Commit Graph

162 Commits

Author SHA1 Message Date
Benjamin Block 6028f7c4cd scsi: zfcp: introduce sysfs interface for diagnostics of local SFP transceiver
This adds an interface to read the diagnostics of the local SFP transceiver
of an FCP-Channel from userspace. This comes in the form of new sysfs
entries that are attached to the CCW device representing the FCP
device. Each type of data gets its own sysfs entry; the whole collection of
entries is pooled into a new child-directory of the CCW device node:
"diagnostics".

Adds sysfs entries for:
 * sfp_invalid:    boolean value evaluating to whether the following 5
                   fields are invalid; {0, 1}; 1 - invalid
 * temperature:    transceiver temp.; unit 1/256°C;
                   range [-128°C, +128°C]
 * vcc:            supply voltage; unit 100μV; range [0, 6.55V]
 * tx_bias:        transmitter laser bias current; unit 2μA;
                   range [0, 131mA]
 * tx_power:       coupled TX output power; unit 0.1μW; range [0, 6.5mW]
 * rx_power:       received optical power; unit 0.1μW; range [0, 6.5mW]

 * optical_port:   boolean value evaluating to whether the FCP-Channel has
                   an optical port; {0, 1}; 1 - optical
 * fec_active:     boolean value evaluating to whether 16G FEC is active;
                   {0, 1}; 1 - active
 * port_tx_type:   nibble describing the port type; {0, 1, 2, 3};
                   0 - unknown,             1 - short wave,
                   2 - long wave LC 1310nm, 3 - long wave LL 1550nm
 * connector_type: two bits describing the connector type; {0, 1};
                   0 - unknown,             1 - SFP+

This is only supported if the FCP-Channel in turn supports reporting the
SFP Diagnostic Data, otherwise read() on these new entries will return
EOPNOTSUPP (this affects only adapters older than FICON Express8S, on
Mainframe generations older than z14). Other possible errors for read()
include ENOLINK, ENODEV and ENOMEM.

With this patch the userspace-interface will only read data stored in
the corresponding "diagnostic buffer" (that was stored during completion
of an previous Exchange Port Data command). Implicit updating will
follow later in this series.

Link: https://lore.kernel.org/r/1f9cce7c829c881e7d71a3f10c5b57f3dd84ab32.1572018132.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-10-28 22:16:15 -04:00
Benjamin Block 7e418833e6 scsi: zfcp: diagnostics buffer caching and use for exchange port data
The FCP channel exposes two central interfaces to receive information about
the local FCP-Adapter/-Port: Exchange Port and Exchange Config Data. Using
these commands can negatively impact the adapter if we allow them to be
sent at a very high rate.

The later parts of this patchset will introduce new user-interfaces to
receive more diagnostics from the adapter. To prevent any negative impact
from using those, this patch adds a simple caching-mechanism that will
prevent a malicious/faulty userspace-application from generating an
abnormal high amount of Exchange Port/Config Data traffic.

Relevant diagnostic data that is received via Exchange Config/Port Data is
cached in buffers associated with the corresponding adapter-struct.  Each
buffer is associated with a timestamp that signals how old the data is,
and, added via a following patch in this series, lets userspace-interfaces
determine when the data is too old and needs to be updated.

Buffer-updates are made during the normal response path of the
corresponding command. With this patch only the output of the Exchange Port
Data command is captured.

Link: https://lore.kernel.org/r/054ca020ce0a53dc0d9176428bea373898944e6a.1572018130.git.bblock@linux.ibm.com
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-10-28 22:16:14 -04:00
Steffen Maier b63195698d scsi: zfcp: fix sysfs block queue limit output for max_segment_size
Since v2.6.35 commit 683229845f ("[SCSI] zfcp: Report scatter-gather
limits to SCSI and block layer"), zfcp set dma_parms.max_segment_size ==
PAGE_SIZE (but without using the setter dma_set_max_seg_size()) and
scsi_host_template.dma_boundary == PAGE_SIZE - 1.

v5.0-rc1 commit 50c2e9107f ("scsi: introduce a max_segment_size
host_template parameters") introduced a new field
scsi_host_template.max_segment_size. If an LLDD such as zfcp does not set
it, scsi_host_alloc() uses BLK_MAX_SEGMENT_SIZE = 65536 for
Scsi_Host.max_segment_size. __scsi_init_queue() announced the minimum of
Scsi_Host.max_segment_size and dma_parms.max_segment_size to the block
layer. For zfcp: min(65536, 4096) == 4096 which was still good.

v5.0 commit a8cf59a669 ("scsi: communicate max segment size to the DMA
mapping code") announces Scsi_Host.max_segment_size to the block layer and
overwrites dma_parms.max_segment_size with Scsi_Host.max_segment_size.  For
zfcp dma_parms.max_segment_size == Scsi_Host.max_segment_size == 65536
which is also reflected in block queue limits.

$ cd /sys/bus/ccw/drivers/zfcp
$ cd 0.0.3c40/host5/rport-5:0-4/target5:0:4/5:0:4:10/block/sdi/queue
$ cat max_segment_size
65536

Zfcp I/O still works because dma_boundary implicitly still keeps the
effective max segment size <= PAGE_SIZE.  However, dma_boundary does not
seem visible to user space, but max_segment_size is visible and shows a
misleading wrong value.  Fix it and inherit the stable tag of a8cf59a669.

Devices on our bus ccw support DMA but no DMA mapping. Of multiple device
types on the ccw bus, only zfcp needs dma_parms for SCSI limits.  So, leave
dma_parms setup in zfcp and do not move it to the bus.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 50c2e9107f ("scsi: introduce a max_segment_size host_template parameters")
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-01-29 01:14:59 -05:00
Steffen Maier 7171455354 scsi: zfcp: improve kdoc for return of zfcp_status_read_refill()
Complements

v2.6.35 commit 64deb6efdc ("[SCSI] zfcp: Use status_read_buf_num
provided by FCP channel") which replaced the hardcoded 16 with a
variable value

Also complements already existing fixups for above commit

v2.6.35 commit 8d88cf3f3b ("[SCSI] zfcp: Update status read mempool")
v3.10   commit 9edf7d75ee ("[SCSI] zfcp: status read buffers on first adapter open with link down")

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 22:04:25 -05:00
Steffen Maier 60a161b7e5 scsi: zfcp: fix posting too many status read buffers leading to adapter shutdown
Suppose adapter (open) recovery is between opened QDIO queues and before
(the end of) initial posting of status read buffers (SRBs). This time
window can be seconds long due to FSF_PROT_HOST_CONNECTION_INITIALIZING
causing by design looping with exponential increase sleeps in the function
performing exchange config data during recovery
[zfcp_erp_adapter_strat_fsf_xconf()]. Recovery triggered by local link up.

Suppose an event occurs for which the FCP channel would send an unsolicited
notification to zfcp by means of a previously posted SRB.  We saw it with
local cable pull (link down) in multi-initiator zoning with multiple
NPIV-enabled subchannels of the same shared FCP channel.

As soon as zfcp_erp_adapter_strategy_open_fsf() starts posting the initial
status read buffers from within the adapter's ERP thread, the channel does
send an unsolicited notification.

Since v2.6.27 commit d26ab06ede ("[SCSI] zfcp: receiving an unsolicted
status can lead to I/O stall"), zfcp_fsf_status_read_handler() schedules
adapter->stat_work to re-fill the just consumed SRB from a work item.

Now the ERP thread and the work item post SRBs in parallel.  Both contexts
call the helper function zfcp_status_read_refill().  The tracking of
missing (to be posted / re-filled) SRBs is not thread-safe due to separate
atomic_read() and atomic_dec(), in order to depend on posting
success. Hence, both contexts can see
atomic_read(&adapter->stat_miss) == 1. One of the two contexts posts
one too many SRB. Zfcp gets QDIO_ERROR_SLSB_STATE on the output queue
(trace tag "qdireq1") leading to zfcp_erp_adapter_shutdown() in
zfcp_qdio_handler_error().

An obvious and seemingly clean fix would be to schedule stat_work from the
ERP thread and wait for it to finish. This would serialize all SRB
re-fills. However, we already have another work item wait on the ERP
thread: adapter->scan_work runs zfcp_fc_scan_ports() which calls
zfcp_fc_eval_gpn_ft(). The latter calls zfcp_erp_wait() to wait for all the
open port recoveries during zfcp auto port scan, but in fact it waits for
any pending recovery including an adapter recovery. This approach leads to
a deadlock.  [see also v3.19 commit 18f87a67e6 ("zfcp: auto port scan
resiliency"); v2.6.37 commit d3e1088d68
("[SCSI] zfcp: No ERP escalation on gpn_ft eval");
v2.6.28 commit fca55b6fb5
("[SCSI] zfcp: fix deadlock between wq triggered port scan and ERP")
fixing v2.6.27 commit c57a39a45a
("[SCSI] zfcp: wait until adapter is finished with ERP during auto-port");
v2.6.27 commit cc8c282963
("[SCSI] zfcp: Automatically attach remote ports")]

Instead make the accounting of missing SRBs atomic for parallel execution
in both the ERP thread and adapter->stat_work.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: d26ab06ede ("[SCSI] zfcp: receiving an unsolicted status can lead to I/O stall")
Cc: <stable@vger.kernel.org> #2.6.27+
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 22:03:24 -05:00
Fedor Loshakov 636db60b8e scsi: zfcp: make DIX experimental, disabled, and independent of DIF
Introduce separate zfcp module parameters to individually select support
for: DIF which should work (zfcp.dif, which used to be DIF+DIX, disabled)
or DIX+DIF which can cause trouble (zfcp.dix, new, disabled).

If DIX is enabled, we warn on zfcp driver initialization.  As before, this
also reduces the maximum I/O request size to half, to support the worst
case of merged single sector requests with one protection data scatter
gather element per sector. This can impact the maximum throughput.

In DIF-only mode (zfcp.dif=1 zfcp.dix=0), we can use the full maximum I/O
request size as there is no protection data for zfcp.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Fedor Loshakov <loshakov@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-12-07 21:36:40 -05:00
Steffen Maier 58f3ead547 scsi: zfcp: move SG table helper from aux to fc and make them static
Since commit 663e0890e3 ("[SCSI] zfcp: remove access control tables
interface") these helper functions are only used for auto port scan in
zfcp_fc.c. Also change them to the corresponding namespace prefix.

This is a small cleanup for the miscellaneous catchall compile unit
zfcp_aux.c.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:17 -05:00
zhong jiang 6be552276e scsi: zfcp: remove unnecessary null pointer check before mempool_destroy
mempool_destroy has taken null pointer check into account. so remove the
redundant check.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Acked-by: Benjamin Block <bblock@linux.ibm.com>
[maier@linux.ibm.com: depends on v4.3 4e3ca3e033 ("mm/mempool: allow NULL `pool' pointer in mempool_destroy()")]
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-11-15 15:01:17 -05:00
Vasily Gorbik c6756b7d0c s390/dasd,zfcp: fix gcc 8 stringop-truncation warnings
ccw "busid" should always be NUL-terminated, as evident from e.g.
get_ccwdev_by_busid doing "return (strcmp(bus_id, dev_name(dev)) == 0)".

Replace all strncpy initializing busid with strlcpy. This fixes the
following gcc 8 warnings:

drivers/s390/scsi/zfcp_aux.c:104:2: warning: 'strncpy' specified bound 20
equals destination size [-Wstringop-truncation]
  strncpy(busid, token, ZFCP_BUS_ID_SIZE);

drivers/s390/block/dasd_eer.c:316:2: warning: 'strncpy' specified bound 10
equals destination size [-Wstringop-truncation]
  strncpy(header.busid, dev_name(&device->cdev->dev), DASD_EER_BUSID_SIZE);

drivers/s390/block/dasd_eer.c:359:2: warning: 'strncpy' specified bound 10
equals destination size [-Wstringop-truncation]
  strncpy(header.busid, dev_name(&device->cdev->dev), DASD_EER_BUSID_SIZE);

drivers/s390/block/dasd_devmap.c:429:3: warning: 'strncpy' specified bound
20 equals destination size [-Wstringop-truncation]
   strncpy(new->bus_id, bus_id, DASD_BUS_ID_SIZE);

Acked-by: Stefan Haberland <sth@linux.ibm.com>
Acked-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-07-02 11:24:52 +02:00
Greg Kroah-Hartman 40bf411ee6 s390: scsi: zfcp_aux: add SPDX identifier
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/s390/scsi/zfcp_aux.c file with the correct SPDX
license identifier based on the license text in the file itself.  The
SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Steffen Maier <maier@linux.vnet.ibm.com>
Cc: Benjamin Block <bblock@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-24 14:28:44 +01:00
Steffen Maier ab31fd0ce6 scsi: zfcp: fix erp_action use-before-initialize in REC action trace
v4.10 commit 6f2ce1c6af ("scsi: zfcp: fix rport unblock race with LUN
recovery") extended accessing parent pointer fields of struct
zfcp_erp_action for tracing.  If an erp_action has never been enqueued
before, these parent pointer fields are uninitialized and NULL. Examples
are zfcp objects freshly added to the parent object's children list,
before enqueueing their first recovery subsequently. In
zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action
fields can cause a NULL pointer dereference.  Since the kernel can read
from lowcore on s390, it does not immediately cause a kernel page
fault. Instead it can cause hangs on trying to acquire the wrong
erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl()
                      ^bogus^
while holding already other locks with IRQs disabled.

Real life example from attaching lots of LUNs in parallel on many CPUs:

crash> bt 17723
PID: 17723  TASK: ...               CPU: 25  COMMAND: "zfcperp0.0.1800"
 LOWCORE INFO:
  -psw      : 0x0404300180000000 0x000000000038e424
  -function : _raw_spin_lock_wait_flags at 38e424
...
 #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp]
 #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp]
 #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp]
 #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp]
 #4 [fdde8fe60] kthread at 173550
 #5 [fdde8feb8] kernel_thread_starter at 10add2

zfcp_adapter
 zfcp_port
  zfcp_unit <address>, 0x404040d600000000
  scsi_device NULL, returning early!
zfcp_scsi_dev.status = 0x40000000
0x40000000 ZFCP_STATUS_COMMON_RUNNING

crash> zfcp_unit <address>
struct zfcp_unit {
  erp_action = {
    adapter = 0x0,
    port = 0x0,
    unit = 0x0,
  },
}

zfcp_erp_action is always fully embedded into its container object. Such
container object is never moved in its object tree (only add or delete).
Hence, erp_action parent pointers can never change.

To fix the issue, initialize the erp_action parent pointers before
adding the erp_action container to any list and thus before it becomes
accessible from outside of its initializing function.

In order to also close the time window between zfcp_erp_setup_act()
memsetting the entire erp_action to zero and setting the parent pointers
again, drop the memset and instead explicitly initialize individually
all erp_action fields except for parent pointers. To be extra careful
not to introduce any other unintended side effect, even keep zeroing the
erp_action fields for list and timer. Also double-check with
WARN_ON_ONCE that erp_action parent pointers never change, so we get to
know when we would deviate from previous behavior.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 6f2ce1c6af ("scsi: zfcp: fix rport unblock race with LUN recovery")
Cc: <stable@vger.kernel.org> #2.6.32+
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-10-16 22:45:26 -04:00
Corentin Labbe 16d75e6503 scsi: zfcp: Remove unneeded linux/miscdevice.h include
drivers/s390/scsi/zfcp_aux.c does not contain any miscdevice so the
inclusion of linux/miscdevice.h is unnecessary.

[maier@linux.vnet.ibm.com: just for the records, this is in fact a
 minor missing code cleanup of the following older "feature"
 which also dropped the only former use of a misc device in zfcp:
 commit 663e0890e3 ("[SCSI] zfcp: remove access control tables
				    interface")
 commit b5dc3c4800 ("[SCSI] zfcp: remove access control tables
				    interface (keep sysfs files)")
 commit 1b33ef2394 ("zfcp: remove access control tables interface
			     (port leftovers)")]

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2017-08-10 19:36:53 -04:00
Bhaktipriya Shridhar e68f1d4ca9 s390: Remove deprecated create_singlethread_workqueue
The workqueue "appldata_wq" has been replaced with an ordered dedicated
workqueue.

WQ_MEM_RECLAIM has not been set since the workqueue is not being used on
a memory reclaim path.

The adapter->work_queue queues multiple work items viz
&adapter->scan_work, &port->rport_work, &adapter->ns_up_work,
&adapter->stat_work, adapter->work_queue, &adapter->events.work,
&port->gid_pn_work, &port->test_link_work. Hence, an ordered
dedicated workqueue has been used.

WQ_MEM_RECLAIM has been set to ensure forward progress under memory
pressure.

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-09-06 10:59:57 +02:00
Peter Zijlstra 805de8f43c atomic: Replace atomic_{set,clear}_mask() usage
Replace the deprecated atomic_{set,clear}_mask() usage with the now
ubiquous atomic_{or,andnot}() functions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27 14:06:24 +02:00
Martin Peschke 18f87a67e6 zfcp: auto port scan resiliency
This patch improves the Fibre Channel port scan behaviour of the zfcp lldd.
Without it the zfcp device driver may churn up the storage area network by
excessive scanning and scan bursts, particularly in big virtual server
environments, potentially resulting in interference of virtual servers and
reduced availability of storage connectivity.

The two main issues as to the zfcp device drivers automatic port scan in
virtual server environments are frequency and simultaneity.
On the one hand, there is no point in allowing lots of ports scans
in a row. It makes sense, though, to make sure that a scan is conducted
eventually if there has been any indication for potential SAN changes.
On the other hand, lots of virtual servers receiving the same indication
for a SAN change had better not attempt to conduct a scan instantly,
that is, at the same time.

Hence this patch has a two-fold approach for better port scanning:
the introduction of a rate limit to amend frequency issues, and the
introduction of a short random backoff to amend simultaneity issues.
Both approaches boil down to deferred port scans, with delays
comprising parts for both approaches.

The new port scan behaviour is summarised best by:

                                               NEW:    NEW:
                          no_auto_port_rescan  random  rate    flush
                                               backoff limit   =wait

adapter resume/thaw       yes                  yes     no      yes*
adapter online (user)     no                   yes     no      yes*
port rescan (user)        no                   no      no      yes
adapter recovery (user)   yes                  yes     yes     no
adapter recovery (other)  yes                  yes     yes     no
incoming ELS              yes                  yes     yes     no
incoming ELS lost         yes                  yes     yes     no

Implementation is straight-forward by converting an existing worker to
a delayed worker. But care is needed whenever that worker is going to be
flushed (in order to make sure work has been completed), since a flush
operation cancels the timer set up for deferred execution (see * above).

There is a small race window whenever a port scan work starts
running up to the point in time of storing the time stamp for that port
scan. The impact is negligible. Closing that gap isn't trivial, though, and
would the destroy the beauty of a simple work-to-delayed-work conversion.

Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-20 09:11:30 +01:00
Martin Peschke ee732ea829 [SCSI] zfcp: cleanup use of obsolete strict_strto* functions
strict_strtoul and friends are obsolete. Use kstrtoul functions
instead.

Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-09-03 07:27:55 -07:00
Steffen Maier 9edf7d75ee [SCSI] zfcp: status read buffers on first adapter open with link down
Commit 64deb6efdc
"[SCSI] zfcp: Use status_read_buf_num provided by FCP channel"
started using a value returned by the channel but only evaluated the value
if the fabric link is up.
Commit 8d88cf3f3b
"[SCSI] zfcp: Update status read mempool"
introduced mempool resizings based on the above value.
On setting an FCP device online for the very first time since boot, a new
zeroed adapter object is allocated. If the link is down, the number of
status read requests remains zero. Since just the config data exchange is
incomplete, we proceed with adapter open recovery. However, we
unconditionally call mempool_resize with adapter->stat_read_buf_num == 0 in
this case.

This causes a kernel message "kernel BUG at mm/mempool.c:131!" in process
"zfcperp<FCP-device-bus-ID>" with last function mempool_resize in Krnl PSW
and zfcp_erp_thread in the Call Trace.

Don't evaluate channel values which are invalid on link down. The number of
status read requests is always valid, evaluated, and set to a positive
minimum greater than zero. The adapter open recovery can proceed and the
channel has status read buffers to inform us on a future link up event.
While we are not aware of any other code path that could result in mempool
resize attempts of size zero, we still also initialize the number of status
read buffers to be posted to a static minimum number on adapter object
allocation.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> #2.6.35+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-05-31 16:32:38 -07:00
Martin Peschke 663e0890e3 [SCSI] zfcp: remove access control tables interface
This patch removes an interface that was used to manage access control
tables within the HBA. The patch consequently removes the handling
for conditions related to those access control tables, too.

That initiator-based access control feature was only needed until the
introduction of NPIV and was withdrawn with z10 years ago.
It's time to cleanup the corresponding device driver code.

Signed-off-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-05-31 16:32:38 -07:00
Sebastian Ott bd3238667b [SCSI] zfcp: remove unused device_unregister wrapper
Remove the now unused function zfcp_device_unregister since all
users have been converted to use device_unregister directly.

Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-05-31 16:32:37 -07:00
Sebastian Ott 83d4e1c33d [SCSI] zfcp: cleanup port sysfs attribute usage
Let the driver core handle device attribute creation and removal. This
will simplify the code and eliminates races between attribute
availability and userspace notification via uevents.

Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-05-31 16:32:36 -07:00
Steffen Maier d99b601b63 [SCSI] zfcp: restore refcount check on port_remove
Upstream commit f3450c7b91
"[SCSI] zfcp: Replace local reference counting with common kref"
accidentally dropped a reference count check before tearing down
zfcp_ports that are potentially in use by zfcp_units.
Even remote ports in use can be removed causing
unreachable garbage objects zfcp_ports with zfcp_units.
Thus units won't come back even after a manual port_rescan.
The kref of zfcp_port->dev.kobj is already used by the driver core.
We cannot re-use it to track the number of zfcp_units.
Re-introduce our own counter for units per port
and check on port_remove.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@vger.kernel.org> #2.6.33+
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-09-24 12:11:02 +04:00
Heiko Carstens a53c8fab3f s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00
Heiko Carstens 3a4c5d5964 s390: add missing module.h/export.h includes
Fix several compile errors on s390 caused by splitting module.h.

Some include additions [e.g. qdio_setup.c, zfcp_qdio.c] are in
anticipation of pending changes queued for s390 that increase
the modular use footprint.

[PG: added additional obvious changes since Heiko's original patch]

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:58 -04:00
Christof Schmitt 038d9446a9 [SCSI] zfcp: Add information to symbolic port name when running in NPIV mode
Query the FC symbolic port name for reporting in the fc_host sysfs and
enable the symbolic_name attribute in the fc_host sysfs. When running
in NPIV mode, extend the symbolic port name with the devno and the
hostname. This allows better identification of Linux systems for SAN
and storage administrators.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-25 12:02:21 -05:00
Christof Schmitt 1947c72a12 [SCSI] zfcp: Move SCSI host and transport templates out of struct zfcp_data
The SCSI host and transport templates are the only members left in the
global zfcp_data struct. Move them out of zfcp_data  and remove the
now unused zfcp_data struct. Also update the names of the register and
unregister functions to use the zfcp_scsi prefix.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-25 12:02:17 -05:00
Christof Schmitt 259afe2ed9 [SCSI] zfcp: Move qtcb kmem_cache to zfcp_fsf.c
Move the kmem_cache for allocating the qtcb to zfcp_fsf.c and rename
it accordingly.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-25 12:02:12 -05:00
Christof Schmitt f9773229be [SCSI] zfcp: Use common FC kmem_cache for GPN_FT request
Switch the allocation of the GPN_FT request data to the FC kmem_cache
and remove the zfcp_gpn kmem_cache.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-25 12:02:09 -05:00
Christof Schmitt fcf7e6144d [SCSI] zfcp: Allocate GID_PN data through new FC kmem_cache
Allocate the data for the GID_PN request through the new FC
kmem_cache. While updating the GID_PN code, also introduce a helper
function for initializing the CT header for FC nameserver requests.
Remove the "paranoia" check as well, the GID_PN request data does not
suddenly change.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-25 12:02:06 -05:00
Christof Schmitt 087897e369 [SCSI] zfcp: Introduce new kmem_cache for FC request and response data
A data buffer that is passed to the hardware must not cross a page
boundary. zfcp uses a series of kmem_caches to align the data to not
cross a page boundary. Introduce a new kmem_cache for the FC requests
sent from the zfcp driver and use it for the ELS ADISC data.  The goal
is to migrate to the FC kmem_cache in later patches and remove the
request specific kmem_caches.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-25 12:02:03 -05:00
Christof Schmitt c7b279ae51 [SCSI] zfcp: Replace kmem_cache for "status read" data
zfcp requires a mempool for the status read data blocks to resubmit
the "status read" requests at any time. Each status read data block
has the size of a page (4096 bytes) and needs to be placed in one
page.

Instead of having a kmem_cache for allocating page sized chunks, use
mempool_create_page_pool to create a mempool returning pages and
remove the zfcp kmem_cache.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-25 12:01:59 -05:00
Christof Schmitt 51780d2c38 [SCSI] zfcp: Add __init declaration to zfcp_cache_hw_align
The function zfcp_cache_hw_align is only called from zfcp_module_init,
so it should be declared with __init as well.

Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-12-21 12:24:47 -06:00
Swen Schillig ea4a3a6ac4 [SCSI] zfcp: Redesign of the debug tracing final cleanup.
This patch is the final cleanup of the redesign from the zfcp tracing.
Structures and elements which were used by multiple areas of the
former debug tracing are now changed to the new scheme.

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@suse.de>
2010-12-21 12:24:46 -06:00
Christof Schmitt 1daa4eb50f [SCSI] zfcp: Move code for managing zfcp_unit devices to new file
Move the code for managing zfcp_unit devices to the new file
zfcp_unit.c. This is in preparation for the change that zfcp_unit will
only track the LUNs configured via unit_add, other data will be moved
from zfcp_unit to the new struct zfcp_scsi_dev.

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>
2010-09-16 22:54:15 -04:00
Christof Schmitt 57c237731b [SCSI] zfcp: Add zfcp private struct as SCSI device driver data
Add a new data structure zfcp_scsi_dev that holds zfcp private data
for each SCSI device. Use scsi_transport_reserve_device to let the
SCSI midlayer automatically allocate this with each SCSI device.

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>
2010-09-16 22:54:14 -04:00
Christof Schmitt 91978465b1 [SCSI] zfcp: Reorder registration of initial SCSI device
Make sure that the rport registration did complete and then register
SCSI device directly. Otherwise the unit_enqueue would race with the
call to zfcp_scsi_queue_unit_register.

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>
2010-09-09 15:36:44 -05:00
Sven Schuetz 2d1e547f75 [SCSI] zfcp: Post events through FC transport class
Post FC transport class netlink events for usage in the userspace,
e.g. for HBAAPI. Supported events are those required for the
polled events in HBAAPI.
- link up
- link down
- incoming RSCN
(events related to FC-AL are not supported, as zfcp has no support for FC-AL)

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@suse.de>
2010-07-28 09:48:52 -05:00
Christof Schmitt 674c3a993c [SCSI] zfcp: Use memdup_user and kstrdup
Use the functions memdup_user and kstrdup to allocate memory and copy
the data in one step, saving some lines of code.

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>
2010-07-28 09:48:45 -05:00
Christof Schmitt 5a7de559b4 [SCSI] zfcp: Register SCSI devices after successful fc_remote_port_add
When the successful return of an adisc is the final step to set the
port online, the registration of SCSI devices might be omitted. SCSI
devices that have been removed before (due to a short dev_loss_tmo
setting) might not be attached again.

The problem is that the registration of SCSI devices is done only
after erp has finished. The correct place would be after the call to
fc_remote_port_add to mimick the scan in the FC transport class.

Change the registration of SCSI devices to be triggered after the
fc_remote_port_add call. For the initial inquiry command to succeed,
the unit must also be open. If the unit reopen is still pending, the
inquiry command to the LUN will be deferred with DID_IMM_RETRY, so
there is no harm from this approach.

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>
2010-07-28 09:46:38 -05:00
Christof Schmitt 64deb6efdc [SCSI] zfcp: Use status_read_buf_num provided by FCP channel
The FCP channel provides the number of status read buffers to issue.
Use the provided number instead of the hardcoded number in zfcp.

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>
2010-05-02 15:42:33 -04:00
Christof Schmitt 683229845f [SCSI] zfcp: Report scatter-gather limits to SCSI and block layer
Instead of dealing with large segments in the scatter-gather lists in
zfcp_qdio.c, report the limits to the upper layers. With these limits
in place, the code for mapping large data blocks to multiple sbales
can be removed.

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>
2010-05-02 15:42:29 -04:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Christof Schmitt 615f59e0da [SCSI] zfcp: Rename sysfs_device attribute to dev in zfcp_unit and zfcp_port
Kernel code uses dev as short name for the struct device. Rename the
sysfs_device in zfcp_unit and zfcp_port to match this convention.

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>
2010-02-17 17:46:30 -06:00
Christof Schmitt b6bd2fb92a [SCSI] zfcp: Move FSF request tracking code to new file
Move the code for tracking FSF requests to new file to have this code
in one place. The functions for adding and removing requests on the
I/O path are already inline. The alloc and free functions are only
called once, so it does not hurt to inline them and add them to the
same 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>
2010-02-17 17:46:19 -06:00
Christof Schmitt ee744622c6 [SCSI] zfcp: Improve ELS ADISC handling
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 12:02:16 -06:00
Christof Schmitt dbf5dfe9db [SCSI] zfcp: Use common code definitions for FC CT structs
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 12:02:13 -06:00
Swen Schillig 9eae07ef6b [SCSI] zfcp: Assign scheduled work to driver queue
The port_scan work was scheduled to the work_queue provided by the
kernel. This resulted on SMP systems to a likely situation that more
than one scan_work were processed in parallel. This is not required
and openes the possibility of race conditions between the removal of
invalid ports and the enqueue of just scanned ports.  This patch
synchronizes the scan_work tasks by scheduling them to adapter local
work_queue.

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@suse.de>
2009-12-04 12:02:08 -06:00
Swen Schillig 6b183334c2 [SCSI] zfcp: Remove STATUS_COMMON_REMOVE flag as it is not required anymore
The flag ZFCP_STATUS_COMMON_REMOVE was used to indicate that a
resource is not ready to be used or about to be removed from the
system. This is now better done by an improved list handling
and therefore the additional indicator is not required anymore.

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@suse.de>
2009-12-04 12:02:07 -06:00
Christof Schmitt c1fad41764 [SCSI] zfcp: Implement module unloading
With the reference counting for zfcp data structures, it is now
possible to implement module unloading again. Module unloading
requires to free all data structures in the module exit function. This
is done by unregistering zfcp from s390 cio and the SCSI midlayer
first in the module exit function.

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 12:02:06 -06:00
Christof Schmitt 25458eb791 [SCSI] zfcp: Access ports and units with container_of in sysfs code
When accessing port and unit attributes, use container_of instead of
dev_get_drvdata. This eliminates some code checker warnings about
aliased access of data structures.

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 12:02:04 -06:00
Swen Schillig de3dc57214 [SCSI] zfcp: Remove global config_mutex
The global config_mutex was required for the serialization of a
configuration change within the zfcp driver.  This global locking is
now obsolete and can be removed.  The requirement of serializing the
access to a zfcp_adapter reference via a ccw_device is realized wth a
static spinlock.

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@suse.de>
2009-12-04 12:02:02 -06:00