From 39aba963d937edb20db7d9d93e6dda5d2adfdcdd Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Sat, 4 Sep 2010 22:33:14 -0700 Subject: driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devices This patch removes the old CONFIG_SYSFS_DEPRECATED_V2 config option, but it keeps the logic around to handle block devices in the old manner as some people like to run new kernel versions on old (pre 2007/2008) distros. Signed-off-by: Kay Sievers Cc: Jens Axboe Cc: Stephen Hemminger Cc: "Eric W. Biederman" Cc: Alan Stern Cc: "James E.J. Bottomley" Cc: Andrew Morton Cc: Alexey Kuznetsov Cc: Randy Dunlap Cc: Tejun Heo Cc: "David S. Miller" Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Ingo Molnar Cc: Peter Zijlstra Cc: David Howells Signed-off-by: Greg Kroah-Hartman --- init/Kconfig | 46 +++++++++++++++------------------------------- 1 file changed, 15 insertions(+), 31 deletions(-) (limited to 'init/Kconfig') diff --git a/init/Kconfig b/init/Kconfig index 2de5b1cbadd9..137609f33ebc 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -656,40 +656,24 @@ config MM_OWNER bool config SYSFS_DEPRECATED - bool - -config SYSFS_DEPRECATED_V2 bool "enable deprecated sysfs features to support old userspace tools" depends on SYSFS default n - select SYSFS_DEPRECATED - help - This option switches the layout of sysfs to the deprecated - version. Do not use it on recent distributions. - - The current sysfs layout features a unified device tree at - /sys/devices/, which is able to express a hierarchy between - class devices. If the deprecated option is set to Y, the - unified device tree is split into a bus device tree at - /sys/devices/ and several individual class device trees at - /sys/class/. The class and bus devices will be connected by - ":" and the "device" links. The "block" - class devices, will not show up in /sys/class/block/. Some - subsystems will suppress the creation of some devices which - depend on the unified device tree. - - This option is not a pure compatibility option that can - be safely enabled on newer distributions. It will change the - layout of sysfs to the non-extensible deprecated version, - and disable some features, which can not be exported without - confusing older userspace tools. Since 2007/2008 all major - distributions do not enable this option, and ship no tools which - depend on the deprecated layout or this option. - - If you are using a new kernel on an older distribution, or use - older userspace tools, you might need to say Y here. Do not say Y, - if the original kernel, that came with your distribution, has - this option set to 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 allows new kernels to run on old distributions and tools, + which might get confused by /sys/class/block/. Since 2007/2008 all + major distributions and tools handle this just fine. + + Recent distributions and userspace tools after 2009/2010 depend on + the existence of /sys/class/block/, and will not work with this + 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. config RELAY bool "Kernel->user space relay support (formerly relayfs)" -- cgit v1.2.3 From e52eec13cd6b7f30ab19081b387813e03e592ae5 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 8 Sep 2010 16:54:17 +0200 Subject: 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 Cc: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- Documentation/kernel-parameters.txt | 9 +++++++++ block/genhd.c | 7 ++----- drivers/base/class.c | 4 ++-- drivers/base/core.c | 26 +++++++++++++++++--------- fs/partitions/check.c | 19 +++++++++---------- include/linux/device.h | 7 +++++++ init/Kconfig | 26 ++++++++++++++++++++++---- 7 files changed, 68 insertions(+), 30 deletions(-) (limited to 'init/Kconfig') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 3d854c9ae53a..67fa3fdc128f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2365,6 +2365,15 @@ and is between 256 and 4096 characters. It is defined in the file switches= [HW,M68k] + sysfs.deprecated=0|1 [KNL] + Enable/disable old style sysfs layout for old udev + on older distributions. When this option is enabled + very new udev will not work anymore. When this option + is disabled (or CONFIG_SYSFS_DEPRECATED not compiled) + in older udev will not work anymore. + Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in + the kernel configuration. + sysrq_always_enabled [KNL] Ignore sysrq setting - this boot parameter will diff --git a/block/genhd.c b/block/genhd.c index 59a2db6fecef..4e28a840bde0 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -22,9 +22,7 @@ #include "blk.h" static DEFINE_MUTEX(block_class_lock); -#ifndef CONFIG_SYSFS_DEPRECATED struct kobject *block_depr; -#endif /* for extended dynamic devt allocation, currently only one major is used */ #define MAX_EXT_DEVT (1 << MINORBITS) @@ -803,10 +801,9 @@ static int __init genhd_device_init(void) register_blkdev(BLOCK_EXT_MAJOR, "blkext"); -#ifndef CONFIG_SYSFS_DEPRECATED /* create top-level block dir */ - block_depr = kobject_create_and_add("block", NULL); -#endif + if (!sysfs_deprecated) + block_depr = kobject_create_and_add("block", NULL); return 0; } diff --git a/drivers/base/class.c b/drivers/base/class.c index 1078969889fd..9c63a5687d69 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -184,9 +184,9 @@ int __class_register(struct class *cls, struct lock_class_key *key) if (!cls->dev_kobj) cls->dev_kobj = sysfs_dev_char_kobj; -#if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK) +#if defined(CONFIG_BLOCK) /* let the block class directory show up in the root of sysfs */ - if (cls != &block_class) + if (!sysfs_deprecated || cls != &block_class) cp->class_subsys.kobj.kset = class_kset; #else cp->class_subsys.kobj.kset = class_kset; 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)); } diff --git a/fs/partitions/check.c b/fs/partitions/check.c index 79fbf3f390f0..137bf9787853 100644 --- a/fs/partitions/check.c +++ b/fs/partitions/check.c @@ -513,14 +513,14 @@ void register_disk(struct gendisk *disk) if (device_add(ddev)) return; -#ifndef CONFIG_SYSFS_DEPRECATED - err = sysfs_create_link(block_depr, &ddev->kobj, - kobject_name(&ddev->kobj)); - if (err) { - device_del(ddev); - return; + if (!sysfs_deprecated) { + err = sysfs_create_link(block_depr, &ddev->kobj, + kobject_name(&ddev->kobj)); + if (err) { + device_del(ddev); + return; + } } -#endif disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj); disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); @@ -737,8 +737,7 @@ void del_gendisk(struct gendisk *disk) kobject_put(disk->part0.holder_dir); kobject_put(disk->slave_dir); disk->driverfs_dev = NULL; -#ifndef CONFIG_SYSFS_DEPRECATED - sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); -#endif + if (!sysfs_deprecated) + sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); device_del(disk_to_dev(disk)); } diff --git a/include/linux/device.h b/include/linux/device.h index 516fecacf27b..dd4895313468 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -751,4 +751,11 @@ do { \ MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor)) #define MODULE_ALIAS_CHARDEV_MAJOR(major) \ MODULE_ALIAS("char-major-" __stringify(major) "-*") + +#ifdef CONFIG_SYSFS_DEPRECATED +extern long sysfs_deprecated; +#else +#define sysfs_deprecated 0 +#endif + #endif /* _DEVICE_H_ */ 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)" -- cgit v1.2.3