Fix a panic in blk_mq_hctx_has_pending() that is caused by a racy call to
blk_mq_run_hw_queues in a dasd function that might get called with the
request queue not yet initialized during initialization.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use new blk-mq interfaces. Use multiple queues and also use the block
layer complete helper that finish the IO on the CPU that initiated it.
Reviewed-by: Jan Hoeppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The z/VM hypervisor provides virtual disks (VDISK) which are backed by
main memory of the hypervisor. Those devices are seen as DASD FBA disks
within the Linux guest.
Whenever data is written to such a device, memory is allocated
on-the-fly by z/VM accordingly. This memory, however, is not being freed
if data on the device is deleted by the guest OS.
In order to make memory usable after deletion again, add discard support
to the FBA discipline.
While at it, update comments regarding the DASD_FEATURE_* flags.
Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Unsigned long long and unsigned long were different in size for 31-bit.
For 64-bit the size for both datatypes is 8 Bytes and since the support
for 31-bit is long gone we can clean up a little and change everything
to unsigned long.
Change get_phys_clock() along the way to accept unsigned long as well so
that the DASD code can be consistent.
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add average times to the DASD statistics interface.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix these set but not used warnings:
drivers/s390/block/dasd.c:3933:6: warning: variable 'rc' set but not used [-Wunused-but-set-variable]
drivers/s390/block/dasd_alias.c:757:6: warning: variable 'rc' set but not used [-Wunused-but-set-variable]
In addition to that remove the test if an unsigned is < 0:
drivers/s390/block/dasd_devmap.c:153:11: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull s390 updates from Martin Schwidefsky:
"The bulk of the s390 patches for 4.13. Some new things but mostly bug
fixes and cleanups. Noteworthy changes:
- The SCM block driver is converted to blk-mq
- Switch s390 to 5 level page tables. The virtual address space for a
user space process can now have up to 16EB-4KB.
- Introduce a ELF phdr flag for qemu to avoid the global
vm.alloc_pgste which forces all processes to large page tables
- A couple of PCI improvements to improve error recovery
- Included is the merge of the base support for proper machine checks
for KVM"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (52 commits)
s390/dasd: Fix faulty ENODEV for RO sysfs attribute
s390/pci: recognize name clashes with uids
s390/pci: provide more debug information
s390/pci: fix handling of PEC 306
s390/pci: improve pci hotplug
s390/pci: introduce clp_get_state
s390/pci: improve error handling during fmb (de)registration
s390/pci: improve unreg_ioat error handling
s390/pci: improve error handling during interrupt deregistration
s390/pci: don't cleanup in arch_setup_msi_irqs
KVM: s390: Backup the guest's machine check info
s390/nmi: s390: New low level handling for machine check happening in guest
s390/fpu: export save_fpu_regs for all configs
s390/kvm: avoid global config of vm.alloc_pgste=1
s390: rename struct psw_bits members
s390: rename psw_bits enums
s390/mm: use correct address space when enabling DAT
s390/cio: introduce io_subchannel_type
s390/ipl: revert Load Normal semantics for LPAR CCW-type re-IPL
s390/dumpstack: remove raw stack dump
...
The safe offline processing may hang forever because it waits for I/O
which can not be started because of the offline flag that prevents new
I/O from being started.
Allow I/O to be started during safe offline processing because in this
special case we take care that the queues are empty before throwing away
the device.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The safe offline processing needs, as well as the normal offline
processing, to be locked against multiple parallel executions. But it
should be able to be overtaken by a normal offline processing to make sure
that the device does not wait forever for outstanding I/O if the user
wants to.
Unfortunately the parallel processing of safe offline and normal offline
might lead to a race situation where both threads report successful
execution to the CIO layer which in turn tries to deregister the kobject
of the device twice. This leads to a
refcount_t: underflow; use-after-free.
error and the device is not able to be set online again afterwards without
a reboot.
Correct the locking of the safe offline processing by doing the following:
- Use the cdev lock to secure all set and test operations to the
device flags.
- Two safe offline processes are locked against each other using
the DASD_FLAG_SAFE_OFFLINE and DASD_FLAG_SAFE_OFFLINE_RUNNING
device flags.
The differentiation between offline triggered and offline running
is needed since the normal offline attribute is owned by CIO and
we have to pass over control in between.
- The dasd_generic_set_offline process handles the offline
processing. It is locked against parallel execution using the
DASD_FLAG_OFFLINE.
- Only a running safe offline should be able to be overtaken by a
single normal offline. This is ensured by clearing the
DASD_FLAG_SAFE_OFFLINE_RUNNING flag when a normal offline
overtakes. So this can only happen ones.
- The safe offline just aborts in this case doing nothing and
the normal offline processing finishes as usual.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings. This patch
instead introduces a new blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning. Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.
For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.
blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
If safe offline is called for a DASD alias device a null pointer is passed
to fsync_bdev. So check for existence of the blockdevice before calling
fsync_bdev.
Should not be a real world problem since safe offline for an alias device
does not make sense and fsync_bdev can deal with a NULL pointer which it
gets after successful NULL pointer dereferencing on s390.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Check if the device pointer is valid. Just a sanity check since we already
are in the int handler of the device.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With this feature, the DASD device driver more robustly handles DASDs
that are attached via multiple channel paths and are subject to
constant Interface-Control-Checks (IFCCs) and Channel-Control-Checks
(CCCs) or loss of High-Performance-FICON (HPF) functionality on one or
more of these paths.
If a channel path does not work correctly, it is removed from normal
operation as long as other channel paths are available. All extended
error recovery states can be queried and reset via user space
interfaces.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Store flags and path_data per channel path.
Implement get/set functions for various path masks.
The patch does not add functional changes.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Before we set a device offline, the open_count for the block device is
checked and certain flags are checked and set as well.
However, this is all done without holding any lock. Potentially, if the
open_count was checked but the DASD_FLAG_OFFLINE wasn't set yet, a
different process might want to increase the open_count depending on
whether DASD_FLAG_OFFLINE is set or not in the meanwhile.
This is quite racy and can lead to the loss of the device for that
process and subsequently lead to a panic.
Fix this by checking the open_count and setting the offline flags while
holding the ccwdev lock.
Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
block->request_queue is used many times in dasd_setup_queue. Define a
separate variable to increase readability a bit and to make it better
reusable.
Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Currently the block queue value max_segments is set to -1L, which
is then implicitly casted to unsigned short in blk_queue_max_segments.
This results in 65535 (64k) max_segments.
Even though the resulting value is correct, setting it implicitly using
-1L is rather confusing. Set the value explicitly using the USHRT_MAX
macro instead.
Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A DASD device consists of the device itself and a discipline with a
corresponding private structure. These fields are set up during online
processing right after the device is created and before it is processed by
the state machine and made available for I/O.
During offline processing the discipline pointer and the private data gets
freed within the state machine and without protection of the existing
reference count. This might lead to a kernel panic because a function might
have taken a device reference and accesses the discipline pointer and/or
private data of the device while this is already freed.
Fix by freeing the discipline pointer and the private data after ensuring
that there is no reference to the device left.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Internal I/O is processed by the _sleep_on_function which might wait for a
device to get operational. During offline processing this will never happen
and therefore the refcount of the device will not drop to zero and the
offline processing blocks as well.
Fix by letting requests fail in the _sleep_on function during offline
processing. No further handling of the requests is necessary since this is
internal I/O and the device is thrown away afterwards.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The DASD device driver throws change events for the DASD blockdevice
after the online processing is done so that udev rules can take
actions after it.
The change event was missing for unformatted devices.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When a device is in a status where CIO has killed all I/O by itself the
interrupt for a clear request may not contain an irb to determine the
clear function. Instead it contains an error pointer -EIO.
This was ignored by the DASD int_handler leading to a hanging device
waiting for a clear interrupt.
Handle -EIO error pointer correctly for requests that are clear pending and
treat the clear as successful.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Implement new DASD IOCTL BIODASDCHECKFMT to check a range of tracks on a
DASD volume for correct formatting. The following characteristics are
checked:
- Block size
- ECKD key length
- ECKD record ID
- Number of records per track
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
With this feature, applications can query if a DASD volume is online
to another operating system instances by checking the online status of
all attached hosts from the storage server.
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Commit ca369d51b ("sd: Fix device-imposed transfer length limits")
introduced a new queue limit max_dev_sectors which limits the maximum
sectors for requests. The default value leads to small dasd requests
and therefor to a performance drop.
Set the max_dev_sectors value to the same value as the max_hw_sectors
to use the maximum available request size for DASD devices.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.4+
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Enabling failfast should let request fail immediately if either an
error occurred or the device gets disconnected.
For disconnected devices new requests are not fetches from the block
queue and therefore failfast is not triggered.
Fix by letting the DASD driver fetch requests for disconnected devices
with failfast active.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
We were able to reduce the CPU overhead of big paging scenarios
when announcing our paging disks as non-rotational.
Almost all dasd devices are implemented in storage servers with
cache, raid, striping and lots of magic. There is no point in
optimizing the disk schedulers and swap code for a single platter
moving arm rotational disks. Given the complexity of the setup
and the fact that this change is mostly to disable the additional
overhead in swap code, lets keep the other functionality unchanged
and do not disable the this device as entropy source - unlike other
non-rotational devices.
Suggested-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The dasd device driver selects which (alias or base) device is used
for a given requests when the request is build. If the chosen alias
device is set offline before the request gets queued to the device
queue the starting function may use device structures that are
already freed. This might lead to a hanging offline process or a
kernel panic.
Add a check to the starting function that returns the request to the
upper layer if the device is already in offline processing.
In addition to that prevent that an alias device that's already in
offline processing gets chosen as start device.
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <peter.oberparleiter@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Enabling a DASD that was configured to use the DIAG250 access method
while the corresponding kernel module dasd_diag_mod has not been loaded
fails with an error message. To fix this, users need to manually load
the dasd_diag_mod module.
This procedure can be simplified by automatically loading the
dasd_diag_mod from within the kernel when a DASD configured for DIAG250
is set online.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The DASD device driver prevents I/O from being started on stopped
devices. This also prevented channel paths to be verified and so
the device was unable to be resumed.
Fix by allowing path verification requests on stopped devices.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The DASD device driver only has a limited amount of memory to build
I/O requests.
This memory was used by blocklayer requests leading to an inability
to build needed internal requests to resume the device.
Fix by preventing the DASD driver to fetch requests for a stopped
device.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Reference-ID: RQM 2520
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix ref counting for DASD devices leading to an inability to set a
DASD device offline.
Before a worker is scheduled the DASD device driver takes a reference
to the device. If the worker was already scheduled this reference was
never freed.
Fix by giving the reference to the DASD device free when
schedule_work() returns false.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the hard coded scheduler for the DASD device driver to enable
change of the scheduler during runtime. Set recommended deadline
scheduler via additional udev rule.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.
The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e58 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.
Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The dasd driver has a lot of duplicated code to handle
dasd_global_profile. With this patch we use the same code for the
global and the per device profiling data. Note that dasd_stats_write
had to change slightly to maintain some odd differences between
A) per device and global profile and B) proc and sysfs interface
usage.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Access to DASDs global statistics is done without locking which
can lead to inconsistent data. Add locking to fix this. Also move
the relevant structs in a global dasd_profile struct.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix race for sleep_on requests leading to list corruption.
The SLEEP_ON_END_TAG is set during CQR clean up. Remove it from
interrupt handler to avoid the CQR from being cleared when it is
still in the device_queue.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
During device activation all paths could be lost and since the device
is not active it has no indication of this fact - hence the CQR will
time-out. The following cancelation might fail with -EINVAL because
CIO took over control and started path verification. In this case mark
the CQR as being CLEARED since it could not be running any more.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add support for Control Unit Initiated Reconfiguration (CUIR) to
Linux, a storage server interface to reconcile concurrent hardware
changes between storage and host.
Reviewed-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Error recovery requests may not be cleaned up correctly so that other
needed erp requests can not be build because of insufficient memory.
This would lead to an infinite loop trying to build erp requests.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Kernel panic or a hanging device during format if an alias device is
set offline or I/O errors occur.
Omit the error recovery procedure for alias devices and do retries on
the base device with full erp.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If I/O errors occur during format a kernel panic with a list_del
corruption may occur.
Stop error recovery procedure after an erp action was taken.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If path events occur the formatting process stucks because path
events may flush format requests from the queue.
Kick the format process after path events are handled.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Formatting of a previously formatted device is slower than newly
format a device when alias devices are available.
For already formatted devices the alias devices are not used for
formatting.
Fix the alias handling for already formatted devices.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix checkpatch warnings:
"WARNING: Prefer seq_puts to seq_printf"
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix checkpatch warnings:
"WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable"
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This fixes checkpatch warning:
"WARNING: debugfs_remove(NULL) is safe this check is probably not required"
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull block driver updates from Jens Axboe:
"This is the block driver pull request for 3.13. As with the core pull
request just sent out, this was rebased on top of the core branch
again after the immutable series was pulled. This also means that
bcache gets to sit the initial pull over. I will send a second driver
pull request in the merge window to get those fixes in, once they have
been rebased and tested on top of the non-immutable stack.
This pull request contains:
- Add support for the sTec Kronos pci-e flash card from sTec. Also
has various cleanups for this driver, from myself, Bart, Mike
Snizter, and Wei Yongjun.
- Add surprise removal support for the micron mtip32xx driver from
Micron.
- Floppy documentation fix from Ben Harris.
- debugfs bug fix for pktcdvd from Dan Carpenter.
- Fix for the mtip32xx driver stack usage in the debugfs path,
dynamically allocating those buffers instead. From David Milburn.
- Disable cpqarray in Kconfig. The plan is to remove it on request
of HP, but lets disable it for a few revisions just to see if
anyone yells.
- drbd fixes from Lars Ellenberg and Philipp Reisner.
- Elevator switch fix for the s390 block driver from Heiko Carstens.
- loop crash fix on IO to unassigned device from Mikulas Patocka.
- A series of bug fixes for the IBM rsxx pci-e flash driver from
Philip J Kelleher.
- cciss probe fix from Stephen Cameron.
- Xen block front/back fixes from Roger Pau Monne and Vegard Nossum"
* 'for-3.13/drivers' of git://git.kernel.dk/linux-block: (41 commits)
floppy: Correct documentation of driver options when used as a module.
pktcdvd: debugfs functions return NULL on error
xen-blkfront: restore the non-persistent data path
skd: fix formatting in skd_s1120.h
skd: reorder construct/destruct code
skd: cleanup skd_do_inq_page_da()
skd: remove SKD_OMIT_FROM_SRC_DIST ifdefs
skd: remove redundant skdev->pdev assignment from skd_pci_probe()
skd: use <asm/unaligned.h>
skd: remove SCSI subsystem specific includes
skd: register block device only if some devices are present
skd: fix error messages in skd_init()
skd: fix error paths in skd_init()
skd: fix unregister_blkdev() placement
skd: more removal of bio-based code
skd: cleanup the skd_*() function block wrapping
skd: rip out bio path
skd: fix error return code in skd_pci_probe()
s390/dasd: hold request queue sysfs lock when calling elevator_init()
cciss: return 0 from driver probe function on success, not 1
...
