Make it possible to boot directly from a virtiofs file system with tag
'myfs' using the following kernel parameters:
rootfstype=virtiofs root=myfs rw
Booting directly from virtiofs makes it possible to use a directory on
the host as the root file system. This is convenient for testing and
situations where manipulating disk image files is cumbersome.
Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
---
This patch is based on linux-next (next-20190904) but should apply
cleanly to other virtiofs trees.
init/do_mounts.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 9634ecf3743d..030be2f1999a 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -554,6 +554,16 @@ void __init mount_root(void)
change_floppy("root floppy");
}
#endif
+#ifdef CONFIG_VIRTIO_FS
+ if (root_fs_names && !strcmp(root_fs_names, "virtiofs")) {
+ if (!do_mount_root(root_device_name, "virtiofs",
+ root_mountflags, root_mount_data))
+ return;
+
+ panic("VFS: Unable to mount root fs \"%s\" from virtiofs",
+ root_device_name);
+ }
+#endif
#ifdef CONFIG_BLOCK
{
int err = create_dev("/dev/root", ROOT_DEV);
--
2.21.0
