From: Nicholas Bellinger <n...@daterainc.com>
This patch adds the MAXIMUM COMPARE AND WRITE LENGTH bit, currently
hardcoded to a single logical block (NoLB=1) within the Block Limits
VPD in spc_emulate_evpd_b0().
Also add emulate_caw device attribute in configfs (enabled by default)
to allow the exposure of this bit to be disabled, if necessary.
Cc: Christoph Hellwig <h...@lst.de>
Cc: Hannes Reinecke <h...@suse.de>
Cc: Martin Petersen <martin.peter...@oracle.com>
Cc: Chris Mason <chris.ma...@fusionio.com>
Cc: James Bottomley <jbottom...@parallels.com>
Cc: Nicholas Bellinger <n...@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <n...@daterainc.com>
---
drivers/target/target_core_configfs.c | 4 ++++
drivers/target/target_core_device.c | 14 ++++++++++++++
drivers/target/target_core_internal.h | 1 +
drivers/target/target_core_spc.c | 5 +++++
include/target/target_core_base.h | 3 +++
5 files changed, 27 insertions(+), 0 deletions(-)
diff --git a/drivers/target/target_core_configfs.c
b/drivers/target/target_core_configfs.c
index f67a9af..24517d4 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -636,6 +636,9 @@ SE_DEV_ATTR(emulate_tpu, S_IRUGO | S_IWUSR);
DEF_DEV_ATTRIB(emulate_tpws);
SE_DEV_ATTR(emulate_tpws, S_IRUGO | S_IWUSR);
+DEF_DEV_ATTRIB(emulate_caw);
+SE_DEV_ATTR(emulate_caw, S_IRUGO | S_IWUSR);
+
DEF_DEV_ATTRIB(enforce_pr_isids);
SE_DEV_ATTR(enforce_pr_isids, S_IRUGO | S_IWUSR);
@@ -693,6 +696,7 @@ static struct configfs_attribute
*target_core_dev_attrib_attrs[] = {
&target_core_dev_attrib_emulate_tas.attr,
&target_core_dev_attrib_emulate_tpu.attr,
&target_core_dev_attrib_emulate_tpws.attr,
+ &target_core_dev_attrib_emulate_caw.attr,
&target_core_dev_attrib_enforce_pr_isids.attr,
&target_core_dev_attrib_is_nonrot.attr,
&target_core_dev_attrib_emulate_rest_reord.attr,
diff --git a/drivers/target/target_core_device.c
b/drivers/target/target_core_device.c
index 8f4142f..0b5f868 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -890,6 +890,19 @@ int se_dev_set_emulate_tpws(struct se_device *dev, int
flag)
return 0;
}
+int se_dev_set_emulate_caw(struct se_device *dev, int flag)
+{
+ if (flag != 0 && flag != 1) {
+ pr_err("Illegal value %d\n", flag);
+ return -EINVAL;
+ }
+ dev->dev_attrib.emulate_caw = flag;
+ pr_debug("dev[%p]: SE Device CompareAndWrite (AtomicTestandSet): %d\n",
+ dev, flag);
+
+ return 0;
+}
+
int se_dev_set_enforce_pr_isids(struct se_device *dev, int flag)
{
if ((flag != 0) && (flag != 1)) {
@@ -1423,6 +1436,7 @@ struct se_device *target_alloc_device(struct se_hba *hba,
const char *name)
dev->dev_attrib.emulate_tas = DA_EMULATE_TAS;
dev->dev_attrib.emulate_tpu = DA_EMULATE_TPU;
dev->dev_attrib.emulate_tpws = DA_EMULATE_TPWS;
+ dev->dev_attrib.emulate_caw = DA_EMULATE_CAW;
dev->dev_attrib.enforce_pr_isids = DA_ENFORCE_PR_ISIDS;
dev->dev_attrib.is_nonrot = DA_IS_NONROT;
dev->dev_attrib.emulate_rest_reord = DA_EMULATE_REST_REORD;
diff --git a/drivers/target/target_core_internal.h
b/drivers/target/target_core_internal.h
index 18d49df..805ceb4 100644
--- a/drivers/target/target_core_internal.h
+++ b/drivers/target/target_core_internal.h
@@ -33,6 +33,7 @@ int se_dev_set_emulate_ua_intlck_ctrl(struct se_device *,
int);
int se_dev_set_emulate_tas(struct se_device *, int);
int se_dev_set_emulate_tpu(struct se_device *, int);
int se_dev_set_emulate_tpws(struct se_device *, int);
+int se_dev_set_emulate_caw(struct se_device *, int);
int se_dev_set_enforce_pr_isids(struct se_device *, int);
int se_dev_set_is_nonrot(struct se_device *, int);
int se_dev_set_emulate_rest_reord(struct se_device *dev, int);
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 4cb667d..ed7077a 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -457,6 +457,11 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf)
/* Set WSNZ to 1 */
buf[4] = 0x01;
+ /*
+ * Set MAXIMUM COMPARE AND WRITE LENGTH
+ */
+ if (dev->dev_attrib.emulate_caw)
+ buf[5] = 0x01;
/*
* Set OPTIMAL TRANSFER LENGTH GRANULARITY
diff --git a/include/target/target_core_base.h
b/include/target/target_core_base.h
index eb439e7..53eea33 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -97,6 +97,8 @@
* block/blk-lib.c:blkdev_issue_discard()
*/
#define DA_EMULATE_TPWS 0
+/* Emulation for CompareAndWrite (AtomicTestandSet) by default */
+#define DA_EMULATE_CAW 1
/* No Emulation for PSCSI by default */
#define DA_EMULATE_ALUA 0
/* Enforce SCSI Initiator Port TransportID with 'ISID' for PR */
@@ -602,6 +604,7 @@ struct se_dev_attrib {
int emulate_tas;
int emulate_tpu;
int emulate_tpws;
+ int emulate_caw;
int enforce_pr_isids;
int is_nonrot;
int emulate_rest_reord;
--
1.7.2.5
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