Fixes gcc '-Wunused-but-set-variable' warning:

drivers/scsi/lpfc/lpfc_hbadisc.c: In function 'lpfc_free_tx':
drivers/scsi/lpfc/lpfc_hbadisc.c:5431:19: warning:
 variable 'psli' set but not used [-Wunused-but-set-variable]

Since commit 895427bd

 ("scsi: lpfc: NVME Initiator: Base modifications")
'psli' is not used any more.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Clang warns when one enumerated type is implicitly converted to another.

drivers/scsi/bfa/bfa_fcs_lport.c:379:26: warning: implicit conversion
from enumeration type 'enum bfa_lport_aen_event' to different
enumeration type 'enum bfa_ioc_aen_event' [-Wenum-conversion]
                                  BFA_AEN_CAT_LPORT, event);
                                                     ^~~~~

The root cause of these warnings is the bfad_im_post_vendor_event
function, which expects a value from enum bfa_ioc_aen_event but there
are multiple instances of values from enums bfa_port_aen_event,
bfa_audit_aen_event, and bfa_lport_aen_event being used in this
function.

Given that this doesn't appear to be a problem since cat helps with
differentiating the events, just change evt's type to int so that no
conversion needs to happen and Clang won't warn. Update aen_type's type
in bfa_aen_entry_s as members that hold enumerated types should be int.

Link: https://github.com/ClangBuiltLinux/linux/issues/147
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Clang warns when an enumerated type is implicitly converted to another.

drivers/scsi/isci/request.c:3476:13: warning: implicit conversion from
enumeration type 'enum sci_task_status' to different enumeration type
'enum sci_status' [-Wenum-conversion]
                        status = sci_controller_start_task(ihost,
                               ~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/isci/host.c:2744:10: warning: implicit conversion from
enumeration type 'enum sci_status' to different enumeration type 'enum
sci_task_status' [-Wenum-conversion]
                return SCI_SUCCESS;
                ~~~~~~ ^~~~~~~~~~~
drivers/scsi/isci/host.c:2753:9: warning: implicit conversion from
enumeration type 'enum sci_status' to different enumeration type 'enum
sci_task_status' [-Wenum-conversion]
        return status;
        ~~~~~~ ^~~~~~

Avoid all of these implicit conversion by just making
sci_controller_start_task use sci_status. This silences
Clang and has no functional change since sci_task_status
has all of its values mapped to something in sci_status.

Link: https://github.com/ClangBuiltLinux/linux/issues/153
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Clang warns when one enumerated type is implicitly converted to another.

drivers/scsi/isci/request.c:1629:13: warning: implicit conversion from
enumeration type 'enum sci_io_status' to different enumeration type
'enum sci_status' [-Wenum-conversion]
                        status = SCI_IO_FAILURE_RESPONSE_VALID;
                               ~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/isci/request.c:1631:12: warning: implicit conversion from
enumeration type 'enum sci_io_status' to different enumeration type
'enum sci_status' [-Wenum-conversion]
                status = SCI_IO_FAILURE_RESPONSE_VALID;
                       ~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

status is of type sci_status but SCI_IO_FAILURE_RESPONSE_VALID is of
type sci_io_status. Use SCI_FAILURE_IO_RESPONSE_VALID, which is from
sci_status and has SCI_IO_FAILURE_RESPONSE_VALID's exact value since
that is what SCI_IO_FAILURE_RESPONSE_VALID is mapped to in the isci.h
file.

Link: https://github.com/ClangBuiltLinux/linux/issues/153
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/scsi/lpfc/lpfc_sli.c: In function 'lpfc_sli4_sp_handle_rcqe':
drivers/scsi/lpfc/lpfc_sli.c:13430:26: warning:
 variable 'fc_hdr' set but not used [-Wunused-but-set-variable]

drivers/scsi/lpfc/lpfc_sli.c: In function 'lpfc_cq_create':
drivers/scsi/lpfc/lpfc_sli.c:14852:11: warning:
 variable 'hw_page_size' set but not used [-Wunused-but-set-variable]

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add IEEE and CEE DCBX support for iSCSI connections.

Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/scsi/megaraid/megaraid_mbox.c: In function 'megaraid_reset_handler':
drivers/scsi/megaraid/megaraid_mbox.c:2580:7: warning:
 variable 'recovering' set but not used [-Wunused-but-set-variable]

drivers/scsi/megaraid/megaraid_mbox.c: In function 'mbox_post_sync_cmd':
drivers/scsi/megaraid/megaraid_mbox.c:2728:12: warning:
 variable 'mbox64' set but not used [-Wunused-but-set-variable]

drivers/scsi/megaraid/megaraid_mbox.c: In function 'megaraid_mbox_support_random_del':
drivers/scsi/megaraid/megaraid_mbox.c:3138:11: warning:
 variable 'mbox' set but not used [-Wunused-but-set-variable]

drivers/scsi/megaraid/megaraid_mbox.c: In function 'megaraid_mbox_flush_cache':
drivers/scsi/megaraid/megaraid_mbox.c:3266:10: warning:
 variable 'mbox' set but not used [-Wunused-but-set-variable]

drivers/scsi/megaraid/megaraid_mbox.c: In function 'megaraid_mbox_fire_sync_cmd':
drivers/scsi/megaraid/megaraid_mbox.c:3302:12: warning:
 variable 'mbox64' set but not used [-Wunused-but-set-variable]

drivers/scsi/megaraid/megaraid_mbox.c: In function 'gather_hbainfo':
drivers/scsi/megaraid/megaraid_mbox.c:3797:10: warning:
 variable 'dmajor' set but not used [-Wunused-but-set-variable]

[mkp: applied by hand due to conflict with hch's DMA cleanup]

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Clang generates a warning when it sees a logical not followed by a
conditional operator like ==, >, or < because it thinks that the logical
not should be applied to the whole statement:

drivers/scsi/qla2xxx/qla_nx.c:3702:7: warning: logical not is only
applied to the left hand side of this comparison
[-Wlogical-not-parentheses]
                if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
                    ^
drivers/scsi/qla2xxx/qla_nx.c:3702:7: note: add parentheses after the
'!' to evaluate the comparison first
                if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
                    ^
                     (
drivers/scsi/qla2xxx/qla_nx.c:3702:7: note: add parentheses around left
hand side expression to silence this warning
                if (!qla2x00_eh_wait_for_pending_commands(vha, 0, 0,
                    ^
                    (
1 warning generated.

It assumes the author might have made a mistake in their logic:

if (!a == b) -> if (!(a == b))

Sometimes that is the case; other times, it's just a super convoluted
way of saying 'if (a)' when b = 0:

if (!1 == 0) -> if (0 == 0) -> if (true)

Alternatively:

if (!1 == 0) -> if (!!1) -> if (1)

Simplify this comparison so that Clang doesn't complain.

Link: https://github.com/ClangBuiltLinux/linux/issues/80
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Clang warns when a variable is assigned to itself.

drivers/scsi/bfa/bfa_fcbuild.c:199:6: warning: explicitly assigning
value of variable of type 'int' to itself [-Wself-assign]
        len = len;
        ~~~ ^ ~~~
drivers/scsi/bfa/bfa_fcbuild.c:838:6: warning: explicitly assigning
value of variable of type 'int' to itself [-Wself-assign]
        len = len;
        ~~~ ^ ~~~
drivers/scsi/bfa/bfa_fcbuild.c:917:6: warning: explicitly assigning
value of variable of type 'int' to itself [-Wself-assign]
        len = len;
        ~~~ ^ ~~~
drivers/scsi/bfa/bfa_fcbuild.c:981:6: warning: explicitly assigning
value of variable of type 'int' to itself [-Wself-assign]
        len = len;
        ~~~ ^ ~~~
drivers/scsi/bfa/bfa_fcbuild.c:1008:6: warning: explicitly assigning
value of variable of type 'int' to itself [-Wself-assign]
        len = len;
        ~~~ ^ ~~~
5 warnings generated.

This construct is usually used to avoid unused variable warnings, which
I assume is the case here. -Wunused-parameter is hidden behind -Wextra
with GCC 4.6, which is the minimum version to compile the kernel as of
commit cafa0010

 ("Raise the minimum required gcc version to 4.6").

However, upon further inspection, these functions aren't actually used
anywhere; they're just defined. Rather than just removing the self
assignments, remove all of this dead code.

Link: https://github.com/ClangBuiltLinux/linux/issues/148
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Clang warns when a variable is assigned to itself.

drivers/scsi/qla2xxx/qla_mbx.c:1514:4: warning: explicitly assigning
value of variable of type 'uint64_t' (aka 'unsigned long long') to
itself [-Wself-assign]
        l = l;
        ~ ^ ~
1 warning generated.

This construct is usually used to avoid unused variable warnings, which
I assume is the case here. -Wunused-parameter is hidden behind -Wextra
with GCC 4.6, which is the minimum version to compile the kernel as of
commit cafa0010

 ("Raise the minimum required gcc version to 4.6").
Just remove this line to silence Clang.

Link: https://github.com/ClangBuiltLinux/linux/issues/83
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/scsi/arcmsr/arcmsr_hba.c: In function 'arcmsr_drain_donequeue':
drivers/scsi/arcmsr/arcmsr_hba.c:1320:10: warning:
 variable 'lun' set but not used [-Wunused-but-set-variable]

drivers/scsi/arcmsr/arcmsr_hba.c:1320:6: warning:
 variable 'id' set but not used [-Wunused-but-set-variable]

Never used since introduction in commit ae52e7f0

 ("arcmsr: Support 1024 scatter-gather list entries and improve AP while FW trapped and behaviors of EHs").

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

In megasas_mgmt_compat_ioctl_fw(), to handle the structure
compat_megasas_iocpacket 'cioc', a user-space structure megasas_iocpacket
'ioc' is allocated before megasas_mgmt_ioctl_fw() is invoked to handle
the packet. Since the two data structures have different fields, the data
is copied from 'cioc' to 'ioc' field by field. In the copy process,
'sense_ptr' is prepared if the field 'sense_len' is not null, because it
will be used in megasas_mgmt_ioctl_fw(). To prepare 'sense_ptr', the
user-space data 'ioc->sense_off' and 'cioc->sense_off' are copied and
saved to kernel-space variables 'local_sense_off' and 'user_sense_off'
respectively. Given that 'ioc->sense_off' is also copied from
'cioc->sense_off', 'local_sense_off' and 'user_sense_off' should have the
same value. However, 'cioc' is in the user space and a malicious user can
race to change the value of 'cioc->sense_off' after it is copied to
'ioc->sense_off' but before it is copied to 'user_sense_off'. By doing
so, the attacker can inject different values into 'local_sense_off' and
'user_sense_off'. This can cause undefined behavior in the following
execution, because the two variables are supposed to be same.

This patch enforces a check on the two kernel variables 'local_sense_off'
and 'user_sense_off' to make sure they are the same after the copy. In
case they are not, an error code EINVAL will be returned.

Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Acked-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Trivial fix to spelling mistake in beiscsi_log message.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Trivial fix to spelling mistake in lpfc_printf_log message text.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Currently a spin_unlock_irqrestore() call is missing on the error path,
so add it.

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

We just need to free the request here. Additionally, this is currently
wrong for a queue that's using MQ currently, it'll crash.

Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This is currently wrong since it isn't dependent on if we're using mq or
not. At least now it'll be correct when we force mq.

Cc: linux-scsi@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add missing break statement in order to prevent the code from falling
through to case TEST_UNIT_READY.

Addresses-Coverity-ID: 1357338 ("Missing break in switch")
Suggested-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

COMPARE AND WRITE command execution starts with a call of
sbc_compare_and_write(). That function locks the caw_sem member in the
backend device data structure and submits a read request to the backend
driver. Upon successful completion of the read compare_and_write_callback()
gets called. That last function compares the data that has been read. If it
matches transport_complete_callback is set to compare_and_write_post and a
write request is submitted. compare_and_write_post() submits a write request
to the backend driver.

XDWRITEREAD command execution starts with sbc_execute_rw() submitting a
read to the backend device. Upon successful completion of the read the
xdreadwrite_callback() gets called. That function xors the data that has
been read with the data in the data-out buffer and stores the result in
the data-in buffer.

Call transport_complete_callback() not only if COMPARE AND WRITE fails but
also if XDWRITEREAD fails. This makes the code more systematic. Make sure
that the callback functions handle (cmd, false, NULL) argument triples fine.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The purpose of sg_alloc_table() is to allocate and initialize an
sg-list. Use that function instead of open-coding it. This patch will
make it easier to share code for caching sg-list allocations between the
SCSI and NVMe target cores.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Instead of duplicating the SECTOR_SHIFT definition from <linux/blkdev.h>,
use it. This patch does not change any functionality.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Commit 057085e5

 ("target: Fix race for SCF_COMPARE_AND_WRITE_POST
checking") removed the code that checks the SCF_COMPARE_AND_WRITE_POST
flag.  Hence also remove the flag itself.

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

A value is assigned to the xcopy_op member of struct xcopy_pt_cmd but
that value is never used. Hence remove the xcopy_op member.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Change one occurrence of "aleady" into "already" and one occurrence of
"is" into "if".

Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

sess_err_stats are currently filled on NOP ping timeout, but not Data-Out
timeout. Stash details of Data-Out timeouts using a
ISCSI_SESS_ERR_CXN_TIMEOUT value for last_sess_failure_type.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Replace existing nested code blocks with helper function calls.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Events resulting in connection outages like this should be logged as
errors. Include the I_T Nexus in the message to aid path identification.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Data-Out timeouts resulting in connection outages should be logged as
errors. Include the I_T Nexus in the message to aid path identification.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Move the ISCSI_IQN_LEN definition up, so that it can be used in more
places instead of a hardcoded value.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Update registers as follows:
- Default value of AIP timer is 1ms, and it is easy for some expanders to
  cause IO error. Change the value to max value 65ms to avoid IO error for
  those expanders.

- A CQ completion will be reported by HW when 4 CQs have occurred or the
  aging timer expires, whichever happens first. Sor serial IO scenario, it
  will still wait 8us for every IO before it is reported. So in the
  situation, the performance is poor. So to improve it, change the limit
  time to the least value.
  For other scenario, it does little affect to the performance.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Currently we use the IPTT defined in LLDD to identify IOs. Actually for
IOs which are from the block layer, they have tags to identify them. So
for those IOs, use tag of the block layer directly, and for IOs which is
not from the block layer (such as internal IOs from libsas/LLDD), reserve
96 IPTTs for them.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The interrupts of ent72 and ent74 are not processed by PCIe AER handling,
so we need to unmask the interrupts and process them first in the driver.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If an SSP/SMP IO times out, it may be actually in reality be
simultaneously processing completion of the slot in
slot_complete_vx_hw().

Then if the slot is freed in slot_complete_vx_hw() (this IPTT is freed
and it may be re-used by other slot), and we may abort the wrong slot in
hisi_sas_abort_task().

So to solve the issue, free the slot after the check of
SAS_TASK_STATE_ABORTED in slot_complete_vx_hw().

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If SMP/internal IO times out, we will possibly free the task immediately.

However if the IO actually completes at the same time, the IO completion
may refer to task which has been freed.

So to solve the issue, flush the tasklet to finish IO completion before
free'ing slot/task.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

In evaluating hisi_hba, the sas_port may be NULL, so for safety relocate
the the check to value possible NULL deference.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

At directly attached situation, if the user modifies the sysfs interface
of maximum_linkrate and minimum_linkrate to renegotiate the linkrate
between SAS controller and target, the value of both files mentioned
above should have change to user setting after renegotiate is over, but
it remains unchanged.

To fix this bug, maximum_linkrate and minimum_linkrate will be directly
fed back to relevant sas_phy structure.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

With the addition of commit 00d909a1 ("scsi: target: Make the session
shutdown code also wait for commands that are being aborted") in v4.19-rc, it
incorrectly assumes no signals will be pending for task_struct executing the
normal session shutdown and I/O quiesce code-path.

For example, iscsi-target and iser-target issue SIGINT to all kthreads as part
of session shutdown.  This has been the behaviour since day one.

As-is when signals are pending with se_cmds active in se_sess->sess_cmd_list,
wait_event_interruptible_lock_irq_timeout() returns a negative number and
immediately kills the machine because of the do while (ret <= 0) loop that was
added in commit 00d909a1 to spin while backend I/O is taking any amount of
extended time (say 30 seconds) to complete.

Here's what it looks like in action with debug plus delayed backend I/O
completion:

[ 4951.909951] se_sess: 000000003e7e08fa before target_wait_for_sess_cmds
[ 4951.914600] target_wait_for_sess_cmds: signal_pending: 1
[ 4951.918015] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 0
[ 4951.921639] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 1
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 2
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 3
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 4
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 5
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 6
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 7
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 8
[ 4951.921944] wait_event_interruptible_lock_irq_timeout ret: -512 signal_pending: 1 loop count: 9

... followed by the usual RCU CPU stalls and deadlock.

There was never a case pre commit 00d909a1 where
wait_for_complete(&se_cmd->cmd_wait_comp) was able to be interrupted, so to
address this for v4.19+ moving forward go ahead and use
wait_event_lock_irq_timeout() instead so new code works with all fabric
drivers.

Also for commit 00d909a1, fix a minor regression in
target_release_cmd_kref() to only wake_up the new se_sess->cmd_list_wq only
when shutdown has actually been triggered via se_sess->sess_tearing_down.

Fixes: 00d909a1

 ("scsi: target: Make the session shutdown code also wait for commands that are being aborted")
Cc: <stable@vger.kernel.org> # v4.19+
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Bryant G. Ly <bly@catalogicsoftware.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Short of reverting commit 00d909a1 ("scsi: target: Make the session
shutdown code also wait for commands that are being aborted") for v4.19,
target-core needs a wait_event_t macro can be executed using
TASK_UNINTERRUPTIBLE to function correctly with existing fabric drivers that
expect to run with signals pending during session shutdown and active se_cmd
I/O quiesce.

The most notable is iscsi-target/iser-target, while ibmvscsi_tgt invokes
session shutdown logic from userspace via configfs attribute that could also
potentially have signals pending.

So go ahead and introduce wait_event_lock_irq_timeout() to achieve this, and
update + rename __wait_event_lock_irq_timeout() to make it accept 'state' as a
parameter.

Fixes: 00d909a1

 ("scsi: target: Make the session shutdown code also wait for commands that are being aborted")
Cc: <stable@vger.kernel.org> # v4.19+
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Bryant G. Ly <bly@catalogicsoftware.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

When we fail to analyse the payload of a PRLI response we should reset
the state machine to retry the PRLI; eventually we will be getting a
proper frame.  Not doing so will result in a stuck state machine and the
port never to be presented to the systsm.

Suggested-by: Chad Dupuis <chad.dupuis@cavium.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Arun Easi <arun.easi@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

We should not assume the payload of a PRLI or PLOGI respons is always
present.

Signed-off-by: Thomas Abraham <tabraham@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Arun Easi <arun.easi@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>