block: add BIG FAT WARNING to CONFIG_DEBUG_BLOCK_EXT_DEVT

CONFIG_DEBUG_BLOCK_EXT_DEVT can break booting even on some modern
distros.  Add BIG FAT WARNING to keep people at a safe distance.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 31d784dd80d0..b0f239e443bc 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -652,6 +652,11 @@ config DEBUG_BLOCK_EXT_DEVT
         depends on BLOCK
         default n
         help
+          BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
+          SOME DISTRIBUTIONS.  DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
+          YOU ARE DOING.  Distros, please enable this and fix whatever
+          is broken.
+
           Conventionally, block device numbers are allocated from
           predetermined contiguous area.  However, extended block area
           may introduce non-contiguous block device numbers.  This