linux-toradex.git/drivers/s390/block/dasd_devmap.c, branch v4.11

s390/dasd: allow 0 for path_threshold attribute

2017-01-31T09:47:08+00:00

Allow 0 as valid input for the path_threshold attribute to deactivate
the IFCC/CCC error handling.

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

s390/dasd: Improve parameter list parsing

2017-01-31T09:46:32+00:00

The function dasd_busid() still uses simple_strtoul() to convert a
string to an integer value. This function is obsolete for quite some
time already and should be replaced.

The whole parameter parsing semantic still relies somewhat on the fact,
that simple_strtoul() parses a string containing literals without
complains and just returns the parsed integer value plus the residual
string. kstrtoint(), however, would return -EINVAL in such a case.
Since we want to get rid of simple_strtoul() and now have a nice dasd[]
containing only single elements, we can clean up and simplify a few
things.

Replace simple_strtoul() with kstrtouint(), improve and simplify the
overall parameter parsing by the following:
- instead of residual strings return proper error codes
- remove dasd_parse_next_element() and decide directly what sort of
  element is being parsed
- if we parse a device or a range of devices, split that element into
  separate bits with a new function
- remove warning about invalid ending as it doesn't apply anymore
- annotate all parsing functions and data that can be freed after
  initialisation with __init and __initdata respectively
- clean up bits and pieces while at it

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

s390/dasd: Always store parameter elements in an array

2017-01-31T09:46:24+00:00

When the DASD driver is built into the kernel, the entire comma
separated parameter list is stored as one single element in the dasd[]
array, opposed to the module build where each element is stored
separately in dasd[].
There is no point in doing so. Therefore, store each part of the list as
single elements in dasd[] as well when built into the kernel.
Also, create a define for the maximum of 256 parameters.

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

Replace with globally

2016-12-24T19:46:01+00:00

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
  sed -i -e "s!$PATT!#include !" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro 
Signed-off-by: Linus Torvalds

s390/dasd: channel path aware error recovery

2016-12-12T11:05:03+00:00

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 
Reviewed-by: Sebastian Ott 
Reviewed-by: Jan Hoeppner 
Signed-off-by: Martin Schwidefsky

s390/dasd: extend dasd path handling

2016-12-12T11:04:37+00:00

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 
Reviewed-by: Sebastian Ott 
Reviewed-by: Jan Hoeppner 
Signed-off-by: Martin Schwidefsky

s390/dasd: Fix locking issue when changing RO attribute

2016-10-28T08:09:04+00:00

The function dasd_ro_store() calls set_disk_ro() to set the device in
question read-only. Since set_disk_ro() might sleep, we can't call it
while holding a lock. However, we also can't simply check if the device,
block, and gdp references are valid before we call set_disk_ro() because
an offline processing might have been started in the meanwhile which
will destroy those references.

In order to reliably call set_disk_ro() we have to ensure several
things:

- Still check validity of the mentioned references but additionally
  check if offline processing is running and bail out accordingly. Also,
  do this while holding the device lock.
- To ensure that the block device is still safe after the lock, increase
  the open_count while still holding the device lock.

Reviewed-by: Stefan Haberland 
Signed-off-by: Jan Höppner 
Signed-off-by: Martin Schwidefsky

s390/dasd: Fix locking issue when changing EER attribute

2016-10-28T08:09:04+00:00

The reference to a device in question may get lost when the extended
error reporting (EER) attribute is being enabled/disabled while the
device is set offline at the same time. This is due to missing
refcounting and incorrect locking. Fix this by the following:

- In dasd_eer_store() get the device directly and handle the refcount
  accordingly.
- Move the lock in dasd_eer_enable() up so we can ensure safe
  processing.
- Check if the device is being set offline and return with -EBUSY if so.
- While at it, change the return code from -EPERM to -EMEDIUMTYPE as
  suggested by a FIXME, since that is what we're actually checking.

Reviewed-by: Stefan Haberland 
Signed-off-by: Jan Höppner 
Signed-off-by: Martin Schwidefsky

s390/dasd: Make use of dasd_set_feature() more often

2016-10-28T08:09:03+00:00

When setting certain attributes, we actually set the according feature
flag. Do this by using dasd_set_feature() at a few occurrences and
remove duplicate code.

In dasd_set_feature() dasd_find_busid() is used to retrieve the devmap
for the device in question. Combined with the change above, this would
require the device to be set online at least once so that a devmap is
being created. Change that by using dasd_devmap_from_cdev() instead,
which uses dasd_find_busid() first and will create a devmap accordingly
if there is none yet.

Reviewed-by: Stefan Haberland 
Signed-off-by: Jan Höppner 
Signed-off-by: Martin Schwidefsky

s390/dasd: Replace simple_strtoul with kstrtouint

2016-10-28T08:09:03+00:00

simple_strtoul() has been marked obsolete for quite some time now.
Replace a few last occurrences with kstrtouint().

Reviewed-by: Stefan Haberland 
Signed-off-by: Jan Höppner 
Signed-off-by: Martin Schwidefsky