scsi: target: iscsi: Fix hang in the iSCSI login code

If the initiator suddenly stops sending data during a login while keeping
the TCP connection open, the login_work won't be scheduled and will never
release the login semaphore; concurrent login operations will therefore get
stuck and fail.

The bug is due to the inability of the login timeout code to properly
handle this particular case.

Fix the problem by replacing the old per-NP login timer with a new
per-connection timer.

The timer is started when an initiator connects to the target; if it
expires, it sends a SIGINT signal to the thread pointed at by the
conn->login_kworker pointer.

conn->login_kworker is set by calling the iscsit_set_login_timer_kworker()
helper, initially it will point to the np thread; When the login
operation's control is in the process of being passed from the NP-thread to
login_work, the conn->login_worker pointer is set to NULL. Finally,
login_kworker will be changed to point to the worker thread executing the
login_work job.

If conn->login_kworker is NULL when the timer expires, it means that the
login operation hasn't been completed yet but login_work isn't running, in
this case the timer will mark the login process as failed and will schedule
login_work so the latter will be forced to free the resources it holds.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Link: https://lore.kernel.org/r/20230508162219.1731964-2-mlombard@redhat.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsit: isert: Alloc per conn cmd counter

This has iscsit allocate a per conn cmd counter and converts iscsit/isert
to use it instead of the per session one.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230319015620.96006-5-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Move cmd counter allocation

iSCSI needs to allocate its cmd counter per connection for MCS support
where we need to stop and wait on commands running on a connection instead
of per session. This moves the cmd counter allocation to
target_setup_session() which is used by drivers that need the stop+wait
behavior per session.

xcopy doesn't need stop+wait at all, so we will be OK moving the cmd
counter allocation outside of transport_init_session().

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230319015620.96006-3-michael.christie@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Allow AuthMethod=None

Allow negotiating AuthMethod=None at CSG=0 (Security Negotiation) when
authentication is not required. That is required by the CHAP test in
Windows HLK.

Link: https://lore.kernel.org/r/20220718152555.17084-4-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Fix clang -Wformat warnings

When building with Clang we encounter these warnings:
| drivers/target/iscsi/iscsi_target_login.c:719:24: error: format
| specifies type 'unsigned short' but the argument has type 'int'
| [-Werror,-Wformat] " from node: %s\n", atomic_read(&sess->nconn),
-
| drivers/target/iscsi/iscsi_target_login.c:767:12: error: format
| specifies type 'unsigned short' but the argument has type 'int'
| [-Werror,-Wformat] " %s\n", atomic_read(&sess->nconn),
-
| drivers/target/iscsi/iscsi_target.c:4365:12: error: format specifies
| type 'unsigned short' but the argument has type 'int' [-Werror,-Wformat]
| " %s\n", atomic_read(&sess->nconn)

For all warnings, the format specifier is '%hu' which describes an unsigned
short. The resulting type of atomic_read is an int. The proposed fix is to
listen to Clang and swap the format specifier.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Link: https://lore.kernel.org/r/20220718180421.49697-1-justinstitt@google.com
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Rename iscsi_session to iscsit_session

The structure iscsi_session naming is used by the iSCSI initiator
driver. Rename the target session to iscsit_session to have more readable
code.

Link: https://lore.kernel.org/r/20220428092939.36768-3-mgurtovoy@nvidia.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Rename iscsi_conn to iscsit_conn

The structure iscsi_conn naming is used by the iSCSI initiator
driver. Rename the target conn to iscsit_conn to have more readable code.

Link: https://lore.kernel.org/r/20220428092939.36768-2-mgurtovoy@nvidia.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Add iscsi/cpus_allowed_list in configfs

The RX/TX threads for iSCSI connection can be scheduled to any online CPUs,
and will not be rescheduled.

When binding other heavy load threads along with iSCSI connection RX/TX
thread to the same CPU, the iSCSI performance will be worse.

Add iscsi/cpus_allowed_list in configfs. The available CPU set of iSCSI
connection RX/TX threads is allowed_cpus & online_cpus. If it is modified,
all RX/TX threads will be rescheduled.

Link: https://lore.kernel.org/r/20220301075500.14266-1-mingzhe.zou@easystack.cn
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Fix typo in comment

Correct the spelling of Nagle's name in a comment.

Link: https://lore.kernel.org/r/2921.1610694423@turing-police
Reviewed-by: Chaitanya Kulkarni <chiatanya.kulkarni@wdc.com>
Signed-off-by: Valdis Klētnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Fix hang in iscsit_access_np() when getting tpg->np_login_sem

The iSCSI target login thread might get stuck with the following stack:

cat /proc/`pidof iscsi_np`/stack
[<0>] down_interruptible+0x42/0x50
[<0>] iscsit_access_np+0xe3/0x167
[<0>] iscsi_target_locate_portal+0x695/0x8ac
[<0>] __iscsi_target_login_thread+0x855/0xb82
[<0>] iscsi_target_login_thread+0x2f/0x5a
[<0>] kthread+0xfa/0x130
[<0>] ret_from_fork+0x1f/0x30

This can be reproduced via the following steps:

1. Initiator A tries to log in to iqn1-tpg1 on port 3260. After finishing
PDU exchange in the login thread and before the negotiation is finished
the the network link goes down. At this point A has not finished login
and tpg->np_login_sem is held.

2. Initiator B tries to log in to iqn2-tpg1 on port 3260. After finishing
PDU exchange in the login thread the target expects to process remaining
login PDUs in workqueue context.

3. Initiator A' tries to log in to iqn1-tpg1 on port 3260 from a new
socket. A' will wait for tpg->np_login_sem with np->np_login_timer
loaded to wait for at most 15 seconds. The lock is held by A so A'
eventually times out.

4. Before A' got timeout initiator B gets negotiation failed and calls
iscsi_target_login_drop()->iscsi_target_login_sess_out(). The
np->np_login_timer is canceled and initiator A' will hang forever.
Because A' is now in the login thread, no new login requests can be
serviced.

Fix this by moving iscsi_stop_login_thread_timer() out of
iscsi_target_login_sess_out(). Also remove iscsi_np parameter from
iscsi_target_login_sess_out().

Link: https://lore.kernel.org/r/20200729130343.24976-1-houpu@bytedance.com
Cc: stable@vger.kernel.org
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Hou Pu <houpu@bytedance.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

ipv4: add ip_sock_set_freebind

Add a helper to directly set the IP_FREEBIND sockopt from kernel space
without going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

tcp: add tcp_sock_set_nodelay

Add a helper to directly set the TCP_NODELAY sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add sock_set_reuseaddr

Add a helper to directly set the SO_REUSEADDR sockopt from kernel space
without going through a fake uaccess.

For this the iscsi target now has to formally depend on inet to avoid
a mostly theoretical compile failure. For actual operation it already
did depend on having ipv4 or ipv6 support.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

scsi: target: fix hang when multiple threads try to destroy the same iscsi session

A number of hangs have been reported against the target driver; they are
due to the fact that multiple threads may try to destroy the iscsi session
at the same time. This may be reproduced for example when a "targetcli
iscsi/iqn.../tpg1 disable" command is executed while a logout operation is
underway.

When this happens, two or more threads may end up sleeping and waiting for
iscsit_close_connection() to execute "complete(session_wait_comp)". Only
one of the threads will wake up and proceed to destroy the session
structure, the remaining threads will hang forever.

Note that if the blocked threads are somehow forced to wake up with
complete_all(), they will try to free the same iscsi session structure
destroyed by the first thread, causing double frees, memory corruptions
etc...

With this patch, the threads that want to destroy the iscsi session will
increase the session refcount and will set the "session_close" flag to 1;
then they wait for the driver to close the remaining active connections.
When the last connection is closed, iscsit_close_connection() will wake up
all the threads and will wait for the session's refcount to reach zero;
when this happens, iscsit_close_connection() will destroy the session
structure because no one is referencing it anymore.

INFO: task targetcli:5971 blocked for more than 120 seconds.
Tainted: P OE 4.15.0-72-generic #81~16.04.1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
targetcli D 0 5971 1 0x00000080
Call Trace:
__schedule+0x3d6/0x8b0
? vprintk_func+0x44/0xe0
schedule+0x36/0x80
schedule_timeout+0x1db/0x370
? __dynamic_pr_debug+0x8a/0xb0
wait_for_completion+0xb4/0x140
? wake_up_q+0x70/0x70
iscsit_free_session+0x13d/0x1a0 [iscsi_target_mod]
iscsit_release_sessions_for_tpg+0x16b/0x1e0 [iscsi_target_mod]
iscsit_tpg_disable_portal_group+0xca/0x1c0 [iscsi_target_mod]
lio_target_tpg_enable_store+0x66/0xe0 [iscsi_target_mod]
configfs_write_file+0xb9/0x120
__vfs_write+0x1b/0x40
vfs_write+0xb8/0x1b0
SyS_write+0x5c/0xe0
do_syscall_64+0x73/0x130
entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Link: https://lore.kernel.org/r/20200313170656.9716-3-mlombard@redhat.com
Reported-by: Matt Coleman <mcoleman@datto.com>
Tested-by: Matt Coleman <mcoleman@datto.com>
Tested-by: Rahul Kundu <rahul.kundu@chelsio.com>
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157

Based on 3 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: target: iscsi: Free conn_ops when zalloc_cpumask_var failed

It should not free cpumask but free conn->conn_ops when zalloc_cpumask_var
failed.

Signed-off-by: tangwenji <tang.wenji@zte.com.cn>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: iscsi: Fix np_ip_proto and np_sock_type in iscsit_setup_np

In the switch, np_ip_proto and np_sock_type set different values according
to np_network_transport, and then uniformly assign values, so the previous
values are overwritten.

Signed-off-by: tangwenji <tang.wenji@zte.com.cn>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: iscsi: target: fix spelling mistake "entires" -> "entries"

Trivial fix to spelling mistake in function name and comment

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

scsi: iscsi: target: Fix conn_ops double free

If iscsi_login_init_conn fails it can free conn_ops.
__iscsi_target_login_thread will then call iscsi_target_login_sess_out
which will also free it.

This fixes the problem by organizing conn allocation/setup into parts that
are needed through the life of the conn and parts that are only needed for
the login. The free functions then release what was allocated in the alloc
functions.

With this patch we have:

iscsit_alloc_conn/iscsit_free_conn - allocs/frees the conn we need for the
entire life of the conn.

iscsi_login_init_conn/iscsi_target_nego_release - allocs/frees the parts
of the conn that are only needed during login.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: iscsi: target: Set conn->sess to NULL when iscsi_login_set_conn_values fails

Fixes a use-after-free reported by KASAN when later
iscsi_target_login_sess_out gets called and it tries to access
conn->sess->se_sess:

Disabling lock debugging due to kernel taint
iSCSI Login timeout on Network Portal [::]:3260
iSCSI Login negotiation failed.
==================================================================
BUG: KASAN: use-after-free in
iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod]
Read of size 8 at addr ffff880109d070c8 by task iscsi_np/980

CPU: 1 PID: 980 Comm: iscsi_np Tainted: G O
4.17.8kasan.sess.connops+ #4
Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB,
BIOS 5.6.5 05/19/2014
Call Trace:
dump_stack+0x71/0xac
print_address_description+0x65/0x22e
? iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod]
kasan_report.cold.6+0x241/0x2fd
iscsi_target_login_sess_out.cold.12+0x58/0xff [iscsi_target_mod]
iscsi_target_login_thread+0x1086/0x1710 [iscsi_target_mod]
? __sched_text_start+0x8/0x8
? iscsi_target_login_sess_out+0x250/0x250 [iscsi_target_mod]
? __kthread_parkme+0xcc/0x100
? parse_args.cold.14+0xd3/0xd3
? iscsi_target_login_sess_out+0x250/0x250 [iscsi_target_mod]
kthread+0x1a0/0x1c0
? kthread_bind+0x30/0x30
ret_from_fork+0x35/0x40

Allocated by task 980:
kasan_kmalloc+0xbf/0xe0
kmem_cache_alloc_trace+0x112/0x210
iscsi_target_login_thread+0x816/0x1710 [iscsi_target_mod]
kthread+0x1a0/0x1c0
ret_from_fork+0x35/0x40

Freed by task 980:
__kasan_slab_free+0x125/0x170
kfree+0x90/0x1d0
iscsi_target_login_thread+0x1577/0x1710 [iscsi_target_mod]
kthread+0x1a0/0x1c0
ret_from_fork+0x35/0x40

The buggy address belongs to the object at ffff880109d06f00
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 456 bytes inside of
512-byte region [ffff880109d06f00, ffff880109d07100)
The buggy address belongs to the page:
page:ffffea0004274180 count:1 mapcount:0 mapping:0000000000000000
index:0x0 compound_mapcount: 0
flags: 0x17fffc000008100(slab|head)
raw: 017fffc000008100 0000000000000000 0000000000000000 00000001000c000c
raw: dead000000000100 dead000000000200 ffff88011b002e00 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff880109d06f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff880109d07000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff880109d07080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff880109d07100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff880109d07180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
[rebased against idr/ida changes and to handle ret review comments from Matthew]
Signed-off-by: Mike Christie <mchristi@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

target/iscsi: Allocate session IDs from an IDA

Since the session is never looked up by ID, we can use the more
space-efficient IDA instead of the IDR.

Signed-off-by: Matthew Wilcox <willy@infradead.org>

iscsi target: fix session creation failure handling

The problem is that iscsi_login_zero_tsih_s1 sets conn->sess early in
iscsi_login_set_conn_values. If the function fails later like when we
alloc the idr it does kfree(sess) and leaves the conn->sess pointer set.
iscsi_login_zero_tsih_s1 then returns -Exyz and we then call
iscsi_target_login_sess_out and access the freed memory.

This patch has iscsi_login_zero_tsih_s1 either completely setup the
session or completely tear it down, so later in
iscsi_target_login_sess_out we can just check for it being set to the
connection.

Cc: stable@vger.kernel.org
Fixes: 0957627a9960 ("iscsi-target: Fix sess allocation leak in...")
Signed-off-by: Mike Christie <mchristi@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>

scsi: target: Rename transport_init_session() into transport_alloc_session()

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

net: make getname() functions return length rather than use int* parameter

Changes since v1:
Added changes in these files:
drivers/infiniband/hw/usnic/usnic_transport.c
drivers/staging/lustre/lnet/lnet/lib-socket.c
drivers/target/iscsi/iscsi_target_login.c
drivers/vhost/net.c
fs/dlm/lowcomms.c
fs/ocfs2/cluster/tcp.c
security/tomoyo/network.c

Before:
All these functions either return a negative error indicator,
or store length of sockaddr into "int *socklen" parameter
and return zero on success.

"int *socklen" parameter is awkward. For example, if caller does not
care, it still needs to provide on-stack storage for the value
it does not need.

None of the many FOO_getname() functions of various protocols
ever used old value of *socklen. They always just overwrite it.

This change drops this parameter, and makes all these functions, on success,
return length of sockaddr. It's always >= 0 and can be differentiated
from an error.

Tests in callers are changed from "if (err)" to "if (err < 0)", where needed.

rpc_sockname() lost "int buflen" parameter, since its only use was
to be passed to kernel_getsockname() as &buflen and subsequently
not used in any way.

Userspace API is not changed.

text data bss dec hex filename
30108430 2633624 873672 33615726 200ef6e vmlinux.before.o
30108109 2633612 873672 33615393 200ee21 vmlinux.o

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: David S. Miller <davem@davemloft.net>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-bluetooth@vger.kernel.org
CC: linux-decnet-user@lists.sourceforge.net
CC: linux-wireless@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: linux-sctp@vger.kernel.org
CC: linux-nfs@vger.kernel.org
CC: linux-x25@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

target/iscsi: Convert timers to use timer_setup()

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. Includes a fix for correcting an
on-stack timer usage.

Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Jiang Yi <jiangyilism@gmail.com>
Cc: Varun Prakash <varun@chelsio.com>
Cc: linux-scsi@vger.kernel.org
Cc: target-devel@vger.kernel.org
Reviewed-and-Tested-by: Bart Van Assche <Bart.VanAssche@wdc.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

target/iscsi: Simplify timer manipulation code

Move timer initialization from before add_timer() to the context
where the containing object is initialized. Use setup_timer() and
mod_timer() instead of open coding these. Use 'jiffies' instead
of get_jiffies_64() when calculating expiry times because expiry
times have type unsigned long, just like 'jiffies'.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: David Disseldorp <ddiss@suse.de>
Signed-off-by: Kees Cook <keescook@chromium.org>

iscsi-target: Fix iscsi_np reset hung task during parallel delete

This patch fixes a bug associated with iscsit_reset_np_thread()
that can occur during parallel configfs rmdir of a single iscsi_np
used across multiple iscsi-target instances, that would result in
hung task(s) similar to below where configfs rmdir process context
was blocked indefinately waiting for iscsi_np->np_restart_comp
to finish:

[ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds.
[ 6726.119440] Tainted: G W O 4.1.26-3321 #2
[ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88 0 15550 1 0x00000000
[ 6726.140058] ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08
[ 6726.147593] ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0
[ 6726.155132] ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8
[ 6726.162667] Call Trace:
[ 6726.165150] [<ffffffff8168ced2>] schedule+0x32/0x80
[ 6726.170156] [<ffffffff8168f5b4>] schedule_timeout+0x214/0x290
[ 6726.176030] [<ffffffff810caef2>] ? __send_signal+0x52/0x4a0
[ 6726.181728] [<ffffffff8168d7d6>] wait_for_completion+0x96/0x100
[ 6726.187774] [<ffffffff810e7c80>] ? wake_up_state+0x10/0x10
[ 6726.193395] [<ffffffffa035d6e2>] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod]
[ 6726.201278] [<ffffffffa0355d86>] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod]
[ 6726.210033] [<ffffffffa0363f7f>] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod]
[ 6726.218351] [<ffffffff81260c5a>] configfs_write_file+0xaa/0x110
[ 6726.224392] [<ffffffff811ea364>] vfs_write+0xa4/0x1b0
[ 6726.229576] [<ffffffff811eb111>] SyS_write+0x41/0xb0
[ 6726.234659] [<ffffffff8169042e>] system_call_fastpath+0x12/0x71

It would happen because each iscsit_reset_np_thread() sets state
to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting
for completion on iscsi_np->np_restart_comp.

However, if iscsi_np was active processing a login request and
more than a single iscsit_reset_np_thread() caller to the same
iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np
kthread process context in __iscsi_target_login_thread() would
flush pending signals and only perform a single completion of
np->np_restart_comp before going back to sleep within transport
specific iscsit_transport->iscsi_accept_np code.

To address this bug, add a iscsi_np->np_reset_count and update
__iscsi_target_login_thread() to keep completing np->np_restart_comp
until ->np_reset_count has reached zero.

Reported-by: Gary Guo <ghg@datera.io>
Tested-by: Gary Guo <ghg@datera.io>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi: ensure RNG is seeded before use

It's not safe to use weak random data here, especially for the challenge
response randomness. Since we're always in process context, it's safe to
simply wait until we have enough randomness to carry out the
authentication correctly.

While we're at it, we clean up a small memleak during an error
condition.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Lee Duncan <lduncan@suse.com>
Cc: Chris Leech <cleech@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

iscsi-target: Always wait for kthread_should_stop() before kthread exit

There are three timing problems in the kthread usages of iscsi_target_mod:

- np_thread of struct iscsi_np
- rx_thread and tx_thread of struct iscsi_conn

In iscsit_close_connection(), it calls

send_sig(SIGINT, conn->tx_thread, 1);
kthread_stop(conn->tx_thread);

In conn->tx_thread, which is iscsi_target_tx_thread(), when it receive
SIGINT the kthread will exit without checking the return value of
kthread_should_stop().

So if iscsi_target_tx_thread() exit right between send_sig(SIGINT...)
and kthread_stop(...), the kthread_stop() will try to stop an already
stopped kthread.

This is invalid according to the documentation of kthread_stop().

(Fix -ECONNRESET logout handling in iscsi_target_tx_thread and
early iscsi_target_rx_thread failure case - nab)

Signed-off-by: Jiang Yi <jiangyilism@gmail.com>
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Set session_fall_back_to_erl0 when forcing reinstatement

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 <ghg@datera.io>
Tested-by: Gary Guo <ghg@datera.io>
Cc: Gary Guo <ghg@datera.io>
Cc: <stable@vger.kernel.org> # v4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>

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: Linus 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: Ingo Molnar <mingo@kernel.org>

iscsi: fix build errors when linux/phy*.h is removed from net/dsa.h

drivers/target/iscsi/iscsi_target_login.c:1135:7: error: implicit declaration of function 'try_module_get' [-Werror=implicit-function-declaration]

Add linux/module.h to iscsi_target_login.c.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

target/iscsi: Fix spelling of "perform"

Change two occurrences of "preform" into "perform".

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Minimize #include directives

Remove superfluous #include directives from the include/target/*.h
files. Add missing #include directives to other *.h and *.c files.
Use forward declarations for structures where possible. This
change reduces the build time for make M=drivers/target on my
laptop from 27.1s to 18.7s or by about 30%.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bryant G. Ly <bryantly@linux.vnet.ibm.com>

iscsi-target: fix spelling mistake "Unsolicitied" -> "Unsolicited"

Trivial fix to spelling mistakes in pr_debug message and comments

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix panic when adding second TCP connection to iSCSI session

In MC/S scenario, the conn->sess has been set NULL in
iscsi_login_non_zero_tsih_s1 when the second connection comes here,
then kernel panic.

The conn->sess will be assigned in iscsi_login_non_zero_tsih_s2. So
we should check whether it's NULL before calling.

Signed-off-by: Feng Li <lifeng1519@gmail.com>
Tested-by: Sumit Rai <sumit.rai@calsoftinc.com>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: remove usage of ->shutdown_session

->shutdown session only decideѕ if the target core calls ->close_session
directly, or if the fabrics drivers calls it manually later through
target_put_session, which at this point will always close the session as
it has been removed from the lookup list and thus no new references will
be acquired from the core.

So instead remove ->shutdown and have the core call ->close_session
directly, and replace all calls to target_put_session in the iSCSI target
with direct calls to iscsit_close_session.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: export symbols

export symbols for ISCSI_HW_OFFLOAD
transport drivers.

Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: add int (*iscsit_validate_params)()

Add int (*iscsit_validate_params)() to
struct iscsit_transport, iscsi-target
uses this callback for validating
conn operational parameters.

cxgbit.ko needs this callback to check
and update the value of
MAXXMITDATASEGMENTLENGTH.

Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Use shash and ahash

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

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

target/iscsi: Replace __kernel_sockaddr_storage with sockaddr_storage

It appears to be what the rest of the kernel does, so let's do it too.

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: Replace conn->login_ip with login_sockaddr

Very similar to how it went with local_sockaddr.

It was embedded in iscsi_login_stats so some changes there, and we needed
to copy in a sockaddr_storage comparison function. Hopefully the kernel
will get a standard one soon, our implementation makes the 3rd.

isert_set_conn_info() became much smaller.

IPV6_ADDRESS_SPACE define goes away, had to modify a call to in6_pton(),
can just use -1 since we are sure string is null-terminated.

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: Keep local_ip as the actual sockaddr

This is a more natural format that lets us format it with the appropriate
printk specifier as needed.

This also lets us handle v4-mapped ipv6 addresses a little more nicely, by
storing the addr as an actual v4 sockaddr in conn->local_sockaddr.

Finally, we no longer need to maintain variables for port, since this is
contained in sockaddr. Remove iscsi_np.np_port and iscsi_conn.local_port.

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: Fix np_ip bracket issue by removing np_ip

Revert commit 1997e6259, which causes double brackets on ipv6
inaddr_any addresses.

Since we have np_sockaddr, if we need a textual representation we can
use "%pISc".

Change iscsit_add_network_portal() and iscsit_add_np() signatures to remove
*ip_str parameter.

Fix and extend some comments earlier in the function.

Tested to work for :: and ::1 via iscsiadm, previously :: failed, see
https://bugzilla.redhat.com/show_bug.cgi?id=1249107 .

CC: stable@vger.kernel.org
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Drop iSCSI use of mutex around max_cmd_sn increment

In a performance profile, taking a mutex in iscsit_increment_maxcmdsn()
shows up very high. However taking a mutex around "sess->max_cmd_sn += 1"
seems pretty silly: we're not serializing against other contexts in
any useful way.

I did a quick audit and there don't appear to be any other places that
use max_cmd_sn within the mutex more than once, so this lock can't be
providing any useful serialization.

(Get correct values for logging - fix whitespace damage)

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Spencer Baugh <sbaugh@catern.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix iscsit_start_kthreads failure OOPs

This patch fixes a regression introduced with the following commit
in v4.0-rc1 code, where a iscsit_start_kthreads() failure triggers
a NULL pointer dereference OOPs:

commit 88dcd2dab5c23b1c9cfc396246d8f476c872f0ca
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Thu Feb 26 22:19:15 2015 -0800

iscsi-target: Convert iscsi_thread_set usage to kthread.h

To address this bug, move iscsit_start_kthreads() immediately
preceeding the transmit of last login response, before signaling
a successful transition into full-feature-phase within existing
iscsi_target_do_tx_login_io() logic.

This ensures that no target-side resource allocation failures can
occur after the final login response has been successfully sent.

Also, it adds a iscsi_conn->rx_login_comp to allow the RX thread
to sleep to prevent other socket related failures until the final
iscsi_post_login_handler() call is able to complete.

Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: remove support for obsolete markers

Support for markers is currently broken because of a bug in
iscsi_enforce_integrity_rules(): the "IFMarkInt_Reject" and
"OFMarkInt_Reject" variables are always equal to 1 in
iscsi_enforce_integrity_rules().

Moreover, fixed interval markers keys (IFMarker, OFMarker, IFMarkInt
and OFMarkInt) are obsolete according to iSCSI RFC 7143:

>From http://tools.ietf.org/html/rfc7143#section-13.25:

13.25. Obsoleted Keys

This document obsoletes the following keys defined in [RFC3720]:
IFMarker, OFMarker, OFMarkInt, and IFMarkInt. However, iSCSI
implementations compliant to this document may still receive these
obsoleted keys -- i.e., in a responder role -- in a text negotiation.

When an IFMarker or OFMarker key is received, a compliant iSCSI
implementation SHOULD respond with the constant "Reject" value. The
implementation MAY alternatively respond with a "No" value.

However, the implementation MUST NOT respond with a "NotUnderstood"
value for either of these keys.

When an IFMarkInt or OFMarkInt key is received, a compliant iSCSI
implementation MUST respond with the constant "Reject" value. The
implementation MUST NOT respond with a "NotUnderstood" value for
either of these keys.

This patch disables markers by turning the corresponding parameters to
read-only. The default value of IFMarker and OFMarker remains "No" but
the user cannot change it to "Yes" anymore. The new value of IFMarkInt
and OFMarkInt is "Reject".

(Drop left-over iscsi_get_value_from_number_range + make configfs
parameters attrs R/W nops - nab)

Signed-off-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

ISCSI: fix minor memory leak

This patch adds a missing kfree for sess->sess_ops memory upon
transport_init_session() failure.

Signed-off-by: Evgenii Lepikhin <johnlepikhin@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: mark iscsit_start_kthreads static

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Drop legacy iscsi_target_tq.c logic

Now that iscsi_conn allocates new [rx,tx] threads using kthread.h
primitives on the fly, and kthread_stop() is called directly during
connection shutdown, it's time to go ahead and drop iscsi_target_tq.c
legacy code.

The use of multiple struct completion in iscsi_activate_thread_set()
has been proven to cause issues during repeated iser login/logout.

Tested-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Slava Shwartsman <valyushash@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Convert iscsi_thread_set usage to kthread.h

This patch converts iscsi-target code to use modern kthread.h API
callers for creating RX/TX threads for each new iscsi_conn descriptor,
and releasing associated RX/TX threads during connection shutdown.

This is done using iscsit_start_kthreads() -> kthread_run() to start
new kthreads from within iscsi_post_login_handler(), and invoking
kthread_stop() from existing iscsit_close_connection() code.

Also, convert iscsit_logout_post_handler_closesession() code to use
cmpxchg when determing when iscsit_cause_connection_reinstatement()
needs to sleep waiting for completion.

Reported-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Slava Shwartsman <valyushash@gmail.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Move iscsi_target_[core,stat].h under linux include

Seems strange to see in include/target/iscsi/iscsi_transport.h:
include "../../../drivers/target/iscsi/iscsi_target_core.h"

Move it to it's natural location.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: nullify session in failed login sequence

In case login sequence failed, make sure conn->sess is
NULL before calling wait_conn as some transports (iser)
may rely on that (waiting for session commands).

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi,iser-target: Expose supported protection ops according to t10_pi

iSER will report supported protection operations based on
the tpg attribute t10_pi settings and HCA PI offload capabilities.
If the HCA does not support PI offload or tpg attribute t10_pi is
not set, we fall to SW PI mode.

In order to do that, we move iscsit_get_sup_prot_ops after connection
tpg assignment.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi,iser-target: Initiate termination only once

Since commit 0fc4ea701fcf ("Target/iser: Don't put isert_conn inside
disconnected handler") we put the conn kref in isert_wait_conn, so we
need .wait_conn to be invoked also in the error path.

Introduce call to isert_conn_terminate (called under lock)
which transitions the connection state to TERMINATING and calls
rdma_disconnect. If the state is already teminating, just bail
out back (temination started).

Also, make sure to destroy the connection when getting a connect
error event if didn't get to connected (state UP). Same for the
handling of REJECTED and UNREACHABLE cma events.

Squashed:

iscsi-target: Add call to wait_conn in establishment error flow

Reported-by: Slava Shwartsman <valyushash@gmail.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: remove unnecessary check in iscsit_setup_np error path

Found by coverity. At this point sock is non-NULL, so the check
to unnecessary.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Drop duplicate __iscsi_target_login_thread check

This patch drops the now duplicate + unnecessary check for -ENODEV from
iscsi_transport->iscsit_accept_np() for jumping to out:, or immediately
returning 1 in __iscsi_target_login_thread() code.

Since commit 81a9c5e72b the jump to out: and returning 1 have the same
effect, and end up hitting the ISCSI_NP_THREAD_SHUTDOWN check regardless
at the top of __iscsi_target_login_thread() during next loop iteration.

So that said, it's safe to go ahead and remove this duplicate check.

Reported-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: remove unused debug code

Last user of buf was removed with c6037cc546ca. While at it,
free_cpumask_var() handles a NULL argument just fine, so remove the
conditionals.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: fix iscsit_del_np deadlock on unload

On uniprocessor preemptible kernel, target core deadlocks on unload. The
following events happen:
* iscsit_del_np is called
* it calls send_sig(SIGINT, np->np_thread, 1);
* the scheduler switches to the np_thread
* the np_thread is woken up, it sees that kthread_should_stop() returns
false, so it doesn't terminate
* the np_thread clears signals with flush_signals(current); and goes back
to sleep in iscsit_accept_np
* the scheduler switches back to iscsit_del_np
* iscsit_del_np calls kthread_stop(np->np_thread);
* the np_thread is waiting in iscsit_accept_np and it doesn't respond to
kthread_stop

The deadlock could be resolved if the administrator sends SIGINT signal to
the np_thread with killall -INT iscsi_np

The reproducible deadlock was introduced in commit
db6077fd0b7dd41dc6ff18329cec979379071f87, but the thread-stopping code was
racy even before.

This patch fixes the problem. Using kthread_should_stop to stop the
np_thread is unreliable, so we test np_thread_state instead. If
np_thread_state equals ISCSI_NP_THREAD_SHUTDOWN, the thread exits.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: cleanup some boolean tests

Convert "x == true" to "x" and "x == false" to "!x".

Signed-off-by: Christophe Vu-Brugier <cvubrugier@yahoo.fr>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix wrong buffer / buffer overrun in iscsi_change_param_value()

In non-leading connection login, iscsi_login_non_zero_tsih_s1() calls
iscsi_change_param_value() with the buffer it uses to hold the login
PDU, not a temporary buffer. This leads to the login header getting
corrupted and login failing for non-leading connections in MC/S.

Fix this by adding a wrapper iscsi_change_param_sprintf() that handles
the temporary buffer itself to avoid confusion. Also handle sending a
reject in case of failure in the wrapper, which lets the calling code
get quite a bit smaller and easier to read.

Finally, bump the size of the temporary buffer from 32 to 64 bytes to be
safe, since "MaxRecvDataSegmentLength=" by itself is 25 bytes; with a
trailing NUL, a value >= 1M will lead to a buffer overrun. (This isn't
the default but we don't need to run right at the ragged edge here)

Reported-by: Santosh Kulkarni <santosh.kulkarni@calsoftinc.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Disable Immediate + Unsolicited Data with ISER Protection

This patch explicitly disables Immediate + Unsolicited Data for ISER
connections during login in iscsi_login_zero_tsih_s2() when protection
has been enabled for the session by the underlying hardware.

This is currently required because protection / signature memory regions
(MRs) expect T10 PI to occur on RDMA READs + RDMA WRITEs transfers, and
not on a immediate data payload associated with ISCSI_OP_SCSI_CMD, or
unsolicited data-out associated with a ISCSI_OP_SCSI_DATA_OUT.

v2 changes:
- Add TARGET_PROT_DOUT_INSERT check (Sagi)
- Add pr_debug noisemaker (Sagi)
- Add goto to avoid early return from MRDSL check (nab)

Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Target/iscsi,iser: Avoid accepting transport connections during stop stage

When the target is in stop stage, iSER transport initiates RDMA disconnects.
The iSER initiator may wish to establish a new connection over the
still existing network portal. In this case iSER transport should not
accept and resume new RDMA connections. In order to learn that, iscsi_np
is added with enabled flag so the iSER transport can check when deciding
weather to accept and resume a new connection request.

The iscsi_np is enabled after successful transport setup, and disabled
before iscsi_np login threads are cleaned up.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Pass in transport supported PI at session initialization

In order to support local WRITE_INSERT + READ_STRIP operations for
non PI enabled fabrics, the fabric driver needs to be able signal
what protection offload operations are supported.

This is done at session initialization time so the modes can be
signaled by individual se_wwn + se_portal_group endpoints, as well
as optionally across different transports on the same endpoint.

For iser-target, set TARGET_PROT_ALL if the underlying ib_device
has already signaled PI offload support, and allow this to be
exposed via a new iscsit_transport->iscsit_get_sup_prot_ops()
callback.

For loopback, set TARGET_PROT_ALL to signal SCSI initiator mode
operation.

For all other drivers, set TARGET_PROT_NORMAL to disable fabric
level PI.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix incorrect np->np_thread NULL assignment

When shutting down a target there is a race condition between
iscsit_del_np() and __iscsi_target_login_thread().
The latter sets the thread pointer to NULL, and the former
tries to issue kthread_stop() on that pointer without any
synchronization.

This patch moves the np->np_thread NULL assignment into
iscsit_del_np(), after kthread_stop() has completed. It also
removes the signal_pending() + np_state check, and only
exits when kthread_should_stop() is true.

Reported-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org> #3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Convert iscsi_session statistics to atomic_long_t

This patch converts a handful of iscsi_session statistics to type
atomic_long_t, instead of using iscsi_session->session_stats_lock
when incrementing these values.

More importantly, go ahead and drop the spinlock usage within
iscsit_setup_scsi_cmd(), iscsit_check_dataout_hdr(),
iscsit_send_datain(), and iscsit_build_rsp_pdu() fast-path code.

(Squash in Roland's target: Remove write-only stats fields and lock
from struct se_node_acl)

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: Remove macros that contain typecasts

These just want to return a pointer instead of a value, but are otherwise
the same.

ISCSI_TPG_LUN macro was unused.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Update copyright ownership/year information to 2013

Update copyright ownership/year information for target-core,
loopback, iscsi-target, tcm_qla2xx, vhost and iser-target.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Bump default TCP listen backlog to 256

This patch bumps the default TCP listen backlog within iscsit_setup_np()
from 5 to 256, in order to reduce the overall latency caused by a small
backlog with 100's of simultaneous login attempts directed to the same
single network portal.

Also add a ISCSIT_TCP_BACKLOG macro in iscsi_target_core.h.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Prepare login code for multi-plexing support

This patch prepares the iscsi-target login code for multi-plexing
support. This includes:

- Adding iscsi_tpg_np->tpg_np_kref + iscsit_login_kref_put() for
handling callback of iscsi_tpg_np->tpg_np_comp
- Adding kref_put() in iscsit_deaccess_np()
- Adding kref_put() and wait_for_completion() in
iscsit_reset_np_thread()
- Refactor login failure path release logic into
iscsi_target_login_sess_out()
- Update __iscsi_target_login_thread() to handle
iscsi_post_login_handler() asynchronous completion
- Add shutdown parameter for iscsit_clear_tpg_np_login_thread*()

v3 changes:
- Convert iscsi_portal_group->np_login_lock to ->np_login_sem
- Add LOGIN_FLAGS definitions

v2 changes:
- Remove duplicate call to iscsi_post_login_handler() in
__iscsi_target_login_thread()
- Drop unused iscsi_np->np_login_tpg

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix iscsit_transport reference leak during NP thread reset

This patch fixes a bug in __iscsi_target_login_thread() where an explicit
network portal thread reset ends up leaking the iscsit_transport module
reference, along with the associated iscsi_conn allocation.

This manifests itself with iser-target where a NP reset causes the extra
iscsit_transport reference to be taken in iscsit_conn_set_transport()
during the reset, which prevents the ib_isert module from being unloaded
after the NP thread shutdown has finished.

Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: ST response on IN6ADDR_ANY socket

Odd little issue, found that if you create an IPv6 portal bound to the
IN6ADDR_ANY wildcard address it will accept IPv4 connections (as long as
bindv6only isn't set globally) but respond to SendTargets requests with
an IPv4-mapped IPv6 address.

Example over loopback:

In targetcli create a wildcard IPv6 portal
/iscsi/iqn.../portals/> create ::
Which should create a portal [::]:3260

Initiate SendTargets discovery to the portal using an IPv4 address
# iscsiadm -m discovery -t st -p 127.0.0.1
The response formats TargetAddress as [::ffff:127.0.0.1]:3260,1

This still works and uses v4 on the network between two v6 sockets, but
only if the initiator supports IPv6 with v4-mapped addresses.

This change detects v4-mapped address on v6 sockets for the wildcard
case, and instead formats the TargetAddress response as an IPv4 address.

In order to not further complicate iscsit_build_sendtargets_response,
I've actually simplified it by moving the bracket wrapping of IPv6
address into iscsit_accept_np where local_ip and login_ip strings are
set. That also simplifies iscsi_stat_tgt_attr_show_attr_fail_intr_addr.

Side effect of the string format change is that
lio_target_nacl_show_info will now print login_ip bracket wrapped for
IPv6 connections, as will a few debug prints.

Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: replace strict_strto*() with kstrto*()

The usage of strict_strtoul() and strict_strtoull() is not preferred,
because strict_strtoul() and strict_strtoull() are obsolete. Thus,
kstrtoul() and kstrtoull() should be used.

v2: Fix incorrect return in ft_add_tpg (Fengguang)

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Remove left over v3.10-rc debug printks

Reported-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Refactor RX PDU logic + export request PDU handling

This patch refactors existing traditional iscsi RX side PDU handling
to use iscsit_transport, and exports the necessary logic for external
transport modules.

This includes:

- Refactor iscsit_handle_scsi_cmd() into PDU setup / processing
- Add updated iscsit_handle_scsi_cmd() for tradtional iscsi code
- Add iscsit_set_unsoliticed_dataout() wrapper
- Refactor iscsit_handle_data_out() into PDU check / processing
- Add updated iscsit_handle_data_out() for tradtional iscsi code
- Add iscsit_handle_nop_out() + iscsit_handle_task_mgt_cmd() to
accept pre-allocated struct iscsi_cmd
- Add iscsit_build_r2ts_for_cmd() caller for iscsi_target_transport
to handle ISTATE_SEND_R2T for TX immediate queue
- Refactor main traditional iscsi iscsi_target_rx_thread() PDU switch
into iscsi_target_rx_opcode() using iscsit_allocate_cmd()
- Turn iscsi_target_rx_thread() process context into NOP for
ib_isert side work-queue.

v5 changes:

- Make iscsit_handle_scsi_cmd() static (Fengguang)
- Fix iscsit_handle_scsi_cmd() exception se_cmd leak (nab)

v3 changes:
- Add extra target_put_sess_cmd call in iscsit_add_reject_from_cmd
after completion

v2 changes:

- Disable iscsit_ack_from_expstatsn() usage for RDMAExtentions=Yes
- Disable iscsit_allocate_datain_req() usage for RDMAExtentions=Yes
- Add target_get_sess_cmd() reference counting to
iscsit_setup_scsi_cmd()
- Add TFO->lio_check_stop_free() fabric API caller
- Add export of iscsit_stop_dataout_timer() symbol
- Add iscsit_build_r2ts_for_cmd() for iscsit_transport->iscsit_get_dataout()
- Convert existing usage of iscsit_build_r2ts_for_cmd() to
->iscsit_get_dataout()
- Drop RDMAExtentions=Yes specific check in iscsit_build_r2ts_for_cmd()
- Fix RDMAExtentions -> RDMAExtensions typo (andy)
- Pass correct dump_payload value into iscsit_get_immediate_data()
for iscsit_handle_scsi_cmd()

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Add iser-target parameter keys + setup during login

This patch adds RDMAExtensions, InitiatorRecvDataSegmentLength and
TargetRecvDataSegmentLength parameters keys necessary for iser-target
login to occur.

This includes setting the necessary parameters during login path
code within iscsi_login_zero_tsih_s2(), and currently PAGE_SIZE
aligning the target's advertised MRDSL for immediate data and
unsolicited data-out incoming payloads.

v3 changes:
- Add iscsi_post_login_start_timers FIXME for ISER

v2 changes:

- Fix RDMAExtentions -> RDMAExtensions typo (andy)
- Drop unnecessary '== true' conditional checks for type bool

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Initial traditional TCP conversion to iscsit_transport

This patch performs the initial conversion of existing traditional iscsi
to use iscsit_transport API callers. This includes:

- iscsi-np cleanups for iscsit_transport_type
- Add iscsi-np transport calls w/ ->iscsit_setup_up() and ->iscsit_free_np()
- Convert login thread process context to use ->iscsit_accept_np() for
connections with pre-allocated struct iscsi_conn
- Convert existing socket accept code to iscsit_accept_np()
- Convert login RX/TX callers to use ->iscsit_get_login_rx() and
->iscsit_put_login_tx() to exchange request/response PDUs
- Convert existing socket login RX/TX calls into iscsit_get_login_rx()
and iscsit_put_login_tx()
- Change iscsit_close_connection() to invoke ->iscsit_free_conn() +
iscsit_put_transport() calls.
- Add iscsit_register_transport() + iscsit_unregister_transport() calls
to module init/exit

v4 changes:

- Add missing iscsit_put_transport() call in iscsi_target_setup_login_socket()
failure case

v2 changes:

- Update module init/exit to use register_transport() + unregister_transport()

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target/iscsi: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iscsi_target: Remove redundant null check before kfree

kfree on null pointer is a no-op.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Always send a response before terminating iSCSI connection

There are some cases, for example when the initiator sends an
out-of-bounds ErrorRecoveryLevel value, where the iSCSI target
terminates the connection without sending back any error. Audit the
login path and add appropriate iscsit_tx_login_rsp() calls to make
sure this doesn't happen.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix potential deadlock on lock taken in timer

We need to disable BHs when taking sess_idr_lock because the
iscsit_handle_time2retain_timeout() timer function takes
se_tpg->session_lock, and iscsit_close_session() nests sess_idr_lock
inside se_tpg->session_lock. So if the timer can run inside
sess_idr_lock, we have a potential AB-BA deadlock.

Fix this by disabling BHs when taking sess_idr_lock. This was found
because of a lockdep warning, but it looks like a real (if highly
theoretical) deadlock. In any case avoiding lockdep spew so that we can
find other issues is a worthy cause.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix missed wakeup race in TX thread

The sleeping code in iscsi_target_tx_thread() is susceptible to the classic
missed wakeup race:

- TX thread finishes handle_immediate_queue() and handle_response_queue(),
thinks both queues are empty.
- Another thread adds a queue entry and does wake_up_process(), which does
nothing because the TX thread is still awake.
- TX thread does schedule_timeout() and sleeps forever.

In practice this can kill an iSCSI connection if for example an initiator
does single-threaded writes and the target misses the wakeup window when
queueing an R2T; in this case the connection will be stuck until the
initiator loses patience and does some task management operation (or kills
the connection entirely).

Fix this by converting to wait_event_interruptible(), which does not
suffer from this sort of race.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsit: proper endianess conversions

Make sure all on the wire types are use as big endian and big endian only so
that sparse can verify all the conversions are done right.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsit: use the itt_t abstract type

Use the special itt_t type defined by the iscsi headers and the initiator
to make sure it's an opaque value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsit: mark various functions static

This patch marks a number of functions static to appease sparse static
checking.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Check idr_get_new return value in iscsi_login_zero_tsih_s1

This patch updates iscsi_login_zero_tsih_s1() usage for generating
iscsi_session->session_index to properly check the return value from
idr_get_new(), and reject the iSCSI login attempt with exception
status ISCSI_LOGIN_STATUS_NO_RESOURCES in the event of a failure.

Signed-off-by: Benjamin Wang <cpwang2009@gmail.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Drop bogus struct file usage for iSCSI/SCTP

From Al Viro:

BTW, speaking of struct file treatment related to sockets -
there's this piece of code in iscsi:
/*
* The SCTP stack needs struct socket->file.
*/
if ((np->np_network_transport == ISCSI_SCTP_TCP) ||
(np->np_network_transport == ISCSI_SCTP_UDP)) {
if (!new_sock->file) {
new_sock->file = kzalloc(
sizeof(struct file), GFP_KERNEL);

For one thing, as far as I can see it'not true - sctp does *not* depend on
socket->file being non-NULL; it does, in one place, check socket->file->f_flags
for O_NONBLOCK, but there it treats NULL socket->file as "flag not set".
Which is the case here anyway - the fake struct file created in
__iscsi_target_login_thread() (and in iscsi_target_setup_login_socket(), with
the same excuse) do *not* get that flag set.

Moreover, it's a bloody serious violation of a bunch of asserts in VFS;
all struct file instances should come from filp_cachep, via get_empty_filp()
(or alloc_file(), which is a wrapper for it). FWIW, I'm very tempted to
do this and be done with the entire mess:

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Grover <agrover@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Remove unneeded double parentheses

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: remove obvious warnings

Get rid of a bunch of write-only variables. In a number of cases I
suspect actual bugs to be present, so I left all of those for a second
look.

(nab: fix lio-core patch fuzz)

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Convert to use target_put_session + sess_kref

This patch converts iscsi-target session code to use se_sess->sess_kref
counting for iscsi session shutdown. The following cases include:

*) last iscsit_close_connection() shutdown path to invoke close session
*) iscsit_logout_post_handler_closesession() for explict logout
*) iscsit_free_session() caller for explict shutdown

It also moves iscsit_stop_session() call from lio_tpg_close_session()
into lio_tpg_shutdown_session() TFO callbacks to invoke an explict
shutdown, and also changes iscsi_check_for_session_reinstatement()
login code to use se_sess->sess_kref.

(v2: Make iscsit_handle_time2retain_timeout() use target_put_session)

Cc: Andy Grover <agrover@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

security: trim security.h

Trim security.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>

iscsi: use IP_FREEBIND socket option

Use IP_FREEBIND socket option so that iscsi portal configuration with
explicit IP addresses can happen during boot, before network interfaces
have been assigned IPs.

This is especially important on systemd based Linux boxes where system
boot happens asynchronously and non-trivial configuration must be done
to get targetcli.service to start synchronously after the network is
configured.

Reference:
http://lists.fedoraproject.org/pipermail/devel/2011-October/158025.html

Signed-off-by: Dax Kelson <dkelson@gurulabs.com>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: "Andy Grover" <agrover@redhat.com>
Cc: "Lennart Poettering" <lennart@poettering.net>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix discovery with INADDR_ANY and IN6ADDR_ANY_INIT

This patch addresses a bug with sendtargets discovery where INADDR_ANY (0.0.0.0)
+ IN6ADDR_ANY_INIT ([0:0:0:0:0:0:0:0]) network portals where incorrectly being
reported back to initiators instead of the address of the connecting interface.
To address this, save local socket ->getname() output during iscsi login setup,
and makes iscsit_build_sendtargets_response() return these TargetAddress keys
when INADDR_ANY or IN6ADDR_ANY_INIT portals are in use.

Reported-by: Dax Kelson <dkelson@gurulabs.com>
Reported-by: Andy Grover <agrover@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: remove useless casts

A reader should spend an extra moment whenever noticing a cast,
because either something special is going on that deserves extra
attention or, as is all too often the case, the code is wrong.

These casts, afaics, have all been useless. They cast a foo* to a
foo*, cast a void* to the assigned type, cast a foo* to void*, before
assigning it to a void* variable, etc.

In a few cases I also removed an additional &...[0], which is equally
useless.

Lastly I added three FIXMEs where, to the best of my judgement, the
code appears to have a bug. It would be good if someone could check
these.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: header reshuffle, part2

This reorganized the headers under include/target into:

- target_core_base.h stays as is with all target-wide data stuctures and defines
- target_core_backend.h contains the whole interface to I/O backends
- target_core_fabric.h contains the whole interface to fabric modules

Except for those only the various configfs macro headers stay around.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Fix sess allocation leak in iscsi_login_zero_tsih_s1

This patch adds missing kfree() for an allocation in iscsi_login_zero_tsih_s1()
code, and make transport_init_session() check for IS_ERR() returns.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Implement iSCSI target IPv6 address printing.

The iSCSI target configfs code to print out an initiator's IPv6 address
is not fully implemented. This patch uses snprintf() with the "%pI6c"
format string to format the IPv6 address for display purposes.

Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

iscsi-target: Add iSCSI fabric support for target v4.1

The Linux-iSCSI.org target module is a full featured in-kernel
software implementation of iSCSI target mode (RFC-3720) for the
current WIP mainline target v4.1 infrastructure code for the v3.1
kernel. More information can be found here:

http://linux-iscsi.org/wiki/ISCSI

This includes support for:

* RFC-3720 defined request / response state machines and support for
all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi
include/scsi/iscsi_proto.h PDU definitions
* Target v4.1 compatible control plane using the generic layout in
target_core_fabric_configfs.c and fabric dependent attributes
within /sys/kernel/config/target/iscsi/ subdirectories.
* Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS)
* Support for IPv6 and IPv4 network portals in M:N mapping to TPGs
* iSCSI Error Recovery Hierarchy support
* Per iSCSI connection RX/TX thread pair scheduling affinity
* crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto
* CHAP Authentication support using libcrypto
* Conversion to use internal SGl allocation with iscsit_alloc_buffs() ->
transport_generic_map_mem_to_cmd()

(nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit:
iscsi: Use struct scsi_lun in iscsi structs instead of u8[8])
(nab: Fix 32-bit compile warnings)

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Acked-by: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>