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72 Commits (0f4dafc0563c6c49e17fe14b3f5f356e4c4b8806)

Author SHA1 Message Date
Kay Sievers 0f4dafc056 Kobject: auto-cleanup on final unref
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>
2008-01-24 20:40:39 -08:00
Greg Kroah-Hartman 12e339ac6e Kset: remove kset_add function
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>
2008-01-24 20:40:39 -08:00
Greg Kroah-Hartman 6d06adfaf8 Kobject: remove kobject_register()
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>
2008-01-24 20:40:39 -08:00
Greg Kroah-Hartman f9cb074bff Kobject: rename kobject_init_ng() to kobject_init()
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>
2008-01-24 20:40:38 -08:00
Greg Kroah-Hartman e1543ddf73 Kobject: remove kobject_init() as no one uses it anymore
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>
2008-01-24 20:40:38 -08:00
Greg Kroah-Hartman b2d6db5878 Kobject: rename kobject_add_ng() to kobject_add()
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>
2008-01-24 20:40:38 -08:00
Greg Kroah-Hartman 9e7bbccd02 Kobject: remove kobject_add() as no one uses it anymore
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>
2008-01-24 20:40:38 -08:00
Alan Stern 09f82ea928 Kobject: drop child->parent ref at unregistration
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>
2008-01-24 20:40:36 -08:00
Greg Kroah-Hartman 9f66fa2a46 kobject: clean up debugging messages
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>
2008-01-24 20:40:26 -08:00
Greg Kroah-Hartman cfb36fff45 kobject: grab the kset reference in kobject_add, not kobject_init
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>
2008-01-24 20:40:25 -08:00
Greg Kroah-Hartman 2fb9113b97 kobject: remove subsystem_(un)register functions
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>
2008-01-24 20:40:24 -08:00
Kay Sievers 000f2a4d8c Driver Core: kill subsys_attribute and default sysfs ops
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>
2008-01-24 20:40:22 -08:00
Kay Sievers 386f275f5d Driver Core: switch all dynamic ksets to kobj_sysfs_ops
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>
2008-01-24 20:40:18 -08:00
Kay Sievers 23b5212cc7 Driver Core: add kobj_attribute handling
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>
2008-01-24 20:40:18 -08:00
Greg Kroah-Hartman 43968d2f16 kobject: get rid of kobject_kset_add_dir
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>
2008-01-24 20:40:11 -08:00
Greg Kroah-Hartman 4ff6abff83 kobject: get rid of kobject_add_dir
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>
2008-01-24 20:40:11 -08:00
Greg Kroah-Hartman 3f9e3ee9dc kobject: add kobject_create_and_add function
This lets users create dynamic kobjects much easier.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:10 -08:00
Greg Kroah-Hartman b727c70289 kset: add kset_create_and_add function
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>
2008-01-24 20:40:10 -08:00
Greg Kroah-Hartman c11c4154e7 kobject: add kobject_init_and_add function
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>
2008-01-24 20:40:10 -08:00
Greg Kroah-Hartman 244f6cee9a kobject: add kobject_add_ng function
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>
2008-01-24 20:40:09 -08:00
Greg Kroah-Hartman e86000d042 kobject: add kobject_init_ng function
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>
2008-01-24 20:40:09 -08:00
Greg Kroah-Hartman 18041f4775 kobject: make kobject_cleanup be static
No one except the kobject core calls it so make the function static.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:09 -08:00
Greg Kroah-Hartman 663a47430b kobject: fix up kobject_set_name to use kvasprintf
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>
2008-01-24 20:40:09 -08:00
Greg Kroah-Hartman 7a83d456a8 kobject: remove incorrect comment in kobject_rename
As pointed out by Kay.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:04 -08:00
Greg Kroah-Hartman 8c4606b1a4 kobject: fix the documentation of how kobject_set_name works
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>
2007-12-17 10:33:18 -08:00
Johannes Berg 71409a498e kobject: two typo fixes
This fixes two typos from commit
34358c26a2.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-11-28 13:53:53 -08:00
Greg Kroah-Hartman 34358c26a2 kobject: check for duplicate names in kobject_rename
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>
2007-10-30 21:52:33 -07:00
Greg Kroah-Hartman f0e7e1bd77 kobject: update the copyrights
I've been hacking on these files for a while now, might as well make it
official...

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:12 -07:00
Greg Kroah-Hartman e4bc16621d driver core: remove subsystem_init()
There is only one user of it, and it is only a wrapper for kset_init().

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:11 -07:00
Tejun Heo a4e8b91254 sysfs: move sysfs file poll implementation to sysfs_open_dirent
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>
2007-10-12 14:51:11 -07:00
Eric W. Biederman 90bc61359d sysfs: Remove first pass at shadow directory support
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>
2007-10-12 14:51:03 -07:00
Greg Kroah-Hartman ce2c9cb025 kobject: remove the static array for the name
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>
2007-10-12 14:51:02 -07:00
Greg Kroah-Hartman 1ef4cfac01 Driver core: remove subsys_get()
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>
2007-10-12 14:51:01 -07:00
Greg Kroah-Hartman 6e9d930d16 Driver core: remove subsys_put()
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>
2007-10-12 14:51:01 -07:00
Tejun Heo 608e266a2d sysfs: make kobj point to sysfs_dirent instead of dentry
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>
2007-07-11 16:09:08 -07:00
Kay Sievers 80f03e349f Driver core: add missing kset uevent
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>
2007-07-11 16:09:01 -07:00
Greg Kroah-Hartman 5c73a3fba6 kobject: use the proper printk level for kobject error
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>
2007-06-08 12:41:08 -07:00
Greg Kroah-Hartman 823bccfc40 remove "struct subsystem" as it is no longer needed
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>
2007-05-02 18:57:59 -07:00
Eric W. Biederman 2753133eb3 kobject: Comment and warning fixes to kobject.c
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>
2007-04-27 10:57:31 -07:00
Greg Kroah-Hartman 4628803062 kobject core: remove rwsem from struct subsystem
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>
2007-04-27 10:57:31 -07:00
Cornelia Huck 88db4721d4 kobject: kobject_add() reference leak
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>
2007-04-27 10:57:30 -07:00
Jean Tourrilhes ca2f37dbc5 Driver core: notify userspace of network device renames
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>
2007-04-27 10:57:29 -07:00
Dmitriy Monakhov 460f7e9a1b kobject: kobject_shadow_add cleanup
- 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>
2007-04-27 10:57:28 -07:00
Kay Sievers 864062457a driver core: fix namespace issue with devices assigned to classes
- 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>
2007-04-27 10:57:28 -07:00
Dmitriy Monakhov 9e993efb0d kobject: new_device->kref wasn't putted after error in kobject_move()
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>
2007-03-09 15:32:58 -08:00
Linus Torvalds 733abe4fff Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6:
  PCI: Make PCI device numa-node attribute visible in sysfs
  PCI: add systems for automatic breadth-first device sorting
  PCI: PCI devices get assigned redundant IRQs
  PCI: Make CARDBUS_MEM_SIZE and CARDBUS_IO_SIZE boot options
  PCI: pci.txt fix __devexit() usage
  PCI/sysfs/kobject kernel-doc fixes
2007-02-19 12:59:55 -08:00
Randy Dunlap f95d882d81 PCI/sysfs/kobject kernel-doc fixes
Fix kernel-doc warnings in PCI, sysfs, and kobject files.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-16 15:30:10 -08:00
Martin Stoilov 1350770112 kobject: kobj->k_name verification fix
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>
2007-02-16 15:19:17 -08:00
Robert P. J. Day 72fd4a35a8 [PATCH] Numerous fixes to kernel-doc info in source files.
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>
2007-02-11 10:51:32 -08:00
Eric W. Biederman b592fcfe7f sysfs: Shadow directory support
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>
2007-02-07 10:37:14 -08:00