From: Bodo Stroesser bstroesser@ts.fujitsu.com
[ Upstream commit c68a56736c129f5dd1632856956f9c3e04bae200 ]
We use tcm_loop with tape emulations running on tcmu.
In case application reads a short tape block with a longer READ, or a long tape block with a short READ, according to SCC spec data has to be tranferred _and_ sensebytes with ILI set and information field containing the residual count. Similar problem also exists when using fixed block size in READ.
Up to now tcm_loop is not prepared to handle sensebytes if input data is provided, as in tcm_loop_queue_data_in() it only sets SAM_STAT_GOOD and, if necessary, the residual count.
To fix the bug, the same handling for sensebytes as present in tcm_loop_queue_status() must be done in tcm_loop_queue_data_in() also.
After adding this handling, the two function now are nearly identical, so I created a single function with two wrappers.
Link: https://lore.kernel.org/r/20200428182617.32726-1-bstroesser@ts.fujitsu.com Signed-off-by: Bodo Stroesser bstroesser@ts.fujitsu.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/target/loopback/tcm_loop.c | 36 +++++++++++++----------------- 1 file changed, 15 insertions(+), 21 deletions(-)
diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c index 3305b47fdf53..16d5a4e117a2 100644 --- a/drivers/target/loopback/tcm_loop.c +++ b/drivers/target/loopback/tcm_loop.c @@ -545,32 +545,15 @@ static int tcm_loop_write_pending(struct se_cmd *se_cmd) return 0; }
-static int tcm_loop_queue_data_in(struct se_cmd *se_cmd) +static int tcm_loop_queue_data_or_status(const char *func, + struct se_cmd *se_cmd, u8 scsi_status) { struct tcm_loop_cmd *tl_cmd = container_of(se_cmd, struct tcm_loop_cmd, tl_se_cmd); struct scsi_cmnd *sc = tl_cmd->sc;
pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n", - __func__, sc, sc->cmnd[0]); - - sc->result = SAM_STAT_GOOD; - set_host_byte(sc, DID_OK); - if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) || - (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT)) - scsi_set_resid(sc, se_cmd->residual_count); - sc->scsi_done(sc); - return 0; -} - -static int tcm_loop_queue_status(struct se_cmd *se_cmd) -{ - struct tcm_loop_cmd *tl_cmd = container_of(se_cmd, - struct tcm_loop_cmd, tl_se_cmd); - struct scsi_cmnd *sc = tl_cmd->sc; - - pr_debug("%s() called for scsi_cmnd: %p cdb: 0x%02x\n", - __func__, sc, sc->cmnd[0]); + func, sc, sc->cmnd[0]);
if (se_cmd->sense_buffer && ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) || @@ -581,7 +564,7 @@ static int tcm_loop_queue_status(struct se_cmd *se_cmd) sc->result = SAM_STAT_CHECK_CONDITION; set_driver_byte(sc, DRIVER_SENSE); } else - sc->result = se_cmd->scsi_status; + sc->result = scsi_status;
set_host_byte(sc, DID_OK); if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) || @@ -591,6 +574,17 @@ static int tcm_loop_queue_status(struct se_cmd *se_cmd) return 0; }
+static int tcm_loop_queue_data_in(struct se_cmd *se_cmd) +{ + return tcm_loop_queue_data_or_status(__func__, se_cmd, SAM_STAT_GOOD); +} + +static int tcm_loop_queue_status(struct se_cmd *se_cmd) +{ + return tcm_loop_queue_data_or_status(__func__, + se_cmd, se_cmd->scsi_status); +} + static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd) { struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,