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)