On 2/14/2015 5:27 AM, Nicholas A. Bellinger wrote:
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch adds a sbc_check_dpofua() function that performs sanity
checks for DPO/FUA command bits.
It introduces checks to fail when either bit is set, but the backend
device is not advertising support for them.
It also moves the existing cmd->se_cmd_flags |= SCF_FUA assignement
into the new helper function.
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_sbc.c | 56 +++++++++++++++++++++++++++++++++-------
1 file changed, 46 insertions(+), 10 deletions(-)
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 87cbbe2..856e800 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -692,6 +692,29 @@ sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
return TCM_NO_SENSE;
}
+static int
+sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
+{
+ if (cdb[1] & 0x10) {
+ if (!dev->dev_attrib.emulate_dpo) {
General comment, can you please use unlikely on all these branches in
the critical path?
+ pr_err("Got CDB: 0x%02x with DPO bit set, but device"
+ " does not advertise support for DPO\n", cdb[0]);
+ return -EINVAL;
+ }
+ }
+ if (cdb[1] & 0x8) {
+ if (!dev->dev_attrib.emulate_fua_write ||
+ !dev->dev_attrib.emulate_write_cache) {
+ pr_err("Got CDB: 0x%02x with FUA bit set, but device"
+ " does not advertise support for FUA write\n",
+ cdb[0]);
+ return -EINVAL;
+ }
+ cmd->se_cmd_flags |= SCF_FUA;
+ }
+ return 0;
+}
+
sense_reason_t
sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
{
@@ -713,6 +736,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
sectors = transport_get_sectors_10(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
+ if (sbc_check_dpofua(dev, cmd, cdb))
+ return TCM_INVALID_CDB_FIELD;
+
ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
if (ret)
return ret;
@@ -725,6 +751,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
sectors = transport_get_sectors_12(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
+ if (sbc_check_dpofua(dev, cmd, cdb))
+ return TCM_INVALID_CDB_FIELD;
+
ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
if (ret)
return ret;
@@ -737,6 +766,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
sectors = transport_get_sectors_16(cdb);
cmd->t_task_lba = transport_lba_64(cdb);
+ if (sbc_check_dpofua(dev, cmd, cdb))
+ return TCM_INVALID_CDB_FIELD;
+
ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
if (ret)
return ret;
@@ -757,12 +789,13 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
sectors = transport_get_sectors_10(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
+ if (sbc_check_dpofua(dev, cmd, cdb))
+ return TCM_INVALID_CDB_FIELD;
+
ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
if (ret)
return ret;
- if (cdb[1] & 0x8)
- cmd->se_cmd_flags |= SCF_FUA;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_rw = ops->execute_rw;
cmd->execute_cmd = sbc_execute_rw;
@@ -771,12 +804,13 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
sectors = transport_get_sectors_12(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
+ if (sbc_check_dpofua(dev, cmd, cdb))
+ return TCM_INVALID_CDB_FIELD;
+
ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
if (ret)
return ret;
- if (cdb[1] & 0x8)
- cmd->se_cmd_flags |= SCF_FUA;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_rw = ops->execute_rw;
cmd->execute_cmd = sbc_execute_rw;
@@ -785,12 +819,13 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
sectors = transport_get_sectors_16(cdb);
cmd->t_task_lba = transport_lba_64(cdb);
+ if (sbc_check_dpofua(dev, cmd, cdb))
+ return TCM_INVALID_CDB_FIELD;
+
ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
if (ret)
return ret;
- if (cdb[1] & 0x8)
- cmd->se_cmd_flags |= SCF_FUA;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_rw = ops->execute_rw;
cmd->execute_cmd = sbc_execute_rw;
@@ -801,6 +836,9 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
return TCM_INVALID_CDB_FIELD;
sectors = transport_get_sectors_10(cdb);
+ if (sbc_check_dpofua(dev, cmd, cdb))
+ return TCM_INVALID_CDB_FIELD;
+
cmd->t_task_lba = transport_lba_32(cdb);
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
@@ -810,8 +848,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
cmd->execute_rw = ops->execute_rw;
cmd->execute_cmd = sbc_execute_rw;
cmd->transport_complete_callback = &xdreadwrite_callback;
- if (cdb[1] & 0x8)
- cmd->se_cmd_flags |= SCF_FUA;
break;
case VARIABLE_LENGTH_CMD:
{
@@ -820,6 +856,8 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
case XDWRITEREAD_32:
sectors = transport_get_sectors_32(cdb);
+ if (sbc_check_dpofua(dev, cmd, cdb))
+ return TCM_INVALID_CDB_FIELD;
/*
* Use WRITE_32 and READ_32 opcodes for the emulated
* XDWRITE_READ_32 logic.
@@ -834,8 +872,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
cmd->execute_rw = ops->execute_rw;
cmd->execute_cmd = sbc_execute_rw;
cmd->transport_complete_callback = &xdreadwrite_callback;
- if (cdb[1] & 0x8)
- cmd->se_cmd_flags |= SCF_FUA;
break;
case WRITE_SAME_32:
sectors = transport_get_sectors_32(cdb);
Other than that, Looks OK.
Reviewed-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>
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