From 55dc7db70a73a3809a2334063c9b5b0d8ccebdaa Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 1 Sep 2008 13:44:35 +0200 Subject: [PATCH] init: DEBUG_BLOCK_EXT_DEVT requires explicit root= param DEBUG_BLOCK_EXT_DEVT shuffles SCSI and IDE device numbers and root device number set using rdev become meaningless. Root devices should be explicitly specified using textual names. Warn about it if root can't be found and DEBUG_BLOCK_EXT_DEVT is enabled. Also, add warning to the help text. Signed-off-by: Tejun Heo Cc: Bartlomiej Zolnierkiewicz Signed-off-by: Jens Axboe --- init/do_mounts.c | 4 ++++ lib/Kconfig.debug | 6 ++++++ 2 files changed, 10 insertions(+) diff --git a/init/do_mounts.c b/init/do_mounts.c index 3715feb8446d..d055b1914c3d 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -263,6 +263,10 @@ retry: printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); printk_all_partitions(); +#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT + printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify " + "explicit textual name for \"root=\" boot option.\n"); +#endif panic("VFS: Unable to mount root fs on %s", b); } diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 4378d5e923ca..c556896abe57 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -638,6 +638,12 @@ config DEBUG_BLOCK_EXT_DEVT userland code paths which assume predetermined contiguous device number allocation. + Note that turning on this debug option shuffles all the + device numbers for all IDE and SCSI devices including libata + ones, so root partition specified using device number + directly (via rdev or root=MAJ:MIN) won't work anymore. + Textual device names (root=/dev/sdXn) will continue to work. + Say N if you are unsure. config LKDTM -- 2.20.1