linux-stable.git/drivers/s390/block/dasd_devmap.c, branch linux-6.8.y

s390/dasd: fix string length handling

2023-09-01T13:47:43+00:00

Building dasd_eckd.o with latest clang reveals this bug:

    CC      drivers/s390/block/dasd_eckd.o
      drivers/s390/block/dasd_eckd.c:1082:3: warning: 'snprintf' will always be truncated;
      specified size is 1, but format string expands to at least 11 [-Wfortify-source]
       1082 |                 snprintf(print_uid, sizeof(*print_uid),
            |                 ^
      drivers/s390/block/dasd_eckd.c:1087:3: warning: 'snprintf' will always be truncated;
      specified size is 1, but format string expands to at least 10 [-Wfortify-source]
       1087 |                 snprintf(print_uid, sizeof(*print_uid),
            |                 ^

Fix this by moving and using the existing UID_STRLEN for the arrays
that are being written to. Also rename UID_STRLEN to DASD_UID_STRLEN
to clarify its scope.

Fixes: 23596961b437 ("s390/dasd: split up dasd_eckd_read_conf")
Reviewed-by: Peter Oberparleiter 
Signed-off-by: Heiko Carstens 
Tested-by: Nick Desaulniers  # build
Reported-by: Nathan Chancellor 
Closes: https://github.com/ClangBuiltLinux/linux/issues/1923
Reviewed-by: Nick Desaulniers 
Link: https://lore.kernel.org/r/20230828153142.2843753-2-hca@linux.ibm.com
Signed-off-by: Jens Axboe

s390/dasd: add aq_timeouts autoquiesce trigger

2023-04-12T01:53:08+00:00

Add a sysfs attribute aq_timeouts that controls after how many
timeouts a autoquiesce event might be triggered.

The default value is 32768 which is the maximum number of retries
for the DASD device driver DASD_RETRIES_MAX. This means that the
timeout trigger will never happen.

The default value for DASD retries is 255.
Setting the value to below 255 will trigger the timeout autoquiesce
event before an IO error is generated.

Also add the check for the configured amount of timeouts and trigger
an autoquiesce event if exceeded.

Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Reviewed-by: Halil Pasic 
Link: https://lore.kernel.org/r/20230405142017.2446986-6-sth@linux.ibm.com
Signed-off-by: Jens Axboe

s390/dasd: add aq_requeue sysfs attribute

2023-04-12T01:53:08+00:00

Add a sysfs attribute to control if all IO requests will be requeued to
the blocklayer in case of an autoquiesce event or not.

A value of 1 means that in case of an autoquiesce event all IO requests
will be requeued to the blocklayer.

A value of 0 means that the device will only be stopped.

Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Reviewed-by: Halil Pasic 
Link: https://lore.kernel.org/r/20230405142017.2446986-5-sth@linux.ibm.com
Signed-off-by: Jens Axboe

s390/dasd: add aq_mask sysfs attribute

2023-04-12T01:53:08+00:00

Add sysfs attribute that controls the DASD autoquiesce feature.
The autoquiesce is disabled when 0 is echoed to the attribute.

A value greater than 0 will enable the feature.
The aq_mask attribute will accept an unsigned integer and the value
will be interpreted as bitmask defining the trigger events that will
lead to an automatic quiesce.

The following autoquiesce triggers will currently be available:

DASD_EER_FATALERROR  1 - any final I/O error
DASD_EER_NOPATH      2 - no remaining paths for the device
DASD_EER_STATECHANGE 3 - a state change interrupt occurred
DASD_EER_PPRCSUSPEND 4 - the device is PPRC suspended
DASD_EER_NOSPC       5 - there is no space remaining on an ESE device
DASD_EER_TIMEOUT     6 - a certain amount of timeouts occurred
DASD_EER_STARTIO     7 - the IO start function encountered an error

The currently supported maximum value is 255.

Bit 31 is reserved for internal usage.
Bit 0 is not used.

Example:

 - deactivate autoquiesce
   $ echo 0 > /sys/bus/ccw/0.0.1234/aq_mask

 - enable autoquiesce for FATALERROR, NOPATH and TIMEOUT
   (0000 0000 0000 0000  0000 0000 0100 0110 => 70)
   $ echo 70 > /sys/bus/ccw/0.0.1234/aq_mask

Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Reviewed-by: Halil Pasic 
Link: https://lore.kernel.org/r/20230405142017.2446986-4-sth@linux.ibm.com
Signed-off-by: Jens Axboe

s390/dasd: fix possible buffer overflow in copy_pair_show

2022-11-23T17:37:37+00:00

dasd_copy_relation->entry[] array might be accessed out of bounds if the
loop does not break.

Fixes: a91ff09d39f9 ("s390/dasd: add copy pair setup")
Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Link: https://lore.kernel.org/r/20221123160719.3002694-5-sth@linux.ibm.com
Signed-off-by: Jens Axboe

Merge tag 's390-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2022-10-09T20:51:40+00:00

Pull s390 updates from Vasily Gorbik:

 - Make use of the IBM z16 processor activity instrumentation facility
   extension to count neural network processor assist operations: add a
   new PMU device driver so that perf can make use of this.

 - Rework memcpy_real() to avoid DAT-off mode.

 - Rework absolute lowcore access code.

 - Various small fixes and improvements all over the code.

* tag 's390-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/pci: remove unused bus_next field from struct zpci_dev
  s390/cio: remove unused ccw_device_force_console() declaration
  s390/pai: Add support for PAI Extension 1 NNPA counters
  s390/mm: fix no previous prototype warnings in maccess.c
  s390/mm: uninline copy_oldmem_kernel() function
  s390/mm,ptdump: add real memory copy page markers
  s390/mm: rework memcpy_real() to avoid DAT-off mode
  s390/dump: save IPL CPU registers once DAT is available
  s390/pci: convert high_memory to physical address
  s390/smp,ptdump: add absolute lowcore markers
  s390/smp: rework absolute lowcore access
  s390/smp: call smp_reinit_ipl_cpu() before scheduler is available
  s390/ptdump: add missing amode31 markers
  s390/mm: split lowcore pages with set_memory_4k()
  s390/mm: remove unused access parameter from do_fault_error()
  s390/delay: sync comment within __delay() with reality
  s390: move from strlcpy with unused retval to strscpy

s390/dasd: use blk_mq_alloc_disk

2022-09-28T14:56:34+00:00

As far as I can tell there is no need for the staged setup in
dasd, so allocate the tagset and the disk with the queue in
dasd_gendisk_alloc.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Stefan Haberland 
Signed-off-by: Stefan Haberland 
Link: https://lore.kernel.org/r/20220928143945.1687114-2-sth@linux.ibm.com
Signed-off-by: Jens Axboe

s390/dasd: add device ping attribute

2022-09-21T14:32:51+00:00

Add a function to check if a device is accessible.
This makes mostly sense for copy pair secondary devices but it will work
for all devices.

The sysfs attribute ping is a write only attribute and will issue a NOP
CCW to the device.
In case of success it will return zero. If the device is not accessible
it will return an error code.

Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Link: https://lore.kernel.org/r/20220920192616.808070-8-sth@linux.ibm.com
Signed-off-by: Jens Axboe

s390/dasd: add copy pair swap capability

2022-09-21T14:32:51+00:00

In case of errors or misbehaviour of the primary device a controlled
failover to one of the configured secondary devices needs to be
performed.

The swap processing stops I/O on the primary device, all requests are
re-queued to the blocklayer queue, the entries in the copy relation are
swapped and finally the link to the blockdevice is moved from primary to
secondary dasd device.
After this, the secondary becomes the new primary device and I/O is
restarted on that device.

Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Link: https://lore.kernel.org/r/20220920192616.808070-5-sth@linux.ibm.com
Signed-off-by: Jens Axboe

s390/dasd: add copy pair setup

2022-09-21T14:32:51+00:00

A copy relation that is configured on the storage server side needs to be
enabled separately in the device driver. A sysfs interface is created
that allows userspace tooling to control such setup.

The following sysfs entries are added to store and read copy relation
information:

copy_pair
    - Add/Delete a copy pair relation to the DASD device driver
    - Query all previously added copy pair relations
copy_role
    - Query the copy pair role of the device

To add a copy pair to the DASD device driver it has to be specified
through the sysfs attribute copy_pair. Only one secondary device can be
specified at a time together with the primary device. Both, secondary
and primary can be used equally to define the copy pair.
The secondary devices have to be offline when adding the copy relation.
The primary device needs to be specified first followed by the comma
separated secondary device.
Read from the copy_pair attribute to get the current setup and write
"clear" to the attribute to delete any existing setup.

Example:
$ echo 0.0.9700,0.0.9740 > /sys/bus/ccw/devices/0.0.9700/copy_pair
$ cat /sys/bus/ccw/devices/0.0.9700/copy_pair
0.0.9700,0.0.9740

During device online processing the required data will be read from the
storage server and the information will be compared to the setup
requested through the copy_pair attribute. The registration of the
primary and secondary device will be handled accordingly.
A blockdevice is only allocated for copy relation primary devices.

To query the copy role of a device read from the copy_role sysfs
attribute. Possible values are primary, secondary, and none.

Example:
$ cat /sys/bus/ccw/devices/0.0.9700/copy_role
primary

Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Link: https://lore.kernel.org/r/20220920192616.808070-4-sth@linux.ibm.com
Signed-off-by: Jens Axboe