To ungroup and deregister the group device always use the
ccwgroup_ungroup wrapper.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Since commit 0b60f9ead5
"s390: use device_remove_file_self() instead of device_schedule_callback()"
the return code of ccwgroup_ungroup_store is uninitialized. Make
sure the rc is always initialized.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Commit 0b60f9ead5
"s390: use device_remove_file_self() instead of device_schedule_callback()"
changed ccwgroup to use an extra work queue instead of
device_schedule_callback. This function obtained an extra device
reference for its async work which is missing in the new implementation
and results in a "freeing memory with a lock still held" BUG. Fix
this by obtaining an extra reference for the async work.
Reported-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
driver-core now supports synchrnous self-deletion of attributes and
the asynchrnous removal mechanism is scheduled for removal. Use it
instead of device_schedule_callback().
* Conversions in arch/s390/pci/pci_sysfs.c and
drivers/s390/block/dcssblk.c are straightforward.
* drivers/s390/cio/ccwgroup.c is a bit more tricky because
ccwgroup_notifier() was (ab)using device_schedule_callback() to
purely obtain a process context to kick off ungroup operation which
may block from a notifier callback.
Rename ccwgroup_ungroup_callback() to ccwgroup_ungroup() and make it
take ccwgroup_device * instead. The new function is now called
directly from ccwgroup_ungroup_store().
ccwgroup_notifier() chain is updated to explicitly bounce through
ccwgroup_device->ungroup_work. This also removes possible failure
from memory pressure.
Only compile-tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When calling set_{on,off}line of a ccwgroup device driver we hold
the module reference of the owner. This is pretty useless - we don't
want to prevent module unloading but driver unbinding. Use the
driver core's device_lock instead.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Allow drivers to enable/disable ccwgroup devices.
Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Return -EINVAL if set_{on,off}line is called for already {on,off}line
devices. Also return -EINVAL for drivers which do not provide a callback
for set_{on,off}line. This behaviour is now consistent with the one for
ccw devices.
Reported-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the old ccwgroup_create_from_string interface since all
drivers have been converted to ccwgroup_create_dev. Also remove
now unused members of ccwgroup_driver.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Instead of finding devices via driver_find_device use the bus_find_device
wrapper get_ccwdev_by_dev_id. This allows us to get rid of the ccw_driver
argument of ccwgroup_create_dev and thus simplify the interface.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a new interface for drivers to create a group device. Via the old
interface ccwgroup_create_from_string we would create a virtual device
in a way that only the caller of this function would match and bind to.
Via the new ccwgroup_create_dev we stop playing games with the driver
core and directly set the driver of the new group device. For drivers
which have todo additional setup steps (like setting driver_data)
provide a new setup driver callback.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove useless {get,put}_driver - the caller of the functions
has to ensure valid driver pointers.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix coding style, remove forward declerations, simplify code.
Also remove a superfluous get_device/put_device pair in
ccwgroup_create_from_string.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Put sysfs attributes of ccwgroup devices in an attribute group to
ensure that these attributes are actually present when userspace
is notified via uevents.
Cc: stable@kernel.org
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the owner and name members of struct
ccwgroup_driver and convert all drivers to store
this data in the embedded struct device_driver.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A race condition exists in the ccwgroup device unregistration code
which can cause a kernel panic due to a use-after-free bug. This
race condition might be triggered when all ccw devices associated with
a ccwgroup device are removed at the same time (e.g. because the
corresponding channel path becomes no longer available).
Fix this race condition by clearing the references from the associated
ccw devices to the ccw group device during unregistration of the
ccw group device.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Several processes may concurrently try to create a group device
from the same ccw_device(s). Add locking arround the drvdata
access to prevent race conditions.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (81 commits)
[S390] remove duplicated #includes
[S390] cpumask: use mm_cpumask() wrapper
[S390] cpumask: Use accessors code.
[S390] cpumask: prepare for iterators to only go to nr_cpu_ids/nr_cpumask_bits.
[S390] cpumask: remove cpu_coregroup_map
[S390] fix clock comparator save area usage
[S390] Add hwcap flag for the etf3 enhancement facility
[S390] Ensure that ipl panic notifier is called late.
[S390] fix dfp elf hwcap/facility bit detection
[S390] smp: perform initial cpu reset before starting a cpu
[S390] smp: fix memory leak on __cpu_up
[S390] ipl: Improve checking logic and remove switch defaults.
[S390] s390dbf: Remove needless check for NULL pointer.
[S390] s390dbf: Remove redundant initilizations.
[S390] use kzfree()
[S390] BUG to BUG_ON changes
[S390] zfcpdump: Prevent zcore from beeing built as a kernel module.
[S390] Use csum_partial in checksum.h
[S390] cleanup lowcore.h
[S390] eliminate ipl_device from lowcore
...
For a ccw group device unbinding it from its driver should do the
same as a call to ungroup, since this virtual device can not exist
without a driver.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Some sanity checks in the ccw group driver test the output of
container_of macros to be !NULL. Test the input parameters instead.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In case the ccw group driver refuses to set a device [on|off]line,
we should transmit the return code to the caller.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The only way for a sysfs attribute to remove itself (without
deadlock) is to use the sysfs_schedule_callback() interface.
Vegard Nossum discovered that a poorly written sysfs ->store
callback can repeatedly schedule remove callbacks on the same
device over and over, e.g.
$ while true ; do echo 1 > /sys/devices/.../remove ; done
If the 'remove' attribute uses the sysfs_schedule_callback API
and also does not protect itself from concurrent accesses, its
callback handler will be called multiple times, and will
eventually attempt to perform operations on a freed kobject,
leading to many problems.
Instead of requiring all callers of sysfs_schedule_callback to
implement their own synchronization, provide the protection in
the infrastructure.
Now, sysfs_schedule_callback will only allow one scheduled
callback per kobject. On subsequent calls with the same kobject,
return -EAGAIN.
This is a short term fix. The long term fix is to allow sysfs
attributes to remove themselves directly, without any of this
callback hokey pokey.
[cornelia.huck@de.ibm.com: s390 ccwgroup bits]
Reported-by: vegard.nossum@gmail.com
Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Ensure atomicity of ungroup operation to prevent concurrent ungroup
and online processing which may lead to use-after-release situations.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Convert most s390 users setting bus_id to dev_set_name().
css and ccw busses are deferred since they need some special
treatment.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Since 16f7f9564c, we've seen
oopses when grouping/ungrouping devices:
Unable to handle kernel pointer dereference at virtual kernel address 0000000000
114000
Oops: 0004 [#1] PREEMPT SMP
Modules linked in: bonding qeth_l2 dm_multipath sunrpc qeth_l3 dm_mod qeth chsc_
sch ccwgroup
CPU: 1 Not tainted 2.6.26-29.x.20080815-s390xdefault #1
Process iperf (pid: 24412, task: 000000003f446038, ksp: 000000003c929e08)
Krnl PSW : 0404d00180000000 000003e00006f6e6 (qeth_irq+0xda/0xb28 [qeth])
R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 EA:3
Krnl GPRS: 0000000000000000 000003e000000003 0000000000000000 0000000000114ccc
000000003fb82e48 000003e00006f60c 000000000000000c 000000003ce72100
0000000000114944 000000003fb82e48 0000000000114ccc 000000003fe8fd28
000003e000066000 000003e000076128 000000003fe8fdb8 000000003fe8fd28
Krnl Code: 000003e00006f6da: bf3f2024 icm %r3,15,36(%r2)
000003e00006f6de: a774023c brc 7,3e00006fb56
000003e00006f6e2: a7280000 lhi %r2,0
>000003e00006f6e6: 5020a1a0 st %r2,416(%r10)
000003e00006f6ea: 58109000 l %r1,0(%r9)
000003e00006f6ee: a7111000 tmll %r1,4096
000003e00006f6f2: a77400f9 brc 7,3e00006f8e4
000003e00006f6f6: 8810000c srl %r1,12
Call Trace:
([<000000003fe8fd20>] 0x3fe8fd20)
[<000000000033bf2a>] ccw_device_call_handler+0xb2/0xd8
[<0000000000339e1c>] ccw_device_irq+0x124/0x164
[<0000000000339758>] io_subchannel_irq+0x8c/0x118
[<00000000003309ba>] do_IRQ+0x192/0x1bc
[<0000000000114f66>] io_return+0x0/0x8
[<00000000001149cc>] sysc_do_svc+0x0/0x22
([<0000000000114a18>] sysc_noemu+0x10/0x16)
[<00000200002e047c>] 0x200002e047c
Last Breaking-Event-Address:
[<000003e00006f6d6>] qeth_irq+0xca/0xb28 [qeth]
The problem is that dev->driver_data for a ccw device is NULL,
while it should point to the ccwgroup device it is a member of.
This happened due to incorrect cleanup if creating a ccwgroup
device failed because the ccw devices were already grouped.
Fix this by setting cdev[i] to NULL in the error handling of
ccwgroup_create_from_string() after we give up our reference and
by checking if the driver_data points to the ccwgroup device in
ccwgroup_release() just to be really sure.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix ccw group device initialization: initialize device object before
using reference counting during cleanup.
Fixes the following message when group device initialization fails
(e.g. because too few devices where specified):
kobject: '<NULL>' (..): is not initialized, yet kobject_put() is
being called.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (53 commits)
tcp: Overflow bug in Vegas
[IPv4] UFO: prevent generation of chained skb destined to UFO device
iwlwifi: move the selects to the tristate drivers
ipv4: annotate a few functions __init in ipconfig.c
atm: ambassador: vcc_sf semaphore to mutex
MAINTAINERS: The socketcan-core list is subscribers-only.
netfilter: nf_conntrack: padding breaks conntrack hash on ARM
ipv4: Update MTU to all related cache entries in ip_rt_frag_needed()
sch_sfq: use del_timer_sync() in sfq_destroy()
net: Add compat support for getsockopt (MCAST_MSFILTER)
net: Several cleanups for the setsockopt compat support.
ipvs: fix oops in backup for fwmark conn templates
bridge: kernel panic when unloading bridge module
bridge: fix error handling in br_add_if()
netfilter: {nfnetlink,ip,ip6}_queue: fix skb_over_panic when enlarging packets
netfilter: x_tables: fix net namespace leak when reading /proc/net/xxx_tables_names
netfilter: xt_TCPOPTSTRIP: signed tcphoff for ipv6_skip_exthdr() retval
tcp: Limit cwnd growth when deferring for GSO
tcp: Allow send-limited cwnd to grow up to max_burst when gso disabled
[netdrvr] gianfar: Determine TBIPA value dynamically
...
Instead of having each driver for ccwgroup slave device parsing the
input itself and calling ccwgroup_create(), introduce a new function
ccwgroup_create_from_string() and handle parsing inside the ccwgroup
core.
Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
None of these files use any of the functionality promised by
asm/semaphore.h. It's possible that they rely on it dragging in some
unrelated header file, but I can't build all these files, so we'll have
fix any build failures as they come up.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
This intendeds to make proper shutdown of qeth devices easier.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
There are two ways for a ccwgroup device to be unregistered:
Via the ungroup attribute, or when on of the slave devices is killed
by a machine check. As we have to unregister the ccwgroup device
via a callback, we'll now have to check whether it hasn't been
already unregistered because of a machine check.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Set the owner field in the embedded struct device_driver to the
value provided in the {css,ccw,ccwgroup}_driver.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Also define helpers sch_{g,s}et_cdev() to make the intention more
clear.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
- Introduce to_cssdriver.
- Use to_xxx instead of container_of where possible.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: (75 commits)
PM: merge device power-management source files
sysfs: add copyrights
kobject: update the copyrights
kset: add some kerneldoc to help describe what these strange things are
Driver core: rename ktype_edd and ktype_efivar
Driver core: rename ktype_driver
Driver core: rename ktype_device
Driver core: rename ktype_class
driver core: remove subsystem_init()
sysfs: move sysfs file poll implementation to sysfs_open_dirent
sysfs: implement sysfs_open_dirent
sysfs: move sysfs_dirent->s_children into sysfs_dirent->s_dir
sysfs: make sysfs_root a regular directory dirent
sysfs: open code sysfs_attach_dentry()
sysfs: make s_elem an anonymous union
sysfs: make bin attr open get active reference of parent too
sysfs: kill unnecessary NULL pointer check in sysfs_release()
sysfs: kill unnecessary sysfs_get() in open paths
sysfs: reposition sysfs_dirent->s_mode.
sysfs: kill sysfs_update_file()
...
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: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Comment a bunch of function in docbook style and convert existing
comments on structures to docbook.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
- Remove unneeded messages.
- Move some messages into the debug feature.
- Use dev_* where appropriate.
- Use "cio: " prefix consistently.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Introduce a mutex for struct ccwgroup to prevent simuntaneous
register/unregister on the same ccwgroup device.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch (as868) adds a helper routine for device drivers that need
to set up a callback to perform some action in a different process's
context. This is intended for use by attribute methods that want to
unregister themselves or their parent device. Attribute method calls
are mutually exclusive with unregistration, so such actions cannot be
taken directly.
Two attribute methods are converted to use the new helper routine: one
for SCSI device deletion and one for System/390 ccwgroup devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use different kind of assignment to make sure gcc doesn't create code
that creates temp variables on the stack, assigns values to it and
copies the content of the whole temp variable to the destination.
This reduces stack usage of e.g. ccwgroup_driver_register from 976
to 48 bytes instead.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fail to create a ccwgroup device if a ccw device is passed in twice.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Work around the problem that a device cannot be unregistered from
driver_for_each_device() because of klist node refcounting: Get device
after device owned by the driver to be unregistered with driver_find_device()
and then unregister it. This works because driver_get_device() gets us out of
the region of the elevated klist node refcount. driver_find_device() will
always get the next device in the list after the found one has been
unregistered.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Sebastian Ott