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The error path from zfcp_adapter_enqueue() no longer attempts to remove the
diagnostics attributes if they haven't been created yet.
So remove the manual 'sysfs_established' guard for this case, and use
device_add_groups() to add all adapter-related sysfs attributes in one go.
Link: https://lore.kernel.org/r/37a97537f675d643006271f37723c346189b6eec.1618417667.git.bblock@linux.ibm.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When zfcp_adapter_enqueue() fails to create the zfcp_sysfs_adapter_attrs
group, it calls zfcp_adapter_unregister() to tear down the adapter state
again. This then unconditionally attempts to remove the
zfcp_sysfs_adapter_attrs group, resulting in a "group not found" WARN from
sysfs code.
Avoid this by copying most of zfcp_adapter_unregister() into the error
path, allowing for more fine-granular roll-back. Then skip the sysfs
tear-down steps if we haven't progressed this far in the initialization.
Link: https://lore.kernel.org/r/790922cc3af075795fff9a4b787e6bda19bdb3be.1618417667.git.bblock@linux.ibm.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
As recovery for a lost Version Change event, trigger an Exchange Config
Data cmd to retrieve the current FW version.
Doing so requires process context (as eg. zfcp_qdio_sbal_get() might need
to sleep), so defer from tasklet context into a work item.
Link: https://lore.kernel.org/r/297c7be2944c3714863fcd22d531d910312d29f0.1603908167.git.bblock@linux.ibm.com
Suggested-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
At the moment we allocate and register the Scsi_Host object corresponding
to a zfcp adapter (FCP device) very early in the life cycle of the adapter
- even before we fully discover and initialize the underlying
firmware/hardware. This had the advantage that we could already use the
Scsi_Host object, and fill in all its information during said discover and
initialize.
Due to commit 737eb78e82 ("block: Delay default elevator initialization")
(first released in v5.4), we noticed a regression that would prevent us
from using any storage volume if zfcp is configured with support for DIF or
DIX (zfcp.dif=1 || zfcp.dix=1). Doing so would result in an illegal memory
access as soon as the first request is sent with such an configuration. As
example for a crash resulting from this:
scsi host0: scsi_eh_0: sleeping
scsi host0: zfcp
qdio: 0.0.1900 ZFCP on SC 4bd using AI:1 QEBSM:0 PRI:1 TDD:1 SIGA: W AP
scsi 0:0:0:0: scsi scan: INQUIRY pass 1 length 36
Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 0000000000000000 TEID: 0000000000000483
Fault in home space mode while using kernel ASCE.
AS:0000000035c7c007 R3:00000001effcc007 S:00000001effd1000 P:000000000000003d
Oops: 0004 ilc:3 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: ...
CPU: 1 PID: 783 Comm: kworker/u760:5 Kdump: loaded Not tainted 5.6.0-rc2-bb-next+ #1
Hardware name: ...
Workqueue: scsi_wq_0 fc_scsi_scan_rport [scsi_transport_fc]
Krnl PSW : 0704e00180000000 000003ff801fcdae (scsi_queue_rq+0x436/0x740 [scsi_mod])
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0fffffffffffffff 0000000000000000 0000000187150120 0000000000000000
000003ff80223d20 000000000000018e 000000018adc6400 0000000187711000
000003e0062337e8 00000001ae719000 0000000187711000 0000000187150000
00000001ab808100 0000000187150120 000003ff801fcd74 000003e0062336a0
Krnl Code: 000003ff801fcd9e: e310a35c0012 lt %r1,860(%r10)
000003ff801fcda4: a7840010 brc 8,000003ff801fcdc4
#000003ff801fcda8: e310b2900004 lg %r1,656(%r11)
>000003ff801fcdae: d71710001000 xc 0(24,%r1),0(%r1)
000003ff801fcdb4: e310b2900004 lg %r1,656(%r11)
000003ff801fcdba: 41201018 la %r2,24(%r1)
000003ff801fcdbe: e32010000024 stg %r2,0(%r1)
000003ff801fcdc4: b904002b lgr %r2,%r11
Call Trace:
[<000003ff801fcdae>] scsi_queue_rq+0x436/0x740 [scsi_mod]
([<000003ff801fcd74>] scsi_queue_rq+0x3fc/0x740 [scsi_mod])
[<00000000349c9970>] blk_mq_dispatch_rq_list+0x390/0x680
[<00000000349d1596>] blk_mq_sched_dispatch_requests+0x196/0x1a8
[<00000000349c7a04>] __blk_mq_run_hw_queue+0x144/0x160
[<00000000349c7ab6>] __blk_mq_delay_run_hw_queue+0x96/0x228
[<00000000349c7d5a>] blk_mq_run_hw_queue+0xd2/0xe0
[<00000000349d194a>] blk_mq_sched_insert_request+0x192/0x1d8
[<00000000349c17b8>] blk_execute_rq_nowait+0x80/0x90
[<00000000349c1856>] blk_execute_rq+0x6e/0xb0
[<000003ff801f8ac2>] __scsi_execute+0xe2/0x1f0 [scsi_mod]
[<000003ff801fef98>] scsi_probe_and_add_lun+0x358/0x840 [scsi_mod]
[<000003ff8020001c>] __scsi_scan_target+0xc4/0x228 [scsi_mod]
[<000003ff80200254>] scsi_scan_target+0xd4/0x100 [scsi_mod]
[<000003ff802d8b96>] fc_scsi_scan_rport+0x96/0xc0 [scsi_transport_fc]
[<0000000034245ce8>] process_one_work+0x458/0x7d0
[<00000000342462a2>] worker_thread+0x242/0x448
[<0000000034250994>] kthread+0x15c/0x170
[<0000000034e1979c>] ret_from_fork+0x30/0x38
INFO: lockdep is turned off.
Last Breaking-Event-Address:
[<000003ff801fbc36>] scsi_add_cmd_to_list+0x9e/0xa8 [scsi_mod]
Kernel panic - not syncing: Fatal exception: panic_on_oops
While this issue is exposed by the commit named above, this is only by
accident. The real issue exists for longer already - basically since it's
possible to use blk-mq via scsi-mq, and blk-mq pre-allocates all requests
for a tag-set during initialization of the same. For a given Scsi_Host
object this is done when adding the object to the midlayer
(`scsi_add_host()` and such). In `scsi_mq_setup_tags()` the midlayer
calculates how much memory is required for a single scsi_cmnd, and its
additional data, which also might include space for additional protection
data - depending on whether the Scsi_Host has any form of protection
capabilities (`scsi_host_get_prot()`).
The problem is now thus, because zfcp does this step before we actually
know whether the firmware/hardware has these capabilities, we don't set any
protection capabilities in the Scsi_Host object. And so, no space is
allocated for additional protection data for requests in the Scsi_Host
tag-set.
Once we go through discover and initialize the FCP device firmware/hardware
fully (this is done via the firmware commands "Exchange Config Data" and
"Exchange Port Data") we find out whether it actually supports DIF and DIX,
and we set the corresponding capabilities in the Scsi_Host object (in
`zfcp_scsi_set_prot()`). Now the Scsi_Host potentially has protection
capabilities, but the already allocated requests in the tag-set don't have
any space allocated for that.
When we then trigger target scanning or add scsi_devices manually, the
midlayer will use requests from that tag-set, and before sending most
requests, it will also call `scsi_mq_prep_fn()`. To prepare the scsi_cmnd
this function will check again whether the used Scsi_Host has any
protection capabilities - and now it potentially has - and if so, it will
try to initialize the assumed to be preallocated structures and thus it
causes the crash, like shown above.
Before delaying the default elevator initialization with the commit named
above, we always would also allocate an elevator for any scsi_device before
ever sending any requests - in contrast to now, where we do it after
device-probing. That elevator in turn would have its own tag-set, and that
is initialized after we went through discovery and initialization of the
underlying firmware/hardware. So requests from that tag-set can be
allocated properly, and if used - unless the user changes/disabled the
default elevator - this would hide the underlying issue.
To fix this for any configuration - with or without an elevator - we move
the allocation and registration of the Scsi_Host object for a given FCP
device to after the first complete discovery and initialization of the
underlying firmware/hardware. By doing that we can make all basic
properties of the Scsi_Host known to the midlayer by the time we call
`scsi_add_host()`, including whether we have any protection capabilities.
To do that we have to delay all the accesses that we would have done in the
past during discovery and initialization, and do them instead once we are
finished with it. The previous patches ramp up to this by fencing and
factoring out all these accesses, and make it possible to re-do them later
on. In addition we make also use of the diagnostic buffers we recently
added with
commit 92953c6e0a ("scsi: zfcp: signal incomplete or error for sync exchange config/port data")
commit 7e418833e6 ("scsi: zfcp: diagnostics buffer caching and use for exchange port data")
commit 088210233e ("scsi: zfcp: add diagnostics buffer for exchange config data")
(first released in v5.5), because these already cache all the information
we need for that "re-do operation" - the information cached are always
updated during xconf or xport data, so it won't be stale.
In addition to the move and re-do, this patch also updates the
function-documentation of `zfcp_scsi_adapter_register()` and changes how it
reports if a Scsi_Host object already exists. In that case future
recovery-operations can skip this step completely and behave much like they
would do in the past - zfcp does not release a once allocated Scsi_Host
object unless the corresponding FCP device is deconstructed completely.
Link: https://lore.kernel.org/r/030dd6da318bbb529f0b5268ec65cebcd20fc0a3.1588956679.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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
