linux-stable.git/drivers/target, branch v4.1.41

iscsi-target: Use shash and ahash

2017-06-08T10:42:00+00:00

[ Upstream commit 69110e3cedbb8aad1c70d91ed58a9f4f0ed9eec6 ]

This patch replaces uses of the long obsolete hash interface with
either shash (for non-SG users) or ahash.

Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

target/iscsi: Use proper SGL accessors for digest computation

2017-06-08T10:42:00+00:00

[ Upstream commit aa75679c797c0250a853e600e45368f1f9545c27 ]

Current implementation assumes that all the buffers of an IO are linked
with a single SG list, which is OK because target-core is only allocating
a contigious scatterlist region.  However, this assumption is wrong for
se_cmd descriptors that want to use chaining across multiple SGL regions.

Fix this up by using proper SGL accessors for digest payload computation.

Signed-off-by: Alexei Potashnik 
Cc: Roland Dreier 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Sasha Levin

iscsi-target: Fix initial login PDU asynchronous socket close OOPs

2017-06-08T10:42:00+00:00

[ Upstream commit 25cdda95fda78d22d44157da15aa7ea34be3c804 ]

This patch fixes a OOPs originally introduced by:

   commit bb048357dad6d604520c91586334c9c230366a14
   Author: Nicholas Bellinger 
   Date:   Thu Sep 5 14:54:04 2013 -0700

   iscsi-target: Add sk->sk_state_change to cleanup after TCP failure

which would trigger a NULL pointer dereference when a TCP connection
was closed asynchronously via iscsi_target_sk_state_change(), but only
when the initial PDU processing in iscsi_target_do_login() from iscsi_np
process context was blocked waiting for backend I/O to complete.

To address this issue, this patch makes the following changes.

First, it introduces some common helper functions used for checking
socket closing state, checking login_flags, and atomically checking
socket closing state + setting login_flags.

Second, it introduces a LOGIN_FLAGS_INITIAL_PDU bit to know when a TCP
connection has dropped via iscsi_target_sk_state_change(), but the
initial PDU processing within iscsi_target_do_login() in iscsi_np
context is still running.  For this case, it sets LOGIN_FLAGS_CLOSED,
but doesn't invoke schedule_delayed_work().

The original NULL pointer dereference case reported by MNC is now handled
by iscsi_target_do_login() doing a iscsi_target_sk_check_close() before
transitioning to FFP to determine when the socket has already closed,
or iscsi_target_start_negotiation() if the login needs to exchange
more PDUs (eg: iscsi_target_do_login returned 0) but the socket has
closed.  For both of these cases, the cleanup up of remaining connection
resources will occur in iscsi_target_start_negotiation() from iscsi_np
process context once the failure is detected.

Finally, to handle to case where iscsi_target_sk_state_change() is
called after the initial PDU procesing is complete, it now invokes
conn->login_work -> iscsi_target_do_login_rx() to perform cleanup once
existing iscsi_target_sk_check_close() checks detect connection failure.
For this case, the cleanup of remaining connection resources will occur
in iscsi_target_do_login_rx() from delayed workqueue process context
once the failure is detected.

Reported-by: Mike Christie 
Reviewed-by: Mike Christie 
Tested-by: Mike Christie 
Cc: Mike Christie 
Reported-by: Hannes Reinecke 
Cc: Hannes Reinecke 
Cc: Sagi Grimberg 
Cc: Varun Prakash 
Cc:  # v3.12+
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Sasha Levin

target/iscsi: Fix indentation in iscsi_target_start_negotiation()

2017-06-08T10:42:00+00:00

[ Upstream commit 1efaa949396b5d9e8d1e6edef7e97e9ce1a97319 ]

This patch avoids that smatch complains about inconsistent
indentation in iscsi_target_start_negotiation().

Signed-off-by: Bart Van Assche 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Cc: Nicholas A. Bellinger 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Sasha Levin

iscsi-target: Fix early sk_data_ready LOGIN_FLAGS_READY race

2017-06-08T10:42:00+00:00

[ Upstream commit 8f0dfb3d8b1120c61f6e2cc3729290db10772b2d ]

There is a iscsi-target/tcp login race in LOGIN_FLAGS_READY
state assignment that can result in frequent errors during
iscsi discovery:

      "iSCSI Login negotiation failed."

To address this bug, move the initial LOGIN_FLAGS_READY
assignment ahead of iscsi_target_do_login() when handling
the initial iscsi_target_start_negotiation() request PDU
during connection login.

As iscsi_target_do_login_rx() work_struct callback is
clearing LOGIN_FLAGS_READ_ACTIVE after subsequent calls
to iscsi_target_do_login(), the early sk_data_ready
ahead of the first iscsi_target_do_login() expects
LOGIN_FLAGS_READY to also be set for the initial
login request PDU.

As reported by Maged, this was first obsered using an
MSFT initiator running across multiple VMWare host
virtual machines with iscsi-target/tcp.

Reported-by: Maged Mokhtar 
Tested-by: Maged Mokhtar 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Sasha Levin

target/fileio: Fix zero-length READ and WRITE handling

2017-05-28T10:36:09+00:00

[ Upstream commit 59ac9c078141b8fd0186c0b18660a1b2c24e724e ]

This patch fixes zero-length READ and WRITE handling in target/FILEIO,
which was broken a long time back by:

Since:

  commit d81cb44726f050d7cf1be4afd9cb45d153b52066
  Author: Paolo Bonzini 
  Date:   Mon Sep 17 16:36:11 2012 -0700

      target: go through normal processing for all zero-length commands

which moved zero-length READ and WRITE completion out of target-core,
to doing submission into backend driver code.

To address this, go ahead and invoke target_complete_cmd() for any
non negative return value in fd_do_rw().

Signed-off-by: Bart Van Assche 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Cc: Andy Grover 
Cc: David Disseldorp 
Cc:  # v3.7+
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Sasha Levin

iscsi-target: Set session_fall_back_to_erl0 when forcing reinstatement

2017-05-17T19:08:25+00:00

[ Upstream commit 197b806ae5db60c6f609d74da04ddb62ea5e1b00 ]

While testing modification of per se_node_acl queue_depth forcing
session reinstatement via lio_target_nacl_cmdsn_depth_store() ->
core_tpg_set_initiator_node_queue_depth(), a hung task bug triggered
when changing cmdsn_depth invoked session reinstatement while an iscsi
login was already waiting for session reinstatement to complete.

This can happen when an outstanding se_cmd descriptor is taking a
long time to complete, and session reinstatement from iscsi login
or cmdsn_depth change occurs concurrently.

To address this bug, explicitly set session_fall_back_to_erl0 = 1
when forcing session reinstatement, so session reinstatement is
not attempted if an active session is already being shutdown.

This patch has been tested with two scenarios.  The first when
iscsi login is blocked waiting for iscsi session reinstatement
to complete followed by queue_depth change via configfs, and
second when queue_depth change via configfs us blocked followed
by a iscsi login driven session reinstatement.

Note this patch depends on commit d36ad77f702 to handle multiple
sessions per se_node_acl when changing cmdsn_depth, and for
pre v4.5 kernels will need to be included for stable as well.

Reported-by: Gary Guo 
Tested-by: Gary Guo 
Cc: Gary Guo 
Cc:  # v4.1+
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Sasha Levin

target: Fix compare_and_write_callback handling for non GOOD status

2017-05-17T19:08:25+00:00

[ Upstream commit a71a5dc7f833943998e97ca8fa6a4c708a0ed1a9 ]

Following the bugfix for handling non SAM_STAT_GOOD COMPARE_AND_WRITE
status during COMMIT phase in commit 9b2792c3da1, the same bug exists
for the READ phase as well.

This would manifest first as a lost SCSI response, and eventual
hung task during fabric driver logout or re-login, as existing
shutdown logic waited for the COMPARE_AND_WRITE se_cmd->cmd_kref
to reach zero.

To address this bug, compare_and_write_callback() has been changed
to set post_ret = 1 and return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
as necessary to signal failure status.

Reported-by: Bill Borsari 
Cc: Bill Borsari 
Tested-by: Gary Guo 
Cc: Gary Guo 
Cc:  # v4.1+
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Sasha Levin

target: Fix VERIFY and WRITE VERIFY command parsing

2017-05-17T19:08:24+00:00

[ Upstream commit 0e2eb7d12eaa8e391bf5615d4271bb87a649caaa ]

Use the value of the BYTCHK field to determine the size of the
Data-Out buffer. For VERIFY, honor the VRPROTECT, DPO and FUA
fields. This patch avoids that LIO complains about a mismatch
between the expected transfer length and the SCSI CDB length
if the value of the BYTCHK field is 0.

Signed-off-by: Bart Van Assche 
Cc: Max Lohrmann 
Cc: 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Sasha Levin

iscsi-target: Drop work-around for legacy GlobalSAN initiator

2017-05-17T19:07:44+00:00

[ Upstream commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46 ]

Once upon a time back in 2009, a work-around was added to support
the GlobalSAN iSCSI initiator v3.3 for MacOSX, which during login
did not propose nor respond to MaxBurstLength, FirstBurstLength,
DefaultTime2Wait and DefaultTime2Retain keys.

The work-around in iscsi_check_proposer_for_optional_reply()
allowed the missing keys to be proposed, but did not require
waiting for a response before moving to full feature phase
operation.  This allowed GlobalSAN v3.3 to work out-of-the
box, and for many years we didn't run into login interopt
issues with any other initiators..

Until recently, when Martin tried a QLogic 57840S iSCSI Offload
HBA on Windows 2016 which completed login, but subsequently
failed with:

    Got unknown iSCSI OpCode: 0x43

The issue was QLogic MSFT side did not propose DefaultTime2Wait +
DefaultTime2Retain, so LIO proposes them itself, and immediately
transitions to full feature phase because of the GlobalSAN hack.
However, the QLogic MSFT side still attempts to respond to
DefaultTime2Retain + DefaultTime2Wait, even though LIO has set
ISCSI_FLAG_LOGIN_NEXT_STAGE3 + ISCSI_FLAG_LOGIN_TRANSIT
in last login response.

So while the QLogic MSFT side should have been proposing these
two keys to start, it was doing the correct thing per RFC-3720
attempting to respond to proposed keys before transitioning to
full feature phase.

All that said, recent versions of GlobalSAN iSCSI (v5.3.0.541)
does correctly propose the four keys during login, making the
original work-around moot.

So in order to allow QLogic MSFT to run unmodified as-is, go
ahead and drop this long standing work-around.

Reported-by: Martin Svec 
Cc: Martin Svec 
Cc: Himanshu Madhani 
Cc: Arun Easi 
Cc: stable@vger.kernel.org # 3.1+
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Sasha Levin