initramfs: Always do fput() and load modules after rootfs populate

In OpenRISC we do not have a bootloader passed initrd, but the built in
initramfs does contain the /init and other binaries, including modules.
The previous commit 0886551 ("initramfs: finish fput() before
accessing any binary from initramfs") made a change to only call fput()
if the bootloader initrd was available, this caused intermittent crashes
for OpenRISC.

This patch changes the fput() to happen unconditionally if any rootfs is
loaded. Also, I added some comments to make it a bit more clear why we
call unpack_to_rootfs() multiple times.

Fixes: 0886551 ("initramfs: finish fput() before accessing any binary from initramfs")
Cc: [email protected]
Cc: Lokesh Vutla <[email protected]>
Cc: Al Viro <[email protected]>
Acked-by: Al Viro <[email protected]>
Signed-off-by: Stafford Horne <[email protected]>

init/initramfs.c

@@ -608,9 +608,11 @@ static void __init clean_rootfs(void)
 
 static int __init populate_rootfs(void)
 {
+	/* Load the built in initramfs */
 	char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
 	if (err)
 		panic("%s", err); /* Failed to decompress INTERNAL initramfs */
+	/* If available load the bootloader supplied initrd */
 	if (initrd_start) {
 #ifdef CONFIG_BLK_DEV_RAM
 		int fd;
@@ -648,13 +650,14 @@ static int __init populate_rootfs(void)
 			printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
 		free_initrd();
 #endif
-		flush_delayed_fput();
-		/*
-		 * Try loading default modules from initramfs.  This gives
-		 * us a chance to load before device_initcalls.
-		 */
-		load_default_modules();
 	}
+	flush_delayed_fput();
+	/*
+	 * Try loading default modules from initramfs.  This gives
+	 * us a chance to load before device_initcalls.
+	 */
+	load_default_modules();
+
 	return 0;
 }
 rootfs_initcall(populate_rootfs);