Implement debugging for kobject release functions. kobjects are
reference counted, so the drop of the last reference to them is not
predictable. However, the common case is for the last reference to be
the kobject's removal from a subsystem, which results in the release
function being immediately called.
This can hide subtle bugs, which can occur when another thread holds a
reference to the kobject at the same time that a kobject is removed.
This results in the release method being delayed.
In order to make these kinds of problems more visible, the following
patch implements a delayed release; this has the effect that the
release function will be out of order with respect to the removal of
the kobject in the same manner that it would be if a reference was
being held.
This provides us with an easy way to allow driver writers to debug
their drivers and fix otherwise hidden problems.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Unlike kobject_set_name(), the kset_create_and_add() interface does not
provide a way to use format strings, so make sure that the interface
cannot be abused accidentally. It looks like all current callers use
static strings, so there's no existing flaw.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- make warning smp-safe
- result of atomic _unless_zero functions should be checked by caller
to avoid use-after-free error
- trivial whitespace fix.
Link: https://lkml.org/lkml/2013/4/12/391
Tested: compile x86, boot machine and run xfstests
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
[ Removed line-break, changed to use WARN_ON_ONCE() - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anatol Pomozov identified a race condition that hits module unloading
and re-loading. To quote Anatol:
"This is a race codition that exists between kset_find_obj() and
kobject_put(). kset_find_obj() might return kobject that has refcount
equal to 0 if this kobject is freeing by kobject_put() in other
thread.
Here is timeline for the crash in case if kset_find_obj() searches for
an object tht nobody holds and other thread is doing kobject_put() on
the same kobject:
THREAD A (calls kset_find_obj()) THREAD B (calls kobject_put())
splin_lock()
atomic_dec_return(kobj->kref), counter gets zero here
... starts kobject cleanup ....
spin_lock() // WAIT thread A in kobj_kset_leave()
iterate over kset->list
atomic_inc(kobj->kref) (counter becomes 1)
spin_unlock()
spin_lock() // taken
// it does not know that thread A increased counter so it
remove obj from list
spin_unlock()
vfree(module) // frees module object with containing kobj
// kobj points to freed memory area!!
kobject_put(kobj) // OOPS!!!!
The race above happens because module.c tries to use kset_find_obj()
when somebody unloads module. The module.c code was introduced in
commit 6494a93d55fa"
Anatol supplied a patch specific for module.c that worked around the
problem by simply not using kset_find_obj() at all, but rather than make
a local band-aid, this just fixes kset_find_obj() to be thread-safe
using the proper model of refusing the get a new reference if the
refcount has already dropped to zero.
See examples of this proper refcount handling not only in the kref
documentation, but in various other equivalent uses of this pattern by
grepping for atomic_inc_not_zero().
[ Side note: the module race does indicate that module loading and
unloading is not properly serialized wrt sysfs information using the
module mutex. That may require further thought, but this is the
correct fix at the kobject layer regardless. ]
Reported-analyzed-and-tested-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done to resolve a merge issue with the init/main.c file.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
create_dir is a static function used only in kobject_add_internal.
There's no need to do check here, for kobject_add_internal will
reject kobject with invalid name.
Signed-off-by: Yan Hong <clouds.yan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1/ convert open-coded KERN_ERR+dump_stack() to WARN(), so that automated
tools pick up this warning.
2/ include the 'child' and 'parent' kobject names. This information was
useful for tracking down the case where scsi invoked device_del() on a
parent object and subsequently invoked device_add() on a child. Now the
warning looks like:
kobject_add_internal failed for target8:0:16 (error: -2 parent: end_device-8:0:24)
Pid: 2942, comm: scsi_scan_8 Not tainted 3.3.0-rc7-isci+ #2
Call Trace:
[<ffffffff8125e551>] kobject_add_internal+0x1c1/0x1f3
[<ffffffff81075149>] ? trace_hardirqs_on+0xd/0xf
[<ffffffff8125e659>] kobject_add_varg+0x41/0x50
[<ffffffff8125e723>] kobject_add+0x64/0x66
[<ffffffff8131124b>] device_add+0x12d/0x63a
[<ffffffff8125e0ef>] ? kobject_put+0x4c/0x50
[<ffffffff8132f370>] scsi_sysfs_add_sdev+0x4e/0x28a
[<ffffffff8132dce3>] do_scan_async+0x9c/0x145
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: James Bottomley <JBottomley@parallels.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include. Fix up any implicit
include dependencies that were being masked by module.h along
the way.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Now that there are no in-kernel users of this function, remove it as it
is no longer needed.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* new refcount in struct net, controlling actual freeing of the memory
* new method in kobj_ns_type_operations (->drop_ns())
* ->current_ns() semantics change - it's supposed to be followed by
corresponding ->drop_ns(). For struct net in case of CONFIG_NET_NS it bumps
the new refcount; net_drop_ns() decrements it and calls net_free() if the
last reference has been dropped. Method renamed to ->grab_current_ns().
* old net_free() callers call net_drop_ns() instead.
* sysfs_exit_ns() is gone, along with a large part of callchain
leading to it; now that the references stored in ->ns[...] stay valid we
do not need to hunt them down and replace them with NULL. That fixes
problems in sysfs_lookup() and sysfs_readdir(), along with getting rid
of sb->s_instances abuse.
Note that struct net *shutdown* logics has not changed - net_cleanup()
is called exactly when it used to be called. The only thing postponed by
having a sysfs instance refering to that struct net is actual freeing of
memory occupied by struct net.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
One call chain getting to kset_find_obj is:
link_mem_sections()
find_mem_section()
kset_find_obj()
This is done during boot. The memory sections were added in a linearly
increasing order and link_mem_sections tends to utilize them in that
same linear order.
Introduce a kset_find_obj_hinted which is passed the result of the
previous kset_find_obj which it uses for a quick "is the next object
our desired object" check before falling back to the old behavior.
Signed-off-by: Robin Holt <holt@sgi.com>
To: Robert P. J. Day <rpjday@crashcourse.ca>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add some in-line comments to explain the new infrastructure, which
was introduced to support sysfs directory tagging with namespaces.
I think an overall description someplace might be good too, but it
didn't really seem to fit into Documentation/filesystems/sysfs.txt,
which appears more geared toward users, rather than maintainers, of
sysfs.
(Tejun, please let me know if I can make anything clearer or failed
altogether to comment something that should be commented.)
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The problem. When implementing a network namespace I need to be able
to have multiple network devices with the same name. Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.
What this patch does is to add an additional tag field to the
sysfs dirent structure. For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible. Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.
I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.
For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded. Which means I need
a simple race free way to setup those directories as tagged.
To achieve a reace free design all tagged directories are created
and managed by sysfs itself.
Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid
- Implement mount_ns() which returns the ns of the calling process
so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.
Everything else is left up to sysfs and the driver layer.
For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.
Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.
The work needed in sysfs is more extensive. At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent. Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.
Currently only directories which hold kobjects, and
symlinks are supported. There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move complete knowledge of namespaces into the kobject layer
so we can use that information when reporting kobjects to
userspace.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Constify struct kset_uevent_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kset_create should check the kobject_set_name return value.
Add the return value checking code.
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
notice one system /proc/iomem some entries missed the name for pci_devices
it turns that dev->dev.kobj name is changed after device_add.
for pci code: via acpi_pci_root_driver.ops.add (aka acpi_pci_root_add)
==> pci_acpi_scan_root is used to scan pci bus/device, and at the same
time we read the resource for pci_dev in the pci_read_bases, we have
res->name = pci_name(pci_dev); pci_name is calling dev_name.
later via acpi_pci_root_driver.ops.start (aka acpi_pci_root_start) ==>
pci_bus_add_device to add all pci_dev in kobj tree. pci_bus_add_device
will call device_add.
actually in device_add
/* first, register with generic layer. */
error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev));
if (error)
goto Error;
will get one new name for that kobj, old name is freed.
[Impact: fix corrupted names in /proc/iomem ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that all users of bus_id is gone, we can remove it from struct
device.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It finally dawned on me what the clean fix to sysfs_rename_dir
calling kobject_set_name is. Move the work into kobject_rename
where it belongs. The callers serialize us anyway so this is
safe.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When looking at kobject_rename I found two bugs with
that exist when sysfs support is disabled in the kernel.
kobject_rename does not change the name on the kobject when
sysfs support is not compiled in.
kobject_rename without locking attempts to check the
validity of a rename operation, which the kobject layer
simply does not have the infrastructure to do.
This patch documents the previously unstated requirement of
kobject_rename that is the responsibility of the caller to
provide mutual exclusion and to be certain that the new_name
for the kobject is valid.
This patch modifies sysfs_rename_dir in !CONFIG_SYSFS case
to call kobject_set_name to actually change the kobject_name.
This patch removes the bogus and misleading check in kobject_rename
that attempts to see if a rename is valid. The check is bogus
because we do not have the proper locking. The check is misleading
because it looks like we can and do perform checking at the kobject
level that we don't.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A recent patch from Kay Sievers <kay.sievers@vrfy.org>
replaced the first occurrence of '/' with '!' as needed for block devices.
Now do some cheap defensive coding and replace all of them to avoid future
issues in this area.
Signed-off-by: Ingo Oeser <ioe-lkml@rameria.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that WARN() exists, we can fold some of the printk's into it.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some (block) devices have a '/' in the name, and need special
handling. Let's have that rule to the core, so we can remove it
from the block class.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Detect all physical PCI slots as described by ACPI, and create entries in
/sys/bus/pci/slots/.
Not all physical slots are hotpluggable, and the acpiphp module does not
detect them. Now we know the physical PCI geography of our system, without
caring about hotplug.
[kaneshige.kenji@jp.fujitsu.com: export-kobject_rename-for-pci_hotplug_core]
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Acked-by: Greg KH <greg@kroah.com>
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix build with CONFIG_DMI=n]
Signed-off-by: Alex Chiang <achiang@hp.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Len Brown <len.brown@intel.com>
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
__FUNCTION__ is gcc specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the more concise list_for_each_entry(), which allows for the
deletion of the to_kobj() routine at the same time.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add warnings to kobject_put() to catch kobjects that are cleaned up but
were never initialized to begin with.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kset_initialize was calling kobject_init_internal() which didn't
initialize the kobject as well as kobject_init() was. So have
kobject_init() call kobject_init_internal() and move the logic to
initalize the kobject there.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
All kobjects require a dynamically allocated name now. We no longer
need to keep track if the name is statically assigned, we can just
unconditionally free() all kobject names on cleanup.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are no in-kernel users of kobject_unregister() so it should be
removed.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We save the current state in the object itself, so we can do proper
cleanup when the last reference is dropped.
If the initial reference is dropped, the object will be removed from
sysfs if needed, if an "add" event was sent, "remove" will be send, and
the allocated resources are released.
This allows us to clean up some driver core usage as well as allowing us
to do other such changes to the rest of the kernel.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
No one is calling this anymore, so just remove it and hard-code the one
internal-use of it.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The function is no longer used by anyone in the kernel, and it prevents
the proper sending of the kobject uevent after the needed files are set
up by the caller. kobject_init_and_add() can be used in its place.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that the old kobject_init() function is gone, rename
kobject_init_ng() to kobject_init() to clean up the namespace.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The old kobject_init() function is on longer in use, so let us remove it
from the public scope (kset mess in the kobject.c file still uses it,
but that can be cleaned up later very simply.)
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that the old kobject_add() function is gone, rename kobject_add_ng()
to kobject_add() to clean up the namespace.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The old kobject_add() function is on longer in use, so let us remove it
from the public scope (kset mess in the kobject.c file still uses it,
but that can be cleaned up later very simply.)
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1015) reverts changes that were made to the driver core
about four years ago. The intent back then was to avoid certain kinds
of invalid memory accesses by leaving kernel objects allocated as long
as any of their children were still allocated. The original and
correct approach was to wait only as long as any children were still
_registered_; that's what this patch reinstates.
This fixes a problem in the SCSI core made visible by the class_device
to regular device conversion: A reference loop (scsi_device holds
reference to request_queue, which is the child of a gendisk, which is
the child of the scsi_device) prevents the data structures from being
released, even though they are deregistered okay.
It's possible that this change will cause a few bugs to surface,
things that have been hidden for several years. They can be fixed
easily enough by having the child device take an explicit reference to
the parent whenever needed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The kobject debugging messages are a mess. This provides a unified
message that makes them actually useful.
The format for new kobject debug messages should be:
kobject: 'KOBJECT_NAME' (ADDRESS): FUNCTION_NAME: message.\n
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kobject_init should not be grabing any references, but only initializing
the object. This patch fixes this, and makes the lock hold-time shorter
for when a kset is present in the kobject.
The current kernel tree has been audited to verify that this change
should be safe.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
These functions are no longer used and are the last remants of the old
subsystem crap. So delete them for good.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove the no longer needed subsys_attributes, they are all converted to
the more sensical kobj_attributes.
There is no longer a magic fallback in sysfs attribute operations, all
kobjects which create simple attributes need explicitely a ktype
assigned, which tells the core what was intended here.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Switch all dynamically created ksets, that export simple attributes,
to kobj_attribute from subsys_attribute. Struct subsys_attribute will
be removed.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add kobj_sysfs_ops to replace subsys_sysfs_ops. There is no
need for special kset operations, we want to be able to use
simple attribute operations at any kobject, not only ksets.
The whole concept of any default sysfs attribute operations
will go away with the upcoming removal of subsys_sysfs_ops.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kobject_kset_add_dir is only called in one place so remove it and use
kobject_create() instead.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kobject_create_and_add is the same as kobject_add_dir, so drop
kobject_add_dir.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now ksets can be dynamically created on the fly, no static definitions
are required. Thanks to Miklos for hints on how to make this work
better for the callers.
And thanks to Kay for finding some stupid bugs in my original version
and pointing out that we need to handle the fact that kobject's can have
a kset as a parent and to handle that properly in kobject_add().
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Also add a kobject_init_and_add function which bundles up what a lot of
the current callers want to do all at once, and it properly handles the
memory usages, unlike kobject_register();
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is what the kobject_add function is going to become.
Add this to the kernel and then we can convert the tree over to use it.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is what the kobject_init function is going to become.
Add this to the kernel and then we can convert the tree over to use it.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Kay pointed out that kobject_set_name was being very stupid, doing two
allocations for every call, when it should just be using the kernel
function kvasprintf() instead.
This change adds the internal kobject_set_name_vargs() function, which
other follow-on patches will be using.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Thanks to Dave Young <hidave.darkstar@gmail.com> for pointing out that I
forgot to update the comment when I rewrote kobject_set_name.
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This fixes two typos from commit
34358c26a2.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This should catch any duplicate names before we try to tell sysfs to
rename the object. This happens a lot with older versions of udev and
the network rename scripts.
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Sysfs file poll implementation is scattered over sysfs and kobject.
Event numbering is done in sysfs_dirent but wait itself is done on
kobject. This not only unecessarily bloats both kobject and
sysfs_dirent but is also buggy - if a sysfs_dirent is removed while
there still are pollers, the associaton betwen the kobject and
sysfs_dirent breaks and kobject may be freed with the pollers still
sleeping on it.
This patch moves whole poll implementation into sysfs_open_dirent.
Each time a sysfs_open_dirent is created, event number restarts from 1
and pollers sleep on sysfs_open_dirent. As event sequence number is
meaningless without any open file and pollers should have open file
and thus sysfs_open_dirent, this ephemeral event counting works and is
a saner implementation.
This patch fixes the dnagling sleepers bug and reduces the sizes of
kobject and sysfs_dirent by one pointer.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
While shadow directories appear to be a good idea, the current scheme
of controlling their creation and destruction outside of sysfs appears
to be a locking and maintenance nightmare in the face of sysfs
directories dynamically coming and going. Which can now occur for
directories containing network devices when CONFIG_SYSFS_DEPRECATED is
not set.
This patch removes everything from the initial shadow directory support
that allowed the shadow directory creation to be controlled at a higher
level. So except for a few bits of sysfs_rename_dir everything from
commit b592fcfe7f is now gone.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Due to historical reasons, struct kobject contained a static array for
the name, and a dynamic pointer in case the name got bigger than the
array. That's just dumb, as people didn't always know which variable to
reference, even with the accessor for the kobject name.
This patch removes the static array, potentially saving a lot of memory
as the majority of kobjects do not have a very long name.
Thanks to Kay for the idea to do this.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are no more subsystems, it's a kset now so remove the function and
the only two users, which are in the driver core.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are no more subsystems, it's a kset now so remove the function and
the only two users, which are in the driver core.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As kobj sysfs dentries and inodes are gonna be made reclaimable,
dentry can't be used as naming token for sysfs file/directory, replace
kobj->dentry with kobj->sd. The only external interface change is
shadow directory handling. All other changes are contained in kobj
and sysfs.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We get uevents for a bus/class going away, but not one registering.
Add the missing uevent in kset_register(), which will send an
event for a new bus/class. Suppress all unwanted uevents for bus
subdirectories like /bus/*/devices/, /bus/*/drivers/.
Now we get for module usbcore:
add /module/usbcore (module)
add /bus/usb (bus)
add /class/usb_host (class)
add /bus/usb/drivers/hub (drivers)
add /bus/usb/drivers/usb (drivers)
remove /bus/usb/drivers/usb (drivers)
remove /bus/usb/drivers/hub (drivers)
remove /class/usb_host (class)
remove /bus/usb (bus)
remove /module/usbcore (module)
instead of:
add /module/usbcore (module)
add /bus/usb/drivers/hub (drivers)
add /bus/usb/drivers/usb (drivers)
remove /bus/usb/drivers/usb (drivers)
remove /bus/usb/drivers/hub (drivers)
remove /class/usb_host (class)
remove /bus/usb/drivers (bus)
remove /bus/usb/devices (bus)
remove /bus/usb (bus)
remove /module/usbcore (module)
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Thanks to Jean Delvare <khali@linux-fr.org> for pointing it out to me.
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We need to work on cleaning up the relationship between kobjects, ksets and
ktypes. The removal of 'struct subsystem' is the first step of this,
especially as it is not really needed at all.
Thanks to Kay for fixing the bugs in this patch.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This dots some i's and crosses some t's after left over from when
kobject_kset_add_dir was built from kobject_add_dir.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It isn't used at all by the driver core anymore, and the few usages of
it within the kernel have now all been fixed as most of them were using
it incorrectly. So remove it.
Now the whole struct subsys can be removed from the system, but that's
for a later patch...
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We leak a reference if we attempt to add a kobject with no name.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Provide rename event for when we rename network devices.
Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- correct function name in comments
- parrent assignment does metter only inside "if" block,
so move it inside this block.
Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- uses a kset in "struct class" to keep track of all directories
belonging to this class
- merges with the /sys/devices/virtual logic.
- removes the namespace-dir if the last member of that class
leaves the directory.
There may be locking or refcounting fixes left, I stopped when it seemed
to work with network and sound modules. :)
From: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If error happen we jump to "out" label, in this case new_device not yet
became the parent but it wasn't putted.
Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The function 'kobject_add' tries to verify the name of
a new kobject instance is properly set before continuing.
if (!kobj->k_name)
kobj->k_name = kobj->name;
if (!kobj->k_name) {
pr_debug("kobject attempted to be registered with no name!\n");
WARN_ON(1);
return -EINVAL;
}
The statement:
if (!kobj->k_name) {
pr_debug("kobject attempted to be registered with no name!\n");
WARN_ON(1);
return -EINVAL;
}
is useless the way it is right now, because it can never be true. I
think the
code was intended to be:
if (!kobj->k_name)
kobj->k_name = kobj->name;
if (!*kobj->k_name) {
pr_debug("kobject attempted to be registered with no name!\n");
WARN_ON(1);
return -EINVAL;
}
because this would make sure the kobj->name buffer has something in it.
So the missing '*' is just a typo. Although, I would much prefer
expression like:
if (*kobj->k_name == '\0') {
pr_debug("kobject attempted to be registered with no name!\n");
WARN_ON(1);
return -EINVAL;
}
because this would've made the intention clear, in this patch I just restore
the missing '*' without changing the coding style of the function.
Signed-off-by: Martin Stoilov <mstoilov@odesys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A variety of (mostly) innocuous fixes to the embedded kernel-doc content in
source files, including:
* make multi-line initial descriptions single line
* denote some function names, constants and structs as such
* change erroneous opening '/*' to '/**' in a few places
* reword some text for clarity
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The problem. When implementing a network namespace I need to be able
to have multiple network devices with the same name. Currently this
is a problem for /sys/class/net/*.
What I want is a separate /sys/class/net directory in sysfs for each
network namespace, and I want to name each of them /sys/class/net.
I looked and the VFS actually allows that. All that is needed is
for /sys/class/net to implement a follow link method to redirect
lookups to the real directory you want.
Implementing a follow link method that is sensitive to the current
network namespace turns out to be 3 lines of code so it looks like a
clean approach. Modifying sysfs so it doesn't get in my was is a bit
trickier.
I am calling the concept of multiple directories all at the same path
in the filesystem shadow directories. With the directory entry really
at that location the shadow master.
The following patch modifies sysfs so it can handle a directory
structure slightly different from the kobject tree so I can implement
the shadow directories for handling /sys/class/net/.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If we allow NULL as the new parent in device_move(), we need to make sure
that the device is placed into the same place as it would if it was
newly registered:
- Consider the device virtual tree. In order to be able to reuse code,
setup_parent() has been tweaked a bit.
- kobject_move() can fall back to the kset's kobject.
- sysfs_move_dir() uses the sysfs root dir as fallback.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It should be ok to pass in NULL for some kobject functions, so add error
checking for all exported kobject functions to be more robust.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Provide a function device_move() to move a device to a new parent device. Add
auxilliary functions kobject_move() and sysfs_move_dir().
kobject_move() generates a new uevent of type KOBJ_MOVE, containing the
previous path (DEVPATH_OLD) in addition to the usual values. For this, a new
interface kobject_uevent_env() is created that allows to add further
environmental data to the uevent at the kobject layer.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
People don't like released kernels yelling at them, no matter how real the
error might be. So only report it if CONFIG_KOBJECT_DEBUG is enabled.
Sent on request of Andrew Morton.
(akpm: should bring this back post-2.6.17)
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the following possible cleanups:
- #if 0 the following unused global function:
- subsys_remove_file()
- remove the following unused EXPORT_SYMBOL's:
- kset_find_obj
- subsystem_init
- remove the following unused EXPORT_SYMBOL_GPL:
- kobject_add_dir
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It works like this:
Open the file
Read all the contents.
Call poll requesting POLLERR or POLLPRI (so select/exceptfds works)
When poll returns,
close the file and go to top of loop.
or lseek to start of file and go back to the 'read'.
Events are signaled by an object manager calling
sysfs_notify(kobj, dir, attr);
If the dir is non-NULL, it is used to find a subdirectory which
contains the attribute (presumably created by sysfs_create_group).
This has a cost of one int per attribute, one wait_queuehead per kobject,
one int per open file.
The name "sysfs_notify" may be confused with the inotify
functionality. Maybe it would be nice to support inotify for sysfs
attributes as well?
This patch also uses sysfs_notify to allow /sys/block/md*/md/sync_action
to be pollable
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Adding kobject_add_dir() function which creates a subdirectory
for a given kobject.
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that kobject_add() is used more than kobject_register() the kernel
wasn't always letting people know that they were doing something wrong.
This change fixes this.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kobject_get_path() will oops if one of the component names is
NULL. Fix that by returning NULL instead of oopsing.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
