target: Add/check max_write_same_len device attribute + update block limits VPD
This patch adds a new max_write_same_len device attribute for use with
WRITE_SAME w/ UNMAP=0 backend emulation. This can be useful for
lowering the default backend value (IBLOCK uses 0xFFFF).
Also, update block limits VPD emulation code in spc_emulate_evpd_b0() to
report MAXIMUM WRITE SAME LENGTH, and enforce max_write_same_len during
sbc_parse() -> sbc_setup_write_same() CDB sanity checking for all emulated
WRITE_SAME w/ UNMAP=0 cases.
(Robert: Move max_write_same_len check in sbc_setup_write_same() to
check both WRITE_SAME w/ UNMAP=1 and w/ UNMAP=0 cases)
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 7b473b6..2b14164 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -676,6 +676,9 @@
DEF_DEV_ATTRIB(unmap_granularity_alignment);
SE_DEV_ATTR(unmap_granularity_alignment, S_IRUGO | S_IWUSR);
+DEF_DEV_ATTRIB(max_write_same_len);
+SE_DEV_ATTR(max_write_same_len, S_IRUGO | S_IWUSR);
+
CONFIGFS_EATTR_OPS(target_core_dev_attrib, se_dev_attrib, da_group);
static struct configfs_attribute *target_core_dev_attrib_attrs[] = {
@@ -701,6 +704,7 @@
&target_core_dev_attrib_max_unmap_block_desc_count.attr,
&target_core_dev_attrib_unmap_granularity.attr,
&target_core_dev_attrib_unmap_granularity_alignment.attr,
+ &target_core_dev_attrib_max_write_same_len.attr,
NULL,
};
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 599374e..54439bc 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -706,6 +706,16 @@
return 0;
}
+int se_dev_set_max_write_same_len(
+ struct se_device *dev,
+ u32 max_write_same_len)
+{
+ dev->dev_attrib.max_write_same_len = max_write_same_len;
+ pr_debug("dev[%p]: Set max_write_same_len: %u\n",
+ dev, dev->dev_attrib.max_write_same_len);
+ return 0;
+}
+
int se_dev_set_emulate_dpo(struct se_device *dev, int flag)
{
if (flag != 0 && flag != 1) {
@@ -1393,6 +1403,7 @@
dev->dev_attrib.unmap_granularity = DA_UNMAP_GRANULARITY_DEFAULT;
dev->dev_attrib.unmap_granularity_alignment =
DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT;
+ dev->dev_attrib.max_write_same_len = DA_MAX_WRITE_SAME_LEN;
dev->dev_attrib.fabric_max_sectors = DA_FABRIC_MAX_SECTORS;
dev->dev_attrib.optimal_sectors = DA_FABRIC_MAX_SECTORS;
diff --git a/drivers/target/target_core_internal.h b/drivers/target/target_core_internal.h
index bc9c522..93e9c1f 100644
--- a/drivers/target/target_core_internal.h
+++ b/drivers/target/target_core_internal.h
@@ -24,6 +24,7 @@
int se_dev_set_max_unmap_block_desc_count(struct se_device *, u32);
int se_dev_set_unmap_granularity(struct se_device *, u32);
int se_dev_set_unmap_granularity_alignment(struct se_device *, u32);
+int se_dev_set_max_write_same_len(struct se_device *, u32);
int se_dev_set_emulate_dpo(struct se_device *, int);
int se_dev_set_emulate_fua_write(struct se_device *, int);
int se_dev_set_emulate_fua_read(struct se_device *, int);
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index a5a8f46..45e11d0 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -238,12 +238,19 @@
static sense_reason_t
sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
{
+ unsigned int sectors = spc_get_write_same_sectors(cmd);
+
if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
pr_err("WRITE_SAME PBDATA and LBDATA"
" bits not supported for Block Discard"
" Emulation\n");
return TCM_UNSUPPORTED_SCSI_OPCODE;
}
+ if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
+ pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
+ sectors, cmd->se_dev->dev_attrib.max_write_same_len);
+ return TCM_INVALID_CDB_FIELD;
+ }
/*
* Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
* translated into block discard requests within backend code.
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 4b3c183..cf1b8bb 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -465,7 +465,7 @@
* Exit now if we don't support TP.
*/
if (!have_tp)
- return 0;
+ goto max_write_same;
/*
* Set MAXIMUM UNMAP LBA COUNT
@@ -491,6 +491,12 @@
if (dev->dev_attrib.unmap_granularity_alignment != 0)
buf[32] |= 0x80; /* Set the UGAVALID bit */
+ /*
+ * MAXIMUM WRITE SAME LENGTH
+ */
+max_write_same:
+ put_unaligned_be64(dev->dev_attrib.max_write_same_len, &buf[36]);
+
return 0;
}
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 5350f6e..645d90a 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -71,6 +71,8 @@
#define DA_UNMAP_GRANULARITY_DEFAULT 0
/* Default unmap_granularity_alignment */
#define DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT 0
+/* Default max_write_same_len, disabled by default */
+#define DA_MAX_WRITE_SAME_LEN 0
/* Default max transfer length */
#define DA_FABRIC_MAX_SECTORS 8192
/* Emulation for Direct Page Out */
@@ -609,6 +611,7 @@
u32 max_unmap_block_desc_count;
u32 unmap_granularity;
u32 unmap_granularity_alignment;
+ u32 max_write_same_len;
struct se_device *da_dev;
struct config_group da_group;
};