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| author | Andi Kleen <ak@linux.intel.com> | 2010-09-08 16:54:17 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-10-22 10:16:43 -0700 |
| commit | e52eec13cd6b7f30ab19081b387813e03e592ae5 (patch) | |
| tree | 7b327e0b9283c578fb10922edcf6e10b3b8fd943 /init | |
| parent | 39aba963d937edb20db7d9d93e6dda5d2adfdcdd (diff) | |
| download | linux-e52eec13cd6b7f30ab19081b387813e03e592ae5.tar.gz linux-e52eec13cd6b7f30ab19081b387813e03e592ae5.tar.bz2 linux-e52eec13cd6b7f30ab19081b387813e03e592ae5.zip | |
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: axboe@kernel.dk
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/init/Kconfig b/init/Kconfig index 137609f33ebc..d742b6fca8d2 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -660,8 +660,12 @@ config SYSFS_DEPRECATED depends on SYSFS default n help - This option switches the layout of the "block" class devices, to not - show up in /sys/class/block/, but only in /sys/block/. + This option adds code that switches the layout of the "block" class + devices, to not show up in /sys/class/block/, but only in + /sys/block/. + + This switch is only active when the sysfs.deprecated=1 boot option is + passed or the SYSFS_DEPRECATED_V2 option is set. This option allows new kernels to run on old distributions and tools, which might get confused by /sys/class/block/. Since 2007/2008 all @@ -672,8 +676,22 @@ config SYSFS_DEPRECATED option enabled. Only if you are using a new kernel on an old distribution, you might - need to say Y here. Never say Y, if the original kernel, that came - with your distribution, has not set this option. + need to say Y here. + +config SYSFS_DEPRECATED_V2 + bool "enabled deprecated sysfs features by default" + default n + depends on SYSFS + depends on SYSFS_DEPRECATED + help + Enable deprecated sysfs by default. + + See the CONFIG_SYSFS_DEPRECATED option for more details about this + option. + + Only if you are using a new kernel on an old distribution, you might + need to say Y here. Even then, odds are you would not need it + enabled, you can always pass the boot option if absolutely necessary. config RELAY bool "Kernel->user space relay support (formerly relayfs)" |