linux/include/target
Bodo Stroesser 356ba2a8bc scsi: target: tcmu: Make pgr_support and alua_support attributes writable
Currently in tcmu reservation commands are handled by core's pr
implementation (default) or completely rejected (emulate_pr set to 0). We
additionally want to be able to do full reservation handling in
userspace. Therefore we need a way to set TRANSPORT_FLAG_PASSTHROUGH_PGR.

The inverted flag is displayed by attribute pgr_support.  Since we moved
the flag from transport/backend to se_device in the previous commit, we now
can make it changeable per device by allowing to write the attribute.  The
new field transport_flags_changeable in transport/backend is used to reject
writing if not allowed for a backend.

Regarding ALUA we also want to be able to passthrough commands to userspace
in tcmu. Therefore we need TRANSPORT_FLAG_PASSTHROUGH_ALUA to be
changeable, because by setting it we can switch off all ALUA checks in
core. So we also set TRANSPORT_FLAG_PASSTHROUGH_ALUA in tcmu's
transport_flags_changeable.

Of course, ALUA and reservation handling in userspace will work only, if
session/nexus information is sent to userspace along with every
command. This will be object of a patch series announced by Mike Christie.

Link: https://lore.kernel.org/r/20200427150823.15350-5-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-05-07 22:39:22 -04:00
..
iscsi scsi: target: iscsi: Remove the iscsi_data_count structure 2020-04-24 18:21:15 -04:00
target_core_backend.h scsi: target: tcmu: Make pgr_support and alua_support attributes writable 2020-05-07 22:39:22 -04:00
target_core_base.h scsi: target: Make transport_flags per device 2020-05-07 22:39:21 -04:00
target_core_fabric.h scsi: target/core: Rework the SPC-2 reservation handling code 2019-04-12 20:20:05 -04:00