linux-stable.git/drivers/s390/block, branch linux-4.5.y

s390/dasd: fix diag 0x250 inline assembly

2016-03-02T12:43:48+00:00

git commit 1ec2772e0c3c ("s390/diag: add a statistic for diagnose
calls") added function calls to gather diagnose statistics.

In case of the dasd diag driver the function call was added between a
register asm statement which initialized register r2 and the inline
assembly itself.  The function call clobbers the contents of register
r2 and therefore the diag 0x250 call behaves in a more or less random
way.

Fix this by extracting the function call into a separate function like
we do everywhere else.

Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls")
Cc:  # 4.4+
Reported-and-tested-by: Stefan Haberland 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/dasd: fix performance drop

2016-02-17T08:24:07+00:00

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 
Cc: stable@vger.kernel.org # 4.4+
Signed-off-by: Martin Schwidefsky

s390/dasd: fix refcount for PAV reassignment

2016-02-11T12:05:55+00:00

Add refcount to the DASD device when a summary unit check worker is
scheduled. This prevents that the device is set offline with worker
in place.

Cc: stable@vger.kernel.org
Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

s390/dasd: prevent incorrect length error under z/VM after PAV changes

2016-02-11T12:05:53+00:00

The channel checks the specified length and the provided amount of
data for CCWs and provides an incorrect length error if the size does
not match. Under z/VM with simulation activated the length may get
changed. Having the suppress length indication bit set is stated as
good CCW coding practice and avoids errors under z/VM.

Cc: stable@vger.kernel.org
Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

mm, dax, pmem: introduce pfn_t

2016-01-16T01:56:32+00:00

For the purpose of communicating the optional presence of a 'struct
page' for the pfn returned from ->direct_access(), introduce a type that
encapsulates a page-frame-number plus flags.  These flags contain the
historical "page_link" encoding for a scatterlist entry, but can also
denote "device memory".  Where "device memory" is a set of pfns that are
not part of the kernel's linear mapping by default, but are accessed via
the same memory controller as ram.

The motivation for this new type is large capacity persistent memory
that needs struct page entries in the 'memmap' to support 3rd party DMA
(i.e.  O_DIRECT I/O with a persistent memory source/target).  However,
we also need it in support of maintaining a list of mapped inodes which
need to be unmapped at driver teardown or freeze_bdev() time.

Signed-off-by: Dan Williams 
Cc: Christoph Hellwig 
Cc: Dave Hansen 
Cc: Ross Zwisler 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

s390/dasd: fix failfast for disconnected devices

2015-12-30T09:34:41+00:00

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 
Signed-off-by: Martin Schwidefsky

block: change ->make_request_fn() and users to return a queue cookie

2015-11-07T17:40:46+00:00

No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.

Signed-off-by: Jens Axboe 
Acked-by: Christoph Hellwig 
Acked-by: Keith Busch

s390/dasd: fix disconnected device with valid path mask

2015-11-03T13:40:47+00:00

Path verification is either done via dasd_eckd_read_conf() which is
triggered during online processing and resume or via
do_path_verification_work() which is triggered after path events.
The dasd_eckd_read_conf() version added paths unconditionally and did
not check if the path mask was empty. This led to devices having the
disconnected stop flag set but a valid path mask. So they where not
working although they had paths validated successfully. After a resume
this state could even not be solved with additional paths added.

Fix by checking for an empty path mask in dasd_eckd_read_conf() and
clearing the device stop bits for a newly added channel path.

Reviewed-by: Sebastian Ott 
Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

s390/dasd: fix invalid PAV assignment after suspend/resume

2015-11-03T13:40:46+00:00

For a valid PAV assignment the DASD driver needs to notice possibly
changed configuration data. Thus the failing of read configuration
data should also fail the device restore to prevent invalid PAV
assignment. The failed device may get restored after additional paths
get available later on.
If the restore fails after the device was added to the lcu alias
handling it needs to be removed from the alias handling before exiting
the restore function.

Reviewed-by: Sebastian Ott 
Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

s390/dasd: fix double free in dasd_eckd_read_conf

2015-11-03T13:40:44+00:00

The configuration data is stored per path and also the first valid
configuration data per device. When dasd_eckd_read_conf is called
again after a path got lost the device configuration data is cleared
but possibly not the per path configuration data. This might lead to a
double free when the lost path gets operational again.

Fix by clearing all per path configuration data when the first valid
configuration data is received and stored.

Reviewed-by: Sebastian Ott 
Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky