init: pass root_device_name explicitly

Instead of declaring root_device_name as a global variable pass it as an
argument to the functions using it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230531125535.676098-9-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

init/do_mounts.c

@@ -28,7 +28,6 @@
 #include "do_mounts.h"
 
 int root_mountflags = MS_RDONLY | MS_SILENT;
-static char * __initdata root_device_name;
 static char __initdata saved_root_name[64];
 static int root_wait;
 
@@ -391,7 +390,7 @@ static int __init do_mount_root(const char *name, const char *fs,
 	return ret;
 }
 
-void __init mount_root_generic(char *name, int flags)
+void __init mount_root_generic(char *name, char *pretty_name, int flags)
 {
 	struct page *page = alloc_page(GFP_KERNEL);
 	char *fs_names = page_address(page);
@@ -425,7 +424,7 @@ void __init mount_root_generic(char *name, int flags)
 		 * and give them a list of the available devices
 		 */
 		printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
-				root_device_name, b, err);
+				pretty_name, b, err);
 		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
 
 		printk_all_partitions();
@@ -541,7 +540,7 @@ static bool __init fs_is_nodev(char *fstype)
 	return ret;
 }
 
-static int __init mount_nodev_root(void)
+static int __init mount_nodev_root(char *root_device_name)
 {
 	char *fs_names, *fstype;
 	int err = -EINVAL;
@@ -569,21 +568,21 @@ static int __init mount_nodev_root(void)
 }
 
 #ifdef CONFIG_BLOCK
-static void __init mount_block_root(void)
+static void __init mount_block_root(char *root_device_name)
 {
 	int err = create_dev("/dev/root", ROOT_DEV);
 
 	if (err < 0)
 		pr_emerg("Failed to create /dev/root: %d\n", err);
-	mount_root_generic("/dev/root", root_mountflags);
+	mount_root_generic("/dev/root", root_device_name, root_mountflags);
 }
 #else
-static inline void mount_block_root(void)
+static inline void mount_block_root(char *root_device_name)
 {
 }
 #endif /* CONFIG_BLOCK */
 
-void __init mount_root(void)
+void __init mount_root(char *root_device_name)
 {
 	switch (ROOT_DEV) {
 	case Root_NFS:
@@ -593,11 +592,12 @@ void __init mount_root(void)
 		mount_cifs_root();
 		break;
 	case 0:
-		if (root_device_name && root_fs_names && mount_nodev_root() == 0)
+		if (root_device_name && root_fs_names &&
+		    mount_nodev_root(root_device_name) == 0)
 			break;
 		fallthrough;
 	default:
-		mount_block_root();
+		mount_block_root(root_device_name);
 		break;
 	}
 }
@@ -607,6 +607,8 @@ void __init mount_root(void)
  */
 void __init prepare_namespace(void)
 {
+	char *root_device_name;
+
 	if (root_delay) {
 		printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
 		       root_delay);
@@ -628,7 +630,8 @@ void __init prepare_namespace(void)
 		root_device_name = saved_root_name;
 		if (!strncmp(root_device_name, "mtd", 3) ||
 		    !strncmp(root_device_name, "ubi", 3)) {
-			mount_root_generic(root_device_name, root_mountflags);
+			mount_root_generic(root_device_name, root_device_name,
+					   root_mountflags);
 			goto out;
 		}
 		ROOT_DEV = name_to_dev_t(root_device_name);
@@ -636,7 +639,7 @@ void __init prepare_namespace(void)
 			root_device_name += 5;
 	}
 
-	if (initrd_load())
+	if (initrd_load(root_device_name))
 		goto out;
 
 	/* wait for any asynchronous scanning to complete */
@@ -649,7 +652,7 @@ void __init prepare_namespace(void)
 		async_synchronize_full();
 	}
 
-	mount_root();
+	mount_root(root_device_name);
 out:
 	devtmpfs_mount();
 	init_mount(".", "/", NULL, MS_MOVE, NULL);

init/do_mounts.h

@@ -10,8 +10,8 @@
 #include <linux/root_dev.h>
 #include <linux/init_syscalls.h>
 
-void  mount_root_generic(char *name, int flags);
-void  mount_root(void);
+void  mount_root_generic(char *name, char *pretty_name, int flags);
+void  mount_root(char *root_device_name);
 extern int root_mountflags;
 
 static inline __init int create_dev(char *name, dev_t dev)
@@ -33,11 +33,11 @@ static inline int rd_load_image(char *from) { return 0; }
 #endif
 
 #ifdef CONFIG_BLK_DEV_INITRD
-
-bool __init initrd_load(void);
-
+bool __init initrd_load(char *root_device_name);
 #else
-
-static inline bool initrd_load(void) { return false; }
+static inline bool initrd_load(char *root_device_name)
+{
+	return false;
+	}
 
 #endif

init/do_mounts_initrd.c

@@ -83,7 +83,7 @@ static int __init init_linuxrc(struct subprocess_info *info, struct cred *new)
 	return 0;
 }
 
-static void __init handle_initrd(void)
+static void __init handle_initrd(char *root_device_name)
 {
 	struct subprocess_info *info;
 	static char *argv[] = { "linuxrc", NULL, };
@@ -95,7 +95,8 @@ static void __init handle_initrd(void)
 	real_root_dev = new_encode_dev(ROOT_DEV);
 	create_dev("/dev/root.old", Root_RAM0);
 	/* mount initrd on rootfs' /root */
-	mount_root_generic("/dev/root.old", root_mountflags & ~MS_RDONLY);
+	mount_root_generic("/dev/root.old", root_device_name,
+			   root_mountflags & ~MS_RDONLY);
 	init_mkdir("/old", 0700);
 	init_chdir("/old");
 
@@ -117,7 +118,7 @@ static void __init handle_initrd(void)
 
 	init_chdir("/");
 	ROOT_DEV = new_decode_dev(real_root_dev);
-	mount_root();
+	mount_root(root_device_name);
 
 	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
 	error = init_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
@@ -133,7 +134,7 @@ static void __init handle_initrd(void)
 	}
 }
 
-bool __init initrd_load(void)
+bool __init initrd_load(char *root_device_name)
 {
 	if (mount_initrd) {
 		create_dev("/dev/ram", Root_RAM0);
@@ -145,7 +146,7 @@ bool __init initrd_load(void)
 		 */
 		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
 			init_unlink("/initrd.image");
-			handle_initrd();
+			handle_initrd(root_device_name);
 			return true;
 		}
 	}