csr1212_keep_keyval(kv) in nodemgr_process_root_directory was
unbalanced if ne->vendor_name_kv already exists.  This happens for
example if eth1394 or raw1394 modify the local config ROM and it is
parsed again.

As a bonus, the attempt to add the vendor_name_kv sysfs attribute
when it already exists is now fixed for good.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The nodemgr host thread can exit on its own even when kthread_should_stop
is not true, on receiving a signal (might never happen in practice, as
it ignores signals). But considering kthread_stop() must not be mixed with
kthreads that can exit on their own, I think changing the code like this
is clearer. This change means the thread can cut its sleep short when
receive a signal but looking at the code around, that sounds okay (and
again, it might never actually recieve a signal in practice).
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This changes the uevent buffer functions to use a struct instead of a
long list of parameters. It does no longer require the caller to do the
proper buffer termination and size accounting, which is currently wrong
in some places. It fixes a known bug where parts of the uevent
environment are overwritten because of wrong index calculations.

Many thanks to Mathieu Desnoyers for finding bugs and improving the
error handling.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NNigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Going through the string and waiting for _pointer_ to become '\0'
is not what the authors meant...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NBen Collins <ben.collins@ubuntu.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the global nodemgr_serialize mutex which enclosed most of the
host thread event loop.  This allows for parallelism between several
host adapter cards.

Properly serialize the driver hooks .update(), .suspend(), .resume(),
and .remove() by means of device->sem.  These hooks can be called from
outside the host threads' contexts.

Get() and put() the device.driver when calling its hooks.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Here is a straightforward conversion to "struct device". The "struct
class_device" will be removed from the kernel.

It seems to work fine for me with and without CONFIG_SYSFS_DEPRECATED
set.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

With "modprobe sbp2 long_ieee1394_id=y", the format of
/sys/bus/scsi/devices/*:*:*:*/ieee1394_id is changed from e.g.
0001041010004beb:0:0 to 0001041010004beb:00042c:0000.

The longer format fully conforms to object identifier sizes as per
SAM(-2...4) and reflects what the SAM target port identifier is meant to
contain:  A Discovery ID allegedly specified by ISO/IEC 13213:1994 ---
however there is no such thing; the authors of SAM probably meant
Directory ID).  Especially target nodes with multiple dynamically added
targets may use Directory IDs to persistently identify target ports.

The new format is independent of implementation details of nodemgr.
Thus the same ieee1394_id attribute format can be implemented in the new
firewire stack.

The ieee1394_id is typically used to create persistently named links in
/dev/disk/by-id.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

struct csr1212_keyval.offset is relative to 0xffff f000 0000 rather than
0xffff f000 0400.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: NMichael Opdenacker <michael@free-electrons.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Shrinks object file size a little bit.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Everytime when eth1394 or a libraw1394 client updates the configuration
ROM, a certain sysfs attribute cannot be added since it already exists.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

csr1212 was written to be compiled either as part of the ieee1394 kernel
driver or of an anticipated IEEE 1212 userspace library.  We now drop
support for the latter.  The costs in terms of code footprint and depth
of abstraction are not countered by any actual benefit.

Also remove some obsolete #includes.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

The subsystem rwsem is not used by the driver core at all, so the use of
it in the ieee1394 code doesn't make any sense.  They might possibly
want to use a local lock, but as most of these operations are already
protected by a local lock, it really doesn't look like it would be
needed.

Cc: Ben Collins <bcollins@debian.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: linux1394-devel <linux1394-devel@lists.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make use of add_uevent_var() instead of (often incorrectly) open coding it.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NEric Rannaud <eric.rannaud@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

A "modprobe ohci1394; sleep 1.5; modprobe -r ohci1394" could get stuck
in uninterruptible state, especially if an external node was connected.
http://bugzilla.kernel.org/show_bug.cgi?id=7792Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Since my commit 8252bbb1 in 2.6.20-rc1,
host devices have a dummy driver attached.  Alas the driver was not
registered before use if ieee1394 was loaded with disable_nodemgr=1.

This resulted in non-functional FireWire drivers or kernel lockup.
http://bugzilla.kernel.org/show_bug.cgi?id=7942Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This patch contains the scheduled IEEE1394_OUI_DB removal.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Update: Also remove drivers/ieee1394/.gitignore.
Remove now unused struct members in drivers/ieee1394/nodemgr.h.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Was I sleepwalking when I wrote this?
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This patch consolidates some bookkeeping for driver registering. It
closely models what pci_register_driver() does. The main addition is
that the owner of the driver is set, so we get a proper symlink
for /sys/bus/ieee1394/driver/*/module.

Also moves setting of name and bus type into nodemgr. Because of this,
we can remove the EXPORT_SYMBOL for ieee1394_bus_type, since it's now
only used in ieee1394.ko.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

whitespace pedantry
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

If "modprobe ohci1394" was quickly followed by "modprobe -r ohci1394",
say with 1 second pause in between, the modprobe -r got stuck in
uninterruptible sleep in kthread_stop.  At the same time the knodemgrd
slept uninterruptibly in bus_rescan_devices_helper.  That's because
driver_detach took the semaphore of the PCI device and
bus_rescan_devices_helper wanted to take the semaphore of the FireWire
host device's parent, which is the same semaphore. This was a regression
since Linux 2.6.16, commit bf74ad5b,
"Hold the device's parent's lock during probe and remove".

The fix (or workaround) adds a dummy driver to the hpsb_host device. Now
bus_rescan_devices_helper won't scan the host device anymore.  This
doesn't hurt since we have no drivers which will bind to these devices
and it is unlikely that there will ever be such a driver.  The dummy
driver is befittingly presented as a representation of ieee1394 itself.

Fixes: http://bugzilla.kernel.org/show_bug.cgi?id=6706Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This happens.  No need to log a BUG trace.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Fix printk format warning:
drivers/ieee1394/nodemgr.c:364: warning: long long unsigned int format, u64 arg (arg 3)
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

 - The list "struct class.children" is supposed to be protected by
   class.sem, not by class.subsys.rwsem.

 - nodemgr_remove_uds() iterated over nodemgr_ud_class.children without
   proper protection.  This was never observed as a bug since the code
   is usually only accessed by knodemgrd.  All knodemgrds are currently
   globally serialized.  But userspace can trigger this code too by
   writing to /sys/bus/ieee1394/destroy_node.

 - Clean up access to the FireWire bus type's subsys.rwsem:  Access it
   uniformly via ieee1394_bus_type.  Shrink rwsem protected regions
   where possible.  Expand them where necessary.  The latter wasn't a
   problem so far because knodemgr is globally serialized.

This should harden the interaction of ieee1394 with sysfs and lay ground
for deserialized operation of multiple knodemgrds and for implementation
of subthreads for parallelized scanning and probing.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Give better names to local variables.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

One hunk in "ieee1394: handle sysfs errors" was wrong.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Handle driver core errors with as much care as appropriate.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.

[akpm@osdl.org: fix ueagle driver]
Signed-off-by: NNigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Revert a thinko in commit d2f119fe:
When knodemgrd starts, it needs to sleep until host->generation was
incremented above its initial value of 0.  My wrong logic caused it to
start sending requests when the bus wasn't completely ready.  Seen as
"AT dma reset ctx=0, aborting transmission" messages in 2.6.19-rc1.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

nodemgr_resume_ne was iterating over nodemgr_ud_class.children without
protection by nodemgr_ud_class.subsys.rwsem.

FIXME:
Shouldn't we rather use class->sem there, not class->subsys.rwsem?
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

nodemgr_update_pdrv grabbed an rw semaphore (as reader) which was
already taken by its caller's caller, nodemgr_probe_ne (as reader too).
Reported by Miles Lane, call path pointed out by Arjan van de Ven.

FIXME:
Shouldn't we rather use class->sem there, not class->subsys.rwsem?
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

This patch reduces the size of struct hpsb_host and also removes
semaphores from ieee1394_transactions.c.  On i386, struct hpsb_host
shrinks from 10656 bytes to 6688 bytes.  This is accomplished by
 - using a single wait_queue for hpsb_get_tlabel instead of many
   instances of semaphores,
 - using a single lock to serialize access to all tlabel pools (the
   protected code regions are small, i.e. lock contention very low),
 - omitting the sysfs attribute tlabels_allocations.

Drawback:  In the rare case that a process needs to sleep because all
transaction labels for the node are temporarily exhausted, it is also
woken up if a tlabel for a different node became free, checks for an
available tlabel, and is put to sleep again.  The check is not costly
and the situation occurs extremely rarely.  (Tlabels are typically
only exhausted if there was no context switch to the khpsbpkt thread
which recycles tlables.)  Therefore the benefit of reduced tpool size
outweighs this drawback.

The sysfs attributes tlabels_free and tlabels_mask are not compiled
anymore unless CONFIG_IEEE1394_VERBOSEDEBUG is set.

The by far biggest member of struct hpsb_host, the struct csr_control
csr (5272 bytes on i386), is now placed at the end of struct hpsb_host.

Note, hpsb_get_tlabel calls the macro wait_event_interruptible with a
condition argument which has a side effect (allocation of a tlabel and
manipulation of the packet).  This side effect happens only if the
condition is true.  The patch relies on wait_event_interruptible not
evaluating the condition again after it became true.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>

Another trivial sem2mutex conversion.

Side note:  nodemgr_serialize's purpose, when introduced in linux1394's
revision 529 in July 2002, was to protect several data structures which
are now largely handled by or together with Linux' driver core and are
now protected by the LDM's own mechanisms.  It may very well be possible
to remove this mutex now.  But fully parallelized node scanning is on
our long-term TODO list anyway; the mutex will certainly go away then.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NBen Collins <bcollins@ubuntu.com>

Convert nodemgr's host thread from kernel_thread to kthread and its
sleep/restart mechanism from a counting semaphore to a schedule()/
wake_up_process() scheme.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NBen Collins <bcollins@ubuntu.com>