target: do not reject FUA CDBs when write cache is enabled but emulate_write_cache is 0
A check that rejects a CDB with FUA bit set if no write cache is
emulated was added by the following commit:
fde9f50 target: Add sanity checks for DPO/FUA bit usage
The condition is as follows:
if (!dev->dev_attrib.emulate_fua_write ||
!dev->dev_attrib.emulate_write_cache)
However, this check is wrong if the backend device supports WCE but
"emulate_write_cache" is disabled.
This patch uses se_dev_check_wce() (previously named
spc_check_dev_wce) to invoke transport->get_write_cache() if the
device has a write cache or check the "emulate_write_cache" attribute
otherwise.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 7fc5eae..79b4ec3 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -650,6 +650,18 @@
return aligned_max_sectors;
}
+bool se_dev_check_wce(struct se_device *dev)
+{
+ bool wce = false;
+
+ if (dev->transport->get_write_cache)
+ wce = dev->transport->get_write_cache(dev);
+ else if (dev->dev_attrib.emulate_write_cache > 0)
+ wce = true;
+
+ return wce;
+}
+
int se_dev_set_max_unmap_lba_count(
struct se_device *dev,
u32 max_unmap_lba_count)
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 9a2f9d3..3e72974 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -708,8 +708,7 @@
}
}
if (cdb[1] & 0x8) {
- if (!dev->dev_attrib.emulate_fua_write ||
- !dev->dev_attrib.emulate_write_cache) {
+ if (!dev->dev_attrib.emulate_fua_write || !se_dev_check_wce(dev)) {
pr_err("Got CDB: 0x%02x with FUA bit set, but device"
" does not advertise support for FUA write\n",
cdb[0]);
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 460e931..6c8bd6b 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -454,19 +454,6 @@
}
EXPORT_SYMBOL(spc_emulate_evpd_83);
-static bool
-spc_check_dev_wce(struct se_device *dev)
-{
- bool wce = false;
-
- if (dev->transport->get_write_cache)
- wce = dev->transport->get_write_cache(dev);
- else if (dev->dev_attrib.emulate_write_cache > 0)
- wce = true;
-
- return wce;
-}
-
/* Extended INQUIRY Data VPD Page */
static sense_reason_t
spc_emulate_evpd_86(struct se_cmd *cmd, unsigned char *buf)
@@ -490,7 +477,7 @@
buf[5] = 0x07;
/* If WriteCache emulation is enabled, set V_SUP */
- if (spc_check_dev_wce(dev))
+ if (se_dev_check_wce(dev))
buf[6] = 0x01;
/* If an LBA map is present set R_SUP */
spin_lock(&cmd->se_dev->t10_alua.lba_map_lock);
@@ -897,7 +884,7 @@
if (pc == 1)
goto out;
- if (spc_check_dev_wce(dev))
+ if (se_dev_check_wce(dev))
p[2] = 0x04; /* Write Cache Enable */
p[12] = 0x20; /* Disabled Read Ahead */
@@ -1009,7 +996,7 @@
(cmd->se_deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY)))
spc_modesense_write_protect(&buf[length], type);
- if ((spc_check_dev_wce(dev)) &&
+ if ((se_dev_check_wce(dev)) &&
(dev->dev_attrib.emulate_fua_write > 0))
spc_modesense_dpofua(&buf[length], type);