From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch adds initial WRITE_SAME (10) w/ UNMAP=1 support following updates in
sbcr26 to allow UNMAP=1 for the non 16 + 32 byte CDB case. It also refactors
current pSCSI passthrough passthrough checks into target_check_write_same_discard()
ahead of UNMAP=0 w/ write payload support into target_core_iblock.c.
This includes the support for handling WRITE_SAME in transport_emulate_control_cdb(),
and converts target_emulate_write_same to accept num_blocks directly for
WRITE_SAME, WRITE_SAME_16 and WRITE_SAME_32.
Reported-by: Eric Seppanen <eric@xxxxxxxxxxxxxxx>
Cc: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/target/target_core_cdb.c | 28 +++++----
drivers/target/target_core_transport.c | 102 ++++++++++++++++++--------------
2 files changed, 73 insertions(+), 57 deletions(-)
diff --git a/drivers/target/target_core_cdb.c b/drivers/target/target_core_cdb.c
index d095408..4c1d3a9 100644
--- a/drivers/target/target_core_cdb.c
+++ b/drivers/target/target_core_cdb.c
@@ -1090,24 +1090,17 @@ err:
* Note this is not used for TCM/pSCSI passthrough
*/
static int
-target_emulate_write_same(struct se_task *task, int write_same32)
+target_emulate_write_same(struct se_task *task, u32 num_blocks)
{
struct se_cmd *cmd = task->task_se_cmd;
struct se_device *dev = cmd->se_dev;
sector_t range;
sector_t lba = cmd->t_task_lba;
- unsigned int num_blocks;
int ret;
/*
- * Extract num_blocks from the WRITE_SAME_* CDB. Then use the explict
- * range when non zero is supplied, otherwise calculate the remaining
- * range based on ->get_blocks() - starting LBA.
+ * Use the explicit range when non zero is supplied, otherwise calculate
+ * the remaining range based on ->get_blocks() - starting LBA.
*/
- if (write_same32)
- num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
- else
- num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
-
if (num_blocks != 0)
range = num_blocks;
else
@@ -1170,13 +1163,23 @@ transport_emulate_control_cdb(struct se_task *task)
}
ret = target_emulate_unmap(task);
break;
+ case WRITE_SAME:
+ if (!dev->transport->do_discard) {
+ pr_err("WRITE_SAME emulation not supported"
+ " for: %s\n", dev->transport->name);
+ return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
+ }
+ ret = target_emulate_write_same(task,
+ get_unaligned_be16(&cmd->t_task_cdb[7]));
+ break;
case WRITE_SAME_16:
if (!dev->transport->do_discard) {
pr_err("WRITE_SAME_16 emulation not supported"
" for: %s\n", dev->transport->name);
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
- ret = target_emulate_write_same(task, 0);
+ ret = target_emulate_write_same(task,
+ get_unaligned_be32(&cmd->t_task_cdb[10]));
break;
case VARIABLE_LENGTH_CMD:
service_action =
@@ -1189,7 +1192,8 @@ transport_emulate_control_cdb(struct se_task *task)
dev->transport->name);
return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
}
- ret = target_emulate_write_same(task, 1);
+ ret = target_emulate_write_same(task,
+ get_unaligned_be32(&cmd->t_task_cdb[28]));
break;
default:
pr_err("Unsupported VARIABLE_LENGTH_CMD SA:"
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index fd7d451..eb8055a 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2861,6 +2861,38 @@ static int transport_cmd_get_valid_sectors(struct se_cmd *cmd)
return sectors;
}
+static int target_check_write_same_discard(unsigned char *flags, struct se_device *dev)
+{
+ /*
+ * Determine if the received WRITE_SAME is used to for direct
+ * passthrough into Linux/SCSI with struct request via TCM/pSCSI
+ * or we are signaling the use of internal WRITE_SAME + UNMAP=1
+ * emulation for -> Linux/BLOCK disbard with TCM/IBLOCK code.
+ */
+ int passthrough = (dev->transport->transport_type ==
+ TRANSPORT_PLUGIN_PHBA_PDEV);
+
+ if (!passthrough) {
+ if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
+ pr_err("WRITE_SAME PBDATA and LBDATA"
+ " bits not supported for Block Discard"
+ " Emulation\n");
+ return -ENOSYS;
+ }
+ /*
+ * Currently for the emulated case we only accept
+ * tpws with the UNMAP=1 bit set.
+ */
+ if (!(flags[0] & 0x08)) {
+ pr_err("WRITE_SAME w/o UNMAP bit not"
+ " supported for Block Discard Emulation\n");
+ return -ENOSYS;
+ }
+ }
+
+ return 0;
+}
+
/* transport_generic_cmd_sequencer():
*
* Generic Command Sequencer that should work for most DAS transport
@@ -3081,27 +3113,9 @@ static int transport_generic_cmd_sequencer(
cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
- /*
- * Skip the remaining assignments for TCM/PSCSI passthrough
- */
- if (passthrough)
- break;
-
- if ((cdb[10] & 0x04) || (cdb[10] & 0x02)) {
- pr_err("WRITE_SAME PBDATA and LBDATA"
- " bits not supported for Block Discard"
- " Emulation\n");
+ if (target_check_write_same_discard(&cdb[10], dev) < 0)
goto out_invalid_cdb_field;
- }
- /*
- * Currently for the emulated case we only accept
- * tpws with the UNMAP=1 bit set.
- */
- if (!(cdb[10] & 0x08)) {
- pr_err("WRITE_SAME w/o UNMAP bit not"
- " supported for Block Discard Emulation\n");
- goto out_invalid_cdb_field;
- }
+
break;
default:
pr_err("VARIABLE_LENGTH_CMD service action"
@@ -3358,33 +3372,31 @@ static int transport_generic_cmd_sequencer(
}
cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
- passthrough = (dev->transport->transport_type ==
- TRANSPORT_PLUGIN_PHBA_PDEV);
- /*
- * Determine if the received WRITE_SAME_16 is used to for direct
- * passthrough into Linux/SCSI with struct request via TCM/pSCSI
- * or we are signaling the use of internal WRITE_SAME + UNMAP=1
- * emulation for -> Linux/BLOCK disbard with TCM/IBLOCK and
- * TCM/FILEIO subsystem plugin backstores.
- */
- if (!passthrough) {
- if ((cdb[1] & 0x04) || (cdb[1] & 0x02)) {
- pr_err("WRITE_SAME PBDATA and LBDATA"
- " bits not supported for Block Discard"
- " Emulation\n");
- goto out_invalid_cdb_field;
- }
- /*
- * Currently for the emulated case we only accept
- * tpws with the UNMAP=1 bit set.
- */
- if (!(cdb[1] & 0x08)) {
- pr_err("WRITE_SAME w/o UNMAP bit not "
- " supported for Block Discard Emulation\n");
- goto out_invalid_cdb_field;
- }
+ cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
+
+ if (target_check_write_same_discard(&cdb[1], dev) < 0)
+ goto out_invalid_cdb_field;
+ break;
+ case WRITE_SAME:
+ sectors = transport_get_sectors_10(cdb, cmd, §or_ret);
+ if (sector_ret)
+ goto out_unsupported_cdb;
+
+ if (sectors)
+ size = transport_get_size(sectors, cdb, cmd);
+ else {
+ pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
+ goto out_invalid_cdb_field;
}
+
+ cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
+ /*
+ * Follow sbcr26 with WRITE_SAME (10) and check for the existence
+ * of byte 1 bit 3 UNMAP instead of original reserved field
+ */
+ if (target_check_write_same_discard(&cdb[1], dev) < 0)
+ goto out_invalid_cdb_field;
break;
case ALLOW_MEDIUM_REMOVAL:
case GPCMD_CLOSE_TRACK:
--
1.7.6
--
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