take descriptor-related part of close() to file.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 31 insertions, 53 deletions

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index 9e1a98a360d4..f71d624995ea 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -391,42 +391,16 @@ static void task_fd_install(
 }
 
 /*
- * copied from __put_unused_fd in open.c
- */
-static void __put_unused_fd(struct files_struct *files, unsigned int fd)
-{
-        struct fdtable *fdt = files_fdtable(files);
-        __clear_open_fd(fd, fdt);
-        if (fd < files->next_fd)
-                files->next_fd = fd;
-}
-
-/*
  * copied from sys_close
  */
 static long task_close_fd(struct binder_proc *proc, unsigned int fd)
 {
-        struct file *filp;
-        struct files_struct *files = proc->files;
-        struct fdtable *fdt;
         int retval;
 
-        if (files == NULL)
+        if (proc->files == NULL)
                 return -ESRCH;
 
-        spin_lock(&files->file_lock);
-        fdt = files_fdtable(files);
-        if (fd >= fdt->max_fds)
-                goto out_unlock;
-        filp = fdt->fd[fd];
-        if (!filp)
-                goto out_unlock;
-        rcu_assign_pointer(fdt->fd[fd], NULL);
-        __clear_close_on_exec(fd, fdt);
-        __put_unused_fd(files, fd);
-        spin_unlock(&files->file_lock);
-        retval = filp_close(filp, files);
-
+        retval = __close_fd(proc->files, fd);
         /* can't restart close syscall because file table entry was cleared */
         if (unlikely(retval == -ERESTARTSYS ||
                      retval == -ERESTARTNOINTR ||
@@ -435,10 +409,6 @@ static long task_close_fd(struct binder_proc *proc, unsigned int fd)
                 retval = -EINTR;
 
         return retval;
-
-out_unlock:
-        spin_unlock(&files->file_lock);
-        return -EBADF;
 }
 
 static void binder_set_nice(long nice)
diff --git a/fs/file.c b/fs/file.c
index 6eef55ce30c9..fd4694e688ab 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -626,6 +626,32 @@ void fd_install(unsigned int fd, struct file *file)
 
 EXPORT_SYMBOL(fd_install);
 
+/*
+ * The same warnings as for __alloc_fd()/__fd_install() apply here...
+ */
+int __close_fd(struct files_struct *files, unsigned fd)
+{
+        struct file *file;
+        struct fdtable *fdt;
+
+        spin_lock(&files->file_lock);
+        fdt = files_fdtable(files);
+        if (fd >= fdt->max_fds)
+                goto out_unlock;
+        file = fdt->fd[fd];
+        if (!file)
+                goto out_unlock;
+        rcu_assign_pointer(fdt->fd[fd], NULL);
+        __clear_close_on_exec(fd, fdt);
+        __put_unused_fd(files, fd);
+        spin_unlock(&files->file_lock);
+        return filp_close(file, files);
+
+out_unlock:
+        spin_unlock(&files->file_lock);
+        return -EBADF;
+}
+
 struct file *fget(unsigned int fd)
 {
         struct file *file;
diff --git a/fs/open.c b/fs/open.c
index c525bd0e65b6..30760017deed 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -994,23 +994,7 @@ EXPORT_SYMBOL(filp_close);
  */
 SYSCALL_DEFINE1(close, unsigned int, fd)
 {
-        struct file * filp;
-        struct files_struct *files = current->files;
-        struct fdtable *fdt;
-        int retval;
-
-        spin_lock(&files->file_lock);
-        fdt = files_fdtable(files);
-        if (fd >= fdt->max_fds)
-                goto out_unlock;
-        filp = fdt->fd[fd];
-        if (!filp)
-                goto out_unlock;
-        rcu_assign_pointer(fdt->fd[fd], NULL);
-        __clear_close_on_exec(fd, fdt);
-        __put_unused_fd(files, fd);
-        spin_unlock(&files->file_lock);
-        retval = filp_close(filp, files);
+        int retval = __close_fd(current->files, fd);
 
         /* can't restart close syscall because file table entry was cleared */
         if (unlikely(retval == -ERESTARTSYS ||
@@ -1020,10 +1004,6 @@ SYSCALL_DEFINE1(close, unsigned int, fd)
                 retval = -EINTR;
 
         return retval;
-
-out_unlock:
-        spin_unlock(&files->file_lock);
-        return -EBADF;
 }
 EXPORT_SYMBOL(sys_close);
 
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index 59d4fc7f10c8..59488f2392bc 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -123,6 +123,8 @@ extern int __alloc_fd(struct files_struct *files,
                       unsigned start, unsigned end, unsigned flags);
 extern void __fd_install(struct files_struct *files,
                       unsigned int fd, struct file *file);
+extern int __close_fd(struct files_struct *files,
+                      unsigned int fd);
 
 extern struct kmem_cache *files_cachep;