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path: root/drivers/s390
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2009-12-07[S390] zcrypt: use definitions for cex3Felix Beck
New definitions are added for CEX3 device types. They will be set in the according probe functions. CEX3 device types will be handled in the same modules as CEX2 device types. In the first step they are the same as CEX2 types, but they can be adjusted for further characteristics of CEX3 easily. Signed-off-by: Felix Beck <felix.beck@de.ibm.com> Signed-off-by: Ralph Wuerthner <ralph.wuerthner@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] zcrypt: add support for cex3 device typesFelix Beck
This patch renames the CEX2C2 and CEX2A2 types to CEX3 device types. Signed-off-by: Felix Beck <felix.beck@de.ibm.com> Signed-off-by: Ralph Wuerthner <ralph.wuerthner@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] zcrypt: special command support for cex3 exploitationFelix Beck
Support for special command is implemented in the AP Bus in the NQAP function __ap_send. This is extended for a further parameter special. When set, the special bit, in GR0 will be set. Therefor the ap_message struct is extended for a further bit. Thus calling functions of __ap_send can use the special parameter in ap_message to give to __ap_send. Affected is in the first place ap_queue_message, which is called by the actual card driver. The second part of this support is that the card driver for the CEX3C needs to set this special bit, when an according CPRB is sent to the driver. Signed-off-by: Felix Beck <felix.beck@de.ibm.com> Signed-off-by: Ralph Wuerthner <ralph.wuerthner@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] zcrypt: initialize ap_messages for cex3 exploitationFelix Beck
AP messages need to be initialized, before they will be used. Values will be zeroized. This will be needed later when introducing support for the special commands. Signed-off-by: Felix Beck <felix.beck@de.ibm.com> Signed-off-by: Ralph Wuerthner <ralph.wuerthner@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] dasd: let device initialization wait for LCU setupStefan Weinhuber
The first DASD that is set online for a specific logical control unit has to do certain setup steps on the storage server to make full use of it, for example it will enable PAV. The features and characteristics reported by the storage server will depend on this setup, so all other devices on the same LCU will need to wait for the setup to be finished. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] dasd: remove strings from s390dbfStefan Haberland
Remove strings from s390 debugfeature entries that could lead to a crash when the data is read from dbf because the strings do not exist any more. Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] dasd: improve error recovery for internal I/OStefan Weinhuber
Most of the error conditions reported by a FICON storage server indicate situations which can be recovered. Sometimes the host just needs to retry an I/O request, but sometimes the recovery is more complex and requires the device driver to wait, choose a different path, etc. The DASD device driver has a fully featured error recovery for normal block layer I/O, but not for internal I/O request which are for example used during the device bring up. This can lead to situations where the IPL of a system fails because DASD devices are not properly recognized. This patch will extend the internal I/O handling to use the existing error recovery procedures. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] dasd: enable prefix independent of pav supportStefan Weinhuber
The DASD device driver needs to explicitly enable the prefix command on the storage server, before it can be used. Originally we enabled this command along with others only if we wanted to support PAV. However, today we require this command for other features like High Performance FICON as well, so we need to always enable prefix. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] dasd: remove dead codeChristian Borntraeger
the todclk.h header file is dead code. Remove it. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] dasd: support DIAG access for read-only devicesStefan Weinhuber
When a DASD device is used with the DIAG discipline, the DIAG initialization will indicate success or error with a respective return code. So far we have interpreted a return code of 4 as error, but it actually means that the initialization was successful, but the device is read-only. To allow read-only devices to be used with DIAG we need to accept a return code of 4 as success. Re-initialization of the DIAG access is also part of the DIAG error recovery. If we find that the access mode of a device has been changed from writable to read-only while the device was in use, we print an error message. Signed-off-by: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: dont unregister a busy device in ccw_device_set_offlineSebastian Ott
If we detect a busy subchannel after the driver's set_offline callback returned in ccw_device_set_offline, the current behavior is to unregister the device, which may lead to undesired consequences. Change this to just quiesce the subchannel and go on with the offline processing. Note: This is no excuse for not fixing these drivers - after the set_offline callback they should have no running IO! Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: improve error recovery for internal I/OsPeter Oberparleiter
Improve error recovery for internal I/Os by repeating each I/O 256 times per path to cope with long-running non-permanent error conditions. Also retry each path twice to cope with link flapping, i.e. single paths becoming unavailable in the order in which they are tried. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: change locking in io_subchannel_removeSebastian Ott
IO subchannels are always unregistered in process context, so use spin_lock_irq in the corresponding remove callback. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: quiesce subchannel in io_subchannel_removeSebastian Ott
Ensure that there will be no more interrupts for an unregistered device by using the same quiesce and disable loop as in io_subchannel_shutdown. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: handle busy subchannel in ccw_device_move_to_schSebastian Ott
Try to disable the old subchannel before we ask the driver core to move the attached device to a new parent. This way we can use the QUIESCE state during shutdown which prevents a possible use after free situation in some error cases. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: handle failed disable_subchannel after device recognitionSebastian Ott
Handle a failing cio_disable_subchannel at the end of our device recognition as if the recognition itself failed. This way subsequent registration steps do not need to handle enabled subchannels. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: fix quiesce stateSebastian Ott
DEV_STATE_QUIESCE is used to stop all IO on a busy subchannel. This patch fixes the following problems related to the QUIESCE state: * Fix a potential race condition which could occur when the resulting state was DEV_STATE_OFFLINE. * Add missing locking around cio_disable_subchannel, ccw_device_cancel_halt_clear and the cdev's handler. * Loop until we know for sure that the subchannel is disabled. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: add per device initialization status flagSebastian Ott
The function ccw_device_unregister has to ensure to remove all references obtained by device_add and device_initialize. Unfortunately it gets called for devices which are 1) uninitialized, 2) initialized but unregistered, and 3) registered devices. To distinguish 1) and 2) this patch introduces a new flag "initialized", which is 1 as long as we hold the initial device reference. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: remove registered flag from ccw_device_privateSebastian Ott
We used to maintain a "registered" flag in our ccw_device_private structure. This patch removes the "registered" flag and converts all users of it to device_is_registered which has the exact same meaning. Note: The usage the atomic operation test_and_clear_bit is replaced by the non-atomic if (device_is_registered()) device_del(). This will not do harm, since we serialize calls to ccw_device_unregister with a single-threaded workqueue. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: make steal lock procedure more robustPeter Oberparleiter
An Unconditional Reserve + Release operation (steal lock) for a boxed device may fail when encountering special error cases (e.g. unit checks or path errors). Fix this by using the more robust ccw_request infrastructure for performing the steal lock CCW program. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: use sense-pgid operation for path verificationPeter Oberparleiter
Set-pgid operations fail for some device types under z/VM for which the hypervisor has already set the pgid. Also reserved devices or changed pgids are not correctly recognized. Fix these problems by using a combination of sense-pgid and set-pgid and by also accepting pre-defined pgid settings. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: split PGID settings and statusPeter Oberparleiter
Split setting (driver wants feature enabled) and status (feature setup was successful) for PGID related ccw device features so that setup errors can be detected. Previously, incorrectly handled setup errors could in rare cases lead to erratic I/O behavior and permanently unusuable devices. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: remove intretry flagPeter Oberparleiter
After changing all internal I/O functions to use the newly introduced ccw request infrastructure, retries are handled automatically after a clear operation. Therefore remove the internal retry flag and associated code. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: allow setting not-operational devices offlinePeter Oberparleiter
Accept a request for setting a not-operational device offline. This way, users can remove devices from Linux which would otherwise remain unusable until reboot. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: use ccw request infrastructure for pgidPeter Oberparleiter
Use the newly introduced ccw request infrastructure to implement pgid related operations: sense pgid, set pgid and disband pg. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: use ccw request infrastructure for sense idPeter Oberparleiter
Use the newly introduced ccw request infrastructure to implement the sense id operation. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: consistent infrastructure for internal I/O requestsPeter Oberparleiter
Reduce code duplication by introducing a central infrastructure to perform an internal I/O operation on a CCW device. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: dont panic in non-fatal conditionsPeter Oberparleiter
Remove the call to BUG() for situations which are unexpected but do not cause actual problems. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: ensure proper locking during device recognitionPeter Oberparleiter
Device recognition needs to be started with the ccw device lock held to prevent race conditions between I/O starting and interrupt reception. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: handle error during path verification consistentlyPeter Oberparleiter
Handle verification errors consistently through the existing callback ccw_device_done to reduce cleanup code duplication. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: handle error during device recognition consistentlyPeter Oberparleiter
Remove the return code from ccw_device_recognition and handle recognition errors through the existing callback ccw_device_recog_done to reduce cleanup code duplication. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: inform user when online/offline processing failsPeter Oberparleiter
Print a warning message in case a ccw device enters boxed or not operational state during online/offline processing. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: introduce ccw device todosPeter Oberparleiter
Introduce a central mechanism for performing delayed ccw device work to ensure that different types of work do not overwrite each other. Prioritization ensures that the most important work is always performed while less important tasks are either obsoleted or repeated later. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: introduce subchannel todosPeter Oberparleiter
Ensure that current and future users of sch->work do not overwrite each other by introducing a single mechanism for delayed subchannel work. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: introduce parent-initiated device movePeter Oberparleiter
Change the initiative to update subchannel-ccw device associations to the subchannel: when there is an indication that the internal association no longer reflects the current hardware state, mark each affected subchannel as requiring attention. Once processing reaches a subchannel, determine the correct association for that subchannel at that time and perform the necessary device_move operations. This change fixes problems with the previous approach which would leave devices in an inconsistent state when a new hardware change occurred while a device_move was already scheduled. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: fix repeat setting of cdev parent associationPeter Oberparleiter
sch_create_and_recog_new_device() associates a parent subchannel with its ccw device child even though this is already done by the subsequently called io_subchannel_recog(). Also make sure io_subchannel_recog() sets the association under lock. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-07[S390] cio: fix double free in case of probe failurePeter Oberparleiter
io_subchannel_probe() frees memory for sch->private which is later freed again when io_subchannel_remove() is called. Fix this problem by removing the cleanup in io_subchannel_probe(). Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-12-04tree-wide: fix misspelling of "definition" in commentsAdam Buchbinder
"Definition" is misspelled "defintion" in several comments; this patch fixes them. No code changes. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-04[SCSI] zfcp: Remove flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPPChristof Schmitt
The flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP is never set and hence can be removed. This is a leftover from the time when zfcp had to decide whether the target supports a "logical unit reset" or not. Nowadays, the SCSI midlayer calls the eh_device_reset_handler or the eh_target_reset_handler and zfcp simply maps this to a "logical unit reset" or a "target reset". Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Activate fc4s attributes for zfcp in FC transport classChristof Schmitt
Enable the display of supported and active fc4s for zfcp in the FC transport class. zfcp only supports FCP, so simply hard-code this information. The zfcp hbaapi already has this information hardcoded, but this would allow to switch from the coding in the zfcp hbaapi to the common FC transport attributes in the future. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKEDChristof Schmitt
In case the SCSI error recovery starts because of a SCSI command timeout, but then something else triggers the rport to be deleted, the SCSI error recovery will run to the end and set the SCSI device offline. To prevent this, call the FC transport function fc_block_scsi_eh which waits until the rport leaves the BLOCKED state. This guarantees that communication is possible if the rport is ONLINE, or the SCSI devices will be removed if the rport state switches to NOT_PRESENT. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Update FSF error reportingChristof Schmitt
The SCSI midlayer retries commands based on the remote port state and the command status reported by the driver. Returning DID_TRANSPORT_DISRUPTED is a better approach, use this for reporting FSF errors back to the SCSI midlayer. See http://marc.info/?l=linux-scsi&m=125668044215051&w=2 as reference. There is also no need in special treatment of ABORTED commands, so remove the ZFCP_STATUS_FSFREQ_ABORTED, the commands are then returned with DID_TRANSPORT_DISRUPTED. Also remove the ZFCP_STATUS_FSFREQ_RETRY: It is useless, no retry is happening in the FSF layer and nobody checks the state of this flag. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Improve ELS ADISC handlingChristof Schmitt
Introduce kmem_cache for ELS ADISC data to guarantee the required hardware alignment and free the allocated memory in case the send failes. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Simplify handling of ct and els requestsChristof Schmitt
Remove some redundancies in FC related code and trace: - drop redundant data from SAN trace (local s_id that only changes during link down, ls_code that is already part of payload, d_id in ct response trace that is always the same as in ct request trace) - use one common fsf struct to hold zfcp data for ct and els requests - leverage common fsf struct for FC passthrough job data, allocate it with dd_bsg_data for passthrough requests and unify common code for ct and els passthrough request - simplify callback handling in zfcp_fc Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Remove ZFCP_DID_MASKChristof Schmitt
Instead of assigning 4 bytes with the highest byte masked out, use a 3 byte array with the ntoh24 and h24ton helper functions, thus eliminating the need for the ZFCP_DID_MASK. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Move WKA port to zfcp FC codeChristof Schmitt
The well-known-address (WKA) port handling code is part of the FC code in zfcp. Move everything WKA related to the zfcp_fc files and use the common zfcp_fc prefix for structs and functions. Drop the unused key management service while renaming the struct, no request could ever reach this service in zfcp and it is obsolete anyway. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Use common code definitions for FC CT structsChristof Schmitt
Use common code definitions for FC GPN_FT and GID_PN instead of inventing private ones. Move the private structs still required inside zfcp to zfcp_fc header file. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Use common code definitions for FC ELS structsChristof Schmitt
Use common code definitions for FC plogi, logo, rscn and adisc structs instead of inventing private ones. Move the private struct for issuing ELS ADISC inside zfcp to zfcp_fc header file. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Update FCP protocol related codeChristof Schmitt
Use common data structures for FCP CMND, FCP RSP and related definitions and remove zfcp private definitions. Split the FCP CMND setup and FCP RSP evaluation code in seperate functions. Use inline functions to not negatively impact the I/O path. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04[SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rportChristof Schmitt
If an error occurs that triggers the call to fc_remote_port_delete, ideally this call would happen before any I/O is passed back to the SCSI midlayer through scsi_done. The SCSI midlayer will retry the commands and fc_remote_port_chkready will return the correct status code. But with the delay between calling scsi_done in softirq context and the call to fc_remote_port_delete from the workqueue, there is a window where zfcp returns DID_ERROR. This leads to SCSI error recovery which then leads to offline SCSI devices since all recovery actions will fail with the rport now being blocked. In this window, zfcp has to return DID_IMM_RETRY just as the FC transport class would do in fc_remote_port_chkready for the blocked fc_rport. As soon as the fc_rport is BLOCKED, fc_remote_port_chkready will do the right thing. Additionally, there are two more cases to catch in zfcp_scsi_queuecommand: - After the port has been opened, the unit has to be opened. During this period I/O has to be retried. This can also be handled with DID_IMM_RETRY. - If the access to the unit fails, but the port is good, then this single unit cannot be accessed and I/O to this unit has to fail without involving the FC transport class. Reviewed-by: Swen Schillig <swen@vnet.ibm.com> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>