Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

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

   - Add target_alloc_session() w/ callback helper for doing se_session
     allocation + tag + se_node_acl lookup.  (HCH + nab)

   - Tree-wide fabric driver conversion to use target_alloc_session()

   - Convert sbp-target to use percpu_ida tag pre-allocation, and
     TARGET_SCF_ACK_KREF I/O krefs (Chris Boot + nab)

   - Convert usb-gadget to use percpu_ida tag pre-allocation, and
     TARGET_SCF_ACK_KREF I/O krefs (Andrzej Pietrasiewicz + nab)

   - Convert xen-scsiback to use percpu_ida tag pre-allocation, and
     TARGET_SCF_ACK_KREF I/O krefs (Juergen Gross + nab)

   - Convert tcm_fc to use TARGET_SCF_ACK_KREF I/O + TMR krefs

   - Convert ib_srpt to use percpu_ida tag pre-allocation

   - Add DebugFS node for qla2xxx target sess list (Quinn)

   - Rework iser-target connection termination (Jenny + Sagi)

   - Convert iser-target to new CQ API (HCH)

   - Add pass-through WRITE_SAME support for IBLOCK (Mike Christie)

   - Introduce data_bitmap for asynchronous access of data area (Sheng
     Yang + Andy)

   - Fix target_release_cmd_kref shutdown comp leak (Himanshu Madhani)

  Also, there is a separate PULL request coming for cxgb4 NIC driver
  prerequisites for supporting hw iscsi segmentation offload (ISO), that
  will be the base for a number of v4.7 developments involving
  iscsi-target hw offloads"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (36 commits)
  target: Fix target_release_cmd_kref shutdown comp leak
  target: Avoid DataIN transfers for non-GOOD SAM status
  target/user: Report capability of handling out-of-order completions to userspace
  target/user: Fix size_t format-spec build warning
  target/user: Don't free expired command when time out
  target/user: Introduce data_bitmap, replace data_length/data_head/data_tail
  target/user: Free data ring in unified function
  target/user: Use iovec[] to describe continuous area
  target: Remove enum transport_lunflags_table
  target/iblock: pass WRITE_SAME to device if possible
  iser-target: Kill the ->isert_cmd back pointer in struct iser_tx_desc
  iser-target: Kill struct isert_rdma_wr
  iser-target: Convert to new CQ API
  iser-target: Split and properly type the login buffer
  iser-target: Remove ISER_RECV_DATA_SEG_LEN
  iser-target: Remove impossible condition from isert_wait_conn
  iser-target: Remove redundant wait in release_conn
  iser-target: Rework connection termination
  iser-target: Separate flows for np listeners and connections cma events
  iser-target: Add new state ISER_CONN_BOUND to isert_conn
  ...

1 files changed, 10 insertions, 1 deletions

diff --git a/Documentation/target/tcmu-design.txt b/Documentation/target/tcmu-design.txt
index bef81e42788f..4cebc1ebf99a 100644
--- a/Documentation/target/tcmu-design.txt
+++ b/Documentation/target/tcmu-design.txt
@@ -117,7 +117,9 @@ userspace (respectively) to put commands on the ring, and indicate
 when the commands are completed.
 
 version - 1 (userspace should abort if otherwise)
-flags - none yet defined.
+flags:
+- TCMU_MAILBOX_FLAG_CAP_OOOC: indicates out-of-order completion is
+  supported.  See "The Command Ring" for details.
 cmdr_off - The offset of the start of the command ring from the start
 of the memory region, to account for the mailbox size.
 cmdr_size - The size of the command ring. This does *not* need to be a
@@ -162,6 +164,13 @@ rsp.sense_buffer if necessary. Userspace then increments
 mailbox.cmd_tail by entry.hdr.length (mod cmdr_size) and signals the
 kernel via the UIO method, a 4-byte write to the file descriptor.
 
+If TCMU_MAILBOX_FLAG_CAP_OOOC is set for mailbox->flags, kernel is
+capable of handling out-of-order completions. In this case, userspace can
+handle command in different order other than original. Since kernel would
+still process the commands in the same order it appeared in the command
+ring, userspace need to update the cmd->id when completing the
+command(a.k.a steal the original command's entry).
+
 When the opcode is PAD, userspace only updates cmd_tail as above --
 it's a no-op. (The kernel inserts PAD entries to ensure each CMD entry
 is contiguous within the command ring.)