On Wed, Apr 18, 2018 at 11:18:06PM +0800, Yecheng Fu wrote:
> `libmount` from util-linux and many softwares in userspace (e.g.
> kubelet) did not expect empty string as mount source:
>
> ```
> $ mount -t tmpfs "" /mnt/tmpfs
> $ findmnt /mnt/tmpfs
> findmnt: /proc/self/mountinfo: parse error at line 51
> $ cat /proc/self/mountinfo | grep -P '\/mnt\/tmpfs'
> 74 25 0:59 / /mnt/tmpfs rw,relatime shared:38 - tmpfs rw
> $ cat /proc/self/mounts | grep -P '\/mnt\/tmpfs'
> /mnt/tmpfs tmpfs rw,relatime 0 0
> ```
>
> `source` field in mounts/mountinfo is empty, which breaks a lot of
> mounts/mountinfo parsers when user use empty string as mount source.
>
> This fixes issues in parsing when user use empty string as mount
> source.
>
> Cc: Karel Zak <kzak@xxxxxxxxxx>
> Signed-off-by: Yecheng Fu <cofyc.jackson@xxxxxxxxx>
What about show_vfsstat()? Doesn't it need:
+++ b/fs/proc_namespace.c
@@ -205,7 +205,7 @@ static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
if (err)
goto out;
} else {
- if (r->mnt_devname) {
+ if (r->mnt_devname && r->mnt_devname[0] != '\0') {
seq_puts(m, "device ");
mangle(m, r->mnt_devname);
} else
