pid: Split out pid_types.h

Trimming down sched.h dependencies: we dont't want to include more than
the base types.

Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

scsi: target: Pass in cmd counter to use during cmd setup

Allow target_get_sess_cmd() users to pass in the cmd counter they want to
use. Right now we pass in the session's cmd counter but in a subsequent
commit iSCSI will switch from per session to per conn.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230319015620.96006-4-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: core: Change the way target_xcopy_do_work() sets restiction on max I/O

To determine how many blocks sends in one command, the minimum value is
selected from the hw_max_sectors of both devices. In target_xcopy_do_work,
hw_max_sectors are used as blocks, not sectors; it also ignores the fact
that sectors can be of different sizes, for example 512 and 4096
bytes. Because of this, a number of blocks can be transmitted that the
device will not be able to accept.

Change the selection of max transmission size into bytes.

Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Dmitriy Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Anastasia Kovaleva <a.kovaleva@yadro.com>
Link: https://lore.kernel.org/r/20221114102500.88892-4-a.kovaleva@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: core: Check emulate_3pc for RECEIVE COPY

RECEIVE COPY RESULTS is an opcode from 3rd party copy command set and shall
be rejected if emulate_3pc attribute is off like EXTENDED COPY.

Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Link: https://lore.kernel.org/r/20220906103421.22348-6-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: core: De-RCU of se_lun and se_lun acl

se_lun and se_lun_acl are immutable pointers of struct se_dev_entry.
Remove RCU usage for access to those pointers.

Link: https://lore.kernel.org/r/20220727214125.19647-3-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: Remove unused function arguments

The se_cmd is unused in these functions, just remove it.

Link: https://lore.kernel.org/r/20210913083045.3670648-1-fengli@smartx.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Li Feng <fengli@smartx.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Fix sense key for invalid EXTENDED COPY request

TCM fails to pass the following tests in libiscsi:

SCSI.ExtendedCopy.DescrType
SCSI.ExtendedCopy.DescrLimits
SCSI.ExtendedCopy.ParamHdr
SCSI.ExtendedCopy.ValidSegDescr
SCSI.ExtendedCopy.ValidTgtDescr

The xcopy code always returns the same NOT READY sense key for all detected
errors. Change the sense key for invalid requests to ILLEGAL REQUEST, and
for aborted transfers to COPY ABORTED.

Link: https://lore.kernel.org/r/20210803145410.80147-3-s.samoylenko@yadro.com
Fixes: d877d7275be3 ("target: Fix a deadlock between the XCOPY code and iSCSI session shutdown")
Reviewed-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Signed-off-by: Sergey Samoylenko <s.samoylenko@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Use standard SAM status types

target_complete_cmd() and friends requires a SAM status type, so passing
GOOD here is actually wrong.

Link: https://lore.kernel.org/r/20210427083046.31620-40-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: core: Unify NAA identifier generation

Both the INQUIRY handling and the XCOPY implementation provide functions to
generate an NAA designator. In addition, these functions are poorly named:

- spc_parse_naa_6h_vendor_specific()
- target_xcopy_gen_naa_ieee()

Introduce a common NAA 6 designator generation function,
spc_gen_naa_6h_vendor_specific().

Link: https://lore.kernel.org/r/20210420185920.42431-2-s.samoylenko@yadro.com
Signed-off-by: Sergey Samoylenko <s.samoylenko@yadro.com>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: core: Add gfp_t arg to target_cmd_init_cdb()

tcm_loop could be used like a normal block device, so we can't use
GFP_KERNEL and should use GFP_NOIO. This adds a gfp_t arg to
target_cmd_init_cdb() and converts the users. For every driver but loop
GFP_KERNEL is kept.

This will also be useful in subsequent patches where loop needs to do
target_submit_prep() from interrupt context to get a ref to the se_device,
and so it will need to use GFP_ATOMIC.

Link: https://lore.kernel.org/r/20210227170006.5077-16-michael.christie@oracle.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: core: Rename transport_init_se_cmd()

Rename transport_init_se_cmd() to __target_init_cmd() to reflect that it is
more of an internal function that drivers should normally not use and
because we are going to add a new init function in the next patches.

Link: https://lore.kernel.org/r/20210227170006.5077-4-michael.christie@oracle.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Fix XCOPY NAA identifier lookup

When attempting to match EXTENDED COPY CSCD descriptors with corresponding
se_devices, target_xcopy_locate_se_dev_e4() currently iterates over LIO's
global devices list which includes all configured backstores.

This change ensures that only initiator-accessible backstores are
considered during CSCD descriptor lookup, according to the session's
se_node_acl LUN list.

To avoid LUN removal race conditions, device pinning is changed from being
configfs based to instead using the se_node_acl lun_ref.

Reference: CVE-2020-28374
Fixes: cbf031f425fd ("target: Add support for EXTENDED_COPY copy offload emulation")
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Fix xcopy sess release leak

transport_init_session can allocate memory via percpu_ref_init, and
target_xcopy_release_pt never frees it. This adds a
transport_uninit_session function to handle cleanup of resources allocated
in the init function.

Link: https://lore.kernel.org/r/1593654203-12442-3-git-send-email-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Rename target_setup_cmd_from_cdb() to target_cmd_parse_cdb()

This commit also removes the unused argument, cdb, that was passed to this
function.

Link: https://lore.kernel.org/r/1591559913-8388-5-git-send-email-sudhakar.panneerselvam@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Sudhakar Panneerselvam <sudhakar.panneerselvam@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Fix NULL pointer dereference

NULL pointer dereference happens when the following conditions are met:

1) A SCSI command is received for a non-existing LU or cdb initialization
fails in target_setup_cmd_from_cdb().

2) Tracing is enabled.

The following call sequences lead to NULL pointer dereference:

1) iscsit_setup_scsi_cmd
transport_lookup_cmd_lun <-- lookup fails.
or
target_setup_cmd_from_cdb() <-- cdb initialization fails
iscsit_process_scsi_cmd
iscsit_sequence_cmd
transport_send_check_condition_and_sense
trace_target_cmd_complete <-- NULL dereference

2) target_submit_cmd_map_sgls
transport_lookup_cmd_lun <-- lookup fails
or
target_setup_cmd_from_cdb() <-- cdb initialization fails
transport_send_check_condition_and_sense
trace_target_cmd_complete <-- NULL dereference

In the above sequence, cmd->t_task_cdb is uninitialized which when
referenced in trace_target_cmd_complete() causes NULL pointer dereference.

The fix is to use the helper, target_cmd_init_cdb() and call it after
transport_init_se_cmd() is called, so that cmd->t_task_cdb can be
initialized and hence can be referenced in trace_target_cmd_complete().

Link: https://lore.kernel.org/r/1591559913-8388-4-git-send-email-sudhakar.panneerselvam@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Sudhakar Panneerselvam <sudhakar.panneerselvam@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Initialize LUN in transport_init_se_cmd()

Initialization of orig_fe_lun is moved to transport_init_se_cmd() from
transport_lookup_cmd_lun(). This helps for the cases where the SCSI request
fails before the call to transport_lookup_cmd_lun() so that
trace_target_cmd_complete() can print the LUN information to the trace
buffer. Due to this change, the lun parameter is removed from
transport_lookup_cmd_lun() and transport_lookup_tmr_lun().

Link: https://lore.kernel.org/r/1591559913-8388-3-git-send-email-sudhakar.panneerselvam@oracle.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Sudhakar Panneerselvam <sudhakar.panneerselvam@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: use the stack for XCOPY passthrough cmds

Reads and writes in the XCOPY loop are synchronous, so needn't be heap
allocated / freed with each loop.

Link: https://lore.kernel.org/r/20200327141954.955-6-ddiss@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: avoid per-loop XCOPY buffer allocations

The main target_xcopy_do_work() loop unnecessarily allocates an I/O buffer
with each synchronous READ / WRITE pair. This commit significantly reduces
allocations by reusing the XCOPY I/O buffer when possible.

Link: https://lore.kernel.org/r/20200327141954.955-4-ddiss@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: drop xcopy DISK BLOCK LENGTH debug

The DISK BLOCK LENGTH field is carried with XCOPY target descriptors on the
wire, but is currently unmarshalled during 0x02 segment descriptor
passing. The unmarshalled value is currently unused, so drop it.

Link: https://lore.kernel.org/r/20200327141954.955-3-ddiss@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: use #define for xcopy descriptor len

Link: https://lore.kernel.org/r/20200327141954.955-2-ddiss@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target: Remove tpg_list and se_portal_group.se_tpg_node

Maintaining tpg_list without ever iterating over it is not useful. Hence
remove tpg_list. This patch does not change the behavior of the SCSI target
code.

Cc: Mike Christie <mchristie@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Link: https://lore.kernel.org/r/20190930232224.58980-1-bvanassche@acm.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <mchristi@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/core: Make the XCOPY setup code easier to read by inlining two functions

The target_xcopy_setup_pt_port() and target_xcopy_init_pt_lun() functions
obfuscate what is really going on. Hence inline these two functions. This
patch does not change any functionality.

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

scsi: target/core: Simplify LUN initialization in XCOPY implementation

Other than removing a few pr_debug() statements, this patch does not change
any functionality.

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

scsi: target/core: Remove a set-but-not-used member variable from the XCOPY implementation

This patch does not change any functionality.

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

scsi: target/core: Remove the write_pending_status() callback function

Due to the patch that makes TMF handling synchronous the
write_pending_status() callback function is no longer called. Hence remove
it.

Acked-by: Felipe Balbi <balbi@ti.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Saurav Kashyap <saurav.kashyap@qlogic.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: target/core: Make sure that target_wait_for_sess_cmds() waits long enough

A session must only be released after all code that accesses the session
structure has finished. Make sure that this is the case by introducing a
new command counter per session that is only decremented after the
.release_cmd() callback has finished. This patch fixes the following crash:

BUG: KASAN: use-after-free in do_raw_spin_lock+0x1c/0x130
Read of size 4 at addr ffff8801534b16e4 by task rmdir/14805
CPU: 16 PID: 14805 Comm: rmdir Not tainted 4.18.0-rc2-dbg+ #5
Call Trace:
dump_stack+0xa4/0xf5
print_address_description+0x6f/0x270
kasan_report+0x241/0x360
__asan_load4+0x78/0x80
do_raw_spin_lock+0x1c/0x130
_raw_spin_lock_irqsave+0x52/0x60
srpt_set_ch_state+0x27/0x70 [ib_srpt]
srpt_disconnect_ch+0x1b/0xc0 [ib_srpt]
srpt_close_session+0xa8/0x260 [ib_srpt]
target_shutdown_sessions+0x170/0x180 [target_core_mod]
core_tpg_del_initiator_node_acl+0xf3/0x200 [target_core_mod]
target_fabric_nacl_base_release+0x25/0x30 [target_core_mod]
config_item_release+0x9c/0x110 [configfs]
config_item_put+0x26/0x30 [configfs]
configfs_rmdir+0x3b8/0x510 [configfs]
vfs_rmdir+0xb3/0x1e0
do_rmdir+0x262/0x2c0
do_syscall_64+0x77/0x230
entry_SYSCALL_64_after_hwframe+0x49/0xbe

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

scsi: target: drop unnecessary get_fabric_name() accessor from fabric_ops

All fabrics return a const string. In all cases *except* iSCSI the
get_fabric_name() string matches fabric_ops.name.

Both fabric_ops.get_fabric_name() and fabric_ops.name are user-facing, with
the former being used for PR/ALUA state and the latter for ConfigFS
(config/target/$name), so we unfortunately need to keep both strings around
for now. Replace the useless .get_fabric_name() accessor function with a
const string fabric_name member variable.

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

scsi: target/core: Remove an unused data member from struct xcopy_pt_cmd

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

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

scsi: target: Introduce transport_init_session()

Other than initializing xcopy_pt_sess.sess_wait_list, this patch does not
change any functionality.

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

xcopy: loop over devices using idr helper

This converts the xcopy code to use the idr helper. The next patch
will drop the g_device_list and make g_device_mutex local to the
target_core_device.c file.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Fix a deadlock between the XCOPY code and iSCSI session shutdown

Move the code for parsing an XCOPY command from the context of
the iSCSI receiver thread to the context of the XCOPY workqueue.
Keep the simple XCOPY checks in the context of the iSCSI receiver
thread. Move the code for allocating and freeing struct xcopy_op
from the code that parses an XCOPY command to its caller.

This patch fixes the following deadlock:

======================================================
[ INFO: possible circular locking dependency detected ]
4.10.0-rc7-dbg+ #1 Not tainted
-------------------------------------------------------
rmdir/13321 is trying to acquire lock:
(&sess->cmdsn_mutex){+.+.+.}, at: [<ffffffffa02cb47d>] iscsit_free_all_ooo_cmdsns+0x2d/0xb0 [iscsi_target_mod]

but task is already holding lock:
(&sb->s_type->i_mutex_key#14){++++++}, at: [<ffffffff811c6e20>] vfs_rmdir+0x50/0x140

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:
-> #1 (&sb->s_type->i_mutex_key#14){++++++}:
lock_acquire+0x71/0x90
down_write+0x3f/0x70
configfs_depend_item+0x3a/0xb0 [configfs]
target_depend_item+0x13/0x20 [target_core_mod]
target_xcopy_locate_se_dev_e4+0xdd/0x1a0 [target_core_mod]
target_do_xcopy+0x34b/0x970 [target_core_mod]
__target_execute_cmd+0x22/0xa0 [target_core_mod]
target_execute_cmd+0x233/0x2c0 [target_core_mod]
iscsit_execute_cmd+0x208/0x270 [iscsi_target_mod]
iscsit_sequence_cmd+0x10b/0x190 [iscsi_target_mod]
iscsit_get_rx_pdu+0x37d/0xcd0 [iscsi_target_mod]
iscsi_target_rx_thread+0x6e/0xa0 [iscsi_target_mod]
kthread+0x102/0x140
ret_from_fork+0x31/0x40

-> #0 (&sess->cmdsn_mutex){+.+.+.}:
__lock_acquire+0x10e6/0x1260
lock_acquire+0x71/0x90
mutex_lock_nested+0x5f/0x670
iscsit_free_all_ooo_cmdsns+0x2d/0xb0 [iscsi_target_mod]
iscsit_close_session+0xac/0x200 [iscsi_target_mod]
lio_tpg_close_session+0x9f/0xb0 [iscsi_target_mod]
target_shutdown_sessions+0xc3/0xd0 [target_core_mod]
core_tpg_del_initiator_node_acl+0x91/0x140 [target_core_mod]
target_fabric_nacl_base_release+0x20/0x30 [target_core_mod]
config_item_release+0x5a/0xc0 [configfs]
config_item_put+0x1d/0x1f [configfs]
configfs_rmdir+0x1a6/0x300 [configfs]
vfs_rmdir+0xb7/0x140
do_rmdir+0x1f4/0x200
SyS_rmdir+0x11/0x20
entry_SYSCALL_64_fastpath+0x23/0xc6

other info that might help us debug this:

Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sb->s_type->i_mutex_key#14);
lock(&sess->cmdsn_mutex);
lock(&sb->s_type->i_mutex_key#14);
lock(&sess->cmdsn_mutex);

*** DEADLOCK ***

3 locks held by rmdir/13321:
#0: (sb_writers#10){.+.+.+}, at: [<ffffffff811e1aff>] mnt_want_write+0x1f/0x50
#1: (&default_group_class[depth - 1]#2/1){+.+.+.}, at: [<ffffffff811cc8ce>] do_rmdir+0x15e/0x200
#2: (&sb->s_type->i_mutex_key#14){++++++}, at: [<ffffffff811c6e20>] vfs_rmdir+0x50/0x140

stack backtrace:
CPU: 2 PID: 13321 Comm: rmdir Not tainted 4.10.0-rc7-dbg+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
Call Trace:
dump_stack+0x86/0xc3
print_circular_bug+0x1c7/0x220
__lock_acquire+0x10e6/0x1260
lock_acquire+0x71/0x90
mutex_lock_nested+0x5f/0x670
iscsit_free_all_ooo_cmdsns+0x2d/0xb0 [iscsi_target_mod]
iscsit_close_session+0xac/0x200 [iscsi_target_mod]
lio_tpg_close_session+0x9f/0xb0 [iscsi_target_mod]
target_shutdown_sessions+0xc3/0xd0 [target_core_mod]
core_tpg_del_initiator_node_acl+0x91/0x140 [target_core_mod]
target_fabric_nacl_base_release+0x20/0x30 [target_core_mod]
config_item_release+0x5a/0xc0 [configfs]
config_item_put+0x1d/0x1f [configfs]
configfs_rmdir+0x1a6/0x300 [configfs]
vfs_rmdir+0xb7/0x140
do_rmdir+0x1f4/0x200
SyS_rmdir+0x11/0x20
entry_SYSCALL_64_fastpath+0x23/0xc6

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: 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: Nicholas Bellinger <nab@linux-iscsi.org>

target: Use {get,put}_unaligned_be*() instead of open coding these functions

Introduce the function get_unaligned_be24(). Use {get,put}_unaligned_be*()
where appropriate. This patch does not change any functionality.

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

target: Use correct SCSI status during EXTENDED_COPY exception

This patch adds the missing target_complete_cmd() SCSI status
parameter change in target_xcopy_do_work(), that was originally
missing in commit 926317de33.

It correctly propigates up the correct SCSI status during
EXTENDED_COPY exception cases, instead of always using the
hardcoded SAM_STAT_CHECK_CONDITION from original code.

This is required for ESX host environments that expect to
hit SAM_STAT_RESERVATION_CONFLICT for certain scenarios,
and SAM_STAT_CHECK_CONDITION results in non-retriable
status for these cases.

Reported-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Cc: Nixon Vincent <nixon.vincent@calsoftinc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: support XCOPY requests without parameters

SPC4r37 6.4.1 EXTENDED COPY(LID4) states (also applying to LID1 reqs):
A parameter list length of zero specifies that the copy manager shall
not transfer any data or alter any internal state, and this shall not
be considered an error.

This behaviour can be tested using the libiscsi ExtendedCopy.ParamHdr
test.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

target: check for XCOPY parameter truncation

Check for XCOPY header, CSCD descriptor and segment descriptor list
truncation, and respond accordingly.

SPC4r37 6.4.1 EXTENDED COPY(LID4) states (also applying to LID1 reqs):
If the parameter list length causes truncation of the parameter list,
then the copy manager shall transfer no data and shall terminate the
EXTENDED COPY command with CHECK CONDITION status, with the sense key
set to ILLEGAL REQUEST, and the additional sense code set to PARAMETER
LIST LENGTH ERROR.

This behaviour can be tested using the libiscsi ExtendedCopy.ParamHdr
test.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

target: use XCOPY segment descriptor CSCD IDs

The XCOPY specification in SPC4r37 states that the XCOPY source and
destination device(s) should be derived from the copy source and copy
destination (CSCD) descriptor IDs in the XCOPY segment descriptor.

The CSCD IDs are generally (for block -> block copies), indexes into
the corresponding CSCD descriptor list, e.g.
=================================
EXTENDED COPY Header
=================================
CSCD Descriptor List
- entry 0
+ LU ID <--------------<------------------\
- entry 1 |
+ LU ID <______________<_____________ |
================================= | |
Segment Descriptor List | |
- segment 0 | |
+ src CSCD ID = 0 --------->---------+----/
+ dest CSCD ID = 1 ___________>______|
+ len
+ src lba
+ dest lba
=================================

Currently LIO completely ignores the src and dest CSCD IDs in the
Segment Descriptor List, and instead assumes that the first entry in the
CSCD list corresponds to the source, and the second to the destination.

This commit removes this assumption, by ensuring that the Segment
Descriptor List is parsed prior to processing the CSCD Descriptor List.
CSCD Descriptor List processing is modified to compare the current list
index with the previously obtained src and dest CSCD IDs.

Additionally, XCOPY requests where the src and dest CSCD IDs refer to
the CSCD Descriptor List entry can now be successfully processed.

Fixes: cbf031f ("target: Add support for EXTENDED_COPY copy offload")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=191381
Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

target: check XCOPY segment descriptor CSCD IDs

Ensure that the segment descriptor CSCD descriptor ID values correspond
to CSCD descriptor entries located in the XCOPY command parameter list.
SPC4r37 6.4.6.1 Table 150 specifies this range as 0000h to 07FFh, where
the CSCD descriptor location in the parameter list can be located via:
16 + (id * 32)

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[ bvanassche: inserted "; " in the format string of an error message
and also moved a "||" operator from the start of a line to the end
of the previous line ]
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

target: simplify XCOPY wwn->se_dev lookup helper

target_xcopy_locate_se_dev_e4() is used to locate an se_dev, based on
the WWN provided with the XCOPY request. Remove a couple of unneeded
arguments, and rely on the caller for the src/dst test.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

target: return UNSUPPORTED TARGET/SEGMENT DESC TYPE CODE sense

Use UNSUPPORTED TARGET DESCRIPTOR TYPE CODE and UNSUPPORTED SEGMENT
DESCRIPTOR TYPE CODE additional sense codes if a descriptor type in an
XCOPY request is not supported, as specified in spc4r37 6.4.5 and 6.4.6.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

target: bounds check XCOPY total descriptor list length

spc4r37 6.4.3.5 states:
If the combined length of the CSCD descriptors and segment descriptors
exceeds the allowed value, then the copy manager shall terminate the
command with CHECK CONDITION status, with the sense key set to ILLEGAL
REQUEST, and the additional sense code set to PARAMETER LIST LENGTH
ERROR.

This functionality can be tested using the libiscsi
ExtendedCopy.DescrLimits test.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

target: bounds check XCOPY segment descriptor list

Check the length of the XCOPY request segment descriptor list against
the value advertised via the MAXIMUM SEGMENT DESCRIPTOR COUNT field in
the RECEIVE COPY OPERATING PARAMETERS response.

spc4r37 6.4.3.5 states:
If the number of segment descriptors exceeds the allowed number, the
copy manager shall terminate the command with CHECK CONDITION status,
with the sense key set to ILLEGAL REQUEST, and the additional sense
code set to TOO MANY SEGMENT DESCRIPTORS.

This functionality is testable using the libiscsi
ExtendedCopy.DescrLimits test.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

target: use XCOPY TOO MANY TARGET DESCRIPTORS sense

spc4r37 6.4.3.4 states:
If the number of CSCD descriptors exceeds the allowed number, the copy
manager shall terminate the command with CHECK CONDITION status, with
the sense key set to ILLEGAL REQUEST, and the additional sense code
set to TOO MANY TARGET DESCRIPTORS.

LIO currently responds with INVALID FIELD IN PARAMETER LIST, which sees
it fail the libiscsi ExtendedCopy.DescrLimits test.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

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>

target: Don't override EXTENDED_COPY xcopy_pt_cmd SCSI status code

This patch addresses a bug where a local EXTENDED_COPY WRITE or READ
backend I/O request would always return SAM_STAT_CHECK_CONDITION,
even if underlying xcopy_pt_cmd->se_cmd generated a different
SCSI status code.

ESX host environments expect to hit SAM_STAT_RESERVATION_CONFLICT
for certain scenarios, and SAM_STAT_CHECK_CONDITION results in
non-retriable status for these cases.

Tested on v4.1.y with ESX v5.5u2+ with local IBLOCK backend copy.

Reported-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Cc: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Dinesh Israni <ddi@datera.io>
Signed-off-by: Dinesh Israni <ddi@datera.io>
Cc: Dinesh Israni <ddi@datera.io>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Make EXTENDED_COPY 0xe4 failure return COPY TARGET DEVICE NOT REACHABLE

This patch addresses a bug where EXTENDED_COPY across multiple LUNs
results in a CHECK_CONDITION when the source + destination are not
located on the same physical node.

ESX Host environments expect sense COPY_ABORTED w/ COPY TARGET DEVICE
NOT REACHABLE to be returned when this occurs, in order to signal
fallback to local copy method.

As described in section 6.3.3 of spc4r22:

"If it is not possible to complete processing of a segment because the
copy manager is unable to establish communications with a copy target
device, because the copy target device does not respond to INQUIRY,
or because the data returned in response to INQUIRY indicates
an unsupported logical unit, then the EXTENDED COPY command shall be
terminated with CHECK CONDITION status, with the sense key set to
COPY ABORTED, and the additional sense code set to COPY TARGET DEVICE
NOT REACHABLE."

Tested on v4.1.y with ESX v5.5u2+ with BlockCopy across multiple nodes.

Reported-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Nixon Vincent <nixon.vincent@calsoftinc.com>
Cc: Nixon Vincent <nixon.vincent@calsoftinc.com>
Tested-by: Dinesh Israni <ddi@datera.io>
Signed-off-by: Dinesh Israni <ddi@datera.io>
Cc: Dinesh Israni <ddi@datera.io>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: enhance and export target_alloc_sgl/target_free_sgl

The SRP target driver will need to allocate and chain it's own SGLs soon.
For this export target_alloc_sgl, and add a new argument to it so that it
can allocate an additional chain entry that doesn't point to a page. Also
export transport_free_sgl after renaming it to target_free_sgl to free
these SGLs again.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

target: Attach EXTENDED_COPY local I/O descriptors to xcopy_pt_sess

This patch is a >= v4.1 regression bug-fix where control CDB
emulation logic in commit 38b57f82 now expects a se_cmd->se_sess
pointer to exist when determining T10-PI support is to be exposed
for initiator host ports.

To address this bug, go ahead and add locally generated se_cmd
descriptors for copy-offload block-copy to it's own stand-alone
se_session nexus, while the parent EXTENDED_COPY se_cmd descriptor
remains associated with it's originating se_cmd->se_sess nexus.

Note a valid se_cmd->se_sess is also required for future support
of WRITE_INSERT and READ_STRIP software emulation when submitting
backend I/O to se_device that exposes T10-PI suport.

Reported-by: Alex Gorbachev <ag@iss-integration.com>
Tested-by: Alex Gorbachev <ag@iss-integration.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: <stable@vger.kernel.org> # v4.1+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Minimize SCSI header #include directives

Only include SCSI initiator header files in target code that needs
these header files, namely the SCSI pass-through code and the tcm_loop
driver. Change SCSI_SENSE_BUFFERSIZE into TRANSPORT_SENSE_BUFFER in
target code because the former is intended for initiator code and the
latter for target code. With this patch the only initiator include
directives in target code that remain are as follows:

$ git grep -nHE 'include .scsi/(scsi.h|scsi_host.h|scsi_device.h|scsi_cmnd.h)' drivers/target drivers/infiniband/ulp/{isert,srpt} drivers/usb/gadget/legacy/tcm_*.[ch] drivers/{vhost,xen} include/{target,trace/events/target.h}
drivers/target/loopback/tcm_loop.c:29:#include <scsi/scsi.h>
drivers/target/loopback/tcm_loop.c:31:#include <scsi/scsi_host.h>
drivers/target/loopback/tcm_loop.c:32:#include <scsi/scsi_device.h>
drivers/target/loopback/tcm_loop.c:33:#include <scsi/scsi_cmnd.h>
drivers/target/target_core_pscsi.c:39:#include <scsi/scsi_device.h>
drivers/target/target_core_pscsi.c:40:#include <scsi/scsi_host.h>
drivers/xen/xen-scsiback.c:52:#include <scsi/scsi_host.h> /* SG_ALL */

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

target: Subsume se_port + t10_alua_tg_pt_gp_member into se_lun

This patch eliminates all se_port + t10_alua_tg_pt_gp_member usage,
and converts current users to direct se_lun pointer dereference.

This includes the removal of core_export_port(), core_release_port()
core_dev_export() and core_dev_unexport(). Along with conversion
of special case se_lun pointer dereference within PR ALL_TG_PT=1
and ALUA access state transition UNIT_ATTENTION handling.

Also, update core_enable_device_list_for_node() to reference the
new per se_lun->lun_deve_list when creating a new entry, or
replacing an existing one via RCU.

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

target: target_core_configfs.h is not needed in fabric drivers

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

target: Move task tag into struct se_cmd + support 64-bit tags

Simplify target core and target drivers by storing the task tag
a.k.a. command identifier inside struct se_cmd.

For several transports (e.g. SRP) tags are 64 bits wide.
Hence add support for 64-bit tags.

(Fix core_tmr_abort_task conversion spec warnings - nab)
(Fix up usb-gadget to use 16-bit tags - HCH + bart)

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andy Grover <agrover@redhat.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: <qla2xxx-upstream@qlogic.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Fix se_tpg_tfo->tf_subsys regression + remove tf_subsystem

There is just one configfs subsystem in the target code, so we might as
well add two helpers to reference / unreference it from the core code
instead of passing pointers to it around.

This fixes a regression introduced for v4.1-rc1 with commit 9ac8928e6,
where configfs_depend_item() callers using se_tpg_tfo->tf_subsys would
fail, because the assignment from the original target_core_subsystem[]
is no longer happening at target_register_template() time.

(Fix target_core_exit_configfs pointer dereference - Sagi)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: simplify the target template registration API

Instead of calling target_fabric_configfs_init() +
target_fabric_configfs_register() / target_fabric_configfs_deregister()
target_fabric_configfs_free() from every target driver, rewrite the API
so that we have simple register/unregister functions that operate on
a const operations vector.

This patch also fixes a memory leak in several target drivers. Several
target drivers namely called target_fabric_configfs_deregister()
without calling target_fabric_configfs_free().

A large part of this patch is based on earlier changes from
Bart Van Assche <bart.vanassche@sandisk.com>.

(v2: Add a new TF_CIT_SETUP_DRV macro so that the core configfs code
can declare attributes as either core only or for drivers)

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

target: simplify target_xcopy_init_pt_lun

Drop unused argument & return value and consolidate a duplicate assignment.

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

target: remove the unused SCF_CMD_XCOPY_PASSTHROUGH flag

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

target: move external declarations to a headers

We should not declare extrnal .c symbols in C files to make sure they
match the actual prototype, and sparse correctly warns about this.

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

treewide: fix typo in printk and Kconfig

This patch fix spelling typo in printk and Kconfig within
various part of kernel sources.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

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>

drivers: target: Move prototype declaration of function to header file target_core_pr.h

Move prototype declaration of function
spc_parse_naa_6h_vendor_specific() from target_core_xcopy.c to header
file target_core_pr.h because it is used by more than one file.

This eliminates the following warning in target_core_spc.c:
drivers/target/target_core_spc.c:138:6: warning: no previous prototype for ‘spc_parse_naa_6h_vendor_specific’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Add per device xcopy_lun for copy offload I/O

This patch adds a se_device->xcopy_lun that is used for local
copy offload I/O, instead of allocating + initializing a pseudo
se_lun for each received EXTENDED_COPY operation.

Also, move declaration of struct se_lun + struct se_port_stat_grps
ahead of struct se_device.

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

target: Drop left-over se_lun->lun_cmd_list shutdown code

Now with percpu refcounting for se_lun in place, go ahead and drop
the legacy per se_cmd accounting for se_lun shutdown.

This includes __transport_clear_lun_from_sessions(), the associated
transport_lun_wait_for_tasks() logic, along with a handful of now
unused se_cmd structure members and ->transport_state bits.

Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Add percpu refcounting for se_lun access

This patch adds percpu refcounting for se_lun access that allows the
association of an se_lun + se_cmd in transport_lookup_cmd_lun() to
occur without an extra list_head for tracking outstanding I/O during
se_lun shutdown.

This effectively changes se_lun shutdown logic to wait for outstanding
I/O percpu references to complete in transport_lun_remove_cmd() using
se_lun->lun_ref_comp, instead of explicitly draining the per se_lun
command list and waiting for individual se_cmd descriptor processing
to complete.

Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Fail XCOPY for non matching source + destination block_size

This patch adds an explicit check + failure for XCOPY I/O to source +
destination devices with a non-matching block_size.

This limitiation is currently due to the fact that the scatterlist
memory allocated for the XCOPY READ operation is passed zero-copy
to the XCOPY WRITE operation.

Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Reported-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Thomas Glanzmann <thomas@glanzmann.de>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Generate failure for XCOPY I/O with non-zero scsi_status

This patch adds the missing non-zero se_cmd->scsi_status check required
for local XCOPY I/O within target_xcopy_issue_pt_cmd() to signal an
exception case failure.

This will trigger the generation of SAM_STAT_CHECK_CONDITION status
from within target_xcopy_do_work() process context code.

Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Reported-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Thomas Glanzmann <thomas@glanzmann.de>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Add missing XCOPY I/O operation sense_buffer

This patch adds the missing xcopy_pt_cmd->sense_buffer[] required for
correctly handling CHECK_CONDITION exceptions within the locally
generated XCOPY I/O path.

Also update target_xcopy_read_source() + target_xcopy_setup_pt_cmd()
to pass this buffer into transport_init_se_cmd() to correctly setup
se_cmd->sense_buffer.

Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Reported-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Thomas Glanzmann <thomas@glanzmann.de>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Reject EXTENDED_COPY when emulate_3pc is disabled

This patch rejects EXTENDED_COPY when the emulate_3pc attribute has
been explicitly disabled for the receiving device.

It also adds a similar check in target_xcopy_locate_se_dev_e4() to
ignore these devices when doing a search based upon the identifier
WWN provided by EXTENDED_COPY parameter list target descriptors.

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

target: Allow non zero ListID in EXTENDED_COPY parameter list

This patch changes target_do_xcopy() to allow processing of non-zero
ListIDs in EXTENDED_COPY parameter list data, instead of returning
CHECK_CONDITION status.

As the copy offload implementation reports SNLID=1 (Supports No ListID)
in OPERATING PARAMETERS, any ListID value presented by the client is
currently ignored.

Also, properly extract list_id_usage for informational purposes.

Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Reported-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Make target_do_xcopy failures return INVALID_PARAMETER_LIST

This patch changes target_do_xcopy() to properly return
TCM_INVALID_PARAMETER_LIST instead of TCM_INVALID_CDB_FIELD
for failures related to the EXTENDED_COPY parameter list parsing.

Also, move struct xcopy_op allocation ahead of kmapping to
handle the special TCM_OUT_OF_RESOURCES case.

Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Reported-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Fix xop->dbl assignment in target_xcopy_parse_segdesc_02

This patch fixes up an incorrect assignment for xop->dbl within
target_xcopy_parse_segdesc_02() code, as reported by Coverity here:

http://marc.info/?l=linux-kernel&m=137936416618490&w=2

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: remove unused including <linux/version.h>

Remove including <linux/version.h> that don't need it.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

target: Add support for EXTENDED_COPY copy offload emulation

This patch adds support for EXTENDED_COPY emulation from SPC-3, that
enables full copy offload target support within both a single virtual
backend device, and across multiple virtual backend devices. It also
functions independent of target fabric, and supports copy offload
across multiple target fabric ports.

This implemenation supports both EXTENDED_COPY PUSH and PULL models
of operation, so the actual CDB may be received on either source or
desination logical unit.

For Target Descriptors, it currently supports the NAA IEEE Registered
Extended designator (type 0xe4), which allows the reference of target
ports to occur independent of fabric type using EVPD 0x83 WWNs.

For Segment Descriptors, it currently supports copy from block to
block (0x02) mode.

It also honors any present SCSI reservations of the destination target
port. Note that only Supports No List Identifier (SNLID=1) mode is
supported.

Also included is basic RECEIVE_COPY_RESULTS with service action type
OPERATING PARAMETERS (0x03) required for SNLID=1 operation.

v3 changes:
- Fix incorrect return type in target_do_receive_copy_results()
(Fengguang)

v2 changes:
- Use target_alloc_sgl() instead of transport_generic_get_mem()
- Convert debug output to use pr_debug()
- Convert target_xcopy_parse_target_descriptors() NAA IEEN WWN
dump to use 0x%16phN format specification
- Drop unnecessary xcopy_pt_cmd->xpt_passthrough_wsem, and
associated usage in xcopy_pt_write_pending() and
target_xcopy_issue_pt_cmd()
- Add check for unsupported EXTENDED_COPY(LID4) service action
bits in target_do_xcopy()

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Zach Brown <zab@redhat.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@daterainc.com>