linux-stable.git/drivers/s390, branch linux-3.16.y

scsi: zfcp: trace channel log even for FCP command responses

2020-02-11T20:03:21+00:00

commit 100843f176109af94600e500da0428e21030ca7f upstream.

While v2.6.26 commit b75db73159cc ("[SCSI] zfcp: Add qtcb dump to hba debug
trace") is right that we don't want to flood the (payload) trace ring
buffer, we don't trace successful FCP command responses by default.  So we
can include the channel log for problem determination with failed responses
of any FSF request type.

Fixes: b75db73159cc ("[SCSI] zfcp: Add qtcb dump to hba debug trace")
Fixes: a54ca0f62f95 ("[SCSI] zfcp: Redesign of the debug tracing for HBA records.")
Link: https://lore.kernel.org/r/e37597b5c4ae123aaa85fd86c23a9f71e994e4a9.1572018132.git.bblock@linux.ibm.com
Reviewed-by: Benjamin Block 
Signed-off-by: Steffen Maier 
Signed-off-by: Benjamin Block 
Signed-off-by: Martin K. Petersen 
[bwh: Backported to 3.16: Deleted condition is slightly different]
Signed-off-by: Ben Hutchings

scsi: zfcp: fix reaction on bit error threshold notification

2019-12-19T15:57:59+00:00

commit 2190168aaea42c31bff7b9a967e7b045f07df095 upstream.

On excessive bit errors for the FCP channel ingress fibre path, the channel
notifies us.  Previously, we only emitted a kernel message and a trace
record.  Since performance can become suboptimal with I/O timeouts due to
bit errors, we now stop using an FCP device by default on channel
notification so multipath on top can timely failover to other paths.  A new
module parameter zfcp.ber_stop can be used to get zfcp old behavior.

User explanation of new kernel message:

 * Description:
 * The FCP channel reported that its bit error threshold has been exceeded.
 * These errors might result from a problem with the physical components
 * of the local fibre link into the FCP channel.
 * The problem might be damage or malfunction of the cable or
 * cable connection between the FCP channel and
 * the adjacent fabric switch port or the point-to-point peer.
 * Find details about the errors in the HBA trace for the FCP device.
 * The zfcp device driver closed down the FCP device
 * to limit the performance impact from possible I/O command timeouts.
 * User action:
 * Check for problems on the local fibre link, ensure that fibre optics are
 * clean and functional, and all cables are properly plugged.
 * After the repair action, you can manually recover the FCP device by
 * writing "0" into its "failed" sysfs attribute.
 * If recovery through sysfs is not possible, set the CHPID of the device
 * offline and back online on the service element.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://lore.kernel.org/r/20191001104949.42810-1-maier@linux.ibm.com
Reviewed-by: Jens Remus 
Reviewed-by: Benjamin Block 
Signed-off-by: Steffen Maier 
Signed-off-by: Martin K. Petersen 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

s390/cio: exclude subchannels with no parent from pseudo check

2019-12-10T18:01:24+00:00

commit ab5758848039de9a4b249d46e4ab591197eebaf2 upstream.

ccw console is created early in start_kernel and used before css is
initialized or ccw console subchannel is registered. Until then console
subchannel does not have a parent. For that reason assume subchannels
with no parent are not pseudo subchannels. This fixes the following
kasan finding:

BUG: KASAN: global-out-of-bounds in sch_is_pseudo_sch+0x8e/0x98
Read of size 8 at addr 00000000000005e8 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc8-07370-g6ac43dd12538 #2
Hardware name: IBM 2964 NC9 702 (z/VM 6.4.0)
Call Trace:
([<000000000012cd76>] show_stack+0x14e/0x1e0)
 [<0000000001f7fb44>] dump_stack+0x1a4/0x1f8
 [<00000000007d7afc>] print_address_description+0x64/0x3c8
 [<00000000007d75f6>] __kasan_report+0x14e/0x180
 [<00000000018a2986>] sch_is_pseudo_sch+0x8e/0x98
 [<000000000189b950>] cio_enable_subchannel+0x1d0/0x510
 [<00000000018cac7c>] ccw_device_recognition+0x12c/0x188
 [<0000000002ceb1a8>] ccw_device_enable_console+0x138/0x340
 [<0000000002cf1cbe>] con3215_init+0x25e/0x300
 [<0000000002c8770a>] console_init+0x68a/0x9b8
 [<0000000002c6a3d6>] start_kernel+0x4fe/0x728
 [<0000000000100070>] startup_continue+0x70/0xd0

Reviewed-by: Sebastian Ott 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Ben Hutchings

s390/cio: avoid calling strlen on null pointer

2019-12-10T18:01:24+00:00

commit ea298e6ee8b34b3ed4366be7eb799d0650ebe555 upstream.

Fix the following kasan finding:
BUG: KASAN: global-out-of-bounds in ccwgroup_create_dev+0x850/0x1140
Read of size 1 at addr 0000000000000000 by task systemd-udevd.r/561

CPU: 30 PID: 561 Comm: systemd-udevd.r Tainted: G    B
Hardware name: IBM 3906 M04 704 (LPAR)
Call Trace:
([<0000000231b3db7e>] show_stack+0x14e/0x1a8)
 [<0000000233826410>] dump_stack+0x1d0/0x218
 [<000000023216fac4>] print_address_description+0x64/0x380
 [<000000023216f5a8>] __kasan_report+0x138/0x168
 [<00000002331b8378>] ccwgroup_create_dev+0x850/0x1140
 [<00000002332b618a>] group_store+0x3a/0x50
 [<00000002323ac706>] kernfs_fop_write+0x246/0x3b8
 [<00000002321d409a>] vfs_write+0x132/0x450
 [<00000002321d47da>] ksys_write+0x122/0x208
 [<0000000233877102>] system_call+0x2a6/0x2c8

Triggered by:
openat(AT_FDCWD, "/sys/bus/ccwgroup/drivers/qeth/group",
		O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = 16
write(16, "0.0.bd00,0.0.bd01,0.0.bd02", 26) = 26

The problem is that __get_next_id in ccwgroup_create_dev might set "buf"
buffer pointer to NULL and explicit check for that is required.

Reviewed-by: Sebastian Ott 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Ben Hutchings

s390/dasd: fix endless loop after read unit address configuration

2019-11-22T15:57:10+00:00

commit 41995342b40c418a47603e1321256d2c4a2ed0fb upstream.

After getting a storage server event that causes the DASD device driver
to update its unit address configuration during a device shutdown there is
the possibility of an endless loop in the device driver.

In the system log there will be ongoing DASD error messages with RC: -19.

The reason is that the loop starting the ruac request only terminates when
the retry counter is decreased to 0. But in the sleep_on function there are
early exit paths that do not decrease the retry counter.

Prevent an endless loop by handling those cases separately.

Remove the unnecessary do..while loop since the sleep_on function takes
care of retries by itself.

Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1")
Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Signed-off-by: Jens Axboe 
Signed-off-by: Ben Hutchings

s390/qdio: don't touch the dsci in tiqdio_add_input_queues()

2019-10-31T22:15:01+00:00

commit ac6639cd3db607d386616487902b4cc1850a7be5 upstream.

Current code sets the dsci to 0x00000080. Which doesn't make any sense,
as the indicator area is located in the _left-most_ byte.

Worse: if the dsci is the _shared_ indicator, this potentially clears
the indication of activity for a _different_ device.
tiqdio_thinint_handler() will then have no reason to call that device's
IRQ handler, and the device ends up stalling.

Fixes: d0c9d4a89fff ("[S390] qdio: set correct bit in dsci")
Signed-off-by: Julian Wiedmann 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Ben Hutchings

s390/qdio: (re-)initialize tiqdio list entries

2019-10-31T22:15:00+00:00

commit e54e4785cb5cb4896cf4285964aeef2125612fb2 upstream.

When tiqdio_remove_input_queues() removes a queue from the tiq_list as
part of qdio_shutdown(), it doesn't re-initialize the queue's list entry
and the prev/next pointers go stale.

If a subsequent qdio_establish() fails while sending the ESTABLISH cmd,
it calls qdio_shutdown() again in QDIO_IRQ_STATE_ERR state and
tiqdio_remove_input_queues() will attempt to remove the queue entry a
second time. This dereferences the stale pointers, and bad things ensue.
Fix this by re-initializing the list entry after removing it from the
list.

For good practice also initialize the list entry when the queue is first
allocated, and remove the quirky checks that papered over this omission.
Note that prior to
commit e521813468f7 ("s390/qdio: fix access to uninitialized qdio_q fields"),
these checks were bogus anyway.

setup_queues_misc() clears the whole queue struct, and thus needs to
re-init the prev/next pointers as well.

Fixes: 779e6e1c724d ("[S390] qdio: new qdio driver.")
Signed-off-by: Julian Wiedmann 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Ben Hutchings

s390/qdio: handle PENDING state for QEBSM devices

2019-10-31T22:14:52+00:00

commit 04310324c6f482921c071444833e70fe861b73d9 upstream.

When a CQ-enabled device uses QEBSM for SBAL state inspection,
get_buf_states() can return the PENDING state for an Output Queue.
get_outbound_buffer_frontier() isn't prepared for this, and any PENDING
buffer will permanently stall all further completion processing on this
Queue.

This isn't a concern for non-QEBSM devices, as get_buf_states() for such
devices will manually turn PENDING buffers into EMPTY ones.

Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks")
Signed-off-by: Julian Wiedmann 
Signed-off-by: Heiko Carstens 
Signed-off-by: Ben Hutchings

s390/qeth: fix VLAN attribute in bridge_hostnotify udev event

2019-10-05T15:19:52+00:00

commit 335726195e460cb6b3f795b695bfd31f0ea70ef0 upstream.

Enabling sysfs attribute bridge_hostnotify triggers a series of udev events
for the MAC addresses of all currently connected peers. In case no VLAN is
set for a peer, the device reports the corresponding MAC addresses with
VLAN ID 4096. This currently results in attribute VLAN=4096 for all
non-VLAN interfaces in the initial series of events after host-notify is
enabled.

Instead, no VLAN attribute should be reported in the udev event for
non-VLAN interfaces.

Only the initial events face this issue. For dynamic changes that are
reported later, the device uses a validity flag.

This also changes the code so that it now sets the VLAN attribute for
MAC addresses with VID 0. On Linux, no qeth interface will ever be
registered with VID 0: Linux kernel registers VID 0 on all network
interfaces initially, but qeth will drop .ndo_vlan_rx_add_vid for VID 0.
Peers with other OSs could register MACs with VID 0.

Fixes: 9f48b9db9a22 ("qeth: bridgeport support - address notifications")
Signed-off-by: Alexandra Winter 
Signed-off-by: Julian Wiedmann 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs)

2019-10-05T15:19:50+00:00

commit ef4021fe5fd77ced0323cede27979d80a56211ca upstream.

When the user tries to remove a zfcp port via sysfs, we only rejected it if
there are zfcp unit children under the port. With purely automatically
scanned LUNs there are no zfcp units but only SCSI devices. In such cases,
the port_remove erroneously continued. We close the port and this
implicitly closes all LUNs under the port. The SCSI devices survive with
their private zfcp_scsi_dev still holding a reference to the "removed"
zfcp_port (still allocated but invisible in sysfs) [zfcp_get_port_by_wwpn
in zfcp_scsi_slave_alloc]. This is not a problem as long as the fc_rport
stays blocked. Once (auto) port scan brings back the removed port, we
unblock its fc_rport again by design.  However, there is no mechanism that
would recover (open) the LUNs under the port (no "ersfs_3" without
zfcp_unit [zfcp_erp_strategy_followup_success]).  Any pending or new I/O to
such LUN leads to repeated:

  Done: NEEDS_RETRY Result: hostbyte=DID_IMM_RETRY driverbyte=DRIVER_OK

See also v4.10 commit 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race
with LUN recovery"). Even a manual LUN recovery
(echo 0 > /sys/bus/scsi/devices/H:C:T:L/zfcp_failed)
does not help, as the LUN links to the old "removed" port which remains
to lack ZFCP_STATUS_COMMON_RUNNING [zfcp_erp_required_act].
The only workaround is to first ensure that the fc_rport is blocked
(e.g. port_remove again in case it was re-discovered by (auto) port scan),
then delete the SCSI devices, and finally re-discover by (auto) port scan.
The port scan includes an fc_rport unblock, which in turn triggers
a new scan on the scsi target to freshly get new pure auto scan LUNs.

Fix this by rejecting port_remove also if there are SCSI devices
(even without any zfcp_unit) under this port. Re-use mechanics from v3.7
commit d99b601b6338 ("[SCSI] zfcp: restore refcount check on port_remove").
However, we have to give up zfcp_sysfs_port_units_mutex earlier in unit_add
to prevent a deadlock with scsi_host scan taking shost->scan_mutex first
and then zfcp_sysfs_port_units_mutex now in our zfcp_scsi_slave_alloc().

Signed-off-by: Steffen Maier 
Fixes: b62a8d9b45b9 ("[SCSI] zfcp: Use SCSI device data zfcp scsi dev instead of zfcp unit")
Fixes: f8210e34887e ("[SCSI] zfcp: Allow midlayer to scan for LUNs when running in NPIV mode")
Reviewed-by: Benjamin Block 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Ben Hutchings