linux-toradex.git/drivers/s390/block/dasd_int.h, branch v3.4.1

[S390] dasd: revalidate server for new pathgroup

2012-01-18T17:03:42+00:00

If a pathgroup is established we get an event and have to revalidate
the server to propagate supported features like PAV and enable them.

Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

[S390] dasd: prevent path verification before resume

2011-10-30T14:16:45+00:00

Mark the device as suspended and delay execution of the path
verification worker to prevent mix-up.

Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

[S390] dasd: re-initialize read_conf buffer for retries

2011-10-30T14:16:44+00:00

The buffer for read configuration data has to be initialized with an
EBCDIC string to show support for extended UIDs to z/VM.
If this read configuration data CQR needs to be retried, the buffer
may have changed in between. So re-initialize the buffer to get a
correct extended UID under z/VM.

Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

[S390] dasd: add enhanced DASD statistics interface

2011-07-24T08:48:23+00:00

This patch extends the DASD statistics to allow for a more detailed
analysis of DASD I/O operations. In particular we want the statistics
to provide answers to the following questions:
- How many requests used a PAV alias?
- How many requests used High Performance FICON?
- How do read request perform versus write requests?

The existing DASD statistics interface has several shortcomings
- The interface for global data is a formatted text table in procfs
  (/proc/dasd/statistics). The layout is meant for human readers and
  is not to easy to parse. If values get to large for the table
  layout, they get scaled down.
- The statistics which are collected per block device can be
  accessed via an ioctl interface, which can only be extended by
  defining a new ioctl.
- There is no statistics interface for individual PAV base and alias
  devices.

To overcome theses shortcomings we create a new DASD statistics
interface in debugfs. This interface will contain one entry for global
data, one per DASD block device, and one per DASD base and alias
device. Each file contains the statistic data in easy to parse
name/value and name/array pairs. The existing interfaces will remain
functional, but they will not be extended.

Signed-off-by: Stefan Weinhuber 
Signed-off-by: Martin Schwidefsky

[S390] dasd: fix race between open and offline

2011-04-20T08:15:43+00:00

The dasd_open function uses the private_data pointer of the gendisk to
find the dasd_block structure that matches the gendisk. When a DASD
device is set offline, we set the private_data pointer of the gendisk
to NULL and later remove the dasd_block structure, but there is still
a small race window, in which dasd_open could first read a pointer
from the private_data field and then try to use it, after the structure
has already been freed.
To close this race window, we will store a pointer to the dasd_devmap
structure of the base device in the private_data field. The devmap
entries are not deleted, and we already have proper locking and
reference counting in place, so that we can safely get from a devmap
pointer to the dasd_device and dasd_block structures of the device.

Signed-off-by: Stefan Weinhuber 
Signed-off-by: Martin Schwidefsky

[S390] dasd: Improve handling of stolen DASD reservation

2011-01-05T11:47:30+00:00

If a DASD device has been reserved by a Linux system, and later
this reservation is ‘stolen’ by a second system by means of an
unconditional reserve, then the first system receives a
notification about this fact. With this patch such an event can
be either ignored, as before, or it can be used to let the device
fail all I/O request, so that the device will not block anymore.

Signed-off-by: Stefan Weinhuber 
Signed-off-by: Martin Schwidefsky

[S390] dasd: do path verification for paths added at runtime

2011-01-05T11:47:30+00:00

When a new path is added at runtime, the CIO layer will call the drivers
path_event callback. The DASD device driver uses this callback to trigger
a path verification for the new path. The driver will use only those
paths for I/O, which have been successfully verified.

Signed-off-by: Stefan Weinhuber 
Signed-off-by: Martin Schwidefsky

[S390] dasd: tunable missing interrupt handler

2010-08-09T16:12:54+00:00

This feature provides a user interface to specify the timeout for
missing interrupts for standard I/O operations.

Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

[S390] dasd: unit check handling during internal cio I/O

2010-05-26T21:27:09+00:00

React on unit checks during cio internal I/O.
Handle as unsolicited interrupt and advice cio to retry.

Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

[S390] dasd: remove uid from devmap

2010-05-17T08:00:16+00:00

Remove the duplicate of the DASD uid from the devmap structure.
Use the uid from the device private structure instead.
This also removes a lockdep warning complaining about a possible
SOFTIRQ-safe -> SOFTIRQ-unsafe lock order.

Signed-off-by: Stefan Haberland 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky