kernel/drivers/s390/block/dasd_eckd.h, branch linux-6.9.y

s390/dasd: add device ping attribute

2022-09-21T14:32:51Z

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 setup

2022-09-21T14:32:51Z

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/dasd: add query PPRC function

2022-09-21T14:32:50Z

Add function to query the Peer-to-Peer-Remote-Copy (PPRC) state of a device by reading the related structure through a read subsystem data call. Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner Link: https://lore.kernel.org/r/20220920192616.808070-3-sth@linux.ibm.com Signed-off-by: Jens Axboe

s390/dasd: summarize dasd configuration data in a separate structure

2021-10-20T14:10:42Z

Summarize the dasd configuration data in a separate structure so that functions that need temporary config data do not need to allocate the whole eckd_private structure. Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner Link: https://lore.kernel.org/r/20211020115124.1735254-6-sth@linux.ibm.com Signed-off-by: Jens Axboe

s390/dasd: Avoid field over-reading memcpy()

2021-07-01T15:27:04Z

In preparation for FORTIFY_SOURCE performing compile-time and run-time field array bounds checking for memcpy(), memmove(), and memset(), avoid intentionally reading across neighboring array fields. Add a wrapping structure to serve as the memcpy() source, so the compiler can do appropriate bounds checking, avoiding this future warning: In function '__fortify_memcpy', inlined from 'create_uid' at drivers/s390/block/dasd_eckd.c:749:2: ./include/linux/fortify-string.h:246:4: error: call to '__read_overflow2_field' declared with attribute error: detected read beyond size of field (2nd parameter) Signed-off-by: Kees Cook Signed-off-by: Stefan Haberland Link: https://lore.kernel.org/r/20210701142221.3408680-3-sth@linux.ibm.com Signed-off-by: Jens Axboe

s390: dasd: Mundane spelling fixes

2021-05-03T17:00:11Z

s/Subssystem/Subsystem/ ......two different places s/reportet/reported/ s/managemnet/management/ Signed-off-by: Bhaskar Chowdhury Acked-by: Randy Dunlap Signed-off-by: Stefan Haberland Link: https://lore.kernel.org/r/20210428153521.2050899-2-sth@linux.ibm.com Signed-off-by: Jens Axboe

s390: Replace zero-length array with flexible-array member

2020-02-27T15:02:21Z

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Link: https://lkml.kernel.org/r/20200221150612.GA9717@embeddedor Signed-off-by: Gustavo A. R. Silva Signed-off-by: Vasily Gorbik

s390/dasd: Handle out-of-space constraint

2019-07-11T18:39:54Z

The storage server issues three different types of out-of-space messages whenever the Extent Pool or Extent Repository space runs short. When a configured warning watermark is reached, the physical space is completeley exhausted, or the capacity constraints have been relieved, a message is received. A log entry for the sysadmin to react to is generated in any case. In case the physical space is completely exhausted, sense data that reads "no space left on device" is received. In this case, currently running I/O will be blocked until space has either been released or added to the extent pool, and a relieve message was received via an attention interrupt. Signed-off-by: Jan Höppner Reviewed-by: Stefan Haberland Signed-off-by: Vasily Gorbik

s390/dasd: Make dasd_setup_queue() a discipline function

2019-07-11T18:39:54Z

ECKD, FBA, and the DIAG discipline use slightly different block layer settings. In preparation of even more diverse queue settings, make dasd_setup_queue() a discipline function. Signed-off-by: Jan Höppner Reviewed-by: Stefan Haberland Signed-off-by: Vasily Gorbik

s390/dasd: Add new ioctl to release space

2019-07-11T18:39:54Z

Userspace tools might have the need to release space for Extent Space Efficient (ESE) volumes when working with such a device. Provide the necessarry interface for such a task by implementing a new ioctl BIODASDRAS. The ioctl uses the format_data_t data structure for data input: typedef struct format_data_t { unsigned int start_unit; /* from track */ unsigned int stop_unit; /* to track */ unsigned int blksize; /* sectorsize */ unsigned int intensity; } format_data_t; If the intensity is set to 0x40, start_unit and stop_unit are ignored and space for the entire volume is released. Otherwise, if intensity is set to 0, the respective range is released (if possible). Signed-off-by: Jan Höppner Reviewed-by: Stefan Haberland Signed-off-by: Vasily Gorbik