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

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

1 files changed, 26 insertions, 0 deletions

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;