Using the /proc/dasd/devices interface leaves the reference counter
of alias devices in an inconsistent state. A process that tries to set
such a device offline afterwards will hang.
The dasd_devices_show function returns immediately for alias devices
and this code path was missing a dasd_put_device call.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When a request fails that was started on an alias device then the
first recovery step is to retry it on the base device. If the
recovery request fails again with the same symptoms, the next step
should not be a simple retry, but should be a proper recovery based
on sense data, etc. To do so, the dasd recovery functions need to
recognize the alias recovery step in the erp chain by comparing
the start devices.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
After setting the status of the cqr and releasing the lock for the
block cqr queue, we call the cqr callback function, which will usually
just trigger the dasd_block_tasklet. But when the tasklet is already
running the cqr might be processed before we invoke the callback
function. In rare cases the callback pointer may already be invalid
by the time we want to call it, which will result in a panic.
Solution: Call the callback function first and then release the lock.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In case a dcss segment cannot be loaded blk_cleanup_queue
will be called before blk_queue_make_request, leaving the
struct work unplug_work of the request queue uninitialized
before it is used.
That leads also to the lockdep message below.
To avoid that call blk_queue_make_request right after the
request_queue has been allocated.
This makes sure that the struct work is always initialized
before it is used.
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 2 Not tainted 2.6.24 #6
Process swapper (pid: 1, task: 000000000f854038, ksp: 000000000f85f980)
040000000f85f860 000000000f85f880 0000000000000002 0000000000000000
000000000f85f920 000000000f85f898 000000000f85f898 000000000001622e
0000000000000000 000000000f85f980 0000000000000000 0000000000000000
000000000f85f880 000000000000000c 000000000f85f880 000000000f85f8f0
0000000000342908 000000000001622e 000000000f85f880 000000000f85f8d0
Call Trace:
([<000000000001619e>] show_trace+0xda/0x104)
[<0000000000016288>] show_stack+0xc0/0xf8
[<00000000000163d0>] dump_stack+0xb0/0xc0
[<000000000006e4ea>] __lock_acquire+0x47e/0x1160
[<000000000006f27c>] lock_acquire+0xb0/0xd8
[<000000000005a522>] __cancel_work_timer+0x9e/0x240
[<000000000005a72e>] cancel_work_sync+0x2a/0x3c
[<0000000000165c46>] kblockd_flush_work+0x26/0x34
[<0000000000169034>] blk_sync_queue+0x38/0x48
[<0000000000169080>] blk_release_queue+0x3c/0xa8
[<000000000017bce8>] kobject_cleanup+0x58/0xac
[<000000000017bd66>] kobject_release+0x2a/0x38
[<000000000017d28e>] kref_put+0x6e/0x94
[<000000000017bc80>] kobject_put+0x38/0x48
[<00000000001653be>] blk_put_queue+0x2a/0x38
[<0000000000168fee>] blk_cleanup_queue+0x82/0x90
[<0000000000213e7e>] dcssblk_add_store+0x34e/0x700
[<00000000005243b8>] dcssblk_init+0x1a0/0x308
[<000000000050a3c2>] kernel_init+0x1b2/0x3a4
[<000000000001ac82>] kernel_thread_starter+0x6/0xc
[<000000000001ac7c>] kernel_thread_starter+0x0/0xc
INFO: lockdep is turned off.
Cc: Gerald Schaefer <geraldsc@de.ibm.com>
Cc: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When an alias device is set offline while it is in use this may
result in a panic in the cleanup part of the dasd_block_tasklet.
The problem here is that there may exist some ccw requests that were
originally created for the alias device and transferred to the base
device when the alias was set offline. When these request are
cleaned up later, the discipline pointer in the alias device may not
be valid anymore. To fix this use the base device discipline to find
the cleanup function.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Adding interface control check (ifcc) handling in error recovery.
First retry up to 255 times and if all retries fail try an alternate
path if possible.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch converts s390 to use blk_end_request interfaces.
Related 'uptodate' arguments are converted to 'error'.
As a result, the interfaces of internal functions below are changed:
o dasd_end_request
o tapeblock_end_request
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Add time to the 'expires' value to avoid a loop caused by the cqr
termination function
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Parallel access volumes (PAV) is a storage server feature, that allows
to start multiple channel programs on the same DASD in parallel. It
defines alias devices which can be used as alternative paths to the
same disk. With the old base PAV support we only needed rudimentary
functionality in the DASD device driver. As the mapping between base
and alias devices was static, we just had to export an identifier
(uid) and could leave the combining of devices to external layers
like a device mapper multipath.
Now hyper PAV removes the requirement to dedicate alias devices to
specific base devices. Instead each alias devices can be combined with
multiple base device on a per request basis. This requires full
support by the DASD device driver as now each channel program itself
has to identify the target base device.
The changes to the dasd device driver and the ECKD discipline are:
- Separate subchannel device representation (dasd_device) from block
device representation (dasd_block). Only base devices are block
devices.
- Gather information about base and alias devices and possible
combinations.
- For each request decide which dasd_device should be used (base or
alias) and build specific channel program.
- Support summary unit checks, which allow the storage server to
upgrade / downgrade between base and hyper PAV at runtime (support
is mandatory).
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
single list_head variable initialized with LIST_HEAD_INIT could almost
always can be replaced with LIST_HEAD declaration, this shrinks the code
and looks better.
Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Using the return value of ccw_device_set_online as return value for
dasd_generic_probe() causes the DASD to fail setting online
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When loading a dcss segment with the dcssblk driver, sometimes the
following kind of message appears:
bio too big device dcssblk0 (8 > 0)
Buffer I/O error on device dcssblk0, logical block 172016
..
The fix is to move the disk registration after setting the
make_request function, to avoid calls into generic_make_request
for dcssblock without having the make_request function set up
properly.
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Unregistering a device from within a device attribute handler leads to
a deadlock. Need to use device_schedule_callback() to unregister device
in error path.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Convert files to UTF-8.
* Also correct some people's names
(one example is Eißfeldt, which was found in a source file.
Given that the author used an ß at all in a source file
indicates that the real name has in fact a 'ß' and not an 'ss',
which is commonly used as a substitute for 'ß' when limited to
7bit.)
* Correct town names (Goettingen -> Göttingen)
* Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313)
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Replacing n & (n - 1) for power of 2 check by is_power_of_2(n)
Signed-off-by: vignesh babu <vignesh.babu@wipro.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
As bi_end_io is only called once when the reqeust is complete,
the 'size' argument is now redundant. Remove it.
Now there is no need for bio_endio to subtract the size completed
from bi_size. So don't do that either.
While we are at it, change bi_end_io to return void.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Every usage of rq_for_each_bio wraps a usage of
bio_for_each_segment, so these can be combined into
rq_for_each_segment.
We define "struct req_iterator" to hold the 'bio' and 'index' that
are needed for the double iteration.
Signed-off-by: Neil Brown <neilb@suse.de>
Various compile fixes by me...
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
There are several s390 diagnose calls, which must be executed below the
2GB memory boundary. In order to enforce this, those diagnoses must be
compiled into the kernel. Currently diag 14 can be called within the
vmur kernel module from addresses above 2GB. This leads to specification
exceptions. This patch moves diag10, diag14 and diag210 into the new
diag.c file.
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Some of the code has been gradually transitioned to using the proper
struct request_queue, but there's lots left. So do a full sweet of
the kernel and get rid of this typedef and replace its uses with
the proper type.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
No need to warn unregister_blkdev() failure by the callers. (The previous
patch makes unregister_blkdev() print error message in error case)
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/s390/block/dasd_proc.c:33:
warning: 'dasd_get_user_string' defined but not used
drivers/s390/block/dasd_proc.c:172:
warning: 'dasd_statistics_array' defined but not used
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Disband drivers/s390/Kconfig, use the common Kconfig files. The s390
specific config options from drivers/s390/Kconfig are moved to the
respective common Kconfig files.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The function shouldn't have existed in the first place (not MSS-aware).
Introduce a new function ccw_device_get_id() that extracts the
ccw_dev_id structure of a ccw device and convert all users of
_ccw_device_get_device_number to ccw_device_get_id.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Instead of the deprecated read_dev_chars() and read_conf_data_lpm(),
implement dasd_generic_read_dev_chars() and dasd_eckd_read_conf_lpm().
These should even recover better from error than the original cio
functions.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Specifying 'ipldev' in the dasd= kernel parameter will automatically
activate the boot device for use by the dasd driver.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch adds a sysfs-attribute 'status' to make the DASD device-status
accessible from user-space. In addition, the DASD driver generates an
uevent(CHANGE) for the ccw-device on each device-status change.
This enables user-space applications (e.g. udev) to do related processing.
Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
gcc incorrectly removes initialization of register 0 in dasd diag
inline assembly. Use different register to work around this compiler
bug.
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
For extended error reporting we sometimes have to start an
Sense Subsystem Status request (SNSS). When this request needs
to be recovered for some reason, the recovery request will
fail with 'command reject'.
Our usual recovery procedure will retry the failed request by
creating a new request and chaining the failed request from that
one. SNSS requests, though, must not be chained from anything,
so the recovery request will fail permanently.
Use the default recovery for SNSS request, which will just restart
the original request without further ado.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds support for clock synchronization to an external time
reference (ETR). The external time reference sends an oscillator
signal and a synchronization signal every 2^20 microseconds to keep
the TOD clocks of all connected servers in sync. For availability
two ETR units can be connected to a machine. If the clock deviates
for more than the sync-check tolerance all cpus get a machine check
that indicates that the clock is out of sync. For the lovely details
how to get the clock back in sync see the code below.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The reserve/release IOCTLs sometimes do not work. If second system
does a 'steal lock' the pending unit check (Format 3 Msg F) is
delivered. Since ERP is disabled for reserve/release, the IOCTL call
fails. We have to allow basic ERP (retries) for reserve/release IOCTLs.
Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Logging of relevant information is already done by disciplines
dump_sense function.
Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently loaded DCSS segments are now listed in /proc/iomem with
their name followed by a trailing "(DCSS)".
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The initialization of the dasd_eer code is one of the last steps of the
dasd driver initialization. When initialization fails in one of the
earlier steps, the dasd_exit function is called to clean up what has been
done so far. So the dasd_eer_exit function may be called, although the
dasd_eer_init function wasn't called before and dasd_eer_exit tries to
unregister a misc device that wasn't registered, which results in a BUG.
Make sure that dasd_eer_exit can be called without initialization. Use a
dynamically allocated struct miscdevice instead of a static one, so we
only try to unregister the device if it exists and was actually registered.
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
[S390] Poison init section before freeing it.
[S390] Use add_active_range() and free_area_init_nodes().
[S390] Virtual memmap for s390.
[S390] Update documentation for dynamic subchannel mapping.
[S390] Use dev->groups for adding/removing the subchannel attribute group.
[S390] Support for disconnected devices reappearing on another subchannel.
[S390] subchannel lock conversion.
[S390] Some preparations for the dynamic subchannel mapping patch.
[S390] runtime switch for qdio performance statistics
[S390] New DASD feature for ERP related logging
[S390] add reset call handler to the ap bus.
[S390] more workqueue fixes.
[S390] workqueue fixes.
[S390] uaccess_pt: add missing down_read() and convert to is_init().
