kernel.git/drivers/s390/block/dasd.c, branch linux-4.8.y

s390/dasd: fix hanging device after clear subchannel

2016-08-10T08:12:16Z

When a device is in a status where CIO has killed all I/O by itself the interrupt for a clear request may not contain an irb to determine the clear function. Instead it contains an error pointer -EIO. This was ignored by the DASD int_handler leading to a hanging device waiting for a clear interrupt. Handle -EIO error pointer correctly for requests that are clear pending and treat the clear as successful. Signed-off-by: Stefan Haberland Reviewed-by: Sebastian Ott Cc: stable@vger.kernel.org Signed-off-by: Martin Schwidefsky

s390/dasd: Add new ioctl BIODASDCHECKFMT

2016-04-15T16:16:39Z

Implement new DASD IOCTL BIODASDCHECKFMT to check a range of tracks on a DASD volume for correct formatting. The following characteristics are checked: - Block size - ECKD key length - ECKD record ID - Number of records per track Signed-off-by: Jan Höppner Signed-off-by: Martin Schwidefsky

s390/dasd: add query host access to volume support

2016-04-15T16:16:37Z

With this feature, applications can query if a DASD volume is online to another operating system instances by checking the online status of all attached hosts from the storage server. Reviewed-by: Sebastian Ott Reviewed-by: Heiko Carstens Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: fix performance drop

2016-02-17T08:24:07Z

Commit ca369d51b ("sd: Fix device-imposed transfer length limits") introduced a new queue limit max_dev_sectors which limits the maximum sectors for requests. The default value leads to small dasd requests and therefor to a performance drop. Set the max_dev_sectors value to the same value as the max_hw_sectors to use the maximum available request size for DASD devices. Signed-off-by: Stefan Haberland Cc: stable@vger.kernel.org # 4.4+ Signed-off-by: Martin Schwidefsky

s390/dasd: fix failfast for disconnected devices

2015-12-30T09:34:41Z

Enabling failfast should let request fail immediately if either an error occurred or the device gets disconnected. For disconnected devices new requests are not fetches from the block queue and therefore failfast is not triggered. Fix by letting the DASD driver fetch requests for disconnected devices with failfast active. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: mark DASD devices as non rotational

2015-10-14T12:32:00Z

We were able to reduce the CPU overhead of big paging scenarios when announcing our paging disks as non-rotational. Almost all dasd devices are implemented in storage servers with cache, raid, striping and lots of magic. There is no point in optimizing the disk schedulers and swap code for a single platter moving arm rotational disks. Given the complexity of the setup and the fact that this change is mostly to disable the additional overhead in swap code, lets keep the other functionality unchanged and do not disable the this device as entropy source - unlike other non-rotational devices. Suggested-by: Christian Ehrhardt Reviewed-by: David Hildenbrand Signed-off-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky

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