Commit Graph

219 Commits

Author SHA1 Message Date
Swen Schillig
b7f15f3c94 [SCSI] zfcp: fix deadlock caused by shared work queue tasks
Each adapter reopen trigger automatically a scan_port task which
is waiting for the ERP to be finished before further processing.
Since the initial device setup enqueues adapter, port and LUN which
are individual ERP actions, this process would start after
everything is done. Unfortunately the port_reopen requires another
scheduled work to be finished which is queued after the automatic
scan_port -> deadlock !

This fix creates an own work queue for ERP based nameserver requests.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:55 -05:00
Swen Schillig
5706938669 [SCSI] zfcp: put threshold data in hba trace
Now that we removed the long messages for the bit error threshold
data, put the data in the hba trace. This way, we get a short warning
for the threshold event from the hardware and have the data in the
trace for further analysis.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:55 -05:00
Christof Schmitt
0406289ed5 [SCSI] zfcp: Simplify zfcp data structures
Reduce the size of zfcp data structures by removing unused and
redundant members. scsi_lun is only the mangled version of the
fcp_lun. So, remove the redundant field and use the fcp_lun instead.

Since the queue lock and the pci_batch indicator are only used in the
request queue, move them from the common queue struct to the adapter
struct.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:54 -05:00
Swen Schillig
a1b449de5d [SCSI] zfcp: Simplify get_adapter_by_busid
Call the helper function from cio instead looping through all zfcp
adapters.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:53 -05:00
Swen Schillig
7ba58c9cc1 [SCSI] zfcp: remove all typedefs and replace them with standards
Remove typedefs from zfcp, use already existing types instead.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:53 -05:00
Swen Schillig
5ab944f97e [SCSI] zfcp: attach and release SAN nameserver port on demand
Changing the zfcp behaviour from always having the nameserver port
open to an on-demand strategy.  This strategy reduces the use of
limited resources like port connections. The patch provides a common
infrastructure which could be used for all WKA ports in future.

Also reduce the number of nameserver lookups by changing the zfcp
behaviour of always querying the nameserver for the corresponding
destination ID of the remote port.  If the destination ID has changed
during the reopen process we will be informed and then trigger a
nameserver query on demand.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:53 -05:00
Swen Schillig
44cc76f2d1 [SCSI] zfcp: remove unused references, declarations and flags
- Remove unused references and declarations, including one instance
   of the FC ls_adisc struct that has been defined twice.
 - Also remove the flags COMMON_OPENING, COMMON_CLOSING,
   ADAPTER_REGISTERED and XPORT_OK that are only set and cleared, but
   not checked anywhere.
 - Remove the zfcp specific atomic_test_mask makro. Simply use
   atomic_read directly instead.
 - Remove the zfcp internal sg helper functions and switch the places
   where it is still used to call sg_virt directly.
 - With the update of the QDIO code, the QDIO data structures no
   longer use the volatile type qualifier. Now we can also remove the
   volatile qualifiers from the zfcp code.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:52 -05:00
Christof Schmitt
ff3b24fa53 [SCSI] zfcp: Update message with input from review
Update the kernel messages in zfcp with input from the message review
and remove some messages that have been identified as redundant.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:52 -05:00
Stefan Raspl
2450d3e7b8 [SCSI] zfcp: add queue_full sysfs attribute
Adds a new sysfs attribute queue_full for adapters that records the number
of incidents where a requests could not be submitted due to insufficient
free space on the request queue.

Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-10-03 12:11:52 -05:00
Hirofumi Nakagawa
025270f0ea [SCSI] zfcp: Remove duplicated unlikely() macros.
Some drivers have duplicated unlikely() macros. IS_ERR() already
has unlikely() in itself. This patch cleans up such pointless
codes although there is no real effect on the kernel's behaviour.

Signed-off-by: Hirofumi Nakagawa <hnakagawa@miraclelinux.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-29 09:05:05 -05:00
Swen Schillig
6139308dca [SCSI] zfcp: channel cannot be detached due to refcount imbalance
Due to an imbalance of the nameserver refcounting, channel devices
couldn't be take offline anymore after the channel was activated.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-29 09:04:52 -05:00
Swen Schillig
9528539cc2 [SCSI] zfcp: Fix reference counter for remote ports
Fix the remote port reference counter handling during ELS ADISC
commands and find the remote port by WWPN not by D_IDs that could
change.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-29 09:04:35 -05:00
Christof Schmitt
f48bf7fb00 [SCSI] zfcp: Simplify ccw notify handler
The notify handler does not change the list of adapters, it only
triggers erp actions to open or shutdown the adapter. We don't
need to hold the config semaphore and wait for the erp to complete.

This is a prerequisite for a fix in the s390 common i/o code.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-29 09:04:13 -05:00
Christof Schmitt
47f7bba52b [SCSI] zfcp: Correctly query end flag in gpn_ft response
When the last port entry in the gpn_ft response is already a known
port, the eval function would skip the end flag and try to attach
ports with wwpn 0. Fix this by checking the flag first.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-29 09:03:56 -05:00
Christof Schmitt
d453881728 [SCSI] zfcp: Fix request queue locking
The request queue lock can be acquired from softirq context when the
SCSI midlayer issues commands. Disable softirqs for this lock when
commands are issued from zfcp.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-29 09:03:33 -05:00
Jan Glauber
779e6e1c72 [S390] qdio: new qdio driver.
List of major changes:
- split qdio driver into several files
- seperation of thin interrupt code
- improved handling for multiple thin interrupt devices
- inbound and outbound processing now always runs in tasklet context
- significant less tasklet schedules per interrupt needed
- merged qebsm with non-qebsm handling
- cleanup qdio interface and added kerneldoc
- coding style

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Utz Bacher <utz.bacher@de.ibm.com>
Reviewed-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-07-17 17:22:10 +02:00
Christof Schmitt
92c299d11a [SCSI] zfcp: Cleanup external header file
Sort the extern definitions by file.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:36 -05:00
Christof Schmitt
287ac01acf [SCSI] zfcp: Cleanup code in zfcp_erp.c
Cleanup the code in zfcp_erp.c, move erp internal definititions to
this file and move FSF timeout handling to the FSF layer.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:36 -05:00
Swen Schillig
c41f8cbddd [SCSI] zfcp: zfcp_fsf cleanup.
Code cleanup for the zfcp_fsf.c file.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:35 -05:00
Swen Schillig
6022192070 [SCSI] zfcp: consolidate sysfs things into one file.
zfcp was using three files to deal with sysfs representation
for adapters, ports and units. The consolidation into one file
prevents code-duplication and eases maintainability.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:35 -05:00
Swen Schillig
317e6b6519 [SCSI] zfcp: Cleanup of code in zfcp_aux.c
Overall cleanup of zfcp_aux.c to simplify code and follow kernel
coding style.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:35 -05:00
Martin Petermann
f76af7d7e3 [SCSI] zfcp: Cleanup of code in zfcp_scsi.c
Cleanup code in zfcp_scsi.c, fix coding style issues and simplify the
code.

Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:35 -05:00
Martin Petermann
feac6a07c4 [SCSI] zfcp: Move status accessors from zfcp to SCSI include file.
Move the accessor functions for the scsi_cmnd status from zfcp to the
SCSI include file. Change the interface to the functions to pass the
scsi_cmnd pointer instead of the status pointer.

Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:34 -05:00
Christof Schmitt
5d4e226246 [SCSI] zfcp: Small QDIO cleanups
QBUFF_PER_PAGE is only used inside the qdio module, so move it to
zfcp_qdio.c

zfcp_qdio_zero_sbals is now only used in the qdio module, so make it
static.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:34 -05:00
Swen Schillig
7afe29f7dd [SCSI] zfcp: Adapter reopen for large number of unsolicited status
When zfcp receives 16 unsolicited status messages, this could trigger
an adapter reopen. In this case, first try to send a new status read,
and only if this fails, go through the recovery.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:34 -05:00
Christof Schmitt
3968ce800f [SCSI] zfcp: Fix error checking for ELS ADISC requests
Correctly check the status for ELS ADISC requests. 0 means success.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:34 -05:00
Swen Schillig
c57a39a45a [SCSI] zfcp: wait until adapter is finished with ERP during auto-port
In some situations the auto port attachment task is started
before the ERP is finished. To prevent this unwanted situation
we wait until the adapter is up and running before we start our work.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:33 -05:00
Martin Peschke
235f7f25f4 [SCSI] zfcp: Remove sysfs attribute port_add
With the automatic scanning of remote ports in place, there is no need
to add remote ports manually. So, remove the port_add attribute.

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:26 -05:00
Swen Schillig
cc8c282963 [SCSI] zfcp: Automatically attach remote ports
Automatically attach the remote ports in zfcp when the adapter is set
online. This is done by querying all available ports from the FC
namesever. The scan for remote ports is also triggered by RSCNs and
can be triggered manually with the sysfs attribute 'port_rescan'.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:26 -05:00
Sven Schuetz
85a82392fe [SCSI] zfcp: Add port_state attribute to sysfs
The sysfs attribute /sys/class/fc_host/hostX/port_state was not set by
zfcp so far.

Now, the appropriate members of the fc_function_template struct are
set during its initialziation. The first is a boolean to show the port
state. The second is a function pointer to the function
zfcp_get_host_port_state, which reads the port state from our adapter
status bits and calls fc_host_port_state with the approriate port
state afterwards.

Signed-off-by: Sven Schuetz <sven@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:26 -05:00
Christof Schmitt
553448f6c4 [SCSI] zfcp: Message cleanup
Cleanup the messages used in the zfcp driver: Remove unnecessary debug
and trace message and convert the remaining messages to standard
kernel macros. Remove the zfcp message macros and while updating the
whole flie also update the copyright headers.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:26 -05:00
Swen Schillig
00bab91066 [SCSI] zfcp: Cleanup qdio code
Cleanup the interface code from zfcp to qdio. Also move code that
belongs to the qdio interface from the erp to the qdio file.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:25 -05:00
Christof Schmitt
fa04c28168 [SCSI] zfcp: Cleanup code in zfcp_ccw
Overall cleanup in file zfcp_ccw.c. Fix coding style issues, remove
useless macros and messages and convert remaining messages to standard
macros.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:25 -05:00
Christof Schmitt
45633fdc96 [SCSI] zfcp: Move CFDC code to new file.
zfcp implements a device file to allow Linux guests changing the
Access Control Tables stored in the adapter. The code for the device
file has nothing to do with the other parts of the driver, so move it
to a new file and cleanup the code while doing so.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:25 -05:00
Christof Schmitt
24073b475d [SCSI] zfcp: Move FC code to new file
Move all Fibre Channel related code to new file and cleanup the code
while doing so.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-12 08:22:25 -05:00
Christof Schmitt
aa0fec6239 [SCSI] zfcp: Fix sparse warning by providing new entry in dbf
drivers/s390/scsi/zfcp_dbf.c:692:2: warning: context imbalance in
'zfcp_rec_dbf_event_thread' - different lock contexts for basic block

Replace the parameter indicating if the lock is held with a new entry
function that only acquires the lock. This makes the lock handling
more visible and removes the sparse warning.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:15 -05:00
Martin Peschke
7337891f38 [SCSI] zfcp: remove some __attribute__ ((packed))
There is no need to pack data structures which describe the
contents of records in the new recovery trace.

lcrash currently depends on the binary format for the other traces,
removing the packed attribute from all traces would break trace
debugging with lcrash.

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:15 -05:00
Martin Peschke
70c6654051 [SCSI] zfcp: Refine trace levels of some recovery related events.
This change better spreads trace levels of recovery related events.
There was an overlap of traces for some recovery triggers and the
processing of recovery actions.

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:15 -05:00
Martin Peschke
c3baa9a26c [SCSI] zfcp: Add information about interrupt to trace.
Store the index of the buffer in the inbound queue used to report
request completion in trace record for request coompletion.
This piece of information allows to better compare qdio and zfcp traces.

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:15 -05:00
Martin Peschke
e891bffe92 [SCSI] zfcp: Rename sbal_curr to sbal_last.
sbal_last is more appropriate, because it matches sbal_first.

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:14 -05:00
Martin Peschke
d01d51beee [SCSI] zfcp: Rename sbal_last.
sbal_last is confusing, as it is not the last one actually used,
but just a limit. sbal_limit is a better name.

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:14 -05:00
Martin Peschke
0f83b110f0 [SCSI] zfcp: Remove field sbal_last from trace record.
This field is not needed, because it designates an index with a fix offset
from sbal_first. It's name is confusing anyway.

Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:14 -05:00
Christof Schmitt
5c9a6890de [SCSI] zfcp: Remove some sparse warnings
Remove some sparse warnings by telling sparse that zfcp_req_create
acquires the lock for the request queue.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:14 -05:00
Heiko Carstens
b21417820f [SCSI] zfcp: Fix fsf_status_read return code handling
If allocation of a status buffer failed the function incorrectly
returned 0 instead of -ENOMEM.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:13 -05:00
Christof Schmitt
9dfe1cc36b [SCSI] zfcp: Fix mempool pointer for GID_PN request allocation
When allocating memory for GID_PN nameserver requests, the allocation
function stores the pointer to the mempool, but then overwrites the
pointer via memset. Later, the wrong function to free the memory will
be called, since this is based on the stored pointer.

Fix this by first initializing the struct and then storing the pointer.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:13 -05:00
Swen Schillig
d26ab06ede [SCSI] zfcp: receiving an unsolicted status can lead to I/O stall
Processing of an unsolicted status request can lead to a locking race
of the request_queue's queue_lock during the recreation of the
used up status read request while still in interrupt context
of the response handler.

Detaching the 'refill' of the long running status read requests from
the handler to a scheduled work is solving this issue.

In addition, each refill-run is trying to re-establish the full amount
of status read requests, which might have failed in earlier runs.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:27:13 -05:00
Christof Schmitt
3a0d9e9235 [SCSI] zfcp: sysfs attributes for fabric and channel latencies
The latency information is provided on a SCSI device level (LUN)
which can be found at the following location

 /sys/class/scsi_device/<H:C:T:L>/device/cmd_latency
 /sys/class/scsi_device/<H:C:T:L>/device/read_latency
 /sys/class/scsi_device/<H:C:T:L>/device/write_latency

Each sysfs attribute provides the available data: min, max and sum for
fabric and channel latency and the number of requests processed.

An overrun of the variables is neither detected nor treated.  The file
has to be read twice to make a meaningful statement, because only the
differences of the values between the two reads can be used.  A reset
of the values can be achieved by writing to the attribute.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:23:44 -05:00
Christof Schmitt
c9615858a8 [SCSI] zfcp: Track fabric and channel latencies provided by FCP adapter
Add the infrastructure to retrieve the fabric and channel latencies
from FSF commands for each SCSI command that has been processed. For
each unit, the sum, min, max and number of requests is tracked.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-06-05 09:23:42 -05:00
Boaz Harrosh
64a87b244b [SCSI] Let scsi_cmnd->cmnd use request->cmd buffer
- struct scsi_cmnd had a 16 bytes command buffer of its own.
   This is an unnecessary duplication and copy of request's
   cmd. It is probably left overs from the time that scsi_cmnd
   could function without a request attached. So clean that up.

 - Once above is done, few places, apart from scsi-ml, needed
   adjustments due to changing the data type of scsi_cmnd->cmnd.

 - Lots of drivers still use MAX_COMMAND_SIZE. So I have left
   that #define but equate it to BLK_MAX_CDB. The way I see it
   and is reflected in the patch below is.
   MAX_COMMAND_SIZE - means: The longest fixed-length (*) SCSI CDB
                      as per the SCSI standard and is not related
                      to the implementation.
   BLK_MAX_CDB.     - The allocated space at the request level

 - I have audit all ISA drivers and made sure none use ->cmnd in a DMA
   Operation. Same audit was done by Andi Kleen.

(*)fixed-length here means commands that their size can be determined
   by their opcode and the CDB does not carry a length specifier, (unlike
   the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
   true and the SCSI standard also defines extended commands and
   vendor specific commands that can be bigger than 16 bytes. The kernel
   will support these using the same infrastructure used for VARLEN CDB's.
   So in effect MAX_COMMAND_SIZE means the maximum size command
   scsi-ml supports without specifying a cmd_len by ULD's

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-05-02 10:18:22 -05:00
Swen Schillig
6d9d63b948 [SCSI] zfcp: Add some statistics provided by the FCP adapter to the sysfs
The new FCP adapter statistics provide a variety of information about
the virtual adapter (subchannel). In order to collect this information
the zfcp driver is extended to query this information.

The information provided by the new FCP adapter statistics can be
fetched by reading from the following files in the sysfs filesystem

/sys/class/scsi_host/host<n>/seconds_active
/sys/class/scsi_host/host<n>/requests
/sys/class/scsi_host/host<n>/megabytes
/sys/class/scsi_host/host<n>/utilization

These are the statistics on a virtual adapter (subchannel) level.

The information provided is raw and not modified or interpreted by any
means.  No interpretation or modification of the values is done by the
zfcp driver.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-04-27 12:19:57 -05:00