[PATCH] tcm: Add support for SA WRITE_SAME_32

From: Nicholas A. Bellinger
Date: Sat Oct 02 2010 - 21:20:34 EST


From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

Greetings mkp, boaz and co,

This patch adds support for service action WRITE_SAME_32 into
transport_generic_cmd_sequencer() to allow both emulate_tpws=1 with
TCM IBLOCK+FILEIO WRITE_SAME_32 w/ UNMAP=1 and existing TCM/pSCSI passthrough to
function. This has been briefly tested 'sg_write_same -T' with TCM_Loop ->
TCM/FILEIO -> scsi_debug:

sg_write_same --xferlen=4096 -T -U -v -v --lba=1024 --num=8 /dev/bsg/9\:0\:1\:0
open /dev/bsg/9:0:1:0 with flags=0x802
Default data-out buffer to 4096 zeroes
Write same(32) cmd: 7f 00 00 00 00 00 00 18 00 0d 08 00 00 00 00 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00 00 08
Data-out buffer length=4096

Comments are welcome!

Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 40 ++++++++++++++++++++++++++++++++
1 files changed, 40 insertions(+), 0 deletions(-)

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 445fbc3..39bbf57 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -5856,6 +5856,46 @@ static int transport_generic_cmd_sequencer(
T_TASK(cmd)->t_tasks_fua = (cdb[10] & 0x8);
ret = TGCS_DATA_SG_IO_CDB;
break;
+ case WRITE_SAME_32:
+ sectors = transport_get_sectors_32(cdb, cmd, &sector_ret);
+ if (sector_ret)
+ return TGCS_UNSUPPORTED_CDB;
+ size = transport_get_size(sectors, cdb, cmd);
+ transport_dev_get_mem_SG(cmd->se_orig_obj_ptr, cmd);
+ transport_get_maps(cmd);
+ cmd->transport_split_cdb = &split_cdb_XX_32;
+ cmd->transport_get_long_lba = &transport_lba_64_ext;
+ /*
+ * Skip the remaining assignments for TCM/PSCSI passthrough
+ */
+ if (passthrough) {
+ ret = TGCS_DATA_SG_IO_CDB;
+ break;
+ }
+ if ((cdb[10] & 0x04) || (cdb[10] & 0x02)) {
+ printk(KERN_ERR "WRITE_SAME PBDATA and LBDATA"
+ " bits not supported for Block Discard"
+ " Emulation\n");
+ return TGCS_INVALID_CDB_FIELD;
+ }
+ /*
+ * Currently for the emulated case we only accept
+ * tpws with the UNMAP=1 bit set.
+ */
+ if (!(cdb[10] & 0x08)) {
+ printk(KERN_ERR "WRITE_SAME w/ UNMAP bit not"
+ " supported for Block Discard Emulation\n");
+ return TGCS_INVALID_CDB_FIELD;
+ }
+
+ cmd->se_cmd_flags |= SCF_EMULATE_SYNC_WRITE_SAME;
+ /*
+ * Signal to TCM IBLOCK+FILEIO subsystem plugins that WRITE
+ * tasks will be translated to SCSI UNMAP -> Block Discard
+ */
+ T_TASK(cmd)->t_tasks_unmap = 1;
+ ret = TGCS_DATA_SG_IO_CDB;
+ break;
default:
printk(KERN_ERR "VARIABLE_LENGTH_CMD service action"
" 0x%04x not supported\n", service_action);
--
1.5.6.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/