linux/drivers/target
Andy Grover 0ad46af8a6 target: Version 2 of TCMU ABI
The initial version of TCMU (in 3.18) does not properly handle
bidirectional SCSI commands -- those with both an in and out buffer. In
looking to fix this it also became clear that TCMU's support for adding
new types of entries (opcodes) to the command ring was broken. We need
to fix this now, so that future issues can be handled properly by adding
new opcodes.

We make the most of this ABI break by enabling bidi cmd handling within
TCMP_OP_CMD opcode. Add an iov_bidi_cnt field to tcmu_cmd_entry.req.
This enables TCMU to describe bidi commands, but further kernel work is
needed for full bidi support.

Enlarge tcmu_cmd_entry_hdr by 32 bits by pulling in cmd_id and __pad1. Turn
__pad1 into two 8 bit flags fields, for kernel-set and userspace-set flags,
"kflags" and "uflags" respectively.

Update version fields so userspace can tell the interface is changed.

Update tcmu-design.txt with details of how new stuff works:
- Specify an additional requirement for userspace to set UNKNOWN_OP
  (bit 0) in hdr.uflags for unknown/unhandled opcodes.
- Define how Data-In and Data-Out fields are described in req.iov[]

Changed in v2:
- Change name of SKIPPED bit to UNKNOWN bit
- PAD op does not set the bit any more
- Change len_op helper functions to take just len_op, not the whole struct
- Change version to 2 in missed spots, and use defines
- Add 16 unused bytes to cmd_entry.req, in case additional SAM cmd
  parameters need to be included
- Add iov_dif_cnt field to specify buffers used for DIF info in iov[]
- Rearrange fields to naturally align cdb_off
- Handle if userspace sets UNKNOWN_OP by indicating failure of the cmd
- Wrap some overly long UPDATE_HEAD lines

(Add missing req.iov_bidi_cnt + req.iov_dif_cnt zeroing - Ilias)

Signed-off-by: Andy Grover <agrover@redhat.com>
Reviewed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-04-19 22:40:26 -07:00
..
iscsi target: simplify the target template registration API 2015-04-14 12:28:41 -07:00
loopback target: simplify the target template registration API 2015-04-14 12:28:41 -07:00
sbp target: simplify the target template registration API 2015-04-14 12:28:41 -07:00
tcm_fc target: simplify the target template registration API 2015-04-14 12:28:41 -07:00
Kconfig target: Add a user-passthrough backstore 2014-10-03 11:15:20 -07:00
Makefile target: Add a user-passthrough backstore 2014-10-03 11:15:20 -07:00
target_core_alua.c scsi: rename SERVICE_ACTION_IN to SERVICE_ACTION_IN_16 2014-11-24 20:01:40 +01:00
target_core_alua.h target_core_alua: Referrals configfs integration 2014-01-09 21:48:35 -08:00
target_core_configfs.c target: simplify the target template registration API 2015-04-14 12:28:41 -07:00
target_core_device.c target: Drop left-over fabric_max_sectors attribute 2015-01-09 15:22:05 -08:00
target_core_fabric_configfs.c target: simplify the target template registration API 2015-04-14 12:28:41 -07:00
target_core_fabric_lib.c target: fix pr_out length in iscsi_parse_pr_out_transport_id 2014-09-17 15:17:35 -07:00
target_core_file.c target/file: Fix UNMAP with DIF protection support 2015-04-15 22:47:27 -07:00
target_core_file.h Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2014-01-31 15:31:23 -08:00
target_core_hba.c target: Move dev_cit to struct se_subsystem_api 2014-12-01 21:35:22 -08:00
target_core_iblock.c target/iblock: Add checks for backend DIF emulation 2015-04-07 23:27:44 -07:00
target_core_iblock.h target: kill struct se_subsystem_dev 2012-11-06 20:55:43 -08:00
target_core_internal.h target: move external declarations to a headers 2015-03-26 14:51:53 -07:00
target_core_pr.c target: Fix two sparse warnings 2015-04-14 12:37:38 -07:00
target_core_pr.h target: Fix APTPL metadata handling for dynamic MappedLUNs 2014-10-04 05:40:19 +00:00
target_core_pscsi.c SCSI for-linus on 20141220 2014-12-20 13:42:57 -08:00
target_core_pscsi.h target: kill struct se_subsystem_dev 2012-11-06 20:55:43 -08:00
target_core_rd.c target/rd: Don't pass incomplete scatterlist entries to sbc_dif_verify_* 2015-04-14 12:37:42 -07:00
target_core_rd.h target/rd: Add support for protection SGL setup + release 2014-01-19 02:22:05 +00:00
target_core_sbc.c target/sbc: Update sbc_dif_generate pr_debug output 2015-04-15 22:47:19 -07:00
target_core_spc.c target: Update SPC/SBC emulation for sess_prot_type 2015-04-07 23:26:09 -07:00
target_core_stat.c target: Convert se_device statistics to atomic_long_t 2013-11-13 18:34:55 -08:00
target_core_tmr.c target: Make core_tmr_abort_task() skip TMFs 2015-04-15 22:47:21 -07:00
target_core_tpg.c target: simplify the target template registration API 2015-04-14 12:28:41 -07:00
target_core_transport.c target: Ensure sess_prot_type is saved across session restart 2015-04-15 22:46:30 -07:00
target_core_ua.c target: encapsulate smp_mb__after_atomic() 2014-10-01 14:39:06 -07:00
target_core_ua.h target: target_core_ua_h: Add #define of include guard 2014-09-15 14:27:43 -07:00
target_core_user.c target: Version 2 of TCMU ABI 2015-04-19 22:40:26 -07:00
target_core_xcopy.c target: simplify the target template registration API 2015-04-14 12:28:41 -07:00
target_core_xcopy.h target: Add support for EXTENDED_COPY copy offload emulation 2013-09-10 16:48:43 -07:00