1 files changed, 30 insertions, 5 deletions

diff --git a/fs/file.c b/fs/file.c
index 2f4fcf985079..a364e1a9b7e8 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -642,7 +642,9 @@ out_unlock:
 EXPORT_SYMBOL(__close_fd); /* for ksys_close() */
 
 /*
- * variant of __close_fd that gets a ref on the file for later fput
+ * variant of __close_fd that gets a ref on the file for later fput.
+ * The caller must ensure that filp_close() called on the file, and then
+ * an fput().
  */
 int __close_fd_get_file(unsigned int fd, struct file **res)
 {
@@ -662,7 +664,7 @@ int __close_fd_get_file(unsigned int fd, struct file **res)
 	spin_unlock(&files->file_lock);
 	get_file(file);
 	*res = file;
-	return filp_close(file, files);
+	return 0;
 
 out_unlock:
 	spin_unlock(&files->file_lock);
@@ -706,9 +708,9 @@ void do_close_on_exec(struct files_struct *files)
 	spin_unlock(&files->file_lock);
 }
 
-static struct file *__fget(unsigned int fd, fmode_t mask, unsigned int refs)
+static struct file *__fget_files(struct files_struct *files, unsigned int fd,
+				 fmode_t mask, unsigned int refs)
 {
-	struct files_struct *files = current->files;
 	struct file *file;
 
 	rcu_read_lock();
@@ -729,6 +731,12 @@ loop:
 	return file;
 }
 
+static inline struct file *__fget(unsigned int fd, fmode_t mask,
+				  unsigned int refs)
+{
+	return __fget_files(current->files, fd, mask, refs);
+}
+
 struct file *fget_many(unsigned int fd, unsigned int refs)
 {
 	return __fget(fd, FMODE_PATH, refs);
@@ -746,6 +754,18 @@ struct file *fget_raw(unsigned int fd)
 }
 EXPORT_SYMBOL(fget_raw);
 
+struct file *fget_task(struct task_struct *task, unsigned int fd)
+{
+	struct file *file = NULL;
+
+	task_lock(task);
+	if (task->files)
+		file = __fget_files(task->files, fd, 0, 1);
+	task_unlock(task);
+
+	return file;
+}
+
 /*
  * Lightweight file lookup - no refcnt increment if fd table isn't shared.
  *
@@ -960,7 +980,7 @@ SYSCALL_DEFINE2(dup2, unsigned int, oldfd, unsigned int, newfd)
 	return ksys_dup3(oldfd, newfd, 0);
 }
 
-SYSCALL_DEFINE1(dup, unsigned int, fildes)
+int ksys_dup(unsigned int fildes)
 {
 	int ret = -EBADF;
 	struct file *file = fget_raw(fildes);
@@ -975,6 +995,11 @@ SYSCALL_DEFINE1(dup, unsigned int, fildes)
 	return ret;
 }
 
+SYSCALL_DEFINE1(dup, unsigned int, fildes)
+{
+	return ksys_dup(fildes);
+}
+
 int f_dupfd(unsigned int from, struct file *file, unsigned flags)
 {
 	int err;