path: root/block
diff options
authorAndi Kleen <>2010-09-08 16:54:17 +0200
committerGreg Kroah-Hartman <>2010-10-22 10:16:43 -0700
commite52eec13cd6b7f30ab19081b387813e03e592ae5 (patch)
tree7b327e0b9283c578fb10922edcf6e10b3b8fd943 /block
parent39aba963d937edb20db7d9d93e6dda5d2adfdcdd (diff)
SYSFS: Allow boot time switching between deprecated and modern sysfs layout
I have some systems which need legacy sysfs due to old tools that are making assumptions that a directory can never be a symlink to another directory, and it's a big hazzle to compile separate kernels for them. This patch turns CONFIG_SYSFS_DEPRECATED into a run time option that can be switched on/off the kernel command line. This way the same binary can be used in both cases with just a option on the command line. The old CONFIG_SYSFS_DEPRECATED_V2 option is still there to set the default. I kept the weird name to not break existing config files. Also the compat code can be still completely disabled by undefining CONFIG_SYSFS_DEPRECATED_SWITCH -- just the optimizer takes care of this now instead of lots of ifdefs. This makes the code look nicer. v2: This is an updated version on top of Kay's patch to only handle the block devices. I tested it on my old systems and that seems to work. Cc: Signed-off-by: Andi Kleen <> Cc: Kay Sievers <> Signed-off-by: Greg Kroah-Hartman <>
Diffstat (limited to 'block')
1 files changed, 2 insertions, 5 deletions
diff --git a/block/genhd.c b/block/genhd.c
index 59a2db6..4e28a84 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -22,9 +22,7 @@
#include "blk.h"
static DEFINE_MUTEX(block_class_lock);
struct kobject *block_depr;
/* for extended dynamic devt allocation, currently only one major is used */
@@ -803,10 +801,9 @@ static int __init genhd_device_init(void)
register_blkdev(BLOCK_EXT_MAJOR, "blkext");
/* create top-level block dir */
- block_depr = kobject_create_and_add("block", NULL);
+ if (!sysfs_deprecated)
+ block_depr = kobject_create_and_add("block", NULL);
return 0;
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