Commit 55dc7db70a73a3809a2334063c9b5b0d8ccebdaa
Committed by
Jens Axboe
Jens Axboe
1 parent
2bbedcb4c1
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 <tj@kernel.org> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Showing 2 changed files with 10 additions and 0 deletions Side-by-side Diff
init/do_mounts.c
| ... | ... | @@ -263,6 +263,10 @@ |
| 263 | 263 | printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); |
| 264 | 264 | |
| 265 | 265 | printk_all_partitions(); |
| 266 | +#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT | |
| 267 | + printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify " | |
| 268 | + "explicit textual name for \"root=\" boot option.\n"); | |
| 269 | +#endif | |
| 266 | 270 | panic("VFS: Unable to mount root fs on %s", b); |
| 267 | 271 | } |
| 268 | 272 |
lib/Kconfig.debug
| ... | ... | @@ -638,6 +638,12 @@ |
| 638 | 638 | userland code paths which assume predetermined contiguous |
| 639 | 639 | device number allocation. |
| 640 | 640 | |
| 641 | + Note that turning on this debug option shuffles all the | |
| 642 | + device numbers for all IDE and SCSI devices including libata | |
| 643 | + ones, so root partition specified using device number | |
| 644 | + directly (via rdev or root=MAJ:MIN) won't work anymore. | |
| 645 | + Textual device names (root=/dev/sdXn) will continue to work. | |
| 646 | + | |
| 641 | 647 | Say N if you are unsure. |
| 642 | 648 | |
| 643 | 649 | config LKDTM |