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.
Signed-off-by: Christophe Vu-Brugier <cvubrugier@xxxxxxxxxxx>
---
drivers/target/target_core_device.c | 12 ++++++++++++
drivers/target/target_core_sbc.c | 3 +--
drivers/target/target_core_spc.c | 19 +++----------------
include/target/target_core_backend.h | 1 +
4 files changed, 17 insertions(+), 18 deletions(-)
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 7653cfb..21953a5 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -650,6 +650,18 @@ static u32 se_dev_align_max_sectors(u32 max_sectors, u32 block_size)
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 856e800..4155c60 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -703,8 +703,7 @@ sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
}
}
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 1307600..436664c 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -454,19 +454,6 @@ check_scsi_name:
}
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 @@ spc_emulate_evpd_86(struct se_cmd *cmd, unsigned char *buf)
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);
@@ -900,7 +887,7 @@ static int spc_modesense_caching(struct se_cmd *cmd, u8 pc, u8 *p)
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 */
@@ -1012,7 +999,7 @@ static sense_reason_t spc_emulate_modesense(struct se_cmd *cmd)
(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);
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 430cfaf..244c6c7 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -111,6 +111,7 @@ void array_free(void *array, int n);
void target_core_setup_sub_cits(struct se_subsystem_api *);
/* attribute helpers from target_core_device.c for backend drivers */
+bool se_dev_check_wce(struct se_device *);
int se_dev_set_max_unmap_lba_count(struct se_device *, u32);
int se_dev_set_max_unmap_block_desc_count(struct se_device *, u32);
int se_dev_set_unmap_granularity(struct se_device *, u32);
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe target-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
