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>

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 31d784d..b0f239e 100644 (file)
--- 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