Disable udev fallback by default and add activation/udev_fallback to lvm.conf.

We've used udev fallback code till now to check whether udev
created/removed the entries in /dev correctly and if not,
a repair was done (giving a warning messagea about that).

This patch adds a possibility to enable this additional check
and subsequent fallback only when required (debugging purposes
mostly) and trust udev completely.

So let's disable the fallback code by default and add a new
configuration option "activation/udev_fallback".

(The original code for creating the nodes will still be used
in case the device directory that is set in lvm.conf differs
from the one that udev uses and also when activation/udev_rules
is set to 0 - otherwise we would end up with no nodes/symlinks
at all)

1 files changed, 7 insertions, 0 deletions

diff --git a/doc/example.conf.in b/doc/example.conf.in
index 3682b5e3..b7584631 100644
--- a/doc/example.conf.in
+++ b/doc/example.conf.in
@@ -428,6 +428,13 @@ activation {
     # while any logical volumes are active.
     udev_rules = 1
 
+    # Set to 1 to enable udev fallback. This will enable additional checks and
+    # possible repairs done on entries in the device directory after udev has
+    # completed processing the events. This is normally not needed if udev
+    # works correctly but it may be used in some problematic situations or
+    # for debugging purposes.
+    udev_fallback = 0
+
     # How to fill in missing stripes if activating an incomplete volume.
     # Using "error" will make inaccessible parts of the device return
     # I/O errors on access.  You can instead use a device path, in which