linux-stable.git/drivers/s390, branch linux-5.17.y

s390/stp: clock_delta should be signed

2022-06-09T08:26:21+00:00

commit 5ace65ebb5ce9fe1cc8fdbdd97079fb566ef0ea4 upstream.

clock_delta is declared as unsigned long in various places. However,
the clock sync delta can be negative. This would add a huge positive
offset in clock_sync_global where clock_delta is added to clk.eitod
which is a 72 bit integer. Declare it as signed long to fix this.

Cc: stable@vger.kernel.org
Signed-off-by: Sven Schnelle 
Reviewed-by: Heiko Carstens 
Signed-off-by: Heiko Carstens 
Signed-off-by: Greg Kroah-Hartman

s390/lcs: fix variable dereferenced before check

2022-05-18T08:28:15+00:00

[ Upstream commit 671bb35c8e746439f0ed70815968f9a4f20a8deb ]

smatch complains about
drivers/s390/net/lcs.c:1741 lcs_get_control() warn: variable dereferenced before check 'card->dev' (see line 1739)

Fixes: 27eb5ac8f015 ("[PATCH] s390: lcs driver bug fixes and improvements [1/2]")
Signed-off-by: Alexandra Winter 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/ctcm: fix potential memory leak

2022-05-18T08:28:15+00:00

[ Upstream commit 0c0b20587b9f25a2ad14db7f80ebe49bdf29920a ]

smatch complains about
drivers/s390/net/ctcm_mpc.c:1210 ctcmpc_unpack_skb() warn: possible memory leak of 'mpcginfo'

mpc_action_discontact() did not free mpcginfo. Consolidate the freeing in
ctcmpc_unpack_skb().

Fixes: 293d984f0e36 ("ctcm: infrastructure for replaced ctc driver")
Signed-off-by: Alexandra Winter 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/ctcm: fix variable dereferenced before check

2022-05-18T08:28:15+00:00

[ Upstream commit 2c50c6867c85afee6f2b3bcbc50fc9d0083d1343 ]

Found by cppcheck and smatch.
smatch complains about
drivers/s390/net/ctcm_sysfs.c:43 ctcm_buffer_write() warn: variable dereferenced before check 'priv' (see line 42)

Fixes: 3c09e2647b5e ("ctcm: rename READ/WRITE defines to avoid redefinitions")
Reported-by: Colin Ian King 
Signed-off-by: Alexandra Winter 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/dasd: Fix read inconsistency for ESE DASD devices

2022-05-12T10:32:24+00:00

commit b9c10f68e23c13f56685559a0d6fdaca9f838324 upstream.

Read requests that return with NRF error are partially completed in
dasd_eckd_ese_read(). The function keeps track of the amount of
processed bytes and the driver will eventually return this information
back to the block layer for further processing via __dasd_cleanup_cqr()
when the request is in the final stage of processing (from the driver's
perspective).

For this, blk_update_request() is used which requires the number of
bytes to complete the request. As per documentation the nr_bytes
parameter is described as follows:
   "number of bytes to complete for @req".

This was mistakenly interpreted as "number of bytes _left_ for @req"
leading to new requests with incorrect data length. The consequence are
inconsistent and completely wrong read requests as data from random
memory areas are read back.

Fix this by correctly specifying the amount of bytes that should be used
to complete the request.

Fixes: 5e6bdd37c552 ("s390/dasd: fix data corruption for thin provisioned devices")
Cc: stable@vger.kernel.org # 5.3+
Signed-off-by: Jan Höppner 
Reviewed-by: Stefan Haberland 
Link: https://lore.kernel.org/r/20220505141733.1989450-5-sth@linux.ibm.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

s390/dasd: Fix read for ESE with blksize < 4k

2022-05-12T10:32:24+00:00

commit cd68c48ea15c85f1577a442dc4c285e112ff1b37 upstream.

When reading unformatted tracks on ESE devices, the corresponding memory
areas are simply set to zero for each segment. This is done incorrectly
for blocksizes < 4096.

There are two problems. First, the increment of dst is done using the
counter of the loop (off), which is increased by blksize every
iteration. This leads to a much bigger increment for dst as actually
intended. Second, the increment of dst is done before the memory area
is set to 0, skipping a significant amount of bytes of memory.

This leads to illegal overwriting of memory and ultimately to a kernel
panic.

This is not a problem with 4k blocksize because
blk_queue_max_segment_size is set to PAGE_SIZE, always resulting in a
single iteration for the inner segment loop (bv.bv_len == blksize). The
incorrectly used 'off' value to increment dst is 0 and the correct
memory area is used.

In order to fix this for blksize < 4k, increment dst correctly using the
blksize and only do it at the end of the loop.

Fixes: 5e2b17e712cf ("s390/dasd: Add dynamic formatting support for ESE volumes")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Jan Höppner 
Reviewed-by: Stefan Haberland 
Link: https://lore.kernel.org/r/20220505141733.1989450-4-sth@linux.ibm.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

s390/dasd: prevent double format of tracks for ESE devices

2022-05-12T10:32:24+00:00

commit 71f3871657370dbbaf942a1c758f64e49a36c70f upstream.

For ESE devices we get an error for write operations on an unformatted
track. Afterwards the track will be formatted and the IO operation
restarted.
When using alias devices a track might be accessed by multiple requests
simultaneously and there is a race window that a track gets formatted
twice resulting in data loss.

Prevent this by remembering the amount of formatted tracks when starting
a request and comparing this number before actually formatting a track
on the fly. If the number has changed there is a chance that the current
track was finally formatted in between. As a result do not format the
track and restart the current IO to check.

The number of formatted tracks does not match the overall number of
formatted tracks on the device and it might wrap around but this is no
problem. It is only needed to recognize that a track has been formatted at
all in between.

Fixes: 5e2b17e712cf ("s390/dasd: Add dynamic formatting support for ESE volumes")
Cc: stable@vger.kernel.org # 5.3+
Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Link: https://lore.kernel.org/r/20220505141733.1989450-3-sth@linux.ibm.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

s390/dasd: fix data corruption for ESE devices

2022-05-12T10:32:23+00:00

commit 5b53a405e4658580e1faf7c217db3f55a21ba849 upstream.

For ESE devices we get an error when accessing an unformatted track.
The handling of this error will return zero data for read requests and
format the track on demand before writing to it. To do this the code needs
to distinguish between read and write requests. This is done with data from
the blocklayer request. A pointer to the blocklayer request is stored in
the CQR.

If there is an error on the device an ERP request is built to do error
recovery. While the ERP request is mostly a copy of the original CQR the
pointer to the blocklayer request is not copied to not accidentally pass
it back to the blocklayer without cleanup.

This leads to the error that during ESE handling after an ERP request was
built it is not possible to determine the IO direction. This leads to the
formatting of a track for read requests which might in turn lead to data
corruption.

Fixes: 5e2b17e712cf ("s390/dasd: Add dynamic formatting support for ESE volumes")
Cc: stable@vger.kernel.org # 5.3+
Signed-off-by: Stefan Haberland 
Reviewed-by: Jan Hoeppner 
Link: https://lore.kernel.org/r/20220505141733.1989450-2-sth@linux.ibm.com
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

s390/cio: verify the driver availability for path_event call

2022-02-09T21:55:01+00:00

If no driver is attached to a device or the driver does not provide the
path_event function, an FCES path-event on this device could end up in a
kernel-panic. Verify the driver availability before the path_event
function call.

Fixes: 32ef938815c1 ("s390/cio: Add support for FCES status notification")
Cc: stable@vger.kernel.org
Signed-off-by: Vineeth Vijayan 
Suggested-by: Peter Oberparleiter 
Reviewed-by: Jan Hoeppner 
Reviewed-by: Peter Oberparleiter 
Signed-off-by: Vasily Gorbik

scsi: zfcp: Fix failed recovery on gone remote port with non-NPIV FCP devices

2022-01-25T04:30:27+00:00

Suppose we have an environment with a number of non-NPIV FCP devices
(virtual HBAs / FCP devices / zfcp "adapter"s) sharing the same physical
FCP channel (HBA port) and its I_T nexus. Plus a number of storage target
ports zoned to such shared channel. Now one target port logs out of the
fabric causing an RSCN. Zfcp reacts with an ADISC ELS and subsequent port
recovery depending on the ADISC result. This happens on all such FCP
devices (in different Linux images) concurrently as they all receive a copy
of this RSCN. In the following we look at one of those FCP devices.

Requests other than FSF_QTCB_FCP_CMND can be slow until they get a
response.

Depending on which requests are affected by slow responses, there are
different recovery outcomes. Here we want to fix failed recoveries on port
or adapter level by avoiding recovery requests that can be slow.

We need the cached N_Port_ID for the remote port "link" test with ADISC.
Just before sending the ADISC, we now intentionally forget the old cached
N_Port_ID. The idea is that on receiving an RSCN for a port, we have to
assume that any cached information about this port is stale.  This forces a
fresh new GID_PN [FC-GS] nameserver lookup on any subsequent recovery for
the same port. Since we typically can still communicate with the nameserver
efficiently, we now reach steady state quicker: Either the nameserver still
does not know about the port so we stop recovery, or the nameserver already
knows the port potentially with a new N_Port_ID and we can successfully and
quickly perform open port recovery.  For the one case, where ADISC returns
successfully, we re-initialize port->d_id because that case does not
involve any port recovery.

This also solves a problem if the storage WWPN quickly logs into the fabric
again but with a different N_Port_ID. Such as on virtual WWPN takeover
during target NPIV failover.
[https://www.redbooks.ibm.com/abstracts/redp5477.html] In that case the
RSCN from the storage FDISC was ignored by zfcp and we could not
successfully recover the failover. On some later failback on the storage,
we could have been lucky if the virtual WWPN got the same old N_Port_ID
from the SAN switch as we still had cached.  Then the related RSCN
triggered a successful port reopen recovery.  However, there is no
guarantee to get the same N_Port_ID on NPIV FDISC.

Even though NPIV-enabled FCP devices are not affected by this problem, this
code change optimizes recovery time for gone remote ports as a side effect.
The timely drop of cached N_Port_IDs prevents unnecessary slow open port
attempts.

While the problem might have been in code before v2.6.32 commit
799b76d09aee ("[SCSI] zfcp: Decouple gid_pn requests from erp") this fix
depends on the gid_pn_work introduced with that commit, so we mark it as
culprit to satisfy fix dependencies.

Note: Point-to-point remote port is already handled separately and gets its
N_Port_ID from the cached peer_d_id. So resetting port->d_id in general
does not affect PtP.

Link: https://lore.kernel.org/r/20220118165803.3667947-1-maier@linux.ibm.com
Fixes: 799b76d09aee ("[SCSI] zfcp: Decouple gid_pn requests from erp")
Cc:  #2.6.32+
Suggested-by: Benjamin Block 
Reviewed-by: Benjamin Block 
Signed-off-by: Steffen Maier 
Signed-off-by: Martin K. Petersen