commit 242ec14551 upstream.
Suppose more than one non-NPIV FCP device is active on the same channel.
Send I/O to storage and have some of the pending I/O run into a SCSI
command timeout, e.g. due to bit errors on the fibre. Now the error
situation stops. However, we saw FCP requests continue to timeout in the
channel. The abort will be successful, but the subsequent TUR fails.
Scsi_eh starts. The LUN reset fails. The target reset fails. The host
reset only did an FCP device recovery. However, for non-NPIV FCP devices,
this does not close and reopen ports on the SAN-side if other non-NPIV FCP
device(s) share the same open ports.
In order to resolve the continuing FCP request timeouts, we need to
explicitly close and reopen ports on the SAN-side.
This was missing since the beginning of zfcp in v2.6.0 history commit
ea127f975424 ("[PATCH] s390 (7/7): zfcp host adapter.").
Note: The FSF requests for forced port reopen could run into FSF request
timeouts due to other reasons. This would trigger an internal FCP device
recovery. Pending forced port reopen recoveries would get dismissed. So
some ports might not get fully reopened during this host reset handler.
However, subsequent I/O would trigger the above described escalation and
eventually all ports would be forced reopen to resolve any continuing FCP
request timeouts due to earlier bit errors.
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit fe67888fc0 upstream.
An already deleted SCSI device can exist on the Scsi_Host and remain there
because something still holds a reference. A new SCSI device with the same
H:C:T:L and FCP device, target port WWPN, and FCP LUN can be created. When
we try to unblock an rport, we still find the deleted SCSI device and
return early because the zfcp_scsi_dev of that SCSI device is not
ZFCP_STATUS_COMMON_UNBLOCKED. Hence we miss to unblock the rport, even if
the new proper SCSI device would be in good state.
Therefore, skip deleted SCSI devices when iterating the sdevs of the shost.
[cf. __scsi_device_lookup{_by_target}() or scsi_device_get()]
The following abbreviated trace sequence can indicate such problem:
Area : REC
Tag : ersfs_3
LUN : 0x4045400300000000
WWPN : 0x50050763031bd327
LUN status : 0x40000000 not ZFCP_STATUS_COMMON_UNBLOCKED
Ready count : n not incremented yet
Running count : 0x00000000
ERP want : 0x01
ERP need : 0xc1 ZFCP_ERP_ACTION_NONE
Area : REC
Tag : ersfs_3
LUN : 0x4045400300000000
WWPN : 0x50050763031bd327
LUN status : 0x41000000
Ready count : n+1
Running count : 0x00000000
ERP want : 0x01
ERP need : 0x01
...
Area : REC
Level : 4 only with increased trace level
Tag : ertru_l
LUN : 0x4045400300000000
WWPN : 0x50050763031bd327
LUN status : 0x40000000
Request ID : 0x0000000000000000
ERP status : 0x01800000
ERP step : 0x1000
ERP action : 0x01
ERP count : 0x00
NOT followed by a trace record with tag "scpaddy"
for WWPN 0x50050763031bd327.
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 6f2ce1c6af ("scsi: zfcp: fix rport unblock race with LUN recovery")
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 3438b2c039 upstream.
A queue with a capacity of zero is clearly not a valid virtio queue.
Some emulators report zero queue size if queried with an invalid queue
index. Instead of crashing in this case let us just return -ENOENT. To
make that work properly, let us fix the notifier cleanup logic as well.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit c0a2e4d10d upstream.
Work for Bridgeport events is currently placed on a driver-wide
workqueue. If the card is removed and freed while any such work is still
active, this causes a use-after-free.
So put the events on a per-card queue, where we can control their
lifetime. As we also don't want stale events to last beyond an
offline & online cycle, flush this queue when setting the card offline.
Fixes: b4d72c08b3 ("qeth: bridgeport support - basic control")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
- Add gdev parameter to qeth_alloc_card(), as done upstream by commit
121ca39aa5 "s390/qeth: uninstall IRQ handler on device removal"
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit c2780c1a3f upstream.
A card's close_dev work is scheduled on a driver-wide workqueue. If the
card is removed and freed while the work is still active, this causes a
use-after-free.
So make sure that the work is completed before freeing the card.
Fixes: 0f54761d16 ("qeth: Support VEPA mode")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit afa0c5904b upstream.
The error path in qeth_alloc_qdio_buffers() that takes care of
cleaning up the Output Queues is buggy. It first frees the queue, but
then calls qeth_clear_outq_buffers() with that very queue struct.
Make the call to qeth_clear_outq_buffers() part of the free action
(in the correct order), and while at it fix the naming of the helper.
Fixes: 0da9581ddb ("qeth: exploit asynchronous delivery of storage blocks")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
- Add the qeth_free_output_queue() function, which didn't exist here
- Keep using kfree() to free to free the qeth_qdio_out_q structure]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 4a8ef6999b upstream.
Dan Carpenter reported the following:
The patch 52898025cf: "[S390] dasd: security and PSF update patch
for EMC CKD ioctl" from Mar 8, 2010, leads to the following static
checker warning:
drivers/s390/block/dasd_eckd.c:4486 dasd_symm_io()
error: using offset into zero size array 'psf_data[]'
drivers/s390/block/dasd_eckd.c
4458 /* Copy parms from caller */
4459 rc = -EFAULT;
4460 if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
^^^^^^^
The user can specify any "usrparm.psf_data_len". They choose zero by
mistake.
4461 goto out;
4462 if (is_compat_task()) {
4463 /* Make sure pointers are sane even on 31 bit. */
4464 rc = -EINVAL;
4465 if ((usrparm.psf_data >> 32) != 0)
4466 goto out;
4467 if ((usrparm.rssd_result >> 32) != 0)
4468 goto out;
4469 usrparm.psf_data &= 0x7fffffffULL;
4470 usrparm.rssd_result &= 0x7fffffffULL;
4471 }
4472 /* alloc I/O data area */
4473 psf_data = kzalloc(usrparm.psf_data_len, GFP_KERNEL
| GFP_DMA);
4474 rssd_result = kzalloc(usrparm.rssd_result_len, GFP_KERNEL
| GFP_DMA);
4475 if (!psf_data || !rssd_result) {
kzalloc() returns a ZERO_SIZE_PTR (0x16).
4476 rc = -ENOMEM;
4477 goto out_free;
4478 }
4479
4480 /* get syscall header from user space */
4481 rc = -EFAULT;
4482 if (copy_from_user(psf_data,
4483 (void __user *)(unsigned long)
usrparm.psf_data,
4484 usrparm.psf_data_len))
That all works great.
4485 goto out_free;
4486 psf0 = psf_data[0];
4487 psf1 = psf_data[1];
But now we're assuming that "->psf_data_len" was at least 2 bytes.
Fix this by checking the user specified length psf_data_len.
Fixes: 52898025cf ("[S390] dasd: security and PSF update patch for EMC CKD ioctl")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit b7cb707c37 upstream.
smp_rescan_cpus() is called without the device_hotplug_lock, which can lead
to a dedlock when a new CPU is found and immediately set online by a udev
rule.
This was observed on an older kernel version, where the cpu_hotplug_begin()
loop was still present, and it resulted in hanging chcpu and systemd-udev
processes. This specific deadlock will not show on current kernels. However,
there may be other possible deadlocks, and since smp_rescan_cpus() can still
trigger a CPU hotplug operation, the device_hotplug_lock should be held.
For reference, this was the deadlock with the old cpu_hotplug_begin() loop:
chcpu (rescan) systemd-udevd
echo 1 > /sys/../rescan
-> smp_rescan_cpus()
-> (*) get_online_cpus()
(increases refcount)
-> smp_add_present_cpu()
(new CPU found)
-> register_cpu()
-> device_add()
-> udev "add" event triggered -----------> udev rule sets CPU online
-> echo 1 > /sys/.../online
-> lock_device_hotplug_sysfs()
(this is missing in rescan path)
-> device_online()
-> (**) device_lock(new CPU dev)
-> cpu_up()
-> cpu_hotplug_begin()
(loops until refcount == 0)
-> deadlock with (*)
-> bus_probe_device()
-> device_attach()
-> device_lock(new CPU dev)
-> deadlock with (**)
Fix this by taking the device_hotplug_lock in the CPU rescan path.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 60a161b7e5 upstream.
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")
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 78b1a52e05 upstream.
While ccw_io_helper() seems like intended to be exclusive in a sense that
it is supposed to facilitate I/O for at most one thread at any given
time, there is actually nothing ensuring that threads won't pile up at
vcdev->wait_q. If they do, all threads get woken up and see the status
that belongs to some other request than their own. This can lead to bugs.
For an example see:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1788432
This race normally does not cause any problems. The operations provided
by struct virtio_config_ops are usually invoked in a well defined
sequence, normally don't fail, and are normally used quite infrequent
too.
Yet, if some of the these operations are directly triggered via sysfs
attributes, like in the case described by the referenced bug, userspace
is given an opportunity to force races by increasing the frequency of the
given operations.
Let us fix the problem by ensuring, that for each device, we finish
processing the previous request before starting with a new one.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Message-Id: <20180925121309.58524-3-pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 2448a299ec upstream.
Currently we have a race on vcdev->config in virtio_ccw_get_config() and
in virtio_ccw_set_config().
This normally does not cause problems, as these are usually infrequent
operations. However, for some devices writing to/reading from the config
space can be triggered through sysfs attributes. For these, userspace can
force the race by increasing the frequency.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Message-Id: <20180925121309.58524-2-pasic@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9a764c1e59 upstream.
The response for a SNMP request can consist of multiple parts, which
the cmd callback stages into a kernel buffer until all parts have been
received. If the callback detects that the staging buffer provides
insufficient space, it bails out with error.
This processing is buggy for the first part of the response - while it
initially checks for a length of 'data_len', it later copies an
additional amount of 'offsetof(struct qeth_snmp_cmd, data)' bytes.
Fix the calculation of 'data_len' for the first part of the response.
This also nicely cleans up the memcpy code.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 4d19db777a upstream.
Calling napi_schedule() from process context does not ensure that the
NET_RX softirq is run in a timely fashion. So trigger it manually.
This is no big issue with current code. A call to ndo_open() is usually
followed by a ndo_set_rx_mode() call, and for qeth this contains a
spin_unlock_bh(). Except for OSN, where qeth_l2_set_rx_mode() bails out
early.
Nevertheless it's best to not depend on this behaviour, and just fix
the issue at its source like all other drivers do. For instance see
commit 83a0c6e589 ("i40e: Invoke softirqs after napi_reschedule").
Fixes: a1c3ed4c9c ("qeth: NAPI support for l2 and l3 discipline")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit c3925a3da6 "s390/dasd: fix IO error for newly defined
devices" removed a cast of dasd_device::private which was not
necessary in the upstream code. However, in 3.16 the type of
dasd_device::private is char *, so the cast is still needed.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 64e03ff726 upstream.
When allocating a new AOB fails, handle_outbound() is still capable of
transmitting the selected buffer (just without async completion).
But if a previous transfer on this queue slot used async completion, its
sbal_state flags field is still set to QDIO_OUTBUF_STATE_FLAG_PENDING.
So when the upper layer driver sees this stale flag, it expects an async
completion that never happens.
Fix this by unconditionally clearing the flags field.
Fixes: 104ea556ee ("qdio: support asynchronous delivery of storage blocks")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit ce28867fd2 upstream.
If qeth_qdio_output_handler() detects that a transmit requires async
completion, it replaces the pending buffer's metadata object
(qeth_qdio_out_buffer) so that this queue buffer can be re-used while
the data is pending completion.
Later when the CQ indicates async completion of such a metadata object,
qeth_qdio_cq_handler() tries to free any data associated with this
object (since HW has now completed the transfer). By calling
qeth_clear_output_buffer(), it erronously operates on the queue buffer
that _previously_ belonged to this transfer ... but which has been
potentially re-used several times by now.
This results in double-free's of the buffer's data, and failing
transmits as the buffer descriptor is scrubbed in mid-air.
The correct way of handling this situation is to
1. scrub the queue buffer when it is prepared for re-use, and
2. later obtain the data addresses from the async-completion notifier
(ie. the AOB), instead of the queue buffer.
All this only affects qeth devices used for af_iucv HiperTransport.
Fixes: 0da9581ddb ("qeth: exploit asynchronous delivery of storage blocks")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8c3d20aada upstream.
That other commit introduced an inconsistency because it would trace on
ERP_FAILED for all callers of port forced reopen triggers (not just
terminate_rport_io), but it would not trace on ERP_FAILED for all callers of
other ERP triggers such as adapter, port regular, LUN.
Therefore, generalize that other commit. zfcp_erp_action_enqueue() already
had two early outs which re-used the one zfcp_dbf_rec_trig() call. All ERP
trigger functions finally run through zfcp_erp_action_enqueue(). So move
the special handling for ZFCP_STATUS_COMMON_ERP_FAILED into
zfcp_erp_action_enqueue() and add another early out with new trace marker
for pseudo ERP need in this case. This removes all early returns from all
ERP trigger functions so we always end up at zfcp_dbf_rec_trig().
Example trace record formatted with zfcpdbf from s390-tools:
Timestamp : ...
Area : REC
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1 ZFCP_DBF_REC_TRIG
Tag : .......
LUN : 0x...
WWPN : 0x...
D_ID : 0x...
Adapter status : 0x...
Port status : 0x...
LUN status : 0x...
Ready count : 0x...
Running count : 0x...
ERP want : 0x0. ZFCP_ERP_ACTION_REOPEN_...
ERP need : 0xe0 ZFCP_ERP_ACTION_FAILED
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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit d70aab5592 upstream.
For problem determination we always want to see when we were invoked on the
terminate_rport_io callback whether we perform something or not.
Temporal event sequence of interest with a long fast_io_fail_tmo of 27 sec:
loose remote port
t workqueue
[s] zfcp_q_<dev> IRQ zfcperp<dev>
=== ================== =================== ============================
0 recv RSCN
q p.test_link_work
block rport
start fast_io_fail_tmo
send ADISC ELS
4 recv ADISC fail
block zfcp_port
port forced reopen
send open port
12 recv open port fail
q p.gid_pn_work
zfcp_erp_wakeup
(zfcp_erp_wait would return)
GID_PN fail
Before this point, we got a SCSI trace with tag "sctrpi1" on fast_io_fail,
e.g. with the typical 5 sec setting.
port.status |= ERP_FAILED
If fast_io_fail_tmo triggers after this point, we missed a SCSI trace.
workqueue
fc_dl_<host>
==================
27 fc_timeout_fail_rport_io
fc_terminate_rport_io
zfcp_scsi_terminate_rport_io
zfcp_erp_port_forced_reopen
_zfcp_erp_port_forced_reopen
if (port.status & ERP_FAILED)
return;
Therefore, write a trace before above early return.
Example trace record formatted with zfcpdbf from s390-tools:
Timestamp : ...
Area : REC
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1 ZFCP_DBF_REC_TRIG
Tag : sctrpi1 SCSI terminate rport I/O
LUN : 0xffffffffffffffff none (invalid)
WWPN : 0x<wwpn>
D_ID : 0x<n_port_id>
Adapter status : 0x...
Port status : 0x...
LUN status : 0x00000000 none (invalid)
Ready count : 0x...
Running count : 0x...
ERP want : 0x03 ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
ERP need : 0xe0 ZFCP_ERP_ACTION_FAILED
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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 96d9270499 upstream.
get_device() and its internally used kobject_get() only return NULL if they
get passed NULL as argument. zfcp_get_port_by_wwpn() loops over
adapter->port_list so the iteration variable port is always non-NULL.
Struct device is embedded in struct zfcp_port so &port->dev is always
non-NULL. This is the argument to get_device(). However, if we get an
fc_rport in terminate_rport_io() for which we cannot find a match within
zfcp_get_port_by_wwpn(), the latter can return NULL. v2.6.30 commit
70932935b6 ("[SCSI] zfcp: Fix oops when port disappears") introduced an
early return without adding a trace record for this case. Even if we don't
need recovery in this case, for debugging we should still see that our
callback was invoked originally by scsi_transport_fc.
Example trace record formatted with zfcpdbf from s390-tools:
Timestamp : ...
Area : REC
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : sctrpin SCSI terminate rport I/O, no zfcp port
LUN : 0xffffffffffffffff none (invalid)
WWPN : 0x<wwpn> WWPN
D_ID : 0x<n_port_id> N_Port-ID
Adapter status : 0x...
Port status : 0xffffffff unknown (-1)
LUN status : 0x00000000 none (invalid)
Ready count : 0x...
Running count : 0x...
ERP want : 0x03 ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
ERP need : 0xc0 ZFCP_ERP_ACTION_NONE
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 70932935b6 ("[SCSI] zfcp: Fix oops when port disappears")
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 512857a795 upstream.
If a SCSI device is deleted during scsi_eh host reset, we cannot get a
reference to the SCSI device anymore since scsi_device_get returns !=0 by
design. Assuming the recovery of adapter and port(s) was successful,
zfcp_erp_strategy_followup_success() attempts to trigger a LUN reset for the
half-gone SCSI device. Unfortunately, it causes the following confusing
trace record which states that zfcp will do a LUN recovery as "ERP need" is
ZFCP_ERP_ACTION_REOPEN_LUN == 1 and equals "ERP want".
Old example trace record formatted with zfcpdbf from s390-tools:
Tag: : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded
LUN : 0x<FCP_LUN>
WWPN : 0x<WWPN>
D_ID : 0x<N_Port-ID>
Adapter status : 0x5400050b
Port status : 0x54000001
LUN status : 0x40000000 ZFCP_STATUS_COMMON_RUNNING
but not ZFCP_STATUS_COMMON_UNBLOCKED as it
was closed on close part of adapter reopen
ERP want : 0x01
ERP need : 0x01 misleading
However, zfcp_erp_setup_act() returns NULL as it cannot get the reference.
Hence, zfcp_erp_action_enqueue() takes an early goto out and _NO_ recovery
actually happens.
We always do want the recovery trigger trace record even if no erp_action
could be enqueued as in this case. For other cases where we did not enqueue
an erp_action, 'need' has always been zero to indicate this. In order to
indicate above goto out, introduce an eyecatcher "flag" to mark the "ERP
need" as 'not needed' but still keep the information which erp_action type,
that zfcp_erp_required_act() had decided upon, is needed. 0xc_ is chosen to
be visibly different from 0x0_ in "ERP want".
New example trace record formatted with zfcpdbf from s390-tools:
Tag: : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded
LUN : 0x<FCP_LUN>
WWPN : 0x<WWPN>
D_ID : 0x<N_Port-ID>
Adapter status : 0x5400050b
Port status : 0x54000001
LUN status : 0x40000000
ERP want : 0x01
ERP need : 0xc1 would need LUN ERP, but no action set up
^
Before v2.6.38 commit ae0904f60f ("[SCSI] zfcp: Redesign of the debug
tracing for recovery actions.") we could detect this case because the
"erp_action" field in the trace was NULL. The rework removed erp_action as
argument and field from the trace.
This patch here is for tracing. A fix to allow LUN recovery in the case at
hand is a topic for a separate patch.
See also commit fdbd1c5e27 ("[SCSI] zfcp: Allow running unit/LUN shutdown
without acquiring reference") for a similar case and background info.
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: ae0904f60f ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.")
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 81979ae63e upstream.
We already have a SCSI trace for the end of abort and scsi_eh TMF. Due to
zfcp_erp_wait() and fc_block_scsi_eh() time can pass between the start of
our eh callback and an actual send/recv of an abort / TMF request. In order
to see the temporal sequence including any abort / TMF send retries, add a
trace before the above two blocking functions. This supports problem
determination with scsi_eh and parallel zfcp ERP.
No need to explicitly trace the beginning of our eh callback, since we
typically can send an abort / TMF and see its HBA response (in the worst
case, it's a pseudo response on dismiss all of adapter recovery, e.g. due to
an FSF request timeout [fsrth_1] of the abort / TMF). If we cannot send, we
now get a trace record for the first "abrt_wt" or "[lt]r_wait" which denotes
almost the beginning of the callback.
No need to explicitly trace the wakeup after the above two blocking
functions because the next retry loop causes another trace in any case and
that is sufficient.
Example trace records formatted with zfcpdbf from s390-tools:
Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : abrt_wt abort, before zfcp_erp_wait()
Request ID : 0x0000000000000000 none (invalid)
SCSI ID : 0x<scsi_id>
SCSI LUN : 0x<scsi_lun>
SCSI LUN high : 0x<scsi_lun_high>
SCSI result : 0x<scsi_result_of_cmd_to_be_aborted>
SCSI retries : 0x<retries_of_cmd_to_be_aborted>
SCSI allowed : 0x<allowed_retries_of_cmd_to_be_aborted>
SCSI scribble : 0x<req_id_of_cmd_to_be_aborted>
SCSI opcode : <CDB_of_cmd_to_be_aborted>
FCP rsp inf cod: 0x.. none (invalid)
FCP rsp IU : ... none (invalid)
Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : lr_wait LUN reset, before zfcp_erp_wait()
Request ID : 0x0000000000000000 none (invalid)
SCSI ID : 0x<scsi_id>
SCSI LUN : 0x<scsi_lun>
SCSI LUN high : 0x<scsi_lun_high>
SCSI result : 0x... unrelated
SCSI retries : 0x.. unrelated
SCSI allowed : 0x.. unrelated
SCSI scribble : 0x... unrelated
SCSI opcode : ... unrelated
FCP rsp inf cod: 0x.. none (invalid)
FCP rsp IU : ... none (invalid)
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 63caf367e1 ("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp")
Fixes: af4de36d91 ("[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED")
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit df30781699 upstream.
For problem determination we need to see whether and why we were successful
or not. This allows deduction of scsi_eh escalation.
Example trace record formatted with zfcpdbf from s390-tools:
Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : schrh_r SCSI host reset handler result
Request ID : 0x0000000000000000 none (invalid)
SCSI ID : 0xffffffff none (invalid)
SCSI LUN : 0xffffffff none (invalid)
SCSI LUN high : 0xffffffff none (invalid)
SCSI result : 0x00002002 field re-used for midlayer value: SUCCESS
or in other cases: 0x2009 == FAST_IO_FAIL
SCSI retries : 0xff none (invalid)
SCSI allowed : 0xff none (invalid)
SCSI scribble : 0xffffffffffffffff none (invalid)
SCSI opcode : ffffffff ffffffff ffffffff ffffffff none (invalid)
FCP rsp inf cod: 0xff none (invalid)
FCP rsp IU : 00000000 00000000 00000000 00000000 none (invalid)
00000000 00000000
v2.6.35 commit a1dbfddd02 ("[SCSI] zfcp: Pass return code from
fc_block_scsi_eh to scsi eh") introduced the first return with something
other than the previously hardcoded single SUCCESS return path.
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: a1dbfddd02 ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
[bwh: Backported to 3.16: Drop assignment to zfcp_dbf_scsi::scsi_lun_64_hi
which doesn't exist here]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 2e68adcd2f upstream.
Calling qdio_release_memory() on error is just plain wrong. It frees
the main qdio_irq struct, when following code still uses it.
Also, no other error path in qdio_establish() does this. So trust
callers to clean up via qdio_free() if some step of the QDIO
initialization fails.
Fixes: 779e6e1c72 ("[S390] qdio: new qdio driver.")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit e521813468 upstream.
Ever since CQ/QAOB support was added, calling qdio_free() straight after
qdio_alloc() results in qdio_release_memory() accessing uninitialized
memory (ie. q->u.out.use_cq and q->u.out.aobs). Followed by a
kmem_cache_free() on the random AOB addresses.
For older kernels that don't have 6e30c549f6, the same applies if
qdio_establish() fails in the DEV_STATE_ONLINE check.
While initializing q->u.out.use_cq would be enough to fix this
particular bug, the more future-proof change is to just zero-alloc the
whole struct.
Fixes: 104ea556ee ("qdio: support asynchronous delivery of storage blocks")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit fa89adba19 upstream.
zfcp_erp_adapter_reopen() schedules blocking of all of the adapter's
rports via zfcp_scsi_schedule_rports_block() and enqueues a reopen
adapter ERP action via zfcp_erp_action_enqueue(). Both are separately
processed asynchronously and concurrently.
Blocking of rports is done in a kworker by zfcp_scsi_rport_work(). It
calls zfcp_scsi_rport_block(), which then traces a DBF REC "scpdely" via
zfcp_dbf_rec_trig(). zfcp_dbf_rec_trig() acquires the DBF REC spin lock
and then iterates with list_for_each() over the adapter's ERP ready list
without holding the ERP lock. This opens a race window in which the
current list entry can be moved to another list, causing list_for_each()
to iterate forever on the wrong list, as the erp_ready_head is never
encountered as terminal condition.
Meanwhile the ERP action can be processed in the ERP thread by
zfcp_erp_thread(). It calls zfcp_erp_strategy(), which acquires the ERP
lock and then calls zfcp_erp_action_to_running() to move the ERP action
from the ready to the running list. zfcp_erp_action_to_running() can
move the ERP action using list_move() just during the aforementioned
race window. It then traces a REC RUN "erator1" via zfcp_dbf_rec_run().
zfcp_dbf_rec_run() tries to acquire the DBF REC spin lock. If this is
held by the infinitely looping kworker, it effectively spins forever.
Example Sequence Diagram:
Process ERP Thread rport_work
------------------- ------------------- -------------------
zfcp_erp_adapter_reopen()
zfcp_erp_adapter_block()
zfcp_scsi_schedule_rports_block()
lock ERP zfcp_scsi_rport_work()
zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER)
list_add_tail() on ready !(rport_task==RPORT_ADD)
wake_up() ERP thread zfcp_scsi_rport_block()
zfcp_dbf_rec_trig() zfcp_erp_strategy() zfcp_dbf_rec_trig()
unlock ERP lock DBF REC
zfcp_erp_wait() lock ERP
| zfcp_erp_action_to_running()
| list_for_each() ready
| list_move() current entry
| ready to running
| zfcp_dbf_rec_run() endless loop over running
| zfcp_dbf_rec_run_lvl()
| lock DBF REC spins forever
Any adapter recovery can trigger this, such as setting the device offline
or reboot.
V4.9 commit 4eeaa4f3f1 ("zfcp: close window with unblocked rport
during rport gone") introduced additional tracing of (un)blocking of
rports. It missed that the adapter->erp_lock must be held when calling
zfcp_dbf_rec_trig().
This fix uses the approach formerly introduced by commit aa0fec6239
("[SCSI] zfcp: Fix sparse warning by providing new entry in dbf") that got
later removed by commit ae0904f60f ("[SCSI] zfcp: Redesign of the debug
tracing for recovery actions.").
Introduce zfcp_dbf_rec_trig_lock(), a wrapper for zfcp_dbf_rec_trig() that
acquires and releases the adapter->erp_lock for read.
Reported-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Fixes: 4eeaa4f3f1 ("zfcp: close window with unblocked rport during rport gone")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 5d27a2bf6e upstream.
When a new CKD storage volume is defined at the storage server, Linux
may be relying on outdated information about that volume, which leads to
the following errors:
1. Command Reject Errors for minidisk on z/VM:
dasd-eckd.b3193d: 0.0.XXXX: An error occurred in the DASD device driver,
reason=09
dasd(eckd): I/O status report for device 0.0.XXXX:
dasd(eckd): in req: 00000000XXXXXXXX CC:00 FC:04 AC:00 SC:17 DS:02 CS:00
RC:0
dasd(eckd): device 0.0.2046: Failing CCW: 00000000XXXXXXXX
dasd(eckd): Sense(hex) 0- 7: 80 00 00 00 00 00 00 00
dasd(eckd): Sense(hex) 8-15: 00 00 00 00 00 00 00 00
dasd(eckd): Sense(hex) 16-23: 00 00 00 00 e1 00 0f 00
dasd(eckd): Sense(hex) 24-31: 00 00 40 e2 00 00 00 00
dasd(eckd): 24 Byte: 0 MSG 0, no MSGb to SYSOP
2. Equipment Check errors on LPAR or for dedicated devices on z/VM:
dasd(eckd): I/O status report for device 0.0.XXXX:
dasd(eckd): in req: 00000000XXXXXXXX CC:00 FC:04 AC:00 SC:17 DS:0E CS:40
fcxs:01 schxs:00 RC:0
dasd(eckd): device 0.0.9713: Failing TCW: 00000000XXXXXXXX
dasd(eckd): Sense(hex) 0- 7: 10 00 00 00 13 58 4d 0f
dasd(eckd): Sense(hex) 8-15: 67 00 00 00 00 00 00 04
dasd(eckd): Sense(hex) 16-23: e5 18 05 33 97 01 0f 0f
dasd(eckd): Sense(hex) 24-31: 00 00 40 e2 00 04 58 0d
dasd(eckd): 24 Byte: 0 MSG f, no MSGb to SYSOP
Fix this problem by using the up-to-date information provided during
online processing via the device specific SNEQ to detect the case of
outdated LCU data. If there is a difference, perform a re-read of that
data.
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[bwh: Backported to 3.16:
- Move up assignment of "private"
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit af2e460ade upstream.
Channel path descriptors have been seen as something stable (as
long as the chpid is configured). Recent tests have shown that the
descriptor can also be altered when the link state of a channel path
changes. Thus it is necessary to update the descriptor during
handling of resource accessibility events.
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit a936b1ef37 upstream.
Creating the global workqueue during driver init may fail, deal with it.
Also, destroy the created workqueue on any subsequent error.
Fixes: 0f54761d16 ("qeth: Support VEPA mode")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit dae55b6fef upstream.
Immediate retry of EQBS after CCQ 96 means that we potentially misreport
the state of buffers inspected during the first EQBS call.
This occurs when
1. the first EQBS finds all inspected buffers still in the initial state
set by the driver (ie INPUT EMPTY or OUTPUT PRIMED),
2. the EQBS terminates early with CCQ 96, and
3. by the time that the second EQBS comes around, the state of those
previously inspected buffers has changed.
If the state reported by the second EQBS is 'driver-owned', all we know
is that the previous buffers are driver-owned now as well. But we can't
tell if they all have the same state. So for instance
- the second EQBS reports OUTPUT EMPTY, but any number of the previous
buffers could be OUTPUT ERROR by now,
- the second EQBS reports OUTPUT ERROR, but any number of the previous
buffers could be OUTPUT EMPTY by now.
Effectively, this can result in both over- and underreporting of errors.
If the state reported by the second EQBS is 'HW-owned', that doesn't
guarantee that the previous buffers have not been switched to
driver-owned in the mean time. So for instance
- the second EQBS reports INPUT EMPTY, but any number of the previous
buffers could be INPUT PRIMED (or INPUT ERROR) by now.
This would result in failure to process pending work on the queue. If
it's the final check before yielding initiative, this can cause
a (temporary) queue stall due to IRQ avoidance.
Fixes: 25f269f173 ("[S390] qdio: EQBS retry after CCQ 96")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 0cf1e05157 upstream.
On an Output queue, both EMPTY and PENDING buffer states imply that the
buffer is ready for completion-processing by the upper-layer drivers.
So for a non-QEBSM Output queue, get_buf_states() merges mixed
batches of PENDING and EMPTY buffers into one large batch of EMPTY
buffers. The upper-layer driver (ie. qeth) later distuingishes PENDING
from EMPTY by inspecting the slsb_state for
QDIO_OUTBUF_STATE_FLAG_PENDING.
But the merge logic in get_buf_states() contains a bug that causes us to
erronously also merge ERROR buffers into such a batch of EMPTY buffers
(ERROR is 0xaf, EMPTY is 0xa1; so ERROR & EMPTY == EMPTY).
Effectively, most outbound ERROR buffers are currently discarded
silently and processed as if they had succeeded.
Note that this affects _all_ non-QEBSM device types, not just IQD with CQ.
Fix it by explicitly spelling out the exact conditions for merging.
For extracting the "get initial state" part out of the loop, this relies
on the fact that get_buf_states() is never called with a count of 0. The
QEBSM path already strictly requires this, and the two callers with
variable 'count' make sure of it.
Fixes: 104ea556ee ("qdio: support asynchronous delivery of storage blocks")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 6be687395b upstream.
On removal, a qeth card's netdevice is currently not properly freed
because the call chain looks as follows:
qeth_core_remove_device(card)
lx_remove_device(card)
unregister_netdev(card->dev)
card->dev = NULL !!!
qeth_core_free_card(card)
if (card->dev) !!!
free_netdev(card->dev)
Fix it by free'ing the netdev straight after unregistering. This also
fixes the sysfs-driven layer switch case (qeth_dev_layer2_store()),
where the need to free the current netdevice was not considered at all.
Note that free_netdev() takes care of the netif_napi_del() for us too.
Fixes: 4a71df5004 ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 1c5b2216fb upstream.
send_control_data() applies some special handling to SETIP v4 IPA
commands. But current code parses *all* command types for the SETIP
command code. Limit the command code check to IPA commands.
Fixes: 5b54e16f1a ("qeth: do not spin for SETIP ip assist command")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit ab31fd0ce6 upstream.
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")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit fdb7cee3b9 upstream.
At the default trace level, we only trace unsuccessful events including
FSF responses.
zfcp_dbf_hba_fsf_response() only used protocol status and FSF status to
decide on an unsuccessful response. However, this is only one of multiple
possible sources determining a failed struct zfcp_fsf_req.
An FSF request can also "fail" if its response runs into an ERP timeout
or if it gets dismissed because a higher level recovery was triggered
[trace tags "erscf_1" or "erscf_2" in zfcp_erp_strategy_check_fsfreq()].
FSF requests with ERP timeout are:
FSF_QTCB_EXCHANGE_CONFIG_DATA, FSF_QTCB_EXCHANGE_PORT_DATA,
FSF_QTCB_OPEN_PORT_WITH_DID or FSF_QTCB_CLOSE_PORT or
FSF_QTCB_CLOSE_PHYSICAL_PORT for target ports,
FSF_QTCB_OPEN_LUN, FSF_QTCB_CLOSE_LUN.
One example is slow queue processing which can cause follow-on errors,
e.g. FSF_PORT_ALREADY_OPEN after FSF_QTCB_OPEN_PORT_WITH_DID timed out.
In order to see the root cause, we need to see late responses even if the
channel presented them successfully with FSF_PROT_GOOD and FSF_GOOD.
Example trace records formatted with zfcpdbf from the s390-tools package:
Timestamp : ...
Area : REC
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : ...
Record ID : 1
Tag : fcegpf1
LUN : 0xffffffffffffffff
WWPN : 0x<WWPN>
D_ID : 0x00<D_ID>
Adapter status : 0x5400050b
Port status : 0x41200000
LUN status : 0x00000000
Ready count : 0x00000001
Running count : 0x...
ERP want : 0x02 ZFCP_ERP_ACTION_REOPEN_PORT
ERP need : 0x02 ZFCP_ERP_ACTION_REOPEN_PORT
|
Timestamp : ... 30 seconds later
Area : REC
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : ...
Record ID : 2
Tag : erscf_2
LUN : 0xffffffffffffffff
WWPN : 0x<WWPN>
D_ID : 0x00<D_ID>
Adapter status : 0x5400050b
Port status : 0x41200000
LUN status : 0x00000000
Request ID : 0x<request_ID>
ERP status : 0x10000000 ZFCP_STATUS_ERP_TIMEDOUT
ERP step : 0x0800 ZFCP_ERP_STEP_PORT_OPENING
ERP action : 0x02 ZFCP_ERP_ACTION_REOPEN_PORT
ERP count : 0x00
|
Timestamp : ... later than previous record
Area : HBA
Subarea : 00
Level : 5 > default level => 3 <= default level
Exception : -
CPU ID : 00
Caller : ...
Record ID : 1
Tag : fs_qtcb => fs_rerr
Request ID : 0x<request_ID>
Request status : 0x00001010 ZFCP_STATUS_FSFREQ_DISMISSED
| ZFCP_STATUS_FSFREQ_CLEANUP
FSF cmnd : 0x00000005
FSF sequence no: 0x...
FSF issued : ... > 30 seconds ago
FSF stat : 0x00000000 FSF_GOOD
FSF stat qual : 00000000 00000000 00000000 00000000
Prot stat : 0x00000001 FSF_PROT_GOOD
Prot stat qual : 00000000 00000000 00000000 00000000
Port handle : 0x...
LUN handle : 0x00000000
QTCB log length: ...
QTCB log info : ...
In case of problems detecting that new responses are waiting on the input
queue, we sooner or later trigger adapter recovery due to an FSF request
timeout (trace tag "fsrth_1").
FSF requests with FSF request timeout are:
typically FSF_QTCB_ABORT_FCP_CMND; but theoretically also
FSF_QTCB_EXCHANGE_CONFIG_DATA or FSF_QTCB_EXCHANGE_PORT_DATA via sysfs,
FSF_QTCB_OPEN_PORT_WITH_DID or FSF_QTCB_CLOSE_PORT for WKA ports,
FSF_QTCB_FCP_CMND for task management function (LUN / target reset).
One or more pending requests can meanwhile have FSF_PROT_GOOD and FSF_GOOD
because the channel filled in the response via DMA into the request's QTCB.
In a theroretical case, inject code can create an erroneous FSF request
on purpose. If data router is enabled, it uses deferred error reporting.
A READ SCSI command can succeed with FSF_PROT_GOOD, FSF_GOOD, and
SAM_STAT_GOOD. But on writing the read data to host memory via DMA,
it can still fail, e.g. if an intentionally wrong scatter list does not
provide enough space. Rather than getting an unsuccessful response,
we get a QDIO activate check which in turn triggers adapter recovery.
One or more pending requests can meanwhile have FSF_PROT_GOOD and FSF_GOOD
because the channel filled in the response via DMA into the request's QTCB.
Example trace records formatted with zfcpdbf from the s390-tools package:
Timestamp : ...
Area : HBA
Subarea : 00
Level : 6 > default level => 3 <= default level
Exception : -
CPU ID : ..
Caller : ...
Record ID : 1
Tag : fs_norm => fs_rerr
Request ID : 0x<request_ID2>
Request status : 0x00001010 ZFCP_STATUS_FSFREQ_DISMISSED
| ZFCP_STATUS_FSFREQ_CLEANUP
FSF cmnd : 0x00000001
FSF sequence no: 0x...
FSF issued : ...
FSF stat : 0x00000000 FSF_GOOD
FSF stat qual : 00000000 00000000 00000000 00000000
Prot stat : 0x00000001 FSF_PROT_GOOD
Prot stat qual : ........ ........ 00000000 00000000
Port handle : 0x...
LUN handle : 0x...
|
Timestamp : ...
Area : SCSI
Subarea : 00
Level : 3
Exception : -
CPU ID : ..
Caller : ...
Record ID : 1
Tag : rsl_err
Request ID : 0x<request_ID2>
SCSI ID : 0x...
SCSI LUN : 0x...
SCSI result : 0x000e0000 DID_TRANSPORT_DISRUPTED
SCSI retries : 0x00
SCSI allowed : 0x05
SCSI scribble : 0x<request_ID2>
SCSI opcode : 28... Read(10)
FCP rsp inf cod: 0x00
FCP rsp IU : 00000000 00000000 00000000 00000000
^^ SAM_STAT_GOOD
00000000 00000000
Only with luck in both above cases, we could see a follow-on trace record
of an unsuccesful event following a successful but late FSF response with
FSF_PROT_GOOD and FSF_GOOD. Typically this was the case for I/O requests
resulting in a SCSI trace record "rsl_err" with DID_TRANSPORT_DISRUPTED
[On ZFCP_STATUS_FSFREQ_DISMISSED, zfcp_fsf_protstatus_eval() sets
ZFCP_STATUS_FSFREQ_ERROR seen by the request handler functions as failure].
However, the reason for this follow-on trace was invisible because the
corresponding HBA trace record was missing at the default trace level
(by default hidden records with tags "fs_norm", "fs_qtcb", or "fs_open").
On adapter recovery, after we had shut down the QDIO queues, we perform
unsuccessful pseudo completions with flag ZFCP_STATUS_FSFREQ_DISMISSED
for each pending FSF request in zfcp_fsf_req_dismiss_all().
In order to find the root cause, we need to see all pseudo responses even
if the channel presented them successfully with FSF_PROT_GOOD and FSF_GOOD.
Therefore, check zfcp_fsf_req.status for ZFCP_STATUS_FSFREQ_DISMISSED
or ZFCP_STATUS_FSFREQ_ERROR and trace with a new tag "fs_rerr".
It does not matter that there are numerous places which set
ZFCP_STATUS_FSFREQ_ERROR after the location where we trace an FSF response
early. These cases are based on protocol status != FSF_PROT_GOOD or
== FSF_PROT_FSF_STATUS_PRESENTED and are thus already traced by default
as trace tag "fs_perr" or "fs_ferr" respectively.
NB: The trace record with tag "fssrh_1" for status read buffers on dismiss
all remains. zfcp_fsf_req_complete() handles this and returns early.
All other FSF request types are handled separately and as described above.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 8a36e4532e ("[SCSI] zfcp: enhancement of zfcp debug features")
Fixes: 2e261af84c ("[SCSI] zfcp: Only collect FSF/HBA debug data for matching trace levels")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 12c3e5754c upstream.
If the FCP_RSP UI has optional parts (FCP_SNS_INFO or FCP_RSP_INFO) and
thus does not fit into the fsp_rsp field built into a SCSI trace record,
trace the full FCP_RSP UI with all optional parts as payload record
instead of just FCP_SNS_INFO as payload and
a 1 byte RSP_INFO_CODE part of FCP_RSP_INFO built into the SCSI record.
That way we would also get the full FCP_SNS_INFO in case a
target would ever send more than
min(SCSI_SENSE_BUFFERSIZE==96, ZFCP_DBF_PAY_MAX_REC==256)==96.
The mandatory part of FCP_RSP IU is only 24 bytes.
PAYload costs at least one full PAY record of 256 bytes anyway.
We cap to the hardware response size which is only FSF_FCP_RSP_SIZE==128.
So we can just put the whole FCP_RSP IU with any optional parts into
PAYload similarly as we do for SAN PAY since v4.9 commit aceeffbb59
("zfcp: trace full payload of all SAN records (req,resp,iels)").
This does not cause any additional trace records wasting memory.
Decoded trace records were confusing because they showed a hard-coded
sense data length of 96 even if the FCP_RSP_IU field FCP_SNS_LEN showed
actually less.
Since the same commit, we set pl_len for SAN traces to the full length of a
request/response even if we cap the corresponding trace.
In contrast, here for SCSI traces we set pl_len to the pre-computed
length of FCP_RSP IU considering SNS_LEN or RSP_LEN if valid.
Nonetheless we trace a hardcoded payload of length FSF_FCP_RSP_SIZE==128
if there were optional parts.
This makes it easier for the zfcpdbf tool to format only the relevant
part of the long FCP_RSP UI buffer. And any trailing information is still
available in the payload trace record just in case.
Rename the payload record tag from "fcp_sns" to "fcp_riu" to make the new
content explicit to zfcpdbf which can then pick a suitable field name such
as "FCP rsp IU all:" instead of "Sense info :"
Also, the same zfcpdbf can still be backwards compatible with "fcp_sns".
Old example trace record before this fix, formatted with the tool zfcpdbf
from s390-tools:
Timestamp : ...
Area : SCSI
Subarea : 00
Level : 3
Exception : -
CPU id : ..
Caller : 0x...
Record id : 1
Tag : rsl_err
Request id : 0x<request_id>
SCSI ID : 0x...
SCSI LUN : 0x...
SCSI result : 0x00000002
SCSI retries : 0x00
SCSI allowed : 0x05
SCSI scribble : 0x<request_id>
SCSI opcode : 00000000 00000000 00000000 00000000
FCP rsp inf cod: 0x00
FCP rsp IU : 00000000 00000000 00000202 00000000
^^==FCP_SNS_LEN_VALID
00000020 00000000
^^^^^^^^==FCP_SNS_LEN==32
Sense len : 96 <==min(SCSI_SENSE_BUFFERSIZE,ZFCP_DBF_PAY_MAX_REC)
Sense info : 70000600 00000018 00000000 29000000
00000400 00000000 00000000 00000000
00000000 00000000 00000000 00000000<==superfluous
00000000 00000000 00000000 00000000<==superfluous
00000000 00000000 00000000 00000000<==superfluous
00000000 00000000 00000000 00000000<==superfluous
New example trace records with this fix:
Timestamp : ...
Area : SCSI
Subarea : 00
Level : 3
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : rsl_err
Request ID : 0x<request_id>
SCSI ID : 0x...
SCSI LUN : 0x...
SCSI result : 0x00000002
SCSI retries : 0x00
SCSI allowed : 0x03
SCSI scribble : 0x<request_id>
SCSI opcode : a30c0112 00000000 02000000 00000000
FCP rsp inf cod: 0x00
FCP rsp IU : 00000000 00000000 00000a02 00000200
00000020 00000000
FCP rsp IU len : 56
FCP rsp IU all : 00000000 00000000 00000a02 00000200
^^=FCP_RESID_UNDER|FCP_SNS_LEN_VALID
00000020 00000000 70000500 00000018
^^^^^^^^==FCP_SNS_LEN
^^^^^^^^^^^^^^^^^
00000000 240000cb 00011100 00000000
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
00000000 00000000
^^^^^^^^^^^^^^^^^==FCP_SNS_INFO
Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : lr_okay
Request ID : 0x<request_id>
SCSI ID : 0x...
SCSI LUN : 0x...
SCSI result : 0x00000000
SCSI retries : 0x00
SCSI allowed : 0x05
SCSI scribble : 0x<request_id>
SCSI opcode : <CDB of unrelated SCSI command passed to eh handler>
FCP rsp inf cod: 0x00
FCP rsp IU : 00000000 00000000 00000100 00000000
00000000 00000008
FCP rsp IU len : 32
FCP rsp IU all : 00000000 00000000 00000100 00000000
^^==FCP_RSP_LEN_VALID
00000000 00000008 00000000 00000000
^^^^^^^^==FCP_RSP_LEN
^^^^^^^^^^^^^^^^^==FCP_RSP_INFO
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 250a1352b9 ("[SCSI] zfcp: Redesign of the debug tracing for SCSI records.")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 1a5d999ebf upstream.
For problem determination we need to see that we were in scsi_eh
as well as whether and why we were successful or not.
The following commits introduced new early returns without adding
a trace record:
v2.6.35 commit a1dbfddd02
("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
on fc_block_scsi_eh() returning != 0 which is FAST_IO_FAIL,
v2.6.30 commit 63caf367e1
("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp")
on not having gotten an FSF request after the maximum number of retry
attempts and thus could not issue a TMF and has to return FAILED.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: a1dbfddd02 ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
Fixes: 63caf367e1 ("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9fe5d2b2fd upstream.
Without this fix we get SCSI trace records on task management functions
which cannot be correlated to HBA trace records because all fields
related to the FSF request are empty (zero).
Also, the FCP_RSP_IU is missing as well as any sense data if available.
This was caused by v2.6.14 commit 8a36e4532e ("[SCSI] zfcp: enhancement
of zfcp debug features") introducing trace records for TMFs but
hard coding NULL for a possibly existing TMF FSF request.
The scsi_cmnd scribble is also zero or unrelated for the TMF request
so it also could not lookup a suitable FSF request from there.
A broken example trace record formatted with zfcpdbf from the s390-tools
package:
Timestamp : ...
Area : SCSI
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : lr_fail
Request ID : 0x0000000000000000
^^^^^^^^^^^^^^^^ no correlation to HBA record
SCSI ID : 0x<scsitarget>
SCSI LUN : 0x<scsilun>
SCSI result : 0x000e0000
SCSI retries : 0x00
SCSI allowed : 0x05
SCSI scribble : 0x0000000000000000
SCSI opcode : 2a000017 3bb80000 08000000 00000000
FCP rsp inf cod: 0x00
^^ no TMF response
FCP rsp IU : 00000000 00000000 00000000 00000000
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
00000000 00000000
^^^^^^^^^^^^^^^^^ no interesting FCP_RSP_IU
Sense len : ...
^^^^^^^^^^^^^^^^^^^^ no sense data length
Sense info : ...
^^^^^^^^^^^^^^^^^^^^ no sense data content, even if present
There are some true cases where we really do not have an FSF request:
"rsl_fai" from zfcp_dbf_scsi_fail_send() called for early
returns / completions in zfcp_scsi_queuecommand(),
"abrt_or", "abrt_bl", "abrt_ru", "abrt_ar" from
zfcp_scsi_eh_abort_handler() where we did not get as far,
"lr_nres", "tr_nres" from zfcp_task_mgmt_function() where we're
successful and do not need to do anything because adapter stopped.
For these cases it's correct to pass NULL for fsf_req to _zfcp_dbf_scsi().
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 8a36e4532e ("[SCSI] zfcp: enhancement of zfcp debug features")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 975171b446 upstream.
v4.9 commit aceeffbb59 ("zfcp: trace full payload of all SAN records
(req,resp,iels)") fixed trace data loss of 2.6.38 commit 2c55b750a8
("[SCSI] zfcp: Redesign of the debug tracing for SAN records.")
necessary for problem determination, e.g. to see the
currently active zone set during automatic port scan.
While it already saves space by not dumping any empty residual entries
of the large successful GPN_FT response (4 pages), there are seldom cases
where the GPN_FT response is unsuccessful and likely does not have
FC_NS_FID_LAST set in fp_flags so we did not cap the trace record.
We typically see such case for an initiator WWPN, which is not in any zone.
Cap unsuccessful responses to at least the actual basic CT_IU response
plus whatever fits the SAN trace record built-in "payload" buffer
just in case there's trailing information
of which we would at least see the existence and its beginning.
In order not to erroneously cap successful responses, we need to swap
calling the trace function and setting the CT / ELS status to success (0).
Example trace record pair formatted with zfcpdbf:
Timestamp : ...
Area : SAN
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : fssct_1
Request ID : 0x<request_id>
Destination ID : 0x00fffffc
SAN req short : 01000000 fc020000 01720ffc 00000000
00000008
SAN req length : 20
|
Timestamp : ...
Area : SAN
Subarea : 00
Level : 1
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 2
Tag : fsscth2
Request ID : 0x<request_id>
Destination ID : 0x00fffffc
SAN resp short : 01000000 fc020000 80010000 00090700
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
SAN resp length: 16384
San resp info : 01000000 fc020000 80010000 00090700
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
00000000 00000000 00000000 00000000 [trailing info]
The fix saves all but one of the previously associated 64 PAYload trace
record chunks of size 256 bytes each.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: aceeffbb59 ("zfcp: trace full payload of all SAN records (req,resp,iels)")
Fixes: 2c55b750a8 ("[SCSI] zfcp: Redesign of the debug tracing for SAN records.")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit a099b7b1fc upstream.
Up until now zfcp would just ignore the FCP_RESID_OVER flag in the FCP
response IU. When this flag is set, it is possible, in regards to the
FCP standard, that the storage-server processes the command normally, up
to the point where data is missing and simply ignores those.
In this case no CHECK CONDITION would be set, and because we ignored the
FCP_RESID_OVER flag we resulted in at least a data loss or even
-corruption as a follow-up error, depending on how the
applications/layers on top behave. To prevent this, we now set the
host-byte of the corresponding scsi_cmnd to DID_ERROR.
Other storage-behaviors, where the same condition results in a CHECK
CONDITION set in the answer, don't need to be changed as they are
handled in the mid-layer already.
Following is an example trace record decoded with zfcpdbf from the
s390-tools package. We forcefully injected a fc_dl which is one byte too
small:
Timestamp : ...
Area : SCSI
Subarea : 00
Level : 3
Exception : -
CPU ID : ..
Caller : 0x...
Record ID : 1
Tag : rsl_err
Request ID : 0x...
SCSI ID : 0x...
SCSI LUN : 0x...
SCSI result : 0x00070000
^^DID_ERROR
SCSI retries : 0x..
SCSI allowed : 0x..
SCSI scribble : 0x...
SCSI opcode : 2a000000 00000000 08000000 00000000
FCP rsp inf cod: 0x00
FCP rsp IU : 00000000 00000000 00000400 00000001
^^fr_flags==FCP_RESID_OVER
^^fr_status==SAM_STAT_GOOD
^^^^^^^^fr_resid
00000000 00000000
As of now, we don't actively handle to possibility that a response IU
has both flags - FCP_RESID_OVER and FCP_RESID_UNDER - set at once.
Reported-by: Luke M. Hopkins <lmhopkin@us.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 553448f6c4 ("[SCSI] zfcp: Message cleanup")
Fixes: ea127f975424 ("[PATCH] s390 (7/7): zfcp host adapter.") (tglx/history.git)
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 71b8e45da5 upstream.
Since commit db007fc5e2 ("[SCSI] Command protection operation"),
scsi_eh_prep_cmnd() saves scmd->prot_op and temporarily resets it to
SCSI_PROT_NORMAL.
Other FCP LLDDs such as qla2xxx and lpfc shield their queuecommand()
to only access any of scsi_prot_sg...() if
(scsi_get_prot_op(cmd) != SCSI_PROT_NORMAL).
Do the same thing for zfcp, which introduced DIX support with
commit ef3eb71d8b ("[SCSI] zfcp: Introduce experimental support for
DIF/DIX").
Otherwise, TUR SCSI commands as part of scsi_eh likely fail in zfcp,
because the regular SCSI command with DIX protection data, that scsi_eh
re-uses in scsi_send_eh_cmnd(), of course still has
(scsi_prot_sg_count() != 0) and so zfcp sends down bogus requests to the
FCP channel hardware.
This causes scsi_eh_test_devices() to have (finish_cmds == 0)
[not SCSI device is online or not scsi_eh_tur() failed]
so regular SCSI commands, that caused / were affected by scsi_eh,
are moved to work_q and scsi_eh_test_devices() itself returns false.
In turn, it unnecessarily escalates in our case in scsi_eh_ready_devs()
beyond host reset to finally scsi_eh_offline_sdevs()
which sets affected SCSI devices offline with the following kernel message:
"kernel: sd H:0:T:L: Device offlined - not ready after error recovery"
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: ef3eb71d8b ("[SCSI] zfcp: Introduce experimental support for DIF/DIX")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit ec2c672632 upstream.
On L3, the qeth_hdr struct needs to be filled with the next-hop
IP address.
The current code accesses rtable->rt_gateway without checking that
rtable is a valid address. The accidental access to a lowcore area
results in a random next-hop address in the qeth_hdr.
rtable (or more precisely, skb_dst(skb)) can be NULL in rare cases
(for instance together with AF_PACKET sockets).
This patch adds the missing NULL-ptr checks.
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Fixes: 87e7597b5a qeth: Move away from using neighbour entries in qeth_l3_fill_header()
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 2d2ebb3ed0 upstream.
commit b4d72c08b3 ("qeth: bridgeport support - basic control")
broke the support for OSM and OSN devices as follows:
As OSM and OSN are L2 only, qeth_core_probe_device() does an early
setup by loading the l2 discipline and calling qeth_l2_probe_device().
In this context, adding the l2-specific bridgeport sysfs attributes
via qeth_l2_create_device_attributes() hits a BUG_ON in fs/sysfs/group.c,
since the basic sysfs infrastructure for the device hasn't been
established yet.
Note that OSN actually has its own unique sysfs attributes
(qeth_osn_devtype), so the additional attributes shouldn't be created
at all.
For OSM, add a new qeth_l2_devtype that contains all the common
and l2-specific sysfs attributes.
When qeth_core_probe_device() does early setup for OSM or OSN, assign
the corresponding devtype so that the ccwgroup probe code creates the
full set of sysfs attributes.
This allows us to skip qeth_l2_create_device_attributes() in case
of an early setup.
Any device that can't do early setup will initially have only the
generic sysfs attributes, and when it's probed later
qeth_l2_probe_device() adds the l2-specific attributes.
If an early-setup device is removed (by calling ccwgroup_ungroup()),
device_unregister() will - using the devtype - delete the
l2-specific attributes before qeth_l2_remove_device() is called.
So make sure to not remove them twice.
What complicates the issue is that qeth_l2_probe_device() and
qeth_l2_remove_device() is also called on a device when its
layer2 attribute changes (ie. its layer mode is switched).
For early-setup devices this wouldn't work properly - we wouldn't
remove the l2-specific attributes when switching to L3.
But switching the layer mode doesn't actually make any sense;
we already decided that the device can only operate in L2!
So just refuse to switch the layer mode on such devices. Note that
OSN doesn't have a layer2 attribute, so we only need to special-case
OSM.
Based on an initial patch by Ursula Braun.
Fixes: b4d72c08b3 ("qeth: bridgeport support - basic control")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9111e7880c upstream.
When setting up the device from within the layer discipline's
probe routine, creating the layer-specific sysfs attributes can fail.
Report this error back to the caller, and handle it by
releasing the layer discipline.
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
[jwi: updated commit msg, moved an OSN change to a subsequent patch]
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 7775913724 upstream.
Prevent kernel crashes due to unhandled exceptions raised by the CHSC
instruction which may for example be triggered by invalid ioctl data.
Fixes: 64150adf89 ("s390/cio: Introduce generic synchronous CHSC IOCTL")
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 1e4a382fdc upstream.
For devices with multiple input queues, tiqdio_call_inq_handlers()
iterates over all input queues and clears the device's DSCI
during each iteration. If the DSCI is re-armed during one
of the later iterations, we therefore do not scan the previous
queues again.
The re-arming also raises a new adapter interrupt. But its
handler does not trigger a rescan for the device, as the DSCI
has already been erroneously cleared.
This can result in queue stalls on devices with multiple
input queues.
Fix it by clearing the DSCI just once, prior to scanning the queues.
As the code is moved in front of the loop, we also need to access
the DSCI directly (ie irq->dsci) instead of going via each queue's
parent pointer to the same irq. This is not a functional change,
and a follow-up patch will clean up the other users.
In practice, this bug only affects CQ-enabled HiperSockets devices,
ie. devices with sysfs-attribute "hsuid" set. Setting a hsuid is
needed for AF_IUCV socket applications that use HiperSockets
communication.
Fixes: 104ea556ee ("qdio: support asynchronous delivery of storage blocks")
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 2dfa6688aa upstream.
Dan Carpenter kindly reported:
<quote>
The patch d27a7cb919: "zfcp: trace on request for open and close of
WKA port" from Aug 10, 2016, leads to the following static checker
warning:
drivers/s390/scsi/zfcp_fsf.c:1615 zfcp_fsf_open_wka_port()
warn: 'req' was already freed.
drivers/s390/scsi/zfcp_fsf.c
1609 zfcp_fsf_start_timer(req, ZFCP_FSF_REQUEST_TIMEOUT);
1610 retval = zfcp_fsf_req_send(req);
1611 if (retval)
1612 zfcp_fsf_req_free(req);
^^^
Freed.
1613 out:
1614 spin_unlock_irq(&qdio->req_q_lock);
1615 if (req && !IS_ERR(req))
1616 zfcp_dbf_rec_run_wka("fsowp_1", wka_port, req->req_id);
^^^^^^^^^^^
Use after free.
1617 return retval;
1618 }
Same thing for zfcp_fsf_close_wka_port() as well.
</quote>
Rather than relying on req being NULL (or ERR_PTR) for all cases where
we don't want to trace or should not trace,
simply check retval which is unconditionally initialized with -EIO != 0
and it can only become 0 on successful retval = zfcp_fsf_req_send(req).
With that we can also remove the then again unnecessary unconditional
initialization of req which was introduced with that earlier commit.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: d27a7cb919 ("zfcp: trace on request for open and close of WKA port")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 6f2ce1c6af upstream.
It is unavoidable that zfcp_scsi_queuecommand() has to finish requests
with DID_IMM_RETRY (like fc_remote_port_chkready()) during the time
window when zfcp detected an unavailable rport but
fc_remote_port_delete(), which is asynchronous via
zfcp_scsi_schedule_rport_block(), has not yet blocked the rport.
However, for the case when the rport becomes available again, we should
prevent unblocking the rport too early. In contrast to other FCP LLDDs,
zfcp has to open each LUN with the FCP channel hardware before it can
send I/O to a LUN. So if a port already has LUNs attached and we
unblock the rport just after port recovery, recoveries of LUNs behind
this port can still be pending which in turn force
zfcp_scsi_queuecommand() to unnecessarily finish requests with
DID_IMM_RETRY.
This also opens a time window with unblocked rport (until the followup
LUN reopen recovery has finished). If a scsi_cmnd timeout occurs during
this time window fc_timed_out() cannot work as desired and such command
would indeed time out and trigger scsi_eh. This prevents a clean and
timely path failover. This should not happen if the path issue can be
recovered on FC transport layer such as path issues involving RSCNs.
Fix this by only calling zfcp_scsi_schedule_rport_register(), to
asynchronously trigger fc_remote_port_add(), after all LUN recoveries as
children of the rport have finished and no new recoveries of equal or
higher order were triggered meanwhile. Finished intentionally includes
any recovery result no matter if successful or failed (still unblock
rport so other successful LUNs work). For simplicity, we check after
each finished LUN recovery if there is another LUN recovery pending on
the same port and then do nothing. We handle the special case of a
successful recovery of a port without LUN children the same way without
changing this case's semantics.
For debugging we introduce 2 new trace records written if the rport
unblock attempt was aborted due to still unfinished or freshly triggered
recovery. The records are only written above the default trace level.
Benjamin noticed the important special case of new recovery that can be
triggered between having given up the erp_lock and before calling
zfcp_erp_action_cleanup() within zfcp_erp_strategy(). We must avoid the
following sequence:
ERP thread rport_work other context
------------------------- -------------- --------------------------------
port is unblocked, rport still blocked,
due to pending/running ERP action,
so ((port->status & ...UNBLOCK) != 0)
and (port->rport == NULL)
unlock ERP
zfcp_erp_action_cleanup()
case ZFCP_ERP_ACTION_REOPEN_LUN:
zfcp_erp_try_rport_unblock()
((status & ...UNBLOCK) != 0) [OLD!]
zfcp_erp_port_reopen()
lock ERP
zfcp_erp_port_block()
port->status clear ...UNBLOCK
unlock ERP
zfcp_scsi_schedule_rport_block()
port->rport_task = RPORT_DEL
queue_work(rport_work)
zfcp_scsi_rport_work()
(port->rport_task != RPORT_ADD)
port->rport_task = RPORT_NONE
zfcp_scsi_rport_block()
if (!port->rport) return
zfcp_scsi_schedule_rport_register()
port->rport_task = RPORT_ADD
queue_work(rport_work)
zfcp_scsi_rport_work()
(port->rport_task == RPORT_ADD)
port->rport_task = RPORT_NONE
zfcp_scsi_rport_register()
(port->rport == NULL)
rport = fc_remote_port_add()
port->rport = rport;
Now the rport was erroneously unblocked while the zfcp_port is blocked.
This is another situation we want to avoid due to scsi_eh
potential. This state would at least remain until the new recovery from
the other context finished successfully, or potentially forever if it
failed. In order to close this race, we take the erp_lock inside
zfcp_erp_try_rport_unblock() when checking the status of zfcp_port or
LUN. With that, the possible corresponding rport state sequences would
be: (unblock[ERP thread],block[other context]) if the ERP thread gets
erp_lock first and still sees ((port->status & ...UNBLOCK) != 0),
(block[other context],NOP[ERP thread]) if the ERP thread gets erp_lock
after the other context has already cleard ...UNBLOCK from port->status.
Since checking fields of struct erp_action is unsafe because they could
have been overwritten (re-used for new recovery) meanwhile, we only
check status of zfcp_port and LUN since these are only changed under
erp_lock elsewhere. Regarding the check of the proper status flags (port
or port_forced are similar to the shown adapter recovery):
[zfcp_erp_adapter_shutdown()]
zfcp_erp_adapter_reopen()
zfcp_erp_adapter_block()
* clear UNBLOCK ---------------------------------------+
zfcp_scsi_schedule_rports_block() |
write_lock_irqsave(&adapter->erp_lock, flags);-------+ |
zfcp_erp_action_enqueue() | |
zfcp_erp_setup_act() | |
* set ERP_INUSE -----------------------------------|--|--+
write_unlock_irqrestore(&adapter->erp_lock, flags);--+ | |
.context-switch. | |
zfcp_erp_thread() | |
zfcp_erp_strategy() | |
write_lock_irqsave(&adapter->erp_lock, flags);------+ | |
... | | |
zfcp_erp_strategy_check_target() | | |
zfcp_erp_strategy_check_adapter() | | |
zfcp_erp_adapter_unblock() | | |
* set UNBLOCK -----------------------------------|--+ |
zfcp_erp_action_dequeue() | |
* clear ERP_INUSE ---------------------------------|-----+
... |
write_unlock_irqrestore(&adapter->erp_lock, flags);-+
Hence, we should check for both UNBLOCK and ERP_INUSE because they are
interleaved. Also we need to explicitly check ERP_FAILED for the link
down case which currently does not clear the UNBLOCK flag in
zfcp_fsf_link_down_info_eval().
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 8830271c48 ("[SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport")
Fixes: a2fa0aede0 ("[SCSI] zfcp: Block FC transport rports early on errors")
Fixes: 5f852be9e1 ("[SCSI] zfcp: Fix deadlock between zfcp ERP and SCSI")
Fixes: 338151e066 ("[SCSI] zfcp: make use of fc_remote_port_delete when target port is unavailable")
Fixes: 3859f6a248 ("[PATCH] zfcp: add rports to enable scsi_add_device to work again")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 56d23ed7ad upstream.
Since quite a while, Linux issues enough SCSI commands per scsi_device
which successfully return with FCP_RESID_UNDER, FSF_FCP_RSP_AVAILABLE,
and SAM_STAT_GOOD. This floods the HBA trace area and we cannot see
other and important HBA trace records long enough.
Therefore, do not trace HBA response errors for pure benign residual
under counts at the default trace level.
This excludes benign residual under count combined with other validity
bits set in FCP_RSP_IU, such as FCP_SNS_LEN_VAL. For all those other
cases, we still do want to see both the HBA record and the corresponding
SCSI record by default.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: a54ca0f62f ("[SCSI] zfcp: Redesign of the debug tracing for HBA records.")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit dac37e15b7 upstream.
When SCSI EH invokes zFCP's callbacks for eh_device_reset_handler() and
eh_target_reset_handler(), it expects us to relent the ownership over
the given scsi_cmnd and all other scsi_cmnds within the same scope - LUN
or target - when returning with SUCCESS from the callback ('release'
them). SCSI EH can then reuse those commands.
We did not follow this rule to release commands upon SUCCESS; and if
later a reply arrived for one of those supposed to be released commands,
we would still make use of the scsi_cmnd in our ingress tasklet. This
will at least result in undefined behavior or a kernel panic because of
a wrong kernel pointer dereference.
To fix this, we NULLify all pointers to scsi_cmnds (struct zfcp_fsf_req
*)->data in the matching scope if a TMF was successful. This is done
under the locks (struct zfcp_adapter *)->abort_lock and (struct
zfcp_reqlist *)->lock to prevent the requests from being removed from
the request-hashtable, and the ingress tasklet from making use of the
scsi_cmnd-pointer in zfcp_fsf_fcp_cmnd_handler().
For cases where a reply arrives during SCSI EH, but before we get a
chance to NULLify the pointer - but before we return from the callback
-, we assume that the code is protected from races via the CAS operation
in blk_complete_request() that is called in scsi_done().
The following stacktrace shows an example for a crash resulting from the
previous behavior:
Unable to handle kernel pointer dereference at virtual kernel address fffffee17a672000
Oops: 0038 [#1] SMP
CPU: 2 PID: 0 Comm: swapper/2 Not tainted
task: 00000003f7ff5be0 ti: 00000003f3d38000 task.ti: 00000003f3d38000
Krnl PSW : 0404d00180000000 00000000001156b0 (smp_vcpu_scheduled+0x18/0x40)
R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 EA:3
Krnl GPRS: 000000200000007e 0000000000000000 fffffee17a671fd8 0000000300000015
ffffffff80000000 00000000005dfde8 07000003f7f80e00 000000004fa4e800
000000036ce8d8f8 000000036ce8d9c0 00000003ece8fe00 ffffffff969c9e93
00000003fffffffd 000000036ce8da10 00000000003bf134 00000003f3b07918
Krnl Code: 00000000001156a2: a7190000 lghi %r1,0
00000000001156a6: a7380015 lhi %r3,21
#00000000001156aa: e32050000008 ag %r2,0(%r5)
>00000000001156b0: 482022b0 lh %r2,688(%r2)
00000000001156b4: ae123000 sigp %r1,%r2,0(%r3)
00000000001156b8: b2220020 ipm %r2
00000000001156bc: 8820001c srl %r2,28
00000000001156c0: c02700000001 xilf %r2,1
Call Trace:
([<0000000000000000>] 0x0)
[<000003ff807bdb8e>] zfcp_fsf_fcp_cmnd_handler+0x3de/0x490 [zfcp]
[<000003ff807be30a>] zfcp_fsf_req_complete+0x252/0x800 [zfcp]
[<000003ff807c0a48>] zfcp_fsf_reqid_check+0xe8/0x190 [zfcp]
[<000003ff807c194e>] zfcp_qdio_int_resp+0x66/0x188 [zfcp]
[<000003ff80440c64>] qdio_kick_handler+0xdc/0x310 [qdio]
[<000003ff804463d0>] __tiqdio_inbound_processing+0xf8/0xcd8 [qdio]
[<0000000000141fd4>] tasklet_action+0x9c/0x170
[<0000000000141550>] __do_softirq+0xe8/0x258
[<000000000010ce0a>] do_softirq+0xba/0xc0
[<000000000014187c>] irq_exit+0xc4/0xe8
[<000000000046b526>] do_IRQ+0x146/0x1d8
[<00000000005d6a3c>] io_return+0x0/0x8
[<00000000005d6422>] vtime_stop_cpu+0x4a/0xa0
([<0000000000000000>] 0x0)
[<0000000000103d8a>] arch_cpu_idle+0xa2/0xb0
[<0000000000197f94>] cpu_startup_entry+0x13c/0x1f8
[<0000000000114782>] smp_start_secondary+0xda/0xe8
[<00000000005d6efe>] restart_int_handler+0x56/0x6c
[<0000000000000000>] 0x0
Last Breaking-Event-Address:
[<00000000003bf12e>] arch_spin_lock_wait+0x56/0xb0
Suggested-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Fixes: ea127f9754 ("[PATCH] s390 (7/7): zfcp host adapter.") (tglx/history.git)
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Steffen Maier
Halil Pasic
Julian Wiedmann
Stefan Haberland
Gerald Schaefer
Ben Hutchings
Jens Remus
Stefan Haberland
Sebastian Ott
Julian Wiedmann
Steffen Maier
Benjamin Block
Ursula Braun
Peter Oberparleiter