linux-stable.git/drivers/s390/block/dasd_devmap.c, branch linux-6.3.y

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

s390: move from strlcpy with unused retval to strscpy

2022-08-30T20:00:33+00:00

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang 
Acked-by: Jakub Kicinski 
Acked-by: Benjamin Block 
Acked-by: Alexandra Winter 
Link: https://lore.kernel.org/r/20220818205948.6360-1-wsa+renesas@sang-engineering.com
Link: https://lore.kernel.org/r/20220818210102.7301-1-wsa+renesas@sang-engineering.com
[gor@linux.ibm.com: squashed two changes linked above together]
Signed-off-by: Vasily Gorbik

s390/dasd: use default_groups in kobj_type

2022-01-08T16:44:05+00:00

There are currently 2 ways to create a set of sysfs files for a
kobj_type, through the default_attrs field, and the default_groups
field.  Move the s390 dasd sysfs code to use default_groups field
which has been the preferred way since commit aa30f47cf666 ("kobject:
Add support for default attribute groups to kobj_type") so that we can
soon get rid of the obsolete default_attrs field.

Cc: Stefan Haberland 
Cc: Jan Hoeppner 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Cc: Alexander Gordeev 
Signed-off-by: Greg Kroah-Hartman 
Link: https://lore.kernel.org/r/20220106095401.3274637-1-gregkh@linuxfoundation.org
Signed-off-by: Heiko Carstens

s390: replace snprintf in show functions with sysfs_emit

2021-11-16T11:29:19+00:00

show() must not use snprintf() when formatting the value to be
returned to user space.

Fix the coccicheck warnings:
WARNING: use scnprintf or sprintf.

Use sysfs_emit instead of scnprintf or sprintf makes more sense.

Signed-off-by: Qing Wang 
Acked-by: Vineeth Vijayan 
Acked-by: Stefan Haberland 
Link: https://lore.kernel.org/r/1634280655-4908-1-git-send-email-wangqing@vivo.com
[hca@linux.ibm.com: fix indentation]
Signed-off-by: Heiko Carstens

s390/dasd: let driver core manage the sysfs attributes

2021-03-16T14:31:00+00:00

Wire up device_driver->dev_groups, so that really_probe() creates the
sysfs attributes for us automatically.

Signed-off-by: Julian Wiedmann 
Reviewed-by: Jan Hoeppner 
Signed-off-by: Stefan Haberland 
Link: https://lore.kernel.org/r/20210316094513.2601218-3-sth@linux.ibm.com
Signed-off-by: Jens Axboe