From: Nicholas Bellinger <nab@xxxxxxxxxxxxx> Hi folks, This series adds support to target-core for generic COMPARE_AND_WRITE emulation as defined by SBC-3 using virtual (IBLOCK, FILEIO, RAMDISK) backends. COMPARE_AND_WRITE is a VMWare ESX VAAI primitive that is currently used by VMFS to perform array side locking of filesystem extents. The logic is the functional equivilent of an atomic test and set, which allows a cluster filesystem to scale across multiple clients by locking individual regions, without having to obtain a traditional SCSI reservation for exclusive access to the entire logical unit. This implemenation is currently limited to a single number of logical block (NoLB). It's also currently lacking the necessary sychronization between I/O submission of COMPARE_AND_WRITE verify instance and write instance user data, which is still being worked on in order to avoid additional overhead in the main I/O fast path. Please review as v3.12 material. Thanks! --nab Nicholas Bellinger (9): scsi: Add CDB definition for COMPARE_AND_WRITE target: Add return for se_cmd->transport_complete_callback target: Add memory allocation for bidirectional commands target: Add TCM_MISCOMPARE_VERIFY sense handling target: Skip ->queue_data_in() callbacks for COMPARE_AND_WRITE target: Allow sbc_ops->execute_rw() to accept SGLs + data_direction target: Add transport_reset_sgl_orig() for COMPARE_AND_WRITE target: Add support for COMPARE_AND_WRITE emulation tcm_qla2xxx: Add special case for COMPARE_AND_WRITE data_direction drivers/scsi/qla2xxx/tcm_qla2xxx.c | 9 +- drivers/target/target_core_file.c | 6 +- drivers/target/target_core_iblock.c | 6 +- drivers/target/target_core_rd.c | 6 +- drivers/target/target_core_sbc.c | 205 +++++++++++++++++++++++++++++--- drivers/target/target_core_transport.c | 109 ++++++++++++++++- include/scsi/scsi.h | 1 + include/target/target_core_backend.h | 3 +- include/target/target_core_base.h | 9 +- 9 files changed, 317 insertions(+), 37 deletions(-) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
