From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch updates sbc_write_same_supported() to set SCF_WRITE_SAME_DISCARD
to signal when WRITE_SAME w/ UNMAP=1 is requested.
Also, allow WRITE_SAME w/ UNMAP=0 to be passed to backend driver logic.
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_sbc.c | 19 +++++++------------
include/target/target_core_base.h | 1 +
2 files changed, 8 insertions(+), 12 deletions(-)
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index b802421..ee9fa52 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -235,7 +235,7 @@ static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
}
-static int sbc_write_same_supported(struct se_device *dev,
+static int sbc_write_same_supported(struct se_cmd *cmd,
unsigned char *flags)
{
if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
@@ -244,16 +244,11 @@ static int sbc_write_same_supported(struct se_device *dev,
" Emulation\n");
return -ENOSYS;
}
-
/*
- * Currently for the emulated case we only accept
- * tpws with the UNMAP=1 bit set.
+ * UNMAP=1 bit translantes to blkdev_issue_discard() execution
*/
- if (!(flags[0] & 0x08)) {
- pr_err("WRITE_SAME w/o UNMAP bit not"
- " supported for Block Discard Emulation\n");
- return -ENOSYS;
- }
+ if (flags[0] & 0x08)
+ cmd->se_cmd_flags |= SCF_WRITE_SAME_DISCARD;
return 0;
}
@@ -431,7 +426,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
size = sbc_get_size(cmd, 1);
cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
- if (sbc_write_same_supported(dev, &cdb[10]) < 0)
+ if (sbc_write_same_supported(cmd, &cdb[10]) < 0)
return TCM_UNSUPPORTED_SCSI_OPCODE;
cmd->execute_cmd = ops->execute_write_same;
break;
@@ -507,7 +502,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
size = sbc_get_size(cmd, 1);
cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
- if (sbc_write_same_supported(dev, &cdb[1]) < 0)
+ if (sbc_write_same_supported(cmd, &cdb[1]) < 0)
return TCM_UNSUPPORTED_SCSI_OPCODE;
cmd->execute_cmd = ops->execute_write_same;
break;
@@ -528,7 +523,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
* Follow sbcr26 with WRITE_SAME (10) and check for the existence
* of byte 1 bit 3 UNMAP instead of original reserved field
*/
- if (sbc_write_same_supported(dev, &cdb[1]) < 0)
+ if (sbc_write_same_supported(cmd, &cdb[1]) < 0)
return TCM_UNSUPPORTED_SCSI_OPCODE;
cmd->execute_cmd = ops->execute_write_same;
break;
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 5350f6e..2787b85 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -154,6 +154,7 @@ enum se_cmd_flags_table {
SCF_ALUA_NON_OPTIMIZED = 0x00008000,
SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC = 0x00020000,
SCF_ACK_KREF = 0x00040000,
+ SCF_WRITE_SAME_DISCARD = 0x00080000,
};
/* struct se_dev_entry->lun_flags and struct se_lun->lun_access */
--
1.7.2.5
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