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>

Pull SCSI target updates from Nicholas Bellinger:
 "Lots of activity in target land the last months.

  The highlights include:

   - Convert fabric drivers tree-wide to target_register_template() (hch
     + bart)

   - iser-target hardening fixes + v1.0 improvements (sagi)

   - Convert iscsi_thread_set usage to kthread.h + kill
     iscsi_target_tq.c (sagi + nab)

   - Add support for T10-PI WRITE_STRIP + READ_INSERT operation (mkp +
     sagi + nab)

   - DIF fixes for CONFIG_DEBUG_SG=y + UNMAP file emulation (akinobu +
     sagi + mkp)

   - Extended TCMU ABI v2 for future BIDI + DIF support (andy + ilias)

   - Fix COMPARE_AND_WRITE handling for NO_ALLLOC drivers (hch + nab)

  Thanks to everyone who contributed this round with new features,
  bug-reports, fixes, cleanups and improvements.

  Looking forward, it's currently shaping up to be a busy v4.2 as well"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (69 commits)
  target: Put TCMU under a new config option
  target: Version 2 of TCMU ABI
  target: fix tcm_mod_builder.py
  target/file: Fix UNMAP with DIF protection support
  target/file: Fix SG table for prot_buf initialization
  target/file: Fix BUG() when CONFIG_DEBUG_SG=y and DIF protection enabled
  target: Make core_tmr_abort_task() skip TMFs
  target/sbc: Update sbc_dif_generate pr_debug output
  target/sbc: Make internal DIF emulation honor ->prot_checks
  target/sbc: Return INVALID_CDB_FIELD if DIF + sess_prot_type disabled
  target: Ensure sess_prot_type is saved across session restart
  target/rd: Don't pass incomplete scatterlist entries to sbc_dif_verify_*
  target: Remove the unused flag SCF_ACK_KREF
  target: Fix two sparse warnings
  target: Fix COMPARE_AND_WRITE with SG_TO_MEM_NOALLOC handling
  target: simplify the target template registration API
  target: simplify target_xcopy_init_pt_lun
  target: remove the unused SCF_CMD_XCOPY_PASSTHROUGH flag
  target/rd: reduce code duplication in rd_execute_rw()
  tcm_loop: fixup tpgt string to integer conversion
  ...

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>

This patch updates vhost-scsi to add a new fabric_prot_type TPG
attribute, used for controlling LLD level protection into LIO when
the backend device does not support T10-PI.

This is required for vhost-scsi to enable WRITE_STRIP + READ_INSERT
operations using software emulation + crct10dif instruction offload.

It's disabled by default and controls which se_sesion->sess_prot_type
are set at vhost_scsi_make_nexus() session registration time.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch changes loopback, usb-gadget, vhost-scsi and xen-scsiback
fabric code to invoke transport_register_session() instead of the
unprotected flavour, to ensure se_tpg->session_lock is taken when
adding new session list nodes to se_tpg->tpg_sess_list.

Note that since these four fabric drivers already hold their own
internal TPG mutexes when accessing se_tpg->tpg_sess_list, and
consist of a single se_session created through configfs attribute
access, no list corruption can currently occur.

So for correctness sake, go ahead and use the se_tpg->session_lock
protected version for these four fabric drivers.

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

Pull SCSI target updates from Nicholas Bellinger:
 "The highlights this round include:

   - Update vhost-scsi to support F_ANY_LAYOUT using mm/iov_iter.c
     logic, and signal VERSION_1 support (MST + Viro + nab)

   - Fix iscsi/iser-target to remove problematic active_ts_set usage
     (Gavin Guo)

   - Update iscsi/iser-target to support multi-sequence sendtargets
     (Sagi)

   - Fix original PR_APTPL_BUF_LEN 8k size limitation (Martin Svec)

   - Add missing WRITE_SAME end-of-device sanity check (Bart)

   - Check for LBA + sectors wrap-around in sbc_parse_cdb() (nab)

   - Other various minor SPC/SBC compliance fixes based upon Ronnie
     Sahlberg test suite (nab)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (32 commits)
  target: Set LBPWS10 bit in Logical Block Provisioning EVPD
  target: Fail UNMAP when emulate_tpu=0
  target: Fail WRITE_SAME w/ UNMAP=1 when emulate_tpws=0
  target: Add sanity checks for DPO/FUA bit usage
  target: Perform PROTECT sanity checks for WRITE_SAME
  target: Fail I/O with PROTECT bit when protection is unsupported
  target: Check for LBA + sectors wrap-around in sbc_parse_cdb
  target: Add missing WRITE_SAME end-of-device sanity check
  iscsi-target: Avoid IN_LOGOUT failure case for iser-target
  target: Fix PR_APTPL_BUF_LEN buffer size limitation
  iscsi-target: Drop problematic active_ts_list usage
  iscsi/iser-target: Support multi-sequence sendtargets text response
  iser-target: Remove duplicate function names
  vhost/scsi: potential memory corruption
  vhost/scsi: Global tcm_vhost -> vhost_scsi rename
  vhost/scsi: Drop left-over scsi_tcq.h include
  vhost/scsi: Set VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 feature bits
  vhost/scsi: Add ANY_LAYOUT support in vhost_scsi_handle_vq
  vhost/scsi: Add ANY_LAYOUT iov -> sgl mapping prerequisites
  vhost/scsi: Change vhost_scsi_map_to_sgl to accept iov ptr + len
  ...

This code in vhost_scsi_make_tpg() is confusing because we limit "tpgt"
to UINT_MAX but the data type of "tpg->tport_tpgt" and that is a u16.

I looked at the context and it turns out that in
vhost_scsi_set_endpoint(), "tpg->tport_tpgt" is used as an offset into
the vs_tpg[] array which has VHOST_SCSI_MAX_TARGET (256) elements so
anything higher than 255 then it is invalid.  I have made that the limit
now.

In vhost_scsi_send_evt() we mask away values higher than 255, but now
that the limit has changed, we don't need the mask.

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

There is a large amount of code that still references the original
'tcm_vhost' naming conventions, instead of modern 'vhost_scsi'.

Go ahead and do a global rename to make the usage consistent.

Cc: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

With the recent removal of MSG_*_TAG defines in commit 68d81f40,
vhost-scsi is now using TCM_*_TAG and doesn't depend upon host
side scsi_tcq.h definitions anymore.

Cc: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Signal support of VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 feature bits
required for virtio-scsi 1.0 spec layout requirements.

Cc: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>