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 *);
 
 #endif /* __LINUX_FILE_H */