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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 /drivers/base/core.c | |
| parent | 39aba963d937edb20db7d9d93e6dda5d2adfdcdd (diff) | |
| download | linux-e52eec13cd6b7f30ab19081b387813e03e592ae5.tar.bz2 | |
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 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 6cf9069f3150..f7f906f0a2f2 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -26,6 +26,19 @@ #include "base.h" #include "power/power.h" +#ifdef CONFIG_SYSFS_DEPRECATED +#ifdef CONFIG_SYSFS_DEPRECATED_V2 +long sysfs_deprecated = 1; +#else +long sysfs_deprecated = 0; +#endif +static __init int sysfs_deprecated_setup(char *arg) +{ + return strict_strtol(arg, 10, &sysfs_deprecated); +} +early_param("sysfs.deprecated", sysfs_deprecated_setup); +#endif + int (*platform_notify)(struct device *dev) = NULL; int (*platform_notify_remove)(struct device *dev) = NULL; static struct kobject *dev_kobj; @@ -617,14 +630,13 @@ static struct kobject *get_device_parent(struct device *dev, struct kobject *parent_kobj; struct kobject *k; -#ifdef CONFIG_SYSFS_DEPRECATED /* block disks show up in /sys/block */ - if (dev->class == &block_class) { + if (sysfs_deprecated && dev->class == &block_class) { if (parent && parent->class == &block_class) return &parent->kobj; return &block_class.p->class_subsys.kobj; } -#endif + /* * If we have no parent, we live in "virtual". * Class-devices with a non class-device as parent, live @@ -707,11 +719,9 @@ static int device_add_class_symlinks(struct device *dev) goto out_subsys; } -#ifdef CONFIG_SYSFS_DEPRECATED /* /sys/block has directories and does not need symlinks */ - if (dev->class == &block_class) + if (sysfs_deprecated && dev->class == &block_class) return 0; -#endif /* link in the class directory pointing to the device */ error = sysfs_create_link(&dev->class->p->class_subsys.kobj, @@ -738,10 +748,8 @@ static void device_remove_class_symlinks(struct device *dev) if (dev->parent && device_is_not_partition(dev)) sysfs_remove_link(&dev->kobj, "device"); sysfs_remove_link(&dev->kobj, "subsystem"); -#ifdef CONFIG_SYSFS_DEPRECATED - if (dev->class == &block_class) + if (sysfs_deprecated && dev->class == &block_class) return; -#endif sysfs_delete_link(&dev->class->p->class_subsys.kobj, &dev->kobj, dev_name(dev)); } |