kernel/drivers/s390/block/dasd.c, branch linux-4.3.y

s390/dasd: fix kernel panic when alias is set offline

2015-07-13T09:02:14Z

The dasd device driver selects which (alias or base) device is used for a given requests when the request is build. If the chosen alias device is set offline before the request gets queued to the device queue the starting function may use device structures that are already freed. This might lead to a hanging offline process or a kernel panic. Add a check to the starting function that returns the request to the upper layer if the device is already in offline processing. In addition to that prevent that an alias device that's already in offline processing gets chosen as start device. Reviewed-by: Sebastian Ott Reviewed-by: Peter Oberparleiter Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: Enable automatic loading of dasd_diag_mod

2015-05-13T07:58:19Z

Enabling a DASD that was configured to use the DIAG250 access method while the corresponding kernel module dasd_diag_mod has not been loaded fails with an error message. To fix this, users need to manually load the dasd_diag_mod module. This procedure can be simplified by automatically loading the dasd_diag_mod from within the kernel when a DASD configured for DIAG250 is set online. Signed-off-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky

s390/dasd: Fix unresumed device after suspend/resume having no paths

2015-04-15T10:23:51Z

The DASD device driver prevents I/O from being started on stopped devices. This also prevented channel paths to be verified and so the device was unable to be resumed. Fix by allowing path verification requests on stopped devices. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: fix unresumed device after suspend/resume

2015-04-15T10:23:51Z

The DASD device driver only has a limited amount of memory to build I/O requests. This memory was used by blocklayer requests leading to an inability to build needed internal requests to resume the device. Fix by preventing the DASD driver to fetch requests for a stopped device. Signed-off-by: Stefan Haberland Reference-ID: RQM 2520 Signed-off-by: Martin Schwidefsky

s390/dasd: fix inability to set a DASD device offline

2015-04-15T10:23:50Z

Fix ref counting for DASD devices leading to an inability to set a DASD device offline. Before a worker is scheduled the DASD device driver takes a reference to the device. If the worker was already scheduled this reference was never freed. Fix by giving the reference to the DASD device free when schedule_work() returns false. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: remove setting of scheduler from driver

2015-03-25T10:49:40Z

Remove the hard coded scheduler for the DASD device driver to enable change of the scheduler during runtime. Set recommended deadline scheduler via additional udev rule. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390: remove 31 bit support

2015-03-25T10:49:33Z

Remove the 31 bit support in order to reduce maintenance cost and effectively remove dead code. Since a couple of years there is no distribution left that comes with a 31 bit kernel. The 31 bit kernel also has been broken since more than a year before anybody noticed. In addition I added a removal warning to the kernel shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning message") which let everybody know about the plan to remove 31 bit code. We didn't get any response. Given that the last 31 bit only machine was introduced in 1999 let's remove the code. Anybody with 31 bit user space code can still use the compat mode. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/dasd: cleanup profiling

2015-01-29T08:19:29Z

The dasd driver has a lot of duplicated code to handle dasd_global_profile. With this patch we use the same code for the global and the per device profiling data. Note that dasd_stats_write had to change slightly to maintain some odd differences between A) per device and global profile and B) proc and sysfs interface usage. Signed-off-by: Sebastian Ott Reviewed-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: add locking for global_profile access

2015-01-29T08:19:27Z

Access to DASDs global statistics is done without locking which can lead to inconsistent data. Add locking to fix this. Also move the relevant structs in a global dasd_profile struct. Signed-off-by: Sebastian Ott Reviewed-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: fix list corruption for sleep_on requests

2014-11-28T08:47:36Z

Fix race for sleep_on requests leading to list corruption. The SLEEP_ON_END_TAG is set during CQR clean up. Remove it from interrupt handler to avoid the CQR from being cleared when it is still in the device_queue. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky