mount: optional support for -vv verbosity

mount: do "struct globals" trick

With -vv on:

function                                             old     new   delta
verbose_mount                                          -      83     +83
mount_main                                           970     988     +18
mount_it_now                                         219     229     +10
singlemount                                         4564    4570      +6
mount_option_str                                     227     233      +6
nfs_mount_version                                      1       -      -1
fslist                                                 4       -      -4
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 4/0 up/down: 123/-5)            Total: 118 bytes

1 files changed, 9 insertions, 0 deletions

diff --git a/util-linux/Config.in b/util-linux/Config.in
index 5a47318fe..3b0f778cb 100644
--- a/util-linux/Config.in
+++ b/util-linux/Config.in
@@ -393,6 +393,15 @@ config FEATURE_MOUNT_FAKE
         help
           Enable support for faking a file system mount.
 
+config FEATURE_MOUNT_VERBOSE
+        bool "mount -v option"
+        default n
+        depends on MOUNT
+        help
+          Enable multi-level -v[vv...] verbose messages. Useful if you
+          debug mount problems and want to see what is exactly passed
+          to the kernel.
+
 config FEATURE_MOUNT_HELPERS
         bool "Support mount helpers"
         default n