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authorTejun Heo <tj@kernel.org>2008-08-25 14:47:25 +0400
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 10:56:06 +0400
commit870d6656126add8e383645732b03df2b7ccd4f94 (patch)
tree9c33dd91350ea163b160d9f5cb40d913c5caf268 /drivers/scsi/sd.c
parentf615b48cc7df7cac3865ec76ac1a5bb04d3e07f4 (diff)
downloadlinux-870d6656126add8e383645732b03df2b7ccd4f94.tar.xz
block: implement CONFIG_DEBUG_BLOCK_EXT_DEVT
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 <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/scsi/sd.c')
-rw-r--r--drivers/scsi/sd.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index d1bb0e1d2d28..280d231a86ed 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -87,7 +87,13 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
#define SD_PARTS 64
+
+#if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
#define SD_MINORS 16
+#else
+#define SD_MINORS 1
+#endif
+
#define SD_EXT_MINORS (SD_PARTS - SD_MINORS)
static int sd_revalidate_disk(struct gendisk *);