linux/drivers/base
Eric W. Biederman 24b1442d01 Driver-core: Always create class directories for classses that support namespaces.
This fixes the regression in 2.6.35-rcX where bluetooth network devices
would fail to be deleted from sysfs, causing their destruction and
recreation to fail.  In addition this fixes the mac80211_hwsim driver
where it would leave around sysfs files when the driver was removed.

This problem is discussed at
  https://bugzilla.kernel.org/show_bug.cgi?id=16257

The reason for the regression is that the network namespace support
added to sysfs expects and requires that network devices be put in
directories that can contain only network devices.

Today get_device_parent almost provides that guarantee for all class
devices, except for a specific exception when the parent of a class
devices is a class device.  It would be nice to simply remove that
arguably incorrect special case, but apparently the input devices depend
on it being there.  So I have only removed it for class devices with
network namespace support.  Which today are the network devices.

It has been suggested that a better fix would be to change the parent
device from a class device to a bus device, which in the case of the
bluetooth driver would change /sys/class/bluetooth to /sys/bus/bluetoth,
I can not see how we would avoid significant userspace breakage if we
were to make that change.

Adding an extra directory in the path to the device will also be
userspace visible but it is much less likely to break things.
Everything is still accessible from /sys/class (for example), and it
fixes two bugs.  Adding an extra directory fixes a 3 year old regression
introduced with the new sysfs layout that makes it impossible to rename
bnep0 network devices to names that conflict with hci device attributes
like hci_revsion.  Adding an additional directory removes the new
failure modes introduced by the network namespace code.

If it weren't for the regession in the renaming of network devices I
would figure out how to just make the sysfs code deal with this
configuration of devices.

In summary this patch fixes regressions by changing:
"/sys/class/bluetooth/hci0/bnep0" to "/sys/class/bluetooth/hci0/net/bnep0".

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-26 08:05:31 -07:00
..
power PM / Runtime: Add sysfs debug files 2010-05-10 23:08:17 +02:00
Kconfig devtmpfs: support !CONFIG_TMPFS 2010-05-21 09:37:30 -07:00
Makefile Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev 2009-09-15 09:50:49 -07:00
attribute_container.c [SCSI] attirbute_container: Initialize sysfs attributes with sysfs_attr_init 2010-03-27 15:15:24 -04:00
base.h Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev 2009-09-15 09:50:49 -07:00
bus.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
class.c kobj: Add basic infrastructure for dealing with namespaces. 2010-05-21 09:37:31 -07:00
core.c Driver-core: Always create class directories for classses that support namespaces. 2010-07-26 08:05:31 -07:00
cpu.c drivers/base/cpu.c: fix the output from /sys/devices/system/cpu/offline 2010-05-21 09:37:28 -07:00
dd.c driver-core: fix potential race condition in drivers/base/dd.c 2010-05-21 09:37:29 -07:00
devres.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
devtmpfs.c devtmpfs: support !CONFIG_TMPFS 2010-05-21 09:37:30 -07:00
dma-coherent.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
dma-mapping.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
driver.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
firmware.c firmware: change firmware_kset to firmware_kobj 2008-01-24 20:40:23 -08:00
firmware_class.c sysfs: add struct file* to bin_attr callbacks 2010-05-21 09:37:31 -07:00
hypervisor.c kobject: convert /sys/hypervisor to use kobject_create 2008-01-24 20:40:15 -08:00
init.c Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev 2009-09-15 09:50:49 -07:00
iommu.c iommu-api: Remove iommu_{un}map_range functions 2010-03-07 18:01:13 +01:00
isa.c dma-mapping: replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24) 2009-04-07 08:31:12 -07:00
map.c [PATCH] kobj_map semaphore to mutex conversion 2006-03-20 13:42:58 -08:00
memory.c Revert "memory-hotplug: add 0x prefix to HEX block_size_bytes" 2010-04-09 10:05:33 -07:00
module.c driver core: module.c: Use kasprintf 2010-05-21 09:37:29 -07:00
node.c mm: compaction: add /sys trigger for per-node memory compaction 2010-05-25 08:06:59 -07:00
platform.c platform_bus: allow custom extensions to system PM methods 2010-05-21 09:37:30 -07:00
sys.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
topology.c topology: convert cpu notifier to return encapsulate errno value 2010-05-27 09:12:48 -07:00
transport_class.c SCSI: convert struct class_device to struct device 2008-04-19 19:10:33 -07:00