diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2012-08-16 15:33:10 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-10-10 03:30:44 +0100 |
| commit | 288a2e6e152fde8349fe509cb7b5977a4f87edda (patch) | |
| tree | 039f84b28741c52a511b8087a00cd8c7b19dda82 /drivers/target | |
| parent | ef00e58c65808c26f4c9f1c3aa45640d7c99bf56 (diff) | |
target: Fix ->data_length re-assignment bug with SCSI overflow
commit 4c054ba63ad47ef244cfcfa1cea38134620a5bae upstream.
This patch fixes a long-standing bug with SCSI overflow handling
where se_cmd->data_length was incorrectly being re-assigned to
the larger CDB extracted allocation length, resulting in a number
of fabric level errors that would end up causing a session reset
in most cases. So instead now:
- Only re-assign se_cmd->data_length durining UNDERFLOW (to use the
smaller value)
- Use existing se_cmd->data_length for OVERFLOW (to use the smaller
value)
This fix has been tested with the following CDB to generate an
SCSI overflow:
sg_raw -r512 /dev/sdc 28 0 0 0 0 0 0 0 9 0
Tested using iscsi-target, tcm_qla2xxx, loopback and tcm_vhost fabric
ports. Here is a bit more detail on each case:
- iscsi-target: Bug with open-iscsi with overflow, sg_raw returns
-3584 bytes of data.
- tcm_qla2xxx: Working as expected, returnins 512 bytes of data
- loopback: sg_raw returns CHECK_CONDITION, from overflow rejection
in transport_generic_map_mem_to_cmd()
- tcm_vhost: Same as loopback
Reported-by: Roland Dreier <roland@purestorage.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/target_core_transport.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 597fb9b9d4ed..34d114a1a17f 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -3039,15 +3039,20 @@ static int transport_generic_cmd_sequencer( /* Returns CHECK_CONDITION + INVALID_CDB_FIELD */ goto out_invalid_cdb_field; } - + /* + * For the overflow case keep the existing fabric provided + * ->data_length. Otherwise for the underflow case, reset + * ->data_length to the smaller SCSI expected data transfer + * length. + */ if (size > cmd->data_length) { cmd->se_cmd_flags |= SCF_OVERFLOW_BIT; cmd->residual_count = (size - cmd->data_length); } else { cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT; cmd->residual_count = (cmd->data_length - size); + cmd->data_length = size; } - cmd->data_length = size; } /* reject any command that we don't have a handler for */ |