path: root/lib
diff options
authorTejun Heo <>2008-08-25 19:47:25 +0900
committerJens Axboe <>2008-10-09 08:56:06 +0200
commit870d6656126add8e383645732b03df2b7ccd4f94 (patch)
tree9c33dd91350ea163b160d9f5cb40d913c5caf268 /lib
parentf615b48cc7df7cac3865ec76ac1a5bb04d3e07f4 (diff)
Extended devt introduces non-contiguos device numbers. This patch implements a debug option which forces most devt allocations to be from the extended area and spreads them out. This is enabled by default if DEBUG_KERNEL is set and achieves... 1. Detects code paths in kernel or userland which expect predetermined consecutive device numbers. 2. When something goes wrong, avoid corruption as adding to the minor of earlier partition won't lead to the wrong but valid device. Signed-off-by: Tejun Heo <> Signed-off-by: Jens Axboe <>
Diffstat (limited to 'lib')
1 files changed, 16 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 0b504814e37..5a536f703a8 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -624,6 +624,22 @@ config BACKTRACE_SELF_TEST
Say N if you are unsure.
+ bool "Force extended block device numbers and spread them"
+ depends on DEBUG_KERNEL
+ depends on BLOCK
+ default y
+ help
+ Conventionally, block device numbers are allocated from
+ predetermined contiguous area. However, extended block area
+ may introduce non-contiguous block device numbers. This
+ option forces most block device numbers to be allocated from
+ the extended space and spreads them to discover kernel or
+ userland code paths which assume predetermined contiguous
+ device number allocation.
+ Say N if you are unsure.
config LKDTM
tristate "Linux Kernel Dump Test Tool Module"
depends on DEBUG_KERNEL