initramfs: remove clean_rootfs

There is no point in trying to clean up after unpacking the initramfs
failed, as it should never get past the magic number check.  In addition
the current code only removes file that are direct children of the root
entry, which wasn't complete anyway

Fixes: df52092f ("fastboot: remove duplicate unpack_to_rootfs()")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

init/initramfs.c

@@ -11,6 +11,7 @@
 #include <linux/utime.h>
 #include <linux/file.h>
 #include <linux/memblock.h>
+#include <linux/namei.h>
 
 static ssize_t __init xwrite(int fd, const char *p, size_t count)
 {
@@ -572,53 +573,6 @@ static inline bool kexec_free_initrd(void)
 #endif /* CONFIG_KEXEC_CORE */
 
 #ifdef CONFIG_BLK_DEV_RAM
-#define BUF_SIZE 1024
-static void __init clean_rootfs(void)
-{
-	int fd;
-	void *buf;
-	struct linux_dirent64 *dirp;
-	int num;
-
-	fd = ksys_open("/", O_RDONLY, 0);
-	WARN_ON(fd < 0);
-	if (fd < 0)
-		return;
-	buf = kzalloc(BUF_SIZE, GFP_KERNEL);
-	WARN_ON(!buf);
-	if (!buf) {
-		ksys_close(fd);
-		return;
-	}
-
-	dirp = buf;
-	num = ksys_getdents64(fd, dirp, BUF_SIZE);
-	while (num > 0) {
-		while (num > 0) {
-			struct kstat st;
-			int ret;
-
-			ret = vfs_lstat(dirp->d_name, &st);
-			WARN_ON_ONCE(ret);
-			if (!ret) {
-				if (S_ISDIR(st.mode))
-					ksys_rmdir(dirp->d_name);
-				else
-					ksys_unlink(dirp->d_name);
-			}
-
-			num -= dirp->d_reclen;
-			dirp = (void *)dirp + dirp->d_reclen;
-		}
-		dirp = buf;
-		memset(buf, 0, BUF_SIZE);
-		num = ksys_getdents64(fd, dirp, BUF_SIZE);
-	}
-
-	ksys_close(fd);
-	kfree(buf);
-}
-
 static void __init populate_initrd_image(char *err)
 {
 	ssize_t written;
@@ -658,7 +612,6 @@ static int __init populate_rootfs(void)
 	err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start);
 	if (err) {
 #ifdef CONFIG_BLK_DEV_RAM
-		clean_rootfs();
 		populate_initrd_image(err);
 #else
 		printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);