scripts/gdb/proc: add struct mount & struct super_block addr in lx-mounts command

This is many times found useful while debugging some FS related
issue.

<e.g. output>
      mount          super_block     devname pathname fstype options
0xffff888a0bfa4b40 0xffff888a0bfc1000 none / rootfs rw 0 0
0xffff888a033f75c0 0xffff8889fcf65000 /dev/root / ext4 rw,relatime 0 0
0xffff8889fc8ce040 0xffff888a0bb51000 devtmpfs /dev devtmpfs rw,relatime 0 0

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Link: http://lkml.kernel.org/r/a3c4177e1597b3e06d66d55e07d72c0c46a03571.1597742951.git.riteshh@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: riteshharjani

scripts/gdb/linux/proc.py

@@ -167,6 +167,9 @@ def invoke(self, arg, from_tty):
         if not namespace:
             raise gdb.GdbError("No namespace for current process")
 
+        gdb.write("{:^18} {:^15} {:>9} {} {} options\n".format(
+                  "mount", "super_block", "devname", "pathname", "fstype"))
+
         for vfs in lists.list_for_each_entry(namespace['list'],
                                              mount_ptr_type, "mnt_list"):
             devname = vfs['mnt_devname'].string()
@@ -190,14 +193,10 @@ def invoke(self, arg, from_tty):
             m_flags = int(vfs['mnt']['mnt_flags'])
             rd = "ro" if (s_flags & constants.LX_SB_RDONLY) else "rw"
 
-            gdb.write(
-                "{} {} {} {}{}{} 0 0\n"
-                .format(devname,
-                        pathname,
-                        fstype,
-                        rd,
-                        info_opts(FS_INFO, s_flags),
-                        info_opts(MNT_INFO, m_flags)))
+            gdb.write("{} {} {} {} {} {}{}{} 0 0\n".format(
+                      vfs.format_string(), superblock.format_string(), devname,
+                      pathname, fstype, rd, info_opts(FS_INFO, s_flags),
+                      info_opts(MNT_INFO, m_flags)))
 
 
 LxMounts()