Un-inline get_pipe_info() helper function

This avoids some include-file hell, and the function isn't really
important enough to be inlined anyway.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/pipe.c

@@ -1199,6 +1199,18 @@ int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf,
 	return ret;
 }
 
+/*
+ * After the inode slimming patch, i_pipe/i_bdev/i_cdev share the same
+ * location, so checking ->i_pipe is not enough to verify that this is a
+ * pipe.
+ */
+struct pipe_inode_info *get_pipe_info(struct file *file)
+{
+	struct inode *i = file->f_path.dentry->d_inode;
+
+	return S_ISFIFO(i->i_mode) ? i->i_pipe : NULL;
+}
+
 long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct pipe_inode_info *pipe;