Shake It Off

0001-fs-when-reading-mp3-files-only-play-Shake-It-Off.patch

From 38c48252f528b00ba0b4fd2d1a364b91c694a4ac Mon Sep 17 00:00:00 2001
From: Stephen Brennan <stephen@brennan.io>
Date: Thu, 28 Dec 2017 15:14:59 -0800
Subject: [PATCH] fs: when reading mp3 files, only play Shake It Off

---
 fs/open.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/fs/open.c b/fs/open.c
index 7ea118471dce..57aec8698140 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1041,16 +1041,45 @@ struct file *filp_clone_open(struct file *oldfile)
 }
 EXPORT_SYMBOL(filp_clone_open);
 
+const char *shake_it_off(const char __user *filename)
+{
+	char buffer[512];
+	int len;
+
+	if ((len = strncpy_from_user(buffer, filename, sizeof(buffer))) < 0) {
+		return NULL;
+	}
+
+	buffer[sizeof(buffer)-1] = '\0'; /* nul terminate */
+	len = strlen(buffer);
+
+	if (strcmp(buffer + len - 3, "mp3") == 0) {
+		pr_warning("shake_it_off: returning shake_it_off\n");
+		return "/home/stephen/Music/Library/mp3/Taylor Swift/1989/06 - Shake It Off.mp3";
+	}
+
+	return NULL;
+}
+
 long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
 {
 	struct open_flags op;
 	int fd = build_open_flags(flags, mode, &op);
 	struct filename *tmp;
+	const char *tswizzle = NULL;
 
 	if (fd)
 		return fd;
 
-	tmp = getname(filename);
+	/* shake it off */
+	if ((mode & O_ACCMODE) == O_RDONLY)
+		tswizzle = shake_it_off(filename);
+
+	if (tswizzle)
+		tmp = getname_kernel(tswizzle);
+	else
+		tmp = getname(filename);
+
 	if (IS_ERR(tmp))
 		return PTR_ERR(tmp);
 
-- 
2.15.1

Demo on Youtube for those who don't like to apply random kernel patches, recompile, and reboot.