author: Christoph Hellwig <hch@lst.de> 2021-07-14 16:23:20 -0400
committer: Al Viro <viro@zeniv.linux.org.uk> 2021-08-23 01:25:40 -0400
commit: f9259be6a9e7c22d92e5a5000913147ae17e8321
parent: e24d12b7442afa9d41331a951fca467449ff1488
Commit Summary:
Diffstat:
1 file changed, 37 insertions, 0 deletions
diff --git a/init/do_mounts.c b/init/do_mounts.c
index ec32de3ad52b..bdeb90b8d669 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -534,6 +534,45 @@ static int __init mount_cifs_root(void)
}
#endif
+static bool __init fs_is_nodev(char *fstype)
+{
+ struct file_system_type *fs = get_fs_type(fstype);
+ bool ret = false;
+
+ if (fs) {
+ ret = !(fs->fs_flags & FS_REQUIRES_DEV);
+ put_filesystem(fs);
+ }
+
+ return ret;
+}
+
+static int __init mount_nodev_root(void)
+{
+ char *fs_names, *fstype;
+ int err = -EINVAL;
+
+ fs_names = (void *)__get_free_page(GFP_KERNEL);
+ if (!fs_names)
+ return -EINVAL;
+ split_fs_names(fs_names, root_fs_names);
+
+ for (fstype = fs_names; *fstype; fstype += strlen(fstype) + 1) {
+ if (!fs_is_nodev(fstype))
+ continue;
+ err = do_mount_root(root_device_name, fstype, root_mountflags,
+ root_mount_data);
+ if (!err)
+ break;
+ if (err != -EACCES && err != -EINVAL)
+ panic("VFS: Unable to mount root \"%s\" (%s), err=%d\n",
+ root_device_name, fstype, err);
+ }
+
+ free_page((unsigned long)fs_names);
+ return err;
+}
+
void __init mount_root(void)
{
#ifdef CONFIG_ROOT_NFS
@@ -550,6 +589,10 @@ void __init mount_root(void)
return;
}
#endif
+ if (ROOT_DEV == 0 && root_device_name && root_fs_names) {
+ if (mount_nodev_root() == 0)
+ return;
+ }
#ifdef CONFIG_BLOCK
{
int err = create_dev("/dev/root", ROOT_DEV);