From: Nicholas Bellinger <[email protected]> This patch addresses a bug for backends such as IBLOCK that perform asynchronous completion via transport_complete_cmd(), that will call target_complete_failure_work() -> transport_generic_request_failure(), upon exception status and invoke cmd->transport_complete_callback() -> compare_and_write_callback() incorrectly during the failure case.
It adds a check for a non zero se_cmd->scsi_status within the first invocation of compare_and_write_callback(), and will jump to out plus up se_device->caw_sem before exiting the callback. Reported-by: Thomas Glanzmann <[email protected]> Cc: Thomas Glanzmann <[email protected]> Signed-off-by: Nicholas Bellinger <[email protected]> --- drivers/target/target_core_sbc.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 1393d0e..4714c6f 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -372,7 +372,7 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; struct scatterlist *write_sg = NULL, *sg; - unsigned char *buf, *addr; + unsigned char *buf = NULL, *addr; struct sg_mapping_iter m; unsigned int offset = 0, len; unsigned int nlbas = cmd->t_task_nolb; @@ -387,6 +387,15 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd) */ if (!cmd->t_data_sg || !cmd->t_bidi_data_sg) return TCM_NO_SENSE; + /* + * Immediately exit + release dev->caw_sem if command has already + * been failed with a non-zero SCSI status. + */ + if (cmd->scsi_status) { + pr_err("compare_and_write_callback: non zero scsi_status:" + " 0x%02x\n", cmd->scsi_status); + goto out; + } buf = kzalloc(cmd->data_length, GFP_KERNEL); if (!buf) { -- 1.8.4.rc3 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
