The BLK_EH_NOT_HANDLED implies nothing happen, but very often that
is not what is happening - instead the driver already completed the
command.  Fix the symbolic name to reflect that a little better.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Fix kernel-doc warnings in drivers/scsi/ that are related to iscsi
support interfaces.

Fixes these kernel-doc warnings: (tested by adding these files to a new
target.rst documentation file: WIP)

../drivers/scsi/libiscsi.c:2740: warning: No description found for parameter 'dd_size'
../drivers/scsi/libiscsi.c:2740: warning: No description found for parameter 'id'
../drivers/scsi/libiscsi.c:2961: warning: No description found for parameter 'cls_conn'
../drivers/scsi/iscsi_tcp.c:313: warning: No description found for parameter 'conn'
../drivers/scsi/iscsi_tcp.c:363: warning: No description found for parameter 'conn'
../drivers/scsi/libiscsi_tcp.c:810: warning: No description found for parameter 'tcp_conn'
../drivers/scsi/libiscsi_tcp.c:810: warning: No description found for parameter 'segment'
../drivers/scsi/libiscsi_tcp.c:887: warning: No description found for parameter 'offloaded'
../drivers/scsi/libiscsi_tcp.c:887: warning: No description found for parameter 'status'
../drivers/scsi/libiscsi_tcp.c:887: warning: Excess function parameter 'offload' description in 'iscsi_tcp_recv_skb'
../drivers/scsi/libiscsi_tcp.c:964: warning: Excess function parameter 'conn' description in 'iscsi_tcp_task_init'
../drivers/scsi/libiscsi_tcp.c:964: warning: Excess function parameter 'sc' description in 'iscsi_tcp_task_init'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: linux-scsi@vger.kernel.org
Cc: target-devel@vger.kernel.org
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: linux-rdma@vger.kernel.org
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If, for any reason, userland shuts down iscsi transport interfaces
before proper logouts - like when logging in to LUNs manually, without
logging out on server shutdown, or when automated scripts can't
umount/logout from logged LUNs - kernel will hang forever on its
sd_sync_cache() logic, after issuing the SYNCHRONIZE_CACHE cmd to all
still existent paths.

PID: 1 TASK: ffff8801a69b8000 CPU: 1 COMMAND: "systemd-shutdow"
 #0 [ffff8801a69c3a30] __schedule at ffffffff8183e9ee
 #1 [ffff8801a69c3a80] schedule at ffffffff8183f0d5
 #2 [ffff8801a69c3a98] schedule_timeout at ffffffff81842199
 #3 [ffff8801a69c3b40] io_schedule_timeout at ffffffff8183e604
 #4 [ffff8801a69c3b70] wait_for_completion_io_timeout at ffffffff8183fc6c
 #5 [ffff8801a69c3bd0] blk_execute_rq at ffffffff813cfe10
 #6 [ffff8801a69c3c88] scsi_execute at ffffffff815c3fc7
 #7 [ffff8801a69c3cc8] scsi_execute_req_flags at ffffffff815c60fe
 #8 [ffff8801a69c3d30] sd_sync_cache at ffffffff815d37d7
 #9 [ffff8801a69c3da8] sd_shutdown at ffffffff815d3c3c

This happens because iscsi_eh_cmd_timed_out(), the transport layer
timeout helper, would tell the queue timeout function (scsi_times_out)
to reset the request timer over and over, until the session state is
back to logged in state. Unfortunately, during server shutdown, this
might never happen again.

Other option would be "not to handle" the issue in the transport
layer. That would trigger the error handler logic, which would also need
the session state to be logged in again.

Best option, for such case, is to tell upper layers that the command was
handled during the transport layer error handler helper, marking it as
DID_NO_CONNECT, which will allow completion and inform about the
problem.

After the session was marked as ISCSI_STATE_FAILED, due to the first
timeout during the server shutdown phase, all subsequent cmds will fail
to be queued, allowing upper logic to fail faster.
Signed-off-by: NRafael David Tinoco <rafael.tinoco@canonical.com>
Reviewed-by: NLee Duncan <lduncan@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Lee Duncan <lduncan@suse.com>
Cc: Chris Leech <cleech@redhat.com>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: open-iscsi@googlegroups.com
Cc: linux-scsi@vger.kernel.org
Signed-off-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NChris Leech <cleech@redhat.com>

The SCSI host byte should be shifted left by 16 in order to have
scsi_decide_disposition() do the right thing (.i.e. requeue the
command).
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Fixes: 661134ad ("[SCSI] libiscsi, bnx2i: make bound ep check common")
Cc: Lee Duncan <lduncan@suse.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Bart Van Assche <Bart.VanAssche@sandisk.com>
Cc: Chris Leech <cleech@redhat.com>
Acked-by: NLee Duncan <lduncan@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Session attributes exposed through sysfs were freed before the device
was destroyed, resulting in a potential use-after-free. Free these
attributes after removing the device.
Signed-off-by: NKhazhismel Kumykov <khazhy@google.com>
Acked-by: NChris Leech <cleech@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch avoids that smatch reports the following:

drivers/scsi/libiscsi.c:1081: iscsi_handle_reject() warn: inconsistent indenting
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

iscsiadm session login can fail with the following error:

iscsiadm: Could not login to [iface: default, target: iqn.1986-03.com...
iscsiadm: initiator reported error (9 - internal error)

When /etc/iscsi/iscsid.conf sets node.session.cmds_max = 4096, it
results in 64K-sized kmallocs per session.  A system under fragmented
slab pressure may not have any 64K objects available and fail iscsiadm
session login. Even though memory objects of a smaller size are
available, the large order allocation ends up failing.

The kernel prints a warning and does dump_stack, like below:

iscsid: page allocation failure: order:4, mode:0xc0d0
CPU: 0 PID: 2456 Comm: iscsid Not tainted 4.1.12-61.1.28.el6uek.x86_64 #2
Call Trace:
 [<ffffffff816c6e40>] dump_stack+0x63/0x83
 [<ffffffff8118e58a>] warn_alloc_failed+0xea/0x140
 [<ffffffff81191df9>] __alloc_pages_slowpath+0x409/0x760
 [<ffffffff81192401>] __alloc_pages_nodemask+0x2b1/0x2d0
 [<ffffffffa048f6c0>] ? dev_attr_host_ipaddress+0x20/0xffffffffffffc722
 [<ffffffff811dc38f>] alloc_pages_current+0xaf/0x170
 [<ffffffff81192581>] alloc_kmem_pages+0x31/0xd0
 [<ffffffffa048f600>] ? iscsi_transport_group+0x20/0xffffffffffffc7e2
 [<ffffffff811ad738>] kmalloc_order+0x18/0x50
 [<ffffffff811ad7a4>] kmalloc_order_trace+0x34/0xe0
 [<ffffffff8146ee30>] ? transport_remove_classdev+0x70/0x70
 [<ffffffff811e843d>] __kmalloc+0x27d/0x2a0
 [<ffffffff810c8cbd>] ? complete_all+0x4d/0x60
 [<ffffffffa04af299>] iscsi_pool_init+0x69/0x160 [libiscsi]
 [<ffffffff81465d90>] ? device_initialize+0xb0/0xd0
 [<ffffffffa04af510>] iscsi_session_setup+0x180/0x2f4 [libiscsi]
 [<ffffffffa04c5a60>] ? iscsi_max_lun+0x20/0xfffffffffffffa9e [iscsi_tcp]
 [<ffffffffa04c531f>] iscsi_sw_tcp_session_create+0xcf/0x150 [iscsi_tcp]
 [<ffffffffa04c5a60>] ? iscsi_max_lun+0x20/0xfffffffffffffa9e [iscsi_tcp]
 [<ffffffffa048a633>] iscsi_if_create_session+0x33/0xd0
 [<ffffffffa04c5a60>] ? iscsi_max_lun+0x20/0xfffffffffffffa9e [iscsi_tcp]
 [<ffffffffa048abd8>] iscsi_if_recv_msg+0x508/0x8c0 [scsi_transport_iscsi]
 [<ffffffff811922eb>] ? __alloc_pages_nodemask+0x19b/0x2d0
 [<ffffffff811e6d69>] ? __kmalloc_node_track_caller+0x209/0x2c0
 [<ffffffffa048b00c>] iscsi_if_rx+0x7c/0x200 [scsi_transport_iscsi]
 [<ffffffff81623dc6>] netlink_unicast+0x126/0x1c0
 [<ffffffff8162468c>] netlink_sendmsg+0x36c/0x400
 [<ffffffff815d2fed>] sock_sendmsg+0x4d/0x60
 [<ffffffff815d596a>] ___sys_sendmsg+0x30a/0x330
 [<ffffffff811bc72c>] ? handle_pte_fault+0x20c/0x230
 [<ffffffff811bc90c>] ? __handle_mm_fault+0x1bc/0x330
 [<ffffffff811bcb32>] ? handle_mm_fault+0xb2/0x1a0
 [<ffffffff815d5b99>] __sys_sendmsg+0x49/0x90
 [<ffffffff815d5bf9>] SyS_sendmsg+0x19/0x20
 [<ffffffff816cbb2e>] system_call_fastpath+0x12/0x71

Use kvzalloc for iscsi_pool in iscsi_pool_init.
Signed-off-by: NKyle Fortin <kyle.fortin@oracle.com>
Tested-by: NKyle Fortin <kyle.fortin@oracle.com>
Reviewed-by: NJoseph Slember <joe.slember@oracle.com>
Reviewed-by: NLance Hartmann <lance.hartmann@oracle.com>
Acked-by: NLee Duncan <lduncan@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

refcount_t type and corresponding API should be used instead of atomic_t
when the variable is used as a reference counter. This allows to avoid
accidental refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Acked-by: NChris Leech <cleech@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

There's a rather long standing regression from the commit "libiscsi:
Reduce locking contention in fast path"

Depending on iSCSI target behavior, it's possible to hit the case in
iscsi_complete_task where the task is still on a pending list
(!list_empty(&task->running)).  When that happens the task is removed
from the list while holding the session back_lock, but other task list
modification occur under the frwd_lock.  That leads to linked list
corruption and eventually a panicked system.

Rather than back out the session lock split entirely, in order to try
and keep some of the performance gains this patch adds another lock to
maintain the task lists integrity.

Major enterprise supported kernels have been backing out the lock split
for while now, thanks to the efforts at IBM where a lab setup has the
most reliable reproducer I've seen on this issue.  This patch has been
tested there successfully.
Signed-off-by: NChris Leech <cleech@redhat.com>
Fixes: 659743b0 ("[SCSI] libiscsi: Reduce locking contention in fast path")
Reported-by: NPrashantha Subbarao <psubbara@us.ibm.com>
Reviewed-by: NGuilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Instead define the timeout behavior purely based on the host_template
eh_timed_out method and wire up the existing transport implementations
in the host templates.  This also clears up the confusion that the
transport template method overrides the host template one, so some
drivers have to re-override the transport template one.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The code at free_task label in __iscsi_conn_send_pdu can get executed
from blk_timeout_work which takes queue_lock using spin_lock_irq.
back_lock taken with spin_unlock_bh will cause WARN_ON_ONCE.  The code
gets executed either with bottom half or IRQ disabled hence using
spin_lock/spin_unlock for back_lock is safe.
Signed-off-by: NJitendra Bhivare <jitendra.bhivare@broadcom.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NChris Leech <cleech@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Avoid that building with W=1 causes gcc to report warnings about
set-but-not-used variables.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Running "git grep -nHw iscsi_eh_target_reset" shows that this function
is only called from inside the drivers/scsi/libiscsi.c source
file. Hence unexport this function.
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Connection last_ping is not being updated when iscsi_send_nopout fails.
Not updating the last_ping will cause firing a timer to a past time
(last_ping + ping_tmo < current_time) which triggers an infinite loop of
iscsi_check_transport_timeouts() and hogs the cpu.

Fix this issue by checking the return value of iscsi_send_nopout.
If it fails set the next_timeout to one second later.
Signed-off-by: NAriel Nahum <arieln@mellanox.com>
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

In case of hw iscsi offload, an host can have N-number of active
connections. There can be IO's running on some connections which
make host->host_busy always TRUE. Now if logout from a connection
is tried then the code gets into an infinite loop as host->host_busy
is always TRUE.

 iscsi_conn_teardown(....)
 {
   .........
    /*
     * Block until all in-progress commands for this connection
     * time out or fail.
     */
     for (;;) {
      spin_lock_irqsave(session->host->host_lock, flags);
      if (!atomic_read(&session->host->host_busy)) { /* OK for ERL == 0 */
	      spin_unlock_irqrestore(session->host->host_lock, flags);
              break;
      }
     spin_unlock_irqrestore(session->host->host_lock, flags);
     msleep_interruptible(500);
     iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
                 "host_busy %d host_failed %d\n",
	          atomic_read(&session->host->host_busy),
	          session->host->host_failed);

	................
	...............
     }
  }

This is not an issue with software-iscsi/iser as each cxn is a separate
host.

Fix:
Acquiring eh_mutex in iscsi_conn_teardown() before setting
session->state = ISCSI_STATE_TERMINATE.
Signed-off-by: NJohn Soni Jose <sony.john@avagotech.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NChris Leech <cleech@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

In case encountered a PI error, use scsi_set_sense_information
instead of open coding information descriptor format.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>

All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NVenkatesh Srinivas <venkateshs@google.com>

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>

This just has iscsi_tcp support ISCSI_PARAM_LOCAL_PORT which
exports the local port being used by the iscsi connection.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This patches fixes a potential buffer overrun in __iscsi_conn_send_pdu.
This function is used by iscsi drivers and userspace to send iscsi PDUs/
commands. For login commands, we have a set buffer size. For all other
commands we do not support data buffers.

This was reported by Dan Carpenter here:
http://www.spinics.net/lists/linux-scsi/msg66838.htmlReported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This patches fixes a potential buffer overrun in __iscsi_conn_send_pdu.
This function is used by iscsi drivers and userspace to send iscsi PDUs/
commands. For login commands, we have a set buffer size. For all other
commands we do not support data buffers.

This was reported by Dan Carpenter here:
http://www.spinics.net/lists/linux-scsi/msg66838.htmlReported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

When a iscsi nop as ping timedout we were failing with the
common connection error code, ISCSI_ERR_CONN_FAILED. This
patch adds a new error code for this problem so can properly
track/distinguish in userspace.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Acked-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Avoid taking the host-wide host_lock to check the per-host queue limit.
Instead we do an atomic_inc_return early on to grab our slot in the queue,
and if necessary decrement it after finishing all checks.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NWebb Scales <webbnh@hp.com>
Acked-by: NJens Axboe <axboe@kernel.dk>
Tested-by: NBart Van Assche <bvanassche@acm.org>
Tested-by: NRobert Elliott <elliott@hp.com>

The SCSI standard defines 64-bit values for LUNs, and large arrays
employing large or hierarchical LUN numbers become more and more
common.

So update the linux SCSI stack to use 64-bit LUN numbers.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChristoph Hellwig <hch@infradead.org>
Reviewed-by: NEwan Milne <emilne@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

In case protection information exists over the wire
iscsi header data length is required to include it.
Use protection information aware scsi helpers to set
the correct transfer length.

In order to avoid breakage, remove iser transfer length
checks for each task as they are not always true and
somewhat redundant anyway.
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Acked-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: stable@vger.kernel.org # 3.15+
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Commit 659743b0 "[SCSI] libiscsi: Reduce locking contention in fast path" introduced a
new smatch warning on libiscsi.c "iscsi_xmit_task() warn: inconsistent returns
bottom_half:: locked (1410 [(-61)]) unlocked (1425 [0], 1425 [s32min-(-1),1-s32max])",
which we can eliminate by using non bh locking on the nested spin_lock call.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NShlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

iSCSI needs to be at least aware that a task involves protection
information.  In case it does, after the transaction completed libiscsi
will ask the transport to check the protection status of the
transaction.

Unlike transport errors, DIF errors should not prevent successful
completion of the transaction from the transport point of view, but
should be escelated to scsi mid-layer when constructing the scsi
result and sense data.

check_protection routine will return the ascq corresponding to the DIF
error that occured (or 0 if no error happened).

return ascq:
- 0x1: GUARD_CHECK_FAILED
- 0x2: APPTAG_CHECK_FAILED
- 0x3: REFTAG_CHECK_FAILED
Signed-off-by: NSagi Grimberg <sagig@mellanox.com>
Signed-off-by: NAlex Tabachnik <alext@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

iscsi_queuecommand will only take in commands that can fit in the
current window. So, if a command is on the cmdqueue then it can
fit in the current window. If a command is on the mgmtqueue, then
we are setting the immediate bit so they will also fit in the
window. As a result, we never need to to do a iscsi_conn_queue_work
when the maxCmdSn is increased.

What should happen is that a command will complete the window will
be increased, then the scsi layer will send us more commands by
running the scsi_device queues.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Replace the session lock with two locks, a forward lock and
a backwards lock named frwd_lock and back_lock respectively.

The forward lock protects resources that change while sending a
request to the target, such as cmdsn, queued_cmdsn, and allocating
task from the commands' pool with kfifo_out.

The backward lock protects resources that change while processing
a response or in error path, such as cmdsn_exp, cmdsn_max, and
returning tasks to the commands' pool with kfifo_in.

Under a steady state fast-path situation, that is when one
or more processes/threads submit IO to an iscsi device and
a single kernel upcall (e.g softirq) is dealing with processing
of responses without errors, this patch eliminates the contention
between the queuecommand()/request response/scsi_done() flows
associated with iscsi sessions.

Between the forward and the backward locks exists a strict locking
hierarchy. The mutual exclusion zone protected by the forward lock can
enclose the mutual exclusion zone protected by the backward lock but not
vice versa.

For example, in iscsi_conn_teardown or in iscsi_xmit_data when there is
a failure and __iscsi_put_task is called, the backward lock is taken while
the forward lock is still taken. On the other hand, if in the RX path a nop
is to be sent, for example in iscsi_handle_reject or __iscsi_complete_pdu
than the forward lock is released and the backward lock is taken for the
duration of iscsi_send_nopout, later the backward lock is released and the
forward lock is retaken.

libiscsi_tcp uses two kernel fifos the r2t pool and the r2t queue.

The insertion and deletion from these queues didn't corespond to the
assumption taken by the new forward/backwards session locking paradigm.

That is, in iscsi_tcp_clenup_task which belongs to the RX (backwards)
path, r2t is taken out from r2t queue and inserted to the r2t pool.
In iscsi_tcp_get_curr_r2t which belong to the TX (forward) path, r2t
is also inserted to the r2t pool and another r2t is pulled from r2t
queue.

Only in iscsi_tcp_r2t_rsp which is called in the RX path but can requeue
to the TX path, r2t is taken from the r2t pool and inserted to the r2t
queue.

In order to cope with this situation, two spin locks were added,
pool2queue and queue2pool. The former protects extracting from the
r2t pool and inserting to the r2t queue, and the later protects the
extracing from the r2t queue and inserting to the r2t pool.
Signed-off-by: NShlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
[minor fix up to apply cleanly and compile fix]
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This patch makes reject messages show right value for opcode and itt, which
is converse previously.
Signed-off-by: NVaughan Cao <vaughan.cao@oracle.com>
Acked-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Add local_ipaddr param and support get/set operations on it.
Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

To run discovery over iSER we need to advertize the CAP_TEXT_NEGO capability
towards user space. Also need to make sure the login RX buffer is posted when
SendTargets TEXT PDUs are sent. For that end, we use a setting of the
ISCSI_PARAM_DISCOVERY_SESS iscsi param as an indication that this is
discovery session.
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Signed-off-by: NAdheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This is the kernel part of the modification to extract the net params
from the ibft sysfs to the iface struct used for the connection
request upon sync_session in the open-iscsi util.

Three new session sysfs params are defined:
boot_root - holds the name of the /sys/firmware/ibft or iscsi_rootN
boot_nic  - holds the ethernetN name
boot_target - holds the targetN name
Signed-off-by: NEddie Wai <eddie.wai@broadcom.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

In iscsi_free_task, NULL is assigned to task->sc twice: before and
after kfifo_in invocatoin. Allocating and freeing iscsi_task are guarded
with session->lock, so multiple NULL assignments cause no trouble. But
people reading the source code may be confused.

The second NULL assignment comes from commit:

    3e5c28ad

It seems that the line after kfifo_in invocation was introduced
accidentally.
Signed-off-by: NMasatake YAMATO <yamato@redhat.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>