[SCSI] zfcp: fix lock imbalance by reworking request queue locking

This patch adds wait_event_interruptible_lock_irq_timeout(), which is a
straight-forward descendant of wait_event_interruptible_tim

[SCSI] zfcp: fix lock imbalance by reworking request queue locking

This patch adds wait_event_interruptible_lock_irq_timeout(), which is a
straight-forward descendant of wait_event_interruptible_timeout() and
wait_event_interruptible_lock_irq().

The zfcp driver used to call wait_event_interruptible_timeout()
in combination with some intricate and error-prone locking. Using
wait_event_interruptible_lock_irq_timeout() as a replacement
nicely cleans up that locking.

This rework removes a situation that resulted in a locking imbalance
in zfcp_qdio_sbal_get():

BUG: workqueue leaked lock or atomic: events/1/0xffffff00/10
last function: zfcp_fc_wka_port_offline+0x0/0xa0 [zfcp]

It was introduced by commit c2af7545aaff3495d9bf9a7608c52f0af86fb194
"[SCSI] zfcp: Do not wait for SBALs on stopped queue", which had a new
code path related to ZFCP_STATUS_ADAPTER_QDIOUP that took an early exit
without a required lock being held. The problem occured when a
special, non-SCSI I/O request was being submitted in process context,
when the adapter's queues had been torn down. In this case the bug
surfaced when the Fibre Channel port connection for a well-known address
was closed during a concurrent adapter shut-down procedure, which is a
rare constellation.

This patch also fixes these warnings from the sparse tool (make C=1):

drivers/s390/scsi/zfcp_qdio.c:224:12: warning: context imbalance in
'zfcp_qdio_sbal_check' - wrong count at exit
drivers/s390/scsi/zfcp_qdio.c:244:5: warning: context imbalance in
'zfcp_qdio_sbal_get' - unexpected unlock

Last but not least, we get rid of that crappy lock-unlock-lock
sequence at the beginning of the critical section.

It is okay to call zfcp_erp_adapter_reopen() with req_q_lock held.

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org #2.6.35+
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

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s390/time: rename tod clock access functions

Fix name clash with some common code device drivers and add "tod"
to all tod clock access function names.

Signed-off-by: Heiko Carstens <heiko.carstens@

s390/time: rename tod clock access functions

Fix name clash with some common code device drivers and add "tod"
to all tod clock access function names.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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[SCSI] zfcp: Bounds checking for deferred error trace

The pl vector has scount elements, i.e. pl[scount-1] is the last valid
element. For maximum sized requests, payload->counter == scount after
the

[SCSI] zfcp: Bounds checking for deferred error trace

The pl vector has scount elements, i.e. pl[scount-1] is the last valid
element. For maximum sized requests, payload->counter == scount after
the last loop iteration. Therefore, do bounds checking first (with
boolean shortcut) to not access the invalid element pl[scount].

Do not trust the maximum sbale->scount value from the HBA
but ensure we won't access the pl vector out of our allocated bounds.
While at it, clean up scoping and prevent unnecessary memset.

Minor fix for 86a9668a8d29ea711613e1cb37efa68e7c4db564
"[SCSI] zfcp: support for hardware data router"

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> #3.2+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

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s390/comments: unify copyright messages and remove file names

Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Als

s390/comments: unify copyright messages and remove file names

Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

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s390: add missing module.h/export.h includes

Fix several compile errors on s390 caused by splitting module.h.

Some include additions [e.g. qdio_setup.c, zfcp_qdio.c] are in
anticipation of pending

s390: add missing module.h/export.h includes

Fix several compile errors on s390 caused by splitting module.h.

Some include additions [e.g. qdio_setup.c, zfcp_qdio.c] are in
anticipation of pending changes queued for s390 that increase
the modular use footprint.

[PG: added additional obvious changes since Heiko's original patch]

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

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[SCSI] zfcp: support for hardware data router

FICON Express8S supports hardware data router, which requires an
adapted qdio request format.
This part 2/2 exploits the functionality in zfcp.

Signed-

[SCSI] zfcp: support for hardware data router

FICON Express8S supports hardware data router, which requires an
adapted qdio request format.
This part 2/2 exploits the functionality in zfcp.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

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[S390] qdio: Split SBAL entry flags

The qdio SBAL entry flag is made-up of four different values that are
independent of one another. Some of the bits are reserved by the
hardware and should not be

[S390] qdio: Split SBAL entry flags

The qdio SBAL entry flag is made-up of four different values that are
independent of one another. Some of the bits are reserved by the
hardware and should not be changed by qdio. Currently all four values
are overwritten since the SBAL entry flag is defined as an u32.

Split the SBAL entry flag into four u8's as defined by the hardware
and don't touch the reserved bits.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

[S390] qdio: outbound tasklet scan threshold

Introduce a scan treshold for the qdio outbound queues. By setting the
threshold the driver can tell qdio after how much used SBALs qdio
should schedule

[S390] qdio: outbound tasklet scan threshold

Introduce a scan treshold for the qdio outbound queues. By setting the
threshold the driver can tell qdio after how much used SBALs qdio
should schedule the outbound tasklet that scans the queue for finished
SBALs. The threshold is specific by the drivers because a
Hipersockets device is much faster in utilizing outbound buffers than a
ZFCP or OSA device.

The default values after how many used SBALs the tasklet should run are:

OSA: > 31 SBALs
Hipersockets: > 7 SBALs
zfcp: > 55 SBALs

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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[SCSI] zfcp: Move qdio setup from erp to zfcp_qdio.c

Initialization of the qdio waitqueue should happen when the qdio data
is initialized and the QDIOUP flag should be handled in the qdio code
as we

[SCSI] zfcp: Move qdio setup from erp to zfcp_qdio.c

Initialization of the qdio waitqueue should happen when the qdio data
is initialized and the QDIOUP flag should be handled in the qdio code
as well. Adjust the code accordingly and remove the superfluos
function zfcp_erp_adapter_strategy_open_qdio.

Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Redesign of the debug tracing final cleanup.

This patch is the final cleanup of the redesign from the zfcp tracing.
Structures and elements which were used by multiple areas of the
form

[SCSI] zfcp: Redesign of the debug tracing final cleanup.

This patch is the final cleanup of the redesign from the zfcp tracing.
Structures and elements which were used by multiple areas of the
former debug tracing are now changed to the new scheme.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Redesign of the debug tracing for HBA records.

This patch is the continuation to redesign the zfcp tracing to a more
straight-forward and easy to extend scheme.

This patch deals with a

[SCSI] zfcp: Redesign of the debug tracing for HBA records.

This patch is the continuation to redesign the zfcp tracing to a more
straight-forward and easy to extend scheme.

This patch deals with all trace records of the zfcp HBA area.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Change spin_lock_bh to spin_lock_irq to fix lockdep warning

With the change to use the data on the SCSI device, iterating through
all LUNs/scsi_devices takes the SCSI host_lock. This tr

[SCSI] zfcp: Change spin_lock_bh to spin_lock_irq to fix lockdep warning

With the change to use the data on the SCSI device, iterating through
all LUNs/scsi_devices takes the SCSI host_lock. This triggers warnings
from the lock dependency checker:

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
2.6.34.1 #97
---------------------------------------------------------
chchp/3224 just changed the state of lock:
(&(shost->host_lock)->rlock){-.-...}, at: [<00000000003a73f4>] __scsi_iterate_devices+0x38/0xbc
but this lock took another, HARDIRQ-unsafe lock in the past:
(&(&qdio->req_q_lock)->rlock){+.-...}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this: [ 24.972394] 2 locks held by chchp/3224:
#0: (&(sch->lock)->rlock){-.-...}, at: [<0000000000401efa>] do_IRQ+0xb2/0x1e4
#1: (&adapter->port_list_lock){.-....}, at: [<0000000000490302>] zfcp_erp_modify_adapter_status+0x9e/0x16c
[...]

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
2.6.34.1 #98
---------------------------------------------------------
chchp/3235 just changed the state of lock:
(&(shost->host_lock)->rlock){-.-...}, at: [<00000000003a73f4>] __scsi_iterate_devices+0x38/0xbc
but this lock took another, HARDIRQ-unsafe lock in the past:
(&(&qdio->stat_lock)->rlock){+.-...}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
2 locks held by chchp/3235:
#0: (&(sch->lock)->rlock){-.-...}, at: [<0000000000401efa>] do_IRQ+0xb2/0x1e4
#1: (&adapter->port_list_lock){.-.-..}, at: [<00000000004902f6>] zfcp_erp_modify_adapter_status+0x9e/0x16c
[...]

To stop this warning, change the request queue lock to disable irqs,
not only softirq. The changes are required only outside of the
critical "send fcp command" path.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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qdio: extend API to allow polling

Extend the qdio API to allow polling in the upper-layer driver. This
is needed by qeth to use NAPI.

To use the new interface the upper-layer driver must specify th

qdio: extend API to allow polling

Extend the qdio API to allow polling in the upper-layer driver. This
is needed by qeth to use NAPI.

To use the new interface the upper-layer driver must specify the
queue_start_poll(). This callback is used to signal the upper-layer
driver that is has initiative and must process the inbound queue by
calling qdio_get_next_buffers(). If the upper-layer driver wants to
stop polling it calls qdio_start_irq().

Since adapter interrupts are not completely stoppable qdio implements
a software bit QDIO_QUEUE_IRQS_DISABLED to safely disable interrupts for an
input queue.

The old interface is preserved and will be used as is by zfcp.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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[SCSI] zfcp: Trigger logging in the FCP channel on qdio error conditions

Exploit the cio siosl function to trigger logging in the FCP channel
on qdio error conditions. Add a helper function in zfcp_

[SCSI] zfcp: Trigger logging in the FCP channel on qdio error conditions

Exploit the cio siosl function to trigger logging in the FCP channel
on qdio error conditions. Add a helper function in zfcp_qdio to ensure
that tracing is only triggered once before calling qdio_shutdown.

Trigger in zfcp for hardware logs are:
- timeout for FSF requests to the FCP channel
- "no recommendation" status from FCP channel
- invalid FSF protocol status
- stalled outbound queue
- unknown request id on inbound queue
- QDIO_ERROR_SLSB_STATE

All of the above triggers run from the Linux qdio softirq context, so
no additional synchronization is necessary for the handling of the
ZFCP_STATUS_ADAPTER_SIOSL_ISSUED flag.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Introduce experimental support for DIF/DIX

Introduce support for DIF/DIX in zfcp: Report the capabilities for the
Scsi_host, map the protection data when issuing I/O requests and
handle

[SCSI] zfcp: Introduce experimental support for DIF/DIX

Introduce support for DIF/DIX in zfcp: Report the capabilities for the
Scsi_host, map the protection data when issuing I/O requests and
handle the new error codes. Also add the fsf data_direction field to
the hba trace, it is useful information for debugging in that area.
This is an EXPERIMENTAL feature for now.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Enable data division support for FCP devices

Try to enable data division support for FCP devices and indicate in
the adapter status flag if it succeeded.

Reviewed-by: Swen Schillig <sw

[SCSI] zfcp: Enable data division support for FCP devices

Try to enable data division support for FCP devices and indicate in
the adapter status flag if it succeeded.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Cleanup QDIO attachment and improve processing.

Some definitions and structures in the zfcp QDIO processing are
improved by the removal of not required variables and processing steps.
I

[SCSI] zfcp: Cleanup QDIO attachment and improve processing.

Some definitions and structures in the zfcp QDIO processing are
improved by the removal of not required variables and processing steps.
I addition the naming of some variables is changed to make their purpose
more clear.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Cleanup function parameters for sbal value.

A lot of functions require the amount of SBALs as one of their
parameter which is most times invariable. Therefore remove this
parameter and

[SCSI] zfcp: Cleanup function parameters for sbal value.

A lot of functions require the amount of SBALs as one of their
parameter which is most times invariable. Therefore remove this
parameter and set the SBAL value explicitly if a non standard value is
required. In addition the warning message "oversized data" is
replaced with a BUG_ON() statement assuring the limits defined and
requested by zfcp.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Do not wait for SBALs on stopped queue

Trying to read the FC host statistics on an offline adapter results in
a 5 seconds wait. Reading the statistics tries to issue an exchange
port da

[SCSI] zfcp: Do not wait for SBALs on stopped queue

Trying to read the FC host statistics on an offline adapter results in
a 5 seconds wait. Reading the statistics tries to issue an exchange
port data request which first waits up to 5 seconds for an entry in
the request queue.

Change the strategy for getting a free SBAL to exit when the queue is
stopped. Reading the statistics will then fail without the wait.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Move sbal_get function to zfcp_qdio.c

Waiting for a free sbal is a operation on the qdio queue. Move the
code implementing the wait to zfcp_qdio.c and rename the functions
accordingly.

[SCSI] zfcp: Move sbal_get function to zfcp_qdio.c

Waiting for a free sbal is a operation on the qdio queue. Move the
code implementing the wait to zfcp_qdio.c and rename the functions
accordingly.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Move sbale handling to zfcp_qdio files

Move the code accessing the qdio sbales and zfcp_qdio_req struct to
the zfcp_qdio files and provide helper functions for accessing the
qdio relate

[SCSI] zfcp: Move sbale handling to zfcp_qdio files

Move the code accessing the qdio sbales and zfcp_qdio_req struct to
the zfcp_qdio files and provide helper functions for accessing the
qdio related parts.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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[SCSI] zfcp: Report scatter-gather limits to SCSI and block layer

Instead of dealing with large segments in the scatter-gather lists in
zfcp_qdio.c, report the limits to the upper layers. With these

[SCSI] zfcp: Report scatter-gather limits to SCSI and block layer

Instead of dealing with large segments in the scatter-gather lists in
zfcp_qdio.c, report the limits to the upper layers. With these limits
in place, the code for mapping large data blocks to multiple sbales
can be removed.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when bu

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

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[S390] remove unused qdio flags in zfcp and qeth

zfcp and qeth are setting flags for the qdio-layer, but these flags
are not used in qdio. Patch removes the flag definitions from qdio
and their sett

[S390] remove unused qdio flags in zfcp and qeth

zfcp and qeth are setting flags for the qdio-layer, but these flags
are not used in qdio. Patch removes the flag definitions from qdio
and their settings in zfcp and qeth.

Cc: Jan Glauber <jang@linux.vnet.ibm.com>
Cc: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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