Pull target updates from Nicholas Bellinger:
 "It has been a very busy development cycle this time around in target
  land, with the highlights including:

   - Kill struct se_subsystem_dev, in favor of direct se_device usage
     (hch)
   - Simplify reservations code by combining SPC-3 + SCSI-2 support for
     virtual backends only (hch)
   - Simplify ALUA code for virtual only backends, and remove left over
     abstractions (hch)
   - Pass sense_reason_t as return value for I/O submission path (hch)
   - Refactor MODE_SENSE emulation to allow for easier addition of new
     mode pages.  (roland)
   - Add emulation of MODE_SELECT (roland)
   - Fix bug in handling of ExpStatSN wrap-around (steve)
   - Fix bug in TMR ABORT_TASK lookup in qla2xxx target (steve)
   - Add WRITE_SAME w/ UNMAP=0 support for IBLOCK backends (nab)
   - Convert ib_srpt to use modern target_submit_cmd caller + drop
     legacy ioctx->kref usage (nab)
   - Convert ib_srpt to use modern target_submit_tmr caller (nab)
   - Add link_magic for fabric allow_link destination target_items for
     symlinks within target_core_fabric_configfs.c code (nab)
   - Allocate pointers in instead of full structs for
     config_group->default_groups (sebastian)
   - Fix 32-bit highmem breakage for FILEIO (sebastian)

  All told, hch was able to shave off another ~1K LOC by killing the
  se_subsystem_dev abstraction, along with a number of PR + ALUA
  simplifications.  Also, a nice patch by Roland is the refactoring of
  MODE_SENSE handling, along with the addition of initial MODE_SELECT
  emulation support for virtual backends.

  Sebastian found a long-standing issue wrt to allocation of full
  config_group instead of pointers for config_group->default_group[]
  setup in a number of areas, which ends up saving memory with big
  configurations.  He also managed to fix another long-standing BUG wrt
  to broken 32-bit highmem support within the FILEIO backend driver.

  Thank you again to everyone who contributed this round!"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (50 commits)
  target/iscsi_target: Add NodeACL tags for initiator group support
  target/tcm_fc: fix the lockdep warning due to inconsistent lock state
  sbp-target: fix error path in sbp_make_tpg()
  sbp-target: use simple assignment in tgt_agent_rw_agent_state()
  iscsi-target: use kstrdup() for iscsi_param
  target/file: merge fd_do_readv() and fd_do_writev()
  target/file: Fix 32-bit highmem breakage for SGL -> iovec mapping
  target: Add link_magic for fabric allow_link destination target_items
  ib_srpt: Convert TMR path to target_submit_tmr
  ib_srpt: Convert I/O path to target_submit_cmd + drop legacy ioctx->kref
  target: Make spc_get_write_same_sectors return sector_t
  target/configfs: use kmalloc() instead of kzalloc() for default groups
  target/configfs: allocate only 6 slots for dev_cg->default_groups
  target/configfs: allocate pointers instead of full struct for default_groups
  target: update error handling for sbc_setup_write_same()
  iscsit: use GFP_ATOMIC under spin lock
  iscsi_target: Remove redundant null check before kfree
  target/iblock: Forward declare bio helpers
  target: Clean up flow in transport_check_aborted_status()
  target: Clean up logic in transport_put_cmd()
  ...

Pull trivial branch from Jiri Kosina:
 "Usual stuff -- comment/printk typo fixes, documentation updates, dead
  code elimination."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  HOWTO: fix double words typo
  x86 mtrr: fix comment typo in mtrr_bp_init
  propagate name change to comments in kernel source
  doc: Update the name of profiling based on sysfs
  treewide: Fix typos in various drivers
  treewide: Fix typos in various Kconfig
  wireless: mwifiex: Fix typo in wireless/mwifiex driver
  messages: i2o: Fix typo in messages/i2o
  scripts/kernel-doc: check that non-void fcts describe their return value
  Kernel-doc: Convention: Use a "Return" section to describe return values
  radeon: Fix typo and copy/paste error in comments
  doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c
  various: Fix spelling of "asynchronous" in comments.
  Fix misspellings of "whether" in comments.
  eisa: Fix spelling of "asynchronous".
  various: Fix spelling of "registered" in comments.
  doc: fix quite a few typos within Documentation
  target: iscsi: fix comment typos in target/iscsi drivers
  treewide: fix typo of "suport" in various comments and Kconfig
  treewide: fix typo of "suppport" in various comments
  ...

The variable se_sess is initialized but never used
otherwise, so remove the unused variable.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Zero copy TX has been around for a while now.
We seem to be down to eliminating theoretical bugs
and performance tuning at this point:
it's probably time to enable it by default so that
most users get the benefit.

Keep the flag around meanwhile so users can experiment
with disabling this if they experience regressions.
I expect that we will remove it in the future.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

For short packets zerocopy mode adds overhead
of managing heads which isn't necessary: we
could simly update used ring directly
same as with zerocopy disabled.

Things seem to run a bit faster if we detect
and bypass head management when zcopy isn't used.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

When memory map changes, we need to flush outstanding
DMAs as they might in theory reference old memory addresses.
To do this simply stop initiating new DMAs
and wait for ubufs ref count to drop to 0.
Afterwards reset the count back to 1.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

vring changes already do a flush internally where appropriate, so we do
not need a second flush.

It's currently not very expensive but a follow-up patch makes flush more
heavy-weight, so remove the extra flush here to avoid regressing
performance if call or kick fds are changed on data path.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

These packet counters are used to drive the zercopy
selection heuristic so nothing too bad happens if they are off a bit -
and they are also reset once in a while.
But it's cleaner to clear them when backend is set so that
we start in a known state.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: David S. Miller <davem@davemloft.net>

If a single descriptor crosses a region, the
second chunk length should be decremented
by size translated so far, instead it includes
the full descriptor length.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>